Science.gov

Sample records for system corrosion studies

  1. Thermal control system corrosion study

    NASA Technical Reports Server (NTRS)

    Yee, Robert; Folsom, Rolfe A.; Mucha, Phillip E.

    1990-01-01

    During the development of an expert system for autonomous control of the Space Station Thermal Control System (TCS), the thermal performance of the Brassboard TCS began to gradually degrade. This degradation was due to filter clogging by metallic residue. A study was initiated to determine the source of the residue and the basic cause of the corrosion. The investigation focused on the TCS design, materials compatibility, Ames operating and maintenance procedures, and chemical analysis of the residue and of the anhydrous ammonia used as the principal refrigerant. It was concluded that the corrosion mechanisms involved two processes: the reaction of water alone with large, untreated aluminum parts in a high pH environment and the presence of chlorides and chloride salts. These salts will attack the aluminum oxide layer and may enable galvanic corrosion between the aluminum and the more noble stainless steel and other metallic elements present. Recommendations are made for modifications to the system design, the materials used, and the operating and maintenance procedures, which should largely prevent the recurrence of these corrosion mechanisms.

  2. Thermal control system corrosion study

    NASA Astrophysics Data System (ADS)

    Yee, Robert; Folsom, Rolfe A.; Mucha, Phillip E.

    1990-02-01

    During the development of an expert system for autonomous control of the Space Station Thermal Control System (TCS), the thermal performance of the Brassboard TCS began to gradually degrade. This degradation was due to filter clogging by metallic residue. A study was initiated to determine the source of the residue and the basic cause of the corrosion. The investigation focused on the TCS design, materials compatibility, Ames operating and maintenance procedures, and chemical analysis of the residue and of the anhydrous ammonia used as the principal refrigerant. It was concluded that the corrosion mechanisms involved two processes: the reaction of water alone with large, untreated aluminum parts in a high pH environment and the presence of chlorides and chloride salts. These salts will attack the aluminum oxide layer and may enable galvanic corrosion between the aluminum and the more noble stainless steel and other metallic elements present. Recommendations are made for modifications to the system design, the materials used, and the operating and maintenance procedures, which should largely prevent the recurrence of these corrosion mechanisms.

  3. Supplementary safety system corrosion studies

    SciTech Connect

    Anderson, M.H.; Wiersma, B.J.

    1991-05-21

    This memorandum presents experimental data from electrochemical and immersion tests to support the continued use of two sections of nonconforming steel in the Supplementary Safety System. The Reactor Corrosion Mitigation Committee met on May 16, 1991 to evaluate materials that had been installed in the SSS. The materials lacked complete Corrosion Evaluation (CE) and/or Certified Mill Test Reports and had been installed during recent modifications (Project S-4332). Items that lacked proper documentation included AISI Type 304 stainless steel (304) instrument tubing (0.375'' OD) associated with the pressure transmitters and a two-foot section of 304 pipe located on the far side of the system downstream of the pneumatic valves. Cyclic potentiodynamic polarization scans were performed on sensitized and solution-annealed 304 samples in as-mixed and acidified Gd(NO{sub 3}){sub 3}, or ink'', solutions at room temperature to determine the susceptibility of 304 to localized corrosion in this environment. No localized attack was observed on the solution annealed or sensitized 304 in the Gd(NO{sub 3}){sub 3} solution. These tests revealed no significant differences in the behavior of the sensitized and solution-annealed 304 in gadolinium nitrate solution. Therefore, localized corrosion of the nonconforming components is not anticipated, and the performance of the nonconforming components should not differ from that of corrosion evaluated and certified materials. Previous studies have shown that AISI Type 304L stainless steel (304L) did not pit during a three-month exposure in gadolinium nitrate solutions of pH 2 or 5. These combined results support the continued use of the nonconforming steels until replacement can be made at the next scheduled long shut-down.

  4. Supplementary safety system corrosion studies

    SciTech Connect

    Anderson, M.H.; Wiersma, B.J.

    1991-05-21

    This memorandum presents experimental data from electrochemical and immersion tests to support the continued use of two sections of nonconforming steel in the Supplementary Safety System. The Reactor Corrosion Mitigation Committee met on May 16, 1991 to evaluate materials that had been installed in the SSS. The materials lacked complete Corrosion Evaluation (CE) and/or Certified Mill Test Reports and had been installed during recent modifications (Project S-4332). Items that lacked proper documentation included AISI Type 304 stainless steel (304) instrument tubing (0.375`` OD) associated with the pressure transmitters and a two-foot section of 304 pipe located on the far side of the system downstream of the pneumatic valves. Cyclic potentiodynamic polarization scans were performed on sensitized and solution-annealed 304 samples in as-mixed and acidified Gd(NO{sub 3}){sub 3}, or ``ink``, solutions at room temperature to determine the susceptibility of 304 to localized corrosion in this environment. No localized attack was observed on the solution annealed or sensitized 304 in the Gd(NO{sub 3}){sub 3} solution. These tests revealed no significant differences in the behavior of the sensitized and solution-annealed 304 in gadolinium nitrate solution. Therefore, localized corrosion of the nonconforming components is not anticipated, and the performance of the nonconforming components should not differ from that of corrosion evaluated and certified materials. Previous studies have shown that AISI Type 304L stainless steel (304L) did not pit during a three-month exposure in gadolinium nitrate solutions of pH 2 or 5. These combined results support the continued use of the nonconforming steels until replacement can be made at the next scheduled long shut-down.

  5. A cooling water system copper corrosion study

    SciTech Connect

    Pulkrabek, J.W.

    1998-07-01

    The plant has four units that have been operating normally for 12--33 years. Two of the units are 70 MW sister units that have copper alloy once-through condensers. The other two units are 350 MW and 500 MW units with copper alloy condensers and cooling towers. No cooling water related tube leaks had been experienced. Until 1993, the only chemicals used were sulfuric acid for pH control of the cooling tower systems and chlorine for biological control. The units were chlorinated for one hour per day per condenser. In early July 1992, their copper grab sample at the plant discharge to the river exceeded the weekly environmental limit. In fact, it was so high that there was a slim chance of coming in under their monthly average copper limit unless something was done quickly. The result of this incident was an extensive study of their plant wastewater and cooling systems. The study revealed that the elevated copper problem had existed sporadically for several years. Initially, copper control was achieved by altering the wastewater treatment processes and cooling tower blowdown flow path. Two extended trials, one with tolyltriazole (TTA) and one with a chemically modified benzotriazole (BZT) were performed. Optimal control of copper corrosion was eventually achieved by the application of a TTA treatment program in which the feed rates are adjusted based on on-line corrosion monitoring measurements. This report documents experiences and results over the past six years.

  6. Electrochemical corrosion studies

    NASA Technical Reports Server (NTRS)

    Knockemus, W. W.

    1986-01-01

    The objective was to gain familiarity with the Model 350 Corrosion Measurement Console, to determine if metal protection by grease coatings can be measured by the polarization-resistance method, and to compare corrosion rates of 4130 steel coated with various greases. Results show that grease protection of steel may be determined electrochemically. Studies were also conducted to determine the effectiveness of certain corrosion inhibitors on aluminum and steel.

  7. Corrosion Monitoring System

    SciTech Connect

    Dr. Russ Braunling

    2004-10-31

    The Corrosion Monitoring System (CMS) program developed and demonstrated a continuously on-line system that provides real-time corrosion information. The program focused on detecting pitting corrosion in its early stages. A new invention called the Intelligent Ultrasonic Probe (IUP) was patented on the program. The IUP uses ultrasonic guided waves to detect small defects and a Synthetic Aperture Focusing Technique (SAFT) algorithm to provide an image of the pits. Testing of the CMS demonstrated the capability to detect pits with dimensionality in the sub-millimeter range. The CMS was tested in both the laboratory and in a pulp and paper industrial plant. The system is capable of monitoring the plant from a remote location using the internet.

  8. Case study of a fast propagating bacteriogenically induced concrete corrosion in an Austrian sewer system

    NASA Astrophysics Data System (ADS)

    Grengg, Cyrill; Mittermayr, Florian; Baldermann, Andre; Böttcher, Michael; Leis, Albrecht; Koraimann, Günther; Dietzel, Martin

    2015-04-01

    Reaction mechanisms leading to microbially induced concrete corrosion (MICC) are highly complex and often not fully understood. The aim of the present case study is to contribute to a deeper understanding of reaction paths, environmental controls, and corrosion rates related to MICC in a modern Austrian sewer system by introducing an advanced multi proxy approach that comprises gaseous, hydro-geochemical, bacteriological, and mineralogical analyses. Various crucial parameters for detecting alteration features were determined in the field and laboratory, including (i) temperature, pH, alkalinity, chemical compositions of the solutions, (ii) chemical and mineralogical composition of solids, (iii) bacterial analysis, and (iv) concentrations of gaseous H2S, CH4 and CO2 within the sewer pipe atmosphere. An overview of the field site and analytical results, focusing on reaction mechanisms causing the corrosion, as well as possible remediation strategies will be presented.

  9. Lithium-system corrosion/erosion studies for the FMIT project

    SciTech Connect

    Bazinet, G D

    1983-04-01

    The corrosion behavior of selected materials in a liquid lithium environment has been studied in support of system and component designs for the Fusion Materials Irradiation Test (FMIT) Facility. The liquid lithium test resources and the capabilities of several laboratories were used to study specific concerns associated with the overall objective. Testing conditions ranged from approx. 3700 hours to approx. 6500 hours of exposure to flowing lithium at temperatures from 230/sup 0/C to 270/sup 0/C and static lithium at temperatures from 200/sup 0/C to 500/sup 0/C. Principal areas of investigation included lithium corrosion/erosion effects of FMIT lithium system materials (largely Type 304 and Type 304L austenitic stainless steels) and candidate materials for major system components.

  10. Corrosion control and disinfection studies in spacecraft water systems. [considering Saturn 5 orbital workshop

    NASA Technical Reports Server (NTRS)

    Shea, T. G.

    1974-01-01

    Disinfection and corrosion control in the water systems of the Saturn 5 Orbital Workshop Program are considered. Within this framework, the problem areas of concern are classified into four general areas: disinfection; corrosion; membrane-associated problems of disinfectant uptake and diffusion; and taste and odor problems arising from membrane-disinfectant interaction.

  11. NOVEL CORROSION SENSOR FOR VISION 21 SYSTEMS

    SciTech Connect

    Heng Ban

    2004-12-01

    Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the metal loss caused by chemical reactions on surfaces exposed to the combustion environment. Such corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indication of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall objective of this proposed project is to develop a technology for on-line corrosion monitoring based on a new concept. This report describes the initial results from the first-year effort of the three-year study that include laboratory development and experiment, and pilot combustor testing.

  12. Corrosion control study of a typical large usage water distribution system

    SciTech Connect

    Hock, V.F.; Cardenas, H.E.; Zelsdorf, E.D.; Smothers, K.W.; Anderson, J.

    1995-12-01

    This corrosion control study was based on, and closely followed, the AWWA Guidance Manual and AWWARF pipe loop protocol. The primary objective of this study was to provide a corrosion control recommendation for the site to satisfy State of Maryland and EPA requirements to define and maintain optimal corrosion control treatment. A second objective was to identify technical and cost constraints that may affect the application of specific corrosion control treatments in finished water. Blended zinc potassium polyphosphate/zinc orthophosphate showed lower corrosion rates and reduced lead concentrations in finished water for the majority of days studied in plant pipe loop models and remote location (barracks) pipe loop models. Blended potassium monophosphate/potassium tripolyphosphate followed a close second in overall efficacy. The pH adjusted and control strategies exhibited little demonstrated corrosion control benefit. Recommendations based on this study included (1) addition of blended zinc potassium polyphosphate/zinc orthophosphate with a residual concentration between 2.0 and 4.5 mg/L, (2) installation of a chemical feed to buffer well water with sodium bicarbonate to stabilize alkalinity when 100% well water is used, and (3) investigation of lime addition to raw well water to control buffer capacity in the combined raw well water/surface water.

  13. Studies on biologically induced corrosion in heat exchanger systems at the Savannah River Plant, Aiken, SC

    SciTech Connect

    Pope, D.H.; Soracco, R.J.; Wilde, E.W.

    1982-07-01

    Biological fouling and corrosion of stainless steel tubes in the heat exchangers in nuclear reactors at the Savannah River Plant have caused decreased heat transfer efficiency and reduced operational life. This report addresses the microbiology and chemistry of the films present on these tubes, and the relation of this data to the corrosion of the tube material (304L stainless steel). Very few microorganisms other than bacteria were found in the biofilm. Bacteria capable of producing H/sub 2/S, organic acids, anaerobic conditions, and slime have all been isolated from these films. All of these have been implicated in corrosion processes. The most remarkable chemical finding was the inability to detect chloride in the film around areas of presumed chloride induced stress corrosion cracking. Three model systems were used to test the fouling and corrosion potential of metal specimens under a variety of environmental conditions including various biocide regimes. Using these systems, potential improvements in the use of chlorine as a biocidal agent have been observed. It was also shown that larger bacterial populations (including viable and killed cells) were associated with corroded areas as compared to noncorroded areas on the same specimen.

  14. Electrochemical studies of corrosion inhibitors

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1990-01-01

    The effect of single salts, as well as multicomponent mixtures, on corrosion inhibition was studied for type 1010 steel; for 5052, 1100, and 2219-T87 aluminum alloys; and for copper. Molybdate-containing inhibitors exhibit an immediate, positive effect for steel corrosion, but an incubation period may be required for aluminum before the effect of a given inhibitor can be determined. The absence of oxygen was found to provide a positive effect (smaller corrosion rate) for steel and copper, but a negative effect for aluminum. This is attributed to the two possible mechanisms by which aluminum can oxidize. Corrosion inhibition is generally similar for oxygen-rich and oxygen-free environments. The results show that the electrochemical method is an effective means of screening inhibitors for the corrosion of single metals, with caution to be exercised in the case of aluminum.

  15. Corrosion manual for internal corrosion of water distribution systems

    SciTech Connect

    Singley, J.E.; Beaudet, B.A.; Markey, P.H.

    1984-04-01

    Corrosion of distribution piping and of home plumbing and fixtures has been estimated to cost the public water supply industry more than $700 million per year. Two toxic metals that occur in tap water, almost entirely because of corrosion, are lead and cadmium. Three other metals, usually present because of corrosion, cause staining of fixtures, or metallic taste, or both. These are copper (blue stains and metallic taste), iron (red-brown stains and metallic taste), and zinc (metallic taste). Since the Safe Drinking Water Act (P.L. 93-523) makes the supplying utility responsible for the water quality at the customer's tap, it is necessary to prevent these metals from getting into the water on the way to the tap. This manual was written to give the operators of potable water treatment plants and distribution systems an understanding of the causes and control of corrosion.

  16. Electrode polarization studies in hot corrosion systems. Progress report, 1 June 1979-31 April 1980

    SciTech Connect

    Devereux, O.F.

    1980-02-01

    Work on the following discrete tasks is reported: Electrode Polarization Studies in Molten Sodium Carbonate: A comprehensive set of tests has been performed on iron, nickel, and types 304 and 316 stainless steel in gas mixtures of controlled CO, CO/sub 2/, H/sub 2/, and H/sub 2/S pressures at a total pressure of one atmosphere and in a temperature range of 900 to 1000/sup 0/C. The polarization curves thus derived have been reduced to a set of empirical kinetic constants via computer modelling. Gas/Metal Reactions in Mixed Oxidants: Oxidation of iron in gas mixtures of controlled P/sub CO/, P/sub CO//sub 2/, P/sub H//sub 2/ and P/sub H//sub 2//sub S/ at a total pressure of one atmosphere and a temperature of 900/sup 0/C has been studied. In the P/sub S//sub 2/ and P/sub O//sub 2/ ranges employed sulfide scales were formed; P/sub O//sub 2/ influenced the short term sulfidation kinetics. Specimen geometry was seen as a significant factor influencing long term kinetics. Liquid Line Corrosion: A reproducible corrosive attack is seen at the metal/molten carbonate/gas phase junction. This attack can be quantitatively evaluated and explained in terms of a diffusion model. Evaluation of Reaction Kinetics from Polarization Data (addendum): previous modelling procedures have been expanded to include one or more anodic reactions displaying passive behavior.

  17. Corrosion control in water injection systems

    SciTech Connect

    Patton, C.C. )

    1993-08-01

    Corrosion control in water injection systems encompasses a wide range of technologies, including chemicals (corrosion inhibitors, biocides, and oxygen scavengers); corrosion-resistant materials (metallic and nonmetallic); internal coatings and linings; mechanical removal of dissolved oxygen; velocity control; and prevention of oxygen entry and galvanic couples. This article reviews the way that these technologies are used in modern water-injection systems (both seawater and produced water) to provide an acceptable service life and high-quality injection water.

  18. Novel Corrosion Sensor for Vision 21 Systems

    SciTech Connect

    Heng Ban; Bharat Soni

    2007-03-31

    Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indication of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall goal of this project is to develop a technology for on-line fireside corrosion monitoring. This objective is achieved by the laboratory development of sensors and instrumentation, testing them in a laboratory muffle furnace, and eventually testing the system in a coal-fired furnace. This project successfully developed two types of sensors and measurement systems, and successful tested them in a muffle furnace in the laboratory. The capacitance sensor had a high fabrication cost and might be more appropriate in other applications. The low-cost resistance sensor was tested in a power plant burning eastern bituminous coals. The results show that the fireside corrosion measurement system can be used to determine the corrosion rate at waterwall and superheater locations. Electron microscope analysis of the corroded sensor surface provided detailed picture of the corrosion process.

  19. An electrochemical study of corrosion protection by primer-topcoat systems on 4130 steel with ac impedance and dc methods

    NASA Technical Reports Server (NTRS)

    Mendrek, M. J.; Higgins, R. H.; Danford, M. D.

    1988-01-01

    To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac impedance method is applied to six systems of primer coated and primer topcoated 4130 steel. Two primers were used: a zinc-rich epoxy primer and a red lead oxide epoxy primer. The epoxy-polyamine topcoat was used in four of the systems. The EG and G-PARC Model 368 ac impedance measurement system, along with dc measurements with the same system using the polarization resistance method, were used to monitor changing properties of coated 4230 steel disks immersed in 3.5 percent NaCl solutions buffered at pH 5.4 over periods of 40 to 60 days. The corrosion system can be represented by an electronic analog called an equivalent circuit consisting of resistors and capacitors in specific arrangements. This equivalent circuit parallels the impedance behavior of the corrosion system during a frequency scan. Values for the resistors and capacitors, that can be assigned in the equivalent circuit following a least-squares analysis of the data, describe changes that occur on the corroding metal surface and in the protective coatings. Two equivalent circuits have been determined that predict the correct Bode phase and magnitude of the experimental sample at different immersion times. The dc corrosion current density data are related to equivalent circuit element parameters. Methods for determining corrosion rate with ac impedance parameters are verified by the dc method.

  20. The Examination of Afyonkarahisar's Geothermal System Corrosion

    NASA Astrophysics Data System (ADS)

    Buyuksagis, A.; Erol, S.

    2013-02-01

    Corrosion and scaling of metal surfaces are the major problems caused by geothermal fluids when metallic structures are used. This article describes a study of corrosion and scaling problems in the Afyonkarahisar Geothermal Heating System (AFJET) in Afyonkarahisar, Turkey. Water analysis, XRD, SEM, EDX, IC, ICP-OES analyses, and electrochemical methods were used in this study. Pentasodium triphosphate (Na5P3O10), maleic anhydride (C4H2O3), and 1,3-benzendisulfonic acid disodium salt (C6H4Na2O6S2) were used as corrosion inhibitors. Tests were carried out using geothermal water from AF11 well. The experimental temperatures were chosen as 298, 333, and 358 K. Inhibitor concentrations were chosen as 1 × 10-1, 1 × 10-2, 1 × 10-3, and 1 × 10-4 mol/dm3. Moreover, mixed inhibitor solutions were prepared using the inhibitor concentrations that showed the best inhibition. The first mixed inhibitor solution showed 96% inhibition. The second mixed inhibitor solution showed 90% inhibition. The tested inhibitors act as anodic inhibitors. XRD analysis shows that there is CaCO3 aragonite scaling in the system. Increasing TDS, alkalinity, and hardness all promote scale formation. The photomicrographs from SEM-EDX and the metallographic microscope show that the tested inhibitors form a protective film on the surface. IC and ICP-OES analyses show that the concentration of Ca2+ is very high, which supports scale formation.

  1. Corrosion Behavior of an Abradable Seal Coating System

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Xu, Cunguan; Lan, Hao; Huang, Chuanbing; Zhou, Yang; Du, Lingzhong; Zhang, Weigang

    2014-08-01

    A novel NiTi/BN composite abradable coating and two traditional Ni/C and Ni/BN coatings were manufactured with NiAl as the bond layer using thermal spray technology and their corrosion behaviors were investigated. In salt spray corrosion testing of the Ni/BN coating, defective sites of the metal matrix were corroded preferentially. Simulated occlusion experiments and electrochemical tests indicated that migration of ions resulted in pH decrease and Cl- enrichment in defects, and a more aggressive electrolyte led to a decrease of the corrosion potential of the metal inside defects but an increase of the corrosion current density, representing an autocatalytic corrosion process. Moreover, galvanic corrosion between the top and bond coatings of the abradable system was studied via the electrochemical technique. The results showed that, for the NiTi/BN, Ni/BN, and Ni/graphite coatings with a NiAl bond coating, current flow was generated between the anode and cathode. The NiTi/BN coating acted as the cathode due to its passivation, while the Ni/BN and Ni/graphite coatings acted as the anode because of their lower corrosion potential compared with the NiAl coating. The anode suffered serious corrosion damage due to galvanic corrosion, while the cathode corroded only slightly.

  2. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    PubMed Central

    Nascimento, Jehan F.; Silva, Marcionilo J.; Coêlho, Isnaldo J. S.; Cipriano, Eliel; Martins-Filho, Joaquim F.

    2012-01-01

    We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations. PMID:22737017

  3. Study of corrosion in multimetallic systems. Task 2 of solar collector studies for solar heating and cooling applications. Final technical progress report

    SciTech Connect

    Diegle, R B

    1980-04-11

    Corrosion measurements were made on candidate alloys of construction for non-concentrating solar collectors under simulated conditions of collector operation. Materials evaluated were aluminum alloys 1100, 3003, and 6061, copper alloy 122, Type 444 stainless steel, and 1018 plain carbon steel. The solutions used were equivolume mixtures of ethylene glycol and water, and propylene glycol and water. They were used without corrosion inhibitors but with addition of chloride, sulfate, and bicarbonate ions. The influences of dissolved oxygen, solution flow velocity, and heat transfer were evaluated. Corrosion morphologies investigated were general attack, pitting, crevice corrosion, and galvanic corrosion. Experimental results indicated that aluminum alloys can experience severe pitting and crevice corrosion at chloride concentrations approaching 50 ppM. The corrosion rate of copper exceeded about 100 ..mu..m/yr in ethylene glycol solutions and about 80 ..mu..m/yr in propylene glycol solutions. Crevice corrosion was not observed for copper, but severe galvanic corrosion occurred when it was coupled to T444 stainless steel. T444 steel corroded at rates of less than 1 ..mu..m/yr under all exposure conditions. During circulation at 100 C in the presence of air, ethylene glycol solutions acidified because of degradation of the glycol. The initial pH of propylene glycol solutions was already low, about 4.5. The inherent corrosivity of propylene glycol was somewhat less than that of ethylene glycol, although this difference was usually less than a factor of two in measured corrosion rates. It was concluded that he corrosion rates of aluminum alloys and copper were prohibitively high in uninhibited glycol solutions, and that corrosion inhibitors are definitely necessary in operating systems.

  4. Novel Corrosion Sensor for Vision 21 Systems

    SciTech Connect

    Heng Ban

    2005-12-01

    Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the metal loss caused by chemical reactions on surfaces exposed to the combustion environment. Such corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indication of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall objective of this project is to develop a technology for on-line corrosion monitoring based on a new concept. This objective is to be achieved by a laboratory development of the sensor and instrumentation, testing of the measurement system in a laboratory muffle furnace, and eventually testing the system in a coal-fired furnace. The initial plan for testing at the coal-fired pilot-scale furnace was replaced by testing in a power plant, because the operation condition at the power plant is continuous and more stable. The first two-year effort was completed with the successful development sensor and measurement system, and successful testing in a muffle furnace. Because of the potential high cost in sensor fabrication, a different type of sensor was used and tested in a power plant burning eastern bituminous coals. This report summarize the experiences and results of the first two years of the three-year project, which include laboratory

  5. Real-World Water System Lead and Copper Corrosion Control

    EPA Science Inventory

    This presentation provides specific background on lead and copper corrosion control chemistry and strategies, and integrates it with other important distribution system corrosion control objectives. Topics covered include: driving force for corrosion (oxidants); impacts of oxida...

  6. Corrosion behaviour and biocorrosion of galvanized steel water distribution systems.

    PubMed

    Delaunois, F; Tosar, F; Vitry, V

    2014-06-01

    Galvanized steel tubes are a popular mean for water distribution systems but suffer from corrosion despite their zinc or zinc alloy coatings. First, the quality of hot-dip galvanized (HDG) coatings was studied. Their microstructure, defects, and common types of corrosion were observed. It was shown that many manufactured tubes do not reach European standard (NBN EN 10240), which is the cause of several corrosion problems. The average thickness of zinc layer was found at 41μm against 55μm prescribed by the European standard. However, lack of quality, together with the usual corrosion types known for HDG steel tubes was not sufficient to explain the high corrosion rate (reaching 20μm per year versus 10μm/y for common corrosion types). Electrochemical tests were also performed to understand the corrosion behaviours occurring in galvanized steel tubes. Results have shown that the limiting step was oxygen diffusion, favouring the growth of anaerobic bacteria in steel tubes. EDS analysis was carried out on corroded coatings and has shown the presence of sulphur inside deposits, suggesting the likely bacterial activity. Therefore biocorrosion effects have been investigated. Actually sulphate reducing bacteria (SRB) can reduce sulphate contained in water to hydrogen sulphide (H2S), causing the formation of metal sulphides. Although microbial corrosion is well-known in sea water, it is less investigated in supply water. Thus, an experimental water main was kept in operation for 6months. SRB were detected by BART tests in the test water main.

  7. Microprobe study of diode corrosion

    SciTech Connect

    Hlava, P.; Braithwaite, J.; Sorensen, R.

    1996-12-31

    A few diodes from a production lot were discovered to have unacceptable current leak rates after about 5 years of storage. Inspection revealed the presence of copper sulfide deposits that bridged the external body of the diode and presumably provided a leakage path. Figure 1 shows the physical configuration of a diode. The function of this device is performed by a silicon-based semiconductor that is bonded between two cylinders of tungsten with copper headpins (Cu wire with a flat {open_quotes}nail-head{close_quotes} formed on one end) brazed to the opposite ends of the cylinders. A tropical ring of glass protects the Si chip. All exposed metal parts are covered by an immersion plating of Ag. Then the entire assembly is coated with black epoxy and a band of green ink is applied to the cathode end. During storage, each diode was placed in a cardboard holder and secured in stacks of about ten with rubber bands. Analytical and environmental exposure studies were performed at Allied Signal and Sandia to determine the cause and potential long-term significance of this corrosion product and help identify the corrosion mechanism.

  8. Study of corrosion of 1100 aluminum

    NASA Technical Reports Server (NTRS)

    Draley, J. E.; Loess, R. E.; Mori, S.

    1967-01-01

    Corrosion of 1100 aluminum in oxygen-saturated water at 70 degrees C under experimental conditions was studied, emphasizing effects of exposure interruption, the number of specimens, and the refreshment rate. A logarithmic equation was derived to express the corrosion rate.

  9. Evaluation of several corrosion protective coating systems on aluminum

    NASA Technical Reports Server (NTRS)

    Higgins, R. H.

    1981-01-01

    A study of several protective coating systems for use on aluminum in seawater/seacoast environments was conducted to review the developments made on protective coatings since early in the Space Shuttle program and to perform comparative studies on these coatings to determine their effectiveness for providing corrosion protection during exposure to seawater/seacoast environments. Panels of 2219-T87 aluminum were coated with 21 different systems and exposed to a 5 percent salt spray for 4000 hr. Application properties, adhesion measurements, heat resistance and corrosion protection were evaluated. For comparative studies, the presently specified Bostik epoxy system used on the SRB structures was included. Results of these tests indicate four systems with outstanding performance and four additional systems with protection almost as good. These systems are based on a chromated pretreatment, a chromate epoxy primer, and a polyurethane topcoat. Consideration for one of these systems should be included for those applications where superior corrosion protection for aluminum surfaces is required.

  10. Novel systems for corrosion detection in piping

    SciTech Connect

    Raad, J.A. de; Fingerhut, M.P.

    1995-12-31

    Predictive maintenance requires accurate quantitative information. Nondestructive testing (NDT) tools have been able provide the necessary information, economically. Examination of the full surface of components is often required, which is contrary to the more typical spot location measurements. In addition, predictive maintenance inspection often requires the examination of hot and or insulated components. These challenges have been satisfied by recent developments in NDT and are applicable to a broad range of facility types such as tank terminals and pulp and paper plants. For non-insulated and above ground piping systems magnetic flux leakage (MFL) tools have recently been introduced into the marketplace. These tools allow very quick and reliable detection of local and extensive general corrosion, in carbon steel pipes or vessel walls, with nominal wall thicknesses of up to 15 mm. A relatively new method for detection of corrosion under insulated components is the RTD-Incotest, pulse eddy current (PEC) system. This system can also provide the components remaining wall thickness at general corrosion locations. Demand for corrosion detection under insulation on piping has also been satisfied by new dynamic Real-Time-Radiography systems. These systems are relatively fast, but the concept itself and its weight require close human access to the pipe, hence, some method of accessing above ground piping is required. Nevertheless, the systems satisfy a market demand. Time-of-flight-Diffraction (TOFD) for detection and sizing of weld root corrosion as well as coherent color enhanced thickness mapping will also be introduced.

  11. CORROSION STUDY OF AMORPHOUS METAL RIBBONS

    SciTech Connect

    Lian, T; Day, S D; Farmer, J C

    2006-07-31

    Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The potential advantages of amorphous metals have been recognized for some time [Latanison 1985]. Iron-based corrosion-resistant, amorphous-metal coatings under development may prove important for maritime applications [Farmer et al. 2005]. Such materials could also be used to coat the entire outer surface of containers for the transportation and long-term storage of spent nuclear fuel, or to protect welds and heat affected zones, thereby preventing exposure to environments that might cause stress corrosion cracking [Farmer et al. 1991, 2000a, 2000b]. In the future, it may be possible to substitute such high-performance iron-based materials for more-expensive nickel-based alloys, thereby enabling cost savings in a wide variety of industrial applications. It should be noted that thermal-spray ceramic coatings have also been investigated for such applications [Haslam et al. 2005]. This report focuses on the corrosion resistance of iron-based melt-spun amorphous metal ribbons. Melt-Spun ribbon is made by rapid solidification--a stream of molten metal is dropped onto a spinning copper wheel, a process that enables the manufacture of amorphous metals which are unable to be manufactured by conventional cold or hot rolling techniques. The study of melt-spun ribbon allows quick evaluation of amorphous metals corrosion resistance. The melt-spun ribbons included in this study are DAR40, SAM7, and SAM8, SAM1X series, and SAM2X series. The SAM1X series ribbons have

  12. A system for characterizing Mg corrosion in aqueous solutions using electrochemical sensors and impedance spectroscopy.

    PubMed

    Doepke, Amos; Kuhlmann, Julia; Guo, Xuefei; Voorhees, Robert T; Heineman, William R

    2013-11-01

    Understanding Mg corrosion is important to the development of biomedical implants made from Mg alloys. Mg corrodes readily in aqueous environments, producing H2, OH- and Mg2+. The rate of formation of these corrosion products is especially important in biomedical applications where they can affect cells and tissue near the implant. We have developed a corrosion characterization system (CCS) that allows realtime monitoring of the solution soluble corrosion products OH-, Mg2+, and H2 during immersion tests commonly used to study the corrosion of Mg materials. Instrumentation was developed to allow the system to also record electrochemical impedance spectra simultaneously in the same solution to monitor changes in the Mg samples. We demonstrated application of the CCS by observing the corrosion of Mg (99.9%) in three different corrosion solutions: NaCl, HEPES buffer, and HEPES buffer with NaCl at 37°C for 48 h. The solution concentrations of the corrosion products measured by sensors correlated with the results using standard weight loss measurements to obtain corrosion rates. This novel approach gives a better understanding of the dynamics of the corrosion process in realtime during immersion tests, rather than just providing a corrosion rate at the end of the test, and goes well beyond the immersion tests that are commonly used to study the corrosion of Mg materials. The system has the potential to be useful in systematically testing and comparing the corrosion behavior of different Mg alloys, as well as protective coatings.

  13. Current and potential distributions in corrosion systems

    SciTech Connect

    Smyrl, W.H.

    1980-01-01

    Current and potential distribution calculations in corrosion are reviewed. The mathematical methods used, and the specific results for galvanic corrosion, cathodic protection, and localized corrosion are described.

  14. Comparison of TGSCC and crevice corrosion in a brass/nitrite system

    SciTech Connect

    Edgemon, G.L.; Bell, G.E.C.; Mickalonis, J.I.

    1999-11-01

    The use of electrochemical noise based corrosion monitoring equipment to detect localized corrosion in laboratory and process systems has increased markedly over the last five years. One of the most interesting systems to study is the stress corrosion cracking of UNS C22000 brass exposed to 1-M sodium nitrite (NaNO{sub 2}) at ambient temperature. This test has been proposed as a possible standard for evaluating electrochemical noise equipment. Stressed brass specimens exposed to this environment consistently display the same movement from general corrosion to passivation to transgranular stress corrosion cracking. In an effort to better understand the complex patterns of data this system is capable of producing, crevice corrosion tests using similar specimens and environments were performed. Data from the stress corrosion cracking tests are presented and compared with data from the crevice corrosion tests.

  15. Electrode-polarization studies in hot-corrosion systems. Progress report, 1 June 1980-31 May 1981

    SciTech Connect

    Devereux, O.F.

    1981-02-01

    The following tasks are reported on: electrode polarization studies in molten sodium carbonate, liquid line corrosion, and gas/metal reactions in mixed oxidants. Two previously unpublished papers are included as appendices: Reactions at the CO, CO/sub 2//Ni electrode in Molten Sodium Carbonate; and Reactions at the Corroding Nickel Electrode in Molten Sodium Carbonate under CO, CO/sub 2/ Atmospheres. (DLC)

  16. A study of corrosion-resistant materials for pulsed gaseous core nuclear systems

    SciTech Connect

    Whitney, E.D.; Kim, D.J.; Tucker, D.S.

    1985-05-01

    The containment of an aggressive high-temperature reactive fluoride atmosphere, such as exists in a pulsed gaseous core nuclear system, requires the use of protective materials that will either not react in this environment or will form stable nonvolatile fluorides, thus passivating the surface against further reaction. Candidate protective materials for gaseous core reactors were identified for further investigation on the basis of their thermodynamic and mechanical properties. Materials included aluminum oxide (Al/sub 2/O/sub 3/), yttrium oxide (Y/sub 2/O/sub 3/), mixtures of Al/sub 2/O/sub 3/ and Y/sub 2/O/sub 3/, magnesium oxide (MgO), and pyrophyllite (Al/sub 2/(Si/sub 2/O/sub 5/)/sub 2/(OH)/sub 2/). Pioneering studies at the University of Florida on the use of infrared reflection spectroscopy (IRRS) for nondestructive surface analysis, along with x-ray diffraction pattern (XDP) studies, were applied to the analysis of UF/sub 6/ material/surface interactions. Candidate materials were subjected to a UF/sub 6/ atmosphere (973 K, 87 Torr, with 1- to 5-h exposures). The IRRS and XDP analyses of the materials after exposure showed no surface product formation in the case of the first four protective materials. For pyrophyllite, a mechanically and chemically stable protective surface fluoride film was formed.

  17. Report on accelerated corrosion studies.

    SciTech Connect

    Mowry, Curtis Dale; Glass, Sarah Jill; Sorensen, Neil Robert

    2011-03-01

    Sandia National Laboratories (SNL) conducted accelerated atmospheric corrosion testing for the U.S. Consumer Product Safety Commission (CPSC) to help further the understanding of the development of corrosion products on conductor materials in household electrical components exposed to environmental conditions representative of homes constructed with problem drywall. The conditions of the accelerated testing were chosen to produce corrosion product growth that would be consistent with long-term exposure to environments containing humidity and parts per billion (ppb) levels of hydrogen sulfide (H{sub 2}S) that are thought to have been the source of corrosion in electrical components from affected homes. This report documents the test set-up, monitoring of electrical performance of powered electrical components during the exposure, and the materials characterization conducted on wires, screws, and contact plates from selected electrical components. No degradation in electrical performance (measured via voltage drop) was measured during the course of the 8-week exposure, which was approximately equivalent to 40 years of exposure in a light industrial environment. Analyses show that corrosion products consisting of various phases of copper sulfide, copper sulfate, and copper oxide are found on exposed surfaces of the conductor materials including wires, screws, and contact plates. The morphology and the thickness of the corrosion products showed a range of character. In some of the copper wires that were observed, corrosion product had flaked or spalled off the surface, exposing fresh metal to the reaction with the contaminant gasses; however, there was no significant change in the wire cross-sectional area.

  18. Automated corrosion system in a moist environment

    SciTech Connect

    Hallman, R.L. Jr.; Calhoun, C.L.

    1999-03-19

    In an effort to assist researchers investigating the moisture-generated corrosion of metals and ceramics, a unique exposure system was developed. The initial goal of this system was to monitor corrosion ranging from a few monolayers at the outset of the corrosion process to high mass gains in more extensively corroded material. The new system uses a small robot arm for sample manipulation; gravimetric and Fourier transform infrared (FTIR) spectroscopy for corrosion-product determination; and a gas blending system to control the moisture content of the glove box in which the system is housed. The system's computer control can be configured to coordinate the examination of as many as 20 samples by periodic weighing and FTIR scanning. The computer also performs such functions as data logging of the temperature and pressure of the system and of the flow rate and moisture content of the purge gas. One main benefit of the computer-controlled robotic system is its ability to monitor samples 2 4 hours a day with precision control; this reduces problems stemming from human error or inconsistency of human technique.

  19. An electrochemical study of the corrosion behavior of primer coated 2219-T87 aluminum

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Higgins, R. H.

    1985-01-01

    The corrosion behavior for 2219-T87 aluminum coated with various primers, including those used for the external tank and solid rocket boosters of the Space Shuttle Transportation System, were investigated using electrochemical techniques. Corrosion potential time, polarization resistance time, electrical resistance time, and corrosion rate time measurements were all investigated. It was found that electrical resistance time and corrosion rate time measurement were most useful for studying the corrosion behavior of painted aluminum. Electrical resistance time determination give useful information concerning the porosity of paint films, while corrosion rate time curves give important information concerning overall corrosion rates and corrosion mechanisms. In general, the corrosion rate time curves all exhibited at least one peak during the 30 day test period, which was attributed, according to the proposed mechanisms, to the onset of the hydrogen evolution reaction and the beginning of destruction of the protective properties of the paint film.

  20. Task E container corrosion studies: Annual report

    SciTech Connect

    Bunnell, L.R.; Doremus, L.A.; Topping, J.B.; Duncan, D.R.

    1994-06-01

    The Pacific Northwest Laboratory is conducting the Solid Waste Technology Support Program (SWTSP) for Westinghouse Hanford Company (WHC). Task E is the Container Corrosion Study Portion of the SWTSP that will perform testing to provide defensible data on the corrosion of low-carbon steel, as used in drums to contain chemical and radioactive wastes at the Hanford Site. A second objective of Task E is to provide and test practical alternative materials that have higher corrosion resistance than low-carbon steel. The scope of work for fiscal year (FY) 1993 included initial testing of mild steel specimens buried in Hanford soils or exposed to atmospheric corrosion in metal storage sheds. During FY 1993, progress was made in three areas of Task E. First, exposure of test materials began at the Soil Corrosion Test Site where low-carbon steel specimens were placed in the soil in five test shafts at depths of 9 m (30 ft). Second, the corrosion measurement of low-carbon steel in the soil of two solid waste trenches continued. The total exposure time is {approx} 500 days. Third, an atmospheric corrosion test of low-carbon steel was put initiated in a metal shed (Building 2401-W) in the 200 West Area. This annual report describes the Task E efforts and provides a current status.

  1. NON-CORROSIVE REACTOR FUEL SYSTEM

    DOEpatents

    Herrick, C.C.

    1962-08-14

    A non-corrosive nuclear reactor fuel system was developed utilizing a molten plutonium-- iron alloy fuel having about 2 at.% carbon and contained in a tantalum vessel. This carbon reacts with the interior surface of the tantalum vessel to form a plutonium resistant self-healing tantalum carbide film. (AEC)

  2. Corrosion

    ERIC Educational Resources Information Center

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  3. Overcoming corrosion concerns in copper tube systems

    SciTech Connect

    Cohen, A.; Myers, J.R.

    1995-12-01

    Copper water tube systems have had a long and successful application history. On rare occasions, however, there have been failures due to aggressive water, defective workmanship, inappropriate materials selection, or improper system design or operation. This paper describes proper materials selection, system design and operations, correct workmanship practices and effective water treatment alternatives to prevent corrosion, while complying fully with the 1991 Lead-Copper Rule Amendment of the 1974 Safe Drinking Water Act.

  4. Non-Markovian model for the study of pitting corrosion in a water pipe system

    NASA Astrophysics Data System (ADS)

    Rosa, A. C. P.; Vaveliuk, P.; Moret, M. A.

    2015-03-01

    The main studies on pitting consist in proposing Markovian stochastic models, based on the statistics of extreme values and focused on growing the depth of wells, especially the deepest one. We show that a non-Markovian model, described by a nonlinear Fokker-Planck (nFP) equation, properly depicts the time evolution of a distribution of depth values of pits that were experimentally obtained. The solution of this equation in a steady-state regime is a q-Gaussian distribution, i.e. a long-tail probability distribution that is the main characteristic of a nonextensive statistical mechanics. The proposed model, that is applied to data from four inspections conducted on a section of a line of regular water service in power water reactor (PWR) nuclear power plants, is in agreement with experimental results.

  5. Study made of procedures for externally loading and corrosion testing stress corrosion specimens

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1967-01-01

    Study was initiated to determine methods or test specimens for evaluating stress corrosion cracking characteristics of common structural materials. It was found that the methods of externally loading and corrosion testing were reliable in yielding reproducible results for stress corrosion evaluation.

  6. Study of Caustic Corrosion of Carbon Steel Waste Tanks

    SciTech Connect

    Jenkins, C.F.

    1999-02-24

    Solution chemistry of wastes from US atomic weapons production is controlled to inhibit corrosion of carbon steel tanks used in containment and storage. The pH, nitrate ion and nitrite ion concentrations of fresh solutions are maintained within specified limits for this purpose. In the start up process for a new waste evaporator (RHL WE), non-radioactive solutions of similar chemistry will be circulated through carbon steel piping between a steel tank and the evaporator. The evaporator is fabricated from a corrosion resistant nickel base alloy. The equipment will be exposed continuously to the hot corrosive caustic solutions. Published corrosion rates for steel in pure caustic at the elevated temperatures indicate losses >1.3 mm/y. Because the total test period for start up is relatively short, penetration will not occur. However, concern exists because the rust particles will probably circulate and precipitate throughout the system.A laboratory study was performed in order to determine corrosion to be expected for the specific waste solutions being used in start up testing of the new equipment. In summary, the test results indicate that the corrosion rates for steel are acceptable for the short term simulant tests for the new evaporator. The amount of particulate is probably not a concern, through filtration is recommended as an option. the hydrogen formation is also not a concern because it is in a steam environment, and is continuously swept from the storage vessel.

  7. Preliminary review of mass transfer and flow visualization studies and techniques relevant to the study of erosion-corrosion of reactor piping systems

    SciTech Connect

    Kuzay, T.M.; Halle, H.J.; Kasza, K.E.

    1988-06-01

    This report provides some background information on the failed piping at the Surry-2 reactor; a summary of pertinent literature on mass transfer in related geometries; and a description of methodologies for visualization and erosion rate measurements in laboratory model studies that can provide greater insight into the role of flow geometry in erosion-corrosion. 18 refs., 9 figs., 1 tab.

  8. Engineering Task Plan for Fourth Generation Hanford Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-06-20

    This Engineering Task Plan (ETP) describes the activities associated with the installation of cabinets containing corrosion monitoring equipment on tanks 241-AN-102 and 241-AN-107. The new cabinets (one per tank) will be installed adjacent to existing corrosion probes already installed in riser WST-RISER-016 on both tanks. The corrosion monitoring equipment to be installed utilizes the technique of electrochemical noise (EN) for monitoring waste tank corrosion. Typically, EN consists of low frequency (4 Hz) and small amplitude signals that are spontaneously generated by electrochemical reactions occurring at corroding or other surfaces. EN analysis is well suited for monitoring and identifying the onset of localized corrosion, and for measuring uniform corrosion rates. A typical EN based corrosion-monitoring system measures instantaneous fluctuations in corrosion current and potential between three nominally identical electrodes of the material of interest immersed in the environment of interest. Time-dependent fluctuations in corrosion current are described by electrochemical current noise, and time-dependent fluctuations of corrosion potential are described by electrochemical noise. The corrosion monitoring systems are designed to detect the onset of localized corrosion phenomena if tank conditions should change to allow these phenomena to occur. In addition to the EN technique, the systems also facilitate the use of the Linear Polarization Resistance (LPR) technique to collect uniform corrosion rate information. LPR measures the linearity at the origin of the polarization curve for overvoltages up to a few millivolts away from the rest potential or natural corrosion potential. The slope of the current vs. voltage plot gives information on uniform corrosion rates.

  9. Electrochemical studies of corrosion inhibiting effect of polyaniline coatings

    SciTech Connect

    Wei, Yen; Wang, Jianguo; Jia, Xinru

    1995-12-01

    A series of electrochemical measurements, including corrosion potential (E{sub corr}), corrosion current (i{sub corr}), Tafel`s constants and polarization resistance (R{sub p}), have been made on polyaniline-coated cold rolled steel specimen under various conditions. Both the base and acid-doped forms of polyaniline were studied. The base form of polyaniline was found to offer good corrosion protection. This phenomenon may not originate merely from the barrier effect of the coatings, because the nonconjugated polymers such as polystyrene and epoxy did not show the same electrochemical behavior. The polyaniline base with zinc nitrate plus epoxy topcoat appeared to give better overall protection relative to other coating systems in this study.

  10. Instrumentation for potentiostatic corrosion studies with distilled water

    NASA Technical Reports Server (NTRS)

    Loess, R. E.; Youngdahl, C. A.

    1969-01-01

    Corrosion is studied potentiostatically in the corroding environment of distilled water with an instrument that measures the potential of the corroding specimen immediately after interruption of the polarizing current. No current is flowing. The process permits compensation for IR drops when potentiostatic control is used in high resistance systems.

  11. Corrosion Studies of Wrought and Cast NASA-23 Alloy

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1997-01-01

    Corrosion studies were carried out for wrought and cast NASA-23 alloy using electrochemical methods. The scanning reference electrode technique (SRET), the polarization resistance technique (PR), and the electrochemical impedance spectroscopy (EIS) were employed. These studies corroborate the findings of stress corrosion studies performed earlier, in that the material is highly resistant to corrosion.

  12. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.; Deramus, G. E., Jr.

    1977-01-01

    Problems dealing with corrosion and corrosion protection of solar heating and cooling systems are discussed. A test program was conducted to find suitable and effective corrosion inhibitors for systems employing either water or antifreeze solutions for heat transfer and storage. Aluminum-mild-steel-copper-stainless steel assemblies in electrical contact were used to simulate a multimetallic system which is the type most likely to be employed. Several inhibitors show promise for this application.

  13. Method for inhibiting corrosion in aqueous systems

    DOEpatents

    DeMonbrun, James R.; Schmitt, Charles R.; Schreyer, James M.

    1980-01-01

    This invention is a method for inhibiting corrosion in aqueous systems containing components composed of aluminum, copper, iron, or alloys thereof. The method comprises (a) incorporating in the aqueous medium 2-10 ppm by weight of tolyltriazole; an effective amount of a biodegradable organic biocide; 500-1000 ppm by weight of sodium metasilicate; 500-2000 ppm by weight of sodium nitrite; and 500-2000 ppm by weight of sodium tetraborate, all of these concentrations being based on the weight of water in the system; and (b) maintaining the pH of the resulting system in the range of 7.5 to 8.0. The method permits longterm operation with very low corrosion rates and bacteria counts. All of the additives to the system are biodegradable, permitting the treated aqueous medium to be discharged to the environment without violating current regulations. The method has special application to solar systems in which an aqueous medium is circulated through aluminum-alloy heat exchangers.

  14. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique

    PubMed Central

    Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

    2016-01-01

    In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)2 solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete. PMID:27618054

  15. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique.

    PubMed

    Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

    2016-09-08

    In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)₂ solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete.

  16. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique.

    PubMed

    Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

    2016-01-01

    In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)₂ solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete. PMID:27618054

  17. Identification and counteraction of microbe-induced corrosion in metallic systems

    SciTech Connect

    Stein, A.A.

    1986-11-01

    Biological attack of metallic systems is a longstanding problem that affects all structural materials in a variety of environment and systems. Corrosion of buried pipelines by sulfate-reducing bacteria has been studied by the petrochemical industry for years. In the power industry, corrosion studies have focused on condensers and service water systems where slime, barnacles, clams, and other macro-organisms are easily detected. Efforts have been made to eliminate the effect of these organisms through the use of chlorination, back-flushing, organic coatings, or thermal shock. The objective was to maintain component performance by eliminating biofouling and reducing metallic corrosion. Recently, it has been recognized that corrosion caused by micro-organisms can occur even in very clean systems. This article gives guidelines for the identification and counteraction of microbe-induced corrosion in metallic systems.

  18. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    SciTech Connect

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  19. Study of crevice-galvanic corrosion of aluminum

    NASA Technical Reports Server (NTRS)

    Draley, J. E.; Loess, R. E.; Mori, S.

    1967-01-01

    Corrosion effects of aluminum-copper and aluminum-nickel couples in oxygenated distilled water, and aluminum alloys in oxygenated copper sulfate solution were studied. One of each of the couples had a water tight seal, and showed no substantial corrosion, and of the unsealed couples, only the aluminum-copper developed corrosion.

  20. Corrosion inhibitor for aqueous ammonia absorption system

    DOEpatents

    Phillips, B.A.; Whitlow, E.P.

    1998-09-22

    A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

  1. Corrosion inhibitor for aqueous ammonia absorption system

    DOEpatents

    Phillips, Benjamin A.; Whitlow, Eugene P.

    1998-09-22

    A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

  2. A study of copper corrosion control strategies

    SciTech Connect

    Qureshi, N.; Sjolund, W.

    1994-10-01

    In compliance with the Lead and Copper Rule of the 1986 Safe Drinking Water Act, Brainerd Public Utilities tested the first drawn water from 60 sampling sites within the city. Ninety percent of these site samples contained elevated copper levels in excess of the 1.3 mg/L (1,300 ppb) action level established by the EPA standard. The samples, however, did not exceed the 0.015 mg/L (15 ppb) action level for lead. A water quality study evaluated the various options for copper corrosion control using a test stand for approximately five months starting in May 1993. The study evaluated the effectiveness of applying various chemicals for the control of copper corrosion. Chemicals tested included sodium hydroxide (NaOH) (for pH adjustment); sodium silicate; ortho/polyphosphate (Calgon C-4). The study also examined the possibility of reducing the level of dissolved oxygen in the water during aeration as a means of reducing the level of copper corrosion.

  3. Corrosion Study Using Electrochemical Impedance Spectroscopy

    NASA Technical Reports Server (NTRS)

    Farooq, Muhammad Umar

    2003-01-01

    Corrosion is a common phenomenon. It is the destructive result of chemical reaction between a metal or metal alloy and its environment. Stainless steel tubing is used at Kennedy Space Center for various supply lines which service the orbiter. The launch pads are also made of stainless steel. The environment at the launch site has very high chloride content due to the proximity to the Atlantic Ocean. Also, during a launch, the exhaust products in the solid rocket boosters include concentrated hydrogen chloride. The purpose of this project was to study various alloys by Electrochemical Impedance Spectroscopy in corrosive environments similar to the launch sites. This report includes data and analysis of the measurements for 304L, 254SMO and AL-6XN in primarily neutral 3.55% NaCl. One set of data for 304L in neutral 3.55%NaCl + 0.1N HCl is also included.

  4. Design of second generation Hanford tank corrosion monitoring system

    SciTech Connect

    Edgemon, G.L.

    1998-04-02

    small amplitude signals that are spontaneously generated by electrochemical reactions occurring at corroding or other surfaces. Laboratory studies and recent reports on field applications have reported that EN analysis is well suited for monitoring and identifying the onset of localized corrosion, and for measuring uniform corrosion rates. A two year laboratory study was started at Hanford in 1995 to provide a technical basis for using EN in Hanford nuclear waste tanks. Based on this study, a prototype system was constructed and deployed in DST 241-AZ-101 in August, 1996. Based on the successful demonstration of this prototype for more than a year, a first-generation full-scale system was designed and installed into DST 241-AN-107 in September 1997. This document summarizes the design and operational requirements of the second-generation full-scale system scheduled for deployment into 241-AY-102.

  5. Vascular system of the human spinal cord in the prenatal period: a dye injection and corrosion casting study.

    PubMed

    Zawiliński, J; Litwin, J A; Nowogrodzka-Zagórska, M; Gorczyca, J; Miodoński, A J

    2001-07-01

    The vascularization of the spinal cord was investigated in 50 human fetuses aged from 10 to 28 gestational weeks using dye injection methods and corrosion casting accompanied by scanning electron microscopy. In the investigated period of fetal development, the general vascular architecture of the spinal cord, corresponding to that described postnatally, seemed to be already established. The observed changes included: (1) remodeling of the supplying (extrinsic) arterial branches, (2) transformation of the posterior anastomotic chain into two distinct posterior spinal arteries, and (3) development of the capillary networks in the gray and white matter. The remodeling of the radicular arteries supplying the spinal cord was accompanied by a decrease in their number and transition from regular to irregular distribution (appearance of intersegmental differences in their frequency). The anterior spinal artery and regular array of the central arteries were already present in the youngest fetuses examined, but the final remodeling of the posterior anastomotic chain into two posterior spinal arteries occurred between 15th and 20th week of fetal life indicating that the vascularization of the anterior region of the spinal cord in the investigated period of fetal life was more advanced as compared with that of the posterior region. The capillary network of the gray matter in the youngest fetuses had the form of discrete glomerular plexuses supplied by groups of central arteries and mainly vascularizing the anterior horns. Successively, the plexuses fused to form a continuous system along the anterior columns and the system expanded to fully vascularize the posterior horns. The white matter in the earlier fetal period seemed to be partially avascular, later the density of capillaries vascularizing those areas was still much lower than in the gray matter. The veins showed considerably greater variability than the arteries, as far as their topography and distribution was

  6. Corrosion and odor management in sewer systems.

    PubMed

    Jiang, Guangming; Sun, Jing; Sharma, Keshab R; Yuan, Zhiguo

    2015-06-01

    Sewers emit hydrogen sulfide and various volatile organic sulfur and carbon compounds, which require control and mitigation. In the last 5-10 years, extensive research was conducted to optimize existing sulfide abatement technologies based on newly developed in-depth understanding of the in-sewer processes. Recent advances have also led to low-cost novel solutions targeting sewer biofilms. Online control has been demonstrated to greatly reduce the chemical usage. Dynamic models for both the water, air and solid (concrete) phases have been developed and used for the planning and maintenance of sewer systems. Existing technologies primarily focused on 'hotspots' in sewers. Future research should aim to achieve network-wide corrosion and emission control and management of sewers as an integrated component of an urban water system. PMID:25827114

  7. Corrosion and odor management in sewer systems.

    PubMed

    Jiang, Guangming; Sun, Jing; Sharma, Keshab R; Yuan, Zhiguo

    2015-06-01

    Sewers emit hydrogen sulfide and various volatile organic sulfur and carbon compounds, which require control and mitigation. In the last 5-10 years, extensive research was conducted to optimize existing sulfide abatement technologies based on newly developed in-depth understanding of the in-sewer processes. Recent advances have also led to low-cost novel solutions targeting sewer biofilms. Online control has been demonstrated to greatly reduce the chemical usage. Dynamic models for both the water, air and solid (concrete) phases have been developed and used for the planning and maintenance of sewer systems. Existing technologies primarily focused on 'hotspots' in sewers. Future research should aim to achieve network-wide corrosion and emission control and management of sewers as an integrated component of an urban water system.

  8. Corrosion control when using secondary treated municipal wastewater as alternative makeup water for cooling tower systems.

    PubMed

    Hsieh, Ming-Kai; Li, Heng; Chien, Shih-Hsiang; Monnell, Jason D; Chowdhury, Indranil; Dzombak, David A; Vidic, Radisav D

    2010-12-01

    Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21-day average corrosion rate with the last 5-day average corrosion rate, the latter being approximately 50% lower than the former.

  9. Corrosion control when using secondary treated municipal wastewater as alternative makeup water for cooling tower systems.

    PubMed

    Hsieh, Ming-Kai; Li, Heng; Chien, Shih-Hsiang; Monnell, Jason D; Chowdhury, Indranil; Dzombak, David A; Vidic, Radisav D

    2010-12-01

    Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21-day average corrosion rate with the last 5-day average corrosion rate, the latter being approximately 50% lower than the former. PMID:21214028

  10. A NOVEL SENSOR AND MEASUREMENT SYSTEM FOR FIRESIDE CORROSION MONITORING IN COAL-FIRED BOILERS

    SciTech Connect

    Heng Ban; Zuoping Li

    2003-03-01

    Fireside corrosion in coal-fired power plants is a major obstacle to increase the overall efficiency for power producers. The increased use of opportunity fuels and low emission combustion modes have aggravated the corrosion on boiler tube walls in power plants. Corrosion-induced equipment failure could lead to catastrophic damage and inflict significant loss of production and cost for repair. Monitoring fireside corrosion in a reliable and timely manner can provide significant benefits to the plant operation. Current corrosion inspection and measurement are typically performed during scheduled maintenance outages, which is often after the damage is done. In the past, there have been many attempts to develop real time continuous corrosion monitoring technologies. However, there is still no short-term, online corrosion monitoring system commercially available for fireside corrosion to date due to the extremely harsh combustion environment. This report describes the results of a laboratory feasibility study on the development effort of a novel sensor for on-line fireside corrosion monitoring. A novel sensor principle and thin-film technologies were employed in the corrosion sensor design and fabrication. The sensor and the measurement system were experimentally studied using laboratory muffle furnaces. The results indicated that an accurate measure of corrosion rate could be made with high sensitivity using the new sensor. The investigation proved the feasibility of the concept and demonstrated the sensor design, sensor fabrication, and measurement instrumentation at the laboratory scale. An uncertainty analysis of the measurement system was also performed to provide a basis for further improvement of the system for future pilot or full scale testing.

  11. Study of biofilm influenced corrosion on cast iron pipes in reclaimed water

    NASA Astrophysics Data System (ADS)

    Zhang, Haiya; Tian, Yimei; Wan, Jianmei; Zhao, Peng

    2015-12-01

    Biofilm influenced corrosion on cast iron pipes in reclaimed water was systemically studied using the weight loss method and electrochemical impedance spectroscopy (EIS). The results demonstrated that compared to sterile water, the existence of the biofilm in reclaimed water promoted the corrosion process significantly. The characteristics of biofilm on cast iron coupons were examined by the surface profiler, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The bacterial counts in the biofilm were determined using the standard plate count method and the most probable number (MPN). The results demonstrated that the corrosion process was influenced by the settled bacteria, EPS, and corrosion products in the biofilm comprehensively. But, the corrosion mechanisms were different with respect to time and could be divided into three stages in our study. Furthermore, several corresponding corrosion mechanisms were proposed for different immersion times.

  12. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1978-01-01

    Inhibitors which appeared promising in previous tests and additional inhibitors including several proprietary products were evaluated. Evaluation of the inhibitors was based on corrosion protection afforded an aluminum-mild steel-copper-stainless steel assembly in a hot corrosive water. Of the inhibitors tested two were found to be effective and show promise for protecting multimetallic solar heating systems.

  13. Combustion system processes leading to corrosive deposits

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Rosner, D. E.

    1981-01-01

    Degradation of turbine engine hot gas path components by high temperature corrosion can usually be associated with deposits even though other factors may also play a significant role. The origins of the corrosive deposits are traceable to chemical reactions which take place during the combustion process. In the case of hot corrosion/sulfidation, sodium sulfate was established as the deposited corrosive agent even when none of this salt enters the engine directly. The sodium sulfate is formed during the combustion and deposition processes from compounds of sulfur contained in the fuel as low level impurities and sodium compounds, such as sodium chloride, ingested with intake air. In other turbine and power generation situations, corrosive and/or fouling deposits can result from such metals as potassium, iron, calcium, vanadium, magnesium, and silicon.

  14. Mathematical modeling of microbially induced crown corrosion in wastewater collection systems and laboratory investigation and modeling of sulfuric acid corrosion of concrete

    NASA Astrophysics Data System (ADS)

    Jahani, Fereidoun

    In the model for microbially induced crown corrosion, the diffusion of sulfide inside the concrete pores, its biological conversion to sulfuric acid, and the corrosion of calcium carbonate aggregates are represented. The corrosion front is modeled as a moving boundary. The location of the interface between the corrosion layer and the concrete is determined as part of the solution to the model equations. This model consisted of a system of one dimensional reaction-diffusion equations coupled to an equation describing the movement of the corrosion front. The equations were solved numerically using finite element Galerkin approximation. The concentration profiles of sulfide in the air and the liquid phases, the pH as a function of concrete depth, and the position of the corrosion front. A new equation for the corrosion rate was also derived. A more specific model for the degradation of a concrete specimen exposed to a sulfuric acid solution was also studied. In this model, diffusion of hydrogen ions and their reaction with alkaline components of concrete were expressed using Fick's Law of diffusion. The model equations described the moving boundary, the dissolution rate of alkaline components in the concrete, volume increase of sulfuric acid solution over the concrete specimen, and the boundary conditions on the surface of the concrete. An apparatus was designed and experiments were performed to measure pH changes on the surface of concrete. The data were used to calculate the dissolution rate of the concrete and, with the model, to determine the diffusion rate of sulfuric acid in the corrosion layer and corrosion layer thickness. Electrochemical Impedance Spectroscopy (EIS) was used to study the corrosion rate of iron pins embedded in the concrete sample. The open circuit potential (OCP) determined the onset of corrosion on the surface of the pins. Visual observation of the corrosion layer thickness was in good agreement with the simulation results.

  15. Laser Raman Spectroscopy in studies of corrosion and electrocatalysis

    SciTech Connect

    Melendres, C.A.

