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Sample records for carbon steel corrosion

  1. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    This report assesses the factors which cause preferential attack to occur in carbon steel fusion welds. It was concluded that the main factors were: the inclusion content of the weld metal, the potential of the weld metal being less noble than that of the parent, and the presence of low-temperature transformation products in the heat-affected zone of the weld. These factors should be minimized or eliminated as appropriate so that the corrosion allowances determined for carbon steel waste drums is also adequate for the welds. An experimental/theoretical approach is recommended to evaluate the relative corrosion resistance of welds prepared from BS 4360 grade 43A steel to that of the parent material. (author)

  2. Marine atmospheric corrosion of carbon steels

    OpenAIRE

    Morcillo, Manuel; Alcántara, Jenifer; Díaz, Iván; Chico, Belén; Simancas, Joaquín; de la Fuente, Daniel

    2015-01-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products...

  3. Marine atmospheric corrosion of carbon steels

    International Nuclear Information System (INIS)

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  4. Marine atmospheric corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Morcillo, M.; Alcantara, J.; Diaz, I.; Chico, B.; Simancas, J.; Fuente, D. de la

    2015-07-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  5. Microbially influenced corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    White, D.C.; Jack, R.F.; Dowling, N.J.E.; Franklin, M.J.; Nivens, D.E.; Brooks, S.; Mittelman, M.W.; Vass, A.A. (Tennessee Univ., Knoxville, TN (USA). Inst. for Applied Microbiology); Isaacs, H.S. (Brookhaven National Lab., Upton, NY (USA))

    1990-01-01

    Microbially influenced corrosion of pipeline steels is an economically important problem. Microbes form tubercles which block fluid flow and can facilitate localized corrosion leading to through-wall penetrations. Microbes of diverse physiological types and metabolic potentialities have been recovered from fresh tubercles or under-deposit corrosion and have been characterized. In tests utilizing sterilizable flow-through systems containing pipeline steel coupons, corrosion rates determined by nondestructive electrochemical means have indicated that increasing the number of physiological types of microbes inoculated into the system generally increased the severity of the microbially influenced corrosion (MIC). This study reports the MIC of monocultures and combinations of monocultures in an aerobic fresh water system with low sulfate and an anaerobic saline system. In both the aerobic and anaerobic systems, the combination of microbes induced greater MIC responses than the monocultures. In tests involving a combination of microbes in both systems in which one member was a sulfate-reducing bacteria (SRB), the corrosion mechanism was different for the control and the monocultures. This difference was indicated by the phase shift in the electrochemical impedance spectra (EIS). The localization of corrosion, that in many cases is the hallmark of MIC, may be initiated by the inhomogeneities of supposedly smooth metal surfaces. The scanning vibrating electrode technique (SVET) demonstrated non-uniform current densities over carbon steel electrodes polished to a 600 grit finish suggesting pitting and repassivation of pits in sterile medium.

  6. Microbially induced corrosion of carbon steel in deep groundwater environment

    OpenAIRE

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing abil...

  7. Microbially induced corrosion of carbon steel in deep groundwater environment

    Science.gov (United States)

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland) for periods of 3 and 8 months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel. PMID:26257707

  8. Microbially induced corrosion of carbon steel in deep groundwater environment

    Directory of Open Access Journals (Sweden)

    Pauliina eRajala

    2015-07-01

    Full Text Available The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland for periods of three and eight months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel.

  9. Microbially induced corrosion of carbon steel in deep groundwater environment.

    Science.gov (United States)

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland) for periods of 3 and 8 months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel. PMID:26257707

  10. Marine atmospheric corrosion of carbon steels

    Directory of Open Access Journals (Sweden)

    Morcillo, Manuel

    2015-06-01

    Full Text Available Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a environmental conditions necessary for akaganeite formation; (b characterisation of akaganeite in the corrosion products formed; (c corrosion mechanisms of carbon steel in marine atmospheres; (d exfoliation of rust layers formed in highly aggressive marine atmospheres; (e long-term corrosion rate prediction; and (f behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camariñas, Galicia in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM/energy dispersive spectrometry (EDS, X-ray diffraction (XRD, Mössbauer spectroscopy and SEM/μRaman spectroscopy.La investigación fundamental en corrosión atmosférica marina de aceros al carbono es un campo científico relativamente joven que presenta grandes lagunas de conocimiento. La formación de akaganeíta en los productos de corrosión que se forman sobre el acero cuando se expone a atmósferas marinas conduce a un incremento notable de la velocidad de corrosión. En el trabajo se abordan las siguientes cuestiones: (a condiciones ambientales necesarias para la formación de akaganeíta, (b caracterización de la akaganeíta en los productos de corrosión formados, (c mecanismos de corrosión del acero al carbono en atmósferas marinas, (d exfoliación de las capas de herrumbre formadas en atmósferas marinas muy agresivas, (e predicción de la velocidad de corrosión a largo plazo, y (f comportamiento de aceros patinables. La

  11. Increasing corrosion resistance of carbon steels by surface laser cladding

    Science.gov (United States)

    Polsky, V. I.; Yakushin, V. L.; Dzhumaev, P. S.; Petrovsky, V. N.; Safonov, D. V.

    2016-04-01

    This paper presents results of investigation of the microstructure, elemental composition and corrosion resistance of the samples of low-alloy steel widely used in the engineering, after the application of laser cladding. The level of corrosion damage and the corrosion mechanism of cladded steel samples were established. The corrosion rate and installed discharge observed at the total destruction of cladding were obtained. The regularities of structure formation in the application of different powder compositions were obtained. The optimal powder composition that prevents corrosion of samples of low-carbon low-alloy steel was established.

  12. Initial Atmospheric Corrosion of Carbon Steel in Industrial Environment

    Science.gov (United States)

    Han, Wei; Pan, Chen; Wang, Zhenyao; Yu, Guocai

    2015-02-01

    The initial corrosion behavior of carbon steel subjected to Shenyang industrial atmosphere has been investigated by weight-loss measurement, scanning electron microscopy observation, x-ray diffraction, auger electron spectroscopy, and electron probe microanalysis. The experimental results reveal that the corrosion kinetics of the initial corrosion of carbon steel in industrial atmosphere follows empirical equation D = At n , and there is a corrosion rate transition from corrosion acceleration to deceleration; the corrosion products are composed of γ-FeOOH, α-FeOOH, Fe3O4, as well as FeS which is related to the existence of sulfate-reducing bacteria in the rust layers. The effect of dust particles on the corrosion evolution of carbon steel has also been discussed.

  13. Atmospheric corrosion of carbon steel in the prairie regions

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, W.J. [Calgary Univ., AB (Canada). Dept. of Mechanical and Manufacturing Engineering; Andersson, J.I. [Husky Oil Operations Ltd., Calgary, AB (Canada)

    2010-07-01

    A study of atmospheric corrosion and carbon steel located in the prairie regions of Canada was presented. The study considered corrosion behaviour as well as the standards currently used to establish and predict corrosion in atmospheric conditions. The aim of the study was to develop an accurate predictive method of establishing corrosion amounts over time. The controlling parameters for atmospheric corrosion included acidic rainfall; temperature and humidity; time of wetness; and the presence of major contaminants such as sulfur dioxide (SO{sub 2}). The predictive approach involved the study of a protective film of magnetite iron oxide that establishes itself on carbon steel over time. The presence of the film provides increased atmospheric corrosion resistance. An analysis of the atmospheric corrosion of steel tanks at the Hardisty terminal was used to demonstrate the method. 22 refs., 5 tabs., 7 figs.

  14. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria, e.g. on pipelines buried in soil and on marine structures. MIC of carbon steel must be monitored on-line in order to provide an efficient protection and...... control the corrosion. A number of monitoring techniques is industrially used today, and the applicability and reliability of these for monitoring MIC is evaluated. Coupons and ER are recommended as necessary basic techniques even though localised corrosion rate cannot be measured. FSM measures general...... corrosion and detects localised corrosion, but the sensitivity is not high enough for monitoring initiation of pitting and small attacks. Electrochemical techniques as LPR and EIS give distorted data and unreliable corrosion rates, when biofilm and corrosion products cover the steel surface. However, EIS...

  15. MICROBIAL CORROSION OF MILD AND MEDIUM CARBON STEELS

    OpenAIRE

    J. E.O. OVRI; S. I. OKEAHIALAM; O. O. ONYEMAOBI

    2013-01-01

    The role of bacteria in the corrosion of mild and medium carbon steels is reported. The steels were exposed to anaerobic and aerobic, and fresh water (control) environments. The corrosion rates were evaluated at intervals of seven days for a period of 42 days using weight loss and electrochemical methods. The corroded specimens were visually examined and majorities were found to have undergone general corrosion in the three environments (aerobic, anaerobic, and fresh water)....

  16. The anaerobic corrosion of carbon steel in concrete

    International Nuclear Information System (INIS)

    This is the final report of a 2 year programme aimed at (1) determining the rate of anaerobic corrosion of steel in concrete, (2) investigating the nature of the corrosion products formed on carbon steel embedded in cementitious material under anaerobic conditions and (3) evaluating the effect of hydrogen over-pressures on the rate of anaerobic corrosion. All experiments have been carried out at temperatures in the range 20-300C, ie ambient conditions. 4 refs.; 19 figs.; 6 tabs

  17. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    Abstract Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria, e.g. on pipelines buried in soil and on marine structures. MIC of...... carbon steel must be monitored on-line in order to provide an efficient protection and control the corrosion. A number of monitoring techniques is industrially used today, and the applicability and reliability of these for monitoring MIC is evaluated. Coupons and ER are recommended as necessary basic...... techniques even though localised corrosion rate cannot be measured. FSM measures general corrosion and detects localised corrosion, but the sensitivity is not high enough for monitoring initiation of pitting and small attacks. Electrochemical techniques as LPR and EIS give distorted data and unreliable...

  18. Modeling Corrosion Reactions of Steel in a Dilute Carbonate Solution

    Science.gov (United States)

    Eliyan, Faysal Fayez; Alfantazi, Akram

    2016-02-01

    This research models the corrosion reactions of a high-strength steel in an aerated, dilute, carbonate solution during a single-cycle voltammetry. Based on a previous study (Eliyan et al. in J Mater Eng Perform 24(6):1-8, 2015) and a literature survey, the corrosion reactions of the cathodic reduction, anodic dissolution, and passivation, as well as the interfacial interactions and the chemistry of the corrosion products are illustrated in schematics. The paper provides a visual guide on the corrosion reactions for steel in carbonate solutions based on the available mechanistic details that were reported and are still being investigated in literature.

  19. Corrosion and Stress Corrosion Behaviors of Low and Medium Carbon Steels in Agro-Fluid Media

    Directory of Open Access Journals (Sweden)

    Ayo Samuel AFOLABI

    2007-01-01

    Full Text Available Investigations were carried out to study critically the corrosion behaviour and Stress Corrosion Cracking (SCC of low and medium carbon steels in cassava and cocoa extracts by weight loss measurement and constant extension to fracture method respectively. The results obtained showed that medium carbon steel is more susceptible to corrosion than low carbon steel in both media. SCC is also more in medium carbon steel than low carbon steel in the two media under study. These deductions are due to higher carbon content in medium carbon steel coupled with various aggressive corrosion constituents contained in these media. Hydrogen embrittlement, as well as carbon cracking, is responsible for SCC of these materials in the agro-fluid media.

  20. Effect of magnetite as a corrosion product on the corrosion of carbon steel overpack

    International Nuclear Information System (INIS)

    It is necessary to clear the effects of corrosion products on the corrosion life time of carbon steel overpack for geological isolation of high-level radioactive waste (HLW). Especially, it is important to understand the effects of magnetite because magnetite as a simulated corrosion product is reported to accelerate the corrosion rate of carbon steel. In this study, corrosion tests to reproduce the acceleration of corrosion due to magnetite was performed and the mechanism of the acceleration was investigated to evaluate the effects of magnetite as a corrosion product. Based on the results of experiments, following conclusions are obtained; (1) Magnetite powder accelerates the corrosion rate of carbon steel. The main reaction of corrosion under the presence of magnetite is the reduction of Fe(III) in magnetite to Fe(II), but the reaction of hydrogen generation is also accelerated. The contribution of hydrogen generation reaction was estimated to be about 30% in the total corrosion reaction based on the experimental result of immersion test under the presence of magnetite. (2) Actual corrosion products containing magnetite generated by the corrosion of carbon steel protect the metal from the propagation of corrosion. The corrosion depth of carbon steel overpack due to magnetite was estimated to be about 1 mm based on the results of experiments. Even if the effect of magnetite is taken into the assessment of corrosion lifetime of overpack, total corrosion depth in 1000 years is estimated to be 33 mm, which is smaller than the corrosion allowance of 40 mm described in the second progress report on research and development for the geological disposal of HLW in Japan. It was concluded that the effect of magnetite on the corrosion life time of carbon steel overpack is negligible. (author)

  1. Volatile corrosion inhibitor film formation on carbon steel surface and its inhibition effect on the atmospheric corrosion of carbon steel

    International Nuclear Information System (INIS)

    A novel volatile corrosion inhibitor (VCI), bis-piperidiniummethyl-urea (BPMU), was developed for temporary protection of carbon steel. Its vapor corrosion inhibition property was evaluated under simulated operational conditions. Electrochemical impedance spectroscopy was applied to study the inhibition effect of BPMU on the corrosion of carbon steel with a thin stimulated atmospheric corrosion water layers. Adsorption of BPMU on carbon steel surfaces was investigated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The results indicate that BPMU can form a protective film on the metal surface, which protects the metal against further corrosion. The structure of the protective film was suggested as one BPMU molecule chelated with one Fe atom to form a complex with two hexa-rings

  2. Volatile corrosion inhibitor film formation on carbon steel surface and its inhibition effect on the atmospheric corrosion of carbon steel

    Science.gov (United States)

    Zhang, Da-quan; An, Zhong-xun; Pan, Qing-yi; Gao, Li-xin; Zhou, Guo-ding

    2006-11-01

    A novel volatile corrosion inhibitor (VCI), bis-piperidiniummethyl-urea (BPMU), was developed for temporary protection of carbon steel. Its vapor corrosion inhibition property was evaluated under simulated operational conditions. Electrochemical impedance spectroscopy was applied to study the inhibition effect of BPMU on the corrosion of carbon steel with a thin stimulated atmospheric corrosion water layers. Adsorption of BPMU on carbon steel surfaces was investigated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The results indicate that BPMU can form a protective film on the metal surface, which protects the metal against further corrosion. The structure of the protective film was suggested as one BPMU molecule chelated with one Fe atom to form a complex with two hexa-rings.

  3. Corrosion behavior of carbon steels under tuff repository environmental conditions

    International Nuclear Information System (INIS)

    Carbon steels may be used for borehole liners in a potential high-level nuclear waste repository in tuff in Nevada. Borehole liners are needed to facilitate emplacement of the waste packages and to facilitate retrieval of the packages, if required. Corrosion rates of low carbon structural steels AISI 1020 and ASTM A-36 were determined in J-13 well water and in saturated steam at 1000C. Tests were conducted in air-sparged J-13 water to attain more oxidizing conditions representative of irradiated aqueous environments. A limited number of irradiation corrosion and stress corrosion tests were performed. Chromium-molybdenum alloy steels and cast irons were also tested. These materials showed lower general corrosion but were susceptible to stress corrosion cracking when welded. 4 references, 4 tables

  4. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    OpenAIRE

    Renato Altobelli Antunes; Rodrigo Uchida Ichikawa; Luis Gallego Martinez; Isolda Costa

    2014-01-01

    The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron micr...

  5. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    Science.gov (United States)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  6. Corrosion of carbon steel nuclear waste containers in marine sediment

    International Nuclear Information System (INIS)

    The report describes a study of the corrosion of carbon steel nuclear waste containers in deep ocean sediments, which had the objective of estimating the metal allowance needed to ensure that the containers were not breached by corrosion for 1000 years. It was concluded that under such disposal conditions carbon steel would not be subject to localised corrosion or hydrogen embrittlement, and therefore the study concentrated on evaluating the rate of general attack. This was carried out by developing a mechanistically based mathematical model which was formulated on the conservative assumption that the corrosion would be under activation control, and would not be impeded by the formation of corrosion product layers. This model predicted that an allowance of 33 mm would be required for a 1000 year life. (author)

  7. Internal corrosion of carbon steel piping in hot aquifers service

    Directory of Open Access Journals (Sweden)

    Simičić Miloš V.

    2011-01-01

    Full Text Available Internal corrosion of carbon steel pipelines is a major problem encountered in water service. In terms of prediction of the remaining lifetime for water pipelines based on the corrosion allowance, the three main approaches are corrosion modelling, corrosion inhibitor availability, and corrosion monitoring. In this study we used two theoretical corrosion models, CASSANDRA and NORSOK M-506 of quite different origin in order to predict uniform corrosivity of hot aquifers in eight different pipelines. Because of the varying calculation criteria for the different models, these can give very different corrosion rate predictions for the same data input. This is especially true under conditions where the formation of protective films may occur, such as at elevated temperatures. The evaluation of models was conducted by comparison using weight-loss coupons and three corrosion inhibitors were obtained from commercial suppliers. The tests were performed during the 60-day period. Even though inhibitors’ efficiencies of 98% had been achieved in laboratory testing, inhibitors’ availabilities of 85% have been used due to logistics problems and other issues. The results, given in mmpy, i.e. millimeter per year, are very consistent with NORSOK M-506 prediction. This is presumably because the model considers the effect of the formation of a passive iron carbonate film at temperatures above 80 °C and significant reduction in corrosion rate. Corrosion inhibitor A showed a better performance than inhibitors B and C in all cases but the target corrosion rates of less than 0.1 mmpy were achieved for all inhibitors. The chemical type of corrosion inhibitor A is based on quaternary amines mixed with methanol, isopropyl alcohol, xylene and ethylbenzene. Based on the obtained results the carbon steel lifetime of 30 years, provided proper inhibitors are present and 3mm corrosion allowance, can be achieved for hot aquifers service with presented water compositions.

  8. Corrosion rate of carbon steel in NS tank water

    International Nuclear Information System (INIS)

    Neutron shield tank (NST) is an open tank 12.5 meters in height and 12 meters dia constructed around the research reactor. It is filled with water to (i) provide shielding from the neutron radiation, (ii) to remove the heat from the Pressure suppression system during LOCA and (iii) to act as a heat sink. NST is made of IS2062 carbon steel and it contains the stainless steel tanks, CS support structures, forged carbon steel gas cylinders, steel containment and its supports and emergency cooling down system condensers made of ASTM 350 grade LF2 carbon steel. All the equipments/systems located inside NST are painted with epoxy paint. NST is filled up 12 meters ie with 1200 m3 of water. The water chemistry parameters and microbiological parameters and corrosion rate of carbon steel materials in NST water at various water chemistry and various depths are discussed in the paper. (author)

  9. Analysis of corrosion products of carbon steel in wet bentonite

    International Nuclear Information System (INIS)

    As a part of evaluation of the long-term durability for the overpack containers for high-level radioactive waste, we have conducted corrosion tests for carbon steel in wet bentonite, a candidate buffer material. The corrosion rates were evaluated by weight difference of carbon steel and corrosion products were analyzed by Fourier transform infrared spectroscopy (FT-IR) and colorimetry. At 40degC, the corrosion rate of carbon steel in wet bentonite was smaller than that in pure water. At 95degC, however, the corrosion rate in wet bentonite was much higher than that in pure water. This high corrosion rate in wet bentonite at 95degC was considered to result from evaporation of moisture in bentonite in contact with the metal. This evaporation led to dryness and then to shrinkage of the bentonite, which generated ununiform contact of the metal with bentonite. Probably, this ununiform contact promoted the local corrosion. The locally corroded parts of specimen in wet bentonite at 95degC were analyzed by Fourier transform infrared microspectroscopy (micro-FT-IR), and lepidocrocite γ-FeO(OH) was found as well as goethite α-FeO(OH). In wet bentonite at 95degC, hematite α-Fe2O3 was identified by means of colorimetry. (author)

  10. General corrosion of carbon steels in high temperature water

    International Nuclear Information System (INIS)

    This short paper seeks to provide a summary of the main knowledge about the general corrosion of carbon steels in high temperature water. In pure water or slightly alkaline deaerated water, steels develop a protective coating of magnetite in a double layer (Potter and Mann oxide) or a single layer (Bloom oxide). The morphology of the oxide layer and the kinetics of corrosion depend on the test parameters controlling the solubility of iron. The parameters exercising the greatest influence are partial hydrogen pressure and mass transfer: hydrogen favours the solubilization of the magnetite; the entrainment of the dissolved iron prevents a redeposition of magnetite on the surface of the steel. Cubic or parabolic in static conditions, the kinetics of corrosion tends to be linear in dynamic conditions. In dynamic operation, corrosion is at least one order of magnitude lower in water with a pH of 10 than in pure water with a pH of 7. The activation energy of corrosion is 130 kJ/mol (31 kcal/mol). This results in the doubling of corrosion at around 300 deg C for a temperature increase of 15 deg C. Present in small quantities (100-200 ppb), oxygen decreases general corrosion but increases the risk of pitting corrosion - even for a low chloride content - and stress corrosion cracking or corrosion-fatigue. The steel composition has probably an influence on the kinetics of corrosion in dynamic conditions; further work would be required to clarify the effect of some residual elements. (author). 31 refs., 9 figs., 2 tabs

  11. Corrosion of Carbon Steel and Corrosion-Resistant Rebars in Concrete Structures Under Chloride Ion Attack

    Science.gov (United States)

    Mohamed, Nedal; Boulfiza, Mohamed; Evitts, Richard

    2013-03-01

    Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., highway bridges, marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed to avoid these high-cost repairs. Thus, it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements. This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three-electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4™ potentiostat manufactured by Gamry Instruments (Warminster, PA). DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution.

  12. Corrosion behaviour of carbon steel in the Tournemire clay

    International Nuclear Information System (INIS)

    Carbon steels are possible materials for the fabrication of nuclear waste containers for long term geological disposal in argillaceous environments. Experimental studies of the corrosion behaviour of such materials has been conducted in various conditions. Concerning the numerous laboratory experiments, these conditions (water and clay mixture or compacted clay) mainly concern the bentonite clay that would be used for the engineered barrier. On the opposite, only few in-situ experiments has been conducted directly in the local clay of the repository site (such as Boom clay, etc.). In order to better estimate the corrosion behaviour of carbon steels in natural clay site conditions, an experimental study has been conducted jointly by EDF and IRSN in the argillaceous French site of Tournemire. In this study, A42 carbon steel specimens have been exposed in 3 different zones of the Tournemire clay formation. The first type of environmental conditions concerns a zone where the clay has not been affected by the excavation (EDZ) of the main tunnel neither by the main fracture zone of the clay formation. The second and third ones are located in the EDZ of the tunnel. In the second zone, an additional aerated water flows from the tunnel, whereas it does not in the third place. Some carbon steel specimens have been extracted after several years of exposure to these conditions. The average corrosion rate has been measured by the weight loss technique and the pitting corrosion depth has been evaluated under an optical microscope. Corrosion products have also been characterised by scanning electron microscopy and X-ray diffraction technique. Results are then discussed regarding the surrounding environmental conditions. Calculations of the oxygen transport from the tunnel through the clay and of the clay re-saturation can explain, in a first approach, the corrosion behaviour of the carbon steel in the different tested zones. (authors)

  13. In situ 3D monitoring of corrosion on carbon steel and ferritic stainless steel embedded in cement paste

    International Nuclear Information System (INIS)

    Highlights: • The morphology of the corrosion of steel in cement paste was studied in situ. • During galvanostatic corrosion, carbon steel reinforcement corroded homogeneously. • On ferritic stainless steel, deep corrosion pits formed and caused wider cracks. • The measured rate of steel loss correlated well with Faraday’s law of electrolysis. - Abstract: In a X-ray microcomputed tomography study, active corrosion was induced by galvanostatically corroding steel embedded in cement paste. The results give insight into corrosion product build up, crack formation, leaching of products into the cracks and voids, and differences in morphology of corrosion attack in the case of carbon steel or stainless steel reinforcement. Carbon steel was homogeneously etched away with a homogeneous layer of corrosion products forming at the steel/cement paste interface. For ferritic stainless steel, pits were forming, concentrating the corrosion products locally, which led to more extensive damage on the cement paste cover

  14. Microbial corrosion of carbon steel by sulfate-reducing bacteria:

    DEFF Research Database (Denmark)

    Nielsen, Lars Vendelbo; Hilbert, Lisbeth Rischel

    1997-01-01

    Electrochemical measurements (EIS and DC-polarisation curves) have been conducted on carbon steel coupons exposed in SRB-active environments. Results from EIS measurements show that very large interfacial capacities are found in such systems, and consequently high capacitive currents are to be ex...... misleading conclusion that increasing corrosion rates are caused by cathodic depolarisation in SRB-active environments....

  15. MICROBIAL CORROSION OF MILD AND MEDIUM CARBON STEELS

    Directory of Open Access Journals (Sweden)

    J. E. O. OVRI

    2013-10-01

    Full Text Available The role of bacteria in the corrosion of mild and medium carbon steels is reported. The steels were exposed to anaerobic and aerobic, and fresh water (control environments. The corrosion rates were evaluated at intervals of seven days for a period of 42 days using weight loss and electrochemical methods. The corroded specimens were visually examined and majorities were found to have undergone general corrosion in the three environments (aerobic, anaerobic, and fresh water. The mild steel was found to corrode more than the medium carbon steel in anaerobic environment-mild steel: 6.43×10-4 mpy and -0.93 mV, due to limited available oxygen whilst it had -0.89 mV in aerobic and -0.77 mV in the fresh water. The medium carbon steel had -5.30×10-4 mpy and -0.91 mV in anaerobic: -0.84mV in aerobic and -0.74mV in freshwater.

  16. Corrosion of a carbon steel in simulated liquid nuclear wastes

    International Nuclear Information System (INIS)

    This work is part of a collaboration agreement between CNEA (National Atomic Energy Commission of Argentina) and USDOE (Department of Energy of the United States of America), entitled 'Tank Corrosion Chemistry Cooperation', to study the corrosion behavior of carbon steel A537 class 1 in different simulated non-radioactive wastes in order to establish the safety concentration limits of the tank waste chemistry at Hanford site (Richland-US). Liquid high level nuclear wastes are stored in tanks made of carbon steel A537 (ASTM nomenclature) that were designed for a service life of 20 to 50 years. A thickness reduction of some tank walls, due to corrosion processes, was detected at Hanford site, beyond the existing predicted values. Two year long-term immersion tests were started using non radioactive simulated liquid nuclear waste solutions at 40 C degrees. This work extends throughout the first year of immersion. The simulated solutions consist basically in combinations of the 10 most corrosion significant chemical components: 5 main components (NaNO3, NaCl, NaF, NaNO2 and NaOH) at three concentration levels and 5 secondary components at two concentration levels. Measurements of the general corrosion rate with time were performed for carbon steel coupons, both immersed in the solutions and in the vapor phases, using weight loss and electrochemistry impedance spectroscopy techniques. Optic and scanning electron microscopy examination, analysis of U-bend samples and corrosion potential measurements, were also done. Localized corrosion susceptibility (pitting and crevice corrosion) was assessed in isolated short-term tests by means of cyclic potentiodynamic polarization curves. The effect of the simulated waste composition on the corrosion behavior of A537 steel was studied based on statistical analyses. The Surface Response Model could be successfully applied to the statistical analysis of the A537 steel corrosion in the studied solutions. General corrosion was not

  17. Corrosion fatigue behavior of carbon steel in drilling fluids

    Energy Technology Data Exchange (ETDEWEB)

    Chaoyang, F.; Jiashen, Z. [Huazhong Univ. of Science and Technology, Wuhan (China)

    1998-08-01

    Corrosion fatigue of carbon steel (CS) in drilling fluids was studied using a self-made rotary bending corrosion fatigue testing apparatus under simulated drilling conditions. Mechanisms of the effects of cyclic stress, chloride (Cl{sup {minus}}), sulfide (S{sup 2{minus}}), and pH of drilling fluids on corrosion fatigue of CS as well as the inhibiting action of the imidazoline inhibitor and oxygen (O{sub 2}) scavenger sodium sulfite (Na{sub 2}SO{sub 3}) on corrosion fatigue were studied. Results showed Cl{sup {minus}} and S{sup 2{minus}} promoted corrosion fatigue crack initiation and growth. Fatigue life was lengthened after reducing subjected stress, increasing the pH of the drilling fluids, or adding the inhibitor and O{sub 2} scavenger.

  18. An evaluation of carbon steel corrosion under stagnant seawater conditions.

    Science.gov (United States)

    Lee, Jason S; Ray, Richard I; Lemieux, Edward J; Falster, Alexander U; Little, Brenda J

    2004-01-01

    Corrosion of 1020 carbon steel coupons in natural seawater over a 1-year period was more aggressive under strictly anaerobic stagnant conditions than under aerobic stagnant conditions as measured by weight loss and instantaneous corrosion rate (polarization resistance). Under oxygenated conditions, a two-tiered oxide layer of lepidocrocite/goethite formed. The inner layer was extremely tenacious and resistant to acid cleaning. Under anaerobic conditions, the corrosion product was initially a non-tenacious sulphur-rich corrosion product, mackinawite, with enmeshed bacteria. As more sulphide was produced the mackinawite was transformed to pyrrhotite. In both aerobic and anaerobic exposures, corrosion was more aggressive on horizontally oriented coupons compared to vertically oriented samples. PMID:15621645

  19. Carbon exchange between steel and sodium as a corrosion phenomenon

    International Nuclear Information System (INIS)

    New analytical methods are applied to measure carbon in liquid sodium in the concentration range below 1 μg C/gNa. The carbon exchange between sodium and austenitic steel under decarburising conditions can be understood on the basis of the results of these analyses. The decarburisation of austenitic steel by sodium may cause a corrosive effect of the surface region of the materials. Some tests with the steel no. 1.4948 have demonstrated a reduction of its creep-rupture strength at 550deg C. The corrosion due to decarburisation proceeds slowly, specimens with a larger diameter were not affected, a significant reduction of the creep-rupture strength did not occur. (orig.)

  20. Mechanical Properties and Corrosion Behavior of Low Carbon Steel Weldments

    Directory of Open Access Journals (Sweden)

    Mohamed Mahdy

    2013-01-01

    Full Text Available This research involves studying the mechanical properties and corrosion behavior of “low carbon steel” (0.077wt% C before and after welding using Arc, MIG and TIG welding. The mechanical properties include testing of microhardness, tensile strength, the results indicate that microhardness of TIG, MIG welding is more than arc welding, while tensile strength in arc welding more than TIG and MIG.The corrosion behavior of low carbon weldments was performed by potentiostat at scan rate 3mV.sec-1 in 3.5% NaCl to show the polarization resistance and calculate the corrosion rate from data of linear polarization by “Tafel extrapolation method”. The results indicate that the TIG welding increase the corrosion current density and anodic Tafel slop, while decrease the polarization resistance compared with unwelded low carbon steel. Cyclic polarization were measured to show resistance of specimens to pitting corrosion and to calculate the forward and reveres potentials. The results show shifting the forward, reverse and pitting potentials toward active direction for weldments samples compared with unwelded sample.

  1. In situ 3D monitoring of corrosion on carbon steel and ferritic stainless steel embedded in cement paste

    KAUST Repository

    Itty, Pierre-Adrien

    2014-06-01

    In a X-ray microcomputed tomography study, active corrosion was induced by galvanostatically corroding steel embedded in cement paste. The results give insight into corrosion product build up, crack formation, leaching of products into the cracks and voids, and differences in morphology of corrosion attack in the case of carbon steel or stainless steel reinforcement. Carbon steel was homogeneously etched away with a homogeneous layer of corrosion products forming at the steel/cement paste interface. For ferritic stainless steel, pits were forming, concentrating the corrosion products locally, which led to more extensive damage on the cement paste cover. © 2014 Elsevier Ltd.

  2. Corrosion Behavior of Carbon Steels in CCTS Environment

    Directory of Open Access Journals (Sweden)

    M. Cabrini

    2016-01-01

    Full Text Available The paper reports the results of an experimental work on the effect of steel microstructures on morphology and protectiveness of the corrosion scale formed in water saturated by supercritical CO2. Two HSLA steels were tested. The microstructures were modified by means of different heat treatments. Weight loss was measured after exposure at CO2 partial pressure of 80 bar and 60°C temperature. The morphology of the scale was analyzed by means of scanning electron microscope (SEM energy-dispersive X-ray spectroscopy (EDX. Cathodic potentiodynamic tests were carried out on precorroded specimens for evaluating the effect of preformed scales on cathodic polarization curves in CO2 saturated sulphuric acid solution at pH 3, which is the value estimated for water saturated by supercritical CO2. The results are discussed in order to evaluate the effect of iron carbide network on scale growth and corrosion rate. Weight loss tests evidenced average corrosion rate values in the range 1–2.5 mm/y after 150-hour exposure. The presence of thick siderite scale significantly reduces the corrosion rate of carbon steel. A slight decrease of the corrosion rate was observed as the scale thickness increases and moving from martensite to microstructures containing carbides.

  3. The kinetics of pitting corrosion of carbon steel

    International Nuclear Information System (INIS)

    This report describes progress between April 1986 and May 1987 in a programme studying the kinetics of pitting corrosion in carbon steel containers for the disposal of high level nuclear waste in a granitic repository. Experimental studies are being undertaken with the following objectives: (a) To improve the validation of a mathematical model for the propagation of pitting corrosion. (b) To develop an improved statistical method for analysing experimental pit growth data to take account of the difference in area of laboratory specimens and full size waste containers. (c) To estimate the maximum period during which pitting attack is feasible under repository conditions by calculating the time during which the diffusion of oxygen to the containers will be sufficient to maintain carbon steel in its passive state. Work in the first 14 months of the project has concentrated on (b) and to a lesser extent on (c). (orig./MM)

  4. Nanocrystallization of aluminized surface of carbon steel for enhanced resistances to corrosion and corrosive wear

    International Nuclear Information System (INIS)

    Aluminizing is often used to improve steel's resistances to corrosion, oxidation and wear. This article reports our recent attempts to further improve aluminized carbon steel through surface nanocrystallization for higher resistances to corrosion and corrosive wear. The surface nanocrystallization was achieved using a process combining sandblasting and recovery heat treatment. The entire surface modification process includes dipping carbon steel specimens into a molten Al pool to form an Al coat, subsequent diffusion treatment at elevated temperature to form an aluminized layer, sandblasting to generate dislocation network or cells, and recovery treatment to turn the dislocation cells into nano-sized grains. The grain size of the nanocrystallized aluminized surface layer was in the range of 20-100 nm. Electrochemical properties, electron work function (EWF), and corrosive wear of the nanocrystalline alloyed surfaces were investigated. It was demonstrated that the nanocrystalline aluminized surface of carbon steel exhibited improved resistances to corrosion, wear and corrosive wear. The passive film developed on the nanocrystallized aluminized surface was also evaluated in terms of its mechanical properties and adherence to the substrate.

  5. Nanocrystallization of aluminized surface of carbon steel for enhanced resistances to corrosion and corrosive wear

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [Dept. of Materials Physical and Chemical, University of Science and Technology Beijing, Beijing 100083 (China); Dept. of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Li, D.Y., E-mail: dongyang.li@ualberta.c [Dept. of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Shang, C.J. [Dept. of Materials Physical and Chemical, University of Science and Technology Beijing, Beijing 100083 (China)

    2009-12-15

    Aluminizing is often used to improve steel's resistances to corrosion, oxidation and wear. This article reports our recent attempts to further improve aluminized carbon steel through surface nanocrystallization for higher resistances to corrosion and corrosive wear. The surface nanocrystallization was achieved using a process combining sandblasting and recovery heat treatment. The entire surface modification process includes dipping carbon steel specimens into a molten Al pool to form an Al coat, subsequent diffusion treatment at elevated temperature to form an aluminized layer, sandblasting to generate dislocation network or cells, and recovery treatment to turn the dislocation cells into nano-sized grains. The grain size of the nanocrystallized aluminized surface layer was in the range of 20-100 nm. Electrochemical properties, electron work function (EWF), and corrosive wear of the nanocrystalline alloyed surfaces were investigated. It was demonstrated that the nanocrystalline aluminized surface of carbon steel exhibited improved resistances to corrosion, wear and corrosive wear. The passive film developed on the nanocrystallized aluminized surface was also evaluated in terms of its mechanical properties and adherence to the substrate.

  6. Microbiological Corrosion in Low Carbon Steels

    Directory of Open Access Journals (Sweden)

    O. Medina–Custodio

    2009-01-01

    Full Text Available The Microbiologically Induced Corrosion affects several industries, such as oil industry where it is estimated that 20% to 30% pipes failures are related with microorganism . The chemical reactions generate ions transfer, this validate the use of electrochemical techniques for its analysis. Coupons submerged in a nutritional medium with presence and absence of three different microorganisms during two periods, 48 hours and 28 days we restudied. Polarization resistance (Rp and Electrochemical Impedance Spectroscopy (EIS techniques we re applied to determine the corrosivity of the systems. The results show a greater corrosive effect of abiotic system, this indicates a microorganisms protection effect to the metal, opposite to the first hypothesis. This result was ratified observing surfaces coupons by using Scanning Electron Microscopy (SEM technique. A possible mechanism based on Evans – Tafel graph is proposed to explain inhibitor microorganism effect.

  7. Corrosion Products and Formation Mechanism During Initial Stage of Atmospheric Corrosion of Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    XIAO Kui; DONG Chao-fang; LI Xiao-gang; WANG Fu-ming

    2008-01-01

    The formation and development of corrosion products on carbon steel surface during the initial stage of atmospheric corrosion in a laboratory simulated environment have been studied by scanning electron microscopy (SEM)and Raman spectroscopy.The results showed that two different shapes of corrosion products,that is,ring and chain,were formed in the initial stage of corrosion.MnS clusters were found in the nuclei of corrosion products at the active local corrosion sites.The ring-shaped products were composed of lepidocrocite (γ-FeOOH) and maghemite(γ-Fe2 O3) transformed from lepidocrocite.The chain-type products were goethite (α-FeOOH).A formation mechanism of the corrosion products is proposed.

  8. Corrosion behavior of carbon steel in wet Na-bentonite medium

    International Nuclear Information System (INIS)

    Corrosion behaviors of carbon steel in wet Na-bentonite medium were studied. Corrosion rate of carbon steel in wet bentonite was measured to be 20 μm/yr at 25 deg C using the AC impedance technique. This value is agreed with that obtained by weight loss at 40 deg C for 1 year. The effect of bicarbonate ion on the corrosion of carbon steel in wet bentonite was also evaluated. The carbon steels in wet bentonite having 0.001, 0.01, and 0.1 M concentration of bicarbonate ion gave corrosion rates of 20, 8, and 0.2 μm/yr, respectively. Corrosion potentials of specimens were also measured and compared with the AC impedance results. Both results indicated that bicarbonate ion could effectively reduce the corrosion rate of carbon steels in bentonite due to the formation of protective layer on the carbon steel. (author)

  9. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    Directory of Open Access Journals (Sweden)

    Renato Altobelli Antunes

    2014-01-01

    Full Text Available The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron microscopy. The main product found was lepidocrocite. Goethite and magnetite were also found on the corroded specimens but in lower concentrations. The results showed that the accelerated test based on the ASTM B117 procedure presented poor correlation with the atmospheric corrosion tests whereas an alternated fog/dry cycle combined with UV radiation exposure provided better correlation.

  10. Influence of Heat Treatments on the Corrosion Resistance of Medium -Carbon Steel using Sulfuric Spring Water

    Directory of Open Access Journals (Sweden)

    Ikhlas Basheer

    2013-04-01

    Full Text Available The corrosion is one of the important problems that may be occur to the parts of machinery and equipment after manufactured and when used as a result of exposure to corrosive media. Plain-carbon steel is considered as one of the most common minerals used in industrial applications. Some of heat treatments can have direct effect on the corrosion rate of steel by building up galvanic corrosion cells between its microscopic phases. Therefore, to adopt one of kinds of the plain-carbon steel and the most commonly used in industry to be study subject, that is medium carbon steel and took samples of this steel has been treated thermally in three methods which the normalising, annealing, and hardening .The corrosive media used in the research is Sulfuric Spring, it contains many chemical compounds to show its influence on the corrosion of steel. The weight loss method is used to determine corrosion rate and to compare between the results obtained, show that the greatest corrosion resistance of the annealed steel and the corrosion resistance of the hardened steel is the lowest while the corrosion  resistance of the normalised steel is in-between them.         Calcium carbonate was formed on the metal surface which acts as an isolating layer which decrease corrosion rate with time

  11. Corrosion inhibition of carbon steel by extract of Buddleia perfoliata

    Directory of Open Access Journals (Sweden)

    ROY LOPES-SESENES

    2012-06-01

    Full Text Available Buddleia perfoliata leaves extract has been investigated as a carbon steel corrosion inhibitor in 0.5 M sulfuric acid by using polarization curves, electrochemical impedance spectroscopy and weight-loss tests at different concentrations (0, 100, 200, 300, 400 and 500 ppm and temperatures, namely 25, 40 and 60 °C. Results showthat inhibition efficiency increases as the inhibitor concentration increases, decreases with temperature, and reaches a maximum value after 12 h of exposure, decreasing with a further increase in the exposure time. It was found that the inhibitory effect is due to the presence of tannines on this extract.

  12. Corrosion Inhibition of Carbon Steel in Chloride and Sulfate Solutions

    Directory of Open Access Journals (Sweden)

    Amr Ahmed Elsayed

    2016-02-01

    Full Text Available Corrosion is a major problem in industry and in infrastructure; a huge sum of expenditure every year is spent on preventing, retarding, and repairing its damages. This work studies the engineering of an inhibitor for carbon steel metal used in the cooling systems containing high concentration of chloride and sulfate ions. For this purpose, the synergy between the dichromate, molybdate and nitrite inhibitors is examined and optimized to the best results. Moreover, care was taken that the proposed inhibitor is compliant with the environmental laws and regulations.

  13. Corrosion inhibition of carbon steel by sodium metavanadate

    Directory of Open Access Journals (Sweden)

    VIJAYA GOPAL SRIBHARATHY

    2012-08-01

    Full Text Available The inhibition efficiency of sodium metavanadate (SMV-adipic acid (AA system in controlling corrosion of carbon steel in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight-loss method; 250 ppm of SMV exhibits inhibition efficiency of 56 %. Addition of adipic acid to SMV improves the inhibition efficiency of the system. The formulation consisting of 250 ppm of SMV and 250 ppm of adipic acid has inhibition efficiency of 98 %. A synergistic effect exists between SMV and adipic acid with the synergism parameters greater than 1. Mecha¬nistic aspects of corrosion inhibition have been studied by electrochemical methods like potentiodynamic polarization and electrochemical impedance spectroscopy. FTIR spectra reveal that the protective film consists of Fe2+-SMV complex and Fe2+-adipic acid complex. The protective film has been analyzed by fluorescence spectra, SEM and EDAX.

  14. Boric acid corrosion of carbon and low alloy steels

    International Nuclear Information System (INIS)

    Leakage of borated water from the reactor coolant system of pressurized water reactors (PWRs) and the resulting corrosion of carbon and low alloy steel components are concerns that have been addressed by utilities for many years. Significant corrosion has been observed in instances where such leakage has gone undetected for several months. In 1990, the B and W Owners Group (B and WOG) sponsored a test program to determine the levels of wastage that are possible when primary water leakage occurs. In this test program, carbon and stainless steel specimens were exposed to borated water at temperatures from 300 F to 550 F. Initial boric acid concentration was controlled within the limits of 13,000 to 15,000 ppm (as H3BO3) with 1.0--2.0 ppm lithium (as LiOH) added to duplicate the primary water chemistry. Testing was performed to determine the degree of attack caused by a leak traveling along a pipe both with and without insulation. These tests show the importance of temperature and boric acid concentrations on the wastage that can occur from such a leak

  15. 77 FR 13093 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2012-03-05

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... administrative review of the countervailing duty (``CVD'') order on corrosion-resistant carbon steel flat... Review'' below. \\1\\ See Corrosion-Resistant Carbon Steel Flat Products from the Republic of...

  16. 77 FR 31877 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five...

    Science.gov (United States)

    2012-05-30

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five... duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to lead...

  17. 77 FR 24221 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission...

    Science.gov (United States)

    2012-04-23

    ... COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission... countervailing duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to...

  18. A Corrosion Sensor for Monitoring the Early-Stage Environmental Corrosion of A36 Carbon Steel

    Directory of Open Access Journals (Sweden)

    Dong Chen

    2014-08-01

    Full Text Available An innovative prototype sensor containing A36 carbon steel as a capacitor was explored to monitor early-stage corrosion. The sensor detected the changes of the surface- rather than the bulk- property and morphology of A36 during corrosion. Thus it was more sensitive than the conventional electrical resistance corrosion sensors. After being soaked in an aerated 0.2 M NaCl solution, the sensor’s normalized electrical resistance (R/R0 decreased continuously from 1.0 to 0.74 with the extent of corrosion. Meanwhile, the sensor’s normalized capacitance (C/C0 increased continuously from 1.0 to 1.46. X-ray diffraction result indicates that the iron rust on A36 had crystals of lepidocrocite and magnetite.

  19. Zn-10.2% Fe coating over carbon steel atmospheric corrosion resistance. Comparison with zinc coating

    International Nuclear Information System (INIS)

    Zn-10.2% Fe galvanized coating versus hot galvanized coating over carbon steel corrosion performance has been studied. Different periods of atmospheric exposures in various Valencia Community sites, and salt spray accelerated test have been done. Carbon steel test samples have been used simultaneously in order to classify exposure atmosphere corrosivity, and environmental exposure atmosphere characteristics have been analyzed. Corrosion Velocity versus environmental parameters has been obtained. (Author) 17 refs

  20. Corrosion behaviour of carbon steel in contact with bentonite under anaerobic condition

    International Nuclear Information System (INIS)

    Full text of publication follows: The geological disposal system of high-level radioactive waste (HLW) consists of vitrified waste, overpack, buffer material and surrounding rock. In this system, overpack is required to prevent the contact of groundwater from vitrified waste for 1000 years. The main factor limiting this function is corrosion due to the contact with groundwater infiltrated to buffer material which is the mixture of bentonite and sand. Carbon steel is selected as one of the candidate materials for overpacks in Japan as a corrosion allowance metal. The deep underground environment for geological disposal of HLW is expected to be relatively oxidizing condition at the initial stage of repository, but it will be returned to reducing as the consumption of oxygen by the corrosion of overpack and the redox reactions with the minerals in buffer material. It is necessary to understand the corrosion behaviour of carbon steel under such anaerobic condition for the lifetime prediction of carbon steel overpack. In this study, immersion tests of carbon steel in buffer material were performed in nitrogen atmosphere in which oxygen gas concentration was controlled less than 1 ppm. The corrosion rates of carbon steel were measured by weight loss of the specimens and the corrosion products were analysed by SEM, XRD and EPMA. For investigating the influence of welding of overpack, welded samples by electron-beam welding (EBW) were used in some of the tests. Synthetic sea water (SSW) and aqueous solutions containing bicarbonate ion and chloride ion were chosen as simulated groundwater. The results indicated that the corrosion form of carbon steel under anaerobic condition was uniform corrosion and no localised corrosion such as pitting, crevice corrosion was found within our experimental conditions. Ferrous carbonate such as FeCO3 or Fe2(OH)2CO3 was identified as crystalline corrosion products by XRD. Although the corrosion rate was affected by test solution and buffer

  1. Corrosion behaviour of carbon steel in contact with bentonite under anaerobic condition

    Energy Technology Data Exchange (ETDEWEB)

    Naoki, Taniguchi; Susumu, Kawakami [Japan Nuclear Cycle Development Institute, Tokai-mura, Ibaraki (Japan); Manabu, Kawasaki; Mitsuru, Kubota [Inspection Development Corporation, Tokai-mura, Ibaraki (Japan)

    2004-07-01

    Full text of publication follows: The geological disposal system of high-level radioactive waste (HLW) consists of vitrified waste, overpack, buffer material and surrounding rock. In this system, overpack is required to prevent the contact of groundwater from vitrified waste for 1000 years. The main factor limiting this function is corrosion due to the contact with groundwater infiltrated to buffer material which is the mixture of bentonite and sand. Carbon steel is selected as one of the candidate materials for overpacks in Japan as a corrosion allowance metal. The deep underground environment for geological disposal of HLW is expected to be relatively oxidizing condition at the initial stage of repository, but it will be returned to reducing as the consumption of oxygen by the corrosion of overpack and the redox reactions with the minerals in buffer material. It is necessary to understand the corrosion behaviour of carbon steel under such anaerobic condition for the lifetime prediction of carbon steel overpack. In this study, immersion tests of carbon steel in buffer material were performed in nitrogen atmosphere in which oxygen gas concentration was controlled less than 1 ppm. The corrosion rates of carbon steel were measured by weight loss of the specimens and the corrosion products were analysed by SEM, XRD and EPMA. For investigating the influence of welding of overpack, welded samples by electron-beam welding (EBW) were used in some of the tests. Synthetic sea water (SSW) and aqueous solutions containing bicarbonate ion and chloride ion were chosen as simulated groundwater. The results indicated that the corrosion form of carbon steel under anaerobic condition was uniform corrosion and no localised corrosion such as pitting, crevice corrosion was found within our experimental conditions. Ferrous carbonate such as FeCO{sub 3} or Fe{sub 2}(OH){sub 2}CO{sub 3} was identified as crystalline corrosion products by XRD. Although the corrosion rate was affected by

  2. Corrosion-electrochemical behavior of diffusionally chromized carbon steels in aggressive environments

    International Nuclear Information System (INIS)

    One generalized the experimental data of many year investigations into corrosion-electrochemical behavior of diffusionally chromized carbon steels (steel 45) depending on diffusion saturation process factors and on composition of saturating powder mixture. One formulated compositions of saturating powder enabling to improve essentially corrosion resistance of treated carbon steels in the aggressive environments. Resistance is improved due to introduction of calcium hydride into saturating mixture

  3. Corrosion-resistant Foamed Cements for Carbon Steels

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Gill, S.; Pyatina, T., Muraca, A.; Keese, R.; Khan, A.; Bour, D.

    2012-12-01

    The cementitious material consisting of Secar #80, Class F fly ash, and sodium silicate designed as an alternative thermal-shock resistant cement for the Enhanced Geothermal System (EGS) wells was treated with cocamidopropyl dimethylamine oxide-based compound as foaming agent (FA) to prepare numerous air bubble-dispersed low density cement slurries of and #61603;1.3 g/cm3. Then, the foamed slurry was modified with acrylic emulsion (AE) as corrosion inhibitor. We detailed the positive effects of the acrylic polymer (AP) in this emulsion on the five different properties of the foamed cement: 1) The hydrothermal stability of the AP in 200 and #61616;C-autoclaved cements; 2) the hydrolysis-hydration reactions of the slurry at 85 and #61616;C; 3) the composition of crystalline phases assembled and the microstructure developed in autoclaved cements; 4) the mechanical behaviors of the autoclaved cements; and, 5) the corrosion mitigation of carbon steel (CS) by the polymer. For the first property, the hydrothermal-catalyzed acid-base interactions between the AP and cement resulted in Ca-or Na-complexed carboxylate derivatives, which led to the improvement of thermal stability of the AP. This interaction also stimulated the cement hydration reactions, enhancing the total heat evolved during cement’s curing. Addition of AP did not alter any of the crystalline phase compositions responsible for the strength of the cement. Furthermore, the AP-modified cement developed the porous microstructure with numerous defect-free cavities of disconnected voids. These effects together contributed to the improvement of compressive-strength and –toughness of the cured cement. AP modification of the cement also offered an improved protection of CS against brine-caused corrosion. There were three major factors governing the corrosion protection: 1) Reducing the extents of infiltration and transportation of corrosive electrolytes through the cement layer deposited on the underlying CS

  4. The effect of oil on carbon dioxide corrosion inhibition on carbon steel - potential for improved corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Foss, Martin Smedstad

    2009-07-01

    The search for robust and cost efficient ways to prevent internal corrosion of carbon steel piping and equipment in oil and gas production and transportation has lead to the development of highly sophisticated CO{sub 2} corrosion inhibitor products. This thesis studies oil wetting and corrosion inhibitor performance on bare steel and steel with corrosion product deposits on the surface, in the presence of a refined, low aromatic hydrocarbon oil. Three surfactants were used in the experiments; two commercial inhibitor base chemicals; an oleic imidazoline salt (OI) and a phosphate ester (PE), and cetyl trimethyl ammonium bromide (CTAB), a well characterized quaternary ammonium compound. Adsorption characteristics of the inhibitors on corroding iron and FeCO{sub 3} particles were also studied. Polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) techniques were used to study the effect of the oil on the performance of the inhibitors. The performance testing was done on corroding carbon steel without any surface deposits and on carbon steel with either ferrous carbonate (FeCO{sub 3}) or ferric corrosion products on the surface. The results showed that the addition of oil in the inhibitor tests had a significant, positive effect on the performance of the two commercial corrosion inhibitors; decrease in corrosion rate of about one order of magnitude compared to the rate without oil was found. Based on the EIS data it was concluded that the improved performance was caused by a modification of the inhibitor film and not the formation of a macroscopic oil film on the steel surface. Indications of oil wetting of the steel surface were only found when ferric corrosion products were present and OI was used as the inhibitor. No such effects were seen on bare steel or on FeCO{sub 3} covered surfaces. Contact angle measurements and dispersion tests were used to investigate the effect of the inhibitors on the wettability of the three types of surfaces when

  5. The effect of oil on carbon dioxide corrosion inhibition on carbon steel - potential for improved corrosion protection

    International Nuclear Information System (INIS)

    The search for robust and cost efficient ways to prevent internal corrosion of carbon steel piping and equipment in oil and gas production and transportation has lead to the development of highly sophisticated CO2 corrosion inhibitor products. This thesis studies oil wetting and corrosion inhibitor performance on bare steel and steel with corrosion product deposits on the surface, in the presence of a refined, low aromatic hydrocarbon oil. Three surfactants were used in the experiments; two commercial inhibitor base chemicals; an oleic imidazoline salt (OI) and a phosphate ester (PE), and cetyl trimethyl ammonium bromide (CTAB), a well characterized quaternary ammonium compound. Adsorption characteristics of the inhibitors on corroding iron and FeCO3 particles were also studied. Polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) techniques were used to study the effect of the oil on the performance of the inhibitors. The performance testing was done on corroding carbon steel without any surface deposits and on carbon steel with either ferrous carbonate (FeCO3) or ferric corrosion products on the surface. The results showed that the addition of oil in the inhibitor tests had a significant, positive effect on the performance of the two commercial corrosion inhibitors; decrease in corrosion rate of about one order of magnitude compared to the rate without oil was found. Based on the EIS data it was concluded that the improved performance was caused by a modification of the inhibitor film and not the formation of a macroscopic oil film on the steel surface. Indications of oil wetting of the steel surface were only found when ferric corrosion products were present and OI was used as the inhibitor. No such effects were seen on bare steel or on FeCO3 covered surfaces. Contact angle measurements and dispersion tests were used to investigate the effect of the inhibitors on the wettability of the three types of surfaces when they were exposed to

  6. Stress corrosion cracking of A515 grade 60 carbon steel

    International Nuclear Information System (INIS)

    An investigation was conducted to evaluate the effect of welding method plate thickness, and subsequent stress relief treatment on the stress corrosion cracking propensity of ASTM A515 Grade 60 carbon steel plate exposed to a 5 M NaNO3 solution at 1900F for eight weeks. It was found that all weld coupons receiving no thermal stress relief treatment cracked within eight weeks; all weld coupons given a vibratory stress relief cracked within eight weeks; two of the eight weld coupons stress relieved at 6000F for one hour cracked within eight weeks; none of the weld coupons stress relieved at 11000F for one hour cracked within eight weeks; and that cracking was generally more severe in coupons fabricated from 7/8 inch plate by shielded metal arc welding than it was in coupons fabricated by other welding methods. (U.S.)

  7. 78 FR 16832 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Revocation...

    Science.gov (United States)

    2013-03-19

    ...-Year (``Sunset'') Review, 77 FR 85 (January 3, 2012). \\2\\ See Corrosion-Resistant Carbon Steel Flat... Corrosion- Resistant Carbon Steel Flat Products From Germany and Korea, 77 FR 301 (January 4, 2012). As a... Steel Flat Products From Germany and Korea, 78 FR 15376 (March 11, 2013) and Corrosion-Resistant...

  8. Corrosion of stainless and carbon steels in molten mixtures of industrial nitrates

    Energy Technology Data Exchange (ETDEWEB)

    Goods, S.H.; Bradshaw, R.W. [Sandia National Labs., Livermore, CA (United States); Prairie, M.R.; Chavez, J.M. [Sandia National Labs., Albuquerque, NM (United States)

    1994-03-01

    Corrosion behavior of two stainless steels and carbon steel in mixtures of NaNO{sub 3} and KNO{sub 3} was evaluated to determine if impurities found in commodity grades of alkali nitrates aggravate corrosivity as applicable to an advanced solar thermal energy system. Corrosion tests were conducted for 7000 hours with Types 304 and 316 stainless steels at 570C and A36 carbon steel at 316C in seven mixtures of NaNO{sub 3} and KNO{sub 3} containing variations in impurity concentrations. Corrosion tests were also conducted in a ternary mixture of NaNO{sub 3}, KNO{sub 3}, and Ca(NO{sub 3}){sub 2}. Corrosion rates were determined by descaled weight losses while oxidation products were examined by scanning electron microscopy, electron microprobe analysis, and X-ray diffraction. The nitrate mixtures were periodically analyzed for changes in impurity concentrations and for soluble corrosion products.

  9. Inhibition of carbon steel corrosion by 11-aminoundecanoic acid

    Directory of Open Access Journals (Sweden)

    Saad Ghareba

    2015-12-01

    Full Text Available The current study reports results on the investigation of the possibility of using 11-aminoundecanoic acid (AA as an inhibitor of general corrosion of carbon steel (CS in HCl under a range of experimental conditions: inhibitor concentration, exposure time, electrolyte temperature and pH and CS surface roughness. It was found that AA acts as a mixed-type inhibitor, yielding maximum inhibition efficiency of 97 %. The adsorption of AA onto the CS surface was described by the Langmuir adsorption isotherm. The corresponding apparent Gibbs free energy of AA adsorption on CS at 295 K was calculated to be −30.2 kJ mol–1. The adsorption process was found to be driven by a positive change in entropy of the system. PM-IRRAS measurements revealed that the adsorbed AA layer is amorphous, which can be attributed to the repulsion between the neighboring positively charged amine groups and a high heterogeneity of the CS surface. It was also found that the AA provides very good corrosion protection of CS of various surface roughness, and over a prolonged time.

