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. A cooling water system copper corrosion study

    SciTech Connect

    Pulkrabek, J.W.

    1998-07-01

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

  3. SEATTLE DISTRIBUTION SYSTEM CORROSION CONTROL STUDY. VOLUME 5. COUNTERACTIVE EFFECTS OF DISINFECTION AND CORROSION CONTROL

    EPA Science Inventory

    This study consisted of three research phases designed to evaluate the counteractive effects of corrosion treatment (pH adjustment) and disinfection (chlorination): (1) Electrochemical Tests - Copper corrosion rates were measured under varying pH, free chlorine residual and chlor...

  4. SEATTLE DISTRIBUTION SYSTEM CORROSION CONTROL STUDY. VOLUME 4. ON-SITE EVALUATION OF CORROSION TREATMENT

    EPA Science Inventory

    For 8 months, the Seattle Water Department conducted a corrosion treatment pilot plant study, obtaining data on the treatment of Tolt River water with lime and sodium carbonate. Pipe loop tests were conducted to determine the appropriate chemical start-up procedures for two full-...

  5. Seattle distribution system corrosion control study. Volume 2. Tolt River water pilot plant study

    SciTech Connect

    Herrera, C.E.; Hoyt, B.P.

    1984-03-01

    For 6 months, the Seattle Water Department conducted a corrosion treatment pilot plant study, obtaining data on the treatment of Tolt River water with lime/sodium carbonate, lime/sodium bicarbonate, and lime/bicarbonate/silicate. Continuous-flow pipe coupon tests were conducted to determine corrosion rates, penetration rates, and corrosion types for copper, galvanized steel and black steel pipes. Metal leaching tests were conducted using small diameter pipes. Research showed that using lime plus sodium carbonate, lime plus sodium bicarbonate, and lime plus bicarbonate plus silicate will significantly reduce corrosion in home plumbing systems. Based on this pilot study, lime plus sodium carbonate treatment is recommended for the Cedar River water supply at an average dosage of 1.7 mg/L CaO. This dose should achieve an average distribution system pH of 7.9 and an alkalinity of 18 mg/l CaCO3.

  6. Stress-corrosion cracking studies in coal-liquefaction systems

    SciTech Connect

    Baylor, V.B.; Keiser, J.R.

    1981-01-01

    Coal liquefaction plants with 6000 ton/d capacity are currently being planned by DOE as a step toward commercial production of synthetic fossil fuels. These plants will demonstrate the large-scale viability of the Solvent Refined Coal (SRC) process, which has been used since 1974 in two operating pilot plants: a 50-ton/d unit at Fort Lewis, Washington, and a 6-ton/d plant in Wilsonville, Alabama. Experience in these plants has shown that austenitic stainless steels are susceptible to stress corrosion cracking associated with residual stresses from cold working or welding. The corrodants responsible for the cracking have not yet been positively identified but are suspected to include polythionic acids and chlorides. To screen candidate materials of construction for resistance to stress corrosion cracking, racks of stressed U-bend specimens in welded and as-wrought conditions have been exposed at the Wilsonville and Fort Lewis SRC pilot plants. These studies have identified alloys that are suitable for critical plant applications.

  7. Parametric study of a corrosion model applied to lead-bismuth flow systems

    NASA Astrophysics Data System (ADS)

    Zhang, Jinsuo; Li, Ning

    2003-09-01

    The corrosion of steels exposed to flowing liquid metals is influenced by local and axial conditions of the flow systems. Despite of this, most existing corrosion models only consider the mean values based on local conditions. The present study refines a model for flowing liquid metal under non-isothermal conditions. The model is based on solving the mass transport equation in the boundary layer. Two kinds of flows are investigated: through an open pipe system and through a closed loop system. The model is applied to a lead-bismuth eutectic (LBE) test loop. A parametric study illustrates the effects of the axial temperature profile on corrosion. The study provides important insight to the design, operation and testing of such loop systems.

  8. 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.

  9. 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.

  10. 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.

  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. 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.

  13. Metal corrosion coupon contamination, corrosion study design, and interpretation problems

    SciTech Connect

    Lytle, D.A.; Schock, M.R.; Tackett, S.

    1992-01-01

    As a result of the new Lead and Copper Rule, some water utilities in the United States have begun or will soon begin corrosion demonstration studies. Demonstration studies may include pipe rig/loop tests, metal coupon tests, and partial-system tests (full-scale). Evaluation of corrosion control treatment through testing may be accomplished by weight loss measurement, metal leaching, corrosion rate, or coupon surface inspection techniques. The purpose of the paper is to (1) briefly introduce 2 corrosion control studies being conducted at the EPA Research Facility, (2) discuss design and operational problems and considerations associated with each of the studies, and (3) present solutions to the problems. The experiences related to the paper may provide useful and time-saving insights into the design, operation, and interpretation of corrosion control studies to water utilities and suppliers.

  14. 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

  15. SEATTLE DISTRIBUTION SYSTEM CORROSION CONTROL STUDY. VOLUME I: CEDAR RIVER WATER PILOT PLANT STUDY

    EPA Science Inventory

    A study was conducted in Seattle, Washington, to evaluate the use of lime and sodium bicarbonate in surface water supplies to control corrosion of plumbing materials. Continuous-flow pipe-coupon test loops were used to test the effectiveness of two water treatments - addition of ...

  16. SEATTLE DISTRIBUTION SYSTEM CORROSION CONTROL STUDY. VOLUME 2. TOLT RIVER WATER PILOT PLANT STUDY

    EPA Science Inventory

    For 6 months, the Seattle Water Department conducted a corrosion treatment pilot plant study, obtaining data on the treatment of Tolt River water with lime/sodium carbonate, lime/sodium bicarbonate, and lime/bicarbonate/silicate. Continuous-flow pipe coupon tests were conducted t...

  17. 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.

  18. Corrosion studies on Mo- and Cr-bearing alloys for flue gas desulfurization systems

    SciTech Connect

    Maiya, P.S.

    1983-01-01

    Critical components of flue gas desulfurization (FGD) systems, especially those in downstream locations (e.g., stack linings, ducts, bypass-duct junctions, and reheaters), are subjected to environments in which the pH can vary from as low as 0.5 to about 4.0. Hence, proper selection of materials of construction through an appropriate research and development plan can be expected to have great economic impact on current FGD technology. Also to facilitate a mechanistic understanding of the corrosion process in FGD environments, a quantitative description of the effects of pertinent variables such as pH, alloy composition, and chloride ion concentration on corrosion rates is required. In the present study, the corrosion rates of several alloys of interest to FGD systems (viz., 316L, 317LX, 317LM, 904L, A1-4X, A1-6X, Hastelloys G and C-276, Incoloy 825, Inconel 625, and 29-4-2) have been evaluated in sulfuric acid containing 0.03-5.0 wt% Cl/sup -/ at different pH levels (0.5-3.0) and at a temperature of 85/sup 0/C.

  19. 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.

  20. 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.

  1. Selection of a Microbiological Corrosion System for Studying Effects on Structural Aluminum Alloys

    PubMed Central

    Hedrick, H. G.; Miller, C. E.; Halkias, J. E.; Hildebrand, J. E.

    1964-01-01

    Two laboratory methods, a metal-strip test and a tank test, were evaluated as microbiological corrosion systems for producing corroded test specimens on a structural aluminum alloy. The results show that corrosion of the test alloy occurred best in the metal-strip test in a deionized water-fuel medium inoculated with a mixture of microorganisms under aerated conditions. The metal-strip test was more successful for producing large numbers of corroded test specimens and proved more economical than the tank-type test, since less structural material is needed to obtain a specimen with sufficient corrosion areas, and since the corrosion can more easily be restricted by maskants to certain areas for specific test purposes. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 FIG. 8 FIG. 9 FIG. 10 FIG. 11 FIG. 12 FIG. 13 PMID:16349646

  2. Selection of a Microbiological Corrosion System for Studying Effects on Structural Aluminum Alloys.

    PubMed

    Hedrick, H G; Miller, C E; Halkias, J E; Hildebrand, J E

    1964-05-01

    Two laboratory methods, a metal-strip test and a tank test, were evaluated as microbiological corrosion systems for producing corroded test specimens on a structural aluminum alloy. The results show that corrosion of the test alloy occurred best in the metal-strip test in a deionized water-fuel medium inoculated with a mixture of microorganisms under aerated conditions. The metal-strip test was more successful for producing large numbers of corroded test specimens and proved more economical than the tank-type test, since less structural material is needed to obtain a specimen with sufficient corrosion areas, and since the corrosion can more easily be restricted by maskants to certain areas for specific test purposes. PMID:16349646

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

    SciTech Connect

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

    1995-12-01

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

  4. METAL CORROSION COUPON CONTAMINATION, CORROSION STUDY DESIGN, AND INTERPRETATION PROBLEMS

    EPA Science Inventory

    As a result of the new Lead and Copper Rule, some water utilities in the United States have begun or will soon begin corrosion demonstration studies. emonstration studies may include pipe rig/loop tests, metal coupon tests, and partial-system tests (fullscale). valuation of corro...

  5. 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.

  6. 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

  7. DWPF corrosion study

    SciTech Connect

    Selby, C.L.

    1986-12-17

    Corrosion of candidate alloys for the DWPF SRAT, SME, and melter was tested in the large (1/3 scale) SRAT/SME, the 200th scale SRAT/SME, and the LSFM. Flat or twisted coupons with or without a weld bead and U-bend specimens (specimens bent into a ''U'' shape and bolted together at the ends to stress the bend area) were installed on racks that ensured electrical isolation to avoid galvanic effects. Teflon/reg sign/ washers isolated the low temperature exposure racks and ceramic washers isolated the high temperature exposure racks. Serrated washers simulated crevices, but crevice corrosion did not result. 9 refs., 9 tabs.

  8. Corrosion studies on construction materials for flue-gas-desulfurization systems. [Effects of Ph, chloride content, and alloy composition

    SciTech Connect

    Maiya, P.S.

    1982-08-01

    Several Mo- and Cr-bearing alloys of interest to flue-gas desulfurization (FGD) systems have been examined for corrosion in simulated FGD environments at 85/sup 0/C. To evaluate the importance of hydrogen and chloride ion concentrations, Type 316L stainless steel was exposed for varying times at different pH levels (0.5 to 3.0) and chloride content (0.03 to 5.0 wt% Cl/sup -/). To determine the effects of pH and composition in acid solution that contains a fixed amount of chloride (approx. 0.34 wt% Cl/sup -/), a number of alloys were used in which the composition parameter (defined as the sum of Cr and Mo) varied from 19.5 to 33.5 wt%. In all cases, the general corrosion or dissolution as determined from weight loss measurements (mg mm/sup -2/) varied linearly with time. The corrosion rate (mg mm/sup -2/ h/sup -1/) for the alloys decreased with an increase in pH in a consistent manner regardless of the alloy crystal structure. The composition effects on corrosion rate were most significant at pH = 0.5. The dependence of corrosion rate on pH, chloride ion concentration, and alloy composition is discussed in a quantitative manner. The relationships developed from the kinetic data provide useful guidance in the selection of appropriate alloys for more comprehensive studies under more realistic FGD testing environments that include environmental and stress cycling. Also, the materials evaluation approach adopted in the present study enables predictions of the life of components subjected to different environments and is relevant to alloy development work in progress elsewhere. In addition, testing and evaluation procedures have been developed for two alternative materials, namely, a fiber-reinforced plastic (Atlac 4010-A from ICI Americas, Inc.) and an epoxy coating on mild steel (Markote 300 System from Martek Engineering, Inc.); preliminary results are presented.

  9. A corrosivity classification system for geothermal resources

    SciTech Connect

    Conover, Marshall F.

    1982-10-08

    The most important difference between traditional steam systems and those that utilize geothermal fluids is the potential for corrosion of metals. The recently developed sourcebook ''Materials Selection Guidelines for Geothermal Energy Utilization Systems'' is expected to facilitate corrosion engineering decision making and reduce the cost of geothermal systems where new resources are similar to those presented by the corrosivity classification system.

  10. Preliminary corrosion studies of candidate materials for supercritical water oxidation reactor systems. Master's thesis

    SciTech Connect

    Orzalli, J.C.

    1994-05-01

    An experimental test facility has been designed and constructed for investigation of the corrosion behavior of candidate materials in a supercritical water oxidation environment. The high temperatures (500 deg C) and high pressures (300 atm) required in this process, made the experimental apparatus construction and control a complex engineering problem. The facility consists of two systems. The first is an exposure autoclave internal volume 850 ml, with associated monitoring and control systems for conducting long term exposure testing of test coupons and U-bends. The second is an electrochemical cell with a potentiostat and frequency response analyzer for conducting Electronic Impedance Spectroscopy (EIS) in the supercritical water environment. Exposure testing of three candidate materials; Inconel 625, Hastelloy C-276 and 316 stainless steel was conducted at three temperature regimes corresponding to three locations in a SCWO waste treatment system. Preliminary results are presented in an environment of demineralized water as a control. Experimental results indicate evidence of a film on the materials characterized by slight weight gain. Light and confocal laser light microscopic evaluations revealed the presence of localized pitting corrosion on the Inconel 625.

  11. 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.

  12. Corrosion and scaling in solar heating systems

    NASA Astrophysics Data System (ADS)

    Foresti, R. J., Jr.

    1981-12-01

    Corrosion, as experienced in solar heating systems, is described in simplistic terms to familiarize designers and installers with potential problems and their solutions. The role of a heat transfer fluid in a solar system is briefly discussed, and the choice of an aqueous solution is justified. The complexities of the multiple chemical and physical reactions are discussed in order that uncertainties of corrosion behavior can be anticipated. Some basic theories of corrosion are described, aggressive environments for some common metals are identified, and the role of corrosion inhibitors is delineated. The similarities of thermal and material characteristics of a solor system and an automotive cooling system are discussed. Based on the many years of experience with corrosion in automotive systems, it is recommended that similar antifreezes and corrosion inhibitors should be used in solar systems. The importance of good solar system design and fabrication is stressed and specific characteristics that affect corrosion are identified.

  13. 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.

  14. STATISTICAL PROCEDURES FOR CORROSION STUDIES

    EPA Science Inventory

    Many utilities will be conducting pipe loop and other experimental studies to optimize corrosion control under the Lead and Copper Rule. his paper presents a discussion of the background and justifications for the selection of different statistical techniques to evaluate experime...

  15. Corrosion control in water injection systems

    SciTech Connect

    Patton, C.C. )

    1993-08-01

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

  16. 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.

  17. 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.

  18. The Examination of Afyonkarahisar's Geothermal System Corrosion

    NASA Astrophysics Data System (ADS)

    Buyuksagis, A.; Erol, S.

    2013-02-01

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

  19. 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.

  20. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    PubMed Central

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

    2012-01-01

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

  1. 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.

  2. 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

  3. SEATTLE DISTRIBUTION SYSTEM CORROSION CONTROL STUDY. VOLUME III: POTENTIAL FOR DRINKING WATER CONTAMINATION FROM TIN/ANTIMONY SOLDER

    EPA Science Inventory

    This study was conducted to evaluate the potential for leaching of metals into drinking water from tin/antimony solder. The study consisted of five research phases: (1) A theoretical investigation of the corrosion products formed from the solder was conducted using pe-pH diagrams...

  4. A corrosion database system for exposure tests

    SciTech Connect

    Yamamoto, Masahiro; Kato, Chuichi; Nogami, Atsushi; Matsuoka, Ai

    1997-12-31

    A computerized corrosion database system for exposure tests has been designed and developed. This system was developed to help researchers carry out each experimental procedure in exposure tests. The system includes a function to manage not only the experimental data but also the timetable of exposure tests and the environmental factors of exposure sites. An easily used graphical user interface (GUI) and graph plot software are provided for users to help analyze exposure test results from various viewpoints. The data accumulated in this system are measurements of past exposure tests and exposure tests in progress. The analyses of past exposure tests using the present database system resulted in several ideas on atmospheric corrosion different from the conventional ideas on atmospheric corrosion. If the data of exposure tests in progress are compared with past data, the relationships between atmospheric corrosion and environmental factors will be more clarified.

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

    EPA Science Inventory

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

  6. REDUCED-POLLUTION CORROSION-PROTECTION SYSTEMS

    EPA Science Inventory

    Coating systems, designed to protect metallic components against corrosive attack using environmentally compatible materials and processes, were evaluated as potential alternatives for their higher polluting counterparts. Viable replacements were established for cyanide cadmium, ...

  7. TRW CHARGED DROPLET SCRUBBER CORROSION STUDIES

    EPA Science Inventory

    The report gives results of corrosion studies to provide definitive data concerning the corrosive nature of coke-oven waste-heat flue gas and its effects on wet electrostatic precipitators, and specifically on TRW's Charged Droplet Scrubber (CDS). The study characterized the chem...

  8. Study of corrosion of 1100 aluminum

    NASA Technical Reports Server (NTRS)

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

    1967-01-01

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

  9. Evaluation of several corrosion protective coating systems on aluminum

    NASA Technical Reports Server (NTRS)

    Higgins, R. H.

    1981-01-01

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

  10. 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

  11. 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)

  12. 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.

  13. Cooling tower hardware corrosion studies

    SciTech Connect

    Blue, S.C.

    1983-01-31

    The data presented in this report are interim results of a continuing investigation into the corrosion resistance of metals in the environment of a large cooling tower. Some of the significant observations are as follows: the corrosion of susceptible metals occurs most rapidly in the warm fog conditions between the deck and mist filters; the application of stainless steel must be made on the basis of alloy chemistry and processing history. Some corrosion resistant alloys may develop cracking problems after improper heat treating or welding; combinations of aluminum bronze, stainless steel, and silicon bronze hardware were not susceptible to galvanic corrosion; the service life of structural steel is extended by coal tar epoxy coatings; aluminum coatings appear to protect structural steel on the tower deck and below the distribution nozzles. The corrosion of cooling tower hardware can be easily controlled through the use of 316 stainless steel and silicon bronze. The use of other materials which exhibit general resistance should be specified only after they have been tested in the form of structural assemblies such as weldments and bolted joints in each of the different tower zones.

  14. 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.

  15. 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.

  16. 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)

  17. The use of experimental designs for corrosive oilfield systems

    SciTech Connect

    Biagiotti, S.F. Jr.; Frost, R.H.

    1997-08-01

    A Design of Experiment approach was used to investigate the effect of hydrogen sulfide, carbon dioxide and brine composition on the corrosion rate of carbon steel. Three of the most common experimental design approaches (Full Factorial, Taguchi L{sub 4}, and Alternate Fractional) were used to evaluate the results. This work concluded that: CO{sub 2} and brine both have significant main and two-factor effects on corrosion rate, H{sub 2}S concentration has a moderate effect on corrosion rate, and higher total dissolved solids (TDS) brine compositions appear to force gases out of solution, thereby decreasing the corrosion rate of carbon steel. The Full Factorial Design correctly identified all independent variables and the significant interactions between CO{sub 2}/H{sub 2}S and CO{sub 2}/Brine on corrosion rate. The two fractional factorial experimental methods resulted in incorrect conclusions. The Taguchi L{sub 4} method gave misleading results as it did not identify H{sub 2}S as having a positive effect on corrosion rate, and only identified the strong interactions in the experimental matrix. The Alternative Fractional design also yielded incorrect interpretations with regard to the effect of brine on corrosion. This study has shown that reduced experimental designs (e.g., half fractional) may be inappropriate for distinguishing the synergistic interactions likely to form in chemically reactive systems. Therefore, based upon the size of the data set collected in this work, the authors recommend that full factorial designs be used for corrosion evaluations. When the number of experimental variables make it impractical to perform a full factorial design, the aliasing relationships should be carefully evaluated.

  18. 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. PMID:17764316

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

    NASA Astrophysics Data System (ADS)

    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.

  20. 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.

  1. 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)

  2. CORROSION AND CALCIUM CARBONATE SATURATION INDEX IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Corrosion in water distribution systems was studied to gain a better understanding of the processes and to develop control strategies. Equations and calculation methods for determining the pH(sub s) were developed using a chemical model with and without ionic speciation. Several ...

  3. 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.

  4. 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.

  5. 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.

  6. Electrochemical studies of corrosion inhibiting effect of polyaniline coatings

    SciTech Connect

    Wei, Yen; Wang, Jianguo; Jia, Xinru

    1995-12-01

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

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

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1997-01-01

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

  8. 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.

  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. 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.

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

    PubMed

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

    2016-01-01

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

  12. 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.

  13. Microbiological corrosion control in a cooling water system

    SciTech Connect

    Honneysett, D.G.; vanden Bergh, W.D.; O'Brien, P.F.

    1985-10-01

    The failure of a corrosion control program in a closed cooling water system coincided with the use of reclaimed sewage water and the contamination of the system with oil. Other problems were increased corrosion rates, downward pH excursions, increased fouling by corrosion by-products, and increased microbiological activity in the system. The major cause of corrosion was microbiological in origin. The unsuccessful use of a biocide led to the initiation of a full-scale microbiological investigation. The nature of the microflora was determined, biocide selection tests made, and an effective control treatment program initiated. Chromate corrosion treatment was replaced by a coordinated program using an organic filming corrosion inhibitor, a polyacrylate/phosphonate dispersant, and a combination of biocides.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Corrosion and odor management in sewer systems.

    PubMed

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

    2015-06-01

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

  19. Design of second generation Hanford tank corrosion monitoring system

    SciTech Connect

    Edgemon, G.L.

    1998-04-02

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

  20. Corrosion study of simulated evaporator components

    SciTech Connect

    Schreiber, S.B.; Dunn, S.L.

    1989-07-01

    At the Los Alamos Plutonium Facility, ion exchange effluents and precipitation filtrates containing discardable levels of transuranic elements are concentrated using a thermosiphon evaporator before cement fixation for waste disposal. Because of changing process feed streams and scrap recovery requirements, trace amounts of free chloride ions (Cl/sup /minus//) are being introduced into the stainless steel (SS) evaporator, potentially increasing corrosion rates and thereby reducing its useful life. This study was performed to determine the effects of Cl/sup /minus// in simulated evaporator feed solutions that contain significant amounts of ferric ions (Fe/sup 3+/) in nitric acid (HNO/sub 3/). A simulated environment was produced by heating 316 SS cans that contained various tests solutions. The surface was monitored for signs of pitting or stress cracking, and vessel weight loss was measured on a daily basis to establish a rough corrosion rate. The final conclusion is that the nitric acid solution provides enough free nitrate ions (NO/sub 3//sup /minus//) to maintain minimal corrosion in a dilute ferric chloride environment. 3 refs., 5 figs., 10 tabs.

  1. 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.

  2. A study on corrosion test methods for automotive steel sheet

    SciTech Connect

    Miyoshi, Y.; Kitayama, M.; Ito, Y.; Koyahara, H.

    1984-01-01

    The corrosion behavior of an automobile body caused by de-icing salt was classified into various corrosion phenomena, of which paint exfoliation and perforation were studied fundamentally. There are 2 types of paint exfoliation. One is paint adhesion, where underfilm corrosion plays a decisive role. Another is wet adhesion, where water immersion through the paint film into the paint/substrate interface is important. Perforation corrosion can be simulated by corrosion test using lapped panel specimens. CCT conditions which should be applied for all exposure tests were determined on the basis of experimental data.

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

    PubMed

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

    2010-12-01

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

  4. 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.

  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 of copper-based materials in gamma-irradiated air/water vapor systems

    SciTech Connect

    Reed, D.T.