    1988-01-01

    Laser Raman Spectroscopy (LRS) has become an important tool for the in-situ structural study of electrochemical systems and processes in recent years. Following a brief introduction of the experimental techniques involved in applying LRS to electrochemical systems, we survey the literature for examples of studies in the inhibition of electrode reactions by surface films (e.g., corrosion and passivation phenomena) as well as the acceleration of reactions by electro-sorbates (electrocatalysis). We deal mostly with both normal and resonance Raman effects on fairly thick surface films in contrast to surface-enhanced Raman investigations of monolayer adsorbates, which is covered in another lecture. Laser Raman spectroelectrochemical studies of corrosion and film formation on such metals as Pb, Ag, Fe, Ni, Co, Cr, Au, stainless steel, etc. in various solution conditions are discussed. Further extension of the technique to studies in high-temperature and high-pressure aqueous environments is demonstrated. Results of studies of the structure of corrosion inhibitors are also presented. As applications of the LRS technique in the area of electrocatalysis, we cite studies of the structure of transition metal macrocyclic compounds, i.e., phthalocyanines and porphyrins, used for catalysis of the oxygen reduction reaction. 104 refs., 20 figs.

  16. Titanium-potassium heat pipe corrosion studies

    SciTech Connect

    Lundberg, L.B.

    1984-07-01

    An experimental study of the susceptibility of wickless titanium/potassium heat pipes to corrosive attack has been conducted in vacuo at 800/sup 0/K for 6511h and at 900/sup 0/K for 4797h without failure or degradation. Some movement of carbon, nitrogen and oxygen was observed in the titanium container tube, but no evidence of attack could be detected in metallographic cross sections of samples taken along the length of the heat pipes. The lack of observable attack of titanium by potassium under these conditions refutes previous reports of Ti-K incompatibility.

  17. Corrosion study for a radioactive waste vitrification facility

    SciTech Connect

    Imrich, K.J.; Jenkins, C.F.

    1993-10-01

    A corrosion monitoring program was setup in a scale demonstration melter system to evaluate the performance of materials selected for use in the Defense Waste Processing Facility (DWPF) at the DOE`s Savannah River Site. The system is a 1/10 scale prototypic version of the DWPF. In DWPF, high activity radioactive waste will be vitrified and encapsulated for long term storage. During this study twenty-six different alloys, including DWPF reference materials of construction and alternate higher alloy materials, were subjected to process conditions and environments characteristic of the DWPF except for radioactivity. The materials were exposed to low pH, elevated temperature (to 1200{degree}C) environments containing abrasive slurries, molten glass, mercury, halides and sulfides. General corrosion rates, pitting susceptibility and stress corrosion cracking of the materials were investigated. Extensive data were obtained for many of the reference materials. Performance in the Feed Preparation System was very good, whereas coupons from the Quencher Inlet region of the Melter Off-Gas System experienced localized attack.

  18. Electrometrical Methods Application for Detection of Heating System Pipeline Corrosion

    NASA Astrophysics Data System (ADS)

    Vetrov, A.; Ilyin, Y.; Isaev, V.; Rondel, A.; Shapovalov, N.

    2004-12-01

    Coated steel underground pipelines are widely used for the petroleum and gaze transportation, for the water and heat supply. The soils, where the pipelines are placed, are usually highly corrosive for pipe's metal. In the places of crippling of external coating the corrosion processes begin, and this can provoke a pipe breakage. To ensure the pipeline survivability it is necessary to carry out the control of pipeline conditions. The geophysical methods are used to provide such diagnostic. Authors have studied the corrosion processes of the municipal heating system pipelines in Saint-Petersburg (Russia) using the air thermal imaging method, the investigation of electromagnetic fields and spontaneous polarization, measurements of electrode potentials of metal tubes. The pipeline reparation works, which have been provided this year, allowed us to make the visual observation of pipes. The investigation object comprises a pipeline composed of two parallel tubes, which are placed 1-2 meters deep. The fact that the Russian Federation and CIS countries still use the direct heat supply system makes impossible any addition of anticorrosion components to circulating water. Pipelines operate under high pressure (up to 5 atm) and high temperature (designed temperature is 150°C). Tube's isolation is meant for heat loss minimization, and ordinary has poor hydro-isolation. Some pipeline construction elements (sliding and fixed bearings, pressure compensators, heat enclosures) are often non-isolated, and tube's metal contacts with soil. Hard usage condition, ingress of technical contamination cause, stray currents etc. cause high accidental rate. Realization of geophysical diagnostics, including electrometry, is hampered in a city by underground communication systems, power lines, isolating ground cover (asphalt), limitation of the working area with buildings. These restrictions form the investigation conditions. In order to detect and localize isolation (coat) defects authors

  19. The study of palm oil methyl ester and its corrosiveness

    NASA Astrophysics Data System (ADS)

    Sani, W. B. Wan; Samo, K. B.; Da, T. H.; Zulkifli, M. F. R.

    2012-06-01

    The present aim of this study is to determine the corrosion effect of palm oil methyl ester (POME) on aluminium alloy 5083 (AA5083). The static immersion test was carried out at 60°C for 68 days according to ASTM G-31-72. The corrosion analysis was done by using weight loss method and electrochemical test. The POME was analyzed by using Fourier Transform Infrared (FTIR) to determine its functional group. The result from weight loss method shows the decreasing in weight loss of AA5083 which signifies the ability of POME to reduce corrosion rate. The electrochemical test shows the decreasing in polarization resistance, Rp while the corrosion current densities, icorr increase. The corrosion rate reduces from 2.250mpy to 0.1946mpy. The low concentration of fatty acid C18:2 and high anti oxidant element contributes to the reduction of corrosion rate of AA5083 in POME.

  20. Corrosion/96 conference papers

    SciTech Connect

    1996-07-01

    Topics covered by this conference include: cathodic protection in natural waters; cleaning and repassivation of building HVAC systems; worldwide opportunities in flue gas desulfurization; advancements in materials technology for use in oil and gas service; fossil fuel combustion and conversion; technology of corrosion inhibitors; computers in corrosion control--modeling and information processing; recent experiences and advances of austenitic alloys; managing corrosion with plastics; corrosion measurement technology; corrosion inhibitors for concrete; refining industry; advances in corrosion control for rail and tank trailer equipment; CO{sub 2} corrosion--mechanisms and control; microbiologically influenced corrosion; corrosion in nuclear systems; role of corrosion in boiler failures; effects of water reuse on monitoring and control technology in cooling water applications; methods and mechanisms of scale and deposit control; corrosion detection in petroleum production lines; underground corrosion control; environmental cracking--relating laboratory results and field behavior; corrosion control in reinforced concrete structures; corrosion and its control in aerospace and military hardware; injection and process addition facilities; progress reports on the results of reinspection of deaerators inspected or repaired per RP0590 criteria; near 100% volume solids coating technology and application methods; materials performance in high temperature environments containing halides; impact of toxicity studies on use of corrosion/scale inhibitors; mineral scale deposit control in oilfield related operations; corrosion in gas treating; marine corrosion; cold climate corrosion; corrosion in the pulp and paper industry; gaseous chlorine alternatives in cooling water systems; practical applications of ozone in recirculating cooling water systems; and water reuse in industry. Over 400 papers from this conference have been processed separately for inclusion on the data base.

  1. Corrosion consequences of microfouling in water reclamation systems

    NASA Technical Reports Server (NTRS)

    Ford, Tim; Mitchell, Ralph

    1991-01-01

    This paper examines the potential fouling and corrosion problems associated with microbial film formation throughout the water reclamation system (WRS) designed for the Space Station Freedom. It is shown that the use of advanced metal sputtering techiques combined with image analysis and FTIR spectroscopy will present realistic solutions for investigating the formation and function of biofilm on different alloys, the subsequent corrosion, and the efficiency of different treatments. These techniques, used in combination with electrochemical measurements of corrosion, will provide a powerful approach to examinations of materials considered for use in the WRS.

  2. Study of stress corrosion in aluminum alloys

    NASA Technical Reports Server (NTRS)

    Brummer, S. B.

    1967-01-01

    Mechanism of the stress corrosion cracking of high-strength aluminum alloys was investigated using electrochemical, mechanical, and electron microscopic techniques. The feasibility of detecting stress corrosion damage in fabricated aluminum alloy parts by nondestructive testing was investigated using ultrasonic surface waves and eddy currents.

  3. Review and study of physics driven pitting corrosion modeling in 2024-T3 aluminum alloys

    NASA Astrophysics Data System (ADS)

    Yu, Lingyu; Jata, Kumar V.

    2015-04-01

    Material degradation due to corrosion and corrosion fatigue has been recognized to significantly affect the airworthiness of civilian and military aircraft, especially for the current fleet of airplanes that have served beyond their initial design life. The ability to predict the corrosion damage development in aircraft components and structures, therefore, is of great importance in managing timely maintenance for the aging aircraft vehicles and in assisting the design of new ones. The assessment of aircraft corrosion and its influence on fatigue life relies on appropriate quantitative models that can evaluate the initiation of the corrosion as well as the accumulation during the period of operation. Beyond the aircraft regime, corrosion has also affected the maintenance, safety and reliability of other systems such as nuclear power systems, steam and gas turbines, marine structures and so on. In the work presented in this paper, we reviewed and studied several physics based pitting corrosion models that have been reported in the literature. The classic work of particle induced pitting corrosion by Wei and Harlow is reviewed in detail. Two types of modeling, a power law based simplified model and a microstructure based model, are compared for 2024-T3 alloy. Data from literatures are used as model inputs. The paper ends with conclusions and recommendations for future work.

  4. SQUID magnetometers for studying corrosion and corrosion protection in aircraft aluminum

    SciTech Connect

    Wikswo, J.P. Jr.

    1997-12-01

    Studies at Vanderbilt and elsewhere have demonstrated that superconducting quantum interference (SQUID) magnetometers can be utilized for quantitative measurements of both corrosion activity and material loss in aircraft aluminum alloys. SQUIDs provide sufficient spatial resolution the distribution of hidden corrosion currents can be mapped. The sensitivity of SQUIDs operating at 4 K in liquid helium is such that corrosion can be detected for salt concentrations as low as 1 part per million, and corrosion in 4% NaCl can be detected through 1.4 cm of aluminum. While measurements of the magnetic field from galvanic currents is straightforward in the laboratory, where ferromagnetic fasteners can be eliminated and low frequency noise and the earth`s magnetic field can be shielded, this technique has yet to be demonstrated on aircraft on the flight line. Advanced, low-frequency SQUID eddy current measurements utilizing sheet inducers and phase-sensitive detection offers a depth-selective technique to image material loss deep in aluminum structures. The size of the signal makes this approach highly suitable for implementation with 77 K, liquid- nitrogen cooled SQUIDs. Thus SQUIDs may be useful both for quantitative, laboratory assessment of the rate of hidden corrosion in aircraft samples, and for imaging the extent of second- and third-layer corrosion damage in aircraft. 56 refs.

  5. Electrochemical study of aluminum corrosion in boiling high purity water

    NASA Technical Reports Server (NTRS)

    Draley, J. E.; Legault, R. A.

    1969-01-01

    Electrochemical study of aluminum corrosion in boiling high-purity water includes an equation relating current and electrochemical potential derived on the basis of a physical model of the corrosion process. The work involved an examination of the cathodic polarization behavior of 1100 aluminum during aqueous oxidation.

  6. Distribution system water age can create premise plumbing corrosion hotspots.

    PubMed

    Masters, Sheldon; Parks, Jeffrey; Atassi, Amrou; Edwards, Marc A

    2015-09-01

    Cumulative changes in chemical and biological properties associated with higher "water age" in distribution systems may impact water corrosivity and regulatory compliance with lead and copper action levels. The purpose of this study was to examine the effects of water age and chemistry on corrosivity of various downstream premise plumbing pipe materials and configurations using a combination of controlled laboratory studies and a field survey. Examination of lead pipe, copper pipe with lead solder, and leaded brass materials in a replicated lab rig simulating premise plumbing stagnation events indicated that lead or copper release could increase as much as ∼440 % or decrease as much as 98 % relative to water treatment plant effluent. In field studies at five utilities, trends in lead and copper release were highly dependent on circumstance; for example, lead release increased with water age in 13 % of cases and decreased with water age in 33 % of conditions tested. Levels of copper in the distribution system were up to 50 % lower and as much as 30 % higher relative to levels at the treatment plant. In many cases, high-risks of elevated lead and copper did not co-occur, demonstrating that these contaminants will have to be sampled separately to identify "worst case" conditions for human exposure and monitoring. PMID:26251058

  7. Distribution system water age can create premise plumbing corrosion hotspots.

    PubMed

    Masters, Sheldon; Parks, Jeffrey; Atassi, Amrou; Edwards, Marc A

    2015-09-01

    Cumulative changes in chemical and biological properties associated with higher "water age" in distribution systems may impact water corrosivity and regulatory compliance with lead and copper action levels. The purpose of this study was to examine the effects of water age and chemistry on corrosivity of various downstream premise plumbing pipe materials and configurations using a combination of controlled laboratory studies and a field survey. Examination of lead pipe, copper pipe with lead solder, and leaded brass materials in a replicated lab rig simulating premise plumbing stagnation events indicated that lead or copper release could increase as much as ∼440 % or decrease as much as 98 % relative to water treatment plant effluent. In field studies at five utilities, trends in lead and copper release were highly dependent on circumstance; for example, lead release increased with water age in 13 % of cases and decreased with water age in 33 % of conditions tested. Levels of copper in the distribution system were up to 50 % lower and as much as 30 % higher relative to levels at the treatment plant. In many cases, high-risks of elevated lead and copper did not co-occur, demonstrating that these contaminants will have to be sampled separately to identify "worst case" conditions for human exposure and monitoring.

  8. Evaluation of corrosion and scaling tendency indices in a drinking water distribution system: a case study of Bandar Abbas city, Iran.

    PubMed

    Alipour, Vali; Dindarloo, Kavoos; Mahvi, Amir Hossein; Rezaei, Leila

    2015-03-01

    Corrosion and scaling is a major problem in water distribution systems, thus evaluation of water corrosivity properties is a routine test in water networks. To evaluate water stability in the Bandar Abbas water distribution system, the network was divided into 15 clusters and 45 samples were taken. Langelier, Ryznar, Puckorius, Larson-Skold (LS) and Aggressive indices were determined and compared to the marble test. The mean parameters included were pH (7.8 ± 0.1), electrical conductivity (1,083.9 ± 108.7 μS/cm), total dissolved solids (595.7 ± 54.7 mg/L), Cl (203.5 ± 18.7 mg/L), SO₄(174.7 ± 16.0 mg/L), alkalinity (134.5 ± 9.7 mg/L), total hardness (156.5 ± 9.3 mg/L), HCO₃(137.4 ± 13.0 mg/L) and calcium hardness (71.8 ± 4.3 mg/L). According to the Ryznar, Puckorius and Aggressive Indices, all samples were stable; based on the Langelier Index, 73% of samples were slightly corrosive and the rest were scale forming; according to the LS index, all samples were corrosive. Marble test results showed tested water of all 15 clusters tended to scale formation. Water in Bandar Abbas is slightly scale forming. The most appropriate indices for the network conditions are the Aggressive, Puckorius and Ryznar indices that were consistent with the marble test.

  9. Impact of chlorinated disinfection on copper corrosion in hot water systems

    NASA Astrophysics Data System (ADS)

    Montes, J. Castillo; Hamdani, F.; Creus, J.; Touzain, S.; Correc, O.

    2014-09-01

    In France, hot water quality control inside buildings is occasionally ensured by disinfection treatments using temperature increases or addition of sodium hypochlorite (between 0.5 ppm and 1 ppm residual free chlorine). This disinfectant is a strong oxidiser and it could interact with metallic pipes usually used in hot water systems. This work deals with the study of the impact of these treatments on the durability of copper pipes. The objective of this work was to investigate the influence of sodium hypochlorite concentration and temperature on the copper corrosion mechanism. Copper samples were tested under dynamic and static conditions of ageing with sodium hypochlorite solutions ranging from 0 to 100 ppm with temperature at 50 °C and 70 °C. The efficiency of a corrosion inhibitor was investigated in dynamic conditions. Visual observations and analytical analyses of the internal surface of samples was studied at different ageing duration. Corrosion products were characterised by X-ray diffraction and Raman spectroscopy. Temperature and disinfectant were found to considerably affect the copper corrosion mechanism. Surprisingly, the corrosiveness of the solution was higher at lower temperatures. The temperature influences the nature of corrosion products. The protection efficiency is then strongly depend on the nature of the corrosion products formed at the surface of copper samples exposed to the aggressive solutions containing different concentration of disinfectant.

  10. Development of Computational Capabilities to Predict the Corrosion Wastage of Boiler Tubes in Advanced Combustion Systems

    SciTech Connect

    Kung, Steven; Rapp, Robert

    2014-08-31

    A comprehensive corrosion research project consisting of pilot-scale combustion testing and long-term laboratory corrosion study has been successfully performed. A pilot-scale combustion facility available at Brigham Young University was selected and modified to enable burning of pulverized coals under the operating conditions typical for advanced coal-fired utility boilers. Eight United States (U.S.) coals were selected for this investigation, with the test conditions for all coals set to have the same heat input to the combustor. In addition, the air/fuel stoichiometric ratio was controlled so that staged combustion was established, with the stoichiometric ratio maintained at 0.85 in the burner zone and 1.15 in the burnout zone. The burner zone represented the lower furnace of utility boilers, while the burnout zone mimicked the upper furnace areas adjacent to the superheaters and reheaters. From this staged combustion, approximately 3% excess oxygen was attained in the combustion gas at the furnace outlet. During each of the pilot-scale combustion tests, extensive online measurements of the flue gas compositions were performed. In addition, deposit samples were collected at the same location for chemical analyses. Such extensive gas and deposit analyses enabled detailed characterization of the actual combustion environments existing at the lower furnace walls under reducing conditions and those adjacent to the superheaters and reheaters under oxidizing conditions in advanced U.S. coal-fired utility boilers. The gas and deposit compositions were then carefully simulated in a series of 1000-hour laboratory corrosion tests, in which the corrosion performances of different commercial candidate alloys and weld overlays were evaluated at various temperatures for advanced boiler systems. Results of this laboratory study led to significant improvement in understanding of the corrosion mechanisms operating on the furnace walls as well as superheaters and reheaters in

  11. Study of fluoride corrosion of nickel alloys

    NASA Technical Reports Server (NTRS)

    Gunther, W. H.; Steindler, M. J.

    1969-01-01

    Report contains the results of an investigation of the corrosion resistance of nickel and nickel alloys exposed to fluorine, uranium hexafluoride, and volatile fission product fluorides at high temperatures. Survey of the unclassified literature on the subject is included.

  12. Could non-destructive methodologies enhance the microbiologically influenced corrosion (MIC) in pipeline systems?

    NASA Astrophysics Data System (ADS)

    Al-Abbas, F.; Kakpovbia, A.; Mishra, B.; Olson, D.; Spear, J.

    2013-01-01

    Stringent corrosion management programs are being deployed by oil and gas industry to ensure the integrity of pipeline systems. Parts of this program are the corrosion protection systems and inspection detection methods included non-destructive techniques. Those measures induce remnant magnetic field (RMF) in the pipeline steel. Potentially the RMF could affect the corrosion process in the pipeline including microbiologically influenced corrosion (MIC). Microorganisms in pipelines have surface charges and produce a wide variety of metabolic products. Consequently, when they are exposed to RMF generated at the linepipe steel surface by the aforementioned sources there will be potential effects. This sequentially will increase the likelihood of biofilm formation and hence enhance/promote MIC. This study investigates the potential effects of RFM on the MIC by sulfate reducing bacteria (SRB).

  13. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: CORROSION STUDIES RESULTS: FY2010

    SciTech Connect

    Wiersma, B.

    2010-09-29

    Due to the need to close High Level Waste storage tanks, chemical cleaning methods are needed for the removal of sludge heel materials remaining at the completion of mechanical tank cleaning efforts. Oxalic acid is considered the preferred cleaning reagent for heel dissolution of iron-based sludge. However, the large quantity of chemical reagents added to the tank farm from oxalic acid based cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acidic systems may be required for specific waste components that have low solubility in oxalic acid, and as a means to reduce oxalic acid usage in general. Electrochemical corrosion studies were conducted with 1 wt. % oxalic acid at mineral acid concentrations above and below the optimal conditions for this oxalic acid concentration. Testing environments included pure reagents, pure iron and aluminum phases, and sludge simulants. Mineral acid concentrations greater than 0.2 M and temperatures greater than 50 C result in unacceptably high corrosion rates. Results showed that manageable corrosion rates of carbon steel can be achieved at dilute mineral acid concentrations (i.e. less than 0.2 M) and low temperatures based on the contact times involved. Therefore, it is recommended that future dissolution and corrosion testing be performed with a dilute mineral acid and a less concentrated oxalic acid (e.g., 0.5 wt.%) that still promotes optimal dissolution. This recommendation requires the processing of greater water volumes than those for the baseline process during heel dissolution, but allows for minimization of oxalic acid additions. The following conclusions can be drawn from the test results: (1) In both nitric and sulfuric acid based reagents, the low temperature and

  14. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect

    Wilson, DF

    2002-10-22

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

  15. SILICATES FOR CORROSION CONTROL IN BUILDING POTABLE WATER SYSTEMS

    EPA Science Inventory

    Silicates have been used to control the corrosion of drinking water distribution system materials. Previous work has shown that they are particularly useful in reducing the release of zinc from galvanized materials in hot water systems. Negatively charged silicate species were re...

  16. Task E container corrosion studies: Annual report. Revision 1

    SciTech Connect

    Bunnell, L.R.; Doremus, L.A.; Topping, J.B.; Duncan, D.R.

    1994-06-01

    The Pacific Northwest Laboratory is conducting the Solid Waste Technology Support Program (SWTSP) for Westinghouse Hanford Company (WHC). Task E is the Container Corrosion Study Portion of the SWTSP that will perform testing to provide defensible data on the corrosion of low-carbon steel, as used in drums to contain chemical and radioactive wastes at the Hanford Site. A second objective of Task E is to provide and test practical alternative materials that have higher corrosion resistance than low-carbon steel. The scope of work for fiscal year (FY) 1993 included initial testing of mild steel specimens buried in Hanford soils or exposed to atmospheric corrosion in metal storage sheds. During FY 1993, progress was made in three areas of Task E. First, exposure of test materials began at the Soil Corrosion Test Site where low-carbon steel specimens were placed in the soil in five test shafts at depths of 9 m (30 ft). Second, the corrosion measurement of low-carbon steel in the soil of two solid waste trenches continued. The total exposure time is {approx} 500 days. Third, an atmospheric corrosion test of low-carbon steel was initiated in a metal shed (Building 2401-W) in the 200 West Area. This annual report describes the Task E efforts and provides a current status.

  17. A laboratory study on metal corrosion by ammonia gas

    SciTech Connect

    Zhu, J.; Riskowski, G.L.; Mackie, R.I.

    1999-06-01

    The effects of aerial ammonia on metal corrosion was examined in this study. Tests were conducted using three environmentally controlled chambers at three different ammonia levels (0 ppm, 100 ppm, and 200 ppm). Four types of metal products (uncoated 1010 carbon steel, galvanized steel, Galvalume, and pure zinc) were evaluated for weight losses and corrosion rates over a two-month test period. The test results showed that aerial ammonia, instead of accelerating metal corrosion, reduced the corrosion rates for steel. Weight losses for uncoated 1010 carbon steel samples in the chamber without ammonia were three and six times higher than those in chambers with ammonia levels of 100 ppm and 200 ppm, respectively. The corrosion rates were greatly reduced from 7.3 {micro}m/year to 1.2 {micro}m/year over the two-month period when ammonia level increased from 0 ppm to 200 ppm. For galvanized steel and pure zinc samples, the influence of ammonia on the corrosion processes was not apparent; however, there was a slight increase in corrosion rate for Galvalume samples with the increase of aerial ammonia concentrations.

  18. NON-CORROSIVE PLUTONIUM FUEL SYSTEMS

    DOEpatents

    Coffinberry, A.S.; Waber, J.T.

    1962-10-23

    An improved plutonium reactor liquid fuel is described for utilization in a nuclear reactor having a tantalum fuel containment vessel. The fuel consists of plutonium and a diluent such as iron, cobalt, nickel, cerium, cerium-- iron, cerium--cobalt, cerium--nickel, and cerium--copper, and an additive of carbon and silicon. The carbon and silicon react with the tantalum container surface to form a coating that is self-healing and prevents the corrosive action of liquid plutonium on the said tantalum container. (AEC)

  19. Assessment of Microbiologically Influenced Corrosion Potential in the International Space Station Internal Active Thermal Control System Heat Exchanger Materials: A 6-Momths Study

    NASA Technical Reports Server (NTRS)

    Roman, Monsi C.; Macuch, Patrick; McKrell, Thomas; VanDerSchijff, Ockert J.; Mitchell, Ralph

    2005-01-01

    The fluid in the Internal Active Thermal Control System (IATCS) of the International Space Station (ISS) is water based. The fluid in the ISS Laboratory Module and Node 1 initially contained a mix of water, phosphate (corrosion control), borate (pH buffer), and silver sulfate (Ag2SO4) (microbial control) at a pH of 9.5+/-0.5. Over time, the chemistry of the fluid changed. Fluid changes included a pH drop from 9.5 to 8.3 due to diffusion of carbon dioxide (CO2) through Teflon(reistered Trademark) (DuPont) hoses, increases in dissolved nickel (Ni) levels, deposition of silver (Ag) to metal surfaces, and precipitation of the phosphate (PO4) as nickel phosphate (NiPO4). The drop in pH and unavailability of a antimicrobial has provided an environment conducive to microbial growth. Microbial levels in the fluid have increased from >10 colony-forming units (CFUs)/100 ml to 10(exp 6) CFUs/100 ml. The heat exchangers in the IATCS loops are considered the weakest point in the loop because of the material thickness (=7 mil). It is made of a Ni-based braze filler/CRES 347. Results of a preliminary test performed at Hamilton Sundstrand indicated the possibility of pitting on this material at locations where Ag deposits were found. Later, tests have confirmed that chemical corrosion of the materials is a concern for this system. Accumulation of micro-organisms on surfaces (biofilm) can also result in material degradation and can amplify the damage caused by the chemical corrosion, known as microbiologically influenced corrosion (MIC). This paper will discuss the results of a 6-mo test performed to characterize and quantify the damage from microbial accumulation on the surface of the ISS/ATCS heat exchanger materials. The test was designed to quantify the damage to the materials under worst-case conditions with and without micro-organisms present at pH 8.3 and 9.5.

  20. COPPER PITTING CORROSION: A CASE STUDY

    EPA Science Inventory

    Localized or pitting corrosion of copper pipes used in household drinking-water plumbing is a problem for many water utilities and their customers. Extreme attack can lead to pinhole water leaks that may result in water damage, mold growth, and costly repairs. Water quality has b...

  1. Surface- and microanalysis as a tool for studying the corrosion of aluminium

    NASA Astrophysics Data System (ADS)

    Van craen, M. J. A.; Adams, F. C.; Van Beek, L. J. A.; Vanden Berghe, R. A. L.

    Corrosion phenomena of Al-1 % Si bond wires, observed after life testing of certain transistors, are studied. The following information is derived from laboratory simulation tests: the kinetics of the corrosion process, information about the corrosion mechanism and critical parameters, especially the influence of the environmental gas and Si content and finally the identification of the corrosion products and their comparison with those found for the transistor. It is demonstrated, using a combination of several surface analytical techniques, that the A1 pitting corrosion is induced and enhanced by the presence of water as a transport medium and surface electrolyte in an oxygen-rich atmosphere, with chloride ions as a stimulating and activating species. The effect of 1 % Si in the wire consists in acceleration of the corrosion rate, and is probably due to grain boundary effects. All critical corrosion parameters could be traced in the transistor system by electron microscopy, laser microprobe mass analysis and residual gas (and moisture) analysis by mass spectrometry.

  2. Electrochemical impedance spectroscopy study on corrosion inhibition of benzyltriethylammonium chloride

    NASA Astrophysics Data System (ADS)

    Idris, Mohd Nazri; Daud, Abdul Razak; Othman, Norinsan Kamil

    2013-11-01

    Electrochemical Impedance Spectroscopy (EIS) was employed to study the corrosion inhibition behavior of benzyltriethylammonium chloride (BTC) for carbon steel corrosion. The inhibition efficiency was investigated in 1.0 M HCl solution at room temperature (25°C) by varying the BTC concentration. EIS results indicated that the double layer capacitance of electrolyte/carbon steel interface decreases with the increasing of BTC concentration and consequently enhances the polarization resistance of equivalence Randles circuit. The results indicated that inhibition efficiency of as high as 65% could be achieved when 10mM BTC was present in 1.0 M HCl solution as compared to inhibitor-free solution. The inhibition process of BTC on the carbon steel corrosion was found to obey Langmuir adsorption isotherm. This study revealed that BTC is suitable to be used as a corrosion inhibitor in acid media.

  3. Studying localized corrosion using liquid cell transmission electron microscopy

    DOE PAGESBeta

    Chee, See Wee; Pratt, Sarah H.; Hattar, Khalid; Duquette, David; Ross, Frances M.; Hull, Robert

    2014-11-07

    Using liquid cell transmission electron microscopy (LCTEM), localized corrosion of Cu and Al thin films immersed in aqueous NaCl solutions was studied. We demonstrate that potentiostatic control can be used to initiate pitting and that local compositional changes, due to focused ion beam implantation of Au+ ions, can modify the corrosion susceptibility of Al films. Likewise, a discussion on strategies to control the onset of pitting is also presented.

  4. Studying localized corrosion using liquid cell transmission electron microscopy

    SciTech Connect

    Chee, See Wee; Pratt, Sarah H.; Hattar, Khalid; Duquette, David; Ross, Frances M.; Hull, Robert

    2014-11-07

    Using liquid cell transmission electron microscopy (LCTEM), localized corrosion of Cu and Al thin films immersed in aqueous NaCl solutions was studied. We demonstrate that potentiostatic control can be used to initiate pitting and that local compositional changes, due to focused ion beam implantation of Au+ ions, can modify the corrosion susceptibility of Al films. Likewise, a discussion on strategies to control the onset of pitting is also presented.

  5. UNSOLVED PROBLEMS WITH CORROSION AND DISTRIBUTION SYSTEM INORGANICS

    EPA Science Inventory

    This presentation provides an overview of new research results and remaining research needs with respect to both corrosion control issues (lead, copper, iron) and to issues of inorganic contaminants that can form or accumulate in distribution system water, pipe scales and distrib...

  6. Development and deployment of advanced corrosion monitoring systems for high-level waste tanks.

    SciTech Connect

    Terry, M. T.; Edgemon, G. L.; Mickalonis, J. I.; Mizia, R. E.

    2002-01-01

    This paper describes the results of a collaborative technology development program, sponsored by the Tanks Focus Area, to use electrochemical noise (EN) for corrosion monitoring in underground storage tanks. These tanks, made of carbon or stainless steels, contain high-level radioactive liquid waste (HLW) generated by weapons production or radioactive liquid waste from nuclear fuel reprocessing activities at several Department of Energy (DOE) sites. The term EN is used to describe low frequency fluctuations in current and voltage measurements associated with corrosion. In their most basic form, EN-based corrosion monitoring systems measure and record these fluctuations over time from electrodes immersed in the environment of interest - in this case, radioactive tank waste. The resulting EN signals have characteristic patterns for different corrosion mechanisms. In recent years, engineers and scientists from several DOE sites, in collaboration with several private companies, have conducted laboratory studies and field applications to correlate the EN signals with corrosion mechanisms active in the radioactive waste tanks. The participating DOE sites are Hanford, Savannah River, Oak Ridge Reservation and the Idaho National Engineering and Environmental Laboratory. The commercial vendors have included HiLine Engineering and Fabrication, Inc., EIC Laboratories, Inc., and M A Technologies. Successful deployment of the EN technology will yield improved information of waste tank corrosion conditions, better tank management, and lower overall cost.

  7. Development and Deployment of Advanced Corrosion Monitoring Systems for High-Level Waste Tanks

    SciTech Connect

    Terry, M. T.; Edgemon, G. L.; Mickalonis, J. I.; Mizia, R. E.

    2002-02-26

    This paper describes the results of a collaborative technology development program, sponsored by the Tanks Focus Area, to use electrochemical noise (EN) for corrosion monitoring in underground storage tanks. These tanks, made of carbon or stainless steels, contain high-level radioactive liquid waste (HLW) generated by weapons production or radioactive liquid waste from nuclear fuel reprocessing activities at several Department of Energy (DOE) sites. The term EN is used to describe low frequency fluctuations in current and voltage measurements associated with corrosion. In their most basic form, EN-based corrosion monitoring systems measure and record these fluctuations over time from electrodes immersed in the environment of interest--in this case, radioactive tank waste. The resulting EN signals have characteristic patterns for different corrosion mechanisms. In recent years, engineers and scientists from several DOE sites, in collaboration with several private companies, have conducted laboratory studies and field applications to correlate the EN signals with corrosion mechanisms active in the radioactive waste tanks. The participating DOE sites are Hanford, Savannah River, Oak Ridge Reservation and the Idaho National Engineering and Environmental Laboratory. The commercial vendors have included HiLine Engineering and Fabrication, Inc., EIC Laboratories, Inc., and AEA Technologies. Successful deployment of the EN technology will yield improved information of waste tank corrosion conditions, better tank management, and lower overall cost.

  8. Engineering Task Plan for the 241-AN-105 Multi-Function Corrosion Monitoring System

    SciTech Connect

    EDGEMON, G.L.

    1999-08-25

    This Engineering Task Plan (ETP) describes the activities associated with the installation of the corrosion probe assembly into riser WST-RISER-016 (formerly 15B) of tank 241-AN-105. The corrosion monitoring system utilizes the technique of electrochemical noise (EN) for monitoring waste tank corrosion. Typically, EN consists of low frequency (4 Hz) and small amplitude signals that are spontaneously generated by electrochemical reactions occurring at corroding or other surfaces. EN analysis is well suited for monitoring and identifying the onset of localized corrosion, and for measuring uniform corrosion rates. A typical EN based corrosion-monitoring system measures instantaneous fluctuations in corrosion current and potential between three nominally identical electrodes of the material of interest immersed in the environment of interest. Time-dependent fluctuations in corrosion current are described by electrochemical current noise, and time-dependent fluctuations of corrosion potential are described by electrochemical noise. The corrosion monitoring system is designed to detect the onset of localized corrosion phenomena if tank conditions should change to allow these phenomena to occur. In addition to the EN technique, the system also facilitates the use of the Linear Polarization Resistance (LPR) technique to collect uniform corrosion rate information. LPR measures the linearity at the origin of the polarization curve for overvoltages up to a few millivolts away from the rest potential or natural corrosion potential. The slope of the current vs. voltage plot gives information on uniform corrosion rates.

  9. A comparative study of atmospheric corrosion in the Caribbean area

    SciTech Connect

    Maldonado, L.; Castro, P.; Echeverria, M.

    1995-10-01

    Atmospheric corrosion is a phenomenon of such a magnitude that has been cause of study in several countries for decades. Nevertheless, in Mexico, it became of recent interest due to new economic factors that have involved the Peninsula of Yucatan too. The Yucatan Peninsula is limited to the North and West by the Gulf of Mexico and to the East by the Caribbean Sea. This is a non industrialized region so that in the past very little importance was given to the atmospheric corrosion damage or to the quantification of the high corrosion rates, empirically observed. However, in recent times increased tourism, industrial growth and petroleum extraction have exhibited the need for a better understanding of the atmospheric corrosion processes, as well as a realistic correlation to parameters such as time-of-wetness, levels of pollution by airborne salinity, atmospheric S0{sub 2} and corrosivity categories for the metals. To evaluate these parameters, five tests sites were selected following ISO recommendations. Three sites are marines atmospheres, one urban and one rural. Corrosion rates for commercial laminated Cu and carbon steel, as well as deposition rates of pollutants, were determined after one year exposure in the test sites. Applying the standard practice ISO 9223 a categorization of the corrosivity and of the level of pollutants was carried out. The marine environments were classified as of atmospheric corrosivity C{sub 5}, while the urban and the rural could be classified as C{sub 3}, respectively. The pollution values showed that the exposure sites were essentially contaminated with chloride with classification S{sub 1} for the rural site and S{sub 3} for the marine atmosphere.

  10. Inhibition of heavy metal ion corrosion on aluminum in fresh water cooling systems using propylene glycol anti-freeze

    SciTech Connect

    Hack, H.P.; Corbett, R.; Krantz, B.

    1998-12-31

    Electronics cooling and environmental control systems are required in enclosed manned spaces such as the inside of spacecraft or submersibles. Because egress from such spaces may not be possible in a short time frame, coolant leaks must have minimum toxicity. For this reason, propylene glycol coolants are preferred over the traditional ethylene glycol coolants. Corrosion inhibitor formulations are well developed for ethylene glycol coolants, but there is concern that the inhibitor suite for propylene glycol systems may not be as mature. In particular, coolant systems with a mixture of aluminum and copper can develop heavy metal ion corrosion of the aluminum due to precipitation of copper ions from solution onto the aluminum. This type of accelerated corrosion of aluminum does not require electrical contact with copper, as is the case for galvanic corrosion, nor is significant coolant conductivity required for corrosion to occur. This paper presents a study of the ability of a commercial inhibited propylene glycol coolant to prevent heavy metal ion corrosion of aluminum when copper is also present in the coolant system. The inhibited propylene glycol`s performance is compared to that of reagent propylene glycol without inhibitors, a mature ethylene glycol inhibited coolant, and to tap water. The inhibitor suite in the inhibited propylene glycol was found to be as effective in controlling heavy metal ion corrosion as that of the inhibited ethylene glycol coolant, while uninhibited reagent propylene glycol was ineffective in controlling heavy metal ion corrosion.

  11. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    SciTech Connect

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  12. Characterization of microfouling and corrosive bacterial community of a firewater distribution system.

    PubMed

    Palaniappan, Balamurugan; Toleti, Subba Rao

    2016-04-01

    This investigation provides generic information on the culturable corrosive and the microfouling bacterial community in a firewater distribution system that uses freshwater. Conventional microbiological methods were used for the selective isolation of the major microfouling bacteria. The isolates were characterized by 16S rRNA gene sequencing and the biofilm as well as the corrosion characteristics of the isolates were evaluated. Pseudomonas aeruginosa and Bacillus cereus were predominantly observed in all the samples analysed. Denaturing gradient gel electrophoresis (DGGE) was carried out for the various samples of firewater system (FWS) and the high intensity bands were sequenced to identify the predominant bacteria. Bacterial groups such as Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes were identified. Biofilm thickness was recorded using confocal scanning laser microscopy (CSLM). This was the first study to report Lysinibacillus fusiformis in a firewater system and its role in iron corrosion. Sulphidogenic bacteria Tissierella sp. and Clostridium bifermentans generated sulphides in the range of 400-900 ppm. Significant corrosion rates of carbon steel (CS) coupons were observed up to 4.3 mpy. C. bifermentans induced more localized corrosion in CS with a pit diameter of 50 μm. Overall, the data on the characterization of the fouling bacteria, their biofilm forming potential and subsequent metal deterioration studies supported in designing an effective water treatment program.

  13. Design of multi-function Hanford tank corrosion monitoring system

    SciTech Connect

    EDGEMON, G.L.

    1999-04-01

    A multi-fiction corrosion monitoring system has been designed for installation into DST 241-AN-105 at the Hanford Site in fiscal year 1999. The 241-AN-105 system is the third-generation corrosion monitoring system described by TTP RLO-8-WT-21. Improvements and upgrades from the second-generation system (installed in 241-AN-102) that have been incorporated into the third-generation system include: Gasket seating surfaces utilize O-rings instead of a washer type gasket for improved seal; Probe design contains an equally spaced array of 22 thermocouples; Probe design contains an adjustable verification thermocouple; Probe design contains three ports for pressure/gas sampling; Probe design contains one set of strain gauges to monitor probe flexure if flexure occurs; Probe utilizes an adjustable collar to allow depth adjustment of probe during installation; System is capable of periodically conducting LPR scans; System is housed in a climate controlled enclosure adjacent to the riser containing the probe; System uses wireless Ethernet links to send data to Hanford Local Area Network; System uses commercial remote access software to allow remote command and control; and Above ground wiring uses driven shields to reduce external electrostatic noise in the data. These new design features have transformed what was primarily a second-generation corrosion monitoring system into a multi-function tank monitoring system that adds a great deal of functionality to the probe, provides for a better understanding of the relationship between corrosion and other tank operating parameters, and optimizes the use of the riser that houses the probe in the tank.

  14. Technological aspects of corrosion control in metallic systems

    NASA Astrophysics Data System (ADS)

    Taylor, Matthew Logan

    Three corrosion control technologies were investigated, including the effect of nitrogen on the passivity of chromium in sulfate solutions, possible issues associated with the use of amines in steam turbine environments and the microstructure of naval advanced amorphous coatings. Nitrogen (N) is a minor alloying element commonly used to increase the strength of steels by stabilizing the austenite phase. Physical vapor deposited chromium + nitrogen (0, 6.8 and 8.9 at.%N) coatings were investigated as a model system, to test the model. Because Cr passive films have been observed to be generally n-type semiconductors, an impedance function containing a n-type Faradaic impedance was constructed and optimized to electrochemical impedance spectra for the model system at pH 4,7 and 10 1M sulfate solution at 30°C. An apparent deviation from theory was observed, however. The n-type model predicted steady state currents which were independent of potential, while the observed current densities had a positive correlation with potential. Mott-Schottky analysis revealed that the test potentials were within the n-p transition and p-type potential range, which resolves the apparent deviation. Despite this difficulty, however, the impedance model produced reasonably accurate results, calculating current densities to within one order of magnitude of the measured steady state currents where anodic currents were available and passive film thicknesses on the order of 1-2 nm. Various amines are commonly used to inhibit corrosion in thermal power generation systems, including steam turbines, by increasing the pH. However, during the shutdown phase of the power plant, it is possible for these inhibitors to concentrate and cause corrosion of the turbine rotor. The effect of two ammine inhibitors (monoethanolamine and dimethylamine) on the passivity of ASTM A470/471 steel is investigated in a simulated turbine environment at pH 7, and temperatures of 95°C and at 175°C. Potentiodynamic

  15. The opisthonephric blood vascular system of the chicken embryo as studied by scanning electron microscopy of microvascular corrosion casts and critical point dried preparations.

    PubMed

    Ditrich, H; Splechtna, H

    1989-06-01

    Microvascular corrosion casts of chicken embryos between four and 19 days after fertilization have been prepared. The developing kidney was investigated with scanning electron microscopy (SEM). The injection technique and resin composition were modified in order to facilitate the complete replication of native blood vascular systems of specimens as small as 15 mm body length. The development of the opisthonephros was followed from near the beginning of its function until a vascular development comparable to the adult situation was reached. Critical point dried glomeruli show the differentiation of the glomerular visceral epithelium (podocytes) from initially epithelioid to highly branched forms. The embryonic kidney (cranial part of the opisthonephros-mesonephros) shows a construction-principle resembling amphibians that is entirely different from the definitive excretory organ (caudal part of the opisthonephros-metanephros). PMID:2814402

  16. Factors affecting the corrosion rates of ceramics in coal combustion systems

    SciTech Connect

    Hurley, J.P.

    1995-08-01

    The concentrations of approximately a dozen elements in the products of coal combustion affect the corrosion rates of ceramics used to construct the combustion system. The elements, including H, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, and Fe, affect corrosion rates in three ways: as primary corrodants of the materials, as secondary corrodants that affect the activities of the primary corrodants, and by affecting the mass transport rate of the primary corrodants. A full factorial study of corrosion rates performed by varying the concentrations of these elements would involve X{sup n} tests, where X is the number of variations of each element and n is the number of different elements. For three variations (low, medium, and high concentrations) of each of 12 elements, the number of tests is 531,441 for a single temperature and pressure condition. The numbers can be reduced with the use of a fractional factorial test matrix, but the most effective way to perform corrosion tests is to base them on realistic system conditions. In this paper, the effects of the composition and physical state of the products of coal combustion on ceramic corrosion rates are given along with suggestions of appropriate test conditions for specific system components.

  17. Sustain solar system's efficiency by protecting against corrosion

    SciTech Connect

    Avery, J.G.; Krall, J.J.

    1982-04-01

    In the last of a three part series, the use of water and nonaqueous heat transfer fluids in active solar systems is examined. Emphasis is on corrosion protection of the system. Scaling, caused by impurities in the water, is discussed as well as methods to prevent scaling. Interaction of water with metals (copper, aluminum, and steel) are described and suggestions are given for minimization of corrosion. Use of nonaqueous heat transfer fluids (hydrocarbons, silicones, and fluorocarbons) is reviewed briefly as well as interaction of these fluids with metals. It is concluded that long-life (> 20 year) of performance of the solar system is aided by: (1) proper design and installation; (2) choosing a heat transfer fluid compatible with the metal (3) in the system; and (3) periodic monitoring and maintenance of the fluid used. Recommendations are made for addition work in this area. 10 references. (MJJ)

  18. Corrosion and degradation studies utilizing X-ray photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Hixson, Holly Gwyndolen

    1997-08-01

    This dissertation involves studies of corrosion behavior at the surface of various metal samples, as well as the degradation of wool fibers obtained from the Star-Spangled Banner. Molybdenum metal and iron-zinc alloys were examined under corrosive conditions, and the degradation of the wool fibers was studied. The behavior of a polished molybdenum metal surface upon exposure to both aerated and deaerated water and 1.0 M NaCl solution was studied by X-ray Photoelectron Spectroscopy (XPS). Exposure to deaerated water and NaCl failed to produce oxidation of the metal surfaces, but exposing the polished metal surface to aerated water produced significant oxidation. Metal surfaces cleaned by argon-ion etching were found to be inert to oxidation by aerated water. The etching process also appears to passivate the metal surface. The behavior of molybdenum metal in 0.5 M Hsb2SOsb4 treated at various potentials has been studied using core and valence band XPS. The study indicates that Mosp{IV} and Mosp{VI} (including possibly Mosp{V} in some cases) were formed as the potential of the system was increased within the active range of molybdenum. The corrosive behavior of iron-zinc alloys that have been electroplated on plain steel in both aerated and deaerated quadruply-distilled water has been studied using XPS. Several different iron-zinc alloys were electroplated for comparative purposes: an iron-rich alloy, a zinc-rich alloy, and an alloy of similar iron and zinc composition. Treatment in aerated water produces oxidation for the iron-rich and similar composition alloys, but the oxide is reduced for the zinc-rich alloy. Degradation of the fibers in the original Star-Spangled Banner has been monitored using XPS and Scanning Electron Microscopy (SEM). Comparison of white and red wool fibers and linen fibers from the flag with new, mechanically-abraded, and chemically-treated white, red, and linen fibers, respectively, was performed in an attempt to determine the fibers' levels

  19. Twelve Year Study of Underground Corrosion of Activated Metals

    SciTech Connect

    M. Kay Adler Flitton; Timothy S. Yoder

    2012-03-01

    The subsurface radioactive disposal facility located at the U.S. Department of Energy’s Idaho site contains neutron-activated metals from non-fuel nuclear-reactor-core components. A long-term corrosion study is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The study uses non-radioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, two types of stainless steels, welded stainless steel, welded nickel-chromium steel alloy, zirconium alloy, beryllium, and aluminum. Additionally, carbon steel (the material used in cask disposal liners and other disposal containers) and duplex stainless steel (high-integrity containers) are also included in the study. This paper briefly describes the test program and presents the corrosion rate results through twelve years of underground exposure.

  20. PERFORMACE OF MULTI-PROBE CORROSION MONITORING SYSTEMS AT THE HANFORD SITE

    SciTech Connect

    CAROTHERS KD; BOOMER KD; ANDA VS; DAHL MM; EDGEMON GL

    2010-01-14

    Between 2007 and 2009, several different multi-probe corrosion monitoring systems were designed and installed in high-level nuclear waste tanks at the U.S. Department of Energy's Hanford Site in WaShington State. The probe systems are being monitored to ensure waste tanks operate in regions that minimize localized corrosion (i.e., pitting) and stress corrosion cracking. The corrosion monitoring systems have been installed in wastes with different chemistry types. An ongoing effort during the same time period has generated non-radioactive simulants that are tested in the laboratory to establish baseline corrosion monitoring system performance and characterize data to allow interpretation of readings from the multiple corrosion monitoring systems. Data collection from these monitoring systems has reached the point where the results allow comparison with the laboratory testing. This paper presents analytical results from the corrosion monitoring system development program.

  1. Materials studies for preventing corrosion in condensing environments

    SciTech Connect

    Kukacka, L.E.; Sugama, T. )

    1991-10-01

    The objective of this project is to determine the fundamental interfacial requirements for low-cost, organic and inorganic materials resistive to corrosion in condensing furnace exhausts. This research effort is being focused to provide information regarding corrosion resistance, heat transfer, material cost, fabrication method and cost, and product reliability since all are important in the final design and production of a heat exchanger. Results to date indicate that organic and inorganic-type polymer coating systems applied to low cost metals such as mild steel and aluminum provide good corrosion protection. The thermal stability of these polymers plus the identification of the interfacial requirements needed to utilize them with reactive filler materials should also make their use as bulk composites feasible.

  2. Development of a commercial micro corrosion monitoring system

    NASA Astrophysics Data System (ADS)

    Niblock, Trevor G. E.; Surangalikar, Harshal S.; Morse, Jeffrey; Laskowski, Bernard C.; Castro-Cedeno, Mario H.; Wilson, Alan R.

    2002-11-01

    Analatom Inc. in conjunction with the DSTO (Defence Science & Technology Organisation) has been developing a micro Linear Polarization Resistance (LPR) system for assessing the integrity of high value structures. The device operates on the principle that as a metal corrodes, the oxide formed effectively creates an anodic cell. Hence, if the metal can be separated into two sections, a potential and resistance can be measured between each section. These values can be used to compute the effective mass loss of the device. By matching the material properties of the device with that of the structure whose "health" is being monitored, it is possible to establish a corrosion rate of the structure. Previous research at DSTO has shown that such a system can be fabricated and operated on the micro scale. The task has now been to develop the device into a commercially viable system; it is this development that is examined in this paper. In the original system, a potentiostat is used to evaluate the device for data relating the mass loss during corrosion. This system is now replaced with simplified electronics to reduce both the cost and size of the device. Signal conditioning into the LPR is critical as potentials over 20mV across the terminals can be a source of corrosion of the device. Micro controllers and small board computers are used to run this signal conditioning process and the LPR interface circuit.

  3. A study of the effects of phosphates on copper corrosion in drinking water: Copper release, electrochemical, and surface analysis approach

    NASA Astrophysics Data System (ADS)

    Kang, Young C.

    The following work is the study to evaluate the impact of corrosion inhibitors on the copper metal in drinking water and to investigate the corrosion mechanism in the presence and absence of inhibitors. Electrochemical experiments were conducted to understand the effect of specific corrosion inhibitors in synthetic drinking water which was prepared with controlled specific water quality parameters. Water chemistry was studied by Inductively Coupled Plasma--Atomic Emission Spectroscopy (ICP--AES) to investigate the copper leaching rate with time. Surface morphology, crystallinity of corrosion products, copper oxidation status, and surface composition were characterized by various solid surface analysis methods, such as Scanning Electron Microscopy/Energy--Dispersive Spectrometry (SEM/EDS), Grazing-Incidence-angle X-ray Diffraction (GIXRD), X-ray Photoelectron Spectroscopy (XPS), and Time-of-Flight Secondary Ions Mass Spectrometry (ToF-SIMS). The purpose of the first set of experiments was to test various electrochemical techniques for copper corrosion for short term before studying a long term loop system. Surface analysis techniques were carried out to identify and study the corrosion products that form on the fresh copper metal surface when copper coupons were exposed to test solutions for 2 days of experiments time. The second phase of experiments was conducted with a copper pipe loop system in a synthetic tap water over an extended period of time, i.e., 4 months. Copper release and electrochemically measured corrosion activity profiles were monitored carefully with and without corrosion inhibitor, polyphosphate. A correlation between the copper released into the solution and the electrochemically measured corrosion activities was also attempted. To investigate corrosion products on the copper pipe samples, various surface analysis techniques were applied in this study. Especially, static mass spectra acquisition and element distribution mapping were carried out

  4. Inhibition and promotion of copper corrosion by CTAB in a microreactor system.

    PubMed

    Murira, Caroline M; Punckt, Christian; Schniepp, Hannes C; Khusid, Boris; Aksay, Ilhan A

    2008-12-16

    We report on an optical microscopy technique for the analysis of corrosion kinetics of metal thin films in microreactor systems and use it to study the role of cetyltrimethylammonium bromide surfactant as a corrosion inhibitor in a copper-gold galvanic coplanar microsystem. A minimum in the dissolution rate of copper is observed when the surfactant concentration is approximately 0.8 mM. To explain why the inhibitory role of the surfactant does not extend to higher concentrations, we use zero resistance ammetry with separated half cells and show that while the surfactant inhibits cathodic reactions on gold, it also promotes the corrosion of copper because of the catalytic action of bromide counterions. These two competing processes lead to the observed minimum in the dissolution rate.

  5. Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: laboratory investigation.

    PubMed

    Stipanicev, Marko; Turcu, Florin; Esnault, Loïc; Rosas, Omar; Basseguy, Régine; Sztyler, Magdalena; Beech, Iwona B

    2014-06-01

    Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion of S235JR carbon steel was studied in a flow bioreactor; operating anaerobically for 100days with either inoculated or filtrated seawater. Deposits formed on steel placed in reactors contained magnesium and calcium minerals plus iron sulfide. The dominant biofilm-forming organism was an anaerobic bacterium, genus Caminicella, known to produce hydrogen sulfide and carbon dioxide. Open Circuit Potentials (OCP) of steel in the reactors was, for nearly the entire test duration, in the range -800corrosion rate, expressed as 1/(Rp/Ω), was lower in the inoculated seawater though they varied significantly on both reactors. Initial and final corrosion rates were virtually identical, namely initial 1/(Rp/Ω)=2×10(-6)±5×10(-7) and final 1/(Rp/Ω)=1.1×10(-5)±2.5×10(-6). Measured data, including electrochemical noise transients and statistical parameters (0.0545), suggested pitting on steel samples within the inoculated environment. However, the actual degree of corrosion could neither be directly correlated with the electrochemical data and nor with the steel corrosion in the filtrated seawater environment. Further laboratory tests are thought to clarify the noticed apparent discrepancies.

  6. Research needs for corrosion control and prevention in energy conservation systems

    SciTech Connect

    Brooman, E.W.; Hurwitch, J.W.

    1985-06-01

    A group of 28 electrochemists, materials scientists and corrosion engineers was brought together to determine if the government could have a role as a focal point for corrosion R and D, discuss opportunities in fundamental research and solving corrosion problems, and develop a research agenda. Participants from government, industry and academia assembled into four technical discussion groups: localized corrosion, general corrosion, high temperature corrosion, and corrosion control and prevention. Research needs were identified, discussed, then assigned a figure of merit. Some 44 corrosion control and prevention topics were identified as having a high priority for consideration for funding. Another 35 topics were identified as having a medium priority for funding. When classified according to corrosion phenomenon, the areas which should receive the most attention are molten salt attack, crevice corrosion, stress-corrosion cracking, erosion-corrosion, pitting attack, intergranular attack and corrosion fatigue. When classified according to the sector or system involved, those which should receive the most attention are chemical processes, transportation, buildings and structures, electric power generation, and batteries and fuel cells.

  7. DIFFUSION COATINGS FOR CORROSION RESISTANT COMPONENTS IN COAL GASIFICATION SYSTEMS

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Angel Sanjurjo

    2004-05-01

    Heat-exchangers, filters, turbines, and other components in integrated coal gasification combined cycle system must withstand demanding conditions of high temperatures and pressure differentials. Under the highly sulfiding conditions of the high temperature coal gas, the performance of components degrade significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy may improve is resistance to such sulfidation attack and decrease capital and operating costs. A review of the literature indicates that the corrosion reaction is the competition between oxidation and sulfidation reactions. The Fe- and Ni-based high-temperature alloys are susceptible to sulfidation attack unless they are fortified with high levels of Cr, Al, and Si. To impart corrosion resistance, these elements need not be in the bulk of the alloy and need only be present at the surface layers.

  8. Corrosion Studies of 2195 Al-Li Alloy and 2219 Al Alloy with Differing Surface Treatments

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Mendrek, M. J.

    1998-01-01

    Corrosion studies of 2195 Al-Li and 2219 Al alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of Al203 blasted, soda blasted and conversion coated 2219 Al were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.

  9. A study of differential-flow-rate-cell corrosion in seawater

    SciTech Connect

    Miyasaka, M.; Kishimoto, K.; Aoki, S.

    1995-10-01

    Mechanisms of differential-flow-rate-cell corrosion (differential-aeration-cell corrosion caused by differential flow rates) of cast iron in seawater were studied. Potential and current density distributions produced by the differential-flow-rate-cell were on actual pumps and a model test cell. Boundary element analysis was also performed on differential-flow-rate-cell corrosion occurred in the model test cell. These studies demonstrate that differential-flow-rate-cell corrosion has characteristics similar to those of galvanic corrosion, and thus can be treated in the same manner as galvanic corrosion.

  10. The effect of corrosion inhibitors on microbial communities associated with corrosion in a model flow cell system.

    PubMed

    Duncan, Kathleen E; Perez-Ibarra, Beatriz Monica; Jenneman, Gary; Harris, Jennifer Busch; Webb, Robert; Sublette, Kerry

    2014-01-01

    A model flow cell system was designed to investigate pitting corrosion in pipelines associated with microbial communities. A microbial inoculum producing copious amounts of H₂S was enriched from an oil pipeline biofilm sample. Reservoirs containing a nutrient solution and the microbial inoculum were pumped continuously through six flow cells containing mild steel corrosion coupons. Two cells received corrosion inhibitor "A", two received corrosion inhibitor "B", and two ("untreated") received no additional chemicals. Coupons were removed after 1 month and analyzed for corrosion profiles and biofilm microbial communities. Coupons from replicate cells showed a high degree of similarity in pitting parameters and in microbial community profiles, as determined by 16S rRNA gene sequence libraries but differed with treatment regimen, suggesting that the corrosion inhibitors differentially affected microbial species. Viable microbial biomass values were more than 10-fold higher for coupons from flow cells treated with corrosion inhibitors than for coupons from untreated flow cells. The total number of pits >10 mils diameter and maximum pitting rate were significantly correlated with each other and the total number of pits with the estimated abundance of sequences classified as Desulfomicrobium. The maximum pitting rate was significantly correlated with the sum of the estimated abundance of Desulfomicrobium plus Clostridiales, and with the sum of the estimated abundance of Desulfomicrobium plus Betaproteobacteria. The lack of significant correlation with the estimated abundance of Deltaproteobacteria suggests not all Deltaproteobacteria species contribute equally to microbiologically influenced corrosion (MIC) and that it is not sufficient to target one bacterial group when monitoring for MIC.

  11. Prompt gamma analysis of chlorine in concrete for corrosion study.

    PubMed

    Naqvi, A A; Nagadi, M M; Al-Amoudi, O S B

    2006-02-01

    Measurement of chlorine in concrete is very important for studying of corrosion of reinforcing steel in concrete. Corrosion of reinforcing steel is primarily ascribed to the penetration of chloride ions to the steel surface. Preventive measures for avoiding concrete structure reinforcement corrosion requires monitoring the chloride ion concentration in concrete so that its concentration does not exceed a threshold limit to initiate reinforcement concrete corrosion. An accelerator based prompt gamma neutron activation analysis (PGNAA) setup has been developed for non-destructive analysis of elemental composition of concrete samples. The setup has been used to measure chlorine concentration in concrete samples over a 1-3 wt% concentration range. Although a strong interference has been observed between the chlorine gamma-rays and calcium gamma-rays from concrete, the chlorine concentration in concrete samples has been successfully measured using the 1.164 and 7.643 MeV chlorine gamma-rays. The experimental data were compared with the results of the Monte Carlo simulations. An excellent agreement has been achieved between the experimental data and results of Monte Carlo simulations. The study has demonstrated the successful use of the accelerator-based PGNAA setup in non-destructive analysis of chlorine in concrete samples. PMID:16129605

  12. Characterization of biofilm and corrosion of cast iron pipes in drinking water distribution system with UV/Cl2 disinfection.

    PubMed

    Zhu, Ying; Wang, Haibo; Li, Xiaoxiao; Hu, Chun; Yang, Min; Qu, Jiuhui

    2014-09-01

    The effect of UV/Cl2 disinfection on the biofilm and corrosion of cast iron pipes in drinking water distribution system were studied using annular reactors (ARs). Passivation occurred more rapidly in the AR with UV/Cl2 than in the one with Cl2 alone, decreasing iron release for higher corrosivity of water. Based on functional gene, pyrosequencing assays and principal component analysis, UV disinfection not only reduced the required initial chlorine dose, but also enhanced denitrifying functional bacteria advantage in the biofilm of corrosion scales. The nitrate-reducing bacteria (NRB) Dechloromonas exhibited the greatest corrosion inhibition by inducing the redox cycling of iron to enhance the precipitation of iron oxides and formation of Fe3O4 in the AR with UV/Cl2, while the rhizobia Bradyrhizobium and Rhizobium, and the NRB Sphingomonas, Brucella producing siderophores had weaker corrosion-inhibition effect by capturing iron in the AR with Cl2. These results indicated that the microbial redox cycling of iron was possibly responsible for higher corrosion inhibition and lower effect of water Larson-Skold Index (LI) changes on corrosion. This finding could be applied toward the control of water quality in drinking water distribution systems.

  13. Biochemical Contributions to Corrosion of Carbon Steel and Alloy 22 in a Continual Flow System

    SciTech Connect

    Horn, J.; Martin, S.; Masterson, B.; Lian, T.

    1998-12-03

    Microbiologically influenced corrosion (MIC) may decrease the functional lifetime of nuclear waste packaging materials in the potential geologic repository at Yucca Mountain (YM), Nevada. Biochemical contributions to corrosion of package materials are being determined in reactors containing crushed repository-site rock with the endogenous microbial community, and candidate waste package materials. These systems are being continually supplied with simulated ground water. Periodically, bulk chemistries are analyzed on the system outflow, and surfacial chemistries are assessed on withdrawn material coupons. Both Fe and Mn dissolved from C1020 coupons under conditions that included the presence of YM microorganisms. Insoluble corrosion products remained in a reduced state at the coupon surface, indicating at least a localized anoxic condition; soluble reduced Mn and Fe were also detected in solution, while precipitated and spalled products were oxidized. Alloy 22 surfaces showed a layer of chrome oxide, almost certainly in the Cr(III) oxidation state, on microcosm-exposed coupons, while no soluble chrome was detected in solution. The results of these studies will be compared to identical testing on systems containing sterilized rock to generate, and ultimately predict, microbial contributions to waste package corrosion chemistries.

  14. Laboratory stress corrosion cracking studies in polythionic acid

    SciTech Connect

    Baylor, V.B.; Newsome, J.F.

