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. 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.

  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. Corrosion and corrosivity monitoring system

    NASA Astrophysics Data System (ADS)

    Braunling, Russ; Dietrich, Paul

    2005-05-01

    Honeywell International has developed and flight-tested a Corrosion and Corrosivity Monitoring System (C2MS). The C2MS detects galvanic corrosion in the main gearbox feet fasteners of helicopters. In addition, it monitors the environmental conditions inside the main floorboard compartment to determine the need for structural maintenance. The C2MS sensor on a main gearbox feet fastener sends a small electrical signal through the fastener and housing to measure the conductivity of the assembly. The measured conductivity value is used to determine if galvanic corrosion is present in the fastener assembly. The floorboard compartment sensors use a surrogate metal coupon to measure the corrosivity of the environment. The information from this sensor is used to recommend an extension to the calendar-based maintenance schedule. Fleet-wide information can be gathered by the system. The C2MS uses two Data Collection Units (DCUs) to store the corrosion data: one for the main gearbox feet fasteners and one for the main floorboard compartment. The DCU design addresses the issues of long battery life for the C2MS (greater than 2 years) and compactness. The data from the DCUs is collected by a personal digital assistant and downloaded to a personal computer where the corrosion algorithms reside. The personal computer display provides the location(s) of galvanic corrosion in the main gearbox feet fasteners as well as the recommended date for floorboard compartment maintenance. This paper discusses the methodology used to develop the C2MS software and hardware, presents the principles of the galvanic corrosion detection algorithm, and gives the laboratory and flight test results that document system performance in detecting galvanic corrosion (detection and false alarm rate). The paper also discusses the benefits of environmental sensors for providing a maintenance scheduling date.

  5. 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.

  6. 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.

  7. 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.

  8. Corrosion consultant expert system

    SciTech Connect

    Mo, Y.L.

    1994-12-31

    The development and use of an expert system to recommend coatings for flue gas desulfurization (FGD) plant is described. The system ranks coatings by their material properties, experimental test and plant performance scores when the component to be coated and its working environment are specified. The user interface, the inference engine, the knowledge base and the implementation of the expert system are presented with comments on its suitability and application for corrosion consultations.

  9. Corrosion potential analysis system

    NASA Astrophysics Data System (ADS)

    Kiefer, Karl F.

    1998-03-01

    Many cities in the northeastern U.S. transport electrical power from place to place via underground cables, which utilize voltages from 68 kv to 348 kv. These cables are placed in seamless steel pipe to protect the conductors. These buried pipe-type-cables (PTCs) are carefully designed and constantly pressurized with transformer oil to prevent any possible contamination. A protective coating placed on the outside diameter of the pipe during manufacture protects the steel pipe from the soil environment. Notwithstanding the protection mechanisms available, the pipes remain vulnerable to electrochemical corrosion processes. If undetected, corrosion can cause the pipes to leak transformer oil into the environment. These leaks can assume serious proportions due to the constant pressure on the inside of the pipe. A need exists for a detection system that can dynamically monitor the corrosive potential on the length of the pipe and dynamically adjust cathodic protection to counter local and global changes in the cathodic environment surrounding the pipes. The northeastern United States contains approximately 1000 miles of this pipe. This milage is critical to the transportation and distribution of power. So critical, that each of the pipe runs has a redundant double running parallel to it. Invocon, Inc. proposed and tested a technically unique and cost effective solution to detect critical corrosion potential and to communicate that information to a central data collection and analysis location. Invocon's solution utilizes the steel of the casing pipe as a communication medium. Each data gathering station on the pipe can act as a relay for information gathered elsewhere on the pipe. These stations must have 'smart' network configuration algorithms that constantly test various communication paths and determine the best and most power efficient route through which information should flow. Each network station also performs data acquisition and analysis tasks that ultimately

  10. Laser diagnostics for NTP fuel corrosion studies

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Viewgraphs and explanations on laser diagnostics for nuclear thermal propulsion (NTP) fuel corrosion studies are presented. Topics covered include: NTP fuels; U-Zr-C system corrosion products; planar laser-induced fluorescence (PLIF); utilization of PLIF for corrosion product characterization of nuclear thermal rocket fuel elements under test; ZrC emission spectrum; and PLIF imaging of ZrC plume.

  11. 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.

  12. Vehicle Corrosion Expert System (CES)

    DTIC Science & Technology

    2000-07-19

    Report developed under SBlR contract for topic A99-092. This report describes the design and development of a vehicle Corrosion Expert System (CES). CES has immediate utility in the automotive industry by vehicle manufactures that have the...eliminate or reduce the expensive Accelerated Corrosion Testing phase of the new vehicle development effort. The Vehicle Corrosion Expert System supports...and level of detail required to allow the user to use the Expert System for his area of interest.

  13. 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.

  14. 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.

  15. Computerized system for corrosion control

    SciTech Connect

    Hall, C. )

    1991-10-01

    This paper reports that computerization of basic corrosion measurements to provide record-keeping and graphical output has been used by pipeline companies over the lst decade. Northwest Pipeline Corp. has embarked on an ambition project to expand well beyond the scope of standard computer record-keeping by integrating data analysis and management with computer-aided advanced corrosion engineering practices. Most maturing pipeline systems require immense capital and maintenance expenditures to maintain regulatory levels of cathodic protection consistent with traditional corrosion control methods. Major pipeline coating rehabilitation programs and the installation of numerous anode-bed systems will continue in the absence of sophisticated computer-aided corrosion control methods.

  16. Studies on adhesion characteristics and corrosion behaviour of vinyltriethoxysilane/epoxy coating protective system on aluminium

    NASA Astrophysics Data System (ADS)

    Bajat, Jelena B.; Milošev, Ingrid; Jovanović, Željka; Mišković-Stanković, Vesna B.

    2010-03-01

    The corrosion stability of vinyltriethoxysilane/epoxy coating protective system on aluminium is strongly related to the strength of bonds forming at the metal/organic coating interface. This article is a study of adhesion, composition, electrochemical and transport properties of epoxy coatings electrodeposited on bare aluminium and aluminium pretreated by vinyltriethoxysilane (VTES) during exposure to 3% NaCl. The VTES film was deposited on aluminium surface from 2% vinyltriethoxysilane solution during 30 s. From the values of adhesion strength (pull-off test), time dependence of pore resistance and coating capacitance of epoxy coating (impedance measurements) and diffusion coefficient of water through epoxy coating (gravimetric liquid sorption measurements), the influence of VTES sublayer on the corrosion stability of the electrodeposited epoxy coating was shown. The work discusses the role of the VTES pretreatment in the enhanced adhesion and corrosion stability of epoxy cataphoretic coating. The electrochemical results showed that the aluminium pretreatment by VTES film improved barrier properties of epoxy coating (greater pore resistance and lower coating capacitance). The lower value of diffusion coefficient of water through epoxy coating indicates the lower porosity, while the smaller adhesion reduction points to better adhesion of epoxy coating on aluminium pretreated by VTES film. The composition of the deposited coatings investigated by XPS enabled the clarification of the bonding mechanism.

  17. Mössbauer spectroscopy study of iron corrosion underneath painting system

    NASA Astrophysics Data System (ADS)

    Nigam, R. K.; Hajela, B. P.; Sengupta, S.; Srivastava, B. C.; Gupta, K. M.

    1986-02-01

    The effect of pigments on the development of corrosion products between the painting system and metal surface when exposed to marine environments has been discussed. The pigments studied were; Red Mud Zinc chromate, Zinc chromate, Red oxide Zinc Phosphate, Manganese Phosphate Barium chromate and Basic Lead Silico Chromate. Mossbauer Spectroscopy revealed that the upper rust layer in all the cases consisted of γ-Fe203, γ-FeOOH and α-FeOOH. The lower rust layer immediately in contact with the metal surface consisted of an asymmetrical doublet due to γ-FeOOH.

  18. Evaluation of biological stability and corrosion potential in drinking water distribution systems: a case study.

    PubMed

    Chien, C C; Kao, C M; Chen, C W; Dong, C D; Chien, H Y

    2009-06-01

    The appearance of assimilable organic carbon (AOC), microbial regrowth, disinfection by-products (DBPs), and pipe corrosion in drinking water distribution systems are among those major safe drinking water issues in many countries. The water distribution system of Cheng-Ching Lake Water Treatment Plant (CCLWTP) was selected in this study to evaluate the: (1) fate and transport of AOC, DBPs [e.g., trihalomethanes (THMs), haloacetic acids (HAAs)], and other organic carbon indicators in the selected distribution system, (2) correlations between AOC (or DBPs) and major water quality parameters [e.g. dissolved oxygen (DO), free residual chlorine, and bacteria, and (3) causes and significance of corrosion problems of the water pipes in this system. In this study, seasonal water samples were collected from 13 representative locations in the distribution system for analyses of AOC, DBPs, and other water quality indicators. Results indicate that residual free chlorine concentrations in the distribution system met the drinking water standards (0.2 to 1 mg l(-1)) established by Taiwan Environmental Protection Administration (TEPA). Results show that AOC measurements correlated positively with total organic carbon (TOC) and UV-254 (an organic indicator) values in this system. Moreover, AOC concentrations at some locations were higher than the 50 microg acetate-C l(-1) standard established by Taiwan Water Company. This indicates that the microbial regrowth might be a potential water quality problem in this system. Higher DO measurements (>5.7 mg l(-1)) might cause the aerobic biodegradation of THMs and HAAs in the system, and thus, low THMs (<0.035 mg l(-1)) and HAAs (<0.019 mg l(-1)) concentrations were observed at all sampling locations. Results from the observed negative Langelier Saturation Index (LSI) values, higher Ryznar Stability Index (RSI) values, and high Fe3+ concentrations at some pipe-end locations indicate that highly oxidative and corrosive conditions occurred

  19. ECLSS Universal Waste Management System (UWMS) Metal Materials Compatibility Study- Electrochemical and Crevice Corrosion Evaluation

    NASA Technical Reports Server (NTRS)

    Lee, R. E.

    2017-01-01

    Electrochemical and crevice corrosion laboratory test results are presented for three noble metal candidates with possible application on the Universal Waste Management System (UWMS) in support of the Environmental Control and Life Support System (ECLSS) aboard the International Space Station (ISS). The three metal candidates, which included Inconel 625, Hastelloy C276 and Titanium 6Al-4V, were evaluated in two solutions representative of the acidic pretreatment formulations utilized during processing of waste liquids within the ECLSS. Final test results and data analysis indicated that the passive layer on all three metals provides excellent corrosion protection in both solutions under standard test conditions.

  20. 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.

  1. 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.

  2. 219-S CORROSION STUDY

    SciTech Connect

    DIVINE JR; PARSONS GL

    2008-12-01

    A minor leak was detected in a drain line for Hood 2B located in the 222-S Laboratory. The line transfers radioactive waste, spent analytical standards, and chemicals used in various analytical procedures. Details are in the report provided by David Comstock, 2B NDE June 2008, work package LAB-WO-07-2012. Including the noted leak, the 222-S Laboratory has experienced two drain line leaks in approximately the last two years of operation. As a consequence, CH2M HILL Hanford Group, Inc. (CH2M HILL) requested the support of ChemMet, Ltd., PC (ChemMet) at the Hanford Site 222-S Laboratory. The corrosion expertise from ChemMet was required prior to preparation of a compatibility assessment for the 222-S Laboratory waste transfer system to assure the expected life of the piping system is extended as much as practicable. The system includes piping within the 222-S Laboratory and the 219-S Waste Storage and Transfer Facility and Operations Process. The ChemMet support was required for an assessment by 222-S staff to analyze what improvements to operational activities may be implemented to extend the tank/piping system life. This assessment will include a summary of the various material types, age, and locations throughout the facility. The assessment will also include a discussion of materials that are safe for drain line disposal on a regular basis, materials that are safe for disposal on a case-by-case basis including specific additional requirements such as flushing, neutralization to a specific pH, and materials prohibited from disposal. The assessment shall include adequate information for 222-S Laboratory personnel to make informed decisions in the future disposal of specific material types by discussing types of compatibility of system materials and potential wastes. The assessment is expected to contain some listing of acceptable waste materials but is not anticipated to be a complete or comprehensive list. Finally the assessment will encompass a brief discussion of

  3. GIC effects on pipeline corrosion and corrosion control systems

    NASA Astrophysics Data System (ADS)

    Gummow, R. A.; Eng, P.

    2002-11-01

    The impact of telluric current activity on the corrosion control systems for pipelines in northern regions is examined. Three specific areas of concern are identified. These factors are corrosion of the pipe during positive cycles of the telluric disturbances, accurate measurement of cathodic protection performance parameters, and coating damage during negative cycles of the telluric activity. Corrosion rates are calculated versus the magnitude of the pipe potential change caused by discharging telluric current for different values of the Kp geomagnetic index. Methods of compensating and mitigating telluric current effects are discussed in the context of the cathodic protection design and monitoring procedures.

  4. Corrosion studies with pixe

    NASA Astrophysics Data System (ADS)

    Anwar Chaudhri, M.; Crawford, A.

    1981-03-01

    To investigate the possible causes of corrosion of some of the tooth paste tubes of a major international cosmetic product manufacturer, the elemental compositions of corroded and clean unused tubes were compared, using PIXE. It was observed that some of the corroded tubes contained much higher amounts of Ti, Fe, Ga and Zn than the clean tubes, while the concentrations of Cr and Ni showed no significant difference between the two types of tubes. Only certain regions of one of the tubes were found to contain higher concentrations of Cu. Those regions were badly corroded and had the highest concentrations of Ti, Fe, Ga and Zn, too. It is suggested that the presence of higher amounts of Ti, Fe, Ga and Zn, and especially of Cu, in the aluminium sheets used to manufacture the tooth paste tubes, may be one of the reasons for the corrosion of some of the tooth paste tubes.

  5. 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.

  6. A Study of Magnesium-Base Metallic Systems and Development of Principles for Creation of Corrosion-Resistant Magnesium Alloys

    NASA Astrophysics Data System (ADS)

    Mukhina, I. Yu.

    2014-11-01

    The effect of 26 alloying elements on the corrosion resistance of high-purity magnesium in a 0.5-n solution of sodium chloride and in a humid atmosphere (0.005 n) is studied. The Mg - Li, Mg - Ag, Mg - Zn, Mg - Cu, Mg - Gd, Mg - Al, Mg - Zr, Mg - Mn and other binary systems, which present interest as a base for commercial or perspective castable magnesium alloys, are studied. The characteristics of corrosion resistance of the binary alloys are analyzed in accordance with the group and period of the Mendeleev's periodic law. The roles of the electrochemical and volume factors and of the factor of the valence of the dissolved element are determined.

  7. Avionics Corrosion Control Study

    DTIC Science & Technology

    1974-01-01

    contact with-caustic soda , washing soda , or lime. One of the most har:iiful materials when In contact with aluminum is mercury or any of its salts. Mercury...used with weaker acids such as vinegar . lemon juice, etc. In general, aluminum and its alloys exhibit a wide range of corrosive attack, varying front...SM-43) -(TT-1-7435) 6850-X.13-1544 San-Del #2 Technical Cleaner Baking SoaM. P. Odell Co. Armor (’ 1348) $950-29)2-9611 1169-A Insulating Lacquer Base

  8. Structural, theoretical and corrosion inhibition studies on some transition metal complexes derived from heterocyclic system

    NASA Astrophysics Data System (ADS)

    Gupta, Shraddha Rani; Mourya, Punita; Singh, M. M.; Singh, Vinod P.

    2017-06-01

    A Schiff base, (E)-N‧-((1H-indol-3-yl)methylene)-2-aminobenzohydrazide (Iabh) and its Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. These compounds have been characterized by different physico-chemical and spectroscopic tools (UV-Vis, IR, NMR and ESI-Mass). The molecular structure of Iabh is determined by single crystal X-ray diffraction technique. The ligand Iabh displays E-configuration about the >Cdbnd N- bond. The structure of ligand is stabilized by intra-molecular H-bonding. In all the metal complexes the ligand coordinates through azomethine-N and carbonyl-O resulting a distorted octahedral geometry for Mn(II), Co(II) and Cu(II) complexes in which chloride ions occupy axial positions. Ni(II) and Zn(II) complexes, however, form 4-coordinate distorted square planer and tetrahedral geometry around metal ion, respectively. The structures of the complexes have been satisfactorily modeled by calculations based on density functional theory (DFT) and time dependent-DFT (TD-DFT). The corrosion inhibition study of the compounds have been performed against mild steel in 0.5 M H2SO4 solution at 298 K by using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). They show appreciable corrosion inhibition property.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. 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

  16. 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.

  17. Aerospace Non Chrome Corrosion Inhibiting Primer Systems

    DTIC Science & Technology

    2009-09-01

    Aerospace Coatings | Title 1 AsetsDefense 2009 Workshop Aerospace Non Chrome Corrosion Inhibiting Primer Systems Roger Brown, Akzonobel Aerospace...DATE SEP 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE Aerospace Non Chrome Corrosion Inhibiting Primer...Title 2 Overview comments and a historical perspective on non chrome systems A quick test; Technology development for replacement of chromated

  18. 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.

  19. Evaluation of several corrosion protective coating systems on aluminum

    SciTech Connect

    Higgins, R.H.

    1981-02-01

    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 h. 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.

  20. 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.

  1. 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.

  2. Long-term corrosion studies

    SciTech Connect

    Gdowski, G.

    1998-05-29

    The scope of this activity is to assess the long-term corrosion properties of metallic materials under consideration for fabricating waste package containers. Three classes of metals are to be assessed: corrosion resistant, intermediate corrosion resistant, and corrosion allowance. Corrosion properties to be evaluated are general, pitting and crevice corrosion, stress-corrosion cracking, and galvanic corrosion. The performance of these materials will be investigated under conditions that are considered relevant to the potential emplacement site. Testing in four aqueous solutions, and vapor phases above them, and at two temperatures are planned for this activity. (The environmental conditions, test metals, and matrix are described in detail in Section 3.0.) The purpose and objective of this activity is to obtain the kinetic and mechanistic information on degradation of metallic alloys currently being considered for waste package containers. This information will be used to provide assistance to (1) waste package design (metal barrier selection) (E-20-90 to E-20-92), (2) waste package performance assessment activities (SIP-PA-2), (3) model development (E-20-75 to E-20-89). and (4) repository license application.

  3. 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.

  4. 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.

  5. Electrochemical study on metal corrosion in chemical mechanical planarization process

    NASA Astrophysics Data System (ADS)

    Kondo, Seiichi; Ichige, Yasuhiro; Otsuka, Yuya

    2017-07-01

    Typical metal corrosions caused by the chemical mechanical planarization (CMP) process are discussed in this review paper. By categorizing them into seven kinds of corrosion, namely, chemical corrosion, crevice corrosion, crystal-orientation-dependent corrosion, narrow trench corrosion, photocorrosion, galvanic corrosion, and electrostatic-charge induced corrosion, we discuss their mechanisms and how to suppress them on the basis of electrochemical studies. Moreover, we demonstrate the usefulness of three-dimensional pH-potential diagrams for predicting corrosion issues in an actual CMP process.

  6. Vibrational Spectroscopy in Studies of Atmospheric Corrosion

    PubMed Central

    Hosseinpour, Saman; Johnson, Magnus

    2017-01-01

    Vibrational spectroscopy has been successfully used for decades in studies of the atmospheric corrosion processes, mainly to identify the nature of corrosion products but also to quantify their amounts. In this review article, a summary of the main achievements is presented with focus on how the techniques infrared spectroscopy, Raman spectroscopy, and vibrational sum frequency spectroscopy can be used in the field. Several different studies have been discussed where these instruments have been used to assess both the nature of corrosion products as well as the properties of corrosion inhibitors. Some of these techniques offer the valuable possibility to perform in-situ measurements in real time on ongoing corrosion processes, which allows the kinetics of formation of corrosion products to be studied, and also minimizes the risk of changing the surface properties which may occur during ex-situ experiments. Since corrosion processes often occur heterogeneously over a surface, it is of great importance to obtain a deeper knowledge about atmospheric corrosion phenomena on the nano scale, and this review also discusses novel vibrational microscopy techniques allowing spectra to be acquired with a spatial resolution of 20 nm. PMID:28772781

  7. Corrosion of coupled metals in a dental magnetic attachment system.

    PubMed

    Iimuro, F T; Yoneyama, T; Okuno, O

    1993-12-01

    Implants and magnetic attachments are becoming widespread in dental treatment. Their associated use, implants and magnetic attachments, can be seen often too. In those cases, it is difficult to avoid coupling of different metals. The corrosion behavior of the metals is expected to be different depending on whether it is found in an isolated or a coupled condition. Potential corrosion couples in a dental magnetic attachment system among titanium, ferromagnetic stainless steel, gold alloy type IV, and gold-silver-palladium alloy were studied by an immersion test in 1% lactic acid for 7 days and potential/current density curves were measured. Corrosion of titanium and ferromagnetic stainless steel seemed to be accelerated by coupling with gold alloys or gold-silver-palladium alloys. On the other hand, the corrosion amount of gold alloy and gold-silver-palladium alloys were attenuated by coupling.

  8. 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

  9. 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.

  10. Electrochemical Studies of Atmospheric Corrosion.

    DTIC Science & Technology

    1979-01-01

    Todynamlc polarization curves using a mod ifiedatmospheric corrosion mon i tor (ACM). Norma l Tafel behavior was observed , the limiting current for oxygen...following a suggestion of Peter Serada, who is heading a task group on time-of-wetness measurements In ASTM GO1 .04, in which the author is participating...about 5 papers except for 1968 where a symposium on atmospheric corrosion was held which resulted in the publ ication of an ASTM Special Technical

  11. 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.

  12. Study of corrosion in archaeological gilded irons by Raman imaging and a coupled scanning electron microscope-Raman system.

    PubMed

    Veneranda, Marco; Costantini, Ilaria; de Vallejuelo, Silvia Fdez-Ortiz; Garcia, Laura; García, Iñaki; Castro, Kepa; Azkarate, Agustín; Madariaga, Juan Manuel

    2016-12-13

    In this work, analytical and chemical imaging tools have been applied to the study of a gilded spur found in the medieval necropolis of Erenozar (Bizkaia, Spain). As a first step, a lot of portable equipment has been used to study the object in a non-invasive way. The hand-held energy-dispersive X-ray fluorescence equipment allowed us to characterize the artefact as a rare example of an iron matrix item decorated by means of a fire gilding technique. On the other hand, the use of a portable Raman system helped us to detect the main degradation compounds affecting the spur. Afterwards, further information was acquired in the laboratory by analysing detached fragments. The molecular images obtained using confocal Raman microscopy permitted us to characterize the stratigraphic succession of iron corrosions. Furthermore, the combined use of this technique with a scanning electron microscope (SEM) was achieved owing to the use of a structural and chemical analyser interface. In this way, the molecular characterization, enhanced by the magnification feature of the SEM, allowed us to identify several micrometric degradation compounds. Finally, the effectiveness of one of the most used desalination baths (NaOH) was evaluated by comparing its effects with those provided by a reference bath (MilliQ). The comparison proved that basic treatment avoided any side effects on the spur decorated by fire gilding, compensating for the lack of bibliographic documentation in this field.This article is part of the themed issue 'Raman spectroscopy in art and archaeology'.

  13. Study of corrosion in archaeological gilded irons by Raman imaging and a coupled scanning electron microscope-Raman system

    NASA Astrophysics Data System (ADS)

    Veneranda, Marco; Costantini, Ilaria; de Vallejuelo, Silvia Fdez-Ortiz; Garcia, Laura; García, Iñaki; Castro, Kepa; Azkarate, Agustín; Madariaga, Juan Manuel

    2016-12-01

    In this work, analytical and chemical imaging tools have been applied to the study of a gilded spur found in the medieval necropolis of Erenozar (Bizkaia, Spain). As a first step, a lot of portable equipment has been used to study the object in a non-invasive way. The hand-held energy-dispersive X-ray fluorescence equipment allowed us to characterize the artefact as a rare example of an iron matrix item decorated by means of a fire gilding technique. On the other hand, the use of a portable Raman system helped us to detect the main degradation compounds affecting the spur. Afterwards, further information was acquired in the laboratory by analysing detached fragments. The molecular images obtained using confocal Raman microscopy permitted us to characterize the stratigraphic succession of iron corrosions. Furthermore, the combined use of this technique with a scanning electron microscope (SEM) was achieved owing to the use of a structural and chemical analyser interface. In this way, the molecular characterization, enhanced by the magnification feature of the SEM, allowed us to identify several micrometric degradation compounds. Finally, the effectiveness of one of the most used desalination baths (NaOH) was evaluated by comparing its effects with those provided by a reference bath (MilliQ). The comparison proved that basic treatment avoided any side effects on the spur decorated by fire gilding, compensating for the lack of bibliographic documentation in this field. This article is part of the themed issue "Raman spectroscopy in art and archaeology".

  14. 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.

  15. 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)

  16. 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)

  17. Corrosion in HVDC valve cooling systems

    SciTech Connect

    Jackson, P.O.; Abrahamsson, B.; Gustavsson, D.; Igetoft, L.

    1997-04-01

    Stainless steel couplings in the main cooling water pipes of HVDC thyristor valves have been in use since 1983, with an overall satisfactory behavior. However, some water leakage due to corrosion below the sealing O-rings of the couplings was observed during 1992. An extensive investigation and follow-up worldwide showed a direct correlation between water quality and the corrosion rate of the stainless steel couplings. Recommendations are given about actions to be taken in order to maintain a long lifetime for the fine water systems.

  18. 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)

  19. 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)

  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. Experiment Study on Corrosion Control Using Coking Wastewater as Circulating Cooling Water

    NASA Astrophysics Data System (ADS)

    Zhang, Huanzhen; Dong, Changqing; Bian, Lei; Zhao, Qian

    The coking wastewater drainage will bring severe water environmental pollution, so it is necessary to change the coking wastewater into resource. The reuse of pre-treated coking wastewater as make-up water for circulating cooling system is an important way. To prevent the circulating cooling system corrosion, the characteristic and the corrosion control technology and the effect of the classic corrosion inhibitors in the circulating cooling water system were studied by static experiment and dynamic experiment based on water quality stabilization theory. The results indicate that the corrosion in circulating cooling system is mainly spot corrosion caused by pollutants in coking wastewater, and the corrosion inhibition technology on the model of precipitated membrane based on phosphor series should be preferred. The mixed corrosion inhibitors HEDP and Zn 2+ optimally selected by experiment can form a firm corrosion inhibition membrane on heat transfer surface, and the corrosion inhibition rate could reach 85.6%. The corrosion rate of common carbon steel is 0.105 mm/a, which could satisfy the criterion of > Design criterion of the industrial circulating cooling water treatment > (GB 50050-95). The practical application to the circulating cooling system shows that the mixed corrosion inhibitors HEDP and Zn 2+ can control the corrosion in the system economically when the concentration multiple is 2-2.2, which opens up a feasible way for changing the coking wastewater into resource.

  2. Microbial Influenced Corrosion (MIC) Study

    DTIC Science & Technology

    2012-05-23

    Incubation Conditions 26± 2C; 75-80% Rel. Humidity Microbacterium saperdae Bacteria Consortium Rhodococcus equi Staphylococcus epidermidis Aspergillus...Aluminum Coupon Results: 3 Month Exposure, Cleaned (Representative Samples) Bacteria ConsortiaCoupon ID 302 Copper Aluminum) Dried biofilm and corrosion

  3. Corrosion inhibitor evaluation for a gas compression system

    SciTech Connect

    Perdomo, J.J.; Ramirez, M.; Viloria, A.; Morales, J.L.

    1999-11-01

    The injection of chemicals for gas systems is a common practice to prevent corrosion and asphaltene deposition. A laboratory study was conducted to evaluate 5 commercially available corrosion inhibitors and an asphaltene dispersant for a gas compression plant. This study was set out to look at the compatibility of a pipeline corrosion inhibitor with both an anti asphaltene and a gas compression inhibitor which is required to have a relatively large flammable point and resist the pressure and temperature of the process without igniting or aging. Also, the effect of precorroded surfaces was studied to establish its effect on the performance of the pipeline inhibitor. The efficiency of the products was evaluated through either coupon weight loss tests or polarization resistance. Corrosion inhibitor aging was carried out in autoclaves emulating operating conditions, subsequently, gel permeation chromatography (GPC), total nitrogen and viscosity measurements were performed on the products before and after aging to establish the variation of their physical and chemical properties. Additionally, X-ray diffraction analysis (XRD) and energy dispersion spectroscopy (EDS) were used to identify corrosion products. From the study, an efficiency of 86% was obtained for a line inhibitor at a 45-PPM dosage (at 36 psi pCO{sub 2} and 0.006 psi of H{sub 2}S at 120 F), lowering its efficiency to 76% after precorroding the surface for three days. The presence of asphaltene may reduce the corrosion rate; however, the injection of a dispersant accelerates the corrosion process. No significant changes in efficiency and physical properties were observed during the evaluation of one of the compression-line inhibitor mixtures tested.

  4. 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.

  5. System for in situ studies of atmospheric corrosion of metal films using soft x-ray spectroscopy and quartz crystal microbalance.

    PubMed

    Forsberg, J; Duda, L-C; Olsson, A; Schmitt, T; Andersson, J; Nordgren, J; Hedberg, J; Leygraf, C; Aastrup, T; Wallinder, D; Guo, J-H

    2007-08-01

    We present a versatile chamber ("atmospheric corrosion cell") for soft x-ray absorption/emission spectroscopy of metal surfaces in a corrosive atmosphere allowing novel in situ electronic structure studies. Synchrotron x rays passing through a thin window separating the corrosion cell interior from a beamline vacuum chamber probe a metal film deposited on a quartz crystal microbalance (QCM) or on the inside of the window. We present some initial results on chloride induced corrosion of iron surfaces in humidified synthetic air. By simultaneous recording of QCM signal and soft x-ray emission from the corroding sample, correlation between mass changes and variations in spectral features is facilitated.

  6. Preliminary Corrosion Studies of Candidate Materials for Supercritical Water Oxidation Reactor Systems

    DTIC Science & Technology

    1994-05-01

    2 Effluent Samples of Various Waste Streams in 36 SCWO Reactors. 2-3 Effluent Samples of Ammonium Perchlorate and 37 Nitromethane Feedstock in...testing. Feedstock Flow Rate Tern "C Cr (ppm) Mo (ppm) Ni (ppm) 0.1 M Ammonium Perchlorate 2 ml/min 500 59 10 26 0.1 M Ammonium Perchlorate 4 ml/min 500...3 Effluent Samples of Ammonium Perchlorate and Nitromethane Feedstock in Hastelloy C-276 Reactor. From Buelow et. al.27 2.5 Exposure Studies Exposure

  7. Corrosion of Aluminum Jackets on Aboveground Heat Distribution Systems.

    DTIC Science & Technology

    1986-09-01

    Society of Metals , 1967), p 255. Studies of Corrosion of Aluminum in Natural Waters," Corrosion, Vol 20, No. 10 (October Corrosion of Aluminum Jackets...Volume 1: Properties, Physical Metal- lurgy, and Phase Diagrams, K. R. Van Horn, ed. Murray, G. A. W., "Artificial Pits for Quantitative ( American

  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. 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.

  10. 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.

  11. Localized corrosion studies on materials proposed for a safety-grade sodium-to- air decay-heat removal system for fast breeder reactors

    NASA Astrophysics Data System (ADS)

    Kamachi Mudali, U.; Khatak, H. S.; Dayal, R. K.; Gnanamoorthy, J. B.

    1993-02-01

    The present investigation was carried out to assess the localized corrosion resistance of materials proposed for the construction of the safety-grade sodium-to-air decay-heat removal system for fast breeder reactors. The materials, such as Alloy 800,9Cr-lMo steel, and type 316LN stainless steel, in different microstructural conditions were assessed for pitting and stress-corrosion cracking resistances in a chloride medium. The results indicated that 9Cr-lMo steel in the normalized and tempered condition can be considered for the above application from the standpoint of corrosion resistance.

  12. Localized corrosion studies on materials proposed for a safety-grade sodium-to-air decay-heat removal system for fast breeder reactors

    SciTech Connect

    Mudali, U.K.; Khatak, H.S.; Dayal, R.K.; Gnanamoorthy, J.B. )

    1993-02-01

    The present investigation was carried out to assess the localized corrosion resistance of materials proposed for the construction of the safety-grade sodium-to-air decay-heat removal system for fast breeder reactors. The materials, such as Alloy 800, 9Cr-1 Mo steel, and type 316LN stainless steel, in different microstructural conditions were assessed for pitting and stress-corrosion cracking resistances in a chloride medium. The results indicated that 9Cr-1Mo steel in the normalized and tempered condition can be considered for the above application from the standpoint of corrosion resistance.

