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Sample records for steel corrosion products

  1. Regularities of transition of steel corrosion products into aqueous medium

    International Nuclear Information System (INIS)

    Nikitin, V.I.; Gvozd', A.M.; Karpova, T.Ya.

    1981-01-01

    Effect of different factors on a degree of steel corrosion product transition to a water medium has been studied. Ratio of a specific masm qsub(c) of the corrosion products transferring to the water and a specific masm q of all the steel corrosion products produced under the given conditions was used as a criterium characterizing a degree of corrosion product transition from steel surfaces to water. The transition degree to water at a high temperature of different kind steel corrosion products differs relatively few (qsub(c)/q=0.5-0.7) in the water containing oxygen and different salts on increasing temperature, the corrosion process is characterized with continuous decrease of a relative amount of the corrosion products transferring to the medium. On the contrary, in the deaerated water the transition degree of perlite steel corrosion products to water remains constant in a wide temperature range (100-320 deg C). Besides chromium, nickel being a part of austenitic steel composition affects positively decrease of the transition degree of the corrosion products to water as well as q and qsub(c) reduction. The most difference in corrosion characteristics and the transition degree to water is observed when affecting colant steels in the low-temperature zone of the steam generator [ru

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

    International Nuclear Information System (INIS)

    Osada, Kazuo; Nagano, Tetsushi; Nakayama, Shinichi; Muraoka, Susumu

    1992-02-01

    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-Fe 2 O 3 was identified by means of colorimetry. (author)

  3. Spatial distribution of crystalline corrosion products formed during corrosion of stainless steel in concrete

    KAUST Repository

    Serdar, Marijana

    2015-05-01

    © 2015 Elsevier Ltd All rights reserved. The mineralogy and spatial distribution of nano-crystalline corrosion products that form in the steel/concrete interface were characterized using synchrotron X-ray micro-diffraction (μ-XRD). Two types of low-nickel high-chromium reinforcing steels embedded into mortar and exposed to NaCl solution were investigated. Corrosion in the samples was confirmed by electrochemical impedance spectroscopy (EIS). μ-XRD revealed that goethite (α-FeOOH) and akaganeite (β-FeOOH) are the main iron oxide-hydroxides formed during the chloride-induced corrosion of stainless steel in concrete. Goethite is formed closer to the surface of the steel due to the presence of chromium in the steel, while akaganeite is formed further away from the surface due to the presence of chloride ions. Detailed microstructural analysis is shown and discussed on one sample of each type of steel.

  4. Spatial distribution of crystalline corrosion products formed during corrosion of stainless steel in concrete

    KAUST Repository

    Serdar, Marijana; Meral, Cagla; Kunz, Martin; Bjegovic, Dubravka; Wenk, Hans-Rudolf; Monteiro, Paulo J.M.

    2015-01-01

    © 2015 Elsevier Ltd All rights reserved. The mineralogy and spatial distribution of nano-crystalline corrosion products that form in the steel/concrete interface were characterized using synchrotron X-ray micro-diffraction (μ-XRD). Two types of low-nickel high-chromium reinforcing steels embedded into mortar and exposed to NaCl solution were investigated. Corrosion in the samples was confirmed by electrochemical impedance spectroscopy (EIS). μ-XRD revealed that goethite (α-FeOOH) and akaganeite (β-FeOOH) are the main iron oxide-hydroxides formed during the chloride-induced corrosion of stainless steel in concrete. Goethite is formed closer to the surface of the steel due to the presence of chromium in the steel, while akaganeite is formed further away from the surface due to the presence of chloride ions. Detailed microstructural analysis is shown and discussed on one sample of each type of steel.

  5. 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...