  10. Influence of carbon steel grade on the initial attachment of bacteria and microbiologically influenced corrosion.

    Science.gov (United States)

    Javed, M A; Neil, W C; Stoddart, P R; Wade, S A

    2016-01-01

    The influence of the composition and microstructure of different carbon steel grades on the initial attachment (≤ 60 min) of Escherichia coli and subsequent longer term (28 days) corrosion was investigated. The initial bacterial attachment increased with time on all grades of carbon steel. However, the rate and magnitude of bacterial attachment varied on the different steel grades and was significantly less on the steels with a higher pearlite phase content. The observed variations in the number of bacterial cells attached across different steel grades were significantly reduced by applying a fixed potential to the steel samples. Longer term immersion studies showed similar levels of biofilm formation on the surface of the different grades of carbon steel. The measured corrosion rates were significantly higher in biotic conditions compared to abiotic conditions and were found to be positively correlated with the pearlite phase content of the different grades of carbon steel coupons. PMID:26785935

  11. Effect of silty sand in formation water on CO2 corrosion behavior of carbon steel

    Science.gov (United States)

    Liu, Wei; Dou, Juanjuan; Lu, Songle; Zhang, Peng; Zhao, Qinghe

    2016-03-01

    Corrosion behavior of carbon steel in CO2 aqueous environment containing silty sand was investigated using corrosion mass loss method, scanning electron microscopy (SEM), energy diffraction spectrum (EDS), and various electrochemical measurements. The results show that the corrosion rate of carbon steel was obviously reduced due to the existence of silty sand. Silty sand promoted the rapid heterogeneous nucleation of corrosion product FeCO3 and simultaneously decreased its grains growth. Silty sand mixed with corrosion product to form the outer layer of corrosion scale with high compactness, blocking the transport of ferrous ions and leading to the formation of the inner layer of corrosion scale without silty sand. The existence of silty sand in the outer layer of corrosion scale inhibited anodic and cathodic currents.

  12. Corrosion behaviour of carbon steel in buffer material under anaerobic condition

    International Nuclear Information System (INIS)

    The deep underground environment for geological disposal of HLW will be relatively oxidizing condition at the initial stage of repository, but it will be returned to reducing as the consumption of oxygen by the corrosion of overpack and the reactions with the minerals in buffer material. It is necessary to understand the corrosion behaviour of carbon steel under such reducing condition for the lifetime prediction of carbon steel overpack. In this study, immersion tests of carbon steel in buffer material were performed in nitrogen atmosphere in which oxygen gas concentration was controlled less than 1 ppm. The corrosion rates of carbon steel were measured by weight loss of the specimens and the corrosion products were analysed by SEM, XRD and EPMA. For investigating the influence of welding of overpack, welded samples by electron-beam welding (EBW) were used for some of the tests. Synthetic sea water (SSW) and aqueous solutions containing bicarbonate ion and chloride ion were chosen as simulated groundwater. According to the experimental results, corrosion products layer contained ferrous carbonate such as FeCO3 and Fe2(OH)2CO3. The average corrosion rates within 1 year were relatively high (4-18 μm/y), but the growths of corrosion after 1 year were decreased rapidly. The increase in average corrosion depths from 1 to 3 (or 4) years was only less than several micro-meters, and the realistic corrosion rates after 1 year were estimated to be less than 1 μm/y in many cases. There was no influence of welding on the corrosion rate of carbon steel up to 3 years of immersion period. The effects of the density of buffer material and the mixing ratio of sand in buffer material on the corrosion rate of carbon steel were also investigated in this study. (author)

  13. Corrosion monitoring of carbon steel in the bentonite in deep underground

    International Nuclear Information System (INIS)

    In previous study, a corrosion sensor has been developed and its applicability to monitoring of the corrosion behavior of carbon steel overpack has been confirmed. In this study, a simulated overpack was placed with buffer material composed mainly of bentonite in test tunnel of 350 m deep underground constructed at Horonobe underground research laboratory. The corrosion monitoring was performed by AC impedance method using the corrosion sensors embeded in the buffer material. (author)

  14. Effect of Rare Earths on Corrosion Resisting Properties of Carbon-Manganese Clean Steels

    Institute of Scientific and Technical Information of China (English)

    郭锋; 林勤; 孙学义

    2004-01-01

    Electrochemistry experiments were made on carbon-manganese clean steel with rare earths Ce and La respectively to observe corrosion parameters such as corrosion current icorr, and characteristic potential of pitting Eb. The results indicate that the rare earths have effect on corrosion resisting properties of carbon-manganese clean steel, and the optimum contents of La is about 0.011% (mass fraction) and Ce about 0.014% (mass fraction) respectively. The change of corrosion resistance is related to the action of rare earths on microstructure and effect on surface state of samples in the process of polarization.

  15. Development of corrosion rate measuring apparatus for carbon steel under reducing environment

    International Nuclear Information System (INIS)

    In order to monitor the corrosion rate of carbon steel under deep under-ground environment which is depleted with oxygen, the corrosion rate measuring apparatus using the hydrogen permeation current was developed. Inner surface of the carbon steel monitor electrode made of beverage can was coated with Ni or Pd-Ni plating, which was used as the hydrogen detecting electrode. Corrosion rate which was estimated from hydrogen permeation current well consisted with literature data. Corrosion rate in acidic solution at pH 2 after long time elapsed. (author)

  16. 77 FR 72827 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Final...

    Science.gov (United States)

    2012-12-06

    ... Carbon Steel Flat Products from Germany, 71 FR 66163 (November 13, 2006). Analysis of Comments Received... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic... on certain corrosion- resistant carbon steel flat products (``CORE'') from Germany and the...

  17. 78 FR 19210 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2013-03-29

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... carbon steel flat products from the Republic of Korea for the period January 1, 2010, through December 31...\\ See Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results...

  18. Corrosion of carbon steel, zinc and copper by air pollution in Chongqing

    Institute of Scientific and Technical Information of China (English)

    YE Di; ZHAO Da-wei; CHEN Gang-cai; ZHANG Dong-bao

    2007-01-01

    This paper presents the research on the atmospheric corrosion rates of carbon steel, zinc and copper in Chongqing, which was a corrosion subprogram of an international project, Regional Air Pollution in Developing Countries. We performed field exposure tests of carbon steel, zinc and copper at an urban site Guanyinqiao and a rural site Tieshanping inChongqing, then used grey relational analysis, based on the database of the whole corrosion project, to determine the order of the effect of environmental factors on corrosion rates of tested metals, and established dose-response functions for these three metals. The results showed that the two crucial agents of acidic environment, SO2 and H+, were common factors that contributed most to the corrosion of the tested metals. The established dose-response functions for outdoor carbon steel and zinc are proved applicable to use in Chongqing, but the function for copper needs further modifying. We employed these dose-response functions and general environmental data to elaborate the maps of corrosion rate respectively of carbon steel and zinc by geological information system (GIS) technique which help to identify areas of high corrosion damage risk. An acceptable annual average SO2 level of 21 μg/m3 for carbon steel and that of 61 μg/m3 for zinc are also put forward to control the air pollution impact on atmospheric corrosion in Chongqing urban areas.

  19. Corrosion Behavior of Carbon Steels in CCTS Environment

    OpenAIRE

    Cabrini, M; S. Lorenzi; T. Pastore

    2016-01-01

    The paper reports the results of an experimental work on the effect of steel microstructures on morphology and protectiveness of the corrosion scale formed in water saturated by supercritical CO2. Two HSLA steels were tested. The microstructures were modified by means of different heat treatments. Weight loss was measured after exposure at CO2 partial pressure of 80 bar and 60°C temperature. The morphology of the scale was analyzed by means of scanning electron microscope (SEM) energy-dispers...

  20. Welded, sandblasted, stainless steel corrugated bars in non-carbonated and carbonated mortars: A 9-year corrosion study

    OpenAIRE

    Bautista, A.; Paredes, E. C.; Álvarez, S. M.; Velasco, F.

    2016-01-01

    Three different stainless steel corrugated grades (UNS S20430, S30403 and S32205) were similar welded to stainless steel bars with the same composition and dissimilar welded to carbon steel (CS). After cleaning the welding oxides by sandblasting, the reinforcements were embedded in mortar with chlorides and some of the samples were carbonated. Corrosion activity was monitored using corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS). After 8 years of exposure, the sam...

  1. Synergistic corrosion inhibition of environment-friendly inhibitors on the corrosion of carbon steel in soft water

    International Nuclear Information System (INIS)

    Highlights: • The composite demonstrated synergistic effects and exhibited mixed-type corrosion inhibition behaviour. • The composite showed remarkable corrosion inhibition property at a relatively low dosage. • The composite functioned more environmental-friendly compared to traditional inhibitors. • The composite have been adsorbed on the carbon steel surface as a protective film against corrosion attack. - Abstract: The synergistic effect of the combination of polyaspartic acid (PASP), polyepoxysuccinic acid (PESA), polyamino polyether methylenephosphonate (PAPEMP), sodium gluconate (Glu) and Zn2+ on carbon steel corrosion was investigated using weight loss and electrochemical measurements. The combination of PASP, PESA, PAPEMP, Glu and Zn2+ is an environment-friendly inhibitor and exhibited mixed-type inhibition behaviour. The composite efficiently inhibited corrosion on carbon steel at relatively low dosages in severely corrosive soft water media. Atomic force microscopy (AFM) images and X-ray photoelectron spectroscopic (XPS) spectra further confirmed the formation of a protective film composed of the adsorbed inhibitor molecules on the carbon steel surface against corrosion attack

  2. Galvanic corrosion between carbon steel 1018 and Alloy 600 in crevice with boric acid solution

    International Nuclear Information System (INIS)

    This work dealt with the evaluation of galvanic corrosion rate in a corrosion cell having annular gap of 0.5 mm between carbon steel 1018 and alloy 600 as a function of temperature and boron concentration. Temperature and boron concentration were ranged from 110 to 300 .deg. C and 2000∼10000 ppm, respectively. After the operating temperature of the corrosion cell where the electrolyte was injected was attained at setting temperature, galvanic coupling was made and at the same time galvanic current was measured. The galvanic corrosion rate decreased with time, which was described by corrosion product such as protective film as well as boric acid deposit formed on the carbon steel with time. From the galvanic current obtained as a function of temperature and boron concentration, it was found that the galvanic corrosion rate decreased with temperature while the corrosion rate increased with boron concentration. The experimental results obtained from galvanic corrosion measurement were explained by adhesive property of corrosion product such as protective film, boric acid deposit formed on the carbon steel wall and dehydration of boric acid to be slightly soluble boric acid phase. Moreover the galvanic corrosion rate calculated using initial galvanic coupling current instead of steady state coupling current was remarked, which could give us relatively closer galvanic corrosion rate to real pressurized water reactor

  3. Characterisation of initial atmospheric corrosion carbon steels by field exposure and laboratory simulation

    International Nuclear Information System (INIS)

    The early stages of the evolution of atmospheric corrosion of carbon steels exposed in both a laboratory simulated and a natural atmosphere environment in Shenyang have been observed by in situ scanning electron microscopy. In the case of laboratory cyclic wet-dry tests, even though the chloride content level is very low, filiform corrosion is initiated in the early stage. The filiform corrosion grows in random directions, forming a network of ridges. White nodules nucleate and grow on the ridges during continued corrosion and eventually connect with each other to form the initial corrosion scale. Pits were also found on the surface beneath corrosion products. In the case of a natural atmospheric environment, both filiform corrosion and other localized corrosion, such as pitting and inter-granular attack take place in the initial stage. It is obvious that there is variety of localized corrosion in the initial stage of atmospheric corrosion

  4. Corrosion and Runoff Behavior of Carbon Steel in Simulated Acid Rain

    Institute of Scientific and Technical Information of China (English)

    Baigang AN; Xueyuan ZHANG; Enhou HAN; Honxi LI

    2004-01-01

    Under the condition of simulated rain precipitation in the laboratory, with ElS and SEM observation, the effects of pH value of simulated rain on corrosion and runoff behavior of carbon steel A3 were studied. The corrosion rate of A3 steel increased and runoff action of rain precipitation on A3 steel surface was intensified with decreasing pH value, of simulated rainwater.The runoff and corrosion traces were formed along the flowing direction of rainwater, which appeared more apparently with decreasing pH value.

  5. Control of microbiological corrosion on carbon steel with sodium hypochlorite and biopolymer.

    Science.gov (United States)

    Oliveira, Sara H; Lima, Maria Alice G A; França, Francisca P; Vieira, Magda R S; Silva, Pulkra; Urtiga Filho, Severino L

    2016-07-01

    In the present work, the interaction of a mixture of a biocide, sodium hypochlorite (NaClO), and a biopolymer, xanthan, with carbon steel coupons exposed to seawater in a turbulent flow regime was studied. The cell concentrations, corrosion rates, biomasses, and exopolysaccharides (EPSs) produced on the coupon surfaces with the various treatments were quantified. The corrosion products were evaluated using X-ray diffraction (XRD), and the surfaces of steels were analysed by scanning electron microscopy (SEM). The results indicated that xanthan and the hypochlorite-xanthan mixture reduced the corrosion rate of steel. PMID:26997238

  6. 77 FR 44213 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea...

    Science.gov (United States)

    2012-07-27

    ... Corrosion-Resistant Carbon Steel Flat Products from Germany, 71 FR 66163 (November 13, 2006). Analysis of... Steel Flat Products From Canada and Germany, 71 FR 14498 (March 22, 2006). \\7\\ See Notice of Final... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From Germany and the...

  7. The effects of bacteria on the corrosion behavior of carbon steel in compacted bentonite

    International Nuclear Information System (INIS)

    As a part of evaluation of corrosion life of carbon steel overpack, the experimental studies have been performed on the effects of bacteria on the corrosion behavior of carbon steel in compacted bentonite using iron bacteria (IB) as a representative oxidizing bacteria and sulphur reducing bacteria (SRB) as a representative reducing bacteria. The results of the experimental studies showed that; The activity of SRB was low in compacted bentonite in spite of applying suitable condition for the action of bacteria such as temperature and nutritious solution. Although the corrosion behavior of carbon steel was affected by the existence of bacteria in simple solution, the corrosion rates of carbon steel in compacted bentonite were several μ m/year -10 μ m/year irrespective of coexistence of bacteria and that the corrosion behavior was not affected by the existence of bacteria. According to these results, it was concluded that the bacteria would not affect the corrosion behavior of carbon steel overpack under repository condition. (author)

  8. Enhancement of corrosion resistance of carbon steel by Dioscorea Hispida starch in NaCl

    Science.gov (United States)

    Zulhusni, M. D. M.; Othman, N. K.; Lazim, Azwan Mat

    2015-09-01

    Starch is a one of the most abundant natural product in the world and has the potential as corrosion inhibitor replacing harmful synthetic chemical based corrosion inhibitor. This research was aimed to examines the potential of starch extracted from local Malaysian wild yam (Dioscorea hispida), as corrosion inhibitor to carbon steel in NaCl media replicating sea water. By using gravimetric test and analysis, in which the carbon steel specimens were immersed in NaCl media for 24, 48 and 60 hours with the starch as corrosion inhibitor. the corrosion rate (mmpy) and inhibition efficiencies (%) was calculated. The results obtained showed decrease in corrosion rate as higher concentration of starch was employed. The inhibition efficiencies also shows an increasing manner up to 95.97 % as the concentration of the inhibitor increased.

  9. Stress-corrosion crack initiation behavior of carbon steel in simulated BWR environment

    International Nuclear Information System (INIS)

    Carbon steels and low-alloy steels are said to possess, even though susceptible to stress-corrosion cracking themselves, conspicuously longer life than weld-sensitized Type 304 stainless steels in actual boiling water reactor (BWR) primary coolant environments of high-temperature, high-purity water containing some dissolved oxygen. This has been examined for a carbon steel pipe material and its weld by conducting uniaxial constant-load tests as a laboratory accelerated test. By statistically analyzing the distribution of stress-corrosion cracking lifetimes and metallographical examining the features of stress-corrosion crack initiation in an SEM, following results have been obtained: (1) the stress-corrosion cracking lifetime obeys the exponential distribution model; (2) stress-corrosion cracks are initiated at the bottom of corrosion pits, and it appears possible to analyze their initiation conditions in terms of stress-intensity calculated regarding the pit as a sharp crack; (3) the microcracks as initiated at the corrosion pit are non-propagative per se, so that it is only when they have grown into a main crack by coalescence with nearby microcracks that steady propagation becomes possible; and (4) both the process of pit initiation and that of microcrack coalescence can be described as a Poisson stochastic process just as for the stainless steels in the same environment, so that the whole process of stress-corrosion crack initiation can be conceived as consisting of these two independent Poisson stochastic processes connected in serial succession

  10. The effect of environmental variables on atmospheric corrosion of carbon steel in Shenyang

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan; WANG ZhenYao; KE Wei

    2009-01-01

    A study was carried out in order to investigate the effect of contaminants and meteorological variables on the rust layer of carbon steel exposed in Shenyang urban atmosphere. Seven kinds of contaminants and twelve kinds of meteorological parameters were also registered in order to correlate the data with respect to corrosion rate and the stepwise multiple regression analysis was carried out in order to obtain the best regression model. The sum of rainfall time as well as sunshine time and the concentration of H_2S could stimulate initial atmospheric corrosion of carbon steel. The initial atmospheric corrosion kinetics of carbon steel was observed to follow the cubic equation. The corrosion products were analyzed by XRD and the transformation of phases in different periods was discussed.

  11. Reinforcement steel corrosion in passive state and by carbonation: Consideration of galvanic currents and interface steel - concrete defaults

    International Nuclear Information System (INIS)

    This thesis aims to study the durability of nuclear waste deep storage structures. The work carried out is essentially an experimental study, and focuses on the corrosion of steel in the passive state with aerated or non-aerated conditions on the one hand, and the corrosion of steel in carbonated concrete during the propagation phase on the other hand. Indeed, the pore solution of concrete in contact with the metal is alkaline (pH between 12 and 13). Under these conditions, steel reinforced concrete remains passive by forming a stable and protective oxide layer (corrosion of steel in the passive state). This passive layer limits the steel corrosion rate at very low values (negligible on a short life time) but not null. For the nuclear waste storage structures due to a very long life time (up to several hundred years), this low corrosion rate can become a risk. Therefore, it is necessary to study the evolution of the oxide layer growth over time. The objectives of the thesis are to study the influence of the steel-concrete interface quality on reinforcement corrosion in passive and active state, and the possible occurrence of galvanic corrosion currents between different reinforcement steel areas. (author)

  12. Corrosion of carbon steel in sodium methanoate solutions

    International Nuclear Information System (INIS)

    The behaviour of steel electrodes in sodium methanoate solutions was studied by coupling electrochemical techniques (voltammetry, OCP vs. time) with in situ micro-Raman spectroscopy analyses of the corrosion products. The polarisation curves depended strongly on the methanoate concentration. For the smallest concentration (10-3 mol L-1), the current density increased regularly with the applied potential. So the behaviour of the electrode was typical of an active material. In contrast, for the largest concentration (10-1 mol L-1), the curves obtained were typical of a passive material. Methanoate ions favoured growth and stability of a passive oxide film more likely by adsorbing on its surface. The polarisation curve obtained for the intermediate concentration (10-2 mol L-1) was unusual and testified of an imperfect passivation of the steel surface. Finally, steel electrodes were left at the open circuit potential in the methanoate solutions. In any case, the passivity was rapidly lost and a general corrosion of the surface took place. In situ Raman spectroscopy analyses at the early stage of the corrosion process demonstrated that the first product to form was a green rust, GR(HCOO-). It was oxidised later into γ-FeOOH (lepidocrocite) by dissolved O2. The process is then typical of what is usually observed in neutral or alkaline media, whatever the anions present and responsible of the GR formation. A new and detailed characterisation of GR(HCOO-) by X-ray diffraction was performed and a crystal structure is proposed.

  13. Carbide formation on carbon steels in CO2 corrosion by use of applied anodic current

    OpenAIRE

    Laethaisong, Nushjarin

    2011-01-01

    The present study aims to validate the method in enriching of iron carbide surface from carbon steels in CO2 corrosion. Applying an anodic current to carbon steel electrodes by galvanostatic measurement was a selected approach. Influence of magnitude of the applied current and exposure time on the corrosion process was studied. The experiments were conducted with CO2-saturated-0.5M NaCl solution as an electrolyte at room temperature and atmospheric pressure. Three different steels, X-65, St52...

  14. N-heterocyclic Amine Derivatives as Efficient Corrosion Inhibitors for Carbon Steel in Acidic Medium

    International Nuclear Information System (INIS)

    A novel heterocyclic amine derivatives, namely N, N'-substituted pyridinyl ethylene diamine tetra acetic acid sodium salt (A) and ethylene diamine N, N'-diacetic acid di (2-methylene tetra hydro furfuryl) acetate (B) were synthesized and their structure confirmations were performed by FTIR, HNMR and CNMR spectra. The inhibition effectiveness was evaluated against the corrosion of carbon steel in 1 M HCl by weight loss and polarization techniques. The results showed that the synthesized derivatives are good corrosion inhibitors for carbon steel in 1 M HCl medium, their inhibition efficiency, increased with inhibitor concentration, and (A) is slightly more effective than (B). The potentiostatic polarization study showed that (A) and (B) are mixed-type inhibitors in 1 M HCl. These compounds prevent carbon steel from corrosion by adsorption to the steel surface and forming insoluble complexes with ferrous species. The weight loss results and potentiostatic polarization studies were in reasonable agreement. (author)

  15. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    Directory of Open Access Journals (Sweden)

    M. Mazur

    2010-07-01

    Full Text Available The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundaries of retained austenite on rate anddevelopment of stress corrosion processes. The lowest corrosion resistance was obtained for W3 steel characterized by high contents ofmolybdenum (2.94% Mo which should be connected with the intensity precipitate processes of Fe2Mo phase. For steels W1 and W2which contents molybdenum equals 1.02% and 1.88%, respectively were obtained similar courses of corrosive cracking.

  16. Effect of chloride content of molten nitrate salt on corrosion of A516 carbon steel.

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, Robert W.; Clift, W. Miles

    2010-11-01

    The corrosion behavior of A516 carbon steel was evaluated to determine the effect of the dissolved chloride content in molten binary Solar Salt. Corrosion tests were conducted in a molten salt consisting of a 60-40 weight ratio of NaNO{sub 3} and KNO{sub 3} at 400{sup o}C and 450{sup o}C for up to 800 hours. Chloride concentrations of 0, 0.5 and 1.0 wt.% were investigated to determine the effect on corrosion of this impurity, which can be present in comparable amounts in commercial grades of the constituent salts. Corrosion rates were determined by descaled weight losses, corrosion morphology was examined by metallographic sectioning, and the types of corrosion products were determined by x-ray diffraction. Corrosion proceeded by uniform surface scaling and no pitting or intergranular corrosion was observed. Corrosion rates increased significantly as the concentration of dissolved chloride in the molten salt increased. The adherence of surface scales, and thus their protective properties, was degraded by dissolved chloride, fostering more rapid corrosion. Magnetite was the only corrosion product formed on the carbon steel specimens, regardless of chloride content or temperature.

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

    International Nuclear Information System (INIS)

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

  18. The anaerobic corrosion of carbon steel and cast iron in artificial groundwaters

    International Nuclear Information System (INIS)

    In Sweden, high level radioactive waste will be disposed of in a canister with a copper outer and a cast iron or carbon steel inner. If the iron insert comes into contact with anoxic geological water, anaerobic corrosion leading to the generation of hydrogen will occur. This paper presents a study of the anaerobic corrosion of carbon steel and cast iron in artificial Swedish granitic groundwaters. Electrochemical methods and gas collection techniques were used to assess the mechanisms and rates of corrosion and the associated hydrogen gas production over a range of conditions. The corrosion rate is high initially but is anodically limited by the slow formation of a duplex magnetite film. The effects of key environmental parameters such as temperature and ionic strength on the anaerobic corrosion rate are discussed

  19. Reliability of Electrochemical Techniques for Determining Corrosion Rates on Carbon Steel in Sulfide Media

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, T.; Nielsen, Lars Vendelbo; Richter, S.

    2007-01-01

    Effects of film formation on carbon steel in hydrogen sulfide (H2S) media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from H2S solutions, biological sulfide media, and natural sulfide containing geothermal water have been collected, and the process of...... biofilm in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemicel impedance spectroscopy (EIS). Oxygen entering the system...

  20. Corrosion of carbon steel in sodium methanoate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Barchiche, C.; Sabot, R.; Jeannin, M. [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Univ. La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France); Refait, Ph., E-mail: prefait@univ-lr.f [Laboratoire d' etude des materiaux en milieux agressifs (LEMMA), EA 3167, Univ. La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France)

    2010-02-15

    The behaviour of steel electrodes in sodium methanoate solutions was studied by coupling electrochemical techniques (voltammetry, OCP vs. time) with in situ micro-Raman spectroscopy analyses of the corrosion products. The polarisation curves depended strongly on the methanoate concentration. For the smallest concentration (10{sup -3} mol L{sup -1}), the current density increased regularly with the applied potential. So the behaviour of the electrode was typical of an active material. In contrast, for the largest concentration (10{sup -1} mol L{sup -1}), the curves obtained were typical of a passive material. Methanoate ions favoured growth and stability of a passive oxide film more likely by adsorbing on its surface. The polarisation curve obtained for the intermediate concentration (10{sup -2} mol L{sup -1}) was unusual and testified of an imperfect passivation of the steel surface. Finally, steel electrodes were left at the open circuit potential in the methanoate solutions. In any case, the passivity was rapidly lost and a general corrosion of the surface took place. In situ Raman spectroscopy analyses at the early stage of the corrosion process demonstrated that the first product to form was a green rust, GR(HCOO{sup -}). It was oxidised later into gamma-FeOOH (lepidocrocite) by dissolved O{sub 2}. The process is then typical of what is usually observed in neutral or alkaline media, whatever the anions present and responsible of the GR formation. A new and detailed characterisation of GR(HCOO{sup -}) by X-ray diffraction was performed and a crystal structure is proposed.

  1. Accelerated corrosion of stainless steels with the presence of molten carbonates below 923 K

    International Nuclear Information System (INIS)

    The high-temperature corrosion of stainless steels (SUS316L and SUS310S) in the presence of lithium-potassium eutectic carbonate and lithium-sodium eutectic carbonate has been studied by thermogravimetry and the metal consumption method under a carbon dioxide-oxygen atmosphere in the temperature range of 773-1123 K. Although the corrosion of SUS310S obeyed the parabolic rate law for all reaction conditions, the corrosion of SUS316L significantly depended on the reaction conditions. At or above 923 K, the corrosion of SUS316L obeyed the parabolic rate law, even with a carbonate coating. The corrosion rates were accelerated during the initial period of corrosion tests below 923 K, especially around 823 K with a lithium-sodium carbonates coating. The initial accelerated corrosion was a local corrosion, which produced through holes in the metal specimens, and occurred more clearly at higher carbon dioxide partial pressures with the lithium-sodium carbonate coating than with the lithium-potassium carbonate coating. (author)

  2. Synergistic inhibition of carbon steel corrosion in seawater by cerium chloride and sodium gluconate

    International Nuclear Information System (INIS)

    Highlights: • Significant synergistic effect was determined for cerium and gluconate. • The mixture showed significant corrosion inhibition of carbon steel in seawater. • Predominant anodic inhibition mechanism was observed. • The presence of cerium ions incorporated in the protective layer was confirmed. - Abstract: In this research the effect of cerium (III) chloride heptahydrate (CC) and sodium gluconate (SG) on the corrosion inhibition of carbon steel C45 (1531) in natural seawater has been evaluated using electrochemical methods and scanning electron microscopy (SEM). The results show that substantial corrosion inhibition (94.98%) using CC and SG can be obtained in synergistic manner. Surface analysis confirmed the presence of cerium ions incorporated in the protective layer of carbon steel specimen. SG acts predominantly as anodic inhibitor whereas CC acts as a mixed type inhibitor. Using both inhibitors predominant mechanism of anodic inhibition is observed

  3. Investigation on Preferential Corrosion of Welded Carbon Steel Under Flowing Conditions by EIS

    Science.gov (United States)

    Alawadhi, K.; Aloraier, A. S.; Joshi, S.; Alsarraf, J.; Swilem, S.

    2013-08-01

    Carbon steels are used extensively in construction of oil and gas pipes but they exhibit poor corrosion-resistance properties because of internal corrosion. In this research, a rotating cylinder electrode apparatus was designed so that electrodes machined from the weld metal, heat-affected zone, and parent material of a welded X65 pipeline steel could be tested in high shear stress conditions using electromechanical impedance spectroscopy. The aim was to investigate the cause of the severe localized corrosion that sometimes occurs at welds in carbon steel pipelines carrying hydrocarbons and inhibited brine solutions saturated with carbon dioxide. It was concluded that the surface films play an important role in effective inhibition, and this inhibition is more effective on a clean surface rather than on a precorroded one.

  4. Operating conditions influence corrosion of carbon steel in a freshwater distribution system

    International Nuclear Information System (INIS)

    The influence of operating conditions (flow and no flow situations) on the corrosion of carbon steel (CS) were simulated and investigated. Conventional microbial culture methods and molecular tools were used to characterize the biofilm and corrosion causing bacteria. Denaturing gradient gel electrophoresis showed significant diversity and variation in the bacterial community. Raman spectroscopy was used to characterize the corrosion deposits, the following iron oxide phases were identified; lepidocrocite, goethite, hematite and magnetite. Transformation of two iron oxides hematite and magnetite vice versa was noticed in the experimental system. In conclusion a plausible CS corrosion control method was described. (author)

  5. Stress corrosion cracking of carbon and low alloy steels in high temperature water

    International Nuclear Information System (INIS)

    A new set of fracture mechanics stress corrosion crack growth rate data is presented for transgranular cracking of carbon and low alloy steels exposed to high temperature water. The essential observations are as follows. Fast stress corrosion crack growth rates between 10-9 and 10-8 m/s may be observed down to 400 ppb dissolved oxygen at water conductivities of 0.5 microS/cm in refreshed autoclaves. There is no effect of specimen thickness on the stress corrosion crack growth rates. Temperature, however, clearly is a major influential parameter on stress corrosion cracking

  6. 78 FR 55057 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-09

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea... antidumping duty order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea... Requests for Revocation in Part, 77 FR 59168 (September 26, 2012). \\2\\ The period of review (POR) ends...

  7. 76 FR 4291 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Partial Rescission of...

    Science.gov (United States)

    2011-01-25

    ... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... administrative review of the countervailing duty order on corrosion- resistant carbon steel flat products from... FR 60078 (September 29, 2010) (Initiation). As a result of withdrawals of request for review, we...

  8. 76 FR 77775 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-12-14

    ... FR 54209 (August 31, 2011) (``Preliminary Results''). The final results were originally due no later... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea... countervailing duty order on corrosion-resistant carbon steel flat products from the Republic of Korea...

  9. Corrosion Behaviour of Nickel Plated Low Carbon Steel in Tomato Fluid

    OpenAIRE

    Oluleke OLUWOLE; Oluwadamilola OLAWALE

    2010-01-01

    This research work investigated the corrosion resistance of nickel plated low carbon steel in tomato fluid. It simulated the effect of continuous use of the material in a tomato environment where corrosion products are left in place. Low carbon steel samples were nickel electroplated at 4V for 20, 25, 30 and 35 mins using Watts solution.The plated samples were then subjected to tomato fluid environment for for 30 days. The electrode potentials mV (SCE) were measured every day. Weight loss was...

  10. Semi-empirical model for carbon steel corrosion in long term geological nuclear waste disposal

    International Nuclear Information System (INIS)

    In France and other countries, carbon and low alloy steels have been proposed as suitable materials for nuclear waste containers for long term geological disposal since, for such types of steels, general and localised corrosion can be fairly well predicted in geological environments (mainly argillaceous and granitic conditions) during the initial oxic and the following anoxic stages. This paper presents a model developed for the long term estimation of general and localised corrosion of carbon steel in argillaceous and granitic environments. In the case of localised corrosion, the model assumes that pitting and crevice corrosion propagation rates are similar. The estimations are based on numerous data coming from various experimental programmes conducted by the following laboratories: UKAEA (United Kingdom); NAGRA (Switzerland); SCK-CEN (Belgium); JNC (Japan) and ANDRA-CEA-EDF (France). From these data, the corrosion rates measured over long periods (from six months to several years) and derived from mass loss measurements have been selected to construct the proposed models. For general corrosion, the model takes into account an activation energy deduced from the experimental results (Arrhenius law) and proposes three equations for the corrosion rate: one for the oxic conditions, one for the early stage of the anoxic conditions and one for the long term anoxic corrosion. Concerning localised corrosion, a semi-empirical model, based on the evolution of the pitting factor (ratio between the maximum pit depth and the average general corrosion depth) as a function of the general corrosion depth, is proposed. This model is compared to other approaches where the maximum pit depth is directly calculated as a function of time, temperature and oxic or anoxic conditions. Finally, the presented semi-empirical models for long term corrosion estimation are applied to the case of nuclear waste storage. The results obtained by the different methods are then discussed and compared

  11. Influence of hydrogen-oxidizing bacteria on the corrosion of low carbon steel: Local electrochemical investigations.

    Science.gov (United States)

    Moreira, Rebeca; Schütz, Marta K; Libert, Marie; Tribollet, Bernard; Vivier, Vincent

    2014-06-01

    Low carbon steel has been considered a suitable material for component of the multi-barrier system employed on the geological disposal of high-level radioactive waste (HLW). A non negligible amount of dihydrogen (H2) is expected to be produced over the years within the geological repository due to the anoxic corrosion of metallic materials and also to the water radiolysis. The influence of the activity of hydrogen-oxidizing bacteria (HOB) and iron-reducing bacteria (IRB) on carbon steel corrosion is considered in this study because of the high availability of energetic nutriments (H2, iron oxides and hydroxides) produced in anoxic disposal conditions. Local electrochemical techniques were used for investigating the activity of IRB as a promoter of local corrosion in the presence of H2 as electron donor. A local consumption of H2 by the bacteria has been evidenced and impedance measurements indicate the formation of a thick layer of corrosion products. PMID:24177135

  12. HYDROTHERMALLY SELF-ADVANCING HYBRID COATINGS FOR MITIGATING CORROSION OF CARBON STEEL.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.

    2006-11-22

    Hydrothermally self-advancing hybrid coatings were prepared by blending two starting materials, water-borne styrene acrylic latex (SAL) as the matrix and calcium aluminate cement (CAC) as the hydraulic filler, and then their usefulness was evaluated as the room temperature curable anti-corrosion coatings for carbon steel in CO{sub 2}-laden geothermal environments at 250 C. The following two major factors supported the self-improving mechanisms of the coating during its exposure in an autoclave: First was the formation of a high temperature stable polymer structure of Ca-complexed carboxylate groups containing SAL (Ca-CCG-SAL) due to hydrothermal reactions between SAL and CAC; second was the growth with continuing exposure time of crystalline calcite and boehmite phases coexisting with Ca-CCG-SAL. These two factors promoted the conversion of the porous microstructure in the non-autoclaved coating into a densified one after 7 days exposure. The densified microstructure not only considerably reduced the conductivity of corrosive ionic electrolytes through the coatings' layers, but also contributed to the excellent adherence of the coating to underlying steel' s surface that, in turn, retarded the cathodic oxygen reduction reaction at the corrosion site of steel. Such characteristics including the minimum uptake of corrosive electrolytes by the coating and the retardation of the cathodic corrosion reaction played an important role in inhibiting the corrosion of carbon steel in geothermal environments.

  13. Corrosion Behavior of Medium Carbon Steel in Simulated Concentrated Yucca Mountain Waters

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, A; Chandra, D; Rebak, R B

    2004-04-09

    Medium carbon steel (MCS) is the candidate material for rock bolts to reinforce the borehole liners and emplacement drifts of the proposed Yucca Mountain (YM) high-level nuclear waste repository. Corrosion performance of this structural steel -AISI 1040- was investigated by techniques such as linear polarization, electrochemical impedance spectroscopy (EIS), and laboratory immersion tests in lab simulated concentrated YM ground waters. Corrosion rates of the steel were determined for the temperatures in the range from 25 C to 85 C, for the ionic concentrations of 1 time (1x), 10 times (10x), and hundred times (100x) ground waters. The MCS corroded uniformly at the penetration rates of 35-200 {micro}m/year in the de-aerated YM waters, and 200-1000 {micro}m/year in the aerated waters. Increasing temperatures in the de-aerated waters increased the corrosion rates of the steel. However, increasing ionic concentrations influenced the corrosion rates only slightly. In the aerated 1x and 10x waters, increasing temperatures increased the rates of MCS significantly. Inhibitive precipitates, which formed in the aerated 100x waters at higher temperatures (65 C and up) decreased the corrosion rates to the values that obtained for the de-aerated YM aqueous environments. The steel suffered pitting corrosion in the both de-aerated and aerated hot YM environments after anodic polarization.

  14. The anaerobic corrosion of carbon steel in alkaline media – Phase 2 results

    Directory of Open Access Journals (Sweden)

    Fennell P.A.H.

    2013-07-01

    Full Text Available In the Belgian Supercontainer concept a carbon steel overpack will surround high-level waste and spent fuel containers and be encased in a cementitious buffer material. A programme of research was carried out to investigate and measure the rate of anaerobic corrosion of carbon steel in an artificial alkaline porewater that simulates the aqueous phase in the cementitious buffer material. The corrosion rates were measured by monitoring hydrogen evolution using a manometric gas cell technique and by applying electrochemical methods. Phase 2 of the programme has repeated and extended previous Phase 1 measurements of the effects of radiation, temperature and chloride concentration of the anaerobic corrosion rate. This paper provides an update on the results from Phase 2 of the programme. The results confirm previous conclusions that the long-term corrosion rate of carbon steel in alkaline simulated porewater is determined by the formation of a thin barrier layer and a thicker outer layer composed of magnetite. Anaerobic corrosion of steel in cement requires an external supply of water.

  15. The anaerobic corrosion of carbon steel in alkaline media - Phase 2 results

    International Nuclear Information System (INIS)

    In the Belgian Super-container concept a carbon steel overpack will surround high-level waste and spent fuel containers and be encased in a cementitious buffer material. A programme of research was carried out to investigate and measure the rate of anaerobic corrosion of carbon steel in an artificial alkaline pore water that simulates the aqueous phase in the cementitious buffer material. The corrosion rates were measured by monitoring hydrogen evolution using a manometric gas cell technique and by applying electrochemical methods. Phase 2 of the programme has repeated and extended previous Phase 1 measurements of the effects of radiation, temperature and chloride concentration of the anaerobic corrosion rate. This paper provides an update on the results from Phase 2 of the programme. The results confirm previous conclusions that the long-term corrosion rate of carbon steel in alkaline simulated pore water is determined by the formation of a thin barrier layer and a thicker outer layer composed of magnetite. Anaerobic corrosion of steel in cement requires an external supply of water. (authors)

  16. The effect of Pseudoxanthomonas sp. as manganese oxidizing bacterium on the corrosion behavior of carbon steel

    International Nuclear Information System (INIS)

    The present study investigated the role of manganese oxidizing bacterium (MOB), namely Pseudoxanthomonas sp. on the corrosion behavior of carbon steel. This bacterium was isolated from sewage treatment plants and identified by biochemical and molecular methods. The electrochemical techniques such as open circuit potentiometry, electrochemical impedance spectroscopy, potentiodynamic and cyclic polarization were used to measure the corrosion rate and observe the corrosion mechanism. Also, scanning electron microscopy and X-ray diffraction studies were applied to surface analysis. This study revealed the strong adhesion of the biofilm on the metal surface in the presence of Pseudoxanthomonas sp. that enhanced the corrosion of carbon steel. X-ray diffraction patterns identified a high content of MnO2 deposition within these biofilms. This is the first report that discloses the involvement of Pseudoxanthomonas sp. as manganese oxidizing bacteria on the corrosion of carbon steel. - Highlights: ► A new type of manganese oxidizing bacteria, namely Pseudoxanthomonas sp. was indicated. ► This bacterium can create a biofilm on the part of metal surface and affect localized corrosion. ► In the presence of biofilm, the diffusion of oxygen vacancies and manganese ions has occurred.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Effect of phosphonium-based ionic liquids on the corrosion of carbon steel under gamma radiation

    International Nuclear Information System (INIS)

    The interactions of two ionic liquids with carbon steel surfaces were studied in absence and presence of γ-radiation. Both studied ionic liquids were found to corrode the carbon steel. One of the ionic liquids (labelled [P66614]+ [Br]-) was found to produce corrosion products both with and without radiation present. The second ionic liquid (labelled [P66614]+ [NTf2]-) did not corrode the steel in absence of γ-radiation, but did corrode it in the presence of γ-radiation. (author)

  19. Corrosion behavior of plasma sprayed ceramic and metallic coatings on carbon steel in simulated seawater

    International Nuclear Information System (INIS)

    Highlights: • Plasma sprayed Ni60 coating can provide corrosion protect for the substrate. • Depositing ceramic coatings on metallic coating can improve the corrosion resistance. • The corrosion resistance of Al2O3 coating was better than that of ZrO2 coating. • The porosity had direct effect on the corrosion rate of the plasma sprayed coatings. • The top layer and the bond layer were treated as one coating in the EIS tests. - Abstract: Al2O3, ZrO2 and Ni60 coatings were produced on carbon steels by plasma spray. Ni60 was used as the bond coat in all the cases. The microstructure of these coatings was analyzed by scanning electron microscopy (SEM). The corrosion behavior of the plasma spray coated samples as well as uncoated samples was evaluated by open circuit potential (OCP) measurements, potentiodynamic polarization tests, and electrochemical impedance spectroscopy (EIS) in simulated seawater. The results showed that Ni60 coating protected carbon steels against the corrosion and plasma spraying ceramic powders on metallic coating improved the corrosion resistance of the coatings further. The corrosion resistance of the Al2O3 coating was superior to that of the ZrO2 coating due to the relatively few defects in Al2O3 coating

  20. 78 FR 55241 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-10

    ...: Certain Steel Products From Korea, 58 FR 43752 (August 17, 1993) (Order). \\3\\ See the ``Decision... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea... carbon steel flat products (CORE) from the Republic of Korea (Korea) for the period of review...

  1. Influence of temperature on corrosion rate and porosity of corrosion products of carbon steel in anoxic bentonite environment

    International Nuclear Information System (INIS)

    Highlights: •The corrosion rate is not significantly dependent on temperature. •Corrosion products at higher temperatures have different color. •Corrosion products at higher temperatures are more compact. •The change in corrosion products nature is reversible. -- Abstract: The study focuses on the porosity of layers of corrosion products and its impact on corrosion rate of carbon steel in moist bentonite. Measurements were performed in an aggressive Czech type of bentonite – Rokle B75 at temperatures of 90 and 40 °C. Aggressiveness of B75 bentonite consists in low content of chlorides. Presence of chlorides in pore solution allows formation of more protective magnetite. The evaluation was made by electrochemical techniques (red/ox potential, open circuit potential, linear polarization resistance, impedance spectroscopy) and resistometric sensor measurements. The result imply that the higher the temperature the more compact is the layer of corrosion products that slightly decelerates corrosion rate compared to the state at 40 °C. The state of corrosion products at both temperatures is reversible

  2. CO2 corrosion resistance of carbon steel in relation with microstructure changes

    International Nuclear Information System (INIS)

    The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO2 was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to characterize the formation of the corrosion product layers. Electrochemical results revealed that corrosion resistance increased in the following order: B < N < Q&T < A. From the polarization curves it was shown that specifically, cathodic current densities were affected by microstructural changes. SEM images indicated that ferrite dissolved earlier than cementite and a thin layer of corrosion products was deposited on the steel surface. XPS analyses revealed that this layer was composed of a mixture of iron carbonate and non-dissolved cementite. It was also found that the quantity of FeCO3 content on the steel surface was greater for Q&T and A microstructures. These results, in agreement with the electrochemical data, indicate that the deposition mechanism of iron carbonate is closely related to the morphology of the non-dissolved cementite, determining the protective properties of the corrosion product layers. - Highlights: • The effect of change in microstructure on CO2 corrosion resistance was evaluated. • An API 5LX 42 carbon steel was immersed in a 0.5 M NaCl solution saturated with CO2. • Banded, normalized, quenched-tempered and annealed microstructures were considered. • Electrochemical measurements were coupled with surface analysis. • Morphology and distribution of undissolved Fe3C control corrosion kinetics

  3. CO{sub 2} corrosion resistance of carbon steel in relation with microstructure changes

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa, Nathalie, E-mail: nochoa@usb.ve [Departamento de Ciencia de los Materiales, Universidad Simón Bolívar, Aptdo., 89000, Caracas (Venezuela, Bolivarian Republic of); Vega, Carlos [Departamento de Ciencia de los Materiales, Universidad Simón Bolívar, Aptdo., 89000, Caracas (Venezuela, Bolivarian Republic of); Pébère, Nadine; Lacaze, Jacques [Université de Toulouse, CIRIMAT, UPS/INPT/CNRS, ENSIACET, 4 Allée Emile Monso, CS 44362, 31030 Toulouse Cedex 4 (France); Brito, Joaquín L. [Laboratorio de Físico-química de Superficies, Centro de Química, Instituto Venezolano de Investigaciones Cientificas (IVIC), Carretera Panamericana, Km 11, Altos de Pipe, Estado Miranda (Venezuela, Bolivarian Republic of)

    2015-04-15

    The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO{sub 2} was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to characterize the formation of the corrosion product layers. Electrochemical results revealed that corrosion resistance increased in the following order: B < N < Q&T < A. From the polarization curves it was shown that specifically, cathodic current densities were affected by microstructural changes. SEM images indicated that ferrite dissolved earlier than cementite and a thin layer of corrosion products was deposited on the steel surface. XPS analyses revealed that this layer was composed of a mixture of iron carbonate and non-dissolved cementite. It was also found that the quantity of FeCO{sub 3} content on the steel surface was greater for Q&T and A microstructures. These results, in agreement with the electrochemical data, indicate that the deposition mechanism of iron carbonate is closely related to the morphology of the non-dissolved cementite, determining the protective properties of the corrosion product layers. - Highlights: • The effect of change in microstructure on CO{sub 2} corrosion resistance was evaluated. • An API 5LX 42 carbon steel was immersed in a 0.5 M NaCl solution saturated with CO{sub 2}. • Banded, normalized, quenched-tempered and annealed microstructures were considered. • Electrochemical measurements were coupled with surface analysis. • Morphology and distribution of undissolved Fe{sub 3}C control corrosion kinetics.

  4. Reliability of Electrochemical Techniques for Determining Corrosion Rates on Carbon Steel in Sulfide Media

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, T.; Nielsen, Lars Vendelbo;

    2007-01-01

    film formation in sulfide solutins was followed by video. It can be shown that capacitative and diffusional effects due to porous reactive deposits tend to dominate the data, resulting in unreliable corrosion rates measured using electrochemical techniques. The effect is strongly increased if the......Effects of film formation on carbon steel in hydrogen sulfide (H2S) media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from H2S solutions, biological sulfide media, and natural sulfide containing geothermal water have been collected, and the process of...... biofilm in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemicel impedance spectroscopy (EIS). Oxygen entering the system...

  5. When can Electrochemical Techniques give Reliable Corrosion Rates on Carbon Steel in Sulfide Media?

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, Tor; Nielsen, Lars Vendelbo;

    2005-01-01

    of film formation in sulfide solutions was followed by video. It can be shown that capacitative and diffusional effects due to porous reactive deposits tend to dominate the data resulting in unreliable corrosion rates measured by electrochemical techniques. The effect is strongly increased if biofilm......Effects of film formation on carbon steel in hydrogen sulfide media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from hydrogen sulfide solutions, biological sulfide media and natural sulfide containing geothermal water have been collected and the process...... in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). Oxygen entering the system...

  6. Influence of EPS isolated from thermophilic sulphate-reducing bacteria on carbon steel corrosion.

    Science.gov (United States)

    Dong, Ze Hua; Liu, Tao; Liu, Hong Fang

    2011-05-01

    Extracellular polymeric substances (EPS) were isolated by centrifugation of thermophilic sulphate-reducing bacteria (SRB) grown in API-RP38 culture medium. The protein and polysaccharide fractions were quantified and the highest concentrations were extracted from a 14-day old culture. The effect of EPS on carbon steel corrosion was investigated by electrochemical techniques. At 30°C, a small amount of EPS in 3% NaCl solution inhibited corrosion, whilst excessive amounts of EPS facilitated corrosion. In addition, the inhibition efficiency of EPS decreased with temperature due to thermal desorption of the EPS. The results suggest that adsorbed EPS layers could be beneficial to anti-corrosion by hindering the reduction of oxygen. However, the accumulation of an EPS film could stimulate the anodic dissolution of the underlying steel by chelation of Fe2+ ions. PMID:21604218

  7. The effect of water vapor on the corrosion of carbon steel at 65 degree C

    International Nuclear Information System (INIS)

    AISI 1020 carbon steel was exposed to air at various relative humidities at 65 degrees C. A ''critical relative humidity'' (CRH) of 75--85% was determined. The CRH is the transitional relative humidity where oxidation/corrosion changes from dry oxidation to aqueous film electrochemical corrosion. Short term testing suggests that aqueous film electrochemical corrosion results in the formation of an inner oxide of Fe3O4, and an outer oxide of a powdery Fe2O3 and/or Fe2O3·xH2O

  8. Inhibition of carbon dioxide corrosion of mild steel by imidazolines and their precursors

    Energy Technology Data Exchange (ETDEWEB)

    Jovancicevic, V.; Ramachandran, S.; Prince, P. (Baker Petrolite, Sugar Land, TX (United States))

    1999-05-01

    Corrosion inhibition of mild steel by imidazolines and their precursors in a carbon dioxide (CO[sub 2])-containing environment was studied using rotating cylinder electrode (RCE) and linear polarization resistance (LPR) techniques. Corrosion rate-time/concentration profiles and minimum effective concentrations obtained for a series of imidazolines and amides were evaluated in terms of the respective contributions of their constituents parts (imidazoline ring, amide/amine group, and hydrocarbon chain) to overall corrosion inhibition. Formation of the inhibitor film was studied in terms of the bilayer-multilayer film model.

  9. Corrosion of carbon steel and Monel-400 in EDTA based steam generator cleaning formulations

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, S.V.; Padma, S.; Veena, S.N.; Rufus, A.L.; Sathyaseelan, V.S.; Velmurugan, S. [Water and Steam Chemistry Lab., BARC Facilities Kalpakkam, Tamilnadu (India)

    2001-10-01

    Corrosion products and the scale forming impurities foul the steam generators of pressurized water reactors (PWR) and pressurized heavy water reactors (PHWR). The impurities from the make-up water, the condenser leaks and the corrosion product oxides leached from the feed train structural materials are carried along with the feed water and concentrate in the steam generators. These impurities deposit/precipitate over the steam generator surfaces and cause several problems such as reduction in heat transfer efficiency, under deposit attack, tube failures and production loss. In order to solve this problem, the power utilities are resorting increasingly to chemical cleaning of the steam generators. The chemical formulation selected for cleaning should be able to dissolve the accumulated corrosion products/sludge and at the same time should be compatible with the steam generator structural materials. Of the various chemical-cleaning formulations, the EDTA based formulations are more popular and have been used in the chemical cleaning of many nuclear steam generators. Its corrosion compatibility with the structural-materials of the steam generators needs a thorough evaluation. In this work, the effect of various additives added to the EDTA such as pH additive, reducing agent, oxidizing agent and corrosion inhibitors have been investigated. Increase in the concentration of hydrazine has been found to increase the corrosion rate of carbon steel. The variation in corrosion release from carbon steel with time was found to fit a second order equation. The variation in corrosion rate with time was attributed entirely to the increase in surface area caused by roughening of the surface. Presence of dissolved oxygen in EDTA based iron formulation enhanced the corrosion rate of carbon steel and pitted the Monel-400. The study indicated the need for strict oxygen control and the necessity of using a suitable corrosion inhibitor during the iron removal step. The role of copper in

  10. Ni-W coatings electrodeposited on carbon steel: Chemical composition, mechanical properties and corrosion resistance

    International Nuclear Information System (INIS)

    Highlights: → Hard, ductile and adherent nanostructured Ni-W coatings on carbon steel. → New procedures for achieving deposits by current pulse techniques. → Current pulse frequency was the dominant factor to define coating characteristics. → Ni-W coatings protect the carbon steel from corrosion induced by sulphate anions. - Abstract: Hard, ductile and adherent nanostructured Ni-W coatings were electrodeposited on carbon steel from electrolyte solutions containing sodium tungstate, nickel sulfate and sodium citrate, using different current pulse programs. Current pulse frequency was the dominant factor to define chemical composition, grain size, thickness and hardness. According to the electrodeposition conditions the deposited coatings showed 15-30 at% W, the grain size ranged from 65 to 140 nm, and the hardness varied from 650 to 850 Hv. Tungsten carbide also present in the coating contributed to its hardness. The corrosion resistance of the Ni-W coated steel was tested by potentiodynamic polarization in a neutral medium containing sulphate ions. The Ni-W coating protected the carbon steel from localized corrosion induced by sulphate anions.

  11. Corrosion of low-carbon cast steel in concentrated synthetic groundwater at 80 to 150 C

    International Nuclear Information System (INIS)

    Corrosion properties of American Society for Testing and Materials (ASTM) A216-Grade WCA low-carbon steel were evaluated in concentrated synthetic groundwater at 80 to 150 C. The evaluation provides information on the use of the steel as a container material in the proposed Yucca Mountain high-level waste repository. Uniform corrosion rates measured over 4 months ranged from 10 to 40 microm/year, in initially aerated static solutions under gamma irradiation at 1.3 x 106 rad/h. Irradiation effects on uniform corrosion rates were not discernible after 4 months. Pitting corrosion was also found, but the pitting factor was small. Microstructural effects on corrosion were not significant. During corrosion under irradiation, there was an indication of a large amount of hydrogen absorption in the steel. Constant extension rate tests showed evidence for environmental assisted cracking under free corrosion conditions, and strong evidence of hydrogen embrittlement and moisture-induced ductility loss. The use of the test results in support of the Yucca Mountain project is discussed

  12. Modeling of chemical transition of nitrate accompanied with corrosion of carbon steel under alkaline conditions

    International Nuclear Information System (INIS)

    Interaction between carbon steel and nitrate was modeled using the mixed potential concept. Carbon steel was selected as an example of metal components in the repository of radioactive wastes. The nitrate reduction accompanied with the corrosion of carbon steel was modeled as a reaction series of NO3- → NO2- → NH3. The sum of the current of the reaction series of NO3- → NO2- → NH3 and that of water reduction was assumed to be balanced with the oxidation current of carbon steel. The input parameters for this kinetic model were determined by electrochemical measurements and immersion tests. The results of the immersion tests can be interpreted by the analyses of the model. (author)

  13. Effect of Rice Straw Extract and Alkali Lignin on the Corrosion Inhibition of Carbon Steel

    International Nuclear Information System (INIS)

    A paddy residue based corrosion inhibitor was prepared by treating finely powdered rice straw with aqueous ethanol under acid catalyst (0.01 M H2SO4). Commercial alkali lignin was obtained from Sigma-Aldrich. Prior to the corrosion test, the extraction yield and alkali lignin was characterized via FTIR to determine the functional group. The effect of paddy residue extract and commercial alkali lignin on the corrosion inhibition of carbon steel in 1 M HCl was investigated through the weight loss method, potentiodynamic polarization technique and scanning electron microscopy (SEM). The corrosion inhibition efficiency of the extract and alkali lignin at different immersion times (3 h, 24 h and 42 h) was evaluated. The results show that the paddy waste extract exhibited lesser weight loss of carbon steel in the acidic medium in comparison to the commercial alkali lignin, suggesting that the paddy residue extract is more effective than the commercial alkali lignin in terms of its corrosion inhibition properties. The results obtained proves that the extract from paddy residue could serve as an effective inhibitor for carbon steel in acidic mediums. (author)

  14. Effects of solution chemistry and flow on the corrosion of carbon steel in sweet production

    Energy Technology Data Exchange (ETDEWEB)

    Herce, J.A.; Wright, E.J.; Efird, K.D.; Boros, J.A.; Hailey, T.G. [Exxon Production Research Co., Houston, TX (United States)

    1995-10-01

    The corrosion rate of AISI 1018 carbon steel was measured over a range of temperatures, CO{sub 2} partial pressures, flow rates, and solution chemistry under turbulent pipe flow conditions. The combined effects of CO{sub 2} partial pressure, ionic strength, temperature, and initial bicarbonate ion concentration, i.e., solution chemistry, may be described by a single variable, pH. The effects of flow can be combined with pH to form a new variable, hydrogen ion flux, to describe the overall effect of solution chemistry and flow on the sweet corrosion of a film free carbon steel surface. Sweet corrosion rates are directly proportional to hydrogen ion flux over a wide range of temperatures and solution pH`s. Finally, the separate effects of dissolved iron and chloride ion concentration are described.

  15. Green corrosion inhibitors for carbon steel by green leafy vegetables extracts in 1 M HCl

    Directory of Open Access Journals (Sweden)

    Ghadah M. Al-Senani

    2015-12-01

    Full Text Available The effect of some Green Leafy Vegetables (GLV extracts namely Lactuca sativa (Lactuca, Eruca Sativa (Arugula, Petroselinum crispum (Parsley, and Anethum Graveolens (Dill were investigated on inhibition of corrosion carbon steel in 1 M HCl solution using gravimetric (weight loss method. The inhibition efficiency has increased as concentration of the extract increased. The inhibition efficiency has decreased as the temperature increased. The results obtained showed that GLV extracts inhibited the corrosion process by a physical adsorption mechanism that followed the Langmuir, Freundlich, and Temkin adsorption isotherm models. The adsorption thermodynamic parameters that were calculated include, free energy of adsorption (∆G°ads, activation energy (Ea, enthalpy of adsorption (ΔH°ads, and entropy of adsorption (ΔS°ads are proposed for the corrosion of carbon steel in 1 M HCl in the absence and presence of GLV extract.