  13. Corrosion experiments and materials developed for the Japanese HLM systems

    NASA Astrophysics Data System (ADS)

    Kurata, Yuji

    2011-08-01

    The static corrosion tests in lead-bismuth eutectic (LBE) were conducted from 450 °C to 600 °C to understand corrosion behavior and develop corrosion resistant materials for heavy liquid metal systems. While increase of Cr content in steels enhances corrosion resistance in LBE, the effect approaches a constant value above 12 wt% of Cr. Corrosion depth in LBE increases with increasing temperature and corrosion attack becomes severe above 550 °C even under the condition of high oxygen concentration. Nickel dissolution and Pb-Bi penetration occur in 316SS and JPCA above 550 °C under the condition of high oxygen concentration. When oxygen concentration decreases below the level of Fe oxide formation, corrosion attack on these steels also becomes violent due to dissolution of various elements and grain boundary corrosion. Whereas additions of 1.5 wt% Si to T91 and 2.5 wt% Si to 316SS improve corrosion resistance, the effect is insufficient taking fluctuation of oxygen concentration in LBE into consideration. Furthermore, addition of 1.5 wt% Si to T91 causes rise in DBTT. A new coating method using Al, Ti and Fe powders produces corrosion resistant coating layers on 316SS. The coating layers containing 6-8 wt% Al exhibit good corrosion resistance at 550 °C for 3000 h in LBE containing 10 -6-10 -4 wt% of oxygen.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Experimental study on corrosion and precipitation in non-isothermal Pb-17Li system for development of liquid breeder blanket of fusion reactor

    NASA Astrophysics Data System (ADS)

    Kondo, Masatoshi; Ishii, Masaomi; Norimatsu, Takayoshi; Muroga, Takeo

    2017-07-01

    The corrosion characteristics of RAFM steel JLF-1 in a non-isothermal Pb-17Li flowing system were investigated by means of the corrosion test using a non-isothermal mixing pot. The corrosion test was performed at 739K with a temperature gradient of 14K for 500 hours. The corrosion tests at a static and a flowing conditions in an isothermal Pb-17Li system were also performed at the same temperature for the same duration with the non-isothermal test. Then, the effect of mass transfer both by the flow and the temperature gradient on the corrosion behaviors was featured by the comparison of these results. The corrosion was caused by the dissolution of Fe and Cr from the steel surface into the flowing Pb-17Li. The specimen surface revealed a fine granular microstructure after the corrosion tests. A large number of pebbleshaped protrusions were observed on the specimen surface. This microstructure was different from the original martensite microstructure of the steel, and might be formed by the influence of the reaction with Li component in the alloy. The formation of the granular microstructure was accelerated by the flow and the temperature gradient. Some pebble-shaped protrusions had gaps at their bases. The removal of these pebble-shaped granules by the flowing Pb-17Li might cause a small-scale corrosion-erosion. The results of metallurgical analysis indicated that a large-scale corrosion-erosion was also caused by their destruction of the corroded layer on the surface. The non-isothermal mixing pot equipped a cold trap by a metal mesh in the low temperature region. The metal elements of Fe and Cr were recovered as they precipitated on the surface of the metal mesh. It was found that a Fe-Cr binary intermetallic compound was formed in the precipitation procedure. The overall mass transfer coefficient for the dissolution type corrosion in the non-isothermal system was much bigger than that in the isothermal system. This model evaluation indicated that the temperature

  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. 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.

  3. 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.

  4. 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.

  5. 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.

  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.

  7. Deployment of a wireless corrosion monitoring system for aircraft applications

    NASA Astrophysics Data System (ADS)

    Demo, J.; Andrews, C.; Friedersdorf, F.; Morgan, A.; Jostes, L.

    With its extremely negative effects on critical military assets, corrosion continues to be one of the top maintenance cost drivers for the Department of Defense. As of 2010, an estimated $22.9B was required to cover the costs associated with corrosion in the DoD annually. Proper management of corrosion on high value military assets such as aircraft can significantly reduce costs associated with maintenance, component removal, and aircraft availability. This paper will discuss the design, validation, and deployment of a wireless, flight qualified corrosion monitoring system as well as analysis of data collected during field trials.

  8. Corrosive Wear in Wet Ore Grinding Systems

    NASA Astrophysics Data System (ADS)

    Jones, Denny A.

    1985-06-01

    Wear processes in ball and rod mills have recently received increased attention in order to increase efficiency and conserve grinding media. Direct removal of metal from the grinding media surface by abrasive wear occurs in both dry and wet grinding. Additional corrosive wear is apparent during wet grinding, in which less resistant corrosion product films are abraded away. Inhibitors and higher pH solutions, in which corrosion product films are more tenacious, improve wear resistance during wet grinding. Softer surfaces are less resistant to corrosive wear, suggesting that film formation and subsequent film abrasion on newly furrowed surfaces must be a factor.

  9. 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.

  10. 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.

  11. Environmental Considerations in the Studies of Corrosion Resistant Alloys for High-Level Radioactive Waste Containment

    SciTech Connect

    Ilevbare, G O; Lian, T; Farmer, J C

    2001-11-26

    The corrosion resistance of Alloy 22 (UNS No.: N06022) was studied in simulated ground water of different pH values and ionic contents at various temperatures. Potentiodynamic polarization techniques were used to study the electrochemical behavior and measure the critical potentials in the various systems. Alloy 22 was found to be resistant to localized corrosion in the simulated ground waters tested.

  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.

    1983-01-01

    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, anad silicon. Previously announced in STAR as N81-23243

  14. Combustion system processes leading to corrosive deposits

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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, anad silicon. Previously announced in STAR as N81-23243

  15. 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.

  16. Engineering Evaluation of the Effectiveness of DST Annulus Ventilation Systems for Corrosion Mitigation

    SciTech Connect

    DALPIAZ, E.L.

    2001-06-20

    This engineering study evaluates the corrosion mitigation effectiveness of the annulus ventilation systems for the 241-AN, 241-AP, 241-AW, 241-AY, 241-AZ, and 241-SY tank farms, and provides the technical basis for the Administrative Control for DST annulus ventilation systems. The study shows that maintenance of annulus ventilation is important to mitigating risk of condensation and resulting corrosion due to postulated water ingress into DST annuli.

  17. Grain boundary defects initiation at the outer surface of dissimilar welds: Corrosion mechanism studies

    SciTech Connect

    Bouvier, O. De; Yrieix, B.

    1995-12-31

    Dissimilar welds located on the primary coolant system of the French PWR plants exhibit grain boundary defects in the true austenitic zones of the first buttering layer. If grain boundaries reach the interface, they can extend to the martensitic band. Those defects are filled with compact oxides. In addition, the ferritic base metal presents some pits along the interface. Nowadays, three mechanisms are proposed to explain the initiation of those defects: stress corrosion cracking, intergranular corrosion and high temperature intergranular oxidation. This paper is dealing with the study of the mechanisms involved in the corrosion phenomenon. Intergranular corrosion tests performed on different materials show that only the first buttering layer, even with some {delta} ferrite, is sensitized. The results of stress corrosion cracking tests in water solutions show that intergranular cracking is possible on a bulk material representative of the first buttering layer. It is unlikely on actual dissimilar welds where the ferritic base metal protects the first austenitic layer by galvanic coupling. Therefore, the stress corrosion cracking assumption cannot explain the initiation of the defects in aqueous environment. The results of the investigations and of the corrosion studies led to the conclusion that the atmosphere could be the only possible aggressive environment. This conclusion is based on natural atmospheric exposure and accelerated corrosion tests carried out with SO{sub 2} additions in controlled atmosphere. They both induce a severe intergranular corrosion on true sensitized austenitic materials.

  18. 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.

  19. Corrosion and Scaling Potential in Drinking Water Distribution System of Tabriz, Northwestern Iran

    PubMed Central

    Taghipour, Hassan; Shakerkhatibi, Mohammad; Pourakbar, Mojtaba; Belvasi, Mehdi

    2012-01-01

    Background: This paper discusses the corrosion and scaling potential of Tabriz drinking water distribution system in Northwest of Iran. Internal corrosion of piping is a serious problem in drinking water industry. Corrosive water can cause intrusion of heavy metals especially lead in to water, therefore effecting public health. The aim of this study was to determine corrosion and scaling potential in potable water distribution system of Tabriz during the spring and summer in 2011. Methods: This study was carried out using Langlier Saturation Index, Ryznar Stability Index, Puckorius Scaling Index, and Aggressiveness indices. Eighty samples were taken from all over the city within two seasons, spring, and summer. Related parameters including temperature, pH, total dissolved solids, calcium hardness, and total alkalinity in all samples were measured in laboratory according to standard method manual. For the statistical analysis of the results, SPSS software (version 11.5) was used Results: The mean and standard deviation values of Langlier, Ryznar, Puckorius and Aggressiveness Indices were equal to -0.68 (±0.43), 8.43 (±0.55), 7.86 (±0.36) and 11.23 (±0.43), respectively. By survey of corrosion indices, it was found that Tabriz drinking water is corrosive. Conclusion: In order to corrosion control, it is suggested that laboratorial study with regard to the distribution system condition be carried out to adjust effective parameters such as pH. PMID:24688924

  20. Corrosion and scaling potential in drinking water distribution system of tabriz, northwestern iran.

    PubMed

    Taghipour, Hassan; Shakerkhatibi, Mohammad; Pourakbar, Mojtaba; Belvasi, Mehdi

    2012-01-01

    This paper discusses the corrosion and scaling potential of Tabriz drinking water distribution system in Northwest of Iran. Internal corrosion of piping is a serious problem in drinking water industry. Corrosive water can cause intrusion of heavy metals especially lead in to water, therefore effecting public health. The aim of this study was to determine corrosion and scaling potential in potable water distribution system of Tabriz during the spring and summer in 2011. This study was carried out using Langlier Saturation Index, Ryznar Stability Index, Puckorius Scaling Index, and Aggressiveness indices. Eighty samples were taken from all over the city within two seasons, spring, and summer. Related parameters including temperature, pH, total dissolved solids, calcium hardness, and total alkalinity in all samples were measured in laboratory according to standard method manual. For the statistical analysis of the results, SPSS software (version 11.5) was used The mean and standard deviation values of Langlier, Ryznar, Puckorius and Aggressiveness Indices were equal to -0.68 (±0.43), 8.43 (±0.55), 7.86 (±0.36) and 11.23 (±0.43), respectively. By survey of corrosion indices, it was found that Tabriz drinking water is corrosive. In order to corrosion control, it is suggested that laboratorial study with regard to the distribution system condition be carried out to adjust effective parameters such as pH.

  1. 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.

  2. 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.

  3. Corrosion in quench systems of entrained slagging gasifiers: a laboratory study. Final report. [1 1/4Cr-1/2Mo(T-11)

    SciTech Connect

    Bhattacharyya, S.

    1985-11-01

    The objective of this program was to conduct laboratory autoclave tests simulating environments of the gray water system of an entrained slagging gasifier plant. Five tests (one 200-h and four 1000-h) were conducted using ferritic steel material 1 1/4Cr-1/2Mo (T-11) and 14% silicon cast iron; austenitic stainless steels 304L, 316, 321, and Sanicro 28; duplex stainless steel 2205; and Incoloy 825. In the vapor phase with autoclave solution pH in the 4.5 to 4.8 range, 304L SS, 316 SS, 321 SS, and Incoloy 825 double U-bends suffered significant intergranular SCC. Some crevice-assisted cracking is suspected. Pitting corrosion, as measured by maximum pit depth, may become serious since the rate of growth is not known. At the pit base, preferential dissolution was identified similar to grain- and twin-boundary preferential corrosion. General corrosion of the stainless steels was low, but T-11 and 14% silicon cast iron cannot be used unprotected. High acidic pH (6.2 and 6.4) and lower total chloride levels eliminated SCC problems and reduced pitting and corrosion. Of the two phases in a quench system, the vapor phase poses more danger to the materials of construction, particularly to the internal attachments and extensions where welding is required. 13 refs., 31 figs., 4 tabs.

  4. Development of the pipe-loop system for determining effectiveness of corrosion-control chemicals in potable water systems. Final report

    SciTech Connect

    Prakash, T.M.; Scholze, R.J.; Neff, C.H.; Maloney, S.W.; Heath, M.

    1988-08-01

    In the Army's 12,000 miles of water lines, internal corrosion slowly destroys a large investment and creates significant problems for Army water-treatment-plant operators, who try to maintain the water quality at acceptable levels. Corrosion can be slowed using corrosion-inhibiting chemicals, but it is difficult to measure the extent of corrosion and the effectiveness of inhibitors without excavating actual pipes. This study surveyed corrosion-inhibiting water-quality control chemicals and methods for monitoring corrosion. With this knowledge, a pipe-loop system was developed and installed at Fort Bragg, NC and Fort Monroe, VA. It was shown to be effective in gathering data on corrosion rates. After a standard procedure has been established, this loop will allow a water-treatment-plant operator to monitor with ease the effectiveness of corrosion-inhibiting treatments.

  5. 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.

  6. 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.

  7. 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.

  8. Aircraft Integral Fuel Tank Corrosion Study

    DTIC Science & Technology

    2007-11-02

    sensor is formed by two concentric metallic electrodes, separated by an insulator material , between which an electric current circulates when a given... materials are used to make the mentioned current, proportional to the concentration of corrosive contaminants in the water and to the amount of microbial...contamination level, detected in the respective fuel tank. REFERENCES 1. C. B. Ward. Corrosion resulting from corrosion fuel tank contamination. Materials

  9. On-line corrosion control in refinery overhead systems

    SciTech Connect

    Correa, L.A.

    1995-11-01

    Corrosion is one of the great causes of accidents and economic losses in petroleum and petrochemical industries. Crude unit overheads are one of the most corrosion affected parts and large amounts of work and money has been spent on its control and prevention. Thus, new materials, inhibitors and monitoring techniques are constantly under testing in order to improve corrosion prevention and plant reliability. Expert Systems are a rising technology in industrial process monitoring and problem diagnosing. This sort of computer program is developed trying to simulate the human expert intelligent behavior in the task of solving a specific problem. The crude units overhead corrosion control is a hard and time consuming task that seems to be a fruitful field to expert systems application.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. Studying localized corrosion using liquid cell transmission electron microscopy.

    PubMed

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

    2015-01-04

    Localized corrosion of Cu and Al thin films exposed to aqueous NaCl solutions was studied using liquid cell transmission electron microscopy (LCTEM). 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.

  16. Study Of Corrosion Of Lead-Sheathed Cables

    NASA Technical Reports Server (NTRS)

    Lee, Rupert U.

    1995-01-01

    Report presents statistical analysis of corrosion failures of lead-sheathed cables that serve as primary communication links at Kennedy Space Center. In study, corrosion-failure data analyzed by use of Weibull distribution in effort to assess effectiveness of cathodic protection and to predict future failures.

  17. 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.

  18. 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).

  19. Heavy Liquid Metal Corrosion of Structural Materials in Advanced Nuclear Systems

    NASA Astrophysics Data System (ADS)

    Caro, M.; Woloshun, K.; Rubio, F.; Maloy, S. A.; Hosemann, P.

    2013-08-01

    Interest in advanced nuclear concepts using liquid metal coolant has increased in the past few years. Liquid metal coolants have been proposed for the next generation of small-sized nuclear reactors, which offer exceptional safety and reliability, sustainability, nonproliferation, and economic competitiveness. Heavy liquid metal coolants are investigated for advanced fast reactors that operate at high temperatures, reaching high efficiencies. Lead and lead-bismuth eutectic (LBE) coolants are also proposed as coolants and targets of accelerator driven systems. High temperature, corrosive environment, high fast neutron flux, high fluence, and radiation damage, among other physical phenomena, challenge the integrity of materials in these advanced systems. Excellent compatibility with the liquid coolant is recognized as a key factor in the selection of structural materials for advanced concepts. In this article, we review materials requirements for heavy metal cooled systems with emphasis on lead and LBE materials corrosion properties. We describe experimental corrosion tests currently ongoing at the Los Alamos National Laboratory (LANL) Development of Lead Alloy Technical Applications (DELTA) loop. DELTA is a facility designed to study the long-term corrosive effects of LBE on structural materials under relevant conditions of chemistry, flow, and temperature. The research studies will provide data of corrosion rates and corrosion mechanisms in selected steel exposed to high velocity (above 2 m/s) in flowing LBE at 500°C. Fundamental research studies will help support conceptual design efforts and further the development of heavy liquid metals technology.

  20. Effects of disinfectant and biofilm on the corrosion of cast iron pipes in a reclaimed water distribution system.

    PubMed

    Wang, Haibo; Hu, Chun; Hu, Xuexiang; Yang, Min; Qu, Jiuhui

    2012-03-15

    The effects of disinfection and biofilm on the corrosion of cast iron pipe in a model reclaimed water distribution system were studied using annular reactors (ARs). The corrosion scales formed under different conditions were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), while the bacterial characteristics of biofilm on the surface were determined using several molecular methods. The corrosion scales from the ARs with chlorine included predominantly α-FeOOH and Fe2O3, while CaPO3(OH)·2H2O and α-FeOOH were the predominant phases after chloramines replaced chlorine. Studies of the consumption of chlorine and iron release indicated that the formation of dense oxide layers and biofilm inhibited iron corrosion, causing stable lower chlorine decay. It was verified that iron-oxidizing bacteria (IOB) such as Sediminibacterium sp., and iron-reducing bacteria (IRB) such as Shewanella sp., synergistically interacted with the corrosion product to prevent further corrosion. For the ARs without disinfection, α-FeOOH was the predominant phase at the primary stage, while CaCO3 and α-FeOOH were predominant with increasing time. The mixed corrosion-inducing bacteria, including the IRB Shewanella sp., the IOB Sediminibacterium sp., and the sulfur-oxidizing bacteria (SOB) Limnobacter thioxidans strain, promoted iron corrosion by synergistic interactions in the primary period, while anaerobic IRB became the predominant corrosion bacteria, preventing further corrosion via the formation of protective layers.

  1. 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.

  2. Simple laser-based pipeline corrosion assessment system

    SciTech Connect

    Bruce, W.A.; Yapp, D.; Barborak, D.M.; Fingerhut, M.P.; Kania, R.

    1997-03-01

    The article focuses on development and use of a simpler laser-based system for accurately and efficiently measuring and assessing corrosion damage on the external surface of an exposed pipeline. The system uses a laser-based range sensor, which relies on optical spray, sensor movement, and the principal of triangulation to construct a three-dimensional measurement. Baseline subtraction, where a polynomial curve-fit is used to approximate the ideal pipe profile above the corroded area, is used. Future profiles are subtracted from the ideal profile, and when differences are significant, corrosion depth measurements are made by constructing normal vectors at points along the ideal profile. The use of such a system for accurately mapping corrosion damage allows more accurate assessments, thereby reducing the number of unnecessary repairs and cut outs, and reduces the risk of non-conservative assessments. The use of this system also results in reduced labor costs associated with mapping corrosion damage and allows the assessment process to be carried out over a much shorter period of time. The system can also be used to develop an accurate correlation between inline inspection (ILI) results and corrosion geometry during the first few excavations following ILI, resulting in the need to excavate fewer areas.

  3. 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.

  4. 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

  5. Study of surface interactions of ionic liquids with aluminium alloys in corrosion and erosion corrosion processes

    NASA Astrophysics Data System (ADS)

    Bermúdez, María-Dolores; Jiménez, Ana-Eva; Martínez-Nicolás, Ginés

    2007-06-01

    Surface interactions of alkylimidazolium ionic liquids (ILs) with aluminium alloy Al 2011 have been studied by immersion tests in seven neat ILs [1- n-alkyl-3-methylimidazolium X - (X = BF 4; n = 2 (IL1), 6 (IL2), 8 (IL3). X = CF 3SO 3; n = 2 (IL4). X = (4-CH 3C 6H 4SO 3); n = 2 (IL5). X = PF 6; n = 6 (IL6)] and 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide (IL7)]. Immersion tests for Al 2011 have also been carried out in 1 wt.% and 5 wt.% solutions of 1-ethyl,3-methylimidazolium tetrafluoroborate (IL1) in water. No corrosion of Al 2011 by neat ILs is observed. The highest corrosion rate for Al 2011 in water is observed in the presence of a 5 wt.% IL1 due to hydrolysis of the anion with hydrogen evolution and formation of aluminium fluoride. Erosion-corrosion processes have been studied for three aluminium alloys (Al 2011, Al 6061 and Al 7075) in a 90 wt.% IL1 solution in water in the presence of α-alumina particles. The erosion-corrosion rates are around 0.2 mm/year or lower, and increase with increasing copper content to give a corrosion resistance order of Al 6061 > Al 7075 > Al 2011. Results are discussed on the basis of scanning electron microscopy (SEM) observations, energy dispersive spectroscopy (EDS) analysis, X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) determinations.

  6. 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.

  7. Review of the studies on fundamental issues in LBE corrosion

    NASA Astrophysics Data System (ADS)

    Zhang, Jinsuo; Li, Ning

    2008-02-01

    Lead bismuth eutectic (LBE) technology is being developed for applications in advanced nuclear systems and high-power spallation neutron targets. In this paper, the current understanding of corrosion and the fundamental issues relevant to corrosion when using LBE as a heavy liquid metal nuclear coolant are reviewed. Corrosion mechanisms and processes in LBE are examined. Prospective methods to mitigate corrosion are briefly surveyed. We then discuss the oxygen control technique for corrosion mitigation in detail, including the range of oxygen concentrations in LBE, oxygen sensors, and the surface oxidation kinetics. Existing experimental results are summarized and reviewed. Theoretical corrosion models for non-isothermal liquid metal loops are refined and compared each other. The applications of these models to a few practical lead-alloy systems are used to illustrate the corrosion mechanisms and the parameter dependency, and to benchmark. Based on the current state of knowledge, a number of R&D tasks are proposed to fill the gaps and firmly establish the scientific underpinning before LBE nuclear coolant technology is ready for programmatic and industrial applications.

  8. Corrosion in the oral cavity--potential local and systemic effects.

    PubMed

    Bergman, M

    1986-03-01

    The main current-generating corrosion cells in the oral cavity are the bimetallic cell and the concentration cell, the latter mainly occurring due to differences in access to oxygen in the various parts of the metallic material. Corrosion resistance is not an intrinsic property of a metal or an alloy for it depends on an interaction with the environment. Thus, the contents of the oral cavity, have a decisive influence. This implies that corrosion tests in vitro are of limited value in predicting the clinical corrosion behaviour of a metallic material. Results from a series of clinical studies concerning a possible relationship between galvanic currents and certain oral and other symptoms in a group of patients who had been referred to the Faculty of Odontology, University of Umeå, are briefly presented. The possibility of local and systemic effects of intra-oral galvanic cells is discussed.

  9. Corrosion of orthodontic brackets in different spices: in vitro study.

    PubMed

    Chaturvedi, T P

    2014-01-01

    Moist environment in the mouth varies and causes variable amounts of corrosion of dental materials. This is of concern particularly when metallic implants, metallic fillings, orthodontic appliances are placed in the hostile electrolytic environment in the human mouth. Components of diet rich in salt and spices are important factors influencing the corrosion of metallic appliances placed in the oral cavity. To study in vitro corrosion of orthodontic metallic brackets immersed in solutions of salt and spices in artificial saliva. Orthodontic brackets were used for corrosion studies in artificial saliva, salt, and spices using electrochemical technique and surface analysis. Electrochemical studies using different parameters were done in solutions of artificial saliva containing salt and spices. Photomicrographs from the optical microscope were also obtained. RESULTS of corrosion studies have clearly demonstrated that certain spices such as turmeric and coriander are effective in reducing corrosion, whereas salt and red chili have been found to enhance it. Surface analysis of small pits present on the surface of the as-received bracket will initiate corrosion which leads to more pitting.

  10. 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...

  11. Copper corrosion & clogging in APS deionized water cooling system

    NASA Astrophysics Data System (ADS)

    Adak, Bijaya

    An extensive amount of work has been performed on copper corrosion in last century due to its abundant use in domestic and industrial water systems. However, work on copper corrosion in deionized water is very limited. The water cooling system of Advanced Photon Source (APS) at Argonne National Laboratory uses deionized water containing very low dissolved oxygen (less than 10 ppb). Therefore, It is expected that copper corrosion would be less in this system. On the contrary, APS suffers significant clogging in its water cooling circuit resulting from the deposition of corrosion product and carries out frequent expensive maintenance to retain the required flow rate. The location of pH and corrosion potential of APS water cooling system is very close to the boundary condition of the two oxides (CuO and Cu 2O) of the Pourbaix diagram of copper. While a single phase presence of either of these two oxides is stable as a protective layer, a mixture of the two oxides is unstable. An unstable protective layer results in spalling of the oxide layer. A fluctuation in water chemistry (which is common in an industrial facility) triggers a phase transformation between these two oxides due to its near boundary values. It was observed that the location of pH and corrosion potential was away from the boundaries in high dissolved oxygen condition (more than 2000 ppm). Hence, the possibility of phase transformation becomes lesser in high dissolved oxygen condition than in low dissolved oxygen condition. A test station, that was a replica of the APS water cooling system, was used to perform experiments in both high and low oxygen condition. It was demonstrated that high oxygen condition results in less clogging than in low oxygen condition. Microstructural characterization was performed on the coupons from test station and on some components from APS to evaluate oxide surface and determine phases. Mechanism of the phase transformation was suggested.

  12. Data Analysis and reduction in Hanford's corrosion monitoring systems

    SciTech Connect

    EDGEMON, G.L.

    1999-06-23

    A project to improve the Hanford Site's corrosion monitoring strategy was started in 1995. The project is designed to integrate EN-based corrosion monitoring into the site's corrosion monitoring strategy. In order to monitor multiple tanks, a major focus of this project has been to automate the data collection and analysis process. Data collection and analysis from the early EN corrosion monitoring equipment (241-AZ-101 and 241-AN-107) was primarily performed manually by a trained operator skilled in the analysis of EN data. Thousands of raw data files were collected, manually sorted and stored. Further statistical analysis of these files was performed by manually stripping out data from thousands of raw data files and calculating statistics in a spreadsheet format. Plotting and other graphical display analyses were performed by manually exporting data from the data files or spreadsheet into another plotting or presentation software package. In 1999, an Amulet/PRP system was procured and employed on the 241-AN-102 corrosion monitoring system. A duplicate system was purchased for use on the upcoming 241-AN-105 system. A third system has been procured and will eventually be used to upgrade the 241-AN-107 system. The Amulet software has greatly improved the automation of waste tank EN data analysis. In contrast with previous systems, the Amulet operator no longer has to manually collect, sort, store, and analyze thousands of raw EN data files. Amulet writes all data to a single database. Statistical analysis, uniform corrosion rate, and other derived parameters are automatically calculated in Amulet from the raw data while the raw data are being collected. Other improvements in plotting and presentation make inspection of the data a much quicker and relatively easy task. These and other improvements have greatly improved the speed at which EN data can be analyzed in addition to improving the quality of the final interpretation. The increase in data automation offered

  13. 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)

  14. Assessment of tap water quality and corrosion scales from the selected distribution systems in northern Pakistan.

    PubMed

    Baig, Shams Ali; Lou, Zimo; Baig, Muzaffar Ali; Qasim, Muhammad; Shams, Dilawar Farhan; Mahmood, Qaisar; Xu, Xinhua

    2017-04-01

    Corrosion deposits formed within drinking water distribution systems deteriorate drinking water quality and resultantly cause public health consequences. In the present study, an attempt was made to investigate the concurrent conditions of corrosion scales and the drinking water quality in selected water supply schemes (WSS) in districts Chitral, Peshawar, and Abbottabad, northern Pakistan. Characterization analyses of the corrosion by-products revealed the presence of α-FeOOH, γ-FeOOH, Fe3O4, and SiO2 as major constituents with different proportions. The constituents of all the representative XRD peaks of Peshawar WSS were found insignificant as compared to other WSS, and the reason could be the variation of source water quality. Well-crystallized particles in SEM images indicated the formation of dense oxide layer on corrosion by-products. A wider asymmetric vibration peak of SiO2 appeared only in Chitral and Abbottabad WSS, which demonstrated higher siltation in the water source. One-way ANOVA analysis showed significant variations in pH, turbidity, TDS, K, Mg, PO4, Cl, and SO4 values, which revealed that these parameters differently contributed to the source water quality. Findings from this study suggested the implementation of proper corrosion prevention measures and the establishment of international collaboration for best corrosion practices, expertise, and developing standards.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. Army Aviation Corrosion Engineering Case Studies

    DTIC Science & Technology

    2010-02-10

    Support Rod 7 Yourfilename.ppt H-47 FRIES Bar Support Rod Corrosion • Resolution • ASAM H-47-09- ASAM -04 is issued • Requires inspection and grading...Analysis • Failure Analysis • Risk Analysis 12 Yourfilename.ppt H-60 SAS Link SCC Failure • The Resolution • Issue a message H060-10- ASAM -04 • Inspect all

  6. Kinetic studies of stress-corrosion cracking

    NASA Technical Reports Server (NTRS)

    Noronha, P. J.

    1977-01-01

    Use of time-to-failure curves for stress-corrosion cracking processes may lead to incorrect estimates of structural life, if material is strongly dependent upon prestress levels. Technique characterizes kinetics of crackgrowth rates and intermediate arrest times by load-level changes.

  7. Studying localized corrosion using liquid cell transmission electron microscopy

    DOE PAGES

    Chee, See Wee; Pratt, Sarah H.; Hattar, Khalid; ...

    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.

  8. 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.

  9. 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. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. 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.

  11. Development of boundary element analysis system for corrosion protection design

    SciTech Connect

    Miyasaka, M.; Takayama, H.; Amaya, K.; Aoki, S.

    1997-12-01

    In order to make a practical application of boundary element method (BEM) for quantitative predictions of cathodic protection and macro-cell corrosion, a BEM analysis system based on the 2D, 3D and axi-symmetric programs was developed. The system consists of a polarization curve database and programs to perform element discretization, input file set-up, boundary element analysis and graphic display of input and output data. Even an engineer with no knowledge of corrosion will be able to operate this system easily and perform effective analyses. The usefulness of the system was demonstrated by an application example for the cathodic protection design of a seawater pump. In this system, the effects of flow-rate and time on the polarization curve can be taken into account for defining the boundary conditions.

  12. An EIS study of the corrosive behavior of propellant hydrazine

    SciTech Connect

    Bhardwaj, R.C.; Davis, D.D.; Baker, D.L.

    1996-11-01

    Corrosion behavior of iron (Fe), nickel (Ni), cobalt (Co) and titanium (Ti) alloys in hydrazine (N{sub 2}H{sub 4}) and CO{sub 2}-contaminated N{sub 2}H{sub 4} were studied using Electrochemical Impedance Spectroscopy (EIS). The corrosion rate of Fe and Ti alloys increased in hydrazine and CO{sub 2}-contaminated hydrazine as a function of time and CO{sub 2} concentration; however, the corrosion rate of Ni and Co alloy decreased as a function of time in contaminated hydrazine. The corrosion rate of Ni and Co alloys were significantly higher when compared with corrosion rates of Fe and Ti alloys in CO{sub 2}-contaminated hydrazine. The effects of CO{sub 2} concentration on corrosion rate has been explained in terms of alloy composition and the role of CO{sub 2} in forming carbazic acid and its metal complexes. The polarization values obtained from EIS studies were used to calculate the exchange current density and decomposition rate of hydrazine.

  13. 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

  14. A study on the effect of magnetic field on the corrosion behavior of materials

    NASA Astrophysics Data System (ADS)

    Pondichery, Soundarya

    Corrosion causes deterioration of a material due to its environment. Corrosion control has been one of the biggest challenges in most industries since many years. There are various notable and unknown factors that influence the rate of corrosion of a certain material/environment system. Magnetic fields and their driven effects on an electrochemical system has been recently gained interest. Various magnetic field driven forces occurring in an electrolyte have been reported during an electrochemical reaction. Lorentz force driven convection in the electrolyte, known as MHD effect and paramagnetic gradient forces are reported to be the most effective. This research studies the effects of an external magnetic field on the electrochemical nature of materials in 3.5% NaCl solution. To understand and analyze magnetic field effects on a wide range of materials, both ferromagnetic and non-magnetic materials which are active, active-passive type are studied in near sea water solution i.e. 3.5% NaCl solution. Potentiodynamic polarization and corrosion potential vs time tests were carried out to study and analyze corrosion behavior in 3.5% NaCl solution. Corrosion tests results were obtained both with and without the influence of an external magnetic field of 0.75T. On comparing the electrochemical analysis results of both conditions in 3.5% NaCl solution, it clearly depicts the effect of an external magnetic field on the corrosion potential and corrosion rate. In the case of ferromagnetic materials like 416 SS and 1018 carbon steel, a cathodic shift of the corrosion potential and increase in the corrosion rate was observed. While for ferrous but non-magnetic and passivating material like 304 SS, no effect of the magnetic field was observed which can be attributed to its non-magnetic austenitic phase and highly stable oxide formation tendency. Also, no effect was observed on the non-ferrous alloys like Ti alloy (Ti6Al4V) and Zn due to not only because of diamagnetic nature of

  15. 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.

  16. 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.