    1992-04-01

    Experiments were performed to investigate the atmospheric corrosion of copper-based materials in an irradiated air/water vapor system. The three materials investigated were oxygen-free copper (CDA-102), 7% aluminum-bronze (CDA-613), and 70-30 cupronickel (CDA-715). To support the corrosion studies, a number of irradiation studies were performed to characterize the gas phase radiation chemistry of the system. Both copper oxide and nitrate phases were identified as corrosion products depending on the dose rate, humidity and temperature. Uniform corrosion rates increased with temperature, humidity, and dose rate. A clear tie between the radiolytic products generated in the gas phase and the corrosion observed was established.

  7. Corrosion of copper-based materials in gamma-irradiated air/water vapor systems

    SciTech Connect

    Reed, D.T.

    1992-01-01

    Experiments were performed to investigate the atmospheric corrosion of copper-based materials in an irradiated air/water vapor system. The three materials investigated were oxygen-free copper (CDA-102), 7% aluminum-bronze (CDA-613), and 70-30 cupronickel (CDA-715). To support the corrosion studies, a number of irradiation studies were performed to characterize the gas phase radiation chemistry of the system. Both copper oxide and nitrate phases were identified as corrosion products depending on the dose rate, humidity and temperature. Uniform corrosion rates increased with temperature, humidity, and dose rate. A clear tie between the radiolytic products generated in the gas phase and the corrosion observed was established.

  8. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Tabony, J. H.

    1978-01-01

    Candidate materials were tested for their ability to limit corrosion under conditions that approximate those found in typical solar-energy system. In addition to presentation of data, report also includes discussion of different forms of corrosion and recommendations for future work.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Jahani, Fereidoun

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

  15. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

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

  17. 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

  18. 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.

  19. Study of stress corrosion in aluminum alloys

    NASA Technical Reports Server (NTRS)

    Brummer, S. B.

    1967-01-01

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

  20. 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.

  1. 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. PMID:25719479

  2. 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.

  3. Corrosion/96 conference papers

    SciTech Connect

    1996-07-01

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

  4. 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.

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

    PubMed

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

    2015-09-01

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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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).

  11. 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.

  12. 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.

  13. Corrosion inhibitor film formation studied by ATR-FTIR

    SciTech Connect

    Campbell, S.; Jovancicevic, V.

    1999-11-01

    The development of an inhibitor film is essential for the effective performance of a corrosion inhibitor. The use of attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR) allows the development of inhibitor films on iron oxides to be monitored. For two distinct corrosion inhibitor chemistries, oleic imidazoline and phosphate ester, the film formation and corrosion processes are monitored on Fe{sub 3}O{sub 4} in a powdered form (a model surface). Additional data following on the physical and chemical properties are obtained using XPS and SEM techniques, which allows for a more complete characterization of the model inhibitor/oxide system. By the proper choice of system and measurement techniques, the complex phenomenon of corrosion inhibition may be analyzed directly.

  14. 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.

  15. 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. PMID:3457767

  16. 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)

  17. 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...

  18. Study on the corrosiveness of wood pyrolysis oils

    SciTech Connect

    Aubin, H.; Roy, C. . Dept. of Chemical Engineering)

    1990-01-01

    The authors discuss a study conducted on the rate of corrosion of wood pyrolysis oils in presence of carbon and stainless steel plates. Tests were performed to simulate the conditions existing in storage tanks. The effects of temperature, water content and acetic/formic acid concentration on the rate of corrosion of metals were studied, as well as their possible interaction effects. The method used involved a factorial design of experiments. All primary effects with their interactions were found statistically significant.

  19. 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.

  20. COPPER PITTING CORROSION: A CASE STUDY

    EPA Science Inventory

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

  1. 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

  2. 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.

  3. Studying localized corrosion using liquid cell transmission electron microscopy

    DOE PAGESBeta

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

    2014-11-07

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

  4. Engineering considerations for corrosion monitoring of gas gathering pipeline systems

    SciTech Connect

    Braga, T.G.; Asperger, R.G.

    1987-01-01

    Proper corrosion monitoring of gas gathering pipelines requires a system review to determine the appropriate monitor locations and types of monitoring techniques. This paper develops and discusses a classification of conditions such as flow regime and gas composition. Also discussed are junction categories which, for corrosion monitoring, need to be considered from two points of view. The first is related to fluid flow in the line and the second is related corrosion inhibitor movement along the pipeline. The appropriate application of the various monitoring techniques such as coupons, hydrogen detectors, electrical resistance probe and linear polarization probes are discussed in relation to flow regime and gas composition. Problems caused by semi-conduction from iron sulfide are considered. Advantages and disadvantages of fluid gathering methods such as pots and flow-through drips are discussed in relation to their reliability as on-line monitoring locations.

  5. 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.

  6. In-situ electrochemical study of corrosion of steel and aluminum/steel couples during cyclic corrosion test

    SciTech Connect

    Gao, G.

    1998-12-31

    Use of aluminum alloys for automotive applications is growing steadily. Galvanic corrosion is a major concern for those alloys. Because of the predominate use of steels in the automotive industry, the majority of accelerated test procedures commonly accepted by the industry are designed for cosmetic corrosion and perforation of steels. SAE 52334 and Ford Arizona Proving Ground (Ford APG) tests are two examples. Adopting those tests for galvanic corrosion of Al alloys without any fundamental understanding of the process may lead to misleading results. In this paper, electrochemical studies were conducted to examine the acceleration effects of several parameters on different types of corrosion. Galvanic corrosion of aluminum 6111 alloy and cold rolled steel (Al/ CRS) couples and general corrosion of cold rolled steel substrates were studied.

  7. 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...

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

    PubMed

    Ditrich, H; Splechtna, H

    1989-06-01

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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Corrosion in lithium-stainless steel thermal-convection systems

    SciTech Connect

    Tortorelli, P.F.; DeVan, J.H.; Selle, J.E.

    1980-01-01

    The corrosion of types 304L and 316 austenitic stainless steel by flowing lithium was studied in thermal-convection loops operated at 500 to 650/sup 0/C. Both weight and compositional changes were measured on specimens distributed throughout each loop and were combined with metallographic examinations to evaluate the corrosion processes. The corrosion rate and mass transfer characteristics did not significantly differ between the two austenitic stainless steels. Addition of 500 or 1700 wt ppM N to purified lithium did not increase the dissolution rate or change the attack mode of type 316 stainless steel. Adding 5 wt % Al to the lithium reduced the weight loss of this steel by a factor of 5 relative to a pure lithium-thermal-convection loop.

  15. Aging of distribution and other lifeline systems due to corrosion

    SciTech Connect

    Isenberg, J. )

    1993-05-01

    Statistics derived from public works maintenance records for buried steel and cast iron pipelines indicate that aging may be seen in increasing rates of repairs. Maintenance increases with age due to cumulative traffic loads, ground settlement and, among the most important causes, corrosion. The tendency for repair rates gradually to increase and the opposing effects of corrosion control and planned replacement are punctuated by the rapid rise in leakage and required maintenance in the aftermath of an earthquake. These data were uncovered as a byproduct of studying five western US earthquakes in which performance of steel pipelines under seismic conditions and under normal operating conditions appear to be correlated. Evidence also points to temporary and, sometimes, to permanent increase in the rate of leakage and failure in the aftermath of an earthquake. The underlying cause of this correlation is thinning of pipe walls due to corrosion, which is facilitated by stray current and conductive soil. 6 refs., 4 figs., 1 tab.

  16. 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.

  17. 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. PMID:26467696

  18. A Nationwide Population-Based Study of Corrosive Ingestion in Taiwan: Incidence, Gender Differences, and Mortality

    PubMed Central

    Chen, Chuan-Mei; Chung, Yueh-Chin; Tsai, Li-Hung; Tung, Yi-Chen; Lee, Horng-Mo; Lin, Mei-Ling; Liu, Hsin-Li; Tang, Woung-Ru

    2016-01-01

    Corrosive injury results from the intake of corrosive-acid-based chemicals. However, this phenomenon is limited to a small number of cases and cannot be extrapolated to the epidemiology of corrosive injuries in actual situations. This study focuses on the annual incidence of corrosive injury and its connection to gender, risk factors, and in-hospital mortality. All patients with corrosive injury (ICD-9 947.0–947.3) were identified using a nationwide inpatient sample from 1996 until 2010. Chi-squared tests and multivariate logistic regression were used to examine risk factors of gender differences and in-hospital mortality of corrosive injury. Young adults comprised the majority of patients (71.2%), and mean age was 44.6 ± 20.9 years. Women showed a higher incidence rate of corrosive injuries, age, suicide, psychiatric disorder, and systemic complications compared with men (p < 0.001). The present study demonstrated that age (OR = 10.93; 95% CI 5.37–22.27), systemic complications (OR = 5.43; 95% CI 4.61–6.41), malignant neoplasms (OR = 2.23; 95% CI 1.37–3.62), gastrointestinal complications (OR = 2.02; 95% CI 1.63–2.51), chronic disease (OR = 1.30; 95% CI 1.08–1.56), and suicide (OR = 1.23; 95% CI 1.05–1.44) were strongly associated with in-hospital mortality. Educational programs may be helpful for reducing the incidence of ingestion of corrosive chemicals. PMID:26819610

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Development of a corrosion inhibition model. 1: Laboratory studies

    SciTech Connect

    Hausler, R.H.; Martin, T.G.; Stegmann, D.W.; Ward, M.B.

    1999-11-01

    The production of a CO{sub 2} flood in the Oklahoma panhandle led to severe corrosion of the carbon steel production tubing and casing. Traditional approaches to chemical corrosion inhibition were unsuccessful. A laboratory study was initiated to determine first the best corrosion inhibitor, and second the optimum effective inhibitor concentration in the produced fluids as a function of the production rate, CO{sub 2} partial pressure, and water to oil ratio. The tool used was the high speed autoclave test (HSACT) discussed in earlier publications. Statistical experimental designs were used to study the three major parameters. The results were expressed in terms of the inhibitor concentration necessary to achieve a desired corrosion rate (for example 1 mpy), and presented either in the form of response surfaces or linear multiple regression equations. While it was generally known that higher fluid velocities require a higher inhibitor concentration for equal target corrosion rates, it was less well appreciated that the CO{sub 2} partial pressure also has a significant effect on the effective inhibitor concentration. The model as represented either by the response surface or the predictive equations is both inhibitor and field specific.

  6. 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.

  7. 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.

  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. 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. PMID:24169516

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:23636692

  15. 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.

  16. Laboratory stress corrosion cracking studies in polythionic acid

    SciTech Connect

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

    1984-08-01

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

  17. Corrosion studies in molten calcium chloride with chlorine

    SciTech Connect

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

    1990-01-01

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

  18. 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. PMID:24859195

  19. Process Test Plan for 4TH Generation Hanford Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-06-20

    Instrumentation and cabinets for the 241-AN-107 and 241-AN-102 corrosion monitoring systems will be upgraded in FY 2000. The bulk of the field work involved in this task will involve placement of the corrosion monitoring data collection hardware closer to the risers that house the existing corrosion probes. This will be accomplished by placing a new climate controlled cabinet by the risers containing corrosion probes on these two tanks (one cabinet per tank). Once installed the systems will feed data back to a centralized corrosion monitoring station in the 241-AN-271 instrument building. The upgraded systems will be operated under the bounds of this Process Test Plan (PTP) for six principle reasons. These reasons were established prior to installing the original systems in 1997 (241-AN-107) and 1998 (241-AN-102). They are as follows: (1) Acquire corrosion data on the waste in 241-AN-107 and 241-AN-102. (2) Provide supporting data to the site's Integrity Assessment program. (3) Demonstrate that corrosion monitoring by evaluation of electrochemical noise data is possible in waste tank systems, particularly with regard to the detection of general corrosion and (if present) pitting and stress corrosion cracking. (4) Demonstrate the durability of the design of the corrosion monitoring equipment. (5) Extend tank life and reduce annual operations cost. (6) Provide basis to control corrosion in double shell tanks though the use of direct corrosion monitoring rather than waste sampling and analysis. The designs of the existing corrosion probes in 241-AN-107 and 241-AN-102 were reviewed and documented prior to the original installation activities in 1997 and 1998. Initial programmatic documentation for Hanford's corrosion monitoring program was also established prior to the original installation activities.

  20. 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)

  1. Case study: Minimization of corrosion using activated sodium bromide in a medium-size cooling tower

    SciTech Connect

    Nalepa, C.J.; Moore, R.M.; Golson, G.L.; Wolfe, T.W.; Puckorius, P.R.

    1996-10-01

    The process loop cooling tower at the Albemarle Process Development Center in Baton Rouge, LA has historically used chlorine as the biocide together with industry accepted phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron build-up was a recurring problem, especially in low-velocity, small cross-sectional areas of piping. A general clean-up of the system was performed in April, 1995. This clean-up was followed with a switch to a two-component corrosion inhibitor/dispersant package. It was decided to study alternate biocides as well at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel while maintaining prior performance on admiralty brass. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, BART (biological activity reaction test) tests, and visual observations of the tower sump and heat exchanger surfaces.

  2. 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). PMID:22073728

  3. 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.

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

    SciTech Connect

    Lin, Y. J.

    1999-01-13

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

  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. PMID:25448906

  6. Electrochemical corrosion studies in low conductivity propellants

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  7. Electrochemical study on microbiology-related corrosion of metallic dental materials.

    PubMed

    Chang, Jui-Chung; Oshida, Yoshiki; Gregory, Richard L; Andres, Carl J; Barco, Thomas M; Brown, David T

    2003-01-01

    Microbiology-related corrosion has been noted in industry for many years. It is widely recognized that microorganisms affect the corrosion of metal and alloys immersed in aqueous environments. Under similar conditions, the effect of bacteria in the oral environment on the corrosion of dental metallic materials remains unknown. The purpose of this study is to investigate the corrosion behavior of dental metallic materials in the presence of Streptococcus mutans and its growth byproducts. Samples were commercially pure titanium (CPT), Ti-6Al-4V (TAV), Ti-Ni (TN), Co-Cr-Mo alloy (CCM), 316L stainless steel (SSL), 17Cr-4Ni PH-type stainless steel (PH), and Ni-Cr alloy (NC). Using Gamry corrosion test system, surfaces were exposed to (1) sterilized Ringer's solution as a control for (2), (2) S. mutans mixed with sterilized Ringer's solution; (3) sterilized tryptic soy broth as a control for (4), and (4) byproducts of S. mutans mixed with sterilized tryptic soy broth. Corrosion parameters (EOCP, ECORR, ICORR, etc.) were corrected for all tested samples. Averaged values of these parameters were statistically analyzed by t-test to identify significant differences. It was concluded that (1) S. mutans reduced the EOCP of CPT, TAV, TN, and SSL, and the byproducts of S. mutans reduced the EOCP of TAV, TN, SSL, and PH. (2) S. mutans increased the ICORR of PH, and byproducts of S. mutans increased the ICORR of all the samples. (3) S. mutans reduced the ECORR of CPT, TAV and TN, and the byproducts of S. mutans reduced the ECORR of TN, SSL, PH, and NC. (4) S. mutans increased the IPASS of CPT, and the byproducts of S. mutans increased the IPASS of CPT, PH, and NC. PMID:12883177

  8. 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.

  9. 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.

  10. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  12. PRINCIPLES OF CORROSION AND CORROSION MONITORING

    EPA Science Inventory

    Recent amendments to the National Interim Primary Drinking Water Regulations deal with corrosion and require utilities to assess corrosion in their distribution and home plumbing systems. Problems caused by corrosion can be grouped into 3 categories: health, aesthetics and econom...

  13. Simultaneous corrosion and fouling monitoring under heat transfer in cooling water systems

    SciTech Connect

    Winters, M.A.; Stokes, P.S.N.; Nichols, H.F.

    1996-12-31

    Corrosion and fouling in cooling water systems can potentially reduce heat-transfer capability, increase maintenance costs, reduce plant availability, and contaminate process lines. Conventional monitoring systems have measured corrosion and fouling separately. Fouling monitors alone are not able to indicate real-time corrosion activity beneath surface deposits. Traditionally, corrosion information has been derived from destructive evaluation of heat exchanger tubes, weight loss coupons, and probes under nonheat flux conditions. To overcome these shortcomings, a monitoring system has been developed that measures corrosion and fouling simultaneously. By using electrochemical noise measurement technology, the system is particularly sensitive to detecting localized corrosion beneath a fouled surface, a major and frequent mode of corrosion failure in heat exchangers. Development of the system has progressed from field trials with a prototype unit to a commercially available system. This paper reports and discusses the most recent evaluation of the system at Amoco`s Corporate Research facility in Naperville, Illinois, focusing on the sensitivity of electrochemical noise measurement in detecting localized corrosion (pitting and so forth) on a heat transfer surface in a cooling water environment.

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

    SciTech Connect

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

    1997-08-01

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

  15. Corrosion cracking

    SciTech Connect

    Goel, V.S.

    1986-01-01

    Various papers on corrosion cracking are presented. The topics addressed include: unique case studies on hydrogen embrittlement failures in components used in aeronautical industry; analysis of subcritical cracking in a Ti-5Al-2.5Sn liquid hydrogen control valve; corrosion fatigue and stress corrosion cracking of 7475-T7351 aluminum alloy; effects of salt water environment and loading frequency on crack initiation in 7075-T7651 aluminum alloy and Ti-6Al-4V; stress corrosion cracking of 4340 steel in aircraft ignition starter residues. Also discussed are: stress corrosion cracking of a titanium alloy in a hydrogen-free environment; automation in corrosion fatigue crack growth rate measurements; the breaking load method, a new approach for assessing resistance to growth of early stage stress corrosion cracks; stress corrosion cracking properties of 2090 Al-Li alloy; repair welding of cracked free machining Invar 36; radial bore cracks in rotating disks.

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

    SciTech Connect

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

    1992-01-01

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

  17. Stress Corrosion Cracking Study of Aluminum Alloys Using Electrochemical Noise Analysis

    NASA Astrophysics Data System (ADS)

    Rathod, R. C.; Sapate, S. G.; Raman, R.; Rathod, W. S.

    2013-12-01

    Stress corrosion cracking studies of aluminum alloys AA2219, AA8090, and AA5456 in heat-treated and non heat-treated condition were carried out using electrochemical noise technique with various applied stresses. Electrochemical noise time series data (corrosion potential vs. time) was obtained for the stressed tensile specimens in 3.5% NaCl aqueous solution at room temperature (27 °C). The values of drop in corrosion potential, total corrosion potential, mean corrosion potential, and hydrogen overpotential were evaluated from corrosion potential versus time series data. The electrochemical noise time series data was further analyzed with rescaled range ( R/ S) analysis proposed by Hurst to obtain the Hurst exponent. According to the results, higher values of the Hurst exponents with increased applied stresses showed more susceptibility to stress corrosion cracking as confirmed in case of alloy AA 2219 and AA8090.

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

    SciTech Connect

    Gopala N. Krishnan

    2004-05-01

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

  19. Corrosion/95 conference papers

    SciTech Connect

    1995-09-01

    The papers in this conference represent the latest technological advances in corrosion control and prevention. The following subject areas are covered: cathodic protection in natural waters; materials for fossil fuel combustion and conversion systems; modern problems in atmospheric corrosion; innovative ideas for controlling the decaying infrastructure; deposits and their effects on corrosion in industry; volatile high temperature and non aqueous corrosion inhibitors; corrosion of light-weight and precoated metals for automotive application; refining industry corrosion; corrosion in pulp and paper industry; arctic/cold weather corrosion; materials selection for waste incinerators and associated equipment; corrosion measurement technology; environmental cracking of materials; advancing technology in the coating industry; corrosion in gas treating; green inhibition; recent advances in corrosion control of rail equipment; velocity effects and erosion corrosion in oil and gas production; marine corrosion; corrosion of materials in nuclear systems; underground corrosion control; corrosion in potable and industrial water systems in buildings and its impact on environmental compliance; deposit related boiler tube failures; boiler systems monitoring and control; recent developments and experiences in reactive metals; microbiologically influenced corrosion; corrosion and corrosion control for steel reinforced concrete; international symposium on the use of 12 and 13 Cr stainless steels in oil and gas production environments; subsea corrosion /erosion monitoring in production facilities; fiberglass reinforced pipe and tubulars in oilfield service; corrosion control technology in power transmission and distribution; mechanisms and methods of scale and deposit control; closing the loop -- results oriented cooling system monitoring and control; and minimization of aqueous discharge.

  20. 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.

  1. Permeability and corrosion behavior of phenoxy coatings

    SciTech Connect

    Tiburcio, A.C.; Manson, J.A.

    1993-12-31

    The corrosion behavior of a glass-bead-filled phenoxy coating system was studied by correlating permeability and electrochemical measurements with actual corrosion performance. The study emphasized the effects of filler and filler/polymer matrix interactions on corrosion behavior. Water vapor permeability, dissolved oxygen permeability and conductivity measurements were made to determine the rate of transport of the three key ingredients in cathodic delamination and corrosion process (H{sub 2}O, O{sub 2}, and cation). The glass bead filler had a greater effect on both cathodic delamination and corrosion behavior than filler/polymer matrix interaction. Overall, the permeability behavior controlled the delamination and corrosion performance.

  2. Corrosion 99: Proceedings

    SciTech Connect

    1999-11-01

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

  3. Corrosion 99: Proceedings

    SciTech Connect

    Not Available

    1999-01-01

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

  4. 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...

  5. Mitigation of copper corrosion and agglomeration in APS process water systems.

    SciTech Connect

    Dortwegt, R.; Putnam, C.; Swetin, E.

    2002-10-10

    Copper corrosion has been observed in process water (PW) systems at the Advanced Photon Source (APS) dating to the early postcommissioning phase of the project. In time, copper corrosion products agglomerated significantly in certain preferred locations. Significant agglomerations (or deposits) can occur in copper cooling passages such as magnet conductors and x-ray absorbers having relatively large length-to-diameter ratios and where heat is removed by water cooling. Such agglomerations also occur at restrictions found in noncopper system components such as valve seats, fixed orifices, pump seal faces, etc. Modifications to the APS process water system that significantly reduce the rate of copper corrosion are discussed. These modifications have not prevented corrosion altogether. Other means used to prevent component clogging and malfunction as a result of current copper corrosion rates are listed.

  6. Acceptance Test Report for Fourth Generation Hanford Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-10-23

    This Acceptance Test Report (ATR) will document the satisfactory operation of the corrosion probe cabinets destined for installation on tanks 241-AN-102 and 241-AN-107. This ATR will be performed by the manufacturer on each cabinet prior to delivery to the site. The objective of this procedure is to demonstrate and document the acceptance of the corrosion monitoring cabinets to be installed on tanks 241-AN-102 and 241-AN-107. One cabinet will be installed on each tank. Each cabinet will contain corrosion monitoring hardware to be connected to existing corrosion probes already installed in each tank. The test will consist of a continuity test of the cabinet wiring from the end of cable to be connected to corrosion probe, through the appropriate intrinsic safety barriers and out to the 15 pin D-shell connectors to be connected to the corrosion monitoring instrument. Additional testing will be performed using a constant current and voltage source provided by the corrosion monitoring hardware manufacturer to verify proper operation of corrosion monitoring instrumentation (input a known signal and see if the instrumentation records the proper value).

  7. Acceptance test plan for fourth generation Hanford corrosion monitoring system

    SciTech Connect

    NORMAN, E.C.