  16. The effect of temperature on carbon steel corrosion under geological conditions

    International Nuclear Information System (INIS)

    Graphical abstract: The carbon steel corrosion under simulated geological conditions has been investigated and the results show the formation of iron sulphide on steel surface due to microbial corrosion at 30 °C and to the reduction by hydrogen of pyrite originating from claystone into iron monosulphide and hydrogen sulphide at 90 °C. - Highlights: • The role of temperature and microbial activity on steel corrosion was investigated. • At 30 °C, steel developed iron sulphide surface due to microbial activity. • At 90 °C, the microbial activity was inhibited. • At 90 °C, H2S was produced via pyrite reduction by H2. • Sulphide production may occur at high temperature. - Abstract: We investigated the role of temperature on the carbon steel corrosion under simulated geological conditions. To simulate the effect of temperature increase due to radioactive decay, we conducted batch experiments using Callovo-Oxfordian (COx) claystone and synthetic water formation with steel coupons at 30 °C and 90 °C for 6 months. The corrosion products have been studied by scanning electron microscope/energy dispersive X-ray spectroscopy, X-ray diffraction and micro-Raman spectroscopy. At 30 °C, experiments showed the formation of magnetite and iron sulphide, indicating the activation of sulphate-reducing bacteria. At 90 °C a continuous iron sulphide layer was identified on steel surface due to the reduction by hydrogen of pyrite originating from claystone into pyrrhotite and hydrogen sulphide. Thus, sulphide production may occur even in the absence of microbial activity at high temperature and must be taken into consideration regarding the near-field geochemical evolution

  17. Holographic interferometry as electrochemical emission spectroscopy of carbon steel in seawater with low concentration of RA-41 corrosion inhibitor

    International Nuclear Information System (INIS)

    In the present investigation, holographic interferometry was utilized for the first time to determine the rate change of the number of the fringe evolutions during the corrosion test of carbon steel in blank seawater and with seawater with different concentrations of a corrosion inhibitor. In other words, the anodic dissolution behaviors (corrosion) of the carbon steel were determined simultaneously by holographic interferometry, an electromagnetic method, and by the electrochemical impedance (EI) spectroscopy, an electronic method. So, the abrupt rate change of the number of the fringe evolutions during corrosion test (EI) spectroscopy, of the carbon steel is called electrochemical emission spectroscopy. The corrosion process of the steel samples was carried out in blank seawater and seawater with different concentrations, 5-20 ppm, of RA-41 corrosion inhibitor using the EI spectroscopy method, at room temperature. The electrochemical emission spectra of the carbon steel in different solutions represent a detailed picture of the rate change of the anodic dissolution of the steel throughout the corrosion processes. Furthermore, the optical interferometry data of the carbon steel were compared to the data, which were obtained from the EI spectroscopy. Consequently, holographic interferometric is found very useful for monitoring the anodic dissolution behaviors of metals, in which the number of the fringe evolutions of the steel samples can be determined in situ. (Author)

  18. Corrosion behavior of oil tube steel in simulant solution with hydrogen sulfide and carbon dioxide

    International Nuclear Information System (INIS)

    Electrochemical measurement techniques, X-ray diffraction and scanning electron microscopy were applied to investigate the corrosion behavior of N80 tube steel in simulant static solution with carbon dioxide (CO2) and hydrogen sulfide (H2S) at a temperature of 100 deg. C. Sweet corrosion occurred when a very small partial pressure of H2S was added. At this condition, uniform corrosion was found. The added H2S only accelerated the general corrosion rate. Sour corrosion was primary as the partial pressure of H2S increased to 0.010 MPa. The general corrosion rate decreased quickly, but severe pitting was found. The corrosion scale, mainly composed of coarse grains of mackinawite (FeS1-x), was loose and brittle. In sour corrosion, general corrosion rate decreased slowly and pitting became slight with increasing partial pressure of H2S because the primary corrosion product, fine grains of pyrrhotite (FeS1+x), made the scale more compact and continuous

  19. Corrosion Protection of Carbon Steel Using Poly aniline Composite with Inorganic Pigments

    International Nuclear Information System (INIS)

    Two inorganic pigments (TiO2 and SiO2) were used to prepare composites with poly aniline (PANI) by situ polymerization method. PANI and PANI composites with SiO2 and TiO2 were characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The morphology of the synthesized pigments (PANI , PANI-SiO2 and PANI-TiO2) was examined using scanning electron microscopy. Samples were then used as pigments through blending them with acrylic paint and applied on the surface of carbon steel panels. Corrosion was evaluated for coating of carbon steel panels through full immersion test up to standard ASTMG 31. Mass loss was calculated after they have been exposed in acidic media. A digital camera was also used for monitoring corrosion visually on the surface of carbon steel specimens. The results revealed that acrylic paint pigmented by PANI-SiO2 composite was more efficient in corrosion protection for carbon steel compared with the other synthesized pigments. (author)

  20. Microstructure, mechanical properties and corrosion behavior of laser welded dissimilar joints between ferritic stainless steel and carbon steel

    International Nuclear Information System (INIS)

    Highlights: • Laser welding of ferritic stainless steel to carbon steel joints was made. • The microstructure of this dissimilar joint is lath martensite and ferrite. • Decarburized layer and type II grain boundary was observed in joints. • The hardness distribution of two heat input joints across interface were analyzed. • Ecorr of dissimilar joint is between two base metals and joint has greatest icorr. - Abstract: The joint of dissimilar metals between ferritic stainless steel (FSS) and low carbon steel (CS) are welded by laser beam with two different welding speeds: 12 mm/s and 24 mm/s. Microstructure of dissimilar joint were investigated using optical microscope, X-ray diffraction and scanning electron microscope. The results show that the microstructure of this dissimilar joint is lath martensite and few ferrite, upper bainite and widmanstatten ferrite formed in heat-affected zone (HAZ) of CS. An increase of welding speed leads to narrower HAZ of CS and higher hardness of weld bead close to FSS side. The joints with different welding speed have similar ultimate tensile strength but superior elongation is obtained of high welding speed joint. Electrochemical corrosion test indicates the corrosion potential of dissimilar joint falls in between FSS and CS. And dissimilar joint has greatest corrosion current density which is attributed to the effect of galvanic corrosion

  1. Influence of carbon steel and its corrosion products on the leaching of elements from a simulated waste glass. Research document

    International Nuclear Information System (INIS)

    The influence of carbon steel and its corrosion products on leaching of elements from simulated high level radioactive waste glass (P0798) has been investigated in batch-type experiments of up to one year at 25±3degC under argon atmosphere (-1. For each series, a polished glass cube or glass particles were immersed in double distilled deoxidized water with powder of carbon steel or of magnetite, as an assumed carbon steel corrosion product, in the ratio of 10 gram carbon steel (or magnetite) to 1 litter of water. Normalized mass losses of Si, B, Na and Cs in the system of glass-carbon steel-water and of glass-magnetite-water apparently increased compared with those in the glass-water system. The glass dissolution could be accelerated by increasing hydroxyl ion resulting from hydrolysis of carbon steel or of magnetite. The pH values of leachate become eventually almost constant and it indicates that a steady state has been attained between these hydroxyl ion releases and its consumption, which is a disruption process of siloxane bond by hydroxyl ion in solution. The influence of carbon steel and its corrosion products on leaching of elements from the waste glass can be predominantly attributed to a pH effect in this experiment. The increase of glass corrosion rate, however, could be assessed within one order as an influence of the existence of carbon steel and/or its corrosion products. (author)

  2. Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution

    International Nuclear Information System (INIS)

    Highlights: → N-Alkyl-sodium phthalamates as corrosion inhibitors for industry in acidic medium. → Compounds behaved as mixed type inhibitors and followed Langmuir adsorption isotherm. → Efficiencies were proportional to aliphatic chain length and inhibitor concentration. → Iron complexes and chelates with phthalamates contributed to carbon steel protection. - Abstract: Three compounds of N-alkyl-sodium phthalamates were synthesized and tested as corrosion inhibitors for carbon steel in 0.5 M aqueous hydrochloric acid. Tests showed that inhibitor efficiencies were related to aliphatic chain length and dependent on concentration. N-1-n-tetradecyl-sodium phthalamate displayed moderate efficiency against uniform corrosion, 42-86% at 25 deg. C and 25-60% at 40 oC. Tests indicated that compounds behave as mixed type inhibitors where molecular adsorption on steel followed Langmuir isotherm, whereas thermodynamic suggested that a physisorption process occurred. XPS analysis confirmed film formation on surface, where Fe+2 complexes and Fe+2 chelates with phthalamates prevented steel from further corrosion.

  3. Insight into the mechanism of carbon steel corrosion under aerobic and anaerobic conditions.

    Science.gov (United States)

    El Mendili, Y; Abdelouas, A; Bardeau, J-F

    2013-06-21

    We particularly focused our study on identifying the corrosion products formed at 30 °C on carbon steel under aerobic and anaerobic conditions and on following their evolution with time due to enhanced microbial activity under environmental and geological conditions. The nature and structural properties of corrosion products were investigated by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) and confocal micro-Raman spectroscopy. Structural characterisation clearly showed the formation of iron oxides (magnetite and maghemite) under aerobic conditions. Under anaerobic conditions, the first corrosion product formed on the steel surface was nanocrystalline mackinawite, which was then followed by a fast transformation process into the pyrrhotite phase, and the Raman spectrum of monoclinic pyrrhotite was proposed for the first time. Finally, this study also shows that in the context of geological disposal of radioactive waste, the corrosion of carbon steel containers in anoxic and sulphidogenic environments sustained by sulphate-reducing bacteria may not be a problem notably due to the formation of a passive layer on the steel surface. PMID:23652337

  4. Microbial Methane Production Associated with Carbon Steel Corrosion in a Nigerian Oil Field.

    Science.gov (United States)

    Mand, Jaspreet; Park, Hyung S; Okoro, Chuma; Lomans, Bart P; Smith, Seun; Chiejina, Leo; Voordouw, Gerrit

    2015-01-01

    Microbially influenced corrosion (MIC) in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC. PMID:26793176

  5. Microbial methane production associated with carbon steel corrosion in a Nigerian oil field

    Directory of Open Access Journals (Sweden)

    Jaspreet eMand

    2016-01-01

    Full Text Available Microbially influenced corrosion (MIC in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a basal salts medium, in the presence of carbon steel and carbon dioxide. Methane formation was measured in all enrichments and correlated with metal weight loss. Methanogens were prominently represented in pipeline solids samples, scraped from the inside of a pipeline, comprising over 85% of all pyrosequencing reads. Methane production was only witnessed when carbon steel beads were added to these pipeline solids samples, indicating that no methane was formed as a result of degradation of the oil organics present in these samples. These results were compared to those obtained for samples taken from a low temperature oil field in Canada, which had been incubated with oil, either in the presence or in the absence of carbon steel. Again, methanogens present in these samples catalyzed methane production only when carbon steel was present. Moreover, acetate production was also found in these enrichments only in the presence of carbon steel. From these studies it appears that carbon steel, not oil organics, was the predominant electron donor for acetate production and methane formation in these low temperature oil fields, indicating that the methanogens and acetogens found may contribute significantly to MIC.

  6. The kinetics of pitting corrosion of carbon steel

    International Nuclear Information System (INIS)

    The development of an improved statistical method for analysing pit growth data to take account of the difference in area of laboratory specimens and full sized high level nuclear waste containers is described. Statistical analysis of data from pit growth experiments with large area (460 cm2) plates of BS 4360 steel have indicated that the depth distributions correlate most closely with a limited distribution function. This correlation implies that previous statistical analyses to estimate the maximum pit depths in full size containers, which were made using unlimited distribution functions, will be pessimistic. An evaluation of the maximum feasible pitting period based on estimating the period during which the oxygen diffusion flux is sufficient to stabilise a passive film on carbon steel containers has indicated that this is of the order of 125 years rather than the full 1000 year container life. The estimate is sensitive to the value of the leakage current assumed to flow through the passive film, and therefore work is planned to measure this accurately in relevant granitic environments. (author)

  7. Corrosion Testing of Carbon Steel in Oxalic Acid that Contains Dissolved Iron

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, Bruce J.; Mickalonis, John I.; Subramanian, Karthik H.

    2012-10-11

    Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid (OA) will be used to chemically clean the tanks after waste retrieval is completed. The waste tanks at SRS were constructed from carbon steel materials and thus are vulnerable to corrosion in acidic media. In addition to structural impacts, the impact of corrosion on the hydrogen generated during the process must be assessed. Electrochemical and coupon immersion tests were used to investigate the corrosion mechanism at anticipated process conditions. The testing showed that the corrosion rates were dependent upon the reduction of the iron species that had dissolved in solution. Initial corrosion rates were elevated due to the reduction of the ferric species to ferrous species. At later times, as the ferric species depleted, the corrosion rate decreased. On the other hand, the hydrogen evolution reaction became more dominant.

  8. A pharmaceutical product as corrosion inhibitor for carbon steel in acidic environments.

    Science.gov (United States)

    Samide, Adriana

    2013-01-01

    A pharmaceutical product, Trimethoprim (TMP), IUPAC name: 5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine was investigated, as inhibitor to prevent carbon steel corrosion in acidic environments. The study was performed using weight loss and electrochemical measurements, in temperatures ranging between 25-55°C. The surface morphology before and after corrosion of carbon steel in 1.0 M HCl solution in the presence and absence of TMP was evaluated using scanning electron microscopy (SEM). The inhibition efficiency (IE) increased with the increasing of the inhibitor concentration, reaching a maximum value of 92% at 25°C and 0.9 mM TMP, and decreased with increasing temperature. The inhibition of carbon steel corrosion by TMP can be attributed to the adsorption ability of inhibitor molecules onto the reactive sites of the metal surface. The adsorption is spontaneous and it is best described by the Langmuir isotherm. The apparent activation energy (E(a)) for the corrosion process in the absence and presence of TMP was evaluated from Arrhenius equation, to elucidate its inhibitive properties. PMID:23043337

  9. Influence of mechanical stress level in preliminary stress-corrosion testing on fatigue strength of a low-carbon steel

    International Nuclear Information System (INIS)

    Effect of corrosion and mechanical factors of preliminary stress corrosion of a metal in its fatigue strength, has been investigated. Smooth cylindrical samples of 20 steel have been tested. Preliminary corrosion under stress has been carried out under natural sea conditions. It is shown that mechanical stresses in the case of preliminary corrosion affect fatigue strength of low-carbon steels, decreasing the range of limited durability and fatigue limit. This effect increases with the increase of stress level and agressivity of corrosive medium

  10. Corrosion behavior of each phase in low carbon microalloyed ferrite–bainite dual-phase steel: Experiments and modeling

    International Nuclear Information System (INIS)

    Highlights: •Establishing a model for describing the corrosion behavior of multiphase steel. •Quantitatively assessing the corrosion rate of each phase in multiphase steel. •Establishing a function to predict the surface roughness of corrosion morphology. •Defining an index to assess galvanic corrosion at phase-scale in multiphase steel. •The phase distribution affects the service safety of multiphase steel. -- Abstract: In situ observation of the initial corrosion behavior of a low carbon microalloyed ferrite–bainite dual-phase steel showed that the corrosion originated from the inside of ferrite and ferrite boundary. In addition, a model for describing the corrosion behavior of each phase in multiphase steel was established. Based on this model, a method to quantitatively assess the corrosion rate of each phase was presented by white light interference, and the relationship between the surface roughness and corrosion morphology was also established. Meanwhile, the galvanic corrosion at phase-scale and the influence of phase distribution on service safety of multiphase steel were discussed

  11. Corrosion rate evaluation of the carbon steel trough electrochemical techniques

    OpenAIRE

    Jeimmy González-Masís; Luis Garita-Arce

    2014-01-01

    Usually the atmospheric corrosion studies are cha­racterized by their long duration, months and even years. However electrochemical techniques have been developed, recent in comparison to other methods, allowing obtain real-time data, including corrosion rate. In this research electrochemical noise and lineal polarization resistance tests are valued, so obtained data were analyzed, relations were establis­hed between the graphics form and the corrosion type, as well as the relationship betwee...

  12. Corrosion and cathodic protection of carbon steel in the tidal zone: Products, mechanisms and kinetics

    International Nuclear Information System (INIS)

    Highlights: • The corrosion product layer forming in the tidal zone is mainly made up of magnetite. • A thin film of magnetite is formed on the steel surface under cathodic protection. • Magnetite is formed during cathodic protection under the calcareous deposit. • Pre-existing corrosion product layers are almost not modified by cathodic protection. - Abstract: Carbon steel coupons were set in the tidal zone of a French seaport for 7 years with or without cathodic protection. The average corrosion rates decreased from 90 μm yr−1 to 9 μm yr−1 under cathodic protection. The corrosion product layers covering the unprotected coupons, characterized by Raman spectroscopy and X-ray diffraction, were mainly made up of magnetite and Fe(III) oxyhydroxides, with magnetite being clearly predominant. The products of the residual corrosion process under cathodic protection, similar to those observed at open circuit potential, formed a thin layer on the steel surface under the calcareous deposit

  13. Corrosion Inhibition of Carbon Steel In Sulfuric Acid by Sodium Caprylate

    Directory of Open Access Journals (Sweden)

    Saad Ghareba

    2016-01-01

    Full Text Available The interaction of a sodium salt of octanoic acid, sodium caprylate (SC, with a carbon steel (CS surface was investigated, using range of experimental techniques. It was shown that SC acts as a good CS general corrosion inhibitor, yielding a maximum corrosion inhibition efficiency of 77%. This high inhibition efficiency is maintained even at higher temperatures. It was determined that SC inhibits both partial corrosion reactions, and can thus be considered to be a mixed-type inhibitor. The adsorption of SC on the CS surface was described by the Langmuir adsorption isotherm. It was found that this process is spontaneous, irreversible and driven by the entropy gain. The CS surface morphology was studied by SEM and it was demonstrated that SC is a very effective general corrosion inhibitor of CS. This also was confirmed by contact angle measurements which showed that the CS surface became more hydrophobic when the SC was added to the solution.

  14. Evaluation of Flow Accelerated Corrosion of Carbon Steel with Rotating Cylinder

    International Nuclear Information System (INIS)

    Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. Rotating cylinder FAC test facility was designed and fabricated and then performance of the facility was evaluated. The facility is very simple in design and economic in fabrication and can be used in material and chemistry screening test. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO), and temperature. Fluid velocity is controlled with rotating speed of the cylinder with a test specimen. FAC test of SA106 Gr. B carbon steel under 4 m/s flow velocity was performed with the rotating cylinder at DO concentration of less than 1 ppb and of 1.3 ppm. Also a corrosion test of the carbon steel at static condition, that is at zero fluid velocity, of test specimen and solution was performed at pH from 8 to 10 for comparison with the FAC data. For corrosion test in static condition, the amount of non adherent corrosion product was almost constant at pH ranging from 8 to 10. But adherent corrosion product decreased with increasing pH. This trend is consistent with decrease of Fe solubility with an increase in pH. For FAC test with rotating cylinder FAC test facility, the amount of non adherent corrosion product was also almost same for both DO concentrations. The rotating cylinder FAC test facility will be further improved by redesigning rotating cylinder and FAC specimen geometry for future work

  15. 77 FR 301 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year...

    Science.gov (United States)

    2012-01-04

    ... corrosion-resistant carbon steel flat products from Germany and Korea (72 FR 7009). The Commission is now... part 207), as most recently amended at 74 FR 2847 (January 16, 2009). \\1\\ No response to this request...-resistant carbon steel flat products from Korea (58 FR 43752). On August 19, 1993, Commerce...

  16. Inhibition of the corrosion of carbon steel in HCl solution by methionine and its derivatives

    International Nuclear Information System (INIS)

    Highlights: • The methionine derivatives were good corrosion inhibitors for 1045 carbon steel (CS). • The XPS indicated that the FMOC self-assembled on CS surface by chemisorption. • The Fukui surface distribution and the radial distribution function were used. - Abstract: The self-assembled films of methionine and its derivatives were prepared on a 1045 carbon steel (CS) surface. EIS and potentiodynamic measurements showed that these films could effectively protect CS against corrosion in 0.5 M HCl, with a maximal protection efficiency of 95.01% achieved by FMOC films. An XPS study confirmed that methionine and its derivatives could form films by chemical adsorption on CS. The inhibition mechanism was theoretically investigated through the quantum chemical calculation and dynamic simulation

  17. Study on the Corrosion Inhibition Characteristics of Carbon Steel by Sodium Phosphate and Sodium Nitrite

    International Nuclear Information System (INIS)

    Sodium nitrite is widely used as one of the popular corrosion inhibitors for the protection of ferrous metal in closed cooling water system, such as a diesel engine and a chiller. The optimum treatment conditions are studied through laboratory tests using linear polarization resistance (LPR) technique. Corrosion rate of the carbon steel electrode could be maintained less than 2.5x10-3 mmpy in the test condition of 500 ppm as NO2-, 200 ppm as CT, 70 .deg. C and pH 6.8. The pH control is confirmed not to be an important factor in the protection of carbon steel by sodium nitrite inhibitor. The addition of tolyltriazole was needed for the protection of the copper alloy in the sodium nitrite treatment system

  18. CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B.; Mickalonis, J.; Subramanian, K.; Ketusky, E.

    2011-10-14

    Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid has been selected for this purpose because it is an effective chelating agent for the solids and is not as corrosive as other acids. Electrochemical and immersion studies were conducted to investigate the corrosion behavior of carbon steel in simulated chemical cleaning environments. The effects of temperature, agitation, and the presence of sludge solids in the oxalic acid on the corrosion rate and the likelihood of hydrogen evolution were determined. The testing showed that the corrosion rates decreased significantly in the presence of the sludge solids. Corrosion rates increased with agitation, however, the changes were less noticeable.

  19. [Effect of the biofilm biopolymers on the microbial corrosion rate of the low-carbon steel].

    Science.gov (United States)

    Borets'ka, M O; Kozlova, I P

    2007-01-01

    The relationship between exopolymer's specific production, relative carbohydrate and protein content in the biofilm exopolymers of the pure and mixed Thiobacillus thioparus and Stenotrophomonas maltophilia cultures and their corrosion activity was studied. Change of growth model of investigated cultures from plankton to biofilm led to an increase of specific exopolymer's production. In the biofilm formed by T. thioparus and S. maltophilia biofilm on the low-carbon steel surface one could observe an increase of relative protein content in the exopolymer complex in comparison with those in the pure culture. The development of such biofilms stimulatied the 7-fold corrosion activity. PMID:17977451

  20. Corrugated stainless steels embedded in carbonated mortars with and without chlorides: 9-year corrosion results

    OpenAIRE

    Bautista, A.; Álvarez, S. M.; Paredes, E. C.; Velasco, F.; Guzmán, S.

    2015-01-01

    The corrosion behavior of 5 corrugated stainless steel bars was evaluated in carbonated mortars: UNS S20430, S30400, S31603, S31635 and S32205. The tests were carried out under 3 different exposure conditions: at high relative humidity (C-HRH); partially immersed in 3.5% NaCl (C-PD; and with CaCl2 added during mortar mixing and exposed to high relative humidity (C-HRHCl). Corrosion potential (Ecorr) measurements and electrochemical impedance spectroscopy (EIS) were used to monitor the behavio...

  1. Evaluation of the Microbiologically Influenced Corrosion in a carbon steel making use of electrochemical techniques

    International Nuclear Information System (INIS)

    The Microbiologically Influenced Corrosion (MIC) has been identified as a problem of the nuclear plants systems in the last years. The electrochemical behavior of metal coupons of carbon steel submitted to the action of sulfate reducing bacteria (SRB) was evaluated, making use of the electrochemical techniques of direct current as well as electrochemical noise. The generated results show a little variation in the corrosion velocities which obtained by Tafel extrapolation and resistance to the linear polarization, whereas the electrochemical noise technique presented important differences as regards the registered behavior in environment with and without microorganisms. (Author)

  2. CO2 corrosion resistance of carbon steel in relation with microstructure changes

    OpenAIRE

    Ochoa, Nathalie; Vega, Carlos; Pébère, Nadine; Lacaze, Jacques; Joaquín L. Brito

    2015-01-01

    International audience The microstructural effects on the corrosion resistance of an API 5L X42 carbon steel in 0.5 M NaCl solution saturated with CO2 was investigated. Four microstructures were considered: banded (B), normalized (N), quenched and tempered (Q&T), and annealed (A). Electrochemical measurements (polarization curves and electrochemical impedance spectroscopy) were coupled with surface analyses (scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS)) to ...

  3. Green corrosion inhibitors for carbon steel by green leafy vegetables extracts in 1 M HCl

    OpenAIRE

    Ghadah M. Al-Senani; Sameerah I. Al-Saeedi; Rasmiah Almufarij

    2015-01-01

    The effect of some Green Leafy Vegetables (GLV) extracts namely Lactuca sativa (Lactuca), Eruca Sativa (Arugula), Petroselinum crispum (Parsley), and Anethum Graveolens (Dill) were investigated on inhibition of corrosion carbon steel in 1 M HCl solution using gravimetric (weight loss) method. The inhibition efficiency has increased as concentration of the extract increased. The inhibition efficiency has decreased as the temperature increased. The results obtained showed that GLV extracts inh...

  4. Localized Corrosion of Zn-Plated Carbon Steel Used as a Fire Sprinkler Pipe

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hee [SK Engineering and Construction Corp., Seoul (Korea, Republic of); Lee, You Kee [Ui duk University, Gyeongju (Korea, Republic of); Lee, Kyu Hwan [Korea Institute of Materials Science, Changwon (Korea, Republic of); Kim, Dong Kyu; Lee, Sung Gun; Lee, Sang Hwa; Kim, In Soo [Dong-A University, Busan (Korea, Republic of)

    2009-08-15

    The failure of a Zn-plated carbon steel pipe that served as a fire sprinkler was investigated in terms of the pope's corrosion products. The pipes leaked through holes formed beneath the tubercles. The formation of oxygen concentration cell involves colonization of metal surface by aerobic bacteria or other slime formers, and anodic reaction beneath tubercle is accelerated by the presence of SRB, leading to the formation of hole beneath tubercle.

  5. Mechanistic model of stress corrosion cracking (scc) of carbon steel in acidic solution with the presence of H2s

    International Nuclear Information System (INIS)

    In oil and gas industrial environments, H2S gas is one of the corrosive species which should be a main concern in designing infrastructure made of carbon steel. Combination between the corrosive environment and stress condition will cause degradation of carbon steel increase unpredictably due to their simultaneous effects. This paper will design a model that involves electrochemical and mechanical theories to study crack growth rate under presence of H2S gas. Combination crack and corrosion propagation of carbon steel, with different hydrogen concentration has been investigated. The results indicated that high concentration of hydrogen ions showed a higher crack propagation rate. The comparison between corrosion prediction models and corrosion model developed by researchers used to verify the model accuracy showed a good agreement

  6. Stress corrosion cracking tests for low carbon stainless steels with work hardened layer

    International Nuclear Information System (INIS)

    To avoid introduction of Cr depletion at grain boundaries by welding process, low carbon stainless steels (SSs) were used in corrosive environment as one of countermeasures for Stress Corrosion Cracking (SCC). Recently, it is reported that SCCs were introduced at portion with work hardened layer although low carbon SSs had been used at core shrouds and primary loop recirculation piping in Boiling Water Reactors. To simulate and examine the phenomenon, mechanical working, metallographic observation, hardness test and SCC tests in chloride solutions were conducted for low carbon SSs. From the results of metallographic observation and hardness test, it was confirmed that slip bands were observed around the surface and hardened layer was introduced by mechanical working. From the results of SCC tests, it was noticed that cracks which introduced from the surface, had grown into the matrix. It is thought that low carbon SSs with work hardened layer have susceptibility to SCC from the above. (author)

  7. MECHANIZM OF ANODE DISSOLVING OF CORROSION-RESISTING AND STRUCTURAL CARBON STEELS UNDER ELECTROPULSE POLISHING

    Directory of Open Access Journals (Sweden)

    I. Yunkovsky

    2013-01-01

    Full Text Available In this article were suggested the schemes of anode processes, taking into account the nature of metals, anion structure, pH solution of electrolyte and anode potential by electropulse polishing of corrosion- resisting and structural carbon steels.It is shown and experimentally confirmed, that under conditions of electropulse polishing of anode dissolving of metals, which are contained into corrosion-resisting and structural carbon steels, carried out according to mechanism of complex formation through a set of series and series-parallel of intermediate stages. In the 1st stage on the surface of metals adsorption complexes with participation of chemisorption molecules of water are formed. In the next stages anions of electrolyte’s solution and molecules of water take part. In final stage of dissolving on the surface of anode soluble compounds are formed, which by transition into solution into simple ions are dissociated. It is determined that by electrical-impulse polishing in dissolving of components of corrosion-resisting carbon steels the important role play chemical processes, and anode dissolving of metals take place in the field of mixed electrochemical and diffusion kinetics . Diffusion limitations appear as a result of difficult ion mass transfer through surface salt, oxide and hydro-oxide and absorption-phase coatings.

  8. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    OpenAIRE

    Mazur, M.; R. Bogucki; Pytel, S.

    2010-01-01

    The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy) was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundarie...

  9. The corrosion of carbon steel in aqueous lithium hydroxide under a hydrogen blanket

    International Nuclear Information System (INIS)

    The corrosion behavior of carbon steel in 3 and 5 mol/L aqueous solutions of lithium hydroxide at 95 degrees C under a hydrogen atmosphere was investigated in immersion tests lasting ten days. Corrosion rates were determined by wight loss, and the corrosion products were characterized by bulk chemical analysis, by light and electron microscopy, and by powder X-ray diffraction. Corrosion was uniform and the corrosion rates were moderately high (0.42 mm/y in 3 mol/L and 0.56 mm/y in 5 mol/L). The corrosion products consisted of a mixture of well-formed, octahedral crystals, and poorly crystallized masses and spherules that formed by precipitation from solution. These products formed a scale on the metal surface that continually sloughed off and afforded only minor protection. Both phases were identified as lithium-iron oxides, each possessing a disordered, non-stoichiometric structure. The predominant phase was a magnetic spinel LiFe508 and the minor phase was LiFe02. A corrosion mechanism is outlined. (2 figs., 5 tabs., 20 refs.)

  10. Erosion resistance of CO2 corrosion scales formed on API P110 carbon steel

    International Nuclear Information System (INIS)

    Highlights: • Erosion resistance of CO2 corrosion scales studied in water–sand two-phase flow. • Observations of different trends in the erosion rate versus the corrosion rate. • Accumulation of Fe3C cathodic phase helping to enhance erosion resistance. • Fluid dynamics important to the erosion mechanism of CO2 corrosion scales. - Abstract: The erosion resistance of CO2 corrosion scales formed on carbon steel was investigated in water–sand two-phase flow utilizing weight loss test, scanning electron microscopy, and X-ray diffraction. The effects of CO2 partial pressure, stirring speed, test time, and grain size on the erosion resistance of the scales were analysed. Results show that several characteristics of CO2 corrosion scales are key factors affecting erosion resistance. Cubic polynomials are used to fit the erosion rate data, and effectively evaluate the ability of CO2 corrosion scales to resist erosion. An erosion mechanism, based on fluid dynamics and CO2 corrosion scales characteristics, is discussed

  11. Corrosion rate evaluation of the carbon steel trough electrochemical techniques

    Directory of Open Access Journals (Sweden)

    Jeimmy González-Masís

    2014-02-01

    Full Text Available Usually the atmospheric corrosion studies are cha­racterized by their long duration, months and even years. However electrochemical techniques have been developed, recent in comparison to other methods, allowing obtain real-time data, including corrosion rate. In this research electrochemical noise and lineal polarization resistance tests are valued, so obtained data were analyzed, relations were establis­hed between the graphics form and the corrosion type, as well as the relationship between the corro­sion data and atmospheric conditions, to find, finally, there is a more consistent behavior when the lineal polarization resistance test is used with the three comb-type electrodes electrochemical monitor.

  12. Influences of Spray Parameters on the Structure and Corrosion Resistance of Stainless Steel Layers Coated on Carbon Steel by Plasma Spray Treatment

    International Nuclear Information System (INIS)

    Stainless steel powders were sprayed on the grit-blasted SM45C carbon steel substrates using a plasma spray method. The influences of the spray parameters on the structure and corrosion resistance of the layers coated on the carbon steel were investigated. Corrosion behavior of the layers were analyzed by the anodic polarization tests in deaerated 0.1 M NaCl + 0.01 M NaOH solution at 80 .deg. C. The surface roughness and porosity were observed to decrease with decreasing the particle size. The surface hardness of the coating was always higher than that of the matrix, SM45C, implying that the higher resistance of the coating to erosion-corrosion than that of matrix, and increased as the spray power and the spray distance increase. Stainless steel coats showed more corrosion resistance than the carbon steel did, due to their passivity. The corrosion resistance of the coats, however, were inferior to that of the bulk stainless steels due to the inherent defects formed in the coats. The defects such as rough surface and pores provided the occluded sites favorable for the initiation of localized corrosion, resulting in the conclusion that finer the powder is, higher the corrosion resistance is. And the Cr oxides formation resulting in Cr depletion around the oxides reduced the corrosion resistance of the coats

  13. Corrosion of low carbon steel by microorganisms from the 'pigging' operation debris in water injection pipelines.

    Science.gov (United States)

    Cote, Claudia; Rosas, Omar; Sztyler, Magdalena; Doma, Jemimah; Beech, Iwona; Basseguy, Régine

    2014-06-01

    Present in all environments, microorganisms develop biofilms adjacent to the metallic structures creating corrosion conditions which may cause production failures that are of great economic impact to the industry. The most common practice in the oil and gas industry to annihilate these biofilms is the mechanical cleaning known as "pigging". In the present work, microorganisms from the "pigging" operation debris are tested biologically and electrochemically to analyse their effect on the corrosion of carbon steel. Results in the presence of bacteria display the formation of black corrosion products allegedly FeS and a sudden increase (more than 400mV) of the corrosion potential of electrode immersed in artificial seawater or in field water (produced water mixed with aquifer seawater). Impedance tests provided information about the mechanisms of the interface carbon steel/bacteria depending on the medium used: mass transfer limitation in artificial seawater was observed whereas that in field water was only charge transfer phenomenon. Denaturing Gradient Gel Electrophoresis (DGGE) results proved that bacterial diversity decreased when cultivating the debris in the media used and suggested that the bacteria involved in the whole set of results are mainly sulphate reducing bacteria (SRB) and some other bacteria that make part of the taxonomic order Clostridiales. PMID:24355513

  14. Corrosion and deposition during the exposure of carbon steel to hydrogen sulphide-water solutions

    International Nuclear Information System (INIS)

    Complex multi-phase corrosion films develop on rotating carbon steel discs exposed to aqueous hydrogen sulphide solutions; their structure and morphology can have a profound effect on the corrosion process. Iron sulphide corrosion products formed on corroding carbon steel discs in titanium autoclaves have been characterized after exposure periods ranging from 1 to 840 h at temperatures of 308, 373 and 433 K and a total initial pressure of 1.5 MPa. These reaction conditions pertain to the Girdler-Sulphide process for separating heavy water. In oxygen-free solutions, the evolution of corrosion products on the discs progresses from iron-rich to sulphur-rich phases according to the sequence, mackinawite (tetragonal FeSsub(1-x)) → ferrous sulphide (cubic FeS) → troilite (hexagonal FeS) → pyrrhotite (hexagonal Fesub(1-x)S) → pyrite (cubic FeS2), the latter phase being thermodynamically favoured. All phases except mackinawite appear as characteristic microcrystals of regular geometry, indicating relatively slow solution growth at low supersaturation. Higher temperatures accelerate the sequential transformations while higher speeds of rotation of the disc retard it. Edge turbulence induced at high rotation frequencies prevents the formation of solution-grown phases. Added oxidants promote the formation of the disulphide ion required for FeS2 formation. Fe2+ ions released to the bulk solution by dissolution of the base metal and metastable sulphides are deposited as pyrrhotite or pyrite on the titanium vessel. (author)

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

    Science.gov (United States)

    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.

  16. Surface analysis study of gamma-radiation-induced carbon steel corrosion

    International Nuclear Information System (INIS)

    The corrosion rate of a metal depends on the nature of the surface oxide and its redox environment. Ionizing radiation can significantly alter the redox environment in water. We have investigated the impact of γ-radiation on the kinetics of carbon steel corrosion by characterizing the oxide films formed on carbon steel as a function of pH, cover gas, temperature, and irradiation time, using a range of surface analysis techniques. Results show that continuous irradiation enhances surface oxide formation with the type of oxide depending on the solution pH. For tests at 150oC and a [OH-] equivalent to that for pH25°C = 10.6, the surface oxide on carbon steel after γ-irradiation was non-porous and uniform; no localized corrosion was observed. However, this oxide appears to be susceptible to brittle fracture during cooling. Raman spectroscopy of the surface film shows that it is a mixed phase of Fe3O4 and γ-Fe2O3. In contrast, for tests at 150oC with [OH-] equivalent to neutral pH25°C, metal dissolution is significant and the surface oxide film is very porous. While Raman spectra show an oxide mostly composed of a similar mixed phase of Fe3O4 and γ-Fe2O3, SEM micrographs provide an image of the porous nature of the oxide grown at neutral pH25°C. At both pHs, α-Fe2O3 phase oxide, the most thermodynamically stable oxide under oxidizing conditions, has not been observed. The combination of this study and previously reported electrochemical studies provide a clearer understanding of the temperature dependence of oxide film formation/conversion processes on carbon steel, and allows us to distinguish radiation effects from those of temperature. (author)

  17. Oleic acid-grafted chitosan/graphene oxide composite coating for corrosion protection of carbon steel.

    Science.gov (United States)

    Fayyad, Eman M; Sadasivuni, Kishor Kumar; Ponnamma, Deepalekshmi; Al-Maadeed, Mariam Al Ali

    2016-10-20

    An anticorrosion coating film based on the formation of nanocomposite coating is reported in this study. The composite consisted of chitosan (green matrix), oleic acid, and graphene oxide (nano filler). The nanocomposite coating was arranged on the surface of carbon steel, and the corrosion resistance was monitored using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP). Compared to the pure chitosan (CS) coating, the corrosion resistance of oleic acid-modified chitosan/graphene oxide film (CS/GO-OA) is increased by 100 folds. Since the well-dispersed smart grafted nanolayers delayed the penetration rate of corrosive species and thus maintained long term anticorrosive stability which is correlated with hydrophobicity and permeability. PMID:27474635

  18. Stress corrosion cracking tests on electron beam welded carbon steel specimens in carbonate-bicarbonate solution

    International Nuclear Information System (INIS)

    Stress corrosion cracking tests have been performed on tapered carbon steel test pieces containing electron beam welds with a view to defining susceptibility to such cracking in a carbonate-bicarbonate solution at 90 C and an appropriate electrode potential. The tests involved applying cyclic loads to the specimens and it is shown that the threshold stress for cracking reduces linearly with increase in the magnitude of the cyclic load component. Extrapolation of these trends to zero fluctuating stress indicates static load threshold stresses in the vicinity of the yield stress (i.e. about 300 N/mm2 for parent plate without a weld, 400 N/mm2 for specimens with welds on one side only and 600 N/mm2 for specimens having welds penetrating through the thickness of the specimen). The averages of the maximum crack velocities observed were least for parent plate material and greatest for weld metal, the former being essentially intergranular in morphology and the latter mostly transgranular, with heat affected zone material being intermediate between these extremes. (author)

  19. Use of Homogeneously-Sized Carbon Steel Ball Bearings to Study Microbially-Influenced Corrosion in Oil Field Samples

    OpenAIRE

    Gerrit eVoordouw; Priyesh eMenon; Tijan ePinnock; Mohita eSharma; Yin eShen; Amanda eVenturelli; Johanna eVoordouw; Aoife eSexton

    2016-01-01

    Microbially-influenced corrosion (MIC) contributes to the general corrosion rate (CR), which is typically measured with carbon steel coupons. Here we explore the use of carbon steel ball bearings, referred to as beads (55.0 ± 0.3 mg; Ø = 0.238 cm), for determining CRs. CRs for samples from an oil field in Oceania incubated with beads were determined by the weight loss method, using acid treatment to remove corrosion products. The release of ferrous and ferric iron was also measured and CRs ba...

  20. A Study on the Effect of Electrolyte Thickness on Atmospheric Corrosion of Carbon Steel

    International Nuclear Information System (INIS)

    Effect of electrolyte layer thickness and increase in concentration of electrolyte during electrolyte thining on the atmospheric corrosion of carbon steel were investigated using EIS and cathodic polarization technique. The electrolyte layer thickness was controlled via two methods : one is mechanical method with microsyringe applying a different amount of electrolyte onto the metal surface to give different electrolyte thickness with the same electrolyte concentration. The other is drying method in which water layer thickness decreases through drying, causing increase in concentration of electrolyte during electrolyte thinning. In the region whose corrosion rate is controlled by cathodic reaction, corrosion rate for mechanical method is larger than that for drying method. However, for the electrolyte layers thinner than 20 ∼ 30 m, increase in concentration of electrolyte cause a higher corrosion rate for the case of the mechanical method compared with that of drying method. For a carbon steel covered with 0.1M Na2SO4, maximum corrosion rate is found at an electrolyte thickness of 45 ∼ 55 μm for mechanical method. However, maximum corrosion rate is found at an electrolyte thickness of 20 ∼ 35 μm for drying method. The limiting current is inversely proportional to electrolyte thickness for electrolyte thicker than 20 ∼ 30 μm. However, further decrease of the electrolyte thickness leads to an electrolyte thickness-independent limiting current reagion, where the oxygen rate is controlled by the solvation of oxygen at the electrolyte/gas interface. Diffusion limiting current for drying method is smaller compared with that for mechanica control. This can be attributed to decreasing in O2 solubility caused by increase in concentration of electrolyte during electrolyte thining

  1. Early stages of pitting corrosion of UNS K03014 carbon steel in sour corrosion environments: The influence of CO2, H2S and temperature

    OpenAIRE

    Pessu, F; Barker, R; A. Neville

    2015-01-01

    The challenges in managing localized corrosion failures in oilfields are of serious concern. In environments containing both CO2 and H2S gas, pitting corrosion of carbon steel is considered to be a common occurrence and particularly complex. The actual mechanisms and sequence of electrochemical activities for pitting corrosion in these environments is still not fully understood. The film formation characteristics and morphology in CO2 and H2S-containing systems is also known to influence the ...

  2. Factors affecting stress assisted corrosion cracking of carbon steel under industrial boiler conditions

    Science.gov (United States)

    Yang, Dong

    Failure of carbon steel boiler tubes from waterside has been reported in the utility boilers and industrial boilers for a long time. In industrial boilers, most waterside tube cracks are found near heavy attachment welds on the outer surface and are typically blunt, with multiple bulbous features indicating a discontinuous growth. These types of tube failures are typically referred to as stress assisted corrosion (SAC). For recovery boilers in the pulp and paper industry, these failures are particularly important as any water leak inside the furnace can potentially lead to smelt-water explosion. Metal properties, environmental variables, and stress conditions are the major factors influencing SAC crack initation and propagation in carbon steel boiler tubes. Slow strain rate tests (SSRT) were conducted under boiler water conditions to study the effect of temperature, oxygen level, and stress conditions on crack initation and propagation on SA-210 carbon steel samples machined out of boiler tubes. Heat treatments were also performed to develop various grain size and carbon content on carbon steel samples, and SSRTs were conducted on these samples to examine the effect of microstructure features on SAC cracking. Mechanisms of SAC crack initation and propagation were proposed and validated based on interrupted slow strain tests (ISSRT). Water chemistry guidelines are provided to prevent SAC and fracture mechanics model is developed to predict SAC failure on industrial boiler tubes.

  3. Anti-Corrosive Effect of Tridax Procumbens – Zn2+ System Controlling the Corrosion of Carbon Steel

    Directory of Open Access Journals (Sweden)

    C. Kumar

    2014-03-01

    Full Text Available The corrosion inhibition efficiency (IE of an aqueous extract Tridax Procumbens(TP in controlling the corrosion of carbon steel aqueous medium containing 60 ppm of chloride ions in absence and presence of Zn2+ has been studied by weight loss method. The formulation consisting of 1 ml of Tridax Procumbens extract and 150 ppm of Zn2+ offers 96% inhibition efficiency. The synergistic effect exists between Tridax Procumbens and Zn2+ system. Polarization study shows that the Tridax Procumbens – Zn2+ system function as a cathodic inhibitor. AC impedance spectra reveal that a protective film formed on the surface. The Adsorption equilibrium exhibited better fit to Langmuir isotherm than Freundlich isotherm. FTIR spectra reveal that the protective film consists of Fe2+ -Tridax Procumbens and Zn(OH2.

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

    Science.gov (United States)

    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

  5. Microbial Corrosion of API 5L X-70 Carbon Steel by ATCC 7757 and Consortium of Sulfate-Reducing Bacteria

    OpenAIRE

    2014-01-01

    Various cases of accidents involving microbiology influenced corrosion (MIC) were reported by the oil and gas industry. Sulfate reducing bacteria (SRB) have always been linked to MIC mechanisms as one of the major causes of localized corrosion problems. In this study, SRB colonies were isolated from the soil in suspected areas near the natural gas transmission pipeline in Malaysia. The effects of ATCC 7757 and consortium of isolated SRB upon corrosion on API 5L X-70 carbon steel coupon were i...

  6. 76 FR 55004 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary...

    Science.gov (United States)

    2011-09-06

    ..., 75 FR 55769 (September 14, 2010) (unchanged in CORE 16 Final Results); Certain Corrosion-Resistant... for Revocation in Part, 75 FR 60076, 60077 (September 29, 2010) (Initiation Notice). In addition... Carbon Steel Flat Products from Korea, 58 FR 44159 (August 19, 1993) (Orders on Certain Steel from...

  7. Microbiologically influenced corrosion of carbon steel from secondary circuit of nuclear power plant

    International Nuclear Information System (INIS)

    Microbiologically influenced corrosion (MIC) is the initiation or acceleration of the corrosion due to the interaction between the microbial activity and the corrosion processes. During 1980s , the electric power industry, particularly the nuclear industry , has devoted increased attention to MIC that affect reliability, operating and maintenance costs of plant systems. The economic impact of failures in such systems in large nuclear units can be extremely costly, about USD 1,000,000 per day. Costs for chemicals and delivery systems for water treatments to prevent MIC and biofouling can approach about USD 1,000,000 per year. Several plants have been forced to undertake replacement or to make extensive repairs of their service water system at a cost of about USD 30,000,000 per plant. Nuclear power plant can exhibit MIC as a result of their basic design philosophy. The large number of stand-by and redundant systems in nuclear plant design establishes stagnant or intermittent flow conditions, a situation in which a number of systems, some of which are safety-related, will be susceptible to MIC. The large size of nuclear generating facilities and the often prolonged licensing process has resulted in an extended construction phase, often with structural materials in contact with stagnant, untreated water used for hydrostat testing. This also produces a condition amenable to microbial growth. Carbon steels may experience random pitting, general corrosion, or severe degradation in flow as a result of MIC. Tubercles (comprising corrosion products, microbes, sticky exopolymer associated with both living and dead cells, and debris) often form on carbon steel pipes and other components. The tubercles create a hydraulic resistance to cooling water flow as well as sites for additional microbial activity. Tubercles can grow together, eventually becoming a severe impediment to cooling water flow. Pitting is also often observed beneath tubercles as mechanical and chemical

  8. Flow accelerated corrosion of carbon steel piping in nuclear power plants

    International Nuclear Information System (INIS)

    Flow accelerated corrosion (FAC) is a process whereby the normally protective oxide layer on carbon or low alloy steel dissolved into a stream of flowing water resulting in increasing the corrosion rate. Major influencing factors that affect the FAC are flow velocity, temperature, pH, dissolved oxygen concentration, and steel composition. The experimental study described in this paper was focused on evaluating the FAC behavior of carbon steel according to environment conditions. Feasibility tests for the mitigation method against the FAC were also carried out with controlling the water chemistry and with applying the magnetic field. A high temperature rotating cylinder electrode (HTRCE) and a water chemistry control system was developed to perform the electrochemical test in high temperature water environments. The main design concept of HTRCE is to assure stable operation of working electrode in a severe environment, to insulate electrode housing except working electrode surface against external fluid, and to extract corrosion parameter from the rotating cylinder to outside of the autoclave safely. The electrochemical corrosion potential (ECP) and current density were measured as a function of temperature and rotating speed using polarization monitoring. ECP values dropped at a rate of -1.51 mV/.deg. C above 150 .deg. C, which may be come from the formation of magnetite on the steel surface. With increasing rotation of the RCE, the ECP shifted upward in all temperature ranges. This shift may be attributed to the diffusion enhancement of the oxidizing agents in the rapidly flowing of fluid. From the velocity exponent of the cathodic half-cell current density on the steel surface, it was evident that a mass transfer process first dominated the corrosion reaction at 150 .deg. C, and then an activation process partly controlled the corrosion kinetics with increasing temperature. From the results of corrosion experiment at high temperature water, HTRCE has been proved

  9. Novel cationic gemini surfactants as corrosion inhibitors for carbon steel pipelines

    International Nuclear Information System (INIS)

    In the present investigation novel cationic gemini surfactants namely: bis(p-(N,N,N-octyldimethylammonium bromide)benzylidene)benzene-1,4-diamine (I), bis(p-(N,N,N-decyldimethylammonium bromide)benzylidene)benzene-1,4-diamine (II), and bis(p-(N,N,N-dodecyldimethylammonium bromide)benzylidene)benzene-1,4-diamine (III) were synthesized, characterized, and tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency was measured by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss methods. The obtained results showed that, the synthesized inhibitors are excellent inhibitors for carbon steel in 1 M HCl solution. The inhibition efficiency decreased in the temperature range 30-40 oC and then increased in the temperature range 40-60 oC. The prepared inhibitors act as mixed inhibitors. Thermodynamic and activation parameters were discussed. Adsorption of the synthesized inhibitors was found to follow the Langmuir's adsorption isotherm. Mixed physical and chemical adsorption mechanism is proposed. The morphology of carbon steel samples was investigated by scanning electron microscopy (SEM).

  10. Synthesis of bolaamphiphile surfactants and their inhibitive effect on carbon steel corrosion in hydrochloric acid medium

    International Nuclear Information System (INIS)

    Corrosion inhibition by surfactant molecules is related to the surfactant's ability to aggregate at interfaces and in solution. In this work some new triazole bolaamphiphiles in the series of 1,n-bis(1,2,4-triazolyl)alkane where n=10, 12 have been synthesized. The purity of surfactants synthesized was checked by rutinary methodologies (IR, 1H NMR, 13C NMR, mass spectra and elemental analysis). The aggregation of 1,n-bis(1,2,4-triazolyl)alkane have been determined by surface tension at the air-HCl 1 M interface. The inhibiting action of these compounds towards the corrosion of carbon steel in 1 M HCl solution was investigated using gravimetric, potentiodynamic and electrochemical impedance spectroscopy measurements. Polarization data indicate that these compounds act as very good cathodic inhibitors for carbon steel in 1 M HCl. The values of the transfer resistance, obtained from impedance plots of carbon steel, increase by increasing product concentration. From all measurements carried out, the variation of the inhibition efficiency versus concentration shows the same trend. The electrochemical study shows that DTC12 is the best inhibitor and its efficiency increases with concentration and the highest value obtained is around 94%

  11. Chemical transition of nitrate ions accompanied with corrosion of carbon steel under alkaline conditions

    International Nuclear Information System (INIS)

    Carbon steel was immersed in an aqueous solution of NaNO3 in a closed system for observing both the chemical interaction between metal and NO3-, and the effect of nitrate on the generation rate of H2 gas. The experimental pH range of the solution was 10.0-13.5 which corresponds to that of pore fluid in cementitious material. The cathodic current density showed a 'Tafel equation type' potential dependency in aqueous solution containing NO3- or NO2-. In spite of the accelerated cathodic reaction due to the existence of nitrate, the corrosion rate of carbon steel was not accelerated in the nitrate solutions. This fact suggests that the system is controlled by the anodic reaction. The nitrate reduction accompanied by the corrosion of carbon steel is considered to be a series reaction such as NO3-→NO2-→NH3. The nitrate reduction reaction competes with the water reduction reaction (hydrogen evolution reaction) within the anodic controlled condition, therefore nitrate strongly reduces the hydrogen generation rate (1/100-1/500 of the cases without nitrate in 1.0 mol dm-3 NaNO3 cases). The generation rates of NH3 were independent of the concentration of NO3- over the range of 1.0 x 10-3 - 1.0 mol dm-3. (author)

  12. High temperature corrosion of low and high alloy steels under molten carbonate fuel cell conditions

    Energy Technology Data Exchange (ETDEWEB)

    Biedenkopf, P.; Spiegel, M.; Grabke, H.J. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

    1997-08-01

    The corrosion behavior of eight low and high alloy steels was investigated under simulating the conditions at the cathode of a molten carbonate fuel cell at 650 C. Different Li-containing iron oxides (LiFeO{sub 2} and LiFe{sub 5}O{sub 8}) were formed in contact with the eutectic (Li, K)-carbonate melt depending on the Cr-content of the steel. These oxides show low solubility in the melt and protect the metallic material against further corrosive attack. Fast growing scales of Fe{sub 3}O{sub 4} and LiFe{sub 5}O{sub 8} were observed on the low alloy ferritic steel 10 CrMo 9 10. Higher alloy steels form LiFeO{sub 2} in contact with the melt and mixed Fe-Cr-spinels underneath. Steels with Cr-contents over 20 wt.% Cr form a mixed LiCr{sub 1-x}Fe{sub x}O{sub 2} and LiCrO{sub 2} layer in contact with the metal. Marker experiments on the commercial steel 1.4404 (X2 CrNiMo 17 13 2) show that the outer LiFeO{sub 2} layer grows mainly by outward diffusion of iron ions (Fe{sup 3+}), whereas the inner (Fe,Ni)Cr{sub 2}O{sub 4} spinel layer grows inward. After 500 hours, LiFe{sub 5}O{sub 8} was formed between the spinel and the LiFeO{sub 2} layer, but it had disappeared after several thousand hours of exposure as it was fully transformed to LiFeO{sub 2}. Co-containing LiFeO{sub 2} was found after 500 hours on the high Co-containing steel 1.4971 (X12 CrCoNi 21 20), but is not stable after several thousand hours exposure. Co diffuses outward to form a protective LiCoO{sub 2} layer of a few microns in thickness. Protective Cr{sub 2}O{sub 3} layers were not observed on steels with high Co-content ({>=}25 wt.% Cr) due to peroxide ions in the melt, which cause oxidation Cr{sub 2}O{sub 3} and flux to chromate, which is highly soluble in the melt. Further quantitative investigations on total corrosion considering the chromate formation have shown that high alloy steels with high amounts of Cr form mainly K{sub 2}CrO{sub 4}. (orig.) 22 refs.

  13. High temperature corrosion of low and high alloy steels under molten carbonate fuel cell conditions

    International Nuclear Information System (INIS)

    The corrosion behavior of eight low and high alloy steels was investigated under simulating the conditions at the cathode of a molten carbonate fuel cell at 650 C. Different Li-containing iron oxides (LiFeO2 and LiFe5O8) were formed in contact with the eutectic (Li, K)-carbonate melt depending on the Cr-content of the steel. These oxides show low solubility in the melt and protect the metallic material against further corrosive attack. Fast growing scales of Fe3O4 and LiFe5O8 were observed on the low alloy ferritic steel 10 CrMo 9 10. Higher alloy steels form LiFeO2 in contact with the melt and mixed Fe-Cr-spinels underneath. Steels with Cr-contents over 20 wt.% Cr form a mixed LiCr1-xFexO2 and LiCrO2 layer in contact with the metal. Marker experiments on the commercial steel 1.4404 (X2 CrNiMo 17 13 2) show that the outer LiFeO2 layer grows mainly by outward diffusion of iron ions (Fe3+), whereas the inner (Fe,Ni)Cr2O4 spinel layer grows inward. After 500 hours, LiFe5O8 was formed between the spinel and the LiFeO2 layer, but it had disappeared after several thousand hours of exposure as it was fully transformed to LiFeO2. Co-containing LiFeO2 was found after 500 hours on the high Co-containing steel 1.4971 (X12 CrCoNi 21 20), but is not stable after several thousand hours exposure. Co diffuses outward to form a protective LiCoO2 layer of a few microns in thickness. Protective Cr2O3 layers were not observed on steels with high Co-content (≥25 wt.% Cr) due to peroxide ions in the melt, which cause oxidation Cr2O3 and flux to chromate, which is highly soluble in the melt. Further quantitative investigations on total corrosion considering the chromate formation have shown that high alloy steels with high amounts of Cr form mainly K2CrO4. (orig.)

  14. The role of bacterial communities and carbon dioxide on the corrosion of steel

    International Nuclear Information System (INIS)

    Highlights: • Two natural bacterial communities grew with only water, CO2 and steel. • One of these cultures increased corrosion rates by 45.5% in two months. • The species may serve different roles as electron donor or acceptor and fixing CO2. • Organic carbon was not required for growth. CO2 was the final electron acceptor and carbon source. • Each species required the others to grow in our culture conditions. - Abstract: Natural microbial communities were grown anaerobically with steel as the electron source and CO2 the electron acceptor and carbon source, without organic carbon and typical electron acceptors. The cultures increased corrosion by up to 45.5% compared to sterile controls in two months. Pyrosequencing showed the presence of sulphate reducing bacteria (SRB), sulphur reducing bacteria (S0RB) and acetogens likely growing in a syntrophic relationship where SRB extracted electrons from iron, acetogens accepted electrons and reduced CO2 to acetate, which served as carbon source for SRB and/or S0RB. The SRB Desulfovibrio mexicanus comprised up to 90.1% of the community

  15. Anti-corrosive Effects of Multi-Walled Carbon Nano Tube and Zinc Particle Shapes on Zinc Ethyl Silicate Coated Carbon Steel

    Energy Technology Data Exchange (ETDEWEB)

    Jang, JiMan; Shon, MinYoung; Kwak, SamTak [Pukyong National University, Busan (Korea, Republic of)

    2016-01-15

    Zinc ethyl silicate coatings containing multi walled carbon nanotubes (MWCNTs) were prepared, to which we added spherical and flake shaped zinc particles. The anti-corrosive effects of MWCNTs and zinc shapes on the zinc ethyl silicate coated carbon steel was examined, using electrochemical impedance spectroscopy and corrosion potential measurement. The results of EIS and corrosion potential measurement showed that the zinc ethyl silicate coated with flake shaped zinc particles and MWCNT showed lesser protection to corrosion. These outcomes were in agreement with previous results of corrosion potential and corrosion occurrence.