  17. 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

  18. Ballast Water Treatment Corrosion Scoping Study

    DTIC Science & Technology

    2011-10-01

    12  Table 7. Mass-loss derived corrosion rates for stainless steels exposed to various ClO2 solutions... ClO2 ). Chlorine dioxide is unstable when stored as a gas so it is typically generated onsite and injected into the ballast water stream. There are...acid are injected into the mixing chamber. The formation of chlorine dioxide is illustrated in Equation 13 ( ClO2 Technology, 2011). Equation 13

  19. Atomic level characterization in corrosion studies

    NASA Astrophysics Data System (ADS)

    Marcus, Philippe; Maurice, Vincent

    2017-06-01

    Atomic level characterization brings fundamental insight into the mechanisms of self-protection against corrosion of metals and alloys by oxide passive films and into how localized corrosion is initiated on passivated metal surfaces. This is illustrated in this overview with selected data obtained at the subnanometre, i.e. atomic or molecular, scale and also at the nanometre scale on single-crystal copper, nickel, chromium and stainless steel surfaces passivated in well-controlled conditions and analysed in situ and/or ex situ by scanning tunnelling microscopy/spectroscopy and atomic force microscopy. A selected example of corrosion modelling by ab initio density functional theory is also presented. The discussed aspects include the surface reconstruction induced by hydroxide adsorption and formation of two-dimensional (hydr)oxide precursors, the atomic structure, orientation and surface hydroxylation of three-dimensional ultrathin oxide passive films, the effect of grain boundaries in polycrystalline passive films acting as preferential sites of passivity breakdown, the differences in local electronic properties measured at grain boundaries of passive films and the role of step edges at the exposed surface of oxide grains on the dissolution of the passive film. This article is part of the themed issue 'The challenges of hydrogen and metals'.

  20. Atomic level characterization in corrosion studies.

    PubMed

    Marcus, Philippe; Maurice, Vincent

    2017-07-28

    Atomic level characterization brings fundamental insight into the mechanisms of self-protection against corrosion of metals and alloys by oxide passive films and into how localized corrosion is initiated on passivated metal surfaces. This is illustrated in this overview with selected data obtained at the subnanometre, i.e. atomic or molecular, scale and also at the nanometre scale on single-crystal copper, nickel, chromium and stainless steel surfaces passivated in well-controlled conditions and analysed in situ and/or ex situ by scanning tunnelling microscopy/spectroscopy and atomic force microscopy. A selected example of corrosion modelling by ab initio density functional theory is also presented. The discussed aspects include the surface reconstruction induced by hydroxide adsorption and formation of two-dimensional (hydr)oxide precursors, the atomic structure, orientation and surface hydroxylation of three-dimensional ultrathin oxide passive films, the effect of grain boundaries in polycrystalline passive films acting as preferential sites of passivity breakdown, the differences in local electronic properties measured at grain boundaries of passive films and the role of step edges at the exposed surface of oxide grains on the dissolution of the passive film.This article is part of the themed issue 'The challenges of hydrogen and metals'. © 2017 The Author(s).

  1. 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.

  2. In vitro studying corrosion behavior of porous titanium coating in dynamic electrolyte.

    PubMed

    Chen, Xuedan; Fu, Qingshan; Jin, Yongzhong; Li, Mingtian; Yang, Ruisong; Cui, Xuejun; Gong, Min

    2017-01-01

    Porous titanium (PT) is considered as a promising biomaterials for orthopedic implants. Besides biocompatibility and mechanical properties, corrosion resistance in physiological environment is the other important factor affecting the long stability of an implant. In order to investigate the corrosion behavior of porous titanium implants in a dynamic physiological environment, a dynamic circle system was designed in this study. Then a titanium-based implant with PT coating was fabricated by plasma spraying. The corrosion resistance of PT samples in flowing 0.9% NaCl solution was evaluated by electrochemical measurements. Commercial pure solid titanium (ST) disc was used as a control. The studies of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that the pores in the PT play a negetive part in corrosion resistance and the flowing electrolyte can increase the corrosive rate of all titanium samples. The results suggest that pore design of titanium implants should pay attention to the effect of dynamic process of a physiological environment on the corrosion behavior of implants.

  3. A computational study on corrosion inhibition performances of novel quinoline derivatives against the corrosion of iron

    NASA Astrophysics Data System (ADS)

    Erdoğan, Şaban; Safi, Zaki S.; Kaya, Savaş; Işın, Dilara Özbakır; Guo, Lei; Kaya, Cemal

    2017-04-01

    In this computational study, the adsorption and corrosion inhibition properties of some novel quinoline derivatives namely, 2-amino-7-hydroxy-4-phenyl-1,4-dihydroquinoline-3-carbonitrile (Q1), 2-amino-7-hydroxy-4-(p-tolyl)-1,4-dihydroquinoline-3-carbonitrile (Q2), 2-amino-7-hydroxy-4-(4-methoxyphenyl)-1,4-dihydroquinoline-3-carbonitrile) (Q3) and 2-amino-4-(4-(dimethylamino)phenyl)-7-hydroxy-1,4-dihydroquinoline-3-carbonitrile (Q4) on the corrosion of iron were investigated using quantum chemical and molecular dynamics simulation approaches. Quantum chemical calculations section of the study provides enough calculation and discussion on the relationship between corrosion inhibition and global reactivity descriptors such as EHOMO, ELUMO, HOMO-LUMO energy gap (ΔE), chemical hardness (η), softness (σ), electronegativity (χ), chemical potential (μ), electrophilicity (ω), nucleophilicity (ɛ), electrons transferred from inhibitors to metal surface (ΔN), initial molecule-metal interaction energy (Δψ), total electronic energy (E), the energy change during electronic back-donation process (ΔEb-d). The adsorption behaviors of studied compounds on Fe (110) surface were investigated with the help of molecular dynamics simulation approach. The binding energies calculated on Fe (110) surface of mentioned quinoline derivatives followed the order: Q4 > Q3 > Q2 > Q1. It should be noted that the results obtained in the study are in good agreement with experimental inhibition efficiency results earlier reported.

  4. Identification of corrosion modes in steam pipes from the secondary system at Indian Point 2

    SciTech Connect

    Gmurczyk, M.U.; Barkatt, A.; Ballard, D.; Cherepakbov, G.; Kessler, W.; Burns, R.

    1998-12-31

    Failure analysis of specimens removed from secondary side piping at Indian Point 2 was performed. The study included visual examination, wall thickness measurements, metallographic (optical and SEM) studies, and measurements of mechanical properties. Chemical analysis was carried out on the bulk metal, the surface region, and the overlying deposits. Oxide speciation was performed using XRD and Moessbauer spectroscopy. The results of the evaluation showed that erosion-corrosion was the principal pipe degradation mechanism. The factors contributing to significant erosion-corrosion were found to include a lower Cr content of the steel than needed to suppress erosion-corrosion, relatively low pH (8.8--9.2 during most of the period of plant operation), and high flow rates. The combination of these factors also gave rise to relatively high transport of iron oxides (predominantly magnetite) in the secondary system, which further increased the extent of erosion-corrosion. One important finding was the observation that magnetite particles in the wet steam were apparently responsible for the significant extent of erosion-corrosion of the pipes.

  5. Digital mapping of corrosion risk in coastal urban areas using remote sensing and structural condition assessment: case study in cyprus

    NASA Astrophysics Data System (ADS)

    Neocleous, Kyriacos; Christofe, Andreas; Agapiou, Athos; Evagorou, Evagoras; Themistocleous, Kyriacos; Hadjimitsis, Diofantos

    2016-01-01

    Atmospheric corrosion is one of the main factors leading to performance deterioration of reinforced concrete buildings; and, hence, periodic structural condition monitoring is required to assess and repair the adverse effects of corrosion. However, this can become a cumbersome and expensive task to undertake for large populations of buildings, scattered in large urban areas. To optimize the use of available resources, appropriate tools are required for the assessment of corrosion risk of reinforced concrete construction. This paper proposes a framework for the production of digital corrosion risk maps for urban areas; Cyprus was used as a case study. This framework explored multi-temporal satellite remote sensing data from the Landsat sensors as well as corrosion risk factors derived from the results of a recently completed research project, entitled "STEELCOR". This framework was used to develop two corrosion risk scenarios within Geographical Information Systems, and to produce corrosion risk maps for three coastal cities of Cyprus. The thematic maps indicated that, for slight corrosion damage, the distance of reinforced concrete buildings from the coast was more influential than the building age. While, for significant corrosion damage, the maps indicated that the age of RC buildings was more influential than the distance from the coast.

  6. Corrosion cracking

    SciTech Connect

    Goel, V.S.

    1985-01-01

    This book presents the papers given at a conference on alloy corrosion cracking. Topics considered at the conference included the effect of niobium addition on intergranular stress corrosion cracking, corrosion-fatigue cracking in fossil-fueled-boilers, fracture toughness, fracture modes, hydrogen-induced thresholds, electrochemical and hydrogen permeation studies, the effect of seawater on fatigue crack propagation of wells for offshore structures, the corrosion fatigue of carbon steels in seawater, and stress corrosion cracking and the mechanical strength of alloy 600.

  7. Corrosion in a distribution system: Steady water and its composition.

    PubMed

    Nawrocki, Jacek; Raczyk-Stanisławiak, Urszula; Swietlik, Joanna; Olejnik, Anna; Sroka, Mirosława J

    2010-03-01

    Corrosion processes in drinking water distribution systems have been investigated for years. This paper proves the existence of a layer of steady water surrounding and partly filling corrosion scale in corroded water pipes. It is expected that steady water may substantially influence the corrosion. The idea of steady water explains why longer retention times would lead to more turbid waters containing more suspended Fe oxides (hydroxides). During stagnation period stagnant water mixes partially with steady water and the compensation of ions' concentration as well as particle diffusion is observed. Steady water is rich in ions and has reductive properties causing quick disappearance of nitrates and unwanted ammonia formation. Ammonia in turn may be responsible for fast oxygen and chlorine decay in the distribution system due to nitrification. Nitrates may also undergo denitrification in steady water, i.e. they would support bacterial existence in the distribution system. Such an environment makes favourable conditions for sulphate reducing bacteria and in fact in all of the steady water samples we have detected sulphides. Moreover, our results have shown that considerable amounts of assimilable organic carbon (AOC) can be formed in the corroded distribution system. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. 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

  9. 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.

  10. 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

  11. Corrosion and Biofouling of OTEC System Surfaces - Design Factors

    DTIC Science & Technology

    1978-11-01

    coupled with fracture mechan- ics can be used to determine the maximum flaw size that can be tolerated in a given material and to define the level of...inspection required to locate flaws of this critical size . ILI The following materials are recognized to be susceptible to stress corrosion cracking in...large amounts of downtime. Since OTEC plants Pe significantly different from any system built to date in both size and operating characteristics, there is

  12. 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.

  13. 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.

  14. 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.

  15. Hydrofluoric Acid Corrosion Study of High-Alloy Materials

    SciTech Connect

    Osborne, P.E.

    2002-09-11

    proven to have a finite life due to failure, most often at the bellows flange ring. It was discovered that the entire bellows assembly was not all alloy 600 but that alloy 600 bellows had been welded to a stainless steel alloy 316 (SS-316) flange ring. A previous study documents and addresses this problem.1 The fabricators of the valves immediately corrected the problem and began fabricating all wetted parts of the bellows assembly from alloy 600. At the same time, the fabricators began to make alloy C-276 valve bodies and stem tips available for sale. This material is known to be superior to the alloy 400 valve bodies and stem tips of the standard UG valves that had already been installed in the CP. A decision was made to purchase alloy C-276 bodies and stem tips and to change out those alloy 400 components that had already been installed. Due to the enormity of this task (both in terms of time and money), it was desirable to determine the longevity of alloy C-276 vs alloy 400 components in a side-by-side comparison. Also of interest was the question of how long the new (all-alloy 600) bellows would last in comparison with the original alloy 600/SS-316 bellows. A basic HF corrosion test was proposed to compare corrosion rates of several high-alloy materials. Because much of the alloy 400 in the system had been gold plated, some gold-plated alloy 400 coupons were included. Due to time and funding limitations, actual CP variables such as temperature and pressure were not duplicated. Instead, a simple partial-immersion test at ambient temperature was conducted. The purpose of this test was to gain information on the rate of corrosion of different alloys in the CP and to attempt to derive some idea of their expected lifetimes in the operating environment.

  16. Sulphonamides as corrosion inhibitor: Experimental and DFT studies

    NASA Astrophysics Data System (ADS)

    Obayes, Hasan R.; Al-Amiery, Ahmed A.; Alwan, Ghadah H.; Abdullah, Thamer Adnan; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2017-06-01

    Inhibitors are synthetic and natural molecules have various functional groups like double or triple bonds and heteroatoms; N, O or S, which permit adsorption onto the MS (metal surface). These inhibitors have the ability to adsorb onto the MS and block the active site that was reducing the corrosion rate. Inhibition efficiencies of the investigated compounds: Sulfacetamide (SAM), Sulfamerazine (SMR), Sulfapyridine (SPY) and Sulfathiazole (STI), as inhibitors in corrosive solution were evaluated based on weight loss technique. Nitro and Amino groups were chosen for the study of the substituted reaction of four corrosion inhibitor compounds: SAM, SMR, SPY and STI, theoretically utilizing the thickness capacities hypothesis DFT (density functions theory) method with the level [rB3LYP/6-311G(d,p)]. Our research demonstrated that the nitration of studied molecules lead to a diminishing in inhibition efficiencies, group lead to an increase in inhibition efficiency. Compared with corrosion inhibitor molecules these results gave a significant improvement in inhibition efficiency for corrosion inhibitor molecules.

  17. 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.

  18. Antimony tartrate corrosion inhibitive composition for coolant systems

    SciTech Connect

    Payerle, N.E.

    1987-08-11

    An automobile coolant concentrate is described comprising (a) a liquid polyhydric alcohol chosen from the group consisting of ethylene glycol, propylene glycol, diethylene glycol and mixtures thereof, and (b) corrosion inhibitors in a corrosion inhibitory amount with respect to corrosion of lead-containing solders, the corrosion inhibitors comprising (i) an alkali metal antimony tartrate, and (ii) an azole compound.

  19. 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.

  20. 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.

  1. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Stem Migration and Fretting Corrosion of the Antirotation Pin in the K2/Apex Hip System.

    PubMed

    Kent, Michael; Edmondson, Mark; Ebert, Jay; Nivbrant, Nils; Kop, Alan; Wood, David; De Steiger, Richard

    2016-03-01

    Many exchangeable neck hip systems have been withdrawn because of fretting corrosion at the neck/stem coupling. Our prospective randomized study evaluating stem stability (Roentgen stereophotogrammetric analysis, dual-energy x-ray absorptiometry) and clinical outcomes between the K2/Apex hip systems was ceased early because of a withdrawal of the stems which had an unfavorably high early revision rate reported in the Australian Orthopaedic Association National Joint Registry (9.3% at 3 years). At 2 years, there are no clinical differences between the stems. Roentgen stereophotogrammetric analysis has identified a high proportion of potentially concerning subsidence and retroversion in both groups, more marked in the K2 stem, although mostly in asymptomatic patients. Dual-energy x-ray absorptiometry has shown similar bone density around the stems. Retrieval analysis of 3 study patients showed fretting corrosion of the antirotation pin and aseptic lymphocyte-dominated vasculitis-associated lesion, with no relationship to bearing type or size. Analysis of 7 further nonstudy K2/Apex stems confirmed similar corrosion. This study shows potentially concerning subsidence of both stems and is the first to describe corrosion at the neck-stem interface and a relationship to metal-related pathology. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  3. 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.

  4. 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.

  5. Assessment of groundwater corrosiveness for unconfined aquifer system at Kalpakkam.

    PubMed

    Sasidhar, P; Vijay Kumar, S B

    2008-10-01

    Groundwater samples from the shallow unconfined aquifer were collected from fifteen borewells in Kalpakkam nuclear plant site and were analysed for various physico-chemical parameters. The pH, temperature, salinity, TDS and EC were measured in the field. The borewell samples were analysed in the laboratory for Ca(2+), Mg(2+), Na(+), Cl(-), CO(2-)(3), HC(O-)(3), N(O-)(3) and SO(2-)(4). The Piper Trilinear diagram showed that majority of the borewell samples fall in Na - Cl +SO(4) type and Na - CO(3)+HCO(3) type. The Cl: HCO3 ratio of some borewell samples are categorized under injuriously contaminated to highly injurious type. The higher salinity levels encountered in some borewells emphasized the need for better understanding of groundwater corrosiveness. Accordingly, the Langeliar saturation Index (SI), Aggressivity index (AI) and Larson ratio (LnR) were evaluated for assessing the corrosive nature of the groundwater. The saline water incursion in the southern part of the study area increased the ionic concentration of Cl(-) and [Formula: see text] that made the groundwater corrosive.

  6. 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).

  7. 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.

  8. 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)

  9. 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)

  10. Effect of pipe corrosion scales on chlorine dioxide consumption in drinking water distribution systems.

    PubMed

    Zhang, Zhe; Stout, Janet E; Yu, Victor L; Vidic, Radisav

    2008-01-01

    Previous studies showed that temperature and total organic carbon in drinking water would cause chlorine dioxide (ClO(2)) loss in a water distribution system and affect the efficiency of ClO(2) for Legionella control. However, among the various causes of ClO(2) loss in a drinking water distribution system, the loss of disinfectant due to the reaction with corrosion scales has not been studied in detail. In this study, the corrosion scales from a galvanized iron pipe and a copper pipe that have been in service for more than 10 years were characterized by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The impact of these corrosion scale materials on ClO(2) decay was investigated in de-ionized water at 25 and 45 degrees C in a batch reactor with floating glass cover. ClO(2) decay was also investigated in a specially designed reactor made from the iron and copper pipes to obtain more realistic reaction rate data. Goethite (alpha-FeOOH) and magnetite (Fe(3)O(4)) were identified as the main components of iron corrosion scale. Cuprite (Cu(2)O) was identified as the major component of copper corrosion scale. The reaction rate of ClO(2) with both iron and copper oxides followed a first-order kinetics. First-order decay rate constants for ClO(2) reactions with iron corrosion scales obtained from the used service pipe and in the iron pipe reactor itself ranged from 0.025 to 0.083 min(-1). The decay rate constant for ClO(2) with Cu(2)O powder and in the copper pipe reactor was much smaller and it ranged from 0.0052 to 0.0062 min(-1). Based on these results, it can be concluded that the corrosion scale will cause much more significant ClO(2) loss in corroded iron pipes of the distribution system than the total organic carbon that may be present in finished water.

  11. Titanium Corrosion Mechanisms in the Oral Environment: A Retrieval Study

    PubMed Central

    Rodrigues, Danieli C.; Valderrama, Pilar; Wilson, Thomas G.; Palmer, Kelli; Thomas, Anie; Sridhar, Sathyanarayanan; Adapalli, Arvind; Burbano, Maria; Wadhwani, Chandur

    2013-01-01

    Corrosion of titanium dental implants has been associated with implant failure and is considered one of the triggering factors for peri-implantitis. This corrosion is concerning, because a large amount of metal ions and debris are generated in this process, the accumulation of which may lead to adverse tissue reactions in vivo. The goal of this study is to investigate the mechanisms for implant degradation by evaluating the surface of five titanium dental implants retrieved due to peri-implantitis. The results demonstrated that all the implants were subjected to very acidic environments, which, in combination with normal implant loading, led to cases of severe implant discoloration, pitting attack, cracking and fretting-crevice corrosion. The results suggest that acidic environments induced by bacterial biofilms and/or inflammatory processes may trigger oxidation of the surface of titanium dental implants. The corrosive process can lead to permanent breakdown of the oxide film, which, besides releasing metal ions and debris in vivo, may also hinder re-integration of the implant surface with surrounding bone. PMID:28788388

  12. Review and Study of Physics Driven Pitting Corrosion Modeling in 2024-T3 Aluminum Alloys (Postprint)

    DTIC Science & Technology

    2015-05-01

    AFRL-RX-WP-JA-2015-0218 REVIEW AND STUDY OF PHYSICS DRIVEN PITTING CORROSION MODELING IN 2024-T3 ALUMINUM ALLOYS (POSTPRINT) Lingyu...2014 – 1 April 2015 4. TITLE AND SUBTITLE REVIEW AND STUDY OF PHYSICS DRIVEN PITTING CORROSION MODELING IN 2024-T3 ALUMINUM ALLOYS (POSTPRINT) 5a...12.2086274. 14. ABSTRACT Material degradation due to corrosion and corrosion fatigue has been recognized to significantly affect the airworthiness of

  13. 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.

  14. Seminole Electric FGD study reveals corrosion mechanisms, duct material performance

    SciTech Connect

    Wess, T.J.; Crum, J.R.; Shoemaker, L.E.

    1994-12-01

    This article describes how once the corrosion rates of the materials used in the construction of scrubbers are known, specifying for longevity becomes an easier task. To properly evaluate the corrosion resistance of the materials used to fabricate the ducts, dampers, structural supports and other elements of a particular system, a testing scheme that systematically exposes material samples to the many environments representing areas of varying corrosivity is ideal. Because the exact composition, pH, and temperature of liquids and vapors in these areas are usually not known, gathering and analyzing samples of these elements is a prudent part of a systems' evaluation. Field testing of this type was conducted at the Seminole Generating Station which consists of two 650-MW coal-fired electric generating units that typically burn western Kentucky and eastern Illinois sub-bituminous coal with a sulfur content up to 3% and a 0.2%--0.3% chloride content. The plant has a typical wet limestone FGD system that sprays a solution of crushed limestone downward in a vertical rubber-lined scrubber module against a rising flue gas flow stream. There are five parallel scrubber modules available and a direct chimney bypass line that is used only during start up or during emergency conditions. Specially-welded test panels containing four different alloys and two weld filler metals were used in the field tests.

  15. Nitrite reduction and formation of corrosion coatings in zerovalent iron systems.

    PubMed

    Huang, Yong H; Zhang, Tian C

    2006-08-01

    Batch tests were conducted to investigate nitrite reduction in a zerovalent iron (Fe0) system under various conditions. Nitrite at 1.4 mM initial concentration was slowly reduced to nitrogen gas in the first stage (days 1-6), which was mediated by an amorphous, Fe(II)-rich iron oxide coating. The second stage (days 7-14) featured a rapid reduction of nitrite to both ammonia and nitrogen gas and the formation of a more crystalline, magnetite form iron oxide coating. Water reduction by Fe0 occurred concurrently with nitrite reduction from the beginning and contributed significantly to the overall iron corrosion. Nitrite at 14 mM was found to passivate the surface of Fe0 grains with respect to nitrite reduction. Adding aqueous Fe2+ significantly accelerated reduction of nitrite by Fe0 to nitrogen gas with lepidocrocite as the main iron corrosion product. Substantially, though still substoichiometrically, 0.55 mol of Fe2+ were concomitantly consumed per 1.0 mol nitrite reduction, indicating that Fe0 was the main electron source. In the presence of Fe2+, nitrite reduction out-competed water reduction in terms of contributing to the overall iron corrosion. Results of this study help understand complicated interactions between water reduction and nitrite reduction, the roles of surface-bound Fe2+, and the evolution of the iron corrosion coating.

  16. Studies of volatile high temperature corrosion products via the free-jet MBMS technique

    SciTech Connect

    Jacobson, N.S.

    1995-03-01

    In high temperature applications such as heat engines, heat exchangers, and chemical process plants, metal and ceramic structural materials are exposed to harsh chemical environments. It is important to understand the mechanism of corrosion of these materials under such conditions. Most laboratory studies of corrosion involve a sensitive microbalance with the sample suspended in a furnace and particular gas atmosphere (thermogravimetric apparatus--TGA). This system allows one to follow the kinetics of reaction and then characterize the corrosion products. Corrosion products are often condensed phase oxides, sulfides, carbides, etc. However, they may often be volatile products such as volatile oxides, hydroxides, chlorides, and oxychlorides. In a TGA, these form as down-stream deposits, which must be chemically analyzed after an experiment. In such a {open_quotes}pseudo-transpiration{close_quotes} experiment, speculations can then be made regarding the composition of these vapor species. Clearly, an in-situ mass spectrometric sampling method is far superior for such analysis. The free-jet expansion, molecular beam mass spectrometric technique allows direct identification of these species. The features of this technique--a rapid transition to collisionless flow, beam cooling, and a high velocity molecular beam--preserve the chemical and dynamic integrity of the beam. In this paper, several studies on volatile corrosion products will be summarized. It will be shown how the mass spectrometric results are combined with other data to elucidate the reaction mechanism. These studies fall into two categories: volatile chlorides and oxychlorides, and volatile hydroxides. Corrosion by chlorine occurs in waste incineration and chemical process plants; formation of volatile hydroxides occurs in combustion environments since water is always a product of combustion.

  17. General Corrosion Resistance Comparisons of Medium- and High-Strength Aluminum Alloys for DOD Systems Using Laboratory-Based Accelerated Corrosion Methods

    DTIC Science & Technology

    2009-09-01

    General Corrosion Resistance Comparisons of Medium- and High-Strength Aluminum Alloys for DOD Systems Using Laboratory-Based Accelerated... Aluminum Alloys for DOD Systems Using Laboratory-Based Accelerated Corrosion Methods Brian E. Placzankis Weapons and Materials Research Directorate...March 2006–October 2008 4. TITLE AND SUBTITLE General Corrosion Resistance Comparisons of Medium- and High-Strength Aluminum Alloys for DOD

  18. A Survey of Corrosion and Conditions of Corrosion Protection Systems in Civil Works Structures of the U.S. Army Corps of Engineers

    DTIC Science & Technology

    2014-09-01

    hydraulic steel structures ( HSS ) throughout its 45 districts. Many of these structures suffer from the adverse effects of cor- rosion. Efforts to minimize...maintenance are crucial elements of the corrosion protection systems that will allow continued safe use of HSS . Many of the Corps’ HSS are aged beyond...the condition of HSS within select Corps districts, their current corrosion protection systems, the degree to which corrosion monitoring and

  19. More experiences with corrosion and fouling in a refinery amine system

    SciTech Connect

    Litschewski, M.J.

    1996-08-01

    This paper describes a roller coaster ride of corrosion and subsequent fouling in a Refinery MDEA system. The accelerated corrosion was first initiated by addition of caustic and the following up and down corrosion rate was a result of operating conditions imposed by increased sour crude charge, fouling and misapplication of MDEA. System variables that were controlled during this period included equipment metallurgy, the addition of caustic to neutralize heat stable salts (HSS), ion exchange to remove HSS and sodium, amine circulation rate, reboiler steam rate and the injection of a corrosion inhibitor.

  20. 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.

  1. Feasibility Study of Non-Destructive Techniques to Measure Corrosion in SAVY Containers

    SciTech Connect

    Davenport, Matthew Nicholas

    2016-07-15

    Stainless Steel SAVY containers are used to transport and store nuclear material. They are prone to interior corrosion in the presence of certain chemicals and a low-oxygen environment. SAVY containers also have relatively thin walls to reduce their weight, making their structural integrity more vulnerable to the effects of corrosion. A nondestructive evaluation system that finds and monitors corrosion within containers in use would improve safety conditions and preclude hazards. Non-destructive testing can determine whether oxidation or corrosion is occurring inside the SAVY containers, and there are a variety of non-destructive testing methods that may be viable. The feasibility study described will objectively decide which method best fits the requirements of the facility and the problem. To improve efficiency, the containers cannot be opened during the non-destructive examination. The chosen technique should also be user-friendly and relatively quick to apply. It must also meet facility requirements regarding wireless technology and maintenance. A feasibility study is an objective search for a new technology or product to solve a particular problem. First, the design, technical, and facility feasibility requirements are chosen and ranked in order of importance. Then each technology considered is given a score based upon a standard ranking system. The technology with the highest total score is deemed the best fit for a certain application.

  2. [Study of an optical fiber grating sensor for monitoring corrosion of reinforcing steel].

    PubMed

    Li, Jun; Wu, Jin; Gao, Jun-qi

    2010-01-01

    Based on the principle of the fiber Bragg grating strain sensor as well as the volume expansion of the reinforcing steel due to corrosion, an optical fiber grating sensor for monitoring corrosion of reinforcing steel and the method of temperature compensation were studied in the present paper. The sensor construction is that one Bragg grating is stuck on the inner center of two bars against each other, and the reinforcement volume as well as the diameter will expand due to corrosion. Based upon sensing mechanism, monitoring will be carried out by transforming the diameter increase to the fiber strain, and as a result the degree and rate of reinforcement corrosion can be obtained. The principle of corrosion monitoring is that the strain induced by corrosion and temperature fluctuation is measured by a reinforcing steel fiber grating sensor. At the same time, the strain induced by temperature fluctuation is also measured by an individual stainless fiber grating sensor. Therefore by two independent fiber grating sensors, the volume changed by corrosion can be separated. By the concrete encapsulating and embedding method of FBG corrosion sensor, the degree of corrosion of reinforcing reinforcement will be measured directly, which is not affected by corrosion factors and can be used in the early corrosion monitoring of reinforcement in concrete structures. Finally the relationship between corrosion rate and shift in center wavelength was calibrated by experiment.

  3. Corrosion studies of LiH thin films

    NASA Astrophysics Data System (ADS)

    Tonks, J. P.; King, M. O.; Galloway, E. C.; Watts, J. F.

    2017-02-01

    Thin films of LiH and its corrosion products were studied using temperature programmed decomposition (TPD), x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Thin films were grown on Ni(100) in an ultra high vacuum system using an electron beam evaporator. Characteristic Li KLL AES peaks were identified for Li, LiH, Li2O and LiOH which facilitated identification of thin film composition. XPS of the O 1s region revealed three distinct chemical shifts which were attributed to Li2O, LiOH and chemisorbed H2O. We show that exposing LiH to very low H2O partial pressures results in formation of LiOH/Li2O domains on LiH. We also show that these XPS peaks can be linked to reaction mechanisms in the TPD profiles. TPD traces have been explicitly modelled to determine the activation energies of the reactions and compare favourably with previous measurements on bulk LiH samples.

  4. High-temperature corrosion in advanced combustion systems

    SciTech Connect

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

    1993-11-01

    Conceptual designs of advanced combustion systems that utilize coal as a feedstock require high temperature furnaces and heat transfer surfaces capable of operation at much elevated temperatures than those prevalent in current coal-fired power plants. The combination of elevated temperatures and hostile combustion environments necessitate development/application of advanced ceramic materials in these designs. The present paper characterizes the chemistry of coal-fired combustion environments over a wide temperature range of interest in these systems and discusses preliminary experimental results on several materials with potential for application in these systems. An experimental program has been initiated to evaluate materials for advanced combustion systems. Several candidate materials have been identified for evaluation. The candidates included advanced metallic alloys, monolithic ceramics, ceramic particulate/ceramic matrix composites, ceramic fiber/ceramic matrix composites, and ceramic whisker/ceramic matrix composites. The materials examined so far included nickel-base superalloys, alumina, stabilized zirconia, different types of silicon carbide, and silicon nitride. Coupon specimens of several of the materials have been tested in an air environment at 1000, 1200, and 1400{degree}C for 168 h. In addition, specimens were exposed to sodium-sulfate-containing salts at temperatures of 1000 and 1200{degree}C for 168 h. Extensive microstructural analyses were conducted on the exposed specimens to evaluate the corrosion performance of the materials for service in air and fireside environments of advanced coal-fired boilers. Additional tests are underway with several of the materials to evaluate their corrosion performance as a function of salt chemistry, alkali vapor concentration, gas chemistry, exposure temperature, and exposure time.

  5. 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.

  6. Long-term corrosion study at nuclear power plant Bohunice (Slovakia)

    NASA Astrophysics Data System (ADS)

    Slugen, V.; Lipka, J.; Dekan, J.; Tóth, I.; Smieško, I.

    2010-03-01

    Steam generators of four VVER-440 units at nuclear power plants V-1 and V-2 in Jaslovske Bohunice (Slovakia) were gradually changed by new original "Bohunice" design in period 1994-1998. Corrosion processes before and after these design and material changes in Bohunice secondary circuit were studied using Mössbauer spectroscopy during last 25 years. Innovations in the feed water pipeline design as well as material composition improvements were evaluated positively. Mössbauer spectroscopy studies of phase composition of corrosion products were performed on real specimens scrapped from water pipelines or in form of filter deposits. The corrosion of new feed water pipelines system (from austenitic steel) in combination to innovated operation regimes goes dominantly to magnetite. The hematite presence is mostly on the internal surface of steam generator body and its concentration increases towards the top of the body. In the results interpretation it is necessary to consider also erosion as well as scope and type of maintenance activities. The long-term study of phase composition of corrosion products at VVER reactors is one of precondition for the safe operation over the projected NPP lifetime.

  7. Design for Corrosion Control of Potable Water Distribution Systems

    DTIC Science & Technology

    1975-02-01

    plastic composites as a substitute for metals. Problem areas such as galvanic corrosion, proper surface preparation and techniques for application of...Corrosion Surveys A -orrosion survey consists of the determination of soil and water composition , resistivity, pH, water table level, and for existing...conditions also play a role in corrosion design require- ments. Factors such as ambient temperature, chemical composition of the water, and frequency

  8. 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

  9. Determining optimal corrosion control techniques for small water systems: A unique and systematic approach

    SciTech Connect

    Tarallo, S.M.; Beardsley, E.; Pytel, D.; Chaplin, T.

    1996-11-01

    The Lead and Copper Rule represents one of the most complex rules currently in effect for small water treatment systems. In an effort to attain timely compliance by small systems with limited technical and financial resources, the Rhode Island Department of Health (RIDOH) Division of Drinking Water Quality initiated a study to recommend appropriate corrosion control approaches. The study encompassed three goals: to continue a good compliance record, to help small systems reduce their lead and copper levels, and to avoid unnecessary safety risks to operators and customers.