    2000-07-27

    This Acceptance Test Plan (ATP) will document the satisfactory operation of the corrosion probe cabinets destined for installation on tanks 241-AN-102 and 241-AN-107. This ATP will be performed by the manufacturer on each cabinet prior to delivery to the site. The objective of this procedure is to demonstrate and document the acceptance of the corrosion monitoring cabinets to be installed on tanks 241-AN-102 and 241-AN-107. One cabinet will be installed on each tank. Each cabinet will contain corrosion monitoring hardware to be connected to existing corrosion probes already installed in each tank. The test will consist of a continuity test of the cabinet wiring from the end of cable to be connected to corrosion probe, through the appropriate intrinsic safety barriers and out to the 15 pin D-shell connectors to be connected to the corrosion monitoring instrument. Additional testing will be performed using a constant current and voltage source provided by the corrosion monitoring hardware manufacturer to verify proper operation of corrosion monitoring instrumentation (input a known signal and see if the instrumentation records the proper value).

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

    PubMed

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

    2013-06-01

    Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction. PMID:23618271

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

    SciTech Connect

    1997-05-01

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

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

    SciTech Connect

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

    2005-03-01

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

  11. Nitric acid measurements in connection with corrosion studies

    NASA Astrophysics Data System (ADS)

    Ferm, Martin; De Santis, Franco; Varotsos, Costas

    Atmospheric nitric acid does not only contribute to acidification and eutrophication but causes also deterioration of many materials. Material belonging to our cultural heritage is irreplaceable and its lifetime can depend on the corrosion rate. Nowadays, only very few long-term measurements of nitric acid concentration in Europe and elsewhere have been published so far. Due to the fact that atmospheric corrosion is a long-term effect, the relevant research does not necessarily require monitoring of nitric acid on a daily basis. Moreover, power supply is often not available at sites where it is of interest to study the corrosion rate of objects belonging to our cultural heritage. Besides, such measurements must not disturb the impression of the objects. In this context, the diffusive sampling technique provides average concentrations over long-term periods at a low cost. In addition, the samplers used are noiseless, comparatively small in size, and thus, their ambient exposure can be made inconspicuously and with discretion. The present paper is focussed on an intensive corrosion study, which was performed at 11 rural and 23 urban sites in Europe and one rural site in Canada during 2002/2003. For the above-mentioned reasons, the diffusive sampler's technique was employed for the nitric acid monitoring, where the diffusive samplers were first tested against the denuder technique and bi-monthly measurements of nitric acid were thus obtained. The bi-monthly concentrations varied from 0.05 to 4.3 μg m -3 and the annual averages from 0.16 to 2.0 μg m -3. The observations collected, depicted a summertime maximum and a wintertime minimum in the nitric acid concentrations, except at the northern rural sites, where a maximum in the winter was observed. Furthermore, the observed nitric acid concentrations in Southern Europe were higher than in Northern Europe. In a few places, close to the sites of urban measurements, rural measurements of nitric acid were also performed

  12. 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.

  13. 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.

  14. 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.

  15. The iron powder test for naphthenic acid corrosion studies

    SciTech Connect

    Hau, J.L.; Yepez, O.; Specht, M.I.; Lorenzo, R.

    1999-11-01

    In the course of an ongoing investigation into the phenomenon of naphthenic acid corrosion, a new test method has evolved and is currently being further developed to substitute the total acid number (TAN or neutralization number) as an indicator for naphthenic acid corrosion potential. It can also be used to complement conventional autoclave corrosion tests in high temperature environments, which are based on weight loss of steel coupons. In this new method an oil sample reacts with pure iron powder within an autoclave heated to the testing temperature. The result is based on the amount of dissolved iron found in the oil sample. The oil sample can dissolve an amount of iron for a given time at a given temperature, depending on the naphthenic acid corrosion, since these acids react with iron to produce oil soluble iron naphthenates. This paper describes the method, compares it with conventional crude corrosiveness testing, and proposes it as a new way of measuring naphthenic acid corrosion potential.

  16. 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

  17. 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

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

    SciTech Connect

    Schorr, M.; Mureinik, R.J.

    1985-09-01

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

  19. 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 ...

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

    SciTech Connect

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

    2005-01-01

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

  1. A critical review of expert systems for corrosion prevention and control

    SciTech Connect

    Roberge, P.R.

    1994-12-31

    The serious gap that exists between modern corrosion science and the real world, where a heavy toll is continuously paid to corrosion, is a clear indication that the present knowledge of corrosion mechanisms is not always translated into sound practices. The dichotomy between prevention principles discovered in a laboratory environment and their application on an industrial scale can often be felt at specialized conferences where scientists and operational engineers seem to be speaking different languages. The application of artificial intelligence to perform expert functions has opened new communication channels between various strata of corrosion knowledge holders. This paper reviews the efforts recently made public on the applications of the expert system technology to corrosion prevention and control.

  2. Natural compounds as corrosion inhibitors for highly cycled systems

    SciTech Connect

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

    1999-11-01

    Strict environmental legislations have led to the development of green inhibitors in recent years. In continuation of the authors` research work on development of green inhibitors, they have investigated the aqueous extracts of three plants namely: Azadirachta indica, Punica Granatum and Momordica charantia as corrosion inhibitors for mild steel in 3% NaCl using weight loss and electrochemical methods. All the investigated compounds exhibited excellent corrosion inhibition properties comparable to that of HEDP. Azadirachta showed better scale inhibition effect than HEDP.

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

    SciTech Connect

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

    1980-08-01

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

  4. 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

  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. 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. PMID:25150521

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

    SciTech Connect

    Gopala N. Krishnan; Ripudaman Malhotra; Angel Sanjurjo

    2004-05-01

    Heat-exchangers, 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.

  8. 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...

  9. Corrosion coupon studies at coal liquefaction pilot plants

    SciTech Connect

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

    1983-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  11. 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.

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

    PubMed

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

    2006-03-01

    A new passive particle collector (inert surrogate surface) that collects particles from all directions has been developed. It was used to measure particle deposition at 35 test sites as part of a project that examined corrosion of materials in order that variation in particulate material could be used in development of dose-response functions in a modern multi-pollutant environment. The project, MULTI-ASSESS, was funded by the EU to examine the effects of air pollution on cultural heritage. Passive samplers were mounted rain-protected, and both in wind-protected and wind-exposed positions, to match the exposure of the samples for corrosion studies. The particle mass and its chemical content (nitrate, ammonium, sulfate, calcium, sodium, chloride, magnesium and potassium) were analysed. The loss of light reflectance on the surrogate surface was also measured. Very little ammonium and potassium was found, and one or more anions are missing in the ion balance. There were many strong correlations between the analysed species. The mass of analysed water-soluble ions was fairly constant at 24% of the total mass. The particle mass deposited to the samplers in the wind-protected position was about 25% of the particles deposited to an openly exposed sampler. The Cl-/Na+ ratios indicate a reaction between HNO(3) and NaCl. The deposited nitrate flux corresponds to the missing chloride. The Ca2+ deposition equals the SO4(2-) deposition and the anion deficiency. The SO4(2-) deposition most likely originates from SO2 that has reacted with basic calcium-containing particles either before or after they were deposited. The particle depositions at the urban sites were much higher than in nearby rural sites. The deposited mass correlated surprisingly well with the PM(10) concentration, except at sites very close to traffic. PMID:16518649

  13. Corrosion inhibitor evaluation for materials used in closed cooling water systems

    SciTech Connect

    Moccari, A.A.

    1999-09-01

    Electrochemical tests were conducted to evaluate the inhibition effects of a commercial sodium nitrite (NaNO{sub 2})/sodium tolyltriazole (nitrite/TTA)-based corrosion inhibitor added to deionized water at 50 C. General and pitting corrosion of materials commonly used in closed cooling water systems were examined. Tests also were performed in deionized water to which Cl{sup {minus}} had been added. At the tested concentrations, nitrite/TTA was found to be an effective corrosion inhibitor for all of the materials tested in plain deionized water and Cl{sup {minus}}-containing water.

  14. 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.

  15. 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. PMID:26930447

  16. Study on corrosion resistance of high - entropy alloy in medium acid liquid and chemical properties

    NASA Astrophysics Data System (ADS)

    Florea, I.; Buluc, G.; Florea, R. M.; Soare, V.; Carcea, I.

    2015-11-01

    High-entropy alloy is a new alloy which is different from traditional alloys. The high entropy alloys were started in Tsing Hua University of Taiwan since 1995 by Yeh et al. Consisting of a variety of elements, each element occupying a similar compared with other alloy elements to form a high entropy. We could define high entropy alloys as having approximately equal concentrations, made up of a group of 5 to 11 major elements. In general, the content of each element is not more than 35% by weight of the alloy. During the investigation it turned out that this alloy has a high hardness and is also corrosion proof and also strength and good thermal stability. In the experimental area, scientists used different tools, including traditional casting, mechanical alloying, sputtering, splat-quenching to obtain the high entropy alloys with different alloying elements and then to investigate the corresponding microstructures and mechanical, chemical, thermal, and electronic performances. The present study is aimed to investigate the corrosion resistance in a different medium acid and try to put in evidence the mechanical properties. Forasmuch of the wide composition range and the enormous number of alloy systems in high entropy alloys, the mechanical properties of high entropy alloys can vary significantly. In terms of hardness, the most critical factors are: hardness/strength of each composing phase in the alloy, distribution of the composing phases. The corrosion resistance of an high entropy alloy was made in acid liquid such as 10%HNO3-3%HF, 10%H2SO4, 5%HCl and then was investigated, respectively with weight loss experiment. Weight loss test was carried out by put the samples into the acid solution for corrosion. The solution was maintained at a constant room temperature. The liquid formulations used for tests were 3% hydrofluoric acid with 10% nitric acid, 10% sulphuric acid, 5% hydrochloric acid. Weight loss of the samples was measured by electronic scale.

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

    SciTech Connect

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

    2011-04-01

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

  18. Preceedings of the International Congress (12th), corrosion control for low-cost reliability, held in Houston, Texas on September 19 -24, 1993. Volume 5a. Corrosion: Specific issues

    SciTech Connect

    Not Available

    1993-09-24

    Partial contents include: (1) The role of corrosion in aging aircraft; (2) Hidden corrosion - needs and requirements; (3) Corrosion control as a necessary treatment; (4) Computer assisted aircraft paint stripping technology; (5) Reducing aircraft corrosion with desiccant dehumidifiers; (6) Corrosion contribution to environmental cracking failures of critical aircraft parts; (7) Designing metallic surface coatings for improved corrosion resistance; (8) Development of chromium based composite coatings; (9) In-situ analysis of corrosion in the crevice of automotive body by A.C. impedance measurement; (10) Designing a reinforced concrete against corrosion in chloride containing environments; (11) Carbonation of flyash-containing concrete electrochemical studies; (12) Evaluation of concrete corrosion inhibitors; (13) Cathodic protection of new steel reinforced concrete structure; (14) Reliability and corrosion testing of electronic components and assemblies; (15) Corrosion study of polymer-on-metal systems modified by processing conditions; (16) How to formulate corrosion knowledge for expert systems; and (17) Corrosion prediction form laboratory tests using artificial neural networks.

  19. 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

  20. 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. PMID:26347374

  1. 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.

  2. 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.

  3. 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.

  4. Corrosion of 90-10 Cupronickel Alloys in Seawater Systems

    NASA Astrophysics Data System (ADS)

    Frick, J. P.; Scharfstein, L. R.; Parrill, T. M.; Haaland, G.

    1985-03-01

    This paper documents the presence of a detrimental iron based grain boundary phase that develops during extended time at sensitizing temperature. This defect has been responsible for premature failure. Standard electrochemical testing techniques fail to predict accelerated corrosion rates that are due to galvanic coupling within the material.

  5. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

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

    PubMed

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

    2012-02-01

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

  8. Corrosion studies of A216 grade WCA steel in hydrothermal magnesium-containing brines

    SciTech Connect

    Haberman, J.H.; Frydrych, D.J.

    1988-02-01

    The US Department of Energy's Salt Repository Project (SRP) is investigating the general corrosion resistance of cast mild steel as a candidate material for waste package containers. Evaluation of this material is being performed at the Pacific Northwest Laboratory in environments simulating expected repository conditions. General corrosion studies of mild steel (ASTM A216 grade WCA) in the as-cast and normalized conditions were conducted in hydrothermal halite-saturated (saturated at ambient temperature) brine environments simulating a ''dissolution'' and an ''inclusion'' brine. Corrosion tests were also performed in brines similar to the inclusion brine but containing magnesium concentrations ranging from 1000 to 30,000 ppM to investigate the effect of magnesium on the corrosion behavior. Corrosion rates of the cast mild steel were found to increase with increasing temperature and with increasing magnesium concentration. Some possible mechanisms that explain the observed behavior are presented. 8 refs., 7 figs., 2 tabs.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

    Ni, Hai

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

  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. Corrosion of iron: A study for radioactive waste canisters

    NASA Astrophysics Data System (ADS)

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

    2007-05-01

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

  13. 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.

  14. 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/.

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  16. A Review of 25 Years of Corrosion Studies on HLW Container Materials at the CEA

    SciTech Connect

    Helie, Max

    2007-07-01

    The Commissariat a l'Energie Atomique (CEA, French Atomic Energy Commission) has been involved in researches on nuclear waste management for more than 25 years. One of the key issues is the prediction of the long term behavior and aging of the High Level Waste (HLW) containers in order to develop concepts that will ensure the confinement of the activity over extremely long periods of time. Preliminary studies were carried out on two concepts, one of a thin 'corrosion resistant' container made of titanium or nickel base alloy, and the other on a thick 'corrosion allowance' container made or carbon steel. The results of these experiments showed that the 'corrosion resistant' concept led to a high uncertainty on the development and propagation rate of localized forms of corrosion, and the concept of geological disposal in an argillaceous host formation of thick waste containers made of carbon steel was chosen as the reference for further studies. This eventually led to the voting of a law relative to nuclear waste management on June 28 2006, which endorses the geological disposal of corrosion allowance containers as the reference solution, while stating than an effort must be kept on the research on actinides transmutation to reduce the time during which a geological disposal facility has to be proven capable to ensure the confinement of the radioactive waste. Studies are still in progress to better assess the corrosion mechanisms relevant to this situation in order to provide reliable models for the long term prediction of the containers corrosion behavior. (author)

  17. 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.

  18. 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.

  19. 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.

  20. 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…

  1. 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).

  2. Stress corrosion cracking of carbon steel in amine systems

    SciTech Connect

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

    1988-01-01

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

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

    SciTech Connect

    Roy, A. K., LLNL

    1997-11-01

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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. Uranium speciation in glass corrosion layers: An XAFS study

    SciTech Connect

    Biwer, B.M.; Soderholm, L.; Greegor, R.B.; Lytle, F.W.

    1997-12-31

    Uranium L{sub 3} X-ray absorption data were obtained from two borosilicate glasses, which are considered as models for radioactive wasteforms, both before and after leaching. Surface sensitivity to uranium speciation was attained by a novel application of simultaneous fluorescence and electron-yield detection. Changes in speciation are clearly discernible, from U(VI) in the bulk to (UO{sub 2}){sup 2+}-uranyl in the corrosion layer. The uranium concentrations within the corrosion layer also show variations with leaching times that can be determined from the data.

  9. A potentiostatic study of the corrosion behavior of anodized and nonanodized aluminum alloy.

    PubMed

    White, K C; Svare, C W; Taylor, T D

    1985-06-01

    The clinical implication of this study is that some improvement in the corrosion resistance of denture bases made with aluminum alloy D-214 may be obtained by anodization. However, since this study does not exactly duplicate an oral environment or take into consideration the variation in oral environments, it cannot be assumed that the additional corrosion resistance would be discernible in a particular patient. PMID:3859652

  10. 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. PMID:10496152

  11. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  13. 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...

  14. 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...

  15. 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.

  16. 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...

  17. ASSESSMENT OF CORROSION PRODUCTS FROM ONCE-THROUGH COOLING SYSTEMS WITH MECHANICAL ANTIFOULING DEVICES

    EPA Science Inventory

    The report gives results of an assessment of corrosion products from steam-electric power plant once-through cooling systems equipped with mechanical antifouling devices. (About 67% of the currently operating plants in the U.S. use once-through cooling systems. Various cleaning m...

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

    NASA Astrophysics Data System (ADS)

    Chidambaram, Devicharan

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

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  1. XPS study on double glow plasma corrosion-resisting surface alloying layer

    NASA Astrophysics Data System (ADS)

    Ai, Jiahe; Xu, Jiang; He, Fei; Xie, Xishan; Xu, Zhong

    2003-02-01

    Double glow plasma corrosion-resisting surface alloying layer (SAL) formed on low carbon steel 1020 was studied by X-ray photoelectron spectroscopy (XPS) and other means. Results show that the passive film of the surface alloying layer after electrochemical test in 3.5% NaCl solution consists of Cr and Fe oxide such as CrO 3, Cr 2O 3, Fe 2O 3 and FeO and metallic Ni and Mo, and it attributes to the fact that a continuous and compact corrosion-resisting surface alloying layer with rich Cr, Ni and Mo was formed on the surface of steel 1020 so as to increase its corrosion resistance greatly. Therefore, double glow plasma technique will be widely used in corrosion-resisting surface science.

  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. Corrosion of retractable type fall arresters.

    PubMed

    Baszczyński, Krzysztof; Jachowicz, Marcin

    2009-01-01

    Retractable type fall arresters constitute a most effective group of components used in personal protection systems protecting against falls from a height. They are designed primarily for outdoor use, which results in exposure to atmospheric factors associated with risk of corrosion of metal elements. This paper presents the results of a study, in which retractable type fall arresters were exposed to a simulated corrosive environment, a neutral salt spray. It discusses the development of corrosion processes depending on the duration of exposure to corrosive conditions. Tests demonstrated that corrosion of elements decreased their strength and impaired the functioning of mobile parts. The article presents methods of testing the correct functioning of devices, necessary for assessing their resistance to corrosion, which have been developed for this purpose. It also analyzes the correlation between corrosion-related damage of retractable type fall arresters and potential hazards for their users. PMID:19744368

  4. Influence of NOM on copper corrosion

    SciTech Connect

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

    1996-07-01

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

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

    SciTech Connect

    NORMAN, E.C.

    2000-08-30

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-09-01

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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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. PMID:23488591

  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. Study on Corrosion Resistance of Fe-based Amorphous Coating by Laser Cladding in Hydrochloric Acid

    NASA Astrophysics Data System (ADS)

    Chen, Q. J.; Guo, S. B.; Yang, X. J.; Zhou, X. L.; Hua, X. Z.; Zhu, X. H.; Duan, Z.

    In this study, the Fe41Co7Cr15Mo14C15B6Y2 bulk amorphous alloy with high glass-forming ability was prepared using the arc- melting copper mold casting technique, and corresponding amorphous coating was obtained using the laser melt amorphous powders on the surface of carbon steel. The corrosion resistance performance of the laser cladding coating in hydrochloric acid was analyzed and tested in experiments under the conditions of different laser cladding speeds. The amorphous alloy coating with different fabrication parameters have the difference internal structure, which lead to the difference corrosion resistance in the same environment to some extent. The nature of amorphous alloy and the corrosion morphology were investigated using XRD and SEM method, respectively. The corrosion experiments showed that: when the laser power was 3300W, the corrosion resistance of four kinds of samples in hydrochloric acid from strong to weak as follows: as-cast sample > the coating with laser cladding speed 110 mm/min > the coating with laser cladding speed 120 mm/min > the coating with laser cladding speed 130 mm/min. The free corrosion current density of casting sample, sample 1, sample 2 and sample 3 is 3.304 × 10-6 A/cm2, 2.600×10-3 A/cm2, 2.030×10-3 A/cm2 and 3.396×10-4 A/cm2, respectively.

  14. 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

  15. 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.

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

    SciTech Connect

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

    1982-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-08-01

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

  18. 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.

  19. Influence of the state of the surface of steel St3 on the adsorption of inhibitor EMFTs and the corrosion retardation produced by it in water recirculation systems

    SciTech Connect

    Ivanov, E.S.; Nikitina, R.A.

    1985-07-01

    Adsorption of the inhibitor on metal surfaces prepared in various ways, is studied in this paper. The investigations of the kinetics of adsorption and desorption of the inhibitor EMFTs on St3 with various surface states have revealed that EMFTs is best adsorbed on a clean polished surface of metal which has not been in contact with a corrosion medium, giving the maximal protective effect. The corrosion inhibitor EMFTs can be recommended for new water recycling systems and also for old systems after preparation by pickling with inhibited acids.

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

    SciTech Connect

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

    2007-07-01

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

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

    SciTech Connect

    Eric Loewen; Ronald Ballinger; Jeongyoun Lim

    2004-09-01

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

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

    SciTech Connect

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

    2004-09-15

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

  3. 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.

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

    SciTech Connect

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

    1998-12-01

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

  5. 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.

  6. 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

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

    PubMed

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

    2004-09-30

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

  8. 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.

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

    PubMed

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

    1996-07-01

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

  10. 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).

  11. 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. PMID:26899639

  12. Study of the corrosion resistance of metals in a lithium bromide solution

    SciTech Connect

    Mel'nik, V.V.; Spivak, R.Sh.; Sokolov, V.V.; Trofimenko, A.G.

    1988-07-01

    Results are reported of a study of the corrosion resistance of the stainless steels 12Kh19N10T, 10Kh17N13M3T, 08Kh17N15M3T, 10Kh21N6M2T, and 06KhI28MDT, cupronickel MNZhMts 30-1-1, nickel NP-2, and titanium alloys VT1-0, PT-1M, and PT-3V in a solution of lithium bromide for purposes of assessing these alloys for use in absorption-type refrigerating units using the bromide as an absorbent. The uniform corrosion rate was determined from the weight loss; the nonuniform corrosion rate was determined by measuring the maximum depth of the pits under a microscope. Results are comparatively evaluated.

  13. 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.

  14. 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.

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

    SciTech Connect

    Wyman, D.P.

    1998-12-31

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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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. PMID:20119943

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

    SciTech Connect

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

    1995-11-01

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

  10. Corrosion of 310 stainless steel in H2- H2O- H2S gas mixtures: Studies at constant temperature and fixed oxygen potential

    NASA Astrophysics Data System (ADS)

    Rao, D. Bhogeswara; Jacob, K. T.; Nelson, Howard G.

    1983-02-01

    Corrosion of SAE 310 stainless steel in H2-H2O-H2S gas mixtures was studied at a constant temperature of 1150 K. Reactive gas mixtures were chosen to yield a constant oxygen potential of approximately 6 × 10-13 Nm-2 and sulfur potentials ranging from 0.19 × 10-2 Nm-2 to 33 × 10-2 Nm-2. The kinetics of corrosion were determined using a thermobalance, and the scales were analyzed using metallography, scanning electron microscopy, and energy dispersive X-ray analysis. Two corrosion regimes, which were dependent on sulfur potential, were identified. At high sulfur potentials ( P S 2 ± 2.7 × 10-2 Nm-2) the corrosion rates were high, the kinetics obeyed a linear rate equation, and the scales consisted mainly of sulfide phases similar to those observed from pure sulfidation. At low sulfur potentials ( P S 2 ± 0.19 × 10-2 Nm-2) the corrosion rates were low, the kinetics obeyed a parabolic rate equation, and scales consisted mainly of oxide phases. Thermochemical diagrams for the Fe-Cr-S-O, Fe-Ni-S-O, Cr-Ni-S-O, and Si-Cr-S-O systems were constructed, and the experimental results are discussed in relation to these diagrams. Based on this comparison, reasonable corrosion mechanisms were developed. At high sulfur potentials, oxide and sulfide phases initially nucleate as separate islands. Overgrowth of the oxide by the sulfide occurs and an exchange reaction governs the corrosion process. Preoxidation at low oxygen potentials and 1150 K is beneficial in suppressing sulfidation at high sulfur potentials.