  6. Rhenium Uptake as Analogue 96Tc by Steel Corrosion Products

    International Nuclear Information System (INIS)

    K.M. Krupka; C.F. Brown; H. Todd Schaef; S. M. Heald; M. M. Valenta; B. W. Arey

    2006-01-01

    Static batch experiments were used to examine the sorption of dissolved perrhenate [Re(VII)], as a surrogate for pertechnetate [Tc(VII)], on corrosion products of A-516 carbon steel coupons contacted with synthetic groundwater or dilute water. After 109 days of contact time, the concentration of dissolved Re(VII) in the synthetic groundwater matrix decreased by approximately 26%; the dilute water matrix experienced a 99% decrease in dissolved Re(VII) over the same time period. Bulk x-ray diffraction (XRD) results for the corroded steel coupons showed that the corrosion products consisted primarily of maghemite, lepidocrocite, and goethite. Analyses of the coupons by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) indicated that Re was present with the morphologically complex assemblages of Fe oxide/hydroxide corrosion products for samples spiked with the highest dissolved Re(VII) concentration (1.0 mmol/L) used for these experiments. Analyses of corroded steel coupons contacted with solutions containing 1.0 mmol/L Re(VII) by synchrotron-based methods confirmed the presence of Re sorbed with the corrosion product on the steel coupons. Analyses showed that the Re sorbed on these corroded coupons was in the +7 oxidation state, suggesting that the Re(VII) uptake mechanism did not involve reduction of Re to a lower oxidation state, such as +4. The results of our studies using Re(VII) as an analogue for 99 Tc(VII) suggest that 99 Tc(VII) would also be sorbed with steel corrosion products and that the inventory of 99 Tc(VII) released from breached waste packages would be lower than what is now conservatively estimated

  7. Spatial distribution of crystalline corrosion products formed during corrosion of stainless steel in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Serdar, Marijana [Department of Materials, Faculty of Civil Engineering, University of Zagreb, 10000 Zagreb (Croatia); Meral, Cagla [Middle East Technical University, Department of Civil Engineering, Ankara (Turkey); Kunz, Martin [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Bjegovic, Dubravka [Department of Materials, Faculty of Civil Engineering, University of Zagreb, 10000 Zagreb (Croatia); Wenk, Hans-Rudolf [Department of Earth and Planetary Science, University of California, Berkeley, CA 94720 (United States); Monteiro, Paulo J.M., E-mail: monteiro@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)

    2015-05-15

    The mineralogy and spatial distribution of nano-crystalline corrosion products that form in the steel/concrete interface were characterized using synchrotron X-ray micro-diffraction (μ-XRD). Two types of low-nickel high-chromium reinforcing steels embedded into mortar and exposed to NaCl solution were investigated. Corrosion in the samples was confirmed by electrochemical impedance spectroscopy (EIS). μ-XRD revealed that goethite (α-FeOOH) and akaganeite (β-FeOOH) are the main iron oxide–hydroxides formed during the chloride-induced corrosion of stainless steel in concrete. Goethite is formed closer to the surface of the steel due to the presence of chromium in the steel, while akaganeite is formed further away from the surface due to the presence of chloride ions. Detailed microstructural analysis is shown and discussed on one sample of each type of steel. - Highlights: • Synchrotron micro-diffraction used to map the distribution of crystalline phases. • Goethite and akaganeite are the main corrosion products during chloride induced corrosion in mortar. • Layers of goethite and akaganeite are negatively correlated. • EDS showed Cr present in corrosion products identified by SEM.

  8. Spatial distribution of crystalline corrosion products formed during corrosion of stainless steel in concrete

    International Nuclear Information System (INIS)

    Serdar, Marijana; Meral, Cagla; Kunz, Martin; Bjegovic, Dubravka; Wenk, Hans-Rudolf; Monteiro, Paulo J.M.