  10. Profiling iron corrosion coating on iron grains in a zerovalent iron system under the influence of dissolved oxygen.

    PubMed

    Zhang, Tian C; Huang, Yong H

    2006-07-01

    Rapid oxidation of Fe(0) by O(2) occurred when Fe(0) grains were bathed in 0.54 mM FeCl(2) solution saturated with dissolved oxygen (DO), forming a substantial corrosion coating on Fe(0) grains. A sonication method was developed to strip the corrosion coating off the iron grains layer by layer. The transformation of the constituents and the morphology of the corrosion coating along its depth and over reaction time were investigated with composition analysis, X-ray diffraction and scanning electron microscopy. Results indicate that the sonication method could consistently recover >90% iron oxides produced by the Fe(0)-DO redox reaction. Magnetite (Fe(3)O(4)) and lepidocrocite (gamma-FeOOH) were identified as the corrosion products. Initially, lepidocrocite was the preferential product in the presence of DO. As the oxide coating thickened, the inner layer transformed to magnetite, which retained as the only stable corrosion product once DO was depleted. The study confirms the phase transformations between gamma-FeOOH and Fe(3)O(4) within a stratified corrosion coating. The sonication technique exemplifies a new approach for investigating more complicated processes in Fe(0)/oxides/contaminants systems.

  11. 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

  12. Recent advances in the study of microbiologically influenced corrosion

    SciTech Connect

    Little, B.; Wagner, P.

    1993-12-31

    The study of microbiologically influenced corrosion (MIC) has progressed from phenomenological case histories to a mature interdisciplinary science including electrochemical, metallurgical, surface analytical, microbiological, biotechnological and biophysical techniques. With gene probes and microelectrodes it is now possible to measure interfacial dissolved oxygen, dissolved sulfide and pH and to further determine the microbial species responsible for the localized chemistry. Biofilms can be tailored to contain consortia of specific microorganisms and naturally occurring biofilms can be dissected into cellular and extracellular constituents. Scanning vibrating electrodes can be used to map the distribution of anodes and cathodes so that localized corrosion can be correlated with the location of microorganisms. The development of environmental scanning electron, atomic force, and laser confocal microscopy makes it possible to image cells on surfaces and to accurately determine the spatial relationship between microorganisms and corrosion. Transport of nutrients through biofilms is being modeled using techniques including optical density measurements to precisely locate the water/biofilm interface and nuclear magnetic resonance imaging to visualize flow characteristics near surfaces colonized with microorganisms. The ways in which these new techniques can be used to understand fundamental mechanisms and to discriminate critical issues of MIC will be discussed.

  13. 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 ...

  14. 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 ...

  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. 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...

  17. 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.

  18. Characteristics of iron corrosion scales and water quality variations in drinking water distribution systems of different pipe materials.

    PubMed

    Li, Manjie; Liu, Zhaowei; Chen, Yongcan; Hai, Yang

    2016-12-01

    Interaction between old, corroded iron pipe surfaces and bulk water is crucial to the water quality protection in drinking water distribution systems (WDS). Iron released from corrosion products will deteriorate water quality and lead to red water. This study attempted to understand the effects of pipe materials on corrosion scale characteristics and water quality variations in WDS. A more than 20-year-old hybrid pipe section assembled of unlined cast iron pipe (UCIP) and galvanized iron pipe (GIP) was selected to investigate physico-chemical characteristics of corrosion scales and their effects on water quality variations. Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Inductively Coupled Plasma (ICP) and X-ray Diffraction (XRD) were used to analyze micromorphology and chemical composition of corrosion scales. In bench testing, water quality parameters, such as pH, dissolved oxygen (DO), oxidation reduction potential (ORP), alkalinity, conductivity, turbidity, color, Fe(2+), Fe(3+) and Zn(2+), were determined. Scale analysis and bench-scale testing results demonstrated a significant effect of pipe materials on scale characteristics and thereby water quality variations in WDS. Characteristics of corrosion scales sampled from different pipe segments show obvious differences, both in physical and chemical aspects. Corrosion scales were found highly amorphous. Thanks to the protection of zinc coatings, GIP system was identified as the best water quality stability, in spite of high zinc release potential. It is deduced that the complicated composition of corrosion scales and structural break by the weld result in the diminished water quality stability in HP system. Measurement results showed that iron is released mainly in ferric particulate form.

  19. Effects of sulfate on heavy metal release from iron corrosion scales in drinking water distribution system.

    PubMed

    Sun, Huifang; Shi, Baoyou; Yang, Fan; Wang, Dongsheng

    2017-05-01

    Trace heavy metals accumulated in iron corrosion scales within a drinking water distribution system (DWDS) could potentially be released to bulk water and consequently deteriorate the tap water quality. The objective of this study was to identify and evaluate the release of trace heavy metals in DWDS under changing source water conditions. Experimental pipe loops with different iron corrosion scales were set up to simulate the actual DWDS. The effects of sulfate levels on heavy metal release were systemically investigated. Heavy metal releases of Mn, Ni, Cu, Pb, Cr and As could be rapidly triggered by sulfate addition but the releases slowly decreased over time. Heavy metal release was more severe in pipes transporting groundwater (GW) than in pipes transporting surface water (SW). There were strong positive correlations (R(2) > 0.8) between the releases of Fe and Mn, Fe and Ni, Fe and Cu, and Fe and Pb. When switching to higher sulfate water, iron corrosion scales in all pipe loops tended to be more stable (especially in pipes transporting GW), with a larger proportion of stable constituents (mainly Fe3O4) and fewer unstable compounds (β-FeOOH, γ-FeOOH, FeCO3 and amorphous iron oxides). The main functional iron reducing bacteria (IRB) communities were favorable for the formation of Fe3O4. The transformation of corrosion scales and the growth of sulfate reducing bacteria (SRB) accounted for the gradually reduced heavy metal release with time. The higher metal release in pipes transporting GW could be due to increased Fe6(OH)12CO3 content under higher sulfate concentrations.

  20. Understanding Corrosion Mechanisms in Oxy-Fired Systems

    SciTech Connect

    Pint, Bruce A; Dryepondt, Sebastien N; Zhang, Ying

    2011-01-01

    Replacing air with oxygen in coal-fired boilers (i.e. oxy-firing) combined with flue gas recirculation is a leading strategy to concentrate CO{sub 2} and assist in carbon capture and sequestration. A significant area of concern is the fireside corrosion with oxy-firing due to the higher CO{sub 2} levels in the combustion gas and potentially higher SO{sub x} and H{sub 2}O levels. In order to investigate this complicated issue, laboratory experiments are being conducted with and without synthetic ash to assess the potential effect of oxy-firing on fireside corrosion rates. The initial results of this project focus on commercial and model Fe-base alloys at 600 C. Without ash, a 50%H{sub 2}O-50%(CO{sub 2}-0.15O{sub 2}) environment was the most aggressive condition, requiring higher Cr contents than 100% H{sub 2}O or Ar-50%CO{sub 2}. With the specimens covered in ash, several gas compositions were examined, including different levels of H{sub 2}O and SO{sub 2} to simulate various oxy-firing strategies. Results also are presented for several laser-clad coating compositions for protecting tubes. An additional task is examining the effect of environment on mechanical properties. Initial work studied Ni-base alloys in steam at 800 C and found little effect of steam on the creep rupture life of alloy 230 but a 35% decrease for alloy 740.

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

    PubMed

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

    2013-06-05

    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.

  2. 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.

  3. 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

  4. Electrochemical Corrosion Studies for Modeling Metallic Waste Form Release Rates

    SciTech Connect

    Poineau, Frederic; Tamalis, Dimitri

    2016-08-01

    The isotope 99Tc is an important fission product generated from nuclear power production. Because of its long half-life (t1/2 = 2.13 ∙ 105 years) and beta-radiotoxicity (β⁻ = 292 keV), it is a major concern in the long-term management of spent nuclear fuel. In the spent nuclear fuel, Tc is present as an alloy with Mo, Ru, Rh, and Pd called the epsilon-phase, the relative amount of which increases with fuel burn-up. In some separation schemes for spent nuclear fuel, Tc would be separated from the spent fuel and disposed of in a durable waste form. Technetium waste forms under consideration include metallic alloys, oxide ceramics and borosilicate glass. In the development of a metallic waste form, after separation from the spent fuel, Tc would be converted to the metal, incorporated into an alloy and the resulting waste form stored in a repository. Metallic alloys under consideration include Tc–Zr alloys, Tc–stainless steel alloys and Tc–Inconel alloys (Inconel is an alloy of Ni, Cr and iron which is resistant to corrosion). To predict the long-term behavior of the metallic Tc waste form, understanding the corrosion properties of Tc metal and Tc alloys in various chemical environments is needed, but efforts to model the behavior of Tc metallic alloys are limited. One parameter that should also be considered in predicting the long-term behavior of the Tc waste form is the ingrowth of stable Ru that occurs from the radioactive decay of 99Tc (99Tc → 99Ru + β⁻). After a geological period of time, significant amounts of Ru will be present in the Tc and may affect its corrosion properties. Studying the effect of Ru on the corrosion behavior of Tc is also of importance. In this context, we studied the electrochemical behavior of Tc metal, Tc-Ni alloys (to model Tc-Inconel alloy) and Tc-Ru alloys in acidic media. The study of Tc-U alloys has also been performed in order to better understand the

  5. A Meta-Analysis Of Corrosion Studies for Maritime Patrol and Reconnaissance Aircraft (MPRA)

    DTIC Science & Technology

    2016-09-01

    corrosion treatment and prevention is detrimental in the consumption of manpower and resources, is a high readiness degrader, and diverts funding that...could be used for future programs. Corrosion treatment and prevention processes of the past may not be environmentally acceptable today. This study...man-hour reduction studies are needed to optimize a balance between corrosion prevention and treatment cost and man-hours. One recommendation is to

  6. Microbially influenced corrosion of galvanized steel pipes in aerobic water systems.

    PubMed

    Bolton, N; Critchley, M; Fabien, R; Cromar, N; Fallowfield, H

    2010-07-01

    To investigate the role of heterotrophic bacteria in the corrosion of galvanized steel in the presence of water. Samples were taken from corroding galvanized steel pipes conveying water for specialist applications, and heterotrophic bacteria were isolated and cultured. The majority of bacteria were Gram-negative aerobes and included Pseudomonas sp., Bacillus pumilus, Afipia spp. and Blastobacter denitrificans/Bradyrhizobium japonicum. Zinc tolerance was assessed through growth and zinc disc diffusion experiments. In general, zinc negatively influenced growth rates. An unidentified yeast also isolated from the system demonstrated a high tolerance to zinc at concentrations up to 4 g l(-1) . Coupon experiments were performed to assess corrosion by the bacteria on galvanized steel and steel coupons. The majority of isolates as pure culture biofilms (69%) accelerated corrosion of galvanized coupons, assessed as zinc release, relative to sterile control coupons (P < 0·05). Pure culture biofilms did not increase the corrosion of steel, with four isolates demonstrating protective effects. Pure culture biofilms of heterotrophic bacteria isolated from a corroding galvanized pipe system were found to accelerate the corrosion of galvanized steel coupons. Microbially influenced corrosion is a potential contributor to sporadically occurring failures in galvanized steel systems containing water. Management strategies should consider microbial control as a means for corrosion prevention in these systems. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

  7. Study on Corrosion and Stress Corrosion Cracking Behaviors of AZ31 Alloy in Sodium Sulfate Solution

    NASA Astrophysics Data System (ADS)

    He, Xiuli; Yan, Zhifeng; Liang, Hongyu; Wei, Yinghui

    2017-05-01

    The potentiodynamic polarization test and slow strain rate tensile test were carried out in 3.5 wt.% Na2SO4 solution with different pH values (2, 7, and 12). It was found that the SCC susceptibility of AZ31 magnesium alloy in 3.5 wt.% Na2SO4 solution was deteriorated significantly with the decreasing pH. This was consistent with the electrochemical properties. There were filiform corrosion forms on the specimen surface after slow strain rate tensile test in 3.5 wt.% Na2SO4 solution, which indicated the characteristics of general corrosion. Moreover, there were multiple stress corrosion crack initiation sources. The SCC fracture of AZ31 magnesium alloy in air was a mix type, while it was cleavage fracture in 3.5 wt.% Na2SO4 solution.

  8. 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.

  9. Experimental Study on the Electrochemical Anti-Corrosion Properties of Steel Structures Applying the Arc Thermal Metal Spraying Method

    PubMed Central

    Choe, Hong-Bok; Lee, Han-Seung; Shin, Jun-Ho

    2014-01-01

    The arc thermal metal spraying method (ATMSM) provides proven long-term protective coating systems using zinc, aluminum and their alloys for steel work in a marine environment. This paper focuses on studying experimentally the anti-corrosion criteria of ATMSM on steel specimens. The effects of the types of spraying metal and the presence or absence of sealing treatment from the thermal spraying of film on the anti-corrosion performance of TMSM were quantitatively evaluated by electrochemical techniques. The results showed that ATMSM represented a sufficient corrosion resistance with the driving force based on the potential difference of more than approximately 0.60 V between the thermal spraying layer and the base substrate steel. Furthermore, it was found that the sealing treatment of specimens had suppressed the dissolution of metals, increased the corrosion potential, decreased the corrosion current density and increased the polarization resistance. Metal alloy Al–Mg (95%:5%) by mass with epoxy sealing coating led to the most successful anti-corrosion performance in these electrochemical experiments. PMID:28788271

  10. 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.

  11. 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...

  12. 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...

  13. 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.

  14. Study of corrosion between a titanium implant and dental alloys.

    PubMed

    Reclaru, L; Meyer, J M

    1994-06-01

    The infiltration of saliva into the multi-metallic structures on titanium implants brings different types of alloys into temporary or permanent contact. In this way a galvanic cell is established as a result of their potential difference. The galvanic cell phenomenon is compounded by another type of corrosion resulting from the geometry of the assembly: localized crevice corrosion. Fifteen galvanic couples (Ti/gold-based alloys, Ti/palladium-based alloy and Ti/non-precious alloys) were studied. Various electrochemical parameters (Ecorr, Ecommon, Ecouple corr, Ecrevice, icorr, icouple corr and Tafel slopes) were analysed. The galvanic currents measured are of the same order of magnitude (except Ti/stainless steel). They remain low. Application of the mixed-potential theory shows that titanium in coupling with the alloys studied will be under either cathodic or anodic control. According to the results obtained, an alloy that is potentially usable for superstructures in a galvanic coupling with titanium must fulfil a certain number of parameters: in a coupling, titanium must have a weak anodic polarization; the current generated by the galvanic cell must also be weak; the crevice potential must be markedly higher than the common potential.

  15. 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.

  16. 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.

  17. 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.

  18. Pipe corrosion and deposit study using neutron- and gamma- radiation sources

    NASA Astrophysics Data System (ADS)

    Balaskó, Márton; Sváb, Erzsébet; Kuba, Attila; Kiss, Zoltán; Rodek, Lajos; Nagy, Antal

    2005-04-01

    The problems of corrosion and deposit are crucial issues in the pipelines of the chemical, nuclear and petrochemical industries. Radiography (neutron, gamma, X-ray) has long been used as a technique for pipe inspection and corrosion monitoring. The 10 MW Budapest research reactor site is a source of various energy neutron (thermal and epithermal) and gamma radiation. The detector system was a Peltier-cooled LLL CCD camera controlled by a PC with Image ProLite software and imaging plate equipment with a BAS 2500 scanner that used AIDA software. The objects inspected were corroded tubes and various kinds of test specimens with a large wall thickness (25 mm) inside and outside steps. In the evaluation part we used tomographic algorithms. A software simulation study was made as well. Fan-beam projections were computed of the given software phantoms and a new discrete tomography method was used to reconstruct the unknown objects from these projections.

  19. Electrochemical corrosion studies of carbon supports and electrocatalysts and their effects on the durability of low-temperature PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Dowlapalli, Madhusudhana R.

    Performance of a PEM fuel cell relies heavily on the durability of the platinum and platinum-alloy based electrocatalysts supported on carbon blacks. Carbon corrosion has been widely accepted as an important issue affecting the degradation of the catalytic layer in PEMFCs. Traditional carbon blacks used in today's fuel cell industry are not tailored to suit the corrosive conditions encountered in PEMFCs. Advanced carbon supports should have excellent electrochemical corrosion resistance, good conductivity, high surface area and optimum hydrophilic properties. The principal objective of this work is to investigate the corrosive behavior of carbon blacks and electrocatalysts supported on such carbon blacks in conditions that are typical for fuel cells. Physical and chemical changes during oxidation of these carbon blacks have been reviewed along with methodology for studying their corrosion in a low-temperature fuel cell environment. This study provides an ex-situ corrosion measurement protocol and a gas diffusion electrode half-cell setup to study the electrochemical oxidation resistance behavior of standard carbon blacks, modified carbon blacks, and advanced carbon supports in acid electrolyte at 25°C. Corrosion current-time relationships were evaluated and transient mode of corrosion study was employed to simulate automobile startup/shutdown. The effects of various surface modifications on carbon corrosion behavior have been studied in detail. The aggravated corrosion of carbon supports at potentials higher than the thermodynamic stable regime of water was investigated and a mechanism is proposed to address the same. The role of the metal phase on carbon corrosion at the catalyst-support interphase has also been investigated. The corrosion current dependence on the microstructure and nature of surface groups present on these carbons was examined. Further, measuring carbon corrosion effects on the durability of a single membrane-electrode assembly (MEA) cathode

  20. 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.

  1. Corrosion monitoring system based on measurement and analysis of electrochemical noise

    SciTech Connect

    Legat, A.; Dolecek, V.

    1995-04-01

    A corrosion monitoring system using electrochemical noise measurements and their numerical analysis was developed. Electrochemical noise was measured in a freely corroding system containing three identical metal electrodes. A voltage signal generated by the first pair of electrodes and a current signal generated by the second pair were measured, and the data were fed into a computer. A mathematical model that included signal processing and pattern recognition was implemented using computer software. Analysis of the electrochemical noise enabled determination of the corrosion rate and the corrosion type. The reliability of the corrosion monitoring system was tested against various reference methods (visual inspection, scanning electron microscopy, current-vs-potential curves, and electrical resistance). Tests were performed on steel and aluminum in aqueous solutions of various pH and conductivity values.

  2. Corrosion monitoring system based on measurements and analysis of electrochemical noise

    SciTech Connect

    Legat, A.; Dolecek, V.

    1994-12-31

    A corrosion monitoring system using electrochemical noise measurements and their numerical analysis is described. Electrochemical noise was measured in a freely corroding system containing three identical metal electrodes. A voltage signal generated by the first pair of electrodes and a current signal generated by the second pair were measured and the data fed into a computer. A mathematical model including signal processing and pattern recognition was developed and implemented in computer software. Analysis of the electrochemical noise enabled determination of the corrosion rate and the corrosion type. The reliability of the corrosion monitoring system was tested with various reference methods (visual inspection, SEM analysis, I vs E curves, electrical resistance). Tests were performed on steel and aluminium in aqueous solutions of various pH and conductivity values.

  3. Laboratory corrosion studies in low- and high-salinity geobrines of the Imperial Valley, California

    SciTech Connect

    Cramer, S.D.; Carter, J.P.

    1980-01-01

    Corrosion research is being conducted by the Federal Bureau of Mines to determine suitable construction materials for geothermal resource recovery plants. As part of this research, the corrosion resistance of 31 iron-, nickel-, aluminum-, copper-, titanium-, and molybdenum-base alloys was characterized and evaluated in laboratory corrosion studies in low- and high-salinity geobrines representative of those found in the Imperial Valley, California. General, crevice, pitting, weld, and stress corrosion were measured at 105/sup 0/ and 232/sup 0/C in deaerated brines and brines containing dissolved O/sub 2/, CO/sub 2/, and CH/sub 4/.

  4. Experimental and theoretical studies of parameters that influence corrosion of Zircaloy-4

    SciTech Connect

    Billot, P.; Robin, J.C.; Giordano, A.; Peybernes, J.; Thomazet, J.; Amanrich, H.

    1994-12-31

    Waterside corrosion of Zircaloy cladding in pressurized water reactors (PWRs) is largely dependent upon the operating parameters and microstructure of the zirconium alloys. The impact of these parameters on the corrosion kinetics of Zircaloys is investigated on the basis of empirical data and experiences that can be interpreted using existing corrosion models. The influence of thermo-hydraulic data, heat flux, local boiling conditions, and of the growing oxide films has been studied from corrosion tests performed in static autoclaves or in out-of-pile loops. These parametric investigations are described as well as the models that were developed. The impact of microstructure is studied from the comparison of the corrosion behavior of different Zircaloy-4 specimens corroded in out-of-pile tests. In particular, a poor corrosion resistance of an experimental Zircaloy-4 material is analyzed as a function of the microstructure close to the metal/oxide interface. The impact of the alloy composition and primary coolant chemistry on the corrosion kinetics of Zircaloy-4 is modeled empirically or uses a mechanistic approach that proposes a series of chemical equations with a mathematical representation of the kinetics. These proposed models are then used to investigate the corrosion behavior of Zircaloy-4 cladding in 17 by 17 plants for rods irradiated at high burnups. Higher PWR operating cycles, core average coolant temperature, power, and elevated primary coolant lithium concentrations (3.5 to 4 ppm) are then simulated and discussed in terms of Zircaloy corrosion resistance considerations.

  5. 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.

  6. Electrochemical corrosion behavior of hot dip coating in artificial seawater

    NASA Astrophysics Data System (ADS)

    Sun, Hu-Yuan; Hou, Bao-Rong; Ma, Shi-de; Wei, Xu-Jun

    1999-06-01

    The corrosion behavior of a zinc-based alloy (compared with that of pure zinc) coating was studied in this research on the electrochemical corrosion behavior of hot dip coating in artificial seawater. The electrochemical parameters of these two hot dip coatings were measured by the galvanostatic method and accelerated corrosion test. The two coatings showed uniform corrosion, but the corrosion of the pure zinc coating was actively sustained continuously. The corrosion of the zinc-based alloy coating was very slow because of the formation of a stable anti-corrosion membrane. The corrosion mechanisms of these two coatings were also compared by the weak polarization curve fitting method. The corrosion of the zinc-based alloy coating is typical of that in natural passive corrosion system.

  7. 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.

  8. Corrosion protection of equipment in recirculating water supply systems

    SciTech Connect

    Teslya, B.M.; Burlov, V.V.; Shadrina, A.N.; Vyazhevich, A.V.

    1983-01-01

    The metals in the condensers, coolers and heat exchangers of petroleum refineries and petrochemical plants are subject to corrosion, and this is responsible for forced shutdowns. This paper notes that the shortest service life is given by the carbon and silicon-manganese steels, the longest by the chrome-nickel steels and arsenic-alloyed brasses. It reports that a high level of protection is provided by the use of the inhibitor IKB-4V at the Industrial Association ''Novopolotsknefteorgsintez'' and a so-called complex corrosion retarder consisting of a mixture of zinc sulfate and orthophosphoric acid at the Novo-Ufa refinery. It also points out that the most desirable method for corrosion protection of cooling towers, from the standpoint of technical and economic justification, is the use of protective paint coatings. It urges scientific research and design organizations and also the plants of the petroleum refining and petrochemical industry to take a multipronged approach in solving problems in corrosion control. It is pointed out that protection by inhibitors must be combined with the use of paints and other types of organic and inorganic coatings, protection against salt deposition and biological overgrowth, and the rational use of corrosion-resistant materials of construction.

  9. Research on corrosion mechanism of suspension insulator steel foot of direct current system and measures for corrosion inhibition

    NASA Astrophysics Data System (ADS)

    Chen, He; Yang, Yueguang; Su, Guolei; Wang, Xiaoqing; Zhang, Hourong; Sun, Xiaoyu; Fan, Youping

    2017-09-01

    There are increasingly serious electrocorrosion phenomena on insulator hardware caused by direct current transmission due to the wide-range popularization of extra high voltage direct current transmission engineering in our country. Steel foot corrosion is the main corrosion for insulators on positive polarity side of transmission lines. On one hand, the corrosion leads to the tapering off of steel foot diameter, having a direct influence on mechanical property of insulators; on the other hand, in condition of corrosion on steel foot wrapped in porcelain ware, the volume of the corrosion product is at least 50% more than that of the original steel foot, leading to bursting of porcelain ware, threatening safe operation of transmission lines. Therefore, it is necessary to conduct research on the phenomenon and propose feasible measures for corrosion inhibition. Starting with the corrosion mechanism, this article proposes two measures for corrosion inhibition, and verifies the inhibition effect in laboratory conditions, providing reference for application in engineering.

  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. Monitoring corrosion and chemistry phenomena in supercritical aqueous systems

    SciTech Connect

    Macdonald, D.D.; Pang, J.; Liu, C.; Kriksunov, L.; Medina, E.; Villa, J.; Bueno, J.

    1994-12-31

    The in situ monitoring of the chemistry and electrochemistry of aqueous heat transport fluids in thermal (nuclear and fossil) power plants is now considered essential if adequate assessment and close control of corrosion and mass transfer phenomena are to be achieved. Because of the elevated temperatures and pressures involved. new sensor technologies are required that are able to measure key parameters under plant operating conditions for extended periods of time. In this paper, the authors outline a research and development program that is designed to develop practical sensors for use in thermal power plants. The current emphasis is on sensors for measuring corrosion potential, pH, the concentrations of oxygen and hydrogen, and the electrochemical noise generated by corrosion processes at temperatures ranging from {approximately}250 C to 500 C. The program is currently at the laboratory stage, but testing of prototype sensors in a coal-fired supercritical power plant in Spain will begin shortly.

  12. 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.

  13. 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

  14. Corrosive acid ingestion in man - a clinical and endoscopic study.

    PubMed Central

    Dilawari, J B; Singh, S; Rao, P N; Anand, B S

    1984-01-01

    Sixteen patients with corrosive acid ingestion were studied. The majority of patients (n = 10) had ingested sulphuric acid, and three other patients had ingested hydrochloric acid. The extent and severity of upper gastrointestinal tract injury was determined by fibreoptic endoscopy and necropsy. All the patients had oesophageal and gastric involvement but the duodenum was spared in the majority. The injury was not considered as mild (grade I) in any of these patients; five patients having moderate (grade II) and 10 patients having severe (grade III) injury. Complications and mortality occurred only in patients with grade III injury. Feeding jejunostomy for nutritional support was used in five patients (all grade III) with good results. PMID:6693046

  15. 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…

  16. Corrosion of an alloy studied in situ with synchrotron x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Renner, Frank; Lee, Tien-Lin; Kolb, Dieter M.; Stierle, Andreas; Dosch, Helmut; Zegenhagen, Jorg

    2004-03-01

    Corrosion processes are mostly electrochemical in nature. For the basic understanding of corrosion and similar technical processes, in-situ structural methods capable of atomic resolution, such as scanning probe microscopy or hard X-ray techniques are necessary. We used in-situ X-ray diffraction and in addition ex-situ AFM, to study Cu_3Au(111) single crystal surfaces in 0.1M H_2SO4 electrolyte as a function of electrode potential in the sub-critical regime. This binary metal alloys serves as model systems for more complicated technically utilized metal alloys. During the initial electrochemical corrosion, Cu atoms are dissolved and a passivating layer is formed. The experiments show the formation of an epitaxial and highly strained ultra-thin Cu_xAu_1-x(111) phase on the surface at a potential where Cu dissolution starts. At higher potentials, thicker epitaxial Au islands are growing on the surface. AFM images reveal a surface, densely packed with Au islands of a homogeneous size-distribution. On a prolonged timescale, a percolating, porous morphology of the surface evolves by ripening, even at an electrode potential well below the critical potential.

  17. 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.

  18. ELECTROCHEMICAL STUDIES OF URANIUM METAL CORROSION MECHANISM AND KINETICS IN WATER

    SciTech Connect

    Boudanova, Natalya; Maslennikov, Alexander; Peretroukhine, Vladimir F.; Delegard, Calvin H.

    2006-10-01

    During long-term underwater storage of low burn-up uranium metal fuel, a corrosion product sludge forms containing uranium metal grains1, uranium dioxide1,2, uranates1 and, in some cases, uranium peroxide1,3. Literature data on the corrosion of non-irradiated uranium metal and its alloys2,4 do not allow unequivocal prediction of the paragenesis of irradiated uranium in water. The goal of the present work conducted under the program «CORROSION OF IRRADIATED URANIUM ALLOYS FUEL IN WATER» is to study the corrosion of uranium and uranium alloys and the paragenesis of the corrosion products during long-term underwater storage of uranium alloy fuel irradiated at the Hanford Site. The elucidation of the physico-chemical nature of the corrosion of irradiated uranium alloys in comparison with non-irradiated uranium metal and its alloys is one of the most important aspects of this work. Electrochemical methods are being used to study uranium metal corrosion mechanism and kinetics. The present part of work aims to examine and revise, where appropriate, the understanding of uranium metal corrosion mechanism and kinetics in water.

  19. Use of differential pulse polarography to study corrosion of galvanized steel in aqueous lithium bromide solution

    SciTech Connect

    Garcia-Anton, J.; Perez-Herranz, V.; Guinon, J.L. . Dept. de Ingenieria Quimica y Nuclear); Lacoste, G. )

    1994-02-01

    Static and dynamic corrosion of galvanized steel in 4.6 M lithium bromide (LiBr) solution at 20 C and at 70 C was studied using a new polarographic method for the determination of zinc (Zn) in LiBr solution. Static and dynamic corrosion of galvanize steel at 20 C and 70 C followed a linear tendency with exposure time. However, a change in the slope of dynamic corrosion was observed at 20 C. The corrosion product was studied using energy dispersive x-ray analysis (EDXA) and x-ray diffractometry and was considered to be a mixture of zinc hydroxide Zn(OH)[sub 2] and oxides. The corrosion product morphology was amorphous and gelatinous at 20 C and crystalline at 70 C.

  20. 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.

  1. Study of Corrosion Resistance Improvement by Metallic Coating for Overhead Transmission Line Conductor

    NASA Astrophysics Data System (ADS)

    Isozaki, Masanori; Adachi, Kouichi; Hita, Takanori; Asano, Yuji

    Applying anti-corrosion grease and aluminum clad steel (AC) wires to ACSR has adopted as general methods to prevent overhead transmission line conductors and/or wires from corrosion. However, there are some cases that ineffectiveness of those means are reported on some transmission lines passing through acid atmosphere in the vicinity of a factory exhausting acid smoke. The feature of the corrosion caused by acid atmosphere is to show a higher speed in its progressing as well known. As means against such acid corrosion, application of high purity aluminum, selective removal of inter-metallic compound in aluminum and plastic coating wires has been reported before, and each has both of advantage and disadvantage actually. In the former letter, we reported the new type of anti-corrosion grease that shows an excellent property against acid atmosphere as well as in a salty circumstance. Here presents a new type of anti-corrosion technology of applying high corrosion resistance aluminum alloy or zinc coatings on each component wires of a conductor that we succeed in developing through a serial study of anti-corrosion methods on overhead transmission lines.

  2. 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.

  3. 3D study of intermetallics and their effect on the corrosion morphology of rheocast aluminium alloy

    SciTech Connect

    Mingo, B.; Arrabal, R.; Pardo, A.; Matykina, E.; Skeldon, P.

    2016-02-15

    In the present study, the effect of heat treatment T6.1 on the microstructure and corrosion behaviour of rheocast aluminium alloy A356 is investigated on the basis of 2D/3D characterization techniques and electrochemical and SKPFM measurements. Heat treatment strengthens the α-Al matrix, modifies the intermetallic particles and spheroidizes eutectic Si. These changes do not modify significantly the corrosion behaviour of the alloy. 3D SEM-Tomography clearly shows that the corrosion advances in the shape of narrow paths between closely spaced intermetallics without a major influence of eutectic Si. - Highlights: • T6.1 spheroidizes Si, strengthens the matrix and modifies the intermetallics. • Electrochemical behaviour of untreated and heat-treated alloys is similar. • 3D SEM-Tomography provides additional information on the corrosion morphology. • Corrosion advances as paths between intermetallics with little influence of Si.

  4. 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.

  5. The Corrosion Study in the Tubing for Gas Production on the CBM Reservoir including CO2

    NASA Astrophysics Data System (ADS)

    Kim, K. H.; Kang, I. O.; Han, J. M.; Lee, S. M.