  11. Caroline pipeline failure: Findings on corrosion mechanisms in wet sour gas systems containing significant CO{sub 2}

    SciTech Connect

    Bich, N.N.; Goerz, K.

    1996-08-01

    A leak occurred in the 5-32S flowline between Junction 1 and the South Compressor Station in the Canada Limited Caroline Complex gathering system near Sundre, Alberta, due to internal wet H{sub 2}S (hydrogen sulfide) and CO{sub 2} (carbon dioxide) pitting corrosion at the bottom of the pipeline. The significant contributing factors to the extremely high pitting corrosion rate, approximately 30 mm/y (1,200 mpy), are considered to be unexpectedly high amounts of chloride ions in the produced well fluids, settling of the produced water under low flow conditions, high condensate/water ratio, inadequate inhibition and pigging, and insufficient monitoring programs. Corrosion mechanisms in sour gas gathering systems with significant CO{sub 2} concentration were reviewed. Preliminary findings pointed to CO{sub 2} partial pressure, not H{sub 2}S, as a main corrosion rate determining factor. The steps taken to prevent similar future incidents were also reviewed.

  12. 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.

  13. 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.

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

    SciTech Connect

    Jasty, S.; Epstein, A.J.

    1995-12-01

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

  15. 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.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

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

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

    SciTech Connect

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

    1996-05-01

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

  19. 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

  20. Atmospheric corrosion model and monitor for low cost solar arrays

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.; Mansfeld, F. B.; Jeanjaquet, S. L.; Kendig, M.

    1981-01-01

    An atmospheric corrosion model and corrosion monitoring system has been developed for low cost solar arrays (LSA). The corrosion model predicts that corrosion rate is the product of the surface condensation probability of water vapor and the diffusion controlled corrosion current. This corrosion model is verified by simultaneous monitoring of weather conditions and corrosion rates at the solar array test site at Mead, Nebraska.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

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

    SciTech Connect

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

    1984-10-01

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

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

    PubMed Central

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

    2014-01-01

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

  7. 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.

  8. 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)

  9. Study of materials to resist corrosion in condensing gas fired furnaces

    NASA Astrophysics Data System (ADS)

    Lahtvee, T.; Khoo, S. W.; Schaus, O. O.

    1981-02-01

    Based on a thorough review of background information on the performance of materials in condensing gas fired furnace heat exchangers and in similar corrosive environments candidate materials were selected and tested on one of two identical test rigs built to provide the varying corrosive conditions encountered in an actual gas fired condensing system heat exchanger. The 32 different materials tested in a one month screening test included: mild, low alloy, galvanized, solder coated and CaCO3 dipped galvanized steel, porcelain, epoxy, teflon and nylon coated and alonized mild steel; austenitic, ferritic, low interstitial Ti stabilized ferritic, and high alloy stainless steels; aluminum alloy anodized and porcelain coated aluminum; copper and cupronickel alloys, solder coated copper; and titanium.

  10. Corrosion Detection Devices

    SciTech Connect

    Howard, B.

    2003-12-01

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

  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. 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.

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

    NASA Astrophysics Data System (ADS)

    Gambina, Federico

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

  14. Electrochemical and surface studies of some Porphines as corrosion inhibitor for J55 steel in sweet corrosion environment

    NASA Astrophysics Data System (ADS)

    Singh, Ambrish; Lin, Yuanhua; Ansari, K. R.; Quraishi, M. A.; Ebenso, Eno. E.; Chen, Songsong; Liu, Wanying

    2015-12-01

    Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO2 by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), Contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). Adsorption of such Porphines on the J55 steel surface obeyed to the Langmuir adsorption isotherm. Atomic force microscopy (AFM), SECM, and Contact angle results confirm the formation of inhibitor film on J55 steel surface thereby mitigating corrosion.

  15. Metal levels in corrosion of spinal implants

    PubMed Central

    Beguiristain, Jose; Duart, Julio

    2007-01-01

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

  16. Microvascular architecture of the rabbit eye: a scanning electron microscopic study of vascular corrosion casts.

    PubMed

    Ninomiya, Hiroyoshi; Inomata, Tomo; Kanemaki, Nobuyuki

    2008-09-01

    The microvasculature of the eyes of 5 rabbits was investigated using scanning electron microscopy on corrosion casts. The study revealed that the pars plana vessels draining blood from the iris and ciliary body coursed directly into the anterior vortex venous system constituting the scleral venous plexus (the venous circle of Hovius). The episcleral vasculature was found to possess a specialized morphology, with channels draining the aqueous humor. The capillaries of the third palpebral, bulbar and palpebral conjunctiva formed a single-layered capillary network approximately parallel to the epithelium and formed a well-developed venous plexus in the stroma. The retina was found to be merangiotic, meaning that vessels were present only in a small part of the retina, extending in a horizontal direction to form bands on either side of the optic disc. Channels representing the aqueous veins that drained blood mixed with aqueous humor were found to derive directly from the suprachoroidal space and communicate with the scleral venous plexus via the anterior vortex veins. The functional significance of the microvasculature of the iris, cilia, retina and choroid is discussed in this report as well. The elaborate microvasculature of the conjunctiva may be a prerequisite for the exchange of nutrients and gasses between the cornea and the vessels across the conjunctival epithelium when the eyelids are shut during sleep, and possibly for the dynamics of eye drop delivery. The scleral venous plexus in rabbits may be analogous to the scleral venous sinus (Schlemm's canal) in rats, primates and humans. PMID:18840961

  17. Systems Studies

    SciTech Connect

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  18. A superconducting quantum interference device magnetometer system for quantitative analysis and imaging of hidden corrosion activity in aircraft aluminum structures

    NASA Astrophysics Data System (ADS)

    Abedi, A.; Fellenstein, J. J.; Lucas, A. J.; Wikswo, J. P.

    1999-12-01

    We have designed and built a magnetic imaging system for quantitative analysis of the rate of ongoing hidden corrosion of aircraft aluminum alloys in planar structures such as intact aircraft lap joints. The system utilizes a superconducting quantum interference device (SQUID) magnetometer that measures the magnetic field associated with corrosion currents. It consists of a three-axis (vector) SQUID differential magnetometer, magnetic, and rf shielding, a computer controlled x-y stage, sample registration, and positioning mechanisms, and data acquisition and analysis software. The system is capable of scanning planar samples with dimensions of up to 28 cm square, with a spatial resolution of 2 mm, and a sensitivity of 0.3 pT/Hz1/2 (at 10 Hz). In this article we report the design and technical issues related to this system, outline important data acquisition techniques and criteria for accurate measurements of the rate of corrosion, especially for weakly corroding samples, and present preliminary measurements.

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

    PubMed Central

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

    2013-01-01

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

  20. 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}.

  1. 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. PMID:22051087

  2. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  4. Corrosion behaviour of Alloy 800 in high temperature aqueous solutions: long term autoclave studies

    NASA Astrophysics Data System (ADS)

    Alvarez, M. G.; Olmedo, A. M.; Villegas, M.

    1996-04-01

    Generalized corrosion of Alloy 800 under primary coolant conditions was investigated by measuring the average thickness of oxide layers grown after long isothermal exposures in the autoclaves located out of core in the Embalse Nuclear Power Plant and shorter exposures in laboratory static autoclaves. The films exhibited the familiar double layer structure but after long exposures the inner layer was found to be hidden by the formation of overlayers and/or by the deposition of species inevitably present in high temperature coolant. The samples exposed to the primary coolant showed greater average oxide thickness than those in the static autoclave studies, indicating the deposition of corrosion products from the coolant. Analysis of the films grown in static autoclaves showed the presence of hydrated species at the oxide/solution interface and spinel structures inside the film. Oxidized nickel was found only within few nanometers in the outermost layer of the films whereas elementary nickel predominated in the rest of the oxide.

  5. The Studies of Thiosulfate and Lead-induced Stress Corrosion Cracking of Alloy 800

    NASA Astrophysics Data System (ADS)

    Yu, Liang

    Scratch test and scanning electrochemical microscopy (SECM) were applied to study the effects of thiosulfate on stress corrosion cracking (SCC) of Alloy 800 in simulated crevice solutions. The results showed that thiosulfate cathodically shifted the pitting potential of Alloy 800 significantly and the pitting morphology on the electrode surface was also different from that formed in the absence of thiosulfate. The synergistic effect between thiosulfate and stress was also observed, which was mainly promoting enhanced anodic dissolution at active sites. In the lead-induced stress corrosion crackings (PbSCC) work, the crack propagation rate (CPR) of Alloy 800 double cantilever specimen were estimated in neutral crevice chemistries solutions at 300 degree Celsius. The PbSCC of alloy 800 at high temperature were investigated by comparing the CPR rate of Pb-contaminated and Pb-free conditions. A repetitive behavior of crack advance was observed from the measurement. This observation is consistent with the film rupture model.

  6. [Study on the infrared spectra and raman spectra of steel rusty layer with atmospheric corrosion].

    PubMed

    Yang, Xiao-mei

    2006-12-01

    In the present study two methods, infrared and Raman spectral analyses, were used to measure the rusty layer of samples with atmospheric corrosion from Qingdao. The main component rust phase of the rusty layer was observed, showing that the relative content of the rust phase varies with the change in corrosion time. The main component rust phases of the rusty layer were found to be alpha-Fe2O3 , gamma-FeOOH, alpha-FeOOH, delta-FeOOH and Fe3O4, with the relative content of each rust phase of A3 (1) rusty layer sample exhibiting the following relation: gamma-FeOOH> alpha-FeOOH>delta-FeOOH, and the relative contents of other rusty layer samples were found to follow the relation: gamma-FeOOH> delta-FeOOH>alpha-FeOOH. PMID:17361722

  7. 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.

  8. 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.

  9. Corrosion in volcanic hot springs

    SciTech Connect

    Lichti, K.A.; Swann, S.J.; Sanada, N.

    1997-12-31

    Volcanic hot pool environments on White Island, New Zealand have been used to study the corrosion properties of materials which might be used for engineering plant for energy production from deep-seated and magma-ambient geothermal systems. The corrosion chemistry of hot pools encountered in natural volcanic features varies, from being of near neutral pH- or alkalie pH-chloride type waters to acidic-chloride/sulfate waters which are more aggressive to metals and alloys. Potential-pH (Pourbaix) diagram models of corrosion product phase stability for common alloy elements contained in engineering alloys have been developed for hot pool environments using thermodynamic principles and conventional corrosion theory. These diagramatic models give reasons for the observed corrosion kinetics and can be used to help to predict the performance of other alloys in similar environments. Deficiencies in the knowledge base for selection of materials for aggressive geothermal environments are identified, and directions for future research on materials having suitable corrosion resistance for deep-seated and magma-ambient production fluids which have acidic properties are proposed.

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

    PubMed

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

    2016-01-01

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

  11. 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.

  12. 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

  13. Coupling of acoustic emission and electrochemical noise measurement techniques in slurry erosion-corrosion studies

    SciTech Connect

    Oltra, R.; Chapey, B.; Huet, F.; Renaud, L.

    1996-12-31

    This study deals with the measurement and the subsequent signal analysis of acoustic emission and current noise recorded during continuous slurry erosion of a metallic target in a corrosive environment. According to a phenomenologic model, the localized corrosion results from the repetitive damage caused by particle impacts. The fluctuations of the acoustic signal and of the electrochemical signal both can be modeled as a shot-noise-like process. The main purpose of this work is to compare two processing techniques for the fluctuating signals: time analysis (mean value) and spectral analysis (power spectral density [PSD] spectrum) to determine the more suitable signal treatment. Another purpose is also to quantify the balance between the mechanical wear and the corrosive damage of the abraded metallic target. It will be shown that the mean value of the RMS acoustic signal, A(t), and also the PSD of A(t), are related to the mechanical wear of the target and allow real-time measurement of the actual mechanical perturbation in terms of the mass of the ablated material.

  14. The role of carbon dioxide in the atmospheric corrosion of zinc: A laboratory study

    SciTech Connect

    Falk, T.; Svensson, J.E.; Johansson, L.G.

    1998-01-01

    The authors report on a laboratory study of the atmospheric corrosion of zinc in air containing different concentrations of carbon dioxide (CO{sub 2}) (< 1,350, 1,000, and 40,000 ppm CO{sub 2}). The samples were exposed to synthetic atmospheres with careful control of CO{sub 2} concentration, sulfur dioxide (SO{sub 2}) concentration, relative humidity, and flow conditions. The relative humidity was 95%. Mass gain and metal loss results are reported. The corrosion products were analyzed quantitatively and qualitatively by a combination of grazing-angle x-ray diffraction, scanning electron microscopy, gravimetry, and quantitative analysis for carbonate. The corrosion rate of zinc increased with increasing CO{sub 2} concentration. In the presence of carbon dioxide Zn{sub 4}CO{sub 3}(OH){sub 6} {center_dot} H{sub 2}O formed. Hydrozincite, Zn{sub 5}(CO{sub 3}){sub 2}(OH){sub 6} was only identified after exposure to high CO{sub 2} concentration. Zinc hydroxycarbonate was converted into hydroxysulfate exposed to air containing 225 ppb SO{sub 2}. Zn{sub 4}SO{sub 4}(OH){sub 6} {center_dot} 4H{sub 2}O was produced in all exposures including SO{sub 2}. The zinc hydroxycarbonate surface film formed in the presence of CO{sub 2} was not protective in humid SO{sub 2} polluted air.

  15. 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. PMID:23182693

  16. 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.

  17. Study on stainless steel electrode based on dynamic aluminum liquid corrosion mechanism.

    PubMed

    Hou, Hua; Yang, Ruifeng

    2009-01-01

    Scanning electrion microscope (SEM) was performed for investigations on the corrosion mechanism of stainless steel electrode in dynamic melting aluminum liquid. Microstructures and composition analysis was made by electron probe analysis (EPA) combined with metallic phase analysis. It can be concluded that the corrosion process is mainly composed of physical corrosion (flowing and scouring corrosion) and chemical corrosion (forming FeAl and Fe2Al5) and the two mechanisms usually exist simultaneously. The corrosion interface thickness is about 10 μm, which is different to usual interface width of hundreds μm in the static melting Al with iron matrix. PMID:25084422

  18. Effective corrosion monitoring

    SciTech Connect

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

    1988-04-01

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

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

    SciTech Connect

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

    2006-12-31

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

  20. 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.

  1. Density functional theory and molecular dynamics simulation study on corrosion inhibition performance of mild steel by mercapto-quinoline Schiff base corrosion inhibitor

    NASA Astrophysics Data System (ADS)

    Saha, Sourav Kr.; Ghosh, Pritam; Hens, Abhiram; Murmu, Naresh Chandra; Banerjee, Priyabrata

    2015-02-01

    Corrosion inhibition mechanism of two mercapto-quinoline Schiff bases, eg., 3-((phenylimino)methyl)quinoline-2-thiol (PMQ) and 3-((5-methylthiazol-2-ylimino)methyl) quinoline-2-thiol (MMQT) on mild steel surface is investigated by quantum chemical calculation and molecular dynamics simulation. Quantum chemical parameters such as EHOMO, ELUMO, energy gap (ΔE), dipolemoment (μ), electronegativity (χ), global hardness (η) and fraction of electron transfers from the inhibitor molecule to the metallic atom surface (ΔN) have been studied to investigate their relative corrosion inhibition performance. Parameters like local reactive sites of the present molecule have been analyzed through Fukui indices. Moreover, adsorption behavior of the inhibitor molecules on Fe (1 1 0) surface have been analyzed using molecular dynamics simulation. The binding strength of the concerned inhibitor molecules on mild steel surface follows the order MMQT>PMQ, which is in good agreement with the experimentally determined inhibition efficiencies. In view of the above, our approach will be helpful for quick prediction of a potential inhibitor from a lot of similar inhibitors and subsequently in their rational designed synthesis for corrosion inhibition application following a wet chemical synthetic route.

  2. 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.

  3. A fractographic study of iodine-induced stress corrosion cracking in irradiated Zircaloy-2 cladding

    NASA Astrophysics Data System (ADS)

    Shimada, Sachio; Nagai, Masayuki

    1983-02-01

    A fractographic interpretation of stress corrosion cracking (SCC) of Zircaloy-2 was made through detailed scanning electron microscope (SEM) examination of cladding tubes irradiated and subjected to internal pressurization SCC tests in an iodine environment. The SEM examination of the fracture surface revealed that both intergranular and transgranular fracture appeared in the regions of crack initiation. The W-type voids were observed in the intergranular fracture. As the crack proceeded, transgranular fracture, or cleavage facet, became predominant. Cleavage facets were separated by tearing ridges as well as by fluting marks. The appearance of tearing ridges is consistent with the increase of slip systems in α-zirconium with increasing temperature.

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

    PubMed

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

    2015-01-01

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

  5. SUMMARY REPORT ON CORROSIVITY STUDIES IN COINCINERATION OF SEWAGE SLUDGE AND SOLID WASTE

    EPA Science Inventory

    Corrosion probe exposures were conducted in the Harrisburg, Pennsylvania Incinerator to determine the effects of burning low-chloride sewage sludge with municipal refuse. Probes having controlled temperature gradients were used to measure corrosion rates for exposure times up to ...

  6. 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.

  7. 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

  8. Experimental and quantum study of corrosion of A36 mild steel towards 1-butyl-3-methylimidazolium tetrachloroferrate ionic liquid

    NASA Astrophysics Data System (ADS)

    Ullah, Sami; Bustam, Mohamad Azmi; Shariff, Azmi Mohamad; Gonfa, Girma; Izzat, Khairul

    2016-03-01

    The corrosion behaviour of ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate ([C4C1im][FeCl4]) towards A36 mild steel was studied through experiments and quantum calculations. The corrosion rates were obtained through immersion tests both in open and controlled environments. The surface morphology of the A36 mild steel was investigated using scanning electron microscopy (SEM). The effects of temperature and water content on the corrosion of the ionic liquid towards A36 mild steel were studied through electrochemical corrosion measurement techniques. The results show that the corrosion of [C4C1im][FeCl4] towards the mild steel in the open environment is 17 times higher than in the control environment. The corrosion rate increases with increasing temperature and water content in [C4C1im][FeCl4]. Density Functional Theory (DFT) calculations were performed to gain some insight into the interactions of [C4C1im][FeCl4] with the A36 mild steels surface.

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

    PubMed

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

    2013-01-01

    The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments. PMID:23630603

  10. 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

  11. 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.

  12. 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. PMID:20576284

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Microsensors for corrosion control

    SciTech Connect

    Chawla, S.K.; Anguish, T.; Payer, J.H. )

    1990-05-01

    Sensors have been developed and manufactured by microelectronic fabrication techniques to directly measure corrosion rates and to determine the effectiveness of corrosion control systems. Microsensors based on measurements of corrosion rate by linear polarization, electrical resistance change, and galvanic currents have been devised. Analytical measurements by potentiometric and amperometric techniques using thick-film planar transducers are illustrated. The use of generic sensor elements individually and in combination to attest the status of corrosion control and to provide data for the evaluation of future performance is highlighted.

  19. 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

  20. 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

  1. Oxidation/corrosion of metallic and ceramic materials in an aluminum remelt furnace. [For fluidized bed waste heat recovery systems

    SciTech Connect

    Federer, J.I.; Jones, P.J.

    1985-12-01

    Both metallic alloys and ceramic materials are candidates for the distributor plate and other components of fluidized bed waste heat recovery (FBWHR) systems. Eleven Fe-, Ni-, and Co-base alloys were exposed to air at elevated temperatures in laboratory furnaces and to flue gases in an aluminum remelt furnace to assess their resistance to oxidation and corrosion. Four SiC ceramics and two oxide ceramics were also tested in the aluminum remelt furnace. Some alloys were coated with aluminum or SiO2 by commercial processes in an effort to enhance their oxidation and corrosion resistance.

  2. Hot Corrosion Studies of HVOF-Sprayed Coating on T-91 Boiler Tube Steel at Different Operating Temperatures

    NASA Astrophysics Data System (ADS)

    Bhatia, Rakesh; Singh, Hazoor; Sidhu, Buta Singh

    2013-11-01

    The aim of the present work is to investigate the usefulness of high velocity oxy fuel-sprayed 75% Cr3C2-25% (Ni-20Cr) coating to control hot corrosion of T-91 boiler tube steel at different operating temperatures viz 550, 700, and 850 °C. The deposited coatings on the substrates exhibit nearly uniform, adherent and dense microstructure with porosity less than 2%. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of uncoated and coated samples. The corrosion products of the coating on the substrate are analyzed by using XRD, SEM, and FE-SEM/EDAX to reveal their microstructural and compositional features for the corrosion mechanisms. It is found that the coated specimens have shown minimum weight gain at all the operating temperatures when compared with uncoated T-91 samples. Hence, coating is effective in decreasing the corrosion rate in the given molten salt environment. Oxides and spinels of nickel-chromium may be the reason for successful resistance against hot corrosion.

  3. 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.

  4. 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.

  5. Wear and Corrosion Resistance of Fe-Based Coatings Reinforced by TiC Particles for Application in Hydraulic Systems

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Linke, T. F.; Malik, K. M.

    2016-01-01

    Thermally sprayed Fe-based coatings reinforced by TiC particles are a cost-effective alternative to carbide coatings such as WC/CoCr, Cr3C2/NiCr, and hard chrome coatings. They feature a good wear resistance and—with sufficient amount of alloying elements like Cr and Ni—also a high corrosion resistance. In hydraulic systems, the piston is usually coated with hard chrome coatings for protection against corrosion and wear. New water-based hydraulic fluids require an adaption of the coating system. In order to investigate the wear and corrosion resistance of Fe/TiC, a novel powder consisting of a FeCr27Ni18Mo3 matrix and 34 wt.% TiC was applied by HVOF and compared to reference samples made of WC/CoCr (HVAF) and hard chrome. Besides an in-depth coating characterization (metallographic analyses, electron microprobe analyzer-EMPA), wear resistance was tested under reverse sliding in a water-based hydraulic fluid. The novel Fe/TiC coatings showed good wear protection properties, which are comparable to conventional coatings like WC/CoCr (HVAF) and electroplated hard chrome coatings. Corrosion resistance was determined by polarization in application-oriented electrolytes (hydraulic fluid at 60 °C, artificial sea water at RT). The corrosion resistance of the investigated iron-based coatings at 60 °C was superior to the references coatings for both hydraulic fluids. Selected coatings were tested in an application-oriented hydraulic test bench with HFC hydraulic fluid (water polymer solutions) showing comparably good wear and corrosion resistance as the hard chrome-coated reference.

  6. 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 treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and...

  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. 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 treatment steps to small, medium-size and large water systems. 141.81 Section 141.81 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and...

  9. 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. PMID:25976915

  10. 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

  11. A Study on Atmospheric Corrosion of 304 Stainless Steel in a Simulated Marine Atmosphere

    NASA Astrophysics Data System (ADS)

    Lv, Wangyan; Pan, Chen; Su, Wei; Wang, Zhenyao; Liu, Shinian; Wang, Chuan

    2015-07-01

    The atmospheric corrosion behavior of 304 stainless steel in a simulated marine atmosphere has been investigated using scanning electron microscope, optical microscope, x-ray photoelectron spectroscopy (XPS), and electrochemical measurements. The experimental results indicate that the main corrosion type of 304 stainless steel in a simulated marine atmosphere is pitting corrosion and the initiation of pits is associated with the dissolution of MnS inclusion. The maximum pit depth of 304 stainless steel increased in linear relationship with the extension of corrosion time. XPS results reveal that the corrosion products possess more hydroxide, and the ratio of [Cr]/{[Cr]+[Fe]} in the corrosion products gradually increases with the increasing time. The protective ability of corrosion products formed on 304 stainless steel has also been discussed.