    2015-01-01

    The mineralogy and spatial distribution of nano-crystalline corrosion products that form in the steel/concrete interface were characterized using synchrotron X-ray micro-diffraction (μ-XRD). Two types of low-nickel high-chromium reinforcing steels embedded into mortar and exposed to NaCl solution were investigated. Corrosion in the samples was confirmed by electrochemical impedance spectroscopy (EIS). μ-XRD revealed that goethite (α-FeOOH) and akaganeite (β-FeOOH) are the main iron oxide–hydroxides formed during the chloride-induced corrosion of stainless steel in concrete. Goethite is formed closer to the surface of the steel due to the presence of chromium in the steel, while akaganeite is formed further away from the surface due to the presence of chloride ions. Detailed microstructural analysis is shown and discussed on one sample of each type of steel. - Highlights: • Synchrotron micro-diffraction used to map the distribution of crystalline phases. • Goethite and akaganeite are the main corrosion products during chloride induced corrosion in mortar. • Layers of goethite and akaganeite are negatively correlated. • EDS showed Cr present in corrosion products identified by SEM

  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. Corrosion resistant steel

    International Nuclear Information System (INIS)

    Zubchenko, A.S.; Borisov, V.P.; Latyshev, V.B.

    1980-01-01

    Corrosion resistant steel for production of sheets and tubes containing C, Mn, Cr, Si, Fe is suggested. It is alloyed with vanadium and cerium for improving tensile properties and ductility. The steel can be melted by a conventional method in electric-arc or induction furnaces. The mentioned steel is intended to be used as a substitute for nickel-bearing austenitic steels

  11. Characterisation of corrosion products on pipeline steel under cathodic protection

    Energy Technology Data Exchange (ETDEWEB)

    Lanarde, Lise [Gaz de France Research and Development Division, 361 avenue du President Wilson, BP33, 93211 Saint Denis La Plaine (France)]|[UPR15 du CNRS, Laboratoire des Interfaces et Systemes Electrochimiques, Universite Pierre et Marie Curie, C.P. 133, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Campaignolle, Xavier; Karcher, Sebastien; Meyer, Michel [Gaz de France Research and Development Division, 361 avenue du President Wilson, BP33, 93211 Saint Denis La Plaine (France); Joiret, Suzanne [UPR15 du CNRS, Laboratoire des Interfaces et Systemes Electrochimiques, Universite Pierre et Marie Curie, C.P. 133, 4 Place Jussieu 75252 Paris Cedex 05 (France)

    2004-07-01

    Onshore gas transmission lines are conjointly protected against external corrosion by cathodic protection (CP) and organic coatings. If both protection systems are simultaneously faulty, the pipe may be subjected to local loss of protection criteria. Consequently, the development of a corrosion due to the ground intrinsic corrosiveness may occur. To guarantee an optimal and safe use of its 31000 km buried gas transmission network, Gaz de France regularly inspects its pipelines. When indications of metal damage are suspected, excavations are realized to carry out a finer diagnosis and, if necessary, to repair. Whenever, corrosions are encountered, although it occurs very scarcely, it is necessary to evaluate its degree of gravity: activity, mechanism, and kinetics. Among corrosion defects, it is indeed essential to differentiate those active, from those older inactive at the time of excavation, since those last ones may possibly have been annihilated, by a PC reinforcement for instance. Eventually, the identification of the corrosion mechanism and its associated rate will provide an assessment of the risks encountered by other sections of the pipeline similar to that excavated. This study investigates to what extent the degree of gravity (activity, kinetics) of a corrosion can be determined by the characterization and identification of its associated corrosion products. Moreover, it will attempt to relate it to the close environment features as well as to the operating conditions of the pipe. The preliminary results presented in this paper consist in a laboratory study of the time evolution of corrosion products formed on the surface of ordinary low carbon steel samples. The specimens have been previously subjected to various polarization conditions in various aqueous media. The selected solutions are characteristic of ground waters. The main parameters considered for the definition of the media were its initial chemical composition, pH and dissolved gas composition

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

    International Nuclear Information System (INIS)

    Osada, K.; Nagano, T.; Kozai, N.; Nakashima, S.; Nakayama, S.; Muraoka, S.