    2016-12-01

    In the CBM reservoir, although the gas mainly contains more than 85% CH4, it actually consists of multi-component such as CH4, CO2 and N2. Both the multi-component gas including CO2 and water are produced together from Coalbed into tubing. Because the reaction between CO2 and water always acts as the heart of the corrosion mechanisms, the presence of CO2 can produce several aspects of corrosion problem in the coalbed. In this study, we analyzed the experimental report of the sorption and gas content about the specific CBM field. By the using reservoir simulator, we have calculated about the changing the composition of desorption gas for production period. Applied on the simulation results, we identified corrosion rate of the tubing for applied dewaad corrosion model. Firstly, we conducted sensitivity analysis on the variable ranges of the properties. Secondly, we checked the maximum corrosion rate into the production well. Finally, we measured the cumulative corrosion rate for production duration. Although the CO2 mole fraction existed in coal reaches 20 percents, the amount of CO2 is left into the coal matrix without desorption because CO2 is preferentially adsorbed onto the coal matrix. Thus, the CO2 mole fraction into production well is lowly calculated from 5 to 6 percents. Since the water rate is especially changing for production period in CBM, the water gas ratio which is mainly affected by corrosion rate dramatically varies with the production period. Applied on these results from CBM, the CO2 corrosion rate becomes higher at the higher pressure of a deeper place in general, because the CO2 partial pressure increases. However, as it generated FeCO3 protection above the specific temperature, the corrosion rate is inversely decreased at the deeper tubing section above critical depth. From the sensitivity studies on CBM reservoir including CO2, it was identified that corrosion rate relatively shows the low value as compared with CO2 composition due to the

  6. 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.

  7. Corrosion properties of Ag-Au-Cu-Pd system alloys containing indium.

    PubMed

    Hattori, Masayuki; Tokizaki, Teruhiko; Matsumoto, Michihiko; Oda, Yutaka

    2010-01-01

    In this study, the corrosion resistance of Ag-Au-Cu-Pd system alloys consisting of 5 or 10 mass% indium was evaluated. Levels of element release and tarnish were determined and electrochemical measurements performed. Results were compared with those for commercial silver-palladium-gold alloy. In terms of electrochemical behavior, the transpassive potential of these experimental alloys was 168-248mV. Experimental alloys with 25 mass% Au showed similar corrosion resistance to control gold-silver-palladium alloy. Amount of released elements was 14-130microg/cm(2) at 7 days, which is in the allowable range for dental alloys. Addition of indium to Ag-Au-Cu-10mass%Pd system alloys was effective in increasing resistance to tarnish and alloys containing 10 mass% of indium showed a minimal decrease in L(*) values after immersion. These findings indicate that 25Au-37.5Ag-15Cu-10Pd-2Zn-10In-0.5Ir alloy is applicable in dental practice.

  8. F-16 Microbially Influenced Corrosion (MIC) Characterization & Prevention Study

    DTIC Science & Technology

    2011-05-12

    Staphylococcus epidermidis Fungal Consortium Aspergillus fumigatus Fusarium oxysporum Penicillium oxalicum Rhodoturula sp. Trichoderma sp. Control...Copper Dried biofilm and corrosion products inside pit area, with evidence of selective metal ion extraction or dealloying from metal or alloying

  9. 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).

  10. 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

  11. 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.

  12. Studies on Corrosion Prevention of Mardan Connectors by Organic Coatings.

    DTIC Science & Technology

    1980-06-09

    because of its previous use as a lubricant in electronic components (17). Sodium hexametaphosphate is a corrosion-preventive com- pound that is...continued) 18 Table 1 (continued) P4P3E NAHEX Code MCS 210 Sodium Hexametaphosphate Mfgrs. Name High temperature lubri- Corrosion Inhibitor cant Purpose...Polyphenyl ether, 4P3E Sodium hexametaphosphate Composition - Solvent Additives Fluid Solid, dissolved in H20 Physical State Swab Swab Applic. Method Fluid

  13. Corrosion and Fatigue Study of JSTARS Aircraft. Volume 1

    DTIC Science & Technology

    1997-04-01

    are made of 7075- T6 aluminum Corrosion resistant steel borders are used around door and window cutouts, The tail skin panels aft of BS 1440 are made...and vertical stabilizers utilize similar materials. The leading edge is made of 7075- T6 aluminum . The skin panels are made of either 2024-T3 or 2024...2024 - T3 aluminum planks removes material in the fastener holes and develops initiation sites for fatigue cracking. Corrosion damage and material loss

  14. Field studies of microbiological corrosion in water injection plant

    SciTech Connect

    Elboujdaini, M.; Sastri, V.S.

    1995-12-01

    Electrochemical impedance, weight loss and potentiodyne techniques were used to determine the corrosion rates of carbon steel along with the determination of activities of both sulphate-reducing bacteria (SRB) and acid-producing bacteria (APB) in a water injection field test facility. Corrosion rates determined by the potentiodyne technique did not correlate with the bacterial activity. Corrosion rates obtained by electrochemical impedance spectroscopy (EIS) were comparable to the rates obtained by weight loss measurements. The average corrosion rates obtained by EIS paralleled the cumulative SRB activity over 84 days, and the addition of biocide resulted in reduced bacterial activity and corrosion rate. The depression angles in Nyquist plots were high (30{degree}, 29{degree}) for control and biocide lines respectively indicating a fair degree of pitting corrosion. After 42 days, the values were lower, 11{degree} for biocide line compared to 22{degree} for control he showing the decrease in pitting tendency in line to which biocide was added at the end of 28 days.

  15. Corrosion performance of structural alloys for oxy-fuel combustion systems.

    SciTech Connect

    Natesan, K.; Rink, D. L.; Nuclear Engineering Division

    2007-01-01

    The U.S. Department of Energy (DOE) Office of Fossil Energy is intensely promoting research and development of oxyfuel combustion systems that employ oxygen, instead of air, for burning the fuel. The resulting flue gas primarily consists of H{sub 2}O and CO{sub 2} that facilitates sequestration of CO{sub 2}, thereby leading to reduction in CO{sub 2} emissions. Also, as the oxidant is bereft of N{sub 2}, NO{sub x} emissions are minimized to a great extent from the exhaust gas. Studies at NETL have indicated that oxy-fuel combustion can increase efficiency in the power plants from the current 30-35% to 50-60%. However, the presence of H{sub 2}O/CO{sub 2} and trace constituents like nitrogen and sulfur in the environment at the operating temperatures and pressures can have adverse effects on the corrosion and mechanical properties of structural alloys. Thus, there is a critical need to evaluate the response of structural and turbine materials in simulated H{sub 2}O/CO{sub 2} environments in an effort to select materials that have adequate high temperature mechanical properties and environmental performance. During the past year, a program was initiated to evaluate the corrosion performance of structural alloys in CO{sub 2} and CO{sub 2}-steam environments at elevated temperatures. Materials selected for the study include intermediate-chromium ferritic steels, Fe-Cr-Ni heat-resistant alloys, and nickelbased superalloys. Coupon specimens of several of the alloys were exposed to pure CO{sub 2} at temperatures between 650 and 850C for times up to 1450 h. The corrosion tests in CO{sub 2}-50% steam environment was conducted at temperatures between 650 and 850C for times up to 1250 h. The steam for the experiment was generated by pumping distilled water and converting it to steam in the preheat portion of the furnace, ahead of the specimen exposure location. Preliminary results will be presented on weight change, scale thickness, internal penetration, and microstructural

  16. A multi-mode sensing system for corrosion detection using piezoelectric wafer active sensors

    NASA Astrophysics Data System (ADS)

    Yu, Lingyu; Giurgiutiu, Victor; Pollock, Patrick

    2008-03-01

    As an emerging technology for in-situ damage detection and nondestructive evaluation, structural health monitoring with active sensors (active SHM) plays as a promising candidate for the pipeline inspection and diagnosis. Piezoelectric wafer active sensor (PWAS), as an active sensing device, can be permanently attached to the structure to interrogate it at will and can operate in propagating wave mode or electromechanical impedance mode. Its small size and low cost (about $10 each) make itself a potential and unique technology for in-situ SHM application. The objective of the research in this paper is to develop a permanently installed in-situ "multi-mode" sensing system for the corrosion monitoring and prediction of critical pipeline systems. Such a system is used during in-service period, recording and monitoring the changes of the pipelines over time, such as corrosion, wall thickness, etc. Having the real-time data available, maintenance strategies based on these data can then be developed to ensure a safe and less expensive operation of the pipeline systems. After a detailed review of PWAS SHM methods, including ultrasonic, impedance, and thickness measurement, we introduce the concept of PWAS-based multi-mode sensing approach for corrosion detection in pipelines. Particularly, we investigate the potential for using PWAS waves for in thickness mode experimentally. Finally, experiments are conducted to verify the corrosion detection ability of the PWAS network in both metallic plate and pipe in a laboratory setting. Results show successful corrosion localization in both tests.

  17. 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.

  18. 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.

  19. Corrosion protection of prestressing systems in concrete bridges. Final report

    SciTech Connect

    Perenchio, W.F.; Fraczek, J.; Pfeifer, D.W.

    1989-02-01

    The report reviews techniques and materials to provide enhanced corrosion protection for prestressing steel and its associated metallic hardware in pretensioned and post-tensioned concrete bridges. A year-long, accelerated corrosion test program on epoxy-coated strand, polyethylene duct, epoxy-coated steel duct, epoxy-coated anchorage hardware, grouts modified with silica fume and calcium nitrite, and heat-shrink tubing for sealing post-tensioning duct joints, together with traditional materials was undertaken on pretensioned and post-tensioned members. The use of newer corrosion-resistant duct materials and watertight duct joints was found to be essential since all three grout formulations were highly permeable to chloride at joints sealed with duct tape or after the traditional steel ducts corroded. Bond tests indicated that polyethylene duct and epoxy-coated steel duct can provide structurally composite behavior between the concrete and grout. Friction and abrasion tests demonstrated that a high coefficient of friction and abrasion damage may result if epoxy-coated strand is used in corrugated metal duct with a small radius of curvature.

  20. 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

  1. 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.

  2. Microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system.

    PubMed

    Yang, S S; Lin, J Y; Lin, Y T

    1998-09-01

    To investigate the microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system, aluminum alloys A356, AA 5052, AA 5083 and AA 6061 were chosen as the test alloys and Cladosporium and several fuel-oil contaminated microbes isolated in Taiwan were used as test organisms. Aluminum alloy AA 5083 in fuel-oil/aqueous system was the most susceptible material for microbial corrosion, then followed by aluminum alloys AA 5052 and A356, and AA 6061 was more resistant to microbial aggression. Mixed culture had high capability of corrosion, then followed by Penicillium sp. AM-F5, Fusarium sp. AM-F1, Pseudomonas aeruginosa AM-B5, Ps. fluorescens AM-B9, C. resinae ATCC 22712, Penicillium sp. AM-F2, Candida sp. AM-Y1 and Ps. aeruginosa AM-B11. From energy dispersive spectrometer analysis, aluminum and magnesium contents decreased in the corrosion area, while chlorine and sulfur contents increased. The major organic acid produced in fuel-oil/aqueous system was acetic acid, and the total organic acids content had a positive correlation with the degree of microbial corrosion.

  3. Corrosion studies in fuel element reprocessing environments containing nitric acid

    SciTech Connect

    Beavers, J A; White, R R; Berry, W E; Griess, J C

    1982-04-01

    Nitric acid is universally used in aqueous fuel element reprocessing plants; however, in the processing scheme being developed by the Consolidated Fuel Reprocessing Program, some of the equipment will be exposed to nitric acid under conditions not previously encountered in fuel element reprocessing plants. A previous report presented corrosion data obtained in hyperazeotropic nitric acid and in concentrated magnesium nitrate solutions used in its preparation. The results presented in this report are concerned with the following: (1) corrosion of titanium in nitric acid; (2) corrosion of nickel-base alloys in a nitric acid-hydrofluoric acid solution; (3) the formation of Cr(VI), which enhances corrosion, in nitric acid solutions; and (4) corrosion of mechanical pipe connectors in nitric acid. The results show that the corrosion rate of titanium increased with the refreshment rate of boiling nitric acid, but the effect diminished rapidly as the temperature decreased. The addition of iodic acid inhibited attack. Also, up to 200 ppM of fluoride in 70% HNO/sub 3/ had no major effect on the corrosion of either titanium or tantalum. In boiling 8 M HNO/sub 3/-0.05 M HF, Inconel 671 was more resistant than Inconel 690, but both alloys experienced end-grain attack. In the case of Inconel 671, heat treatment was very important; annealed and quenched material was much more resistant than furnace-cooled material.The rate of oxidation of Cr(III) to Cr(VI) increased significantly as the nitric acid concentration increased, and certain forms of ruthenium in the solution seemed to accelerate the rate of formation. Mechanical connectors of T-304L stainless steel experienced end-grain attack on the exposed pipe ends, and seal rings of both stainless steel and a titanium alloy (6% Al-4% V) underwent heavy attack in boiling 8 M HNO/sub 3/.

  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. Numerical study: Iron corrosion-resistance in lead-bismuth eutectic coolant by molecular dynamics method

    SciTech Connect

    Arkundato, Artoto; Su'ud, Zaki; Abdullah, Mikrajuddin; Widayani,; Celino, Massimo

    2012-06-06

    In this present work, we report numerical results of iron (cladding) corrosion study in interaction with lead-bismuth eutectic coolant of advanced nuclear reactors. The goal of this work is to study how the oxygen can be used to reduce the corrosion rate of cladding. The molecular dynamics method was applied to simulate corrosion process. By evaluating the diffusion coefficients, RDF functions, MSD curves of the iron and also observed the crystal structure of iron before and after oxygen injection to the coolant then we concluded that a significant and effective reduction can be achieved by issuing about 2% number of oxygen atoms to lead-bismuth eutectic coolant.

  6. Laboratory study of corrosion of steam generator tubes: Preliminary results

    SciTech Connect

    Sala, B.; Organista, M.; Henry, K.; Erre, R.; Gelpi, A.; Cattant, F.; Dupin, M.

    1995-12-31

    The secondary side intergranular attack (IGA) and intergranular stress corrosion cracking (IGSCC) of steam generator tubes often occurs in crevices where impurities are concentrated, due to local elevated temperatures and restricted water flow. From the analysis of tubes pulled from plants, it is believed that alumino-silicates deposits and/or organic species may play a role in the development of IGA in near neutral environments. New observations suggest that similar environments and similar processes are operative inside the corroded grain boundaries. A former study using autoclave tests was mainly devoted to the formation of alumino-silicate deposits similar to those observed in plants. The present work pursued the study of local environments responsible for IGA/SC. It confirms former results on the catalytic decomposition of organic species into acetates and presents more details on the mechanism of formation of alumino-silicate deposits on alloy 600, particularly on the role of iron and, to a lesser extent, nickel cations. It was showed that, under the alumino-silicate deposits and in the presence of some organic species, a non-protective chromium rich layer may grow instead of the usual protective spinel oxide. The mechanism responsible for the formation of this layer is believed to involve interaction between iron and, to a lesser extent, nickel with silica and/or possible interaction between chromium and acetates. Preliminary capsule tests indicate that these conditions may induce the initiation of IGA.

  7. Development of the Pipe Loop System for Determining Effectiveness of Corrosion Control Chemicals in Potable Water Systems

    DTIC Science & Technology

    1988-08-01

    control for calcium carbonate precipitation, inorganic phosphates, and sodium silicates. The extent to which these inhibitors provide corrosion...complexes which can also precipitate to form protective coatings. Sodium Silicates Sodium silicates have been used in water systems as corrosion...inhibitors for over 50 years. They exist in dry form ("water glass") or in liquid solutions. In solution they exist in varying proportions of sodium oxide

  8. 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

  9. A field based study of ferrous metal corrosion in groundwater.

    PubMed

    McLaughlan, R G; Stuetz, R M

    2004-01-01

    There is an increased emphasis on adopting explicit management strategies to ensure the effective use of water wells. This can be achieved through identifying the operational and maintenance needs of water wells and associated infrastructure. The types of material used for this infrastructure will impact upon the life of these assets and their maintenance needs. In groundwater environments there is often little available corrosion rate data from historical records of operating wells upon which to make choices about material selection. Under these conditions it is necessary to rely on corrosion test data to inform design choices. A long term field based immersion test using corrosion coupons was undertaken at 24 sites across Australia. The general corrosion rates of mild steel after 9 months were found to range from 0.018 to 0.624 mm per year while stainless steel was found to have minimal corrosion under the same conditions. Galvanised steel was found to offer minimal protection compared with mild steel when the pH was below 7.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. Underground Corrosion After 32 Years: A Study of Fate and Transport - Annual Report, June 2004

    SciTech Connect

    Kay Adler Flitton

    2004-06-01

    In 1970, the National Bureau of Standards (NBS), now call National Institute of Standards and Technology (NIST), implemented the most ambitious and comprehensive long-term corrosion behavior test to date for stainless steels in soil environments. Over 32 years have passed since scientists buried 6,324 specimens from stainless steel types, specialty alloys, composite configurations, and multiple material forms and treatment conditions at six distinctive soil-type sites throughout the country. At the start of this research project, more than 190 specimens per site, exceeding a total of 1000 specimens, remained undisturbed, a buried treasure of subsurface scientific data. This research project advocates the completion of the NIST corrosion study along with a thorough examination of the soil and environment surrounding the specimens. The project takes an interdisciplinary research approach that will correlate 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. The results will provide much-needed data on corrosion rates, underground material degradation, and the behavior of corrosion products in the near-field vadose zone. The data will improve the ability to predict the fate and transport of chemical and radiological contaminants at sites throughout the DOE complex. The research scope is focused on one of the six available sites, Site D, near Wildwood, NJ.

  15. A Study on the Corrosion and Wear Behavior of Electrodeposited Ni-W-P Coating

    NASA Astrophysics Data System (ADS)

    Lee, Hung Bin; Wu, Meng Yen

    2017-07-01

    In this study, the tribocorrosion of electroplated Ni-W-P alloy coating (3.9 to 4.3 at. pct W and 13.1 to 14.7 at. pct P) on a cylindrical copper substrate was investigated using a block-on-ring tester. The wear and corrosion performance of the coating and their synergic effect were measured at different overpotentials. Under simple immersion corrosion conditions with an increasing overpotential from open-circuit potential to +400 mVSCE, the surface of the coating initially showed no obvious corrosion, eventually developing pitting holes that subsequently enlarged and showing the spreading of cracks. The corrosion products were a mixture of NiO, WO3, and phosphate, and the corroded surface was P-rich, porous, and less crystalline than the pristine coating. Corrosion and mechanical wear had little influence on tribocorrosion at low overpotential values. However, the synergic effect drastically became stronger at high overpotentials. The surface was full of large pitting holes and grooves. The weight loss due to the corrosion component increased linearly with the overpotential but was limited in comparison with the wear component, which was the main cause of weight loss. On the other hand, the friction coefficient first increased and then decreased with an increase in overpotential. Both the surface morphology of the corroded coating and the thickness of the corrosion oxide play important roles in this friction characteristic.

  16. A Study on the Corrosion and Wear Behavior of Electrodeposited Ni-W-P Coating

    NASA Astrophysics Data System (ADS)

    Lee, Hung Bin; Wu, Meng Yen

    2017-10-01

    In this study, the tribocorrosion of electroplated Ni-W-P alloy coating (3.9 to 4.3 at. pct W and 13.1 to 14.7 at. pct P) on a cylindrical copper substrate was investigated using a block-on-ring tester. The wear and corrosion performance of the coating and their synergic effect were measured at different overpotentials. Under simple immersion corrosion conditions with an increasing overpotential from open-circuit potential to +400 mVSCE, the surface of the coating initially showed no obvious corrosion, eventually developing pitting holes that subsequently enlarged and showing the spreading of cracks. The corrosion products were a mixture of NiO, WO3, and phosphate, and the corroded surface was P-rich, porous, and less crystalline than the pristine coating. Corrosion and mechanical wear had little influence on tribocorrosion at low overpotential values. However, the synergic effect drastically became stronger at high overpotentials. The surface was full of large pitting holes and grooves. The weight loss due to the corrosion component increased linearly with the overpotential but was limited in comparison with the wear component, which was the main cause of weight loss. On the other hand, the friction coefficient first increased and then decreased with an increase in overpotential. Both the surface morphology of the corroded coating and the thickness of the corrosion oxide play important roles in this friction characteristic.

  17. Computational study: Reduction of iron corrosion in lead coolant of fast nuclear reactor

    SciTech Connect

    Arkundato, Artoto; Su'ud, Zaki; Abdullah, Mikrajuddin; Widayani

    2012-06-20

    In this paper we report molecular dynamics simulation results of iron (cladding) corrosion in interaction with lead coolant of fast nuclear reactor. The goal of this work is to study effect of oxygen injection to the coolant to reduce iron corrosion. By evaluating diffusion coefficients, radial distribution functions, mean-square displacement curves and observation of crystal structure of iron before and after oxygen injection, we concluded that a significant reduction of corrosion can be achieved by issuing about 2% of oxygen atoms into lead coolant.

  18. 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.

  19. Electrochemical Studies on Silicate and Bicarbonate Ions for Corrosion Inhibitors

    NASA Astrophysics Data System (ADS)

    Mohorich, Michael E.; Lamb, Joshua; Chandra, Dhanesh; Daemen, Jaak; Rebak, Raul B.

    2010-10-01

    Several types of carbon and high-strength low-alloy (HSLA) steels are being considered for use in the underground reinforcement of the Yucca Mountain Nuclear Waste Repository. In this study, potentiodynamic polarization under reducing conditions was used to determine the corrosion rates (CRs) and passivity behavior of AISI 4340 steel using different combinations of sodium silicate (Na2SiO3) and sodium bicarbonate (NaHCO3), in both pure water (PW) and simulated seawater (SW, 3.5 pct NaCl). These experiments were carried out to examine the potential inhibiting properties of the silicate or bicarbonate ions on the surface of the steel. The addition of sodium silicate to solution reduced the observed CR at room temperature to 19 μm/y at 0.005 M concentration and 7 μm/y at 0.025 M concentration in PW. The addition of sodium bicarbonate increased the CR from 84 μm/y (C = 0.1 M) to 455 μm/y (C = 1 M). These same behaviors were also observed at higher temperatures.

  20. Complementarity of XRFS and LIBS for corrosion studies.

    PubMed

    Pérez-Serradilla, J A; Jurado-López, A; Luque de Castro, M D

    2007-01-15

    A study of ancient coins with different corrosion degrees and the same or different composition has been carried out by using energy-dispersive X-ray fluorescence spectrometry (XRFS) and laser-induced break-down spectroscopy (LIBS). The results obtained show the complementarity of both techniques: XRFS provides information about the superficial composition which is used for the assignation of atomic lines in LIBS, and this provides in-depth and tomographic information. Thus, some very superficial impurities such as Ag, Cl, Au, Sr and Sb are only detected by XRFS, while highly corroded coins of iron-based alloy provided no iron signal by XRFS but increased concentration of this element up to constant composition by LIBS by increasing the shot number. The average of the same laser-shot number for all sampling positions of a sampling zone produces a significant improvement of the signal-to-noise ratio (SNR) in the detriment of punctual information as that obtained by single-position kinetic series.

  1. Microbiologically Influenced Corrosion in Copper and Nickel Seawater Piping Systems

    DTIC Science & Technology

    1990-09-01

    Ambiente , pp. 163-170. product structure on the corrosion rate of Cu-Ni alloys. Stover, H. E. 1961. Premature failure of copper-nickel alloys...Sons Ltd. 441 pp. Quimica . Verink, E.D. and Pourbaix, M. 1971. Use of electrochemical Pope, D. H., Duquette, D. J., Johannes, A. H., and Wayner...Bacteria. 2nd Ed. Workshop on Biodeterioration (CONICET-NSF), pp. 43-63, 144pp. London: Cambridge University Press. Sao Paulo, Brazil: Aquatec Quimica . MTS Journal • Vol. 24, No. 3 • 17

  2. 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

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Applicability of corrosion control... WATER REGULATIONS Control of Lead and Copper § 141.81 Applicability of corrosion control treatment steps to small, medium-size and large water systems. (a) Systems shall complete the applicable...

  3. 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

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Applicability of corrosion control... WATER REGULATIONS Control of Lead and Copper § 141.81 Applicability of corrosion control treatment steps to small, medium-size and large water systems. (a) Systems shall complete the applicable...

  4. EXPERIMENTAL STUDY TO EVALUATE CORROSION OF THE F-CANYON DISSOLVER DURING THEUNIRRADIATED MARK-42 CAMPAIGN

    SciTech Connect

    Mickalonis, J; Kerry Dunn, K

    1999-08-01

    Unirradiated Mark 42 fuel tubes are to be dissolved in an upcoming campaign in F-canyon. Savannah River Technology Center (SRTC)/Chemical & Hydrogen Technology Section (CHTS) identified a flow sheet for the dissolution of these Mark 42 fuel tubes which required a more aggressive dissolver solution than previously required for irradiated Mark 42 fuel tubes. Subsequently, SRTC/MTS was requested to develop and perform a corrosion testing program to assess the impact of new flow sheets on corrosion of the dissolver wall. The two primary variables evaluated were the fluoride and aluminum concentrations of the dissolver solution. Fluoride was added as Calcium Fluoride (CaF{sub 2}) while the aluminum was added either as metallic aluminum, which was subsequently dissolved, or as the chemical aluminum nitrate (Al(NO{sub 3}){sub 3}). The dissolved aluminum metal was used to simulate the dissolution of the aluminum from the Mark 42 cladding and fuel matrix. Solution composition for the corrosion tests bracketed the flow sheet for the Mark 42. Corrosion rates of AISI Type 304 stainless steel coupons, both welded and non-welded coupons, were calculated from measured weight losses and post-test concentrations of soluble Fe, Cr and Ni. The corrosion rates, which ranged between 2.7 and 32.5 mpy, were calculated from both the one day and the one week weight losses. These corrosion rates indicated a relatively mild corrosion on the dissolver vessel. The welded coupons consistently had a higher corrosion rate than the non-welded coupons. The difference between the two decreased as the solution aggressiveness decreased. In these test solutions, aggressiveness corresponded with the fluoride concentration. Based on the results of this study, any corrosion occurring during the Mark 42 Campaign is not expected to have a deleterious effect on the dissolver vessel.

  5. 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

  6. Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

    DOE PAGES

    Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Motta, Arthur T.; ...

    2016-10-25

    A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction (XRD) studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoringmore » the oxidation of metallic zirconium during exposure to steam at 350°C. Finally, the in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during early stages of corrosion, which can provide a better understanding the oxidation process.« less

  7. Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

    NASA Astrophysics Data System (ADS)

    Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Motta, Arthur T.; Weidner, Randy; Anderson, Thomas; Ecker, Lynne E.

    2016-10-01

    A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoring the oxidation of metallic zirconium during exposure to steam at 350 °C. The in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during the early stages of corrosion, which can provide a better understanding of the oxidation process.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Integral evaluation of the external corrosion control system for buried pipelines

    SciTech Connect

    Kowalski, A.R.

    1998-12-31

    The External Corrosion Control System of a 16 inch diameter (406 mm), 70 miles long (113 km) pipeline, was evaluated using the Direct Current Voltage Gradient DCVG, Close Interval Potential Survey CIPS and Continuous Soil Resistivity Evaluation CSRE techniques. Sixteen thousand five hundred meters (16,500 meters) of the pipeline were evaluated using the three techniques simultaneously and the rest was inspected separately in previous years. The results from the survey were taken as parameters to classify all defects found on the protective coating. A Defect Severity Classification (DSC) was established and used as an input for a maintenance program for the rehabilitation of the pipeline integrity. The parameters taken to establish the DSC were: (a) Instant Off Potential, (b) %IR, (c) Soil Resistivity, (d) defect shape, (e) Geographic location, (f) Distance from drain point. A Maintenance Program for the Pipeline External Corrosion Control System was designed by implementing the Integral Evaluation of the Corrosion Control System for Buried Pipelines (IEECCSBP). The priority was to achieve pipeline integrity and then, gradually improve the protection level of the system. The implementation of IEECCSBP will help to reduce the frequency of Electromagnetic Metal Loss Inspections, which in the future will serve only as an audit of the External Corrosion Control System performance.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. Galvanic Corrosion Studies on Titanium and Zirconium Metals

    DTIC Science & Technology

    1954-06-01

    as the arc-melted metal in oxalic acid solutions. However, corrosion rates are generally higher for titanium prepared from powder. Titanium is more...contact. Conclusions: 1. Uncoupled specimens of titanium are resistant to air-aerated solutions of 1 and 9 percent oxalic acid solutions but contact with

  1. CEMS study of corrosion products formed by NaCl aqueous solution

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.

    2012-03-01

    Conversion electron Mössbauer spectroscopy was used to study corrosion products by NaCl aqueous solution. A drop of the solution is put on an iron foil and the foil is left at RT. During the evaporation of the solution, corrosion products are formed. Conversion electron Mössbauer spectra were taken at temperatures between 15 K and room temperature (RT). In the Mössbauer spectra a ferric doublet is observed at RT, but sextets are found at 15 K. These results show that the corrosion product mainly consists of γ - FeOOH and a small amount of β - FeOOH is noticed. As NaCl concentration increases, the corrosion layer becomes thick and β- FeOOH / γ - FeOOH ratio increases slightly. Consequently, it has been concluded that the produced amount of β- FeOOH increases more rapidly than that of γ - FeOOH with increasing NaCl concentration.

  2. 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.

  3. Flow-induced corrosion of absorbable magnesium alloy: In-situ and real-time electrochemical study

    PubMed Central

    Wang, Juan; Jang, Yongseok; Wan, Guojiang; Giridharan, Venkataraman; Song, Guang-Ling; Xu, Zhigang; Koo, Youngmi; Qi, Pengkai; Sankar, Jagannathan; Huang, Nan; Yun, Yeoheung

    2016-01-01

    An in-situ and real-time electrochemical study in a vascular bioreactor was designed to analyze corrosion mechanism of magnesium alloy (MgZnCa) under mimetic hydrodynamic conditions. Effect of hydrodynamics on corrosion kinetics, types, rates and products was analyzed. Flow-induced shear stress (FISS) accelerated mass and electron transfer, leading to an increase in uniform and localized corrosions. FISS increased the thickness of uniform corrosion layer, but filiform corrosion decreased this layer resistance at high FISS conditions. FISS also increased the removal rate of localized corrosion products. Impedance-estimated and linear polarization-measured polarization resistances provided a consistent correlation to corrosion rate calculated by computed tomography. PMID:28626241

  4. Corrosion-fatigue studies of the Zr-based Vitreloy 105 bulk metallic glass

    SciTech Connect

    Horton Jr, Joe A; Morrison, M. L.; Buchanan, R. A.; Liaw, Peter K; Green, B. A.; Wang, G Y

    2007-01-01

    The purpose of this study was to characterize the stress-life behavior of the Vitreloy 105 BMG alloy in the four-point bending configuration in a 0.6 M NaCl electrolyte. At high stress amplitudes, the corrosion-fatigue life was similar to the fatigue lives observed in air. The environment became increasingly detrimental with decreases in stress, and the corrosion-fatigue endurance limit decreased to about 50 MPa, an 88% decrease relative to testing in air. Similar to the tests conducted in air, oxide particles were found on the fracture surfaces but did not appear to significantly affect the corrosion-fatigue lives. However, wear and the resultant corrosion at the outer loading pins resulted in crack initiation in most of the samples. Thus, these results are considered conservative estimates of the corrosion-fatigue behavior of this BMG alloy. Monitoring of the samples and the open-circuit potentials revealed that the onset of significant crack growth occurred at an average of 92% of the total fatigue life. The mechanism of corrosion-fatigue degradation was found to be anodic dissolution.

  5. MHD channel gas-side element erosion-corrosion studies

    NASA Astrophysics Data System (ADS)

    Pollina, R. J.; Simpsom, W.; Farrar, L. C.

    The problems connected with gas side corrosion for the design of the 1A4 channel hardware are explored and the results to date are presented of gas side wear rate tests in the Mark 7 facility. They show that the proposed designs meet a 2000 hour lifetime criterion based upon materials test results. They also show the improvement in cathode lifetime obtained with lower voltage intercathode gaps. The corrosion is discussed of these materials and how lifetimes are dependent upon gap voltage and average metal temperature is shown. The final choice of materials is determined primarily by the outcome of these tests and also by the question of the manufacturability of the prospective designs.

  6. Prevention for possible microbiologically influenced corrosion (MIC) in RHLWE flush water system

    SciTech Connect

    Hsu, T.C.; Jenkins, C.F.

    1995-07-10

    This report is in response to the request to provide a recommendation for the prevention of possible microbiologically influenced corrosion (MIC) for the RHLWE (Replacement High-Level Waste Evaporator) flush water (FW) system. The recent occurrences of MIC at DWPF prompted HLWE to evaluate the possibility of MIC occurring in this 304L stainless steel RHLWE flush water system. Concern was heightened by the fact that the well water used and the other conditions at H-Tank Farm are similar to those at DWPF. However, only one known leak has occurred in the existing 304L evaporator flush water systems in either tank farm (in 1H system), and no MIC Corrosion has been confirmed in the tank farm area. The design of the RHLWE flush water system (completed long before the occurrence of MIC at DWPF) was modeled after the existing evaporator flush water systems and did not specifically include MIC prevention considerations. Therefore, MIC prevention was not specifically considered during the design phase of this flush water system. The system is presently being installed. After an extensive evaluation, a task team concluded that the best biocide to prevent the occurrence of MIC would be NaOH at fairly low concentration. Sodium hydroxide (NaOH) is optimal in this application, because of its effectiveness, low cost, and familiarity to the Operations personnel (see Appendix A). However, it is the opinion of the task group that application should be withheld until MIC corrosion is demonstrated in the system.