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

    International Nuclear Information System (INIS)

    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

  17. Effect of antimony(III) on carbon steel corrosion inhibition by molybdate in citric acid solution

    International Nuclear Information System (INIS)

    Molybdate is known as a good corrosion inhibitor of carbon steel (CS). But it cannot inhibit CS corrosion in citric acid solution at 85 °C. It has been observed that the presence of small concentration of Sb(III) along with MoO42- inhibits CS corrosion efficiently. The corrosion inhibition by MoO42- have been studied extensively by varying the concentration of Sb(III) and MoO42-. A critical concentration of MoO42- is required to passivate CS in acid medium in the presence of Sb(III). The study shows that molybdate forms a thin protective layer on CS surface in presence of Sb(III) which provides the corrosion inhibition. Inhibition property and the layer composition on CS surface have been studied by electrochemical and surface analytical techniques. The protective layer is found to be composed of both Mo and Sb and appears to be formed due to cathodic reduction of Mo6+ to Mo5+ and Mo4+ and anodic oxidation of Fe and Sb. (author)

  18. Atmospheric corrosion of carbon steel at marine sites in Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Syed, S. [Chemical Engineering Department, King Saud University, Riyadh (Saudi Arabia)

    2010-03-15

    Atmospheric corrosion tests, according to ASTM G50-76, have been carried out in Saudi Arabia, at eight marine sites representing different environmental conditions. Environmental factors such as average temperature, average relative humidity, and deposition rates of atmospheric pollutants (Cl{sup -} and SO{sub 2}) was investigated. X-ray diffraction has been used to determine the composition of the corrosion products. Corrosion rates have been determined for each sample at each of the exposure sites via loss of weight. The obtained data were used for the classification of atmospheric aggressivity, according to ISO 9223. The results obeyed well with the empirical kinetics equation of the form C = Kt{sup n}, where K and C are the corrosion losses in mg/cm{sup 2} after 1 and t years of the exposure respectively, and n is constant. Based on n values, the corrosion mechanism of carbon steel is predicted. The major constituent of the rust formed in marine environment is goethite ({alpha}-FeOOH). Samples also show the presence of a large proportion of lepidocrocite ({gamma}-FeOOH) and small amounts of ferrihydrite and maghemite ({alpha}-Fe{sub 2}0{sub 3}). (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  19. Outdoor corrosion of zinc coated carbon steel, determined by thin layer activation

    International Nuclear Information System (INIS)

    Thin Layer Activation was applied in the frame of a European programme addressed to the evaluation of the corrosion the behaviour of different steels. This included outdoor exposure of zinc coated carbon steel in a rural-marine climatic environment, for a period of several months. The zinc layer of specimens was 10 micrometers thick. For the TLA studies 65Zn radio nuclides were produced along the full depth of the coating, by a cyclotron accelerated deuteron beam. For quantification of the material release, activity versus depth was determined using different thickness of Zn coatings on top the carbon steel. After exposure corrosion product were removed from the surface using a pickling solution and the residual activity was determined by gamma spectrometry. The high sensitivity of the method allowed the evaluation of relatively small thickness losses (i.e. 1.2 micrometer). Thickness loss results, obtained by the TLA method, were compared with those arising from the Atomic Absorption analysis of zinc detected in the pickling solutions. A good agreement was observed between the different methods

  20. Inhibition of the corrosion of carbon steel in neutral solutions by water soluble polyaniline

    International Nuclear Information System (INIS)

    The aim of this work is to study the inhibition effect of water-soluble polyaniline (sulphonate polyaniline) on the corrosion of carbon steel in neutral solutions. The effect on the inhibition efficiency of concentration, temperature has been studied systematically by mass-loss method and by electrochemical measurements. All these methods confirmed that the inhibition efficiency of sulphonate polyaniline increases in increasing its concentration, but decreases in increasing temperature. The studies of potentiodynamic polarization and electrochemical impedance spectroscopy reveal that sulphonate polyaniline acts as an anodic inhibitor. (author)

  1. Corrosion analysis of decommissioned carbon steel waste water tanks at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    A corrosion analysis was carried out on available sections of carbon steels taken from two decommissioned radioactive waste water tanks at Brookhaven National Laboratory. One of the 100,000 gallon tanks suffered from a pinhole failure in the wall which was subsequently patched. From the analysis it was shown that this leak, and two adjacent leaks were initiated by a discarded copper heating coil that had been dropped into the tank during service. The failure mechanism is postulated to have been galvanic attack at points of contact between the tank structure and the coil. Other leaks in the two tanks are also described in this report

  2. Corrosion analysis of decommissioned carbon steel waste water tanks at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Soo, P.; Roberts, T.C.

    1995-07-01

    A corrosion analysis was carried out on available sections of carbon steels taken from two decommissioned radioactive waste water tanks at Brookhaven National Laboratory. One of the 100,000 gallon tanks suffered from a pinhole failure in the wall which was subsequently patched. From the analysis it was shown that this leak, and two adjacent leaks were initiated by a discarded copper heating coil that had been dropped into the tank during service. The failure mechanism is postulated to have been galvanic attack at points of contact between the tank structure and the coil. Other leaks in the two tanks are also described in this report.

  3. The kinetics of pitting corrosion of carbon steel applied to evaluating containers for nuclear waste disposal

    International Nuclear Information System (INIS)

    This is the final summary report on a project, funded by SKB, investigating the pitting corrosion of carbon steel containers for high level nuclear waste or spent reactor fuel under granite disposal conditions. The study has covered a statistically based experimental programme to establish the pit growth kinetics, and a modelling study to determine the maximum pitting period subsequent to repository closure. It is shown that the rate of pit propagation is slower than that suggested by earlier work and that the maximum pitting period is only a small fraction of the target container life of 1000 years. An illustrative example of the methodology for estimating the corrosion allowance needed to prevent pit penetration is given. This could be applied to specific repository conditions as defined by SKB. Finally some limited recommendations are made for further studies to test and validate the methodology. (au)

  4. Corrosion protection of low-carbon steel using exopolysaccharide coatings from Leuconostoc mesenteroides

    Science.gov (United States)

    Corrosion is one of the most serious and challenging problems faced worldwide by industry. This research investigates the inhibition of corrosive behavior of SAE1010 steel by bacterial exopolysaccharides. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion inhibition of diffe...

  5. Basic relationships between corrosion-erosion of carbon steels in power-plant water loops and thermodynamic factors of equilibrium

    International Nuclear Information System (INIS)

    The modern level of development of energetics has brought to the forefront the problem of improving the reliability and safety in the operation of power-generating units in fuel-fired and atomic power plants, by reducing the amount of corrosion-erosion and mass transfer of corrosion products in water loops. The authors have attempted not only to provide a thermodynamic explanation for data on the corrosion-erosion of carbon steels in the water loops of power-generating units with the parameters of state corresponding to specific water-chemistry regimes, but also to develop a semiquantitative physicochemical model of corrosion-erosion in chemically desalted water

  6. A facile electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on carbon steel

    Science.gov (United States)

    Fan, Yi; He, Yi; Luo, Pingya; Chen, Xi; Liu, Bo

    2016-04-01

    Superhydrophobic Fe film with hierarchical micro/nano papillae structures is prepared on C45 steel surface by one-step electrochemical method. The superhydrophobic surface was measured with a water contact angle of 160.5 ± 0.5° and a sliding angle of 2 ± 0.5°. The morphology of the fabricated surface film was characterized by field emission scanning electron microscopy (FE-SEM), and the surface structure seems like accumulated hierarchical micro-nano scaled particles. Furthermore, according to the results of Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS), the chemical composition of surface film was iron complex with organic acid. Besides, the electrochemical measurements showed that the superhydrophobic surface improved the corrosion resistance of carbon steel in 3.5 wt.% NaCl solution significantly. The superhydrophobic layer can perform as a barrier and provide a stable air-liquid interface which inhibit penetration of corrosive medium. In addition, the as-prepared steel exhibited an excellent self-cleaning ability that was not favor to the accumulation of contaminants.

  7. Formation of the self-assembled structures by the ultrasonic cavitation erosion-corrosion effect on carbon steel

    Directory of Open Access Journals (Sweden)

    Dayun Yan

    2015-11-01

    Full Text Available The cavitation erosion-corrosion effect on the metal surface always forms irregular oxide structures. In this study, we reported the formation of regular self-assembled structures of amorphous nanoparticles around the cavitation erosion pits on carbon steel upon the ultrasonic cavitation in methylene blue solution. Each self-assembled structure was composed of linearly aligned nanoparticles of about 100 nm. The formation of self-assembled structures might be due to the combined effect of corrosion, specific sonochemical reaction in methylene blue solution, and the magnetic domain structures on the carbon steel.

  8. Mechanism of pitting corrosion prevention by nitrite in carbon steel exposed to dilute salt solutions. 1998 annual progress report

    International Nuclear Information System (INIS)

    'The overall goal of this project is to develop a fundamental understanding of the role of nitrite in preventing the breakdown of protective oxide(s) on carbon steel and the onset of pitting. Pitting corrosion of carbon steel exposed to dilute alkaline salt solutions can be induced by nitrate, sulfate, and chloride ions and is prevented by sufficient concentration of nitrite. A significant example of this material/electrolyte system is the storage and processing of DOE''s high-level radioactive liquid waste in carbon steel tanks. Added nitrite in the waste has a considerable downstream impact on the immobilization of the waste in a stable glass form. Waste tank integrity and glass production efficiency may benefit from the fundamental understanding of nitrite''s role in preventing pitting. This report summarizes progress after approximately six months of effort in this three-year EMSP project. Initial experimental and theoretical work has focused on the electrochemical behavior of carbon steel in simplified non-radioactive solutions that simulate complex dilute radioactive waste solutions. These solutions contain corrosion-inducing species such as nitrate and chloride and the corrosion-inhibiting nitrite at moderately alkaline pHs. The electrochemical behavior of interest here is that of the open-circuit potential of the steel specimen at equilibrium in the experimental electrolyte and the measures of the steel''s passivity and passivity breakdown.'

  9. Surface coatings on carbon steel for prevention of flow accelerated corrosion under two phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Hee-Sang; Kim, Kyung Mo; Hur, Do Haeng [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Seung Hyun; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    Since the occurrence of a Surry-2 pipe rupture accident, a lot of effort has been made to prevent FAC of carbon steel piping. Some of the chemicals were suggested as a corrosion inhibitor. A platinum decoration was applied as another prevention strategy of carbon steel thinning. The severe FAC-damaged carbon steel pipings were replaced by tolerant materials such as SA335 Gr.P22. However, some components such as the piping materials between moisture separator and turbine have still suffered from the FAC degradation. This work provides a coating method to prevent the FAC degradation of the SA106 Gr.B, which is a piping material between moisture separator and high-pressure turbine, under two-phase flow. We suggested the coating materials to prevent FAC of SA106Gr.B under two-phase water-vapor flow. The FAC resistance of SA106Gr.B was improved with 5 times by electroless-deposited Ni-P protective layer. Other coating materials also enhanced the tolerance up to 5 times for the FAC in a condition of 150 .deg. C and 3.8 bar at 9.5 compared to non-coated SA106Gr.B.

  10. Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    K. T. Kim

    2015-01-01

    Full Text Available While NaNO2 addition can greatly inhibit the corrosion of carbon steel and ductile cast iron, in order to improve the similar corrosion resistance, ca. 100 times more NaNO2 addition is needed for ductile cast iron compared to carbon steel. A corrosion and inhibition mechanism is proposed whereby NO2- ion is added to oxidize. The NO2- ion can be reduced to nitrogen compounds and these compounds may be absorbed on the surface of graphite. Therefore, since nitrite ion needs to oxidize the surface of matrix and needs to passivate the galvanic corroded area and since it is absorbed on the surface of graphite, a greater amount of corrosion inhibitor needs to be added to ductile cast iron compared to carbon steel. The passive film of carbon steel and ductile cast iron, formed by NaNO2 addition showed N-type semiconductive properties and its resistance, is increased; the passive current density is thus decreased and the corrosion rate is then lowered. In addition, the film is mainly composed of iron oxide due to the oxidation by NO2- ion; however, regardless of the alloys, nitrogen compounds (not nitrite were detected at the outermost surface but were not incorporated in the inner oxide.

  11. Assessing resistance of stabilized corrosion resistant steels to intergranular corrosion

    International Nuclear Information System (INIS)

    Resistance to intergranular corrosion was determined for four types of titanium-stabilized steels from the coefficients of stabilization efficiency according to the degree the chemical composition was known. The ATA SUPER steel showed the highest resistance parameter value. The resistance of this type of steel of a specific composition, showing a relatively low value of mean nitrogen content was compared with steel of an optimized chemical composition and with low-carbon niobium stabilized, molybdenum modified steels. The comparison showed guarantees of a sufficient resistance of the steel to intergranular corrosion. The method of assessing the resistance to intergranular corrosion using the calculation of the minimum content of Cr', i.e., the effective chromium content, and the maximum effective carbon content C' giving the resistance parameter k seems to be prospective for practical use in the production of corrosion resistant steels. (author). 1 tab., 5 figs., 15 refs

  12. Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Buchweishaija, Joseph

    1997-12-31

    Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

  13. Chloride induced localized corrosion in simulated concrete pore solution: effect of a phosphate-based inhibitor on the behavior of 304L stainless steel compared to carbon steel

    International Nuclear Information System (INIS)

    In this paper, the acoustic emission technique coupled with electrochemical measurements was used to determine, in simulated concrete pore solution (Ca(OH)2), the critical value [Cl-] / [OH-], which prevents the pitting corrosion initiation of AISI 304L austenitic stainless steel, and to compare this critical value with that of the carbon steel in the same medium with and without inhibitor Na3PO4. The results show that for the austenitic stainless steel, the critical threshold of pitting corrosion initiation is around 5, while for carbon steel without inhibitor in Ca(OH)2 solution, it has a low value of about 0.6. However, the presence of the inhibitor Na3PO4 in this solution leads to the formation of a protective phosphate layer on the steel surface, increasing the critical ratio [Cl-] / [OH-] from 0.6 to 15. Under these conditions, the corrosion behavior of carbon steel is improved and, thanks to the blocking of pitting sites by the Na3PO4 inhibitor, it becomes much more resistant to localized corrosion than AISI 304L austenitic steel. (authors)

  14. Some observations on phosphate based corrosion inhibitors in preventing carbon steel corrosion

    International Nuclear Information System (INIS)

    Among the various types of phosphonic acid based inhibitors assayed, namely HEDP, ATMP and a commercial corrosion inhibitor (code named Betz), it was found that Betz has the maximum amount of organic phosphate followed by HEDP and ATMP. The corrosion rate studies show that Betz gives the highest inhibition efficiency followed by HEDP and ATMP. This shows that organic phosphate plays a significant role in corrosion protection. However, it was observed that due to synergestic effect, HEDP in the presence of Zn2+ gave a better corrosion protection than Betz. The results are discussed in the light of available literature. (author)

  15. Experimental study on corrosion behavior of carbon steel in buffer material-I. Behavior of corrosion propagation based on the results of immersion tests for 10 years

    International Nuclear Information System (INIS)

    The deep underground environment where overpacks will be emplaced is expected to be anaerobic environment. It is necessary to understand the corrosion behavior of carbon steel in such environment for the assessment of corrosion lifetime of carbon steel overpacks. In this study, immersion tests of carbon steel were carried out in buffer material for 10 years duration in nitrogen atmosphere in which oxygen gas concentration was controlled to less than 1 ppm. Synthetic sea water and aqueous solution containing bicarbonate ion and chloride ion were selected as the test solution. The effects of temperature, bentonite purity and atmosphere on the corrosion behavior were investigated. The amount of corrosion of carbon steel was estimated from the weight loss of the test coupon, and its change with time was investigated. The experimental results were summarised as follows; The corrosion rates were decreased with time in every test case, and as the corrosion rate at early stage of immersion was larger, the corrosion propagation was more suppressed after a long term. The influence of purity of bentonite and the atmosphere of gas phase on the behavior of corrosion propagation was small. The amount of corrosion in high carbonate concentration was smaller than those of other test conditions throughout the test periods. The change of corrosion depth, Y with time, X was approximated by power law equation, Y=AXB. The parameter A and B in synthetic sea water system was expressed as a function of dry density of buffer material, ρ(g/cm3), sand mixing ratio, r(0 ≤ r ≤ 1) and temperature, T(K). The corrosion rates calculated from the gradient of the change of the average corrosion depth between 1 to 10 years were in the range of 0.055 - 1.4 μm/y. It was confirmed that the corrosion rate of 10 μm/y used in the past lifetime assessment of overpack was sufficiently conservative in comparison with laboratory test data for 10 years and natural analogue data. (author)

  16. Corrosion Resistance and Pitting Behaviour of Low-Carbon High-Mn Steels in Chloride Solution

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available Corrosion resistance of the X4MnSiAlNbTi27-4-2 and X6MnSiAlNbTi26-3-3 type austenitic steels, after hot deformation as well as after cold rolling, were evaluated in 3.5% NaCl solution using potentiodynamic polarization tests. A type of nonmetallic inclusions and their pitting corrosion behaviour were investigated. Additionally, the effect of cold deformation on the corrosion resistance of high-Mn steels was studied. The SEM micrographs revealed that corrosion damage formed in both investigated steels is characterized by various shapes and an irregular distribution at the metallic matrix, independently on the steel state (thermomechanically treated or cold worked. Corrosion pits are generated both in grain interiors, grain boundaries and along the deformation bands. Moreover, corrosion damage is stronger in cold deformed steels in comparison to the thermomechanically treated specimens. EDS analysis revealed that corrosion pits preferentially nucleated on MnS and AlN inclusions or complex oxysulphides. The morphology of corrosion damage in 3.5% NaCl supports the data registered in potentiodynamic tests.

  17. The Synthesis of Imidazoline Derivative Compounds as Corrosion Inhibitor towards Carbon Steel in 1% NaCl Solution

    Directory of Open Access Journals (Sweden)

    Deana Wahyuningrum

    2008-03-01

    Full Text Available Oleic imidazoline is one of the nitrogen containing heterocyclic compounds that has been widely used as commercial corrosion inhibitor, especially in minimizing the carbon dioxide induced corrosion process in oilfield mining. In this present work, some imidazoline derivative compounds have been synthesized utilizing both conventional and microwave assisted organic synthesis (MAOS methods, in order to determine their corrosion inhibition properties on carbon steel surface. The MAOS method is more effective in synthesizing these compounds than the conventional method regarding to the higher chemical yields of products (91% to 94% and the shorter reaction times (7 to 10 minutes. The characterization of corrosion inhibition activities of the synthesized products towards carbon steel in 1% NaCl solution was determined by the Tafel plot method. The corrosion inhibition activities of compound 1b ((Z-2-(2-(heptadec-8-enyl-4,5-dihydroimidazol-1-ylethanamine, 2b ((Z-2-(2-(heptadec-8-enyl-4,5-dihydroimidazol-1-ylethanol and 3b (2-(2-heptadecyl-4,5-dihydroimidazol-1-ylethanamine at 8 ppm concentration in 1% NaCl solution are, respectively, 32.18%, 39.59% and 12.73%. The heptadec-8-enyl and hydroxyethyl substituents at C(2 and N(1 position of imidazoline ring, respectively, gave the most effective corrosion inhibition activity towards carbon steel compared to the presence of other substituents. The increase in concentrations of compound 1b, 2b and 3b in 1% NaCl solution tends to improve their corrosion inhibition activities. Based on the analysis of the free Gibbs adsorption energy (DG0ads values of compound 1b, 2b and 3b (-32.97, -34.34 and -31.27 kJ/mol, respectively, these compounds have the potential to interact with carbon steel through semi-physiosorption or semi-chemisorption.

  18. Microscale investigation of the corrosion performances of low-carbon and stainless steels in highly alkaline concretes

    OpenAIRE

    Itty, Pierre-Adrien

    2012-01-01

    Low-carbon steel shows good stability with respect to corrosion when embedded in ordinary portland cement concrete. This is due to the high alkaline content of the concrete pore solution favoring the formation of an iron oxide film that naturally keeps the steel in a passive state. With the rise of new types of concretes, based on different chemistries, the durability of reinforcements made out of low-carbon steel is at stake. Among the new concrete types, inorganic polymer concretes are char...

  19. Modification of 1018 carbon steel corrosion process in alkaline sour medium with a formulation of chemical corrosion inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Galicia, Policarpo [Universidad Autonoma Metropolitana - Iztapalapa, Departamento de Quimica, Area de Electroquimica, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico DF (Mexico); Gonzalez, Ignacio [Universidad Autonoma Metropolitana - Iztapalapa, Departamento de Quimica, Area de Electroquimica, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico DF (Mexico)]. E-mail: igm@xanum.uam.mx

    2005-08-10

    This work is focused on researching corrosion mechanism modifications of 1018 carbon steel in alkaline sour medium (0.1 M (NH{sub 4}){sub 2}S and 10 ppm CN{sup -}) using inhibitor formulation (IHF) composed of hydroxyoleic imidazoline (C{sub 12}H{sub 42}ON{sub 2}), HI, and aminoether (C{sub 20}H{sub 28}O{sub 3}N{sub 2}), AE. The accelerated formation of corrosion products was thereby carried out in the presence of the formulation alone and of each of its components separately; these films were subsequently characterized by electrochemical impedance spectroscopy and scanning electron microscopy. The study in the presence of the IHF components revealed that the films formed have different nature, because their physical and chemical properties such as thickness, porosity and (electronic and ionic) conductivity are determined by the media where they are grown. The film formed in the presence of HI has a homogeneous, non-porous topography that impairs the diffusion process of H{sup 0}, in addition, its electronic conductivity is above that observed in the film formed with AE. Then, it was determined that the film formed with IHF presents some distinctive component characteristics which interact in a complementary way improving film passivity.

  20. Corrosion Behavior of Carbon Steel in Synthetically Produced Oil Field Seawater

    Directory of Open Access Journals (Sweden)

    Subir Paul

    2014-01-01

    Full Text Available The life of offshore steel structure in the oil production units is decided by the huge corrosive degradation due to SO42-, S2−, and Cl−, which normally present in the oil field seawater. Variation in pH and temperature further adds to the rate of degradation on steel. Corrosion behavior of mild steel is investigated through polarization, EIS, XRD, and optical and SEM microscopy. The effect of all 3 species is huge material degradation with FeSx and FeCl3 and their complex as corrosion products. EIS data match the model of Randle circuit with Warburg resistance. Addition of more corrosion species decreases impedance and increases capacitance values of the Randle circuit at the interface. The attack is found to be at the grain boundary as well as grain body with very prominent sulphide corrosion crack.

  1. Atmospheric corrosion of hot and cold rolled carbon steel under field exposure in Saudi Arabia

    International Nuclear Information System (INIS)

    Carbon steel (hot and cold rolled) specimens have been exposed to the action of different atmospheres at 20 test sites distributed in Saudi Arabia and was investigated in terms of environmental factors such as average temperature, average relative humidity and deposition rates of atmospheric pollutants (Cl- and SO2). Applying the standard ISO 9223 norm aggressiveness of the atmospheres corresponding to 0the different test sites has been determined. Calculations of corrosion rates were made via loss of weight and characterization of the corrosion products formed on samples has been carried out by means of X-ray diffraction (XRD). The major constituent of the rust formed in marine and marine-industrial environment is goethite (α-FeOOH). These samples also show the presence of a large proportion of lepidocrocite (γ-FeOOH) and small amounts of ferrihydrite and maghemite (γ-Fe2O3). In the case of urban and rural samples goethite is the major constituent of corrosion layers. The rust formed under the urban environment also contains large amounts of ferrihydrite and in a lesser proportion, of goethite and maghemite

  2. Corrosion inhibitor binding in an acidic medium: Interaction of 2-mercaptobenizmidazole with carbon-steel in hydrochloric acid

    International Nuclear Information System (INIS)

    Highlights: • Carbon-steel inhibited by 2-mercaptobenzimidazole in 1 M HCl is examined with XPS. • Data reveal surface termination as a function of corrosion inhibitor concentration. • N 1s spectra suggest that 2-mercaptobenzimidazole adsorbs in two tautomeric forms. • For well-inhibited substrates, adsorption is on film-free carbon-steel. • 2-Mercaptobenzimidazole apparently binds preferentially to active corrosion sites. - Abstract: Mechanistic understanding of the functionality of organic corrosion inhibitors in acidic media is essential to knowledge-based performance optimization. In this study, we address a key issue hindering progress in this area, namely the chemical nature of the corrosion inhibitor/substrate interface. X-ray photoelectron spectroscopy (XPS) is employed to reveal the surface termination of carbon-steel, following immersion in 1 M hydrochloric acid inhibited with 2-mercaptobenzimidazole (MBI). Core level spectra indicate that the termination varies as a function of MBI concentration, with the interface consisting of MBI bound to film-free carbon-steel on highly inhibited substrates

  3. 76 FR 17381 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2011-03-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Final Results of the Sixteenth Administrative Review Correction In notice document...

  4. Measurements of the corrosion of low-carbon steel drums under environmental conditions at Hanford: One-year test results

    International Nuclear Information System (INIS)

    This report describes the methods used to expose low-carbon steel drums to atmospheric and soil corrosion and describes the methods used to examine specimens retrieved from both types of tests. These drums are being tested to meet requirements of radioactive waste storage for both low-level radioactive wastes and transuranic wastes

  5. 77 FR 67395 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Revised Schedule for the...

    Science.gov (United States)

    2012-11-09

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Revised Schedule for the... these five-year reviews (77 FR 31877, May 30, 2012). As noted in the Commission's original...

  6. 78 FR 16247 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea; Final Results of...

    Science.gov (United States)

    2013-03-14

    ... Corrosion-Resistant Carbon Steel Flat Products from Korea, 58 FR 44159 (August 19, 1993). Notification to..., and Partial Rescission, 77 FR 54891 (September 6, 2012) (Preliminary Results). DATES: Effective Date...'s Preliminary Results.\\5\\ \\2\\ See id., 77 FR at 54893. \\3\\ See id., 77 FR at 54896. \\4\\ See...

  7. 75 FR 25841 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2010-05-10

    ... for Revocation in Part, 74 FR 48224 (September 22, 2009). The preliminary results of this review were... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...'') published a notice of initiation of the administrative review of the antidumping duty order on...

  8. 77 FR 25405 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2012-04-30

    ... for Revocation in Part, 76 FR 61076 (October 3, 2011). The preliminary results of this review are... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...'') published a notice of initiation of the administrative review of the antidumping duty order on...

  9. 76 FR 21332 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-04-15

    ... for Revocation in Part, 75 FR 60076 (September 29, 2010). The preliminary results of this review are... International Trade Administration Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea...'') published a notice of initiation of the administrative review of the antidumping duty order on...

  10. Use of an Electrochemical Split Cell Technique to Evaluate the Influence of Shewanella oneidensis Activities on Corrosion of Carbon Steel.

    Science.gov (United States)

    Miller, Robert Bertram; Sadek, Anwar; Rodriguez, Alvaro; Iannuzzi, Mariano; Giai, Carla; Senko, John M; Monty, Chelsea N

    2016-01-01

    Microbially induced corrosion (MIC) is a complex problem that affects various industries. Several techniques have been developed to monitor corrosion and elucidate corrosion mechanisms, including microbiological processes that induce metal deterioration. We used zero resistance ammetry (ZRA) in a split chamber configuration to evaluate the effects of the facultatively anaerobic Fe(III) reducing bacterium Shewanella oneidensis MR-1 on the corrosion of UNS G10180 carbon steel. We show that activities of S. oneidensis inhibit corrosion of steel with which that organism has direct contact. However, when a carbon steel coupon in contact with S. oneidensis was electrically connected to a second coupon that was free of biofilm (in separate chambers of the split chamber assembly), ZRA-based measurements indicated that current moved from the S. oneidensis-containing chamber to the cell-free chamber. This electron transfer enhanced the O2 reduction reaction on the coupon deployed in the cell free chamber, and consequently, enhanced oxidation and corrosion of that electrode. Our results illustrate a novel mechanism for MIC in cases where metal surfaces are heterogeneously covered by biofilms. PMID:26824529

  11. Analysis of flow on grooving corrosion at the weld of a carbon steel pipe made by electrical resistance welding

    International Nuclear Information System (INIS)

    Lots of researches were gone already about grooving corrosion mechanism of ERW carbon steel pipe. But there is seldom study for water hammer happened by fluid and acceleration of corrosion rate by increased flow velocity. Therefore, in this study carried out the analysis based on hydrodynamic and fracture mechanics. Analyzed stress that act on a pipe using ANSYS as a program, and also FLUENT and STAR-CD were used for flow phenomenon confirmation. As the result, fatigue failure is happened by water hammer and corrosion rate was increased because of turbulent flow

  12. Use of Extracted Green Inhibitors as a Friendly Choice in Corrosion Protection of Low Alloy Carbon Steel

    Directory of Open Access Journals (Sweden)

    Jano, A.

    2012-11-01

    Full Text Available Mitigation of corrosion impact on environment is an important step in environmental protection. Use of environmentally friendly corrosion protection methods is very important. It is smart to choose cheap and safe to handle compounds as corrosion inhibitors. The use of green inhibitors (extracted inexpensively, from the seed endosperm of some Leguminosae plants, and investigation of their efficiency in corrosion protection is the aim of this study. As green inhibitor one kind of polysaccharides (galactomannan from locust bean gum (also known as carob gum, carob bean gum extracted from the seed of carob tree is used. Corrosion protection efficiency of these extracted green inhibitors was tested for carbon steel marked as: steel 39, steel 44, and iron B 500 (usually applied as reinforcing bars to concrete. Sulfuric acid solution in the presence of chloride ions was used as corrosion media. The composition of corrosion acid media used was 1 mol L-1 H2SO4 and 10-3 mol L-1 Cl- (in the form of NaCl. Electrochemical techniques such as potentiodynamic polarization methods were used for inhibitor efficiency testing.

  13. The use of Euphorbia falcata extract as eco-friendly corrosion inhibitor of carbon steel in hydrochloric acid solution

    International Nuclear Information System (INIS)

    Euphorbia falcata L. extract (EFE) was investigated as eco-friendly corrosion inhibitor of carbon steel in 1 M HCl using gravimetric, ac impedance, polarization and scanning electron microscopy (SEM) techniques. The experimental results show that EFE is good corrosion inhibitor and the protection efficiency is increased with the EEF concentration. The results obtained from weight loss and ac impedance studies were in reasonable agreement. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Polarization curves indicated that EFE is a mixed inhibitor. The corrosion inhibition was assumed to occur via adsorption of EFE molecules on the metal surface. The adsorption of the E. falcata extract was well described by the Langmuir adsorption isotherm. The calculated ΔGadso value showed that the corrosion inhibition of the carbon steel in 1 M HCl is mainly controlled by a physisorption process. - Graphical abstract: Display Omitted - Highlights: • EFE is a good eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl. • EFE acts as mixed-type inhibitor in 1 M HCl medium. • Weight loss, ac impedance and polarization methods are in reasonable agreement. • The adsorption of EFE is well described by the Langmuir adsorption isotherm

  14. The use of Euphorbia falcata extract as eco-friendly corrosion inhibitor of carbon steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    El Bribri, A. [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Tabyaoui, M., E-mail: hamidtabyaoui@yahoo.fr [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Laboratoire des Matériaux, Nanoparticules et Environnement, Université Mohamed V Agdal, Faculté des Sciences, 4 Av. Ibn Battouta, B.P. 1014 RP, M-10000 Rabat (Morocco); Tabyaoui, B. [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); El Attari, H.; Bentiss, F. [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2013-08-15

    Euphorbia falcata L. extract (EFE) was investigated as eco-friendly corrosion inhibitor of carbon steel in 1 M HCl using gravimetric, ac impedance, polarization and scanning electron microscopy (SEM) techniques. The experimental results show that EFE is good corrosion inhibitor and the protection efficiency is increased with the EEF concentration. The results obtained from weight loss and ac impedance studies were in reasonable agreement. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Polarization curves indicated that EFE is a mixed inhibitor. The corrosion inhibition was assumed to occur via adsorption of EFE molecules on the metal surface. The adsorption of the E. falcata extract was well described by the Langmuir adsorption isotherm. The calculated ΔG{sub ads}{sup o} value showed that the corrosion inhibition of the carbon steel in 1 M HCl is mainly controlled by a physisorption process. - Graphical abstract: Display Omitted - Highlights: • EFE is a good eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl. • EFE acts as mixed-type inhibitor in 1 M HCl medium. • Weight loss, ac impedance and polarization methods are in reasonable agreement. • The adsorption of EFE is well described by the Langmuir adsorption isotherm.

  15. Influence of ph on corrosion control of carbon steel by peroxide injection in sour water

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Martins Magda; Baptista, Walmar; Joia, Carlos Jose Bandeira de Mello [PROTEMP - PETROBRAS/CENPES, Cidade Universitaria, Quadra 7, Rio de Janeiro, CEP 21949-900 (Brazil); Ponciano, Gomes Jose Antonio da Cunha [Departamento de Engenharia Metalurgica e de Materiais-COPPE/UFRJ, Cidade Universitaria, Rio de Janeiro (Brazil)

    2004-07-01

    Sour hydrogen damage is considered the most important corrosive process in the light-ends recovery section of Fluid Catalytic Cracking Units (FCCU). Corrosion in this condition is due to heavy gas oil that originates great amount of contaminants, such as H{sub 2}S, NH{sub 3} and HCN. Hydrogen absorption is promoted by the presence of free cyanides in the environment. The attenuation of this process requires the use of some inhibitors, such as oxygen, hydrogen peroxide (H{sub 2}O{sub 2}) or commercial polysulfides. The effect of these compounds is to neutralize free cyanides (CN{sup -}) into thio-sulfides (SCN{sup -}). When peroxide injection is selected, cyanide concentration in sour water has been used as key parameter to start the peroxide introduction. However, the importance of pH in this system has been pointed out by many authors. The aim of this work is to investigate the influence of pH when peroxide injection is carried out in less alkaline conditions of sour water. Electrochemical techniques - like anodic polarization and hydrogen permeation tests - and weight loss measurements were used to evaluate the effectiveness of corrosion control of carbon steel. It was concluded that at pH 7.5 peroxide injection can drive to an increment of the corrosion rate. Besides that, it was concluded that hydrogen permeation into the metal is promoted. Both detrimental effects were due to elemental sulfur generation in this pH range. The adoption of pH as a key parameter for peroxide injection is then suggested. (authors)

  16. Inhibition of corrosion of carbon steel by heptane sulphonic acid – Zn2+ system

    Directory of Open Access Journals (Sweden)

    C. MARY ANBARAS

    2012-03-01

    Full Text Available Corrosion inhibition of carbon steel in dam water by sodium heptane sulphonate (SHS and zinc ion system was investigated using weight loss and potentiodynamic polarization methods. Results of weight loss method indicated that inhibition efficiency (IE increased as the inhibitor concentration increased. A synergistic effect existed between SHS and Zn2+. The influence of sodium potassium tartrate (SPT on the IE of the SHS-Zn2+ system was evaluated. As the immersion period increased, the IE decreased. Polarization study revealed that SHS-Zn2+ system functioned as a cathodic inhibitor. AC impedance spectra revealed that a protective film was formed on the metal surface. The nature of the metal surface was analyzed by FTIR spectra, SEM and AFM analyses.

  17. Complexes of Imidazole with Poly(ethylene glycol) as a Corrosion Inhibitor for Carbon Steel in Sulphuric Acid

    Science.gov (United States)

    Salimi, Saeed; Nasr-Esfahani, Mojtaba; Umoren, Saviour A.; Saebnoori, Ehsan

    2015-12-01

    The inhibiting action of polyethylene glycol and imidazole (PEG/IMZ)) complexes prepared by a simple deprotonation procedure on carbon steel corrosion in 0.5 mol/L sulphuric acid was evaluated using the weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques complemented by surface analysis using scanning electron microscopy. The inhibiting effect of the PEG/IMZ complexes on carbon steel corrosion was compared with the non-complex forms. Results obtained show that PEG/IMZ complex is a very effective corrosion inhibitor of carbon steel in the acid environment. The inhibition efficiency increased with the increase in the temperature and also with increasing percentage of imidazole in the complex. Corrosion inhibition occurs by virtue of adsorption of PEG/IMZ complexes on the steel surface which was found to follow the Temkin adsorption isotherm model. The PEG/IMZ complexes function as a mixed-type inhibitor. Results from all the methods employed are in a reasonably good agreement.

  18. Effects of chloride content on CO2 corrosion of carbon steel in simulated oil and gas well environments

    International Nuclear Information System (INIS)

    Highlights: • Maximum CO2 corrosion rate is reached with increasing Cl− content. • Cl− can destroy the corrosion product films. • High amounts of Cl− content can inhibit the cathodic reaction in CO2 corrosion. • Mass transfer control becomes more efficient as the Cl− content increases. • Cl− has no effect on the composition of the corrosion product. - Abstract: Effects of chloride content on CO2 corrosion of carbon steel have been studied by immersion tests and electrochemical measurements combined with scanning electron microscopy, X-ray diffraction and analysis of polarization curves. Results show that maximum CO2 corrosion rate is reached with increasing Cl− content at a constant temperature and partial pressure. CO2 corrosion is a mixed-controlled process, i.e., both activation and mass-transfer steps with increasing Cl− content. Increasing Cl− content can reduce CO2 solubility. Moreover, Cl− can destroy corrosion product films and change morphology of corrosion product films, but it has no effect on the composition of the corrosion product

  19. Evaluation of the potential of additives as corrosion inhibitors of CA-50 carbon steel used as reinforcement in concretes

    International Nuclear Information System (INIS)

    In this work, various compounds were tested to evaluate their potential capability for their use as corrosion inhibitors of carbon steel reinforcement in concretes. The additives tested were sodium benzoate, polyethylene glycol, hexamethylenetetramine, benzotriazole and yttrium carbonate. Initially, exploratory tests were carried out to select the ones to be used as corrosion inhibitors, based on the inhibit ion efficiency determined from electrochemical tests, specifically polarization tests and electrochemical impedance spectroscopy. These tests were carried out in a solution composed of 0.01 N sodium hydroxide (NaOH) and 0.05 N potassium hydroxide (KOH) to simulate the composition of the solution inside the pores in concretes. The additive that presented the most promising potential to be used as corrosion inhibitor was benzotriazole (BTA). After the elimination of some compounds and selection of the additive with higher corrosion inhibit ion efficiency in the test medium, the effect of its concentration on the corrosion inhibition efficiency was evaluated. Sodium nitrite solutions with the same concentrations as those solutions with BTA were tested for comparison reasons. Sodium nitrite is a well established corrosion inhibitor for carbon steel reinforcement in concretes but it has been related to toxic effects. The BTA was associated to higher corrosion inhibition efficiencies than that of sodium nitrite in similar concentrations. A blackish adherent film was formed on the steel surface exposed to BTA solutions during long periods of immersion in the alkaline medium. The results suggest that BTA is a potential candidate for substitution of nitrites as corrosion inhibitor of reinforcements in concrete. (author)

  20. Corrosion Inhibition of Carbon Steel in HCl Solution by Some Plant Extracts

    Directory of Open Access Journals (Sweden)

    Ambrish Singh

    2012-01-01

    Full Text Available The strict environmental legislations and increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. In the present work, literature on green corrosion inhibitors has been reviewed, and the salient features of our work on green corrosion inhibitors have been highlighted. Among the studied leaves, extract Andrographis paniculata showed better inhibition performance (98% than the other leaves extract. Strychnos nuxvomica showed better inhibition (98% than the other seed extracts. Moringa oleifera is reflected as a good corrosion inhibitor of mild steel in 1 M HCl with 98% inhibition efficiency among the studied fruits extract. Bacopa monnieri showed its maximum inhibition performance to be 95% at 600 ppm among the investigated stem extracts. All the reported plant extracts were found to inhibit the corrosion of mild steel in acid media.

  1. Corrosion behavior of laser-clad Mo2NiB2 cermet coating on low carbon steel substrate

    International Nuclear Information System (INIS)

    A Mo2NiB2 cermet coating on low carbon steel substrate was fabricated by laser cladding technique. The coating consisted of γ-(Fe, Ni) as a metallic matrix binder and Mo2NiB2 particles as a reinforced phase distributed uniformly in the microstructure. Corrosion behavior of the coating was investigated and the commercial 1Cr, 304SS, and G3 were used for comparison. G3 exhibited the highest corrosion resistance and 1Cr the lowest corrosion resistance, whereas 304SS and the coating exhibited the intermediate and similar corrosion resistance. However, the severe pitting corrosion which was observed in 304SS did not exist for the coating. (author)

  2. Electrochemical corrosion behavior of X52 and X60 steels in carbon dioxide containing saltwater solution

    Directory of Open Access Journals (Sweden)

    Rihan Omar Rihan

    2012-01-01

    Full Text Available X52 and X60 high strength low alloy (HSLA steels are widely used in the construction of petroleum pipelines. This paper discusses the corrosion resistance of X52 and X60 steels in CO2 containing saltwater at pH 4.4 and 50 ºC. A circulating flow loop system inside an autoclave was used for conducting the experimental work. The rotating impeller speed was 2000 rpm. The corrosion rate was monitored using in situ electrochemical methods such as potentiodynamic sweep, linear polarization resistance, and electrochemical impedance spectroscopy (EIS methods. Results indicated that the corrosion rate of X60 steel is relatively higher than that of X52 steel.

  3. Electrochemical corrosion behavior of X52 and X60 steels in carbon dioxide containing saltwater solution

    Directory of Open Access Journals (Sweden)

    Rihan Omar Rihan

    2013-02-01

    Full Text Available X52 and X60 high strength low alloy (HSLA steels are widely used in the construction of petroleum pipelines. This paper discusses the corrosion resistance of X52 and X60 steels in CO2 containing saltwater at pH 4.4 and 50 ºC. A circulating flow loop system inside an autoclave was used for conducting the experimental work. The rotating impeller speed was 2000 rpm. The corrosion rate was monitored using in situ electrochemical methods such as potentiodynamic sweep, linear polarization resistance, and electrochemical impedance spectroscopy (EIS methods. Results indicated that the corrosion rate of X60 steel is relatively higher than that of X52 steel.

  4. Effect of Cr content, hardness and micro structure on flow-accelerated corrosion in carbon steel pipes. Examination of replaced carbon steel pipes

    International Nuclear Information System (INIS)

    68 replaced carbon steel piping in secondary system of pressurized water reactor (PWR) has been investigated by visual examination for checking thinning conditions. It is well known that the flow-accelerated corrosion (FAC) was inhibited by traces of Cr in steel. Therefore, the chemical compositions of those steels have been measured. In addition, the micro structure and hardness of those steels have been investigated. And the relationship between those material variables and FAC rate was considered. As the results, (1) The Cr contents in those steels were below 0.1 wt% except one sample. Minute quantities of chromium increase the resistance against FAC. But the water velocity was thought to be the dominant factor rather than chemical composition in steel, at least such as below 0.1%Cr. (2) Hardness of all piping has been satisfied the specifications of each materials. The hardness of steels was not correlated with wall thinning rate. (3) The micro structure was also not correlated with FAC rate. (author)

  5. Corrosion inhibition behavior of propyl phosphonic acid–Zn2+ system for carbon steel in aqueous solution

    International Nuclear Information System (INIS)

    The effectiveness of propyl phosphonic acid (PPA) as a corrosion inhibitor in association with a bivalent cation like Zn2+ has been studied. An eco-friendly inhibitor in controlling corrosion of carbon steel in neutral aqueous medium in the absence and presence of Zn2+ has been evaluated by gravimetric method. Impedance studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of carbon steel in the aqueous environment. Potentiodynamic polarization studies showed that the inhibitor is a mixed inhibitor. X-ray photoelectron spectroscopic analysis (XPS) of the protective film exhibited the presence of the elements viz., iron, phosphorus, oxygen, carbon and zinc. The chemical shifts in the binding energies of these elements inferred that the surface film is composed of oxides/hydroxides of iron(III), Zn(OH)2 and [Fe(II)/(III)–Zn(II)–PPA] complex. Further, the surface analysis techniques viz., FT-IR, AFM and SEM studies confirm the formation of an adsorbed protective film on the carbon steel surface. Based on all these results, a plausible mechanism of corrosion inhibition is proposed.

  6. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    Science.gov (United States)

    Pasasa, Norman Vincent A.; Bundjali, Bunbun; Wahyuningrum, Deana

    2015-09-01

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,1H-NMR and 13C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir's adsorption isotherm.

  7. Microbiological corrosion in low carbon steels; Corrosion microbiologica en aceros de bajo carbono

    Energy Technology Data Exchange (ETDEWEB)

    Medina-Custodio, O; Ortiz-Prado, A; Jacobo-Armendariz, V. H; Schouwenaars-Franssens, R [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: medina_1979@yahoo.com; armandoo@servidor.unam.mx; vjacobo@dgapa.unam.mx; raf_schouweenaars@yahoo.com

    2009-01-15

    The Microbiologically Induced Corrosion affects several industries, such as oil industry where it is estimated that 20% to 30% pipes failures are related with microorganism. The chemical reactions generate ions transfer, this validate the use of electrochemical technique for its analysis. Coupons submerged in a nutritional medium with presence and absence of three different microorganisms during two periods, 48 hours and 28 days were studied. Polarization resistance (Rp) and Electrochemical Impedance Spectroscopy (EIS) techniques were applied to determine the corrosively of the systems. The results show a greater corrosive effect of abiotic systems, this indicates a microorganisms protection effect to the metal, opposite to the first hypothesis. This result was ratified observing surface coupons by using Scanning Electron Microscopy (SEM) technique. A possible mechanism based on Evans - Tafel graph is proposed to explain inhibitor microorganism effect. [Spanish] La corrosion microbiologica es un tipo comun de deterioro que afecta diversas industrias, una de ellas es la petrolera en la que se estiman que el 20% o 30% de fallas en las tuberias de trasporte de hidrocarburos es favorecida por microorganismos. Las reacciones quimicas que sustentan estos, generan transferencia de iones, lo que justifica el empleo de tecnicas electroquimicas para su analisis. En este trabajo, se estudiaron probetas de acero de bajo carbono SAE 1018, sumergidas en un medio nutritivo rico en cloruros en presencia y ausencia de tres diferentes cargas microbianas, en tiempos de exposicion de 48 horas y 28 dias. Se realizaron ensayos de resistencia a la polarizacion (Rp) y espectroscopia de impedancia electroquimica (EIS) para determinar el efecto corrosivo de los diferentes sistemas. Los resultados muestran que el medio abiotico causa el mayor efecto corrosivo, lo que indica un efecto protector de los microorganismos al metal contradiciendo la hipotesis inicialmente propuesta. La observacion

  8. Characterization of the corrosion behavior of the carbon steel liner in Hanford Site single-shell tanks

    International Nuclear Information System (INIS)

    Six safety initiatives have been identified for accelerating the resolution of waste tank safety issues and closure of unreviewed safety questions. Safety Initiative 5 is to reduce safety and environmental risk from tank leaks. Item d of Safety Initiative 5 is to complete corrosion studies of single-shell tanks to determine failure mechanisms and corrosion control options to minimize further degradation by June 1994. This report has been prepared to fulfill Safety Initiative 5, Item d. The corrosion mechanisms that apply to Hanford Site single-shell tanks are stress corrosion cracking, pitting/crevice corrosion, uniform corrosion, hydrogen embrittlement, and microbiologically influenced corrosion. The corrosion data relevant to the single-shell tanks dates back three decades, when results were obtained from in-situ corrosion coupons in a few single-shell tanks. Since that time there have been intertank transfers, evaporation, and chemical alterations of the waste. These activities have changed the character and the present composition of the waste is not well characterized. All conclusions and recommendations are made in the absence of relevant laboratory experimental data and tank inspection data. The report attempts to identify the failure mechanisms by a literature survey of carbon steel data in environments similar to the single-shell tank wastes, and by a review of the work performed at the Savannah River Site where similar wastes are stored in similar carbon steel tanks. Based on these surveys, and in the absence of data specific to Hanford single-shell tanks, it may be concluded that the single-shell tanks identified as leakers failed primarily by stress corrosion cracking due to the presence of high nitrate/low hydroxide wastes and residual stresses. In addition, some failures may be attributed to pitting under crevices in low hydroxide locations

  9. THE SENSITIVITY OF CARBON STEELS' SUSCEPTIBILITY TO LOCALIZED CORROSION TO THE PH OF NITRATE BASED NUCLEAR WASTES

    Energy Technology Data Exchange (ETDEWEB)

    BOOMER KD

    2010-01-14

    The Hanford tank reservation contains approximately 50 million gallons of liquid legacy radioactive waste from cold war weapons production, which is stored in 177 underground storage tanks. The tanks will be in use until waste processing operations are completed. The wastes tend to be high pH (over 10) and nitrate based. Under these alkaline conditions carbon steels tend to be passive and undergo relatively slow uniform corrosion. However, the presence of nitrate and other aggressive species, can lead to pitting and stress corrosion cracking. This work is a continuation of previous work that investigated the propensity of steels to suffer pitting and stress corrosion cracking in various waste simulants. The focus of this work is an investigation of the sensitivity of the steels' pitting and stress corrosion cracking susceptibility tosimulant pH. Previous work demonstrated that wastes that are high in aggressive nitrate and low in inhibitory nitrite are susceptible to localized corrosion. However, the previous work involved wastes with pH 12 or higher. The current work involves wastes with lower pH of 10 or 11. It is expected that at these lower pHs that a higher nitrite-to-nitrate ratio will be necessary to ensure tank integrity. This experimental work involved both electrochemical testing, and slow strain rate testing at either the free corrosion potential or under anodic polarization. The results of the current work will be discussed, and compared to work previously presented.

  10. Low carbon steel corrosion damage prediction in rural and urban environments

    Directory of Open Access Journals (Sweden)

    Díaz, V.

    2003-12-01

    Full Text Available This paper presents an Artificial Neural Network (ANN model for the damage function of carbon steel, expressed in μm of corrosion penetration as a function of environmental variables. Working in the context of the Iberoamerican Atmospheric Corrosion Map Project, the experimental data comes as result of the corrosion of low alloy steel subtracts in three test sites in Uruguay, South America. In addition, we included experimental values obtained from short time kinetics studies, corresponding to special series from one of the sites. The ANN numerical model shows attractive results regarding goodness of fit and residual distributions. It achieves a RMSE value of 0.5 μm while a classical regression model lies in the range of 4.1 μm. Furthermore, a properly adjusted ANN model can be useful in the prediction of corrosion damage under different climatological and pollution conditions, while linear models cannot.

    Este artículo presenta la metodología de las redes neuronales artificiales (RNA como solución para el modelado de los valores experimentales obtenidos en los procesos de corrosión atmosférica. Se desarrolla el modelo de RNA para la función de daño, expresada en μm de penetración para el acero de bajo carbono en función de las variables medioambientales, en el contexto del Proyecto MICAT (Mapa Iberoamericano de Corrosión Atmosférica y programas de experimentación propios. Los datos experimentales son resultado de los estudios de calibración sobre sustratos ferrosos en tres sitios del territorio uruguayo, Sudamérica. Se incluyen, además, los valores experimentales obtenidos en los estudios de cinéticas iniciales, correspondientes a series especiales de cortos tiempos de exposición en una de las estaciones de ensayo. El modelo numérico de RNA muestra resultados con un valor de RMSE de 0,5 μm, en tanto el modelo de regresión clásico arroja un valor de 4,1 μm.

  11. Corrosion detection of steel reinforced concrete using combined carbon fiber and fiber Bragg grating active thermal probe

    Science.gov (United States)

    Li, Weijie; Ho, Siu Chun Michael; Song, Gangbing

    2016-04-01

    Steel reinforcement corrosion is one of the dominant causes for structural deterioration for reinforced concrete structures. This paper presents a novel corrosion detection technique using an active thermal probe. The technique takes advantage of the fact that corrosion products have poor thermal conductivity, which will impede heat propagation generated from the active thermal probe. At the same time, the active thermal probe records the temperature response. The presence of corrosion products can thus be detected by analyzing the temperature response after the injection of heat at the reinforcement-concrete interface. The feasibility of the proposed technique was firstly analyzed through analytical modeling and finite element simulation. The active thermal probe consisted of carbon fiber strands to generate heat and a fiber optic Bragg grating (FBG) temperature sensor. Carbon fiber strands are used due to their corrosion resistance. Wet-dry cycle accelerated corrosion experiments were performed to study the effect of corrosion products on the temperature response of the reinforced concrete sample. Results suggest a high correlation between corrosion severity and magnitude of the temperature response. The technique has the merits of high accuracy, high efficiency in measurement and excellent embeddability.

  12. Emulgin as an inhibitor of corrosion and hydrogenation of carbon steel in weakly acidic H2S-containing solutions

    International Nuclear Information System (INIS)

    Protective efficiency of emulgin (technological mixture of primary and secondary aliphatic amines) as an inhibitor (0.078-0.625 mmol/l) of acidic, acid carbonate and hydrogen sulfide corrosion and hydrogenation of the St.3 carbon steel is studied. Protection degree of 97% and complete absence of local damages were obtained in the 5-50 mM HCl, saturated by hydrogen sulfide. The anode reaction retardation increases the simultaneous presence of HCl and H2S also does not noticeably decreases it. Hydrogenation of steel under optimal conditions is practically completely removed, what is facilitated by increase in the HCl and H2S concentration and solution temperature

  13. POLYTETRAFLUOROETHYLENE-RICH POLYPHENLENESULFIDE BLEND TOP COATINGS FOR MITIGATING CORROSION OF CARBON STEEL IN 300 DEGREE CELCIUS BRINE.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.; JUNG, D.

    2006-06-01

    We evaluated usefulness of a coating system consisting of an underlying polyphenylenesulfide (PPS) layer and top polytetrafluoroethylene (PTFE)-blended PPS layer as low friction, water repellent, anti-corrosion barrier film for carbon steel steam separators in geothermal power plants. The experiments were designed to obtain information on kinetic coefficient of friction, surface free energy, hydrothermal oxidation, alteration of molecular structure, thermal stability, and corrosion protection of the coating after immersing the coated carbon steel coupons for up to 35 days in CO{sub 2}-laden brine at 300 C. The superficial layer of the assembled coating was occupied by PTFE self-segregated from PPS during the melt-flowing process of this blend polymer; it conferred an outstanding slipperiness and water repellent properties because of its low friction and surface free energy. However, PTFE underwent hydrothermal oxidation in hot brine, transforming its molecular structure into an alkylated polyfluorocarboxylate salt complex linked to Na. Although such molecular transformation increased the friction and surface free energy, and also impaired the thermal stability of PTFE, the top PTFE-rich PPS layer significantly contributed to preventing the permeation of moisture and corrosive electrolytes through the coating film, so mitigating the corrosion of carbon steel.

  14. Inhibition Effect of Dodecylamine on Carbon Steel Corrosion in Hydrochloric Acid Solution

    Science.gov (United States)

    Chen, Zhenyu; Huang, Ling; Qiu, Yubing; Guo, Xingpeng

    2012-12-01

    Dodecylamine spontaneously adsorbs on carbon steel via its polar group (-NH2) in hydrochloric acid solution. Furthermore, it forms a monolayer film on carbon steel surface. The inhibition mechanism of dodecylamine for carbon steel is geometric blocking effect. The adsorption of dodecylamine on carbon steel surface follows Arrhenius equation. The adsorption slightly increases activated energy, but greatly reduces pre-exponential factor value. Atomic force microscopy force curves indicate that at the area without adsorbed dodecylamine, no obvious adhere force occurs. At the area with adsorbed dodecylamine, however, an average 1.3 nN adhere force is observed.

  15. Investigation on carbon dioxide corrosion behaviour of HP13Cr110 stainless steel in simulated stratum water

    Energy Technology Data Exchange (ETDEWEB)

    Mu, L.J. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)], E-mail: mulijunxjtu@126.com; Zhao, W.Z. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2010-01-15

    The carbon dioxide corrosion behaviour of HP13Cr110 stainless steel in simulated stratum water is studied by potentiodynamic curve and electrochemical impedance spectroscopy (EIS); the micro-structure and composition of the corrosion scale formed at high-temperature and high-pressure are analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that 13Cr stainless steel is in passive state in the stratum water, the passive current density increases and the passive potential region decreases with increasing temperature. The corrosion scale formed at high-temperature and high-pressure is mainly composed of iron/chromium oxides and a little amount of FeCO{sub 3}.

  16. The effect of organic matter associated with the corrosion products on the corrosion of mild steel in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Wagh, A.B.

    the corrosion of mild steel and the temperature and dissolved oxygen of seawater. In contrast to this, the corrosion and mild steel was inversely related to the organic carbon and water extractable carbohydrates associated with the corrosion products of mild...

  17. Electrochemical corrosion studies on a selected carbon steel for application in nuclear waste disposal containers: Influence of chemical species in brines on corrosion

    International Nuclear Information System (INIS)

    In previous corrosion studies, carbon steels were identified as promising materials for the manufacture of long-lived high-level waste containers that could act as an engineered barrier in a rock-salt repository. In this paper, the influence of chemical species, potentially present in salt brines, on the electrochemical corrosion behavior of the preselected fine-grained steel TStE 355 was studied. The steel was examined at 90 C in a disposal relevant NaCl-rich brine containing various species (Br-, I-, Cu2+, Mn2+, S2-, B(OH)4- and Fe3+) at concentrations between 10-5 M/I and 10-1 M/I. (orig.)

  18. Use of Homogeneously-Sized Carbon Steel Ball Bearings to Study Microbially-Influenced Corrosion in Oil Field Samples.