    1991-01-01

    The following conclusions were obtained; (1) At 40degC, the average corrosion rate of SS41 carbon steel in wet bentonite was 0.025 mm/y. This is smaller than the value of 0.042 mm/y obtained in pure water at 40degC. However, at 95degC, the corrosion rate of SS41 carbon steel in wet bentonite was 0.27 mm/y, which is much larger than that in pure water at 95degC. (2) At 95degC, γ-FeO(OH) (lepidocrocite) was formed only in wet bentonite, and it was absent in pure water. Evaporation of moisture resulted in the formation of partial covering of bentonite, which promoted local corrosion. Consequently, γ-FeO(OH) was considered to be formed. (3) In wet bentonite at 95degC, α-Fe 2 O 3 (hematite) can be identified by means of colorimetry. The color of corrosion products is orangish, indicating the contribution of α-Fe 2 O 3 in iron hydroxides. (author)

  13. 78 FR 16832 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Revocation...

    Science.gov (United States)

    2013-03-19

    ...] Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Revocation of... ``ITC'') that revocation of the antidumping duty (``AD'') orders on corrosion-resistant carbon steel... (``Sunset'') Review, 77 FR 85 (January 3, 2012). \\2\\ See Corrosion-Resistant Carbon Steel Flat Products From...

  14. X-ray diffraction study of slags forming during corrosion resistant steel production

    International Nuclear Information System (INIS)

    Slavov, V.I.; Zadorozhnaya, V.N.; Shurygina, A.V.

    1990-01-01

    Using X-ray diffraction analysis slags, forming during corrosion-resistant 12Kh18N10T grade steel production by two flowsheets, are studied. Standard two-slag technology of steel production does not provide efficient disintegration of chromospinelides in slags, gives high steel contamination with respect to nonmetallic impurities, coarse structure and, as a consequence, presence of macrodefects on rolled products surface. One-slag steel melting technology with titanium alloying of the steel at vacuum causes fast removal of chromospinelides at the beginning of reduction period, promotes titanium absorption by the steel, refines nonmetallic inclusions, provides more fine structure and steel plasticity, removes surface defects

  15. An X-ray diffraction study of corrosion products from low carbon steel

    International Nuclear Information System (INIS)

    Morales, A. L.

    2003-01-01

    It was found in earlier work a decrease in the corrosion rate from low carbon steel when it was subjected to the action of a combined pollutant concentration (SO 4 ''2-=10''-4 M+Cl=1.5x 10''-3 M). It was also found that large magnetic content of the rust was related to higher corrosion rates. In the present study corrosion products are further analyzed by means of X-ray diffraction to account for composition changes during the corrosion process. it is found that lepidocrocite and goethite are the dominant components for the short-term corrosion in all batches considered while for log-term corrosion lepidocrite and goethite dominates if the corrosion rates is low and magnetite dominates if the corrosion rate is high. The mechanism for decreasing the corrosion rate is related to the inhibition of magnetite production at this particular concentration. (Author) 15 refs

  16. Solubility of corrosion products of plain steel in oxygen-containing water solutions at high parameters

    International Nuclear Information System (INIS)

    Martynova, O.I.; Samojlov, Yu.F.; Petrova, T.I.; Kharitonova, N.L.

    1983-01-01

    Technique for calculation of solubility of iron corrosion products in oxygen-containing aqueous solutions in the 298-573 K temperature range is presented. Solubility of corrosion products of plain steel in deeply-desalinizated water in the presence of oxygen for the such range of the temperatures is experimentally determined. Rather good convergence between calculated and experimental data is noted

  17. 75 FR 55745 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results...

    Science.gov (United States)

    2010-09-14

    ... Products covered by this order are certain corrosion-resistant carbon steel flat products from Korea. These... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... review of the countervailing duty (CVD) order on corrosion-resistant carbon steel flat products (CORE...

  18. Morphology of the ash corrosion products on the P92 steel

    International Nuclear Information System (INIS)

    Hernas, A.; Imosa, M.