  12. 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.

  13. 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

    2016-06-01

    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

  14. 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.

  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. 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...

  17. ENVIRONMENTALLY COMPLIANT CORROSION-ACTIVATED INHIBITOR SYSTEM FOR ALUMINUM ALLOYS - PHASE I

    EPA Science Inventory

    The federal government is estimated to spend $1 billion on painting/repainting aircraft annually. Aircraft have surfaces composed of aluminum alloys that are highly susceptible to corrosion and must be protected with corrosion-preventative treatments that typically conta...

  18. Kinetic studies of the stress corrosion cracking of D6AC steel

    NASA Technical Reports Server (NTRS)

    Noronha, P. J.

    1975-01-01

    The effect of load interactions on the crack growth velocity of D6AC steel under stress corrosion cracking conditions was determined. The environment was a 3.5 percent salt solution. The modified-wedge opening load specimens were fatigue precracked and subjected to a deadweight loading in creep machines. The effects of load shedding on incubation times and crack growth rates were measured using high-sensitivity compliance measurement techniques. Load shedding results in an incubation time, the length of which depends on the amount of load shed and the baseline stress intensity. The sequence of unloading the specimen also controls the subsequent incubation period. The incubation period is shorter when load shedding passes through zero load than when it does not if the specimen initially had the same baseline stress intensity. The crack growth rates following the incubation period are also different from the steady-state crack growth rate at the operating stress intensity. These data show that the susceptibility of this alloy system to stress corrosion cracking depends on the plane-strain fracture toughness and on the yield strength of the material.

  19. The effect of long-term nitrate treatment on SRB activity, corrosion rate and bacterial community composition in offshore water injection systems.

    PubMed

    Bødtker, Gunhild; Thorstenson, Tore; Lillebø, Bente-Lise P; Thorbjørnsen, Bente E; Ulvøen, Rikke Helen; Sunde, Egil; Torsvik, Terje

    2008-12-01

    Biogenic production of hydrogen sulphide (H(2)S) is a problem for the oil industry as it leads to corrosion and reservoir souring. Continuous injection of a low nitrate concentration (0.25-0.33 mM) replaced glutaraldehyde as corrosion and souring control at the Veslefrikk and Gullfaks oil field (North Sea) in 1999. The response to nitrate treatment was a rapid reduction in number and activity of sulphate-reducing bacteria (SRB) in the water injection system biofilm at both fields. The present long-term study shows that SRB activity has remained low at < or =0.3 and < or =0.9 microg H(2)S/cm(2)/day at Veslefrikk and Gullfaks respectively, during the 7-8 years with continuous nitrate injection. At Veslefrikk, 16S rRNA gene based community analysis by PCR-DGGE showed that bacteria affiliated to nitrate-reducing sulphide-oxidizing Sulfurimonas (NR-SOB) formed major populations at the injection well head throughout the treatment period. Downstream of deaerator the presence of Sulfurimonas like bacteria was less pronounced, and were no longer observed 40 months into the treatment period. The biofilm community during nitrate treatment was highly diverse and relative stable for long periods of time. At the Gullfaks field, a reduction in corrosion of up to 40% was observed after switch to nitrate treatment. The present study show that nitrate injection may provide a stable long-term inhibition of SRB in sea water injection systems, and that corrosion may be significantly reduced when compared to traditional biocide treatment. PMID:18752014

  20. A model of corrosion expertise

    SciTech Connect

    Trethewey, K.R.; Roberge, P.R.

    1996-10-01

    This paper describes an approach to reduce the complexity of knowledge engineering projects in corrosion by developing an object-oriented framework to guide the elicitation and organization of corrosion and materials engineering expertise. A model is presented into which corrosion expertise can be structured in a qualitative and quantitative way. This model could be used as the framework for a corrosion management expert system.

  1. Why metals volubility may not be a good indicator of corrosion in alkanolamine systems

    SciTech Connect

    Rooney, P.C.; DuPart, M.S.

    1999-11-01

    Although it is generally believed that Fe, Cr and Ni content in alkanolamine gas treating solutions reflects the corrosivity of the solution, the authors have found that this is not necessarily the case. Comparison of metals volubility by inductively coupled plasma (ICP) with carbon steel and stainless steel weight loss coupons of various alkanolamines heated in an autoclave showed that low metals volubility does not necessarily mean low coupon corrosivity. High metals volubility also did not necessarily mean high coupon corrosivity. One plant having very high metals volubility was found to have very low corrosion upon a thorough plant inspection. Another plant had severe localized corrosion that could not have been predicted based upon the low (200ppm) Fe in the alkanolamine compared to the total surface area of carbon steel in this plant.

  2. 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. PMID:25462724

  3. Influence of Cl- Deposition Content on Corrosion of LY12

    NASA Astrophysics Data System (ADS)

    Han, Desheng; Li, Di; Zheng, Tianliang

    A series of accelerated corrosion tests were conducted in the simulated marine atmosphere environment to study the corrosion of LY12 aluminum alloy under different Cl- deposition content. The change of corrosion morphology, weight gain and electrochemical parameters (Corrosion Electric Potential, AC Impedance) were inspected in the corrosion course. The different corrosion behaviors caused by the variation of Cl- deposition content were also discussed.

  4. Chemical and material studies to understand the source of corrosion in the Geological Survey TRIGA Reactor (GSTR) tank liner

    SciTech Connect

    Rusling, D.H.; Millard, H.T. Jr.; Heifer, P.G.; Perryman, R.E.; Smith, W.L.

    1988-07-01

    Corrosion damage to the aluminum tank liner of the GSTR reactor was discovered and samples of various materials were collected for chemical and mineralogical analyses. The following scenario for the corrosion was suggested: 1. Cyclical temperature changes caused the tank liner to change size repeatedly. It extruded tar as it expanded and created voids as it contracted. 2. Hydrostatic pressure forced ground water through openings in the concrete into voids near the bottom of the tank, and overflow introduced tank water at the top of the tank. 3. The expansion-contraction cycle moved the water around the complex, interconnecting systems of voids and, in some locations, caused the tar-to-aluminum bond to fail. 4. Chemical interactions of the water with the tar and concrete supplied the elements capable of corroding the aluminum (e.g., Zn, Cu). 5. The corrosive solution has reacted with the aluminum over the lifetime of the reactor to produce the present corrosion damage. 6. As corrosion pits became holes, reactor tank water entered the voids.

  5. Comparative study on the corrosion behavior of the cold rolled and hot rolled low-alloy steels containing copper and antimony in flue gas desulfurization environment

    NASA Astrophysics Data System (ADS)

    Park, S. A.; Kim, J. G.; He, Y. S.; Shin, K. S.; Yoon, J. B.

    2014-12-01

    The correlation between the corrosion and microstructual characteristics of cold rolled and hot rolled low-alloy steels containing copper and antimony was established. The corrosion behavior of the specimens used in flue gas desulfurization systems was examined by electrochemical and weight loss measurements in an aggressive solution of 16.9 vol % H2SO4 + 0.35 vol % HCl at 60°C, pH 0.3. It has been shown that the corrosion rate of hot rolled steel is lower than that of cold rolled steel. The corrosion rate of cold rolled steel was increased by grain refinement, inclusion formation, and preferred grain orientation.

  6. Study of materials to resist corrosion in condensing gas-fired furnaces. Final report Oct 79-Dec 81

    SciTech Connect

    Lahtvee, T.; Schaus, O.O.

    1982-02-01

    Based on a thorough review of background information on the performance of materials in condensing gas-fired heat exchangers and similar corrosive environments, candidate materials were examined on test equipment built to provide the varying corrosive conditions encountered in actual gas-fired condensing system heat exchangers. The 32 different materials tested in a one month screening test included: mild, low alloy, galvanized, solder coated steel, porcelain, epoxy, teflon and nylon coated and alonized mild steel; austenitic, ferritic, low interstitial Ti stabilized ferritic, and high alloy stainless steels; aluminum alloys, anodized and porcelain coated aluminum; copper and cupronickel alloys, solder coated copper; and titanium.

  7. 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.

  8. Corrosion related properties of iron (100) surface in liquid lead and bismuth environments: A first-principles study

    NASA Astrophysics Data System (ADS)

    Song, Chi; Li, Dong-Dong; Xu, Yi-Chun; Pan, Bi-Cai; Liu, Chang-Song; Wang, Zhi-Guang

    2014-05-01

    The corrosion of steels in liquid metal lead (Pb) and bismuth (Bi) is a critical challenge in the development of accelerator driven systems (ADS). Using a first-principles method with a slab model, we theoretically investigate the interaction between the Pb (Bi) atom and the iron (Fe) (100) surface to assess the fundamental corrosion properties. Our investigation demonstrates that both Pb and Bi atoms favorably adsorb on the (100) surface. Such an adsorption decreases the energy required for the dissociation of an Fe atom from the surface, enhancing the dissolution tendency significantly. The segregation of six common alloying elements (Cr, Al, Mn, Ni, Nb, and Si) to the surface and their impacts on the corrosion properties are also considered. The present results reveal that Si seems to have a relatively good performance to stabilize the surface and alleviate the dissolving trend caused by Pb and Bi.

  9. A study of the corrosion products of mild steel in high ionic strength brines.

    PubMed

    Wang, Z; Moore, R C; Felmy, A R; Mason, M J; Kukkadapu, R K

    2001-01-01

    The corrosion layer on steel surfaces that formed after exposure to waste isolation pilot plant (WIPP) brines under anoxic conditions was characterized for chemical composition, thickness and phase composition. The chemical composition of the corrosion layer was determined both by X-ray photoelectron spectroscopy (XPS) and by chemical analysis of acid solutions used to remove the corrosion layer. Atomic force microscopic (AFM) images indicated that the brine-corroded surface layer shows extensive granulation along the contours of the steel surface that is characteristic of sharp polishing marks. The corrosion layer seemed to be porous and could be dissolved and detached in dilute hydrochloric acid. The corrosion layer appears to be composed of iron oxides with some ionic substitutions from the brines. The 77 K Mössbauer spectrum recorded for iron powder leached under similar conditions indicated the corrosion layer was comprised principally of green rust. PMID:11300533

  10. Annual Report for EMSP #86803 -- Underground Corrosion After 32 Years: A Study of Fate and Transport

    SciTech Connect

    M.K. Adler Flitton

    2006-09-01

    Researchers from Department of Energy (DOE) National Laboratories at the Idaho and the Savannah River Sites recovered and are analyzing part of a final set of stainless steel specimens buried by the National Bureau of Standards in 1070 at Site D, near Wildwood, NJ. Findings included estimates for 32-year corrosion rates, transport of corrosion product, and elucidation of the site’s hydrogeobiochemistry. An interdisciplinary research team unraveled the complicated interrelationships among metal integrity, corrosion rates, corrosion mechanisms, soil properties, soil microbiology, plant and animal interaction with corrosion products, and fate and transport of metallic ions. This research provides long-term corrosion and transport data that can reduce the uncertainty associated with long-term waste storage and improve fate and transport modeling predictions throughout the DOE complex. The research also provides improvements in several characterization techniques.

  11. Studies on the hot corrosion of a nickel-base superalloy, Udimet 700

    NASA Technical Reports Server (NTRS)

    Misra, A. K.

    1984-01-01

    The hot corrosion of a nickel-base superalloy, Udimet 700, was studied in the temperature range of 884 to 965 C and with different amounts of Na2SO4. Two different modes of degradation were identified: (1) formation of Na2MoO4 - MoO3 melt and fluxing by this melt, and (2) formation of large interconnected sulfides. The dissolution of Cr2O3, TiO2 in the Na2SO4 melt does not play a significant role in the overall corrosion process. The conditions for the formation of massive interconnected sulfides were identified and a mechanism of degradation due to sulfide formation is described. The formation of Ns2MoO4 - MoO3 melt requires an induction period and various physiochemical processes during the induction period were identified. The factors affecting the length of the induction period were also examined. The melt penetration through the oxide appears to be the prime mode of degradation whether the degradation is due to the formation of sulfides or the formation of the Na2MoO4 - MoO3 melt.

  12. An accelerated carbonation procedure for studies of corrosion in reinforced concrete

    SciTech Connect

    Al-Kadhimi, T.K.H.; Banfill, P.F.G.; Millard, S.G.; Bungey, J.H.

    1995-10-01

    Carbonation of the concrete leading to reduced alkalinity around the steel is one of the main reasons for the corrosion of reinforced concrete. Studies of carbonation induced corrosion and of rehabilitation methods, such as electrochemical realkalization, require the convenient preparation of realistically large specimens of carbonated concrete in a sufficiently short time. This paper describes a rapid method of preparing carbonated concrete by exposing concrete, which has been dried to an internal relative humidity of 60%, to a pure atmosphere of carbon dioxide gas at 15 bar pressure (1,500 kPa). The pressure chamber used can accommodate specimens up to 150mm diameter or 100 x 100 mm section and such specimens can be fully carbonated in 2 weeks, much more quickly than by other methods. Carbonation increases the electrical resistivity and strength of the concrete and reduces the water absorption. Optical and electron microscopical investigations on the carbonated concrete confirm that the microstructure is no different from that produced in concrete by carbonation under natural exposure. The accelerated carbonation method can be used for development work on materials and repair methods and has been used by the authors in preparing carbonated concrete specimens for re-alkalization tests.

  13. The blood supply of the human temporalis muscle: a vascular corrosion cast study.

    PubMed Central

    Cheung, L K

    1996-01-01

    Knowledge as to the blood supply of the human temporalis muscle is limited to its extramuscular path and relations, little information existing about the intramuscular vascular architecture. To investigate the 3-dimensional vascular network in the human temporalis muscle, in 5 fresh cadavers an infusion of methylmethacrylate resin was made via the carotid vessels with subsequent removal of the organic tissues by a corrosion process. The vascular corrosion casts of the temporalis muscle were studied by stereomicroscopy and scanning electron microscopy. In 6 well perfused muscle specimens, the temporalis muscle was found to be consistently supplied by 3 arteries: the anterior and posterior deep temporal arteries, and the middle temporal artery. Each primary artery branched into the secondary arterioles and then terminal arterioles. The venous network accompanied the arteries, and double veins pairing a single artery was a common finding. Arteriovenous anastomosis was absent, whereas arterioarterial and venovenous anastomoses were common. The capillaries formed a dense interlacing network with an orientation along the muscle fibres. Understanding of the intramuscular angioarchitecture of the temporalis provides the vascular basis for surgical flap manipulation and splitting design. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8886964

  14. Stainless steel surface biofunctionalization with PMMA-bioglass coatings: compositional, electrochemical corrosion studies and microbiological assay.

    PubMed

    Floroian, L; Samoila, C; Badea, M; Munteanu, D; Ristoscu, C; Sima, F; Negut, I; Chifiriuc, M C; Mihailescu, I N

    2015-06-01

    A solution is proposed to surpass the inconvenience caused by the corrosion of stainless steel implants in human body fluids by protection with thin films of bioactive glasses or with composite polymer-bioactive glass nanostructures. Our option was to apply thin film deposition by matrix-assisted pulsed laser evaporation (MAPLE) which, to the difference to other laser or plasma techniques insures the protection of a more delicate material (a polymer in our case) against degradation or irreversible damage. The coatings composition, modification and corrosion resistance were investigated by FTIR and electrochemical techniques, under conditions which simulate their biological interaction with the human body. Mechanical testing demonstrates the adhesion, durability and resistance to fracture of the coatings. The coatings biocompatibility was assessed by in vitro studies and by flow cytometry. Our results support the unrestricted usage of coated stainless steel as a cheap alternative for human implants manufacture. They will be more accessible for lower prices in comparison with the majority present day fabrication of implants using Ti or Ti alloys. PMID:26085116

  15. ELECTROCHEMICAL CORROSION STUDIES CORE 308 SEGMENTS 14R1 & 14R2 TANK 241-AY-102

    SciTech Connect

    DUNCAN JB; COOKE GA

    2003-10-30

    This document reports the results of electrochemical corrosion tests on AS1S Grade 60 carbon steel coupons exposed to tank 241-AY-102 sludge under conditions similar to those near the bottom of the tank. The tests were performed to evaluate the corrosive behavior of the waste in contact with sludge that does not meet the chemistry control limits of Administrative Control (AC) 5.15, Corrosion Mitigation Program.

  16. The coordinated use of synchrotron spectroelectrochemistry for corrosion studies on heritage metals.

    PubMed

    Adriaens, Annemie; Dowsett, Mark

    2010-06-15

    Corrosion is a major source of degradation in heritage metal objects, and any remedial measures are subject to a strong (Western) ethic that favors conservation as opposed to restoration. Accordingly, major scientific challenges exist for developing appropriate treatment methods to stabilize and protect artifacts after they are recovered from an archaeological site, both before and during their display or storage in a museum. Because inappropriate treatments can cause irreversible damage to irreplaceable objects, it is crucial that the chemical processes involved are fully understood and characterized before any preservation work is undertaken. In this regard, large infrastructural facilities such as synchrotrons, neutron sources, and particle accelerators provide a wealth of analytical possibilities, unavailable in smaller scale laboratories. In general, the intensity of the radiation available allows measurements on a short time scale or with high spatial resolution (or both), so heterogeneous changes induced by a chemical process can be recorded while they occur. The penetrative nature of the radiation (e.g., X-rays, protons, or neutrons) also allows a sample to be studied in air. If necessary, complete artifacts (such as paintings or statuettes) can be examined. In situ analysis in a controlled environment, such as a liquid or corrosive atmosphere, also becomes an exciting possibility. Finally, there are many complementary techniques (local atomic structure or crystal structure determination, macroscopic 3-D imaging (tomographies), imaging chemical analysis, and so on) so the many distinct details of a problem can be thoroughly explored. In this Account, we discuss the application of this general philosophy to studies of corrosion and its prevention in cultural heritage metals, focusing on our recent work on copper alloys. More specifically, we use synchrotron-based techniques to evaluate the use of corrosion potential measurements as a possible monitoring

  17. A mechanistic study of the effects of nitrogen on the corrosion properties of stainless steels

    SciTech Connect

    Levey, P.R.; Bennekom, A. van

    1995-12-01

    The effects of nitrogen alloying on the corrosion properties of stainless steels (SS) is a matter of debate. A number of apparently contradictory results have been presented by various researchers. The actual mechanism by which nitrogen alloying influences the corrosion properties of SS has been the topic of even more controversy. The effects of nitrogen on the corrosion and mechanical properties of SS were reviewed. Various proposals relating to the mechanistic effect of nitrogen alloying on the corrosion properties of SS were evaluated critically by comparing the various theories.

  18. Electrochemical corrosion and modeling studies of types 7075 and 2219 aluminum alloys in a nitric acid + ferric sulfate deoxidizer solution

    NASA Astrophysics Data System (ADS)

    Savas, Terence P.

    The corrosion behavior of types 7075-T73 and 2219-T852 high strength aluminum alloys have been investigated in a HNO3 + Fe2(SO 4)3 solution. The materials are characterized in the time domain using the electrochemical noise resistance parameter (Rn) and in the frequency-domain using the spectral noise impedance parameter ( Rsn). The Rsn parameter is derived from an equivalent electrical circuit model that represents the corrosion test cell schematic used in the present study. These calculated parameters are correlated to each other, and to corresponding scanning electron microscopy (SEM) examinations of the corroded surfaces. In addition, energy dispersive spectroscopy (EDS) spectra are used in conjunction with SEM exams for particle mapping and identification. These constituent particles are characterized with respect to their size and composition and their effect on the localized corrosion mechanisms taking place. Pitting mechanisms are identified as 'circumferential' where the particles appeared noble with respect to the aluminum matrix and by 'selective dissolution' where they are anodic to the aluminum matrix. The electrochemical data are found to be in good agreement with the surface examinations. Specifically, the electrochemical parameters Rn and Rsn were consistent in predicting the corrosion resistance of 7075-T73 to be lower than for the 2219-T852 alloy. Other characteristic features used in understanding the corrosion mechanisms include the open circuit potential (OCP) and coupling-current time records.

  19. Study for Corrosion and Hydrogen Evolution Behavior of Ti-6Al-4V Alloy in Simulated Acid Rain Water

    NASA Astrophysics Data System (ADS)

    Tammam, R. H.; Fekry, A. M.

    2014-03-01

    The electrochemical behavior of Ti-6Al-4V alloy was investigated using electrochemical impedance spectroscopy (EIS) measurements at the open circuit potentials and potentiodynamic polarization measurements in a simulated acid rain containing inorganic additives. The ac circuit model for Ti-6Al-4V alloy at corrosion interface in simulated acid rain containing inorganic additives was proposed, which was based on two time constants equivalent circuit. Ti-6Al-4V alloy in a simulated acid rain of pH 1.5 containing inorganic additives showed a characteristic of a capacitive behavior. The effect of different concentrations of the inorganic additives (iodate, dichromate, phosphate, and nitrate) on the corrosion of the alloy in acid rain water (ARW) was also studied. It was found that the corrosion rate decreases drastically in the solution containing iodate, dichromate, and phosphate anions; however, nitrate anions increase the corrosion rate of the alloy. The investigated inorganic additives had inhibiting effect on the corrosion of the alloy in ARW, and their efficiency decreases according to the order: iodate > dichromate > phosphate > blank > nitrate. Polarization data results are in good agreement with EIS.

  20. Moessbauer spectroscopy study on the corrosion resistance of plasma nitrided ASTM F138 stainless steel in chloride solution

    SciTech Connect

    Souza, S.D. de; Olzon-Dionysio, M.; Basso, R.L.O.; Souza, S. de

    2010-10-15

    Plasma nitriding of ASTM F138 stainless steel samples has been carried out using dc glow discharge under 80% H{sub 2}-20% N{sub 2} gas mixture, at 673 K, and 2, 4, and 7 h time intervals, in order to investigate the influence of treatment time on the microstructure and the corrosion resistance properties. The samples were characterized by scanning electron microscopy, glancing angle X-ray diffraction and conversion electron Moessbauer spectroscopy, besides electrochemical tests in NaCl aerated solution. A modified layer of about 6 {mu}m was observed for all the nitrided samples, independent of nitriding time. The X-ray diffraction analysis shows broad {gamma}{sub N} phase peaks, signifying a great degree of nitrogen supersaturation. Besides {gamma}{sub N,} the Moessbauer spectroscopy results indicated the occurrence of {gamma}' and {epsilon} phases, as well as some other less important phases. Corrosion measurements demonstrate that the plasma nitriding time affects the corrosion resistance and the best performance is reached at 4 h treatment. It seems that the {epsilon}/{gamma}' fraction ratio plays an important role on the resistance corrosion. Additionally, the Moessbauer spectroscopy was decisive in this study, since it was able to identify and quantify the iron phases that influence the corrosion resistance of plasma nitrided ASTM F138 samples.

  1. [Main results of experimental studies on the toxicology of inhibitors of atmospheric corrosion of metals].