    1984-08-01

    Stress corrosion cracking caused by polythionic acid and/or chlorides is a problem in coal liquefaction pilot plants. This problem is also common in refineries and has been the subject of extensive research. This study examines (1) the relationship of the ASTM standard ferric sulfate-sulfuric acid test for determining sensitization to resistance to polythionic stress corrosion cracking, (2) the cracking resistance of higher-alloy Fe-Ni-Cr materials in addition to the common austenitic stainless steels, and (3) the effect of chloride concentrations up to 1% in polythionic acid solutions on cracking behavior. We found that the ferric sulfate-sulfuric acid test can be used as an acceptance test for materials resistant to polythionic acid stress corrosion cracking because of its severity. The more highly alloyed materials were more resistant to sensitization than most of the austenitic stainless steels and were virtually unattacked in polythionic acid solutions containing up to 1% chloride. Chloride increased the corrosion rate and caused localized pitting, but it did not affect significantly the number of failures or the failure mode.

  15. Corrosion studies in molten calcium chloride with chlorine

    SciTech Connect

    McLaughlin, D.F. . Science and Technology Center); Sessions, C.E.; Marra, J.E. )

    1990-01-01

    This study is aimed at testing new materials for use in molten salt processing of plutonium. Because of the high corrosiveness of chlorine, present materials have a high rate of failure. Materials less subject to corrosion are needed to minimize costs resulting from rapid failure of sparge tubes, stirring apparatus, and crucibles; to reduce the quantity of plutonium-contaminated scrap; and to improve the purity of the plutonium product. The processing environment of molten CaCl{sub 2}--CaO salts, molten plutonium, and chlorine-oxygen gas at temperatures from 750{degree} to 900{degree} is extremely severe. Materials with resistance to both corrosion and mechanical failure are desired. Also, the incorporation of corrosion products into the final plutonium product cannot exceed the allowable impurity limits. We require materials for crucibles, sparge tubes, stirrers, and containment and pull cans. Four metallic and two ceramics materials were tested. The metallic materials were Inconel-601, Inconel-617, tantalum, and tungsten. Silicon nitride and magnesium oxide were the ceramics tested.

  16. How Dangerous Can Localized Corrosion Be? An Experiment that Studies Its Effects.

    ERIC Educational Resources Information Center

    Celdran, R.; Gonzalo, P.

    1988-01-01

    Considers three common cases of localized corrosion of metals: pitting, crevice, and stress corrosion. Provides experimental methods for studying all three methods. Includes a discussion of expected results. (ML)

  17. Corrosion control when using passively treated abandoned mine drainage as alternative makeup water for cooling systems.

    PubMed

    Hsieh, Ming-Kai; Chien, Shih-Hsiang; Li, Heng; Monnell, Jason D; Dzombak, David A; Vidic, Radisav D

    2011-09-01

    Passively treated abandoned mine drainage (AMD) is a promising alternative to fresh water as power plant cooling water system makeup water in mining regions where such water is abundant. Passive treatment and reuse of AMD can avoid the contamination of surface water caused by discharge of abandoned mine water, which typically is acidic and contains high concentrations of metals, especially iron. The purpose of this study was to evaluate the feasibility of reusing passively treated AMD in cooling systems with respect to corrosion control through laboratory experiments and pilot-scale field testing. The results showed that, with the addition of the inhibitor mixture orthophosphate and tolyltriazole, mild steel and copper corrosion rates were reduced to acceptable levels (< 0.127 mm/y and < 0.0076 mm/y, respectively). Aluminum had pitting corrosion problems in every condition tested, while cupronickel showed that, even in the absence of any inhibitor and in the presence of the biocide monochloramine, its corrosion rate was still very low (0.018 mm/y).

  18. A STUDY OF CORROSION AND STRESS CORROSION CRACKING OF CARBON STEEL NUCLEAR WASTE STORAGE TANKS

    SciTech Connect

    BOOMER, K.D.

    2007-08-21

    The Hanford reservation Tank Farms in Washington State has 177 underground storage tanks that contain approximately 50 million gallons of liquid legacy radioactive waste from cold war plutonium production. These tanks will continue to store waste until it is treated and disposed. These nuclear wastes were converted to highly alkaline pH wastes to protect the carbon steel storage tanks from corrosion. However, the carbon steel is still susceptible to localized corrosion and stress corrosion cracking. The waste chemistry varies from tank to tank, and contains various combinations of hydroxide, nitrate, nitrite, chloride, carbonate, aluminate and other species. The effect of each of these species and any synergistic effects on localized corrosion and stress corrosion cracking of carbon steel have been investigated with electrochemical polarization, slow strain rate, and crack growth rate testing. The effect of solution chemistry, pH, temperature and applied potential are all considered and their role in the corrosion behavior will be discussed.

  19. Electrochemical noise measurements of sustained microbially influenced pitting corrosion in a laboratory flow loop system.

    SciTech Connect

    Lin, Y. J.

    1999-01-13

    Because of the chaotic nature of the corrosion process and the complexity of the electrochemical noise signals that are generated, there is no generally accepted method of measuring and interpreting these signals that allows the consistent detection and identification of sustained localized pitting (SLP) as compared to general corrosion. We have reexamined electrochemical noise analysis (ENA) of localized corrosion using different hardware, signal collection, and signal processing designs than those used in conventional ENA techniques. The new data acquisition system was designed to identify and monitor the progress of SLP by analyzing the power spectral density (PSD) of the trend of the corrosion current noise level (CNL) and potential noise level (PNL). Each CNL and PNL data point was calculated from the root-mean- square value of the ac components of current and potential fluctuation signals, which were measured simultaneously during a short time period. The PSD analysis results consistently demonstrated that the trends of PNL and CNL contain information that can be used to differentiate between SLP and general corrosion mechanisms. The degree of linear slope in the low-frequency portion of the PSD analysis was correlated with the SLP process. Laboratory metal coupons as well as commercial corrosion probes were tested to ensure the reproducibility and consistency of the results. The on-line monitoring capability of this new ENA method was evaluated in a bench-scale flow-loop system, which simulated microbially influenced corrosion (MIC) activity. The conditions in the test flow-loop system were controlled by the addition of microbes and different substrates to favor accelerated corrosion. The ENA results demonstrated that this in-situ corrosion monitoring system could effectively identify SLP corrosion associated with MIC, compared to a more uniform general corrosion mechanism. A reduction in SLP activity could be clearly detected by the ENA monitoring system

  20. Corrosion cast study of the canine hepatic veins.

    PubMed

    Uršič, M; Vrecl, M; Fazarinc, G

    2014-11-01

    This study presents a detailed description of the distribution, diameters and drainage patterns of hepatic veins on the basis of the corrosion cast analysis in 18 dogs. We classified the hepatic veins in three main groups: the right hepatic veins of the caudate process and right lateral liver lobe, the middle hepatic veins of the right medial and quadrate lobes and the left hepatic veins of both left liver lobes and the papillary process. The corrosion cast study showed that the number of the veins in the Nomina Anatomica Veterinaria and most anatomical textbooks is underestimated. The number of various-sized hepatic veins of the right liver division ranged from 3 to 5 and included 1 to 4 veins from the caudate process and 2 to 4 veins from the right lateral liver lobe. Generally, in all corrosion casts, one middle-sized vein from the right part of the right medial lobe, which emptied separately in the caudal vena cava, was established. The other vein was a large-sized vein from the remainder of the central division, which frequently joined the common left hepatic vein from the left liver lobes. The common left hepatic vein was the largest of all the aforementioned hepatic veins.

  1. Electrochemical corrosion studies in low conductivity propellants

    NASA Technical Reports Server (NTRS)

    Blue, G. D.; Moran, C. M.; Distefano, S.

    1986-01-01

    The Jet Propulsion Laboratory is investigating the possibility of developing advanced electrochemical techniques as accelerated compatibility tests for metal/propellant systems which overcome the problems associated with the low conductivity of the liquid propellants (e.g., hydrazines, nitrogen tetroxide). Both DC techniques and AC electrochemical impedance spectroscopy are being evaluated. Progress has been made in experiments involving stainless steel with hydrazine and nitrogen tetroxide propellants.

  2. Development of a Corrosion Sensor for AN Aircraft Vehicle Health Monitoring System

    NASA Astrophysics Data System (ADS)

    Scott, D. A.; Price, D. C.; Edwards, G. C.; Batten, A. B.; Kolmeder, J.; Muster, T. H.; Corrigan, P.; Cole, I. S.

    2010-02-01

    A Rayleigh-wave-based sensor has been developed to measure corrosion damage in aircraft. This sensor forms an important part of a corrosion monitoring system being developed for a major aircraft manufacturer. This system measures the corrosion rate at the location of its sensors, and through a model predicts the corrosion rates in nearby places on an aircraft into which no sensors can be placed. In order to calibrate this model, which yields corrosion rates rather than the accumulated effect, an absolute measure of the damage is required. In this paper the development of a surface wave sensor capable of measuring accumulated damage will be described in detail. This sensor allows the system to measure material loss due to corrosion regardless of the possible loss of historical corrosion rate data, and can provide, at any stage, a benchmark for the predictive model that would allow a good estimate of the accumulated corrosion damage in similar locations on an aircraft. This system may obviate the need for costly inspection of difficult-to-access places in aircraft, where presently the only way to check for corrosion is by periodic dismantling and reassembly.

  3. Corrosion study of a highly durable electrolyzer based on cold crucible technique for pyrochemical reprocessing of spent nuclear oxide fuel

    NASA Astrophysics Data System (ADS)

    Takeuchi, M.; Arai, Y.; Kase, T.; Nakajima, Y.

    2013-01-01

    The application of the cold crucible technique to a pyrochemical electrolyzer used in the oxide-electrowinning method, which is a method for the pyrochemical reprocessing of spent nuclear oxide fuel, is proposed as a means for improving corrosion resistance. The electrolyzer suffers from a severe corrosion environment consisting of molten salt and corrosive gas. In this study, corrosion tests for several metals in molten 2CsCl-NaCl at 923 K with purging chlorine gas were conducted under controlled material temperature conditions. The results revealed that the corrosion rates of several materials were significantly decreased by the material cooling effect. In particular, Hastelloy C-22 showed excellent corrosion resistance with a corrosion rate of just under 0.01 mm/y in both molten salt and vapor phases by controlling the material surface at 473 K. Finally, an engineering-scale crucible composed of Hastelloy C-22 was manufactured to demonstrate the basic function of the cold crucible. The cold crucible induction melting system with the new concept Hastelloy crucible showed good compatibility with respect to its heating and cooling performances.

  4. Hanford double shell waste tank corrosion studies - final report FY2014

    SciTech Connect

    Wiersma, B. J.; Fuentes, R. E.; Hicks, K.

    2014-12-19

    SRNL tasks for FY14 included studies to evaluate the susceptibility of carbon steel to vapor space corrosion (VSC), liquid-air interface (LAI) corrosion, and pitting corrosion. Additionally, SRNL evaluated the susceptibility of carbon steel to pitting corrosion under buffered waste conditions, with the objective of determining the adequate amount of inhibitor (e.g., nitrite) necessary to mitigate pitting corrosion. Other CPP experiments were performed in historical waste simulants and the results were compared to previously gathered results. The results of these activities were utilized to assess the robustness of the standardized CPP protocol

  5. Evaluating stress corrosion and corrosion aspects in supercritical water oxidation systems for the destruction of hazardous waste

    SciTech Connect

    Mitton, D.B.; Zhang, S.H.; Hautanen, K.E.; Cline, J.A.; Han, E.H.; Latanision, R.M.

    1997-08-01

    There is, currently, simultaneous public resistance to traditional waste handling procedures and a compelling need to destroy both military and civilian hazardous waste. Supercritical water oxidation (SCWO) is one developing technology particularly appropriate for treating a broad range of dilute aqueous organic wastes. Above its critical point (374 C and 221 atm) water is a low density fluid possessing properties intermediate between those of a liquid and a gas, and solvation characteristics more typical of a low polarity organic than water. Although this is a promising technology, a critical issue in its development will be the ability to overcome severe degradation problems of the materials of construction. While titanium and platinum liners have shown promise for some hazardous military feed streams, costs are high. Although nickel alloys are considered important for severe service, the indication is that they will not survive certain SCWO environments. Nevertheless, there is evidence that judicious feed modification may be employed to mitigate corrosion and reduce fabrication cost. Exposure studies have been accomplished for various alloys over a range of temperatures from 300--600 C. Experiments have been carried out in environments as innocuous as deionized water and as aggressive as highly chlorinated aqueous organic feed streams. Analysis of a number of failed components has provided enlightenment on degradation mechanisms and cracking, pitting and elevated corrosion rates are all observed in these systems. For chlorinated feed streams, both dealloying and cracking have been observed for alloy C-276. Samples exposed to a highly chlorinated organic indicate that the high-nickel alloys behave significantly better at 600 C than stainless steel type 316.

  6. Eddy current measurement system evaluation for corrosion depth determination on cast aluminum aircraft structure

    NASA Astrophysics Data System (ADS)

    Singh, Surendra; Greving, Dan; Kinney, Andy; Vensel, Fred; Ohm, Jim; Peeler, Mike

    2013-01-01

    An eddy current (EC) technique was developed to determine the corrosion depth on a bare flange face of a cast aluminum A356-T6 aircraft engine structure. The EC response and the corrosion depths determined through metallurgical cross sections were used to develop an empirical relation between EC response and depth. The EC technique and depth determination are used to inspect the engine structures during overhaul to determine if they are fit for continued service. An accurate and reliable Non-Destructive Inspection is required to ensure that structures returned to service are safe for continued operation. NDE system reliability demonstrations of the eddy current technique are traditionally reported in terms of Probability of Detection (POD) data using MIL-HDBK-1823A. However, the calculation of POD data is based on a simple linear predictive model that is valid only if certain criteria are met. These are: 1) NDE system response is measurable (i.e. continuous data), 2) Flaw size is known and measurable (i.e. continuous data), 3) relationship between the NDE system response and flaw size is linear (or linear on a log scale), 4) variation in measured responseresponse around a predicted response for a given flaw size is normally distributed, 5) the variation around the predicted response is constant (i.e. variation does not change with flaw size), and 6) inherent variability in the NDE system is known and fully understood. In this work, a Measurement System Evaluation (MSE) of the Eddy Current System was used to address some of these concerns. This work was completed on two aircraft structures having varying corrosion depths. The data were acquired in a random manner at fifty regions of interests (ROIs). Three operators participated in this study, and each operator measured Eddy Current response three times in each ROI. In total, there were four hundred and fifty data points collected. Following this, the two structures were sectioned for measuring corrosion depth. The

  7. Stress corrosion in liquid metal fast breeder reactor systems, LMFBR

    SciTech Connect

    Ring, P.J.; Spalaris, C.N.; Odegaard, T.K.; Offer, H.P.

    1980-08-01

    Work has been carried out to determine the degree of reduced SCC susceptibility obtained by the use of remelted rather than air melted 2 1/4 Cr-1 Mo steel. Both Vacuum Arc Remelt (VAR) and Electro Slag Remelt (ESR) material have been evaluated. This work has consisted of the testing of 2 1/4 Cr-1 Mo specimens in 10% and 20% sodium hydroxide at 232/sup 0/C, usng an autoclave system with a tensile loading capability. The work has continued into an evaluation of stress corrosion resistance as a function of post weld heat treatment (PWHT) and as a function of the extent of weld repair by remelting. The second area where attention has been focused is the Sodium Water Reaction Products System (SWRPRS). In the eventuality of a steam generator water leak and the resultant sodium-water reaction, this system is designed to accept the mixture of water-sodium and concomitant reaction products. Specimen holders have been installed in the SWRP system at the Energy Technology Engineering Center (ETEC). This system is connected to the Large Leak Test Vessel (LLTV) which will be used to provide data on the effects of large water leaks in LMFBR steam generator systems. Prototypical materials representing those alloys used for the sodium-water reaction products system are being exposed under large leak conditions. Critical regions of the system piping have been ultrasonically inspected to provide baseline data.

  8. Corrosion 99: Proceedings

    SciTech Connect

    1999-11-01

    This conference includes the following; Corrosion in Gas Treating; Advances in Scale and Deposit Control; Uses of Computers for Improved Corrosion Control; Erosion-Corrosion in Steam Generating Systems; Electrochemical Noise Measurements for Corrosion Evaluations; Materials Performance in Fossil Fuel Combustion and Conversion Systems; Corrosion in Super Critical Processes; Cathodic Protection of External Surfaces for Underground and Aboveground Storage Tanks; Microbiologically Influenced Corrosion; Advances in Materials for Oilfield Applications; Refining Industry Corrosion; Green Corrosion/Scale Inhibition Technologies; Managing Corrosion With Plastics; Corrosion Measurement Technology; Marine Corrosion; Improved Understanding and Mitigation of CO{sub 2} Corrosion; Thermal Spray Coatings for Corrosion Protection; Volatile Corrosion Inhibitors; Corrosion Testing in Concrete; Stress Corrosion Cracking: Field Laboratory Correlations; Materials Performance in Incineration and Waste Fuel Combustion Environments; Water Reuse in Industry; Corrosion Control and Prevention of Military and Aerospace Equipment; Corrosion in Nuclear Systems; Latest Developments in Aboveground Storage Tanks Corrosion Control, Monitoring and Evaluation Technology; Internal In-line Inspection of Pipelines and Evaluation of Results; New Developments in Cathodic Protection of Reinforcing Steels in Concrete; Cathodic Protection in Natural Waters; Corrosion in the Pulp and Paper Industry; Advanced Materials for High Temperature Service in Chemical Process Industry; Advances in Cooling Water Treatment; Materials, Fabrication, and Inspection Guidelines for Wet H{sub 2}S Service; Environmental Wear of Nonmetallics in Oilfield Service; and Corrosion and Scale Control in Low Pressure Boiler and Steam Systems in Buildings. Separate abstracts were prepared for most of the papers.

  9. Corrosion 99: Proceedings

    SciTech Connect

    Not Available

    1999-01-01

    This conference includes the following; Corrosion in Gas Treating; Advances in Scale and Deposit Control; Uses of Computers for Improved Corrosion Control; Erosion-Corrosion in Steam Generating Systems; Electrochemical Noise Measurements for Corrosion Evaluations; Materials Performance in Fossil Fuel Combustion and Conversion Systems; Corrosion in Super Critical Processes; Cathodic Protection of External Surfaces for Underground and Aboveground Storage Tanks; Microbiologically Influenced Corrosion; Advances in Materials for Oilfield Applications; Refining Industry Corrosion; Green Corrosion/Scale Inhibition Technologies; Managing Corrosion With Plastics; Corrosion Measurement Technology; Marine Corrosion; Improved Understanding and Mitigation of CO[sub 2] Corrosion; Thermal Spray Coatings for Corrosion Protection; Volatile Corrosion Inhibitors; Corrosion Testing in Concrete; Stress Corrosion Cracking: Field Laboratory Correlations; Materials Performance in Incineration and Waste Fuel Combustion Environments; Water Reuse in Industry; Corrosion Control and Prevention of Military and Aerospace Equipment; Corrosion in Nuclear Systems; Latest Developments in Aboveground Storage Tanks Corrosion Control, Monitoring and Evaluation Technology; Internal In-line Inspection of Pipelines and Evaluation of Results; New Developments in Cathodic Protection of Reinforcing Steels in Concrete; Cathodic Protection in Natural Waters; Corrosion in the Pulp and Paper Industry; Advanced Materials for High Temperature Service in Chemical Process Industry; Advances in Cooling Water Treatment; Materials, Fabrication, and Inspection Guidelines for Wet H[sub 2]S Service; Environmental Wear of Nonmetallics in Oilfield Service; and Corrosion and Scale Control in Low Pressure Boiler and Steam Systems in Buildings. Separate abstracts were prepared for most of the papers.

  10. Smart aircraft fastener evaluation (SAFE) system: a condition-based corrosion detection system for aging aircraft

    NASA Astrophysics Data System (ADS)

    Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.

    1996-05-01

    The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.

  11. Treating carbon dioxide corrosion in Western Siberian oilfield systems

    SciTech Connect

    Markin, A.N. )

    1994-10-01

    The corrosion mechanism of carbon dioxide (CO[sub 2]) corrosion of carbon steel was investigated. Under conditions of constant outside parameters (for instance, temperature, partial pressure of CO[sub 2], water-phase chemical composition, and rate of medium stirring), differing phase relationships in the scale can produce widely varying corrosion rates. This article shows the application of the produced water saturation to predict iron carbonate scale deposition. Data on the inhibition of CO[sub 2] corrosion of carbon steel under scaling conditions are also given.

  12. Experimental studies of laser-ablated zirconium carbide plasma plumes: Fuel corrosion diagnostic development

    SciTech Connect

    Wantuck, P.J.; Butt, D.P.; Sappey, A.D.

    1992-01-01

    Understanding the corrosion behavior of nuclear fuel materials, such as refractory carbides, in a high temperature hydrogen environment is critical for several proposed nuclear thermal propulsion (NTP) concepts. Monitoring the fuel corrosion products is important not only for understanding corrosion characteristics, but to assess the performance of an actual, operating nuclear propulsion system as well. In this paper, we describe an experimental study initiated to develop, test, and subsequently utilize non-intrusive, laser-based diagnostics to characterize the gaseous product species which are expected to evolve during the exposure of representative fuel samples to hydrogen. Laser ablation is used to produce high temperature, vapor plumes from solid solution, uranium-free, zirconium carbide (ZrC) forms for probing by other laser diagnostic methods; predominantly laser-induced fluorescence (LIF). We discuss the laser ablation technique, results of plume emission measurements, as well as the use of planar LIF to image both the ZrC plumes and actual NTP fuel corrosion constituents.

  13. DIFFUSION COATINGS FOR CORROSION RESISTANT COMPONENTS IN COAL GASIFICATION SYSTEMS

    SciTech Connect

    Gopala N. Krishnan

    2004-05-01

    Advanced electric power generation systems use a coal gasifier to convert coal to a gas rich in fuels such as H{sub 2} and CO. The gas stream contains impurities such as H{sub 2}S and HCl, which attack metal components of the coal gas train, causing plant downtime and increasing the cost of power generation. Corrosion-resistant coatings would improve plant availability and decrease maintenance costs, thus allowing the environmentally superior integrated gasification combined cycle plants to be more competitive with standard power-generation technologies. A startup meeting was held at the National Energy Technology Center, Pittsburgh, PA site on July 28, 2003. SRI staff described the technical approach of the project.

  14. Impact of makeup water system performance on PWR steam generator corrosion. Final report

    SciTech Connect

    Bell, M.J.; Pearl, W.L.; Sawochka, S.G.; Smith, L.A.

    1985-06-01

    The objectives of this project were to review makeup system design and performance and assess the possible relation of pressurized water reactor (PWR) steam generator corrosion to makeup water impurity ingress at fresh water sites. Project results indicated that makeup water transport of most ionic impurities can be expected to have a significant impact on secondary cycle chemistry only if condenser inleakage and other sources of impurities are maintained at very low levels. Since makeup water oxygen control techniques at most study plants were not consistent with state-of-the-art technology, oxygen input to the cycle via makeup can be significant. Leakage of colloidal silica and organics through makeup water systems can be expected to control blowdown silica levels and organic levels throughout the cycle at many plants. Attempts to correlate makeup water quality to steam generator corrosion observations were unsuccessful since (1) other impurity sources were significant compared to makeup at most study plants, (2) many variables are involved in the corrosion process, and (3) in the case of IGA, the variables have not been clearly established. However, in some situations makeup water can be a significant source of contaminants suspected to lead to both IGA and denting.

  15. A Comprehensive Investigation of Copper Pitting Corrosion in a Drinking Water Distribution System

    EPA Science Inventory

    Copper pipe pitting is a complicated corrosion process for which exact causes and solutions are uncertain. This paper presents the findings of a comprehensive investigation of a cold water copper pitting corrosion problem in a drinking water distribution system, including a refi...

  16. Simulation of Deposition the Corrosion Waste in a Water Distribution System

    NASA Astrophysics Data System (ADS)

    Jeleníková, Ivana; Šikula, Ondřej; Peráčková, Jana

    2013-04-01

    In water distribution systems can be found particles of rust and other mechanical contaminants. The particles are deposited in locations where the low velocity of water flow. Where a can cause the pitting corrosion. Is a concern in the systems made of galvanized steel pipes. The contribution deals with CFD (Computational Fluid Dynamics) simulations of water flow and particles deposition in water distribution system. CFD Simulations were compared with the corrosive deposits in real pipeline. Corrosion is a spontaneous process of destruction of metal material due to electrochemical reactions of metal with the aggressive surrounding. Electrochemical corrosion is caused by the thermodynamic instability of metal and therefore can not be completely suppress, it can only influence the speed of corrosion. The requirement is to keep metal properties during the whole its lifetime. Requested service lifetime the water pipe according to EN 806-2 is 50 years.

  17. Corrosion caused by elevator and spider marks on CRA pipe: Comparison of conventional inserts and a new gripping system

    SciTech Connect

    1997-05-01

    Corrosion-resistant alloys (CRA) are used to reduce corrosion damage to casing and tubing strings and prolong the life span of the well pipe. An analysis of various corrosion mechanisms shows that surface integrity is an important factor in corrosion prevention. Surface damage caused by inappropriate handling or conventional slip markings contribute directly to the development and propagation of corrosion. A newly developed gripping system distributes the load equally onto a large number of small peaks, minimizing the indentation of each single peak. The new gripping system does not damage the surface integrity of the pipe, virtually eliminating the corrosion potential.

  18. DIFFUSION COATINGS FOR CORROSION RESISTANT COMPONENTS IN COAL GASIFICATION SYSTEMS

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Angel Sanjurjo

    2005-03-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy may improve is resistance to such sulfidation attack and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this reporting period we conducted two exposure tests with coated and uncoated coupons. The first one was aborted after a short period, because of a leak in the pressure regulator of a CO/CO{sub 2}/H{sub 2} gas mixture gas cylinder that was used to prepare the simulated coal gas stream. Nevertheless, this run was very instructive as it showed that during the brief exposure when the concentration of H{sub 2}S increased to 8.6%, even specialty alloys such as HR160 and I800 were badly corroded, yet the sample of a SS405-steel that was coated with Ti/Ta showed no signs of corrosion. After replacing the pressure regulator, a second run was conducted with a fresh set of coated and uncoated samples. The Ti/Ta-coated on to SS405 steel from the earlier runs was also exposed in this test. The run proceeded smoothly, and at the end of test the uncoated steels were badly damaged, some evidence of corrosion was found on coupons of HR160 and I800 alloys and the Cr-coated steels, but again, the Ti/Ta-coated sample appeared unaffected.

  19. Physicochemical studies of glucose, gellan gum, and hydroxypropyl cellulose--inhibition of cast iron corrosion.

    PubMed

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy

    2013-06-01

    Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction.

  20. Studies of corrosion and corrosion control in a CO{sub 2}-2-amino-2-methyl-1-propanol (AMP) environment

    SciTech Connect

    Veawab, A.; Tontiwachwuthikul, P.; Bhole, S.D.

    1997-01-01

    The carbon dioxide (CO{sub 2}) absorption process is essential for many industrial processing operations, i.e., natural gas purification. Corrosion and corrosion inhibition in a sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), were investigated by static weight loss tests. The corrosion data were compared with those of monoethanolamine (MEA), a conventional alkanolamine, which was simultaneously tested under the same conditions. The results indicated that the AMP system was generally less corrosive to carbon steel than the MEA system, but corrosion control is still necessary. Sodium metavanadate (NaVO{sub 3}) and sodium sulfite (Na{sub 2}SO{sub 3}) were proven to be effective corrosion inhibitors, with more than 90% protection efficiency.

  1. Internal Corrosion and Deposition Control

    EPA Science Inventory

    This chapter reviews the current knowledge of the science of corrosion control and control of scaling in drinking water systems. Topics covered include: types of corrosion; physical, microbial and chemical factors influencing corrosion; corrosion of specific materials; direct ...

  2. Corrosion study of bare and coated stainless steel

    NASA Technical Reports Server (NTRS)

    Morrison, J. D.

    1972-01-01

    A program was conducted at Kennedy Space Center from February 1968 to February 1971 to evaluate the performance of austenitic stainless steel alloys used in fluid systems lines. For several years, there had been numerous failures of stainless steel hardware caused by pitting and stress corrosion cracking. Several alloys were evaluated for effectiveness of certain sacrificial-type protective coverings in preventing corrosion failures. Samples were tested in specially designed racks placed 91 meters (100 yards) above high-tide line at Cape Kennedy. It is concluded that: (1) unprotected tubing samples showed evidence of pitting initiation after 2 weeks; (2) although some alloys develop larger pits than others, it is probable that the actual pitting rate is independent of alloy type; (3) the deepest pitting occurred in the sheltered part of the samples; and (4) zinc-rich coatings and an aluminum-filled coating have afforded sacrificial protection against pitting for at least 28 months. It is believed that a much longer effective coating life can be expected.

  3. ELECTROCHEMICAL STUDIES ON THE CORROSION OF CARBON STEEL IN OXALIC ACID CLEANING SOLUTIONS

    SciTech Connect

    Wiersma, B; John Mickalonis, J

    2007-10-08

    The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS has utilized oxalic acid to accomplish this task. Since the waste tanks are constructed of carbon steel, a significant amount of corrosion may occur. Although the total amount of corrosion may be insignificant for a short contact time, a significant amount of hydrogen may be generated due to the corrosion reaction. Linear polarization resistance and anodic/cathodic polarization tests were performed to investigate the corrosion behavior during the process. The effect of process variables such as temperature, agitation, aeration, sample orientation, light as well as surface finish on the corrosion behavior were evaluated. The results of the tests provided insight into the corrosion mechanism for the iron-oxalic acid system.

  4. Study of MHD Corrosion and Transport of Corrosion Products of Ferritic/Martensitic Steels in the Flowing PbLi and its Application to Fusion Blanket

    NASA Astrophysics Data System (ADS)

    Saeidi, Sheida

    Two important components of a liquid breeder blanket of a fusion power reactor are the liquid breeder/coolant and the steel structure that the liquid is enclosed in. One candidate combination for such components is Lead-Lithium (PbLi) eutectic alloy and advanced Reduced Activation Ferritic/Martensitic (RAFM) steel. The research performed here is aimed at: (1) better understanding of corrosion processes in the system including RAFM steel and flowing PbLi in the presence of a strong magnetic field and (2) prediction of corrosion losses in conditions of a Dual Coolant Lead Lithium (DCLL) blanket, which is at present the key liquid metal blanket concept in the US. To do this, numerical and analytical tools have been developed and then applied to the analysis of corrosion processes. First, efforts were taken to develop a computational suite called TRANSMAG (Transport phenomena in Magnetohydrodynamic Flows) as an analysis tool for corrosion processes in the PbLi/RAFM system, including transport of corrosion products in MHD laminar and turbulent flows. The computational approach in TRANSMAG is based on simultaneous solution of flow, energy and mass transfer equations with or without a magnetic field, assuming mass transfer controlled corrosion and uniform dissolution of iron in the flowing PbLi. Then, the new computational tool was used to solve an inverse mass transfer problem where the saturation concentration of iron in PbLi was reconstructed from the experimental data resulting in the following correlation: CS = e 13.604--12975/T, where T is the temperature of PbLi in K and CS is in wppm. The new correlation for saturation concentration was then used in the analysis of corrosion processes in laminar flows in a rectangular duct in the presence of a strong transverse magnetic field. As shown in this study, the mass loss increases with the magnetic field such that the corrosion rate in the presence of a magnetic field can be a few times higher compared to purely

  5. Effects of fungal and bacterial contaminants of kerosene fuels on the corrosion of storage and distribution systems

    SciTech Connect

    Videla, H.A.; Guiamet, P.S.; DoValle, S.; Reinoso, E.H.

    1988-01-01

    The electrochemical behavior of pure aluminum 2024 alloy and mild steel have been studied in the presence of several species of fungi and bacteria isolated from kerosene fuels storage and distribution systems. Microbial growth facilitates passivity breakdown mainly through the action of organic acidic metabolites derived from hydrocarbon degradation. Their corrosive effect depends on the pH and electrolyte composition of the medium, especially with reference to chloride and nitrate levels. Microbial adhesion to the metal surface enhances metal dissolution. The metabolic activities of different microbial contaminants of fuel/water systems sometimes lead to opposite effects with respect to the corrosion of the metal. Thus, the uptake of nitrate as nitrogen source by Hormoconis resinae can be an important alternative corrosion mechanism. A protective effect has been observed for aluminum and 2024 alloy in the presence of Serratia marcescens in spite of its hydrocarbon degradation capacity.

  6. A case study of corrosion control in a Herreshoff multiple-hearth calciner

    SciTech Connect

    Schorr, M.; Mureinik, R.J.

    1985-09-01

    The calcination of magnesium hydroxide to magnesium oxide is performed in a multi-hearth Herreshoff kiln, which consists of a cylindrical shell enclosing refractory hearths. After several years of operation, corrosion on the shell was studied by mapping the residual shell thickness and temperature. Corrosion products were samples and analyzed, and a mechanism proposed to explain the extent and distribution of the corrosion intensity.

  7. Diffusion Coatings for Corrosion Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Angel Sanjurjo

    2005-01-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy may improve its resistance to such sulfidation attack and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this reporting period we focused on getting a bench-scale test system to expose alloy coupons to simulated gasifier environment. The test facility was designed to allow about 20 specimen coupons to be exposed simultaneously for an extend period to a simulated coal gas stream at temperatures up to 1000 C. The simulated gas stream contained about 26%H{sub 2}, 39%CO, 17%CO{sub 2}, 1.4% H{sub 2}S and balance steam. We successfully ran a 100+h test with coated and uncoated stainless steel coupons. The tested alloys include SS304, SS316, SS405, SS409, SS410, and IN800. The main finding is that Ti/Ta coating provides excellent protection to SS405 under conditions where uncoated austenitic and ferritic stainless steel alloy coupons are badly corroded. Cr coatings also appear to afford some protection against corrosion.

  8. Predicting the corrosivity of an operating FGD system

    SciTech Connect

    Hodge, F.G.; Silence, W.L.; Wright, D.

    1994-12-01

    Utilities burning high sulfur coal are under regulatory pressure to install flue gas desulfurization (FGD) equipment (scrubbers) to remove SO[sub 2] from the flue gas. Wet scrubbers, utilizing ground limestone, appear to be the most economical choice of technology for large generating plants with single or multiple boilers producing 200--660 MW of power. The design and operation of the limestone FGD units shows wide variation from one manufacturer to another. Despite the mechanical variation in each design, the corrosion problems faced by FGD units, as a whole, are very similar. One of the key factors that influences the materials selections process for an FGD system is the anticipated environmental conditions. Due to the wide variations in coal burned, a method was needed that could predict the environment that would be generated. This article describes a computer model that will predict, with some degree of accuracy, the maximum concentration of sulfuric acid that will form by condensation at the inlet and the outlet of the scrubber. Having generated the model, experiments were performed to confirm the predictions by collecting samples from an operating FGD system and analyzing the acid content. The results of these tests have confirmed that acid concentration in the duct work can be anticipated and the effects of other process variables such as reheat can be predicted.

  9. Investigation of corrosion experienced in a spray calciner/ceramic melter vitrification system

    SciTech Connect

    Dierks, R.D.; Mellinger, G.B.; Miller, F.A.; Nelson, T.A.; Bjorklund, W.J.

    1980-08-01

    After periodic testing of a large-scale spray calciner/ceramic melter vitrification system over a 2-yr period, sufficient corrosion was noted on various parts of the vitrification system to warrant its disassembly and inspection. A majority of the 316 SS sintered metal filters on the spray calciner were damaged by chemical corrosion and/or high temperature oxidation. Inconel-601 portions of the melter lid were attacked by chlorides and sulfates which volatilized from the molten glass. The refractory blocks, making up the walls of the melter, were attacked by the waste glass. This attack was occurring when operating temperatures were >1200/sup 0/C. The melter floor was protected by a sludge layer and showed no corrosion. Corrosion to the Inconel-690 electrodes was minimal, and no corrosion was noted in the offgas treatment system downstream of the sintered metal filters. It is believed that most of the melter corrosion occurred during one specific operating period when the melter was operated at high temperatures in an attempt to overcome glass foaming behavior. These high temperatures resulted in a significant release of volatile elements from the molten glass, and also created a situation where the glass was very fluid and convective, which increased the corrosion rate of the refractories. Specific corrosion to the calciner components cannot be proven to have occurred during a specific time period, but the mechanisms of attack were all accelerated under the high-temperature conditions that were experienced with the melter. A review of the materials of construction has been made, and it is concluded that with controlled operating conditions and better protection of some materials of construction corrosion of these systems will not cause problems. Other melter systems operating under similar strenuous conditions have shown a service life of 3 yr.

  10. Effects of microbial redox cycling of iron on cast iron pipe corrosion in drinking water distribution systems.

    PubMed

    Wang, Haibo; Hu, Chun; Zhang, Lili; Li, Xiaoxiao; Zhang, Yu; Yang, Min

    2014-11-15

    Bacterial characteristics in corrosion products and their effect on the formation of dense corrosion scales on cast iron coupons were studied in drinking water, with sterile water acting as a reference. The corrosion process and corrosion scales were characterized by electrochemical and physico-chemical measurements. The results indicated that the corrosion was more rapidly inhibited and iron release was lower due to formation of more dense protective corrosion scales in drinking water than in sterile water. The microbial community and denitrifying functional genes were analyzed by pyrosequencing and quantitative polymerase chain reactions (qPCR), respectively. Principal component analysis (PCA) showed that the bacteria in corrosion products played an important role in the corrosion process in drinking water. Nitrate-reducing bacteria (NRB) Acidovorax and Hydrogenophaga enhanced iron corrosion before 6 days. After 20 days, the dominant bacteria became NRB Dechloromonas (40.08%) with the protective corrosion layer formation. The Dechloromonas exhibited the stronger corrosion inhibition by inducing the redox cycling of iron, to enhance the precipitation of iron oxides and formation of Fe3O4. Subsequently, other minor bacteria appeared in the corrosion scales, including iron-respiring bacteria and Rhizobium which captured iron by the produced siderophores, having a weaker corrosion-inhibition effect. Therefore, the microbially-driven redox cycling of iron with associated microbial capture of iron caused more compact corrosion scales formation and lower iron release.

  11. Selected durability studies of geopolymer concrete with respect to carbonation, elevated temperature, and microbial induced corrosion

    NASA Astrophysics Data System (ADS)

    Badar, Mohammad Sufian

    prepared with certain fly ashes exhibited signs of expansion along with cracking and spalling, while GPC prepared with specific class F fly ash showed superior resistance to thermal shock. Microstructural analysis revealed that the resistance of GPC at elevated temperatures was dependent on the type of fly ash used, its particle size distribution, formation of zeolitic phases such as sodalite, analcime and nepheline, and the overall pore structure of the geopolymer concrete. The work indicates that the chemical composition and particle size distribution of the fly ash, type of fly ash (Class C & F) and the geopolymerization process that took place a vital role in the performance of geopolymer concretes in high temperature applications. Microbial Induced Corrosion: Corrosion is a major form of deterioration in concrete structures. According to a report published by the U.S. FHWA 2002, the cost of corrosion in water and wastewater conveyance, and storage and treatment facilities in the U.S. is about $138 billions. A main form of corrosion in wastewater collection systems is Microbial Induced Corrosion (MIC). However, the conditions present in industrial or municipal wastewater pipes, or storage facility are induced by the production of sulfuric acid by biological processes, which cannot be fully mimicked by simple acid corrosion. The present study intends to provide similar conditions inside pipe specimens that mimic a true sewer atmosphere. The experimental setup consisted of three 12" diameter and 30" long concrete pipe specimens, 2 specimens were coated with different formulations of GPC while the third was a control. Both ends of each pipe specimen were sealed to prevent hydrogen sulfide gas from escaping. One pipe was coated with GPC that had a biocide agent entrained. Another pipe specimen was coated with OPC and the 3rd pipe was used as a control and was not coated. Parameters measured can be divided into three groups: general environmental parameters like pH and

  12. Study of development and utilization of a multipurpose atmospheric corrosion sensor

    NASA Technical Reports Server (NTRS)

    Diwan, Ravinder M.; Raman, A.; Bhattacharya, P. K.

    1994-01-01

    There has been a critical need for analyzing various aspects of atmospheric corrosion and for the development of atmospheric corrosion microsensors. The project work has involved the following activities: (1) making of multielectrode corrosion monitors on dielectric substrates; (2) testing them in the laboratory for functional characteristics; (3) preparing a report on the state of the art of atmospheric corrosion sensor development around the world; and (4) corrosion testing of electrochemical changes of sensor specimens and related fog testing. The study included work on the subject of development and utilization of a multipurpose atmospheric corrosion sensor and this report is the annual report on work carried out on this research project. This has included studies on the development of sensors of two designs, stage 1 and stage 2, and with glass and alumina substrate, experimentation and development and characterization of the coating uniformity, aspects of corrosion monitoring, literature search on the corrosion sensors and their development. A state of the art report on atmospheric corrosion sensor development was prepared and submitted.

  13. Morphological and physicochemical characteristics of iron corrosion scales formed under different water source histories in a drinking water distribution system.

    PubMed

    Yang, Fan; Shi, Baoyou; Gu, Junnong; Wang, Dongsheng; Yang, Min

    2012-10-15

    The corrosion scales on iron pipes could have great impact on the water quality in drinking water distribution systems (DWDS). Unstable and less protective corrosion scale is one of the main factors causing "discolored water" issues when quality of water entering into distribution system changed significantly. The morphological and physicochemical characteristics of corrosion scales formed under different source water histories in duration of about two decades were systematically investigated in this work. Thick corrosion scales or densely distributed corrosion tubercles were mostly found in pipes transporting surface water, but thin corrosion scales and hollow tubercles were mostly discovered in pipes transporting groundwater. Magnetite and goethite were main constituents of iron corrosion products, but the mass ratio of magnetite/goethite (M/G) was significantly different depending on the corrosion scale structure and water source conditions. Thick corrosion scales and hard shell of tubercles had much higher M/G ratio (>1.0), while the thin corrosion scales had no magnetite detected or with much lower M/G ratio. The M/G ratio could be used to identify the characteristics and evaluate the performances of corrosion scales formed under different water conditions. Compared with the pipes transporting ground water, the pipes transporting surface water were more seriously corroded and could be in a relatively more active corrosion status all the time, which was implicated by relatively higher siderite, green rust and total iron contents in their corrosion scales. Higher content of unstable ferric components such as γ-FeOOH, β-FeOOH and amorphous iron oxide existed in corrosion scales of pipes receiving groundwater which was less corroded. Corrosion scales on groundwater pipes with low magnetite content had higher surface area and thus possibly higher sorption capacity. The primary trace inorganic elements in corrosion products were Br and heavy metals. Corrosion

  14. Morphological and physicochemical characteristics of iron corrosion scales formed under different water source histories in a drinking water distribution system.

    PubMed

    Yang, Fan; Shi, Baoyou; Gu, Junnong; Wang, Dongsheng; Yang, Min

    2012-10-15

    The corrosion scales on iron pipes could have great impact on the water quality in drinking water distribution systems (DWDS). Unstable and less protective corrosion scale is one of the main factors causing "discolored water" issues when quality of water entering into distribution system changed significantly. The morphological and physicochemical characteristics of corrosion scales formed under different source water histories in duration of about two decades were systematically investigated in this work. Thick corrosion scales or densely distributed corrosion tubercles were mostly found in pipes transporting surface water, but thin corrosion scales and hollow tubercles were mostly discovered in pipes transporting groundwater. Magnetite and goethite were main constituents of iron corrosion products, but the mass ratio of magnetite/goethite (M/G) was significantly different depending on the corrosion scale structure and water source conditions. Thick corrosion scales and hard shell of tubercles had much higher M/G ratio (>1.0), while the thin corrosion scales had no magnetite detected or with much lower M/G ratio. The M/G ratio could be used to identify the characteristics and evaluate the performances of corrosion scales formed under different water conditions. Compared with the pipes transporting ground water, the pipes transporting surface water were more seriously corroded and could be in a relatively more active corrosion status all the time, which was implicated by relatively higher siderite, green rust and total iron contents in their corrosion scales. Higher content of unstable ferric components such as γ-FeOOH, β-FeOOH and amorphous iron oxide existed in corrosion scales of pipes receiving groundwater which was less corroded. Corrosion scales on groundwater pipes with low magnetite content had higher surface area and thus possibly higher sorption capacity. The primary trace inorganic elements in corrosion products were Br and heavy metals. Corrosion

  15. Formation and Release Behavior of Iron Corrosion Products under the Influence of Bacterial Communities in a Simulated Water Distribution System

    EPA Science Inventory

    Understanding the effects of biofilm on the iron corrosion, iron release and associated corrosion by-products is critical for maintaining the water quality and the integrity of drinking water distribution system (DWDS). In this work, iron corrosion experiments under sterilized a...

  16. Inter-relationships between corrosion and mineral-scale deposition in aqueous systems.

    PubMed

    Hodgkiess, T

    2004-01-01

    The processes of corrosion and scale deposition in natural and process waters are often linked and this paper considers a number of instances of interactions between the two phenomena. In some circumstances a scale layer (e.g. calcium carbonate) can be advantageously utilised as a corrosion-protection coating on components and this feature has been exploited for many decades in the conditioning of water to induce spontaneous precipitation of a scale layer upon the surfaces of engineering equipment. The electrochemical mechanisms associated with some corrosion and corrosion-control processes can promote alkaline-scale deposition directly upon component surfaces. This is a feature that can be exploited in the operation of cathodic protection (CP) of structures and components submerged in certain types of water (e.g. seawater). Similar phenomena can occur during bi-metallic corrosion and a case study, involving carbon steel/stainless steel couples in seawater, is presented. Additional complexities pertain during cyclic loading of submerged reinforced concrete members in which scale deposition may reduce the severity of fatigue stresses but can be associated with severe corrosion damage to embedded reinforcing steel. Also considered are scale-control/corrosion interactions in thermal desalination plant and an indirect consequence of the scale-control strategy on vapourside corrosion is discussed.

  17. Inter-relationships between corrosion and mineral-scale deposition in aqueous systems.

    PubMed

    Hodgkiess, T

    2004-01-01

    The processes of corrosion and scale deposition in natural and process waters are often linked and this paper considers a number of instances of interactions between the two phenomena. In some circumstances a scale layer (e.g. calcium carbonate) can be advantageously utilised as a corrosion-protection coating on components and this feature has been exploited for many decades in the conditioning of water to induce spontaneous precipitation of a scale layer upon the surfaces of engineering equipment. The electrochemical mechanisms associated with some corrosion and corrosion-control processes can promote alkaline-scale deposition directly upon component surfaces. This is a feature that can be exploited in the operation of cathodic protection (CP) of structures and components submerged in certain types of water (e.g. seawater). Similar phenomena can occur during bi-metallic corrosion and a case study, involving carbon steel/stainless steel couples in seawater, is presented. Additional complexities pertain during cyclic loading of submerged reinforced concrete members in which scale deposition may reduce the severity of fatigue stresses but can be associated with severe corrosion damage to embedded reinforcing steel. Also considered are scale-control/corrosion interactions in thermal desalination plant and an indirect consequence of the scale-control strategy on vapourside corrosion is discussed. PMID:14982172

  18. DIFFUSION COATINGS FOR CORROSION RESISTANT COMPONENTS IN COAL GASIFICATION SYSTEMS

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Angel Sanjurjo

    2004-05-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy may improve is resistance to such sulfidation attack and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. A review of the literature indicated that the Fe- and Ni-based high-temperature alloys are susceptible to sulfidation attack unless they are fortified with high levels of Cr, Al, and Si. To impart corrosion resistance, these elements need not be in the bulk of the alloy and need only be present at the surface layers. We selected diffusion coatings of Cr and Al, and surface coatings of Si and Ti for the preliminary testing. These coatings will be applied using the fluidized bed chemical vapor deposition technique developed at SRI which is rapid and relatively inexpensive. We have procured coupons of typical alloys used in a gasifier. These coupons will be coated with Cr, Al, Si, and Ti. The samples will be tested in a bench-scale reactor using simulated coal gas compositions. In addition, we will be sending coated samples for insertion in the gas stream of the coal gasifier.

  19. Corrosion and Fretting Corrosion Studies of Medical Grade CoCrMo Alloy in a Clinically Relevant Simulated Body Fluid Environment

    NASA Astrophysics Data System (ADS)

    Ocran, Emmanuel K.; Guenther, Leah E.; Brandt, Jan-M.; Wyss, Urs; Ojo, Olanrewaju A.

    2015-06-01

    In modular hip implants, fretting corrosion at the head/neck and neck/stem interfaces has been identified as a major cause of early revision in hip implants, particularly those with heads larger than 32 mm. It has been found that the type of fluid used to simulate the fretting corrosion of biomedical materials is crucial for the reliability of laboratory tests. Therefore, to properly understand and effectively design against fretting corrosion damage in modular hips, there is the need to replicate the human body environment as closely as possible during in vitro testing. In this work, corrosion and fretting corrosion behavior of CoCrMo in 0.14 M NaCl, phosphate buffered saline, and in a clinically relevant novel simulated body fluid was studied using a variety of electrochemical characterization techniques and tribological experiments. Electrochemical, spectroscopy and tribo-electrochemical techniques employed include Potentiodynamic polarization, Potentiostatic polarization, Electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, augur electron spectroscopy, inductively coupled plasma mass spectroscopy, and pin-on-disk wear simulation. The presence of phosphate ions in PBS accounted for the higher corrosion rate when compared with 0.14 M NaCl and the clinically relevant novel simulated body fluid. The low corrosion rates and the nature of the protective passive film formed in the clinically relevant simulated body fluid make it suitable for future corrosion and fretting corrosion studies.

  20. Corrosion coupon studies at coal liquefaction pilot plants

    SciTech Connect

    Keiser, J.R.; Baylor, V.B.; Howell, M.; Newsome, J.F.

    1983-09-01

    As part of the Fossil Energy Materials Program at Oak Ridge National Laboratory, we have supplied corrosion coupons to coal-liquefaction pilot plants for exposure in selected vessels. These vessels were chosen on the basis of previous corrosion experience, anticipated corrosion behavior (especially important when operating conditions were changed), accessibility, and availability. Alloys exposed were selected to give a series with a corrosion resistance ranging from less than to greater than that thought to be needed for each application. Corrosion rates calculated from weight changes of the exposed coupons provide information useful in selecting materials for coal-liquefaction plants. The results presented are from coupons exposed in the Wilsonville, Alabama, and Fort Lewis, Washington, Solvent Refined Coal pilot plants; the Catlettsburg, Kentucky, H-Coal Pilot Plant; and the Baytown, Texas, Exxon Coal Liquefaction Pilot Plant.

  1. Real Time Corrosion Monitoring in Lead and Lead-Bismuth Systems

    SciTech Connect

    James F. Stubbins; Alan Bolind; Ziang Chen

    2010-02-25

    The objective of this research program is to develop a real-time, in situ corrosion monitoring technique for flowing liquid Pb and eutectic PbBi (LBE) systems in a temperature range of 400 to 650 C. These conditions are relevant to future liquid metal cooled fast reactor operating parameters. THis program was aligned with the Gen IV Reactor initiative to develp technologies to support the design and opertion of a Pb or LBE-cooled fast reactor. The ability to monitor corrosion for protection of structural components is a high priority issue for the safe and prolonged operation of advanced liquid metal fast reactor systems. In those systems, protective oxide layers are intentionally formed and maintained to limit corrosion rates during operation. This program developed a real time, in situ corrosion monitoring tecnique using impedance spectroscopy (IS) technology.

  2. The use of microelectrodes in the study of localized corrosion of aluminum 6111-like alloys

    NASA Astrophysics Data System (ADS)

    Abdullah, Aboubakr M.

    This thesis is classified into four chapters. While chapter 1 is only an introductory chapter that summarizes the two mechanisms that are trying to explain localized corrosion of metals and alloys, Chapter 4 is the conclusions and future work chapter that presents the new achievements that have been added to the field of corrosion science by this work besides the proposed work to be done in the future. In chapter 2, Crevice corrosion of an experimental Al 6111-like alloy with 0.68% Cu has been studied using potentiodynamic and potentiostatic techniques in different concentrations of sodium chloride and in 0.1M nitric acid solutions. Potentiodynamic experiments show that the alloy has an active/passive transition in a saturated sodium chloride solution at elevated temperatures (90 and 70°C). Also, a steep electrode potential gradient, E(x), within the crevice has been measured using a microprobe connected to a SCE and controlled by a 3-D manipulator, and the observed locations of corrosion on the crevice wall are similar to the locations seen previously for systems in which it was clear that the shift of E(x) into the active peak region of the polarization curve on the crevice wall stabilized the crevice corrosion process. In chapter 3, focuses on the corrosion of a peak aged aluminum 6111-like alloy of 1.47% copper using the artificial pit configuration (pencil electrode) with relatively larger specimens in the form of plates rather than wires. The sample which was flush with the surface of the epoxy resin mount was anodically polarized in neutral NaCl solutions of different concentrations and pH 6.9. The alloy dissolved uniformly at a certain rate to form a local cell with epoxy resin walls and the alloy surface as its bottom. The potential drop profile within the cavity was recorded on a daily basis. It showed that the total potential drop is in the order of 50 mV. The pH in the local cell was measured using a commercial mono pH microelectrode coupled with a

  3. Conditions for testing the corrosion rates of ceramics in coal gasification systems

    SciTech Connect

    Hurley, J.P.; Nowok, J.W.

    1996-08-01

    Coal gasifier operating conditions and gas and ash compositions affect the corrosion rates of ceramics used for construction in three ways: (1) through direct corrosion of the materials, (2) by affecting the concentration and chemical form of the primary corrodents, and (3) by affecting the mass transport rate of the primary corrodents. To perform an accurate corrosion test on a system material, the researcher must include all relevant corrodents and simulate conditions in the gasifier as closely as possible. In this paper, the authors present suggestions for conditions to be used in such corrosion tests. Two main types of corrosion conditions are discussed: those existing in hot-gas cleanup systems where vapor and dry ash may contribute to corrosion and those experienced by high-temperature heat exchangers and refractories where the main corrodent will be coal ash slag. Only the fluidized-bed gasification systems such as the Sierra Pacific Power Company Pinon Pine Power Project system are proposing the use of ceramic filters for particulate cleanup. The gasifier is an air-blown 102-MWe unit employing a Westinghouse{trademark} ceramic particle filter system operating at as high as 1100{degrees}F at 300 psia. Expected gas compositions in the filter will be approximately 25% CO, 15% H{sub 2}, 5% CO{sub 2}, 5% H{sub 2}O, and 50% N{sub 2}. Vapor-phase sodium chloride concentrations are expected to be 10 to 100 times the levels in combustion systems at similar temperatures, but in general the concentrations of the minor primary and secondary corrodents are not well understood. Slag corrosiveness will depend on its composition as well as viscosity. For a laboratory test, the slag must be in a thermodynamically stable form before the beginning of the corrosion test to assure that no inappropriate reactions are allowed to occur. Ideally, the slag would be flowing, and the appropriate atmosphere must be used to assure realistic slag viscosity.

  4. Study of Acidithiobacillus ferrooxidans and enzymatic bio-Fenton process-mediated corrosion of copper-nickel alloy.

    PubMed

    Jadhav, U; Hocheng, H

    2016-10-01

    This study presents the corrosion behavior of the copper-nickel (Cu-Ni) alloy in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans) and glucose oxidase (GOx) enzyme. In both the cases ferric ions played an important role in weight loss and thereby to carry out the corrosion of the Cu-Ni alloy. A corrosion rate of 0.6 (±0.008), 2.11 (±0.05), 3.69 (±0.26), 0.7 (±0.006) and 0.08 (±0.002) mm/year was obtained in 72 h using 9K medium with ferrous sulfate, A. ferrooxidans culture supernatant, A. ferrooxidans cells, GOx enzyme and hydrogen peroxide (H2O2) solution respectively. The scanning electron microscopy (SEM) micrographs showed that a variable extent of corrosion was caused by 9K medium with ferrous sulfate, GOx and A. ferrooxidans cells. An arithmetic average surface roughness (Ra) of 174.78 nm was observed for the control work-piece using optical profilometer. The change in Ra was observed with the treatment of the Cu-Ni alloy using various systems. The Ra for 9K medium with ferrous sulfate, GOx and A. ferrooxidans cells was 374.54, 607.32 and 799.48 nm, respectively, after 24 h. These results suggest that A. ferrooxidans cells were responsible for more corrosion of the Cu-Ni alloy than other systems used.

  5. Deposition measurement of particulate matter in connection with corrosion studies.

    PubMed

    Ferm, Martin; Watt, John; O'Hanlon, Samantha; De Santis, Franco; Varotsos, Costas

    2006-03-01

    A new passive particle collector (inert surrogate surface) that collects particles from all directions has been developed. It was used to measure particle deposition at 35 test sites as part of a project that examined corrosion of materials in order that variation in particulate material could be used in development of dose-response functions in a modern multi-pollutant environment. The project, MULTI-ASSESS, was funded by the EU to examine the effects of air pollution on cultural heritage. Passive samplers were mounted rain-protected, and both in wind-protected and wind-exposed positions, to match the exposure of the samples for corrosion studies. The particle mass and its chemical content (nitrate, ammonium, sulfate, calcium, sodium, chloride, magnesium and potassium) were analysed. The loss of light reflectance on the surrogate surface was also measured. Very little ammonium and potassium was found, and one or more anions are missing in the ion balance. There were many strong correlations between the analysed species. The mass of analysed water-soluble ions was fairly constant at 24% of the total mass. The particle mass deposited to the samplers in the wind-protected position was about 25% of the particles deposited to an openly exposed sampler. The Cl-/Na+ ratios indicate a reaction between HNO(3) and NaCl. The deposited nitrate flux corresponds to the missing chloride. The Ca2+ deposition equals the SO4(2-) deposition and the anion deficiency. The SO4(2-) deposition most likely originates from SO2 that has reacted with basic calcium-containing particles either before or after they were deposited. The particle depositions at the urban sites were much higher than in nearby rural sites. The deposited mass correlated surprisingly well with the PM(10) concentration, except at sites very close to traffic.

  6. Corrosion sensor

    DOEpatents

    Glass, Robert S.; Clarke, Jr., Willis L.; Ciarlo, Dino R.

    1994-01-01

    A corrosion sensor array incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis.

  7. Corrosion sensor

    DOEpatents

    Glass, R.S.; Clarke, W.L. Jr.; Ciarlo, D.R.

    1994-04-26

    A corrosion sensor array is described incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis. 7 figures.

  8. [Analysis of the characteristics of corrosion scale in drinking water distribution systems].

    PubMed

    Niu, Zhang-bin; Wang, Yang; Zhang, Xiao-jian; He, Wen-jie; Han, Hong-da; Yin, Pei-jun

    2006-06-01

    Scanning electron microscopy, X-ray fluorescence spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy were used to analyze the microstructure, chemical composition, crystalline structure and compound constitute of the corrosion scale from cast iron pipe and galvanized steel pipe in drinking water distribution systems. The outer of the corrosion scale was compact, while the inner was porous. Iron was the primary chemical element of the corrosion scale, and the composition of the scale was iron compounds. The outer scale were ferric compounds such as alpha-FeOOH, gamma-FeOOH, alpha-Fe2O3, gamma-Fe2O3, FeCl3, while the inner were ferrous compounds such as Fe3O4, FeCl2, FeCO3. The characteristics of the corrosion scale was lying on hydraulic conditions and water quality in distribution systems, and the characteristics of iron pipe materials.

  9. Study on corrosion behaviors of sintered Nd-Fe-B magnets in different environmental conditions

    SciTech Connect

    Li, J. J.; Li, A. H.; Zhu, M. G.; Pan, W.; Li, W.

    2011-04-01

    Nd-Fe-B magnets have outstanding magnetic properties, but their corrosion resistance is poor because the rare-earth-rich phases in them are easily oxidized. In this article, we report an investigation of the corrosion behaviors of sintered Nd-Fe-B magnets with varied compositions in different corrosion conditions. The weight losses of the magnets after corrosion testing were measured after brushing off the corrosion products. The magnetic flux losses of the magnets were measured using a fluxmeter. A scanning electron microscope equipped with an energy dispersive x-ray analysis system was employed to observe the corrosion morphology. It was found that the humid-heat resistance of the magnets was obviously improved by partially substituting Dy for Nd and adding minor Co. The corrosion products and morphologies of Nd-Fe-B magnets for the autoclave test were different from those for the constant humid-heat test. The corrosion rates of the magnets for the former were much slower than for the latter; this is probably because the high-pressure steam led to an oxygen-deficient atmosphere, and the liquid film on the surface of the magnet specimens hindered the diffusion of oxygen into the bulk for the autoclave test.

  10. Corrosiveness of ground water in the Kirkwood-Cohansey aquifer system of the New Jersey Coastal Plain

    USGS Publications Warehouse

    Barringer, J.L.; Kish, G.R.; Velnich, A.J.

    1993-01-01

    Ground water from the unconfined part of the Kirkwood-Cohansey aquifer system in the New Jersey Coastal Plain typically is corrosive-- that is, it is acidic, soft, and has low concentrations of alkalinity. Corrosive ground water has the potential to leach trace elements and asbestos fibers from plumbing materials used in potable- water systems, thereby causing potentially harmful concentrations of these substances in drinking water. Corrosion indices were calculated from water-quality data for 370 wells in the unconfined Kirkwood-Cohansey aquifer system. Values of the Langelier Saturation Index are predominantly negative, indicating that the water is undersaturated with respect to calcium carbonate, and, therefore, is potentially corrosive. Values of the Aggressive Index, a similar estimator of the corrosiveness of water, range from 3.9 (highly corrosive) to 11.9 (moderately corrosive). The median Aggressive Index value calculated for the 370 wells is 6.0, a value that indicates that the water is highly corrosive. Moderately corrosive ground water is found in some coastal areas. Isolated instances of moderately corrosive water are found in northern Ocean County, and in Burlington, Camden, and Salem Counties. In the vicinity of Ocean County corrosion-index values change little with depth, but in Atlantic, Burlington, and Salem Counties the corrosiveness of ground water generally appears to decrease with depth. Analyses of standing tap water from newly constructed homes in the Coastal Plain show concentrations of lead and other trace elements are significantly higher than those in ambient ground water. The elevated trace-element concentrations are attributed to the corrosion of plumbing materials by ground water. Results of the tap-water analyses substantiate the corrosiveness of Kirkwood-Cohansey ground water, as estimated by corrosion-index values.

  11. Theoretical study of inhibition efficiencies of some amino acids on corrosion of carbon steel in acidic media: green corrosion inhibitors.

    PubMed

    Dehdab, Maryam; Shahraki, Mehdi; Habibi-Khorassani, Sayyed Mostafa

    2016-01-01

    Inhibition efficiencies of three amino acids [tryptophan (B), tyrosine (c), and serine (A)] have been studied as green corrosion inhibitors on corrosion of carbon steel using density functional theory (DFT) method in gas and aqueous phases. Quantum chemical parameters such as EH OMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), hardness (η), polarizability ([Formula: see text]), total negative charges on atoms (TNC), molecular volume (MV) and total energy (TE) have been calculated at the B3LYP level of theory with 6-311++G** basis set. Consistent with experimental data, theoretical results showed that the order of inhibition efficiency is tryptophan (B) > tyrosine (C) > serine (A). In order to determine the possible sites of nucleophilic and electrophilic attacks, local reactivity has been evaluated through Fukui indices.