    2004-01-01

    The P92 steel, owing to its high mechanical strength at an elevated temperature, is one of the new steel types intended for the components of modern boilers in the power engineering industry. Currently, attempts are being undertaken to use the P92 steel for the components of boiler units in municipal waste incineration plants. Therefore, it is important that an analysis be made of the P92 steel resistance to the high-temperature chlorine - sulfur corrosion impact, the latter being the main factor which limits durability of boilers in waste incineration plants. The present article presents the investigation of P92 steel corrosion resistance under the conditions of high-temperature chlorine- sulfur corrosion in an atmosphere of flue gas with ashes. The analyses were conducted by means of laboratory tests in an atmosphere containing sulfur and chlorine compounds. The morphology of corrosion products was determined by scanning microscopy and X-ray analysis methods. (author)

  19. 77 FR 31877 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five...

    Science.gov (United States)

    2012-05-30

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-350 and 731-TA-616 and 618 (Third Review)] Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five-Year Reviews... corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion...

  20. 78 FR 19210 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2013-03-29

    .... Scope of the Order Products covered by this order are certain corrosion-resistant carbon steel flat... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... countervailing duty (CVD) order on corrosion-resistant carbon steel flat products from the Republic of Korea for...

  1. 78 FR 55241 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-10

    ... merchandise covered by this Order \\2\\ is certain corrosion- resistant carbon steel flat products from Korea... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... the countervailing duty (CVD) order on corrosion-resistant carbon steel flat products (CORE) from the...

  2. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

    2011-11-15

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

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

    International Nuclear Information System (INIS)

    Stoulil, J.; Kaňok, J.; Kouřil, M.; Parschová, H.; Novák, P.

    2013-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Stoulil, J., E-mail: jan.stoulil@vscht.cz [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague (Czech Republic); Kaňok, J.; Kouřil, M. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague (Czech Republic); Parschová, H. [Department of Power Engineering, Institute of Chemical Technology, Prague (Czech Republic); Novák, P. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague (Czech Republic)

    2013-11-15

    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.

  5. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    International Nuclear Information System (INIS)

    Young, J.S.

    1986-07-01

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing 60 Co and 63 Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated

  6. Evaluation of corrosion products formed by sulfidation as inhibitors of the naphthenic corrosion of AISI-316 steel

    Science.gov (United States)

    Sanabria-Cala, J. A.; Montañez, N. D.; Laverde Cataño, D.; Y Peña Ballesteros, D.; Mejía, C. A.

    2017-12-01

    Naphthenic acids present in oil from most regions worldwide currently stand as the main responsible for the naphthenic corrosion problems, affecting the oil-refining industry. The phenomenon of sulfidation, accompanying corrosion processes brought about by naphthenic acids in high-temperature refining plant applications, takes place when the combination of sulfidic acid (H2S) with Fe forms layers of iron sulphide (FeS) on the material surface, layers with the potential to protect the material from attack by other corrosive species like naphthenic acids. This work assessed corrosion products formed by sulfidation as inhibitors of naphthenic corrosion rate in AISI-316 steel exposed to processing conditions of simulated crude oil in a dynamic autoclave. Calculation of the sulfidation and naphthenic corrosion rates were determined by gravimetry. The surfaces of the AISI-316 gravimetric coupons exposed to acid systems; were characterized morphologically by X-Ray Diffraction (XRD) and X-ray Fluorescence by Energy Dispersive Spectroscopy (EDS) combined with Scanning Electron Microscopy (SEM). One of the results obtained was the determination of an inhibiting effect of corrosion products at 250 and 300°C, where lower corrosion rate levels were detected. For the temperature of 350°C, naphthenic corrosion rates increased due to deposition of naphthenic acids on the areas where corrosion products formed by sulfidation have lower homogeneity and stability on the surface, thus accelerating the destruction of AISI-316 steel. The above provides an initial contribution to oil industry in search of new alternatives to corrosion control by the attack of naphthenic acids, from the formation of FeS layers on exposed materials in the processing of heavy crude oils with high sulphur content.

  7. 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 immersed at various depths (0-100 m) from three stations of the Arabian Sea was investigated. The corrosion of mild steel decreased with increasing immersion depth. Significant positive relationships were observed between...