    PubMed

    Paustovskaia, V V

    1990-01-01

    Basing on experimental toxicity research it was established that, out of 50 atmosphere metal corrosion inhibitors, some 14 per cent were found extremely hazardous, 42 per cent--of high level hazardous, 33 percent--of moderate and 11 per cent--of low hazardous. Relationships were identified between the structure of polymethylene amine salts, azole compounds and carbonic acid, and the way they influence human organism. It was also found that inhibitors exercise a polytropic action in man, the toxicity action being concentrated on oxidation processes, and the inhibitors specifically influence protein, carbohydrate and phosphoric metabolisms, as well as the red blood system. This causes functional and structural disorders of CNS and in the parenchymal organs. Inhibitors are characterized by local and skin-resorption actions, their degree and specific features depending on their chemical structures. 22 MACs of working zone inhibitors are proposed, along with early diagnostic tests and preventive measures. PMID:2351297

  2. Corrosion detection of mild steel in a two phase hydrocarbon-electrolyte system under flow conditions using electrochemical noise

    SciTech Connect

    Male, J.M.; Uruchurtu, J.; Coron, O.

    1998-12-31

    Electrochemical current noise (ECN) measurements were carried out in mixtures of 3% NaCl electrolyte in diesel under stirred conditions (0 to 2,000 rpm) using a Rotating Electrodes System (RES) which includes three mild steel concentric electrodes embedded in activated polyester resin. Chemical activation of the resin allowed electrochemical measurements in the water in oil emulsion system. A 0.2 to 15% in volume range of 3% NaCl electrolyte additions was studied. Three distinctive noise patterns were obtained from electrochemical current noise (ECN) time-series: (a) a low noise baseline for diesel in absence of electrolyte, diesel with small additions of electrolyte and/or low flow rates, (b) a low noise signal with current bursts superimposed obtained from relatively small additions of electrolyte and high rotation rates and (c) a high amplitude signal for high rotation rates and relatively high additions of electrolyte. For case b, the number and intensity of current bursts is indicative of proximity to cases a or c. These results contrast with experiments carried out with a conventional non-activated resin which is insensitive to the range of electrolyte additions or to stirring conditions. This method can be implemented for water in oil systems where early corrosion detection is desirable.

  3. Experimental investigation of solid by-product as sensible heat storage material: Characterization and corrosion study

    NASA Astrophysics Data System (ADS)

    Ortega-Fernández, Iñigo; Faik, Abdessamad; Mani, Karthik; Rodriguez-Aseguinolaza, Javier; D'Aguanno, Bruno

    2016-05-01

    The experimental investigation of water cooled electrical arc furnace (EAF) slag used as filler material in the storage tank for sensible heat storage application was demonstrated in this study. The physicochemical and thermal properties of the tested slags were characterized by using X-ray diffraction, scanning electron microcopy, Fourier transform infrared spectroscopy, Raman spectroscopy and laser flash analysis, respectively. In addition, the chemical compatibility between slags and molten nitrate salt (60 wt. % NaNO3 and 40 wt. % KNO3) was investigated at 565 °C for 500 hrs. The obtained results were clearly demonstrated that the slags showed a good corrosion resistance in direct contact with molten salt at elevated temperature. The present study was clearly indicated that a low-cost filler material used in the storage tank can significantly reduce the overall required quantities of the relatively higher cost molten salt and consequently reduce the overall cost of the electricity production.

  4. M"ossbauer study of corrosion and abrasion products in oil transporting pipes

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Perez Mazariego, Jose Luis; Marquina, Vivianne; Marquina, Ma. Luisa; Ridaura, Rosalia; Martinez, Lorenzo

    2012-02-01

    It is known that one of the main technological problems in carbon steel oleoducts is the corrosion produced by different substances, such as water, carbon dioxide, sulfur, and microorganisms. In addition, if in such mixture there is sand, aggressive sludge can be form that abrasions material from the oleoduct. A room temperature M"ossbauer study of corroded material taken from different sites of oleoducts is presented. Most of the M"ossbauer spectra reveal the presence of nanoparticles, indicating that in these pipes the abrasion problem is severe. A preliminary identification of the oxidized samples suggests the presence of magnetite, and some Iron hydroxides. Further studies are in course in order to identify unambiguously the products present in the corroded materials.

  5. 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.

  6. An indexing system of corrosion failures for case-based reasoning

    SciTech Connect

    Roberge, P.R.; Trethewey, K.R.

    1996-10-01

    The difficulties associated with the committal of human expert knowledge to computers for the development of more effective knowledge-based systems have raised the possibility of mimicking the process of reasoning from previous experiences. Experts are known to make proficient decisions based more upon analogy with similar events and situations than the kind of sequential mechanisms used in many algorithmic approaches. For many years, both law and business schools have used cases as the foundation for knowledge in their respective disciplines. Computer reasoning by analogy, a technique known as Case-Based Reasoning (CBR) has met with tangible success in such diverse human decision-making applications as banking, autoclave loading, tactical decision-making, and foreign trade negotiations. Failure analysts and corrosion engineers also reason by analogy when faced with new situations or problems. The CBR approach is particularly valuable in cases containing ill-structured problems, uncertainty, ambiguity, and missing data. Dynamic environments can also be tackled, or when there are shifting, ill-defined and competing objectives. Cases where there are action feedback loops, multiple human involvement, and multiple and potentially changing organizational goals and norms can also be tackled. This paper describes a method of indexing case histories for use in a case-based reasoning system in support of failure analysis.

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

    SciTech Connect

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

    2006-06-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. In previous tests, we had frequently encountered problems with our steam generator that were exacerbated by the very low flow rates that we needed. During this period we installed a new computer-controlled system for injecting water into the steam generator that eliminated this problem. We also tested alloy coupons coated by using the improved procedures described in our last quarterly report. Most of these coatings were nitrided Ti and Ta coatings, either by themselves, or sometimes with barrier layers of Al and Si nitrides. The samples were tested for 300 h at 900 C in a gas stream designed to mimic the environment in the high temperature heat recovery unit (HTHRU). Three samples that showed least corrosion were exposed for an additional 100 h.

  8. Electrochemical Study on the Inhibition Effect of Phenanthroline and Its Cobalt Complex as Corrosion Inhibitors for Mild Steel

    NASA Astrophysics Data System (ADS)

    Liu, Xia; Okafor, Peter C.; Jiang, Bin; Hu, Hongxiang; Zheng, Yugui

    2015-09-01

    The corrosion inhibition effect of phenanthroline (Phen) and its cobalt complex (CoPhen) on the corrosion of carbon steel in sulphuric acid solutions was studied using potentiodynamic polarization and electrochemical impedance spectroscopy techniques at 20, 30, and 40 °C. Scanning electron microscopy techniques were used to characterize the mild steel surface. The results indicate that the compounds inhibit the corrosion of mild steel in H2SO4 solutions through a predominant physical adsorption following the Langmuir adsorption isotherm. Polarization curves suggest that the complex and ligand are mixed-type inhibitors. The efficiency of the inhibitors is concentration- and temperature-dependent and follows the trend CoPhen > Phen.

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    The susceptibility to hot corrosion of four nickel base superalloys has been studied at 900 deg and 1000 deg C in one atmosphere of slowly flowing oxygen. Hot corrosion was induced by coating the samples with known doses of NaSO4 and oxidizing the coated samples isothermally on a sensitive microbalance. In general, the order of susceptibility found was: B-1900 is greater than 713C is greater than NASA-TRW VIA and is greater than IN738. This order corresponds to the order of decreasing molybdenum content of the alloys. Chemical evidence for B-1900 indicates that hot corrosion is instigated by acid fluxing of the protective Al2O3 coating by MoO3.

  10. ELECTROCHEMICAL CORROSION STUDIES FOR TANK 241-AN-107 CORE 309 SEGMENTS 21R1 & 21R2

    SciTech Connect

    DUNCAN JB

    2007-11-13

    Liquid waste in tank 241-AN-107 is below Technical Safety Requirements Administrative Control 5.16 (AC 5.16) limits. Electrochemical corrosion testing was performed on Core 309, Segments 21R1 and 21R2, to provide information on the conductivity and corrosive tendencies of the tank saltcake and interstitial liquid. This report describes data obtained under the execution of RPP-PLAN-29001, 'Electrochemical Corrosion Studies for Tank 241-AN-107 Core 309, Segments 21R1 and 21R2'. Analytical results are presented that show supernatant was within the limits while the interstitial liquid remained below the limits for the analytical cores. Applicable AC 5.16 chemistry control limits for AN-107 are presented.

  11. Molecular Survey of Microbial Communities Involved in Concrete Corrosion in Wastewater Collection Systems

    EPA Science Inventory

    This information is relevant to the development of condition assessment tools associated with the aging water infrastructure research program Corrosion of wastewater collection infrastructure, especially concrete sewers, is a significant cause of deterioration and premature failu...

  12. Experimental Design for the Evaluation of Detection Techniques of Hidden Corrosion Beneath the Thermal Protective System of the Space Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    Kemmerer, Catherine C.; Jacoby, Joseph A.; Lomness, Janice K.; Hintze, Paul E.; Russell, Richard W.

    2007-01-01

    The detection of corrosion beneath Space Shuttle Orbiter thermal protective system is traditionally accomplished by removing the Reusable Surface Insulation tiles and performing a visual inspection of the aluminum substrate and corrosion protection system. This process is time consuming and has the potential to damage high cost tiles. To evaluate non-intrusive NDE methods, a Proof of Concept (PoC) experiment was designed and test panels were manufactured. The objective of the test plan was three-fold: establish the ability to detect corrosion hidden from view by tiles; determine the key factor affecting detectability; roughly quantify the detection threshold. The plan consisted of artificially inducing dimensionally controlled corrosion spots in two panels and rebonding tile over the spots to model the thermal protective system of the orbiter. The corrosion spot diameter ranged from 0.100" to 0.600" inches and the depth ranged from 0.003" to 0.020". One panel consisted of a complete factorial array of corrosion spots with and without tile coverage. The second panel consisted of randomized factorial points replicated and hidden by tile. Conventional methods such as ultrasonics, infrared, eddy current and microwave methods have shortcomings. Ultrasonics and IR cannot sufficiently penetrate the tiles, while eddy current and microwaves have inadequate resolution. As such, the panels were interrogated using Backscatter Radiography and Terahertz Imaging. The terahertz system successfully detected artificially induced corrosion spots under orbiter tile and functional testing is in-work in preparation for implementation.

  13. Irritants and corrosives.

    PubMed

    Tovar, Richard; Leikin, Jerrold B

    2015-02-01

    This article reviews toxic chemicals that cause irritation and damage to single and multiple organ systems (corrosion) in an acute fashion. An irritant toxic chemical causes reversible damage to skin or other organ system, whereas a corrosive agent produces irreversible damage, namely, visible necrosis into integumentary layers, following application of a substance for up to 4 hours. Corrosive reactions can cause coagulation or liquefaction necrosis. Damaged areas are typified by ulcers, bleeding, bloody scabs, and eventual discoloration caused by blanching of the skin, complete areas of alopecia, and scars. Histopathology should be considered to evaluate questionable lesions. PMID:25455665

  14. [The corrosion resistance of aluminum and aluminum-based alloys studied in artificial model media].

    PubMed

    Zhakhangirov, A Zh; Doĭnikov, A I; Aboev, V G; Iankovskaia, T A; Karamnova, V S; Sharipov, S M

    1991-01-01

    Samples of aluminum and its alloys, designed for orthodontic employment, were exposed to 4 media simulating the properties of biologic media. The corrosion resistance of the tested alloys was assessed from the degree of aluminum migration to simulation media solutions, which was measured by the neutron activation technique. Aluminum alloy with magnesium and titanium has shown the best corrosion resistance. PMID:1799002

  15. Atmospheric Corrosion on Steel Studied by Conversion Electron Mössbauer Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nakanishi, Akio; Kobayashi, Takayuki

    2004-12-01

    In order to investigate initial products on steel by atmospheric corrosion, conversion electron Mössbauer measurements were carried out at temperatures between 15 K and room temperature. From the results obtained at low temperatures, it was found that the corrosion products on steel consisted of ferrihydrite.

  16. Application of iron electrode corrosion enhanced electrokinetic-Fenton oxidation to remediate diesel contaminated soils: A laboratory feasibility study

    NASA Astrophysics Data System (ADS)

    Tsai, Tzai-Tang; Sah, Jygau; Kao, Chih-Ming

    2010-01-01

    SummaryDiesel soil contamination on gas stations or refinery plants is a worldwide environmental problem. The main objectives of this study were to (1) evaluate the efficiency of electrokinetic (EK) by using different electrode materials (graphite and iron rods) and electrolytes (tap water, 0.01 M NaCl, and 0.1 M NaCl) on the remediation of diesel contaminated soils, and (2) evaluate the feasibility of total petroleum hydrocarbon-diesel (TPH-D) reducing in soils via EK-Fenton oxidation enhanced by corroded iron electrode. The EK and EK-Fenton experiments were conducted in batch and sand box experiments, respectively. Batch experiments reveal that the most appropriate electrolyte was 0.1 M NaCl when iron electrode was used in the EK system. Sand box experiments indicate that the TPH-D concentration dropped from 10,000 to 300 mg kg -1 when amorphous iron/total iron (Fe o/Fe t) ratio increased from 0.1 to 0.33, with the addition of 8% of H 2O 2 and 0.1 M NaCl after 60 days of EK-Fenton operation. Electrokinetically enhanced oxidation with the presence of both H 2O 2 and Fe 3O 4 (iron electrode corrosion) resulted in higher TPH-D removal efficiency (97%) compared to the efficiencies observed from EK (55%) or Fenton oxidation (27%) alone. This demonstrates that EK-Fenton oxidation catalyzed by iron electrode corrosion is a valuable direction to efficiently and effectively remediate diesel contaminated soils.

  17. A new approach to study local corrosion processes on steel surfaces by combining different microscopic techniques

    NASA Astrophysics Data System (ADS)

    Heyer, A.; D'Souza, F.; Bruin, A.; Ferrari, G.; Mol, J. M. C.; de Wit, J. H. W.

    2012-09-01

    Corrosion studies of materials on the micro or even nano-scale level are cumbersome due to instrumental limitations and handling procedures. If biological processes are involved the spatial resolution is even more important and sample preparation is usually the limitation. Attachment of bacteria on stainless steel surface is a complex interfacial process including interactions of bacterial cells and bacterial extracellular polymeric substances with the surface. To overcome the limitations in sample preparations and resolution we present a new stainless steel sample holder to switch among epifluorescent microscope (EFM), AFM and SEM at exactly the same position. Exemplary bacterial accumulation was studied by staining the bacterial DNA with a fluorescent dye over time. It was possible to distinguish among bacteria and other surface characteristic such as deformations or grain structures. Also surface topographic features such as roughness at the grain boundaries and deposits were quantified. All three techniques complement one another in the way that AFM is a high-resolution technique that does not allow to distinguish directly bacterial cell structures, whereas EFM offers excellent bacterial identification based on staining at a low resolution that can complement AFM images. Application of SEM in the last step will reveal inclusions and grain structure and combined with EDX gives the composition of the substrate, inclusions and corrosion deposit. The combination of the three high-resolution techniques enables a more detailed understanding of surface phenomena. The method itself is quite elegant and easy to handle which is an important aspect in materials research, especially when a high sample throughput is needed.

  18. 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.

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

    SciTech Connect

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

    2005-12-01

    Heat exchangers, particle filters, turbines, and other components in an integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high-alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this reporting period, we conducted a simulated gasifier test primarily with TiN-coated steel samples. Although the test showed these coatings to offer significant protection against corrosion, they also revealed a lack of uniformity in the coatings. We spent a considerable amount of effort improving our coatings procedure as well as the fluidized bed reactor and its heater. Based on the results collected thus far, we selected 12 samples and sent them to ConocoPhillips for testing in their gasifier at the Wabash River Energy plant.

  20. Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

    SciTech Connect

    Arnold R. Marder

    2007-06-14

    Due to their excellent corrosion resistance, iron aluminum alloys are currently being considered for use as weld claddings in fossil fuel fired power plants. The susceptibility to hydrogen cracking of these alloys at higher aluminum concentrations has highlighted the need for research into the effect of chromium additions on the corrosion resistance of lower aluminum alloys. In the present work, three iron aluminum alloys were exposed to simulated coal combustion environments at 500 C and 700 C for both short (100 hours) and long (5,000 hours) isothermal durations. Scanning electron microscopy was used to analyze the corrosion products. All alloys exhibited excellent corrosion resistance in the short term tests. For longer exposures, increasing the aluminum concentration was beneficial to the corrosion resistance. The addition of chromium to the binary iron aluminum alloy prevented the formation iron sulfide and resulted in lower corrosion kinetics. A classification of the corrosion products that developed on these alloys is presented. Scanning transmission electron microscopy (STEM) of the as-corroded coupons revealed that chromium was able to form chromium sulfides only on the higher aluminum alloy, thereby preventing the formation of deleterious iron sulfides. When the aluminum concentration was too low to permit selective oxidation of only aluminum (upon initial exposure to the corrosion environment), the formation of chromium oxide alongside the aluminum oxide led to depletion of chromium beneath the oxide layer. Upon penetration of sulfur through the oxide into this depletion layer, iron sulfides (rather than chromium sulfides) were found to form on the low aluminum alloy. Thus, it was found in this work that the role of chromium on alloy corrosion resistance was strongly effected by the aluminum concentration of the alloy. STEM analysis also revealed the encapsulation of external iron sulfide products with a thin layer of aluminum oxide, which may provide a

  1. Pipeline system insulation: Thermal insulation and corrosion prevention. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    Not Available

    1994-05-01

    The bibliography contains citations concerning thermal and corrosion insulation of pipeline systems used to transport liquids and gases. Topics include thermal aging of polyurethane used for foam heating pipes, extrusion film pipeline insulation materials and processes, flexible expanded nitrile rubber pipeline insulation with Class 1 fire rating, and underground fiberglass reinforced polyester insulated pipeline systems. Applications in solar heating systems; underground water, oil, and gas pipelines; interior hot and cold water lines under seawater; and chemical plant pipeline system insulation are included. (Contains 250 citations and includes a subject term index and title list.)

  2. Pipeline system insulation: Thermal insulation and corrosion prevention. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    1995-11-01

    The bibliography contains citations concerning thermal and corrosion insulation of pipeline systems used to transport liquids and gases. Topics include thermal aging of polyurethane used for foam heating pipes, extrusion film pipeline insulation materials and processes, flexible expanded nitrile rubber pipeline insulation with Class 1 fire rating, and underground fiberglass reinforced polyester insulated pipeline systems. Applications in solar heating systems; underground water, oil, and gas pipelines; interior hot and cold water lines under seawater; and chemical plant pipeline system insulation are included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  3. Pipeline system insulation: Thermal insulation and corrosion prevention. (Latest citations from the Rubber and Plastics Research Association database). Published Search

    SciTech Connect

    1995-01-01

    The bibliography contains citations concerning thermal and corrosion insulation of pipeline systems used to transport liquids and gases. Topics include thermal aging of polyurethane used for foam heating pipes, extrusion film pipeline insulation materials and processes, flexible expanded nitrile rubber pipeline insulation with Class 1 fire rating, and underground fiberglass reinforced polyester insulated pipeline systems. Applications in solar heating systems; underground water, oil, and gas pipelines; interior hot and cold water lines under seawater; and chemical plant pipeline system insulation are included. (Contains 250 citations and includes a subject term index and title list.)

  4. Surface Studies of Ultra Strength Drilling Steel after Corrosion Fatigue in Simulated Sour Environment

    SciTech Connect

    M. Ziomek-Moroz; J.A. Hawk; R. Thodla; F. Gui

    2012-05-06

    The Unites States predicted 60% growth in energy demand by 2030 makes oil and natural gas primary target fuels for energy generation. The fact that the peak of oil production from shallow wells (< 5000 m) is about to be reached, thereby pushing the oil and natural gas industry into deeper wells. However, drilling to depths greater than 5000 m requires increasing the strength-to weight ratio of the drill pipe materials. Grade UD-165 is one of the ultra- high yield strength carbon steels developed for ultra deep drilling (UDD) activities. Drilling UDD wells exposes the drill pipes to Cl{sup -}, HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}, and H{sub 2}S-containig corrosive environments (i.e., sour environments) at higher pressures and temperatures compared to those found in conventional wells. Because of the lack of synergism within the service environment, operational stresses can result in catastrophic brittle failures characteristic for environmentally assisted cracking (EAC). Approximately 75% of all drill string failures are caused by fatigue or corrosion fatigue. Since there is no literature data on the corrosion fatigue performance of UD-165 in sour environments, research was initiated to better clarify the fatigue crack growth (FCGR) behavior of this alloy in UDD environments. The FCGR behavior of ultra-strength carbon steel, grade UD-165, was investigated by monitoring crack growth rate in deaerated 5%NaCl solution buffered with NaHCO{sub 3}/Na{sub 2}CO{sub 3} and in contact with H{sub 2}S. The partial pressure of H{sub 2}S (p{sub H2S}) was 0.83 kPa and pH of the solution was adjusted by NaOH to 12. The fatigue experiments were performed at 20 and 85 C in an autoclave with surface investigations augmented by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. In this study, research focused on surface analyses supported by the fatigue crack growth rate measurements. Fig. 1 shows an SEM micrograph of the crack that propagated from the

  5. LWRS Fuels Pathway: Engineering Design and Fuels Pathway Initial Testing of the Hot Water Corrosion System

    SciTech Connect

    Dr. John Garnier; Dr. Kevin McHugh

    2012-09-01

    The Advanced LWR Nuclear Fuel Development R&D pathway performs strategic research focused on cladding designs leading to improved reactor core economics and safety margins. The research performed is to demonstrate the nuclear fuel technology advancements while satisfying safety and regulatory limits. These goals are met through rigorous testing and analysis. The nuclear fuel technology developed will assist in moving existing nuclear fuel technology to an improved level that would not be practical by industry acting independently. Strategic mission goals are to improve the scientific knowledge basis for understanding and predicting fundamental nuclear fuel and cladding performance in nuclear power plants, and to apply this information in the development of high-performance, high burn-up fuels. These will result in improved safety, cladding, integrity, and nuclear fuel cycle economics. To achieve these goals various methods for non-irradiated characterization testing of advanced cladding systems are needed. One such new test system is the Hot Water Corrosion System (HWCS) designed to develop new data for cladding performance assessment and material behavior under simulated off-normal reactor conditions. The HWCS is capable of exposing prototype rodlets to heated, high velocity water at elevated pressure for long periods of time (days, weeks, months). Water chemistry (dissolved oxygen, conductivity and pH) is continuously monitored. In addition, internal rodlet heaters inserted into cladding tubes are used to evaluate repeated thermal stressing and heat transfer characteristics of the prototype rodlets. In summary, the HWCS provides rapid ex-reactor evaluation of cladding designs in normal (flowing hot water) and off-normal (induced cladding stress), enabling engineering and manufacturing improvements to cladding designs before initiation of the more expensive and time consuming in-reactor irradiation testing.