    Science.gov (United States)

    Voordouw, Gerrit; Menon, Priyesh; Pinnock, Tijan; Sharma, Mohita; Shen, Yin; Venturelli, Amanda; Voordouw, Johanna; Sexton, Aoife

    2016-01-01

    Microbially-influenced corrosion (MIC) contributes to the general corrosion rate (CR), which is typically measured with carbon steel coupons. Here we explore the use of carbon steel ball bearings, referred to as beads (55.0 ± 0.3 mg; Ø = 0.238 cm), for determining CRs. CRs for samples from an oil field in Oceania incubated with beads were determined by the weight loss method, using acid treatment to remove corrosion products. The release of ferrous and ferric iron was also measured and CRs based on weight loss and iron determination were in good agreement. Average CRs were 0.022 mm/yr for eight produced waters with high numbers (10(5)/ml) of acid-producing bacteria (APB), but no sulfate-reducing bacteria (SRB). Average CRs were 0.009 mm/yr for five central processing facility (CPF) waters, which had no APB or SRB due to weekly biocide treatment and 0.036 mm/yr for 2 CPF tank bottom sludges, which had high numbers of APB (10(6)/ml) and SRB (10(8)/ml). Hence, corrosion monitoring with carbon steel beads indicated that biocide treatment of CPF waters decreased the CR, except where biocide did not penetrate. The CR for incubations with 20 ml of a produced water decreased from 0.061 to 0.007 mm/yr when increasing the number of beads from 1 to 40. CRs determined with beads were higher than those with coupons, possibly also due to a higher weight of iron per unit volume used in incubations with coupons. Use of 1 ml syringe columns, containing carbon steel beads, and injected with 10 ml/day of SRB-containing medium for 256 days gave a CR of 0.11 mm/yr under flow conditions. The standard deviation of the distribution of residual bead weights, a measure for the unevenness of the corrosion, increased with increasing CR. The most heavily corroded beads showed significant pitting. Hence the use of uniformly sized carbon steel beads offers new opportunities for screening and monitoring of corrosion including determination of the distribution of corrosion rates, which allows

  19. Use of Homogeneously-Sized Carbon Steel Ball Bearings to Study Microbially-Influenced Corrosion in Oil Field Samples

    Science.gov (United States)

    Voordouw, Gerrit; Menon, Priyesh; Pinnock, Tijan; Sharma, Mohita; Shen, Yin; Venturelli, Amanda; Voordouw, Johanna; Sexton, Aoife

    2016-01-01

    Microbially-influenced corrosion (MIC) contributes to the general corrosion rate (CR), which is typically measured with carbon steel coupons. Here we explore the use of carbon steel ball bearings, referred to as beads (55.0 ± 0.3 mg; Ø = 0.238 cm), for determining CRs. CRs for samples from an oil field in Oceania incubated with beads were determined by the weight loss method, using acid treatment to remove corrosion products. The release of ferrous and ferric iron was also measured and CRs based on weight loss and iron determination were in good agreement. Average CRs were 0.022 mm/yr for eight produced waters with high numbers (105/ml) of acid-producing bacteria (APB), but no sulfate-reducing bacteria (SRB). Average CRs were 0.009 mm/yr for five central processing facility (CPF) waters, which had no APB or SRB due to weekly biocide treatment and 0.036 mm/yr for 2 CPF tank bottom sludges, which had high numbers of APB (106/ml) and SRB (108/ml). Hence, corrosion monitoring with carbon steel beads indicated that biocide treatment of CPF waters decreased the CR, except where biocide did not penetrate. The CR for incubations with 20 ml of a produced water decreased from 0.061 to 0.007 mm/yr when increasing the number of beads from 1 to 40. CRs determined with beads were higher than those with coupons, possibly also due to a higher weight of iron per unit volume used in incubations with coupons. Use of 1 ml syringe columns, containing carbon steel beads, and injected with 10 ml/day of SRB-containing medium for 256 days gave a CR of 0.11 mm/yr under flow conditions. The standard deviation of the distribution of residual bead weights, a measure for the unevenness of the corrosion, increased with increasing CR. The most heavily corroded beads showed significant pitting. Hence the use of uniformly sized carbon steel beads offers new opportunities for screening and monitoring of corrosion including determination of the distribution of corrosion rates, which allows

  20. Use of Homogeneously-Sized Carbon Steel Ball Bearings to Study Microbially-Influenced Corrosion in Oil Field Samples

    Directory of Open Access Journals (Sweden)

    Gerrit eVoordouw

    2016-03-01

    Full Text Available Microbially-influenced corrosion (MIC contributes to the general corrosion rate (CR, which is typically measured with carbon steel coupons. Here we explore the use of carbon steel ball bearings, referred to as beads (55.0 ± 0.3 mg; Ø = 0.238 cm, for determining CRs. CRs for samples from an oil field in Oceania incubated with beads were determined by the weight loss method, using acid treatment to remove corrosion products. The release of ferrous and ferric iron was also measured and CRs based on weight loss and iron determination were in good agreement. Average CRs were 0.022 mm/yr for 8 produced waters with high numbers (105/ml of acid-producing bacteria (APB, but no sulfate-reducing bacteria (SRB. Average CRs were 0.009 mm/yr for 5 central processing facility (CPF waters, which had no APB or SRB due to weekly biocide treatment and 0.036 mm/yr for 2 CPF tank bottom sludges, which had high numbers of APB (106/ml and SRB (108/ml. Hence, corrosion monitoring with carbon steel beads indicated that biocide treatment of CPF waters decreased the CR, except where biocide did not penetrate. The CR for incubations with 20 ml of a produced water decreased from 0.061 to 0.007 mm/yr when increasing the number of beads from 1 to 40. CRs determined with beads were higher than those with coupons, possibly also due to a higher weight of iron per unit volume used in incubations with coupons. Use of 1 ml syringe columns, containing carbon steel beads and injected with 10 ml/day of SRB-containing medium for 256 days gave a CR of 0.11 mm/yr under flow conditions. The standard deviation of the distribution of residual bead weights, a measure for the unevenness of the corrosion, increased with increasing CR. The most heavily corroded beads showed significant pitting. Hence the use of uniformly sized carbon steel beads offers new opportunities for screening and monitoring of corrosion including determination of the distribution of corrosion rates, which allows

  1. Electrochemical corrosion behavior of X52 and X60 steels in carbon dioxide containing saltwater solution

    OpenAIRE

    Rihan Omar Rihan

    2013-01-01

    X52 and X60 high strength low alloy (HSLA) steels are widely used in the construction of petroleum pipelines. This paper discusses the corrosion resistance of X52 and X60 steels in CO2 containing saltwater at pH 4.4 and 50 ºC. A circulating flow loop system inside an autoclave was used for conducting the experimental work. The rotating impeller speed was 2000 rpm. The corrosion rate was monitored using in situ electrochemical methods such as potentiodynamic sweep, linear polarization resistan...

  2. Comparison of corrosion behavior between fusion cladded and explosive cladded Inconel 625/plain carbon steel bimetal plates

    International Nuclear Information System (INIS)

    Highlights: ► Both explosive and fusion cladding aggravate the corrosion resistance of Inconel 625. ► Fusion cladding is more detrimental to nonuniform corrosion resistance. ► Single-layered fusion coat does not show any repassivation ability. ► Adding more layers enhance the corrosion resistance of fusion cladding Inconel 625. ► High impact energy spoils the corrosion resistance of explosive cladding Inconel 625. -- Abstract: One of the main concerns in cladding Inconel 625 superalloy on desired substrates is deterioration of corrosion resistance due to cladding process. The present study aims to compare the effect of fusion cladding and explosive cladding procedures on corrosion behavior of Inconel 625 cladding on plain carbon steel as substrate. Also, an attempt has been made to investigate the role of load ratio and numbers of fusion layers in corrosion behavior of explosive and fusion cladding Inconel 625 respectively. In all cases, the cyclic polarization as an electrochemical method has been applied to assess the corrosion behavior. According to the obtained results, both cladding methods aggravate the corrosion resistance of Inconel 625. However, the fusion cladding process is more detrimental to nonuniform corrosion resistance, where the chemical nonuniformity of fusion cladding superalloy issuing from microsegregation, development of secondary phases and contamination of clad through dilution hinders formation of a stable passive layer. Moreover, it is observed that adding more fusion layers can enhance the nonuniform corrosion resistance of fusion cladding Inconel 625, though this resistance still remains weaker than explosive cladding superalloy. Also, the results indicate that raising the impact energy in explosive cladding procedure drops the corrosion resistance of Inconel 625.

  3. Opuntia ficus-indica Extract as Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution

    Directory of Open Access Journals (Sweden)

    J. P. Flores-De los Ríos

    2015-01-01

    Full Text Available The effect of Opuntia ficus-indica (Nopal as green corrosion inhibitor for carbon steel in 1 M HCl solution has been investigated by using weight loss tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. Also, scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR analysis were performed. The inhibitor concentrations used ranged from 0 to 300 ppm at 25, 40, and 60°C. Results indicated the inhibition efficiency increases with increasing extract concentration and decreases with the temperature, and the inhibitor acted as a cathodic-type inhibitor which is physically absorbed onto the steel surface. In fact, the adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm, indicating monolayer adsorption. The presence of heteroatoms such as C, N, and O and OH groups were responsible for the corrosion inhibition.

  4. Metallurgical and Corrosion Properties of Explosively Welded Ti6Al4V/Low Carbon Steel Clad

    Institute of Scientific and Technical Information of China (English)

    Nizamettin Kahraman; Beh(c)et Gülen(c)

    2005-01-01

    Titanium alloy (Ti6Al4V) and Iow carbon steel (LCS) were joined by explosive welding method using different ratios of explosive. Some metallurgical properties of joined samples were investigated. Joined samples were examined by means of optical microscope, scanning electron microscope (SEM) and tensile-shearing tests. Bending, tensile, hardness and corrosion behaviour of the samples were investigated. Separation was not occurred on the joining interface after tensile-shearing and bending tests. It is seen that hardness of both plates were increased with increasing explosive.It is found that increasing explosive ratio leads to an increase in corrosion. It is also found that corrosion rate was high at the beginning of the experiment but the rate of the corrosion decreased subsequently during the experiment.

  5. Atmospheric corrosion effects of HNO 3—Comparison of laboratory-exposed copper, zinc and carbon steel

    Science.gov (United States)

    Samie, Farid; Tidblad, Johan; Kucera, Vladimir; Leygraf, Christofer

    The influence of nitric acid (HNO 3) on the atmospheric corrosion of copper, zinc and carbon steel was investigated in laboratory exposures at 65% relative humidity (RH), 25 °C and 0.03 cm s -1 air velocity. The deposition velocity ( Vd) of HNO 3 on the specimens, the corrosion rates and corrosion products were determined by gravimetry, ion chromatography, X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) microspectroscopy. Comparisons were also made with literature data on the corrosion effects of sulfur dioxide (SO 2), nitrogen dioxide (NO 2) and ozone (O 3). At 65% RH, the Vd of HNO 3 on all metals was at least 70% of that of an ideal absorbent, i.e., an impregnated filter with perfect absorption for HNO 3. The Vd of HNO 3 was much higher than that of SO 2, NO 2 or O 3, which is mainly attributed to the relatively high sticking coefficient, high solubility and high reactivity of HNO 3 compared to the other gases. During identical exposures to HNO 3, the corrosion rate of carbon steel was nearly three times higher than that of copper or zinc. However, when comparing the corrosion effects induced by HNO 3 with those induced by SO 2 alone or in combination with either NO 2 or O 3, HNO 3 turned out to be far more aggressive than SO 2. Relative to SO 2, zinc is the metal most sensitive to HNO 3, followed by copper and with carbon steel least sensitive to HNO 3.

  6. REVIEW ON ATMOSPHERIC CORROSION OF WEATHERING AND CARBON STEELS%碳钢和耐候钢的大气腐蚀

    Institute of Scientific and Technical Information of China (English)

    李巧霞; 王振尧; 韩薇; 韩恩厚

    2009-01-01

    回顾了近年来碳钢和耐候钢大气腐蚀研究,比较了两种钢的腐蚀行为.重点分析了两种钢在腐蚀过程、腐蚀产物组成及影响因素等方面的相似性;同时讨论了两种钢的腐蚀速度和锈层结构的差异性.%The recent progress in the atmospheric corrosion of carbon steel and weathering steel is reviewed. The corrosion behavior of the above two kinds of steels is compared.The similarities in corrosion process, corrosion products,and effect factors of the two steels are analyzed.The differences in the corrosion rate and rust microstructure of the two steels are discussed.

  7. Investigation with slow traction conditions of the stress corrosion of carbon steels in alkaline media. Role of passivating inhibitors

    International Nuclear Information System (INIS)

    The stress corrosion cracking (S.C.C.) sensitivity of carbon steels in basic media, such as carbonates, is well known. A constant strain-rate test have allowed to observe two steels (A42 [E26] and XC38) behaviour in such conditions at pH 9. The S.C.C. potentials susceptibility range has been found. Inter and Trans-granular cracking have been revealed and measured with micrographic methods. A crack growth rate has been studied as a function of strain rate: an experimental rate has been compared to calculated values from methods which have proposed previously, and methods which have been elaborated in this work. These last permit a best approach of cracking in our case. The chromates use, as inhibitor ions, has permit to decrease the corrosive attack and to cancel the crack growth rate. (author)

  8. Predictive models for determination of pitting corrosion versus inhibitor concentrations and temperature for radioactive sludge in carbon steel waste tanks

    International Nuclear Information System (INIS)

    Statistical models were developed to predict the occurrence of pitting corrosion in carbon steel (CS) waste storage tanks exposed to radioactive nuclear waste. Levels of nitrite (NO2-) concentrations necessary to inhibit pitting at various temperatures and nitrate (NO3-) concentrations were determined experimentally via electrochemical polarization and coupon immersion corrosion tests. Models for the pitting behavior were developed based upon various statistical analyses of the experimental data. Freed-forward, artificial neural network (ANN) models, trained using the back-propagation of error algorithm, more accurately predicted conditions at which pitting occurred than the logistic regression models development using the same data

  9. Study of the corrosion products formed on carbon steels in the tropical atmosphere of Panama

    Directory of Open Access Journals (Sweden)

    Jaén, J. A.

    2003-12-01

    Full Text Available Mössbauer spectroscopy and X-ray powder diffraction (in selected samples have been used to characterize corrosion products on carbon steels after atmospheric exposure to the tropical Panamanian locations of Panama and Colon, classified according to ISO 9223 as C3 and C5, respectively. Goethite (α-FeOOH of intermediate particle size (20-100 nm, lepidocrocite (γ-FeOOH, a spinel phase consisting of non-stoichiometric magnetite (Fe3-xO4 and/or maghemite (γ-Fe2O3 and nano-sized particles were identified in the corrosion products. The spinel phase is related to short term atmospheric exposure transforms in time to other corrosion products. The corrosion resistance increased with fraction of goethite following a saturation-type behavior.

    Se caracterizaron los productos de corrosión de aceros al carbono expuestos a las atmósferas tropicales panameñas localizadas en Panamá y Colón, mediante el uso de la espectroscopia Mössbauer y difracción de rayos-X (en muestras seleccionadas. Las atmósferas se clasifican como C3 y C5, respectivamente, de acuerdo a la norma ISO 9223. Se lograron identificar los compuestos goethita (α-FeOOH de tamaño de partícula intermedio (20-100 nm, lepidocrocita (γ-FeOOH, una fase de espinela consistente en magnetita no estequiométrica (Fe3-xO4 y/o maghemita (γ-Fe2O3, y nanopartículas. La fase de espinela se puede correlacionar con exposiciones cortas a la atmósfera, transformándose en el tiempo en otros productos de corrosión. La resistencia a la corrosión se incrementa con la cantidad de goethita siguiendo una conducta de saturación.

  10. Formation of the self-assembled structures by the ultrasonic cavitation erosion-corrosion effect on carbon steel

    OpenAIRE

    Dayun Yan; Jiadao Wang; Fengbin Liu; Kenan Rajjoub

    2015-01-01

    The cavitation erosion-corrosion effect on the metal surface always forms irregular oxide structures. In this study, we reported the formation of regular self-assembled structures of amorphous nanoparticles around the cavitation erosion pits on carbon steel upon the ultrasonic cavitation in methylene blue solution. Each self-assembled structure was composed of linearly aligned nanoparticles of about 100 nm. The formation of self-assembled structures might be due to the combined effect of corr...

  11. Opuntia ficus-indica Extract as Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution

    OpenAIRE

    J. P. Flores-De los Ríos; M. Sánchez-Carrillo; C. G. Nava-Dino; J.G. Chacón-Nava; González-Rodríguez, J. G.; Huape-Padilla, E.; Neri-Flores, M. A.; Martínez-Villafañe, A.

    2015-01-01

    The effect of Opuntia ficus-indica (Nopal) as green corrosion inhibitor for carbon steel in 1 M HCl solution has been investigated by using weight loss tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. Also, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis were performed. The inhibitor concentrations used ranged from 0 to 300 ppm at 25, 40, and 60°C. Results indicated the inhibition efficiency in...

  12. Effects of Inclusions in HSLA Carbon Steel on Pitting Corrosion in CaCl2

    Energy Technology Data Exchange (ETDEWEB)

    M. Ziomek-Moroz; S. Bullard; K. Rozman; J.J. Kruzic

    2011-12-05

    Susceptibility of high strength low alloy steel to localized corrosion was studied in 6.7 M CaCl{sub 2} for oil and natural gas drilling applications. Results of the immersion and electrochemical experiments showed that the steel is susceptible to pitting corrosion. Optical microscopy investigations of the polished samples revealed that 10% of the surface area was occupied by defects in the form of pits. The energy dispersive X-ray (EDX) and wavelength dispersive X-ray (WDX) chemical analyses revealed higher concentrations of Mn and S compared to the metal matrix in defected areas. These areas served as the sites for development of corrosion pits during both immersion and electrochemical experiments. The fatigue results of the corroded samples indicate that if the pit was the most significant defect, the fatigue crack initiated and propagated at this site.

  13. Novel quaternary ammonium hydroxide cationic surfactants as corrosion inhibitors for carbon steel and as biocides for sulfate reducing bacteria (SRB)

    International Nuclear Information System (INIS)

    A series of alkyl dimethylisopropylammonium hydroxide cationic surfactants (DEDIAOH, DODIAOH and HEDIAOH) was synthesized and characterized. The surface properties such as the critical micelle concentration (CMC), the effectiveness of surface tension reduction (ΠCMC), surface excess concentration (Γmax) and surface area per molecule (Amin) have been determined by means of surface tension measurements. The degree of counter ion dissociation (β) and the free energy of micellization (ΔGmic) were calculated. The corrosion inhibition of the synthesized cationic surfactants on carbon steel surface in 1 M HCl solution was investigated. For this purpose, a series of techniques such as gravimetric measurement, potentiodynamic polarization and scanning electron microscope (SEM) were used. The values of activation energy for carbon steel corrosion and the thermodynamic parameters such as adsorption equilibrium constant (Kads), free energy of adsorption (ΔGadso), adsorption heat (ΔHadso) and adsorption entropy (ΔSadso) values were evaluated. Results showed that HEDIAOH had better inhibition effect than DEDIAOH and DODIAOH of the corrosion of carbon steel in 1 M HCl solution and inhibition efficiency is higher than 96% after 24 h at 1 x 10-2 M concentration of the inhibitor. The inhibition efficiency is discussed in terms of strong adsorption of the inhibitor molecules on the metal surface and formation of a protective film. Scanning electron microscope (SEM) showed a good surface coverage on the metal surface. The Biological activity was examined against sulfate reducing bacteria (SRB) by dilution method.

  14. Corrosion behavior of carbon steel containers with organic coating during interim storage and disposal of low-level radioactive wastes

    International Nuclear Information System (INIS)

    In the Federal Republic of Germany low and intermediate level wastes (e.g., solids, concentrates) are conditioned in carbon steel canisters with organic coating. For this purpose waste drums and steel sheet containers are used. They serve as unshielded packagings during interim storage, transport and disposal in the Konrad mine or in the Gorleben salt dome. Considering the licensing situation for the planned repositories, interim storage periods of up to 20 years are possible. During this period, the transport to the repository and in the operation phase of the repository, the integrity of the waste packaging must be guaranteed. Therefore, special attention must be paid to the corrosion behavior of the steel sheet packagings described in this report. For these reasons, corrosion studies were made on epoxy resin coated or polyurethane coated and uncoated stell sheet specimens. In the investigations design details of the containers (e.g., roundings, screwed connections, gaps, welded seams) as well as damage due to handling (cracks in the organic coating) were taken into account. The specimens were stored for six and twelve months, respectively, both in waste form simulates (inner corrosion of container) and under simulated conditions of an interim storage (storage hall) and of a repository (storage galeries in Konrad and Asse, salt brines) in order to be able to describe external container corrosion. Under simplifying boundary conditions an extrapolation is made of the test results. It has been possible to show that the carbon steel containers described here, provided with a 150 μm epoxy resin coating on the inner and external sides, fulfil the requirements imposed on them as regards their corrosion behavior. (orig.)

  15. The inhibition of low carbon steel corrosion in hydrochloric acid solutions by succinic acid

    International Nuclear Information System (INIS)

    The effect of succinic acid (SA) on the corrosion inhibition of a low carbon steel (LCS) electrode has been investigated in aerated non-stirred 1.0 M HCl solutions in the pH range (2-8) at 25 oC. Weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behaviour in the absence and presence of different concentrations of SA under the influence of various experimental conditions. Measurements of open circuit potential (OCP) as a function of time till steady-state potentials (E st) were also established. Surface analysis using energy dispersive X-ray (EDX) and scanning electron microscope (SEM) allowed us to clarify the mechanistic aspects and evaluate the relative inhibition efficiency. Results obtained showed that SA is a good 'green' inhibitor for LCS in HCl solutions. The polarization curves showed that SA behaves mainly as an anodic-type inhibitor. EDX and SEM observations of the electrode surface confirmed existence of a protective adsorbed film of the inhibitor on the electrode surface. The inhibition efficiency increases with increase in SA concentration, pH of solution and time of immersion. Maximum inhibition efficiency (∼97.5%) is obtained at SA concentrations >0.01 M at pH 8. The effect of SA concentration and pH on the potential of zero charge (PZC) of the LCS electrode in 1.0 M HCl solutions has been studied and the mechanism of adsorption is discussed. Results obtained from weight loss, polarization and impedance measurements are in good agreements

  16. Microbial Corrosion of API 5L X-70 Carbon Steel by ATCC 7757 and Consortium of Sulfate-Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Arman Abdullah

    2014-01-01

    Full Text Available Various cases of accidents involving microbiology influenced corrosion (MIC were reported by the oil and gas industry. Sulfate reducing bacteria (SRB have always been linked to MIC mechanisms as one of the major causes of localized corrosion problems. In this study, SRB colonies were isolated from the soil in suspected areas near the natural gas transmission pipeline in Malaysia. The effects of ATCC 7757 and consortium of isolated SRB upon corrosion on API 5L X-70 carbon steel coupon were investigated using a weight loss method, an open circuit potential method (OCP, and a potentiodynamic polarization curves method in anaerobic conditions. Scanning electron microscopy (SEM and energy dispersive X-ray spectroscopy (EDS were then used to determine the corrosion morphology in verifying the SRB activity and corrosion products formation. Results from the study show that the corrosion rate (CR of weight loss method for the isolated SRB is recorded as 0.2017 mm/yr compared to 0.2530 mm/yr for ATCC 7757. The Tafel plot recorded the corrosion rate of 0.3290 mm/yr for Sg. Ular SRB and 0.2500 mm/yr for Desulfovibrio vulgaris. The results showed that the consortia of isolated SRB were of comparable effects and features with the single ATCC 7757 strain.

  17. Modelling carbon steels corrosion during a long period in soils: Contribution of A.C. impedance spectroscopy

    International Nuclear Information System (INIS)

    The corrosion of historical objects from World War I fields were studied by using two methods: characterization of the corrosion products by Raman Laser Spectroscopy, and behaviour of the corrosion layers by using electrochemical studies. The first technique, previously used, had shown that two layers are present on these objects, containing both different oxides and oxy-hydroxides of iron. In the present part of the work, the A.C. Impedance Spectroscopy was used to show the differences between the two layers concerning the corrosion of these objects. In order to observe the different behaviours, the specimens were studied in three surface states: with the two layers, with the internal layer only, and without oxide. The results have shown that the internal layer limits the corrosion kinetics. Then this layer was especially studied, particularly its porosity, by a comparison of the impedance results in two media with very different conductivity, and the evolution of these results with different immersion times. The buried objects had the behaviour of a porous electrode, due to the presence of the internal layer. Thus, this behaviour can be modelled with the simplified De Levie's theory, considering that each porosity is a semi-infinite hole. It appeared that the corrosion process at the oxidized interface corresponds to the transport in the electrolyte in the pores completed by a part of transport in the solid phase. These properties can be used to predict the long term corrosion behaviour of carbon steels in soils for long periods. (authors)

  18. Evaluation of thermal decomposition rate of carbohydrazide and its reducing effect on carbon steel corrosion

    International Nuclear Information System (INIS)

    Hydrazine as an oxygen scavenger has been widely used for the feed water treatment of PWR secondary side and fossil power plants in the world. However, there is some concern over health and safety issues related to the use of hydrazine. Carbohydrazide is listed up as one of alternative oxygen scavengers. In this study, laboratory tests were performed to examine the thermal decomposition rate of carbohydrazide and its reducing effect on carbon steel corrosion in comparison with hydrazine. Test results revealed that carbohydrazide was stable below 373 K. The thermal decomposition ratios of carbohydrazide were less than 50% after 20 minutes exposure in the range of 373 K to 428 K. Its thermal decomposition rate constant was derived from experimental test data. The measurement of dissolved oxygen concentration also showed that carbohydrazide possessed a fairly good oxygen scavenger property. Judging from test results mentioned above, it was concluded that carbohydrazide is applicable as an alternative oxygen scavenger for feedwater treatment in PWR and fossil power plant

  19. Long-term prediction of reinforced concrete structures - Use of thermodynamic data to assess steel corrosion in carbonated concrete

    International Nuclear Information System (INIS)

    In the context of the prediction of the long-term behaviour of reinforced concrete structures involved in the nuclear waste storage, the corrosion mechanisms of the steels have to be assessed and modelled. When nuclear wastes are embedded in reinforced concrete containers, the chemical environment of the reinforcement is progressively modified, due to the diffusion of the carbonation front inside the concrete matrix. This modification leads to the variation of the properties of the iron oxides formed at the steel/concrete interface, and the active corrosion can be initiated. In order to understand and modelled the mechanisms of steel corrosion in concrete, the equilibrium of two main systems must be separately described with the help of thermodynamic data issued from the literature: - The mineral phases, lime and calcium silicate hydrate (C-S-H), in equilibrium with the pore solution during the propagation of the carbonation front; - The iron oxides in equilibrium with the aqueous solution. For this purpose, the nature of aqueous species present in the pore solution was calculated in the whole range of pH encountered during the cement paste degradation by carbonation. As a matter of fact, as the pH decreases, calcium concentration decreases and silicates concentration increases due to the calcium carbonate formation and C-S-H dissolution. The pH of a carbonated concrete ranges between 8.3 and 10, depending on the partial pressure of carbon dioxide in the porosity and the conversion degree of carbonation. In this pH range, the iron oxides equilibria were analysed as a function of the redox potential and aqueous species (carbonates and sulphates present in the solution) present inside the solution. In a reductive solution and in presence of carbonates, the high solubility of iron oxides may prevent passivation or generate the dissolution of the passive film. Moreover, the relevance of thermodynamics calculations has been confirmed by corrosion tests of mild steel

  20. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; I. Díaz; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...

  1. Microbial corrosion and cracking in steel. Fundamental studies on the electrochemical behaviour of carbon steel exposed in sulphide and sulphate-reducing environments

    Energy Technology Data Exchange (ETDEWEB)

    Rischel Hilbert, Lisbeth

    1998-08-01

    The aim of the report is to give a fundamental understanding of the response of different electrochemical techniques on carbon steel in a sulphide environment as well as in a biologically active sulphate-reducing environment (SRB). This will form the basis for further studies and for recommendations in regards to electrochemical monitoring of MIC. The work presented here and further studies are also planned to lead to a Ph.D. thesis on `MIC monitoring based on mechanisms on corrosion`. The results of laboratory experiments conducted in the period 1995 to 1997 are summarised. Conclusions will be based on results from the entire 3 year period, but only selected experimental data primarily from the latest experiments will be presented in detail here. Microbial corrosion of carbon steel under influence of sulphate-reducing bacteria (SRB) is characterised by the formation of both biofilm and corrosion products (ferrous sulphides) on the metal surface. Experiments have been conducted on carbon steel exposed in near neutral (pH 6 to 8.5) saline hydrogen sulphide environment (0 to 100 mg/l total dissolved sulphide) for a period of 14 days. Furthermore coupons have been exposed in a bioreactor for a period of up to 120 days in sulphide-producing environment controlled by biological activity of (SRB). (au)

  2. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10 Bandung, Jawa Barat (Indonesia)

    2015-09-30

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR and {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.

  3. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    International Nuclear Information System (INIS)

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,1H-NMR and 13C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm

  4. Localized corrosion of carbon steels due to sulfate-reducing bacteria. Development of a specific sensor; Corrosion localisee des aciers au carbone induite par des bacteries sulfato-reductrices. Developpement d'un capteur specifique

    Energy Technology Data Exchange (ETDEWEB)

    Monfort Moros, N.

    2001-11-01

    This work concerns the microbiologically influenced corrosion of carbon steels in saline anaerobic media (3% of NaCl) containing sulfato-reducing bacteria (Desulfovibrio gabonensis, DSM 10636). In these media, extreme localised corrosion occurs by pitting under the bio-film covering the metallic substrate. A sensor with concentric electrodes was designed to initiate the phenomenon of bio-corrosion, recreating the favourable conditions for growth of a corrosion pit, and then measuring the corrosion current maintained by bacterial activity. The pit initiation was achieved through either of two methods. The electrochemical conditioning involved driving the potential difference between inner and outer electrodes to values corresponding to a galvanic corrosion that can be maintained by the bacterial metabolism. The mechanical process involved removal of a portion of the bio-film by scratching, yielding galvanic potential differences equivalent to that found by the conditioning technique. This protocol was found to be applicable to a bio-corrosion study on industrial site for the monitoring of the metallic structures deterioration (patent EN 00/06114, May 2000). Thereafter, a fundamental application uses the bio-corrosion sensor for Electrochemical Impedance Spectroscopy (EIS), Electrochemical Noise Analysis (ENA) and current density cartography by the means of micro-electrodes. Thus, the EIS technique reveals the importance of the FeS corrosion products for initiation of bio-corrosion start on carbon steel. In addition, depending on the method used to create a pit, the ENA gives rise to supplementary processes (gaseous release) disturbing the bio-corrosion detection. The beginning of a bio-corrosion process on a clean surface surrounded with bio-film was confirmed by the current density cartography. These different results establish the sensor with concentric electrodes as an indispensable tool for bio-corrosion studies, both in the laboratory and on industrial sites

  5. Carbon steel corrosion under anaerobic-aerobic cycling conditions in near-neutral pH saline solutions - Part 1: Long term corrosion behaviour

    International Nuclear Information System (INIS)

    Highlights: → Anaerobic-aerobic cycling on pipeline steel forms two distinct surface morphologies. → Seventy-five percentage of the surface was covered by a black, compact layer ∼4.5 μm thick. → A tubercle, ∼3 to 4 mm in cross section, covered the remaining 25% of surface. → The tubercle cross section showed a single large pit ∼275 μm deep. - Abstract: The influence of anaerobic-aerobic cycling on pipeline steel corrosion was investigated in near-neutral carbonate/sulphate/chloride solution (pH 9) over 238 days. The corrosion rate increased and decreased as exposure conditions were switched between redox conditions. Two distinct corrosion morphologies were observed. The majority of the surface corroded uniformly to produce a black magnetite/maghemite layer approximately 4.5 μm thick. The remaining surface was covered with an orange tubercle, approximately 3-4 mm in cross section. Analysis of the tubercle cross section revealed a single large pit approximately 275 μm deep. Repeated anaerobic-aerobic cycling localized the corrosion process within this tubercle-covered pit.

  6. Electrochemical and analytical study of some organic inhibitors used for carbon steel corrosion protection in water cooling systems

    International Nuclear Information System (INIS)

    Water is the main cooling fluid in most industrial applications due to its wide existence in nature and its high specific heat capacity and its thermal conductivity. If pure water was used in cooling systems no problems will occur. However, due to the presence of suspended matter and dissolved solids and gases in water three main problems are encountered in industrial cooling systems; corrosion, scale, and growth of microorganisms which all badly affect the heat transfer efficiency of such system. This study is concerned with utilizing organic inhibitors to control corrosion of mild steel. Three inhibitors were used; 1-hydroxyethylene-1,1- diphosphonic acid (HEDP) as an example of phosphonates, sodium octanoate (C7H15-COONa)as an examples of carboxylates, and 2- phosphono-butane -1,2,4-tricarboxylic acid (PBTC) as an example of a compound having two effective groups: carboxylate and phosphonate (PBTC). City water available at site was used in the present study as a large number of cooling systems utilize water available at site together with mechanical and chemical treatment methods to control corrosion among the two other problems. Two experimental techniques were utilized, potentiodynamic polarization technique and gravimetric technique. The gravimetric technique included a flow loop to simulate the flowing condition of a cooling circuit and a one-day immersion test. Carbon steel specimens, polished to 120 and 600 grit size were used to investigate the effect of surface roughness on the corrosion inhibition efficiency.

  7. Prediction of corrosion-fatigue initiation in low-alloy steel and carbon-steel/water systems at 288 degrees C

    International Nuclear Information System (INIS)

    There has been recent concern about corrosion fatigue data (produced on initially smooth specimens) for carbon and low alloy steels in high temperature water. The concern hinges around the decrease in cycles to crack 'initiation' observed with specific combinations of temperature, dissolved oxygen content and loading history, such that the cycles to crack initiation may be less than those given by the current ASME III design code; thus, the concern is relevant to life extension decisions for Light Water Reactors, (LWR's). After a brief review of the laboratory data on this subject, this paper concentrates on the development of a life-prediction model for corrosion-fatigue 'initiation' of such parameters as strain rate, corrosion potential, sulfur content, loading history, strain amplitude, etc. It is concluded that, although the ASME III code approach to corrosion fatigue of carbon and low alloy steels does not specifically account for the wide range of system parameters pertinent to LWR operations, the current ASME III code line is probably conservative for normal operating conditions

  8. A mechanistic model for predicting flow-assisted and general corrosion of carbon steel in reactor primary coolants

    International Nuclear Information System (INIS)

    Flow-assisted corrosion (FAC) of carbon steel in high-temperature lithiated water can be described with a model that invokes dissolution of the protective oxide film and erosion of oxide particles that are loosened as a result. General corrosion under coolant conditions where oxide is not dissolved is described as well. In the model, the electrochemistry of magnetite dissolution and precipitation and the effect of particle size on solubility move the dependence on film thickness of the diffusion processes (and therefore the corrosion rate) away from reciprocal. Particle erosion under dissolving conditions is treated stochastically and depends upon the fluid shear stress at the surface. The corrosion rate dependence on coolant flow under FAC conditions then becomes somewhat less than that arising purely from fluid shear (proportional to the velocity squared). Under non-dissolving conditions, particle erosion occurs infrequently and general corrosion is almost unaffected by flow For application to a CANDU primary circuit and its feeders, the model was bench-marked against the outlet feeder S08 removed from the Point Lepreau reactor, which furnished one value of film thickness and one of corrosion rate for a computed average coolant velocity. Several constants and parameters in the model had to be assumed or were optimised, since values for them were not available. These uncertainties are no doubt responsible for the rather high values of potential that evolved as steps in the computation. The model predicts film thickness development and corrosion rate for the whole range of coolant velocities in outlet feeders very well. In particular, the detailed modelling of FAC in the complex geometry of one outlet feeder (F11) is in good agreement with measurements. When the particle erosion computations are inserted in the balance equations for the circuit, realistic values of crud level are obtained. The model also predicts low corrosion rates and thick oxide films for inlet

  9. Corrosion Inhibition Performance of Lignin Extract of Sun Flower (Tithonia Diversifolia on Medium Carbon Low Alloy Steel Immersed in H2SO4 Solution

    Directory of Open Access Journals (Sweden)

    Kenneth K. ALANEME

    2012-08-01

    Full Text Available The inhibition potentials of lignin extract of sun flower was investigated by evaluating the corrosion behaviour of medium carbon low alloy steel immersed in 1M H2SO4 solution containing varied concentration of the extract. Mass loss, corrosion rate, and adsorption characterization were utilized to evaluate the corrosion inhibition and adsorption properties of the extract. The results revealed that the lignin extract is an efficient inhibitor of corrosion in mild steel immersed in 1M H2SO4. The corrosion rates were observed to decrease with increase in concentration of lignin extract but increase with temperature. The activation energies and the negative free energy of adsorption obtained from the adsorption studies indicate that the lignin extract is physically adsorbed on the surface of the steel and that the adsorption is strong, spontaneous and fit excellently with the assumptions of the Langmuir adsorption isotherm.

  10. The effect of minor elements on corrosion resistance of carbon steel for high level nuclear waste disposal container

    International Nuclear Information System (INIS)

    Controlling the reduction of Fe3O4 film is an important factor to improve corrosion resistance of carbon steel for geological disposal of radioactive waste. In the present study, the effect of alloying elements on the reduction reaction of Fe3O4 film was examined using sputter-deposited complex oxide films and low alloy steels containing the alloying elements. Fe3O4 films containing a small amount of another oxides were cathodically polarized in the simulated solution of bentonite-contacting water. It showed that the addition of Cr2O3, TiO2, Al2O3 and MoO2 to Fe3O4 is effective on the suppression of the reductive reaction. Fe3O4 films formed on the steels containing small amount of Cr, Ti, Al and Mo by alkaline solution treatment at high temperature also showed a high resistance against the reductive dissolution. The steels containing these alloying elements showed excellent corrosion resistances in the simulated solution of bentonite-contacting water. (author)

  11. Effects of heat treatment on the corrosion resistance of carbon steel coated with LaMgAl11O19 thermal barrier coatings

    Science.gov (United States)

    Huang, Liang-liang; Meng, Hui-min; Liang, Li-kang; Li, Sen; Shi, Jin-hui

    2015-10-01

    LaMgAl11O19 thermal barrier coatings (TBCs) were applied to carbon steels with a NiCoCrAlY bond coat by plasma spraying. The effects of heat treatment on the corrosion resistance of carbon steel coated with LaMgAl11O19 TBCs were investigated in 3.5wt% NaCl solution using polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that a large number of cracks are found in the LaMgAl11O19 TBCs after the samples are heat-treated, including some through-thickness cracks. The corrosion forms of the as-sprayed and heat-treated TBCs are uniform corrosion and pitting corrosion, respectively. The as-sprayed TBCs exhibit three EIS time constants after being immersed for less than 7 d, and then a new time constant appears because of steel substrate corrosion. When the immersion time is increased to 56 d, a Warburg impedance ( W) component appears in the EIS data. The EIS data for the heat-treated TBCs exhibit only two time constants after the samples are immersed for less than 14 d, and a new time constant appears when the immersion time is increased further. The heat treatment reduces the corrosion resistance of carbon steel coated with LaMgAl11O19 TBCs. The corrosion products are primarily γ-FeOOH and Fe3O4.

  12. POTENTIAL FOR STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS CONTAINING HIGHLY CAUSTIC SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.; Stripling, C.; Fisher, D.; Elder, J.

    2010-04-26

    The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 x 30.38 x 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The

  13. Molecular modeling of the inhibition of mild steel carbon dioxide corrosion by imidazolines

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, S.; Jovancicevic, V. [Baker Petrolite, Sugar Land, TX (United States)

    1999-03-01

    Imidazolines have been used to inhibit corrosion in carbon dioxide (CO{sub 2}) solutions. Molecular modeling techniques were used to study adsorption and film formation of imidazolines onto iron oxide. studies determined the binding of imidazoline and amide functional groups to an iron oxide surface, the orientation of imidazoline molecules on the surface, and the cohesive energy of formation of a bilayer of imidazoline molecules as a function of alkyl chain length. Molecular modeling techniques should aid the development of improved corrosion inhibitors by quantifying the role of different functional groups in an inhibitor.

  14. Stress corrosion cracking in low carbon stainless steel components in BWRs

    International Nuclear Information System (INIS)

    In recent years, numbers of SCC have occurred in core shrouds and primary loop recirculation piping made of low carbon stainless steels that had been recognized to be an SCC-resistant material. These incidents resulted in long-term shutdown of Japanese boiling water reactors and have drawn social as well as technical interests. This paper will provide an introductory review on (1) background of SCC observed in low carbon stainless steel components in BWRs, (2) characteristics of SCC in core shrouds and PLR piping, (3) structural integrity evaluation, (4) SCC mitigation techniques, (5) SCC mechanism and (6) research topics that should be covered regarding these issues. (author)

  15. MECHANICAL PROPERTIES AND CORROSION PROTECTION OF CARBON STEEL COATED WITH AN EPOXY BASED POWDER COATING CONTAINING MONTMORILONITE FUNCTIONALIZED WITH SILANE

    Directory of Open Access Journals (Sweden)

    Paula Tibola Bertuoli

    2014-06-01

    Full Text Available In the present work the MMT-Na+ clay was functionalized with 3-aminopropyltriethoxysilane (γ-APS and incorporated in a commercial formulation epoxy-based powder coating in a proportion of 8 wt% and applied on 1008 carbon steel panels by electrostatic spray. Adhesion, flexibility, impact and corrosion performance in salt spray chamber tests were performed to evaluate the coatings. The presence of clay did not affect the mechanical properties of the film, however greater subcutaneous migration was assessed after the completion of salt spray testing, which can compromise the use of paints obtained as primers.

  16. Progress and teachings of stress corrosion cracking of low-carbon stainless steels used in BWR NPP (4)

    International Nuclear Information System (INIS)

    In the structural integrity evaluations of low-carbon stainless- or austenitic steel- made shrouds and primary loop recirculation (PLR) pipes used in Boiling Water Reactor Nuclear Power Plants, the stress corrosion crack propagation rates (crack depth) near shroud and near PLR pipe weld joints are assessed from the welding residual stress distribution obtained by the finite element method and by mockup testing, respectively. The structural integrity is evaluated by the plastic and the elastic-plastic fracture mechanics evaluation methods, respectively. (K. Kato)

  17. Characterization of corrosion products of a carbon steel screw-nut set exposed to mountain weather conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C. P., E-mail: ciramos@cnea.gov.ar [Centro Atomico Constituyentes, Departamento de Fisica (Argentina); Duffo, G.; Farina, S. [Centro Atomico Constituyentes, Departamento de Materiales (Argentina); Lauretta, M. [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales (Argentina); Saragovi, C. [Centro Atomico Constituyentes, Departamento de Fisica (Argentina)

    2010-01-15

    In this work we present the results obtained by means of Moessbauer Spectroscopy to determine and characterize different corrosion products coming from a carbon steel screw-nut set exposed to mountain weather conditions for more than 70 years, in Las Cuevas (Mendoza-Argentina). Measurements at room temperature and 15 K were performed, detecting a great quantity of goethite but also lepidocrocite, hematite, magnetite and maghemite. This study was complemented by material characterization in terms of chemical composition, microscopic observation and X-ray diffraction analysis.

  18. Study of the structure and corrosive-electrochemical behavior of chromized carbon steel 45 in nitric acid

    International Nuclear Information System (INIS)

    An evaluation is made of the corrosion resistance of chromized carbon steel 45 in 5-98% solutions of HNO3 at 40 and 80 degree C in relation to its additional surface microalloying with boron and molybdenum. The structure and phase composition of the diffusion layer and the distribution of the principal components in the layer are studied by the methods of track autoradiography, x-ray diffraction and x-ray spectral analysis, Auger electron spectroscopy, scanning electron microscopy, and optical microscopy

  19. Laboratory investigation of microbiologically influenced corrosion of C1018 carbon steel by nitrate reducing bacterium Bacillus licheniformis

    International Nuclear Information System (INIS)

    Nitrate injection is used to suppress reservoir souring in oil and gas fields caused by Sulfate Reducing Bacteria (SRB) through promotion of nitrate respiration by Nitrate Reducing Bacteria (NRB). However, it is not well publicized that nitrate reduction by NRB can cause Microbiologically Influenced Corrosion (MIC) because nitrate reduction coupled with iron oxidation is thermodynamically favorable. NRB benefits bioenergetically from this redox reaction under biocatalysis. This work showed that the Bacillus licheniformis biofilm, when grown as an NRB biofilm, caused a 14.5 μm maximum pit depth and 0.89 mg/cm2 normalized weight loss against C1018 carbon steel in one-week lab tests

  20. Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic Acid in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Najoua Labjar

    2011-01-01

    Full Text Available Tafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic acid (ATMP for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to 60∘C. It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data.

  1. Conductive and corrosion behaviors of silver-doped carbon-coated stainless steel as PEMFC bipolar plates

    Institute of Scientific and Technical Information of China (English)

    Ming Liu; Hong-feng Xu; Jie Fu; Ying Tian

    2016-01-01

    Ni–Cr enrichment on stainless steel SS316L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was depositedin situ to prepare a thin continuous Ag-doped carbon film on a porous carbon-coated SS316L substrate. The corrosion resistance of this film in 0.5 mol·L−1 H2SO4 solution containing 5 ppm F− at 80°C was inves-tigated using polarization tests. The results showed that the surface treatment of the SS316L strongly affected the adhesion of the carbon coating to the stainless steel. Compared to the bare SS316L, the Ag-doped carbon-coated SS316L bipolar plate was remarkably more stable in both the anode and cathode environments of proton exchange membrane fuel cell (PEMFC) and the interface contact resistance between the specimen and Toray 060 carbon paper was reduced from 333.0 mΩ·cm2 to 21.6 mΩ·cm2 at a compaction pressure of 1.2 MPa.

  2. Conductive and corrosion behaviors of silver-doped carbon-coated stainless steel as PEMFC bipolar plates

    Science.gov (United States)

    Liu, Ming; Xu, Hong-feng; Fu, Jie; Tian, Ying

    2016-07-01

    Ni-Cr enrichment on stainless steel SS316L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was deposited in situ to prepare a thin continuous Ag-doped carbon film on a porous carbon-coated SS316L substrate. The corrosion resistance of this film in 0.5 mol·L-1 H2SO4 solution containing 5 ppm F- at 80°C was investigated using polarization tests. The results showed that the surface treatment of the SS316L strongly affected the adhesion of the carbon coating to the stainless steel. Compared to the bare SS316L, the Ag-doped carbon-coated SS316L bipolar plate was remarkably more stable in both the anode and cathode environments of proton exchange membrane fuel cell (PEMFC) and the interface contact resistance between the specimen and Toray 060 carbon paper was reduced from 333.0 mΩ·cm2 to 21.6 mΩ·cm2 at a compaction pressure of 1.2 MPa.

  3. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, Manuel; Fuente, Daniel de la; Díaz Ocaña, Iván; Cano, Heidis

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morpholog...

  4. Microstructure, Wear, and Corrosion Characteristics of TiC-Laser Surface Cladding on Low-Carbon Steel

    Science.gov (United States)

    El-Labban, Hashem F.; Mahmoud, Essam Rabea Ibrahim; Algahtani, Ali

    2016-04-01

    Laser cladding was used to produce surface composite layer reinforced with TiC particles on low-carbon steel alloy for improving the wear and corrosion resistances. The cladding process was carried out at powers of 2800, 2000, 1500, and 1000 W, and a fixed traveling speed of 4 mm/s. The produced layers are free from any cracks. Some of the TiC particles were melted and then re-solidified in the form of fine acicular dendrites. The amount of the melted TiC was increased by increasing the laser power. The hardness of the produced layers was improved by about 19 times of the base metal. Decreasing laser power led to hardness increment at the free surface. The improvement in wear resistance was reached to about 25 times (in case of 1500 W) of the base metal. Moreover, the corrosion resistance shows remarkable improvement after the laser treatment.

  5. Features and mechanism of unusual wall thinning. (Erosion-corrosion) of the carbon steel pipe carrying hot pure water

    International Nuclear Information System (INIS)

    The features of unusual wall thinning of carbon steel piping used in the transport of pure water at elevated temperatures are described. The case of Mihama nuclear power plant is used as a typical example, since the results of investigations conducted by the investigation committee of the Nuclear and Industrial Safety Agency are already available at their web site, and detailed information, such as data on residual wall thickness distribution and clear photographs of the thinned pipe wall surface etc. are readily available. Two models for illustrating the generation mechanism were examined: the FAC (flow accelerated corrosion) model and the macro-cell corrosion model. The latter explained the mechanism reasonably well, and methods for preventing wall thinning, based on this model, are given. Procedures for detecting the progress of wall thinning were also described. (author)

  6. Orbital plasma keyhole welding of 12--13% Cr low carbon martensitic line pipe steels and weld joint corrosion properties

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmeister, H.; Dietrich, S. [Univ. der Bundeswehr Hamburg (Germany); Tystad, M.; Knagenhjelm, H.O.; Andersen, T.R. [Norsk Hydro A/S Porsgrunn (Norway). Forskningssenteret

    1995-10-01

    Based on requirements for more economical pipe laying procedures in the oil and gas industry, the potential of the orbital plasma keyhole process for welding of 12--13% Cr martensitic low carbon steels together with resulting hardness and corrosion properties is investigated. As a result, downhill orbital welding speeds up to 6--7 mm/s at 6--10 mm wall thickness are achieved. For hardness reduction, local postweld heating of 600--700 C at up to 10 min was required. Pitting corrosion resistance of the weld joints was reduced by welding but could be restored by postweld heating above 750--800 C, which, however, might produce hardness levels not satisfying NACE requirements due to formation of untempered martensite.

  7. PREPARATION AND CORROSION RESISTANCE OF NiP/TiO2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

    Institute of Scientific and Technical Information of China (English)

    L.Z. Song; S.Z. Song; J. Zhao

    2006-01-01

    A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM (environmental scanning electron microscopy)and EIS (electrochemical impedance spectroscopy) measurements. Results showed that the NiP/TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS (X-ray photoelectron spectroscopy) spectrum, and an anticorrosion mechanism of the composite film was discussed.

  8. Contribution of archaeological analogs to the estimation of average corrosion rates and long term corrosion mechanisms of low carbon steel in soil

    International Nuclear Information System (INIS)

    In the context of the French nuclear waste storage, a multi-barriers disposal is envisaged. Wastes could be put in metallic overpacks disposed in a clay soil. As these overpacks could be made of low carbon steel, it is important to understand the corrosion behaviour of this material in soil during period of several centuries. Indeed, it is necessary to consolidate the empirical data by a phenomenological approach. This includes laboratory experiments and modelling of the phenomenon which have to be validated and completed by the study of archaeological artefacts. This was the aim of this PhD-work. To this purpose, an analytical protocol has been elaborated: about forty archaeological artefacts coming from five dated sites (2. to 16. centuries) have been studied on cross section in order to observe on the same sample all the constituents of the system: metallic substrate/corrosion products/environment. The corrosion products are divided into two zones: the Dense Product Layer (DPL) in contact with the metal, and the Transformed Medium (TM) which are the corrosion products formed around soil minerals (quartz grains). The metallic substrate has been studied by the classical methods of materials science (optical and scanning electron microscope, energy and wavelength dispersive spectroscopies). It has been verified that despite their heterogeneity of structure and composition, they are all hypo-eutectoids steels that can contain phosphorous until 0.5 wt%. The corrosion products have been analysed by local structural analytical methods as micro-diffraction under synchrotron radiation (μXRD) and Raman micro-spectroscopy. These two complementary techniques and also the elemental composition analysis conducted to the characterisation of the corrosion forms. On the majority of the samples coming from four sites, the DPL are constituted by goethite including marbles of magnetite/maghemite. On the artefacts from the fifth site, a particular corrosion form has been identified

  9. Microbial corrosion of stainless steel.

    Science.gov (United States)

    Ibars, J R; Moreno, D A; Ranninger, C

    1992-11-01

    Stainless steel, developed because of their greater resistance to corrosion in different aggressive environments, have proved to be affected, however, by various processes and types of corrosion. Some of these types of corrosion, mainly pitting, is activated and developed in the presence of microorganisms, which acting in an isolated or symbiotic way, according to their adaptation to the environment, create a favorable situation for the corrosion of these steel. The microorganisms that are involved, mainly bacteria of both the aerobic and anaerobic type, modify the environment where the stainless steel is found, creating crevices, differential aeration zones or a more aggressive environment with the presence of metabolites. In these circumstances, a local break of the passive and passivating layer is produced, which is proper to these types of steel and impedes the repassivation that is more favorable to corrosion. In the study and research of these types of microbiologically influenced corrosion are found electrochemical techniques, since corrosion is fundamentally an electrochemical process, and microbiological techniques for the identification, culture, and evaluation of the microorganisms involved in the process, as well as in the laboratory or field study of microorganism-metal pairs. Microstructural characterization studies of stainless steel have also been considered important, since it is known that the microstructure of steel can substantially modify their behavior when faced with corrosion. As for surface analysis studies, it is known that corrosion is a process that is generated on and progresses from the surface. The ways of dealing with microbiologically influenced corrosion must necessarily include biocides, which are not always usable or successful, the design of industrial equipment or components that do not favor the adherence of microorganisms, using microstructures in steel less sensitive to corrosion, or protecting the materials. PMID:1492953

  10. Influences of Temperature and pH Value on the Corrosion Behaviors of X80 Pipeline Steel in Carbonate/Bicarbonate Buffer Solution

    Institute of Scientific and Technical Information of China (English)

    LI,Jin-Bo; ZUO,Jian-E

    2008-01-01

    The joint effect of temperature and pH value on the corrosion behavior of X80 steel in carbonate/bicarbonate buffer solution was detected by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis. The results show that an unstable corrosion film will be formed on the X80 steel surface in low pH value solutions, and a better protective corrosion film can be formed on the X80 steel surface in high pH value solutions. On the whole, the corrosion film resistance and transfer resistance increase with the increment of pH value, and decrease with increase of solution temperature, which indicates that the protective effect of the corrosion film on X80 steel is enhanced with increasing pH value and decreasing the solution temperature. The corrosion film formed on X80 steel surface in carbonate/bicarbonate buffer solution has an n-type semi-conductive character, and the donor density decreases with increasing the pH value, and increases with increasing the solution temperature. The flat-band potential and pH value have a linear relationship with a positive slope.

  11. The Effect of Temperature and Acid Gas Loading on Corrosion Behavior of API 5L X52 Carbon Steel in Amine Unit

    Science.gov (United States)

    Javidi, M.; Lalehparvar, M. M.; Ghassemi, A.

    2016-05-01

    The effect of temperature and H2S concentration on amine corrosion of API 5L X52 carbon steel in a CO2-saturated 25 wt.% diethanolamine solution was investigated via electrochemical techniques. It was found that increase in temperature from 25 to 80 °C resulted in severe increase in corrosion rate from 0.88 to 16.24 mpy due to increase in degradation rate of amine. Also, it was concluded that increase in H2S concentration led to increase in corrosion rate because of formation of more heat stable amine salts. The effect of temperature on corrosion rate was more significant than acid gas loading.

  12. The effect of pre-oxidation and the influence of deformation on the corrosion behaviour of two heat resistant steels in a sulphur-oxygen-carbon bearing environment

    International Nuclear Information System (INIS)

    The influence of pre-oxidation on the corrosion resistance of the austenitic steels AC 66 (Fe-32Ni-27Cr-0.07Ce) and alloy 800H (Fe-32Ni-20Cr) was studied in a sulphur-oxygen-carbon bearing atmospheric at 700oC. For AC 66 the corrosion resistance was significantly improved by preoxidation, whereas this effect was less marked for Alloy 800H. This can be explained by a much better adherence of the preformed oxide scale for AC 66. The corrosion resistance was shown to decrease by superimposed deformation which leads to deeply penetrating intergranular corrosion paths. (Author)

  13. Extracellular Electron Transfer Is a Bottleneck in the Microbiologically Influenced Corrosion of C1018 Carbon Steel by the Biofilm of Sulfate-Reducing Bacterium Desulfovibrio vulgaris.

    Directory of Open Access Journals (Sweden)

    Huabing Li

    Full Text Available Carbon steels are widely used in the oil and gas industry from downhole tubing to transport trunk lines. Microbes form biofilms, some of which cause the so-called microbiologically influenced corrosion (MIC of carbon steels. MIC by sulfate reducing bacteria (SRB is often a leading cause in MIC failures. Electrogenic SRB sessile cells harvest extracellular electrons from elemental iron oxidation for energy production in their metabolism. A previous study suggested that electron mediators riboflavin and flavin adenine dinucleotide (FAD both accelerated the MIC of 304 stainless steel by the Desulfovibrio vulgaris biofilm that is a corrosive SRB biofilm. Compared with stainless steels, carbon steels are usually far more prone to SRB attacks because SRB biofilms form much denser biofilms on carbon steel surfaces with a sessile cell density that is two orders of magnitude higher. In this work, C1018 carbon steel coupons were used in tests of MIC by D. vulgaris with and without an electron mediator. Experimental weight loss and pit depth data conclusively confirmed that both riboflavin and FAD were able to accelerate D. vulgaris attack against the carbon steel considerably. It has important implications in MIC failure analysis and MIC mitigation in the oil and gas industry.

  14. Corrosion resistance and electrical properties of carbon/chromium-titanium-nitride multilayer coatings on stainless steel

    Science.gov (United States)

    Feng, Kai; Li, Zhuguo; Lu, Fenggui; Huang, Jian; Cai, Xun; Wu, Yixiong

    2014-03-01

    High electrical conductivity and corrosion resistance are central to advances in wider application of metallic bipolar plates in polymer electrolyte membrane fuel cell (PEMFC). In this study, C/Cr-Ti-N multilayer coatings are deposited by physical vapor deposition and the effect of Cr:Ti ratio on the corrosion resistance and interfacial contact resistance (ICR) are systematically investigated. Scanning electron microscopy (SEM) result shows that the carbon layer is compact and uniform. Excellent corrosion resistance of 0.127 μA cm-2 current density at operating voltage in PEMFC cathode environment and low ICR of 2.03 mΩ-cm2 at compaction force of 150 N cm-2 are achieved when Cr:Ti ratio is 2:4 and 3:3, respectively. The significant enhancement in surface conductivity is probably because that the current comes from carbon paper is homogenized by two electrically conductive layers and flows to the passive film with much more contact area. After polarization, ICR increase to 3.07 mΩ-cm2 and 3.02 mΩ-cm2 in the simulated PEMFC cathode and anode environment, respectively. However, the Raman spectroscopy results disclose that the bonding type of top carbon film before and after polarization shows little difference. The results indicate that C/Cr-Ti-N multilayer coating with Cr:Ti ratio of 2:4 achieves the optimal composition.