  12. Erosion-corrosion in carbon dioxide saturated systems in presence of sand, inhibitor, oil, and high concentration of salt

    NASA Astrophysics Data System (ADS)

    Hassani, Shokrollah

    Oil and gas production is usually accompanied by formation water which typically contains high levels of chloride. Some effects of chloride concentration on corrosion are not widely known in the literature, and this can result in misleading conclusions. One goal of this research was to contribute to a better understanding of the effects of chloride concentration in CO2 corrosion. Experimental and theoretical studies conducted in the present work have shown that increasing the NaCl concentration in solution has three important effects on corrosion results. First, standard pH meter readings in high NaCl concentration solutions require corrections. Second, increasing the NaCl concentration decreases the CO2 concentration in solution and therefore contributes to a decrease in the corrosion rate. Third, increasing the NaCl concentration increases the solubility of FeCO3 and therefore reduces the likelihood of forming an iron carbonate scale. High NaCl concentration also decreases the sand erosion rate of the metal slightly by increasing the density and viscosity of the liquid. There are two main contributions of this research. The first contribution is the experimental characterization of inhibited erosion-corrosion behavior of mild steel under CO2-saturated conditions with a high salt concentration. Chemical inhibition is one the most important techniques for controlling erosion-corrosion in offshore mild steel pipelines, tubing and pipe fittings in oil and gas industry. The second contribution is the introduction of a new approach for predicting inhibited erosion-corrosion in mild steel pipes including the effects of flow and environmental conditions, sand production, and an oil phase. Sand erosion can decrease the efficiency of corrosion protection systems including iron-carbonate scale formation and chemical inhibition. The need to be able to predict inhibitor performance under sand production conditions is particularly acute when the wells are deep or off

  13. Indicators for microbiologically induced corrosion of copper pipes in a cold-water plumbing system.

    PubMed

    Arens, P; Tuschewitzki, G J; Wollmann, M; Follner, H; Jacobi, H

    1995-01-01

    Corrosion damage in the copper cold-water plumbing system of a large building was investigated. An unusual combination of corrosion patterns was found on the inner copper pipe surfaces that were in contact with water. Damage was in the form of shallow cavities, a surface cover or pinprick-like pits. The corrosion system was influenced by thermal treatment and also by cefoxitin dosing. The latter fact in particular is a clear indication of microbiological involvement in this corrosive action. Different parameters, to be measured in standing water (24-h stagnation), are considered typical for this type of corrosion: the detection of Sphingomonas spec. and other species in whose cell wall regions copper can accumulate, a copper content of more than 2 mg/l, oxygen consumption of more than 4 mg/l and an increase in pH. With the help of these indicators, it is possible to recognize microbiologically induced corrosion in copper plumbing systems before pipe perforation occur. PMID:7727024

  14. SRNL SHELF LIFE STUDIES - SCC STUDIES AT ROOM TEMPERTURE [stress corrosion cracking

    SciTech Connect

    Mickalonis, J.; Duffey, J.

    2014-11-12

    Phase II, Series 2 corrosion testing performed by the Savannah River National Laboratory (SRNL) for the Department of Energy 3013 container has been completed. The corrosion tests are part of an integrated plan conducted jointly by Los Alamos National Laboratory and the Savannah River Site. SRNL was responsible for conducting corrosion studies in small-scale vessels to address the influence of salt composition, water loading, and type of oxide/salt contact on the relative humidity inside a 3013 container and on the resulting corrosion of Type 304L and 316L stainless steel (304L and 316L). This testing was conducted in two phases: Phase I evaluated a broad spectrum of salt compositions and initial water loadings on the salt mixtures exposed to 304L and 316L and the resulting corrosion; Phase II evaluated the corrosion of 304L at specific water loadings and a single salt composition. During Phase I testing at high initial moisture levels (0.35 to 1.24 wt%)a, the roomtemperature corrosion of 304L exposed to a series of plutonium oxide/chloride salt mixtures ranged from superficial staining to pitting and stress corrosion cracking (SCC). 304L teardrop coupons that exhibited SCC were directly exposed to a mixture composed of 98 wt % PuO2, 0.9 wt % NaCl, 0.9 wt % KCl, and 0.2 wt % CaCl2. Cracking was not observed in a 316L teardrop coupon. Pitting was also observed in this environment for both 304L and 316L with depths ranging from 20 to 100 μm. Neither pitting nor SCC was observed in mixtures with a greater chloride salt concentration (5 and 28 wt%). These results demonstrated that for a corrosive solution to form a balance existed between the water loading and the salt chloride concentration. This chloride solution results from the interaction of loaded water with the hydrating CaCl2 salt. In Phase II, Series 1 tests, the SCC results were shown to be reproducible with cracking occurring in as little as 85 days. The approximate 0.5 wt% moisture level was found to

  15. Corrosion of NiCoCrAlY Coatings and TBC Systems Subjected to Water Vapor and Sodium Sulfate

    NASA Astrophysics Data System (ADS)

    Eriksson, Robert; Yuan, Kang; Li, Xin-Hai; Lin Peng, Ru

    2015-08-01

    Thermal barrier coating (TBC) systems are commonly used in gas turbines for protection against high-temperature degradation. Penetration of the ceramic top coat by corrosive species may cause corrosion damage on the underlying NiCoCrAlY bond coat and cause failure of the TBC system. In the current study, four oxidation/corrosion conditions were tried: (i) lab air, (ii) water vapor, (iii) sodium sulfate deposited on the specimens, and (iv) water vapor + sodium sulfate. The test was done at 750 °C in a cyclic test rig with 48 h cycles. The corrosion damage was studied on NiCoCrAlY-coated specimens, thin APS TBC specimens, and thick APS TBC specimens. Water vapor was found to have very minor influence on the oxidation, while sodium sulfate increased the TGO thickness both for NiCoCrAlY specimens and TBC-coated specimens; the influence of the TBC thickness was found to be very small. Sodium sulfate promoted thicker TGO; more Cr-rich TGO; the formation of Y oxides, and internally, Y sulfides; pore formation in the coating as well as in the substrate; and the formation of a Cr-depleted zone in the substrate.

  16. Study for determination of industrial water corrosivity in Kashan Fajre Sepahan Galvanizing Mills during 2005-2006 Iran.

    PubMed

    Rabbani, D; Miranzadeh, M B; Motlagh, A Ahmadi

    2008-01-01

    This research was carried out in Kashan Fajre Sepahan Galvanizing mills (KFSGM) for evaluation of water corrosivity during 2005-2006. A total of 18 samples were taken from various points of the water supply system for testing the specific parameters and calculation Langelier Index (LI), Ryznar Index (RI) and Pukorious Index (PI). This research showed that in raw water (sand filter effluent) LI were positive as well as RI and PI were lower than 7 which means that mentioned water is not corrosive. Also LI in treated water by reverse osmosis process was negative and RI and PI were higher than 7, so, this water has corrosive properties. Finally, calculated indexes indicate that according to LI, conditioned water is not corrosive but based on RI and P. this water tend to corrosivity which this findings is compatible with literature review statement. So it is recommended that, for water conditioning addition of preservative chemicals to be continued but at the same time another alternatives such as pH adjustment, air stripping and deoxygenating, control of carbonate concentration and split flow treatment should be studied.

  17. Studies of localized corrosion in welded aluminum alloys by the scanning reference electrode technique

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Nunes, A. C.

    1995-01-01

    Localized corrosion in welded samples of 2219-T87 Al alloy (2319 filler), 2090 Al-Li alloy (4043 and 2319 fillers), and 2195 Al-Li alloy (4043 and 2319 fillers) has been investigated using the relatively new scanning reference electrode technique. The weld beads are cathodic in all cases, leading to reduced anode/cathode ratios. A reduction in anode/cathode ratio leads to an increase in the corrosion rates of the welded metals, in agreement with results obtained in previous electrochemical and stress corrosion studies involving the overall corrosion rates of welded samples. The cathodic weld beads are bordered on both sides by strong anodic regions, with high propensity for corrosion.

  18. Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

    PubMed

    Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

    2012-02-01

    Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality.

  19. Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

    PubMed

    Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

    2012-02-01

    Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality. PMID:22380105

  20. An experimental feasibility study of pipeline corrosion pit detection using a piezoceramic time reversal mirror

    NASA Astrophysics Data System (ADS)

    Du, Guofeng; Kong, Qingzhao; Wu, Fanghong; Ruan, Jiabiao; Song, Gangbing

    2016-03-01

    Corrosion pits on pipelines lead to the formation of small holes, which cause further pipeline damage and even catastrophic consequences. Since many pipelines are located underground, the detection of corrosion pits on pipelines in real time is still an engineering challenge. In this paper, an experimental feasibility study on pipeline corrosion pit detection using the time reversal technique with a piezoceramic transducer as a time reversal mirror was investigated. A specimen of steel pipeline section was fabricated with an artificially drilled hole, which was to mimic a corrosion pit. By gradually increasing the depth of the hole, the evolution of the corrosion pit on the pipeline was simulated and studied. Two piezoceramic transducers were employed to generate a stress wave to propagate along the pipeline and to detect the propagated stress wave. With both the properties of sensing and actuating functions, a piezoceramic transducer was used as a time reversal mirror, which first detected the propagated stress wave signal and then sent ‘back’ the time-reversed signal as a propagating stress wave. With the inherent auto-focusing property of the time reversal technique, the detected time-reversed stress wave had a distinct focused peak. A corrosion pit on a pipeline, as a structural defect, reduces the energy of the focused signal received by the piezoceramic sensor and the attenuation ratio of the focused signal depends strongly on the degree of corrosion depth. Experimental results show that the amplitudes of the focused signal peak decrease with the increase of corrosion pit depth and we can use the peak amplitude of the focused signal to determine the state of pipeline corrosion. The time reversal based method proposed in this paper shows the potential to quantitatively monitor the damage degree of corrosion pits on pipelines in real time.

  1. Polyurethane/polysiloxane ceramer coatings: Corrosion resistant unicoat system for aircraft application

    NASA Astrophysics Data System (ADS)

    Ni, Hai

    New organic/inorganic ceramer coating system was developed using polyurethane as an organic phase and polysiloxane as the inorganic phase. The objective of the study was to develop a unicoat corrosion resistant coating which strongly adheres to aluminum substrates. The pre-ceramic silicon-oxo clusters react with the metal substrate, protecting it from oxidation, whereas the organic composition functions as a binder providing mechanical properties, optical properties, and chemical, wear and fluid resistance. The new ceramer coatings were evaluated as a replacement for chromate based coatings. The alkoxysilane-functionalized coupling agent was prepared from hexamethylene diisocyanate (HDI) isocyanurate and 3-aminopropyltriethoxysilane. The functionalized isocyanurate was characterized by 1H, 13C and 29Si NMR and electrospray ionization-mass spectrometry. An organic/inorganic hybrid coating system was formulated using the alkoxysilane-functionalized isocyanurate and HDI isocyanurate. The coating properties indicated that alkoxysilane-functionalized isocyanurate enhanced adhesion up to 500%. Based on the hybrid polyurea/alkoxysilane system, the polyurea/polysiloxane ceramer coating system was formulated with tetraethyl orthosilicate (TEOS) oligomers. Evaluation of ceramer coatings showed that coating properties were affected by both the concentration of TEOS oligomers and alkoxysilane functionalized isocyanurate. In addition, the para-toluene sulfonic acid was used to catalyze the moisture curing process for the ceramer coating system. The addition of acid catalyst further increased the adhesion. A series of high solids cycloaliphatic polyesters were synthesized to improve the UV-resistance for the organic/inorganic unicoat system. The polyurethane/polysiloxane ceramer coatings were formulated with the addition of the cycloaliphatic polyesters into the polyurea/polysiloxane system. The investigation of the polyurethane ceramer coatings indicated that the film

  2. Corrosion Engineering.

    ERIC Educational Resources Information Center

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  3. Corrosion of copper, nickel, and gold dental casting alloys: an in vitro and in vivo study.

    PubMed

    Johansson, B I; Lucas, L C; Lemons, J E

    1989-12-01

    The corrosion behavior of commercially available copper, nickel, and gold alloys for dental castings was investigated. The alloys investigated included: three copper alloys (76-87Cu, 6-11A1, 0-12Zn, 1-5Ni, 0-4Fe, 0.5-1.2Mn), two nickel alloys (68-78Ni, 12-16Cr, 4-14Mo, 0-1.7Be), and one gold alloy (77Au, 14Ag, 8Cu, 1Pd). Anodic and cathodic polarization curves, long-term immersion tests in saline and artificial saliva solutions, and dog crown studies were conducted to evaluate both the in vitro and in vivo corrosion characteristics of the alloys. All evaluations conducted demonstrated that the copper alloys were highly susceptible to corrosion attack. High corrosion currents were observed in the in vitro tests, and SEM of the alloys specimens showed significantly altered surfaces. The anodic polarization curves predicted that the beryllium-containing nickel alloy should be susceptible to localized corrosion and SEM revealed an etched surface with corrosion of certain microstructural features. No significant corrosion was predicted or observed for the non-beryllium nickel alloy and the gold alloy. The in vitro corrosion evaluations predicted the in vivo corrosion behavior for the alloys. Since the three copper alloys and the beryllium-containing nickel alloy demonstrated significant corrosion under the tested conditions, the use of these alloys for restorative procedures is questionable due to the release of significant levels of selected ions to the oral cavity.

  4. WASTE PACKAGE CORROSION STUDIES USING SMALL MOCKUP EXPERIMENTS

    SciTech Connect

    B.E. Anderson; K.B. Helean; C.R. Bryan; P.V. Brady; R.C. Ewing

    2005-10-19

    The corrosion of spent nuclear fuel and subsequent mobilization of radionuclides is of great concern in a geologic repository, particularly if conditions are oxidizing. Corroding A516 steel may offset these transport processes within the proposed waste packages at the Yucca Mountain Repository (YMR) by retaining radionuclides, creating locally reducing conditions, and reducing porosity. Ferrous iron, Fe{sup 2+}, has been shown to reduce UO{sub 2}{sup 2+} to UO{sub 2(s)} [1], and some ferrous iron-bearing ion-exchange materials adsorb radionuclides and heavy metals [2]. Of particular interest is magnetite, a potential corrosion product that has been shown to remove TcO{sub 4}{sup -} from solution [3]. Furthermore, if Fe{sup 2+} minerals, rather than fully oxidized minerals such as goethite, are produced during corrosion, then locally reducing conditions may be present. High electron availability leads to the reduction and subsequent immobilization of problematic dissolved species such as TcO{sub 4}{sup -}, NpO{sub 2}{sup +}, and UO{sub 2}{sup 2+} and can also inhibit corrosion of spent nuclear fuel. Finally, because the molar volume of iron material increases during corrosion due to oxygen and water incorporation, pore space may be significantly reduced over long time periods. The more water is occluded, the bulkier the corrosion products, and the less porosity is available for water and radionuclide transport. The focus of this paper is on the nature of Yucca Mountain waste package steel corrosion products and their effects on local redox state, radionuclide transport, and porosity.

  5. Corrosion of iron: A study for radioactive waste canisters

    NASA Astrophysics Data System (ADS)

    Lagha, S. Ben; Crusset, D.; Mabille, I.; Tran, M.; Bernard, M. C.; Sutter, E.

    2007-05-01

    The purpose of this study is to examine the risks of atmospheric corrosion of steel waste canisters following their deep geological disposal in the temperature range from 303 to 363 K. The work was performed using iron samples deposited as thin films on a quartz crystal microbalance (QCM) and disposed in a climatic chamber. The experiments showed that, in the temperature under study (298-363 K), the mass increase due to the formation of oxide/hydroxide rose sharply above 70% RH, as is commonly observed at room temperatures, indicating that the phenomenon remains electrochemical in nature. Ex situ Raman spectrometric analyses indicate the formation of magnetite, maghemite and oxyhydroxides species in the 298-363 K temperature range, and for oxygen contents above 1 vol.%, whereas only Fe3O4 and γ-Fe2O3 are detected at 363 K. In this work, the kinetics of the rust growth is discussed, on the bases of the rate of mass increase and of the composition of the rust, as a function of the climatic parameters and the oxygen content of the atmosphere.

  6. Assessment of corrosion in a sulfur dioxide vapor emission reduction system for a pulp mill

    SciTech Connect

    Dreisig, R.C.; Beavers, J.A.; Caudill, D.L.

    1996-08-01

    This paper reviews efforts to mitigate corrosion with pulp mill vent odorous gases as they are conveyed to a boiler for thermal oxidation. These moisture laden gases emanate from a sulfite batch operated pulp mill and are sent to a neighboring spent sulfite fueled boiler to comply with the 1990 Clean Air Act. It was recognized early during project definition that sulfuric acid dew point corrosion was a major concern with carbon steel (CS) tubular air heaters. Corrosion studies were conducted in the field prior to and after project startup to determine if heat exchange surfaces were at risk of wastage. Various types of measurements were used such as polarization resistance, weight loss coupons, solution resistance, and electrical resistance to monitor corrosion of CS and 316L stainless steel (SS).

  7. A facility for studying irradiation accelerated corrosion in high temperature water

    NASA Astrophysics Data System (ADS)

    Raiman, Stephen S.; Flick, Alexander; Toader, Ovidiu; Wang, Peng; Samad, Nassim A.; Jiao, Zhijie; Was, Gary S.

    2014-08-01

    A facility for the study of irradiation accelerated corrosion in high temperature water using in situ proton irradiation has been developed and validated. A specially designed beamline and flowing-water corrosion cell added to the 1.7 MV tandem accelerator at the Michigan Ion Beam Laboratory provide the capability to study the simultaneous effects of displacement damage and radiolysis on corrosion. A thin sample serves as both a “window” into the corrosion cell through which the proton beam passes completely, and the sample for assessing irradiation accelerated corrosion. The facility was tested by irradiating stainless steel samples at beam current densities between 0.5 and 10 μA/cm2 in 130 °C and 320 °C deaerated water, and 320 °C water with 3 wppm H2. Increases in the conductivity and dissolved oxygen content of the water varied with the proton beam current, suggesting that proton irradiation was accelerating the corrosion of the sample. Conductivity increases were greatest at 320 °C, while DO increases were highest at 130 °C. The addition of 3 wppm H2 suppressed DO below detectable levels. The facility will enable future studies into the effect of irradiation on corrosion in high temperature water with in situ proton irradiation.

  8. Experimental procedure for crevice corrosion studies of Ni-Cr-Mo alloys in natural seawater

    NASA Astrophysics Data System (ADS)

    Martin, F. J.; Lucas, K. E.; Hogan, E. A.

    2002-03-01

    An experimental procedure intended for crevice corrosion studies on Ni-Cr-Mo alloys is demonstrated. In this procedure a potentiostatic control of crevice corrosion specimens is applied to an immersible crevice cell design that uses a fluoroelastomer gasket crevice former. The procedure is demonstrated for a crevice susceptibility study on Alloy 625 in elevated temperature natural seawater, where crevice corrosion initiation and propagation are shown to be influenced by the electrochemical potential. Potentiostatic current monitoring establishes the crevice initiation time and rate of propagation, while post-mortem inspections confirm the extent of crevice damage.

  9. Laboratory Evaluation of an Electrochemical Noise System for Detection of Localized and General Corrosion of Natural Gas Transmission Pipelines

    SciTech Connect

    Bullard, S.J.; Covino, B.S., Jr.; Russell, J.H.; Holcomb, G.R.; Cramer, S.D.; Ziomek-Moroz, M.; Eden, D.

    2003-03-16

    Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas pipelines in equilibrium with th e corrosive components of natural gas; (2) biologically-active soils typical of wetlands; and (3) a simulated, unpressurized, internal gas/liquid gas pipeline environment. Multiple sensor designs were evaluated in the simulated pipe environment. Gravimetric measurements were conducted in parallel with the electrochemical noise measurements to validate the results.

  10. Stress corrosion cracking of carbon steel in amine systems

    SciTech Connect

    Richert, J.P.; Bagdasarian, A.J.; Shargay, C.A.

    1988-01-01

    NACE Task Group T-8-14 was formed by Group Committee T-8 on Refining Industry Corrosion to conduct a survey on stress corrosion cracking (SCC) of existing amine units. The main purpose of the survey was to determine the extent of cracking problems in such units and to examine possible correlations between cracked and noncracked locations to establish possible cause(s) for cracking. A total of 294 completed survey forms were received and analyzed. Cracking was reported in monoethanolamine (MEA), diethanolamine, methyldiethanolamine, and diisopropanolamine solutions but was most prevalent in MEA units. Cracking occurs in all types of equipment and piping operating at all common temperatures. Cracking has been reported in all typical refinery streams containing H/sub 2/S, CO/sub 2/, or a combination of the two. The use of corrosion inhibitors, soda ash, caustic, filters, or reclaimers has no indicated effect on cracking tendencies. The survey results confirmed that stress relieving is a highly effective means of preventing amine SCC.

  11. Corrosivity monitoring system using RFID-based sensors

    NASA Astrophysics Data System (ADS)

    Lawand, Lydia; Shiryayev, Oleg; Alhandawi, Khalil B.; Vahdati, Nader; Rostron, Paul

    2016-04-01

    In the oil and gas industry, pipeline integrity is a serious concern due to the consequences of pipeline failure. External corrosion was identified as one of the main causes of pipeline failures worldwide. A solution that addresses the issue of detecting and quantifying corrosivity of environment for application to existing exposed pipelines has been developed. The proposed sensor consists of an electric circuit and a sensing array connected to the circuit. The sensing array is an assembly of strips made of a metal identical to that of the pipe, having the same length and width, but different thicknesses. The sensing array is exposed to the same environment as the pipe. As corrosion propagates in the metal strips of the array, it corrodes the metal until it finally breaks the metal strip apart resulting in a discontinuity in the circuit. The sensor circuit is energized using electromagnetic field, and its function is to indicate which strips in the array are fully corroded. Visual indication is provided to the operator via LEDs. The proposed sensor can be installed on existing pipelines without altering the pipe structure or disturbing the production process. It is passive and has low maintenance requirements. Circuit design was validated through lab experiments. Results obtained from experiments were consistent with simulation results.

  12. Corrosion studies by use of the thermogravimetric analyzer

    SciTech Connect

    Brinker, G.M.

    1995-11-01

    A series of tests have been performed by use of the thermogravimetric analyzer. Weight gain vs. time graphs have been generated by exposing one inch by two inch by sixty five hundredths of an inch low carbon (1020) steel specimens to a range of relative humidities (65%-90%) and temperatures (50-70{degrees}C). Data collected from these studies will give insight to both the kinetics of oxide formation and the material`s critical relative humidity. It has been observed that two separate rates and mechanisms for oxide formation exist. It is believed that dry oxidation is prevalent at low relative humidities, while aqueos electrochemical corrosion persists at high relative humidities. The relative humidity(s) and temperatures that oxidation formation transforms from one rate and mechanism to the other is of interest. The critical relative humidity is defined as the relative humidity at which oxide formation will become highly accelerated with respect to its normal growth rate. Hence, a better understanding of 1020 steel`s oxide formation kinetics and the alloy`s critical relative humidity will aid in waste package designs for use in conjunction with the proposed nuclear waste containment center at Yucca Mountain.

  13. An Innovative Ceramic Corrosion Protection System for Zircaloy Cladding

    SciTech Connect

    Ronald H. Baney, Dr. D. Butt, Dr. P. Demkowicz, Dr. G. Fuchs Department of Materials Science; James S. Tulenko, Department of Nuclear and Radiological Engineering; University of Florida.

    2003-02-19

    Light Water reactor (LWR) fuel performance is currently limited by thermal, chemical and mechanical constraints associated with the design, fabrication, and operation of the fuel in incore operation. Corrosion of the zirconium based (Zircaloy-4) alloy cladding of the fuel is a primary limiting factor. Recent success at the University of Florida in developing thin ceramic films with great adhesive properties for metal substrates offers an innovative breakthrough for eliminating a major weakness of the Zircaloy clad. ?The University of Florida proposes to coat the existing Zircaloy clad tubes with a ceramic coating for corrosion protection. An added bonus of this approach would be the implementation of a boron-containing burnable poison outer layer will also be demonstrated as part of the ceramic coating development. In this proposed effort, emphasis will be on the ceramic coating with only demonstration of feasibility on the burnable outer coating approach. This proposed program i s expected to give a step change (approximately a doubling) in clad lifetime before failure due to corrosion. In the development of ceramic coatings for Zircaloy-4 clad, silicon carbide and zirconium carbide coatings will first be applied to Zircaloy-4 coupons and cladding samples by thermal assisted chemical vapor deposition, plasma assisted chemical vapor deposition or by laser ablation deposition. All of these processes are in use at the University of Florida and have shown great potential. The questions of adhesion and thermal expansion mismatch of the ceramic coating to the Zircaloy substrate will be addressed. Several solutions to these conditions will be examined, if needed. These solutions include the use of a zirconium oxide compliant layer, employment of a laser roughened surface and the use of a gradient composition interlayer. These solutions have already been shown to be effective for other high modulus coatings on metal substrates. Mechanical properties and adhesion of the

  14. Galvanic corrosion study of container materials using zero resistance ammeter

    SciTech Connect

    Roy, A. K., LLNL

    1997-11-01

    Galvanic corrosion behavior of A 516 steel separately coupled to six different corrosion-resistant alloys was investigated in an acidic brine (pHa2.70) at 30{degree}C 60{degree}C and 80{degree}C using zero resistance ammeter technique. The corrosion-resistant alloys include Alloys 825, G-3, G-30, C-4 and C-22; and Ti Grade-12, which were coupled to A 516 steel at an anode-to- cathode area ratio of one. The galvanic current and galvanic potential were measured as a function of time at all three temperatures. Optical microscopic examination was also performed on all tested specimens to evaluate the extent of surface degradation due to galvanic coupling. The overall results are presented in this paper.

  15. A Theoretical Study of Carbohydrates as Corrosion Inhibitors of Iron

    NASA Astrophysics Data System (ADS)

    Khalil, Salim M.; Ali-Shattle, Elbashir E.; Ali, Nozha M.

    2013-09-01

    The inhibitive effect of fructose, glucose, lactose, maltose, and sucrose against the iron corrosion is investigated using density functional theory at the B3LYP/6-31 G level (d) to search the relation between the molecular structure and corrosion inhibition. The electronic properties such as the energy of the highest occupied molecular orbital (HOMO), the energy of lowest unoccupied orbital (LUMO), the energy gap (LUMO-HOMO), quantum chemical parameters such as hardness, softness, the fraction of the electron transferred, and the electrophilicity index are reported. The inhibition efficiency of the investigated carbohydrates follows the trend: maltose

  16. X-rays absorption study on medieval corrosion layers for the understanding of very long-term indoor atmospheric iron corrosion

    NASA Astrophysics Data System (ADS)

    Monnier, J.; Réguer, S.; Vantelon, D.; Dillmann, P.; Neff, D.; Guillot, I.

    2010-05-01

    The study and prediction of very long-term atmospheric corrosion behaviour of ferrous alloys is of great importance in different fields. First the conservation of metallic artefacts in museum and the corrosion diagnosis on ferrous reinforcement used in ancient monuments since medieval times needs reliable data to understand the mechanisms. Second, in the frame of the interim storage of nuclear waste in France, it is necessary to model the long-term corrosion of low alloy steel overcontainer. The nature of phases and elements constituting the corrosion layers can greatly influence the corrosion mechanisms. On the one hand, it is crucial to precisely determine the nature of microscopic phases that can be highly reactive. On the other hand, some elements as P and S could modify this reactivity. To clarify this point and complementary to other studies using Raman micro spectroscopy technique, X-rays Absorption Spectroscopy (XAS) under synchrotron radiation plays a crucial role. It allows one to precisely identify the reactive phases in the corrosion layers. Micro-XAS was required in order to refine the spatial variation, at micrometer scale, of the predominant Fe oxidation state and to characterise the corresponding corrosion products. Moreover, the role of minor elements on phase’s stability and the chemical form of these elements in the rust layer, especially phosphorus and sulphur, was investigated.

  17. Electrochemical, Polarization, and Crevice Corrosion Testing of Nitinol 60, A Supplement to the ECLSS Sustaining Materials Compatibility Study

    NASA Technical Reports Server (NTRS)

    Lee, R. E.

    2016-01-01

    In earlier trials, electrochemical test results were presented for six noble metals evaluated in test solutions representative of waste liquids processed in the Environmental Control and Life Support System (ECLSS) aboard the International Space Station (ISS). Subsequently, a seventh metal, Nitinol 60, was added for evaluation and subjected to the same test routines, data analysis, and theoretical methodologies. The previous six test metals included three titanium grades, (commercially pure, 6Al-4V alloy and 6Al-4V low interstitial alloy), two nickel-chromium alloys (Inconel(RegisteredTrademark) 625 and Hastelloy(RegisteredTrademark) C276), and one high-tier stainless steel (Cronidur(RegisteredTrademark) 30). The three titanium alloys gave the best results of all the metals, indicating superior corrosive nobility and galvanic protection properties. For this current effort, the results have clearly shown that Nitinol 60 is almost as noble as titanium, being very corrosion-resistant and galvanically compatible with the other six metals electrochemically and during long-term exposure. is also quite noble as it is very corrosion resistant and galvanically compatible with the other six metals from both an electrochemical perspective and long-term crevice corrosion scenario. This was clearly demonstrated utilizing the same techniques for linear, Tafel and cyclic polarization, and galvanic coupling of the metal candidate as was done for the previous study. The high nobility and low corrosion susceptibility for Nitinol 60 appear to be intermediate to the nickel/chromium alloys and the titanium metals with indications that are more reflective of the titanium metals in terms of general corrosion and pitting behavior.

  18. Surface chemistry and corrosion behavior of aluminum-copper systems: Air-formed films to complex conversion coatings

    NASA Astrophysics Data System (ADS)

    Chidambaram, Devicharan

    Understanding the mechanism of corrosion inhibition by carcinogenic chromates is critical to the development of environmentally safe coatings containing benign chromate substitutes. An integrated approach to correlate the surface chemistry and corrosion behavior of a wide range of systems has been undertaken. Electrochemical behavior was studied by open circuit potential (OCP) measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Surface chemistry was studied using variable-angle X-ray photoelectron spectroscopy (VAXPS), X-ray absorption near edge spectroscopy (XANES), secondary ion mass spectroscopy (SIMS), infrared spectroscopy and synchrotron infrared micro spectroscopy (SIRMS) and Raman spectroscopy. Using SIRMS, the ASTM recommended acetone degreasing was shown to initiate pitting of AA2024-T3 via photochemical formation of acetic acid. Due to the known tendency for photoreduction of Cr6+(3d0) following soft X-ray dosage during XPS, a novel method has been developed to prevent this reduction. This method yields, for the first time, an accurate determination of the Cr6+ content of a CCC. The pretreatment of the alloy prior to conversion coating has been shown to have significant influence on the surface intermetallic distribution, composition and corrosion resistance of the initial oxide film and subsequent conversion coating. AlconoxRTM pretreatment was found to result in a highly protective surface film that inhibits the subsequent formation of CCC. The study also shows that coupling of the alloy to platinum during the bromate pretreatment increases the corrosion resistance of the subsequently formed CCC by over an order of magnitude due to reduction in surface copper content. Adsorption of chromate ion on the passive oxide film formed on the metal surface was observed to induce fixed negative charges that inhibit chloride ingress on planar surfaces. While deprotonation of the aluminum hydroxide film by chromate was

  19. THE RELATIONSHIP BETWEEN THE CORROSION OF DISTRIBUTION SYSTEM MATERIALS, AND OXIDANT AND REDOX POTENTIAL

    EPA Science Inventory

    Scale build-up, corrosion rate, and metal release associated with drinking water distribution system pipes have been suggested to relate to the oxidant type and concentration. Conversely, different distribution system metals may exert different oxidant demands. The impact of ox...

  20. Aqueous corrosion in coal gasification quench systems. Final report January 74-June 82

    SciTech Connect

    Bhattacharyya, S.; Torok, J.

    1983-01-03

    The primary purpose of this program was to characterize the corrosion behavior of candidate quench system alloys in laboratory autoclave tests under environmental conditions approximating those expected in gasifier quench systems. A secondary objective was to quantify the effects of the many variables on different modes of corrosion in these tests. Thirdly, it was hoped to establish a correlation between these tests and data obtained from pilot plant tests to form a sound basis for selection of alloys for a wide spectrum of quench conditions.

  1. COPPER PITTING CORROSION AND PINHOLE LEAKS: A CASE STUDY

    EPA Science Inventory

    Localized corrosion, or "pitting", of copper drinking water pipe continues is a problem for many water utilities and their customers. Extreme attack leads to pinhole leaks that can potentially lead to water damage, mold growth, and costly repairs for the homeowners, as well as th...

  2. IN-HOUSE COPPER AND LEAD SOLUBILITY/CORROSION STUDIES

    EPA Science Inventory

    Understanding and predicting metal release from pipes of all sizes and types from the treatment plant to the consumer’s tap is critical, specifically for regulatory compliance with the Lead and Copper Rule, as well as the performance, corrosion morphology, and longevity of infras...

  3. Case studies of corrosion of mixed waste and transuranic waste drums

    SciTech Connect

    Kosiewicz, S.T.

    1993-12-01

    This paper presents three case studies of corrosion of waste drums at the Los Alamos National Laboratory (LANL). Corrosion was not anticipated by the waste generators, but occurred because of subtle chemical or physical mechanisms. In one case, drums of a cemented transuranic (TRU) sludge experienced general and pitting corrosion. In the second instance, a chemical from a commercial paint stripper migrated from its primary containment drums to chemically attack overpack drums made of mild carbon steel. In the third case, drums of mixed low level waste (MLLW) soil corroded drum packaging even though the waste appeared to be dry when it was placed in the drums. These case studies are jointly discussed as ``lessons learned`` to enhance awareness of subtle mechanisms that can contribute to the corrosion of radioactive waste drums during interim storage.

  4. Influence of NOM on copper corrosion

    SciTech Connect

    Korshin, G.V.; Ferguson, J.F.; Perry, S.A.L.

    1996-07-01

    Natural organic matter (NOM) profoundly affected the corrosion of copper in a moderately alkaline synthetic water. It decreased the rate of corrosion, increased the rate of copper leaching, and dispersed crystalline inorganic corrosion products. The interaction of NOM with corrosion products was modeled using separate phase of malachite and cuprous oxide. The authors concluded that NOM promotes the formation of pits in a certain narrow range of concentrations (0.1--0.2 mg/L in laboratory tests) and suppresses this type of corrosion at higher dosages. At low DOC concentrations, the main interaction between NOM and the surfaces of corroding metal and corrosion products is adsorption. The influence of NOM on corrosion of metals in real distribution systems must be studied in relation to long periods of surface aging, flow rate, concentration and type of oxidants, pH, and alkalinity.

  5. Investigation of some green compounds as corrosion and scale inhibitors for cooling systems

    SciTech Connect

    Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. )

    1999-05-01

    The performance of an open-recirculating cooling system, an important component in most industries, is affected by corrosion and scale formation. Numerous additives have been used in the past for the control of corrosion and scale formation. Effects of the naturally occurring compounds azadirachta indica (leaves), punica granatum (shell), and momordica charantia (fruits), on corrosion of mild steel in 3% sodium chloride (NaCl) were assessed using weight loss, electrochemical polarization, and impedance techniques. Extracts of the compounds exhibited excellent inhibition efficiencies comparable to that of hydroxyethylidine diphosphonic acid (HEDP), the most preferred cooling water inhibitor. The compounds were found effective under static and flowing conditions. Extracts were quite effective in retarding formation of scales, and the maximum antiscaling efficiency was exhibited by the extract of azadirachta indica (98%). The blowdown of the cooling system possessed color and chemical oxygen demand (COD). Concentrations of these parameters were reduced by an adsorption process using activated carbon as an adsorbent.

  6. Method for resisting corrosion in geothermal fluid handling systems

    SciTech Connect

    Love, W.W.; Cron, C.J.

    1988-05-24

    A method for resisting corrosion while conducting a flow of hot, corrosive geothermal fluid is described comprising the steps of: (a) forming a fluid conducting element of a beta and alpha titanium-base product produced by heating to form a metastable beta titantium matrix, and thereafter heat treating the matrix to form sufficient alpha phase therein providing an increase in ultimate tensile strength of at least about 10,000 psi over that of the matrix before the heat treating, the beta and alpha titantium-base product so formed having an average valence electron density of between about 4.15 and about 4.35. The composition consisting essentially of: (i) a total of between about 2 and about 10 weight percent of one or more beta eutectoid elements; (ii) between about 4 and about 10 weight percent of vanadium; (iii) between about 3 and about 6 weight percent of molybdenum; (iv) between about 2 and about 5 weight percent of aluminum; and (v) the balance titanium; and (b) following the geothermal fluid through the fluid conducting element.

  7. In-Plant Corrosion Study of Steels in Distillery Effluent Treatment Plant

    NASA Astrophysics Data System (ADS)

    Ram, Chhotu; Sharma, Chhaya; Singh, A. K.

    2015-05-01

    The present study deals with corrosion and performance of steels observed in an effluent treatment plant (ETP) of a distillery. For this purpose, the metal coupons were exposed in primary (untreated effluent) and secondary tank (anaerobic treatment effluent) of the ETP. The extent of attack has been correlated with the composition of the effluent with the help of laboratory immersion and electrochemical tests. Untreated distillery effluent found to be more corrosive than the anaerobic-treated effluents and is assigned due to chloride, phosphate, calcium, nitrate, and nitrite ions, which enhances corrosivity at acidic pH. Mild steel showed highest uniform and localized corrosion followed by stainless steels 304L and 316L and lowest in case of duplex 2205.

  8. Kinetics and structural studies of the atmospheric corrosion of carbon steels in Panama

    NASA Astrophysics Data System (ADS)

    Jaén, Juan A.; de Villalaz, Mariela Sánchez; de Araque, Lilibeth; de Bósquez, Agnes

    1997-09-01

    The corrosion of a carbon steel was studied in different atmospheres at sites in the Republic of Panama. The weight loss (corrosion penetration) suffered by the carbon steel is related to time by a bilogarithmic law. Mössbauer spectroscopy indicated the rust was composed of non-stoichiometric magnetite (Fe3-xO4), maghemite (γ-Fe2O3), goethite (α-FeOOH) of intermediate particle size, lepidocrocite (γ-FeOOH) and superparamagnetic particles. Magnetite formation is related to the alternating dry--wet cycles. Goethite is related to corrosion penetration by a saturation type of behavior, following a Langmuir type of relationship. Goethite in rust protects steel against further atmospheric corrosion.

  9. Application of induction coil measurements to the study of superalloy hot corrosion and oxidation

    NASA Technical Reports Server (NTRS)

    Deadmore, D. L.

    1984-01-01

    The assessment of the degree of hot corrosion attack on nickel based alloys is a difficult task, especially when the definition specifies that it must be in terms of metal consumed and even more difficult if the measurement must be nondestructive. The inductance of a solenoid coil responds to changes in volume of fill and composition of metal cores, therefore, it may be used for nondestructive measurement of hot corrosion. The hot corrosion of U700 was studied at 900 C in a Mach 0.3 flame doped with 0.85 wppm of sodium. The change of inductance was found to define the known corrosion behavior and to suggest its use as a tool with predictive capabilities. Sufficient sensitivity exists to detect oxidation of this alloy at 900 C.

  10. Design of Hanford Site 4th Generation Multi Function Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-08-30

    This document describes the design of the fourth-generation corrosion monitoring system scheduled to be installed in DST 241-AN-104 early in fiscal year 2001. A fourth-generation multi-function corrosion monitoring system has been designed for installation into a DST in the 241-AN farm at the Hanford Site in FY 2001. Improvements and upgrades from the third-generation system (installed in 241-AN-105) that have been incorporated into the fourth-generation system include: Addition of a built-in water lance to assist installation of probe into tanks with a hard crust layer at the surface of the waste; and Improvement of the electrode mounting apparatus used to attach the corrosion monitoring electrodes to the stainless steel probe body (new design simplifies probe assembly/wiring). These new features improve on the third-generation design and yield a system that is easier to fabricate and install, provides for a better understanding of the relationship between corrosion and other tank operating parameters, and optimizes the use of the riser that houses the probe in the tank.

  11. Stress Corrosion Evaluation of Various Metallic Materials for the International Space Station Water Recycling System

    NASA Technical Reports Server (NTRS)

    Torres, P. D.

    2015-01-01

    A stress corrosion evaluation was performed on Inconel 625, Hastelloy C276, titanium commercially pure (TiCP), Ti-6Al-4V, Ti-6Al-4V extra low interstitial, and Cronidur 30 steel as a consequence of a change in formulation of the pretreatment for processing the urine in the International Space Station Environmental Control and Life Support System Urine Processing Assembly from a sulfuric acid-based to a phosphoric acid-based solution. The first five listed were found resistant to stress corrosion in the pretreatment and brine. However, some of the Cronidur 30 specimens experienced reduction in load-carrying ability.

  12. Galvanic Liquid Applied Coating System for Protection of Embedded Steel Surfaces from Corrosion

    NASA Technical Reports Server (NTRS)

    Curran, Joseph; MacDowell, Louis; Voska, N. (Technical Monitor)

    2002-01-01

    The corrosion of reinforcing steel in concrete is an insidious problem for the Kennedy Space Center, government agencies, and the general public. Existing corrosion protection systems on the market are costly, complex, and time-consuming to install, require continuous maintenance and monitoring, and require specialized skills for installation. NASA's galvanic liquid-applied coating offers companies the ability to conveniently protect embedded steel rebar surfaces from corrosion. Liquid-applied inorganic galvanic coating contains one ore more of the following metallic particles: magnesium, zinc, or indium and may contain moisture attracting compounds that facilitate the protection process. The coating is applied to the outer surface of reinforced concrete so that electrical current is established between metallic particles and surfaces of embedded steel rebar; and electric (ionic) current is responsible for providing the necessary cathodic protection for embedded rebar surfaces.

  13. Can the RUVIS reflected UV imaging system visualize fingerprint corrosion on brass cartridge casings postfiring?

    PubMed

    Leintz, Rachel; Bond, John W

    2013-05-01

    Comparisons are made between the visualization of fingerprint corrosion ridge detail on fired brass cartridge casings, where fingerprint sweat was deposited prefiring, using both ultraviolet (UV) and visible (natural daylight) light sources. A reflected ultraviolet imaging system (RUVIS), normally used for visualizing latent fingerprint sweat deposits, is compared with optical interference and digital color mapping of visible light, the latter using apparatus constructed to easily enable selection of the optimum viewing angle. Results show that reflected UV, with a monochromatic UV source of 254 nm, was unable to visualize fingerprint ridge detail on any of 12 casings analyzed, whereas optical interference and digital color mapping using natural daylight yielded ridge detail on three casings. Reasons for the lack of success with RUVIS are discussed in terms of the variation in thickness of the thin film of metal oxide corrosion and absorption wavelengths for the corrosion products of brass.

  14. RESULTS OF EXPERIMENT TO DETERMINE CORROSION RATES FOR 304L IN HB-LINE DISSOLVER VESSEL VENTILATION SYSTEM

    SciTech Connect

    Mickalonis, J; Kathryn Counts, K

    2008-02-22

    Radioactive material being processed as part of the DE3013 program for HB-Line will result in the presence of chlorides, and in some cases fluorides, in the dissolver. Material Science and Technology developed an experimental plan to evaluate the impact of chloride on corrosion of the dissolver vessel ventilation system. The plan set test variables from the proposed operating parameters, previous test results, and a desired maximum chloride concentration for processing. The test variables included concentrations of nitric acid, fluorides and chlorides, and the presence of a welded and stressed metal coupon. Table 1 contains expected general corrosion rates in the HB-Line vessel vent system from dissolution of 3013 contents of varying nitric acid and chloride content. These general corrosion rates were measured upstream of the condenser in the experiment's offgas system near the entrance to the dissolver. However, they could apply elsewhere in the offgas system, depending on factors not simulated in the testing, including offgas system temperatures and airflow. Localized corrosion was significant in Tests One, Two, and Three. This corrosion is significant because it will probably be the first mode of penetration of the 304L steel in several places in the system. See Table 2. For Tests One and Three, the penetration rate of localized corrosion was much higher than that for general corrosion. It was approximately four times higher in Test One and at least 45 times higher in Test Three, penetrating an entire coupon thickness of 54 mils in 186 hours or less. There was no significant difference in corrosion between welded areas and un-welded areas on coupons. There was also no significant attack on stressed portions of coupons. It is probable that the lack of corrosion was because the stressed areas were facing downwards and offered no place for condensation or deposits to form. Had deposits formed, pitting may have occurred and led to stress corrosion cracking. The

  15. Study of archaeological artefacts to refine the model of iron long-term indoor atmospheric corrosion

    NASA Astrophysics Data System (ADS)

    Monnier, J.; Legrand, L.; Bellot-Gurlet, L.; Foy, E.; Reguer, S.; Rocca, E.; Dillmann, P.; Neff, D.; Mirambet, F.; Perrin, S.; Guillot, I.

    2008-09-01

    The study of long-term indoor atmospheric corrosion is involved in the field of the interim storage of nuclear wastes. Indeed study of archaeological artefacts is one of the only mean to gather information on very long periods. Concerning ancient items, due to the complexity of the system, it is necessary to couple many analytical techniques from the macro to the microscopic scale. This enables to propose a description of the Amiens cathedral chain rust layers, made of a matrix of goethite, with lepidocrocite and akaganeite locally present and marbling of a poor crystallized phase associated to ferrihydrite. Electrochemical measurements permit to study the reduction capacity of the rust layer and to draw reduction mechanisms of the so-called active phases, by in situ experiments coupled with X-ray diffraction and X-ray absorption spectroscopy.

  16. Stress Corrosion Cracking and Fatigue Crack Growth Studies Pertinent to Spacecraft and Booster Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Hall, L. R.; Finger, R. W.

    1972-01-01

    This experimental program was divided into two parts. The first part evaluated stress corrosion cracking in 2219-T87 aluminum and 5Al-2.5Sn (ELI) titanium alloy plate and weld metal. Both uniform height double cantilever beam and surface flawed specimens were tested in environments normally encountered during the fabrication and operation of pressure vessels in spacecraft and booster systems. The second part studied compatibility of material-environment combinations suitable for high energy upper stage propulsion systems. Surface flawed specimens having thicknesses representative of minimum gage fuel and oxidizer tanks were tested. Titanium alloys 5Al-2.5Sn (ELI), 6Al-4V annealed, and 6Al-4V STA were tested in both liquid and gaseous methane. Aluminum alloy 2219 in the T87 and T6E46 condition was tested in fluorine, a fluorine-oxygen mixture, and methane. Results were evaluated using modified linear elastic fracture mechanics parameters.

  17. Fighting Corrosion

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Reinforced concrete structures such as bridges, parking decks, and balconies are designed to have a service life of over 50 years. All too often, however, many structures fall short of this goal, requiring expensive repairs and protection work earlier than anticipated. The corrosion of reinforced steel within the concrete infrastructure is a major cause for this premature deterioration. Such corrosion is a particularly dangerous problem for the facilities at NASA s Kennedy Space Center. Located near the Atlantic Ocean in Florida, Kennedy is based in one of the most corrosive-prone areas in the world. In order to protect its launch support structures, highways, pipelines, and other steel-reinforced concrete structures, Kennedy engineers developed the Galvanic Liquid Applied Coating System. The system utilizes an inorganic coating material that slows or stops the corrosion of reinforced steel members inside concrete structures. Early tests determined that the coating meets the criteria of the National Association of Corrosion Engineers for complete protection of steel rebar embedded in concrete. Testing is being continued at the Kennedy's Materials Science Beach Corrosion Test Site.

  18. Selected durability studies of geopolymer concrete with respect to carbonation, elevated temperature, and microbial induced corrosion

    NASA Astrophysics Data System (ADS)

    Badar, Mohammad Sufian

    prepared with certain fly ashes exhibited signs of expansion along with cracking and spalling, while GPC prepared with specific class F fly ash showed superior resistance to thermal shock. Microstructural analysis revealed that the resistance of GPC at elevated temperatures was dependent on the type of fly ash used, its particle size distribution, formation of zeolitic phases such as sodalite, analcime and nepheline, and the overall pore structure of the geopolymer concrete. The work indicates that the chemical composition and particle size distribution of the fly ash, type of fly ash (Class C & F) and the geopolymerization process that took place a vital role in the performance of geopolymer concretes in high temperature applications. Microbial Induced Corrosion: Corrosion is a major form of deterioration in concrete structures. According to a report published by the U.S. FHWA 2002, the cost of corrosion in water and wastewater conveyance, and storage and treatment facilities in the U.S. is about $138 billions. A main form of corrosion in wastewater collection systems is Microbial Induced Corrosion (MIC). However, the conditions present in industrial or municipal wastewater pipes, or storage facility are induced by the production of sulfuric acid by biological processes, which cannot be fully mimicked by simple acid corrosion. The present study intends to provide similar conditions inside pipe specimens that mimic a true sewer atmosphere. The experimental setup consisted of three 12" diameter and 30" long concrete pipe specimens, 2 specimens were coated with different formulations of GPC while the third was a control. Both ends of each pipe specimen were sealed to prevent hydrogen sulfide gas from escaping. One pipe was coated with GPC that had a biocide agent entrained. Another pipe specimen was coated with OPC and the 3rd pipe was used as a control and was not coated. Parameters measured can be divided into three groups: general environmental parameters like pH and

  19. Coal-liquefaction-plant fractionation-column corrosion-coupon studies

    SciTech Connect

    Keiser, J.R.; Baylor, V.B.; Howell, M.; Newsome, J.F.

    1982-01-01

    Severe corrosion has been observed in fractionation columns at the Fort Lewis, Washington, and Wilsonville, Alabama, solvent refined coal pilot plants. This corrosion is most severe for materials exposed in the 220 to 260/sup 0/C (430 to 500/sup 0/F) range and results in corrosion rates of as much as 6.4 mm/y (250 mils/y) for type 18-8 stainless steels. Studies at ORNL of this corrosion problem include exposure of coupons in the columns, analysis of failed components from the pilot plants, chemical analyses of liquids from the pilot plants, and operation of laboratory experiments. This report describes the coupon exposure studies, gives the results of these studies, and discusses the selection of fractionation column materials on the basis of our experience. The studies show that several high-nickel alloys have corrosion rates of less than 0.25 mm/y (10 mils/y) and would be suitable in a fractionation column environment even if no process changes are made to reduce offending species such as chlorine.

  20. Study of the Susceptibility of Oxygen-Free Phosphorous Doped Copper to Corrosion in Simulated Groundwater in the Presence of Chloride and Sulfide

    SciTech Connect

    Escobar, Ivan; Lamas, Claudia; Werme, Lars |; Oversby, Virginia

    2007-07-01

    Oxygen free high conductivity copper, doped with phosphorus (Cu OFP) has been chosen as the material for the fabrication of high level nuclear waste containers in Sweden. This material will be the corrosion barrier for spent fuel in the environment of a deep geological repository in granitic rock. The service life of this container is expected to exceed 1,000,000 years. During this time, which includes several glaciations, water of different compositions, including high concentration of chloride ions, will contact the copper surface. This work reports a study of the susceptibility of Cu OFP to corrosion when chloride ions are present, in deionized water (DW) and in synthetic groundwater (SGW). The techniques used were electrochemical methods such as corrosion potential evolution and Tafel curves. The system was studied with Electrochemical Impedance Spectroscopy (EIS). We also used as characterization techniques Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The main conclusions are that copper is more susceptible to corrosion at high chloride ion concentration. When the chloride concentration is low, it is possible to form copper chloride crystals, but at the highest concentration, copper chloride complexes are formed, leaving the copper surface without deposits. When the chloride concentration is low (<0.1 M) the corrosion process is mainly controlled by diffusion, while at higher concentrations (0.1 M to 1 M) corrosion is controlled by charge transfer processes. At low concentration of sulfide (<3 . 10{sup -5} M), copper corrosion in the presence of chloride is controlled by diffusional processes, while at higher concentrations corrosion is controlled by charge transfer processes. (authors)

  1. Corrosion behaviour of galvanized steel and electroplating steel in aqueous solution: AC impedance study and XPS

    NASA Astrophysics Data System (ADS)

    Lebrini, M.; Fontaine, G.; Gengembre, L.; Traisnel, M.; Lerasle, O.; Genet, N.

    2008-08-01

    The efficiency of a new triazole derivative, namely, 2-{(2-hydroxyethyl)[(4-methyl-1 H-1,2,3-benzotriazol-1-yl)methyl]amino}ethanol (TTA) has been studied for corrosion inhibition of galvanized steel and electroplating steel in aqueous solution. Corrosion inhibition was studied using electrochemical impedance spectroscopy (EIS). These studies have shown that TTA was a very good inhibitor. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour of galvanized steel and electroplating steel in aqueous solution was also investigated in the presence of 4-methyl-1 H-benzotriazole (TTA unsubstituted) by EIS. These studies have shown that the ability of the molecule to adsorb on the steel surface was dependent on the group in triazole ring substituent. X-ray photoelectron spectroscopy surface analysis with TTA shows that it chemisorbed on surface of galvanized steel and electroplating steel.

  2. Corrosion Studies in Support of Medium Power Lead Alloy Cooled Reactor

    SciTech Connect

    Eric Loewen; Ronald Ballinger; Jeongyoun Lim

    2004-09-01

    The performance of structural materials in lead or lead-bismuth eutectic (LBE) systems is evaluated. The materials evaluated included refractory metals (W, Mo, and Ta), several U.S. steels [austenitic steel (316L), carbon steels (F-22, Fe-Si), ferritic/martensitic steels (HT-9 and 410)], and several experimental Fe-Si-Cr alloys that were expected to demonstrate corrosion resistance. The materials were exposed in either an LBE rotating electrode or a dynamic corrosion cell for periods from 100 to 1000 h at temperatures of 400, 500, 600, and 700°C, depending on material and exposure location. Weight change and optical scanning electron microscopy or X-ray analysis of the specimen were used to characterize oxide film thickness, corrosion depth, microstructure, and composition changes. The results of corrosion tests validate the excellent resistance of refractory metals (W, Ta, and Mo) to LBE corrosion. The tests conducted with stainless steels (410, 316L, and HT-9) produced mass transfer of elements (e.g., Ni and Cr) into the LBE, resulting in degradation of the material. With Fe-Si alloys a Si-rich layer (as SiO2) is formed on the surface during exposure to LBE from the selective dissolution of Fe.

  3. Corrosion Studies in Support of Medium-Power Lead-Alloy-Cooled Reactor

    SciTech Connect

    Loewen, Eric P.; Ballinger, Ronald G.; Lim, Jeongyoun

    2004-09-15

    The performance of structural materials in lead or lead-bismuth eutectic (LBE) systems is evaluated. The materials evaluated included refractory metals (W, Mo, and Ta), several U.S. steels [austenitic steel (316L), carbon steels (F-22, Fe-Si), ferritic/martensitic steels (HT-9 and 410)], and several experimental Fe-Si-Cr alloys that were expected to demonstrate corrosion resistance. The materials were exposed in either an LBE rotating electrode or a dynamic corrosion cell for periods from 100 to 1000 h at temperatures of 400, 500, 600, and 700 deg. C, depending on material and exposure location. Weight change and optical scanning electron microscopy or X-ray analysis of the specimen were used to characterize oxide film thickness, corrosion depth, microstructure, and composition changes. The results of corrosion tests validate the excellent resistance of refractory metals (W, Ta, and Mo) to LBE corrosion. The tests conducted with stainless steels (410, 316L, and HT-9) produced mass transfer of elements (e.g., Ni and Cr) into the LBE, resulting in degradation of the material. With Fe-Si alloys a Si-rich layer (as SiO{sub 2}) is formed on the surface during exposure to LBE from the selective dissolution of Fe.

  4. Study of the corrosion rate behavior of ion implanted Fe-based alloys

    SciTech Connect

    Cai Weiping; Tian Wei; Wu Run ); Godechot, X.; Brown, I. )

    1991-06-01

    We report on some studies we have made of the time evolution of the corrosion behavior of ion implanted samples of pure iron, medium carbon steel, and 18-8 Cr-Ni stainless steel. Ti, Cr, Ni, Cu, Mo and Yb were implanted at mean ion energies near 100 keV and at doses up to 1 {times} 10{sup 17} cm{sup {minus}2} using a Mevva metal ion implantation facility. A novel feature of this experiment was the simultaneous implantation with several different implanted species. The implanted samples were immersed in sulfuric acid solution at 40{degrees}C and the corrosion monitored as a function of time. The loss in mass was accurately measured using atomic absorption spectroscopy. The functional dependence of the corrosion behavior was established for all samples. The cumulative mass loss Q is given as a function of time t by Q = At{sup N}, where A and N are parameters; thus the corrosion rate V is given by V = ANt{sup N-1}. A is dominated by the initial mass loss and N reflects the long-time corrosion behavior. The values of the parameters A and N were obtained by a least-squares regression for all the samples investigated. We determined that for the samples investigated here, N > 1 always and V increases with time throughout the experimental duration. In this paper we summarize the experimental results and discuss the effect of A and N on corrosion rate and the relationship between the corrosion current density and the parameters A and N. 11 refs., 4 figs.

  5. Cyclotron accelerated beams applied in wear and corrosion studies

    NASA Astrophysics Data System (ADS)

    Racolta, P. M.; Popa-Simil, L.; Ivanov, E. A.; Alexandreanu, B.

    1996-05-01

    Wear and corrosion processes are characterized by a loss of material that is, for machine parts and components, usually in a micrometer's range. That is why, in the last two decades, many direct applications in machine construction, petrochemical and metallurgical industries based on the Thin Layer Activation (TLA) technique have been developed. In this paper general working patterns together with a few examples of TLA applications carried out using our laboratory's U-120 Cyclotron are presented. The relation between the counting rate of the radiation originating from the component's irradiated zone and the loss of the worn material can be determined mainly by two methods: the oil circulation method and the remnant radioactivity measuring method. The first method is illustrated with some typical examples such as the optimization of the running-in program of a diesel engine and anti-wear features certifying of lubricant oils. There is also presented an example where the second method mentioned above has been applied to corrosion rate determinations for different kinds of unoxidable steels used in inert gas generator construction.

  6. Galvanic Liquid Applied Coating System For Protection of Embedded Steel Surfaces from Corrosion

    NASA Technical Reports Server (NTRS)

    Curran, Joseph; Curran, Jerome; Voska, N. (Technical Monitor)

    2002-01-01

    Corrosion of reinforcing steel in concrete is an insidious problem facing Kennedy Space Center (KSC), other Government Agencies, and the general public. These problems include KSC launch support structures, highway bridge infrastructure, and building structures such as condominium balconies. Due to these problems, the development of a Galvanic Liquid Applied Coating System would be a breakthrough technology having great commercial value for the following industries: Transportation, Infrastructure, Marine Infrastructure, Civil Engineering, and the Construction Industry. This sacrificial coating system consists of a paint matrix that may include metallic components, conducting agents, and moisture attractors. Similar systems have been used in the past with varying degrees of success. These systems have no proven history of effectiveness over the long term. In addition, these types of systems have had limited success overcoming the initial resistance between the concrete/coating interface. The coating developed at KSC incorporates methods proven to overcome the barriers that previous systems could not achieve. Successful development and continued optimization of this breakthrough system would produce great interest in NASA/KSC for corrosion engineering technology and problem solutions. Commercial patents on this technology would enhance KSC's ability to attract industry partners for similar corrosion control applications.

  7. Mechanically Assisted Taper Corrosion in Modular TKA

    PubMed Central

    Arnholt, Christina; MacDonald, Daniel W.; Tohfafarosh, Mariya; Gilbert, Jeremy L.; Rimnac, Clare M.; Kurtz, Steven M.; Klein, Gregg; Mont, Michael A.; Parvizi, Javad; Cates, Harold E.; Lee, Gwo-Chin; Malkani, Arthur; Kraay, Matthew

    2014-01-01

    The purpose of this study was to characterize the prevalence of taper damage in modular TKA components. 198 modular components were revised after 3.9±4.2y (range: 0.0–17.5y). Modular components were evaluated for fretting corrosion using a semi-quantitative 4-point scoring system. Flexural rigidity, stem diameter, alloy coupling, patient weight, age and implantation time were assessed as predictors of fretting corrosion damage. Mild-to-severe fretting corrosion (score≥2) was observed in 94/101 of the tapers on the modular femoral components and 90/97 of the modular tibial components. Mixed alloy pairs (p=0.03), taper design (p<0.001), and component type (p=0.02) were associated with taper corrosion. The results from this study supported the hypothesis that there is taper corrosion in TKA. However the clinical implications of fretting and corrosion in TKA remain unclear. PMID:24996586

  8. A laboratory study of the effect of acetic acid vapor on atmospheric copper corrosion

    SciTech Connect

    Lopez-Delgado, A.; Cano, E.; Bastidas, J.M.; Lopez, F.A.

    1998-12-01

    A study was made of the copper corrosion rate and corrosion products originated by the action of acetic acid vapor at 100% relative humidity. Copper plates were exposed to an acetic acid contaminated atmosphere for a period of 21 days. Five acetic vapor concentration levels were used. The copper corrosion rate was in the range of 1 to 23 mg/dm{sup 2} day. The corrosion-product layers were characterized using electrochemical, X-ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite (Cu{sub 2}O), copper acetate hydrate [Cu(CH{sub 3}COO){sub 2}{center_dot}2H{sub 2}O], and copper hydroxide acetate [Cu{sub 4}(OH)(CH{sub 3}COO){sub 7}{center_dot}2H{sub 2}O]. This last compound was also characterized. The thickness of the patina layers was 4 to 8 nm for amorphous cuprite, 11 to 48 nm for cuprite, and 225 nm for copper acetate. The patina, in which the cementation process of different corrosion-product layers plays an important role, is formed by the reaction of acetic vapor with copper through porous cuprite paths.

  9. A study on the potential of metal corrosion by sulfate-reducing bacteria in animal buildings

    SciTech Connect

    Zhu, J.; Riskowski, G.L.; Mackie, R.I.

    1999-06-01

    The potential of sulfate-reducing bacteria (SRB) to cause metal corrosion in animal buildings was examined in this study. An analysis was done on the bacterial colonization and the corrosion products on the surfaces of metals exposed to three animal buildings and one environmentally controlled building over a two-year period. Data from this study showed that the levels of SRB on metal surfaces were low after two-year's exposure (maximum count: 1.7 x 10{sup 4}/cm{sup 2}). SRB colonization levels after two years were not sufficient to corrode metal products exposed in animal environments. In addition, metal surface analysis data using X-ray photoelectron spectroscopy showed that the corrosion compounds formed on the surfaces of different metals were not due to the SERB-induced corrosion mechanisms. These compounds were mainly oxides and carbonates (FeO, Fe{sub 2}O{sub 3}, Fe{sub 3}O{sub 4}, and Fe(CO){sub 5} on iron samples; ZnO and ZnCO{sub 3} on galvanized steel samples: Al{sub 2}O{sub 3}, ZnO, and ZnCO{sub 3} on Galvalume samples), and were normally generated due to the classic types of corrosion mechanisms. Some sulfur was present to form ZnS on the galvanized steel samples, but might not be attributed to SRB. The origin of this sulfur was not clear.

  10. Materials studies for preventing corrosion in condensing environments. Annual report, October 1990--September 1991

    SciTech Connect

    Kukacka, L.E.; Sugama, T.