  7. Corrosion control acceptance criteria for sacrificial anode type, cathodic protection systems (user guide)

    NASA Astrophysics Data System (ADS)

    Hock, Vincent F.; Noble, Michael; McLeod, Malcolm E.

    1994-07-01

    The Army currently operates and maintains more than 20,000 underground storage tanks and over 3000 miles of underground gas pipelines, all of which require some form of corrosion control. Cathodic protection is one method of corrosion control used to prevent corrosion-induced leaks when a steel structure is exposed to an aggressive soil. The corrosion control acceptance criteria for sacrificial anode type CP systems provides guidelines for the DEH/DPW cathodic protection installation inspectors whose responsibilities are to ensure that the materials and equipment specified are delivered to the job site and subsequently installed in accordance with the engineering drawings and specifications. The sacrificial anode CP acceptance criteria includes all components for the sacrificial anode system such as insulated conductors, anodes, anode backfills, and auxiliary equipment. The sacrificial anode CP acceptance criteria is composed of a checklist that lists each component and that contains a space for the inspector to either check 'yes' or 'no' to indicate whether the component complies with the job specifications. In some cases, the inspector must measure and record physical dimensions or electrical output and compare the measurements to standards shown in attached tables.

  8. Magnetostriction and corrosion studies in single crystals of iron-gallium alloys

    NASA Astrophysics Data System (ADS)

    Jayaraman, Tanjore V.

    Iron-gallium alloys have an excellent combination of large low-field magnetostriction, good mechanical properties, low hysteresis, and relatively low cost. This dissertation focuses on the magneto striction and corrosion behaviors of single crystals of Fe-Ga alloys. In the first part, the variation of magnetostrictive coefficient: (3/2) lambda100, with composition and heat treatment conditions of Fe-Ga alloys, is examined. Single crystals with compositions Fe-15 at.% Ga, Fe-20 at.% Ga, and Fe-27.5 at.% Ga were obtained by (a) vertical Bridgman technique (DG) and (b) vertical Bridgman technique followed by long-term annealing (LTA) and quenching. Rapid quenching from a phase region improves the (3/2) lambda 100 value in these alloys. X-ray diffraction characterization showed for the first time the direct evidence of short-range ordering in these alloys. The second part reports the first study of alpha" ordering heat treatment on the elastic properties and magnetostriction of Fe-27.5 at.% Ga alloy single crystals. The elastic constants were measured using resonant ultrasound spectroscopy (RUS), and the elastic properties and magneto-elastic coupling constant were calculated. The (3/2) lambda100 and B1 values obtained for a phase were higher than alpha" phase. The third part examines the first study of corrosion behavior of as-cast FeGa and Fe-Ga-Al alloys in acidic, basic, and simulated seawater environments. Corrosion measurements were performed by Tafel scan and polarization resistance method and in general exhibited good corrosion resistance. The fourth part examines the first study of corrosion behavior of Fe-15 at.% Ga, Fe-20 at.% Ga, and Fe-27.5 at.% Ga DG and LTA alloy single crystals and the dependence of corrosion rates on the crystal orientations. The corrosion resistance was better in basic environments followed by simulated seawater and acidic environments. The fifth part examines the effect of magnetostriction on the corrosion behavior of [100]-oriented

  9. Corrosion studies of titanium in borated water for TPX

    SciTech Connect

    Wilson, D.F.; Pawel, S.J.; DeVan, J.H.; Cole, M.J.; Nelson, B.E.

    1995-12-31

    Corrosion testing was performed to demonstrate the compatibility of the titanium vacuum vessel with borated water. Borated water is proposed to fill the annulus of the double wall vacuum vessel to provide effective radiation shielding. Borating the water with 110 grams of boric acid per liter is sufficient to reduce the nuclear heating in the Toroidal Field Coil set and limit the activation of components external to the vacuum vessel. Constant extension rate tensile (CERT) and electrochemical potentiodynamic tests were performed. Results of the CERT tests confirm that stress corrosion cracking is not significant for Ti-6Al4V or Ti-3AI-2.5V. Welded and unwelded specimens were tested in air and in borated water at 150{degree}C. Strength, elongation, and time to failure were nearly identical for all test conditions, and all the samples exhibited ductile failure. Potentiodynamic tests on Ti-6A1-4V and Ti in borated water as a function of temperature showed low corrosion rates over a wide passive potential range. Further, this passivity appeared stable to anodic potentials substantially greater than those expected from MHD effects.

  10. 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.

  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. Control of corrosion and aggression in drinking water systems.

    PubMed

    Loewenthal, R E; Morrison, I; Wentzel, M C

    2004-01-01

    Corrosion and/or aggression are common problems arising in pipelines transporting terrestrial waters. The kinetics and severity of such events depend on both the quality of the water being transported and the material properties of the pipeline. Irrespective of the nature of the problem, its solution (or at least its minimisation) is strongly linked to control of pH, calcium concentration and carbonate chemistry of the water (stabilisation). However, application of such chemistry to water treatment problems is complex and time consuming. Various numerical, graphical and computer techniques have been developed to address this, but these are either of insufficient accuracy, too time consuming or lacking in generality. In this paper algorithms are presented for solving a broad spectrum of problems related to control of mineral precipitation/aggression, pH and chemical dosing in water treatment. These have been incorporated into a computer software package, STASOFT, which offers the requisite framework for use in water treatment. Various stabilisation problems pertinent to water supply are addressed.

  13. 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.

  14. Enhanced Cr(VI) removal from groundwater by Fe(0)-H2O system with bio-amended iron corrosion.

    PubMed

    Yin, Weizhao; Li, Yongtao; Wu, Jinhua; Chen, Guocai; Jiang, Gangbiao; Li, Ping; Gu, Jingjing; Liang, Hao; Liu, Chuansheng

    2017-02-27

    A one-pot bio-iron system was established to investigate synergetic abiotic and biotic effects between iron and microorganisms on Cr(VI) removal. More diverse iron corrosion and reactive solids, such as green rusts, lepidocrocite and magnetite were found in the bio-iron system than in the Fe(0)-H2O system, leading to 4.3 times higher Cr(VI) removal efficiency in the bio-iron system than in the Fe(0)-H2O system. The cycling experiment also showed that the Cr(VI) removal capacity of Fe(0) in the bio-iron system was 12.4 times higher than that in the Fe(0)-H2O system. A 62days of life-span could be achieved in the bio-iron system, while the Fe(0)-H2O system lost its efficacy after 30days. Enhanced effects of extra Fe(2+) on Cr(VI) removal was observed, largely contributed to the adsorbed Fe(2+) on iron surface, which could function as an extra reductant for Cr(VI) and promote the electron transfer on the solid phase. The results also showed that the reduction of Cr(VI) by microorganisms was insignificant, indicating the adsorption/co-precipitation of Cr by iron oxides on iron surface was responsible for the overall Cr(VI) removal. Our study demonstrated that the bio-amended iron corrosion could improve the performance of Fe(0) for Cr(VI) removal from groundwater.

  15. General and crevice corrosion study of the in-wall shielding materials for ITER vacuum vessel

    NASA Astrophysics Data System (ADS)

    Joshi, K. S.; Pathak, H. A.; Dayal, R. K.; Bafna, V. K.; Kimihiro, Ioki; Barabash, V.

    2012-11-01

    Vacuum vessel In-Wall Shield (IWS) will be inserted between the inner and outer shells of the ITER vacuum vessel. The behaviour of IWS in the vacuum vessel especially concerning the susceptibility to crevice of shielding block assemblies could cause rapid and extensive corrosion attacks. Even galvanic corrosion may be due to different metals in same electrolyte. IWS blocks are not accessible until life of the machine after closing of vacuum vessel. Hence, it is necessary to study the susceptibility of IWS materials to general corrosion and crevice corrosion under operations of ITER vacuum vessel. Corrosion properties of IWS materials were studied by using (i) Immersion technique and (ii) Electro-chemical Polarization techniques. All the sample materials were subjected to a series of examinations before and after immersion test, like Loss/Gain weight measurement, SEM analysis, and Optical stereo microscopy, measurement of surface profile and hardness of materials. After immersion test, SS 304B4 and SS 304B7 showed slight weight gain which indicate oxide layer formation on the surface of coupons. The SS 430 material showed negligible weight loss which indicates mild general corrosion effect. On visual observation with SEM and Metallography, all material showed pitting corrosion attack. All sample materials were subjected to series of measurements like Open Circuit potential, Cyclic polarization, Pitting potential, protection potential, Critical anodic current and SEM examination. All materials show pitting loop in OC2 operating condition. However, its absence in OC1 operating condition clearly indicates the activity of chloride ion to penetrate oxide layer on the sample surface, at higher temperature. The critical pitting temperature of all samples remains between 100° and 200°C.

  16. 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

  17. 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.

  18. Corrosion monitoring system for pipes under annular flow conditions, based on distributed AC impedance

    SciTech Connect

    Hernandez, S.; Callarotti, R.; Vera, J.R.

    1997-12-01

    A prototype has been developed to measure both corrosion rates and liquid film thickness in pipes carrying fluids with annular flow. Circuital modeling discretization was used in determining the theoretical sensor response. The purpose of this work was to design and test a device that can be installed in the pipeline so as to determine not only the corrosion rates of the surrounding pipe, but also the characteristics of the flow running through it. The use of this apparatus would not be limited to gas-liquid systems, since oil-water systems, such as those produced when water is used to transport heavy oil, could also be analyzed with the system here described. Results presented in this paper include the theoretical development of the sensor together with the design and verification of a laboratory prototype.

  19. Inhibited ethylene and propylene glycols for corrosion and freeze protection in water-based HVAC systems

    SciTech Connect

    Roo, A.M. de; Lee, B.W.

    1997-12-31

    Industrially inhibited ethylene and propylene glycols are used extensively to provide protection against equipment damage due to corrosion and freezing. This paper will describe the proper use of these glycols, including system preparation, fluid installation, and fluid maintenance. The impact of the use of these glycols on the operation of the system is discussed along with methods for overcoming any declines in heat transfer. From this discussion, it will become clear why automotive antifreeze formulations should not be used in heating, ventilating, and airconditioning (HVAC) systems. Also included are data on the physical properties of aqueous solutions of ethylene and propylene glycol, the concept of burst vs. freeze protection, typical results of corrosion tests, and methods to use to monitor the fluid for each application.

  20. 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).

  1. Corrosion resistance of three orthodontic brackets: a comparative study of three fluoride mouthwashes.

    PubMed

    Schiff, Nicolas; Dalard, Francis; Lissac, Michèle; Morgon, Laurent; Grosgogeat, Brigitte

    2005-12-01

    In the present study, three types of orthodontic brackets were investigated: cobalt-chromium (CoCr), iron-chromium-nickel (FeCrNi) and titanium (Ti) based. Their corrosion resistance was compared with that of platinum (Pt), which was chosen as the reference material because of its excellent electrochemical properties. The test solutions were Elmex, Meridol and Acorea fluoride mouthwashes. Fusayama Meyer artificial saliva was used as the reference solution. The corrosion resistance of the different brackets in the three mouthwashes was assessed electrochemically to determine the corrosion potential and corrosion current density, and polarization resistance values were then calculated. A scanning electron microscopic (SEM) study and an analysis of released metal ions confirmed the electrochemical studies. The results showed that the bracket materials could be divided into two groups: Ti and FeCrNi in one, and CoCr, which has properties close to those of Pt, in the other. Similarly, two groups of electrolytes were identified: Elmex and Acorea mouthwashes in one group, and Meridol mouthwash in the second group. The results indicate that because of the risk of corrosion Meridol mouthwash should not be prescribed for patients wearing Ti or FeCrNi-based orthodontic brackets.

  2. 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.

  3. 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.

  4. 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.

  5. Tribology and Corrosion in CoCrMo Alloys and Similar Systems

    NASA Astrophysics Data System (ADS)

    Hoffman, Emily E.

    The artificial hip is a rich environment for the tribologist. This research investigated tribology and corrosion in CoCrMo alloy hip implants and extended the characterization methods and analyses to similar systems. The first project examined differences in corrosion behavior in the biomedical CoCrMo alloy using TEM and EDS. At the corroding grain boundaries, we found nanoscale chromium-rich carbides. These carbides caused chromium depleted zones which leads to corrosion, a process commonly referred to as sensitization. The chromium depletion and grain boundary crystallography data were used to develop a model showing nanoscale sensitization initiated grain boundary crevice corrosion. The next area of research looked at nanotribology of solid lubricants and formation of tribolayers. In situ TEM was used to directly observe the sliding interface of nanoflakes of molybdenum disulfide. Investigating low friction mechanisms of the lamellar solid lubricant revealed that the deck-of-cards sliding assumption present in the literature was not true. Instead, we showed sliding and transfer layer formation occurred at one interface only. The in situ sliding tests also revealed that the nanoflakes are unstable during sliding due to rolling, reorientation, flake pull apart, and adhesion changes. The final project analyzed a variety of carbon tribofilms, including the tribolayer found in metal-on-metal hips and the varnish tribofilm that forms in industrial machines. We characterized the carbon varnish film and showed similarities to published work on other graphitic carbon films. By comparing the nanoscale bonding and formation mechanisms, striking similarities were found that could inspire future cross-discipline advancements. Together, this work examined the relationships between wear, corrosion, and tribology to connect nanoscale structure and composition to applied performance.

  6. Glass-metal objects from archaeological excavation: corrosion study

    NASA Astrophysics Data System (ADS)

    Greiner-Wronowa, Elżbieta; Zabiegaj, Dominika; Piccardo, Paolo

    2013-12-01

    This paper contributes to the investigations on history, technology, and degradation of middle age objects (metallic rings with mounted glass beads) recently excavated under the Main Square in Krakow (Poland). Moreover, they were discovered in soil layers differing by chemical composition and microclimate parameters. Historical material is indeed very limited in terms of quantity and sample size, and the following nondestructive analyses were applied: scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS), X-ray diffraction (XRD), and X-ray fluorescence spectroscopy (XRF). The glass and the metal were separately tested. Metallography on cross-sections (by both optical and scanning electron microscopy) was applied only on microfragments sampled from metallic rings. The achieved results pointed out how the local microclimate affected the degradation of the analyzed rings developing locally different corrosion processes. Each tested glass of "ring eye" shows a specific chemical composition. All glass pieces were covered by silica gel, and locally more advanced corrosion has been found.

  7. 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.

  8. Development and use of a laser-based pipeline corrosion assessment system

    SciTech Connect

    Bruce, W.A.; Yapp, D.; Barborak, D.M.; Fingerhut, M.P.; Kania, R.

    1997-05-01

    The development and use of a simple laser-based system for accurately and efficiently measuring and assessing corrosion damage on the external surface of an exposed pipeline is described. The system uses a laser-based range sensor, which relies on optical spray, sensor movement, and the principal of triangulation to construct a three-dimensional measurement. Baseline subtraction, where a polynomial curve-fit is used to approximate the ideal pipe profile above the corroded area, is used. Future profiles are subtracted; from the ideal profile, and when differences are significant, corrosion depth measurements are made by constructing normal vectors at points along the ideal profile. A software program titled CorrosionPro 2.1 was developed to provide a means to playback and display data files generated by the system. The program uses the RSTRENG algorithm to assess the significance of the damage. Examples of the application of this system on large-diameter gas and oil pipelines are also described.

  9. 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.

  10. 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.

  11. Stress Corrosion Evaluation of Nitinol 60 for the International Space Station Water Recycling System

    NASA Technical Reports Server (NTRS)

    Torres, P. D.

    2016-01-01

    A stress corrosion cracking (SCC) evaluation of Nitinol 60 was performed because this alloy is considered a candidate bearing material for the Environmental Control and Life Support System (ECLSS), specifically in the Urine Processing Assembly of the International Space Station. An SCC evaluation that preceded this one during the 2013-2014 timeframe included various alloys: Inconel 625, Hastelloy C-276, titanium (Ti) commercially pure (CP), Ti 6Al-4V, extra-low interstitial (ELI) Ti 6Al-4V, and Cronidur 30. In that evaluation, most specimens were exposed for a year. The results of that evaluation were published in NASA/TM-2015-218206, entitled "Stress Corrosion Evaluation of Various Metallic Materials for the International Space Station Water Recycling System,"1 available at the NASA Scientific and Technical Information program web page: http://www.sti.nasa.gov. Nitinol 60 was added to the test program in 2014.

  12. 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.

  13. Fundamental Studies of the Role of Grain Boundaries on Uniform Corrosion of Advanced Nuclear Reactor Materials

    SciTech Connect

    Taheri, Mitra; Motta, Arthur; Marquis, Emmanuelle

    2016-05-20

    The main objective of this proposal is to develop fundamental understanding of the role of grain boundaries in stable oxide growth. To understand the process of oxide layer destabilization, it is necessary to observe the early stages of corrosion. During conventional studies in which a sample is exposed and examined after removal from the autoclave, the destabilization process will normally have already taken place, and is only examined post facto. To capture the instants of oxide destabilization, it is necessary to observe it in situ; however, significant questions always arise as to the influence of the corrosion geometry and conditions on the corrosion process. Thus, a combination of post facto examinations and in situ studies is proposed, which also combines state-of-the-art characterization techniques to derive a complete understanding of the destabilization process and the role of grain boundaries.

  14. Comparative Study on Corrosion Protection of Reinforcing Steel by Using Amino Alcohol and Lithium Nitrite Inhibitors.

    PubMed

    Lee, Han-Seung; Ryu, Hwa-Sung; Park, Won-Jun; Ismail, Mohamed A

    2015-01-14

    In this study, the ability of lithium nitrite and amino alcohol inhibitors to provide corrosion protection to reinforcing steel was investigated. Two types of specimens-reinforcing steel and a reinforced concrete prism that were exposed to chloride ion levels resembling the chloride attack environment-were prepared. An autoclave accelerated corrosion test was then conducted. The variables tested included the chloride-ion concentration and molar ratios of anti-corrosion ingredients in a CaOH₂-saturated aqueous solution that simulated a cement-pore solution. A concentration of 25% was used for the lithium nitrite inhibitor LiNO₂, and an 80% solution of dimethyl ethanolamine ((CH₃)₂NCH₂CH₂OH, hereinafter DMEA) was used for the amino alcohol inhibitor. The test results indicated that the lithium nitrite inhibitor displayed anti-corrosion properties at a molar ratio of inhibitor of ≥0.6; the amino alcohol inhibitor also displayed anti-corrosion properties at molar ratios of inhibitor greater than approximately 0.3.

  15. Comparative Study on Corrosion Protection of Reinforcing Steel by Using Amino Alcohol and Lithium Nitrite Inhibitors

    PubMed Central

    Lee, Han-Seung; Ryu, Hwa-Sung; Park, Won-Jun; Ismail, Mohamed A.

    2015-01-01

    In this study, the ability of lithium nitrite and amino alcohol inhibitors to provide corrosion protection to reinforcing steel was investigated. Two types of specimens—reinforcing steel and a reinforced concrete prism that were exposed to chloride ion levels resembling the chloride attack environment—were prepared. An autoclave accelerated corrosion test was then conducted. The variables tested included the chloride-ion concentration and molar ratios of anti-corrosion ingredients in a CaOH2-saturated aqueous solution that simulated a cement-pore solution. A concentration of 25% was used for the lithium nitrite inhibitor LiNO2, and an 80% solution of dimethyl ethanolamine ((CH3)2NCH2CH2OH, hereinafter DMEA) was used for the amino alcohol inhibitor. The test results indicated that the lithium nitrite inhibitor displayed anti-corrosion properties at a molar ratio of inhibitor of ≥0.6; the amino alcohol inhibitor also displayed anti-corrosion properties at molar ratios of inhibitor greater than approximately 0.3. PMID:28787936

  16. Experimental and modeling study of chloride ingress into concrete and reinforcement corrosion initiation

    NASA Astrophysics Data System (ADS)

    Yu, Hui

    Effects of reinforcement and coarse aggregate on chloride ingression into concrete and reinforcement corrosion initiation have been studied with experimental and modeling (finite element method) analyses. Once specimens were fabricated and exposed to a chloride solution, various experimental techniques were employed to determine the effect of reinforcement and coarse aggregate on time-to-corrosion and chloride ingress and concentration at corrosion locations. Model analyses were performed to verify and explain the experimental results. Based upon the results, it was determined that unexpectedly higher chloride concentrations were present on the top of the rebar trace than that to the side at the same depth and an inverse concentration gradient (increasing [ Cl-] with increasing depth) occurred near the top of rebars. Also, coarse aggregate volume profile in close proximity to the rebar and spatial distribution of these aggregates, in conjunction with the physical obstruction afforded by reinforcement to chloride flow, complicates concrete sampling for Cl- intended to define the critical concentration of this species to initiate corrosion. Modeling analyses that considered cover thickness, chloride threshold concentration, reinforcement size and shape, and coarse aggregate type and percolation confirmed the experimental findings. The results, at least in part, account for the relatively wide spread in chloride corrosion threshold values reported in the literature and illustrate that more consistent chloride threshold concentrations can be acquired from mortar or paste specimens than from concrete ones.

  17. A Study on Electrolytic Corrosion of Boron-Doped Diamond Electrodes when Decomposing Organic Compounds.

    PubMed

    Kashiwada, Takeshi; Watanabe, Takeshi; Ootani, Yusuke; Tateyama, Yoshitaka; Einaga, Yasuaki

    2016-03-02

    Electrolytic corrosion of boron-doped diamond (BDD) electrodes after applying a high positive potential to decompose organic compounds in aqueous solution was studied. Scanning electron microscopy images, Raman spectra, and glow discharge optical emission spectroscopy revealed that relatively highly boron-doped domains were primarily corroded and relatively low boron-doped domains remained after electrolysis. The corrosion due to electrolysis was observed especially in aqueous solutions of acetic acid or propionic acid, while it was not observed in other organic compounds such as formic acid, glucose, and methanol. Electron spin resonance measurements after electrolysis in the acetic acid solution revealed the generation of methyl radicals on the BDD electrodes. Here, the possible mechanisms for the corrosion are discussed. Dangling bonds may be formed due to abstraction of OH groups from C-OH functional groups by methyl radicals generated on the surface of the BDD electrodes. As a result, the sp(3) diamond structure would be converted to the sp(2) carbon structure, which can be easily etched. Furthermore, to prevent electrolytic corrosion during electrolysis, both the current density and the pH condition in the aqueous solution were optimized. At low current densities or high pH, the BDD electrodes were stable without electrolytic corrosion even in the acetic acid aqueous solution.

  18. USS PRINCETON (CG59): Microbiologically Influenced Corrosion (MIC) and Macrofouling Status of Seawater Piping Systems

    DTIC Science & Technology

    1990-06-01

    chest. Due to the recurring nature and the extent of the macrofouling in the seawater piping systems, it appears likely that these microorganisms have...34Effect of High Frequency Fields on Microorganisms ," Electrical Engineering, Jan 1944, pp. 18-21. 53. Murr, L. E., "Biophysics of Plant Growth in an...oxidation; (5) depolarization of cathodic or anodic reactions; (6) disruption of natural or other protective films and breakdown of corrosion inhibitors and

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. Comparison of some dietary habits on corrosion behavior of stainless steel brackets: an in vitro study.

    PubMed

    Shahabi, M; Jahanbin, A; Esmaily, H; Sharifi, H; Salari, S

    2011-01-01

    Resistance to corrosion is an advantageous property of orthodontic brackets; however, due to low levels of pH found in the mouth of a patient, localized corrosion may occur This can affect tooth movement by increasing friction between the arch wire and bracket slot and initiate enamel discoloration. Additionally, corrosion causes the release of elements that may lead to cytotoxic and biological side effects. The aim of this study was to compare the amount of corrosion caused by lemon juice, vinegar and Coca-Cola on orthodontic brackets in vitro and then to recommend the most suitable diet during orthodontic treatment. Sixty orthodontic brackets in three groups of twenty were immersed in a test solution (Fusamaya-Meyer artificial saliva plus lemon juice, vinegar or Coca-Cola) at a temperature of 37 degrees C +/- 1. Moreover, a negative control consisting of twenty brackets were put in pure artificial saliva. After 6 weeks the amount of corrosion was determined by measuring delta W of mean weights of brackets and the results were analyzed by general linear models (repeated measurement). Significant differences were seen during different weeks of the study (P < 0.001) and different solutions (P < 0.001). This study showed the amount of corrosion in orthodontic brackets was the most for cola followed by vinegar and then lemon juice. In addition, mean differences for cola versus lemon juice was -0.010 (sig. <0.001), vinegar versus lemon juice was -0.006 (sig. = 0.001) and cola versus vinegar was -0.004 (sig. = 0.013). Acidic effervescent soft drinks such as cola have to be eliminated or minimized in the nutritional diet of orthodontic patients because of their harmful effects on their brackets.

  5. Marine and offshore corrosion

    SciTech Connect

    Chandler, K.A.

    1985-01-01

    Until recently marine corrosion technology has been preoccupied with the corrosion of ships. Within the last ten years, however, the rapid expansion of oil and gas exploration has changed the course of corrosion research as well as the market for corrosion services and products. So complete has been the change that a new approach, dealing with ships, structures, and plant has been taken in this book. This introduction to the control of corrosion in marine environments will serve as a reference on topics ranging from coating systems to metallurgical considerations in the design of ships, offshore structure, plant and pipelines.

  6. 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.

  7. The Activity of Trace Metals in Aqueous Systems and the Effect of Corrosion Control Inhibitors

    DTIC Science & Technology

    1975-10-01

    Polarography 10 Absorption Spectrophotometric Methods 15 Flame Photometer 16 III MATERIALS STUDIED 18 Ultrapure Water 18 Metals Studi,’ 25 The Corrosion...well known. Detailed water characterization defines the degree of water purity and/or contaminacion una iLs application in atomic absorption, flame ...dial positions are marked for suspended solids testing (infrared light range) and for the measurement of water color. 7. FLAME PHOTOMETER. The flame

  8. Cu-Ti, Co-Ti and Ni-Ti systems: corrosion and microhardness.

    PubMed

    Chern Lin, J H; Moser, J B; Taira, M; Greener, E H

    1990-07-01

    Titanium alloys of 10 wt%-72 wt% Cu, 10 wt%-80 wt% Co and 20 wt%-84 wt% Ni were investigated. Ingots were fabricated in a vacuum/argon tungsten arc furnace. The surfaces of the alloys were examined by optical microscopy and SEM/EDS, and the Knoop hardness values of the alloys were measured. The corrosion resistance of the alloys was determined by a potentiodynamic polarization technique in buffered Ringer's solution. When a threshold composition of 30 wt% alloy was reached, a large decrease in corrosion resistance was found to occur. Knoop hardness measurements showed that similar hardness values of approximately 300 KHN can be obtained in all systems with lower alloy content. These values are similar to those obtained with a commercial dental titanium alloy.

  9. 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.

  10. Sorption of Th(IV) onto iron corrosion products: EXAFS study.

    PubMed

    Seco, Ferran; Hennig, Christoph; de Pablo, Joan; Rovira, Miquel; Rojo, Isabel; Martí, Vicens; Giménez, Javier; Duro, Lara; Grivé, Mireia; Bruno, Jordi

    2009-04-15

    Long-term performance assessment of nuclear waste repositories is affected by the ability of the outer barrier systems to retain radionuclides after possible corrosive leakage of waste containers. The mobility of the radionuclides released from the spent fuel depends strongly on the processes that take place in the backfill material. The interaction of steel corrosion products and radionuclides is part of such a scenario. In this work, the sorption of Th(IV) onto 2-line-ferrihydrite (FeOOH x H2O) and magnetite (Fe3O4), used as models for steel corrosion products, has been studied using EXAFS spectroscopy. Sorption samples were prepared in 0.1 M NaClO4 solutions at acidic pH (initial pH values in the range 3.0-4.2) either from undersaturation and supersaturation conditions with respect to amorphous ThO2. Two oxygen subshells, one at 2.37 A and another at 2.54 A, were observed in the first hydration sphere of Th in the case of the ferrihydrite samples. Th-Fe distances for the different ferrihydrite samples are approximately 3.60 A. These results indicate a corner sharing surface complex of Th(IV) ion onto the ferrihydrite surface where the Th atom shares one O atom with each of two coordinated octahedra. The longer Th-O distance accounts for coordinated water molecules. No significant changes in the structural environment of Th in terms of coordination numbers and distances were detected as a function of Th(IV) concentration. Magnetite samples sorbing Th(IV) also showed also a strong distortion of the O shell, but in contrast to ferrihydrite, two types of nearest Fe atoms were detected at 3.50 A and 3.70 A. These results indicate that Th(IV) ion sorbs onto the magnetite surface as bidentate-corner sharing arrangements to [FeO6] octahedra and [FeO4] tetrahedra.

  11. PPM-based System for Guided Waves Communication Through Corrosion Resistant Multi-wire Cables

    NASA Astrophysics Data System (ADS)

    Trane, G.; Mijarez, R.; Guevara, R.; Pascacio, D.

    Novel wireless communication channels are a necessity in applications surrounded by harsh environments, for instance down-hole oil reservoirs. Traditional radio frequency (RF) communication schemes are not capable of transmitting signals through metal enclosures surrounded by corrosive gases and liquids. As an alternative to RF, a pulse position modulation (PPM) guided waves communication system has been developed and evaluated using a corrosion resistant 4H18 multi-wire cable, commonly used to descend electronic gauges in down-hole oil applications, as the communication medium. The system consists of a transmitter and a receiver that utilizes a PZT crystal, for electrical/mechanical coupling, attached to each extreme of the multi-wire cable. The modulator is based on a microcontroller, which transmits60 kHz guided wave pulses, and the demodulator is based on a commercial digital signal processor (DSP) module that performs real time DSP algorithms. Experimental results are presented, which were obtained using a 1m corrosion resistant 4H18multi-wire cable, commonly used with downhole electronic gauges in the oil sector. Although there was significant dispersion and multiple mode excitations of the transmitted guided wave energy pulses, the results show that data rates on the order of 500 bits per second are readily available employing PPM and simple communications techniques.

  12. Laboratory studies on corrosion of materials for fluidized bed combustion applications

    SciTech Connect

    Natesan, K.

    1990-10-01

    An extensive corrosion test program was conducted at Argonne National Laboratory to evaluate the corrosion performance of metallic structural materials in environments that simulate both steady-state and off-normal exposure conditions anticipated in fluidized bed combustion (FBC) systems. This report discusses the possible roles of key parameters, such as sorbent and gas chemistries, metal temperature, gas cycling conditions, and alloy pretreatment, in the corrosion process. Data on scale thickness and intergranular penetration depth are presented for several alloys as a function of the chemistry of the exposure environment, deposit chemistry, and exposure time. Test results were obtained to compare the corrosion behavior of materials in the presence of reagent grade sorbent compounds and spent-bed materials from bubbling- and circulating-fluid-bed systems. Finally, the laboratory test results were compared with metal wastage information developed over the years in several fluidized bed test facilities. Metallic alloys chosen for the tests were carbon steel, Fe-2 1/4Cr-1Mo and Fe-9Cr-1Mo ferritic steels. Types 304 and 310 stainless steel, and Incoloy 800. 26 refs., 61 figs., 8 tabs.

  13. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Demonstration of Three Corrosion-Resistant Sustainable Roofing Systems

    DTIC Science & Technology

    2013-06-01

    sloped- roof conversion using standing-seam metal roofing system with heat-shedding coating, and (3) a fiber - glass -reinforced plastic (FRP) panel...the location to demonstrate (1) a heat-resistant metal shingle roofing sys- tem with above-sheathing ventilation (ASV), (2) a sloped- roof conversion...51 Appendix A: Roof Design Drawings for Buildings 8-3846 and 3-2631 (Stone- Coated Shingle System

  16. 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

  17. Underground corrosion control

    SciTech Connect

    Not Available

    1993-01-01

    Corrosion of underground metallic structures continues to be a crucial concern within society and the engineering community. Costs associated with corrosion losses are staggering. Indirect costs associated with environmental damage as well as loss of public confidence has in many cases out-stripped direct costs for facility repair and replacement. NACE Group Committee T-10, responsible for the study and advancement of technology necessary for engineering solutions for underground corrosion problems, is divided into five key unit committees as follows: cathodic protection; interference problems; electric power and communications; protective coating systems; and internal corrosion of pipelines. The papers presented in this publication reflect the most recent developments in field practice in all five areas. Cathodic protection criteria, protection of pipelines, tanks and pilings, test methods, transit systems investigations, power and communication cables, and compliance with regulations are addressed. Interference testing, refinery problems, methods of safely mitigating the effects of induced AC on pipelines, and experience with alternate engineering materials such as prestressed concrete cylinder pipe and ductile iron pipe are included. All 37 papers have been processed separately for inclusion on the data base.

  18. 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.

  19. 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.

  20. 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).

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Potentiostatic pulse-deposition of calcium phosphate on magnesium alloy for temporary implant applications--an in vitro corrosion study.