  15. Electrochemical evaluation of antibacterial drugs as environment-friendly inhibitors for corrosion of carbon steel in HCl solution

    International Nuclear Information System (INIS)

    The effect of penicillin G, ampicillin and amoxicillin drugs on the corrosion behavior of carbon steel (ASTM 1015) in 1.0 mol L−1 hydrochloric acid solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration. The effect of temperature on the rate of corrosion in the absence and presence of these drugs was also studied. Some thermodynamic parameters were computed from the effect of temperature on corrosion and inhibition processes. Adsorption of these inhibitors was found to obey Langmuir adsorption isotherm. There was a case of mixed mode of adsorption here but while penicillin was adsorbed mainly through chemisorption, two other drugs were adsorbed mainly through physisorption. Potentiodynamic polarization measurements indicated that the inhibitors were of mixed type. In addition, this paper suggests that the electrochemical noise (EN) technique under open circuit conditions as the truly noninvasive electrochemical method can be employed for the quantitative evaluation of corrosion inhibition. This was done by using the standard deviation of partial signal (SDPS) for calculation of the amount of noise charges at the particular interval of frequency, thereby obtaining the inhibition efficiency (IE) of an inhibitor. These IE values showed a reasonable agreement with those obtained from potentiodynamic polarization and EIS measurements.

  16. Electrochemical evaluation of antibacterial drugs as environment-friendly inhibitors for corrosion of carbon steel in HCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Golestani, Gh.; Shahidi, M., E-mail: shahidi1965@gmail.com; Ghazanfari, D.

    2014-07-01

    The effect of penicillin G, ampicillin and amoxicillin drugs on the corrosion behavior of carbon steel (ASTM 1015) in 1.0 mol L⁻¹ hydrochloric acid solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration. The effect of temperature on the rate of corrosion in the absence and presence of these drugs was also studied. Some thermodynamic parameters were computed from the effect of temperature on corrosion and inhibition processes. Adsorption of these inhibitors was found to obey Langmuir adsorption isotherm. There was a case of mixed mode of adsorption here but while penicillin was adsorbed mainly through chemisorption, two other drugs were adsorbed mainly through physisorption. Potentiodynamic polarization measurements indicated that the inhibitors were of mixed type. In addition, this paper suggests that the electrochemical noise (EN) technique under open circuit conditions as the truly noninvasive electrochemical method can be employed for the quantitative evaluation of corrosion inhibition. This was done by using the standard deviation of partial signal (SDPS) for calculation of the amount of noise charges at the particular interval of frequency, thereby obtaining the inhibition efficiency (IE) of an inhibitor. These IE values showed a reasonable agreement with those obtained from potentiodynamic polarization and EIS measurements.

  17. Influence and role of ethanol minor constituents of fuel grade ethanol on corrosion behavior of carbon steel

    International Nuclear Information System (INIS)

    Highlights: • The pitting factors of the minor contents of ethanol are acetic acid, Cl and H2O. • Formic acid in ethanol promotes general corrosion. • The H2O content in fuel-grade-ethanol (FGE) affects the corrosion morphology. • Acetic acid generates iron acetate, which has high solubility in FGE environments. • A pitting mechanism based on the rupture of passive film is proposed. - Abstract: The influences of organic acids, chloride and water on the corrosion behavior of carbon steel in fuel grade ethanol (FGE) environments were investigated by immersion testing in simulated FGE. The roles of acetic acid, chloride and water in pitting corrosion were studied by using X-ray photoelectron spectroscopy (XPS), auger electron spectroscopy (AES) and electrochemical experiments. The results indicated that iron acetate is generated on oxide film. Iron(II) acetate shows high solubility in FGE environments. The sites where iron(II) acetate is existed become preferential anodic sites, and chloride promotes anodic dissolution at such sites

  18. A Study of N,N-Diethylammonium O,O′-Di(p-methoxyphenyldithiophosphate as New Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Chuan Lai

    2016-01-01

    Full Text Available N,N-Diethylammonium O,O′-di(p-methoxyphenyldithiophosphate (EAPP as a new corrosion inhibitor was synthesized in the present work. The corrosion inhibition of EAPP in hydrochloric acid for carbon steel was evaluated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy, weight loss measurements, and scanning electron microscopy. The results indicate that the EAPP is mixed type inhibitor, and the adsorption of EAPP on carbon steel surface obeys Langmuir isotherm. In addition, the inhibition efficiency increases with increasing the concentration of inhibitor and decreases with increasing the hydrochloric acid concentration, temperature, and storage time.

  19. Adsorption and inhibition effect of Ascorbyl palmitate on corrosion of carbon steel in ethanol blended gasoline containing water as a contaminant

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Inhibition performance was studied using weight loss and EIS methods. •The addition of ethanol and water to gasoline increase the corrosion rate of C-steel. •Ascorbyl palmitate has good inhibition efficiency for C-steel in blend fuel. •Efficiency more than 96% was obtained with 120 mg l−1 AP at 298 K. •The adsorption of AP on C-steel surface obeys Langmuir adsorption isotherm. -- Abstract: The adsorption and inhibition effect of Ascorbyl palmitate (AP) on carbon steel in ethanol blended gasoline containing water as a contaminant (GE10 + 1%water) was studied by weight loss and electrochemical impedance spectroscopic (EIS) techniques. The results showed that the addition of ethanol and water to gasoline increase the corrosion rate of carbon steel. AP inhibits the corrosion of carbon steel in (GE10 + 1% water) solution to a remarkable extent. The adsorption of AP on the carbon steel surface was found to obey the Langmuir adsorption isotherm model. The values of activation energy (Ea) and various thermodynamic parameters were calculated and discussed

  20. A study of electrochemically-induced corrosion of low carbon steel in a medium modelling acid rain

    International Nuclear Information System (INIS)

    Complementary electrochemical, spectrophotometric and electron microsopic investigations were made in addition to the conversion electron Moessbauer spectroscopic (CEMS) measurements to learn more about the mechanism of corrosion of low carbon steel samples in aqueous sulfate and sulfite containing sulfate solutions (pH 3.5, 6.5 and 8.5). Passivation of iron in pure sulfate solution was studied in detail in earlier papers. In the present work, we used a solution containing both sulfate and sulfite anions to obtain more information about the effect of acid rain on low carbon steel samples. The compositions and thicknesses of the passive films formed due to the electrochemical treatments were determined from the CEM spectra. γ-FeOOH was found in each case on the surface of the samples; nevertheless, at pH 3.5 the sextet belonging to Fe3C appears in the CEM spectra, and also FeSO4 . H2O was detected in low concentration after the shortest polarization time (90 min). The results of the applied methods proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements referred to suppressed pitting at pH 8.5. (orig.)

  1. Novel dispersed magnetite core-shell nanogel polymers as corrosion inhibitors for carbon steel in acidic medium

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Research highlights: → Through a one-step thermal reaction, magnetite nanoparticles were synthesized, and self-assembled mixed films of modified cross-linked ionic polymer magnetite nanoparticles were prepared on iron surface. → The size distribution and shape of magnetite nanoparticles were examined using transmission electron microscopy (TEM). → The corrosion inhibition efficiency of carbon steel in 1 M HCl by the synthesized Fe3O4 nanogel polymers has been studied using potentiodynamic polarization and EIS. → Scanning electron microscopy (SEM) measurements were applied to study the morphology of the carbon steel surface. - Abstract: Novel core-shell preparing poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and copolymers with acrylic acid (AA) or acrylamide (AM) magnetic nanogels with controllable particle size produced via free aqueous polymerization at room temperature have been developed for the first time. The crosslinking polymerization was carried out in the presence of N,N'-methylenebisacrylamide (MBA) as a crosslinker, N,N,N',N'-tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogels were characterized by Fourier transform infrared spectroscopy (FTIR), transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations and temperatures. The results showed the nanogel particles act as mixed inhibitors. Adsorption of nanogel particles was found to fit the Langmuir isotherm and was chemisorption.

  2. Corrosion of carbon steel under anaerobic conditions in a repository for SF and HLW in Opalinus Clay. Technical report 08-12

    International Nuclear Information System (INIS)

    Nagra is considering carbon steel as one of the canister material options for the disposal of high level waste and spent fuel in a deep geological repository in Opalinus Clay. Following a brief period of aerobic conditions, the canister will be exposed to an anaerobic environment for much of its service life. Knowledge of the rate of anaerobic corrosion is important not only for estimating the canister lifetime but also for determining the rate of hydrogen generation. This report describes a critical review of the anaerobic corrosion behaviour of carbon steel under environmental conditions similar to those expected in the repository. The aims of the report are: 1. to recommend a (range of) long-term anaerobic corrosion rate(s) for carbon steel canisters, and 2. to justify the use of this rate in safety assessments based on a mechanistic understanding of the structure and properties of the protective corrosion product films. The review is based on selected studies from various national nuclear waste management programs, supplemented where appropriate with studies from other applications and with evidence from archaeological analogues. The corrosion rate of carbon steel decreases with time because of the formation of a protective surface film. There are differences in behaviour in bulk solution and in the presence of compacted bentonite. In bulk solution, the corrosion rate decreases to an apparent steady-state rate after a period of approximately six months, with a long-term rate of the order of 0.1 μm·.yr-1. The surface film comprises a duplex structure, with a magnetite outer layer and a spinel-type inner layer. In compacted clay systems the rate of decrease in corrosion rate is slower, with steady state not being reached after several years of exposure. There is a significant body of evidence from apparently well-conducted experiments that indicate an anaerobic corrosion rate of the order of 1-2 μm·yr-1 in systems containing compacted clay and the protective

  3. Microbial corrosion and cracking in steel. Assessment of soil corrosivity using an electrochemical soil corrosion probe

    Energy Technology Data Exchange (ETDEWEB)

    Vendelbo Nielsen, L.

    1998-08-01

    An electrochemical soil corrosion probe has been designed, manufactured, and tested at five different locations in the field. The probe includes facilities for hydrogen permeation measurements, local soil resistivity measurements by the Wenner fourpoint method, and open circuit potential measurements on carbon steel- and high-alloyed (SMO-254) stainless steel electrodes. The carbon steel electrodes were arranged as two sets of three-electrode arrangements. Using these arrangements, electrochemical impedance spectroscopy (EIS), galvanostatic pulse (GP) measurements, and DC polarisation scans were applied for characterisation of the corrosion conditions present in the soil. (au) EFP-95. 21 refs.

  4. Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies

    Science.gov (United States)

    El Hamdani, Naoual; Fdil, Rabiaa; Tourabi, Mustapha; Jama, Charafeddine; Bentiss, Fouad

    2015-12-01

    Current research efforts now focus on the development of non-toxic, inexpensive and environmentally friendly corrosion inhibitors as alternatives to different organic and non-organic compounds. In this field, alkaloids extract of Retama monosperma (L.) Boiss. seeds (AERS) was tested for the first time as corrosion inhibitor for carbon steel in 1 M HCl medium using electrochemical and surface characterization techniques. The obtained results showed that this plant extract's acts as an efficient corrosion inhibitor for carbon steel in 1 M HCl and an inhibition efficiency of 94.4% was reached with 400 mg/L of AERS at 30 °C. Ac impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Impedance results demonstrated that the addition of the AERS in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Polarization curves indicated that AERS is a mixed inhibitor. Adsorption of such alkaloid extract on the steel surface obeyed to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) showed that the inhibition of steel corrosion in normal hydrochloric solution by AERS is mainly controlled by a physisorption process and the inhibitive layer is composed of an iron oxide/hydroxide mixture where AERS molecules are incorporated.

  5. Comparative study in the induced corrosion by sulfate reducing microorganisms, in a stainless steel 304L sensitized and a carbon steel API X65

    International Nuclear Information System (INIS)

    In spite of the operational experience related with the presence of the phenomenon of microbiological corrosion (MIC) in industrial components, it was not but until the decade of the 80 s when the nuclear industry recognized its influence in some systems of Nuclear Generating Power plants. At the moment, diverse studies that have tried to explain the generation mechanism of this phenomenon exist; however, they are even important queries that to solve, especially those related with the particularities of the affected metallic substrates. Presently work, the electrochemical behavior of samples of stainless steel AISI 304L sensitized is evaluated and the carbon steel APIX65, before the action of sulfate reducing microorganisms low the same experimental conditions; found that for the APIX65 the presence of this type of bacteria promoted the formation of a stable biofilm that allowed the maintenance of the microorganisms that damaged the material in isolated places where stings were generated; while in the AISI 304L, it was not detected damage associated to the inoculated media. The techniques of Resistance to the Polarization and Tafel Extrapolation, allowed the calculation of the speed of uniform corrosion, parameter that doesn't seem to be influenced by the presence of the microorganisms; while that noise electrochemical it distinguished in real time, the effect of the sulfate reducing in the steel APIX65. (Author)

  6. INVESTIGATION OF THE POTENTIAL FOR CAUSTIC STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.

    2009-10-15

    The evaporator recycle streams contain waste in a chemistry and temperature regime that may be outside of the current waste tank corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history (1998-2008) of Tanks 30 and 32 showed that these tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved F-Area tanks. Therefore, for the Type III/IIIA waste tanks the efficacy of the stress relief of welding residual stress is the only corrosion-limiting mechanism. The objective of this experimental program is to test carbon steel small scale welded U-bend specimens and large welded plates (12 x 12 x 1 in.) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in Tanks 30 and 32. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test is currently in progress, but no cracking has been observed after 9 weeks of immersion. Based on the preliminary results, it appears that the environmental conditions of the tests are unable to develop stress corrosion cracking within the duration of these tests.

  7. Inhibition properties of self-assembled corrosion inhibitor talloil diethylenetriamine imidazoline for mild steel corrosion in chloride solution saturated with carbon dioxide

    International Nuclear Information System (INIS)

    Highlights: •Corrosion inhibitor talloil diethylenetriamine imidazoline effectively protects mild steel from CO2 corrosion. •Quartz crystal microbalance measurements were used to the investigate kinetics of corrosion inhibitor adsorption. •Adsorption of talloil diethylenetriamine imidazoline can be described by Langmuir adsorption isotherm. -- Abstract: The inhibition effect of talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) on corrosion of mild steel in chloride solutions saturated with CO2 was investigated by weight loss measurements (WL) and atomic force microscopy (AFM). Adsorption mechanism and kinetics of self-assembled (TOFA/DETA imidazoline) monolayers formation on gold were studied using the quartz crystal microbalance measurements (QCM). WL and AFM results demonstrated that TOFA/DETA imidazoline can effectively protect mild steel surface from corrosion. QCM measurements shown that the adsorption of TOFA/DETA imidazoline onto gold follows Langmuir adsorption isotherm and further investigation of the adsorption process will be carried out on a corroding metal surface

  8. The effect of hydrodynamics and solution chemistry on the corrosion of carbon steel in high-temperature water

    International Nuclear Information System (INIS)

    To understand the effects of temperature, coolant hydrodynamics and chemistry on the corrosion of carbon steel in high-temperature water, electrochemical measurements were carried out on samples subjected to a submerged, impinging jet in an experimental water loop. Samples were mounted on an electrically-insulated holder inside a flow-through autoclave in the loop and made the working electrode of a three-electrode system with platinum as the counter and reference electrodes. The hydrodynamics were varied by changing jet velocity and chemistry was varied with additions of lithium hydroxide (LiOH) and kept reducing with different partial pressures of hydrogen (H2) in the loop reservoir. In one set of experiments, boric acid (H3BO3) was added. Throughout, the coolant was saturated with dissolved iron from contact with loop components of stainless steel. The oxide film formed on the carbon steel during exposure was examined with an electron microscope. A compact, inner oxide film of small particles of magnetite (Fe3O4) developed over the whole specimen surface while an outer oxide film of larger Fe3O4 crystallites grew mainly at the specimen perimeter and decreased towards the jet impinging region at the centre, from where it was absent. Polarization measurements indicated that there was no passivation or localized corrosion and that specimens corroded actively. Corrosion rate, as determined by linear polarization, increased with temperature over the range 25°C to 300°C and decreased with H2 concentration over the range 1 to 18 mL(STP)/kg. At a typical reactor temperature of 300°C and for lithium concentrations of 0.7, 2.9 and 7.4 ppm, corresponding to pH300°C values of 7.4, 8.0 and 8.4, respectively, corrosion rate was a minimum at 2.9 ppm Li. The highest corrosion rate, which coincided with the thinnest oxide film, occurred when the pH300°C was adjusted to a value of 6.8 by adding boric acid to the equivalent level of 2,000 ppm of boron to the 2.9 ppm solution

  9. Microbial Corrosion and Cracking in Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    1998-01-01

    be based on results from the entire 3 year period, but only selected experimental data primarily from the latest experiments will be presented in detail here.Microbial corrosion of carbon steel under influence of sulphate-reducing bacteria (SRB) is characterised by the formation of both biofilm and...... recommendations in regards to electrochemical monitoring of MIC. The work presented here and further studies are also planned to lead to a Ph.D. thesis on "MIC monitoring based on mechanisms of corrosion".The results of laboratory experiments conducted in the period 1995 to 1997 are summarised. Conclusions will...... corrosion products (ferrous sulphides) on the metal surface. Experiments have been conducted on carbon steel exposed in near neutral (pH 6 to 8.5) saline hydrogen sulphide environment (0 to 100 mg/l total dissolved sulphide) for a period of 14 days. Furthermore coupons have been exposed in a bioreactor for...

  10. RECRYSTALLIZATION BEHAVIOR AND PRIOR AUSTENITE GRAIN BOUNDARY CORROSION IN THE PLANE STRAIN COMPRESSION CONDITION FOR A LOW CARBON X70 PIPELINE STEEL

    Institute of Scientific and Technical Information of China (English)

    Y.H. Li; J. Wang; Y.S. Li; Y. Y. Shan

    2004-01-01

    Recrystallization behavior of a low carbon X70 pipeline steel was studied in the plane strain compression condition. It was found that the dynamic recovery but no dynamic recrystallization occurred in the current experimental condition. A method for examining the prior austenite grain boundary corrosion was supposed.

  11. Statistical analysis of a corrosion inhibitor family on three steel surfaces (duplex, super-13 and carbon) in hydrochloric acid solutions

    International Nuclear Information System (INIS)

    Previous studies have addressed the experimental and theoretical investigation of the inhibition corrosion efficiencies (ICE) of single metal surfaces. Along this line we carried out calculations concerning to 23 compounds on three different single-steel surfaces, duplex, super-13 and the carbon steel in hydrochloric acid (15% w/v) solutions. The overall experiment is composed of 69 results of weight loss ICEs at 60 deg. C for amines, alcohols, thiourea and its derivatives acting as corrosion inhibitors for three steel surfaces. In these studies ICEs were correlated with group and quantum AM1 descriptors through the use of three different statistical methodologies based on calibration and validation of regular and modified OLS and PLS (partial least squares) methods. All calculations have shown better results using weight isoesteric Langmuir adsorption function (WILA function), ln(θM/(1-θ)) or ln Kads, calculated from the weight loss data as the response function. The function -log(i) has been used, as well, on all comparisons. Variables describing the metal were added to the previous set of group and quantum IC variables and several models have been designed to fit the three-steel problem. Simple products of metal and IC variables with 250 (25 x 10) products were tested as model I. Selection of the best variable set was carried out for the calibration and validation procedures and these calculations indicated very few descriptors in common, i.e. each particular selection (calibration or validation) finds its own optimal descriptor set. The overall results showed excellent correlations with R2 values between 0.80 and 0.96 and a Q2 values from 0.75 to 0.93. We are unaware of any similar QSPR study on the steels here studied, and neither the study of such massive amount of data concerning molecular inhibitors on three different steel surfaces. Our best result for the second-order cross-validation descriptor selection employs 29 variables, Y29. The results

  12. Investigation of Corrosion and Cathodic Protection in Reinforced Concrete. II: Properties of Steel Surface Layers

    NARCIS (Netherlands)

    Koleva, D.A.; De Wit, J.H.W.; Van Breugel, K.; Lodhi, Z.F.; Ye, G.

    2007-01-01

    The present study explores the formation of corrosion products on the steel surface (using as-received low carbon construction steel) in reinforced concrete in conditions of corrosion and subsequent transformation of these layers in conditions of cathodic protection (CP).

  13. Tungstate as a synergist to phosphonate-based formulation for corrosion control of carbon steel in nearly neutral aqueous environment

    Indian Academy of Sciences (India)

    B V Appa Rao; M Venkateswara Rao; S Srinivasa Rao; B Sreedhar

    2010-07-01

    Synergistic inhibition of corrosion of carbon steel in low chloride aqueous medium using tungstate as a synergist in combination with ,-(phosphonomethyl) glycine (BPMG) and zinc ions is presented. The synergistic action of tungstate has been established through the present studies. The new ternary inhibitor formulation is effective in neutral and slightly acidic as well as slightly alkaline media. Potentiodynamic polarisation studies inferred that the formulation functions as a mixed inhibitor. Impedance studies of the metal/solution interface revealed that the surface film is highly protective. Characterisation by X-ray photoelectron spectroscopy (XPS) of the surface film formed in presence of the inhibitor revealed the presence of iron, phosphorus, nitrogen, oxygen, carbon, zinc and tungsten in the surface film. The chemical shifts in the binding energies of these elements inferred that the surface film is composed of iron oxides/hydroxides, zinc hydroxide, heteropolynuclear complex [Fe(III), Zn(II)-BPMG] and WO3. Reflection absorption FTIR spectroscopic studies also supported the presence of these compounds in the surface film. Morphological features of the metal surface studied in the absence and presence of the inhibitor by scanning electron microscopy (SEM) are also presented. Based on all these results, a plausible mechanism of corrosion inhibition is proposed.

  14. 碳钢在海水环境中的腐蚀和污损特性研究%Corrosion and Biofouling Character of Carbon Steel in Seawater

    Institute of Scientific and Technical Information of China (English)

    杨海洋; 黄桂桥

    2013-01-01

    Change of corrosion rate of carbon steels in seawater was discussed. Corrosion and biofouling character of carbon steels in seawater were summarized. The result showed that corrosion rate of the carbon steel exposed to seawater decreases with time, which is stable after one or two years of exposure;the corrosion course can be divided into the process dynamics controlled stage, the oxygen diffusion controlled stage, the growth of fouling organism controlled stage, and microbiological corrosion controlled stage.%讨论了碳钢材料在海水环境中的腐蚀速率随时间的变化情况,总结了碳钢在海水中不同暴露阶段的腐蚀和生物污损特性。结果显示,碳钢在海水中的腐蚀速度随时间延长而下降,暴露1~2年后腐蚀速率变化不显著,其腐蚀过程可分为腐蚀过程控制阶段、氧扩散控制阶段、污损生物成长控制阶段和微生物腐蚀控制阶段等4个阶段。

  15. The evaluation of erosion/corrosion problems of carbon steel piping in Taiwan PWR nuclear power plant

    International Nuclear Information System (INIS)

    Taiwan pressurized water reactor (PWR), Maanshan nuclear power plant Units 1 and 2 implemented measurements of the wall thinning of the carbon steel piping under the request of regulation authority to prevent the events due to erosion/corrosion since 1989. At first, the licensee established the comprehensive inspection program by itself. Over 2000 components were inspected per unit and 300-500 pipe components were examined by ultrasonic testing per scheduled outage. The simple predictive methodology determined the operability of each individual piping component in the next fuel cycle. Based on the inspection results, the susceptible pipe components were established. Implementation of effective correction management and an improved inspection program can improve the safety, as well as the efficiency, of long-term reactor operations. (orig.)

  16. Investigation of the Corrosion Inhibition of CTAB and SDS on Carbon Steel Using an Experimental Design Strategy

    Science.gov (United States)

    Arjmand, Farzin; Wang, Jiamei; Zhang, Lefu

    2016-03-01

    The corrosion inhibition performance of sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) on carbon steel was investigated in sodium chloride solutions. Using an experimental design strategy pH, chloride concentration, SDS/CTAB concentrations, and temperature were optimized by conducting only 30 experiments. The optimum value of each factor was obtained from the designed matrix of the experiments based on the lowest log I corr value calculated for each experimental condition. The 3D surface plots of the electrochemical response (log I corr) against each factor were constructed. The optimum conditions in which the lowest log I corr can be achieved were found as follows: pH 12, [Cl-] ≈ 1 M, [SDS] ≈ 200 ppm, [CTAB] ≈ 20 ppm, and T ≈ 10 °C.

  17. Benefit of chromium in reducing the rates of flow accelerated corrosion of carbon steel outlet feeders in CANDU reactors

    International Nuclear Information System (INIS)

    In the mid 1990's, wall thinning of outlet feeders due to flow accelerated corrosion (FAC) was recognized as an active mechanism in the outlet feeders of CANDU reactors. To address wall thinning of outlet feeders in new reactor construction and refurbishment projects, AECL introduced a minimum Cr concentration in its specification for the SA-106 carbon steel feeder pipe. The effectiveness of Cr in reducing FAC was subsequently demonstrated in in-reactor and out-reactor loops at AECL's Chalk River Laboratories. More recently, wall-thinning rates have been determined from wall thickness data collected from outlet feeders, containing a specified minimum Cr concentration, installed in the Point Lepreau Generating Station in 2001. This paper presents the FAC rates determined from in-service outlet feeders and compares the rates with data from previous in-reactor and out-reactor test loops, highlighting the consistency observed in results from the three sources. (author)

  18. Effects of heat treatment on the corrosion resistance of carbon steel coated with LaMgAl11O19 thermal barrier coatings

    Institute of Scientific and Technical Information of China (English)

    Liang-liang Huang; Hui-min Meng; Li-kang Liang; Sen Li; Jin-hui Shi

    2015-01-01

    LaMgAl11O19 thermal barrier coatings (TBCs) were applied to carbon steels with a NiCoCrAlY bond coat by plasma spraying. The effects of heat treatment on the corrosion resistance of carbon steel coated with LaMgAl11O19 TBCs were investigated in 3.5wt% NaCl solution using polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray diffrac-tion (XRD). The results show that a large number of cracks are found in the LaMgAl11O19 TBCs after the samples are heat-treated, including some through-thickness cracks. The corrosion forms of the as-sprayed and heat-treated TBCs are uniform corrosion and pitting corrosion, respectively. The as-sprayed TBCs exhibit three EIS time constants after being immersed for less than 7 d, and then a new time constant ap-pears because of steel substrate corrosion. When the immersion time is increased to 56 d, a Warburg impedance (W) component appears in the EIS data. The EIS data for the heat-treated TBCs exhibit only two time constants after the samples are immersed for less than 14 d, and a new time constant appears when the immersion time is increased further. The heat treatment reduces the corrosion resistance of carbon steel coated with LaMgAl11O19 TBCs. The corrosion products are primarilyγ-FeOOH and Fe3O4.

  19. The effect of environmental and meteorological variables on atmospheric corrosion of carbon steel, copper, zinc and aluminium in a limited geographic zone with different types of environment

    International Nuclear Information System (INIS)

    Carbon steel, copper, zinc and aluminium test pieces were exposed to a large variety of environmental conditions in a reduced geographic area close to the coastline in order to ascertain the degree of deterioration of the same due to environmental corrosion. Calculations of corrosion rates were made via loss of weight (in the case of carbon steel, zinc and copper) and analysis of surface deterioration (in the case of aluminium) together with X-ray diffraction analyses. The levels of chlorides, SO2 and time of wetness were also registered in order to be able to correlate the data with respect to corrosion rate with the environmental and meteorological parameters, using the potential law and a modified version of the same

  20. Development of a suppression method for corrosion of carbon steel by double-layer Ni metal-Ni ferrite film

    International Nuclear Information System (INIS)

    Water pH control or dissolved oxygen (DO) in water control is being applied to many thermal and nuclear power plants in order to reduce the corrosion of carbon steel (CS). In the former, a continuous pH adjuster, such as hydrazine, is injected into water during plant operation cycles, and in the latter, oxygen gas is injected into water and is controlled during plant operation. Then, we developed the Hitachi ferrite coating (Hi-F Coat) process to suppress the corrosion of CS in plant operation cycles without pH or DO control. In this process, a fine oxide film is formed on the CS base metal of the piping in solution at 363 K. In this study, we developed a method to form a double-layer Ni metal-Ni ferrite film to suppress the corrosion amount of CS in water. In this process, a double-layer film is formed on the base metal of the piping using four chemical reagents in solutions, Fe(HCOO)2, Ni(HCOO)2, H2O2, and N2H4 at 363 K. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy measurements of the film show a close-packed double-layer thin film formed in the amount of 3.6 g/m2. The inner layer is mainly Ni metal and the outer layer is Ni0.72+Fe0.32+Fe23+O4. After adding the four chemical reagent solutions, Ni2+ ions were reduced on the CS surface and a Ni metal film was formed on the base metal. Then, a Ni0.7Fe0.3Fe2O4 film was formed on the CS surface by oxidation of Fe2+ to Fe3+ with H2O2. We confirmed that the respective corrosion amounts were reduced to 1/5 and 1/2 compared with those obtained without and with oxygen injection at 423 K. Furthermore, we analyzed the film after a corrosion test. The double-layer film changed to a Ni0.7Fe0.3Fe2O4 single-layer film. There is the possibility that the transformation from the double-layer film to the single-layer film reduced the corrosion of CS by preventing the diffusion of Fe ions from base CS to high-temperature water. (author)

  1. Effects of carbon content and microstructure on corrosion rate of 13% chromium steel in wet CO2 environments; Shitsujun CO2 kankyochu deno 13%Cr ko no fushoku ni oyobosu C ryo to kinzoku soshiki no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, T.; Asahi, H. [Nippon Steel Corp., Tokyo (Japan)

    1998-11-15

    Thirteen percent chromium steel is excellent in corrosion resistance of CO2. A large quantity of 13% chromium steel is used in oil and gas fields where CO2 is produced. Usually, AISI 420 13% chromium steel to which C was added 0.2% is used for an oil field tube. Since AISI 420 steel is tempered, chromium carbide is formed and the effective chromium amount in a parent phase is decreased to deteriorate the corrosion resistance of CO2. Therefore, it is desired to decrease the carbon content as far as possible for improvement of corrosion resistance of CO2. AISI 410 13% chromium steel with a carbon content of 0.1% is difficult to form {delta}-ferrite. It has a problem in manufacturing because the hot working performance is low. In this report, on the basis of AISI 420 13% chromium steel, the effects of composition on CO2 corrosion were investigated using the steel whose carbon content was changed. Ferrite, martensite, and tempered martensite differ in a corrosion rate. The corrosion rate increases in the order of martensite, ferrite, and tempered martensite. The corrosion rate of 13% chromium steel is represented by the product of the corrosion rate of each microstructure and the fraction of it. 11 refs., 12 figs., 2 tabs.

  2. The effect of sulfide on the aerobic corrosion of carbon steel in near-neutral pH saline solutions

    International Nuclear Information System (INIS)

    Highlights: ► The corrosion rate is low when steel is exposed to anaerobic conditions (pH = 8.9). ► An anaerobic to aerobic corrosion with sulfide switch increases the corrosion rate. ► Aerobic exposure induces the formation of goethite-covered tubercles. ► Continual sulfide exposure leads to the slow conversion of goethite to mackinawite. - Abstract: Severe corrosion damage may occur when gas transmission pipelines are exposed, at disbonded coating locations, to trapped waters containing sulfide followed by secondary exposure to air. Aerobic corrosion with sulfide was investigated in a long-term corrosion experiment in which corrosion was monitored by measurement of the corrosion potential and polarization resistance obtained from linear polarization resistance measurements. The properties and composition of the corrosion product deposits formed were determined using scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. A switch from aerobic to aerobic-with-sulfide corrosion doubles the relative corrosion rate.

  3. Evaluation of pH control agents influencing on corrosion of carbon steel in secondary water chemistry condition of pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, In Hyoung; Jung, Hyun Jun; Cho, Dae Chul [Dept. of Energy and Environmental Engineering, Soonchunhyang University, Asan (Korea, Republic of)

    2014-06-15

    The effect of various pH agents on the corrosion behavior of carbon steel was investigated under a simulated secondary water chemistry condition of a pressurized water reactor (PWR) in a laboratory, and the steel's corrosion performance was compared with the field data obtained from Uljin NPP unit 2 reactor. All tests were carried out at temperatures of 50 degrees C-250 degrees C and pH of 8.5 - 10. The pH at a given temperature was controlled by adding different agents. Laboratory data indicate that the corrosion rate of carbon steel decreased as the pH increased under the test conditions and the highest corrosion rate was measured at 150 degrees C. This high corrosion rate may be related to high dissolution and instability of Fe oxide (Fe{sub 3}O{sub 4}) at 150 degrees C. It was also found that an addition of ethanolamine (ETA) to ammonia was more effectivefor anticorrosion than ammonia alone, and that mixed treatment reduced 50% of iron or more at pHs of 9.5 or higher, especially in the steam generator (SG) and the moisture separator and re-heater.

  4. Some peculiarities of corrosion of wheel steel

    OpenAIRE

    Alexander SHRAMKO; Alfred KOZLOWSKY; Elena BELAJA; Yuriy PROIDAK; Pinchuk, Sofia; Gubenko, Svetlana

    2009-01-01

    Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosi...

  5. Atmospheric corrosion of mild steel

    Directory of Open Access Journals (Sweden)

    Morcillo, M.

    2011-10-01

    Full Text Available The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a the morphology of steel corrosion products and corrosion product layers; and b long-term atmospheric corrosion ( > 10 years.

    La corrosión atmosférica del acero suave es un tema de gran amplitud que ha sido tratado por muchos autores en numerosas regiones del mundo. Este artículo de compilación incorpora publicaciones relevantes sobre esta temática, en particular sobre la naturaleza de los productos de corrosión atmosférica, mecanismos y cinética de los procesos de corrosión atmosférica, prestando una atención especial a dos aspectos sobre los que la información publicada ha sido menos abundante: a morfología de los productos de corrosión del acero y capas de productos de corrosión, y b corrosión atmosférica a larga duración (> 10 años.

  6. Study of carbon steel corrosion layer by X-ray diffraction and absorption methods

    Energy Technology Data Exchange (ETDEWEB)

    Malinovschi, V. [University of Pitesti, Research Center for Advanced Materials, Targul din Vale Street, No.1, 110040 Pitesti, Arges (Romania)]. E-mail: malinov@electra.upit.ro; Ducu, C. [University of Pitesti, Research Center for Advanced Materials, Targul din Vale Street, No.1, 110040 Pitesti, Arges (Romania); Aldea, N. [National Institutes for Research and Development for Isotopic and Molecular Technologies, P.O. Box 700, 3400 Cluj-Napoca (Romania); Fulger, M. [Institutes for Nuclear Research, P.O. Box 0402, 0300 Pitesti (Romania)

    2006-06-30

    To predict the behavior of structural metallic materials into the CANDU nuclear reactor, the oxide films on the surface were growth in a controlled manner using an autoclave simulating the environment specific to the nuclear reactor. In order to establish the structural changes of the oxide films, the X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and extended X-ray absorption fine structure spectroscopy (EXAFS) analysis were used. Analysis performed showed differences in morphology of the oxide films from carbon steel samples exposed under different conditions corresponding to primary and secondary circuits in CANDU nuclear reactor. The oxide phases were identified and the thicknesses of the films were calculated. The agreement between results obtained by these methods was discussed according to the microstructure of the samples.

  7. The behaviour of praseodymium 4-hydroxycinnamate as an inhibitor for carbon dioxide corrosion and oxygen corrosion of steel in NaCl solutions

    International Nuclear Information System (INIS)

    Highlights: •Praseodymium 4-hydroxycinnamate (Pr(4OHCin)3) highly effective corrosion inhibitor. •Mechanism of inhibition different in CO2-saturated solutions compared to aerated system. •In natural aerated solutions a continuous protective film forms on the steel surface. •In CO2-saturated solutions inhibiting deposits form at active corrosion sites. -- Abstract: Praseodymium 4-hydroxycinnamate (Pr(4OHCin)3) was investigated as a novel corrosion inhibitor for steel in NaCl solutions, and found to be effective at inhibiting corrosion in both CO2-containing and naturally-aerated systems. Surface analysis results suggest that the corrosion inhibition ability of Pr(4OHCin)3 in the naturally-aerated corrosion system could be attributed to the formation of a continuous protective film. For the CO2-containing system, the corrosion inhibition efficiency of Pr(4OHCin)3 was predominantly because of formation of protective inhibiting deposits at the active electrochemical corrosion sites, in addition to a thinner surface film deposit

  8. Corrosion of low-carbon steel under environmental conditions at Hanford: Two-year soil corrosion test results

    International Nuclear Information System (INIS)

    At the Hanford Site, located in southeastern Washington state, nuclear production reactors were operated from 1944 to 1970. The handling and processing of radioactive nuclear fuels produced a large volume of low-level nuclear wastes, chemical wastes, and a combination of the two (mixed wastes). These materials have historically been packaged in US Department of Transportation (DOT) approved drums made from low-carbon steel, then handled in one of three ways: (A) Before 1970, the drums were buried in the dry desert soil. It was assumed that chemical and radionuclide mobility would be low and that the isolated, government-owned site would provide sufficient protection for employees and the public. (B) After 1970, the drums containing long-lived transuranic radionuclides were protected from premature failure by stacking them in an ordered array on an asphalt concrete pad in the bottom of a burial trench. The array was then covered with a large, 0.28-mm- (011-in.-) thick polyethylene tarp and the trench was backfilled with 1.3 m (4 ft) of soil cover. This burial method is referred to as soil-shielded burial . Other configurations were also employed but the soil-shielded burial method contains most of the transuranic drums. (C) Since 1987, US Department of Energy sites have complied with the Resource Conservation and Recovery Act of 1976 (RCRA) regulations. These regulations require mixed waste drums to be stored in RCRA compliant large metal sheds with provisions for monitoring. These sheds are provided with forced ventilation but are not heated or cooled

  9. Erosion-corrosion of carbon steel by products of coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Xie Jianyang [Dept. of Materials Science and Engineering, Pennsylvania State Univ., University Park, PA (United States); Walsh, P.M. [Dept. of Materials Science and Engineering, Pennsylvania State Univ., University Park, PA (United States)

    1995-07-01

    Erosion of carbon steel by fly ash and unburned char particles was measured in the convection section of an industrial boiler firing micronized coal. The rate of erosion was enhanced by directing a small jet of nitrogen, 3 vol.% oxygen in nitrogen, or air toward the surface of a test coupon mounted on an air-cooled tube. Ash and char particles suspended in the flue gas entrained by the jet were accelerated toward the surface of the specimen. Samples were exposed for 2 h with metal temperature at 450, 550, and 650 K (350, 530, and 710 F). Changes in the surface were measured using a surface profiler. Erosion was slowest at the lowest metal temperature, regardless of the jet gas composition. Under the nitrogen jet, erosion increased with increasing temperature over the range of temperatures investigated. In the presence of 3% oxygen, erosion was most rapid at the intermediate temperature. At the highest oxygen concentration, in the air jet, the erosion rate was low at all three temperatures. The temperature and oxygen dependences of the erosion rate were consistent with a model for simultaneous erosion and oxidation. Extrapolation of the results to lower velocity, using experimentally determined coefficients for metal and oxide erosion, provided estimates of erosion of a tube, as a function of impaction angle and gas velocity. Under the conditions of metal temperature, oxygen concentration, particle size, particle loading, and particle composition investigated, erosion of carbon steel tubes is expected to be slower than 0.05 {mu}m h{sup -1} when the gas velocity in the convection section of the boiler is less than approximately 10 m s{sup -1}. (orig.)

  10. New 1H-pyrrole-2,5-dione derivatives as efficient organic inhibitors of carbon steel corrosion in hydrochloric acid medium: Electrochemical, XPS and DFT studies

    International Nuclear Information System (INIS)

    Highlights: • 1H-pyrrole derivatives act as good corrosion inhibitors for carbon steel in 1 M HCl. • Adsorption of the inhibitors on carbon steel surface obeys Langmuir’s isotherm. • XPS showed that the inhibitors are chemisorbed on the metal surface. • Quantum chemical parameters were correlated with experimental results. - Abstract: New 1H-pyrrole-2,5-dione derivatives, namely 1-phenyl-1H-pyrrole-2,5-dione (PPD) and 1-(4-methylphenyl)-1H-pyrrole-2,5-dione (MPPD) were synthesised and their inhibitive action against the corrosion of carbon steel in 1 M HCl solution were investigated at 308 K by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results showed that the investigated 1H-pyrrole-2,5-dione derivatives are good corrosion inhibitors for carbon steel in 1 M HCl medium, their inhibition efficiency increased with inhibitor concentration, and MPPD is slightly more effective than PPD. Potentiostatic polarization study showed that PPD and MPPD are mixed-type inhibitors in 1 M HCl. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. The results obtained from electrochemical and weight loss studies were in reasonable agreement. The adsorption of MPPD and PPD on steel surface obeyed Langmuir’s adsorption isotherm. Thermodynamic data and XPS analysis clearly indicated that the adsorption mechanism of 1H-pyrrole-2,5-dione derivatives on carbon steel surface in 1 M HCl solution is mainly controlled by a chemisorption process. Quantum chemical calculations using the Density Functional Theory (DFT) were performed on 1H-pyrrole-2,5-dione derivatives to determine the relationship between molecular structures and their inhibition efficiencies

  11. BWR steel containment corrosion

    International Nuclear Information System (INIS)

    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

  12. Corrosion Inhibition of Carbon Steel in HCl Solution by Some Plant Extracts

    OpenAIRE

    Ambrish Singh; Ebenso, Eno E.; M. A. Quraishi

    2012-01-01

    The strict environmental legislations and increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. In the present work, literature on green corrosion inhibitors has been reviewed, and the salient features of our work on green corrosion inhibitors have been highlighted. Among the studied leaves, extract Andrographis paniculata showed better inhibition performance (98%) than the other leaves extract. Strychnos nuxvomica showed b...

  13. Pitting corrosion resistant austenite stainless steel

    Science.gov (United States)

    van Rooyen, D.; Bandy, R.

    A pitting corrosion resistant austenite stainless steel comprises 17 to 28 wt. % chromium, 15 to 26 wt. % nickel, 5 to 8 wt. % molybdenum, and 0.3 to 0.5 wt. % nitrogen, the balance being iron, unavoidable impurities, minor additions made in the normal course of melting and casting alloys of this type, and may optionally include up to 10 wt. % of manganese, up to 5 wt. % of silicon, and up to 0.08 wt. % of carbon.

  14. 77 FR 54891 - Certain Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary...

    Science.gov (United States)

    2012-09-06

    ... FR 55769 (September 14, 2010) (unchanged in the final results); Certain Corrosion-Resistant Carbon... Administrative Review, 74 FR 46110, 46112 (September 8, 2009) (unchanged in the final results); Certain Corrosion... Administrative Reviews and Requests for Revocations in Part, 76 FR 61076 (October 3, 2011) (Initiation...

  15. Characterization of corrosion products formed on steels in the first months of atmospheric exposure

    OpenAIRE

    Antunes Renato Altobelli; Costa Isolda; Faria Dalva Lúcia Araújo de

    2003-01-01

    The corrosion products of carbon steel and weathering steel exposed to three different types of atmospheres, at times ranging from one to three months, have been identified. The steels were exposed in an industrial site, an urban site (São Paulo City, Brazil), and a humid site. The effect of the steel type on the corrosion products formed in the early stages of atmospheric corrosion has been evaluated. The corrosion products formed at the various exposure locations were characterized by Raman...

  16. Effect of Al Hot-Dipping on High-Temperature Corrosion of Carbon Steel in N2/0.1% H2S Gas

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Abro

    2016-02-01

    Full Text Available High-temperature corrosion of carbon steel in N2/0.1% H2S mixed gas at 600–800 °C for 50–100 h was studied after hot-dipping in the aluminum molten bath. Hot-dipping resulted in the formation of the Al topcoat and the Al-Fe alloy layer firmly adhered on the substrate. The Al-Fe alloy layer consisted primarily of a wide, tongue-like Al5Fe2 layer and narrow Al3Fe layer. When corroded at 800 °C for 100 h, the Al topcoat partially oxidized to the protective but non-adherent α-Al2O3 layer, and the interdiffusion converted the Al-Fe alloy layer to an (Al13Fe4, AlFe3-mixed layer. The interdiffusion also lowered the microhardness of the hot-dipped steel. The α-Al2O3 layer formed on the hot-dipped steel protected the carbon steel against corrosion. Without the Al hot-dipping, the carbon steel failed by forming a thick, fragile, and non-protective FeS scale.

  17. Steel corrosion in radioactive waste storage tanks

    International Nuclear Information System (INIS)

    A collaborative study is being conducted by CNEA and USDOE (Department of Energy of the United States of America) to investigate the effects of tank waste chemistry on radioactive waste storage tank corrosion. Radioactive waste is stored in underground storage tanks that contain a combination of salts, consisting primarily of sodium nitrate, sodium nitrite and sodium hydroxide. The USDOE, Office of River Protection at the Hanford Site, has identified a need to conduct a laboratory study to better understand the effects of radioactive waste chemistry on the corrosion of waste storage tanks at the Hanford Site. The USDOE science need (RL-WT079-S Double-Shell Tanks Corrosion Chemistry) called for a multi year effort to identify waste chemistries and temperatures within the double-shell tank (DST) operating limits for corrosion control and operating temperature range that may not provide the expected corrosion protection and to evaluate future operations for the conditions outside the existing corrosion database. Assessment of corrosion damage using simulated (non-radioactive) waste is being made of the double-shell tank wall carbon steel alloy. Evaluation of the influence of exposure time, and electrolyte composition and/or concentration is being also conducted. (author)

  18. Predictive Models for the Determination of Pitting Corrosion Versus Inhibitor Concentrations and Temperature for Radioactive Sludge in Carbon Steel Waste Tanks

    International Nuclear Information System (INIS)

    Statistical models have been developed to predict the occurrence of pitting corrosion in carbon steel waste storage tanks exposed to radioactive nuclear waste. The levels of nitrite concentrations necessary to inhibit pitting at various temperatures and nitrate concentrations were experimentally determined via electrochemical polarization and coupon immersion corrosion tests. Models for the pitting behavior were developed based on various statistical analyses of the experimental data. Feed-forward Artificial Neural Network (ANN) models, trained using the Back-Propagation of Error Algorithm, more accurately predicted conditions at which pitting occurred than the logistic regression models developed using the same data

  19. In situ synchrotron X-ray diffraction study of surface scale formation during CO2 corrosion of carbon steel at temperatures up to 90 oC

    International Nuclear Information System (INIS)

    In situ synchrotron X-ray diffraction was used to follow the formation of corrosion product scales on carbon steel in CO2 saturated brine at temperatures from 40 to 90 oC. The corrosion process was accelerated by applying a small anodic current, and in selected tests a scale inhibitor, amino trimethylene phosphonic acid (ATMPA), was added. Siderite was identified as the major phase in the scale formed in all conditions. With increasing temperature, the scale formation rate increased, while the scale thickness and crystallite size decreased. Above 60 oC, the scale became increasingly protective. The scale thickness and crystallite size decreased with increasing ATMPA concentration.

  20. Inhibitory effect of tungstate, molybdate and nitrite ions on the carbon steel pitting corrosion in alkaline formation water containing Cl- ion

    International Nuclear Information System (INIS)

    The pitting corrosion of carbon steel in carbonate-formation water solution in the presence of chloride ions and the effect of addition WO42-, MoO42- and NO2- anions on the pitting corrosion were studied using cyclic voltammetry and potentiostatic current-time measurements and complemented by scan electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) investigations. Cyclic voltammograms of carbon steel in the presence of chloride ions in carbonate-formation water solution show one anodic peak, corresponding to the formation green rust carbonate and the two cathodic peaks. As the addition of Cl- ions concentration increases, the anodic peak current density increases and pitting potential Epit shifts to more negative potential. It is shown that the rate of pit initiation (ti-1) decreases and the pitting potential Epit moves to more positive direction upon the addition of inorganic anions. It was found that pitting inhibition of carbon steel increases in the sequence: (WO4)2- > (MoO4)2- > (NO2)-

  1. Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

    OpenAIRE

    Hang, To Thi Xuan; Truc, Trinh Anh; Duong, Nguyen Thuy; Pébère, Nadine; Olivier, Marie-Georges

    2012-01-01

    International audience The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by...

  2. Effects of Plastic Deformation and Carbon Dioxide on Corrosion of Pipeline Steel in Near-Neutral pH Groundwater

    Science.gov (United States)

    Lu, B. T.; Yu, H.; Luo, J. L.

    2013-05-01

    This paper investigates the effect of plastic deformation on the anodic dissolution behavior of pipeline steel in deaerated groundwater with near-neutral pH. The plastic deformation is introduced via two different ways: cold-rolling and in situ tension. It is observed that the cold-rolling prior to the exposure to corroding environment reduces the corrosion rate but the in situ tension increases corrosion rate slightly. In accord with thermodynamic analysis, the impacts of residual stresses and plastic deformation on active dissolution are very small except a highly non-uniform dislocation structure is formed. A preliminary analysis suggests that the reduced corrosion rate of cold-rolled steel is related to competitive adsorption of CO2 and H+ on the active sites over the surface.

  3. Corrosion behavior of 2205 duplex stainless steel.

    Science.gov (United States)

    Platt, J A; Guzman, A; Zuccari, A; Thornburg, D W; Rhodes, B F; Oshida, Y; Moore, B K

    1997-07-01

    The corrosion of 2205 duplex stainless steel was compared with that of AISI type 316L stainless steel. The 2205 stainless steel is a potential orthodontic bracket material with low nickel content (4 to 6 wt%), whereas the 316L stainless steel (nickel content: 10 to 14 wt%) is a currently used bracket material. Both stainless steels were subjected to electrochemical and immersion (crevice) corrosion tests in 37 degrees C, 0.9 wt% sodium chloride solution. Electrochemical testing indicates that 2205 has a longer passivation range than 316L. The corrosion rate of 2205 was 0.416 MPY (milli-inch per year), whereas 316L exhibited 0.647 MPY. When 2205 was coupled to 316L with equal surface area ratio, the corrosion rate of 2205 reduced to 0.260 MPY, indicating that 316L stainless steel behaved like a sacrificial anode. When 316L is coupled with NiTi, TMA, or stainless steel arch wire and was subjected to the immersion corrosion test, it was found that 316L suffered from crevice corrosion. On the other hand, 2205 stainless steel did not show any localized crevice corrosion, although the surface of 2205 was covered with corrosion products, formed when coupled to NiTi and stainless steel wires. This study indicates that considering corrosion resistance, 2205 duplex stainless steel is an improved alternative to 316L for orthodontic bracket fabrication when used in conjunction with titanium, its alloys, or stainless steel arch wires. PMID:9228844

  4. Development of highly corrosion resistant 18-8 stainless steel for nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Corrosion behavior of ultra low carbon 18-8 stainless steel was evaluated in boiling nitric acid environment. Although ultra low carbon stainless steel shows excellent corrosion resistance, it is, due to low carbon content, easily induced martensite by cold work. Increasing the strain induced martensite by cold work, the corrosion rate of 18-8 stainless steel increased. Corrosion rate is summarized as a function of stability factor with represents a resistance to martensite transformation induced by cold work and highly austenitic stabilized steel showed better corrosion resistance. Ultra low carbon 18-8 stainless steel which is highly stabilized austenite was designed and manufactured with commercial mill. The development steel showed an excellent corrosion resistance in boiling nitric acid even after cold work. The corrosion rate of the welded joint was also excellent as well as matrix

  5. Electrochemical, atomic force microscopy and infrared reflection absorption spectroscopy studies of pre-formed mussel adhesive protein films on carbon steel for corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan, E-mail: fanzhang@kth.se [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Div. of Surface and Corrosion Science, Drottning Kristinas vaeg.51, SE-100 44 Stockholm (Sweden); Pan, Jinshan [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Div. of Surface and Corrosion Science, Drottning Kristinas vaeg.51, SE-100 44 Stockholm (Sweden); Claesson, Per Martin [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Div. of Surface and Corrosion Science, Drottning Kristinas vaeg.51, SE-100 44 Stockholm (Sweden); Institute for Surface Chemistry, P.O. Box 5607, SE-114 86 Stockholm (Sweden); Brinck, Tore [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Physical Chemistry, Division of Physical Chemistry, Teknikringen 36, SE-10044 Stockholm (Sweden)

    2012-10-01

    Electrochemical measurements, in situ and ex situ atomic force microscopy (AFM) experiments and infrared reflection absorption spectroscopy (IRAS) analysis were performed to investigate the formation and stability as well as corrosion protection properties of mussel adhesive protein (Mefp-1) films on carbon steel, and the influence of cross-linking by NaIO{sub 4} oxidation. The in situ AFM measurements show flake-like adsorbed protein aggregates in the film formed at pH 9. The ex situ AFM images indicate multilayer-like films and that the film becomes more compact and stable in NaCl solution after the cross-linking. The IRAS results reveal the absorption bands of Mefp-1 on carbon steel before and after NaIO{sub 4} induced oxidation of the pre-adsorbed protein. Within a short exposure time, a certain corrosion protection effect was noted for the pre-formed Mefp-1 film in 0.1 M NaCl solution. Cross-linking the pre-adsorbed film by NaIO{sub 4} oxidation significantly enhanced the protection efficiency by up to 80%. - Highlights: Black-Right-Pointing-Pointer Mussel protein was tested as 'green' corrosion protection strategy for steel. Black-Right-Pointing-Pointer At pH 9, the protein adsorbs on carbon steel and forms a multilayer-like film. Black-Right-Pointing-Pointer NaIO{sub 4} leads to structural changes and cross-linking of the protein film. Black-Right-Pointing-Pointer Cross-linking results in a dense and compact film with increased stability. Black-Right-Pointing-Pointer Cross-linking of preformed film significantly enhances the corrosion protection.

  6. Electrochemical, atomic force microscopy and infrared reflection absorption spectroscopy studies of pre-formed mussel adhesive protein films on carbon steel for corrosion protection

    International Nuclear Information System (INIS)

    Electrochemical measurements, in situ and ex situ atomic force microscopy (AFM) experiments and infrared reflection absorption spectroscopy (IRAS) analysis were performed to investigate the formation and stability as well as corrosion protection properties of mussel adhesive protein (Mefp-1) films on carbon steel, and the influence of cross-linking by NaIO4 oxidation. The in situ AFM measurements show flake-like adsorbed protein aggregates in the film formed at pH 9. The ex situ AFM images indicate multilayer-like films and that the film becomes more compact and stable in NaCl solution after the cross-linking. The IRAS results reveal the absorption bands of Mefp-1 on carbon steel before and after NaIO4 induced oxidation of the pre-adsorbed protein. Within a short exposure time, a certain corrosion protection effect was noted for the pre-formed Mefp-1 film in 0.1 M NaCl solution. Cross-linking the pre-adsorbed film by NaIO4 oxidation significantly enhanced the protection efficiency by up to 80%. - Highlights: ► Mussel protein was tested as “green” corrosion protection strategy for steel. ► At pH 9, the protein adsorbs on carbon steel and forms a multilayer-like film. ► NaIO4 leads to structural changes and cross-linking of the protein film. ► Cross-linking results in a dense and compact film with increased stability. ► Cross-linking of preformed film significantly enhances the corrosion protection.

  7. The performance of a surface-applied corrosion inhibitor for the carbon steel in saturated Ca(OH)2 solutions

    International Nuclear Information System (INIS)

    In the present work, the performance of an amino alcohol based surface applied inhibitor was studied by the electrochemical techniques in saturated Ca(OH)2 solutions. The surface morphology of the carbon steel was observed by scanning electron microscope, and the energy diffraction spectrum was also tested. Results showed that the inhibitor used in this work demonstrated obvious inhibition efficiency on the carbon steel in saturated Ca(OH)2 solutions. The inhibition mechanism of the inhibitor lies in the quick adsorption of the active component on carbon steel surface

  8. The evaluation of erosion-corrosion problems in Taiwan PWR carbon steel piping

    International Nuclear Information System (INIS)

    Taiwan PWR Nuclear Power Plant Units 1 and 2 implemented the projects of Pipe Wall Thinning Measurement under the request of ROCAEC to prevent the events due to the piping erosion/corrosion. The purpose of this paper is to present the improvements in the evaluation method for the identification of the potential piping systems and components in PWR

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

    International Nuclear Information System (INIS)

    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

  10. 75 FR 55769 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2010-09-14

    ... for Revocation in Part, 74 FR 48224, 48225 (September 22, 2009) (Initiation Notice). In addition... Carbon Steel Flat Products from Korea, 58 FR 44159 (August 19, 1993) (Orders on Certain Steel from Korea..., Finding, or Suspended Investigation; Opportunity to Request Administrative Review, 74 FR 38397 (August...

  11. Formation of corrosion products of carbon steel under condenser operating conditions

    International Nuclear Information System (INIS)

    Corrosion product transport studies conducted more than a decade ago showed that lepidocrocite, hematite and magnetite are the major components of suspended corrosion products filtered from water collected at the outlet of the Condensate Extraction Pump (CEP), Boiler Feed Pump (BFP), and High-Pressure Heater (HPH) in the steam cycles of pressurized water reactors. The presence of lepidocrocite and hematite in these samples was taken as evidence that the low-pressure section of the feed water system is oxidizing during power operation. It follows that a reduction in the concentration of dissolved oxygen in the condenser and an increase in hydrazine concentration in the feed water would be effective steps to reduce the concentration of fully oxidized corrosion products being transported with the feed water to the steam generators. A review of the literature on the formation of iron oxides under oxidizing conditions, however, has revealed that pH is a more important parameter than dissolved oxygen concentration for determining the phase of iron oxide that forms in the secondary heat-transport system at low temperature, i.e., temperature less than about 100 deg. C. Thus, magnetite has been shown to be the dominant phase of iron oxide under oxidizing, alkaline conditions, i.e., pH in the range 9.0 to 11.0, whereas the formation of lepidocrocite and goethite are favoured under mildly acidic to neutral conditions. Goethite also forms under strongly acidic and caustic conditions, but these conditions are not found in the feed water system. Hematite forms under strongly acidic and neutral conditions. It is well known that lepidocrocite and goethite will transform to hematite at elevated temperatures. The only conditions that prevail in the steam cycle during power operation are those that favour the formation of magnetite, yet corrosion product transport studies have consistently shown the presence of hematite and lepidocrocite in samples filtered during power operation. It

  12. Influence of Silicon, Carbon and Phosphorus on Intergranular Corrosion of High Purity Austenitic Stainless Steels Under Transpassive Conditions

    OpenAIRE

    Stolarz, J.

    1995-01-01

    Precipitate-free Fe-Cr-Ni f.c.c. alloys exhibit strong intergranular corrosion in acid solutions at electrochemical potentials from the transpassivity range. Segregation of impurity atoms to grain boundaries is generally considered to be responsible for this specific kind of localized damage. A study of the influence of silicon, phosphorus and carbon on the intergranular transpassive corrosion of the solution treated Fe-17Cr-13Ni alloy in the 2N sulphuric acid at a fixed electrochemical poten...