    1991-10-01

    The objective of this project is to determine the fundamental interfacial requirements for low-cost, organic and inorganic materials resistive to corrosion in condensing furnace exhausts. This research effort is being focused to provide information regarding corrosion resistance, heat transfer, material cost, fabrication method and cost, and product reliability since all are important in the final design and production of a heat exchanger. Results to date indicate that organic and inorganic-type polymer coating systems applied to low cost metals such as mild steel and aluminum provide good corrosion protection. The thermal stability of these polymers plus the identification of the interfacial requirements needed to utilize them with reactive filler materials should also make their use as bulk composites feasible.

  11. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Jordi Perez; Marc Hornbostel; Kai-Hung Lau; Angel Sanjurjo

    2007-05-31

    Advanced electric power generation systems use a coal gasifier to convert coal to a gas rich in fuels such as H{sub 2} and CO. The gas stream contains impurities such as H{sub 2}S and HCl, which attack metal components of the coal gas train, causing plant downtime and increasing the cost of power generation. Corrosion-resistant coatings would improve plant availability and decrease maintenance costs, thus allowing the environmentally superior integrated-gasification-combined-cycle (IGCC) plants to be more competitive with standard power-generation technologies. Heat-exchangers, particle filters, turbines, and other components in the IGCC system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy will improve is resistance to such sulfidation attack and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. The Fe- and Ni-based high-temperature alloys are susceptible to sulfidation attack unless they are fortified with high levels of Cr, Al, and Si. To impart corrosion resistance, these elements need not be in the bulk of the alloy and need only be present at the surface layers. In this study, the use of corrosion-resistant coatings on low alloy steels was investigated for use as high-temperature components in IGCC systems. The coatings were deposited using SRI's fluidized-bed reactor chemical vapor deposition technique. Diffusion coatings of Cr and Al were deposited by this method on to dense and porous, low alloy stainless steel substrates. Bench-scale exposure tests at 900 C with a simulated coal gas stream containing 1.7% H{sub 2}S showed that the low alloy steels such SS405 and SS409 coated with {approx

  12. An impedance study on admiralty brass dezincification originated by microbiologically influenced corrosion.

    PubMed

    Ibars, J R; Polo, J L; Moreno, D A; Ranninger, C; Bastidas, J M

    2004-09-30

    In this article we describe a field study of biofouling and microbiologically influenced corrosion (MIC) of admiralty brass heat exchanger tubes in contact with running fresh water on the river Tagus close to Almaraz nuclear power plant in Spain. Dezincification originated by biofouling and MIC was studied using impedance, polarization resistance, gravimetric, scanning electron microscopy (SEM), and X-ray diffraction (XRD) measurements. Close correlation was observed between the biofilms formed and the corrosion process (dezincification) using the different experimental techniques. Impedance data showed a capacitive behavior including two time constants. Kramers-Kronig (KK) transforms were used to validate impedance data. The admiralty tubes' impedance data satisfied the KK relations.

  13. An impedance study on admiralty brass dezincification originated by microbiologically influenced corrosion.

    PubMed

    Ibars, J R; Polo, J L; Moreno, D A; Ranninger, C; Bastidas, J M

    2004-09-30

    In this article we describe a field study of biofouling and microbiologically influenced corrosion (MIC) of admiralty brass heat exchanger tubes in contact with running fresh water on the river Tagus close to Almaraz nuclear power plant in Spain. Dezincification originated by biofouling and MIC was studied using impedance, polarization resistance, gravimetric, scanning electron microscopy (SEM), and X-ray diffraction (XRD) measurements. Close correlation was observed between the biofilms formed and the corrosion process (dezincification) using the different experimental techniques. Impedance data showed a capacitive behavior including two time constants. Kramers-Kronig (KK) transforms were used to validate impedance data. The admiralty tubes' impedance data satisfied the KK relations. PMID:15334412

  14. Comparative study of the corrosion behavior of MA-956 and conventional metallic biomaterials.

    PubMed

    Escudero, M L; López, M F; Ruiz, J; García-Alonso, M C; Canahua, H

    1996-07-01

    In this work the corrosion behavior of a new biomaterial, the MA-956 superalloy, immersed in Hank's solution is evaluated. A comparison with conventional metallic alloys used as articular implants is established. To determine the corrosion behavior we employed electrochemical methods: evaluation of corrosion potential Ecorr, electrochemical impedance spectroscopy (EIS), and anodic polarization curves. The corrosion resistance of the MA-956 superalloy preoxidized at 1100 degrees C during 100 h is at least two orders of magnitude higher than for the other alloys. This satisfactory behavior is stationary with time. Also the probability of the appearance of the pitting corrosion process is very low. When cracking is generated in the alpha-alumina layer the repassivation process is assured because of the high Cr content in the superalloy. This study is the first step in proposing this new alloy as a biomaterial. The low toxicity of these metallic alloys in the physiological environment suggests that in vivo their biocompatibility could be satisfactory. PMID:8806056

  15. INFLUENCE OF TEMPERATURE ON THE CORROSION POTENTIAL OF THE 241-AN-102 MULTI PROBE CORROSION MONITORING SYSTEM SECONDARY REFERENCE ELECTRODES

    SciTech Connect

    EDGEMON GL; TAYLOR TM

    2008-09-30

    A test program using 241-AN-102 waste simulants and metallic secondary reference electrodes similar to those used on the 241-AN-102 MPCMS was performed to characterize the relationship between temperature and secondary reference electrode open-circuit corrosion potential. This program showed that the secondary reference electrodes can be used to make tank and tank steel corrosion potential measurements, but that a correction factor of approximately 2 mV per degree Celsius of temperature difference must be applied, where temperature difference is defined as the difference between tank temperature at the time of measurement and 30 C, the average tank temperature during the first several months of 241-AN-102 MPCMS operation (when the corrosion potentials of the secondary reference electrodes were being recorded relative to the primary reference electrodes).

  16. Hydroxyl carboxylate based non-phosphorus corrosion inhibition process for reclaimed water pipeline and downstream recirculating cooling water system.

    PubMed

    Wang, Jun; Wang, Dong; Hou, Deyin

    2016-01-01

    A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies (PRWS) and in downstream recirculating cooling water systems (RCWS) using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors (e.g., gluconate, citrate, tartrate) and zinc sulfate heptahydrate, which provided Zn(2+) as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate (which could be utilized as a corrosion inhibitor) content in the reclaimed water was below 1.7 mg/L, and no additional corrosion inhibitors were required for the downstream RCWS. Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO4(3-) and Zn(2+) when the phosphate content in the reclaimed water was more than 1.7 mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result.

  17. Study and Modeling of the Localized Nature of Top of the Line Corrosion

    NASA Astrophysics Data System (ADS)

    Singer, Marc

    The occurrence of localized corrosion in Top of the Line Corrosion (TLC) was investigated both in sweet (CO2-dominated) and sour (H 2S-dominated) environments. The focus of the work was to understand the influence of the environmental parameters on localized corrosion at the top of the line in order to develop a narrative of the mechanism. The first part of this project presents the unique setup developed for the experimental work. Several large scale flow loops were used to perform the tests in order to recreate the field environments as closely as possible. The test section was designed using a carbon steel insert exposed to three different levels of cooling at the same time. This concept was quite successful in simulating realistic localized features. A series of long term exposure (one- to three-month) experiments was conducted to investigate the controlling parameters. The occurrence of localized corrosion could be very clearly correlated to the condensation rate, the gas temperature and the organic acid content. Important observations on the morphology of localized TLC features could be made, providing useful insight on the mechanisms involved. The second part of the study attempted to link the presence or absence of a large droplet on the steel surface to the extent of corrosion occurring underneath it. However, this was not successful as no clear relationship could be established with certainty. Instead, the water condensation rate was thought to control the corrosion and the overall aggressiveness of the environment (CO2, acetic acid). Finally, a modeling approach was proposed for the prediction of the localized attack in a top of the line corrosion scenario. The method was based on the observations made during the experimental part of the work and presented a mechanism for the prediction of the onset and propagation of localized corrosion. The FeCO3 saturation level played a key role in defining the overall corrosiveness of the condensed water, while the

  18. An investigation of microbial diversity in crude oil & seawater injection systems and microbiologically influenced corrosion (MIC) of linepipe steels under different exposure conditions

    NASA Astrophysics Data System (ADS)

    AlAbbas, Faisal Mohammed

    members of Halothiobacillaceae. In the seawater injection sample, the dominant bacterial phylotypes included members of the Rhodobacterales, Flavobacteriales and Oceanospirillales. Interestingly, common bacterial phylotypes that are related to Thermotogaceae were identified in all investigated samples. The impact of the identified microbial communities on MIC of pipeline system was presented. On the implications front, the influence of field SRB (Desulfomicrobium sp. and Clostridiales.) on the corrosion process was complex. The bacterial activities, metabolic reactions and by-products contributed to the corrosion process. Based on the observations and results, corrosion involves multiple synergistic mechanisms. The MIC vulnerability of X52 was higher than X80 due to microstructural effects. On the other hand, the field IRB consortium (Shewanella oneidensis sp. and Brevibacillus sp.) exhibited inhibitory action on the corrosion process. The maximum corrosion rate was ˜4 mpy in the biotic system and ˜18 mpy in the abiotic system. Corrosion mechanisms were proposed to explain the protective behavior of the IRB consortium. On the special effects front, the influence of remnant magnetic fields (3000 Gauss strength) on MIC by a SRB consortium was investigated. The results confirm substantial increases of bacteria cell attachment, biofilm mass, corrosion and pitting penetration rates under magnetized biotic compared to nonmagnetized biotic conditions. The significant enhancement of MIC under magnetized biotic conditions has been attributed to the synergetic interaction between SRB cells and associated metabolic products with magnetic fields. The effect of magnetic fields on the thermodynamics and kinetics of the bacterial cell attachment and the electrochemical process has been presented. On the mitigation front, this work presented a pioneer study on the inhibition effects of azadirachtin (Neem) extracts of SRB influenced corrosion. The results revealed that Neem extracts

  19. Corrosion Behavior of Surface-Treated Implant Ti-6Al-4V by Electrochemical Polarization and Impedance Studies

    NASA Astrophysics Data System (ADS)

    Paul, Subir; Yadav, Kasturi

    2011-04-01

    Implant materials for orthopedic and heart surgical services demand a better corrosion resistance material than the presently used titanium alloys, where protective oxide layer breaks down on a prolonged stay in aqueous physiological human body, giving rise to localized corrosion of pitting, crevice, and fretting corrosion. A few surface treatments on Ti alloy, in the form of anodization, passivation, and thermal oxidation, followed by soaking in Hank solution have been found to be very effective in bringing down the corrosion rate as well as producing high corrosion resistance surface film as reflected from electrochemical polarization, cyclic polarization, and Electrochemical Impedance Spectroscopy (EIS) studies. The XRD study revealed the presence of various types of oxides along with anatase and rutile on the surface, giving rise to high corrosion resistance film. While surface treatment of passivation and thermal oxidation could reduce the corrosion rate by 1/5th, anodization in 0.3 M phosphoric acid at 16 V versus stainless steel cathode drastically brought down the corrosion rate by less than ten times. The mechanism of corrosion behavior and formation of different surface films is better understood from the determination of EIS parameters derived from the best-fit equivalent circuit.

  20. Corrosion behavior of carbon steel in the monoethanolamine-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} system

    SciTech Connect

    Kladkaew, N.; Idem, R.; Tontiwachwuthikul, P.; Saiwan, C.

    2009-10-15

    The effects of operating parameters on the corrosion of carbon steel in the monoethanolamine (MEA)-H{sub 2}O-CO{sub 2}-O{sub 2}-SO{sub 2} system were investigated using two different corrosion measurement techniques. The corrosion studies were conducted using a 273A potentiostat using MEA, O{sub 2}, and SO{sub 2} concentrations and CO{sub 2} loading in the ranges of 1-7 kmol/m{sup 3}, 0-100%, 0-204 ppm, and 0-0.5 mol CO{sub 2}/mol MEA, respectively, at corrosion temperatures in the range of 303-353 K. The experimental results showed, for the first time, that a higher concentration of SO{sub 2} in a simulated flue gas stream induces a higher corrosion rate essentially because of the increase in the hydrogen ion concentration generated by reactions of SO{sub 2} and H{sub 2}O as well as SO{sub 2}, O{sub 2}, and H{sub 2}O. Also, an increase in oxygen concentration in the simulated flue gas stream causes a higher corrosion rate due to the increasing solubility of oxygen and, in turn, a higher amount of dissolved oxygen in the liquid phase. The results further show that an increase in the concentrations of MEA, O{sub 2}, and SO{sub 2} as well as CO{sub 2} loading will cause the generation of higher amounts of hydrogen or hydronium ions, as well as carbonic acid and bicarbonate ions, and this is what leads to a higher corrosion rate.

  1. TANK 241-AN-102 MULTI-PROBE CORROSION MONITORING SYSTEM PROJECT LESSONS LEARNED

    SciTech Connect

    TAYLOR T; HAGENSEN A; KIRCH NW

    2008-07-07

    During 2007 and 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was designed and fabricated for use in double-shell tank 241-AN-102. The system was successfully installed in the tank on May 1, 2008. The 241-AN-102 MPCMS consists of one 'fixed' in-tank probe containing primary and secondary reference electrodes, tank material electrodes, Electrical Resistance (ER) sensors, and stressed and unstressed corrosion coupons. In addition to the fixed probe, the 241-AN-102 MPCMS also contains four standalone coupon racks, or 'removable' probes. Each rack contains stressed and unstressed coupons made of American Society of Testing and Materials A537 CL1 steel, heat-treated to closely match the chemical and mechanical characteristics of the 241-AN-102 tank wall. These coupon racks can be removed periodically to facilitate examination of the attached coupons for corrosion damage. Along the way to successful system deployment and operation, the system design, fabrication, and testing activities presented a number of challenges. This document discusses these challenges and lessons learned, which when applied to future efforts, should improve overall project efficiency.

  2. Organic anti-corrosion systems in FGD lignite-fired units -- 10 years of operation experience

    SciTech Connect

    Schwart, G.; Moellmann, A.

    1998-07-01

    In order to meet the limitation of sulfur dioxide emission that came into force at the 1st July 1988 RWE Energie installed 37 flue gas desulfurizing plants (FGD) in 4 lignite fired stations. These FGD's are operated on basis of the limestone process. The types of scrubber are different. To protect the inner steel surfaces of the scrubbers and the ducts from corrosion by the flue gas and the condensate, rubbers and coatings are used. During 10 years of operation experience with FGD's several types of corrosion protection systems in the surface in the scrubber and the ducts were used. The reliability and break down mechanism of different types of soft rubber linings and resin systems is discussed.

  3. In pursuit of non-phosphorus corrosion inhibitors for cold water cooling systems

    SciTech Connect

    Wyman, D.P.

    1998-12-31

    An exploratory program was conducted to evaluate a number of polymers and carboxylic acid combinations with polymers as non-phosphorus containing, all organic corrosion inhibitors for cold water systems such as evaporative towers. The concentrations of treatment were approximately those which would obtain for current commercial formulations. There was a strong dependency of performance on the aggressiveness of the water, especially the conductivity. The polymers were adequate for non-aggressive waters, and one, polymaleic acid (as the sodium salt) performed reasonably in somewhat more corrosive systems. Certain alkenyl substituted dibasic acids were also found to perform well in the less challenging waters as did simpler dibasic materials such as maleic, fumaric and aspartic acids. A tetrabasic acid with the carboxyl groups located in proximity to each other, BTA, in combination with certain, but, not all, polymers showed considerable promise.

  4. Analysis of ZVI corrosion products and their functions in the combined ZVI and anaerobic sludge system.

    PubMed

    Zhu, Liang; Gao, Kaituo; Jin, Jie; Lin, Haizhuan; Xu, Xiangyang

    2014-11-01

    The zero-valent iron (ZVI) corrosion products and their functions were investigated in the combined ZVI and anaerobic sludge system. Results showed that ZVI corrosion occurred, and the reductive transformation and dechlorination of p-chloronitrobenzene (p-ClNB) by the anaerobic sludge were enhanced. In the combined systems with different types of ZVIs and mass ratios of anaerobic sludge to ZVI, a considerable amount of suspended iron compounds was produced and coated onto the microbial cells. However, the microbial cellular structure was damaged, and the p-ClNB reductive transformation was affected adversely after the long-term presence of nanoscale ZVI (NZVI) or reduced ZVI (RZVI) with a high concentration of 5 g L(-1). The oxidized products of FeOOH and Fe3O4 were found on the surface of ZVI, which are speculated to act as electron mediators and consequently facilitate the utilization of electron donors by the anaerobic microbes.

  5. A Plan to Develop and Demonstrate Electrochemical Noise Based Corrosion Monitoring Systems in Hanford Site Waste Tanks

    SciTech Connect

    NORMAN, E.C.

    2000-08-28

    This document describes changes that need to be made to the site's authorization basis and technical concerns that need to be resolved before proceduralized use of Electrochemical Noise based corrosion monitoring systems is fully possible at the Hanford Site.

  6. Natural analogues of nuclear waste glass corrosion.

    SciTech Connect

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  7. Long-Term Anti-Corrosion Performance of a Conducting Polymer-Based Coating System for Steels

    NASA Astrophysics Data System (ADS)

    Pan, Tongyan; Yu, Qifeng

    2016-06-01

    The long-term durability of a two-layer coating system was evaluated by two accelerated corrosion tests, i.e., the ASTM B117 Salt spray test and the ASTM D5894 Cyclic salt fog/UV exposure test, and a series of surface analyses. The coating system was developed for protecting structural steels from corrosion, including a functional primer made of intrinsically conducting polymer (ICP) and a protective topcoat. The standard pull-off test per ASTM D4541 was employed for characterizing the adhesion of the coating systems to substrate, aided by visual examination of the surface deterioration of the samples. The ICP-based systems demonstrated superior long-term anti-corrosion capacity when a polyurethane topcoat is used. The ICP-based primer made of a waterborne epoxy gave poorer anti-corrosion performance than the ICP-based primer made of regular non-waterborne epoxy, which can be attributed to the lower adhesion the waterborne epoxy demonstrated to the substrate surface. The zinc-rich control systems showed good anti-corrosion durability; however, they may produce excessive oxidative products of zinc to cause coating delamination. Based on the test results, the two-layer coating system consisting of an ICP-based primer and a polyurethane topcoat outperforms the conventional zinc-rich coating systems for corrosion protection of steels.

  8. A study of early corrosion behaviors of FeCrAl alloys in liquid lead-bismuth eutectic environments

    NASA Astrophysics Data System (ADS)

    Lim, Jun; Nam, Hyo On; Hwang, Il Soon; Kim, Ji Hyun

    2010-12-01

    Lead and lead-bismuth eutectic (LBE) alloy have been increasingly receiving attention as heavy liquid metal coolants (HLMC) for future nuclear energy systems. The compatibility of structural materials and components with lead-bismuth eutectic liquid at high temperature is one of key issues for the commercialization of lead fast reactors. In the present study, the corrosion behaviors of iron-based alumina-forming alloys (Kanthal-AF®, PM2000, MA956) were investigated by exposing to stagnant LBE environments at 500 °C and 550 °C for up to 500 h. After exposures, the thickness and chemistry of the oxide layer on the specimens were analyzed by scanning electron microscopy, scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. As a result, the oxide characteristics and the corrosion resistance were compared. In this study, it was shown that the corrosion resistance of FeCrAl ODS steels (PM2000, MA956) are superior to that of FeCrAl ferritic steel (Kanthal-AF®) in higher temperature LBE.

  9. Chemical Industry Corrosion Management: A Comprehensive Information System (ASSET 2). Final Report

    SciTech Connect

    John, Randy C.; Young, Arthur L.; Pelton, Arthur D.; Thompson, William T.; Wright, Ian G.

    2008-10-10

    The research sponsored by this project has greatly expanded the ASSET corrosion prediction software system to produce a world-class technology to assess and predict engineering corrosion of metals and alloys corroding by exposure to hot gases. The effort included corrosion data compilation from numerous industrial sources and data generation at Shell Oak Ridge National Laboratory and several other companies for selected conditions. These data were organized into groupings representing various combinations of commercially available alloys and corrosion by various mechanisms after acceptance via a critical screening process to ensure the data were for alloys and conditions, which were adequately well defined, and of sufficient repeatability. ASSET is the largest and most capable, publicly-available technology in the field of corrosion assessment and prediction for alloys corroding by high temperature processes in chemical plants, hydrogen production, energy conversion processes, petroleum refining, power generation, fuels production and pulp/paper processes. The problems addressed by ASSET are: determination of the likely dominant corrosion mechanism based upon information available to the chemical engineers designing and/or operating various processes and prediction of engineering metal losses and lifetimes of commercial alloys used to build structural components. These assessments consider exposure conditions (metal temperatures, gas compositions and pressures), alloy compositions and exposure times. Results of the assessments are determination of the likely dominant corrosion mechanism and prediction of the loss of metal/alloy thickness as a function of time, temperature, gas composition and gas pressure. The uses of these corrosion mechanism assessments and metal loss predictions are that the degradation of processing equipment can be managed for the first time in a way which supports efforts to reduce energy consumption, ensure structural integrity of equipment

  10. Speciation of trace inorganic contaminants in corrosion scales and deposits formed in drinking water distribution systems.

    PubMed

    Peng, Ching-Yu; Korshin, Gregory V

    2011-11-01

    Sequential extractions utilizing the modified Tessier scheme (Krishnamurti et al., 1995) and measurements of soluble and particulate metal released from suspended solids were used in this study to determine the speciation and mobility of inorganic contaminants (As, Cr, V, U, Cd, Ni, and Mn) found in corrosion scales and particles mobilized during hydraulic flushing events. Arsenic, chromium and vanadium are primarily associated with the mobilization-resistant fraction that is resistant to all eluents used in this study and also bound in highly stable crystalline iron oxides. Very low concentrations of these elements were released in resuspension experiments. X-ray absorbance measurements demonstrated that arsenic in the sample with the highest As concentration was dominated by As(V) bound by iron oxides. Significant fractions of uranium and cadmium were associated with carbonate solids. Nickel and manganese were determined to be more mobile and significantly associated with organic fractions. This may indicate that biofilms and natural organic matter in the drinking water distributions systems play an important role in the accumulation and release of these inorganic contaminants.

  11. Ultrasonic Measurement of Erosion/corrosion Rates in Industrial Piping Systems

    NASA Astrophysics Data System (ADS)

    Sinclair, A. N.; Safavi, V.; Honarvar, F.

    2011-06-01

    Industrial piping systems that carry aggressive corrosion or erosion agents may suffer from a gradual wall thickness reduction that eventually threatens pipe integrity. Thinning rates could be estimated from the very small change in wall thickness values measured by conventional ultrasound over a time span of at least a few months. However, measurements performed over shorter time spans would yield no useful information—minor signal distortions originating from grain noise and ultrasonic equipment imperfections prevent a meaningful estimate of the minuscule reduction in echo travel time. Using a Model-Based Estimation (MBE) technique, a signal processing scheme has been developed that enables the echo signals from the pipe wall to be separated from the noise. This was implemented in a laboratory experimental program, featuring accelerated erosion/corrosion on the inner wall of a test pipe. The result was a reduction in the uncertainty in the wall thinning rate by a factor of four. This improvement enables a more rapid response by system operators to a change in plant conditions that could pose a pipe integrity problem. It also enables a rapid evaluation of the effectiveness of new corrosion inhibiting agents under plant operating conditions.

  12. Towards lightweight nanocomposite coatings for corrosion inhibition: Graphene, carbon nanotubes, and nanostructured magnesium as case studies

    NASA Astrophysics Data System (ADS)

    Dennis, Robert Vincent, III

    The field of nanocomposites is a burgeoning area of research due to the interest in the remarkable properties which can be achieved through their use in a variety of applications, including corrosion resistant coatings. Lightweighting is of increasing importance in the world today due to the ever growing push towards energy efficiency and the green movement and in recent years there has been a vast amount of research performed in the area of developing lightweight nanocomposites for corrosion inhibition. Many new composite materials have been developed through the use of newly developed nanomaterials (including carbonaceous and metallic constituents) and their specialized incorporation in the coating matrix materials. We start with a general review on the development of hybrid nanostructured composites for corrosion protection of base metals from a sustainability perspective in Chapter 1. This review demonstrates the ever swelling requirements for a paradigm shift in the way that we protect metals against corrosion due to the costs and environmental concerns that exist with currently used technology. In Chapter 2, we delve into the much required understanding of graphene oxide and reduced graphene oxide through near-edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements to elucidate information about the electronic structure upon incorporation of nitrogen within the structure. For successful integration of the carbonaceous nanomaterials into a composite coating, a full swath of knowledge is necessary. Within this work we have shown that upon chemical defunctionalization of graphene oxide to reduced graphene oxide by means of hydrazine treatment, nitrogen is incorporated into the structure in the form of a pyrazole ring. In Chapter 3, we demonstrate that by way of in situ polymerization, graphene and multiwalled carbon nanotubes can be incorporated within a polymer (polyetherimide, PEI) matrix. Two systems have been developed including graphene and

  13. Studies on Hot Corrosion of the 2.25 Cr-1Mo Boiler Tube Steel and Its Weldments in the Molten Salt Na2SO4-60 pct V2O5 Environment

    NASA Astrophysics Data System (ADS)

    Kumar, Ravindra; Tewari, V. K.; Prakash, S.

    2007-01-01

    Hot corrosion is mainly due to the dissolution of protective oxides in the molten salt at the metal surface and their reprecipitation at some other sites as nonprotective porous mass. The hot corrosion attack along the grain boundaries leading to subsurface precipitation of oxides and sulfides also contributes to weakening of material. Ferritic steel with 2.25Cr 1Mo is used widely as a candidate material in the steam generating system of power plants. Hot corrosion studies were conducted on 2.25Cr-1Mo unwelded as well as welded steel specimens with molten salt coated after exposure at 900 °C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion X-ray diffraction (XRD); scanning electron microscopy/energy-dispersive analysis (SEM/EDAX) was used to analyze the corrosion products.

  14. Study on possibility for the improvement of corrosion resistance of metals using laser-formed oxide surface structure

    NASA Astrophysics Data System (ADS)

    Ruzankina, J. S.; Vasiliev, O. S.

    2016-08-01

    The laser processes of oxidation are currently known and used extensively, in particular, to improve corrosion resistance of metals possessing certain properties and composition. In this regard, actuality is the methods of laser oxidation of metals and the determination of their modes of treatment in each specific case. Increase of corrosion resistance ST20 can carried out with the formation on the surface oxide films, as well as by reducing surface roughness. Studied various modes of processing of the steel surface. Corrosion resistance investigated for protecting a metal. Defocusing the beam to allow the surface treatment of a wide beam in the low temperature mode of processing. For further study of the irradiated surface on the corrosion resistance was conducted by chemical treatment in acid. Estimated phase composition of films formed under laser treatment simulated in the program astics. The study to increase the corrosion resistance of steel and titanium, have shown that under the chosen methods of processing of materials degradation observed.

  15. T-111 Rankine system corrosion test loop, volume 1

    NASA Technical Reports Server (NTRS)

    Harrison, R. W.; Hoffman, E. E.; Smith, J. P.

    1975-01-01

    Results are given of a program whose objective was to determine the performance of refractory metal alloys in a two loop Rankine test system. The test system consisted of a circulating lithium circuit heated to 1230 C maximum transferring heat to a boiling potassium circuit with a 1170 C superheated vapor temperature. The results demonstrate the suitability of the selected refractory alloys to perform from a chemical compatibility standpoint.

  16. A Study on Cavitation Erosion and Corrosion Behavior of Al-, Zn-, Cu-, and Fe-Based Coatings Prepared by Arc Spraying

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Hong; Lee, Myeong-Hoon

    2010-12-01

    Investigation to find a suitable coating material for a rudder application has been carried out in this study. Ten different coatings were prepared by arc spraying with Al-, Zn-, Cu-, and Fe-based wire feedstock. Both the cavitation erosion and marine corrosion behavior of the arc-sprayed coatings were evaluated, and compared with the conventional anti-corrosion paint. In terms of marine corrosion resistance, aluminum coating was the best among the tested coating systems while stainless steel coating showed the highest resistance against cavitation erosion. In addition, the effects of both the Si composition in Al-based coatings and the Ni composition in Cu- and Fe- based coatings were discussed in this study.

  17. Formation and release behavior of iron corrosion products under the influence of bacterial communities in a simulated water distribution system.

    PubMed

    Sun, Huifang; Shi, Baoyou; Lytle, Darren A; Bai, Yaohui; Wang, Dongsheng

    2014-03-01

    To understand the formation and release behavior of iron corrosion products in a drinking water distribution system, annular reactors (ARs) were used to investigate the development processes of corrosion products and biofilm community as well as the concomitant iron release behavior. Results showed that the formation and transformation of corrosion products and bacterial community are closely related to each other. The presence of sulfate-reducing bacteria (SRB, e.g. Desulfovibrio and Desulfotomaculum), sulfur-oxidizing bacteria (SOB, e.g. Sulfuricella), and iron-oxidizing bacteria (IOB, e.g. Acidovorax, Gallionella, Leptothrix, and Sphaerotilus) in biofilms could speed up iron corrosion; however, iron-reducing bacteria (IRB, e.g. Bacillus, Clostridium, and Pseudomonas) could inhibit iron corrosion and iron release. Corrosion scales on iron coupons could develop into a two-layered structure (top layer and inner layer) with time. The relatively stable constituents such as goethite (α-FeOOH) and magnetite (Fe3O4) mainly existed in the top layers, while green rust (Fe6(OH)12CO3) mainly existed in the inner layers. The IOB (especially Acidovorax) contributed to the formation of α-FeOOH, while IRB and the anaerobic conditions could facilitate the formation of Fe3O4. Compared with the AR test without biofilms, the iron corrosion rate with biofilms was relatively higher (p < 0.05) during the whole experimental period, but the iron release with biofilms was obviously lower both at the initial stage and after 3 months. Biofilm and corrosion scale samples formed under different water supply conditions in an actual drinking water distribution system verified the relationships between the bacterial community and corrosion products.

  18. Formation and release behavior of iron corrosion products under the influence of bacterial communities in a simulated water distribution system.

    PubMed

    Sun, Huifang; Shi, Baoyou; Lytle, Darren A; Bai, Yaohui; Wang, Dongsheng

    2014-03-01

    To understand the formation and release behavior of iron corrosion products in a drinking water distribution system, annular reactors (ARs) were used to investigate the development processes of corrosion products and biofilm community as well as the concomitant iron release behavior. Results showed that the formation and transformation of corrosion products and bacterial community are closely related to each other. The presence of sulfate-reducing bacteria (SRB, e.g. Desulfovibrio and Desulfotomaculum), sulfur-oxidizing bacteria (SOB, e.g. Sulfuricella), and iron-oxidizing bacteria (IOB, e.g. Acidovorax, Gallionella, Leptothrix, and Sphaerotilus) in biofilms could speed up iron corrosion; however, iron-reducing bacteria (IRB, e.g. Bacillus, Clostridium, and Pseudomonas) could inhibit iron corrosion and iron release. Corrosion scales on iron coupons could develop into a two-layered structure (top layer and inner layer) with time. The relatively stable constituents such as goethite (α-FeOOH) and magnetite (Fe3O4) mainly existed in the top layers, while green rust (Fe6(OH)12CO3) mainly existed in the inner layers. The IOB (especially Acidovorax) contributed to the formation of α-FeOOH, while IRB and the anaerobic conditions could facilitate the formation of Fe3O4. Compared with the AR test without biofilms, the iron corrosion rate with biofilms was relatively higher (p < 0.05) during the whole experimental period, but the iron release with biofilms was obviously lower both at the initial stage and after 3 months. Biofilm and corrosion scale samples formed under different water supply conditions in an actual drinking water distribution system verified the relationships between the bacterial community and corrosion products. PMID:24509822

  19. Corrosion Studies Of Raw And Treated Biomass-Derived Pyrolysis Oils

    SciTech Connect

    Keiser, James R; Howell, Michael; Lewis Sr, Samuel Arthur; Connatser, Raynella M

    2012-01-01

    Rapid pyrolysis of biomass generates a liquid with properties that are particularly attractive for production of hydrocarbons that could be substituted for liquid fuels derived from petroleum. However, the high oxygen content of the biomass derived liquids presents a number of problems because of the high water content and the considerable concentration of carboxylic acids. Measurements of total acid number (TAN) of pyrolysis oil (bio-oil) samples show that values in the 90-100 range are fairly common. This level of acidity has been shown to cause corrosion problems that have to be addressed in the selection of structural materials that are used in the production, subsequent processing, storage and transport of the pyrolysis oils. Chemical analyses have been performed and laboratory corrosion studies have been conducted in order to assess the aggressiveness of the raw pyrolysis oil from several sources as well as the corrosion caused by a bio-oil that has been treated to reduce the acid and oxygen content. Components of biomass pyrolyzers have also been fabricated from various candidate alloys, and these components have been exposed for extended periods during operation of the pyrolyzers. This paper will report on results of these analyses and corrosion studies.

  20. Density Functional Theory and Electrochemical Studies: Structure-Efficiency Relationship on Corrosion Inhibition.

    PubMed

    Camacho-Mendoza, Rosa L; Gutiérrez-Moreno, Evelin; Guzmán-Percástegui, Edmundo; Aquino-Torres, Eliazar; Cruz-Borbolla, Julián; Rodríguez-Ávila, José A; Alvarado-Rodríguez, José G; Olvera-Neria, Oscar; Thangarasu, Pandiyan; Medina-Franco, José L

    2015-11-23

    The relationship between structure and corrosion inhibition of a series of 30 imidazol, benzimidazol, and pyridine derivatives has been established through the investigation of quantum descriptors calculated with PBE/6-311++G**. A quantitative structure-property relationship model was obtained by examination of these descriptors using a genetic functional approximation method based on a multiple linear regression analysis. Our results indicate that the efficiency of corrosion inhibitors is strongly associated with aromaticity, electron donor ability, and molecular volume descriptors. In order to calibrate and validate the proposed model, we performed electrochemical impedance spectroscopy (EIS) studies on imidazole, 2-methylimidazole, benzimidazole, 2-chloromethylbenzimidazole, pyridine, and 2-aminopyridine compounds. The experimental values for efficiency of corrosion inhibition are in good agreement with the estimated values obtained by our model, thus confirming that our approach represents a promising and suitable tool to predict the inhibition of corrosion attributes of nitrogen containing heterocyclic compounds. The adsorption behavior of imidazole or benzimidazole heterocyclic molecules on the Fe(110) surface was also studied to elucidate the inhibition mechanism; the aromaticity played an important role in the adsorbate-surface complex.

  1. Corrosion study of iron-cobalt alloys for MRI-based propulsion embedded in untethered microdevices operating in the vascular network.

    PubMed

    Pouponneau, Pierre; Savadogo, Oumarou; Napporn, Teko; Yahia, L'hocine; Martel, Sylvain

    2010-04-01

    Our group have shown in an experiment performed in the carotid artery of a living swine that magnetic gradients generated by a clinical magnetic resonance imaging (MRI) system could propel and navigate untethered medical microdevices and micro-nanorobots in the human vasculature. The main problem with these devices is that the metal necessary for magnetic propulsion may corrode and induce cytotoxic effects. The challenge, then, is to find an alloy with low corrosion yet providing an adequate magnetization level for propulsion in often stringent physiological conditions. Because of their high magnetization, we studied the corrosion behavior of two iron-cobalt alloys, Permendur (49% Fe, 49% Co, 2% V) and Vacoflux 17 (81% Fe, 17% Co, 2% Cr), in physiological solution by potentiodynamic polarization assay, surface analysis, and corrosion electrolyte analysis. Both alloys exhibited low corrosion parameters such as a corrosion potential (E(corr)) of -0.57 V/SCE and E(corr) of -0.42 V/SCE for Vacoflux 17. The surface of Permendur samples was homogenously degraded. Vacoflux 17 surface was impaired by cracks and crevices. Both alloys had a stoichiometric dissolution in the electrolyte, and they released enough cobalt to induce cytotoxic effects. This study concluded that Fe-Co alloys could be used preferably in medical microdevices if they were coated so as not to come in contact with physiological solutions.

  2. Corrosion performance of materials for advanced combustion systems

    SciTech Connect

    Natesan, K.; Yanez-Herrero, M.; Fornasieri, C.

    1993-12-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high-temperature furnaces and heat transfer surfaces capable of operating at more elevated temperatures than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitates development/application of advanced ceramic materials in these designs. This report characterizes the chemistry of coal-fired combustion environments over the wide temperature range that is of interest in these systems and discusses preliminary experimental results on several materials (alumina, Hexoloy, SiC/SiC, SiC/Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4}, ZIRCONIA, INCONEL 677 and 617) with potential for application in these systems.

  3. Corrosion resistance of alloy 803 in environments applicable to fossil energy systems

    SciTech Connect

    Ganesan, P.; Smith, G.D.; Tassen, C.S.

    1995-11-01

    Alloy 803 was developed for applications in the chemical process industries such as ethylene pyrolysis that require enhanced resistance to oxidation and carbonation. In addition to carburization resistance, ethylene pyrolysis furnace tube alloys must also possess adequate stress rupture strength. In environments containing mixed oxidants (oxygen and sulfur), and a high carbon activity such as coal combustion systems, it is known that accelerated oxidation/sulfidation is generally preceded by carburization. An alloy that has a superior oxidation and carburization resistance, would be expected to perform better in environments containing mixed oxidants. This paper will present corrosion performance data for the newly developed alloy in a mixed oxidant environment as well as oxidation and carburization environments. In the case of carburization tests, experiments were conducted to study the effect of carburization on the stress rupture strength of alloy 803 by exposing the stress rupture test specimens in H{sub 2}-5.5 % CH{sub 4}-4.5% CO{sub 2} for 300 hours at 982 C (1,800 F) and then stress rupture testing at 982 C/20.7 MPa (1800 F/3ksi). The results of these tests and other mechanical properties will be presented and compared with alloy HPM, an alloy that is also used for ethylene pyrolysis tubing. Suitable filler metals and welding electrodes to join alloy 803 will also be covered.

  4. The corrosion phenomena in the coin cell BR2325 of the ``superstoichiometric fluorocarbon-lithium'' system

    SciTech Connect

    Mitkin, V.N.; Galkin, P.S.; Denisova, T.N.

    1998-07-01

    It was noted at the earlier study and at the longer observations of the novel various types of superstoichiometric fluorocarbon materials CF{sub 1+x}, where x = 0.1--0.33 (FCM) and their behavior, that despite of their known hygroscopity during a storage of samples in laboratory and technological utensils nevertheless occurs an appreciable sorption of atmospheric moisture. The color of samples does not change but sometimes there appears a smell of hydrogen fluoride and even corrosion of glasswares at a long storage. On the basis of these facts was assumed that at a long storage the slow reactions of HF producing with a sorption moisture can proceed. This phenomena is necessary to take into account for successful manufacturing of long life lithium cells based on superstoichiometric fluorocarbon composite cathodes (FCC). The chemistry of such slow hydrolytic process and especially of processes which can proceed at manufacturing of FCC earlier was not investigated also of any data in the literature in this occasion is not present. Just for this reason the authors undertook a study of the corrosion phenomena which can proceed in industrial sources of a current at a long storage under influence of slow hydrolysis of C-F bonds by moisture. The goal of the study was to search long term damages in the slightly wet FCM and based on these materials cathodic composites for fluorocarbon-lithium cells. As a model for corrosion process investigation they have chosen a standard coin lithium battery of a type BR2325.

  5. Classification of corrosion risk zones using GIS

    NASA Astrophysics Data System (ADS)

    Georgiou, Nikolas; Anastasiou, Constantina; Tantele, Elia A.; Votsis, Renos A.; Danezis, Chris

    2016-08-01

    Corrosion of steel reinforcement is the major deterioration factor of the RC infrastructures. Several factors are contributing towards increasing the corrosion risk like the exposure and environmental conditions which are a function of the geographical location of the infrastructure. Information for these conditions and their affected areas can be proved valuable at design stage and/or during maintenance planning. This study aims to relate corrosion risk of RC infrastructures with their geographical location. The corrosion risk is quantified through data from NDT methods and subsequently correlated with its location. Therefore high risk areas with structures prone to corrosion deterioration are identified. The latter is implemented via GIS tools in order to create maps that describe how corrosion risk is related to the location of each structure. Two GIS methods are suggested, the grid system and the use of classified areas. Corrosion data has been collected from labs about various constructions in Cyprus and used in conjunction with GIS tools to provide useful information on corrosion identification. The outcome is a digitized map of the Limassol area which indicates the risks levels associated with corrosion of the steel reinforcement.

  6. Corrosion and its effect on mechanical properties of materials for advanced combustion systems

    SciTech Connect

    Natesan, K.; Freeman, M.; Mathur, M.

    1996-05-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high-temperature furnaces and heat transfer surfaces that can operate at temperatures much higher than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitates development and application of advanced ceramic materials in these designs. The objectives of the present program are to evaluate (a) the chemistry of gaseous and condensed products that arise during combustion of coal; (b) the corrosion behavior of candidate materials in air, slag and salt environments for application in the combustion environments; and (c) the residual mechanical properties of the materials after corrosion. The program emphasizes temperatures in the range of 1000-1400{degrees}C for ceramic materials and 600-1000{degrees}C for metallic alloys. Coal/ash chemistries developed on the basis of thermodynamic/kinetic calculations, together with slags from actual combustors, are used in the program. The materials being evaluated include monolithic silicon carbide from several sources: silicon, nitride, silicon carbide in alumina composites, silicon carbide fibers in a silicon carbide- matrix composite, and some advanced nickel-base alloys. The paper presents results from an ongoing program on corrosion performance of candidate ceramic materials exposed to air, salt and slag environments and their affect on flexural strength and energy absorbed during fracture of these materials.

  7. Strontium concentrations in corrosion products from residential drinking water distribution systems.

    PubMed

    Gerke, Tammie L; Little, Brenda J; Luxton, Todd P; Scheckel, Kirk G; Maynard, J Barry

    2013-05-21

    The United States Environmental Protection Agency (US EPA) will require some U.S. drinking water distribution systems (DWDS) to monitor nonradioactive strontium (Sr(2+)) in drinking water in 2013. Iron corrosion products from four DWDS were examined to assess the potential for Sr(2+) binding and release. Average Sr(2+) concentrations in the outermost layer of the corrosion products ranged from 3 to 54 mg kg(-1) and the Sr(2+) drinking water concentrations were all ≤0.3 mg L(-1). Micro-X-ray adsorption near edge structure spectroscopy and linear combination fitting determined that Sr(2+) was principally associated with CaCO3. Sr(2+) was also detected as a surface complex associated with α-FeOOH. Iron particulates deposited on a filter inside a home had an average Sr(2+) concentration of 40.3 mg kg(-1) and the associated drinking water at a tap was 210 μg L(-1). The data suggest that elevated Sr(2+) concentrations may be associated with iron corrosion products that, if disturbed, could increase Sr(2+) concentrations above the 0.3 μg L(-1) US EPA reporting threshold. Disassociation of very small particulates could result in drinking water Sr(2+) concentrations that exceed the US EPA health reference limit (4.20 mg kg(-1) body weight).

  8. Predicting the corrosivity of an operating FGD system

    SciTech Connect

    Hodge, F.G.; Silence, W.L.; Wright, D.

    1994-12-31

    One of the key factors that influences the materials selection process for a FGD system is the anticipated environmental conditions. Due to the wide variations in coal burned, a method was needed that could predict the environment that would be generated. A computer model has been generated that will predict, with some degree of accuracy, the maximum concentration of sulfuric acid that will form by condensation at the inlet and the outlet of the scrubber. Having generated the model, experiments were performed to confirm the predictions by collecting samples from an operating FGD system and analyzing the acid content. Results generated have confirmed that acid concentration in the duct work can be anticipated and the effects of other process variables such as reheat can be predicted.

  9. A laboratory study of the effect of NO 2 on the atmospheric corrosion of zinc

    NASA Astrophysics Data System (ADS)

    Castaño, J. G.; de la Fuente, D.; Morcillo, M.

    Studies on the effect of NO x on zinc corrosion are scarce and their results are variable and at times seemingly contradictory. This paper reports laboratory tests involving the dry deposition on zinc surfaces of 800 μg m -3 NO 2, alone and in combination with 800 μg m -3 SO 2, at temperatures of 35 and 25 °C and relative humidities of 90% and 70%. From the gravimetric results obtained and from the characterisation of the corrosion products by optical microscopy, scanning electron microscopy (SEM/EDX), grazing incidence X-ray diffraction (GIXD) and X-ray photoelectron spectroscopy (XPS), it has been verified that the corrosive action of NO 2 alone is negligible compared with SO 2. However, an accelerating effect has been observed when NO 2 acts in conjunction with SO 2 at 25 °C and 90% RH. At 35 °C and 90% RH, the accelerating effect is smaller, and at low relative humidities (70%), the synergistic effect is only slight, which suggests it may be favoured by the presence of moisture. In those cases where an accelerating effect has been observed, a greater proportion of sulphate ions has been found in the corrosion products, and nitrogen compounds have not been detected, indicating that NO 2 participates indirectly as a catalyst of the oxidation of SO 2 to sulphate.

  10. Atomistic Studies of Cation Transport in Tetragonal ZrO2 During Zirconium Corrosion

    SciTech Connect

    Xian-Ming Bai; Yongfeng Zhang; Michael R. Tonks

    2013-10-01

    Zirconium alloys are the major fuel cladding materials in current reactors. The water-side corrosion is one of the major degradation mechanisms of these alloys. During corrosion the transport of oxidizing species in zirconium dioxide (ZrO2) determines the corrosion kinetics. Previously it has been argued that the outward diffusion of cation ions is important for forming protective oxides. In this work, the migration of Zr defects in tetragonal ZrO2 is studied with temperature accelerated dynamics and molecular dynamics simulations. The results show that Zr interstitials have anisotropic diffusion and migrate preferentially along the [001] or c direction in tetragonal ZrO2. The compressive stresses can increase the Zr interstitial migration barrier significantly. The migration barriers of some defect clusters can be much lower than those of point defects. The migration of Zr interstitials at some special grain boundaries is much slower than in a bulk oxide. The implications of these atomistic simulation results in the Zr corrosion are discussed.

  11. Study on the corrosion properties of nanocrystalline nickel electrodepositied by reverse pulse current

    NASA Astrophysics Data System (ADS)

    Cheng, Wen; Ge, Wen; Yang, Qian; Qu, Xinxin

    2013-07-01

    Nanocrystalline nickel coatings were produced by the method of reverse pulse electrodepositing on the surface of steel sheets. The crystallite size of nanocrystalline nickel coatings was determined by X-ray diffraction (XRD). The effect of saccharin concentration on the crystallite size of the coatings was studied. The average crystallite sizes were diminished as a result of increasing saccharin concentration. CHI660C electrochemical workstation was used to determine the Tafel polarization curves and electrochemical impedance spectroscopy (EIS) of the coatings. The value of corrosion potential, natural corrosion current density, polarizaiton resistance and impedance was calculated, the results suggested that smaller grain size led to higher polarization resistance. EIS gave the charge transfer resistance Rct and pore resistance Rpo variation trend from beginning to 30 min. Scanning electron microscopy (SEM) examination showed the surface morphology of the nickel coatings after the neutral salt spray (NSS) test or bathing in 10% HCl. The images indicated that the corrosion behavior of nanocrystalline nickel coatings was pitting corrosion, the mechanism was also discussed.

  12. Comparative study of the corrosion product films formed in biotic and abiotic media

    SciTech Connect

    Videla, H.A.; Mele, M.F.L. de; Swords, C.; Edyvean, R.G.J.; Beech, I.B.

    1999-11-01

    The growth of sulfate-reducing bacteria (SRB) affects several important parameters at the metal/solution interface of carbon steel in liquid media such as pH and redox potential values, as well as modifications of the composition and structure of corrosion product layers. Electrochemical techniques for corrosion assessment and surface analyses by energy dispersion X-ray analysis (EDAX), X-ray photoelectron spectra (XPS), X-ray distraction (XRD) and electron microprobe analysis (EPMA) complemented with scanning electron microscopy (SEM) and atomic force microscopy (MM) observations, were used to study the structure and composition of protective films on carbon steel in abiotic and biotic media containing different sulfur anions. The results revealed that in biotic and abiotic sulfide films the outer layers were formed by both FeS and FeS{sub 2}, although the relative content of these compounds varied in each case. Usually, the corrosion product films biotically formed were more adherent to the metal surface than those developed abiotically. The latter were flaky and loosely adherent, thus differing in their function during the corrosion process.

  13. Corrosion prevention capability of polyaniline (emeraldine base and salt): An XPS study

    SciTech Connect

    Jasty, S.; Epstein, A.J.

    1995-12-01

    There has been a keen interest in the use of polyaniline coatings for the corrosion protection of Fe and its alloys. To date, the primary focus has been on the doped form of the emeraldine oxidation state; also, the polyaniline has been applied, electrochemically or chemically, as an overcoat on the metal. In the present study, the surface sensitive XPS technique has been applied to investigate (1) the effectiveness of the neutral emeraldine base as well as the doped emeraldine hydrochloride forms of polyaniline in corrosion inhibition and (2) the ability of a polyaniline undercoat in providing corrosion protection by passivating the exposed metal surface. Here 350{Angstrom} and 70{Angstrom} thick Fe was sputter deposited onto the polyaniline and control polymer (non-electroactive) substrates and exposed to different environments. We conclude that an undercoat of the neutral emeraldine base form of polyaniline passivates the outer metal (Fe) surface with a thin ({approximately} 30-50{Angstrom}) oxide layer of mainly hematite (Fe{sub 2}O{sub 3}) and that the passivation mechanism has an electronic origin. In contrast, Fe sputtered onto doped emeraldine hydrochloride forms a thicker oxide layer with a distribution of oxidation states, effectively providing much less corrosion protection.

  14. CORROSION MONITORING IN HANFORD NUCLEAR WASTE STORAGE TANKS DESIGN AND DATA FROM 241-AN-102 MULTI-PROBE CORROSION MONITORING SYSTEM

    SciTech Connect

    ANDA VS; EDGEMON GL; HAGENSEN AR; BOOMER KD; CAROTHERS KG

    2009-01-08

    In 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was installed in double-shell tank 241-AN-102 on the U.S. Department of Energy's Hanford Site in Washington State. Developmental design work included laboratory testing in simulated tank 241-AN-102 waste to evaluate metal performance for installation on the MPCMS as secondary metal reference electrodes. The MPCMS design includes coupon arrays as well as a wired probe which facilitates measurement of tank potential as well as corrosion rate using electrical resistance (ER) sensors. This paper presents the MPCMS design, field data obtained following installation of the MPCMS in tank 241-AN-102, and a comparison between laboratory potential data obtained using simulated waste and tank potential data obtained following field installation.

  15. A petrolatum based system for control of external corrosion in, on and around cooling towers

    SciTech Connect

    Berry, M.A.; Steely, C.N.

    1986-01-01

    While it is true that the initial cost of a petroleum based system may be slightly higher than that of paint, this article maintains that the cost can be amortized over a 12 or 15-year period, or in some cases even longer. In service maintenance costs on a square foot per year basis, compared to all other alternatives are minimal. Petrolatum systems for external corrosion control on and around cooling towers have been effective service for over fifteen years, in diversified industrial environments that include oil refineries, chemical process plants, power utilities, hospital and university complexes and steel mills.

  16. Study of caffeine as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    NASA Astrophysics Data System (ADS)

    Solehudin, Agus; Berman, Ega Taqwali; Nurdin, Isdiriayani

    2015-09-01

    The corrosion behaviour of steel surface in the absence and presence of caffeine in 3.5% NaCl solution containing dissolved H2S gas is studied using electrochemical impedance spectroscopy (EIS). The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different caffeine concentrations showed that corrosion rate of carbon steel decreases with increasing of caffeine concentrations from 0 to 0,1 mmol/l. Whereas, the corrosion rate increase with increasing of caffeine concentrations from 1 to 10 mmol/l. It is clear that no inhibition efficiency increases with increasing inhibitor concentration. The optimum value of inhibition efficiency was 90% at a caffeine concentration of 0.1 mmol/l. This suggests that caffeine's performance as a corrosion inhibitor is more effective at a concentration of 0.1 mmol/l.

  17. Corrosive ground water in the Kirkwood-Cohansey aquifer system in the vicinity of Ocean County, east-central New Jersey

    USGS Publications Warehouse

    Kish, George R.; Barringer, Julia L.; Ulery, Randy L.

    1989-01-01

    Corrosive groundwater, which has been linked to trace-metal leaching from plumbing materials in Europe and the United States , has been identified in the Coastal Plain of New Jersey. The corrosiveness of groundwater in the Kirkwood-Cohansey aquifer system in New Jersey has been estimated by calculating values for the Aggressive Index, using groundwater chemistry data. A contour map of Aggressive-Index values shows that groundwater is very corrosive in the vicinity of Ocean County, New Jersey. Areas with the least corrosive water are generally along the coast, whereas areas with the most corrosive water are farther inland. (USGS)

  18. Corrosion Detection Devices

    SciTech Connect

    Howard, B.

    2003-12-01

    Nondestructive Examination Systems' (NDE) specialists at the Department of Energy's Savannah River Site have unique, remotely controllable, corrosion detection capabilities. The corrosion detection devices most frequently used are automated ultrasonic mapping systems, digital radiography imaging devices, infrared imaging, and eddy current mapping systems. These devices have been successfully used in a variety of applications, some of which involve high levels of background radiation. Not only is corrosion located and mapped but other types of anomalies such as cracks have been detected and characterized. Examples of actual corrosion that has been detected will be discussed along with the NDE systems that were used.

  19. High-temperature corrosion and applications of nickel and iron aluminides in coal-conversion power systems

    SciTech Connect

    Natesan, K.; Tortorelli, P.F.

    1996-10-01

    Nickel and iron aluminide intermetallics are being developed for use as structural materials and/or as cladding for conventional engineering alloys. In addition to strength advantages, these materials exhibit excellent resistance to corrosion in single- and multioxidant environments at elevated temperatures by the formation of slow-growing, adherent alumina scales. Corrosion resistance in a given environment is strongly dependent on the composition of the alloy and on the nature of the corrosive species prevalent in the service environment. This paper presents a comprehensive review of the current status of the corrosion performance of these intermetallics in oxidizing, sulfidizing, and multicomponent gas environments of typical coal-conversion systems. Mechanisms of scale development/breakdown, performance envelopes for long-term usage of these materials, approaches to modifying the surfaces of engineering alloys by cladding or coating them with intermetallics, and in-service experience with these materials are emphasized.

  20. 40 CFR 141.81 - Applicability of corrosion control treatment steps to small, medium-size and large water systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of... to small, medium-size and large water systems. (a) Systems shall complete the applicable corrosion...) or (b)(3) of this section. (2) A small system (serving ≤3300 persons) and a medium-size...

  1. 40 CFR 141.81 - Applicability of corrosion control treatment steps to small, medium-size and large water systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of... to small, medium-size and large water systems. (a) Systems shall complete the applicable corrosion...) or (b)(3) of this section. (2) A small system (serving ≤3300 persons) and a medium-size...

  2. 40 CFR 141.81 - Applicability of corrosion control treatment steps to small, medium-size and large water systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of... to small, medium-size and large water systems. (a) Systems shall complete the applicable corrosion...) or (b)(3) of this section. (2) A small system (serving ≤3300 persons) and a medium-size...

  3. 40 CFR 141.81 - Applicability of corrosion control treatment steps to small, medium-size and large water systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of... to small, medium-size and large water systems. (a) Systems shall complete the applicable corrosion...) or (b)(3) of this section. (2) A small system (serving ≤3300 persons) and a medium-size...

  4. 40 CFR 141.81 - Applicability of corrosion control treatment steps to small, medium-size and large water systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of... to small, medium-size and large water systems. (a) Systems shall complete the applicable corrosion...) or (b)(3) of this section. (2) A small system (serving ≤3300 persons) and a medium-size...

  5. DIFFUSION COATINGS FOR CORROSION RESISTANT COMPONENTS IN COAL GASIFICATION SYSTEMS

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Angel Sanjurjo

    2005-01-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy may improve is resistance to such sulfidation attack and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this reporting period we coated coupons of selected alloy steels with diffusion coatings of Cr and Al, as well as with titanium and tantalum nitrides. The coated samples were analyzed for their surface composition. In several instances, the samples were also cut to determine the depth profile of the coating. Several of the early runs did not yield uniform or deep enough coatings and hence a significant portion of the effort in this period was devoted fixing the problems with our fluidized bed reactor. Before the end of the quarter we had prepared a number of samples, many of them in duplicates, and sent one set to Wabash River Energy Laboratory for them to install in their gasifier. The gasifier was undergoing a scheduled maintenance and thus presented an opportunity to place some of our coupons in the stream of an operating gasifier. The samples submitted included coated and uncoated pairs of different alloys.

  6. Secondary effects of anion exchange on chloride, sulfate, and lead release: systems approach to corrosion control.

    PubMed

    Willison, Hillary; Boyer, Treavor H

    2012-05-01

    Water treatment processes can cause secondary changes in water chemistry that alter finished water quality including chloride, sulfate, natural organic matter (NOM), and metal release. Hence, the goal of this research was to provide an improved understanding of the chloride-to-sulfate mass ratio (CSMR) with regards to chloride and sulfate variations at full-scale water treatment plants and corrosion potential under simulated premise plumbing conditions. Laboratory corrosion studies were conducted using Pb-Sn solder/Cu tubing galvanic cells exposed to model waters with low (approx. 5 mg/L Cl(-) and 10 mg/L SO(4)(2-)) and high (approx. 50 mg/L Cl(-) and 100 mg/L SO(4)(2-)) concentrations of chloride and sulfate at a constant CSMR of ≈ 0.5. The role of NOM during corrosion was also evaluated by changing the type of organic material. In addition, full-scale sampling was conducted to quantify the raw water variability of chloride, sulfate, and NOM concentrations and the changes to these parameters from magnetic ion exchange treatment. Test conditions with higher concentrations of chloride and sulfate released significantly more lead than the lower chloride and sulfate test waters. In addition, the source of NOM was a key factor in the amount of lead released with the model organic compounds yielding significantly less lead release than aquatic NOM. PMID:22374301

  7. Part I. Corrosion studies of continuous alumina fiber reinforced aluminum-matrix composites. Part II. Galvanic corrosion between continuous alumina fiber reinforced aluminum-matrix composites and 4340 steel

    NASA Astrophysics Data System (ADS)

    Zhu, Jun

    Part I. The corrosion performance of continuous alumina fiber reinforced aluminum-matrix composites (CF-AMCs) was investigated in both the laboratory and field environments by comparing them with their respective monolithic matrix alloys, i.e., pure Al, A1-2wt%Cu T6, and Al 6061 T6. The corrosion initiation sites were identified by monitoring the changes in the surface morphology. Corrosion current densities and pH profiles at localized corrosion sites were measured using the scanning-vibrating electrode technique and the scanning ion-selective electrode technique, respectively. The corrosion damage of the materials immersed in various electrolytes, as well as those exposed in a humidity chamber and outdoor environments, was evaluated. Potentiodynamic polarization behavior was also studied. The corrosion initiation for the composites in 3.15 wt% NaCl occurred primarily around the Fe-rich intermetallic particles, which preferentially existed around the fiber/matrix interface on the composites. The corrosion initiation sites were also caused by physical damage (e.g., localized deformation) to the composite surface. At localized corrosion sites, the buildup of acidity was enhanced by the formation of micro-crevices resulting from fibers left in relief as the matrix corroded. The composites that were tested in exposure experiments exhibited higher corrosion rates than their monolithic alloys. The composites and their monolithic alloys were subjected to pitting corrosion when anodically polarized in the 3.15 wt% NaCl, while they passivated when anodically polarized in 0.5 M Na2SO4. The experimental results indicated that the composites exhibited inferior corrosion resistance compared to their monolithic matrix alloys. Part II. Galvanic corrosion studies were conducted on CF-AMCs coupled to 4340 steel since CF-AMCs have low density and excellent mechanical properties and are being considered as potential jacketing materials for reinforcing steel gun barrels. Coupled and

  8. Does Taper Angle Clearance Influence Fretting and Corrosion Damage at the Head-Stem Interface? A Matched Cohort Retrieval Study

    PubMed Central

    Kocagöz, Sevi B.; Underwood, Richard J.; Sivan, Shiril; Gilbert, Jeremy L.; MacDonald, Daniel W.; Day, Judd S.; Kurtz, Steven M.

    2014-01-01

    Previous studies have speculated that modular taper design may have an effect on the corrosion and material loss at the taper surfaces. We present a novel method to measure taper angle for retrieved head taper and stem trunnions using a roundness machine (Talyrond 585, Taylor Hobson, UK). We also investigated the relationship between taper angle clearance and visual fretting-corrosion score at the taper-trunnion junction using a matched cohort study of 50 ceramic and 50 metal head-stem pairs. In this study, no correlation was observed between the taper angle clearance and the visual fretting-corrosion scores in either the ceramic or the metal cohorts. PMID:24610994

  9. Metal levels in corrosion of spinal implants

    PubMed Central

    Beguiristain, Jose; Duart, Julio

    2007-01-01

    Corrosion affects spinal instrumentations and may cause local and systemic complications. Diagnosis of corrosion is difficult, and nowadays it is performed almost exclusively by the examination of retrieved instrumentations. We conducted this study to determine whether it is possible to detect corrosion by measuring metal levels on patients with posterior instrumented spinal fusion. Eleven asymptomatic patients, with radiological signs of corrosion of their stainless steel spinal instrumentations, were studied by performing determinations of nickel and chromium in serum and urine. Those levels were compared with the levels of 22 patients with the same kind of instrumentation but without evidence of corrosion and to a control group of 22 volunteers without any metallic implants. Statistical analysis of our results revealed that the patients with spinal implants without radiological signs of corrosion have increased levels of chromium in serum and urine (P < 0.001) compared to volunteers without implants. Corrosion significantly raised metal levels, including nickel and chromium in serum and urine when compared to patients with no radiological signs of corrosion and to volunteers without metallic implants (P < 0.001). Metal levels measured in serum have high sensibility and specificity (area under the ROC curve of 0.981). By combining the levels of nickel and chromium in serum we were able to identify all the cases of corrosion in our series of patients. The results of our study confirm that metal levels in serum and urine are useful in the diagnosis of corrosion of spinal implants and may be helpful in defining the role of corrosion in recently described clinical entities such as late operative site pain or late infection of spinal implants. PMID:17256156

  10. Corrosion studies at the Wilsonville, Alabama, coal liquefaction facility during 1983

    SciTech Connect

    Keiser, J.R.; Olsen, A.R.; Newsome, J.F.; Howell, M.

    1984-10-01

    During 1983, Oak Ridge National Laboratory continued a study of materials performance at the Wilsonville, Alabama, Advanced Coal Liquefaction Research and Development Facility. Materials performance was evaluated by exposure and analysis of corrosion coupons and U-bend specimens, chemical analysis of related process streams, and ultrasonic determination of the thickness of walls of various components. The results of these studies are useful to current plant operators and to designers of future large-scale plants. 18 references, 4 figures, 12 tables.