    PubMed

    Kannan, M Bobby; Wallipa, O

    2013-03-01

    In this study, a magnesium alloy (AZ91) was coated with calcium phosphate using potentiostatic pulse-potential and constant-potential methods and the in vitro corrosion behaviour of the coated samples was compared with the bare metal. In vitro corrosion studies were carried out using electrochemical impedance spectroscopy and potentiodynamic polarization in simulated body fluid (SBF) at 37 °C. Calcium phosphate coatings enhanced the corrosion resistance of the alloy, however, the pulse-potential coating performed better than the constant-potential coating. The pulse-potential coating exhibited ~3 times higher polarization resistance than that of the constant-potential coating. The corrosion current density obtained from the potentiodynamic polarization curves was significantly less (~60%) for the pulse-deposition coating as compared to the constant-potential coating. Post-corrosion analysis revealed only slight corrosion on the pulse-potential coating, whereas the constant-potential coating exhibited a large number of corrosion particles attached to the coating. The better in vitro corrosion performance of the pulse-potential coating can be attributed to the closely packed calcium phosphate particles.

  7. Non-Chromated Coating Systems for Corrosion Protection of Aircraft Aluminum Alloys (Preprint)

    DTIC Science & Technology

    2006-04-01

    an HVLP 3 spray gun in an environmentally controlled paint booth at 75°F and 50% RH. Primers were mixed according to manufacturer’s...the performance of the standard chromate system in the following tests: ASTM B 117 Salt Spray [2], ASTM D 2803 Filiform Corrosion Test [3], ASTM D...weight between 40 and 60 mg/ft2. MSZ, a water-based sol-gel system, was applied by the manufacturer’s suggested spray method. The material was mixed

  8. Effect of Induced Magnetic Field on Electrocrystallization of Zn-Ni Alloy and Their Corrosion Study

    NASA Astrophysics Data System (ADS)

    Rao, Vaishaka R.; Hegde, A. Chitharanjan

    2014-06-01

    Zn-Ni alloy coatings have been deposited galvanostatically on mild steel under the effect of induced magnetic field ( B), using gelatin and glycerol as additives. The effect of field intensity (from 0.05 to 0.4 T) and direction (both parallel and perpendicular) on electrocrystallization process has been studied considering the magnetohydrodynamic effect. The corrosion behaviors of coatings, deposited under different conditions of B, were evaluated by electrochemical AC and DC methods. Under optimal condition of B (perpendicular), Zn-Ni coatings showed about 3 times less corrosion rate (CR) than the one developed under natural convection ( B = 0 T), deposited from same bath for same duration. The significant decrease of CR was attributed to unique electrocrystallization process during deposition, favoring increased γ-Ni5Zn21 (321) and decreased γ-Ni5Zn21 (330) phase. Progressive decrease of CR with increase of B showed that corrosion protection efficacy of the coatings bears close relation with their crystallographic orientations and surface topography, evidenced by XRD study and SEM analysis. The effect of B on thickness, microhardness, surface morphology, phase structure, and the corrosion resistance of coatings was analyzed and results were discussed.

  9. 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.

  10. 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.

  11. Design of a Corrosion Detection System for a Shelter Structure

    DTIC Science & Technology

    2015-08-01

    any damage detection method. Heuristically placing many sensors on a structure does not guarantee damage will be detected. By design, optimally...detection method. Heuristically placing many sensors on a structure does not guarantee damage will be detected. By design, optimally placed sensors...Optimized SHM has demonstrated 6-7 times the sensitivity with 50 percent fewer sensor than heuristically designed systems with the same design goals

  12. 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.

  13. Experimental Study on Flow Technology and Steel Corrosion of Lead-Bismuth

    SciTech Connect

    Minoru Takahashi; Hiroshi Sekimoto; Kotaro Ishikawa; Naoki Sawada; Tadashi Suzuki; Susumu Yoshida; Toyohiko Yano; Masamitsu Imai; Koji Hata; Suizheng Qiu

    2002-07-01

    For the feasibility study of Pb-Bi-cooled fast reactors (FR) and the Pb-Bi target of accelerator-driven nuclear transmutation systems, Pb-Bi flow technologies were developed and steel corrosion behavior in a Pb-Bi flow was investigated using a Pb-Bi circulation loop. The performance of an electro-magnetic flow meter with electrically insulated electrodes plated with Rh was better than those of conventional and tubular types. Oxygen concentration was controlled by continuous injection of Ar, H{sub 2} and H{sub 2}O mixture gas into the Pb-Bi flow. In order to have desired oxygen potential, the partial pressure ratio of P{sub H{sub 2}}/P{sub H{sub 2}}{sub O} was chosen in the range from 0.12 to 2.2 by bubbling the mixture of Ar and H{sub 2} in water columns at the room temperature. By injecting the mixture gas into the loop for sufficient time, the oxygen potentials measured by the oxygen sensor made of solid electrolyte ZrO{sub 2}-Y{sub 2}O{sub 3} agreed well with those in the injected gas mixture. In the first corrosion test, steels were exposed to a Pb-Bi flow at the temperature of 550 deg. C, the velocity of 2 m/s and the oxygen concentration of {approx}5.0x10{sup -7} wt.% for 959 hours. It was found that the weight loss was larger in the order of SS316, low Cr steel (SCM420) and high Cr steels (STBA26, SUS405, SUS430). Corrosion was suppressed by a Cr oxide layer for high Cr steels. A porous layer was formed on SS316 surface due to high solubility of Ni in Pb-Bi,. In the second corrosion test, the oxygen concentration was kept at 3.6x10{sup -7} wt.% by injecting Ar, H{sub 2} and H{sub 2}O mixture gas into a Pb-Bi flow, and steels were exposed to a Pb-Bi flow at the temperature of 550 deg. C, the velocity of 2 m/s for 1000 hours. Serious erosion damage was observed in SCM420 at the entrance, and some erosion damages appeared in low Cr steels: SCM420, F82H, STBA26 and HCM12 downstream. Crack type damage was observed on the surface of HCM12, and pitting-type damage

  14. Detection of the corrosion in reinforced concrete with GPR: the case study of the Park Guell

    NASA Astrophysics Data System (ADS)

    Sossa, Viviana; Perez-Gracia, Vega; Gonzalez-Drigo, Ramon; Caselles, Oriol; Clapes, Jaume

    2017-04-01

    Detection of corrosion is important in cultural heritage assessment. Many structures contain metallic targets embedded in masonry or mortar, and corrosion cab cause important damage. However, detection using non-destructive methods is difficult and highly localized, providing in most cases incomplete results. In order to obtain a more extended analysis, GPR was applied and evaluated to detect damage as consequence of corrosion. This technique is a non-destructive method that covers a large area of study while other methods are constrained to a small areas or specific points. Therefore, some controlled laboratory tests were designed to determine possible differences in radargrams obtained in the case of corroded and non-corroded targets. These analysis allowed to observe that the corrosion seems to increase the attenuation of the radar signal, being difficult to detect targets near the damaged bars. The results were applied to study the mosaic roofs in the Park Guell, in Barcelona. This park is one of the most important Modernista (Art Noveau) complex in Barcelona. It is characterized by structures with roofs and banks with tessellation. Some of these structures are most likely supported by metal elements, and seepage cause important damage observed over the tessellation. The objective of the study was to define the possible existence of those metallic targets, determining their location. And, in the case of existence of metallic elements, defining which are the zones more affected by corrosion. The results demonstrates the existence of metallic supports in many parts, as well as some defined areas that could be damaged. Acknowledgement: This work has been partially funded by the Spanish Government and by the European Commission with FEDER funds, through the research projects CGL2011-23621 and CGL2015-65913-P. The study is also a contribution to the EU funded COST Action TU1208, "Civil Engineering Applications of Ground Penetrating Radar", to the working group 2.2.

  15. Corrosion Behavior of Ceramic Cup of Blast Furnace Hearth by Liquid Iron and Slag

    NASA Astrophysics Data System (ADS)

    Li, Yanglong; Cheng, Shusen; Wang, Zhifeng

    2016-10-01

    Three kinds of sample bricks of ceramic cups for blast furnace hearth were studied by dynamic corrosion tests based on different corrosion systems, i.e., liquid iron system, liquid slag system and liquid iron-slag system. Considering the influence of temperature and sample rotational speed, the corrosion profiles and mass loss of the samples were analyzed. In addition, the microstructure of the corroded samples was observed by optical microscope (OM) and scanning electron microscope (SEM). It was found that the corrosion profiles could be divided into iron corrosion region, slag corrosion region and iron-slag corrosion region via corrosion degree after iron-slag corrosion experiment. The most serious corrosion occurred in iron-slag corrosion region. This is due to Marangoni effect, which promotes a slag film formed between liquid iron and ceramic cup and results in local corrosion. The corrosion of the samples deepened with increasing temperature of liquid iron and slag from 1,623 K to 1,823 K. The variation of slag composition had greater influence on the erosion degree than that of rotational speed in this experiment. Taking these results into account the ceramic cup composition should be close to slag composition to decrease the chemical reaction. A microporous and strong material should be applied for ceramic cup.

  16. 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.

  17. 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.

  18. Study On The Effect Of Corrosion Behaviour Of Stainless Steel Before And After Carburizing Heat Treatment

    NASA Astrophysics Data System (ADS)

    Sulaiman, S. A.; Alias, S. K.; Ahmad, S.; Fauzi, M. H. Mohd; Ahmad, N. N.

    2016-11-01

    This study investigates the effect of corrosion behaviour of stainless steel before and after carburizing process. All samples were prepared based on the testing specification requirement and the chemical compositions of the stainless steel were obtained using spectrometer tester. Samples were then undergoing pack carburizing process by adding 50g of carbon powder as the carburizing agent. Then the samples were heated at 900 °C and 950 °C for 8 hours. To obtain corrosion rate, weight loss test was conducted and the samples were immersed in three different solutions which were distilled water, hydrochloric acid and sodium chloride. Hardness and density test were employed to measure the physical properties of the ASTM 304 stainless steel. The microstructures of all samples were observed using Olympus BX41M optical microscope. The resulting phases after each heat treatment were tested by x-ray diffraction (XRD) tester. The percentage of corrosion values, determined from this technique, showed fairly good agreement. Carburizing process produced a carburizing layer improved mechanical properties and corrosion resistance abilities

  19. 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.

  20. 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.

  1. Time-lapse lab-based x-ray nano-CT study of corrosion damage.

    PubMed

    Bradley, R S; Liu, Y; Burnett, T L; Zhou, X; Lyon, S B; Withers, P J; Gholinia, A; Hashimoto, T; Graham, D; Gibbon, S R; Hornberger, B

    2017-07-01

    An experimental protocol (workflow) has been developed for time-lapse x-ray nanotomography (nano-CT) imaging of environmentally driven morphological changes to materials. Two case studies are presented. First, the leaching of nanoparticle corrosion inhibitor pigment from a polymer coating was followed over 14 days, while in the second case the corrosion damage to an AA2099 aluminium alloy was imaged over 12 hours. The protocol includes several novel aspects relevant to nano-CT with the use of a combination of x-ray absorption and phase contrast data to provide enhanced morphological and composition information, and hence reveal the best information to provide new insights into the changes of different phases over time. For the pigmented polymer coating containing nominally strontium aluminium polyphosphate, the strontium-rich components within the materials are observed to leach extensively whereas the aluminium-rich components are more resistant to dissolution. In the case of AA2099 it is found that the initial grain boundary corrosion is driven by the presence of copper-rich phases and is then followed by the corrosion of grains of specific orientation. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  2. 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.

  3. Corrosion Studies of Fly Ash and Fly Ash-Slag Based Geopolymer

    NASA Astrophysics Data System (ADS)

    Zainal, F. F.; Amli, S. F. M.; Hussin, K.; Rahmat, A.; Abdullah, M. M. A. B.

    2017-06-01

    Abstract This paper presents the results of corrosion studies between Fly Ash Geopolymer (FG) paste and Fly Ash-Slag Geopolymer (FSG) paste. Geopolymer was made from aluminosilicate inorganic polymers mixed with the alkaline activator in order to reduce the carbon dioxide (CO2) to the ecosystem. Samples then were cured at 60ºC for 24 hours in the oven. Reinforcement bar is placed at the center of the paste. The samples were examined after 7, 14 and 28 days in terms of Open Circuit Potential (OCP) test, phase analysis and morphology analysis. The potential values regarding OCP test for FSG paste from 7 days until 28 days are 0.464 V, 0.474 V and 0.498 V more positive than FG paste which the potential values are 0.087 V, 0.133 V and 0.206 V respectively. From the Pourbaix diagram, all the potential values for FG paste and FSG paste were located in the same Fe2O3, passivity region. Passive layer which is the oxide form exists in this region to protect the reinforcement bar from corrosion agents. It can be proved from phase analysis results which iron oxide hydroxide (FeOOH), hematite (Fe2O3) and magnetite (Fe3O4) peaks exist. The differences of morphological structures of these pastes were observed by Scanning Electron Microscope (SEM). It shows that FSG paste had good corrosion resistance and low corrosion rate compared to FG paste.

  4. 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.

  5. 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

  6. 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.

  7. SEM corrosion-casts study of the microcirculation of the flat bones in the rat.

    PubMed

    Pannarale, L; Morini, S; D'Ubaldo, E; Gaudio, E; Marinozzi, G

    1997-04-01

    Little is known about the organization of microcirculation in flat bones in comparison with long bones. This study, therefore, helps us to determine the design of this vascular system in flat bones in relation to their structure and function. The organization of microvasculature in parietal, scapula, and ileum bones of 15 young sexually mature rats, aged 6-7 weeks, was studied by light and scanning electron microscopy (SEM) from vascular corrosion cast (vcc), a resin-cast obtained material. Our observations show that the pattern of the microcirculation in flat bones is different in the thick and thin parts of such bones. Where the bone is thinner than 0.4 mm, only periosteal and dural network exist. Larger vessels which do not form a real network connect the two tables of the bones in these regions. In thicker areas, the organization of the microvasculature is similar to that in long bones, with distinct periosteal, cortical and bone marrow networks. Moreover, in different bones, outer networks show slightly different characteristics according to the different adjacent structures (dura mater, muscles etc.). Different types of vessels were recognized by comparing their different diameter, course and endothelial imprints. The microvascular patterns of the flat bones are strongly influenced by the bone thickness. The different microvascular systems can interact both with the bone modelling and remodeling and with the variable metabolic needs, modifying the microvascular pattern and the blood flow. This is even more important in view of the reciprocal influence of the different networks within the same bone.

  8. Assessment of corrosion in retrieved spine implants.

    PubMed

    Panagiotopoulou, V C; Hothi, H S; Anwar, H A; Molloy, S; Noordeen, H; Rezajooi, K; Sutcliffe, J; Skinner, J A; Hart, A J

    2017-03-09

    Recently the use of dissimilar metals in spine instrumentation has increased, especially in the case of adult deformities, where rods made from Cobalt Chrome alloys (CoCr) are used with Titanium (Ti) screws. The use of dissimilar metals increases the risk of galvanic corrosion and patients have required revision spine surgery due to severe metallosis that may have been caused by corrosion. We aimed to assess the presence of corrosion in spine implant retrievals from constructs with two types of material combinations: similar (Ti/Ti) and dissimilar (CoCr/Ti). First, we devised a grading score for corrosion of the rod-fixture junctions. Then, we applied this score to a collection of retrieved spine implants. Our proposed corrosion grading score was proven reliable (kappa > 0.7). We found no significant difference in the scores between 4 CoCr and 11 Ti rods (p = 0.0642). There was no indication that time of implantation had an effect on the corrosion score (p = 0.9361). We recommend surgeons avoid using implants designs with dissimilar metals to reduce the risk of corrosion whilst a larger scale study of retrieved spine implants is conducted. Future studies can now use our scoring system for spine implant corrosion. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

  9. Detection and Assessment of Aircraft Corrosion

    SciTech Connect

    Maldonado, R L; Jones, K W

    1993-05-22

    The detection and assessment of existing corrosion, or the onset thereof, in aircraft structures, related systems and components is of major concern to the United States aviation community. In this work several types of ion- and photon-beam analytical techniques were applied to the detection and assessment of corrosion. A method of laboratory classification of surface corrosion, and the identification of a corrosion preventative compound (CPC)applied on skin material removed from aircraft structures was developed. The results of this research will be useful in the development of instrumentation and inspection techniques to detect and assess corrosion. These techniques also will be useful in studying the mechanisms and efficacy of current and future CPCs. Developed instrumentation and inspection techniques have enormous potential for commercial and military application in many areas, including the transportation, nuclear, petroleum, and building sectors.

  10. 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}.

  11. Screening and evaluation of microbiologically influenced corrosion (MIC) in seawater and effluent water injection systems in Kuwait

    SciTech Connect

    Al-Hashem, A.; Salman, M.; Carew, J.

    1999-11-01

    Injection water sources in Kuwait range from brackish water (TDS=4000 mg/l) through seawater (TDS = 30,000 mg/l) to high saline brines (TDS = 200,000 mg/l). Some of these water sources are highly sulfide sour and may require treatment to prevent scaling, corrosion or iron sulfide precipitation. Another particular problem in water injection systems is the uncontrolled growth of sulfate-reducing bacteria (SRB) which leads to increased corrosion of the process plant. Therefore, evaluation schemes were undertaken to study the relative risks of MIC in a range of Kuwait`s water sources, using a combination of field sampling and laboratory biofouling trials. Recirculating biofouling loops were set up with the appropriate site water, and inoculated with the bacteria from the system so that an active biofilm was set up on small studs. These biofouled studs were treated with proprietary biocide inhibitors under various dose rates in order to select the most appropriate control regime for particular water chemistries and process options.

  12. Corrosion Inhibition of Stress Corrosion Cracking and Localized Corrosion of Turbo-Expander Materials

    NASA Astrophysics Data System (ADS)

    Bavarian, Behzad; Zhang, Jia; Reiner, Lisa

    Stress corrosion cracking of 7050 aluminum alloy in the turbo expander and steam/gas turbine industry can cause catastrophic failures, especially for turbo machinery systems performing in hostile, corrosive environments. Commercially available inhibitors were investigated for their effectiveness in reducing and controlling the corrosion susceptibility. Inhibitor effectiveness was confirmed with electrochemical corrosion techniques. Polarization resistance increased with concentration of corrosion inhibitor due to film formation and displacement of water molecules. Cyclic polarization behavior for samples in the 1.0% to 10.0% inhibitor concentration showed a shift in the passive film breakdown potential. The substantial increase in the passive range has positive consequences for neutralizing pitting and crevice corrosion cell chemistry. The strain to failure and tensile strength determined from slow strain rate studies for the aluminum alloy showed pronounced improvement resulting from the inhibitors ability to mitigate SCC. Additionally, the fractographic analysis showed a changed morphology with ductile overload as the primary failure mode instead of transgranular or intergranular cracking.

  13. A hospital-based epidemiological study of corrosive alimentary injuries with particular reference to the Indian experience.

    PubMed

    Lakshmi, C P; Vijayahari, Ranjit; Kate, Vikram; Ananthakrishnan, N

    2013-01-01

    Corrosive alimentary tract injuries are a source of considerable morbidity all over the world. Despite this, actual data on the epidemiology of this problem are scarce mainly due to the lack of a well-established reporting system for poisoning in most countries. The burden of the disease is naturally more in countries such as India where the condition is common because of poor regulation of sale of corrosive substances. We analyse the available data on epidemiology of corrosive injuries, as well as patterns of involvement of the alimentary tract, with special reference to Indian data, and also provide an overview of the management options and long-term sequelae of this condition.

  14. 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.

  15. 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.

  16. Development of an advanced system to weld corrosion resistant alloys and clad pipes

    SciTech Connect

    Belloni, A.; Celant, M.

    1993-12-31

    Corrosion problems in hydrocarbon pipeline systems are increasing with the presence of aggressive compounds, like CO{sub 2}, H{sub 2}S, chlorides and elemental sulfur. Clad pipes and corrosion resistant alloys have been made available on the market to solve these problems, but the application of these exotic materials for offshore pipelines is limited because of their cost, which has presently made their use economical for small diameters and short lengths only. This paper introduces a Saipem proposal to significantly reduce the costs related to pipelaying operations. Saipem developed a fully automatic, four welding heads equipment, called roboweld, which by using the hot wire GTAW process (which is faster than the cold wire GTAW process) will, among other benefits, increase the pipelaying productivity and improve the overall system reliability as the weld quality and productivity are no longer dependent on the human factor. This paper includes a description of the welding procedure and equipment as developed by Saipem and an overall analysis of the cost savings arising by the utilization of the automatic Roboweld system instead of the conventional mechanized systems.

  17. Task 20 - Prevention of Chloride Corrosion in High-Temperature Waste Treatment Systems (Corrosives Removals from Vitrification Slurries)

    SciTech Connect

    Timpe, R.C.; Aulich, T.R.

    1998-11-01

    GTS Duratek is working with BNFL Incorporated on a US Department of Energy (DOE) contract to develop a facility to treat and immobilize radioactive waste at the Hanford site in southeast Washington. Development of the 10-ton/day Hanford facility will be based on findings from work at Duratek's 3.3-ton/day pilot plant in Columbia, Maryland, which is in the final stage of construction and scheduled for shakedown testing in early 1999. In prior work with the Catholic University of America Vitreous State Laboratory, Duratek has found that slurrying is the most efficient way to introduce low-level radioactive, hazardous, and mixed wastes into vitrification melters. However, many of the Hanford tank wastes to be vitrified contain species (primarily chloride and sulfate) that are corrosive to the vitrifier or the downstream air pollution control equipment, especially under the elevated temperature conditions existent in these components. Removal of these corrosives presents a significant challenge because most tank wastes contain high (up to 10-molar) concentrations of sodium hydroxide (NaOH) along with significant levels of nitrate, nitrite, and other anions, which render standard ion-exchange, membrane filtration, and other separation technologies relatively ineffective. In Task 20, the Energy and Environmental Research Center (EERC) will work with Duratek to develop and optimize a vitrification pretreatment process for consistent, quantitative removal of chloride and sulfate prior to vitrifier injection.

  18. Studies on the Inhibition of Mild Steel Corrosion by Rauvolfia serpentina in Acid Media

    NASA Astrophysics Data System (ADS)

    Bothi Raja, P.; Sethuraman, M. G.

    2010-07-01

    Alkaloid extract of Rauvolfia serpentina was tested as corrosion inhibitor for mild steel in 1 M HCl and H2SO4 using weight loss method at three different temperatures, viz., 303, 313, and 323 K, potentiodynamic polarization, electrochemical impedance spectroscopy and scanning electron microscope (SEM) studies. It is evident from the results of this study that R. serpentina effectively inhibits the corrosion in both the acids through adsorption process following Tempkin adsorption isotherm. The protection efficiency increased with increase in inhibitor concentration and temperature. Free energy of adsorption calculated from the temperature studies also revealed the chemisorption. The mixed mode of action exhibited by the inhibitor was confirmed by the polarization studies while SEM analysis substantiated the formation of protective layer over the mild steel surface.

  19. 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)

  20. Corrosion studies of a stainless steel structure for the ITER (International Thermonuclear Experimental Reactor) aqueous lithium salt blanket concept

    SciTech Connect

    Duquette, D.J.; Wrisley, K.L.; Motyka, E.; Steiner, D.; Embrechts, M.J.

    1990-10-01

    The aqueous lithium slat blanket (ALSB) employs water, with a dissolved lithium compound, as both the coolant and tritium breeding medium. The ALSB concept is one of three blanket options currently being examined for breeding tritium in the International Thermonuclear Experimental Reactor (ITER). To provide data and recommendations for materials and chemistry selection relevant to application of the ALSB in ITER, corrosion studies have been initiated, focusing on Type 316 stainless steel in lithium hydroxide and lithium nitrate solutions. This report presents the preliminary results of these corrosion studies. The results to date, while preliminary, suggest that even at 90 C, a blanket utilizing 10% LiOH (the current lithium salt of choice for ITER ALSB applications) will not cause catastrophic failure of 316 stainless steel by either stress corrosion cracking or localized corrosion; that the general corrosion rate will not exceed about 40 {mu}m/yr and transport of material will certainly be much less than this value since most of the corrosion product will be included in the strong adherent surface film; and that, although hydrogen may be evolved due to electrolysis, the maximum amount of hydrogen is small compared to that expected to be produced by radiolysis. These observations are predicated on the assumption that the blanket will be completely deaerated, and that the corrosion potential of the alloy will be similar to that observed in the laboratory.

  1. 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.

  2. Comparative corrosion study of Ti-Ta alloys for dental applications.

    PubMed

    Mareci, Daniel; Chelariu, Romeu; Gordin, Doina-Margareta; Ungureanu, Gina; Gloriant, Thierry

    2009-11-01

    Besides other important material features, the corrosion parameters and corrosion products are responsible for limiting the biocompatibility of metallic materials, and can produce undesirable reactions in implant-adjacent and/or more distant tissues. Titanium and some of its alloys are known as being the most biocompatible metallic materials due to their high strength, low modulus, high corrosion resistance in biological media, etc. More recently, Ti-Ta alloys have been developed, and these are expected to become more promising candidates for biomedical and dental applications than commercially pure Ti, Ti-6Al-4V or Ti-6Al-7Nb alloy. The corrosion behavior of the studied Ti-Ta alloys with Ta contents of 30, 40, 50 and 60 wt.% together with the currently used Ti-6Al-7Nb alloy were investigated for dental applications. All alloys were tested by open-circuit potential measurement, linear polarization, potentiodynamic polarization, coulometric zone analysis and electrochemical impedance spectroscopy performed in artificial saliva with different pH, acid lactic and fluoride contents. The passive behavior for all the titanium alloys is observed for artificial saliva, acidified saliva (9.8 gl(-1) lactic acid, pH 2.5) and for fluoridated saliva (1.0 gl(-1) F(-), pH 8). A decrease in corrosion resistance and less protective passive oxide films are observed for all titanium alloys in fluoridated acidified saliva (9.8 gl(-1) lactic acid, 1.0 gl(-1) F(-), pH 2.5) in regard to other electrochemical media used within this work. It is worthy of note that the most important decrease was found for Ti-6Al-7Nb alloy. These conclusions are confirmed by all the electrochemical tests undertaken. However, the results confirm that the corrosion resistance of the studied Ti-Ta alloys in all saliva is better or similar to that of Ti-6Al-7Nb alloy, suggesting that the Ti-Ta alloys have potential for dental applications.

  3. [Evaluation of molybdate and nitrate on sulphate-reducing bacteria related to corrosion processes in industrial systems].

    PubMed

    Torrado Rincón, J R; Calixto Gómez, D M; Sarmiento Caraballo, A E; Panqueva Alvarez, J H

    2008-01-01

    The sulfate-reducing bacteria growth kinetics and the biotransformation of sulfate into hydrogen sulfide were studied under laboratory conditions, using batch and continuous assays to determine the effect of molybdate and nitrate as metabolic inhibitors. The microorganisms were isolated from water coming from a natural gas dehydration plant, where they were associated with Microbiologically Influenced Corrosion (MIC) processes, and later cultured in planktonic and sessile states. The addition of 5 mM molybdate showed a growth reduction to levels of non-detectable floating cells and a six order of magnitude reduction in biofilms, concomitant with a sulfide decrease of around 100% in all cultures inhibited by this compound. The addition of 75 mM nitrate showed a four order of magnitude reduction in free bacterial cells and a two order of magnitude reduction in adhered bacterial cells, respectively, as well as a sulfide decrease of around 80%. The decreased corrosion rate detected suggests that these inorganic salts could be non-conventional biocides for an effective and environmentally non contaminant way of controlling and mitigating internal biocorrosion processes in storage tanks and pipelines in natural gas and petroleum industrial systems.

  4. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    PubMed Central

    Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Musa, Ahmed Y.; Li, Cheong Jiun

    2013-01-01

    A new curcumin derivative, i.e., (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (chlorocurcumin), was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR). The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP) measurements and electrochemical impedance spectroscopy (EIS). The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed. PMID:28788402

  5. 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.

  6. 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.

  7. Maximum: Recent Implementation and Application to the Study of Corrosion-Induced Microstructures in Thin Films of Aluminum-Copper Metallization.

    NASA Astrophysics Data System (ADS)

    Liang, Shoudeng

    We describe the recent implementation of a synchrotron radiation based scanning soft X-ray photoemission microscope - MAXIMUM, and discuss its application to the investigation of corrosion-induced microstructures in Al-Cu-Si thin films. The microscope employs a Mo/Si multilayer-coated Schwarzschild objective to focus 95eV X-rays from an undulator beamline. The photoelectrons are energy-analyzed by a CMA, and the sample is rastered to produce an image. We have achieved 980A spatial and 250meV energy resolution. Recent addition of a sample preparation and transfer system to the microscope enables us to perform surface and materials studies under UHV conditions. Since the spatial resolution of the microscope is determined by the spot size of the focused X-rays, any electrostatic potential from surface charging will not affect the image quality. This allowed the study of highly insulating films with the use of an electron flood gun to compensate for spectral shifts. We have employed MAXIMUM to investigate corrosion -induced surface microstructures in the Al-Cu-Si thin films commonly utilized in VLSI metallization. Spectromicroscopy was performed to characterize the chemical species and their distribution on the film surface after corrosion under 85% relative humidity at 85^circ C. The experimental images demonstrated that Cu -rich precipitates were formed near the surface region beneath the oxide layer upon annealing. We also observed a correlation between the precipitates and the increased corrosion in the alloy film: the localized corrosion occurs only at those sites where precipitation has taken place. This implies that the surface oxide layer is modified by the underlying Cu-rich phase such that it loses protection against moisture. After pitting, the Cu-rich phase acts as a cathode to facilitate corrosion of the surrounding Cu-deficient Al matrix via galvanic action. The corrosion -induced microstructures show characteristic circular features in the micrographs of

  8. Study of the Effect of Swelling on Irradiation Assisted Stress Corrosion Cracking

    SciTech Connect

    Teysseyre, Sebastien Paul

    2016-09-01

    This report describes the methodology used to study the effect of swelling on the crack growth rate of an irradiation-assisted stress corrosion crack that is propagating in highly irradiated stainless steel 304 material irradiated to 33 dpa in the Experimental Breeder Reactor-II. The material selection, specimens design, experimental apparatus and processes are described. The results of the current test are presented.

  9. Demonstration Of A Nanomaterial-Modified Primer For Use In Corrosion-Inhibiting Coating Systems

    DTIC Science & Technology

    2011-11-01

    all environments. Further studies may be necessary to develop the most effective combined corrosion prevention rehabilitation package for many...resin packages /binders, can cause a high-build coating thickness that can be prone to chipping and “mud cracking” if not properly applied. The... packaging 20 n. oz. unJ.pec saus-oes 15 mooths In original unQ>ened pact<~g 5 gal pail 9 months n ai~al unq:>ened packaQing SS gal, pail 9 months in

  10. A DFT study of pyrazine derivatives and their Fe complexes in corrosion inhibition process

    NASA Astrophysics Data System (ADS)

    Behzadi, Hadi; Roonasi, Payman; Momeni, Mohammad Jafar; Manzetti, Sergio; Esrafili, Mehdi D.; Obot, I. B.; Yousefvand, Mostafa; Morteza Mousavi-Khoshdel, S.

    2015-04-01

    The DFT/B3LYP calculations were applied to investigate the relationship between electronic properties and corrosion inhibition efficiency of three pyrazine derivatives, 2-methylpyrazine (MP), 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP). To take into account the solution acidity in experimental conditions, all possible mono-protonated forms, that is protonation at N1, N4 and NH2 sites, as well as the non-protonated form were considered. The molecular orbital analysis showed a good correlation between EHOMO, ELUMO and ΔE (EHOMO - ELUMO) with inhibition efficiency of the three pyrazine derivatives. Four types of interactions between iron and pyrazine molecules, i.e. Fe-π, Fe-N1, Fe-N4 and Fe-NH2 were included in the calculations. As a new approach to this system, inhibition mechanism of the three pyrazine molecules has been discussed in detail based on these four types of interactions. It was found that all four interactions are energetically important. The flat pyrazine ring was substantially deformed followed by a Fe-π interaction. The calculated binding energy of ABP in all forms was found to be higher than two other pyrazines, which is consistent with experimentally observed highest corrosion inhibition efficiency. The lack of Fe-NH2 interaction for MP molecule seems to be the reason for its lower corrosion inhibition efficiency.

  11. Study on evaluation of corrosion condition of reinforcing bar embedded concrete using infrared thermal imaging camera

    NASA Astrophysics Data System (ADS)

    Ruiko, Watanabe; Toshiaki, Mizobuchi

    2017-04-01

    Rapid aging of many concrete structures, which have been developed during rapid economic growth period in Japan, has become a serious problem for us these days. And thus, there is an urgent need to prolong their service life expectancies. For this purpose, the deterioration of reinforcing bars in the concrete structures should be detected quickly and correctly at the early stages. Nevertheless, conventional testing methods such as destructive and nondestructive testing have disadvantages: partial damages on concrete structures; difficulty with quantitative evaluation, etc. Many preceding studies have examined to estimate the deterioration of reinforcing bars based on the temperature of the concrete specimen surfaces. According to those papers, the differences in corrosion degree of reinforcing bars have a certain effect on the temperature of concrete specimen surfaces. In this study, firstly, the quantitative evaluation of the corrosion degree was conducted with 3D scanner which could measure the volume, coverage area and cross-sectional area. Secondly, the surface of the concrete specimen was cooled down with liquid nitrogen, and thirdly, thermographic change was observed up until the air temperature. Finally, the surface of the concrete specimen was detected clearly by the thermal images. As a result, this study shows that the corrosion thickness tends to get bigger, following the uprising temperature of the concrete specimen surfaces. The same kind of tendency can be observed by the thermal images, too.