  6. The influence of liquid Pb-Bi on the anti-corrosion behavior of Fe3O4: a first-principles study.

    PubMed

    Li, Dongdong; Qu, Bingyan; He, H Y; Zhang, Y G; Xu, Yichun; Pan, B C; Zhou, Rulong

    2016-03-01

    In this work, the influence of Pb and Bi atoms on the anti-corrosion behavior of the oxide film (Fe3O4) formed on steel surface is investigated based on first-principles calculations. Through calculations of the formation energies, we find that Pb and Bi atoms can promote the formation of point defects, such as interstitial atoms and vacancies in Fe3O4. Besides, the effects of the concentration of Pb (or Bi) and pressure on the formation of these defects are also studied. Our results depict that a high density of Pb (or Bi) and compression pressure can promote the formation of defects in Fe3O4 significantly. Furthermore, the energy barriers for Pb and Bi atom migration in Fe3O4 are also estimated using the climbing image nudge elastic band (CI-NEB) method, which implies that Pb and Bi can diffuse more easily in Fe3O4 compared to Fe. Our results reveal the underlying mechanism of how Pb and Bi influence the anti-corrosion ability of oxide films in an accelerate driven system (ADS). It is instructive for improving the corrosion resistance of the oxide films in the ADS. PMID:26912208

  7. Microbiologically influenced corrosion testing

    SciTech Connect

    Kearns, J.R.; Little, B.J.

    1994-01-01

    This symposium was held November 16--17, 1992 in Miami, Florida. The purpose of the symposium was to provide a forum for state-of-the-art information on the effects of microorganisms on the corrosion of metals. Many industrial needs in the area of microbial influenced corrosion testing are identified in the presentations along with latest laboratory and field testing techniques. Strategies to monitor and control corrosion and biofouling in water distribution systems, underground pipelines, buildings, and marine vessels are discussed. Individual papers have been processed separately for inclusion in the appropriate data bases.

  8. INFLUENCE OF PHOSPHATE CORROSION CONTROL COMPOUNDS ON BACTERIAL GROWTH

    EPA Science Inventory

    The influence of two phosphate corrosion compounds on the growth and survival of coliform and other heterotrophic bacteria was investigated in laboratory, field, and model system studies. Growth of Citrobacter freundii, Enterobacter cloacae, and Klebsiella pneumoniae was not sign...

  9. Corrosion behavior, biocompatibility and biomechanical stability of a prototype magnesium-based biodegradable intramedullary nailing system.

    PubMed

    Krämer, Manuel; Schilling, Markus; Eifler, Rainer; Hering, Britta; Reifenrath, Janin; Besdo, Silke; Windhagen, Henning; Willbold, Elmar; Weizbauer, Andreas

    2016-02-01

    Implants made of degradable magnesium alloys are a potential alternative to conventional orthopaedic implant materials, e.g. stainless steel or titanium. Intramedullary nails made of the magnesium alloy LAE442 were subjected to cyclic fatigue tests in both distilled water and Hank's Balanced Salt Solution (HBSS) at 37.5°C until implant failure or a limit of 500,000cycles was reached. In distilled water, four of the five nails were still intact after the end of the biomechanical test. In HBSS, a breakage within the first 70,000 bending cycles was observed. Additionally, the degradation rate of this alloy was determined in HBSS according to the weight loss method (0.24±0.12mmyear(-1)) and based on gas release (0.21±0.03mmyear(-1)) with a standard eudiometer. A cytotoxicity test with L929 cells was carried out in accordance with EN ISO 10993-5/12. This test demonstrated sufficient cell viability of the diluted extracts (50%, 25% and 12.5%). The relative metabolic activity of the 100% extract was reduced slightly below 70%, which is classified as a threshold value for cytotoxicity. In conclusion, this in vitro study indicates that intramedullary nails made of LAE442 may not have the required fatigue resistance for load-bearing applications and the development of a corrosion-protective coating may be necessary to prevent early failure of the implant. PMID:26652357

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

    SciTech Connect

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

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

    NASA Astrophysics Data System (ADS)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  12. Corrosion protection

    DOEpatents

    Brown, Donald W.; Wagh, Arun S.

    2003-05-27

    There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

  13. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    SciTech Connect

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  14. A Multifunctional Coating for Autonomous Corrosion Control

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  15. Acceptance test plan for the 241-AN-105 multi-function corrosion monitoring system

    SciTech Connect

    EDGEMON, G.L.

    1999-06-24

    This Acceptance Test Procedure (ATP) will document the satisfactory operation of the corrosion probe tree assembly destined for installation into tank 241-AN-105. This ATP will be performed by the manufacturer prior to delivery to the site. The objective of this procedure is to demonstrate and document the acceptance of the corrosion probe tree assembly to be installed into tank 241-AN-105. The test will consist of a pressure test to verify leak tightness of the probe tree body, a continuity test of the probe tree wiring, a test of the high level detector wiring, a test of the operation of the Type K thermocouples along the probe body, and verification of operation of corrosion monitoring computer and instrumentation.

  16. Research Summary: Corrosion Considerations for Thermochemical Biomass Liquefaction Process Systems in Biofuel Production

    DOE PAGESBeta

    Brady, Michael P; Keiser, James R; Leonard, Donovan N; Whitmer, Lysle; Thomson, Jeffery K

    2014-01-01

    Thermochemical liquifaction processing of biomass to produce bio-derived fuels (e.g. gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc. to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic compounds, which make the bio-oil acidic and a potential source of corrosion issues in in transport, storage, and use. Efforts devoted to modified/further processing of bio-oilsmore » to make them less corrosive are currently being widely pursued. Another aspect that must also be addressed is potential corrosion issues in the bio-oil liquefaction process equipment itself. Depending on the specific process, bio-oil liquefaction production temperatures can reach up to 400-600 C, and involve the presence of aggressive sulfur, and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. This paper summarizes our recent, ongoing efforts to assess the extent to which corrosion of bio-oil process equipment may be an issue, with the ultimate goal of providing the basis to select the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.« less

  17. Corrosion Considerations for Thermochemical Biomass Liquefaction Process Systems in Biofuel Production

    NASA Astrophysics Data System (ADS)

    Brady, M. P.; Keiser, J. R.; Leonard, D. N.; Whitmer, L.; Thomson, J. K.

    2014-12-01

    Thermochemical liquefaction processing of biomass to produce bio-derived fuels (e.g., gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc., to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic oxygenates, including acids, which make the bio-oil a potential source of corrosion issues in transport, storage, and use. Efforts devoted to modified/further processing of bio-oils to make them less corrosive are currently being widely pursued. Another issue that must also be addressed in bio-oil liquefaction is potential corrosion issues in the process equipment. Depending on the specific process, bio-oil liquefaction production temperatures are typically in the 300-600°C range, and the process environment can contain aggressive sulfur and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. This paper summarizes recent, ongoing efforts to assess the extent of corrosion of bio-oil process equipment, with the ultimate goal of providing a basis for the selection of the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.

  18. Corrosion considerations for thermochemical biomass liquefaction process systems in biofuel production

    SciTech Connect

    Brady, Michael P.; Keiser, James R.; Leonard, Donovan N.; Whitmer, Lysle; Thomson, Jeffery K.

    2014-11-11

    Thermochemical liquifaction processing of biomass to produce bio-derived fuels (e.g. gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc. to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic compounds, which make the bio-oil acidic and a potential source of corrosion issues in in transport, storage, and use. Efforts devoted to modified/further processing of bio-oils to make them less corrosive are currently being widely pursued. Another aspect that must also be addressed is potential corrosion issues in the bio-oil liquefaction process equipment itself. Depending on the specific process, bio-oil liquefaction production temperatures can reach up to 400-600 °C, and involve the presence of aggressive sulfur, and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. Lastly, this paper summarizes our recent, ongoing efforts to assess the extent to which corrosion of bio-oil process equipment may be an issue, with the ultimate goal of providing the basis to select the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.

  19. Corrosion considerations for thermochemical biomass liquefaction process systems in biofuel production

    DOE PAGESBeta

    Brady, Michael P.; Keiser, James R.; Leonard, Donovan N.; Whitmer, Lysle; Thomson, Jeffery K.

    2014-11-11

    Thermochemical liquifaction processing of biomass to produce bio-derived fuels (e.g. gasoline, jet fuel, diesel, home heating oil, etc.) is of great recent interest as a renewable energy source. Approaches under investigation include direct liquefaction, hydrothermal liquefaction, hydropyrolysis, fast pyrolysis, etc. to produce energy dense liquids that can be utilized as produced or further processed to provide products of higher value. An issue with bio-oils is that they tend to contain significant concentrations of organic compounds, which make the bio-oil acidic and a potential source of corrosion issues in in transport, storage, and use. Efforts devoted to modified/further processing of bio-oilsmore » to make them less corrosive are currently being widely pursued. Another aspect that must also be addressed is potential corrosion issues in the bio-oil liquefaction process equipment itself. Depending on the specific process, bio-oil liquefaction production temperatures can reach up to 400-600 °C, and involve the presence of aggressive sulfur, and halide species from both the biomass used and/or process additives. Detailed knowledge of the corrosion resistance of candidate process equipment alloys in these bio-oil production environments is currently lacking. Lastly, this paper summarizes our recent, ongoing efforts to assess the extent to which corrosion of bio-oil process equipment may be an issue, with the ultimate goal of providing the basis to select the lowest cost alloy grades capable of providing the long-term corrosion resistance needed for future bio-oil production plants.« less

  20. Nanoplasmonic sensing and QCM-D as ultrasensitive complementary techniques for kinetic corrosion studies of aluminum nanoparticles

    NASA Astrophysics Data System (ADS)

    Schwind, Markus; Langhammer, Christoph; Kasemo, Bengt; Zorić, Igor

    2011-04-01

    Corrosion (oxidation) kinetics of Al nanodisks, 262 nm in diameter and 20 nm in height, was measured in degassed Milli-Q water at 23 °C and neutral pH by quartz crystal microbalance with dissipation monitoring (QCM-D) and nanoplasmonic sensing. The former detects the changes of the resonance frequency and the damping of the oscillation of a piezoelectric quartz crystal resonator. The latter detects the changes of the localized surface plasmon resonance (LSPR) in the metallic part of the Al nanoparticle, caused both by the shrinking metallic core and the changes in the dielectric environment as the oxide grows. Highly resolved kinetic data were obtained which show different corrosion stages. The two techniques yield complementary information not obtainable with one technique alone. Two main corrosion mechanisms, namely homogeneous oxide growth and nanoparticle fragmentation and roughening, are distinguished. The time dependence of the corrosion kinetics, determined using QCM-D, is in agreement with weight gain studies of bulk Al found in literature. The nanoplasmonic sensing measurements are compared to analytical model calculations of LSPR shifts which yield an estimate for the increase of oxide thickness during homogeneous oxide growth.

  1. The effect of frictional torque and bending moment on corrosion at the taper interface : an in vitro study.

    PubMed

    Panagiotidou, A; Meswania, J; Osman, K; Bolland, B; Latham, J; Skinner, J; Haddad, F S; Hart, A; Blunn, G

    2015-04-01

    The aim of this study was to assess the effect of frictional torque and bending moment on fretting corrosion at the taper interface of a modular femoral component and to investigate whether different combinations of material also had an effect. The combinations we examined were 1) cobalt-chromium (CoCr) heads on CoCr stems 2) CoCr heads on titanium alloy (Ti) stems and 3) ceramic heads on CoCr stems. In test 1 increasing torque was imposed by offsetting the stem in the anteroposterior plane in increments of 0 mm, 4 mm, 6 mm and 8 mm when the torque generated was equivalent to 0 Nm, 9 Nm, 14 Nm and 18 Nm. In test 2 we investigated the effect of increasing the bending moment by offsetting the application of axial load from the midline in the mediolateral plane. Increments of offset equivalent to head + 0 mm, head + 7 mm and head + 14 mm were used. Significantly higher currents and amplitudes were seen with increasing torque for all combinations of material. However, Ti stems showed the highest corrosion currents. Increased bending moments associated with using larger offset heads produced more corrosion: Ti stems generally performed worse than CoCr stems. Using ceramic heads did not prevent corrosion, but reduced it significantly in all loading configurations. PMID:25820883

  2. Inhibitive Performance of Benzotriazole for Steel Corrosion Studied by Electrochemical and AFM Characterization

    NASA Astrophysics Data System (ADS)

    Feng, Yuanchao; Cheng, Y. Frank

    2015-12-01

    In this work, the inhibiting effect of benzotriazole (BTA) on corrosion of X65 pipeline steel in bicarbonate solution was investigated by electrochemical measurements, including open-circuit potential, potentiodynamic polarization curves and electrochemical impedance spectroscopy, and atomic force microscopy characterization. It is found that BTA is effective to inhibit the steel corrosion, and the inhibiting efficiency is increased by the increasing inhibitor concentration. The BTA is an anodic inhibitor, which shifts the corrosion potential of the steel less negatively and decreases the anodic current density at individual potential. A layer of inhibitor film is formed on the steel surface to reduce the corrosion rate of the steel. The formed film is quite smooth, with a roughness at the nano-meter scale.

  3. Study on Laser-Assisted Rejuvenation of Inter-Granular Corrosion Damaged Type 304 Stainless Steel

    NASA Astrophysics Data System (ADS)

    Gupta, R. K.; Bhardwaj, V. K.; Agrawal, D. K.; Kumar, Manoj; Upadhyay, B. N.; Sankar, P. Ram; Ganesh, P.; Kaul, R.; Oak, S. M.; Kukreja, L. M.

    2015-09-01

    The paper evaluates laser surface melting treatment for rejuvenation of inter-granular corrosion damaged type 304 stainless steel. Surface melting of inter-granular corrosion damaged specimens with CW CO2 and pulsed Nd:YAG lasers was quite effective in sealing surface damage. However, inter-granular corrosion susceptibility of laser-rejuvenated surface was strongly influenced by associated thermal exposure. With respect to CW CO2 laser, pulsed Nd:YAG laser-rejuvenated surface demonstrated significantly suppressed micro-structural damage and IGC-susceptibility. Compact pulsed Nd:YAG laser, with flexible beam transportation, presents an effective tool for in-situ rejuvenation of inter-granular corrosion damaged in-service stainless steel components operating in susceptible environments.

  4. Development of a geographical information system for risk mapping of reinforced concrete buildings subjected to atmospheric corrosion in Cyprus using optical remote sensing data

    NASA Astrophysics Data System (ADS)

    Neocleous, Kyriacos; Agapiou, Athos; Christofe, Andreas; Themistocleous, Kyriacos; Achillides, Zenon; Panayiotou, Marilia; Hadjimitsis, Diofantos G.

    2014-08-01

    Concrete reinforced with steel rebars remains one of the most widely used construction materials. Despite its excellent mechanical performance and expected service life of at least 50 years, reinforced concrete is subjected to corrosion of the steel rebars which normally leads to concrete spalling, deterioration of the reinforced concrete's (RC) mechanical properties and eventual reduction of the structural load capacity. In Cyprus, especially in coastal regions where almost 60% of the population resides, many structural problems have been identified in RC structures, which are mainly caused by the severe corrosion of steel rebars. Most RC buildings, located in coastal areas, show signs of corrosion within the first 15-20 years of their service life and this affects their structural integrity and reliability, especially against seismic loading. This paper presents the research undertaken as part of the STEELCOR project which aims to extensively evaluate the steel corrosion of RC buildings in coastal areas of Cyprus and conduct a risk assessment relating to steel corrosion. Non-destructive testing of corroded RC structures measurements were used to estimate the simplified index of structural damage. These indices were imported into a Geographical Information System to develop a digital structural integrity map of Cyprus which would show the areas with high risk of steel corrosion of RC buildings. In addition, archive optical remote sensing dataset was used to map the urban expansion footprint during the last 30 years in Cyprus with the aim of undertaking corrosion risk scenarios by utilizing the estimated indices.

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

    SciTech Connect

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

    2006-06-30

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period, we analyzed several coated and exposed samples of 409 steel by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). We report here on findings of this analysis: (1) A SS409 coupon that was coated with multilayered combined nitrides of Ti, Al, and Si showed adherent coatings on the surface; (2) A similarly coated coupon, after exposure to simulated coal gas at 900 C for 300 h, revealed that the coating has cracked during the exposure; (3) An SS409 coupon that was coated with nitrides of Ti and Si with a barrier layer of tungsten in between to improve the adhesion of the coating and to prevent outward diffusion of iron to the surface. (4) A porous coupon was coated with nitrides of Ti and Al and examination of the coupon revealed deposition of Ti at the interior surfaces. A similarly prepared coupon was exposed to simulated coal gas at 370 C for 300 h, and it showed no corrosion.

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

    SciTech Connect

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

    2007-03-31

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the hightemperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period, we analyzed several 409 low alloy steel samples after coating them in our fluidized bed reactor and also after exposing them to our corrosion test. We report the following findings: 1. A protective coating was deposited inside a porous 409 steel sample to protect it from sulfidation attack. The coating was based on a combination of Si diffusion layer, Nb interlayer and nitrides of titanium and silicon. 2. Analysis of solid coupons exposed to simulated coal gas at 900 C for 300 h showed that multilayer metal/ceramic coatings provide a better protection than ceramic coatings. 3. Deposition of several ceramic/metal multilayer coatings showed that coatings with niobium and tantalum interlayers have good adhesion. However, coatings with a tungsten interlayer suffered localized delaminating and coatings with Zr interlayers showed poor adhesion. 4. Analysis of solid coupons, coated with the above-mentioned multilayer films, after exposure to simulated coal gas at 900 C for 300 h showed that niobium is the best candidate for interlayer material.

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

    SciTech Connect

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

    2006-01-01

    Heat-exchangers, particle filters, turbines, and other components in integrated coal gasification combined cycle system must withstand the highly sulfiding conditions of the high-temperature coal gas over an extended period of time. The performance of components degrades significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low-cost alloy may improve its resistance to such sulfidation attack, and decrease capital and operating costs. The alloys used in the gasifier service include austenitic and ferritic stainless steels, nickel-chromium-iron alloys, and expensive nickel-cobalt alloys. During this period we tested coated alloy coupons under conditions designed to mimic the conditions in the filter unit after the high-temperature heat recovery unit (HTHRU). The filter unit is another important area where corrosion has caused unscheduled downtime, and the remedy has been the use of sintered metal tubes made of expensive alloys such as inconel. The objective of our test was to determine if those coatings on 400-series steel that were not able to withstand the harsher conditions of the HTHRU, may be sufficiently resistant for use in the filter unit, at the reduced temperatures. Indeed, most of our coatings survived well; the exceptions were the coated porous samples of SS316. We continued making improvements to our coatings apparatus and the procedure began during the last quarter. As a result of these modifications, the coupons we are now producing are uniform. We describe the improved procedure for preparing diffusion coatings. Finally, because porous samples of steel in grades other than SS316 are not readily available, we also decided to procure SS409 powder and fabricate our own sintered porous coupons.

  8. Experiments and modelling studies concerning localized corrosion of carbon steel and stainless containers for intermediate- and low-level radioactive waste

    SciTech Connect

    Hoch, A.R.; Naish, C.C.; Sharland, S.M.; Smith, A.C.; Taylor, K.J.

    1993-12-31

    Current plans for disposal of low- and intermediate-level radioactive wastes (LLW and ILW) in the UK include enclosing much of the waste in carbon steel or stainless steel containers. Modelling and experimental studies that aim to characterize the period and extent of the localized corrosion in these containers are described. The period, during which localized corrosion can be initiated and sustained in the post-closure phase of the repository is estimated. The likely modes of localized corrosion are identified, based on further consideration of the environmental conditions to which the metals are exposed. Detailed research in progress includes investigation of the rate of pitting corrosion for carbon steel, and the possible occurrence of crevice corrosion of stainless steel.

  9. Microencapsulation Technology for Corrosion Mitigation by Smart Coatings

    NASA Technical Reports Server (NTRS)

    Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.

    2011-01-01

    A multifunctional, smart coating for the autonomous control of corrosion is being developed based on micro-encapsulation technology. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection effectiveness. This paper summarizes the development, optimization, and testing of microcapsules specifically designed to be incorporated into a smart coating that will deliver corrosion inhibitors to mitigate corrosion autonomously. Key words: smart coating, corrosion inhibition, microencapsulation, microcapsule, pH sensitive microcapsule, corrosion inhibitor, corrosion protection pain

  10. Studies on Stress Corrosion Cracking of Super 304H Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Prabha, B.; Sundaramoorthy, P.; Suresh, S.; Manimozhi, S.; Ravishankar, B.

    2009-12-01

    Stress corrosion cracking (SCC) is a common mode of failure encountered in boiler components especially in austenitic stainless steel tubes at high temperature and in chloride-rich water environment. Recently, a new type of austenitic stainless steels called Super304H stainless steel, containing 3% copper is being adopted for super critical boiler applications. The SCC behavior of this Super 304H stainless steel has not been widely reported in the literature. Many researchers have studied the SCC behavior of steels as per various standards. Among them, the ASTM standard G36 has been widely used for evaluation of SCC behavior of stainless steels. In this present work, the SCC behavior of austenitic Fe-Cr-Mn-Cu-N stainless steel, subjected to chloride environments at varying strain conditions as per ASTM standard G36 has been studied. The environments employed boiling solution of 45 wt.% of MgCl2 at 155 °C, for various strain conditions. The study reveals that the crack width increases with increase in strain level in Super 304H stainless steels.

  11. Underground Corrosion after 32 Years: A Study of Fate and Transport

    SciTech Connect

    Flitton, M. K. Adler

    2006-06-01

    Improved estimates for corrosion rates in variably saturated porous media are required by the U.S. Department of Energy to maintain long-term storage of radioactive contaminants in stainless steel containers. To better define these parameters, research was undertaken to complete the National Institute of Standards and Technology's (NIST) long-term study of buried stainless steel began 35 years ago. The 1970 study was initiated by the National Bureau of Standards (NBS), now known as NIST, when over 1000 specimens--including stainless steel Types 201, 202, 301, 304, 316, 409, 410, 430, and 434-configured as plates, U-bend, and tubes in both annealed and cold worked conditions with various treatments--were buried at six distinctive soil-type sites throughout the United States. During the first eight years of the study, four of five planned removals were completed with specimens retrieved after one, two, four, and eight years at each of the six sites. The fifth and final set of specimens remained undisturbed for over 34 years.

  12. Underground Corrosion after 32 Years: A Study of Fate and Transport

    SciTech Connect

    Flitton, M.K. Adler

    2006-06-01

    Improved estimates for corrosion rates in variably saturated porous media are required by the U.S. Department of Energy to maintain long-term storage of radioactive contaminants in stainless steel containers. To better define these parameters, research was undertaken to complete the National Institute of Standards and Technology’s (NIST) long-term study of buried stainless steel began 35 years ago. The 1970 study was initiated by the National Bureau of Standards (NBS), now known as NIST, when over 1000 specimens—including stainless steel Types 201, 202, 301, 304, 316, 409, 410, 430, and 434—configured as plates, U-bend, and tubes in both annealed and cold worked conditions with various treatments—were buried at six distinctive soil-type sites throughout the United States. During the first eight years of the study, four of five planned removals were completed with specimens retrieved after one, two, four, and eight years at each of the six sites. The fifth and final set of specimens remained undisturbed for over 34 years.

  13. Underground Corrosion after 32 years: A Study of Fate and Transport, #80803 Annual Report, June 2005

    SciTech Connect

    M. K. Adler Flitton; Carolyn Bishop

    2005-06-01

    Improved estimates for corrosion rates in variably saturated porous media are required by the U.S. Department of Energy to maintain long-term storage of radioactive contaminants in stainless steel containers. To better define these parameters, research was undertaken to complete the National Institute of Standards and Technology’s (NIST) long-term study of buried stainless steel began 35 years ago. The 1970 study was initiated by the National Bureau of Standards (NBS), now known as NIST, when over 1000 specimens—including stainless steel Types 201, 202, 301, 304, 316, 409, 410, 430, and 434—configured as plates, U-bend, and tubes in both annealed and cold worked conditions with various treatments— were buried at six distinctive soil-type sites throughout the United States. During the first eight years of the study, four of five planned removals were completed with specimens retrieved after one, two, four, and eight years at each of the six sites. The fifth and final set of specimens remained undisturbed for over 34 years.