  13. Apparent Fracture Toughness of Low-carbon Steel CSN 411353 as Related to Stress Corrosion Cracks

    Czech Academy of Sciences Publication Activity Database

    Gajdoš, Lubomír; Šperl, Martin; Siegl, J.

    2011-01-01

    Roč. 32, 8/9 (2011), s. 4348-4353. ISSN 0261-3069 R&D Projects: GA ČR(CZ) GAP105/10/2052; GA ČR(CZ) GPP105/10/P555 Grant ostatní: GAMPO(CZ) FT-TA5/076 Institutional research plan: CEZ:AV0Z20710524 Keywords : corrosion * fracture * fractography Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.200, year: 2011

  14. Microbial Methane Production Associated with Carbon Steel Corrosion in a Nigerian Oil Field

    OpenAIRE

    Mand, Jaspreet; Park, Hyung S.; Okoro, Chuma; Lomans, Bart P.; Smith, Seun; Chiejina, Leo; Voordouw, Gerrit

    2016-01-01

    Microbially influenced corrosion (MIC) in oil field pipeline systems can be attributed to many different types of hydrogenotrophic microorganisms including sulfate reducers, methanogens and acetogens. Samples from a low temperature oil reservoir in Nigeria were analyzed using DNA pyrotag sequencing. The microbial community compositions of these samples revealed an abundance of anaerobic methanogenic archaea. Activity of methanogens was demonstrated by incubating samples anaerobically in a bas...

  15. 电网设备用碳钢、镀锌钢和铜的大气腐蚀%Atmospheric Corrosion of Carbon Steel,Galvanized Steel and Cooper for Power Grid Equipments Reserve

    Institute of Scientific and Technical Information of China (English)

    刘争春; 苏伟; 卢思敏; 吕旺燕

    2016-01-01

    Metal materials of power grid equipments serving in atmospheric environment are prone to be invalid caused by at-mospheric corrosion. Therefore,this paper summarizes laws and influencing factors of atmospheric corrosion for backup metal materials for typical power grid equipments including carbon steel,galvanized steel and copper. By analyzing corrosion dynamics,corrosion influencing factors and research method for atmospheric corrosion of carbon steel,galvanized steel and copper in atmospheric environment,it discovers that corrosion loss laws of three metal materials follow power function equa-tion,progress of atmospheric corrosion is mainly affected by natural environment and pollutants in the atmosphere and cor-rosion outcomes of metals in different atmospheric environment are obviously different. It also states two typical types of re-search methods for atmospheric corrosion and respective boundedness including field exposure test and indoor simulation and acceleration test. It thinks to correctly predict speed rate of atmospheric corrosion of metals by combining these two methods and help adopting specific anti-corrosion measures.%服役于大气环境中的电网设备,其金属材料易被大气腐蚀而失效,基于此,综述了典型电网设备用金属材料———碳钢、镀锌钢和铜的大气腐蚀规律和影响因素。通过分析碳钢、镀锌钢和铜在大气环境中的腐蚀动力学,腐蚀影响因素和大气腐蚀研究方法等,发现三种金属材料的腐蚀失重规律都遵循幂函数方程;其大气腐蚀进程主要受大气的自然环境和污染物种类的影响,金属在不同的大气环境下生成的腐蚀产物明显不同。在此基础上,阐述了现场暴晒试验和室内模拟加速试验两种典型大气腐蚀研究方法及其局限性,认为将二者结合能更准确的预测金属的大气腐蚀速率,有助于采取针对性的防腐措施。

  16. Corrugated stainless steels embedded in mortar for 9 years: corrosion results of non-carbonated, chloride-contaminated samples

    OpenAIRE

    Bautista, A.; Paredes, E. C.; Velasco, F.; Álvarez, S. M.

    2015-01-01

    Mortar samples reinforced with 5 different corrugated stainless steels were tested for 9 years in 2 different conditions: partial immersion (PI) in 3.5% NaCl, and chloride addition to the mortar and exposure to high relative humidity (HRH). The monitoring during the exposures was carried out with corrosion potential (E-corr) and electrochemical impedance spectroscopy (EIS) measurements. A year before finishing (after 8 years of exposure), the reinforced mortar samples were anodically polarise...

  17. Steel corrosion in anoxic mediums with high chloride concentrations

    International Nuclear Information System (INIS)

    Carbon steels are widely used in contact with chloride containing mediums, however most of the literature reports corrosion problems in solutions in contact with air, for example, sea water. There are other applications where the steel is in contact with freshwater in the absence of oxygen as is the case with materials for nuclear repositories or in petroleum production. These mediums can have varied composition but their corrosivity is usually related to the concentration of chlorides. There are no systematic studies in the literature about the influence of high chloride concentrations on the speed of steel corrosion for carbon steels in the absence of oxygen. Some work has been done using Raman and XPS spectroscopy, but these techniques have been carried out ex situ in samples submitted to the action of high chloride concentrations. This results in the appearance of corrosion products on the metal surface due to the oxidation of the surface from exposure to air before and during the use of these techniques, generating confusing and uncertain data. The lack of reliable data is due to the difficulty of applying these techniques in situ under very low oxygen conditions (less than 10 ppb) without allowing any air into the system. Since there are no studies in the literature about the influence of high concentrations of chloride on the corrosion speed of carbon steels in the absence of oxygen, this work aims to generate experimental data to evaluate the influence of high concentrations of this anion on the corrosion speed of steel under anoxic conditions. The corrosivity of each solution was evaluated using electrochemical techniques such as corrosion potential, corrosion speed, anodic and cathodic polarization curves, cyclic voltammetries and electrochemical impedance spectroscopy to study the oxidation-reduction processes that occur with specific temperature, pH and chloride concentration conditions. Concentrated solutions of sodium chloride (50,000, 100,000 and 180

  18. Inhibition of carbon steel corrosion in CO2-saturated brine using some newly surfactants based on palm oil: Experimental and theoretical investigations

    International Nuclear Information System (INIS)

    New surfactants from the type of fatty acids derivatives were synthesized based on palm oil and their inhibitive action against the corrosion of carbon steel in CO2-saturated 1% NaCl solution were investigated at 50 °C. The detailed study of surfactants as corrosion inhibitors is given using polarization curves and electrochemical impedance spectroscopy methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. Results show that, the investigated surfactants are good inhibitors and its inhibition efficiency reaches to 98.95% at 100 ppm for inhibitor V. The high inhibition efficiencies were attributed to the simple blocking effect by adsorption of inhibitor molecules on the steel surface. The surface activity of the synthesized surfactant solutions was determined using surface tension measurements at 25 °C. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir's adsorption isotherm and chemisorption. The correlation between the inhibition efficiencies of the studied surfactants and their molecular structures has been investigated using quantum chemical calculations. The obtained theoretical results have been supported our experimental data. - Graphical abstract: To investigate the relationship between molecular structures of the studied surfactants and their inhibition effect; Quantum chemical molecular calculations were performed. The following quantum chemical indices such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap ΔE = EHOMO − ELUMO, and dipole moment (μ) were considered. The relation between these parameters and the inhibition efficiencies was explained. The obtained theoretical results have been supported our experimental data. - Highlights: • Effect of surfactants on carbon steel corrosion in CO2-saturted brine was investigated. • The high inhibition efficiency attributed to the adherent adsorption of the investigated

  19. Inhibition of carbon steel corrosion in CO{sub 2}-saturated brine using some newly surfactants based on palm oil: Experimental and theoretical investigations

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Lateef, Hany M., E-mail: Hany_shubra@yahoo.co.uk [Chemistry Department, Faculty of Science, Sohag University, Sohag (Egypt); Abbasov, V.M.; Aliyeva, L.I.; Qasimov, E.E.; Ismayilov, I.T. [Mamedaliev Institute of Petrochemical Processes, National Academy of Sciences of Azerbaijan, AZ1025 Baku (Azerbaijan)

    2013-11-01

    New surfactants from the type of fatty acids derivatives were synthesized based on palm oil and their inhibitive action against the corrosion of carbon steel in CO{sub 2}-saturated 1% NaCl solution were investigated at 50 °C. The detailed study of surfactants as corrosion inhibitors is given using polarization curves and electrochemical impedance spectroscopy methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. Results show that, the investigated surfactants are good inhibitors and its inhibition efficiency reaches to 98.95% at 100 ppm for inhibitor V. The high inhibition efficiencies were attributed to the simple blocking effect by adsorption of inhibitor molecules on the steel surface. The surface activity of the synthesized surfactant solutions was determined using surface tension measurements at 25 °C. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir's adsorption isotherm and chemisorption. The correlation between the inhibition efficiencies of the studied surfactants and their molecular structures has been investigated using quantum chemical calculations. The obtained theoretical results have been supported our experimental data. - Graphical abstract: To investigate the relationship between molecular structures of the studied surfactants and their inhibition effect; Quantum chemical molecular calculations were performed. The following quantum chemical indices such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap ΔE = E{sub HOMO} − E{sub LUMO}, and dipole moment (μ) were considered. The relation between these parameters and the inhibition efficiencies was explained. The obtained theoretical results have been supported our experimental data. - Highlights: • Effect of surfactants on carbon steel corrosion in CO{sub 2}-saturted brine was investigated. • The high inhibition efficiency attributed to the adherent adsorption

  20. Role of sulphide species on the behaviour of carbon steel envisioned for high-level radioactive disposal: interaction between sulphide and corrosion products

    International Nuclear Information System (INIS)

    This PhD work deals with the nuclear waste disposal. In France, it is envisaged by Andra (French national radioactive waste management agency) that high-level radioactive wastes will be confined in a glass matrix, stored in a stainless steel canister, it self placed in a carbon steel overpack. The wastes will then be stored at a depth of ∼500 m in a deep geological repository, drilled in a very stiff (indurated) clay (argillite) formation. The kinetics of corrosion expected for the overpack in this disposal concept are low and will stay low if the somehow protective rust layer that will develop initially on the steel surface remains undamaged. Local changes of the physico-chemical conditions may however degrade this layer and induce accelerated kinetics of corrosion. In particular, the growth of sulphate reducing bacteria (SRB) close to the steel overpack cannot be excluded and the sulphide species these micro-organisms produce may modify the corrosion process. The aim of this work was then to achieve a better understanding of the corrosion system constituted with steel, its rust layer mainly made of siderite FeCO3, and a sulphide-containing electrolyte. First, it proved necessary to characterise the iron sulphides involved in the corrosion processes by Raman micro-spectroscopy so as to study their formation and transformation mechanisms in various conditions of Fe(II) and S(-II) concentration, pH, temperature and aeration. It could be demonstrated that the Raman spectrum of mackinawite FeS, the compound that precipitated in any case from dissolved Fe(II) and S(-II) species with the experimental conditions considered here, depended on the crystallinity and oxidation state. Moreover, the mechanisms of the oxidation of mackinawite into greigite Fe3S4 in acidic anoxic solutions at 80 C could be described. Finally, iron sulphides, often present on archaeological artefacts, could be identified using Raman micro-spectroscopy. The compounds present were mainly

  1. Inhibition of corrosion of carbon steel in well water by arginine-Zn2+ system

    Directory of Open Access Journals (Sweden)

    ANTHONY SAMY SAHAYA RAJA

    2012-06-01

    Full Text Available The environmental friendly inhibitor system arginine-Zn2+, has been investigated by weight-loss method. A synergistic effect exists between arginine and Zn2+ system. The formulation consisting of 250 ppm of arginine and 5 ppm of Zn2+ offers good inhibition efficiency of 98 %. Polarization study reveals that this formulation functions as an anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal sur­face. The FTIR spectral study leads to the conclusion that the Fe2+- DL-arginine complex, formed on anodic sites of the metal surface, controls the anodic reaction. Zn(OH2 formed on the cathodic sites of the metal surface controls the cathodic reaction. The surface morphology and the roughness of the metal surface were analyzed with Atomic Force Microscope. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and surface analysis technique.

  2. Study of uncertainty in atmospheric corrosion rate of floe carbon steel

    International Nuclear Information System (INIS)

    The confidence interval of measurements of corrosion rate has been barely reported in the literature. It is a function of both the number of probes and the underlying pdf. We have performed specific experiments with a lot more probes than the standards require, and we evaluated, for exposure times of 1, 2, 3 and 7 months, the effect of using only three (as it is mandatory by the standard for one year exposure time) up to eleven. With the new experimental data, we were able to confirm that the values fit a normal distribution. We also found evidence that the minimum number of probes might depend upon the atmospheric condition and exposure time. The number of probes presently required for studies with exposure times of one year, might not be enough in studies of initial kinetics (exposure times smaller than one year). (Author) 14 refs

  3. Corrosion protection of cold-rolled steel with alkyd paint coatings composited with submicron-structure types polypyrrole-modified nano-size alumina and carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: ► Alumina/carbon nanotube (CNT) supported polypyrrole (PPy) particles were prepared. ► Various paint compositions with alkyd binder were immersion tested. ► Alumina-supported PPy based coating provided steel protection in NaCl solution. ► Polyelectrolyte modified CNT embedded coating afforded long-term stable protection. ► sulphonated CNT loaded coating indicated firm corrosion resistance in HCL solution. ► Results are interpreted on the basis of nano and microstructure of the particles. - Abstract: This paper is focused on studying corrosion protection of cold-rolled steel with alkyd paint coatings comprising nano-size alumina and either polystyrene-sulphonate (PSS) modified or sulphonated multi-walled carbon nanotube (MWCNT) supported polypyrrole (PPy). Single layer coatings (in thickness of 40 ± 5 μm) comprising PPy deposited alumina and PSS modified MWCNT supported PPy afforded viable protection during the 1 M sodium chloride test. The coatings containing PSS modified and weakly sulphonated MWCNTs (at volume fractions of 9.9 × 10−4 and 2.5 × 10−4) with PPy volume fractions of 3.5 × 10−3 and 2.5 × 10−3 provided effective corrosion prevention during the 1 M sodium chloride and hydrochloric acid solution tests. While inhibitor particles were characterised by infrared spectroscopy, corrosion products formed at the paint–steel interface were studied by X-ray photoelectron spectroscopy. Apart from the electron microscopy observations, rheology study of three-dimensional structure of the inhibitor particles was performed in dispersions at similar compositions to those used for the paint formulations. Thus, protection mechanism relating to both types of immersion tests is discussed in terms of properties of the inhibitor particles and their microstructure in the coatings.

  4. Corrosion Inhibitive Potential Of Hibiscus Sabdariffa Calyx Extract For Low Carbon Steel In 0.5M H2SO4 Acid Solution

    Directory of Open Access Journals (Sweden)

    Adzor, S. A., Adaga,

    2014-08-01

    Full Text Available The inhibitive potential of Hibiscus Sabdariffa calyx extract on low carbon steel corrosion in 0.5M H2SO4 have been investigated by weight loss method which is considered more informative than other laboratory methods. The studies were carried out using extracts obtained from 5-25g dried calyx powder. The test coupons were immersed in the corroding media at the time intervals of 24-168hours. The results obtained showed that the concentration of the inhibitor in the corrodent impacted differently on the test coupons. The corrosion rate was found to decrease while inhibition efficiency increase as the concentration of the extract was increased. The maximum inhibition efficiencies of 95.01% and 94.41% were obtained at 96hours exposure time from the extract of 20g and 25g dried calyx powder respectively.The results has clearly shown that the extract has the inhibiting capacity for reducing the corrosion of low carbon steel in the acidic medium.

  5. Update of the water chemistry effect on the flow-accelerated corrosion rate of carbon steel: influence of hydrazine, boric acid, ammonia, morpholine and ethanolamine

    International Nuclear Information System (INIS)

    The influence of the water chemistry on Flow-Accelerated Corrosion (FAC) affecting carbon steel components has been studied for many years and is relatively well known and taken into account by the models. Nonetheless, experimental studies were conducted in the last few years at EDF on the CIROCO loop in order to check the influence of the water chemistry parameters (hydrazine, boric acid, ammonia, morpholine and ethanolamine) on the FAC rate of carbon steel in one phase flow conditions. The hydrazine impact on the FAC rate was shown to be minor in EDF's chemistry recommendation range, compared to other parameters' effects such as the pH effect. The presence of boric acid in the nominal secondary circuit conditions was negligible. Finally, as expected, the nature of the chemical conditioning (ammonia, morpholine or ethanolamine) did not modify the FAC rate, the influencing chemical variable being the at-temperature pH in one-phase flow conditions. (author)

  6. Experimental and theoretical investigation of 3-amino-1,2,4-triazole-5-thiol as a corrosion inhibitor for carbon steel in HCl medium

    International Nuclear Information System (INIS)

    Highlights: → The effect of 3-amino-1,2,4-triazole-5-thiol (3ATA5T) on carbon steel corrosion in 0.5 M HCl was investigated. → The high inhibition efficiency was determined, which attributed to the adherent adsorption of the 3ATA5T. → Langmuir adsorption isotherm exhibited the best fit to the experimental data. → Quantum chemical calculations show there is a correlation between inhibitive property and molecular parameters. - Abstract: The inhibition effect of 3-amino-1,2,4-triazole-5-thiol (3ATA5T) was investigated in 0.5 M HCl on carbon steel (CS) by electrochemical impedance spectroscopy and potentiodynamic measurements at various concentrations and temperatures. Results showed that the correlation between experimental (inhibition efficiencies, ΔGads, Ea) and quantum calculation parameters (dipole moment, EHOMO, ELUMO). The high inhibition efficiency was declined in terms of strongly adsorption of protonated inhibitor molecules on the metal surface and forming a protective film.

  7. Corrosion of plasma nitrided austenitic stainless steels

    International Nuclear Information System (INIS)

    The corrosion behaviour of plasma nitrided austenitic stainless steel grades AISI 304, 316 and 321 was studied at various temperatures. Certain plasma nitriding cycles included a post-oxidation treatment. The corrosion rates were measured using linear polarisation technique. Results showed that corrosion rate increased with the plasma nitriding temperature. Minimum deterioration occurred at 653K. (author). 2 tabs., 4 figs., 10 refs

  8. Flow accelerated corrosion of carbon steel feeder pipes from Indian reactors

    International Nuclear Information System (INIS)

    En-masse feeder replacement was done at RAPS-2 after occurrence of a pinhole leak in B12 (S) outlet feeder elbow. Some of the feeders, removed after a service of 15.67 EFPY were received for detailed investigation. Ultrasonic thickness measurement of the feeders was carried out to ascertain the loss in wall thickness due to Flow Accelerated Corrosion (FAC) and marking the region of interest from outside. Surface morphology of inner surface of a number of feeder samples were carried out by SEM near the HAZ and adjoining area. Maximum FAC had occurred in the heat-affected zone of the weld in 32 NB elbows. Weld was affected to a lower extent than the parent metal due to higher chromium content. IGSCC cracks were also observed in parent metal portion of the middle elbow in 32 NB outlet feeder pipe due to bending residual stresses. There are two life limiting reasons to curtail the useful life in the reactors namely FAC and IGSCC. The problem of FAC can be reduced by increasing chromium content and reducing the flow velocity by opting for higher diameter feeder pipes. The welding defects and residual stresses in HAZ and surrounding areas are detrimental for FAC and IGSCC in the elbow region. This paper presents some of the microstructural observations and findings on FAC to explain the mechanism of degradation of feeders. (author)

  9. Flow accelerated corrosion of carbon steel feeder pipes from pressurized heavy water reactors

    International Nuclear Information System (INIS)

    Detailed investigation of a number of feeder pipes received from Rajasthan Atomic Power Station Unit 2 (RAPS no. 2) after en-masse feeder pipe replacement after 15.67 Effective Full Power Years (EFPYs) was carried out. Investigations included ultrasonic thickness measurement by ultrasonic testing, optical microscopy, scanning electron microscopy, chemical analysis and X-ray Diffraction (XRD). Results showed that maximum thickness reduction of the feeder had occurred downstream and close to the weld in 32 NB (1.25″/32.75 mm ID) elbows. Rate of Flow Accelerated Corrosion (FAC) was measured to be higher in the lower diameter feeder pipes due to high flow velocity and turbulence. Weld regions had thinned to a lower extent than the parent material due to higher chromium content in the weld. A weld protrusion has been shown to add to the thinning due to FAC and lead to faster thinning rate at localized regions. Surface morphology of inner surface of feeder had shown different size scallop pattern over the weld and parent material. Inter-granular cracks were also observed along the weld fusion line and in the parent material in 32 NB outlet feeder elbow.

  10. Investigation of the Corrosion Behavior of Poly(Aniline-co-o-Anisidine)/ZnO Nanocomposite Coating on Low-Carbon Steel

    Science.gov (United States)

    Mobin, M.; Alam, R.; Aslam, J.

    2016-05-01

    A copolymer of aniline (AN) and o-anisidine (OA), Poly(AN-co-OA) and its nanocomposite with ZnO nanoparticles, Poly(AN-co-OA)/ZnO were synthesized by chemical oxidative polymerization using ammonium persulfate as an oxidant in hydrochloric acid medium. The synthesized compounds were characterized using FTIR, XRD, SEM-EDS, TEM, and electrical conductivity techniques. The copolymer and nanocomposite were separately dissolved in N-methyl-2-pyrrolidone and were casted on low-carbon steel specimens using 10% epoxy resin as a binder. The anticorrosive properties of the coatings were studied in different corrosive environments such as 0.1 M HCl, 5% NaCl solution, and distilled water at a temperature of 30 °C by conducting corrosion tests which include immersion test, open circuit potential measurements, potentiodynamic polarization measurements, and atmospheric exposure test. The surface morphology of the coatings prior to and after one-month immersion in corrosive solution was evaluated using SEM. It was observed that the nanocomposite coating exhibited higher corrosion resistance and provided better barrier properties in comparison with copolymer coating. The presence of ZnO nanoparticles improved the anticorrosion properties of copolymer coating in all corrosive media subjected to investigation.

  11. Investigation of the Corrosion Behavior of Poly(Aniline-co-o-Anisidine)/ZnO Nanocomposite Coating on Low-Carbon Steel

    Science.gov (United States)

    Mobin, M.; Alam, R.; Aslam, J.

    2016-07-01

    A copolymer of aniline (AN) and o-anisidine (OA), Poly(AN-co-OA) and its nanocomposite with ZnO nanoparticles, Poly(AN-co-OA)/ZnO were synthesized by chemical oxidative polymerization using ammonium persulfate as an oxidant in hydrochloric acid medium. The synthesized compounds were characterized using FTIR, XRD, SEM-EDS, TEM, and electrical conductivity techniques. The copolymer and nanocomposite were separately dissolved in N-methyl-2-pyrrolidone and were casted on low-carbon steel specimens using 10% epoxy resin as a binder. The anticorrosive properties of the coatings were studied in different corrosive environments such as 0.1 M HCl, 5% NaCl solution, and distilled water at a temperature of 30 °C by conducting corrosion tests which include immersion test, open circuit potential measurements, potentiodynamic polarization measurements, and atmospheric exposure test. The surface morphology of the coatings prior to and after one-month immersion in corrosive solution was evaluated using SEM. It was observed that the nanocomposite coating exhibited higher corrosion resistance and provided better barrier properties in comparison with copolymer coating. The presence of ZnO nanoparticles improved the anticorrosion properties of copolymer coating in all corrosive media subjected to investigation.

  12. Stress Corrosion of Carbon Steel in Three Different Atmospheric Environments%碳钢在三种大气环境中的应力腐蚀

    Institute of Scientific and Technical Information of China (English)

    曹公望; 王振尧; 刘雨薇; 汪川

    2015-01-01

    ABSTRACT:Objective To research the stress corrosion failure of No.45 and Q235 carbon steels in different kinds of atmospheric environments. Methods No.45 and Q235 carbon steels were used to prepare U-shape samples and tensile samples. The corrosion test in atmospheric exposure for three years was conducted in atmospheric environment in Wanning, Jiangjin and Xishuangbanna. The rust layer depth analysis and the tensile failure analysis were performed to investigate the stress corrosion of carbon steel in different atmospheric environments. Results The u-shaped sample under the influence of the tensile stress in the three kinds of atmospheric environment had different depth of corrosion pits. Strength of extension had declined in a short period of time and failured in Wanning atmospheric environment, while it declined slowly in xishuangbanna and Jiangjin atmospheric environment. Conclusion Due to difference inatmospheric contaminants, the corrosion degree varied for U-shape samples under the influence of tensile stress. The tensile strength of tensile samples was periodically decreased during the process of corrosion.%目的:研究45#碳钢和Q235碳钢在不同大气环境中的应力腐蚀失效。方法将45#碳钢和Q235碳钢制备成U型样和拉伸试样,分别在万宁、江津和西双版纳三种大气环境下进行为期3年的暴露试验,利用截面锈层深度分析和拉伸断裂分析两种手段,分析两种碳钢在不同大气环境下的应力腐蚀行为。结果拉应力影响下的U型样在三种大气环境中出现了不同深度的腐蚀坑。拉伸试样在万宁大气环境下短时间内抗拉强度急剧下降并失效,在西双版纳和江津大气环境下抗拉强度缓慢下降。结论在拉应力影响下U型样的腐蚀进程随大气污染物的不同,腐蚀程度不同,拉伸试样的抗拉强度随腐蚀进程的发展而呈周期性衰减。

  13. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy.

    Science.gov (United States)

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M

    2015-01-01

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance. PMID:25594340

  14. Preparation and Application of Crosslinked Poly(sodium acrylate-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2015-01-01

    Full Text Available This work presents a new method to prepare poly(sodium acrylate magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate as shell. Fourier transform infrared spectroscopy (FTIR was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM was used to examine the morphology of the modified poly(sodium acrylate magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS. Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  15. Electrochemistry study of the influence of local hydrogen generation in carbon steel bio-corrosion mechanisms in presence of iron reducing bacteria (Shewanella oneidensis)

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. The safe disposal of nuclear waste is a major concern for the nuclear energy industry. The high-level long-lived waste (HLNW) should be maintained for millions of years in clay formations at 500 metres depth in order to prevent the migration of radionuclides. Thence, different kinds of materials such as, carbon steel, stainless steel, concrete, clay, etc., are chosen aiming to last as long as possible and to preserve the radioactivity properties. In contrast, the anoxic corrosion of the different metallic envelopes is an expected phenomenon due to the changes on the environmental conditions (such as re-saturation) within HLNW repositories. In this context, corrosion products like iron oxides (i.e. magnetite, Fe3O4), and hydrogen will be also expected. On the one hand, hydrogen poses a significant threat to the nuclear waste repository when it is accumulated for a long time in the surrounding clay - such hydrogen production may damage the barrier properties of the geological formation, affecting the safety of the repository. On the other hand, hydrogen production represents a new energy source for bacterial growth, especially in such environments with low content of biodegradable organic matter. Moreover, some hydrogeno-trophic bacteria can also use Fe3+ as an electron acceptor for their development. Therefore, the biological activity and biofilm formation could interfere in the metal corrosion behaviour. This phenomenon is widely known by MIC (Microbiologically Influenced Corrosion), which can represent a huge problem when promoting local corrosion. The objective of this study is to better understand the influence of local hydrogen formation in the carbon steel bio-corrosion process in the presence of Shewanella oneidensis MR-1, a model of Iron Reducing Bacteria (IRB), in order to evaluate the impact of the bacterial activity in terms of long term behaviour of geological disposal materials. In this study, local

  16. Formation of Surface Corrosion-Resistant Nanocrystalline Structures on Steel.

    Science.gov (United States)

    Nykyforchyn, Hryhoriy; Kyryliv, Volodymyr; Maksymiv, Olha; Slobodyan, Zvenomyra; Tsyrulnyk, Oleksandr

    2016-12-01

    Engineering materials with nanocrystalline structure could be exploited under simultaneous action of mechanical loading and corrosion environments; therefore, their corrosion resistance is important. Surface nanocrystalline structure was generated on middle carbon steels by severe plastic deformation using the method of mechanical pulse friction treatment. This treatment additionally includes high temperature phase transformation and alloying. Using a complex of the corrosive, electrochemical and physical investigations, it was established that nanocrystalline structures can be characterized by lower or increased corrosion resistance in comparison with the reference material. It is caused by the action of two confronting factors: arising energy level and anticorrosive alloying of the surface layer. PMID:26831689

  17. Formation of Surface Corrosion-Resistant Nanocrystalline Structures on Steel

    Science.gov (United States)

    Nykyforchyn, Hryhoriy; Kyryliv, Volodymyr; Maksymiv, Olha; Slobodyan, Zvenomyra; Tsyrulnyk, Oleksandr

    2016-02-01

    Engineering materials with nanocrystalline structure could be exploited under simultaneous action of mechanical loading and corrosion environments; therefore, their corrosion resistance is important. Surface nanocrystalline structure was generated on middle carbon steels by severe plastic deformation using the method of mechanical pulse friction treatment. This treatment additionally includes high temperature phase transformation and alloying. Using a complex of the corrosive, electrochemical and physical investigations, it was established that nanocrystalline structures can be characterized by lower or increased corrosion resistance in comparison with the reference material. It is caused by the action of two confronting factors: arising energy level and anticorrosive alloying of the surface layer.

  18. Corrosion Inhibitive Potential Of Hibiscus Sabdariffa Calyx Extract For Low Carbon Steel In 0.5M H2SO4 Acid Solution

    OpenAIRE

    Adzor, S. A.*1

    2014-01-01

    The inhibitive potential of Hibiscus Sabdariffa calyx extract on low carbon steel corrosion in 0.5M H2SO4 have been investigated by weight loss method which is considered more informative than other laboratory methods. The studies were carried out using extracts obtained from 5-25g dried calyx powder. The test coupons were immersed in the corroding media at the time intervals of 24-168hours. The results obtained showed that the concentration of the inhibitor in the corrodent i...

  19. Evaluation of stainless steels for their resistance to intergranular corrosion

    International Nuclear Information System (INIS)

    Austenitic stainless steels are being considered as structural materials for first wall/blanket systems in the international thermonuclear reactor (ITER). The uniform corrosion of stainless steels in water is well known and is not a critical issue limiting its application for the ITER design. The sensitivity of austenitic steels to intergranular corrosion (IGC) can be estimated rather accurately by means of calculation methods, considering structure and chemical composition of steel. There is a maximum permissible carbon content level, at which sensitization of stainless steel is eliminated: K=Creff-αCeff, where α-thermodynamic coefficient, Creff-effective chromium content (regarding molybdenum influence) and Ceff-effective carbon content (taking into account nickel and stabilizing elements). Corrosion tests for 16Cr11Ni3MoTi, 316L and 316LN steel specimens, irradiated up to 2 x 1022 n/cm2 fluence have proved the effectiveness of this calculation technique for determination of austenitic steels tendency to IGC. This method is directly applicable in austenitic stainless steel production and enables one to exclude complicated experiments on determination of stainless steel susceptibility to IGC. (orig.)

  20. Plain carbon steel bipolar plates for PEMFC

    Institute of Scientific and Technical Information of China (English)

    WANG Jianli; SUN Juncai; TIAN Rujin; XU Jing

    2006-01-01

    Bipolar plates are a multifunctional component of PEMFC. Comparing with the machined graphite and stainless steels, the plain carbon steel is a very cheap commercial metal material. In this paper, the possibility of applying the plain carbon steels in the bipolar plate for PEMFC was exploited. In order to improve the corrosion resistance of the low carbon steel in the PEMFCs' environments,two surface modification processes was developed and then the electrochemical performances and interfacial contact resistance (ICR) of the surface modified plate of plain carbon steel were investigated. The results show that the surface modified steel plates have good corrosion resistance and relatively low contact resistance, and it may be a candidate material as bipolar plate of PEMFC.

  1. Conducting polyaniline/multi-wall carbon nanotubes composite paints on low carbon steel for corrosion protection: electrochemical investigations

    Czech Academy of Sciences Publication Activity Database

    Deshpande, P. P.; Vathare, S. S.; Vagge, S. T.; Tomšík, Elena; Stejskal, Jaroslav

    2013-01-01

    Roč. 67, č. 8 (2013), s. 1072-1078. ISSN 0366-6352 R&D Projects: GA ČR GA202/09/1626 Institutional support: RVO:61389013 Keywords : corrosion * polyaniline * conducting polymer Subject RIV: JI - Composite Materials Impact factor: 1.193, year: 2013

  2. A novel triazole-based cationic gemini surfactant: synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid

    International Nuclear Information System (INIS)

    A triazole-based cationic gemini surfactant, 3,5-bis(methylene octadecyl dimethylammonium chloride)-1,2,4-triazole (18-triazole-18) has been synthesized, and its effect on corrosion inhibition of A3 steel in 1 M HCl has been studied using the weight-loss method. The result showed that 18-triazole-18 acted as an excellent inhibitor in 1 M HCl. It was found that the adsorption mechanism of 18-triazole-18 on the steel surface in acid medium was quite different from that of cationic gemini surfactants containing dimethylene as a spacer, as well as that of conventional cationic single-chained surfactants, which is due to unique molecular structure of 18-triazole-18. 18-Triazole-18 may be adsorbed on the steel surface in acid medium through a maximum of four atoms or groups, i.e., the two nitrogen atoms of triazole ring and two quaternary ammonium head groups. Four regions of surfactant concentration could be divided to illustrate the adsorption of 18-triazole-18 on the steel surface, and four different adsorption mechanisms may take place in different regions of surfactant concentration

  3. Effect of CO2 on Atmospheric Corrosion of UNS G10190 Steel under Thin Electrolyte Film

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The atmospheric corrosion of UNS G10190 steel under a thin electrolyte film in the atmosphere polluted by CO2 has been studied in the lab using an atmospheric corrosion monitor(ACM) in combination with XRD and SEM observations of the surface of steel. The ACM study indicated that the corrosion rate of the steel increased with increasing carbon dioxide concentration. The XRD and SEM observations showed that no carbonate was found in the corrosion product on the steel surface. The corrosion product consisted of two layers, i. e., inner and outer layer. From the experimental results, it was concluded that CO2 played an enhancing role in the atmospheric corrosion of UNS G10190 steel. The film of the corrosion product showed slight protection.

  4. Tests Of Protective Coats For Carbon Steel

    Science.gov (United States)

    Macdowell, Louis G., III

    1995-01-01

    Report describes laboratory and field tests of candidate paints (primers, tie coats, and topcoats) for use in protecting carbon-steel structures against corrosion in seaside environment at Kennedy Space Center. Coating materials selected because of utility in preventing corrosion, also on basis of legal requirements, imposed in several urban areas, for reduction of volatile organic contents.

  5. Electrochemical and quantum chemical studies of N,N'-bis(4-hydroxybenzaldehyde)-2,2-dimethylpropandiimine Schiff base as corrosion inhibitor for low carbon steel in HCl solution.

    Science.gov (United States)

    Jafari, Hojat; Danaee, Iman; Eskandari, Hadi; Rashvandavei, Mehdi

    2013-01-01

    A synthesized Schiff base N,N'-bis(4-hydroxybenzaldehyde)-2,2-dimethylpropandiimine (p-HBDP) was studied as green inhibitor for the corrosion of low carbon steel in 1 M HCl solution using electrochemical, surface and quantum chemical methods. Results showed that the inhibition occurs through the adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency was found to increase with increasing inhibitor concentration and de-creased with increasing temper-ature, which is due to the fact that the rate of corrosion of steel is higher than the rate of adsorption. Thermodynamic parameters for adsorp-tion and activation processes were determined. Polarization data indicated that this compound act as mixed-type inhibitors and the adsorption isotherm basically obeys the Langmuir adsorption isotherm. The calculations of reactivity indices of p-HBDP such as softness and natural charge distributions together with local reactivity by means of Fukui indices were used to explain the electron transfer mechanism between the p-HBDP molecules and the steel surface. PMID:23947700

  6. Microstructure, Mechanical Properties & Corrosion Behavior of Duplex 2209 in Electro-Slag Strip Cladding over low carbon steel substrate: a Review Paper

    Directory of Open Access Journals (Sweden)

    Harinder SinghBedi

    2015-03-01

    Full Text Available The purpose of this research work is todetermine the microstructure and mechanical properties of Stainless steel (Duplex 2209 and S.S 309 weld overlay on Low carbon steel plate (SA 516 Grade 70 developing multilayers. The buffer layer is done by using S.S 309 L strip electrode of 60mm width following by top layers of Duplex 2209.The Process used is Electro Slag Strip Cladding due to its unique properties like high deposition rate and low dilution level.The Microstructure characterization will be examinedby the use of SEM/EDS. In mechanical properties Micro hardnesswill be examined. Residual stress analysis will be done by XRD. The intergranular stress corrosion study will also be carried out as per ASTM G-5 standards.

  7. Approach to corrosion mechanisms for a carbon steel in a solution of sodium chloride at 3 pc and its inhibition by means of organic molecules. Compared benefit of the use of stationary and transient electrochemical methods

    International Nuclear Information System (INIS)

    Within the context of an increased use of seawater as coolant in various industrial installations, this research thesis had two main objectives: the search for inhibitor organic compounds with optimal efficiency, and a better understanding of the mechanisms of corrosion inhibition by the best compounds within the considered organic compounds. After having reported a bibliographical study on carbon steel corrosion in seawater or in a sodium chloride solution at 3 pc, and on the inhibition of this corrosion, the author presents the experimental conditions (materials and methods). He reports the use of stationary and un-stationary electrochemical methods for the study of the steel-solution interface without inhibitor in order to get a better knowledge of corrosion electrochemical processes and to determine more precisely the corrosion rate. The last part addresses the study of the same interface but in presence of various inhibitors

  8. A novel Schiff base-based cationic gemini surfactants: Synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Hegazy, M.A. [Petrochemicals Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt)], E-mail: mohamed_hgazy@yahoo.com

    2009-11-15

    The corrosion inhibition characteristics of the synthesized cationic gemini surfactants, namely bis(p-(N,N,N-decyldimethylammonium bromide)benzylidene thiourea (10-S-10), bis(p-(N,N,N-dodecyldimethylammonium bromide)benzylidene thiourea (12-S-12) and bis(p-(N,N,N-tetradecyldimethylammonium bromide)benzylidene thiourea (14-S-14) on the carbon steel corrosion in 1 M hydrochloric acid have been investigated at 25 deg. C by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiencies obtained from all methods employed are in good agreement with each other. The obtained results show that compound 14-S-14 is the best inhibitor with an efficiency of 97.75% at 5 x 10{sup -3} M additive concentration. Generally, the inhibition efficiency increased with increase of the inhibitor concentration. Changes in impedance parameters (charge transfer resistance, R{sub ct}, and double-layer capacitance, C{sub dl}) were indicative of adsorption of 14-S-14 on the metal surface, leading to the formation of a protective film. The potentiodynamic polarization measurements indicated that the inhibitors are of mixed type. The adsorption of the inhibitors on the carbon steel surface in the acid solution was found to obey Langmuir's adsorption isotherm. The free energy of adsorption processes were calculated and discussed. The surface parameters of each synthesized surfactant were calculated from its surface tension including the critical micelle concentration (CMC), maximum surface excess ({gamma}{sub max}) and the minimum surface area (A{sub min}). The free energies of micellization ({delta}G{sup o}{sub mic}) were calculated. The surface morphology of carbon steel sample was investigated by scanning electron microscopy (SEM)

  9. Corrosion resistance of high-strength modified 13% Cr steel

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, M.; Miyata, Y.; Yamane, Y.; Toyooka, T.; Nakano, Y.; Murase, F. [Kawasaki Steel Corp., Handa, Aichi (Japan)

    1999-08-01

    A new 13% Cr martensitic stainless steel (0.025% C-13% Cr-Ni-Mo) with excellent resistance to carbon dioxide (CO{sub 2}) corrosion and good resistance to sulfide stress cracking (SSC) was developed, and its application limits in oil and gas environments were clarified. The CO{sub 2} corrosion rate of the 13% Cr steels with Ni and Mo was < 0.3 mm/y at 180 C (356 F) in 20% sodium chloride (NaCl). It was less than that of the conventional 13% Cr steel (0.2% C-13% Cr). The corrosion rate of the steel slightly decreased with the increase in Mo and Ni content. The SSC resistance improved with the increase in Mo content. The critical partial pressure of hydrogen sulfide (H{sub 2}S) for the 2% Mo steel was > 0.005 MPa at pH 3.5. Effects of Ni and Cu on SSC were not distinctive for this kind of steel. These results depended upon hydrogen permeability. The critical H{sub 2}S partial pressure for the 110-grade steel was the same as that of the 95-grade steel at pH 4.5 and pH 3.0 and was slightly lower at pH values between 3.0 and 4.5. The new 13% Cr steel proved to have excellent properties in the sweet and slightly sour environments.

  10. Corrosion behavior of sensitized duplex stainless steel.

    Science.gov (United States)

    Torres, F J; Panyayong, W; Rogers, W; Velasquez-Plata, D; Oshida, Y; Moore, B K

    1998-01-01

    The present work investigates the corrosion behavior of 2205 duplex stainless steel in 0.9% NaCl solution after various heat-treatments, and compares it to that of 316L austenitic stainless steel. Both stainless steels were heat-treated at 500, 650, and 800 degrees C in air for 1 h, followed by furnace cooling. Each heat-treated sample was examined for their microstructures and Vickers micro-hardness, and subjected to the X-ray diffraction for the phase identification. Using potentiostatic polarization method, each heat-treated sample was corrosion-tested in 37 degrees C 0.9% NaCl solution to estimate its corrosion rate. It was found that simulated sensitization showed an adverse influence on both steels, indicating that corrosion rates increased by increasing the sensitization temperatures. PMID:9713683

  11. Corrosion resistance of zinc-magnesium coated steel

    International Nuclear Information System (INIS)

    A significant body of work exists in the literature concerning the corrosion behaviour of zinc-magnesium coated steel (ZMG), describing its enhanced corrosion resistance when compared to conventional zinc-coated steel. This paper begins with a review of the literature and identifies key themes in the reported mechanisms for the attractive properties of this material. This is followed by an experimental programme where ZMG was subjected to an automotive laboratory corrosion test using acidified NaCl solution. A 3-fold increase in time to red rust compared to conventional zinc coatings was measured. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy were used to characterize the corrosion products formed. The corrosion products detected on ZMG included simonkolleite (Zn5Cl2(OH)8 . H2O), possibly modified by magnesium uptake, magnesium hydroxide (Mg(OH)2) and a hydroxy carbonate species. It is proposed that the oxygen reduction activity at the (zinc) cathodes is reduced by precipitation of alkali-resistant Mg(OH)2, which is gradually converted to more soluble hydroxy carbonates by uptake of atmospheric carbon dioxide. This lowers the surface pH sufficiently to allow thermodynamically for general precipitation of insoluble simonkolleite over the corroding surface thereby retarding the overall corrosion reactions, leaving only small traces of magnesium corrosion products behind. Such a mechanism is consistent with the experimental findings reported in the literature

  12. The nature of rusts and corrosion characteristics of low alloy and plain carbon steels in three kinds of concrete pore solution with salinity and different pH

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J.K. [Corrosion and Surface Engineering Division, CSIR - National Metallurgical Laboratory, Jamshedpur 831 007 (India); Singh, D.D.N., E-mail: ddns@nmlindia.org [Corrosion and Surface Engineering Division, CSIR - National Metallurgical Laboratory, Jamshedpur 831 007 (India)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer LAS rebars corrode 2-3 times slower than PCS in concrete pore solution and mortars. Black-Right-Pointing-Pointer Raman and XRD studies show that goethite and maghemite phases of rusts formed on LAS. Black-Right-Pointing-Pointer On PCS unstable phases of lepidocrocite and akaganite are formed. Black-Right-Pointing-Pointer EIS confirms more stable rust on LAS than on PCS. Black-Right-Pointing-Pointer A model is proposed to explain formation of passive film on surface of steels. - Abstract: Correlation of corrosion characteristics and nature of rusts on low alloy (LA) and plain carbon (PC) steels exposed in simulated concrete pore solution of different pH is studied. Rusts formed under wet/dry conditions are examined by Raman spectroscopy and X-ray diffraction. LA rust is more adherent compared to PC as confirmed by measurement of weight in gain and electrochemical studies. EIS results show improvement in protective properties of steels with passage of time. Both steels are found prone to pitting attack in chloride contaminated pore solution. Rebars embedded in concrete exhibit same trend as recorded in solution exposure tests.

  13. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove

    1997-01-01

    In this paper the corrosion properties of laser welded AISI 316L stainless steel are examined. A number of different welds has been performed to test the influence of the weld parameters of the resulting corrosion properties. It has been chosen to use the potential independent critical pitting...

  14. Corrosion of austenitic steel in sodium loops

    International Nuclear Information System (INIS)

    The possibility of predicting corrosion effects for austenitic steel exposed to liquid sodium with an analytical diffusion model is presented. The analytically predicated corrosion effects are compared with experimental measurements of corrosion effects achieved in an accurately controlled sodium loop. The diffusion model is described with figures showing disc sample weight loss and sodium flow guidance tube chromium and nickel profiles. Finally, the concentration profile in the fuel rod wall (diffusion model) is presented for iron, chromium and nickel

  15. Testing corrosion rates on steel piping in geothermal district heating

    OpenAIRE

    İnce, Umut; Toksoy, Macit; Güden, Mustafa

    2008-01-01

    The corrosion behavior of St-37 pipeline carbon steel (CS) in a geothermal district heating system was tested at two different fluid velocities. An experimental set-up, directly connected the the end of the transmission line of a geothermal well, was used to assess the corrosion of St-37 steel tensile test coupons prepared in accordance with ASTM E8 in geothermal fluid. The geothermal fluid entered the set-up with a relatively low velocity, 0.02 m/s, and then injected into the well with a rel...

  16. Electrochemical Investigation of the Corrosion of Different Microstructural Phases of X65 Pipeline Steel under Saturated Carbon Dioxide Conditions

    Directory of Open Access Journals (Sweden)

    Yuanfeng Yang

    2015-05-01

    Full Text Available The aim of this research was to investigate the influence of metallurgy on the corrosion behaviour of separate weld zone (WZ and parent plate (PP regions of X65 pipeline steel in a solution of deionised water saturated with CO2, at two different temperatures (55 °C and 80 °C and at initial pH~4.0. In addition, a non-electrochemical immersion experiment was also performed at 80 °C in CO2, on a sample portion of X65 pipeline containing part of a weld section, together with adjacent heat affected zones (HAZ and parent material. Electrochemical impedance spectroscopy (EIS was used to evaluate the corrosion behaviour of the separate weld and parent plate samples. This study seeks to understand the significance of the different microstructures within the different zones of the welded X65 pipe in CO2 environments on corrosion performance; with particular attention given to the formation of surface scales; and their composition/significance. The results obtained from grazing incidence X-ray diffraction (GIXRD measurements suggest that, post immersion, the parent plate substrate is scale free, with only features arising from ferrite (α-Fe and cementite (Fe3C apparent. In contrast, at 80 °C, GIXRD from the weld zone substrate, and weld zone/heat affected zone of the non-electrochemical sample indicates the presence of siderite (FeCO3 and chukanovite (Fe2CO3(OH2 phases. Scanning Electron Microscopy (SEM on this surface confirmed the presence of characteristic discrete cube-shaped crystallites of siderite together with plate-like clusters of chukanovite.

  17. Steel Corrosion Inhibition by Acid Garlic Essential Oil as a Green Corrosion Inhibitor a nd Sorption Behavior

    OpenAIRE

    Afia, L.; Benali, O.; Salghi, R.; Ebenso, Eno E.; Jodeh, S.; Zougagh, M.; Hammouti, B.

    2014-01-01

    The aim of this work was to investigate the inhibition effect of acid garlic essential oil (GO oil) as an inhibitor on the corrosion of carbon steel in a 1M HCl solution at different temperatures by weight loss,electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods. The GO oil acts as an effective corrosion inhibitor for carbon steel in a hydrochloric acid medium. The inhibition process is attributed to the formatio...

  18. Corrosion of Steel in Concrete, Part I – Mechanisms

    DEFF Research Database (Denmark)

    Küter, André; Møller, Per; Geiker, Mette Rica

    2006-01-01

    prematurely. Reinforcement corrosion is identified to be the foremost cause of deterioration. Steel in concrete is normally protected by a passive layer due the high alkalinity of the concrete pore solution; corrosion is initiated by neutralization through atmospheric carbon dioxide and by ingress of......Throughout the world reinforced concrete is the most widely used construction material for buildings and civil engineering structures. Most reinforced concrete structures have performed satisfactory over many decades, but there still is an unacceptable large number of structures that deteriorate...... depassivation ions, especially chloride ions. The background and consequences of deterioration of reinforced concrete structures caused by steel corrosion are summarized. Selected corrosion mechanisms postulated in the literature are briefly discussed and related to observations. The key factors controlling...

  19. Carbon dioxide corrosion inhibition of N80 carbon steel in single liquid phase and liquid/particle two-phase flow by hydroxyethyl imidazoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Applied Chemistry, Shenyang Institute of Chemical Technology, Shenyang 110142 (China); Zheng, Y.G. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Okafor, P.C. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Pure and Applied Chemistry, University of Calabar, Calabar (Nigeria)

    2009-07-15

    CO{sub 2} corrosion inhibition of N80 steel in liquid single-phase and liquid/particle two-phase flow by 2-undecyl-1-hydroxyethyl imidazoline (HEI-11) and 2-undecyl-1-hydroxyethyl-1-hydroxyethyl quaternary imidazoline (HQI-11) was investigated using weight loss, potentiodynamic polarization, EIS, and scanning electron microscope (SEM) techniques. The results show that the corrosion rate in the absence and presence of the imidazolines is strongly dependent on the flow condition and presence of entrained sand particles. The imidazolines function via a mixed-type corrosion inhibition mechanism. The inhibition efficiencies of the imidazolines followed the trend HQI-11 > HEI-11 in all the systems studied. Inhibition mechanism has been discussed in relation to the polycentric adsorption sites on the imidazoline molecules. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  20. Corrosion of steel tanks in liquid nuclear wastes

    International Nuclear Information System (INIS)

    The objective of this work is to understand how solution chemistry would impact on the corrosion of waste storage steel tanks at the Hanford Site. Future tank waste operations are expected to process wastes that are more dilute with respect to some current corrosion inhibiting waste constituents. Assessment of corrosion damage and of the influence of exposure time and electrolyte composition, using simulated (non-radioactive) wastes, of the double-shell tank wall carbon steel alloys is being conducted in a statistically designed long-term immersion experiment. Corrosion rates at different times of immersion were determined using both weight-loss determinations and electrochemical impedance spectroscopy measurements. Localized corrosion susceptibility was assessed using short-term cyclic potentiodynamic polarization curves. The results presented in this paper correspond to electrochemical and weight-loss measurements of the immersed coupons during the first year of immersion from a two year immersion plan. A good correlation was obtained between electrochemical measurements, weight-loss determinations and visual observations. Very low general corrosion rates (-1) were estimated using EIS measurements, indicating that general corrosion rate of the steel in contact with liquid wastes would no be a cause of tank failure even for these out-of-chemistry limit wastes. (author)

  1. Electrochemical studies of the corrosion inhibition effect of 2-amino-5-ethyl-1,3,4-thiadiazole on low carbon steel in dilute sulphuric acid

    International Nuclear Information System (INIS)

    The electrochemical behaviour of carbon steel in 0.5 M H/sub 2/SO/sub 4/ was studied in the presence of 2-amino-5-ethyl-1 3 4-thiadiazole (TTD) as inhibitor with the aid of weight loss method, potentiodynamic polarization and open circuit potential measurement technique. The effect of inhibitor concentrations, exposure time, corrosion rate and surface coverage on inhibition efficiency was investigated. Results showed that TTD performed excellently in the acid solution with the inhibition efficiency increasing with increase in inhibitor concentration up to a peak value of 80.67% and 90.5% at maximum concentration from weight loss test and potentiodynamic polarization tests. The compound showed cathodic inhibition tendency in solution with the inhibitor molecules been effectively adsorbed onto the steel surface, stifling the electrochemical reactions responsible for corrosion through the exposure hours. Results from statistical analysis through ANOVA software depicts the overwhelming influence of inhibitor concentration on inhibition efficiency compared to exposure time. (author)

  2. Corrosion behavior of novel 3%Cr pipeline steel in CO2 Top-of-Line Corrosion environment

    International Nuclear Information System (INIS)

    Highlights: ► CO2 Top-of-Line Corrosion environment in wet gas pipelines was simulated. ► Compared with X70, the resistance to CO2 TLC of novel 3%Cr pipeline steel is better. ► The effect of Cr enrichment in the corrosion scale on CO2 TLC is confirmed. -- Abstract: CO2 Top-of-Line Corrosion (TLC) of carbon steel pipelines is a serious problem for wet gas transportation. We have studied the corrosion behavior of novel 3%Cr (3Cr) pipeline steel and conventional carbon steel (X70) in the simulated CO2 TLC environment. The composition and morphology of the corrosion scale are characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and scanning electron microscopy analyses. The results indicate that 3Cr pipeline steel shows superior resistance to CO2 TLC, exhibiting uniform corrosion with duplex corrosion layer, while X70 suffers severe localized corrosion. It was suggested that the inner Cr enriched layer enhanced the protective ability of the scale to steel substrate and improved the resistance to localized corrosion in CO2 TLC environment.

  3. Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H2O mixture

    International Nuclear Information System (INIS)

    The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H2O at room temperature has been evaluated. Used inhibitors included LiNO3 (Lithium Nitrate), Li2MoO4 (Lithium Molybdate) and Li2CrO4 (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li2CrO4, where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li2CrO4, and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control

  4. Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H{sub 2}O mixture

    Energy Technology Data Exchange (ETDEWEB)

    Samiento-Bustos, E. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Rodriguez, J.G. Gonzalez [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico)], E-mail: ggonzalez@uaem.mx; Uruchurtu, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Dominguez-Patino, G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); U.A.E.M. Facultad de Ciencias Quimicas e Ingenieria, Av. Universidad 1001, 62209, Cuernavaca, Morelos (Mexico); Salinas-Bravo, V.M. [Instituto de Investigaciones Electricas, Gerencia de Materiales y Proceso Quimicos, Av. Reforma 113, Col. Palmira, CP 62490, Cuernavaca, Morelos (Mexico)

    2008-08-15

    The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H{sub 2}O at room temperature has been evaluated. Used inhibitors included LiNO{sub 3} (Lithium Nitrate), Li{sub 2}MoO{sub 4} (Lithium Molybdate) and Li{sub 2}CrO{sub 4} (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li{sub 2}CrO{sub 4,} where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li{sub 2}CrO{sub 4}, and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control.

  5. Stress corrosion cracking behavior of 3.5NiCrMoV steel in carbonated pure water

    International Nuclear Information System (INIS)

    SCC susceptibility of 3.5NiCrMoV steel in a carbonated pure water at 157 C decreased with the decrease of P content in steel. SCC susceptibility also decreased by the addition of Nb. It was also confirmed that the SCC cracks were primarily intergranular. An Auger electron spectroscopy (AES) analysis revealed that P segregation to grain boundary might play an essential role in accelerating SCC susceptibility, and Nb could suppress the P segregation to grain boundary. The role of Nb in raising resistance to SCC is thought to be attributed to the decreasing P segregation to grain boundary, resulting from increasing segregation interface due to fine NbC formation in steel. The measurement of anodic current decay in a carbonated solution with and without HPO42- ion showed that HPO42- ion accelerates the repassivation of a fresh surface, indicating that P segregation to grain boundary might be mainly attributed to the crack-sharpening effect due to repassivation by the formation of phosphate species at the crack tip

  6. Effect of microstructure and Cr content in steel on CO{sub 2} corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Masakatsu [Sumitomo Metal Industries, Ltd., Amagasaki (Japan). Iron and Steel Research Labs.; Ikeda, Akio [Sumitomo Metal Industries, Ltd., Osaka (Japan)

    1996-08-01

    The effect of microstructure and Cr content in steels on CO{sub 2} corrosion was investigated by using steels containing Cr content from 0 to 13 mass% melted in laboratory and Steels J55, N80 and L80(API Grade) melted in the mill. Temperatures and H{sub 2}S contamination were considered as environmental factors. In CO{sub 2} environments, the temperature giving a maximum corrosion rate, T{sub max.}, existed in carbon and Cr steels. T{sub max.} increased together with Cr content, and T{sub max.} of 0, 1, 2 and 13% Cr steels was about 80, 100, 120 and 225 C, respectively. Because of this behavior, the relationship between Cr content and corrosion rate was linear at 60 C, but the corrosion rate was highest on the steel with around 1 mass% Cr at 100 C. H{sub 2}S contamination for CO{sub 2} corrosion suppressed the corrosion rate and localized-corrosion in the temperature region whose corrosion rate showed a maximum value. It was clarified that this was related to the formation of Fe-sulfides from EPMA analysis and the solubility of the corrosion products. Concerning microstructure, Steel J55 with ferritic-pearlitic microstructure showed good corrosion resistance for localized-corrosion compared with Steel N80 and L80 with martensitic microstructure.

  7. Superclean steel development: Stress corrosion cracking characteristics

    Energy Technology Data Exchange (ETDEWEB)

    1990-07-01

    Stress corrosion tests (SCC initiation and propagation) were carried out on a high purity version of the 3.5% NiCrMoV low pressure rotor steel in comparison to similar steels of conventional cleanness. In the constant load tests in 30% sodium hydroxide solution the clean steel showed longer times to crack initiation than the conventional steels with comparable strength levels. The amount of scatter makes it difficult to quantify the improvement, which lay at or above 5% in stress level. Neither in pure water (aerated and deaerated) nor in a concentrated caustic solution were differences in the stress corrosion crack velocities detected. Neither the clean steel nor the conventional steel tested in this programme showed any increase in SCC susceptibility after aging at 350 or 450{degree}C for 10,000 hours. 19 refs., 17 figs., 3 tabs.