  12. A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System

    PubMed Central

    Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

    2016-01-01

    This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths. PMID:27999252

  13. A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System.

    PubMed

    Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

    2016-12-16

    This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths.

  14. Study for corrosion characteristics of ferritic stainless steel weld metal with respect to added contents of Ti and Nb

    NASA Astrophysics Data System (ADS)

    Kim, JongMin; Lee, HaeWoo

    2014-03-01

    This paper identified the effects of Ti and Nb on pitting and intergranular corrosion resistance in a ferritic stainless steel weld metal of the automobile exhaust system. We fabricated 4 flux cored wires designed with 0-0.2 wt% Ti and 0-1.0 wt% Nb and performed Flux Cored Arc Welding. Through the potentiodynamic polarization test in 0.5M NaCl, we evaluated pitting resistance. And in order to evaluate the intergranular corrosion resistance, we observed microstructure after we performed DL-EPR test in 0.5M H2SO4+0.01M KSCN. As a result of the test, the specimen added with 0.2%Ti+1.0%Nb showed the highest pitting resistance. From observing the degree of sensitization and microstructure, the intergranular corrosion resistance was higher as the contents of Ti and Nb increased. And through EBSD we observed Cr carbide which affects the corrosion resistance.

  15. Electron Number Diagram for Study of Corrosion Processes.

    DTIC Science & Technology

    1986-09-26

    electrodeposition, hydrometallurgy and geochemistry. Work has focused the single redox element systems Cu, Cr, Fe, S and U and the two redox element systems...find use in such diverse fields as hydrometallurgy , sulfur removal processes, electrolytic processes and geochemistry. 3. SUKMARY OF MST DURTANT RJLTS A

  16. Beowulf Cluster for Computational Corrosion and Catalysis Studies

    DTIC Science & Technology

    2007-11-02

    This DURIP-funded Beowulf cluster will enhance our AFOSR-funded research in several areas. Large-scale modeling of complex systems in the areas of...high accuracy on real-world systems requires significant computational cost. This grant, by funding a Beowulf cluster supercomputing environment, has

  17. Synthesis and Corrosion Study of Zirconia-Coated Carbonyl Iron Particles

    SciTech Connect

    Shen, R.; Shafrir, S.N.; Miao, C.; Wang, M.; Lambropoulos, J.C.; Jacobs, S.D.; Yang, H.

    2010-01-07

    This paper describes the surface modification of micrometer-sized magnetic carbonyl iron particles (CI) with zirconia from zirconium(IV) butoxide using a sol–gel method. Zirconia shells with various thicknesses and different grain sizes and shapes are coated on the surface of CI particles by changing the reaction conditions, such as the amounts of zirconia sol, nitric acid, and CI particles. A silica adhesive layer made from 3-aminopropyl trimethoxysilane (APTMS) can be introduced first onto the surface of CI particles in order to adjust both the size and the shape of zirconia crystals, and thus the roughness of the coating. The microanalyses on these coated particles are studied by field-emission scanning electron microscopy (FE-SEM) and X-ray-diffraction (XRD). Accelerated acid corrosion and air oxidation tests indicate that the coating process dramatically improved oxidation and acid corrosion resistances, which are critical issues in various applications of CI magnetic particles.

  18. 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.

  19. 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.

  20. Corrosion-mechanical and electrochemical properties of Ti-Al-Ni and Ti-V-Nb system alloys

    SciTech Connect

    Belousov, Y.N.; Lebedeva, N.G.; Melekhov, R.K.; Mikheev, V.S.; Shnyrev, G.D.

    1985-11-01

    Electrochemical investigations were made and the corrosion rate of Ti-Al-Ni and Ti-V-Nb system alloys in chloride-containing and acid solutions was determined. The sensitivity of them to corrosion cracking in a sulfuric acid solution was also evaluated. The media were a 3% NaCl solution and a 20% H/sub 2/SO/sub 4/ solution. The uniform corrosion rate of the alloys alloyed with nickel in 20% H/sub 2/SO/sub 4/ solution was parctically two orders of magnitude less than of the nickel-free ones. For parts operating in low-concentration acid and chloride solutions in which acidification is possible, alloys of the Ti-Al-Ni and Ti-V-Nb systems may be promising.

  1. Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

    SciTech Connect

    Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Motta, Arthur T.; Weidner, Randy; Anderson, Thomas; Ecker, Lynne E.

    2016-10-25

    A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction (XRD) studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoring the oxidation of metallic zirconium during exposure to steam at 350°C. Finally, the in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during early stages of corrosion, which can provide a better understanding the oxidation process.

  2. 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.

  3. A study of the mechanism of primary water stress corrosion cracking of Alloy 600

    SciTech Connect

    Gourgues, A.F.; Andrieu, E.; Scott, P.M.

    1995-12-31

    Two aspects of the mechanism of stress corrosion cracking of Alloy 600 in pressurized water reactors (PWR) primary water have been studied in detail. Results are presented showing that grain boundaries of Alloy 600 are embrittled to a depth of several microns by exposure to primary water in an unstressed condition. It has been established that this embrittlement is not reversible by high temperature degassing and cannot be directly due to hydrogen. The results seem to support the hypothesis that oxygen atom penetration of grain boundaries is possible. However, no evidence of formation of grain boundary gas bubbles or oxides has been found. It is envisaged that this embrittlement process could sequentially act at the tip of a growing stress corrosion crack. The second phenomenon under study has been the plastic deformation behavior of Alloy 600 since it is known that cold work and stress have an important effect on stress corrosion cracking sensitivity. Results of plastic deformation during cyclic straining at various controlled strain rates are presented showing that Alloy 600 is not very sensitive to loading history and that cold work is of an essentially kinematic nature.

  4. 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.

  5. Corrosion, microstructure, and metallography

    SciTech Connect

    Northwood, D.O.; White, W.E.; Vander Voort, G.F.

    1985-01-01

    Of the forty-one papers presented, nearly half of them deal with microstructural aspects of corrosion, corrosion control and corrosion failure analysis. They describe various analytical approaches for studying corrosion and for diagnosing corrosion failure mechanisms. Details include microstructural features of corrosion on a wide range of materials or coatings and in environments ranging from within the human body to outer space. Another series of papers handles microstructure-property relationships and contains reports on hydrogen embrittlement of AISI 316 stainless steel, shell and detail cracking in railroad rails, and the precipitation of martensitic Fe-Ni-W alloys. A third grouping looks at microstructure-fracture relationships. Coverage of advancements in metal-lographic techniques includes the use of microcomputers, applied techniques of inplace analysis, and use of the Tandem Van de Graff accelerator facility.

  6. [Experimental study on the corrosion behavior of a type of oral near β-type titanium alloys modified with double glow plasma nitriding].

    PubMed

    Wen, Ke; Li, Fenglan

    2015-12-01

    To study the electrochemical corrosion performance of a type of biomedical materials near beta titanium alloy(Ti-3Zr-2Sn-3Mo-25Nb, TLM) in artificial saliva before and after nitride changing, and to provide clinical basis for clinical application of titanium alloy TLM. The double glow plasma alloying technology was used to nitride the surface of titanium alloy TLM. The surface properties of the modified layer were observed and tested by optical microscope, scanning electron microscope, glow discharge spectrum analyzer, X-ray diffraction and micro hardness tester. Then, electrochemical measurement system was used to test and compare titanium alloy TLM's electrochemical corrosion in artificial saliva before and after its surface change. Finally, the surface morphology of the original titanium alloy and the modified layer was compared by scanning electron microscope. By the technology of double glow plasma nitriding, the surface of the titanium alloy TLM had been successfully nitrided with a modified layer of 4-5 µm in thickness, uniform and compact. Its main compositions were Ti and Ti(2)N. The Microhardness of modified layer also had been improved from (236.8 ± 5.4) to (871.8 ± 5.2) HV. The self-corrosion potential in electrochemical corrosion tests had been increased from -0.559 V to -0.540 V, while the self- corrosion current density had been reduced from 2.091 × 10(-7) A/cm(2) to 7.188 × 10(-8) A/cm(2). Besides, alternating-current impedance(AC Impedance) had also been increased. With the scanning electron microscope, it's obvious that the diameter of corrosion holes on modified layer were approximately 10 µm. As to the diameter and number of corrosion holes on modified layer, they had been decreased comparing with the original titanium alloy. The type of near beta titanium alloy TLM can construct a nitriding modified layer on its surface. Meanwhile, the performance of its anti- corrosion in artificial saliva has been improved, comparing to the original

  7. 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

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

    PubMed

    Bagatin, Cristhiane Ristum; Ito, Izabel Yoko; Andrucioli, Marcela Cristina Damião; Nelson-Filho, Paulo; Ferreira, José Tarcísio Lima

    2011-01-01

    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. 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. 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. 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.

  9. Study on Microstructure and Electrochemical Corrosion Behavior of PEO Coatings Formed on Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Xiang, N.; Song, R. G.; Li, H.; Wang, C.; Mao, Q. Z.; Xiong, Y.

    2015-12-01

    Plasma electrolytic oxidation (PEO) treated 6063 aluminum alloy was applied in a silicate- and borate-based alkaline solution. The microstructure and electrochemical corrosion behavior were studied by scanning electron microscopy, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques. The results showed that the silicate-based PEO coating was of a denser structure compared with that of borate-based PEO coating. In addition, the silicate-based PEO coating was composed of more phased (Al9Si) than borate-based PEO coating. The results of corrosion test indicated that the silicate-based PEO coating provided a superior protection to 6063 aluminum alloy substrate, while borate-based PEO coating with a porous structure showed an inferior conservancy against corrosive electrolyte. Furthermore, the EIS tests proved that both coatings were capable to resist the aggressive erosion in 0.5 M NaCl solution after 72 h of immersion. However, the borate-based PEO coating could not provide sufficient protection to the substrate after 72-h immersion in 1 M NaCl solution.

  10. Recent advances in the study of microbiologically influenced corrosion. (Reannouncement with new availability information)

    SciTech Connect

    Little, B.; Wagner, P.

    1993-12-31

    The study of microbiologically influenced corrosion (MIC) has progressed from phenomenological case histories to a mature interdisciplinary science including electrochemical, metallurgical, surface analytical, microbiological, biotechnological and biophysical techniques. With gene probes and microelectrodes it is now possible to measure interfacial dissolved oxygen, dissolved sulfide and pH and to further determine the microbial species responsible for the localized chemistry. Biofilms can be tailored to contain consortia of specific microorganisms and naturally occurring biofilms can be dissected into cellular and extracellular constituents. Scanning vibrating electrodes can be used to map the distribution of anodes and cathodes so that localized corrosion can be correlated with the location of microorganisms. The development of environmental scanning electron, atomic force, and laser confocal microscopy makes it possible to image cells on surfaces and to accurately determine the spatial relationship between microorganisms and corrosion. Transport of nutrients through biofilms is being modeled using techniques including optical density measurements to precisely locate the water/biofilm interface and nuclear magnetic resonance imaging to visualize flow characteristics near surfaces colonized with microorganisms. The way in which these now techniques can be used to understand fundamental mechanisms and to discriminate critical issues of MIC will be discussed.

  11. Cu-Zn-Al2O3 nanocomposites: study of microstructure, corrosion, and wear properties

    NASA Astrophysics Data System (ADS)

    Baghani, Mohammad; Aliofkhazraei, Mahmood; Askari, Mehdi

    2017-04-01

    Alumina nanoparticles were added to a Cu-Zn alloy to investigate their effect on the microstructural, tribological, and corrosion properties of the prepared alloys. Alloying was performed using a mixture of copper and zinc powders with 0vol% and 5vol% of α-Al nanopowder in a satellite ball mill. The results showed that the Cu-Zn solid solution formed after 18 h of mechanical alloying. The mechanically alloyed powder was compacted followed by sintering of the obtained green compacts at 750°C for 30 min. Alumina nanoparticles were uniformly distributed in the matrix of the Cu-Zn alloy. The tribological properties were evaluated by pin-on-disk wear tests, which revealed that, upon the addition of alumina nanoparticles, the coefficient of friction and the wear rate were reduced to 20% and 40%, respectively. The corrosion properties of the samples exposed to a 3.5wt% NaCl solution were studied using the immersion and potentiodynamic polarization methods, which revealed that the addition of alumina nanoparticles reduced the corrosion current of the nanocomposite by 90%.

  12. In-situ electrochemical study of interaction of tribology and corrosion in artificial hip prosthesis simulators.

    PubMed

    Yan, Yu; Dowson, Duncan; Neville, Anne

    2013-02-01

    The second generation Metal-on-Metal (MoM) hip replacements have been considered as an alternative to commonly used Polyethylene-on-Metal (PoM) joint prostheses due to polyethylene wear debris induced osteolysis. However, the role of corrosion and the biofilm formed under tribological contact are still not fully understood. Enhanced metal ion concentrations have been reported widely from hair, blood and urine samples of patients who received metal hip replacements and in isolated cases when abnormally high levels have caused adverse local tissue reactions. An understanding of the origin of metal ions is really important in order to design alloys for reduced ion release. Reciprocating pin-on-plate wear tester is a standard instrument to assess the interaction of corrosion and wear. However, more realistic hip simulator can provide a better understanding of tribocorrosion process for hip implants. It is very important to instrument the conventional hip simulator to enable electrochemical measurements. In this study, simple reciprocating pin-on-plate wear tests and hip simulator tests were compared. It was found that metal ions originated from two sources: (a) a depassivation of the contacting surfaces due to tribology (rubbing) and (b) corrosion of nano-sized wear particles generated from the contacting surfaces.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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 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.

  18. 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.

  19. Characterization of elemental and structural composition of corrosion scales and deposits formed in drinking water distribution systems.

    PubMed

    Peng, Ching-Yu; Korshin, Gregory V; Valentine, Richard L; Hill, Andrew S; Friedman, Melinda J; Reiber, Steve H

    2010-08-01

    Corrosion scales and deposits formed within drinking water distribution systems (DWDSs) have the potential to retain inorganic contaminants. The objective of this study was to characterize the elemental and structural composition of extracted pipe solids and hydraulically-mobile deposits originating from representative DWDSs. Goethite (alpha-FeOOH), magnetite (Fe(3)O(4)) and siderite (FeCO(3)) were the primary crystalline phases identified in most of the selected samples. Among the major constituent elements of the deposits, iron was most prevalent followed, in the order of decreasing prevalence, by sulfur, organic carbon, calcium, inorganic carbon, phosphorus, manganese, magnesium, aluminum and zinc. The cumulative occurrence profiles of iron, sulfur, calcium and phosphorus for pipe specimens and flushed solids were similar. Comparison of relative occurrences of these elements indicates that hydraulic disturbances may have relatively less impact on the release of manganese, aluminum and zinc, but more impact on the release of organic carbon, inorganic carbon, and magnesium.

  20. Intergranular stress-corrosion cracking of austenitic stainless steels in PWR boric-acid storage systems

    SciTech Connect

    Macdonald, D.D.; Cragnolino, G.A.; Olemacher, J.; Chen, T.Y.; Dhawale, S.

    1982-08-01

    A review is presented of the available literature on the intergranular stress corrosion cracking (IGSCC) of austenitic stainless steels at temperatures below 100/sup 0/C, as well as the results of an experimental investigation of the IGSCC of Types 304, 304L, and 316L stainless steels conducted in boric acid environments of the type employed in pressurized nuclear reactors (PWRs) for nuclear shim control. The susceptibility of furnace sensitized Type 304SS to IGSCC was studied using slow strain rate tests as a function of pH, temperature, potential, and concentration of suspected contaminants: chloride, thiosulfate, and tetrathionate. Possible alternate alloys, such as Types 304L and 316L stainless steels, were also tested under those specific conditions that render Type 304SS susceptible to cracking. Corrosion potentials that can be attained in air-saturated boric acid solutions in the presence of the above mentioned species were measured in order to evaluate the propensity towards intergranular cracking under conditions simulating those that prevail in service.

  1. 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.

  2. Use of Carbon Steel for Construction of Post-combustion CO 2 Capture Facilities: A Pilot-Scale Corrosion Study

    DOE PAGES

    Li, Wei; Landon, James; Irvin, Bradley; ...

    2017-04-13

    Corrosion studies were carried out on metal coated and noncoated carbon steel as well as stainless steel in a pilot-scale post-combustion CO2 capture process. Aqueous 30 wt % monoethanolamine (MEA) solvent was used without any chemical additive for antioxidation to examine a worst-case scenario where corrosion is not mitigated. The corrosion rate of all carbon steels was almost zero in the absorber column and CO2 lean amine piping except for Ni-coated carbon steel (<1.8 mm/yr). Ni2Al3/Al2O3 precoated carbon steels showed initial protection but lost their integrity in the stripping column and CO2 rich amine piping, and severe corrosion was eventuallymore » observed for all carbon steels at these two locations. Stainless steel was found to be stable and corrosion resistant in all of the sampling locations throughout the experiment. This study provides an initial framework for the use of carbon steel as a potential construction material for process units with relatively mild operating conditions (temperature less than 80 °C), such as the absorber and CO2 lean amine piping of a post-combustion CO2 capture process. As a result, it also warrants further investigation of using carbon steel with more effective corrosion mitigation strategies for process units where harsh environments are expected (such as temperatures greater than 100 °C).« less

  3. Accelerated Storage Stability and Corrosion Characteristics Study Protocol

    EPA Pesticide Factsheets

    EPA has determined that studies using this protocol will, in certain circumstances, provide the Agency with all the information it needs to make a determination on the storage stability of pesticides.

  4. 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... WATER REGULATIONS Control of Lead and Copper § 141.81 Applicability of corrosion control treatment steps... review and approve the addition of a new source or long-term change in water treatment before it...

  5. 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... WATER REGULATIONS Control of Lead and Copper § 141.81 Applicability of corrosion control treatment steps... review and approve the addition of a new source or long-term change in water treatment before it...

  6. 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... WATER REGULATIONS Control of Lead and Copper § 141.81 Applicability of corrosion control treatment steps... review and approve the addition of a new source or long-term change in water treatment before it...

  7. 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....

  8. 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....

  9. 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.

  10. 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

  11. 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.

  12. Solutions to corrosion problems of FGD systems providing functional reliability and cost effectiveness

    SciTech Connect

    Agarwal, D.C.

    1986-01-01

    Extensive research programs at various utilities and institutions to find better materials of construction led to higher alloys up the ladder of Ni-Cr-Mo family and new non-metallic coatings. One result of this was the development of the ''wallpaper concept solution'' of lining with thin sheets of highly corrosion-resistant alloy of the Ni-Cr-Mo family which over the last six years has provided maintenance free performance in a very cost effective manner. This paper will describe the simplicity of the wallpaper concept solution, economics as compared to other alternatives, and case histories where maintenance free service is being provided to many utilities in the critical areas of their FGD systems.

  13. 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.

  14. 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.

  15. 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

  16. Electromagnetic methods for corrosion under paint coating measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Tian, Gui Yun; Simm, Anthony; Alamin, Mohammed

    2013-01-01

    Corrosion under coating has a serious effect on the metal conductivity and corrosion layer permittivity. A high frequency (13.56 MHz) Radio Frequency Identification (RFID) based system has been developed to measure corrosion under coating. The corrosion behaviour of coated steel has been investigated from a very fundamental understanding of permittivity using a Vector Network Analyser (VNA). This paper will first review corrosion and dielectric property measurement methods and investigate RFID tag antenna responses under different material properties of corrosion samples with atmospheric exposure times using VNA. The purpose of this study was to examine the RFID system for corrosion detection. The RFID tag's coil and VNA are employed to measure the impedance change to determine the conductivity and relative permittivity variance with different atmospheric exposure times (1 month, 3 months, 6 months, 10 months and 12 months). Different spectrum distributions under different corrosion samples are investigated. Based on the studies, VNA based system testing, phase responses from the mild steel samples with different coating thickness are measured. The experimental results show that these two introduced techniques are able to distinguish between different exposure times with coating. Based on the results, corrosion detection under coating using equivalent permittivity and conductivity are developed and evaluated. Preliminary results show that the high frequency (HF) RFID method can be extended to a new application for detection of corrosion under coating and development of HF RFID systems for corrosion monitoring. Dielectric probe is applied to measure the permittivity variance with different paint thickness. With the paint thickness increasing, the dielectric is getting close to the paint's properties. Waveguide is using here to measure the paint thickness effect for further UHF RFID study.

  17. A Systematic Review of Systemic Cobaltism After Wear or Corrosion of Chrome-Cobalt Hip Implants.

    PubMed

    Gessner, Bradford D; Steck, Thomas; Woelber, Erik; Tower, Stephen S

    2015-06-12

    We sought to synthesize data on systemic arthroprosthetic cobaltism, a recently described syndrome that results from wear or corrosion of chrome-cobalt hip components. We conducted a systematic literature review to identify all reported cases of systemic arthroprosthetic cobaltism. To assess the epidemiologic link between blood cobalt levels (B[Co]), we developed a symptom scoring tool that evaluated 9 different symptom categories and a category of medical utilization. We identified 25 patients reported between 2001 and 2014 with a substantial increase in case reports over the past 3 years. Symptoms were diverse and involved the hip (84%), cardiovascular system (60%), audiovestibular system (52%), peripheral motor-sensory system (48%), thyroid (48%), psychological functioning (32%), visual system (32%), and the hematological, oncological, or immune system (20%). The mean latency from implantation to presentation or revision was 41 months (range, 9-99 months). The mean B[Co] was 324 μg/L and 4 patients had levels less than 20 μg/L. The B[Co] but not blood chromium level was highly associated with a quantitative measure of overall symptom severity (r, 0.81; P < 0.001). Mean B[Co] and symptom scores were substantially higher in patients with revisions of failed ceramic-on-ceramic prostheses than those with primary metal-on-metal prostheses. Systemic arthroprosthetic cobaltism is an increasingly recognized complication of wear or corrosion of chrome-cobalt hip implants, may involve a large number of organ systems, and may occur with relatively low B[Co]. There is an urgent need to better define the overall scope of the problem and to develop screening and management strategies.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.

  18. 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

  19. Analysis of Pipeline Steel Corrosion Data From NBS (NIST) Studies Conducted Between 1922-1940 and Relevance to Pipeline Management.

    PubMed

    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

  20. 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

  1. 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...

  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. Studies on the Inhibitive Effect of Datura Stramonium Extract on the Acid Corrosion of Mild Steel

    NASA Astrophysics Data System (ADS)

    Raja, Pandian Bothi; Sethuraman, Mathur Gopalakrishnan

    The extract of Datura stramonium has been studied as a possible source of green inhibitor for corrosion of mild steel (MS) in HCl and H2SO4 media at different temperatures. The anticorrosion effect was evaluated by conventional weight loss studies, electrochemical studies viz., Tafel polarization, ac impedance, and SEM studies. The studies reveal that the plant extract acts as a good inhibitor in both the acid media and better in H2SO4 medium. Tafel polarization method indicate that the plant extract behaves as a mixed mode inhibitor. Double layer capacitance and charge transfer resistance values derived from Nyquist plots obtained from ac impedance studies give supporting evidence for the anticorrosive effect. The inhibitive effect may be attributed to the adsorption of the inhibitor on the surface of MS, following Temkin adsorption isotherm. Increase of inhibition efficiency with increase of temperature along with Ea values serve as a proof for chemisorption. SEM studies provide the confirmatory evidence for the protection of MS by the green inhibitor. The study reveals the potential of D. stramonium for combating corrosion which may be due to the adsorption of alkaloids and other phytoconstituents.

  4. 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.

  5. 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.

  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.

  7. 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.

  8. Inhibition of slug front corrosion in multiphase flow conditions

    SciTech Connect

    Chen, H.J.; Jepson, W.P.

    1998-12-31

    Corrosion at the slug front at the bottom of a pipeline is identified as one of the worst cases of corrosion occurring in the pipeline which carries unprocessed multiphase production with a high level of CO{sub 2} gas. One objective of the study in recommending a subsea completion to shore was to determine if commercial corrosion inhibitors can control this type of corrosion using carbon steel pipeline. Thus, inhibitors which showed excellent performance in the lab using the Rotating Cylinder Electrode system (RCE) were further evaluated to confirm their performance in a flow loop simulating the test conditions predicted from the flow modeling for the proposed pipeline. The performance profile of two commercial inhibitors were determined in a 4 in. flow loop at 7O C, 100 psig CO{sub 2} partial pressure in corrosive brines with or without ethylene glycol and/or light hydrocarbon. Results showed that the carbon steel pipeline could be adequately protected at low temperature using a commercial corrosion inhibitor to meet the designed life of the pipeline. Ethylene glycol, which is used in the pipeline to prevent hydrate formation, reduces the corrosivity of the brine and gives no effect on inhibitor performance under the slug flow conditions. A good agreement in inhibitor performance was observed between the flow loop and the RCE testing. The uninhibited corrosion rate of the test brine in this study is in good agreement with the predicted value using deWaard and Williams correlation for CO{sub 2} corrosion.

  9. The Tension and Puncture Properties of HDPE Geomembrane under the Corrosion of Leachate.

    PubMed

    Xue, Qiang; Zhang, Qian; Li, Zhen-Ze; Xiao, Kai

    2013-09-17

    To investigate the gradual failure of high-density polyethylene (HDPE) geomembrane as a result of long-term corrosion, four dynamic corrosion tests were conducted at different temperatures and durations. By combining tension and puncture tests, we systematically studied the variation law of tension and puncture properties of the HDPE geomembrane under different corrosion conditions. Results showed that tension and puncture failure of the HDPE geomembrane was progressive, and tensile strength in the longitudinal grain direction was evidently better than that in the transverse direction. Punctures appeared shortly after puncture force reached the puncture strength. The tensile strength of geomembrane was in inversely proportional to the corrosion time, and the impact of corrosion was more obvious in the longitudinal direction than transverse direction. As corrosion time increased, puncture strength decreased and corresponding deformation increased. As with corrosion time, the increase of corrosion temperature induced the decrease of geomembrane tensile strength. Tensile and puncture strength were extremely sensitive to temperature. Overall, residual strength had a negative correlation with corrosion time or temperature. Elongation variation increased initially and then decreased with the increase in temperature. However, it did not show significant law with corrosion time. The reduction in puncture strength and the increase in puncture deformation had positive correlations with corrosion time or temperature. The geomembrane softened under corrosion condition. The conclusion may be applicable to the proper designing of the HDPE geomembrane in landfill barrier system.

  10. The Tension and Puncture Properties of HDPE Geomembrane under the Corrosion of Leachate

    PubMed Central

    Xue, Qiang; Zhang, Qian; Li, Zhen-Ze; Xiao, Kai

    2013-01-01

    To investigate the gradual failure of high-density polyethylene (HDPE) geomembrane as a result of long-term corrosion, four dynamic corrosion tests were conducted at different temperatures and durations. By combining tension and puncture tests, we systematically studied the variation law of tension and puncture properties of the HDPE geomembrane under different corrosion conditions. Results showed that tension and puncture failure of the HDPE geomembrane was progressive, and tensile strength in the longitudinal grain direction was evidently better than that in the transverse direction. Punctures appeared shortly after puncture force reached the puncture strength. The tensile strength of geomembrane was in inversely proportional to the corrosion time, and the impact of corrosion was more obvious in the longitudinal direction than transverse direction. As corrosion time increased, puncture strength decreased and corresponding deformation increased. As with corrosion time, the increase of corrosion temperature induced the decrease of geomembrane tensile strength. Tensile and puncture strength were extremely sensitive to temperature. Overall, residual strength had a negative correlation with corrosion time or temperature. Elongation variation increased initially and then decreased with the increase in temperature. However, it did not show significant law with corrosion time. The reduction in puncture strength and the increase in puncture deformation had positive correlations with corrosion time or temperature. The geomembrane softened under corrosion condition. The conclusion may be applicable to the proper designing of the HDPE geomembrane in landfill barrier system. PMID:28788321

  11. Study of corrosion using long period fiber gratings coated with iron exposed to salty water

    NASA Astrophysics Data System (ADS)

    Coelho, L.; Santos, J. L.; Jorge, P. A. S.; de Almeida, J. M. M.

    2017-04-01

    A study of long period fiber gratings (LPFG) over coated with iron (Fe) and subjected to oxidation in water with different sodium chloride (NaCl) concentrations is presented. The formation of iron oxides and hydroxides was monitored in real time by following the features of the LPFG attenuation band. Preliminary results show that Fe coated LPFGs can be used as sensors for early warning of corrosion in offshore and in coastal projects where metal structures made of iron alloys are in contact with sea or brackish water.

  12. A Fenton-like oxidation process using corrosion of iron metal sheet surfaces in the presence of hydrogen peroxide: a batch process study using model pollutants.

    PubMed

    Namkung, K C; Burgess, A E; Bremner, D H

    2005-03-01

    This study evaluates a new method for chemically destroying organic pollutants in wastewater using spontaneous corrosion of iron metal sheet surfaces in the presence of hydrogen peroxide. Model pollutants (phenol and benzoic acid) were degraded in batch experiments to investigate which parameters affected the process performance. Iron metal sheet surfaces spontaneously corrode under acidic conditions producing iron species (mainly ferrous ions) dissolved in aqueous solution, which react with hydrogen peroxide via the Fenton reaction. In order to optimise the oxidation system, several factors (pH, H2O2 dosage, initial concentration of organic substances) affecting corrosion of the iron metal sheet surface were investigated. Total iron concentration in solution was investigated with different dosages of H2O2 (100 mg l(-1), 1000 mg l(-1) and 1900 mg l(-1)) at different pH values (1.5, 2.5 and 3.0). Iron corrosion increased with the decrease of pH. The addition of H2O2 resulted in a significant increase of iron corrosion. Organic substances also had a marked effect with, for instance, the presence of phenol or benzoic acid resulting in a considerable increase of iron corrosion. In contrast, the absence of either hydrogen peroxide or iron metal brought no change in total organic carbon (TOC). In order to obtain the most effective combination of parameters for TOC removal of phenol solution, experiments were conducted under varied conditions. The experimental results showed that there is an optimum pH requirement (in this work, 2.5). The factors affecting the TOC removal are discussed and the oxidation mechanisms leading to mineralization of organic substances are proposed.

  13. 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

  14. Comparative study of the corrosion behavior of peripheral stents in an accelerated corrosion model: experimental in vitro study of 28 metallic vascular endoprostheses.

    PubMed

    Paprottka, Karolin J; Paprottka, Philipp M; Reiser, Maximilian F; Waggershauser, Tobias

    2015-01-01

    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. 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. 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. 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.

  15. Redox gradients in distribution systems influence water quality, corrosion, and microbial ecology.

    PubMed

    Masters, Sheldon; Wang, Hong; Pruden, Amy; Edwards, Marc A

    2015-01-01

    Simulated distribution systems (SDSs) defined the interplay between disinfectant type (free chlorine and chloramines), water age (1-10.2 days), and pipe material (PVC, iron and cement surfaces) on water chemistry, redox zones and infrastructure degradation. Redox gradients developed as a function of water age and pipe material affected the quality of water consumers would receive. Free chlorine was most stable in the presence of PVC while chloramine was most stable in the presence of cement. At a 3.6 day water age the residual in the chlorinated PVC SDS was more than 3.5 times higher than in the chlorinated iron or cement systems. In contrast, the residual in the chloraminated cement SDS was more than 10 times greater than in the chloraminated iron or PVC systems. Near the point of entry to the SDSs where disinfectant residuals were present, free chlorine tended to cause as much as 4 times more iron corrosion when compared to chloramines. Facultative denitrifying bacteria were ubiquitous, and caused complete loss of nitrogen at distal points in systems with iron, and these bacteria co-occurred with very severe pitting attack (1.6-1.9 mm/year) at high water age.

  16. 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.

  17. 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.

  18. Performance of ferritic stainless steels for automobile muffler corrosion

    SciTech Connect

    Tarutani, Y.; Hashizume, T.

    1995-11-01

    Corrosion behavior of ferritic stainless steels was studied in artificial exhaust gas condensates containing corrosive ions such as Cl{sup {minus}} and SO{sub 3}{sup 2{minus}}. Continuous immersion tests in flasks and Dip and Dry tests by using the alternate corrosion tester with a heating system clarified the effects of chromium and molybdenum additions on the corrosion resistance of a ferritic stainless steel in the artificial exhaust gas condensates. Effects of surface oxidation on the corrosion behavior were investigated in a temperature range of 573K to 673K. Oxidation of 673K reduced the corrosion resistance of the ferritic stainless steels in the artificial environment of the automobile muffler. Particulate matter deposited on the muffler inner shell from the automobile exhaust gas was also examined. Deposited particulate matter increased the corrosion rate of the ferritic stainless steel. Finally, the authors also investigated the corrosion of the automobile mufflers made of Type 436L ferritic stainless steel with 18% chromium-1.2% molybdenum after 24 months, in Japan. The sets of results clarified that Type 436L ferritic stainless steel as the material for the automobile muffler exhibited acceptable corrosion resistance.

  19. 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

  20. 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.