  14. Fireside Corrosion

    SciTech Connect

    Holcomb, Gordon

    2011-07-14

    Oxy-fuel fireside research goals are: (1) determine the effect of oxyfuel combustion on fireside corrosion - flue gas recycle choice, staged combustion ramifications; and (2) develop methods to use chromia solubility in ash as an ash corrosivity measurement - synthetic ashes at first, then boiler and burner rig ashes.

  15. SURVEY OF FOULING, FOAM, CORROSION, AND SCALING CONTROL IN IRON AND STEEL INDUSTRY RECYCLE SYSTEMS

    EPA Science Inventory

    The report gives results of a review of the state-of-the-art for fouling, foaming, corrosion, and scaling control in the treatment and recycle of process waters of integrated iron and steel mills. Areas examined were: (1) the character of the wastewaters generated in the differen...

  16. Corrosion Testing of Brazed Space Station IATCS Materials

    NASA Technical Reports Server (NTRS)

    Pohlman, Matthew J.; Varisik, Jerry; Steele, John W.; Golden, Johnny L.; Boyce, William E.; Pedley, Michael D.

    2004-01-01

    Increased nickel concentrations in the IATCS coolant prompted a study of the corrosion rates of nickel-brazed heat exchangers in the system. The testing has shown that corrosion is occurring in a silicon-rich intermetallic phase in the braze filler of coldplates and heat exchangers as the result of a decrease in the coolant pH brought about by cabin carbon dioxide permeation through polymeric flexhoses. Similar corrosion is occurring in the EMU de-ionized water loop. Certain heat exchangers and coldplates have more silicon-rich phase because of their manufacturing method, and those units produce more nickel corrosion product. Silver biocide additions did not induce pitting corrosion at silver precipitate sites.

  17. Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

    NASA Technical Reports Server (NTRS)

    Pearman, Benjamin Pieter; Calle, Luz M.

    2015-01-01

    This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

  18. Measurement and mitigation of corrosion on self-contained fluid filled (SCFF) submarine circuits for New York Power Authority: Volume 2 -- Stray electrical current measurements and preliminary design of the cathodic protection system. Final report

    SciTech Connect

    1998-10-01

    In 1987, the New York Power Authority (NYPA) installed a 345-kV submarine cable circuit across Long Island Sound between substations at Davenport Neck and Hempstead Harbor. During design and installation of the cable circuit, utility and cable manufacturers engineers identified corrosion as a possible problem for the cable system. They considered such effects in the cable design and discussed preliminary requirements for a cathodic protection system on Long Island Sound circuit. EPRI cosponsored this review of the corrosion effects with NYPA and Empire State Electric Energy Research Corp. (ESEERCO). Volume 1 of this report discusses the results from an in-depth evaluation of the self-contained fluid-filled (SCFF) cable construction materials and their susceptibility to corrosion. Volume 2 provides extended stray current field measurements and a preliminary design for a cathodic protection system to ensure cable service reliability. This study provides a blueprint for East or West Coast utilities evaluating site-specific corrosion processes and cable circuit protection methods suitable for underwater environments.

  19. Plexiform vascular structures in the human digital dermal layer: a SEM--corrosion casting morphological study.

    PubMed

    Manelli, A; Sangiorgi, S; Ronga, M; Reguzzoni, M; Bini, A; Raspanti, M

    2005-01-01

    This study aimed to describe the impressive diversity of vascular plexiform structures of the hypodermal layer of human skin. We chose the human body site with the highest concentration of dermal corpuscles, the human digit, and processed it with the corrosion casting technique and scanning electron microscopy analysis (SEM). This approach proved to be the best tool to study these microvascular architectures, free from any interference by surrounding tissues. We took high-definition pictures of the vascular network of sweat glands, thermoreceptorial and tactile corpuscles, the vessels constituting the glomic bodies and those feeding the hair follicles. We observed that the three-dimensional disposition of these vessels strictly depends on the shape of the corpuscles supplied. We could see the tubular vascularization of the excretory duct of sweat glands and the ovoid one feeding their bodies, sometimes made up of two lobes. In some cases, knowledge of these morphological data regarding the normal disposition in space and intrinsic vascularization structure of the dermal corpuscles can help to explain many of the physiopathological changes occurring during chronic microangiopathic diseases. PMID:16982473

  20. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

    PubMed

    Peme, Thabo; Olasunkanmi, Lukman O; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-01-01

    The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms. PMID:26364631

  1. BWR steel containment corrosion

    SciTech Connect

    Tan, C.P.; Bagchi, G.

    1996-04-01

    The report describes regulatory actions taken after corrosion was discovered in the drywell at the Oyster Creek Plant and in the torus at the Nine Mile Point 1 Plant. The report describes the causes of corrosion, requirements for monitoring corrosion, and measures to mitigate the corrosive environment for the two plants. The report describes the issuances of generic letters and information notices either to collect information to determine whether the problem is generic or to alert the licensees of similar plants about the existence of such a problem. Implementation of measures to enhance the containment performance under severe accident conditions is discussed. A study by Brookhaven National Laboratory (BNL) of the performance of a degraded containment under severe accident conditions is summarized. The details of the BNL study are in the appendix to the report.

  2. Study of materials to resist corrosion in condensing gas fired furnaces. Annual report Oct 79-Oct 80

    SciTech Connect

    Lahtvee, T.; Khoo, S.W.; Schaus, O.O.

    1981-02-01

    Based on a thorough review of background information on the performance of materials in condensing gas-fired furnace heat exchangers and in similar corrosive environments, candidate materials were selected and tested on one of two identical test rigs built to provide the varying corrosive conditions encountered in an actual gas-fired condensing system heat exchanger. The 32 different materials tested in a one month screening test included: mild, low alloy, galvanized, solder coated and CaCO3 dipped galvanized steel, porcelain, epoxy, teflon and nylon coated and alonized mild steel; austenitic, ferritic, low interstitial Ti stabilized ferritic, and high alloy stainless steels; aluminum alloy anodized and porcelain coated aluminum; copper and cupronickel alloys, solder coated copper; and titanium.

  3. The Application of Electrochemical and Surface Analysis Approaches to Studying Copper Corrosion in Water: Fundamentals, Limitations, and Examples

    EPA Science Inventory

    Corrosion control is a concern for many drinking water utilities. The Lead and Copper Rule established a regulatory need to maintain a corrosion control program. Other corrosion-related issues such as “red” water resulting from excessive iron corrosion and copper pinhole leaks ...

  4. Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

    NASA Astrophysics Data System (ADS)

    Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

    2016-07-01

    The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

  5. Study of metal corrosion using ac impedance techniques in the STS launch environment

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.

    1989-01-01

    AC impedance measurements were performed to investigate the corrosion resistance of 19 alloys under conditions similar to the STS launch environment. The alloys were: Zirconium 702, Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, Inconel 600, 7Mo + N, Ferralium 255, Inco Alloy G-3, 20Cb-3, SS 904L, Inconel 825, SS 304LN, SS 316L, SS 317L, ES 2205, SS 304L, Hastelloy B-2, and Monel 400. AC impedance data were gathered for each alloy after one hour immersion time in each of the following three electrolyte solutions: 3.55 percent NaCl, 3.55 percent NaCl-0.1N HCl, and 3.55 percent NaCl-1.0N HCl. The data were analyzed qualitatively using the Nyquist plot and quantitatively using the Bode plot. Polarization resistance, Rp, values were obtained using the Bode plot. Zirconium 702 was the most corrosion resistant alloy in the three electrolytes. The ordering of the other alloys according the their resistance to corrosion varied as the concentration of hydrochloric acid in the electrolyte increased. The corrosion resistance of Zirconium 702 and Ferralium 255 increased as the concentration of hydrochloric acid in the electrolyte increased. The corrosion resistance of the other 17 alloys decreased as the concentration of the hyrdochloric acid in the electrolyte increased.

  6. Electrochemical study of resistance to localized corrosion of stainless steels for biomaterial applications

    SciTech Connect

    Pan, J.; Karlen, C.; Ulfvin, C.

    2000-03-01

    Sandvik Bioline High-N and 316 LVM are two austenitic stainless steels especially developed for biomaterial applications. Their resistance to localized corrosion was investigated by electrochemical methods including cyclic potentiodynamic polarization and potentiostatic polarization measurements in a phosphate-buffered saline solution and in a simulated crevice solution, i.e., designed for crevice corrosion testing. Sandvik SAF 2507 (a high-performance super duplex stainless steel) was included in the tests as a reference material High-N, higher alloyed than 316 LVM, demonstrated excellent resistance to pitting initiation and a strong tendency to repassivation. High-N proved to have an equivalent or even higher resistance to localized corrosion than SAF 2507. The latter is known for its impressive corrosion properties, particularly in chloride containing environments. While 316 LVM may run the risk of crevice corrosion in implant applications, the risk seems negligible for High-N. In view of the fact that also the mechanical properties are superior to those of 316 LVM, High-N is a very attractive implant material.

  7. Friction surfacing for enhanced surface protection of marine engineering components: erosion-corrosion study

    NASA Astrophysics Data System (ADS)

    Rajakumar, S.; Balasubramanian, V.; Balakrishnan, M.

    2016-08-01

    Good mechanical properties combined with outstanding corrosion-resistance properties of cast nickel-aluminum bronze (NAB) alloy lead to be a specific material for many marine applications, including ship propellers. However, the erosion-corrosion resistance of cast-NAB alloy is not as good as wrought NAB alloy. Hence, in this investigation, an attempt has been made to improve the erosion-corrosion resistance of cast NAB alloy by depositing wrought (extruded) NAB alloy applying the friction surfacing (FS) technique. Erosion-corrosion tests were carried out in slurries composed of sand particles of 3.5% NaCl solution. Silica sand having a nominal size range of 250-355 μm is used as an erodent. Specimens were tested at 30° and 90° impingement angles. It is observed that the erosion and erosion-corrosion resistance of friction surfaced NAB alloy exhibited an improvement as compared to cast NAB alloy. Scanning electron microscope (SEM) analysis showed that the erosion tracks developed on the cast NAB alloy were wider and deeper than those formed on the friction surfaced extruded NAB alloy.

  8. OTEC biofouling and corrosion study at the Natural Energy Laboratory of Hawaii, 1983--1987

    SciTech Connect

    Panchal, C.; Stevens, H.; Genens, L.; Thomas, A.; Clark, C.; Yaggee, F.; Darby, J. ); Sasscer, D. Northwestern Univ., Evanston, IL ); Larsen-Basse, J.; Liebert, B.; Berger, L. Hawaii Univ., Honolulu, HI ); Bhargava, A.; Lee, B. Hawaii Natural Energy Inst., Honolulu,

    1990-10-01

    Long-term research on fouling and corrosion has been conducted as a part of the effort to develop heat exchangers for the US Department of Energy's Ocean Energy Technology program. After obtaining initial experimental data from various sites, including Puerto Rico, the Gulf of Mexico, open ocean (a buoy) in Hawaii, and Wrightsville Beach in North Carolina, Argonne National Laboratory carried out a six-year research program at the National Energy Laboratory of Hawaii. In the Phase 1 experimental program, a data base was developed for characterization of biofouling of corrosion-resistant material exposed to two types of seawater -- surface (warm) and deep-ocean (cold). The major objective was to determine optimal biofouling-control methods. The results of the Phase 1 research were published in a report in 1985. The major objective of the Phase 2 research has been to develop a technical data base for the qualification of aluminum alloys for ocean thermal energy conversion (OTEC) heat-exchanger applications. Aluminum alloys have many desirable mechanical properties that can be utilized for the development of low-cost, compact heat exchangers that can be designed on a modular basis. The research program for aluminum alloys has included biofouling, corrosion fouling, uniform corrosion, localized corrosion, and evaluation of brazed joint and epoxy-bonded joints. Conclusions derived in this report represent a major milestone in OTEC materials and fouling research. 70 refs., 109 figs., 18 tabs.

  9. An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral

    NASA Astrophysics Data System (ADS)

    Grassini, S.; Angelini, E.; Parvis, M.; Bouchar, M.; Dillmann, P.; Neff, D.

    2013-12-01

    The corrosion behaviour of Middle Ages wrought iron bar chains exposed to indoor atmospheric corrosion for hundred of years in the Notre Dame Cathedral of Amiens (France) has been evaluated by means of Electrochemical Impedance Spectroscopy (EIS), a well-established electrochemical technique extensively used for testing anticorrosive properties of metal coatings. The measurements have been performed in situ with a portable EIS instrument designed to work as a standalone device, in six different areas of the wrought iron bar chains characterized by different aesthetical appearance. Moreover, a properly designed electrochemical cell has been employed to carry out the impedance measurements without affecting the artefacts surfaces. The wrought iron bar chains, as evidenced by μ-Raman and microscopic analyses, are covered by corrosion products constituted by iron oxides and oxyhydroxides, such as goethite, lepidocrocite, maghemite, akaganeite, organized in complex layered structures. In situ EIS allows one to investigate the phenomena involved at the electrochemical interfaces among the various corrosion products and to assess and predict their corrosion behaviour. From the analysis of the experimental findings of this monitoring campaign, EIS measurements can be proposed to restorers/conservators as a reliable indicator of dangerous situations on which they must act for the preservation of the iron artefacts.

  10. Refractory Materials for Flame Deflector Protection System Corrosion Control: Coatings Systems Literature Survey

    NASA Technical Reports Server (NTRS)

    Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Sampson, Jeffrey W.; Coffman, Brekke E.; Coffman, Brekke E.; Curran, Jerome P.; Kolody, Mark R.; Whitten, Mary; Perisich, Steven; Trejo, David

    2009-01-01

    When space vehicles are launched, extreme heat, exhaust, and chemicals are produced and these form a very aggressive exposure environment at the launch complex. The facilities in the launch complex are exposed to this aggressive environment. The vehicle exhaust directly impacts the flame deflectors, making these systems very susceptible to high wear and potential failure. A project was formulated to develop or identify new materials or systems such that the wear and/or damage to the flame deflector system, as a result of the severe environmental exposure conditions during launches, can be mitigated. This report provides a survey of potential protective coatings for the refractory concrete lining on the steel base structure on the flame deflectors at Kennedy Space Center (KSC).

  11. SERS and DFT study of copper surfaces coated with corrosion inhibitor.

    PubMed

    Muniz-Miranda, Maurizio; Muniz-Miranda, Francesco; Caporali, Stefano

    2014-01-01

    Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS) effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule-metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT) approach. PMID:25671144

  12. Utilizing various test methods to study the stress corrosion behavior of Al-Li-Cu alloys

    NASA Technical Reports Server (NTRS)

    Pizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1984-01-01

    Recently, much attention has been given to aluminum-lithium alloys because of rather substantial specific-strength and specific-stiffness advantages offered over commercial 2000and 7000-series aluminum alloys. An obstacle to Al-Li alloy development has been inherent limited ductility. In order to obtain a more refined microstructure, powder metallurgy (P/M) has been employed in alloy development programs. As stress corrosion (SC) of high-strength aluminum alloys has been a major problem in the aircraft industry, the possibility of an employment of Al-Li alloys has been considered, taking into account a use of Al-Li-Cu alloys. Attention is given to a research program concerned with the evaluation of the relative SC resistance of two P/M processed Al-Li-Cu alloys. The behavior of the alloys, with and without an addition of magnesium, was studied with the aid of three test methods. The susceptibility to SC was found to depend on the microstructure of the alloys.

  13. Stress-corrosion-cracking studies on candidate container alloys for the Tuff Repository

    SciTech Connect

    Beavers, J.A.; Durr, C.L.

    1992-05-01

    Cortest Columbus Technologies, Inc. (CC Technologies) investigated the long-term performance of container materials used for high-level waste package as part of the information needed by the Nuclear Regulatory Commission (NRC) to assess the Department of Energy`s application to construct to geologic repository for high-level radioactive waste. At the direction of the NRC, the program focused on the Tuff Repository. This report summarizes the results of Stress-Corrosion-Cracking (SCC) studies performed in Tasks 3, 5, and 7 of the program. Two test techniques were used; U-bend exposures and Slow-Strain-Rate (SSR) tests. The testing was performed on two copper-base alloys (Alloy CDA 102 and Alloy CDA 175) and two Fe-Cr-Ni alloys (Alloy 304L and Alloy 825) in simulated J-13 groundwater and other simulated solutions for the Tuff Repository. These solutions were designed to simulate the effects of concentration and irradiation on the groundwater composition. All SCC testing on the Fe-Cr-Ni Alloys was performed on solution-annealed specimens and thus issues such as the effect of sensitization on SCC were not addressed.

  14. Microelectrochemical studies on the influence of Cr and Mo on nucleation events of pitting corrosion

    SciTech Connect

    Kobayashi, Y.; Virtanen, S.; Boehni, H.

    2000-01-01

    Nucleation events of pitting corrosion for Fe-Cr and Fe-Cr-Mo alloy series, enabling a single-parameter variation in the alloy composition, was studied with microelectrochemistry. The main effect of Cr and Mo additions in Fe-Cr alloys on the microtransient activity in NaCl solution is a decrease of the transient heights. As a consequence, fewer transients are detected for alloys with higher Cr and Mo contents. However, it cannot be excluded that a high number of small nucleation events takes place on these alloys, leading to undetectable transients. A single transient analysis reveals that Cr and Mo lead to an earlier start of repassivation, but they do not accelerate the repassivation kinetics of the small nucleation events detected by microelectrochemistry. The higher the Cr and Mo content in the alloy, the faster the decrease in the microtransient activity as a function time. The type of transients does not essentially change as a function of time. Hence, only the nucleation activity but not the repassivation behavior are influenced by aging.

  15. SERS and DFT study of copper surfaces coated with corrosion inhibitor

    PubMed Central

    Muniz-Miranda, Francesco; Caporali, Stefano

    2014-01-01

    Summary Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS) effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule–metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT) approach. PMID:25671144

  16. Stage 1 behavior in a stress corrosion study of Type 304 stainless steel

    SciTech Connect

    Lund, A.L.; Jones, R.H.

    1994-03-01

    In stress corrosion studies, crack velocity plotted with respect to stress intensity generally yields a characteristic curve with three distinct regions. Stage I exhibits a threshold (K{sub ISCC}) followed by a rapid increase in crack velocity (da/dt) for small changes in stress intensity. Stage II is characterized by an essentially constant crack velocity with increases in the stress intensity. Stage III exhibits a rapid increase in crack velocity for small increases in stress intensity leading to fracture. Stage I behavior has been poorly characterized in literature due to previous emphasis on determining the threshold K{sub ISCC} and difficulty and uncertainty in measuring of a large increase in crack velocity with only incremental changes in stress intensity. Tests were conducted in the stage I regime to measure crack velocity as a function of constant stress intensity. Constant K specimens were prepared according to the Mostovoy design, (a tapered double cantilever beam). Specimens were prepared from Type 304 stainless steel containing 0.06 wt% C solution annealed at 1100C for 1 hour, water quenched, and annealed at 625C for 24 hours to produce sensitization. A sodium thiosulfate solution at 50{degree}C was chosen as the test environment.

  17. Corrosion `98: 53. annual conference and exposition, proceedings

    SciTech Connect

    1998-12-31

    This conference was divided into the following sections: Corrosion in Gas Treating; Problems and Solutions in Commercial Building Water Systems; Green Corrosion/Scale Inhibitors; Atmospheric Corrosion; AIRPOL Update/98; Rubber Lining--Answers to Many Problems; Interference Problems; Environmental Assisted Cracking: Fundamental Research and Industrial Applications; Corrosion in Nuclear Systems; New Developments in Scale and Deposit Control; Corrosion and Corrosion Protection in the Transportation Industries; What`s All the Noise About--Electrochemical That Is; Refining Industry Corrosion; Corrosion Problems in Military Hardware: Case Histories, Fixes and Lessons Learned; Cathodic Protection Test Methods and Instrumentation for Underground and On-grade Pipelines and Tanks; Recent Developments in Volatile Corrosion Inhibitors; Corrosion in Supercritical Fluids; Microbiologically Influenced Corrosion; Advances in Understanding and Controlling CO{sub 2} Corrosion; Managing Corrosion with Plastics; Material Developments for Use in Exploration and Production Environments; Corrosion in Cold Regions; The Effect of Downsizing and Outsourcing on Cooling System Monitoring and Control Practices; New Developments in Mechanical and Chemical Industrial Cleaning; Mineral Scale Deposit Control in Oilfield Related Operations; Biocides in Cooling Water; Corrosion and Corrosion Control of Reinforced Concrete Structures; Materials Performance for Fossil Energy Conversion Systems; Marine corrosion; Thermal Spray--Coating and Corrosion Control; Flow Effects on Corrosion in Oil and Gas Production; Corrosion Measurement Technologies; Internal Pipeline Monitoring--Corrosion Monitoring, Intelligent Pigging and Leak Detection; Cathodic Protection in Natural Waters; Corrosion in Radioactive Liquid Waste Systems; On-line Hydrogen Permeation Monitoring Equipment and Techniques, State of the Art; Water Reuse and Recovery; Performance of Materials in High Temperature Environments; Advances in Motor

  18. A non-immersed induction conductivity system for controlling supersaturation in corrosive media: the case of gibbsite crystals agglomeration in Bayer liquors

    NASA Astrophysics Data System (ADS)

    Seyssiecq, I.; Veesler, S.; Boistelle, R.

    1996-11-01

    Agglomeration of gibbsite Al(OH) 3 crystallites is an important stage of the Bayer process, aiming at increasing the initial size of the particles. In the present work, a semi-continuous crystallizer working at constant and imposed supersaturation, and equipped with an automatic withdrawal system was developed to study the agglomeration of gibbsite crystals in supersaturated Bayer liquors. The liquor conductivity was measured using an induction conductivity system placed around the crystallizer, the conductivity regulation being used to work at constant supersaturation. Using this system allowed one to work with both a small crystallizer and a highly corrosive and abrasive suspension of gibbsite in a five molar caustic soda solution at 70°C. Analyses of the withdrawals were carried out with an Elzone particle counter, in order to draw {N(t)}/{N(0) = f(t)} plots, representing the decrease of crystal number with time, due to agglomeration.

  19. Corrosion in MDEA sour gas treating plants: Correlation between laboratory testing and field experience

    SciTech Connect

    Bich, N.N.; Vacha, F.; Schubert, R.

    1996-08-01

    Corrosion in MDEA sour gas treating systems operating in severely loaded conditions is investigated using both laboratory data and actual gas plant experience. Effects of acid gas loading, flow turbulence, solution quality, temperature, etc. on corrosion are being studied. Preliminary results indicated severe corrosion of several mm/y would occur if acid gas loading, circulation rate and level of suspended solids are all high. A mitigation strategy based on operating envelopes is formulated.

  20. CORROSION STUDY FOR THE EFFLUENT TREATMENT FACILITY CHROME (VI) REDUCTANT SOLUTION USING 304 AND 316L STAINLESS STEEL

    SciTech Connect

    DUNCAN JB; WYRAS RB

    2007-10-08

    This report documents the laboratory testing and analyses as directed under the test plan, RPP PLAN-34065, and documented in laboratory notebooks HNF 2742 and HNF-N-473-1. The purpose of this study was to evaluate and compare the electrochemical corrosion and pitting susceptibility of the 304 and 316L stainless steel in the acidified reducing solution that will be contained in either the secondary waste receiving tank or concentrate tank.