  11. Mechanically assisted taper corrosion in modular TKA.

    PubMed

    Arnholt, Christina M; MacDonald, Daniel W; Tohfafarosh, Mariya; Gilbert, Jeremy L; Rimnac, Clare M; Kurtz, Steven M; Klein, Gregg; Mont, Michael A; Parvizi, Javad; Cates, Harold E; Lee, Gwo-Chin; Malkani, Arthur; Kraay, Mattheuw

    2014-09-01

    The purpose of this study was to characterize the prevalence of taper damage in modular TKA components. One hundred ninety-eight modular components were revised after 3.9±4.2 years of implantation. Modular components were evaluated for fretting corrosion using a semi-quantitative 4-point scoring system. Design features and patient information were assessed as predictors of fretting corrosion damage. Mild-to-severe fretting corrosion (score ≥2) was observed in 94/101 tapers on the modular femoral components and 90/97 tapers on the modular tibial components. Mixed alloy pairs (p=0.03), taper design (p<0.001), and component type (p=0.02) were associated with taper corrosion. The results from this study supported the hypothesis that there is taper corrosion in TKA. However the clinical implications remain unclear.

  12. Preliminary study of corrosion mechanisms of actinides alloys: calibration of FT-IR spectroscopy

    SciTech Connect

    Magnien, Veronique; Cadignan, Marx; Faivret, Olivier; Rosa, Gaelle

    2008-07-01

    In situ analyzes of gaseous atmospheres could be performed by FT-IR spectroscopy in order to study the corrosion reactions of actinides. Nevertheless experimental conditions and the nature of studied species have a strong effect on IR absorption laws. Thus a prior calibration of our set-up is required to obtain an accurate estimation of gas concentration. For this purpose, the behavior of several air pure gases has been investigated according to their concentration from IR spectra. Reproducible results revealed subsequent increases of the most significant peak areas with gas pressure and small deviations from Beer Lambert's law. This preliminary work allowed to determine precise absorption laws for each studied pure gas in our in situ experimental conditions. Besides our FT-IR set-up was well suitable to quantitative analysis of gaseous atmosphere during corrosion reactions. Finally the effect of foreign gas will be investigated through more complex air mixtures to obtain a complete calibration network. (authors)

  13. Corrosion problems with aqueous coolants, final report

    SciTech Connect

    Diegle, R B; Beavers, J A; Clifford, J E

    1980-04-11

    The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

  14. Development of improved and corrosion-resistant surfaces for fossil power system components

    SciTech Connect

    Sikka, V.K.; Santella, M.L.; Goodwin, G.M.

    1996-06-01

    The purpose of this task is to develop the corrosion-resistant surfaces on a variety of fossil power system components. The Fe-Al alloys ranging in aluminum from 16 to 36 @ % are of interest. The surfaces of Fe-Al alloys can be produced by weld overlay. However, because of their limited room-temperature ductility, the production of weld wire for these compositions is not commercially feasible. The alloying element dilution during weld overlay also makes depositing exact surface composition rather difficult.

  15. Corrosion Resistance Characterization of Coating Systems Used to Protect Aluminum Alloys Using Electrochemical Impedance Spectroscopy and Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Gambina, Federico

    In this study, the corrosion protection provided by of a number of chromate and chromate-free coatings systems was characterized in detail. High-solids SrCrO4-pigmented epoxy primers applied to 2024 and 7075 substrates were subject to salt spray exposure testing for 30 days. Samples were removed periodically and an electrochemical impedance measurement (EIS) was made. Although none of the coatings tested showed visual evidence of corrosion, the total impedance of the samples decreased by as much as two orders of magnitude. An analysis of capacitance showed that the primer coatings rapidly took up water from the exposure environment, but the coating-metal remained passive despite the fact that it was wet. These results support the idea that chromate coatings protect by creating a chromate-rich electrolyte within the coating that is passivating to the underlying metal substrate. They also suggest that indications of metal substrate passivity found in the low-frequency capacitive reactance of the impedance spectra are a better indicator of corrosion protection than the total impedance. The low-frequency capacitive reactance from EIS measurements is also good at assessing the protectiveness of chromate-free coatings systems. Fifteen different coatings systems comprising high-solids, chromate-free primers and chromate-free conversion coatings were applied to 2024 and 7075 substrates. These coatings were subject to salt spray exposure and EIS measurements. All coatings were inferior to coating systems containing chromate, but changes in the capacitive reactance measured in EIS was shown to anticipate visual indications of coating failure. A predictive model based on neural networks was trained to recognize the pattern in the capacitive reactance in impedance spectra measured after 48 hours of exposure and make an estimate of remaining coating life. A sensitivity analysis was performed to prune the impedance inputs. As a result of this analysis, a very simple but highly

  16. Materials problems in fluidized-bed combustion systems: high-temperature erosion-corrosion by high-velocity (200ms/s) particles

    SciTech Connect

    Barkalow, R.H.; Goebel, J.A.; Pettit, F.S.

    1980-05-01

    The response of nickel- and cobalt base superalloys, aluminide coatings for these alloys, and Si/sub 3/N/sub 4/ to erosion-oxidation and erosion-hot corrosion conditions has been studied at 871/sup 0/C (1600/sup 0/F) in a high velocity gas stream 200 m/sec (656 ft/sec). The experiments were performed in a dynamic combustor (burner rig) operated on aircraft-grade jet fuel and compressed air. Erosive conditions were achieved by injecting abrasive powder into the burner rig. Alumina powders with average particle sizes of 20, 2.5, and 0.3 ..mu..m MgO were used as abrasive media. In the erosion-oxidation experiments, Si/sub 3/N/sub 4/ was much more resistant to degradation than all the metallic systems. For all the metallic systems it was found that: with 20 ..mu..m Al/sub 2/O/sub 3/ particles, material loss occurred because of mechanical erosion; with 2 ..mu..m Al/sub 2/O/sub 3/ particles, the materials degradation involved an interaction between oxidation and erosion such that the formation of Al/sub 2/O/sub 3/ scales inhibited erosion; deposition of 0.3 ..mu..m Al/sub 2/O/sub 3/ particles occurred on specimens and these particles did not establish an erosive component; and the magnitude of the erosive component increased as the hardness of the abrasive increased. Silicon nitride was much more resistant than the metallic systems in the erosion-hot corrosion test; erosion-hot corrosion using 2 ..mu..m Al/sub 2/O/sub 3/ occurred at rates greater than the sum of the rates of erosion and hot corrosion acting independent of one another; the interaction between hot corrosion and erosion was not affected by the particle hardness; and deposition of 0.3 ..mu..m Al/sub 2/O/sub 3/ during hot corrosion caused the degradation rates to decrease. The erosion-oxidation behavior of the metallic systems was consistent with the theory for ductile erosion. The synergism between erosion and hot corrosion occurs because each process establishes conditions that accelerate the other.

  17. A corrosion control concept by scale engineering: a novel green inhibitor applied for high temperature and pressure aqueous supercritical CO2 systems

    SciTech Connect

    Jiabin, Han; Carey, James W; Zhang, Jinsuo

    2011-01-27

    Traditional corrosion inhibitors are bio-toxic chemicals with organic components that bond to the fresh metal surface and thus isolate them from corrosive environments. The shortcoming of these inhibitors is that they are less effective in high-temperature and high-pressure environments, and where corrosion scale is formed or particulates are deposited. In this paper, we describe a novel green inorganic inhibitor made of environmentally friendly and cost-effective geo-material that was developed for high-temperature and high-pressure environments, particularly under scale-forming conditions. It inhibits corrosion by enhancing the protectiveness of corrosion scale. In contrast to traditional corrosion inhibitors which are efficient for bare surface corrosion but not effective with scale, the novel inhibitor has no effect on bare surface corrosion but greatly improves corrosion inhibition under scale-formation conditions. This is because a homogeneous scale doped with inhibitor component forms. This enhanced corrosion scale demonstrated excellent protection against corrosion. In high-pressure CO{sub 2} systems (pCO{sub 2}=10 Mpa, T=50 C and [NaCl]=1 wt%) without inhibitor, the bare-surface corrosion rate decreases from ca. 10 mm/y to 0.3 mm/year due to formation of scale. Application of a six hundred ppm solution ofthe new inorganic inhibitor reduced the corrosion rate to 0.01 mm/year, an additional factor of 30. The current inhibitor product was designed for application to CO{sub 2} systems that form corrosion scale, including but not limited to oil and gas wells, offshore production of oil and gas, CO{sub 2} sequestration and enhanced geothermal production involving CO{sub 2}.

  18. Pipe loop demonstration study of corrosion control alternatives at a pH of 10

    SciTech Connect

    Yannoni, C.C.; Clark, S.D.; Rafanovic, R.O.; Covellone, M.A.; Crosby, F.J.; Neff, C.H.

    1995-12-01

    The Federal Safe Drinking Water Act (SDWA) under the Lead and Copper Rule (LCR) requires many water supply utilities to reevaluate their current method of corrosion control and has resulted in the implementation of numerous capital improvements and/or changes in water treatment plant operations. The Providence Water Supply Board (PWSB) serves more than 600,000 people and maintains a pH of 10 through the treatment plant and water distribution system. Maintaining a pH of 10 results in a calcium carbonate precipitation potential (CCPP) of 5 to 12 mg/l expressed as calcium carbonate. Theoretically, a positive CCPP will result in the precipitation of calcium carbonate which maintains a thin protective film along the interior walls of water distribution pipe and helps minimize lead and copper solubility. Monitoring results indicated that lead levels were close to maximum allowable limits. The application of a pipe loop demonstration study provided information on alternative treatment methodologies to minimize lead solubility while maintaining a pH close to 10.0. Sodium silicate inhibition and dissolved inorganic carbonate (DIC) adjustment were two treatment methodologies which resulted in reducing lead levels by 50 percent.

  19. Oral Factors Affecting Titanium Elution and Corrosion: An In Vitro Study Using Simulated Body Fluid

    PubMed Central

    Suito, Hideki; Iwawaki, Yuki; Goto, Takaharu; Tomotake, Yoritoki; Ichikawa, Tetsuo

    2013-01-01

    Objectives Ti, which is biocompatible and resistant to corrosion, is widely used for dental implants, particularly in patients allergic to other materials. However, numerous studies have reported on Ti allergy and the in vitro corrosion of Ti. This study investigated the conditions that promote the elution of Ti ions from Ti implants. Methods Specimens of commercially pure Ti, pure nickel, a magnetic alloy, and a gold alloy were tested. Each specimen was immersed in a simulated body fluid (SBF) whose pH value was controlled (2.0, 3.0, 5.0, 7.4, and 9.0) using either hydrochloric or lactic acid. The parameters investigated were the following: duration of immersion, pH of the SBF, contact with a dissimilar metal, and mechanical stimulus. The amounts of Ti ions eluted were measured using a polarized Zeeman atomic absorption spectrophotometer. Results Eluted Ti ions were detected after 24 h (pH of 2.0 and 3.0) and after 48 h (pH of 9.0). However, even after 4 weeks, eluted Ti ions were not detected in SBF solutions with pH values of 5.0 and 7.4. Ti elution was affected by immersion time, pH, acid type, mechanical stimulus, and contact with a dissimilar metal. Elution of Ti ions in a Candida albicans culture medium was observed after 72 h. Significance Elution of Ti ions in the SBF was influenced by its pH and by crevice corrosion. The results of this study elucidate the conditions that lead to the elution of Ti ions in humans, which results in implant corrosion and Ti allergy. PMID:23762461

  20. An electrochemical and surface analysis study of the influence of phosphorus on the corrosion of iron in calcium nitrate

    SciTech Connect

    Windisch, C.F. Jr.; Baer, D.R.; Jones, R.H.; Engelhard, M.H.

    1990-10-01

    Intergranular stress corrosion cracking (IGSCC) of metallic alloys including iron is strongly influenced by the presence of grain boundary impurities such as phosphorus. In this study to determine how phosphorus affects the corrosion of iron, electrochemical polarization methods were used in conjunction with surface analyses employing ultra-high vacuum transfer. Specifically, these methods were used to examine the corrosion of iron, iron/phosphorus alloys, and iron implanted with phosphorus in deaerated 55 wt % Ca(NO{sub 3}){sub 2} solutions at 60{degree}C. 18 refs., 13 figs., 1 tab.

  1. A study on corrosion resistant graphene films on low alloy steel

    NASA Astrophysics Data System (ADS)

    Sai Pavan, A. S.; Ramanan, Sutapa Roy

    2016-04-01

    Graphene nanosheets were produced after synthesizing graphene oxide via Hummer's method and a modified Hummer's method. The obtained graphene after reduction was dispersed in 1-propanol to get a coating solution. Mild steel coupons were coated with the graphene solution via dip coating method. Corrosion studies were carried out at different environments like water (pH 6.0), HCl (0.1 N), NaCl (3.5 wt%) and NaOH (1 M). Tafel analysis showed a reduction in the corrosion rate up to 99 % after three layer deposition with the graphene developed using the modified Hummer's method. X-ray diffraction and Raman Spectroscopy confirmed the presence of graphene.

  2. Method for studying stabilization of localized corrosion on carbon steel by sulfate-reducing bacteria

    SciTech Connect

    Campaignolle, X.; Crolet, J.L.

    1997-06-01

    Initiation of a corrosion pit in plain carbon steel (CS) was simulated by preconditioning a small area and a larger concentric area as an anode and cathode, respectively. Preconditioning was achieved by applying a galvanic current between the electrodes. During this initial step, the effect of sulfate-reducing bacteria (SRB) on resulting polarization of this artificial galvanic cell was investigated. The previously conditioned electrodes then were left short-circuited, and the naturally flowing galvanic current was measured using a zero-resistance ammeter. In the presence of SRB biofilms, an active and naturally stable galvanic cell was achieved. In sterile conditions, the coupling current either was unstable or very low. This technique was aimed at studying risk factors linking bacterial contamination to the onset of rapid pitting corrosion.

  3. Uncertainty studies of topographical measurements on steel surface corrosion by 3D scanning electron microscopy.

    PubMed

    Kang, K W; Pereda, M D; Canafoglia, M E; Bilmes, P; Llorente, C; Bonetto, R

    2012-02-01

    Pitting corrosion is a damage mechanism quite serious and dangerous in both carbon steel boiler tubes for power plants which are vital to most industries and stainless steels for orthopedic human implants whose demand, due to the increase of life expectation and rate of traffic accidents, has sharply increased. Reliable methods to characterize this kind of damage are becoming increasingly necessary, when trying to evaluate the advance of damage and to establish the best procedures for component inspection in order to determine remaining lives and failure mitigation. A study about the uncertainties on the topographies of corrosion pits from 3D SEM images, obtained at low magnifications (where errors are greater) and different stage tilt angles were carried out using an in-house software previously developed. Additionally, measurements of pit depths on biomaterial surfaces, subjected to two different surface treatments on stainless steels, were carried out. The different depth distributions observed were in agreement with electrochemical measurements.

  4. Study of electrodeposited polypyrrole coatings for the corrosion protection of stainless steel bipolar plates for the PEM fuel cell

    NASA Astrophysics Data System (ADS)

    García, M. A. Lucio; Smit, Mascha A.

    Polypyrrole coatings were prepared on stainless steel SS304 in order to study the corrosion protection provided by the conductive polymer in a simulated PEM fuel cell environment. The polypyrrole was deposited by electrochemical polymerization with 0.04, 0.07 and 0.14 g cm -2 onto SS304 electrodes. Polarization curves, taken after immersion for 1, 3 or 24 h in 0.1 M sulphuric acid at either room temperature or 60 °C were used as an accelerated test. For short immersion times, it was found that corrosion current densities (at free corrosion potentials), diminished up to 2 orders of magnitude for samples tested at room temperature and up to 4 orders of magnitude for samples tested at 60 °C. Furthermore, at potentials in the range of the PEM fuel cell anode potential, corrosion rates also decreased up to several orders of magnitude. However, these protective properties were lost at longer times of immersion. The addition of DBSA to the polypyrrole coatings did lead to improved corrosion current densities at the free corrosion potential, however due to the loss of passivity of these samples, the corrosion rates in the potential range applicable to PEM fuel cells were either similar to or larger than bare metal. SEM was used to determine the morphology of the coatings and showed that the most homogeneous coating was obtained for 0.07 g cm -2 polypyrrole, without the incorporation of DBSA.

  5. Fundamental understanding and life prediction of stress corrosion cracking in BWRs and energy systems

    SciTech Connect

    Andresen, P.L.; Ford, F.P.

    1998-03-01

    The objective of this paper is to present an approach for design and lifetime evaluation of environmental cracking based on experimental and fundamental modeling of the underlying processes operative in crack advance. In detailed this approach and its development and quantification for energy (hot water) systems, the requirements for a life prediction methodology will be highlighted and the shortcomings of the existing design and lifetime evaluation codes reviewed. Examples are identified of its use in a variety of cracking systems, such as stainless steels, low alloy steels, nickel base alloys, and irradiation assisted stress corrosion cracking in boiling water reactor (BWR) water, as well as preliminary use for low alloy steel and Alloy 600 in pressurized water reactors (PWRs) and turbine steels in steam turbines. Identification of the common aspects with environmental cracking in other hot water systems provides a secure basis for its extension to related energy systems. 166 refs., 49 figs.

  6. A study of scale cracking and its effects on oxidation and hot corrosion

    SciTech Connect

    Shores, D.A.; Stout, J.H.; Gerberich, W.W.

    1990-05-01

    For many high temperature applications, oxidation (or hot corrosion) is an important mode of degradation of metals and alloys. Degradation mechanisms may be divided into two categories: one dealing with the chemical and transport aspects of scale growth or dissolution, and the other dealing with mechanical aspects such as stresses and scale fracture. Some applications, such as corrosion/erosion, combine both aspects in a complicated manner. Much research has been concerned with relationships between alloy composition and scale growth rates, attempting to identify alloy compositions and growth mechanisms that form compact, slow-growing scales, such as Cr{sub 2}O{sub 3} or Al{sub 2}O{sub 3}. Nevertheless, in practice a very common mode of scale degradation is cracking and spalling, followed by re-oxidation. Efforts to understand scale stresses and ultimately scale fracture have been hampered by the simultaneous interaction of numerous variables in determining the state of stress. Thus complex issues are involved in both experimental measurements and theoretical models of stresses and fracture of oxide scales. In this study we have considered both chemical/transport issues (as applied to the oxidation and hot corrosion of SiC and Ni-Cr Alloys) and mechanical issues of oxidation, but the emphasis has been on mechanical issues. In the following sections we will briefly describe the highlights of each of several projects, and where appropriate, will attach preprints or reprints of papers that describe in more detail the results of a particular study.

  7. Utilization of artificial recharged effluent as makeup water for industrial cooling system: corrosion and scaling.

    PubMed

    Wei, Liangliang; Qin, Kena; Zhao, Qingliang; Noguera, Daniel R; Xin, Ming; Liu, Chengcai; Keene, Natalie; Wang, Kun; Cui, Fuyi

    2016-01-01

    The secondary effluent from wastewater treatment plants was reused for industrial cooling water after pre-treatment with a laboratory-scale soil aquifer treatment (SAT) system. Up to a 95.3% removal efficiency for suspended solids (SS), 51.4% for chemical oxygen demand (COD), 32.1% for Cl(-) and 30.0% SO4(2-) were observed for the recharged secondary effluent after the SAT operation, which is essential for controlling scaling and corrosion during the cooling process. As compared to the secondary effluent, the reuse of the 1.5 m depth SAT effluent decreased the corrosion by 75.0%, in addition to a 55.1% decline of the scales/biofouling formation (with a compacted structure). The experimental results can satisfy the Chinese criterion of Design Criterion of the Industrial Circulating Cooling Water Treatment (GB 50050-95), and was more efficient than tertiary effluent which coagulated with ferric chloride. In addition, chemical structure of the scales/biofouling obtained from the cooling system was analyzed.

  8. Utilization of artificial recharged effluent as makeup water for industrial cooling system: corrosion and scaling.

    PubMed

    Wei, Liangliang; Qin, Kena; Zhao, Qingliang; Noguera, Daniel R; Xin, Ming; Liu, Chengcai; Keene, Natalie; Wang, Kun; Cui, Fuyi

    2016-01-01

    The secondary effluent from wastewater treatment plants was reused for industrial cooling water after pre-treatment with a laboratory-scale soil aquifer treatment (SAT) system. Up to a 95.3% removal efficiency for suspended solids (SS), 51.4% for chemical oxygen demand (COD), 32.1% for Cl(-) and 30.0% SO4(2-) were observed for the recharged secondary effluent after the SAT operation, which is essential for controlling scaling and corrosion during the cooling process. As compared to the secondary effluent, the reuse of the 1.5 m depth SAT effluent decreased the corrosion by 75.0%, in addition to a 55.1% decline of the scales/biofouling formation (with a compacted structure). The experimental results can satisfy the Chinese criterion of Design Criterion of the Industrial Circulating Cooling Water Treatment (GB 50050-95), and was more efficient than tertiary effluent which coagulated with ferric chloride. In addition, chemical structure of the scales/biofouling obtained from the cooling system was analyzed. PMID:27191579

  9. Corrosion resistance of pseudo-spin-valve systems: Pd vs. Ta capping layers

    NASA Astrophysics Data System (ADS)

    Matthes, P.; Albrecht, M.

    2016-08-01

    An analysis of both magnetic and magneto-transport properties in dependence of the corrosion resistance is presented for a pseudo-spin-valve (PSV) system with different capping layers. The magnetoresistive part of the sample consists of a [Co/Pd] multilayer with perpendicular magnetic anisotropy and a single Co layer with in-plane easy axis separated by a Cu spacer, forming a PSV system with crossed anisotropies. The samples were annealed under ambient conditions up to temperatures of 200 °C to facilitate the corrosion process. Whereas the magnetic properties are stable up to 100 °C independent of the capping layer, the giant magnetoresistance (GMR) effect is more sensitive on annealing. In case of Pd as capping layer, the GMR of the pseudo-spin-valve considerably degrades already after annealing at 60 °C, whereby even by thickening of the Pd layer up to 10 nm, no pronounced improvement was obtained. On the contrary, for Ta as capping layer the GMR ratio stays constant upon heating up to 100 °C, followed by a comparable moderate decay for even higher annealing temperatures.

  10. Effective corrosion monitoring

    SciTech Connect

    Britton, C.F.; Tofield, B.C.

    1988-04-01

    The results of two surveys (conducted in 1981 and 1984) of users of corrosion monitoring equipment are described. The benefits to be obtained from a well-designed corrosion monitoring system, especially if a corrosion control program is used, are outlined together with the difficulties and barriers that can obstruct successful application. Developing methods such as AC impedance, electrochemical noise, and thin layer activation are discussed in view of the comments received from the surveys.

  11. Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study

    PubMed Central

    BAGATIN, Cristhiane Ristum; ITO, Izabel Yoko; ANDRUCIOLI, Marcela Cristina Damião; NELSON-FILHO, Paulo; FERREIRA, José Tarcísio Lima

    2011-01-01

    Objectives The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. Material and Methods Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12% chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5% significance level. Results The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. Conclusion: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12% chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ. PMID:22231004

  12. Electrochemical Impedance Spectroscopy Study on Corrosion Protection of Acrylate Nanocomposite on Mild Steel Doped Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Mahmud, M. R.; Akhir, M. M.; Shamsudin, M. S.; Afaah, A. N.; Aadila, A.; Asib, N. A. M.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Harun, M. K.; Rusop, M.; Abdullah, S.

    2015-05-01

    Acrylate:carbon nanotubes (A:CNTs) nanocomposite thin film was prepared by sol- gel technique. The corrosion coating protection of acrylate:carbon nanotubes (CNTs) nanocomposite thin film has been coated on mild steel characterised by electrochemical impedance spectrometer (EIS) measurement and equivalent circuit model are employed to analyse coating impedance for corrosion protection. In this study, 3.5 w/v % sodium chloride (NaCl) solution was immersed the acrylate:carbon nanotubes nanocomposite thin film. As the results, the surface morphology were found that there formation of carbon nanotubes with good distribution on acrylate-based coating. From EIS measurement, A:CNTs nanocomposite thin film with 0.4 w/v % contain of CNTs was exhibited the highest coating impedance from Nyquist graph after immersed in sodium chloride solution and may provide the excellent corrosion protection. The Bode plots have shown the impedance is high at the beginning from the time at high frequency and slightly decreases with value of frequency become smaller.

  13. A Study of Wear and Corrosion Resistance of Arc-Sprayed Ni-Ti Composite Coatings

    NASA Astrophysics Data System (ADS)

    Chang, C. H.; Jeng, M. C.; Su, C. Y.; Huang, T. S.

    2011-12-01

    In this study, the corrosion and wear performance of Ni-Ti composite coatings with distinct parameters were investigated. The coatings were prepared by arc spraying with Ti and Ni wires fed synchronously. Structural, surface morphological, and compositional analyses of the Ni-Ti composite coatings were performed using microhardness, SEM/EDS, XRD, and DTA analysis. Electrochemical AC impedance and potentiodynamic polarization tests were carried out to examine the anticorrosion performance of the coating. Ball-on-disc dry wear tests based on the ASTM G99 standard were performed at room temperature to evaluate the antiwear properties. The DTA and XRD analysis results indicated that some intermetallic compounds such as TiNi3 and Ni-Ti alloy were present within the Ni-Ti coating. The wear resistance of the Ni-Ti composite coating is superior to that of the Ni-sprayed coating but slightly inferior to that of the Ti-sprayed coating. The corrosion resistance of the arc-sprayed Ni-Ti coating is superior to that of Ti but inferior to that of Ni. The corrosion and wear performance of the composite coating are greatly influenced by the coating microstructure and thickness.

  14. Study of Rust Effect on the Corrosion Behavior of Reinforcement Steel Using Impedance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bensabra, Hakim; Azzouz, Noureddine

    2013-12-01

    Most studies on corrosion of steel reinforcement in concrete are conducted on steel samples with polished surface (free of all oxides) in order to reproduce the same experimental conditions. However, before embedding in concrete, the steel bars are often covered with natural oxides (rust), which are formed during exposure to the atmosphere. The presence of this rust may affect the electrochemical behavior of steel rebar in concrete. In order to understand the effect of rust on the corrosion behavior of reinforcement steel, potentiodynamic and electrochemical impedance spectroscopy (EIS) tests were carried out in a simulated concrete pore solution using steel samples with two different surface conditions: polished and rusted samples. The obtained results have shown that the presence of rust on the steel bar has a negative effect on its corrosion behavior, with or without the presence of chlorides. This detrimental effect can be explained by the fact that the rust provokes a decrease of the electrolyte resistance at the metal-concrete interface and reduces the repassivating ability. In addition, the rust layer acts as a barrier against the hydroxyl ion diffusion, which prevents the realkalinization phenomenon.

  15. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Jordi Perez-Mariano; Angel Sanjurjo

    2006-12-31

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period, we analyzed several coated and exposed samples of 409 steel by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX), and report on the findings of four samples: (1) Analysis of two porous coupons after exposure to the porous metal particulate filter of the coal gasification power plant at 370 C for 2140 hours revealed that corrosion takes place in the bulk of the sample while the most external zone surface survived the test. (2) Coating and characterization of several porous 409 steel coupons after being coated with nitrides of Ti, Al and/or Si showed that adjusting experimental conditions results in thicker coatings in the bulk of the sample. (3) Analysis of coupons exposed to simulated coal gas at 370 C for 300 hours showed that a better corrosion resistance is achieved by improving the coatings in the bulk of the samples.

  16. Development of Self-Powered Wireless-Ready High Temperature Electrochemical Sensors for In-Situ Corrosion Monitoring for Boiler Tubes in Next Generation Coal-based Power Systems

    SciTech Connect

    Liu, Xingbo

    2015-06-30

    The key innovation of this project is the synergy of the high temperature sensor technology based on the science of electrochemical measurement and state-of-the-art wireless communication technology. A novel self-powered wireless high temperature electrochemical sensor system has been developed for coal-fired boilers used for power generation. An initial prototype of the in-situ sensor demonstrated the capability of the wireless communication system in the laboratory and in a pilot plant (Industrial USC Boiler Setting) environment to acquire electrochemical potential and current signals during the corrosion process. Uniform and localized under-coal ash deposit corrosion behavior of Inconel 740 superalloy has been studied at different simulated coal ash hot corrosion environments using the developed sensor. Two typical potential noise patterns were found to correlate with the oxidation and sulfidation stages in the hot coal ash corrosion process. Two characteristic current noise patterns indicate the extent of the corrosion. There was a good correlation between the responses of electrochemical test data and the results from corroded surface analysis. Wireless electrochemical potential and current noise signals from a simulated coal ash hot corrosion process were concurrently transmitted and recorded. The results from the performance evaluation of the sensor confirm a high accuracy in the thermodynamic and kinetic response represented by the electrochemical noise and impedance test data.

  17. Wilsonville SRC-I pilot plant: I. Fractionation area corrosion studies; II. Hot vs. normal separation mode of operation

    SciTech Connect

    Lee, J.M.

    1981-04-01

    Extensive corrosion studies in solvent recovery columns have been done with different coals (mainly Kentucky number 9 Lafayette, Dotiki and Fies). Sodium carbonate (0.1 to 1.1% of coal) was added as neutralizer to control corrosion rate. Chloride balance runs were made for isolation of corrosive streams with high chlorine content. A caustic wash program of inlet streams has been developed for selective treatment of corrosive streams as an alternative means for possible replacement of sodium carbonate addition. High chlorine content coals such as Kentucky number 9 Lafayette and Dotiki (0.2 to 0.3%) were very corrosive, compared to low chlorine content coal, Kentucky number 9 Fies (< 0.1%). Sodium carbonate addition (0.6 to 0.7% of coal) reduced corrosion rate from 500 MPY to an insignificant level of less than 5 MPY. Caustic wash of solvents could reduce corrosion rate by 50%, removing most corrosive compounds present in the 440 to 480/sup 0/F boiling fraction. Extensive studies for the hot separator mode of operation have been done as a means of saving substantial energy by elimination of dissolver slurry cooling (0.3 MM Btu/hr) and reheating for solvent recovery (1 MM Btu/h). Impacts of the hot separator mode on plant operability, product quality and Kerr-McGee CSD Unit recovery have been studied. The hot separator mode of operation was carried out by controlling the V103 temperature to 740/sup 0/F. It was observed that preasphaltene contents increased in the SRC products such as V110 L/F SRC and CSD feed; CSD unit recovery was not affected significantly; solvent quality was not affected significantly.

  18. Hot corrosion studies of four nickel-base superalloys - B-1900, NASA-TRW VIA, 713C and IN738

    NASA Technical Reports Server (NTRS)

    Fryburg, G. C.; Kohl, F. J.; Stearns, C. A.

    1976-01-01

    The susceptibility to hot corrosion of four nickel-base superalloys has been studied at 900 and 1000 C in one atmosphere of slowly flowing oxygen. Hot corrosion was induced by coating the samples with known doses of Na2SO4 and oxidizing the coated samples isothermally on a sensitive microbalance. In order of decending susceptibility to hot corrosion, these alloys were ranked: B-1900, 713C, NASA-TRW VIA, IN738. This order corresponds to the order of decreasing molybdenum content of the alloys. Chemical evidence for B-1900 indicates that hot corrosion is instigated by acid fluxing of the protective Al2O3 coating by MoO3.

  19. Corrosion in supercritical fluids

    SciTech Connect

    Propp, W.A.; Carleson, T.E.; Wai, Chen M.; Taylor, P.R.; Daehling, K.W.; Huang, Shaoping; Abdel-Latif, M.

    1996-05-01

    Integrated studies were carried out in the areas of corrosion, thermodynamic modeling, and electrochemistry under pressure and temperature conditions appropriate for potential applications of supercritical fluid (SCF) extractive metallurgy. Carbon dioxide and water were the primary fluids studied. Modifiers were used in some tests; these consisted of 1 wt% water and 10 wt% methanol for carbon dioxide and of sulfuric acid, sodium sulfate, ammonium sulfate, and ammonium nitrate at concentrations ranging from 0.00517 to 0.010 M for the aqueous fluids. The materials studied were Types 304 and 316 (UNS S30400 and S31600) stainless steel, iron, and AISI-SAE 1080 (UNS G10800) carbon steel. The thermodynamic modeling consisted of development of a personal computer-based program for generating Pourbaix diagrams at supercritical conditions in aqueous systems. As part of the model, a general method for extrapolating entropies and related thermodynamic properties from ambient to SCF conditions was developed. The experimental work was used as a tool to evaluate the predictions of the model for these systems. The model predicted a general loss of passivation in iron-based alloys at SCF conditions that was consistent with experimentally measured corrosion rates and open circuit potentials. For carbon-dioxide-based SCFs, measured corrosion rates were low, indicating that carbon steel would be suitable for use with unmodified carbon dioxide, while Type 304 stainless steel would be suitable for use with water or methanol as modifiers.

  20. Localized dealloying corrosion mediated by self-assembled monolayers used as an inhibitor system.

    PubMed

    Shrestha, B R; Bashir, A; Ankah, G N; Valtiner, M; Renner, F U

    2015-01-01

    The structure and chemistry of thiol or selenol self-assembled organic monolayers have been frequently addressed due to the unique opportunities in functionalization of materials. Such organic films can also act as effective inhibition layers to mitigate oxidation or corrosion. Cu-Au alloy substrates covered by self-assembled monolayers show a different dealloying mechanism compared to bare surfaces. The organic surface layer inhibits dealloying of noble metal alloys by a suppression of surface diffusion at lower potentials but at higher applied potentials dealloying proceeds in localized regions due to passivity breakdown. We present an in situ atomic force microscopy study of a patterned thiol layer applied on Cu-Au alloy surfaces and further explore approaches to change the local composition of the surface layers by exchange of molecules. The pattern for the in situ experiment has been applied by micro-contact printing. This allows the study of corrosion protection with its dependence on different molecule densities at different sites. Low-density thiol areas surrounding the high-density patterns are completely protected and initiation of dealloying proceeds only along the areas with the lowest inhibitor concentration. Dealloying patterns are highly influenced and controlled by molecular thiol to selenol exchange and are also affected by introducing structural defects such as scratches or polishing defects. PMID:25920488

  1. Evaluation of thiosulfate as a substitute for hydrogen sulfide in sour corrosion fatigue studies

    NASA Astrophysics Data System (ADS)

    Kappes, Mariano Alberto

    This work evaluates the possibility of replacing hydrogen sulfide (H 2S) with thiosulfate anion (S2O32- ) in sour corrosion fatigue studies. H2S increases the corrosion fatigue crack growth rate (FCGR) and can be present in carbon steel risers and flowlines used in off-shore oil production. Corrosion tests with gaseous H2S require special facilities with safety features, because H2S is a toxic and flammable gas. The possibility of replacing H2S with S2O32-, a non-toxic anion, for studying stress corrosion cracking of stainless and carbon steels in H2S solutions was first proposed by Tsujikawa et al. ( Tsujikawa et al., Corrosion, 1993. 49(5): p. 409-419). In this dissertation, Tsujikawa work will be extended to sour corrosion fatigue of carbon steels. H2S testing is often conducted in deareated condition to avoid oxygen reaction with sulfide that yields sulfur and to mimic oil production conditions. Nitrogen deareation was also adopted in S2O3 2- testing, and gas exiting the cell was forced through a sodium hydroxide trap. Measurements of the sulfide content of this trap were used to estimate the partial pressure of H2S in nitrogen, and Henry's law was used to estimate the content of H2S in the solution in the cell. H2S was produced by a redox reaction of S2O 32-, which required electrons from carbon steel corrosion. This reaction is spontaneous at the open circuit potential of steel. Therefore, H2S concentration was expected to be maximum at the steel surface, and this concentration was estimated by a mass balance analysis. Carbon steel specimens exposed to S2O32- containing solutions developed a film on their surface, composed by iron sulfide and cementite. The film was not passivating and a good conductor of electrons. Hydrogen permeation experiments proved that this film controls the rate of hydrogen absorption of steels exposed to thiosulfate containing solutions. The absorption of hydrogen in S2O3 2- solutions was compared with the absorption of hydrogen in

  2. TEST PLAN AND PROCEDURE FOR THE EXAMINATION OF TANK 241-AY-101 MULTI-PROBE CORROSION MONITORING SYSTEM

    SciTech Connect

    WYRWAS RB; PAGE JS; COOKE GS

    2012-04-19

    This test plan describes the methods to be used in the forensic examination of the Multi-probe Corrosion Monitoring System (MPCMS) installed in the double-shell tank 241-AY-101 (AY-101). The probe was designed by Applied Research and Engineering Sciences (ARES) Corporation. The probe contains four sections, each of which can be removed from the tank independently (H-14-107634, AY-101 MPCMS Removable Probe Assembly) and one fixed center assembly. Each removable section contains three types of passive corrosion coupons: bar coupons, round coupons, and stressed C-rings (H-14-l07635, AY-101 MPCMS Details). Photographs and weights of each coupon were recorded and reported on drawing H-14-107634 and in RPP-RPT-40629, 241-AY-101 MPCMS C-Ring Coupon Photographs. The coupons will be the subject of the forensic analyses. The purpose of this examination will be to document the nature and extent of corrosion of the 29 coupons. This documentation will consist of photographs and photomicrographs of the C-rings and round coupons, as well as the weights of the bar and round coupons during corrosion removal. The total weight loss of the cleaned coupons will be used in conjunction with the surface area of each to calculate corrosion rates in mils per year. The bar coupons were presumably placed to investigate the liquid-air-interface. An analysis of the waste level heights in the waste tank will be investigated as part of this examination.

  3. Results of stainless steel canister corrosion studies and environmental sample investigations

    SciTech Connect

    Bryan, Charles R.; Enos, David

    2014-12-01

    . First, a full-diameter canister mockup, made using materials and techniques identical to those used to make interim storage canisters, was designed and ordered from Ranor Inc., a cask vendor for Areva/TN. The mockup will be delivered prior to the end of FY14, and will be used for evaluating weld residual stresses and degrees of sensitization for typical interim storage canister welds. Following weld characterization, the mockup will be sectioned and provided to participating organizations for corrosion testing purposes. A test plan is being developed for these efforts. In a second task, experimental work was carried out to evaluate crevice corrosion of 304SS in the presence of limited reactants, as would be present on a dustcovered storage canister. This work tests the theory that limited salt loads will limit corrosion penetration over time, and is a continuation of work carried out in FY13. Laser confocal microscopy was utilized to assess the volume and depth of corrosion pits formed during the crevice corrosion tests. Results indicate that for the duration of the current experiments (100 days), no stifling of corrosion occurred due to limitations in the amount of reactants present at three different salt loadings. Finally, work has been carried out this year perfecting an instrument for depositing sea-salts onto metal surfaces for atmospheric corrosion testing purposes. The system uses an X-Y plotter system with a commercial airbrush, and deposition is monitored with a quartz crystal microbalance. The system is capable of depositing very even salt loadings, even at very low total deposition rates.

  4. In vitro electrochemical corrosion and cell viability studies on nickel-free stainless steel orthopedic implants.

    PubMed

    Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J; Rad, Armin Tahmasbi; Madihally, Sundararajan V; Tayebi, Lobat

    2013-01-01

    The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments.

  5. In Vitro Electrochemical Corrosion and Cell Viability Studies on Nickel-Free Stainless Steel Orthopedic Implants

    PubMed Central

    Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J.; Rad, Armin Tahmasbi; Madihally, Sundararajan V.; Tayebi, Lobat

    2013-01-01

    The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments. PMID:23630603

  6. Study made of corrosion resistance of stainless steel and nickel alloys in nuclear reactor superheaters

    NASA Technical Reports Server (NTRS)

    Greenberg, S.; Hart, R. K.; Lee, R. H.; Ruther, W. E.; Schlueter, R. R.

    1967-01-01

    Experiments performed under conditions found in nuclear reactor superheaters determine the corrosion rate of stainless steel and nickel alloys used in them. Electropolishing was the primary surface treatment before the corrosion test. Corrosion is determined by weight loss of specimens after defilming.

  7. Analysis of Pipeline Steel Corrosion Data From NBS (NIST) Studies Conducted Between 1922–1940 and Relevance to Pipeline Management

    PubMed Central

    Ricker, Richard E.

    2010-01-01

    Between 1911 and 1984, the National Bureau of Standards (NBS) conducted a large number of corrosion studies that included the measurement of corrosion damage to samples exposed to real-world environments. One of these studies was an investigation conducted between 1922 and 1940 into the corrosion of bare steel and wrought iron pipes buried underground at 47 different sites representing different soil types across the Unites States. At the start of this study, very little was known about the corrosion of ferrous alloys underground. The objectives of this study were to determine (i) if coatings would be required to prevent corrosion, and (ii) if soil properties could be used to predict corrosion and determine when coatings would be required. While this study determined very quickly that coatings would be required for some soils, it found that the results were so divergent that even generalities based on this data must be drawn with care. The investigators concluded that so many diverse factors influence corrosion rates underground that planning of proper tests and interpretation of the results were matters of considerable difficulty and that quantitative interpretations or extrapolations could be done “only in approximate fashion” and attempted only in the “restricted area” of the tests until more complete information is available. Following the passage of the Pipeline Safety Improvement Act in 2002 and at the urging of the pipeline industry, the Office of Pipeline Safety of the U.S. Department of Transportation approached the National Institute of Standards and Technology (NBS became NIST in 1988) and requested that the data from this study be reexamined to determine if the information handling and analysis capabilities of modern computers and software could enable the extraction of more meaningful information from these data. This report is a summary of the resulting investigations. The data from the original NBS studies were analyzed using a variety of

  8. Hot Corrosion Studies of HVOF-Sprayed Coating on T-91 Boiler Tube Steel at Different Operating Temperatures

    NASA Astrophysics Data System (ADS)

    Bhatia, Rakesh; Singh, Hazoor; Sidhu, Buta Singh

    2013-11-01

    The aim of the present work is to investigate the usefulness of high velocity oxy fuel-sprayed 75% Cr3C2-25% (Ni-20Cr) coating to control hot corrosion of T-91 boiler tube steel at different operating temperatures viz 550, 700, and 850 °C. The deposited coatings on the substrates exhibit nearly uniform, adherent and dense microstructure with porosity less than 2%. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of uncoated and coated samples. The corrosion products of the coating on the substrate are analyzed by using XRD, SEM, and FE-SEM/EDAX to reveal their microstructural and compositional features for the corrosion mechanisms. It is found that the coated specimens have shown minimum weight gain at all the operating temperatures when compared with uncoated T-91 samples. Hence, coating is effective in decreasing the corrosion rate in the given molten salt environment. Oxides and spinels of nickel-chromium may be the reason for successful resistance against hot corrosion.

  9. Pitting, galvanic, and long-term corrosion studies on candidate container alloys for the Tuff Repository

    SciTech Connect

    Beavers, J.A.; Thompson, N.G.; Durr, C.L.

    1992-01-01

    Contest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials for high-level radioactive waste packages as part of the information needed by the Nuclear Regulatory Commission to assess the Department of Energy`s application to construct a geologic repository for the high-level radioactive waste. The scope of work focused on the Tuff Repository and employed short-term techniques, such as electrochemical and mechanical techniques to examine a wide range of possible failure modes. Two classes of alloys were evaluated for use as container materials for the Tuff Repository; Fe-Cr-Ni alloys and copper-base alloys. The candidate Fe-Cr-Ni alloys were Type 304L Stainless Steel (Alloy 304L) and Incoloy Alloy 825 (Alloy 825). The candidate copper-base alloys were CDA 102 Copper (Alloy CDA 102) and CDA 715 Copper-3D Nickel (Alloy CDA 715). The corrosion testing was performed in a simulated J-13 well water and in solutions selected from an experimental matrix from Task 2 of the program. This report summarizes the results of Task 4 (Pitting Studies), Task 6 (Other Failure Modes) and Task 7 (Long-Term Exposures) of the program. Pit-initiation studies, performed in Task 4, focused on anomalous Cyclic Potentiodynamic Polarization (CPP) behavior of the copper-base alloys reported in Task 2 of the program. Pit propagation studies were performed on Alloy CDA 102 in Task A of the program. Two types of galvanic corrosion studies were performed in Task 6 of the program; thermogalvanic couples and borehole linear-container interactions. In the thermogalvanic couples tests, the effect of temperature variation on the surface of the container on acceleration of corrosion was evaluated for two alloys; Alloy CDA 102 and Alloy 304L. Long-term immersion tests were conducted in Task 7 of the program.

  10. Pitting, galvanic, and long-term corrosion studies on candidate container alloys for the Tuff Repository

    SciTech Connect

    Beavers, J.A.; Thompson, N.G.; Durr, C.L. )

    1992-01-01

    Contest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials for high-level radioactive waste packages as part of the information needed by the Nuclear Regulatory Commission to assess the Department of Energy's application to construct a geologic repository for the high-level radioactive waste. The scope of work focused on the Tuff Repository and employed short-term techniques, such as electrochemical and mechanical techniques to examine a wide range of possible failure modes. Two classes of alloys were evaluated for use as container materials for the Tuff Repository; Fe-Cr-Ni alloys and copper-base alloys. The candidate Fe-Cr-Ni alloys were Type 304L Stainless Steel (Alloy 304L) and Incoloy Alloy 825 (Alloy 825). The candidate copper-base alloys were CDA 102 Copper (Alloy CDA 102) and CDA 715 Copper-3D Nickel (Alloy CDA 715). The corrosion testing was performed in a simulated J-13 well water and in solutions selected from an experimental matrix from Task 2 of the program. This report summarizes the results of Task 4 (Pitting Studies), Task 6 (Other Failure Modes) and Task 7 (Long-Term Exposures) of the program. Pit-initiation studies, performed in Task 4, focused on anomalous Cyclic Potentiodynamic Polarization (CPP) behavior of the copper-base alloys reported in Task 2 of the program. Pit propagation studies were performed on Alloy CDA 102 in Task A of the program. Two types of galvanic corrosion studies were performed in Task 6 of the program; thermogalvanic couples and borehole linear-container interactions. In the thermogalvanic couples tests, the effect of temperature variation on the surface of the container on acceleration of corrosion was evaluated for two alloys; Alloy CDA 102 and Alloy 304L. Long-term immersion tests were conducted in Task 7 of the program.

  11. Application of Terahertz Radiation to the Detection of Corrosion under the Shuttle's Thermal Protection System

    NASA Technical Reports Server (NTRS)

    Madaras, Eric I.; Anastasi, Robert F.; Smith, Stephen W.; Seebo, Jeffrey P.; Walker, James L.; Lomness, Janice K.; Hintze, Paul E.; Kammerer, Catherine C.; Winfree, William P.; Russell, Richard W.

    2007-01-01

    There is currently no method for detecting corrosion under Shuttle tiles except for the expensive process of tile removal and replacement; hence NASA is investigating new NDE methods for detecting hidden corrosion. Time domain terahertz radiation has been applied to corrosion detection under tiles in samples ranging from small lab samples to a Shuttle with positive results. Terahertz imaging methods have been able to detect corrosion at thicknesses of 5 mils or greater under 1" thick Shuttle tiles and 7-12 mils or greater under 2" thick Shuttle tiles.

  12. PREDICTING LEAD DISSOLUTION IN DRINKING WATER DISTRIBUTION SYSTEMS: EFFECT OF FLUORIDE ADDITIVES ON LEAD SOLUBILITY AND CORROSION

    EPA Science Inventory

    Many water systems have encountered difficulties in meeting the action levels established by the Lead and Copper Rule. Several chemical parameters contribute to the corrosion of lead plumbing and may influence the nature of the passivating films formed on distribution materials....

  13. Vanadium corrosion studies. Final report, 1 February 1989-30 June 1993

    SciTech Connect

    Bornstein, N.; Roth, H.; Pike, R.

    1993-06-30

    Vanadium present in certain crude and residual fuel oils, is converted within the burner of the gas turbine engine to the refractory dioxide, which in flight is fully oxidized to the pentoxide. Yttrium oxide, stable in the presence of the oxides of sulfur is identified and verified as a corrosion inhibitor. A chelation process to produce a hydrolytic stable fuel soluble yttrium additive is described.... Vanadium oxide corrosion, Hot corrosion, Sulfidation corrosion, Hot corrosion attenuation, Fuel additives, Water stable fuel soluble yttrium compounds, Chelation.

  14. The effect of abrasion on corrosion of dental Co-Cr alloys. An in vitro study.

    PubMed

    de Melo, J F; Gjerdet, N R; Erichsen, E S

    1985-05-01

    The effect of abrasion on corrosion of two dental Co-Cr alloys was investigated in vitro. The metals were abraded with a toothbrush and with a piece of tooth enamel. Changes in corrosion potentials and metal release due to the abrasion were measured. Abrasion by tooth enamel caused a persistent drop in corrosion potentials. The release of both chromium and, in particular, cobalt was higher than during brushing. The two alloys tested did not significantly differ with regard to mode and rate of corrosion. It was demonstrated that the corrosion behavior of electrochemically passive dental alloys was affected by abrasion of a magnitude normally encountered during clinical service. PMID:3863447

  15. The biocathode of microbial electrochemical systems and microbially-influenced corrosion.

    PubMed

    Kim, Byung Hong; Lim, Swee Su; Daud, Wan Ramli Wan; Gadd, Geoffrey Michael; Chang, In Seop

    2015-08-01

    The cathode reaction is one of the most important limiting factors in bioelectrochemical systems even with precious metal catalysts. Since aerobic bacteria have a much higher affinity for oxygen than any known abiotic cathode catalysts, the performance of a microbial fuel cell can be improved through the use of electrochemically-active oxygen-reducing bacteria acting as the cathode catalyst. These consume electrons available from the electrode to reduce the electron acceptors present, probably conserving energy for growth. Anaerobic bacteria reduce protons to hydrogen in microbial electrolysis cells (MECs). These aerobic and anaerobic bacterial activities resemble those catalyzing microbially-influenced corrosion (MIC). Sulfate-reducing bacteria and homoacetogens have been identified in MEC biocathodes. For sustainable operation, microbes in a biocathode should conserve energy during such electron-consuming reactions probably by similar mechanisms as those occurring in MIC. A novel hypothesis is proposed here which explains how energy can be conserved by microbes in MEC biocathodes.

  16. Aluminum corrosion mitigation in alkaline electrolytes containing hybrid inorganic/organic inhibitor system for power sources applications

    NASA Astrophysics Data System (ADS)

    Gelman, Danny; Lasman, Itay; Elfimchev, Sergey; Starosvetsky, David; Ein-Eli, Yair

    2015-07-01

    The severe corrosion accompanied with hydrogen evolution process is the main obstacle preventing the implementation of Al as an anode in alkaline batteries. It impairs the functionality of alkaline battery, due to a drastic capacity loss and a short shelf life. The possibility to reduce Al corrosion rate in alkaline solution with the use of hybrid organic∖inorganic inhibitor based on poly (ethylene glycol) di-acid (PEG di-acid) and zinc oxide (ZnO) was examined in this work. A correlation between an Al corrosion rates and the concentrations of both PEG di-acid and ZnO in alkaline is shown. Selecting 5000 ppm PEG di-acid and 16 gr/l ZnO provides substantial corrosion protection of Al, reducing the corrosion rate in a strong alkaline solution by more than one order of magnitude. Moreover, utilizing the same formulation results in increase in Al-air battery discharge capacity, from 44.5 (for a battery utilizing only KOH in the electrolyte) to 70 mhA/cm2 (for a battery utilizing ZnO/PEG di-acid hybrid inhibitor in the electrolyte). The morphology and composition of the Al electrode surface (studied by SEM, EDS, and XRD) depend on PEG di-acid and ZnO concentrations.

  17. Systems Studies

    SciTech Connect

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  18. Potentiodynamic Corrosion Testing.

    PubMed

    Munir, Selin; Pelletier, Matthew H; Walsh, William R

    2016-01-01

    Different metallic materials have different polarization characteristics as dictated by the open circuit potential, breakdown potential, and passivation potential of the material. The detection of these electrochemical parameters identifies the corrosion factors of a material. A reliable and well-functioning corrosion system is required to achieve this. Corrosion of the samples was achieved via a potentiodynamic polarization technique employing a three-electrode configuration, consisting of reference, counter, and working electrodes. Prior to commencement a baseline potential is obtained. Following the stabilization of the corrosion potential (Ecorr), the applied potential is ramped at a slow rate in the positive direction relative to the reference electrode. The working electrode was a stainless steel screw. The reference electrode was a standard Ag/AgCl. The counter electrode used was a platinum mesh. Having a reliable and well-functioning in vitro corrosion system to test biomaterials provides an in-expensive technique that allows for the systematic characterization of the material by determining the breakdown potential, to further understand the material's response to corrosion. The goal of the protocol is to set up and run an in vitro potentiodynamic corrosion system to analyze pitting corrosion for small metallic medical devices. PMID:27683978

  19. Potentiodynamic Corrosion Testing.

    PubMed

    Munir, Selin; Pelletier, Matthew H; Walsh, William R

    2016-09-04

    Different metallic materials have different polarization characteristics as dictated by the open circuit potential, breakdown potential, and passivation potential of the material. The detection of these electrochemical parameters identifies the corrosion factors of a material. A reliable and well-functioning corrosion system is required to achieve this. Corrosion of the samples was achieved via a potentiodynamic polarization technique employing a three-electrode configuration, consisting of reference, counter, and working electrodes. Prior to commencement a baseline potential is obtained. Following the stabilization of the corrosion potential (Ecorr), the applied potential is ramped at a slow rate in the positive direction relative to the reference electrode. The working electrode was a stainless steel screw. The reference electrode was a standard Ag/AgCl. The counter electrode used was a platinum mesh. Having a reliable and well-functioning in vitro corrosion system to test biomaterials provides an in-expensive technique that allows for the systematic characterization of the material by determining the breakdown potential, to further understand the material's response to corrosion. The goal of the protocol is to set up and run an in vitro potentiodynamic corrosion system to analyze pitting corrosion for small metallic medical devices.

  20. Comparative study of the corrosion behavior of peripheral stents in an accelerated corrosion model: experimental in vitro study of 28 metallic vascular endoprostheses

    PubMed Central

    Paprottka, Karolin J.; Paprottka, Philipp M.; Reiser, Maximilian F.; Waggershauser, Tobias

    2015-01-01

    PURPOSE Clinical cases of stent-fractures show that corrosion behavior might play a role in these fractures. Implanted in vivo, especially in combination with other implanted foreign materials, these metallic products are exposed to special conditions, which can cause a process of corrosion. Here, we aimed to test the corrosion potential of stents made of different materials in an in vitro setting. METHODS A total of 28 peripheral stents of different materials (nitinol, cobalt-chromium-nickel, tantalum, V4A) and surface treatments (electropolish, mechanical polish, no polish) were tested in vitro. Corrosion was accelerated by applying a constant voltage of 3.5 V and amperage of 1.16 mA in 0.9% NaCl. RESULTS Nitinol stents showed the lowest susceptibility to corrosion and the longest period without damage. The Memotherm II® (BARD Angiomed®) was the only stent that showed neither macroscopic nor microscopic damages. The worst performing material was cobalt-chromium-nickel, which showed corrosion damages about ten times earlier compared to nitinol. Considering the reasons for termination of the test, nitinol stents primarily showed length deficits, while V4A and tantalum stents showed fractures. Cobalt-chromium-nickel stents had multiple fractures or a complete lysis in equal proportions. When placed in direct contact, nitinol stents showed best corrosion resistance, regardless of what material they were combined with. In terms of polishing treatments, electropolished stents performed the best, mechanical-polished stents and those without polishing treatment followed. CONCLUSION The analysis of corrosion behavior may be useful to select the right stent fulfilling the individual needs of the patient within a large number of different stents. PMID:26268301

  1. An investigation of microbial diversity in crude oil & seawater injection systems and microbiologically influenced corrosion (MIC) of linepipe steels under different exposure conditions

    NASA Astrophysics Data System (ADS)

    AlAbbas, Faisal Mohammed

    members of Halothiobacillaceae. In the seawater injection sample, the dominant bacterial phylotypes included members of the Rhodobacterales, Flavobacteriales and Oceanospirillales. Interestingly, common bacterial phylotypes that are related to Thermotogaceae were identified in all investigated samples. The impact of the identified microbial communities on MIC of pipeline system was presented. On the implications front, the influence of field SRB (Desulfomicrobium sp. and Clostridiales.) on the corrosion process was complex. The bacterial activities, metabolic reactions and by-products contributed to the corrosion process. Based on the observations and results, corrosion involves multiple synergistic mechanisms. The MIC vulnerability of X52 was higher than X80 due to microstructural effects. On the other hand, the field IRB consortium (Shewanella oneidensis sp. and Brevibacillus sp.) exhibited inhibitory action on the corrosion process. The maximum corrosion rate was ˜4 mpy in the biotic system and ˜18 mpy in the abiotic system. Corrosion mechanisms were proposed to explain the protective behavior of the IRB consortium. On the special effects front, the influence of remnant magnetic fields (3000 Gauss strength) on MIC by a SRB consortium was investigated. The results confirm substantial increases of bacteria cell attachment, biofilm mass, corrosion and pitting penetration rates under magnetized biotic compared to nonmagnetized biotic conditions. The significant enhancement of MIC under magnetized biotic conditions has been attributed to the synergetic interaction between SRB cells and associated metabolic products with magnetic fields. The effect of magnetic fields on the thermodynamics and kinetics of the bacterial cell attachment and the electrochemical process has been presented. On the mitigation front, this work presented a pioneer study on the inhibition effects of azadirachtin (Neem) extracts of SRB influenced corrosion. The results revealed that Neem extracts

  2. Copper and Lead Corrosion in a Full Scale Home Plumbning system Simulation

    EPA Science Inventory

    The corrosion of household or premise plumbing materials (such as copper, brass, and solder) and the metal release that results from that corrosion can cause numerous problems, ranging from elevated lead and copper levels to blue water and copper pinhole leaks. If left untreate...

  3. Study of the Intergranular Corrosion of Sensitized UNS S31803 Stainless Steel in Transpassive Region

    NASA Astrophysics Data System (ADS)

    Morshed Behbahani, Khashayar; Najafisayar, Pooria; Pakshir, Mahmoud

    2016-08-01

    In this study, intergranular corrosion behavior of UNS S31803 duplex stainless steel was investigated using conventional potentiodynamic polarization, double loop electrochemical potentiokinetic reactivation (DLEPR), and electrochemical impedance spectroscopy (EIS) technique carried out at different potentials in the transpassive region. Different types of heat treatments were used to obtain samples with different degrees of sensitization. The results of the DLEPR tests showed that the solution-annealed sample and that was sensitized for half an hour would be considered as nonsensitized ones. Moreover, the sample that was sensitized for 24 h exhibits the highest value of the degree of sensitization. Polarization test results showed a typical active-passive behavior from which the transpassive potential range was determined and used as the range of the applied DC bias in the EIS experiments. Three different AC responses (including capacitive and inductive responses) were observed depending on the value of applied DC bias in the EIS experiments. In addition, it was observed that the presence of the second inductive loop at high applied DC bias is due to the adsorption of nonsoluble corrosion products on the surface of the samples. Moreover, the fitted values to the charge transfer and polarization resistances ( R ct and R P) decreased as the sensitization time increased from 30 min to 24 h. Such observations were in good accordance with the metallographic examination of the corroded surfaces, carried out by optical and scanning electron microscopy techniques, revealing discontinuous grain boundary attack in nonsensitized samples and a continuous network of grain boundary attack in the case of sensitized ones. Moreover, as the applied DC bias increases the ferrite phase attack also occurs in the sensitized samples. In addition, approximately no pitting corrosion was observed on the surface of the corroded samples which is in accordance with their respective cyclic

  4. Ultra-High Temperature Steam Corrosion of Complex Silicates for Nuclear Applications: A Computational Study

    SciTech Connect

    Rashkeev, Sergey N.; Glazoff, Michael V.; Tokuhiro, Akira

    2014-01-01

    Stability of materials under extreme conditions is an important issue for safety of nuclear reactors. Presently, silicon carbide (SiC) is being studied as a cladding material candidate for fuel rods in boiling-water and pressurized water-cooled reactors (BWRs and PWRs) that would substitute or modify traditional zircaloy materials. The rate of corrosion of the SiC ceramics in hot vapor environment (up to 2200 degrees C) simulating emergency conditions of light water reactor (LWR) depends on many environmental factors such as pressure, temperature, viscosity, and surface quality. Using the paralinear oxidation theory developed for ceramics in the combustion reactor environment, we estimated the corrosion rate of SiC ceramics under the conditions representing a significant power excursion in a LWR. It was established that a significant time – at least 100 h – is required for a typical SiC braiding to significantly degrade even in the most aggressive vapor environment (with temperatures up to 2200 °C) which is possible in a LWR at emergency condition. This provides evidence in favor of using the SiC coatings/braidings for additional protection of nuclear reactor rods against off-normal material degradation during power excursions or LOCA incidents. Additionally, we discuss possibilities of using other silica based ceramics in order to find materials with even higher corrosion resistance than SiC. In particular, we found that zircon (ZrSiO4) is also a very promising material for nuclear applications. Thermodynamic and first-principles atomic-scale calculations provide evidence of zircon thermodynamic stability in aggressive environments at least up to 1535 degrees C.

  5. Ultra-high temperature steam corrosion of complex silicates for nuclear applications: A computational study

    NASA Astrophysics Data System (ADS)

    Rashkeev, Sergey N.; Glazoff, Michael V.; Tokuhiro, Akira

    2014-01-01

    Stability of materials under extreme conditions is an important issue for safety of nuclear reactors. Presently, silicon carbide (SiC) is being studied as a cladding material candidate for fuel rods in boiling-water and pressurized water-cooled reactors (BWRs and PWRs) that would substitute or modify traditional zircaloy materials. The rate of corrosion of the SiC ceramics in hot vapor environment (up to 2200 °C) simulating emergency conditions of light water reactor (LWR) depends on many environmental factors such as pressure, temperature, viscosity, and surface quality. Using the paralinear oxidation theory developed for ceramics in the combustion reactor environment, we estimated the corrosion rate of SiC ceramics under the conditions representing a significant power excursion in a LWR. It was established that a significant time - at least 100 h - is required for a typical SiC braiding to significantly degrade even in the most aggressive vapor environment (with temperatures up to 2200 °C) which is possible in a LWR at emergency condition. This provides evidence in favor of using the SiC coatings/braidings for additional protection of nuclear reactor rods against off-normal material degradation during power excursions or LOCA incidents. Additionally, we discuss possibilities of using other silica based ceramics in order to find materials with even higher corrosion resistance than SiC. In particular, we found that zircon (ZrSiO4) is also a very promising material for nuclear applications. Thermodynamic and first-principles atomic-scale calculations provide evidence of zircon thermodynamic stability in aggressive environments at least up to 1535 °C.

  6. The effect of long-term nitrate treatment on SRB activity, corrosion rate and bacterial community composition in offshore water injection systems.