  8. Susceptibility to corrosion damage of pipeline steels under coating disbondments

    Energy Technology Data Exchange (ETDEWEB)

    Guermazi, N.; Ibrahmi, A.; Hmidi, H.; Elleuch, K.; Ayedi, H.F. [Unite de Recherche de Chimie Industrielle et Materiaux, URCIM - ENIS, Sfax (Tunisia)

    2010-01-15

    This study provides an experimental investigation on the corrosion behaviour of three carbon steels used for pipeline application. The susceptibility of these materials to corrosion damage was analysed in order to simulate its service conditions particularly under disbonded coating. Monitoring of open-circuit potential (E{sub free}), polarization resistance (R{sub p}) and measuring of the weight loss during immersion time were used to evaluate the corrosion behaviour of the studied materials. All the corrosion experiments were performed in two aqueous solutions: natural seawater and synthetic one (3 wt% NaCl solution). The morphology of the corrosion products was examined by optical microscopy. The results obtained from electrochemical tests have shown different behaviour for the studied steels into the retained corrosive environments: more stable potentials (E{sub free}), higher R{sub p}-values with large fluctuations evolution were found in natural seawater. The gravimetric measurements have also shown a continuous variation of the weight loss throughout the exposure period in the sodium chloride solution. However, it seemed that a passive behaviour was observed in natural seawater. A little difference was observed between all the studied steels in terms of corrosion kinetics. The steel, having the little ferritic grain size, seems to be more resistant to corrosion damage. Qualitatively, a porous and non-adherent oxide film was observed on the corroded surface in the synthetic solution; while, the rust layer, which is formed in the natural seawater, has acted as a barrier of corrosion process. Finally, all the results obtained from both electrochemical tests and weight loss measurements were in reasonably good accordance. The important common point that can be concluded was that all the tested materials seem to be more suitable for natural seawater than 3 wt% NaCl solution. Also, they are not recommendable to be used in an environment where chloride attack is

  9. EIS Response of MIC on Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Maahn, Ernst

    1998-01-01

    Abstract Microbially influenced corrosion of carbon steel under sulphate reducing (sulphide-producing) bacterial activity (SRB) results in the formation of both ferrous sulphides as well as biofilm on the metal surface. The electrochemical characteristics of the ferrous sulphide/steel interface as...... identifying the formation of biofilm/ferrous sulphide layers but unfortunately also that corrosion rate estimation by these electrochemical techniques is unreliable when these layers form. These considerations are also relevant for other corrosion systems where film formation might mask the electrochemical...

  10. Mechanism of protective film formation during CO2 corrosion of X65 pipeline steel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Electrochemical techniques,X-ray diffraction (XRD),and scanning electron microscopy (SEM) were applied to study the corrosion behaviors of X65 steel in static solution with carbon dioxide (CO2 at 65℃.The results show that iron carbonate (FeCO3deposits on the steel surface as a corrosion product scale.This iron carbonate scale acts as a barrier to CO2 corrosion,and can reduce the general corrosion rate.The protection ability of the scale is closely related to the scale morphological characteristics.

  11. Investigation of the inhibitive effect of N-phosphono-methyl-glycine on the corrosion of carbon steel in neutral solutions by electrochemical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pech-Canul, M.A.; Chi-Canul, L.P.

    1999-10-01

    Steady-state current-voltage curves for various disk rotation rates were combined with electrochemical impedance measurements to investigate the corrosion inhibition of carbon steel by N-phosphono-methyl-glycine (NPMG)/Zn{sup 2+} mixtures with a concentration ratio of 1:1 between NPMG and zinc cations in a model water. Efficiency of the NPMG/Zn{sup 2+} formulation increased with concentration in the range from 10 ppm to 100 ppm, and it performed as a mixed type inhibitor, retarding the rate of the anodic and cathodic reactions. Analysis of impedance measurements by means of a simple model suggested that the oxygen reduction reaction was under mixed activation-diffusion control in blank solutions and nearly under diffusion control in the inhibited solutions. Results showed that with increasing rotation speeds, the rate of oxygen diffusion through the porous layer covering the electrode surface increased and the anodic dissolution reaction became slower.

  12. Effect of δ-ferrite on stress corrosion cracking behavior of low-carbon stainless steel weld in high temperature water

    International Nuclear Information System (INIS)

    Stress corrosion cracking (SCC) behavior of low-carbon stainless steel welds in high temperature water has been discussed with special attention on relation to the characteristics of microstructure. To investigate the effect of δ-ferrite on SCC behavior, simulated heat-affected zone (partially melted zone) microstructure, where δ-ferrite islands were widely distributed on grain boundary, was made by induction heating up to just below melting point. From the results of constant strain SCC test in high temperature water, it has been obvious that many crack tips located at δ-ferrite. The relative crack growth rate at the δ-γ interface was estimated to be much lower than that at the γ-γ interface. Cracks remained for a considerable period of time just after they reached δ-ferrite islands which act as a crack arrester. (author)

  13. Prediction of external corrosion for steel cylinders

    International Nuclear Information System (INIS)

    The US Department of Energy (DOE) currently manages the UF6 Cylinder Program (the program). The program was formed to address the depleted-uranium hexafluoride (UF6) stored in approximately 50,000 carbon steel cylinders. The cylinders are located at three DOE sites: the K-25 site (K-25) at Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1996a) delineates the requirements of the program. The appropriate actions needed to fulfill these requirements are then specified within the System Engineering Management Plan (SEMP) (LMES 1996b). The report presented herein documents activities that in whole or in part satisfy specific requirements and actions stated in the UF6 Cylinder Program SRD and SEMP with respect to forecasting cylinder conditions. The wall thickness projections made in this report are based on the assumption that the corrosion trends noted will continue. Some activities planned may substantially reduce the rate of corrosion, in which case the results presented here are conservative. The results presented here are intended to supersede those presented previously, as the quality of several of the datasets has improved

  14. Cesium corrosion process in Fe–Cr steel

    International Nuclear Information System (INIS)

    A cesium corrosion out-pile test was performed to Fe–Cr steel in a simulated fuel pin environment. In order to specify the corrosion products, the corroded area was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A cesium corrosion process in Fe–Cr steel was successfully developed proceeding from both experimental results and thermochemical consideration. The corroded area was mainly formed by Fe layer and Fe depleted oxidized layer. The Fe depleted oxidized layer was formed by Cr0.5Fe0.5 and Cr2O3. The presumed main corrosion reactions were 2Cr+2/3 O2→Cr2O3(ΔG650°C=-894.1kJ/mol) and Cr23C6+46Cs+46O2→23Cs2CrO4+6C(ΔG650°C=-25018.1kJ/mol). Factors of these reactions are chromium, carbon, oxygen and cesium. Therefore, cesium corrosion progression must be dependent on the chromium content, carbon content in the steel, the supply rate of oxygen and temperature which correlated with the diffusion rate of cesium and oxygen into the specimen

  15. Plasma coating used to evaluate resistance against flow accelerated corrosion on carbon steel feeder pipe material for pressurized heavy water reactor

    International Nuclear Information System (INIS)

    A collaborative study on plasma nitriding was initiated by Water and Steam Chemistry Division, BARC Facilities, Kalpakkam, with FCIPT, a division of Institute of Plasma Research. In order to control the influence of Flow Accelerated Corrosion (FAC) on feeder pipe of PHWR reactor, coating by plasma nitriding process was carried out inside the pipe as a remedy.This is one of the methods to control the wall thickness reduction of carbon steel feeder pipe and the influence of FAC in PHWR (Pressurized heavy water reactor). Specimen of 15 mm NB Sch 80 straight pipe length of 100 mm pipe module section of low carbon steel ASTM 106 Gr. B were plasma nitrided at FCIPT, IPR for optimization of the process parameters. The wall thickness of the sample was measured axially and circumferentially by Ultrasonic thickness gauge with specific marking with templates before carrying out plasma nitriding process. During plasma nitriding the temperature was maintained at 520 °C for 24 hours. The samples after coating were checked for thickness variation by Raman spectroscopy as well as microscopy, and it was found that the coating was uniform and coating consisted of iron nitrides only. For functional test, to check the corrosion resistance, a specimen holder was designed and fabricated for the treated specimen such that it can withstand a velocity of 7 m/s. The holder was mounted in SIM loop outlet of heater. The SIM loop was maintained at 120 °C and 7 m/s for about 30 days with less than 20 ppb dissolved oxygen condition. Preliminary experiments on plasma nitriding have been carried out and checked in SIM loop in order to check the resistance to FAC under neutral pH condition. (author)

  16. In situ synchrotron X-ray diffraction study of scale formation during CO2 corrosion of carbon steel in sodium and magnesium chloride solutions

    International Nuclear Information System (INIS)

    Highlights: ► We studied the scale formation processes of carbon steel in CO2 saturated brine at 80 °C. ► Protective scales were formed in all tests. ► Only FeCO3 formed in saturated brine while Fe(OH)2CO3 detected with presence of MgCl2. ► MgCl2 accelerates the onset of siderite precipitation. - Abstract: In situ synchrotron X-ray diffraction was used to follow the formation of corrosion products on carbon steel in CO2 saturated NaCl solution and mixed NaCl/magnesium chloride (MgCl2) at 80 °C. Siderite (FeCO3) was the only phase formed in NaCl solution, while Fe(OH)2CO3 was also detected when MgCl2 was present. The proposed model is that siderite precipitation, occurring once the critical supersaturation was exceeded within a defined boundary layer, caused local acidification which accelerated the anodic dissolution of iron. The current fell once a complete surface scale was formed. It is suggested that MgCl2 addition decreased the required critical supersaturation for precipitation.

  17. Evaluation of the potential of additives as corrosion inhibitors of CA-50 carbon steel used as reinforcement in concretes; Avaliacao da potencialidade de aditivos como inibidores de corrosao do aco carbono CA-50 usado como armadura de estruturas de concreto

    Energy Technology Data Exchange (ETDEWEB)

    Mennucci, Marina Martins

    2006-07-01

    In this work, various compounds were tested to evaluate their potential capability for their use as corrosion inhibitors of carbon steel reinforcement in concretes. The additives tested were sodium benzoate, polyethylene glycol, hexamethylenetetramine, benzotriazole and yttrium carbonate. Initially, exploratory tests were carried out to select the ones to be used as corrosion inhibitors, based on the inhibit ion efficiency determined from electrochemical tests, specifically polarization tests and electrochemical impedance spectroscopy. These tests were carried out in a solution composed of 0.01 N sodium hydroxide (NaOH) and 0.05 N potassium hydroxide (KOH) to simulate the composition of the solution inside the pores in concretes. The additive that presented the most promising potential to be used as corrosion inhibitor was benzotriazole (BTA). After the elimination of some compounds and selection of the additive with higher corrosion inhibit ion efficiency in the test medium, the effect of its concentration on the corrosion inhibition efficiency was evaluated. Sodium nitrite solutions with the same concentrations as those solutions with BTA were tested for comparison reasons. Sodium nitrite is a well established corrosion inhibitor for carbon steel reinforcement in concretes but it has been related to toxic effects. The BTA was associated to higher corrosion inhibition efficiencies than that of sodium nitrite in similar concentrations. A blackish adherent film was formed on the steel surface exposed to BTA solutions during long periods of immersion in the alkaline medium. The results suggest that BTA is a potential candidate for substitution of nitrites as corrosion inhibitor of reinforcements in concrete. (author)

  18. Effects of sulphide ion on the corrosion behaviour of X52 steel in a carbon dioxide environment at temperature 40 deg. C

    International Nuclear Information System (INIS)

    Research highlights: → We study the effect of sulphide ion on the corrosion behaviour of X52 steel. → Increasing sulphide ion concentration will increase the corrosion rate of X52 steel. → Increasing sulphide ion concentration will increase cathodic reaction. → Less protective film, also contribute to the increasing the corrosion rate. - Abstract: The electrochemical behaviour of X52 steel in the presence of sulphide at 40 deg. C in a CO2 environment was investigated using the methods of linear polarization resistance (LPR), potentiodynamic sweep, electrochemical impedance spectroscopy (EIS). In addition, the surface of X52 steel was also studied using scanning electron microscopy (SEM). The results showed that the corrosion rate of X52 steel increased with increasing concentration of sulphide ion. Potentiodynamic curve showed that there were changes in cathodic branch due to the change in the nature of cathodic reaction in the presence of sulphide ion. EIS analysis showed the higher sulphide ion concentration, the higher adsorbed species on the steel surface that contributed in the cathodic reaction. Furthermore, SEM results showed crevices on the scale which indicated pitting tendency in sulphide ion solutions. The less protective film, probably mackinawite, also contributed to the increase of corrosion rate in the presence of sulphide ion.

  19. Effects of sulphide ion on the corrosion behaviour of X52 steel in a carbon dioxide environment at temperature 40 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Fatah, M.C., E-mail: m10.fatah@gmail.com [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar sri Iskandar, 31750, Tronoh, Perak (Malaysia); Ismail, M.C. [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar sri Iskandar, 31750, Tronoh, Perak (Malaysia); Ari-Wahjoedi, B. [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750, Tronoh, Perak (Malaysia); Kurnia, K.A. [Department of Chemical Engineering, Universiti Teknologi PETRONAS, 31750, Tronoh, Perak (Malaysia)

    2011-05-16

    Research highlights: {yields} We study the effect of sulphide ion on the corrosion behaviour of X52 steel. {yields} Increasing sulphide ion concentration will increase the corrosion rate of X52 steel. {yields} Increasing sulphide ion concentration will increase cathodic reaction. {yields} Less protective film, also contribute to the increasing the corrosion rate. - Abstract: The electrochemical behaviour of X52 steel in the presence of sulphide at 40 deg. C in a CO{sub 2} environment was investigated using the methods of linear polarization resistance (LPR), potentiodynamic sweep, electrochemical impedance spectroscopy (EIS). In addition, the surface of X52 steel was also studied using scanning electron microscopy (SEM). The results showed that the corrosion rate of X52 steel increased with increasing concentration of sulphide ion. Potentiodynamic curve showed that there were changes in cathodic branch due to the change in the nature of cathodic reaction in the presence of sulphide ion. EIS analysis showed the higher sulphide ion concentration, the higher adsorbed species on the steel surface that contributed in the cathodic reaction. Furthermore, SEM results showed crevices on the scale which indicated pitting tendency in sulphide ion solutions. The less protective film, probably mackinawite, also contributed to the increase of corrosion rate in the presence of sulphide ion.

  20. The effect of aerobic corrosion on anaerobically-formed sulfide layers on carbon steel in dilute near-neutral pH saline solutions

    International Nuclear Information System (INIS)

    Highlights: •The corrosion rate is low when steel is exposed to anaerobic conditions (pH = 8.9). •An anaerobic corrosion with sulfide to aerobic switch increases the corrosion rate. •Aerobic conditions leads to corrosion and oxide deposition beneath FeS. •Continual air exposure leads to the blistering of the original FeS film. -- Abstract: The aerobic corrosion of pipeline steel was investigated in an aqueous sulfide solution by monitoring the corrosion potential and periodically measuring the polarization resistance. The properties and composition of the corrosion product deposits formed were determined using scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy. The establishment of aerobic conditions leads to corrosion and (oxyhydr)oxide deposition beneath the anaerobically-formed mackinawite film originally present on the steel surface. This leads to blistering and spalling of the sulfide film. Chemical conversion of the mackinawite to Fe(III) (oxyhydr)oxides also occurs but is a relatively slow reaction

  1. Corrosion of nickel alloys and stainless steels in polluted or confined PWR environments

    International Nuclear Information System (INIS)

    This document addresses the issue of corrosion of materials used in PWR nuclear reactors, notably in steam generators which have been particularly affected by this kind of degradation due to a progressive accumulation of impurities. The authors first present the different materials used in secondary circuit and in auxiliary circuits of PWRs: carbon steels and low alloyed steels, nickel alloys, stainless steels, and other materials. They discuss the degradation of steam generator tubes by corrosion: corrosion environments, types of corrosion (wastage, pitting, intergranular stress corrosion cracking), and influence of the environment and of the microstructure. They also propose a brief overview of modelling efforts in the case of the 600 alloy, and indicates measures to mitigate the tube degradation by corrosion (water treatment, better design of steam generators and secondary circuit, improvement of corrosion resistance). The next part addresses the degradation by stress corrosion cracking of stainless steels in polluted environments in PWRs reactors: return on experience, stress corrosion cracking in media contaminated by impurities (intergranular corrosion of sensitized or work hardened steels, transgranular corrosion by chloride ions, corrosion by diluted sulphate + chloride, corrosion in concentrated boric acid solutions)

  2. Atmospheric corrosion of low carbon steel in a polar marine environment. Study of the effect of wind regime; Corrosion atmosferica del acero bajo en carbono en un ambiente marino polar. Estudio del efecto del regimen de vientos

    Energy Technology Data Exchange (ETDEWEB)

    Rivero, S.; Chico, B.; Fuente, D. de la; Morcillo, M.

    2007-07-01

    The present work studies the atmospheric corrosion of carbon steel (UNE-EN 10130) in a sub-polar marine environment (Artigas Antarctic Scientific Base (BCAA), Uruguay) as a function of site atmospheric salinity and exposure time. A linear relationship is established between corrosion rate and airborne salinity deposition rate, valid in the deposition range encountered (125-225 mg Cl-l/m{sup 2}.d) and a bi logarithmic relationship established between corrosion and exposure time (1-4 years). Atmospheric salinity is related with the monthly wind speed average, based on the concept of the wind run. chloride ion deposition rates of less than 300 mg Cl-l/m{sup 2}.d are related with remote (oceanic) winds and coastal winds basically of speeds between 1-40 km/h, while higher deposition rates (300-700 mg Cl-/m{sup 2}.d) correspond to coastal marine winds of a certain persistence with speeds of between 41-80 km/h. (Author) 39 refs.

  3. Electrochemical noise from corroding carbon steel and aluminium

    International Nuclear Information System (INIS)

    Electrochemical noise measurements were conducted on carbon steel and aluminium in sodium chloride solutions. Noise parameters like standard deviation of potential and current, noise resistance, pitting index, noise power were studied for the purpose of measuring corrosion rate. These parameters compared well with the corrosion rate. Pitting index was not very reliable. Current noise was more close to the corrosion rates. General corrosion gave rise to white noise type of power spectrum while flicker noise type of spectrum was obtained from pitting attack. Sodium nitrite is shown to inhibit the corrosion of carbon steel. Aluminium corrodes in the early period of exposure and passivates during long exposure

  4. Use of Extracted Green Inhibitors as a Friendly Choice in Corrosion Protection of Low Alloy Carbon Steel

    OpenAIRE

    Jano, A.; Lame (Galo), A.; Kokalari (Teli), E.

    2012-01-01

    Mitigation of corrosion impact on environment is an important step in environmental protection. Use of environmentally friendly corrosion protection methods is very important. It is smart to choose cheap and safe to handle compounds as corrosion inhibitors. The use of green inhibitors (extracted inexpensively, from the seed endosperm of some Leguminosae plants), and investigation of their efficiency in corrosion protection is the aim of this study. As green inhibitor one kind of polys...

  5. Corrosion of steel structures in sea-bed sediment

    Indian Academy of Sciences (India)

    Xiutong Wang; Jizhou Duan; Yan Li; Jie Zhang; Shide Ma; Baorong Hou

    2005-04-01

    Seabed sediment (SBS) is a special soil that is covered by seawater. With the developments in marine oil exploitation and engineering, more and more steel structures have been buried in SBS. SBS corrosion has now become a serious problem in marine environment and an important issue in corrosion science. In this paper, approach in the field of SBS corrosion is reviewed. Electrochemical and microbial corrosion factors, corrosion mechanism, measurement of metal corrosion rate, corrosion evaluation and prediction of corrosion are also discussed here.

  6. A liquid aluminum corrosion resistance surface on steel substrate

    International Nuclear Information System (INIS)

    The process of hot dipping pure aluminum on a steel substrate followed by oxidation was studied to form a surface layer of aluminum oxide resistant to the corrosion of aluminum melt. The thickness of the pure aluminum layer on the steel substrate is reduced with the increase in temperature and time in initial aluminizing, and the thickness of the aluminum layer does not increase with time at given temperature when identical temperature and complete wetting occur between liquid aluminum and the substrate surface. The thickness of the Fe-Al intermetallic layer on the steel base is increased with increasing bath temperature and time. Based on the experimental data and the mathematics model developed by the study, a maximum exists in the thickness of the Fe-Al intermetallic at certain dipping temperature. X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis reveals that the top portion of the steel substrate is composed of a thin layer of α-Al2O3, followed by a thinner layer of FeAl3, and then a much thicker one of Fe2Al5 on the steel base side. In addition, there is a carbon enrichment zone in diffusion front. The aluminum oxide surface formed on the steel substrate is in perfect condition after corrosion test in liquid aluminum at 750 deg. C for 240 h, showing extremely good resistance to aluminum melt corrosion

  7. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    Science.gov (United States)

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  8. POLYETHERSULFONE COATING FOR MITIGATING CORROSION OF STEEL IN GEOTHERMAL ENVIRONMENT.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.

    2005-06-01

    Emphasis was directed toward evaluating the usefulness of a polyethersulfone (PES)-dissolved N-methyl pyrrolidone (NMP) solvent precursor as a low-temperature film-forming anti-corrosion coating for carbon steel in simulated geothermal environments at brine temperatures up to 300 C. A {approx} 75 {micro}m thick PES coating performed well in protecting the steel against corrosion in brine at 200 C. However, at {>=} 250 C, the PES underwent severe hydrothermal oxidation that caused the cleavage of sulfone- and ether-linkages, and the opening of phenyl rings. These, in turn, led to sulfone {yields} benzosulfonic acid and ether {yields} benzophenol-type oxidation derivative transformations, and the formation of carbonyl-attached open rings, thereby resulting in the incorporation of the functional groups, hydroxyl and carbonyl, into the coating. The presence of these functional groups raised concerns about the diminutions in water-shedding and water-repellent properties that are important properties of the anti-corrosion coatings; such changes were reflected in an enhancement of the magnitude of susceptibility of the coatings surfaces to moisture. Consequently, the disintegration of the PES structure by hydrothermal oxidation was detrimental to the maximum efficacy of the coating in protecting the steel against corrosion, allowing the corrosive electrolytes to infiltrate easily through it.

  9. Corrosion behavior of carbon steel undera defected epoxy coating studied by scanning Kelvin probe%扫描Kelvin探针研究破损环氧涂层下碳钢的腐蚀行为

    Institute of Scientific and Technical Information of China (English)

    肖葵; 董超芳; 魏丹; 吴俊升; 徐龙娇; 李晓刚

    2011-01-01

    采用扫描Kelvin探针技术(SKP)对中性盐雾环境条件下破损环氧涂层的碳钢的腐蚀行为进行了研究.不同盐雾试验阶段的伏打电位变化规律的分析结果表明:环氧/碳钢涂层的缺陷为腐蚀介质提供了向碳钢基体传输的通道.破损处碳钢基体的电位比其邻近的膜下碳钢基体更负,成为阳极溶解发生区域.一定时间的盐雾试验后,破损处生成的未溶腐蚀产物可覆盖住裸露基体,使破损处向正的电位变化而成为阴极,而其附近的膜下碳钢基体电位变负而成为新的阳极区.同时,不断形成的新阴极和新阳极的电位差成为膜下腐蚀继续发展的驱动力.随着膜下腐蚀的进行,%Scanning Kelvin probe(SKP) was used for measuring the corrosion behavior of carbon steel with a defected epoxy coating after neutral salt spray test,and the volta potential changes of carbon steel at different stages of neutral salt spray test were analyzed.It is shown that the defect formed by the damaged epoxy/carbon coating provides a way for the corrosive medium to contact the carbon steel matrix.The potential of carbon steel is more negative at the defect point than that under the coating,resulting in anodic dissolution at the defect point.After some time of neutral salt spray test,insoluble corrosion products can cover the bare defect,leading to the potential at this part shifting to more positive values.Consequently,the defect becomes a cathode,while its vicinity under the coating exists as an anode.Meanwhile,the potential difference between the new cathode and the new anode offers a driving force for continuous corrosion under the coating.Therefore,with the corrosion developing,there would be a considerable corrosive medium and corrosion products aggregating at the interface,which destroy the binding between the epoxy coating and carbon steel,leading to the appearances of bubbling and peeling.

  10. Stress-corrosion cracking and/or hydrogen embrittlement susceptibility of low-alloyed and carbon steels for marine applications in sea water with and without sulphide ions

    International Nuclear Information System (INIS)

    The behaviour to corrosion in sea water of some structural steels in different metallurgical conditions has been studied with modified WOL specimens. Particular attention was paid to the effect of the acidity alone and of H2-H2S synergism on the crack growth rate. Other tests were performed aiming to assess the possible correlations between HIC (Hydrogen induced cracking) and HSCC (Hydrogen stress corrosion cracking). The applicability of the K(ISCC) to the said phenomena is also discussed

  11. Microbially Influenced Corrosion of Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Deuk; Ryu, Seung Ki; Kim Young Ho [POSCO Techanical Researh Laboratories, Pohang (Korea, Republic of)

    1996-06-25

    Microbially Influenced Corrosion(MIC) is often a significant factor in controlling the long-term performance of most structural materials in industrial applications. This papers cover MIC mechanism and evaluation of stainless steels in soil and sea water environments. Papers also cover detection, monitoring and mitigation of MIC, biocides and treatments. (author). 28 refs., 2 tabs., 5 figs.

  12. Stress Corrosion Cracking of Pipeline Steels

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper provides a review of the differences between high pH and near-neutral pH stress corrosion cracking ofpipeline steels, influencing factors, and mechanisms. The characteristics and historical information on both forms ofSCC are discussed. The prospect for research in the future is also presented.

  13. Stress corrosion cracking of A471 turbine disk steels: Effects of dissolved oxygen and carbon dioxide in high-purity water: Final report

    International Nuclear Information System (INIS)

    Experiments were performed to determine the effect of dilute impurities in high purity water on the rate of initiation and growth of stress corrosion cracks in NiCrMoV steels. 3.5 NiCrMoV steels of commercial quality, high purity, and high purity with intentionally added tramp elements were investigated. Dissolved oxygen and carbon dioxide were the primary water impurities investigated. The tests were conducted on constant load, smooth bar tensile specimens of the NiCrMoV steels in flowing 1600C high purity water containing various dilute levels of impurities. It was determined that the initiation rate is very sensitive to changes in dissolved oxygen content; the peak initiation rate are achieved between 20 and 80 ppB dissolved oxygen. The initiation rate is less sensitive to dissolved CO2 content. The crack growth rate in high purity water is only weakly dependent on dissolved O2 and CO2. This work shows that the crack growth rate is strongly dependent on the yield strength (and therefore the microstructure that develops as a result of tempering) of the turbine disc alloy, whereas the initiation rate is only weakly dependent on material yield strength. In addition, crack growth rates decrease as grain sizes are decreased. In general, crack growth rates are very slow (less than 10-10 m/s) in these dilute environments in materials with yield strengths below 690 Mpa (100 ksi). The results of these experiments indicate that a hydrogen-assisted process may be an important cracking mechanism in these alloys in these dilute environments. Implication of a hydrogen-assisted mechanism could have important consequences in the design and selection of turbine disc alloys

  14. Stress corrosion cracking of A471 turbine disk steels: Effects of dissolved oxygen and carbon dioxide in high-purity water: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Eiselstein, L.E.; Caligiuri, R.D.

    1987-06-01

    Experiments were performed to determine the effect of dilute impurities in high purity water on the rate of initiation and growth of stress corrosion cracks in NiCrMoV steels. 3.5 NiCrMoV steels of commercial quality, high purity, and high purity with intentionally added tramp elements were investigated. Dissolved oxygen and carbon dioxide were the primary water impurities investigated. The tests were conducted on constant load, smooth bar tensile specimens of the NiCrMoV steels in flowing 160C high purity water containing various dilute levels of impurities. It was determined that the initiation rate is very sensitive to changes in dissolved oxygen content; the peak initiation rate are achieved between 20 and 80 ppB dissolved oxygen. The initiation rate is less sensitive to dissolved CO2 content. The crack growth rate in high purity water is only weakly dependent on dissolved O2 and CO2. This work shows that the crack growth rate is strongly dependent on the yield strength (and therefore the microstructure that develops as a result of tempering) of the turbine disc alloy, whereas the initiation rate is only weakly dependent on material yield strength. In addition, crack growth rates decrease as grain sizes are decreased. In general, crack growth rates are very slow (less than 10 m/s) in these dilute environments in materials with yield strengths below 690 Mpa (100 ksi). The results of these experiments indicate that a hydrogen-assisted process may be an important cracking mechanism in these alloys in these dilute environments. Implication of a hydrogen-assisted mechanism could have important consequences in the design and selection of turbine disc alloys.

  15. ac impedance, X-ray photoelectron spectroscopy and density functional theory studies of 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles as efficient corrosion inhibitors for carbon steel surface in hydrochloric acid solution

    International Nuclear Information System (INIS)

    The corrosion inhibition properties of a new class of oxadiazole derivatives, namely 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles (n-DPOX) for C38 carbon steel corrosion in 1 M HCl medium were analysed by electrochemical impedance spectroscopy (EIS). An adequate structural model of the interface was used and the values of the corresponding parameters were calculated and discussed. The experimental results showed that these compounds are excellent inhibitors for the C38 steel corrosion in acid solution and that the protection efficiency increased with increasing the inhibitors concentration. Electrochemical impedance data demonstrate that the addition of the n-DPOX derivatives in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Adsorption of these inhibitors on the steel surface obeys to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) and the thermodynamic data of adsorption showed that inhibition of steel corrosion in normal hydrochloric solution by n-DPOX is due to the formation of a chemisorbed film on the steel surface. Quantum chemical calculations using the Density Functional Theory (DFT) and the Quantitative Structure Activity Relationship (QSAR) approach were performed on n-DPOX derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that their inhibition effect is closely related to EHOMO, ELUMO, and dipole moment (μ).

  16. ac impedance, X-ray photoelectron spectroscopy and density functional theory studies of 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles as efficient corrosion inhibitors for carbon steel surface in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Outirite, Moha; Lagrenee, Michel; Lebrini, Mounim [Unite de Catalyse et de Chimie du Solide, UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Traisnel, Michel; Jama, Charafeddine [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF UMR-CNRS 8008, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, Herve [Laboratoire de Chimie Organique et Macromoleculaire, UMR-CNRS 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, Fouad, E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2010-02-01

    The corrosion inhibition properties of a new class of oxadiazole derivatives, namely 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles (n-DPOX) for C38 carbon steel corrosion in 1 M HCl medium were analysed by electrochemical impedance spectroscopy (EIS). An adequate structural model of the interface was used and the values of the corresponding parameters were calculated and discussed. The experimental results showed that these compounds are excellent inhibitors for the C38 steel corrosion in acid solution and that the protection efficiency increased with increasing the inhibitors concentration. Electrochemical impedance data demonstrate that the addition of the n-DPOX derivatives in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Adsorption of these inhibitors on the steel surface obeys to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) and the thermodynamic data of adsorption showed that inhibition of steel corrosion in normal hydrochloric solution by n-DPOX is due to the formation of a chemisorbed film on the steel surface. Quantum chemical calculations using the Density Functional Theory (DFT) and the Quantitative Structure Activity Relationship (QSAR) approach were performed on n-DPOX derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that their inhibition effect is closely related to E{sub HOMO}, E{sub LUMO}, and dipole moment (mu).

  17. Corrosion resistance testing of high-boron-content stainless steels

    International Nuclear Information System (INIS)

    Boron steels, i.e. stainless steels with boron contents of 0.2 to 2.25 wt.%, are employed in nuclear engineering for the manufacture of baskets or wells in which radioactive fissile materials are stored, mostly spent nuclear fuel elements. The resistance of such steels to intergranular corrosion and uniform corrosion was examined in the Strauss solution and in boric acid; the dependence of the corrosion rate of the steels on their chemical composition was investigated, and their resistance was compared with that of AISI 304 type steel. Corrosion resistance tests in actual conditions of ''wet'' compact storage (demineralized water or a weak boric acid solution) gave evidence that boron steels undergo nearly no uniform corrosion and, as electrochemical measurements indicated, match standard corrosion-resistant steels. Corrosion resistance was confirmed to decrease slightly with increasing boron content and to increase somewhat with increasing molybdenum content. (Z.S.). 3 tabs., 4 figs., 7 refs

  18. Corrosion Resistibility of Chemical Inhibitors for Carbon Steels in the Closed Cooling Water System of Nuclear Power Plant

    International Nuclear Information System (INIS)

    In the Nuclear Power Plant (NPP), the Closed Cooling Water (CCW) system provides cooling to both safety-related and non-safety-related heat exchange equipment. In general, chemical treatment is used for minimizing corrosion, controlling microbiological growth, and preventing scale in the CCW system. In the NPP, these inhibitors have included chromate, nitrite, molybdate, hydrazine, and polysilicate. In some domestic NPPs in which nitrite inhibitor program was adapted, during overhaul period, saturation of ion exchange resin caused by corrosion inhibitor which has high conductivity is causative for increase in the radiation exposure and the radioactive waste. To prevent corrosion without any disadvantages, we must accurately evaluate influence of inhibitor in the CCW system. The objective of this study is to evaluate the corrosion behavior of CCW materials with various corrosion inhibitors

  19. Effect of the Diesel, Inhibitor, and CO2 Additions on the Corrosion Performance of 1018 Carbon Steel in 3% NaCl Solution

    OpenAIRE

    J. Porcayo-Calderon; M. Casales-Diaz; L. M. Rivera-Grau; Ortega-Toledo, D. M.; Ascencio-Gutierrez, J. A.; L. Martinez-Gomez

    2014-01-01

    In order to determine the diesel contribution in the coadsorption process of the oil-soluble inhibitors, electrochemical impedance spectroscopy measurements have been carried out to study the performance of oil-soluble inhibitors in both presence and absence of diesel and CO2. The results showed that the presence of the oil phase provides some protection to the steel because the water-soluble fractions are capable of being adsorbed on the steel surface thereby reducing the corrosion rate. The...

  20. Corrosion of carbon steel overpacks for the geological disposal of radioactive waste Task 3 Characterization of radioactive waste forms a series of final reports (1985-89) No 29

    International Nuclear Information System (INIS)

    This is the final report of a three-year research programme investigating the long-term corrosion of carbon steel overpacks for the disposal of nuclear waste in granitic and argillaceous environments. The aim of the work has been to develop mechanistic mathematical models of uniform and localized corrosion, and to test their validity by comparison with experimental data. It has been found that both models overestimate the rate of attack by factors of 4-6. It is recommended that additional work should be undertaken to improve the uniform corrosion model by including the retarding influence of accumulated corrosion products. However, in the case of localized corrosion, attention should focus on improving the estimate of the maximum period for localized attack, based on the criterion that such corrosion is only feasible under aerobic conditions. If, as seems likely, this period is only 20-40 years, the extent of penetration may then be estimated with sufficient accuracy form experimental data. However, the localized corrosion model in its present form will still have an important role in investigating the importance of different environmental conditions, with regard to the rate of corrosion penetration. 9 refs.; 17 figs.; 8 tabs

  1. Effect Mo Addition on Corrosion Property and Sulfide Stress Cracking Susceptibility of High Strength Low Alloy Steels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Woo Yong; Koh, Seong Ung; Kim, Kyoo Young [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2005-04-15

    The purpose of this work is to understand the effect of Mo addition on SSC susceptibility of high strength low alloy steels in terms of microstructure and corrosion property. Materials used in this study are high strength low alloy (HSLA) steels with carbon content of 0.04wt% and Mo content varying from 0.1 to 0.3wt%. The corrosion property of steels was evaluated by immersion test in NACE-TM01-77 solution A and by analyzing the growth behavior of surface corrosion products. SSC resistance of steels was evaluated using constant load test. Electrochemical test was performed to investigate initial corrosion rate. Addition of Mo increased corrosion rate of steels by enhancing the porosity of surface corrosion products. however, corrosion rate was not directly related to SSC susceptibility of steels

  2. Corrosion monitoring of different steels by thin layer activation

    International Nuclear Information System (INIS)

    For corrosion monitoring, the behavior of various steels (Sanicro 28, AISI 316 L, SAF 2507) and a carbon steel were investigated by thin layer activation (TLA) in acid solutions containing chloride. A loop system with a sample holder as well as a temperature and a flow control device were used in laboratory tests. Experimental parameters like fluid temperature, H2SO4 concentration and running time were selected as a function of the specific material under investigation. The congruence of Ta results was verified by comparison with mass loss data, obtained by gravimetry

  3. Atmospheric corrosion rate expressed as a function of time. Effects of atmospheric conditions and alloying elements on corrosion resistance of steels and cast irons

    International Nuclear Information System (INIS)

    On the basis of function describing a change in atmospheric corrosion rate (K) in time (t) the published results of long-standing corrosion tests of a great number of cast irons and steels were statistically processed. The effect of chloride - ions, sulfur dioxide, alloying elements (Cu, Ni, Cr, Mn, Si, V, C) on the rate of initial corrosion on the active surface (K0), passivation properties (α0) of corrosion products and corrosion resistance (α0/K0) of iron-carbonic alloys in different climatic areas was revealed. The data permit further investigation of the mechanism of alloying element effect on atmopsheric corrosion of steels

  4. Microbially influenced corrosion of stainless steel by marine bacterium Vibrio natriegens: (I) Corrosion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Sha; Tian Jintao [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Chen Shougang, E-mail: sgchen@ouc.edu.cn [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Lei Yanhua; Chang Xueting; Liu Tao [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Yin Yansheng, E-mail: yys2006@ouc.edu.cn [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2009-04-30

    The microbially influenced corrosion of stainless steel (SS) by marine bacterium Vibrio natriegens (V. natriegens) was investigated using surface analysis (atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA)) and electrochemical techniques (the open circuit potential, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization curves ). AFM images corroborated the results from the EIS models which show biofilm attachment and subsequent detachment over time. The SEM images revealed the occurrence of micro-pitting corrosion underneath the biofilms on the metal surface after the biofilm removal. The presence of carbon, oxygen, phosphor and sulfur obtained from EDXA proved the formation of biofilm. The electrochemical results showed that the corrosion of SS was accelerated in the presence of V. natriegens based on the decrease in the resistance of the charge transfer resistance (R{sub ct}) obtained from EIS and the increase in corrosion current densities obtained from potentiodynamic polarization curves.

  5. Microbially influenced corrosion of stainless steel by marine bacterium Vibrio natriegens: (I) Corrosion behavior

    International Nuclear Information System (INIS)

    The microbially influenced corrosion of stainless steel (SS) by marine bacterium Vibrio natriegens (V. natriegens) was investigated using surface analysis (atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA)) and electrochemical techniques (the open circuit potential, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization curves ). AFM images corroborated the results from the EIS models which show biofilm attachment and subsequent detachment over time. The SEM images revealed the occurrence of micro-pitting corrosion underneath the biofilms on the metal surface after the biofilm removal. The presence of carbon, oxygen, phosphor and sulfur obtained from EDXA proved the formation of biofilm. The electrochemical results showed that the corrosion of SS was accelerated in the presence of V. natriegens based on the decrease in the resistance of the charge transfer resistance (Rct) obtained from EIS and the increase in corrosion current densities obtained from potentiodynamic polarization curves.

  6. Waste of cleaning emulsion sewage as inhibitors of steel corrosion

    Science.gov (United States)

    Fazullin, D. D.; Mavrin, G. V.; Shaikhiev, I. G.

    2016-06-01

    The article describes the corrosion test of steel of the brand 20 in the stratal water. To increase corrosion resistance as a corrosion inhibitor the concentrate waste emulsion of the mark "Incam- 1" was provided. The article presents studies of the corrosion rate with different dosages of corrosion inhibitor in the stratal water. Based on these research results are revealed that the degree of protection of steel is 27% at a dosage of 3.8 g / dm3.

  7. Carbon Dioxide Corrosion:

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup

    2008-01-01

    CO2 corrosion is a general problem in the industry and it is expensive. The focus of this study is an oil gas production related problem. CO2 corrosion is observed in offshore natural gas transportation pipelines. A general overview of the problem is presented in chapter 1. The chemical system co...

  8. Corrosion resistance of modern austenitic-ferritic (duplex) stainless steel. Corrosion of special types. (Review)

    International Nuclear Information System (INIS)

    Recent data on resistance of modern corrosion-resistant austenitic-ferritic steels to different types of corrosion are generalized. It is shown that these steels are characterized by high resistance to general corrosion in acid, alkali, chloride and other solutions, are not inclined to intercrystalline, pitting and crevice corrosion and are noted for high resistance to corrosion cracking and corrosion fatigue. All this is combined with technological and economical effectiveness. It is advisible to use these steels instead of highly-alloyed and expensive steels and alloys in chemical, power and other industries. 59 refs.; 2 tabs

  9. Accelerated low water corrosion of carbon steel in the presence of a biofilm harbouring sulphate-reducing and sulphur-oxidising bacteria recovered from a marine sediment

    International Nuclear Information System (INIS)

    Investigations were undertaken to elucidate causes of accelerated low water corrosion (ALWC) of steel piling in a harbour in Southern England. Visual inspection revealed features characteristic of ALWC such as the presence of poorly adherent, thick corrosion products of varying morphology, often seen as large blisters randomly located on sections of the structure at the low water mark. Upon the removal of blisters, a bright surface covered with shallow pits was exposed. Representative samples of the corrosion products were collected from the structure and water and sediment specimens were retrieved from selected areas in the harbour for microbiological, chemical and microscopy testing. In the laboratory, field samples were enriched to detect and enumerate communities of sulphur-oxidising bacteria (SOB) and sulphate-reducing bacteria (SRB). Biofilms, comprising SRB and SOB populations isolated from a sediment sample were grown under static conditions on surfaces of electrodes manufactured from steel piling material. Linear polarisation resistance (LPR) measurements revealed that the corrosion rate of steel with biofilms (0.518 mm y-1) was higher than that recorded in sterile seawater alone (0.054 mm y-1) and in sterile seawater to which nutrient was added (0.218 mm y-1). Scanning electron microscopy (SEM) imaging demonstrated enhanced pitting under biofilms. The results of our investigation revealed for the first time that the attack on steel piling in the presence of sediment SRB and SOB populations was characteristic of ALWC

  10. Tests Of Materials For Repair Coating Of Carbon Steel

    Science.gov (United States)

    Macdowell, Louis G., III

    1995-01-01

    Report describes tests of paints (primers and topcoats) for use in recoating rusted carbon steel for protection against further corrosion. Paints selected for evaluation all designated by manufacturers as suitable for application over tightly adhering rust.

  11. Corrosion of two kinds of cast steels containing chromium in hot concentrated alkaline

    Directory of Open Access Journals (Sweden)

    LI Wei

    2007-02-01

    Full Text Available A typical hot concentrated alkaline corrosion environment exists in alumina metallurgical industry, so that steel materials with outstanding alkaline corrosion resistance are strongly demanded for its processing equipment. In this paper, the corrosion resistance of two kinds of martensitic cast steels containing chromium in static 303g/L NaOH alkaline solution at 85℃ was studied through polarization and potential-time curves, corrosion weight loss and corrosion morphology analysis. Experimental results showed that protection effect by passive film of cast steel containing Cr was temporary. The low carbon steel without Cr content also exhibited chemical passivity in the same solution. The corrosion mode of the tested Cr-containing cast steel was composed of active dissolving corrosion and caustic embrittlement cracking. Dissolving corrosion was the primary mechanism for the induced weight loss, while severe caustic embrittlement cracking was secondary. With the increase of chromium content in the cast steel, the tendency of the caustic embrittlement cracking decreased, while the active dissolving corrosion increased.

  12. Corrosion of two kinds of cast steels containing chromium in hot concentrated alkaline

    Institute of Scientific and Technical Information of China (English)

    LI Wei; LIU Jun-quan; TU Xiao-hui

    2007-01-01

    A typical hot concentrated alkaline corrosion environment exists in alumina metallurgical industry, so that steel materials with outstanding alkaline corrosion resistance are strongly demanded for its processing equipment. In this paper, the corrosion resistance of two kinds of martensitic cast steels containing chromium in static 303 g/L NaOH alkaline solution at 85℃ was studied through polarization and potential-time curves, corrosion weight loss and corrosion morphology analysis. Experimental results showed that protection effect by passive film of cast steel containing Cr was temporary. The low carbon steel without Cr content also exhibited chemical passivity in the same solution. The corrosion mode of the tested Cr-containing cast steel was composed of active dissolving corrosion and caustic embrittlement cracking. Dissolving corrosion was the primary mechanism for the induced weight loss, while severe caustic embrittlement cracking was secondary. With the increase of chromium content in the cast steel, the tendency of the caustic embrittlement cracking decreased, while the active dissolving corrosion increased.

  13. Research on atmospheric corrosion of steel using synchrotron radiation

    International Nuclear Information System (INIS)

    Correlation between local structure around Cr in the protective rust layer on weathering steel and protective performance of the rust layer is presented as an example of corrosion research using synchrotron radiation which has recently been applied in various research fields as a useful tool. In addition, in situ observation of initial process of rust formation on steel is also mentioned. It was pointed out by considering the X-ray absorption fine structure spectra that the nanostructure of the protective rust layer on weathering steel primarily comprises of small Cr-goethite crystals containing surface adsorbed and/or intergranular CrOx3-2X complex anions. This CrOx3-2X explains the protective performance of the rust layer originated by dense aggregation of fine crystals with cation selectivity of the Cr-goethite. It is very advantageous to employ white X-rays for in situ observation of rusting process of a carbon steel covered with electrolyte thin films because rust structure might change very quickly. This in situ observation revealed the effect of ion species on the change in rust phase during wet/dry repeating. It can be said that application of synchrotron radiation on corrosion research is so useful to understand the nanostructure of surface oxides which closely relate to corrosion behavior of metals and alloys. (author)

  14. Corrosion products release from steel surface into BWR water coolant

    Energy Technology Data Exchange (ETDEWEB)

    Kritsky, V.G.; Korolev, A.S.; Berezina, I.G.; Sofyin, M.V.

    1986-02-01

    Factors influencing steel corrosion product release and transfer into a BWR primary circuit have been studied and reported on in this paper. The study of corrosion kinetics and corrosion product release was carried out on the samples tested under RBMK NPP condensate-feedwater cycle conditions, as well as, under test rig conditions. The ratio of corrosion product specific mass, transferred to the water, to the whole corrosion product specific mass of steel, formed under the given conditions was determined and used as a criterion, characterizing the extent of corrosion product transfer from the steel surface into the water.

  15. Thermoplastic liners for carbon steel pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Mehdi, Mauyed S.; AlDossary, Abdullah K. [Saudi Aramco, Dhahran (Saudi Arabia)

    2009-12-19

    Materials selection for pipe and fittings used to convey corrosive fluids has often been a challenge. Traditionally, exotic Corrosion Resistant Alloys (CRA) have been used in corrosive environments despite their high cost. Plastic lined carbon steel piping offers a cost effective alternative to the use of CRAs by eliminating corrosion, significantly reducing the use of toxic chemicals and the heavy metal usually present in CRAs. Thermoplastic Liners offer the combination of corrosion resistance and mechanical strength, which are unachievable with singular materials. Under pressure conditions, the liner is fully supported by the metalwork, while under vacuum conditions, the liner must be thick enough along with venting system to withstand the collapsing forces created by the negative pressure. Plastic liners have been used successfully to line and protect metallic pipelines for many years and have become an indispensable requirement of the oil and gas industry particularly with water injection and hydrocarbon services. In the case of internally corroded pipes, the use of thermoplastic liners for rehabilitation is an option to extend the lifetime of companies' assets, reduce maintenance cost and increase intervals between T and Is. For new construction, plastic liners in carbon steel pipes can compete technically and economically with pipelines of CRA materials and other corrosion inhibition systems. This paper describes various design features, installations of thermoplastic liners in comparison to other corrosion inhibition methods. (author)

  16. Electrochemical corrosion of carbon-fiber-reinforced plastic-metal electrode couples in corrosion media

    International Nuclear Information System (INIS)

    Polarization diagrams, obtained for carbon-fiber-reinforced plastic(cathode)-metallic material(anode) contact couples are analyzed to predict the corrosion behaviour of some technical metals and alloys (carbon steel, stainless steels, brass, aluminium, titanium) in contact with carbon-fiber-reinforced plastic in differen agressive media (H2SO4, HCl, H3PO4, NaOH solutions in wide temperature and concentration range, synthetic seawater at 30 and 50 deg C). The predicted behaviour was supported by direct investigation into carbon-fiber-reinforced plastic-titanium and carbon-fiber-reinforced plastic-aluminium contact couples at different square ratios. 6 refs.; 4 figs

  17. Application of in-service temperature lowering to reduce radioactivity corrosion product deposition on carbon steel piping of BWR residual heat removal system

    International Nuclear Information System (INIS)

    Assessment of plant data and experiments on deposition of ion species on carbon steel were carried out in order to develop suitable countermeasures to reduce RHR (residual heat removal) piping dose rate. It was thought that radioactivity deposits on the RHR piping were mainly from radioactive ion species in the coolant and they were enhanced by the dehydration reaction of corrosion products on the piping. From an evaluation for temperature dependence of the dehydration reaction, it was proposed to lower the start-up temperature of RHR operation as a way to reduce radioactivity deposition. Feasibility studies of improved RHR operation were conducted and test operations were carried out in the Shika Nuclear Power Station Unit 1. Application of the improved RHR operation resulted in a temperature reduction from 150degC to 110degC, and a radioactivity deposition reduction on the RHR piping to one-fifth of that in conventional RHR operation. The improved RHR operation has now been applied to more than fifteen Japanese BWRs and significant suppression effects of radioactivity deposition have been observed. (author)

  18. Production, properties and application of steels resistant to atmospheric corrosion

    International Nuclear Information System (INIS)

    Steels, resistant to atmospheric corrosion, applied in the USSR and abroad, are reviewed. The influence of alloying elements (Cu, P, Cr, Si, Ni, Mo, Mn, As etc) upon resistance against atmospheric corrosion and mechanical properties of rolled steel is discussed. Technological properties, fields of the above steels application as well as the data on the range of product, are presented

  19. The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, Carlos A. [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)], E-mail: gorc74@yahoo.com; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)

    2008-12-01

    The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

  20. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil [School of Applied Physic, Faculty Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2014-09-03

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  1. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Science.gov (United States)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil

    2014-09-01

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  2. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    International Nuclear Information System (INIS)

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy

  3. An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

    Institute of Scientific and Technical Information of China (English)

    Tuan; Anh; Nguyen; Recep; AVCI

    2009-01-01

    The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion. The admixing of NaCl and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mortar interfacial region. The admixing of the inhibitors increased the risk of carbonation of cement hydrates at the steel-mortar interfacial region, but partially displaced chloride ions. Chloride and the admixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar interfacial region. The admixing of all three inhibitors was found to increase the polarization resistance of steel, indicating reduced corrosion rate of the steel over 48-day exposures to salt ponding.

  4. Atmospheric corrosion of mild steel in Oman

    Science.gov (United States)

    Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Mossbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  5. Atmospheric corrosion of mild steel in Oman

    International Nuclear Information System (INIS)

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  6. Atmospheric corrosion of mild steel in Oman

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, Abbasher, E-mail: abbasher@squ.edu.om; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K. [College of Science, Department of Physics (Oman)

    2006-01-15

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  7. To the corrosion of austenitic steels in sodium loops

    International Nuclear Information System (INIS)

    This report describes the comparison between experimental corrosion and calculated corrosion effects on austenitic steels exposed to liquid sodium. As basis for the calculations served a diffusion model. The comparison showed that the model is able to predict the corrosion effects. In addition the model was used to calculate the corrosion effect along an actual fuel rod. (orig.)

  8. 77 FR 27438 - Certain Corrosion-Resistant Carbon Steel Flat Products From Korea: Final Results of Expedited...

    Science.gov (United States)

    2012-05-10

    ... Tariff Act of 1930, as amended (``the Act''). See Initiation of Five-Year (``Sunset'') Review, 77 FR 85... Products from Korea, 58 FR 43752 (August 17, 1993). On January 3, 2012, the Department initiated the third..., plated, or coated with corrosion-resistant metals such as zinc, aluminum, or zinc-, aluminum-, nickel-...

  9. 75 FR 13490 - Certain Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Notice of...

    Science.gov (United States)

    2010-03-22

    ...: Notice of Preliminary Results of the Antidumping Duty Administrative Review, 74 FR 46110 (September 8... Time Limit for the Final Results of Antidumping Duty Administrative Review, 74 FR 58945 (November 16... with corrosion-resistant metals such as zinc, aluminum, or zinc-, aluminum-, nickel- or...

  10. Corrosion inhibitors for carbon steel in neutral aqueous media based on the products of sugar cane processing. 3. Combined inhibitors

    International Nuclear Information System (INIS)

    Combined (mixed) inhibitors of metal corrosion in aqueous media are developed on the fasis of mixtures of 5-nitro furancarboxylic acid salts (nitrofuroat) with inorganic passivators (nitrite, phosphate, tetraborate) or with nitrogen-containing derivatives of furfural (furfurine, furfurylamine). Their efficiency is confirmed by electrochemical and weighing investigations carried outn under lamoratory and industrial conditions

  11. Effect of nickel and MnS inclusions in the metal on the pitting corrosion of low-carbon stainless steels

    International Nuclear Information System (INIS)

    The resistance to pitting corrosion of steels on the 03Kh17-03Kh18 base containing up to 20 % Ni at different levels of S and Mn impurities contamination is investigated. It is shown that up to 50 % of nickel introduced into ordinary steels with 5-6 % Ni is spent to compensate the resistance decrease caused by MnS inclusions. Full compensation is not attained even in the 10-20 %. Ni range in which nickel practically does not affect the resistance of neither ordinary, nor pure (without MnS) steels. Titanium introduction into ordinary steel on the Kh22N6 base permits to surpass the level of 03Kh17N3 pure steel resistance and attain the level of 03Kh17N6 pure steel almost by all characteristics (including passivated characteristics in sulfuric acid) besides pitting repassivity. In this property pure steels with Ni >or approx. 3 % surpass even the molybdenum containing 03Kh21NbM2T ordinary steel though they by far concede by passivation in sulfuric acid

  12. Sulphur, manganese and titanium effects on high-temperature ductility and corrosion resistance of stainless steels

    International Nuclear Information System (INIS)

    Hot ductility has been studied for stabilized 06Kh18N10T steel and nonstabilized low carbon 03Kh18N11 steel which have been melted with the use of gas-oxygen refining as well as for arc melted steel type 03Kh18N11. It has been shown that from one hand, manganese content increase has a beneficial effect on hot ductility. From the other hand, such steel experiences elevated tendency to pitting corrosion. Titanium addition may assure a combination of satisfactory hot ductility with good resistance to pitting corrosion

  13. Influence of cracks on rebar corrosion in carbonated concretes

    International Nuclear Information System (INIS)

    This paper presents an experimental program allowing the determination of the effect of pre-cracks and their orientations on both initiation and propagation of reinforcement steel corrosion due to carbonation in different environmental conditions, in order to propose an operational model allowing the evaluation of the kinetic of corrosion of the reinforcement steel in cooling towers of nuclear power plants. The cracking mode that generates cracks which are representative of those appearing on the cooling towers is a three-point bending test performed on prismatic samples of 7*7*28 cm3 size with 6 mm steel bars. The length of damaged steel / concrete interface, which appears following a three-point bending test, is then quantified. This length could be determining in the initiation and the propagation of corrosion. Results show that this length is dependent on the residual crack opening and that the length of damaged interface in its lower part is larger than that on the upper part due to the Top Bar effect. After cracking, the samples will be exposed to carbon dioxide to ensure carbonation of the steel bar localized at the bottom of the crack and the concrete/steel interface, damaged by the load applied during the three-point bending test. After carbonation of the interface, samples will be submitted to corrosion in different environmental conditions whose effect on the kinetics of corrosion will be determined. The work done so far permits the definition of the cracking protocol (three points bending) that allows obtaining cracks which are representative of those existing on cooling towers. Moreover, the length of steel/concrete damaged interface with respect to crack opening is quantified. It was found that this length is proportional to the crack opening. In addition, it was shown that the Top Bar effect increases the damaged interface length at the lower part of steel bars

  14. Protective film formation of carbon steel surfaces for corrosion and deposit control in Heavy Water Plant, Manuguru (Paper No. 1.1)

    International Nuclear Information System (INIS)

    Heavy Water Plant, Manuguru based on H2S-H2O bi-thermal chemical exchange process employs carbon steel as major material of construction for towers and piping. Several different phases of iron sulphide form as a result of interaction between aqueous H2S and carbon steel. Development of a procedure for formation of stable film on carbon steel as a preconditioning step was carried out based on work done by Heavy Water Division and the experiences of HWP, Kota. Heavy Water Plant, Manuguru was designed for carrying protective film formation of entire exchange unit including vessels, tanks, pipings etc. under dynamic conditions. This paper describes the procedure followed for the protective film formation of carbon steel surfaces at HWP, Manuguru. (author). 2 refs., 3 tabs., 2 figs

  15. 76 FR 20954 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-04-14

    ... Affirmative Countervailing Duty Determinations: Certain Steel Products from Korea, 58 FR 43752 (August 17... Suspended Investigation; Opportunity to Request Administrative Review, 75 FR 45094 (August 2, 2010). In..., 75 FR 60076 (September 29, 2010). The preliminary results for this review are currently due no...

  16. 77 FR 16810 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2012-03-22

    ... Amendments of Final Affirmative Countervailing Duty Determinations: Certain Steel Products from Korea, 58 FR... Investigation; Opportunity to Request Administrative Review, 76 FR 45773 (August 1, 2011). \\3\\ See Initiation of Antidumping and Countervailing Duty Administrative Reviews and Requests for Revocations in Part, 76 FR...

  17. 76 FR 3613 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2011-01-20

    ... Results and Partial Rescission of Countervailing Duty Administrative Review, 75 FR 55745 (September 14... Countervailing Duty Determinations: Certain Steel Products from Korea, 58 FR 43752 (August 17, 1993). On... Results, 75 FR 55745. In accordance with 19 CFR 351.213(b), this administrative review covers HYSCO,...

  18. 75 FR 18153 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2010-04-09

    ... Affirmative Countervailing Duty Determinations: Certain Steel Products from Korea, 58 FR 43752 (August 17... Suspended Investigation; Opportunity to Request Administrative Review, 74 FR 38397 (August 3, 2009). In... Duty Administrative Reviews and Request for Revocation in Part, 74 FR 48224 (September 22, 2009)....

  19. 76 FR 54209 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2011-08-31

    ..., interest-free contingent liability loan. See Final Results of CORE from Korea 2008, 76 FR 3613 and CORE... Determinations: Certain Steel Products from Korea, 58 FR 43752 (August 17, 1993). On August 2, 2010, the... Administrative Review, 75 FR 45094 (August 2, 2010). On August 31, 2010, we received timely requests for...

  20. 75 FR 55745 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results...

    Science.gov (United States)

    2010-09-14

    ... scarce domestic resources. See Preliminary Results of CORE from Korea 2006, 73 FR 52315; 52326 (September... of CORE from Korea 2007) 74 FR 55192 (October 27, 2008). Pursuant to Article 11 of this Act, the MKE... Countervailing Duty Determinations: Certain Steel Products from Korea, 58 FR 43752 (August 17, 1993). On August...