    PubMed

    Bødtker, Gunhild; Thorstenson, Tore; Lillebø, Bente-Lise P; Thorbjørnsen, Bente E; Ulvøen, Rikke Helen; Sunde, Egil; Torsvik, Terje

    2008-12-01

    Biogenic production of hydrogen sulphide (H(2)S) is a problem for the oil industry as it leads to corrosion and reservoir souring. Continuous injection of a low nitrate concentration (0.25-0.33 mM) replaced glutaraldehyde as corrosion and souring control at the Veslefrikk and Gullfaks oil field (North Sea) in 1999. The response to nitrate treatment was a rapid reduction in number and activity of sulphate-reducing bacteria (SRB) in the water injection system biofilm at both fields. The present long-term study shows that SRB activity has remained low at < or =0.3 and < or =0.9 microg H(2)S/cm(2)/day at Veslefrikk and Gullfaks respectively, during the 7-8 years with continuous nitrate injection. At Veslefrikk, 16S rRNA gene based community analysis by PCR-DGGE showed that bacteria affiliated to nitrate-reducing sulphide-oxidizing Sulfurimonas (NR-SOB) formed major populations at the injection well head throughout the treatment period. Downstream of deaerator the presence of Sulfurimonas like bacteria was less pronounced, and were no longer observed 40 months into the treatment period. The biofilm community during nitrate treatment was highly diverse and relative stable for long periods of time. At the Gullfaks field, a reduction in corrosion of up to 40% was observed after switch to nitrate treatment. The present study show that nitrate injection may provide a stable long-term inhibition of SRB in sea water injection systems, and that corrosion may be significantly reduced when compared to traditional biocide treatment. PMID:18752014

  7. Why metals volubility may not be a good indicator of corrosion in alkanolamine systems

    SciTech Connect

    Rooney, P.C.; DuPart, M.S.

    1999-11-01

    Although it is generally believed that Fe, Cr and Ni content in alkanolamine gas treating solutions reflects the corrosivity of the solution, the authors have found that this is not necessarily the case. Comparison of metals volubility by inductively coupled plasma (ICP) with carbon steel and stainless steel weight loss coupons of various alkanolamines heated in an autoclave showed that low metals volubility does not necessarily mean low coupon corrosivity. High metals volubility also did not necessarily mean high coupon corrosivity. One plant having very high metals volubility was found to have very low corrosion upon a thorough plant inspection. Another plant had severe localized corrosion that could not have been predicted based upon the low (200ppm) Fe in the alkanolamine compared to the total surface area of carbon steel in this plant.

  8. Kinetic studies of the stress corrosion cracking of D6AC steel

    NASA Technical Reports Server (NTRS)

    Noronha, P. J.

    1975-01-01

    The effect of load interactions on the crack growth velocity of D6AC steel under stress corrosion cracking conditions was determined. The environment was a 3.5 percent salt solution. The modified-wedge opening load specimens were fatigue precracked and subjected to a deadweight loading in creep machines. The effects of load shedding on incubation times and crack growth rates were measured using high-sensitivity compliance measurement techniques. Load shedding results in an incubation time, the length of which depends on the amount of load shed and the baseline stress intensity. The sequence of unloading the specimen also controls the subsequent incubation period. The incubation period is shorter when load shedding passes through zero load than when it does not if the specimen initially had the same baseline stress intensity. The crack growth rates following the incubation period are also different from the steady-state crack growth rate at the operating stress intensity. These data show that the susceptibility of this alloy system to stress corrosion cracking depends on the plane-strain fracture toughness and on the yield strength of the material.

  9. Review of state-of-the art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications

    NASA Astrophysics Data System (ADS)

    Clifford, J. E.; Diegle, R. B.

    1980-04-01

    The state of the art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices.

  10. Is increased modularity associated with increased fretting and corrosion damage in metal-on-metal total hip arthroplasty devices?: a retrieval study.

    PubMed

    Higgs, Genymphas B; Hanzlik, Josa A; MacDonald, Daniel W; Gilbert, Jeremy L; Rimnac, Clare M; Kurtz, Steven M

    2013-09-01

    This retrieval study documents taper damage at modular interfaces in retrieved MOM THA systems and investigates if increased modularity is associated with increased fretting and corrosion. One hundred thirty-four (134) heads and 60 stems (41 modular necks) of 8 different bearing designs (5 manufacturers) were analyzed. Damage at the shell-liner interface of 18 modular CoCr acetabular liners and the corresponding 11 acetabular shells was also evaluated. The results of this study support the hypothesis that fretting and corrosion damage occurs at a variety of modular component interfaces in contemporary MOM THAs. We also found that modularity of the femoral stem was associated with increased damage at the head. An analysis of component and patient variables revealed that dissimilar alloy pairing, larger head sizes, increased medio-lateral offsets and longer neck moment arms were all associated with increased taper damage at the modular interfaces.

  11. Aluminum Corrosion and Turbidity

    SciTech Connect

    Longtin, F.B.

    2003-03-10

    Aluminum corrosion and turbidity formation in reactors correlate with fuel sheath temperature. To further substantiate this correlation, discharged fuel elements from R-3, P-2 and K-2 cycles were examined for extent of corrosion and evidence of breaking off of the oxide film. This report discusses this study.

  12. Corrosion by bacteria of concrete in sewerage systems and inhibitory effects of formates on their growth.

    PubMed

    Yamanaka, Tateo; Aso, Iwao; Togashi, Shunsuke; Tanigawa, Minoru; Shoji, Kazuo; Watanabe, Tsugumichi; Watanabe, Naoki; Maki, Kazuo; Suzuki, Hiroshi

    2002-05-01

    Not only sulfur-oxidizing bacteria but also an acidophilic iron-oxidizing bacterium (or bacteria) were found in the corroded concrete from several sewerage systems in Japan. The surface pH of concrete test piece exposed to an atmosphere containing hydrogen sulfide of the concentrations more than 600 ppm in the systems was usually below 2 after a month. This was attributable to ability of the sulfur-oxidizing bacteria to grow in the thin water layer which contained hydrogen sulfide and covered the piece even when the surface pH of concrete was 12-13. When the sulfuroxidizing bacteria grew in the surface of concrete and produced sulfuric acid, the pH of the inner parts of concrete was lowered where the bacteria were hardly found. Probably, sulfuric acid formed by the bacteria in the surface parts penetrated into the inner parts. The different species of sulfur-oxidizing bacteria were found in different sewerage systems. The growth of the sulfur-oxidizing and acidophilic iron-oxidizing bacteria was completely inhibited by formates, especially by calcium formate of concentrations more than 50 mM. Calcium formate can protect concrete in sewerage systems from bacterial corrosion.

  13. Corrosion by bacteria of concrete in sewerage systems and inhibitory effects of formates on their growth.

    PubMed

    Yamanaka, Tateo; Aso, Iwao; Togashi, Shunsuke; Tanigawa, Minoru; Shoji, Kazuo; Watanabe, Tsugumichi; Watanabe, Naoki; Maki, Kazuo; Suzuki, Hiroshi

    2002-05-01

    Not only sulfur-oxidizing bacteria but also an acidophilic iron-oxidizing bacterium (or bacteria) were found in the corroded concrete from several sewerage systems in Japan. The surface pH of concrete test piece exposed to an atmosphere containing hydrogen sulfide of the concentrations more than 600 ppm in the systems was usually below 2 after a month. This was attributable to ability of the sulfur-oxidizing bacteria to grow in the thin water layer which contained hydrogen sulfide and covered the piece even when the surface pH of concrete was 12-13. When the sulfuroxidizing bacteria grew in the surface of concrete and produced sulfuric acid, the pH of the inner parts of concrete was lowered where the bacteria were hardly found. Probably, sulfuric acid formed by the bacteria in the surface parts penetrated into the inner parts. The different species of sulfur-oxidizing bacteria were found in different sewerage systems. The growth of the sulfur-oxidizing and acidophilic iron-oxidizing bacteria was completely inhibited by formates, especially by calcium formate of concentrations more than 50 mM. Calcium formate can protect concrete in sewerage systems from bacterial corrosion. PMID:12153031

  14. Corrosion in methylphosphonic difluoride

    SciTech Connect

    Zabielski, C.V.; Levy, M. )

    1994-12-01

    Electrochemical potentiodynamic polarization studies were conducted for a variety of ferrous and nonferrous metals in methylphosphonic difluoride. Studies were also made of the effects of organic inhibitors on the corrosion rates of 1,020 steel, type 316L, and type 304 stainless steel, and magnesium in methylphosphonic difluoride. Chemical weapons in the US include binary munitions in which two components are kept in separate compartments until activation. These munitions must be stockpiled for long periods of time (up to 30 years) and then must operate reliably when the need arises. The principal cause of failure will be corrosion of the storage container by the highly corrosive methylphosphonic difluoride (DF). The objectives of this study were to: investigate the kinetics and mechanisms of corrosion of Al 6061-T6 and candidate metal alloys in DF; establish effective corrosion inhibitors; and ultimately incorporate or immobilize inhibitors into coatings that provide protection above the liquid line.

  15. Corrosion inhibition behavior of propyl phosphonic acid-Zn2+ system for carbon steel in aqueous solution

    NASA Astrophysics Data System (ADS)

    Prabakaran, M.; Venkatesh, M.; Ramesh, S.; Periasamy, V.

    2013-07-01

    The effectiveness of propyl phosphonic acid (PPA) as a corrosion inhibitor in association with a bivalent cation like Zn2+ has been studied. An eco-friendly inhibitor in controlling corrosion of carbon steel in neutral aqueous medium in the absence and presence of Zn2+ has been evaluated by gravimetric method. Impedance studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of carbon steel in the aqueous environment. Potentiodynamic polarization studies showed that the inhibitor is a mixed inhibitor. X-ray photoelectron spectroscopic analysis (XPS) of the protective film exhibited the presence of the elements viz., iron, phosphorus, oxygen, carbon and zinc. The chemical shifts in the binding energies of these elements inferred that the surface film is composed of oxides/hydroxides of iron(III), Zn(OH)2 and [Fe(II)/(III)-Zn(II)-PPA] complex. Further, the surface analysis techniques viz., FT-IR, AFM and SEM studies confirm the formation of an adsorbed protective film on the carbon steel surface. Based on all these results, a plausible mechanism of corrosion inhibition is proposed.

  16. Study of materials to resist corrosion in condensing gas-fired furnaces. Final report Oct 79-Dec 81

    SciTech Connect

    Lahtvee, T.; Schaus, O.O.

    1982-02-01

    Based on a thorough review of background information on the performance of materials in condensing gas-fired heat exchangers and similar corrosive environments, candidate materials were examined on test equipment built to provide the varying corrosive conditions encountered in actual gas-fired condensing system heat exchangers. The 32 different materials tested in a one month screening test included: mild, low alloy, galvanized, solder coated steel, porcelain, epoxy, teflon and nylon coated and alonized mild steel; austenitic, ferritic, low interstitial Ti stabilized ferritic, and high alloy stainless steels; aluminum alloys, anodized and porcelain coated aluminum; copper and cupronickel alloys, solder coated copper; and titanium.

  17. Annual Report for EMSP #86803 -- Underground Corrosion After 32 Years: A Study of Fate and Transport

    SciTech Connect

    M.K. Adler Flitton

    2006-09-01

    Researchers from Department of Energy (DOE) National Laboratories at the Idaho and the Savannah River Sites recovered and are analyzing part of a final set of stainless steel specimens buried by the National Bureau of Standards in 1070 at Site D, near Wildwood, NJ. Findings included estimates for 32-year corrosion rates, transport of corrosion product, and elucidation of the site’s hydrogeobiochemistry. An interdisciplinary research team unraveled the complicated interrelationships among metal integrity, corrosion rates, corrosion mechanisms, soil properties, soil microbiology, plant and animal interaction with corrosion products, and fate and transport of metallic ions. This research provides long-term corrosion and transport data that can reduce the uncertainty associated with long-term waste storage and improve fate and transport modeling predictions throughout the DOE complex. The research also provides improvements in several characterization techniques.

  18. Stainless steel surface biofunctionalization with PMMA-bioglass coatings: compositional, electrochemical corrosion studies and microbiological assay.

    PubMed

    Floroian, L; Samoila, C; Badea, M; Munteanu, D; Ristoscu, C; Sima, F; Negut, I; Chifiriuc, M C; Mihailescu, I N

    2015-06-01

    A solution is proposed to surpass the inconvenience caused by the corrosion of stainless steel implants in human body fluids by protection with thin films of bioactive glasses or with composite polymer-bioactive glass nanostructures. Our option was to apply thin film deposition by matrix-assisted pulsed laser evaporation (MAPLE) which, to the difference to other laser or plasma techniques insures the protection of a more delicate material (a polymer in our case) against degradation or irreversible damage. The coatings composition, modification and corrosion resistance were investigated by FTIR and electrochemical techniques, under conditions which simulate their biological interaction with the human body. Mechanical testing demonstrates the adhesion, durability and resistance to fracture of the coatings. The coatings biocompatibility was assessed by in vitro studies and by flow cytometry. Our results support the unrestricted usage of coated stainless steel as a cheap alternative for human implants manufacture. They will be more accessible for lower prices in comparison with the majority present day fabrication of implants using Ti or Ti alloys. PMID:26085116

  19. Studies on the hot corrosion of a nickel-base superalloy, Udimet 700

    NASA Technical Reports Server (NTRS)

    Misra, A. K.

    1984-01-01

    The hot corrosion of a nickel-base superalloy, Udimet 700, was studied in the temperature range of 884 to 965 C and with different amounts of Na2SO4. Two different modes of degradation were identified: (1) formation of Na2MoO4 - MoO3 melt and fluxing by this melt, and (2) formation of large interconnected sulfides. The dissolution of Cr2O3, TiO2 in the Na2SO4 melt does not play a significant role in the overall corrosion process. The conditions for the formation of massive interconnected sulfides were identified and a mechanism of degradation due to sulfide formation is described. The formation of Ns2MoO4 - MoO3 melt requires an induction period and various physiochemical processes during the induction period were identified. The factors affecting the length of the induction period were also examined. The melt penetration through the oxide appears to be the prime mode of degradation whether the degradation is due to the formation of sulfides or the formation of the Na2MoO4 - MoO3 melt.

  20. Characterization and corrosion study of NiTi laser surface alloyed with Nb or Co

    NASA Astrophysics Data System (ADS)

    Ng, K. W.; Man, H. C.; Yue, T. M.

    2011-02-01

    The interest in NiTi alloys for medical applications has been steadily growing in recent years because of its biocompatibility, superelasticity and shape memory characteristics. However, the high Ni content in NiTi alloys is still a concern for its long-term applications in the human body. The release of Ni ion into the human body might cause serious problems, as Ni is capable of eliciting toxic and allergic responses. In view of this, surface modification to reduce the surface content of Ni and to improve the corrosion resistance, both of which would reduce Ni release, is an important step in the development of NiTi implants. In the present study, NiTi was surface alloyed with Nb or Co by laser processing. The fine dendritic structure characteristic of laser processing has been described in terms of rapid solidification. The amount of surface elemental Ni was reduced to 10% and 35% for the Nb-alloyed and Co-alloyed layer, respectively. The corrosion resistance in Hanks' solution (a simulated body fluid) was increased as evidenced by a reduced passive current density and a higher pitting potential for both the Nb- and Co-alloyed specimens. The composition and hardness profiles along the depth of the modified layer were correlated with the distribution of the dendrites. The microhardness of the alloyed layers was around 700-800 Hv, which was about four times that of the untreated NiTi specimens.

  1. Heat pipe and thermal energy storage and corrosion studies (1988). Final report, October 1987-September 1988

    SciTech Connect

    Krishnamurthy, M.; Dalton, P.; Jacobson, D.

    1989-06-01

    Corrosion-degradation analysis was performed on a set of three Inconel 617 Thermal Energy Storage capsules filled with different eutectic fluoride mixtures of LiF, MgF{sub 2}, NaF and KF which were thermally cycled near 1000 K for 10,000 hours. These capsules were cut out and various sections were metallographically studied by Optical and Scanning Electron microscopy and by elemental X-ray mapping. Chemical analyses on the metallic container were performed using the Electron Probe Micro-analyser and that of the salts by Atomic Absorption Spectroscopy. It was determined that the container material did not suffer significant microstructural damage except for tiny pits near the edge in contact with the salts and some voids near the surface exposed to vacuum which could not be positively identified as due to corrosion. The region extending to about 50 microns form the inner edge is contact with salt and about 30 microns from the outer edge exposed to vacuum were found to be depleted mainly of aluminum and to a lesser extent chromium.

  2. Laser Raman and x-ray scattering studies of corrosion films on metals

    SciTech Connect

    Melendres, C.A.

    1993-02-01

    Optical spectroscopic and X-ray scattering techniques, coupled with electrochemical methods, are among the most useful in probing the structure of corrosion films on metals in-situ in aqueous environments. Laser Raman spectroscopy has been employed for a number of years to investigate composition of surface films on metals like iron, nickel, chromium, and stainless steel. We illustrate our work by presenting some results of studies of composition of passive film on nickel, using surface enhanced Raman scattering (SERS) with an electrodeposited silver overlayer. We find that both oxide and hydroxide species are present on the surface of Ni in the passive region. We also demonstrate the utility of specular X-ray reflection in providing complementary information on the physical structure of passivated metal surfaces. Thickness of the corrosion films formed, density of surface layers, and development of surface and interface roughness on Cu electrodes have been quantitatively monitored in-situ as a function of potential for the first time.

  3. Stainless steel surface biofunctionalization with PMMA-bioglass coatings: compositional, electrochemical corrosion studies and microbiological assay.

    PubMed

    Floroian, L; Samoila, C; Badea, M; Munteanu, D; Ristoscu, C; Sima, F; Negut, I; Chifiriuc, M C; Mihailescu, I N

    2015-06-01

    A solution is proposed to surpass the inconvenience caused by the corrosion of stainless steel implants in human body fluids by protection with thin films of bioactive glasses or with composite polymer-bioactive glass nanostructures. Our option was to apply thin film deposition by matrix-assisted pulsed laser evaporation (MAPLE) which, to the difference to other laser or plasma techniques insures the protection of a more delicate material (a polymer in our case) against degradation or irreversible damage. The coatings composition, modification and corrosion resistance were investigated by FTIR and electrochemical techniques, under conditions which simulate their biological interaction with the human body. Mechanical testing demonstrates the adhesion, durability and resistance to fracture of the coatings. The coatings biocompatibility was assessed by in vitro studies and by flow cytometry. Our results support the unrestricted usage of coated stainless steel as a cheap alternative for human implants manufacture. They will be more accessible for lower prices in comparison with the majority present day fabrication of implants using Ti or Ti alloys.

  4. Studies on the hot corrosion of a nickel-base superalloy, Udimet 700

    NASA Technical Reports Server (NTRS)

    Misra, A. K.

    1986-01-01

    The hot corrosion of a nickel-base superalloy, Udimet 700, was studied in the temperture range of 884 to 965 C and with different amounts of Na2SO4. Two different modes of degradation were identified: (1) formation of Na2MoO4-MoO3 melt and fluxing by this melt, and (2) formation of large interconnected sulfides. The dissolution of Cr2O3, TiO2 in the Na2SO4 melt does not play a significnt role in the overall corrosion process. The conditions for the formation of massive interconnected sulfides were identified and a mechanism of degradation due to sulfide formation is described. The formation of Na2MoO4-MoO3 melt requires an induction period and various physiochemical processes during the induction period were identified. The factors affecting the length of the induction period were also examined. The melt penetration through the oxide appears to be the prime mode of degradation whether the degradation is due to the formation of sulfides or the formation of the Na2MoO4-MoO3 melt.

  5. Corrosion and Fretting of a Modular Hip System: A Retrieval Analysis of 60 Rejuvenate Stems.

    PubMed

    De Martino, Ivan; Assini, Joseph B; Elpers, Marcella E; Wright, Timothy M; Westrich, Geoffrey H

    2015-08-01

    Femoral stems with dual-taper modularity were introduced to allow independent control of length, offset, and version. Corrosion and fretting related to micromotion at the neck-stem junction are thought to stimulate an adverse local tissue reaction (ALTR). Analysis of 60 consecutively retrieved modular-neck stem implants (Rejuvenate, Stryker) revised primarily for ALTR was done to determine the variables influencing corrosion and fretting patterns at the neck-stem interface. Taper damage evaluation was performed with stereomicrocopic analysis with two observers. Evidence of fretting and corrosion was seen at the neck-stem taper in all implants, including three implants revised for periprosthetic fractures within four weeks of the index surgery indicating that this process starts early. Femoral stems paired with the long overall neck lengths had significantly higher corrosion scores. Correlation of the corrosion severity at particular locations with the length of implantation suggests that the neck-stem junction experiences cyclic cantilever bending in vivo. The positive correlation between the length of implantation and fretting/corrosion scores bodes poorly for patients who still have this implant. Scanning electron microscopy on a subset of specimens was also performed to evaluate the black corrosion material. We strongly urge frequent follow-up exams for every patient with this particular modular hip stem.

  6. Development and the Educational Effect of a System of the Corrosion of Iron and the Anti-corrosion Ability of Conductive Polymer Polyaniline

    NASA Astrophysics Data System (ADS)

    Yano, Jun; Nakamura, Noriyuki; Yamazaki, Suzuko; Ichimori, Hayato; Osaki, Nobukazu; Okano, Hiroshi

    Few general chemistry textbooks of high schools, colleges and universities introduce the corrosion of iron into the oxidation-reduction (redox) section, although the corrosion is very popular phenomena for students. Besides, no description appears about conductive polymers as anti-corrosion materials. The corrosion is a redox reaction proceeding through the local cell mechanism : the iron oxidation half-cell reaction at the local anode and the reduction of oxygen at the local cathode. To prepare a teaching tool for understanding of the mechanism, the visualization of the corrosion was attempted using phenolphthalein and potassium hexacyanoferrate (III) as color couplers for the anodic and cathodic products : Fe2+ and OH-. The local anode and cathode were obviously shown as gradual blue and red coloration when commercial nails were soaked in 4% NaCl aqueous solution containing phenolphthalein and potassium hexacyanoferrate (III) . On the other hand, no coloration occurred for the nail covered with a conductive polymer polyaniline. To know the anti-corrosion mechanism, the open-circuit potential of the nail was measured. The fact that the potential was kept at the potential range where iron was passivated implied that polyaniline acted as an in-situ oxidant. The visualization was experimentally performed at an actual chemistry class and the utility value was estimated. As a result, the visualization is expected to be a useful teaching tool for the corrosion and the understanding of the role of polyaniline as the anti-corrosion material.

  7. ELECTROCHEMICAL CORROSION STUDIES CORE 308 SEGMENTS 14R1 & 14R2 TANK 241-AY-102

    SciTech Connect

    DUNCAN JB; COOKE GA

    2003-10-30

    This document reports the results of electrochemical corrosion tests on AS1S Grade 60 carbon steel coupons exposed to tank 241-AY-102 sludge under conditions similar to those near the bottom of the tank. The tests were performed to evaluate the corrosive behavior of the waste in contact with sludge that does not meet the chemistry control limits of Administrative Control (AC) 5.15, Corrosion Mitigation Program.

  8. A mechanistic study of the effects of nitrogen on the corrosion properties of stainless steels

    SciTech Connect

    Levey, P.R.; Bennekom, A. van

    1995-12-01

    The effects of nitrogen alloying on the corrosion properties of stainless steels (SS) is a matter of debate. A number of apparently contradictory results have been presented by various researchers. The actual mechanism by which nitrogen alloying influences the corrosion properties of SS has been the topic of even more controversy. The effects of nitrogen on the corrosion and mechanical properties of SS were reviewed. Various proposals relating to the mechanistic effect of nitrogen alloying on the corrosion properties of SS were evaluated critically by comparing the various theories.

  9. Moessbauer spectroscopy study on the corrosion resistance of plasma nitrided ASTM F138 stainless steel in chloride solution

    SciTech Connect

    Souza, S.D. de; Olzon-Dionysio, M.; Basso, R.L.O.; Souza, S. de

    2010-10-15

    Plasma nitriding of ASTM F138 stainless steel samples has been carried out using dc glow discharge under 80% H{sub 2}-20% N{sub 2} gas mixture, at 673 K, and 2, 4, and 7 h time intervals, in order to investigate the influence of treatment time on the microstructure and the corrosion resistance properties. The samples were characterized by scanning electron microscopy, glancing angle X-ray diffraction and conversion electron Moessbauer spectroscopy, besides electrochemical tests in NaCl aerated solution. A modified layer of about 6 {mu}m was observed for all the nitrided samples, independent of nitriding time. The X-ray diffraction analysis shows broad {gamma}{sub N} phase peaks, signifying a great degree of nitrogen supersaturation. Besides {gamma}{sub N,} the Moessbauer spectroscopy results indicated the occurrence of {gamma}' and {epsilon} phases, as well as some other less important phases. Corrosion measurements demonstrate that the plasma nitriding time affects the corrosion resistance and the best performance is reached at 4 h treatment. It seems that the {epsilon}/{gamma}' fraction ratio plays an important role on the resistance corrosion. Additionally, the Moessbauer spectroscopy was decisive in this study, since it was able to identify and quantify the iron phases that influence the corrosion resistance of plasma nitrided ASTM F138 samples.

  10. Study for Corrosion and Hydrogen Evolution Behavior of Ti-6Al-4V Alloy in Simulated Acid Rain Water

    NASA Astrophysics Data System (ADS)

    Tammam, R. H.; Fekry, A. M.

    2014-03-01

    The electrochemical behavior of Ti-6Al-4V alloy was investigated using electrochemical impedance spectroscopy (EIS) measurements at the open circuit potentials and potentiodynamic polarization measurements in a simulated acid rain containing inorganic additives. The ac circuit model for Ti-6Al-4V alloy at corrosion interface in simulated acid rain containing inorganic additives was proposed, which was based on two time constants equivalent circuit. Ti-6Al-4V alloy in a simulated acid rain of pH 1.5 containing inorganic additives showed a characteristic of a capacitive behavior. The effect of different concentrations of the inorganic additives (iodate, dichromate, phosphate, and nitrate) on the corrosion of the alloy in acid rain water (ARW) was also studied. It was found that the corrosion rate decreases drastically in the solution containing iodate, dichromate, and phosphate anions; however, nitrate anions increase the corrosion rate of the alloy. The investigated inorganic additives had inhibiting effect on the corrosion of the alloy in ARW, and their efficiency decreases according to the order: iodate > dichromate > phosphate > blank > nitrate. Polarization data results are in good agreement with EIS.

  11. The coordinated use of synchrotron spectroelectrochemistry for corrosion studies on heritage metals.

    PubMed

    Adriaens, Annemie; Dowsett, Mark

    2010-06-15

    Corrosion is a major source of degradation in heritage metal objects, and any remedial measures are subject to a strong (Western) ethic that favors conservation as opposed to restoration. Accordingly, major scientific challenges exist for developing appropriate treatment methods to stabilize and protect artifacts after they are recovered from an archaeological site, both before and during their display or storage in a museum. Because inappropriate treatments can cause irreversible damage to irreplaceable objects, it is crucial that the chemical processes involved are fully understood and characterized before any preservation work is undertaken. In this regard, large infrastructural facilities such as synchrotrons, neutron sources, and particle accelerators provide a wealth of analytical possibilities, unavailable in smaller scale laboratories. In general, the intensity of the radiation available allows measurements on a short time scale or with high spatial resolution (or both), so heterogeneous changes induced by a chemical process can be recorded while they occur. The penetrative nature of the radiation (e.g., X-rays, protons, or neutrons) also allows a sample to be studied in air. If necessary, complete artifacts (such as paintings or statuettes) can be examined. In situ analysis in a controlled environment, such as a liquid or corrosive atmosphere, also becomes an exciting possibility. Finally, there are many complementary techniques (local atomic structure or crystal structure determination, macroscopic 3-D imaging (tomographies), imaging chemical analysis, and so on) so the many distinct details of a problem can be thoroughly explored. In this Account, we discuss the application of this general philosophy to studies of corrosion and its prevention in cultural heritage metals, focusing on our recent work on copper alloys. More specifically, we use synchrotron-based techniques to evaluate the use of corrosion potential measurements as a possible monitoring

  12. Container assessment: corrosion study of HLW container materials. Quarterly progress report, July-September 1981. Volume 1, No. 3

    SciTech Connect

    Ahn, T M; Soo, P

    1982-01-01

    Work has been started on the corrosion and hydrogen embrittlement behavior of commercially pure titanium (ASTM Grade 2), TiCode-12 (ASTM Grade 12), and OFHC copper, which are primary candidate materials for high level waste containers. The test environment used is a simulated brine solution typical of bedded salt at 150 C or room temperature. The immersion test results for these materials are in reasonable agreement with previous screening test results of Sandia National Laboratory; electron beam welded titanium and TiCode-12 samples show higher corrosion rates than the non-welded samples. To understand the difference between titanium and TiCode-12 in uniform and crevice corrosion, electrochemical tests were performed. While the initial repassivation behavior is similar in terms of charge density transfer after scratching tests in 1 M HCl solution at 80 C, titanium shows an active peak in polarization curves in brine at room temperature while TiCode-12 does not. Also, the open circuit corrosion potential of TiCode-12 is about 300 mV more anodic than that of titanium in 0.1 M HCl plus 0.9 M KCl solution at 85 C. Slow strain rate embrittlement and impact embrittlement have been observed in cathodically hydrogen charged commercially pure titanium and TiCode-12 in tension and buckling tests. C-ring and U-bend specimens of titanium and TiCode-12 have been designed and a slow strain rate test machine is being built to study stress corrosion cracking. Alternating Current Impedance and Scanning Reference Electrode Techniques are ready for pitting studies. For the study of radiation-induced corrosion, an irradiation cell was set up in the gamma pool to estimate quantitatively the oxidants as well as hydrogen produced by the gamma radiation in the brine solutions. 35 refs., 18 figs., 5 tabs.

  13. Corrosion detection of mild steel in a two phase hydrocarbon-electrolyte system under flow conditions using electrochemical noise

    SciTech Connect

    Male, J.M.; Uruchurtu, J.; Coron, O.

    1998-12-31

    Electrochemical current noise (ECN) measurements were carried out in mixtures of 3% NaCl electrolyte in diesel under stirred conditions (0 to 2,000 rpm) using a Rotating Electrodes System (RES) which includes three mild steel concentric electrodes embedded in activated polyester resin. Chemical activation of the resin allowed electrochemical measurements in the water in oil emulsion system. A 0.2 to 15% in volume range of 3% NaCl electrolyte additions was studied. Three distinctive noise patterns were obtained from electrochemical current noise (ECN) time-series: (a) a low noise baseline for diesel in absence of electrolyte, diesel with small additions of electrolyte and/or low flow rates, (b) a low noise signal with current bursts superimposed obtained from relatively small additions of electrolyte and high rotation rates and (c) a high amplitude signal for high rotation rates and relatively high additions of electrolyte. For case b, the number and intensity of current bursts is indicative of proximity to cases a or c. These results contrast with experiments carried out with a conventional non-activated resin which is insensitive to the range of electrolyte additions or to stirring conditions. This method can be implemented for water in oil systems where early corrosion detection is desirable.

  14. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Angel Sanjurjo

    2006-06-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. In previous tests, we had frequently encountered problems with our steam generator that were exacerbated by the very low flow rates that we needed. During this period we installed a new computer-controlled system for injecting water into the steam generator that eliminated this problem. We also tested alloy coupons coated by using the improved procedures described in our last quarterly report. Most of these coatings were nitrided Ti and Ta coatings, either by themselves, or sometimes with barrier layers of Al and Si nitrides. The samples were tested for 300 h at 900 C in a gas stream designed to mimic the environment in the high temperature heat recovery unit (HTHRU). Three samples that showed least corrosion were exposed for an additional 100 h.

  15. Pipeline corrosion assessment using embedded Fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Liang, Xiao; Huang, Ying; Galedari, Sahar Abuali; Azarmi, Fardad

    2015-04-01

    Corrosion is a leading cause of failure in metallic transmission pipelines. It significantly impacts the reliability and safety of metallic pipelines. An accurate assessment of corrosion status of the pipelines would contribute to timely pipeline maintenance and repair and extend the service life of the associated pipelines. To assess pipeline corrosion, various technologies have been investigated and the pipe-to-soil voltage potential measurement was commonly applied. However, remote and real-time corrosion assessment approaches are in urgent needs but yet achieved. Fiber optic sensors, especially, fiber Bragg gating (FBG) sensors, with unique advantages of real-time sensing, compactness, immune to EMI and moisture, capability of quasi-distributed sensing, and long life cycle, will be a perfect candidate for longterm pipeline corrosion assessment. In this study, FBG sensors are embedded inside pipeline external coating for corrosion monitoring of on-shore buried metallic transmission pipelines. Detail sensing principle, sensor calibration and embedment are introduced in this paper together with experimental corrosion evaluation testing ongoing. Upon validation, the developed sensing system could serve the purpose of corrosion monitoring to the numerous metallic pipelines across nation and would possibly reduce the pipeline corrosion induced tragedies.

  16. Experimental Design for the Evaluation of Detection Techniques of Hidden Corrosion Beneath the Thermal Protective System of the Space Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    Kemmerer, Catherine C.; Jacoby, Joseph A.; Lomness, Janice K.; Hintze, Paul E.; Russell, Richard W.

    2007-01-01

    The detection of corrosion beneath Space Shuttle Orbiter thermal protective system is traditionally accomplished by removing the Reusable Surface Insulation tiles and performing a visual inspection of the aluminum substrate and corrosion protection system. This process is time consuming and has the potential to damage high cost tiles. To evaluate non-intrusive NDE methods, a Proof of Concept (PoC) experiment was designed and test panels were manufactured. The objective of the test plan was three-fold: establish the ability to detect corrosion hidden from view by tiles; determine the key factor affecting detectability; roughly quantify the detection threshold. The plan consisted of artificially inducing dimensionally controlled corrosion spots in two panels and rebonding tile over the spots to model the thermal protective system of the orbiter. The corrosion spot diameter ranged from 0.100" to 0.600" inches and the depth ranged from 0.003" to 0.020". One panel consisted of a complete factorial array of corrosion spots with and without tile coverage. The second panel consisted of randomized factorial points replicated and hidden by tile. Conventional methods such as ultrasonics, infrared, eddy current and microwave methods have shortcomings. Ultrasonics and IR cannot sufficiently penetrate the tiles, while eddy current and microwaves have inadequate resolution. As such, the panels were interrogated using Backscatter Radiography and Terahertz Imaging. The terahertz system successfully detected artificially induced corrosion spots under orbiter tile and functional testing is in-work in preparation for implementation.

  17. Hot corrosion studies of four nickel-base superalloys: B-1900, NASA-TRW VIA, 713C and IN738

    NASA Technical Reports Server (NTRS)

    Fryburg, G. C.; Kohl, F. J.; Stearns, C. A.

    1976-01-01

    The susceptibility to hot corrosion of four nickel base superalloys has been studied at 900 deg and 1000 deg C in one atmosphere of slowly flowing oxygen. Hot corrosion was induced by coating the samples with known doses of NaSO4 and oxidizing the coated samples isothermally on a sensitive microbalance. In general, the order of susceptibility found was: B-1900 is greater than 713C is greater than NASA-TRW VIA and is greater than IN738. This order corresponds to the order of decreasing molybdenum content of the alloys. Chemical evidence for B-1900 indicates that hot corrosion is instigated by acid fluxing of the protective Al2O3 coating by MoO3.

  18. Electrochemical Study on the Inhibition Effect of Phenanthroline and Its Cobalt Complex as Corrosion Inhibitors for Mild Steel

    NASA Astrophysics Data System (ADS)

    Liu, Xia; Okafor, Peter C.; Jiang, Bin; Hu, Hongxiang; Zheng, Yugui

    2015-09-01

    The corrosion inhibition effect of phenanthroline (Phen) and its cobalt complex (CoPhen) on the corrosion of carbon steel in sulphuric acid solutions was studied using potentiodynamic polarization and electrochemical impedance spectroscopy techniques at 20, 30, and 40 °C. Scanning electron microscopy techniques were used to characterize the mild steel surface. The results indicate that the compounds inhibit the corrosion of mild steel in H2SO4 solutions through a predominant physical adsorption following the Langmuir adsorption isotherm. Polarization curves suggest that the complex and ligand are mixed-type inhibitors. The efficiency of the inhibitors is concentration- and temperature-dependent and follows the trend CoPhen > Phen.

  19. ELECTROCHEMICAL CORROSION STUDIES FOR TANK 241-AN-107 CORE 309 SEGMENTS 21R1 & 21R2

    SciTech Connect

    DUNCAN JB

    2007-11-13

    Liquid waste in tank 241-AN-107 is below Technical Safety Requirements Administrative Control 5.16 (AC 5.16) limits. Electrochemical corrosion testing was performed on Core 309, Segments 21R1 and 21R2, to provide information on the conductivity and corrosive tendencies of the tank saltcake and interstitial liquid. This report describes data obtained under the execution of RPP-PLAN-29001, 'Electrochemical Corrosion Studies for Tank 241-AN-107 Core 309, Segments 21R1 and 21R2'. Analytical results are presented that show supernatant was within the limits while the interstitial liquid remained below the limits for the analytical cores. Applicable AC 5.16 chemistry control limits for AN-107 are presented.

  20. In vivo electrochemical corrosion study of a CoCrMo biomedical alloy in human synovial fluids.

    PubMed

    Igual Munoz, A; Schwiesau, J; Jolles, B M; Mischler, S

    2015-07-01

    The present study was initiated with the aim to assess the in vivo electrochemical corrosion behaviour of CoCrMo biomedical alloys in human synovial fluids in an attempt to identify possible patient or pathology specific effects. For this, electrochemical measurements (open circuit potential OCP, polarization resistance Rp, potentiodynamic polarization curves, electrochemical impedance spectroscopy EIS) were carried out on fluids extracted from patients with different articular pathologies and prosthesis revisions. Those electrochemical measurements could be carried out with outstanding precision and signal stability. The results show that the corrosion behaviour of CoCrMo alloy in synovial fluids not only depends on material reactivity but also on the specific reactions of synovial fluid components, most likely involving reactive oxygen species. In some patients the latter were found to determine the whole cathodic and anodic electrochemical response. Depending on patients, corrosion rates varied significantly between 50 and 750 mg dm(-2)year(-1).

  1. Molecular Survey of Microbial Communities Involved in Concrete Corrosion in Wastewater Collection Systems

    EPA Science Inventory

    This information is relevant to the development of condition assessment tools associated with the aging water infrastructure research program Corrosion of wastewater collection infrastructure, especially concrete sewers, is a significant cause of deterioration and premature failu...

  2. Experimental investigation of solid by-product as sensible heat storage material: Characterization and corrosion study

    NASA Astrophysics Data System (ADS)

    Ortega-Fernández, Iñigo; Faik, Abdessamad; Mani, Karthik; Rodriguez-Aseguinolaza, Javier; D'Aguanno, Bruno

    2016-05-01

    The experimental investigation of water cooled electrical arc furnace (EAF) slag used as filler material in the storage tank for sensible heat storage application was demonstrated in this study. The physicochemical and thermal properties of the tested slags were characterized by using X-ray diffraction, scanning electron microcopy, Fourier transform infrared spectroscopy, Raman spectroscopy and laser flash analysis, respectively. In addition, the chemical compatibility between slags and molten nitrate salt (60 wt. % NaNO3 and 40 wt. % KNO3) was investigated at 565 °C for 500 hrs. The obtained results were clearly demonstrated that the slags showed a good corrosion resistance in direct contact with molten salt at elevated temperature. The present study was clearly indicated that a low-cost filler material used in the storage tank can significantly reduce the overall required quantities of the relatively higher cost molten salt and consequently reduce the overall cost of the electricity production.

  3. M"ossbauer study of corrosion and abrasion products in oil transporting pipes

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Perez Mazariego, Jose Luis; Marquina, Vivianne; Marquina, Ma. Luisa; Ridaura, Rosalia; Martinez, Lorenzo

    2012-02-01

    It is known that one of the main technological problems in carbon steel oleoducts is the corrosion produced by different substances, such as water, carbon dioxide, sulfur, and microorganisms. In addition, if in such mixture there is sand, aggressive sludge can be form that abrasions material from the oleoduct. A room temperature M"ossbauer study of corroded material taken from different sites of oleoducts is presented. Most of the M"ossbauer spectra reveal the presence of nanoparticles, indicating that in these pipes the abrasion problem is severe. A preliminary identification of the oxidized samples suggests the presence of magnetite, and some Iron hydroxides. Further studies are in course in order to identify unambiguously the products present in the corroded materials.

  4. Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

    SciTech Connect

    Arnold R. Marder

    2007-06-14

    Due to their excellent corrosion resistance, iron aluminum alloys are currently being considered for use as weld claddings in fossil fuel fired power plants. The susceptibility to hydrogen cracking of these alloys at higher aluminum concentrations has highlighted the need for research into the effect of chromium additions on the corrosion resistance of lower aluminum alloys. In the present work, three iron aluminum alloys were exposed to simulated coal combustion environments at 500 C and 700 C for both short (100 hours) and long (5,000 hours) isothermal durations. Scanning electron microscopy was used to analyze the corrosion products. All alloys exhibited excellent corrosion resistance in the short term tests. For longer exposures, increasing the aluminum concentration was beneficial to the corrosion resistance. The addition of chromium to the binary iron aluminum alloy prevented the formation iron sulfide and resulted in lower corrosion kinetics. A classification of the corrosion products that developed on these alloys is presented. Scanning transmission electron microscopy (STEM) of the as-corroded coupons revealed that chromium was able to form chromium sulfides only on the higher aluminum alloy, thereby preventing the formation of deleterious iron sulfides. When the aluminum concentration was too low to permit selective oxidation of only aluminum (upon initial exposure to the corrosion environment), the formation of chromium oxide alongside the aluminum oxide led to depletion of chromium beneath the oxide layer. Upon penetration of sulfur through the oxide into this depletion layer, iron sulfides (rather than chromium sulfides) were found to form on the low aluminum alloy. Thus, it was found in this work that the role of chromium on alloy corrosion resistance was strongly effected by the aluminum concentration of the alloy. STEM analysis also revealed the encapsulation of external iron sulfide products with a thin layer of aluminum oxide, which may provide a

  5. Application of iron electrode corrosion enhanced electrokinetic-Fenton oxidation to remediate diesel contaminated soils: A laboratory feasibility study

    NASA Astrophysics Data System (ADS)

    Tsai, Tzai-Tang; Sah, Jygau; Kao, Chih-Ming

    2010-01-01

    SummaryDiesel soil contamination on gas stations or refinery plants is a worldwide environmental problem. The main objectives of this study were to (1) evaluate the efficiency of electrokinetic (EK) by using different electrode materials (graphite and iron rods) and electrolytes (tap water, 0.01 M NaCl, and 0.1 M NaCl) on the remediation of diesel contaminated soils, and (2) evaluate the feasibility of total petroleum hydrocarbon-diesel (TPH-D) reducing in soils via EK-Fenton oxidation enhanced by corroded iron electrode. The EK and EK-Fenton experiments were conducted in batch and sand box experiments, respectively. Batch experiments reveal that the most appropriate electrolyte was 0.1 M NaCl when iron electrode was used in the EK system. Sand box experiments indicate that the TPH-D concentration dropped from 10,000 to 300 mg kg -1 when amorphous iron/total iron (Fe o/Fe t) ratio increased from 0.1 to 0.33, with the addition of 8% of H 2O 2 and 0.1 M NaCl after 60 days of EK-Fenton operation. Electrokinetically enhanced oxidation with the presence of both H 2O 2 and Fe 3O 4 (iron electrode corrosion) resulted in higher TPH-D removal efficiency (97%) compared to the efficiencies observed from EK (55%) or Fenton oxidation (27%) alone. This demonstrates that EK-Fenton oxidation catalyzed by iron electrode corrosion is a valuable direction to efficiently and effectively remediate diesel contaminated soils.

  6. Liquid-metal corrosion

    SciTech Connect

    Chopra, O.K.; DeVan, J.H.; Smith, D.L.; Sze, D.K.; Tortorelli, P.F.

    1985-09-01

    A review of corrosion and environmental effects on the mechanical properties of candidate structural alloys for use with liquid metals in fusion reactors is presented. The corrosion/mass transfer behavior of austenitic and ferritic steels and vanadium-base alloys is evaluated to determine the preliminary operating temperature limits for circulating and static liquid-lithium and Pb-17Li systems. The influence of liquid-metal environment on the mechanical properties of structural materials is discussed. Corrosion effects of nitrate and fluoride salts are presented. Requirements for additional data are identified.

  7. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Angel Sanjurjo

    2005-12-01

    Heat exchangers, particle filters, turbines, and other components in an integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high-alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this reporting period, we conducted a simulated gasifier test primarily with TiN-coated steel samples. Although the test showed these coatings to offer significant protection against corrosion, they also revealed a lack of uniformity in the coatings. We spent a considerable amount of effort improving our coatings procedure as well as the fluidized bed reactor and its heater. Based on the results collected thus far, we selected 12 samples and sent them to ConocoPhillips for testing in their gasifier at the Wabash River Energy plant.

  8. Evaluation of long-term corrosion durability and self-healing ability of scratched coating systems on carbon steel in a marine environment

    NASA Astrophysics Data System (ADS)

    Zhao, Xia; Chen, Changwei; Xu, Weichen; Zhu, Qingjun; Ge, Chengyue; Hou, Baorong

    2016-09-01

    Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications. A composite coating system, including a primer, middle coat and topcoat, were used to protect carbon steel from corrosion in a marine environment. Two environmental additives, glass fibers and thiourea, were applied in the middle coat to modify the coating system. The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods. Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.% fibers and 0.5 wt.% thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5% NaCl for 120 d. Evolution of localized corrosion factors with time, as obtained from the current distribution showed that fibers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development significantly. Surface characterization suggested that adequate thiourea could be absorbed uniformly on fibers for a long time to play an important role in protecting the carbon steel. Finally, schematic models were established to demonstrate the action of fibers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.

  9. Copper corrosion in coastal Oregon

    SciTech Connect

    Ballard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S. Jr.; Holcomb, Gordon R.

    1998-01-01

    The US Department of Energy is studying the atmospheric corrosion performance of copper and other metals along the Oregon coast. Only the copper results will be presented in this paper. Atmospheric corrosion measurements of copper samples were made at seven bridges, eight coastal communities, and three inland reference sites to quantify and understand the effect of high chloride environments on the corrosion performance of copper. The materials were atmospherically exposed for 1, 2, and 3 years to examine the effects of sheltering, orientation, distance from the ocean, and coastal microclimates on the rate of corrosion and the composition of the corrosion film.

  10. A Multifunctional Coating for Autonomous Corrosion Control

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  11. Pipeline system insulation: Thermal insulation and corrosion prevention. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    1995-01-01

    The bibliography contains citations concerning thermal and corrosion insulation of pipeline systems used to transport liquids and gases. Topics include thermal aging of polyurethane used for foam heating pipes, extrusion film pipeline insulation materials and processes, flexible expanded nitrile rubber pipeline insulation with Class 1 fire rating, and underground fiberglass reinforced polyester insulated pipeline systems. Applications in solar heating systems; underground water, oil, and gas pipelines; interior hot and cold water lines under seawater; and chemical plant pipeline system insulation are included. (Contains 250 citations and includes a subject term index and title list.)

  12. Pipeline system insulation: Thermal insulation and corrosion prevention. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    1995-11-01

    The bibliography contains citations concerning thermal and corrosion insulation of pipeline systems used to transport liquids and gases. Topics include thermal aging of polyurethane used for foam heating pipes, extrusion film pipeline insulation materials and processes, flexible expanded nitrile rubber pipeline insulation with Class 1 fire rating, and underground fiberglass reinforced polyester insulated pipeline systems. Applications in solar heating systems; underground water, oil, and gas pipelines; interior hot and cold water lines under seawater; and chemical plant pipeline system insulation are included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  13. Pipeline system insulation: Thermal insulation and corrosion prevention. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    Not Available

    1994-05-01

    The bibliography contains citations concerning thermal and corrosion insulation of pipeline systems used to transport liquids and gases. Topics include thermal aging of polyurethane used for foam heating pipes, extrusion film pipeline insulation materials and processes, flexible expanded nitrile rubber pipeline insulation with Class 1 fire rating, and underground fiberglass reinforced polyester insulated pipeline systems. Applications in solar heating systems; underground water, oil, and gas pipelines; interior hot and cold water lines under seawater; and chemical plant pipeline system insulation are included. (Contains 250 citations and includes a subject term index and title list.)

  14. Corrosion protection

    DOEpatents

    Brown, Donald W.; Wagh, Arun S.

    2003-05-27

    There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

  15. LWRS Fuels Pathway: Engineering Design and Fuels Pathway Initial Testing of the Hot Water Corrosion System

    SciTech Connect

    Dr. John Garnier; Dr. Kevin McHugh

    2012-09-01

    The Advanced LWR Nuclear Fuel Development R&D pathway performs strategic research focused on cladding designs leading to improved reactor core economics and safety margins. The research performed is to demonstrate the nuclear fuel technology advancements while satisfying safety and regulatory limits. These goals are met through rigorous testing and analysis. The nuclear fuel technology developed will assist in moving existing nuclear fuel technology to an improved level that would not be practical by industry acting independently. Strategic mission goals are to improve the scientific knowledge basis for understanding and predicting fundamental nuclear fuel and cladding performance in nuclear power plants, and to apply this information in the development of high-performance, high burn-up fuels. These will result in improved safety, cladding, integrity, and nuclear fuel cycle economics. To achieve these goals various methods for non-irradiated characterization testing of advanced cladding systems are needed. One such new test system is the Hot Water Corrosion System (HWCS) designed to develop new data for cladding performance assessment and material behavior under simulated off-normal reactor conditions. The HWCS is capable of exposing prototype rodlets to heated, high velocity water at elevated pressure for long periods of time (days, weeks, months). Water chemistry (dissolved oxygen, conductivity and pH) is continuously monitored. In addition, internal rodlet heaters inserted into cladding tubes are used to evaluate repeated thermal stressing and heat transfer characteristics of the prototype rodlets. In summary, the HWCS provides rapid ex-reactor evaluation of cladding designs in normal (flowing hot water) and off-normal (induced cladding stress), enabling engineering and manufacturing improvements to cladding designs before initiation of the more expensive and time consuming in-reactor irradiation testing.

  16. Surface Studies of Ultra Strength Drilling Steel after Corrosion Fatigue in Simulated Sour Environment

    SciTech Connect

    M. Ziomek-Moroz; J.A. Hawk; R. Thodla; F. Gui

    2012-05-06

    The Unites States predicted 60% growth in energy demand by 2030 makes oil and natural gas primary target fuels for energy generation. The fact that the peak of oil production from shallow wells (< 5000 m) is about to be reached, thereby pushing the oil and natural gas industry into deeper wells. However, drilling to depths greater than 5000 m requires increasing the strength-to weight ratio of the drill pipe materials. Grade UD-165 is one of the ultra- high yield strength carbon steels developed for ultra deep drilling (UDD) activities. Drilling UDD wells exposes the drill pipes to Cl{sup -}, HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}, and H{sub 2}S-containig corrosive environments (i.e., sour environments) at higher pressures and temperatures compared to those found in conventional wells. Because of the lack of synergism within the service environment, operational stresses can result in catastrophic brittle failures characteristic for environmentally assisted cracking (EAC). Approximately 75% of all drill string failures are caused by fatigue or corrosion fatigue. Since there is no literature data on the corrosion fatigue performance of UD-165 in sour environments, research was initiated to better clarify the fatigue crack growth (FCGR) behavior of this alloy in UDD environments. The FCGR behavior of ultra-strength carbon steel, grade UD-165, was investigated by monitoring crack growth rate in deaerated 5%NaCl solution buffered with NaHCO{sub 3}/Na{sub 2}CO{sub 3} and in contact with H{sub 2}S. The partial pressure of H{sub 2}S (p{sub H2S}) was 0.83 kPa and pH of the solution was adjusted by NaOH to 12. The fatigue experiments were performed at 20 and 85 C in an autoclave with surface investigations augmented by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. In this study, research focused on surface analyses supported by the fatigue crack growth rate measurements. Fig. 1 shows an SEM micrograph of the crack that propagated from the

  17. Galvanic corrosion behavior of dissimilar metals in tropical marine environment

    SciTech Connect

    Subramanian, G.; Palraj, S.; Sundaram, M.; Balakrishnan, K.

    1995-11-01

    The galvanic corrosion behavior of aluminium 3004-70/30 brass and aluminium 3004-copper have been studied in the tropical marine environment of Mandapam, over a period of 436 days, under different area ratios. The area ratios, viz. A{sub Al} : A{sub brass} and A{sub Al} : A{sub copper}, studied are 0.125, 0.25, 0.5, 1, 2, 4 an 8. The galvanic corrosion behavior of the metals are studied in terms of the relative increase in the corrosion rate of Al due to galvanic coupling with brass and copper, the relative decrease in the corrosion rates of brass and copper due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with brass and copper. The galvanic potential and galvanic current of the systems are monitored. Pits of different dimensions ranging from mild etchings to perforations are experienced on the borders and the surfaces of the interface of aluminium in contact with copper and brass. The weathering parameters and the environmental pollutants have a major role in influencing the galvanic corrosion of metals are also been monitored. The corrosion products resulting from galvanic corrosion are analyzed with XRD and the pitting on aluminium resulting from galvanic corrosion is highlighted in terms of pit depth, size and density of pit, using a high resolution microscope.

  18. Considerations for cold weather construction using high density polyethylene for corrosion control systems

    SciTech Connect

    Szklarz, K.E.; Baron, J.J.

    1995-12-01

    High Density Polyethylene (HDPE) is commonly used as material for corrosion-resistant piping in the petroleum industry. It is used as thick-walled self-supporting linepipes, as internal liners for steel linepipe, and as protective jackets for insulated linepipes. In Canada, it is not uncommon for operations, such as pipeline installation, to be performed during the winter season when temperatures are in the 0 C to {minus}20 C range. Brittle failures of HDPE materials have been experienced during such sub-zero operations, particularly when pipe handling and bending is involved. This study evaluated the changes in HDPE mechanical properties within the temperature range of 10 C to {minus}40 C to understand any embrittlement phenomena that may be occurring. HDPE undergoes substantial increases in modulus and strength at lower temperatures and increasing strain rate. The changes are gradual and over a wide range of temperature with no sharp cut-off temperature at which brittle behavior will occur. Flexural properties behave in a similar manner. A notch, causing a local increased strain rate, has a significant effect on the failure behavior of HDPE material with a gradual transition in behavior of ductility and load at below 0 C.

  19. Corrosion behavior, biocompatibility and biomechanical stability of a prototype magnesium-based biodegradable intramedullary nailing system.

    PubMed

    Krämer, Manuel; Schilling, Markus; Eifler, Rainer; Hering, Britta; Reifenrath, Janin; Besdo, Silke; Windhagen, Henning; Willbold, Elmar; Weizbauer, Andreas

    2016-02-01

    Implants made of degradable magnesium alloys are a potential alternative to conventional orthopaedic implant materials, e.g. stainless steel or titanium. Intramedullary nails made of the magnesium alloy LAE442 were subjected to cyclic fatigue tests in both distilled water and Hank's Balanced Salt Solution (HBSS) at 37.5°C until implant failure or a limit of 500,000cycles was reached. In distilled water, four of the five nails were still intact after the end of the biomechanical test. In HBSS, a breakage within the first 70,000 bending cycles was observed. Additionally, the degradation rate of this alloy was determined in HBSS according to the weight loss method (0.24±0.12mmyear(-1)) and based on gas release (0.21±0.03mmyear(-1)) with a standard eudiometer. A cytotoxicity test with L929 cells was carried out in accordance with EN ISO 10993-5/12. This test demonstrated sufficient cell viability of the diluted extracts (50%, 25% and 12.5%). The relative metabolic activity of the 100% extract was reduced slightly below 70%, which is classified as a threshold value for cytotoxicity. In conclusion, this in vitro study indicates that intramedullary nails made of LAE442 may not have the required fatigue resistance for load-bearing applications and the development of a corrosion-protective coating may be necessary to prevent early failure of the implant. PMID:26652357

  20. Corrosion behavior, biocompatibility and biomechanical stability of a prototype magnesium-based biodegradable intramedullary nailing system.

    PubMed

    Krämer, Manuel; Schilling, Markus; Eifler, Rainer; Hering, Britta; Reifenrath, Janin; Besdo, Silke; Windhagen, Henning; Willbold, Elmar; Weizbauer, Andreas

    2016-02-01

    Implants made of degradable magnesium alloys are a potential alternative to conventional orthopaedic implant materials, e.g. stainless steel or titanium. Intramedullary nails made of the magnesium alloy LAE442 were subjected to cyclic fatigue tests in both distilled water and Hank's Balanced Salt Solution (HBSS) at 37.5°C until implant failure or a limit of 500,000cycles was reached. In distilled water, four of the five nails were still intact after the end of the biomechanical test. In HBSS, a breakage within the first 70,000 bending cycles was observed. Additionally, the degradation rate of this alloy was determined in HBSS according to the weight loss method (0.24±0.12mmyear(-1)) and based on gas release (0.21±0.03mmyear(-1)) with a standard eudiometer. A cytotoxicity test with L929 cells was carried out in accordance with EN ISO 10993-5/12. This test demonstrated sufficient cell viability of the diluted extracts (50%, 25% and 12.5%). The relative metabolic activity of the 100% extract was reduced slightly below 70%, which is classified as a threshold value for cytotoxicity. In conclusion, this in vitro study indicates that intramedullary nails made of LAE442 may not have the required fatigue resistance for load-bearing applications and the development of a corrosion-protective coating may be necessary to prevent early failure of the implant.

  1. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    SciTech Connect

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  2. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    NASA Astrophysics Data System (ADS)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  3. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    SciTech Connect

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  4. New titanium alloys for biomaterials: a study of mechanical and corrosion properties and cytotoxicity.

    PubMed

    Kim, T I; Han, J H; Lee, I S; Lee, K H; Shin, M C; Choi, B B

    1997-01-01

    Three new titanium alloys with Zr, Nb, Ta, Pd and In as alloying elements were developed and compared with currently used implant metals, namely, pure Ti and Ti-6Al-4V alloy, in terms of mechanical and corrosion properties, and cytotoxicity. New alloys showed comparable mechanical properties with that of the Ti-6Al-4V alloy, but increased corrosion potential, somewhat decreased breakdown potential and increased corrosion rate. There were no significant differences in cell growth on the surface of the various metal specimens, indicating that the cells cannot differentiate between the passivated surfaces of the various Ti metals.

  5. Microencapsulation Technology for Corrosion Mitigation by Smart Coatings

    NASA Technical Reports Server (NTRS)

    Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.

    2011-01-01

    A multifunctional, smart coating for the autonomous control of corrosion is being developed based on micro-encapsulation technology. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection effectiveness. This paper summarizes the development, optimization, and testing of microcapsules specifically designed to be incorporated into a smart coating that will deliver corrosion inhibitors to mitigate corrosion autonomously. Key words: smart coating, corrosion inhibition, microencapsulation, microcapsule, pH sensitive microcapsule, corrosion inhibitor, corrosion protection pain

  6. Corrosion considerations for thermochemical biomass liquefaction process systems in biofuel production

    DOE PAGESBeta

    Brady, Michael P.; Keiser, James R.; Leonard, Donovan N.; Whitmer, Lysle; Thomson, Jeffery K.

    2014-11-11

    Thermochemical liquifaction processing of biomass to produce bio-derived fuels (e.g. gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc. to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic compounds, which make the bio-oil acidic and a potential source of corrosion issues in in transport, storage, and use. Efforts devoted to modified/further processing of bio-oilsmore » to make them less corrosive are currently being widely pursued. Another aspect that must also be addressed is potential corrosion issues in the bio-oil liquefaction process equipment itself. Depending on the specific process, bio-oil liquefaction production temperatures can reach up to 400-600 °C, and involve the presence of aggressive sulfur, and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. Lastly, this paper summarizes our recent, ongoing efforts to assess the extent to which corrosion of bio-oil process equipment may be an issue, with the ultimate goal of providing the basis to select the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.« less

  7. Corrosion considerations for thermochemical biomass liquefaction process systems in biofuel production

    SciTech Connect

    Brady, Michael P.; Keiser, James R.; Leonard, Donovan N.; Whitmer, Lysle; Thomson, Jeffery K.

    2014-11-11

    Thermochemical liquifaction processing of biomass to produce bio-derived fuels (e.g. gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc. to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic compounds, which make the bio-oil acidic and a potential source of corrosion issues in in transport, storage, and use. Efforts devoted to modified/further processing of bio-oils to make them less corrosive are currently being widely pursued. Another aspect that must also be addressed is potential corrosion issues in the bio-oil liquefaction process equipment itself. Depending on the specific process, bio-oil liquefaction production temperatures can reach up to 400-600 °C, and involve the presence of aggressive sulfur, and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. Lastly, this paper summarizes our recent, ongoing efforts to assess the extent to which corrosion of bio-oil process equipment may be an issue, with the ultimate goal of providing the basis to select the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.

  8. Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

    NASA Technical Reports Server (NTRS)

    Pearman, Benjamin Pieter; Calle, Luz M.

    2015-01-01

    This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

  9. Fireside Corrosion

    SciTech Connect

    Holcomb, Gordon

    2011-07-14

    Oxy-fuel fireside research goals are: (1) determine the effect of oxyfuel combustion on fireside corrosion - flue gas recycle choice, staged combustion ramifications; and (2) develop methods to use chromia solubility in ash as an ash corrosivity measurement - synthetic ashes at first, then boiler and burner rig ashes.

  10. Corrosion inhibitor

    SciTech Connect

    Wisotsky, M.J.; Metro, S.J.

    1989-10-31

    A corrosion inhibitor for use in synthetic ester lubricating oils is disclosed. It comprises an effective amount of: at least one aromatic amide; and at least one hydroxy substituted aromatic compound. The corrosion inhibitor thus formed is particularly useful in synthetic ester turbo lubricating oils.

  11. The effect of frictional torque and bending moment on corrosion at the taper interface : an in vitro study.

    PubMed

    Panagiotidou, A; Meswania, J; Osman, K; Bolland, B; Latham, J; Skinner, J; Haddad, F S; Hart, A; Blunn, G

    2015-04-01

    The aim of this study was to assess the effect of frictional torque and bending moment on fretting corrosion at the taper interface of a modular femoral component and to investigate whether different combinations of material also had an effect. The combinations we examined were 1) cobalt-chromium (CoCr) heads on CoCr stems 2) CoCr heads on titanium alloy (Ti) stems and 3) ceramic heads on CoCr stems. In test 1 increasing torque was imposed by offsetting the stem in the anteroposterior plane in increments of 0 mm, 4 mm, 6 mm and 8 mm when the torque generated was equivalent to 0 Nm, 9 Nm, 14 Nm and 18 Nm. In test 2 we investigated the effect of increasing the bending moment by offsetting the application of axial load from the midline in the mediolateral plane. Increments of offset equivalent to head + 0 mm, head + 7 mm and head + 14 mm were used. Significantly higher currents and amplitudes were seen with increasing torque for all combinations of material. However, Ti stems showed the highest corrosion currents. Increased bending moments associated with using larger offset heads produced more corrosion: Ti stems generally performed worse than CoCr stems. Using ceramic heads did not prevent corrosion, but reduced it significantly in all loading configurations. PMID:25820883

  12. The effect of frictional torque and bending moment on corrosion at the taper interface : an in vitro study.

    PubMed

    Panagiotidou, A; Meswania, J; Osman, K; Bolland, B; Latham, J; Skinner, J; Haddad, F S; Hart, A; Blunn, G

    2015-04-01

    The aim of this study was to assess the effect of frictional torque and bending moment on fretting corrosion at the taper interface of a modular femoral component and to investigate whether different combinations of material also had an effect. The combinations we examined were 1) cobalt-chromium (CoCr) heads on CoCr stems 2) CoCr heads on titanium alloy (Ti) stems and 3) ceramic heads on CoCr stems. In test 1 increasing torque was imposed by offsetting the stem in the anteroposterior plane in increments of 0 mm, 4 mm, 6 mm and 8 mm when the torque generated was equivalent to 0 Nm, 9 Nm, 14 Nm and 18 Nm. In test 2 we investigated the effect of increasing the bending moment by offsetting the application of axial load from the midline in the mediolateral plane. Increments of offset equivalent to head + 0 mm, head + 7 mm and head + 14 mm were used. Significantly higher currents and amplitudes were seen with increasing torque for all combinations of material. However, Ti stems showed the highest corrosion currents. Increased bending moments associated with using larger offset heads produced more corrosion: Ti stems generally performed worse than CoCr stems. Using ceramic heads did not prevent corrosion, but reduced it significantly in all loading configurations.

  13. Use of Microwaves for the Detection of Corrosion Under Insulation: a Sensitivity Study

    NASA Astrophysics Data System (ADS)

    Jones, R. E.; Simonetti, F.; Lowe, M. J. S.; Bradley, I. P.

    2011-06-01

    Corrosion under insulation is a significant cause of pipeline failure in the oil and gas industry. This paper describes the initial developmental stages of a technique which uses the structure of an insulated pipeline as a coaxial waveguide to support the propagation of microwaves. These microwaves are used to inspect the insulation layer for the presence of water, which will indicate the regions of the pipe at risk from corrosion.

  14. Eliminating air heater plugging and corrosion caused by SCR/SNCR systems for NOx control on coal-fired boilers

    SciTech Connect

    Guffre, J.

    2007-10-15

    In a typical coal-fired power plant the rotary regenerative air heater is responsible for 5-10% of the boiler's total efficiency. The three biggest threats to air heater performance deterioration are corrosion of the heat exchange surfaces, plugging, and air heater leakage through the seals. The article concentrates on the vastly increased level of corrosion and plugging issues associated with installing selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) systems for controlling nitrogen oxide emissions. Some injected ammonia in the SCR process reacts with SO{sub 2} to form ammonium sulphate and bisulphate (ABS) which is deposited on the air heater element surfaces. This can be overcome by applying coatings, using corrosion-resistant steels, reconfiguring the air heaters to a two layer design, improving air heater blowers, improving technologies for removing ammonia 'slip' before it enters the air heater, and using new catalysts that reduce the oxidation of SO{sub 2} to SO{sub 3}. 4 figs.

  15. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Jordi Perez-Mariano; Angel Sanjurjo

    2007-03-31

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the hightemperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period, we analyzed several 409 low alloy steel samples after coating them in our fluidized bed reactor and also after exposing them to our corrosion test. We report the following findings: 1. A protective coating was deposited inside a porous 409 steel sample to protect it from sulfidation attack. The coating was based on a combination of Si diffusion layer, Nb interlayer and nitrides of titanium and silicon. 2. Analysis of solid coupons exposed to simulated coal gas at 900 C for 300 h showed that multilayer metal/ceramic coatings provide a better protection than ceramic coatings. 3. Deposition of several ceramic/metal multilayer coatings showed that coatings with niobium and tantalum interlayers have good adhesion. However, coatings with a tungsten interlayer suffered localized delaminating and coatings with Zr interlayers showed poor adhesion. 4. Analysis of solid coupons, coated with the above-mentioned multilayer films, after exposure to simulated coal gas at 900 C for 300 h showed that niobium is the best candidate for interlayer material.

  16. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Angel Sanjurjo

    2006-01-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period we tested coated alloy coupons under conditions designed to mimic the conditions in the filter unit after the high-temperature heat recovery unit (HTHRU). The filter unit is another important area where corrosion has caused unscheduled downtime, and the remedy has been the use of sintered metal tubes made of expensive alloys such as inconel. The objective of our test was to determine if those coatings on 400-series steel that were not able to withstand the harsher conditions of the HTHRU, may be sufficiently resistant for use in the filter unit, at the reduced temperatures. Indeed, most of our coatings survived well; the exceptions were the coated porous samples of SS316. We continued making improvements to our coatings apparatus and the procedure began during the last quarter. As a result of these modifications, the coupons we are now producing are uniform. We describe the improved procedure for preparing diffusion coatings. Finally, because porous samples of steel in grades other than SS316 are not readily available, we also decided to procure SS409 powder and fabricate our own sintered porous coupons.

  17. Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Esperanza Alvarez; Kai-Hung Lau; Jordi Perez-Mariano; Angel Sanjurjo

    2006-06-30

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period, we analyzed several coated and exposed samples of 409 steel by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). We report here on findings of this analysis: (1) A SS409 coupon that was coated with multilayered combined nitrides of Ti, Al, and Si showed adherent coatings on the surface; (2) A similarly coated coupon, after exposure to simulated coal gas at 900 C for 300 h, revealed that the coating has cracked during the exposure; (3) An SS409 coupon that was coated with nitrides of Ti and Si with a barrier layer of tungsten in between to improve the adhesion of the coating and to prevent outward diffusion of iron to the surface. (4) A porous coupon was coated with nitrides of Ti and Al and examination of the coupon revealed deposition of Ti at the interior surfaces. A similarly prepared coupon was exposed to simulated coal gas at 370 C for 300 h, and it showed no corrosion.

  18. BWR steel containment corrosion

    SciTech Connect

    Tan, C.P.; Bagchi, G.

    1996-04-01

    The report describes regulatory actions taken after corrosion was discovered in the drywell at the Oyster Creek Plant and in the torus at the Nine Mile Point 1 Plant. The report describes the causes of corrosion, requirements for monitoring corrosion, and measures to mitigate the corrosive environment for the two plants. The report describes the issuances of generic letters and information notices either to collect information to determine whether the problem is generic or to alert the licensees of similar plants about the existence of such a problem. Implementation of measures to enhance the containment performance under severe accident conditions is discussed. A study by Brookhaven National Laboratory (BNL) of the performance of a degraded containment under severe accident conditions is summarized. The details of the BNL study are in the appendix to the report.

  19. Measurement and mitigation of corrosion on self-contained fluid filled (SCFF) submarine circuits for New York Power Authority: Volume 2 -- Stray electrical current measurements and preliminary design of the cathodic protection system. Final report

    SciTech Connect

    1998-10-01

    In 1987, the New York Power Authority (NYPA) installed a 345-kV submarine cable circuit across Long Island Sound between substations at Davenport Neck and Hempstead Harbor. During design and installation of the cable circuit, utility and cable manufacturers engineers identified corrosion as a possible problem for the cable system. They considered such effects in the cable design and discussed preliminary requirements for a cathodic protection system on Long Island Sound circuit. EPRI cosponsored this review of the corrosion effects with NYPA and Empire State Electric Energy Research Corp. (ESEERCO). Volume 1 of this report discusses the results from an in-depth evaluation of the self-contained fluid-filled (SCFF) cable construction materials and their susceptibility to corrosion. Volume 2 provides extended stray current field measurements and a preliminary design for a cathodic protection system to ensure cable service reliability. This study provides a blueprint for East or West Coast utilities evaluating site-specific corrosion processes and cable circuit protection methods suitable for underwater environments.

  20. OTEC-1 Power System Test Program: biolfouling and corrosion monitoring on OTEC-1

    SciTech Connect

    Gavin, A.P.; Kuzay, T.M.

    1981-09-01

    Biofouling and corrosion experiments performed on board The Ocean Energy Converter during the OTEC-1 deployment are summarized. The equipment installed for the experiments, details of the operating history of the experiments, and results obtained are described. Details of equipment and operating experience are included which it is hoped will be of use in planning future experiments of this type.

  1. PD/MG BIMETALLIC CORROSION SYSTEMS FOR DECHLORINATION OF PCB CONTAMINATED MATRICES

    EPA Science Inventory

    Polychlorinated biphenyls (PCBs), a family of 209 compounds manufactured till mid70's, are toxic pollutants that persist in the environment. Enhanced corrosion of an active metal combined with catalytic hydrogenation properties of Pd in bimetallic cells can effectively reduce PCB...

  2. Corrosion `98: 53. annual conference and exposition, proceedings

    SciTech Connect

    1998-12-31

    This conference was divided into the following sections: Corrosion in Gas Treating; Problems and Solutions in Commercial Building Water Systems; Green Corrosion/Scale Inhibitors; Atmospheric Corrosion; AIRPOL Update/98; Rubber Lining--Answers to Many Problems; Interference Problems; Environmental Assisted Cracking: Fundamental Research and Industrial Applications; Corrosion in Nuclear Systems; New Developments in Scale and Deposit Control; Corrosion and Corrosion Protection in the Transportation Industries; What`s All the Noise About--Electrochemical That Is; Refining Industry Corrosion; Corrosion Problems in Military Hardware: Case Histories, Fixes and Lessons Learned; Cathodic Protection Test Methods and Instrumentation for Underground and On-grade Pipelines and Tanks; Recent Developments in Volatile Corrosion Inhibitors; Corrosion in Supercritical Fluids; Microbiologically Influenced Corrosion; Advances in Understanding and Controlling CO{sub 2} Corrosion; Managing Corrosion with Plastics; Material Developments for Use in Exploration and Production Environments; Corrosion in Cold Regions; The Effect of Downsizing and Outsourcing on Cooling System Monitoring and Control Practices; New Developments in Mechanical and Chemical Industrial Cleaning; Mineral Scale Deposit Control in Oilfield Related Operations; Biocides in Cooling Water; Corrosion and Corrosion Control of Reinforced Concrete Structures; Materials Performance for Fossil Energy Conversion Systems; Marine corrosion; Thermal Spray--Coating and Corrosion Control; Flow Effects on Corrosion in Oil and Gas Production; Corrosion Measurement Technologies; Internal Pipeline Monitoring--Corrosion Monitoring, Intelligent Pigging and Leak Detection; Cathodic Protection in Natural Waters; Corrosion in Radioactive Liquid Waste Systems; On-line Hydrogen Permeation Monitoring Equipment and Techniques, State of the Art; Water Reuse and Recovery; Performance of Materials in High Temperature Environments; Advances in Motor

  3. Underground Corrosion after 32 Years: A Study of Fate and Transport

    SciTech Connect

    Flitton, M. K. Adler

    2006-06-01

    Improved estimates for corrosion rates in variably saturated porous media are required by the U.S. Department of Energy to maintain long-term storage of radioactive contaminants in stainless steel containers. To better define these parameters, research was undertaken to complete the National Institute of Standards and Technology's (NIST) long-term study of buried stainless steel began 35 years ago. The 1970 study was initiated by the National Bureau of Standards (NBS), now known as NIST, when over 1000 specimens--including stainless steel Types 201, 202, 301, 304, 316, 409, 410, 430, and 434-configured as plates, U-bend, and tubes in both annealed and cold worked conditions with various treatments--were buried at six distinctive soil-type sites throughout the United States. During the first eight years of the study, four of five planned removals were completed with specimens retrieved after one, two, four, and eight years at each of the six sites. The fifth and final set of specimens remained undisturbed for over 34 years.

  4. Underground Corrosion after 32 years: A Study of Fate and Transport, #80803 Annual Report, June 2005

    SciTech Connect

    M. K. Adler Flitton; Carolyn Bishop

    2005-06-01

    Improved estimates for corrosion rates in variably saturated porous media are required by the U.S. Department of Energy to maintain long-term storage of radioactive contaminants in stainless steel containers. To better define these parameters, research was undertaken to complete the National Institute of Standards and Technology’s (NIST) long-term study of buried stainless steel began 35 years ago. The 1970 study was initiated by the National Bureau of Standards (NBS), now known as NIST, when over 1000 specimens—including stainless steel Types 201, 202, 301, 304, 316, 409, 410, 430, and 434—configured as plates, U-bend, and tubes in both annealed and cold worked conditions with various treatments— were buried at six distinctive soil-type sites throughout the United States. During the first eight years of the study, four of five planned removals were completed with specimens retrieved after one, two, four, and eight years at each of the six sites. The fifth and final set of specimens remained undisturbed for over 34 years.

  5. Underground Corrosion after 32 Years: A Study of Fate and Transport

    SciTech Connect

    Flitton, M.K. Adler

    2006-06-01

    Improved estimates for corrosion rates in variably saturated porous media are required by the U.S. Department of Energy to maintain long-term storage of radioactive contaminants in stainless steel containers. To better define these parameters, research was undertaken to complete the National Institute of Standards and Technology’s (NIST) long-term study of buried stainless steel began 35 years ago. The 1970 study was initiated by the National Bureau of Standards (NBS), now known as NIST, when over 1000 specimens—including stainless steel Types 201, 202, 301, 304, 316, 409, 410, 430, and 434—configured as plates, U-bend, and tubes in both annealed and cold worked conditions with various treatments—were buried at six distinctive soil-type sites throughout the United States. During the first eight years of the study, four of five planned removals were completed with specimens retrieved after one, two, four, and eight years at each of the six sites. The fifth and final set of specimens remained undisturbed for over 34 years.

  6. Studies on Stress Corrosion Cracking of Super 304H Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Prabha, B.; Sundaramoorthy, P.; Suresh, S.; Manimozhi, S.; Ravishankar, B.

    2009-12-01

    Stress corrosion cracking (SCC) is a common mode of failure encountered in boiler components especially in austenitic stainless steel tubes at high temperature and in chloride-rich water environment. Recently, a new type of austenitic stainless steels called Super304H stainless steel, containing 3% copper is being adopted for super critical boiler applications. The SCC behavior of this Super 304H stainless steel has not been widely reported in the literature. Many researchers have studied the SCC behavior of steels as per various standards. Among them, the ASTM standard G36 has been widely used for evaluation of SCC behavior of stainless steels. In this present work, the SCC behavior of austenitic Fe-Cr-Mn-Cu-N stainless steel, subjected to chloride environments at varying strain conditions as per ASTM standard G36 has been studied. The environments employed boiling solution of 45 wt.% of MgCl2 at 155 °C, for various strain conditions. The study reveals that the crack width increases with increase in strain level in Super 304H stainless steels.

  7. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

    PubMed

    Peme, Thabo; Olasunkanmi, Lukman O; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-09-02

    The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  8. Study of ferrous corrosion products on iron archaeological objects by electron backscattered diffraction (EBSD)

    NASA Astrophysics Data System (ADS)

    Azoulay, Ilanith; Conforto, Egle; Refait, Philippe; Rémazeilles, Céline

    2013-02-01

    The corrosion of iron-based archaeomaterials in anoxic environments leads mainly to Fe(II) compounds, like the hydroxychloride β-Fe2(OH)3Cl, chukanovite Fe2(OH)2CO3 or siderite FeCO3. The understanding of the mechanisms then necessarily implies a thorough investigation of the chemical, mechanical and morphological characteristics of the Fe(II)-based layer that develops between the metal surface and the environment. In the peculiar case of Fe(II) compounds, generally very reactive towards O2, the main concern is to prevent any transformation by air during the analysis. The EBSD technique is adapted on a scanning electron microscope (SEM) where the samples are analysed under vacuum and consequently sheltered from air. Different options offered by EBSD for phase characterisation and microstructural study were tested for the first time on the rust layers of two archaeological iron nails. Results were confronted to those obtained by micro-Raman spectroscopy, which was used as reference method. Magnetite, Fe(II) hydroxychloride β-Fe2(OH)3Cl and siderite were analysed successfully but improvements have to be brought for the study of other compounds such as iron oxyhydroxides and chukanovite. The choice of experimental parameters in our approach as well as the potentialities and limits of the technique for this kind of application are discussed.

  9. The Application of Electrochemical and Surface Analysis Approaches to Studying Copper Corrosion in Water: Fundamentals, Limitations, and Examples

    EPA Science Inventory

    Corrosion control is a concern for many drinking water utilities. The Lead and Copper Rule established a regulatory need to maintain a corrosion control program. Other corrosion-related issues such as “red” water resulting from excessive iron corrosion and copper pinhole leaks ...

  10. Corrosion testing in natural waters: Second volume

    SciTech Connect

    Kain, R.M.; Young, W.T.

    1997-12-31

    This is the second STP of the same title. The first volume, STP 1086, was published in 1990 and contained papers on seawater corrosivity, crevice corrosion resistance of stainless steels, corrosion fatigue testing, and corrosion in potable water. Since then, final results have become available from the worldwide study on corrosion behavior of metals in seawater, and additional studies have been performed that should be brought to the attention of the corrosion engineering community. The second volume contains these studies. Papers have been processed separately for inclusion on the data base.

  11. Study of materials to resist corrosion in condensing gas fired furnaces. Annual report Oct 79-Oct 80

    SciTech Connect

    Lahtvee, T.; Khoo, S.W.; Schaus, O.O.

    1981-02-01

    Based on a thorough review of background information on the performance of materials in condensing gas-fired furnace heat exchangers and in similar corrosive environments, candidate materials were selected and tested on one of two identical test rigs built to provide the varying corrosive conditions encountered in an actual gas-fired condensing system heat exchanger. The 32 different materials tested in a one month screening test included: mild, low alloy, galvanized, solder coated and CaCO3 dipped galvanized steel, porcelain, epoxy, teflon and nylon coated and alonized mild steel; austenitic, ferritic, low interstitial Ti stabilized ferritic, and high alloy stainless steels; aluminum alloy anodized and porcelain coated aluminum; copper and cupronickel alloys, solder coated copper; and titanium.

  12. Corrosion in a temperature gradient

    SciTech Connect

    Covino, Bernard S., Jr.; Holcomb, Gordon R.; Cramer, Stephen D.; Bullard, Sophie J.; Ziomek-Moroz, Margaret; White, M.L.

    2003-01-01

    High temperature corrosion limits the operation of equipment used in the Power Generation Industry. Some of the more destructive corrosive attack occurs on the surfaces of heat exchangers, boilers, and turbines where the alloys are subjected to large temperature gradients that cause a high heat flux through the accumulated ash, the corrosion product, and the alloy. Most current and past corrosion research has, however, been conducted under isothermal conditions. Research on the thermal-gradient-affected corrosion of various metals and alloys is currently being studied at the Albany Research Center’s SECERF (Severe Environment Corrosion and Erosion Research Facility) laboratory. The purpose of this research is to verify theoretical models of heat flux effects on corrosion and to quantify the differences between isothermal and thermal gradient corrosion effects. The effect of a temperature gradient and the resulting heat flux on corrosion of alloys with protective oxide scales is being examined by studying point defect diffusion and corrosion rates. Fick’s first law of diffusion was expanded, using irreversible thermodynamics, to include a heat flux term – a Soret effect. Oxide growth rates are being measured for the high temperature corrosion of cobalt at a metal surface temperature of 900ºC. Corrosion rates are also being determined for the high temperature corrosion of carbon steel boiler tubes in a simulated waste combustion environment consisting of O2, CO2, N2, and water vapor. Tests are being conducted both isothermally and in the presence of a temperature gradient to verify the effects of a heat flux and to compare to isothermal oxidation.

  13. Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

    NASA Astrophysics Data System (ADS)

    Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

    2016-07-01

    The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

  14. Aluminum corrosion: Correlations of corrosion rate with surface coverage and tunneling spectra of organic inhibitors

    NASA Astrophysics Data System (ADS)

    Shu, Q. Q.; Love, P. J.; Bayman, A.; Hansma, P. K.

    Thin films of evaporated aluminum form a convenient model system for studying corrosion and corrosion inhibition on aluminum because (1) corrosion can be conveniently and continuously monitored by both electrical resistance measurements and optical transmission, (2) surface coverage of inhibitor species can be measured by either radiotracer techniques or tunneling spectroscopy and (3) the nature of surface adsorbed species can be determined with tunneling spectroscopy. The corrosion rate for these films is of order 20 μm/year in pure water at flow rates of order 20 cm/s. The corrosion is inhibited by roughly one order of magnitude by monolayer surface coverages of the surface species that result when acetic acid, benzoic acid, cupferron or ethylene glycol are added to the water. At surface coverages of order 1/100 of a monolayer, the corrosion rate is increased by roughly an order of magnitude for the first three additives but not for ethylene glycol. From the previous studies of tunneling spectra, it is clear that the acetic and benzoic acids lose a proton to become benzoate and acetate ions on the surface. The ethylene glycol loses the protons from both of its OH groups during bonding. The spectrum of the adsorbed cupferron species is presented but not analyzed.

  15. Smart Coatings for Launch Site Corrosion Protection

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.

    2014-01-01

    Smart, environmentally friendly paint system for early corrosion detection, mitigation, and healing that will enable supportability in KSC launch facilities and ground systems through their operational life cycles. KSC's Corrosion Technology Laboratory is developing a smart, self-healing coating that can detect and repair corrosion at an early stage. This coating is being developed using microcapsules specifically designed to deliver the contents of their core when corrosion starts.

  16. Corrosivity Of Pyrolysis Oils

    SciTech Connect

    Keiser, James R; Bestor, Michael A; Lewis Sr, Samuel Arthur; Storey, John Morse

    2011-01-01

    Pyrolysis oils from several sources have been analyzed and used in corrosion studies which have consisted of exposing corrosion coupons and stress corrosion cracking U-bend samples. The chemical analyses have identified the carboxylic acid compounds as well as the other organic components which are primarily aromatic hydrocarbons. The corrosion studies have shown that raw pyrolysis oil is very corrosive to carbon steel and other alloys with relatively low chromium content. Stress corrosion cracking samples of carbon steel and several low alloy steels developed through-wall cracks after a few hundred hours of exposure at 50 C. Thermochemical processing of biomass can produce solid, liquid and/or gaseous products depending on the temperature and exposure time used for processing. The liquid product, known as pyrolysis oil or bio-oil, as produced contains a significant amount of oxygen, primarily as components of water, carboxylic acids, phenols, ketones and aldehydes. As a result of these constituents, these oils are generally quite acidic with a Total Acid Number (TAN) that can be around 100. Because of this acidity, bio-oil is reported to be corrosive to many common structural materials. Despite this corrosive nature, these oils have the potential to replace some imported petroleum. If the more acidic components can be removed from this bio-oil, it is expected that the oil could be blended with crude oil and then processed in existing petroleum refineries. The refinery products could be transported using customary routes - pipelines, barges, tanker trucks and rail cars - without a need for modification of existing hardware or construction of new infrastructure components - a feature not shared by ethanol.

  17. Competitive effects of metal dissolution and passivation modulated by surface structure: An AFM and EBSD study of the corrosion of alloy 22

    NASA Astrophysics Data System (ADS)

    Gray, J. J.; El Dasher, B. S.; Orme, C. A.

    2006-06-01

    Electron backscatter diffraction (EBSD) and atomic force microscopy (AFM) are used to correlate crystallographic grain orientation with corrosion rates of polycrystalline alloy 22 following immersion in 1 and 3 molar (M) hydrochloric acid. For each acid concentration, relative corrosion rates are simultaneously characterized for approximately 50 unique grain orientations. The results demonstrate that the corrosion rate anisotropies are markedly different in the two acid concentrations. In very aggressive acidic environments (3M HCl), where electrochemical impedance spectroscopy and spectroscopic ellipsometry data demonstrate that the passive oxide film of alloy 22 is completely dissolved, alloy dissolution rates scale inversely with the average coordination number of surface atoms for a given grain orientation, where highly correlated surfaces dissolve the slowest. Thus, similar to simple metallic systems, the corrosion rates scale with the surface plane-normal crystallographic orientations as {1 1 1} < {1 0 0} < {1 1 0}. Less intuitively, in milder corrosive environments (1M HCl), where the passive film of the alloy is still intact, the dissolution does not scale inversely with surface atomic density. Rather, corrosion rates scale with crystallographic orientations as {1 1 1} < {1 1 0} < {1 0 0}. This is attributed to the fact that facets most susceptible to corrosion (least coordinated) are also the most able to form protective oxides, so that the dissolution anisotropy is a result of the delicate balance between metal dissolution and oxide growth.

  18. Electrochemical study of resistance to localized corrosion of stainless steels for biomaterial applications

    SciTech Connect

    Pan, J.; Karlen, C.; Ulfvin, C.

    2000-03-01

    Sandvik Bioline High-N and 316 LVM are two austenitic stainless steels especially developed for biomaterial applications. Their resistance to localized corrosion was investigated by electrochemical methods including cyclic potentiodynamic polarization and potentiostatic polarization measurements in a phosphate-buffered saline solution and in a simulated crevice solution, i.e., designed for crevice corrosion testing. Sandvik SAF 2507 (a high-performance super duplex stainless steel) was included in the tests as a reference material High-N, higher alloyed than 316 LVM, demonstrated excellent resistance to pitting initiation and a strong tendency to repassivation. High-N proved to have an equivalent or even higher resistance to localized corrosion than SAF 2507. The latter is known for its impressive corrosion properties, particularly in chloride containing environments. While 316 LVM may run the risk of crevice corrosion in implant applications, the risk seems negligible for High-N. In view of the fact that also the mechanical properties are superior to those of 316 LVM, High-N is a very attractive implant material.

  19. An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral

    NASA Astrophysics Data System (ADS)

    Grassini, S.; Angelini, E.; Parvis, M.; Bouchar, M.; Dillmann, P.; Neff, D.

    2013-12-01

    The corrosion behaviour of Middle Ages wrought iron bar chains exposed to indoor atmospheric corrosion for hundred of years in the Notre Dame Cathedral of Amiens (France) has been evaluated by means of Electrochemical Impedance Spectroscopy (EIS), a well-established electrochemical technique extensively used for testing anticorrosive properties of metal coatings. The measurements have been performed in situ with a portable EIS instrument designed to work as a standalone device, in six different areas of the wrought iron bar chains characterized by different aesthetical appearance. Moreover, a properly designed electrochemical cell has been employed to carry out the impedance measurements without affecting the artefacts surfaces. The wrought iron bar chains, as evidenced by μ-Raman and microscopic analyses, are covered by corrosion products constituted by iron oxides and oxyhydroxides, such as goethite, lepidocrocite, maghemite, akaganeite, organized in complex layered structures. In situ EIS allows one to investigate the phenomena involved at the electrochemical interfaces among the various corrosion products and to assess and predict their corrosion behaviour. From the analysis of the experimental findings of this monitoring campaign, EIS measurements can be proposed to restorers/conservators as a reliable indicator of dangerous situations on which they must act for the preservation of the iron artefacts.

  20. Friction surfacing for enhanced surface protection of marine engineering components: erosion-corrosion study

    NASA Astrophysics Data System (ADS)

    Rajakumar, S.; Balasubramanian, V.; Balakrishnan, M.

    2016-08-01

    Good mechanical properties combined with outstanding corrosion-resistance properties of cast nickel-aluminum bronze (NAB) alloy lead to be a specific material for many marine applications, including ship propellers. However, the erosion-corrosion resistance of cast-NAB alloy is not as good as wrought NAB alloy. Hence, in this investigation, an attempt has been made to improve the erosion-corrosion resistance of cast NAB alloy by depositing wrought (extruded) NAB alloy applying the friction surfacing (FS) technique. Erosion-corrosion tests were carried out in slurries composed of sand particles of 3.5% NaCl solution. Silica sand having a nominal size range of 250-355 μm is used as an erodent. Specimens were tested at 30° and 90° impingement angles. It is observed that the erosion and erosion-corrosion resistance of friction surfaced NAB alloy exhibited an improvement as compared to cast NAB alloy. Scanning electron microscope (SEM) analysis showed that the erosion tracks developed on the cast NAB alloy were wider and deeper than those formed on the friction surfaced extruded NAB alloy.

  1. Study of metal corrosion using ac impedance techniques in the STS launch environment

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.

    1989-01-01

    AC impedance measurements were performed to investigate the corrosion resistance of 19 alloys under conditions similar to the STS launch environment. The alloys were: Zirconium 702, Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, Inconel 600, 7Mo + N, Ferralium 255, Inco Alloy G-3, 20Cb-3, SS 904L, Inconel 825, SS 304LN, SS 316L, SS 317L, ES 2205, SS 304L, Hastelloy B-2, and Monel 400. AC impedance data were gathered for each alloy after one hour immersion time in each of the following three electrolyte solutions: 3.55 percent NaCl, 3.55 percent NaCl-0.1N HCl, and 3.55 percent NaCl-1.0N HCl. The data were analyzed qualitatively using the Nyquist plot and quantitatively using the Bode plot. Polarization resistance, Rp, values were obtained using the Bode plot. Zirconium 702 was the most corrosion resistant alloy in the three electrolytes. The ordering of the other alloys according the their resistance to corrosion varied as the concentration of hydrochloric acid in the electrolyte increased. The corrosion resistance of Zirconium 702 and Ferralium 255 increased as the concentration of hydrochloric acid in the electrolyte increased. The corrosion resistance of the other 17 alloys decreased as the concentration of the hyrdochloric acid in the electrolyte increased.

  2. A non-immersed induction conductivity system for controlling supersaturation in corrosive media: the case of gibbsite crystals agglomeration in Bayer liquors

    NASA Astrophysics Data System (ADS)

    Seyssiecq, I.; Veesler, S.; Boistelle, R.

    1996-11-01

    Agglomeration of gibbsite Al(OH) 3 crystallites is an important stage of the Bayer process, aiming at increasing the initial size of the particles. In the present work, a semi-continuous crystallizer working at constant and imposed supersaturation, and equipped with an automatic withdrawal system was developed to study the agglomeration of gibbsite crystals in supersaturated Bayer liquors. The liquor conductivity was measured using an induction conductivity system placed around the crystallizer, the conductivity regulation being used to work at constant supersaturation. Using this system allowed one to work with both a small crystallizer and a highly corrosive and abrasive suspension of gibbsite in a five molar caustic soda solution at 70°C. Analyses of the withdrawals were carried out with an Elzone particle counter, in order to draw {N(t)}/{N(0) = f(t)} plots, representing the decrease of crystal number with time, due to agglomeration.

  3. CORROSION ISSUES ASSOCIATED WITH AUSTENITIC STAINLESS STEEL COMPONENTS USED IN NUCLEAR MATERIALS EXTRACTION AND SEPARATION PROCESSES

    SciTech Connect

    Mickalonis, J.; Louthan, M.; Sindelar, R.

    2012-12-17

    This paper illustrated the magnitude of the systems, structures and components used at the Savannah River Site for nuclear materials extraction and separation processes. Corrosion issues, including stress corrosion cracking, pitting, crevice corrosion and other corrosion induced degradation processes are discussed and corrosion mitigation strategies such as a chloride exclusion program and corrosion release testing are also discussed.

  4. Utilizing various test methods to study the stress corrosion behavior of Al-Li-Cu alloys

    NASA Technical Reports Server (NTRS)

    Pizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1984-01-01

    Recently, much attention has been given to aluminum-lithium alloys because of rather substantial specific-strength and specific-stiffness advantages offered over commercial 2000and 7000-series aluminum alloys. An obstacle to Al-Li alloy development has been inherent limited ductility. In order to obtain a more refined microstructure, powder metallurgy (P/M) has been employed in alloy development programs. As stress corrosion (SC) of high-strength aluminum alloys has been a major problem in the aircraft industry, the possibility of an employment of Al-Li alloys has been considered, taking into account a use of Al-Li-Cu alloys. Attention is given to a research program concerned with the evaluation of the relative SC resistance of two P/M processed Al-Li-Cu alloys. The behavior of the alloys, with and without an addition of magnesium, was studied with the aid of three test methods. The susceptibility to SC was found to depend on the microstructure of the alloys.

  5. SERS and DFT study of copper surfaces coated with corrosion inhibitor

    PubMed Central

    Muniz-Miranda, Francesco; Caporali, Stefano

    2014-01-01

    Summary Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS) effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule–metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT) approach. PMID:25671144

  6. Electrochemical and conversion electron mössbauer study of corrosion induced by acid rain

    NASA Astrophysics Data System (ADS)

    Vértes, Cs.; Lakatos-Varsányi, M.; Meisel, W.; Vértes, A.; Gütlich, P.

    1993-04-01

    The passivation of low carbon steel was studied in aqueous solution of 0.5M Na 2SO 4 +0.001M NaHSO 3 (pH 3.5, 6.5 and 8.5) which can be considered as a model of acid rain. The used conversion electron Mössbauer spectroscopy (CEMS) with the complementary electrochemical investigations proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6 5 while the measurements showed much weaker pitting at pH 8.5. The compositions and thicknesses of the passive films formed during the electrochemical treatments are determined from the CEM spectra. Only γ-FeOOH was found on the surface of the samples at pH 6.5 and 8.5. Nevertheless, at pH 3.5 the sextet belonging to Fe 3C appears in the spectra, and also FeS0 4H 2O could be detected in low concentration.

  7. Stress-corrosion-cracking studies on candidate container alloys for the Tuff Repository

    SciTech Connect

    Beavers, J.A.; Durr, C.L.

    1992-05-01

    Cortest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials used for high-level waste package as part of the information needed by the Nuclear Regulatory Commission (NRC) to assess the Department of Energy`s application to construct to geologic repository for high-level radioactive waste. At the direction of the NRC, the program focused on the Tuff Repository. This report summarizes the results of Stress-Corrosion-Cracking (SCC) studies performed in Tasks 3, 5, and 7 of the program. Two test techniques were used; U-bend exposures and Slow-Strain-Rate (SSR) tests. The testing was performed on two copper-base alloys (Alloy CDA 102 and Alloy CDA 175) and two Fe-Cr-Ni alloys (Alloy 304L and Alloy 825) in simulated J-13 groundwater and other simulated solutions for the Tuff Repository. These solutions were designed to simulate the effects of concentration and irradiation on the groundwater composition. All SCC testing on the Fe-Cr-Ni Alloys was performed on solution-annealed specimens and thus issues such as the effect of sensitization on SCC were not addressed.

  8. Corrosion Behavior of Plasma-Passivated Cu

    SciTech Connect

    Barbour, J.C.; Braithwaite, J.W.; Son, K.A.; Sullivan, J.P.; Missert, N,; Sorensen, N.R.

    1999-07-09

    A new approach is being pursued to study corrosion in Cu alloy systems by using combinatorial analysis combined with microscopic experimentation (the Combinatorial Microlab) to determine mechanisms for copper corrosion in air. Corrosion studies are inherently difficult because of complex interactions between materials and environment, forming a multidimensional phase space of corrosion variables. The Combinatorial Microlab was specifically developed to address the mechanism of Cu sulfidation, which is an important reliability issue for electronic components. This approach differs from convention by focusing on microscopic length scales, the relevant scale for corrosion. During accelerated aging, copper is exposed to a variety of corrosive environments containing sulfidizing species that cause corrosion. A matrix experiment was done to determine independent and synergistic effects of initial Cu oxide thickness and point defect density. The CuO{sub x} was controlled by oxidizing Cu in an electron cyclotron resonance (ECR) O{sub 2} plasma, and the point defect density was modified by Cu ion irradiation. The matrix was exposed to 600 ppb H{sub 2}S in 65% relative humidity air atmosphere. This combination revealed the importance of oxide quality in passivating Cu and prevention of the sulfidizing reaction. A native oxide and a defect-laden ECR oxide both react at 20 C to form a thick Cu{sub 2}S layer after exposure to H{sub 2}S, while different thicknesses of as-grown ECR oxide stop the formation of Cu{sub 2}S. The species present in the ECR oxide will be compared to that of an air oxide, and the sulfide layer growth rate will be presented.

  9. Refractory Materials for Flame Deflector Protection System Corrosion Control: Coatings Systems Literature Survey

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Sampson, Jeffrey W.; Coffman, Brekke E.; Coffman, Brekke E.; Curran, Jerome P.; Kolody, Mark R.; Whitten, Mary; Perisich, Steven; Trejo, David

    2009-01-01

    When space vehicles are launched, extreme heat, exhaust, and chemicals are produced and these form a very aggressive exposure environment at the launch complex. The facilities in the launch complex are exposed to this aggressive environment. The vehicle exhaust directly impacts the flame deflectors, making these systems very susceptible to high wear and potential failure. A project was formulated to develop or identify new materials or systems such that the wear and/or damage to the flame deflector system, as a result of the severe environmental exposure conditions during launches, can be mitigated. This report provides a survey of potential protective coatings for the refractory concrete lining on the steel base structure on the flame deflectors at Kennedy Space Center (KSC).

  10. CORROSION STUDY FOR THE EFFLUENT TREATMENT FACILITY CHROME (VI) REDUCTANT SOLUTION USING 304 AND 316L STAINLESS STEEL

    SciTech Connect

    DUNCAN JB; WYRAS RB

    2007-10-08

    This report documents the laboratory testing and analyses as directed under the test plan, RPP PLAN-34065, and documented in laboratory notebooks HNF 2742 and HNF-N-473-1. The purpose of this study was to evaluate and compare the electrochemical corrosion and pitting susceptibility of the 304 and 316L stainless steel in the acidified reducing solution that will be contained in either the secondary waste receiving tank or concentrate tank.

  11. Intraoral corrosion resulting from coupling dental implants and restorative metallic systems.

    PubMed

    Lemons, J E; Lucas, L C; Johansson, B I

    1992-01-01

    Materials used for the construction of dental restorations and implants include a wide range of metals and alloys, ceramics and carbons, and polymers. When metals and alloys are placed in direct contact in the oral cavity, a galvanic cell can be formed that may compromise the longevity of one or more of the materials in the couple. In vitro electrochemical corrosion analyses have proven to be a valuable tool for providing guidance on the selection of metallic materials. These analyses can provide basic data on electrochemical potentials, current rates, and the evaluation of galvanic corrosion conditions. This article seeks to provide the clinician with information that can be valuable in the selection of metallic materials that may be placed in direct contact with one another in the oral cavity.

  12. Study of localized corrosion in aluminum alloys by the scanning reference electrode technique

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1995-01-01

    Localized corrosion in 2219-T87 aluminum (Al) alloy, 2195 aluminum-lithium (Al-Li) alloy, and welded 2195 Al-Li alloy (4043 filler) have been investigated using the relatively new scanning reference electrode technique (SRET). Anodic sites are more frequent and of greater strength in the 2195 Al-Li alloy than in the 2219-T87 Al alloy, indicating a greater tendency toward pitting for the latter. However, the overall corrosion rates are about the same for these two alloys, as determined using the polarization resistance technique. In the welded 2195 Al-Li alloy, the weld bean is entirely cathodic, with rather strongly anodic heat affected zones (HAZ) bordering both sides, indicating a high probability of corrosion in the HAZ parallel to the weld bead.

  13. [Study on the corrosion of Yuan Dynasty bronze mirror by Raman spectrum].

    PubMed

    Wang, Yi-lin; Yang, Qun; Zhang, Peng-xiang; Li, Chao-zhen

    2002-02-01

    Over the past 17 years, Raman microscopy has proven to be a valuable tool for the non-destructive evaluation of pigments in artwork and artifacts. Here Raman microscopy and electro probe technique were used to identify the corrosion products and their locations on and within of ancient Yuan Dynasty bronze mirror from Lufeng of Yunnan province. The most corrosive compounds are CuCO3.Cu(OH)2 and Cu2O. There is a thin layer of Fe-Al alloy on bronze mirror, which can protect the mirror from corrosion. The Raman microscopy is shown to be a useful tool to complement more traditional characterizations such as scanning electron microscopy and x-ray energy-dispersive spectrometry in the analysis of metal artifacts.

  14. Effect of microstructure on the corrosion of CVD-SiC exposed to supercritical water

    NASA Astrophysics Data System (ADS)

    Tan, L.; Allen, T. R.; Barringer, E.

    2009-10-01

    Silicon carbide (SiC) is an important engineering material being studied for potential use in multiple nuclear energy systems including high-temperature gas-cooled reactors and water-cooled reactors. The corrosion behavior of SiC exposed to supercritical water (SCW) is critical for examining its applications in nuclear reactors. Although the hydrothermal corrosion of SiC has been the subject of many investigations, the study on the microstructural effects on the corrosion is limited. This paper presents the effect of residual strain, grain size, grain boundary types, and surface orientations on the corrosion of chemical vapor deposited (CVD) β-SiC exposed to SCW at 500 °C and 25 MPa. Weight loss occurred on all the samples due to localized corrosion. Residual strains associated with small grains showed the most significant effect on the corrosion compared to the other factors.

  15. Copper corrosion in potable water systems: Impacts of natural organic matter and water treatment processes

    SciTech Connect

    Rehring, J.P.; Edwards, M.

    1996-04-01

    Copper corrosion was examined in the presence of natural organic matter (NOM) and in situations where NOM was altered by drinking water treatment. Corrosion rates (i{sub corr}) increased with higher NOM concentration at pH 6, whereas insignificant effects were observed at pH 7.5 and 9.0. Corrosion byproduct release was affected adversely by 4 mg/L NOM at pH 6.0, 7.5 and 9.0, with soluble copper increasing by 0.6 mg/L to 0.7 mg/L when compared to solutions without NOM. Alum-coagulated waters had higher i{sub corr} than untreated waters, but ferric chloride (FeCl{sub 3}{center_dot}6H{sub 2}O)-coagulated waters exhibited reduced i{sub corr}. This difference was attributed to the relative effects of added sulfate via alum coagulation vs added chloride via FeCl{sub 3}{center_dot}6H{sub 2}O coagulation. The effect of combined treatment (alum coagulation, ozonation, and granular activated carbon) was similar to that using alum coagulation alone.

  16. Corrosion Inhibition of Mild Steel in 1.0 M HCl by Amino Compound: Electrochemical and DFT Studies

    NASA Astrophysics Data System (ADS)

    Musa, Ahmed Y.; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Takriff, Mohd Sobri

    2012-05-01

    The purpose of this study was to examine the inhibitory effect of 4-amino-5-methyl-4H-1, 2, 4-triazole-3-thiol (AMTT) on the corrosion of mild steel in 1.0 M HCl solution using weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. The results indicate that AMTT performed as a good mixed-type inhibitor for mild steel corrosion in a 1.0 M HCl solution, and the inhibition efficiencies increased and tend to saturate with inhibitor concentration. Potentiodynamic polarization results showed that AMTT is a mixed-type inhibitor. Adsorption of AMTT molecules is a spontaneous process, and its adsorption behavior obeys Langmuir's adsorption isotherm model. The reactivity of AMTT was analyzed through theoretical calculations based on density functional theory. Results showed that the reactive sites were located on the nitrogen and sulfur (N1, N2, and S) atoms.

  17. Corrosion Inhibition of Mild Steel in 1.0 M HCl by Amino Compound: Electrochemical and DFT Studies

    NASA Astrophysics Data System (ADS)

    Musa, Ahmed Y.; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Takriff, Mohd Sobri

    2012-09-01

    The purpose of this study was to examine the inhibitory effect of 4-amino-5-methyl-4H-1, 2, 4-triazole-3-thiol (AMTT) on the corrosion of mild steel in 1.0 M HCl solution using weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. The results indicate that AMTT performed as a good mixed-type inhibitor for mild steel corrosion in a 1.0 M HCl solution, and the inhibition efficiencies increased and tend to saturate with inhibitor concentration. Potentiodynamic polarization results showed that AMTT is a mixed-type inhibitor. Adsorption of AMTT molecules is a spontaneous process, and its adsorption behavior obeys Langmuir's adsorption isotherm model. The reactivity of AMTT was analyzed through theoretical calculations based on density functional theory. Results showed that the reactive sites were located on the nitrogen and sulfur (N1, N2, and S) atoms.

  18. Case studies in management of THA failure secondary to taper corrosion, modular junctions and metal-on-metal bearings.

    PubMed

    Lombardi, Adolph V

    2014-04-01

    The diagnosis and treatment of patients with painful total hip arthroplasties secondary to taper corrosion and wear of modular junctions and metal-on-metal bearings represents a major challenge for the orthopaedic clinician. Guidelines are evolving as we analyze the growing body of evidence regarding metal-related failures of orthopaedic implants and adverse reactions to metal debris. In this article 6 case examples are presented to enhance understanding and application of current evidence into practice. Clinical expertise is integrated with the best available evidence from research and national joint registries data into the decision making process relevant for patient care in everyday practice. Issues addressed include understanding taper corrosion and metal failure mechanisms, clinical presentation of adverse soft tissue reactions, utility of specialized tests such as metal ion analysis and cross-sectional imaging studies, the utility of modular components for primary THA, dealing with recalled component, and current recommendations.

  19. STUDY ON CHARACTERISTICS OF RESIDUAL STRENGTH OF RC BEAMS WITH DEFECTIVE ANCHORAGES DUE TO CORROSION OF REINFORCEMENTS

    NASA Astrophysics Data System (ADS)

    Murakami, Yuki; Dong, Wei; Oshita, Hideki; Suzuki, Shuichi; Tsutsumi, Tomoaki

    In this study, to evaluate flexural strength and shear strength with def ective anchorages due to corrosion of reinforcemen t, the bending test of the RC beams r eceived damage in the anchorage region due to corrosion was carried out. As a result, it is se ems that the residual shear strength of RC beams with defective anchorages depends on shear span ratio in addition to the anchorage performance. Furthermore, the authors propose an evaluation model for an shear strength of RC beams with defective anchorages on the basis of these experimental results and analy tical result. The value of residual shear strength calculated using this model corresponds to the test results in the past.

  20. Stress corrosion study of PH13-8Mo stainless steel using the Slow Strain Rate Technique

    NASA Technical Reports Server (NTRS)

    Torres, Pablo D.

    1989-01-01

    The need for a fast and reliable method to study stress corrosion in metals has caused increased interest in the Slow Strain Rate Technique (SSRT) during the last few decades. PH13-8MoH950 and H1000 round tensile specimens were studied by this method. Percent reduction-in-area, time-to-failure, elongation at fracture, and fracture energy were used to express the loss in ductility, which has been used to indicate susceptibility to stress corrosion cracking (SCC). Results from a 3.5 percent salt solution (corrosive medium) were compared to those in air (inert medium). A tendency to early failure was found when testing in the vicinity of 1.0 x 10(-6) mm/mm/sec in the 3.5 percent salt solution. PH13-8Mo H1000 was found to be less likely to suffer SCC than PH13-8Mo H950. This program showed that the SSRT is promising for the SCC characterization of metals and results can be obtained in much shorter times (18 hr for PH steels) than those required using conventional techniques.

  1. Micro-Raman study of copper hydroxychlorides and other corrosion products of bronze samples mimicking archaeological coins.

    PubMed

    Bertolotti, Giulia; Bersani, Danilo; Lottici, Pier Paolo; Alesiani, Marcella; Malcherek, Thomas; Schlüter, Jochen

    2012-02-01

    Three bronze samples created by CNR-ISMN (National Research Council-Institute of Nanostructured Materials) to be similar to Punic and Roman coins found in Tharros (OR, Sardinia, Italy) were studied to identify the corrosion products on their surfaces and to evaluate the reliability of the reproduction process. Micro-Raman spectroscopy was chosen to investigate the corroded surfaces because it is a non-destructive technique, it has high spatial resolution, and it gives the opportunity to discriminate between polymorphs and to correlate colour and chemical composition. A significant amount of green copper hydroxychlorides (Cu(2)(OH)(3)Cl) was detected on all the coins. Their discrimination by Raman spectroscopy was challenging because the literature on the topic is currently confusing. Thus, it was necessary to determine the characteristic peaks of atacamite, clinoatacamite, and the recently discovered anatacamite by acquiring Raman spectra of comparable natural mineral samples. Clinoatacamite, with different degrees of order in its structure, was the major component identified on the three coins. The most widespread corrosion product, besides hydroxychlorides, was the red copper oxide cuprite (Cu(2)O). Other corrosion products of the elements of the alloy (laurionite, plumbonacrite, zinc carbonate) and those resulting from burial in the soil (anatase, calcite, hematite) were also found. This study shows that identification of corrosion products, including discrimination of copper hydroxychlorides, could be accomplished by micro-Raman on valuable objects, for example archaeological findings or works of art, avoiding any damage because of extraction of samples or the use of a destructive analytical technique.

  2. Spontaneous activation of CO2 and corrosion pathways on iron surface Fe(100): a quantum mechanical study informed by DFT-based dynamics

    NASA Astrophysics Data System (ADS)

    Glezakou, V. A.; McGrail, P.; Dang, L. X.

    2009-12-01

    Because of the rapidly increasing interest in technologies for capturing and permanently sequestering CO2 as part of a climate change mitigation strategy, understanding the interaction of CO2 with materials that comprise a sequestration system (steels, cements, silicate minerals, etc.) is of fundamental importance. The majority of models for corrosion of metals involve water-mediated processes, with CO2 dissolved in the aqueous phase playing a minor role in the process. In contrast, recent experiments with mild steels have shown that much greater corrosivity actually occurs in the dense CO2 phase, provided sufficient molecular water is present in the CO2 phase to catalyse certain reactions. In our study, we use DFT-based dynamics to study the internal structure of the the super-critical CO2/(H2O)n system, with n=0-4. While water does not disturb the super-critical CO2 phase, it also gives rise to short-lived CO2...H2O bonds which are likely to facilitate the activation of CO2 on the surface, but otherwise maintains its molecular form. We also use DFT methods to probe the fundamental interactions of CO2 or SO2 and H2O with clean or doped iron surfaces and determine the reactive pathways that lead to CO2 chemisorption, dissociation and further formation of corrosion products in the form of carbonates or sulfites. DFT-based molecular dynamics are employed to sample the configurational space of reactants and products more efficiently. CO2 adsorbs readily on the surface assuming a bent geometry, indicative of charge transfer from the surface to CO2, which closely resembles a CO2- moiety. Once CO2 is adsorbed, it can decompose to adsorbed O+CO, which further reacts with CO2 or SO2 to form corrosion products. Molecularly adsorbed water acts as catalyst to lower these reaction barriers. Clearly, the reactive pathways on the surface are quite different than those in aqueous solution. Battelle operates Pacific Northwest National Laboratory for the US Department of Energy.

  3. A multi-analytical approach to gold in Ancient Egypt: Studies on provenance and corrosion

    NASA Astrophysics Data System (ADS)

    Tissot, I.; Troalen, L. G.; Manso, M.; Ponting, M.; Radtke, M.; Reinholz, U.; Barreiros, M. A.; Shaw, I.; Carvalho, M. L.; Guerra, M. F.

    2015-06-01

    Recent results from a three-year multi-disciplinary project on Ancient Egyptian gold jewellery revealed that items of jewellery from the Middle Kingdom to the New Kingdom were manufactured using a variety of alluvial gold alloys. These alloys cover a wide range of colours and the majority contain Platinum Group Elements inclusions. However, in all the gold foils analysed, these inclusions were found to be absent. In this work a selection of gilded wood and leather items and gold foil fragments, all from the excavations by John Garstang at Abydos (primarily from Middle Kingdom graves), were examined using Scanning Electron Microscopy-Energy Disperse Spectroscopy (SEM-EDS), X-Ray Fluorescence (μXRF), Particle Induced X-Ray Emission (μPIXE) and Double Dispersive X-Ray Fluorescence (D2XRF). The work allowed us to characterise the composition of the base-alloys and also to reveal the presence of Pt at trace levels, confirming the use of alluvial gold deposits. Corrosion products were also investigated in the foils where surface tarnish was visually observed. Results showed that the differences in the colour of corrosion observed for the foils are related not only to the thickness of the corrosion layer but also to a multi-layer structure containing the various corrosion products.

  4. Copper Corrosion in Nuclear Waste Disposal: A Swedish Case Study on Stakeholder Insight

    ERIC Educational Resources Information Center

    Andersson, Kjell

    2013-01-01

    The article describes the founding principles, work program, and accomplishments of a Reference Group with both expert and layperson stakeholders for the corrosion of copper canisters in a proposed deep repository in Sweden for spent nuclear fuel. The article sets the Reference Group as a participatory effort within a broader context of…

  5. Application of x-ray absorption spectroscopy to the study of corrosion and inhibition

    SciTech Connect

    Davenport, A.J.; Isaacs, H.S.

    1991-01-01

    X-ray absorption spectroscopy is a powerful technique for determination of valency and coordination. Measurements can be made in air or in situ under electrochemical control. The technique will be described and its application to the analysis of passive oxide films, corrosion products, and inhibitors will be reviewed.

  6. Solving A Corrosion Problem

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The corrosion problem, it turned out, stemmed from the process called electrolysis. When two different metals are in contact, an electrical potential is set up between them; when the metals are surrounded by an electrolyte, or a conducting medium, the resulting reaction causes corrosion, often very rapid corrosion. In this case the different metals were the copper grounding system and the ferry's aluminum hull; the dockside salt water in which the hull was resting served as the electrolyte. After identifying the source of the trouble, the Ames engineer provided a solution: a new wire-and-rod grounding system made of aluminum like the ferry's hull so there would no longer be dissimilar metals in contact. Ames research on the matter disclosed that the problem was not unique to the Golden Gate ferries. It is being experienced by many pleasure boat operators who are probably as puzzled about it as was the Golden Gate Transit Authority.

  7. Comparative study on lithium borates as corrosion inhibitors of aluminum current collector in lithium bis(fluorosulfonyl)imide electrolytes

    NASA Astrophysics Data System (ADS)

    Park, Kisung; Yu, Sunghun; Lee, Chulhaeng; Lee, Hochun

    2015-11-01

    Lithium bis(fluorosulfonyl)imide (LiFSI) is a promising salt that can possibly overcome the limitations of lithium hexafluorophosphate (LiPF6) in current Li-ion batteries (LIBs). Aluminum (Al) corrosion issue, however, is a major bottleneck for the wide use of LiFSI. This study investigates lithium borate salts as Al corrosion inhibitors in LiFSI electrolytes. Through a systematic comparison among lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), and lithium difluoro(oxalato)borate (LiDFOB), and LiPF6, the inhibition ability of the additives is revealed to be in the following order: LiDFOB > LiBF4 ≈ LiPF6 > LiBOB. In particular, the inhibition effect of LiDFOB is outstanding; the anodic behavior of Al in 0.8 M LiFSI + 0.2 M LiDFOB ethylene carbonate (EC)-based electrolyte is comparable to that of corrosion-free 1 M LiPF6 solution. The superior inhibition ability of LiDFOB is attributed to the formation of a passive layer composed of Al-F, Al2O3, and B-O species, as evidenced by X-ray photoelectron spectroscopy (XPS) measurements. A LiCoO2/graphite cell with 0.8 M LiFSI + 0.2 M LiDFOB electrolyte exhibits a rate capability comparable to a cell with 1 M LiPF6 solution, whereas a cell with 0.8 M LiFSI solution without LiDFOB suffers from poor power performance resulting from severe Al corrosion.

  8. Study of mechanical joint strength of aluminum alloy 7075-T6 and dual phase steel 980 welded by friction bit joining and weld-bonding under corrosion medium

    SciTech Connect

    Lim, Yong Chae; Squires, Lile; Pan, Tsung-Yu; Miles, Michael; Song, Guang-Ling; Wang, Yanli; Feng, Zhili

    2014-12-30

    We have employed a unique solid-sate joining process, called friction bit joining (FBJ), to spot weld aluminum alloy (AA) 7075-T6 and dual phase (DP) 980 steel. Static joint strength was studied in the lap shear tension configuration. In addition, weld-bonding (adhesive + FBJ) joints were studied in order to evaluate the ability of adhesive to mitigate the impact of corrosion on joint properties. Accelerated laboratory cyclic corrosion tests were carried out for both FBJ only and weld-bonding joints. Furthermore, the FBJ only joints that emerged from corrosion testing had lap shear failure loads that were significantly lower than freshly prepared joints. However, weld-bonding specimens retained more than 80% of the lap shear failure load of the freshly prepared weld-bonding specimens. Moreover, examination of joint cross sections confirmed that the presence of adhesive in the weld-bonding joints mitigated the effect of the corrosion environment, compared to FBJ only joints.

  9. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers

    NASA Astrophysics Data System (ADS)

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O.; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B.; Ebenso, Eno E.

    2016-08-01

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.

  10. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers

    PubMed Central

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O.; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B.; Ebenso, Eno E.

    2016-01-01

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results. PMID:27515383

  11. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers.

    PubMed

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B; Ebenso, Eno E

    2016-01-01

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results. PMID:27515383

  12. Alternating and direct current electrochemical studies of a wool wax-based corrosion preventive coating on aluminum alloy 2024

    SciTech Connect

    Su, P.C.; Devereux, O.F.

    1998-06-01

    The corrosion behavior of Al 2024-T3 treated with a wool wax (lanolin)-based corrosion preventive coating in aqueous 0.5 M sodium chloride was studied using electrochemical impedance spectroscopy (EIS) and direct current electrode polarization. DC measurements were modeled by three reactions: oxidation of aluminum, reduction of oxygen, and reduction of hydrogen. Alternating current behavior of untreated specimens was modeled using the Randles circuit, and that of inhibited specimens was modeled using parallel resistance-capacitance circuits representing the coating and the charge-transfer process. AC and DC estimates of the polarization resistance of coated specimens were 50 M{Omega}-cm{sup 2} and 32 M{Omega}-cm{sup 2}, respectively. AC and DC values for bare control specimens were of the order of 3 k{Omega}-cm{sup 2} and 15 k{Omega}-cm{sup 2}, respectively. The wool wax coating was found to be a very effective corrosion preventative for this alloy in the aqueous saline environment whether applied to freshly prepared surfaces or to corroded specimens removed from simulated service.

  13. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers.

    PubMed

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B; Ebenso, Eno E

    2016-08-12

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.

  14. Effect of multiphase slug flow on the stability of corrosion product layer

    SciTech Connect

    Gopal, M.; Rajappa, S.

    1999-11-01

    Corrosion experiments were carried out under iron carbonate scale-forming conditions in a large diameter, multiphase flow system. Both oil/water and oil/water/gas slug flows were studied at pressures up to 0.79 MPa and temperatures of 60 C and 80 C. It was found that with increasing iron concentration, the corrosion rates were reduced to negligible values in oil/water flows. However, significant corrosion was seen in slug flow with clear evidence of damage to the corrosion product layer due to impact and possible collapse of gas bubbles and a considerable reduction in the layer thickness. Details of corrosion rates and corrosion coupon surface analysis are presented.

  15. Naphthenic acid corrosion in the refinery

    SciTech Connect

    Craig, H.L. Jr.

    1995-11-01

    Field tests and laboratory studies of refinery process streams are presented. The effects of temperature, velocity and physical state were studied with respect to alloy selection for corrosion resistant service. The amount of molybdenum in the austenitic stainless steel alloys is the dominant factor in conferring corrosion resistance. The Naphthenic Acid Corrosion Index (NACI) is useful in assessing the severity of corrosion under a variety of circumstances.

  16. Microencapsulation of Corrosion Indicators for Smart Coatings

    NASA Technical Reports Server (NTRS)

    Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott T.; Calle, Luz M.; Hanna,Joshua S.; Rawlins, James W.

    2011-01-01

    A multifunctional smart coating for the autonomous detection, indication, and control of corrosion is been developed based on microencapsulation technology. This paper summarizes the development, optimization, and testing of microcapsules specifically designed for early detection and indication of corrosion when incorporated into a smart coating. Results from experiments designed to test the ability of the microcapsules to detect and indicate corrosion, when blended into several paint systems, show that these experimental coatings generate a color change, indicative of spot specific corrosion events, that can be observed with the naked eye within hours rather than the hundreds of hours or months typical of the standard accelerated corrosion test protocols.. Key words: smart coating, corrosion detection, microencapsulation, microcapsule, pH-sensitive microcapsule, corrosion indicator, corrosion sensing paint

  17. Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

    SciTech Connect

    R. P. Martukanitz and S. Babu

    2007-05-03

    Laser surfacing in the form of cladding, alloying, and modifications are gaining widespread use because of its ability to provide high deposition rates, low thermal distortion, and refined microstructure due to high solidification rates. Because of these advantages, laser surface alloying is considered a prime candidate for producing ultra-hard coatings through the establishment or in situ formation of composite structures. Therefore, a program was conducted by the Applied Research Laboratory, Pennsylvania State University and Oak Ridge National Laboratory to develop the scientific and engineering basis for performing laser-based surface modifications involving the addition of hard particles, such as carbides, borides, and nitrides, within a metallic matrix for improved wear, fatigue, creep, and corrosion resistance. This has involved the development of advanced laser processing and simulation techniques, along with the refinement and application of these techniques for predicting and selecting materials and processing parameters for the creation of new surfaces having improved properties over current coating technologies. This program has also resulted in the formulation of process and material simulation tools capable of examining the potential for the formation and retention of composite coatings and deposits produced using laser processing techniques, as well as positive laboratory demonstrations in producing these coatings. In conjunction with the process simulation techniques, the application of computational thermodynamic and kinetic models to design laser surface alloying materials was demonstrated and resulted in a vast improvement in the formulation of materials used for producing composite coatings. The methodology was used to identify materials and to selectively modify microstructures for increasing hardness of deposits produced by the laser surface alloying process. Computational thermodynamic calculations indicated that it was possible to induce the

  18. Study of the corrosion products formed on a multiphase CuAlBe alloy in a sodium chloride solution by micro-Raman and in situ AFM measurements

    NASA Astrophysics Data System (ADS)

    Montecinos, S.; Simison, S. N.

    2011-06-01

    The corrosion products formed on a multiphase Cu-11.40Al-0.55Be (wt.%) alloy in 3.5% NaCl at open circuit potential, and their evolution with immersion time were studied mainly by micro-Raman and in situ AFM measurements. The aluminium content of each phase affects the formation of the corrosion products on them. After 1 day of immersion, γ 2 precipitates were more susceptible to dealuminization, while α' phase exhibited a high corrosion stability. The corrosion products evolved with immersion time, and CuCl 2 and a Cu 2O/CuO double layer film were the stable products formed on all the phases after long times.

  19. Impacts of Transport Properties of Porous Corrosion Product Layer on Effective Corrosion Rate

    NASA Astrophysics Data System (ADS)

    Li, Xiaobai; Cook, David

    2012-11-01

    Condensing exhaust gases containing H2O, SO3 and NOx cause serious corrosion failure in various industry processes. For example, in modern compact heat cells, corrosion products deposit on top of the heat exchanger cooling fins, blocking the flow passages and drastically decreasing system performance. The transport properties of porous corrosion product layers play important role in determining the corrosion tendency and observed corrosion rate. To understand the corrosion mechanism for Aluminum alloy in sulfuric acid environment, impacts of transport properties of corrosion residual layers are investigated with different numerical models for porous layer diffusivity. The effective corrosion rates resulted from these models are compared to corresponding experimental measurements. A multilayer diffusivity model in which diffusivity depends both on porous layer structure and composition shows excellent agreements with experimental data. This model is currently being used in a multi-scale flow simulation framework to predict corrosion phenomena in heat cells.

  20. Corrosion by liquid lead and lead-bismuth: experimental results review and analysis

    SciTech Connect

    Zhang, Jinsuo

    2008-01-01

    Liquid metal technologies for liquid lead and lead-bismuth alloy are under wide investigation and development for advanced nuclear energy systems and waste transmutation systems. Material corrosion is one of the main issues studied a lot recently in the development of the liquid metal technology. This study reviews corrosion by liquid lead and lead bismuth, including the corrosion mechanisms, corrosion inhibitor and the formation of the protective oxide layer. The available experimental data are analyzed by using a corrosion model in which the oxidation and scale removal are coupled. Based on the model, long-term behaviors of steels in liquid lead and lead-bismuth are predictable. This report provides information for the selection of structural materials for typical nuclear reactor coolant systems when selecting liquid lead or lead bismuth as heat transfer media.