  8. Evaluation of hydrogen production from CO2 corrosion of steel drums in SFR, Part 2

    International Nuclear Information System (INIS)

    Dugstad, A.; Videm, K.

    1987-06-01

    An experimental program has been carried out for the investigation of the hydrogen formation due to corrosion of steel by water containing CO 2 produced by microbiologic decomposition of paper in waste drums. The hydrogen production will be limited by a limited rate of CO 2 production, as CO 2 is consumed by corrosive reactions producing carbonate containing corrosion products. Experiments indicated that also iron oxide and hydroxides were formed together with FeCO 3 at low CO 2 partial pressures but at a rate which leads to a rather slow increase in hydrogen production. Hydrogen evaluation has been overestimated in previous reports on this subject. (authors)

  9. Spectral Analysis of CO2 Corrosion Product Scales on 13Cr Tubing Steel

    International Nuclear Information System (INIS)

    Guan-fa, Lin; Zhen-quan, Bai; Yao-rong, Feng; Xun-yuan, Xu

    2008-01-01

    CO 2 corrosion product scales formed on 13 Cr tubing steel in autoclave and in the simulated corrosion environment of oil field are investigated in the paper. The surface and cross-section profiles of the scales were observed by scanning electron microscopy (SEM), the chemical compositions of the scales were analyzed using energy dispersion analyzer of X-ray (EDAX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to confirm the corrosion mechanism of the 13 Cr steel in the simulated CO 2 corrosion environment. The results show that the corrosion scales are formed by the way of fashion corrosion, consist mainly of four elements, i.e. Fe, Cr, C and O, and with a double-layer structure, in which the surface layer is constituted of bulky and incompact crystals of FeCO 3 , and the inner layer is composed of compact fine FeCO 3 crystals and amorphous Cr(OH) 3 . Because of the characteristics of compactness and ionic permeating selectivity of the inner layer of the corrosion product scales, 13 Cr steel is more resistant in CO 2 corrosion environment

  10. 75 FR 18153 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2010-04-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time Limit for Preliminary Results of... countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea. See Countervailing...

  11. 77 FR 16810 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2012-03-22

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for Preliminary Results of... Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea...

  12. 76 FR 20954 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-04-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for Preliminary Results of... Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea...

  13. 77 FR 25405 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2012-04-30

    ... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for the Preliminary Results of...

  14. 76 FR 21332 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-04-15

    ... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limits for the Preliminary Results of...

  15. 75 FR 25841 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2010-05-10

    ... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limits for the Preliminary Results of...

  16. 77 FR 27438 - Certain Corrosion-Resistant Carbon Steel Flat Products From Korea: Final Results of Expedited...

    Science.gov (United States)

    2012-05-10

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Certain Corrosion-Resistant... order on certain corrosion-resistant carbon steel flat products (``CORE'') from the Republic of Korea.... Scope of the Order The merchandise covered by the order includes flat-rolled carbon steel products, of...

  17. Coupled modelling of convergence, steel corrosion, gas production and brine flow in a rock salt repository

    International Nuclear Information System (INIS)

    Becker, D.A.; Hirsekorn, R.P.

    2013-01-01

    This poster presents the global simulation of the behaviour of thick-walled steel containers piled up in a borehole in a rock salt repository. The simulation takes into account: the convergence by the creeping of rock salt, the backfill and waste compaction, the porosity dependent flow resistance, the anaerobic corrosion (iron to magnetite transformation, gas production, brine consumption, water consumption and salt precipitation) and pressure development. Mechanical influence of corrosion has not yet been taken into account in the integrated code LOPOS

  18. PRODUCTION OF POROUS POWDER MATERIALS OF SPHERICAL POWDERS OF CORROSION-RESISTANT STEEL

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevskij

    2012-01-01

    Full Text Available Production of porous powder materials from spherical powders of corrosion-resistant steel 12Х18н10Т with formation at low pressures 120–140 mpa in the mold with the subsequent activated sintering became possible due to increase of duration of process of spattering and formation of condensate particles (Si–C or (Mo–Si on surface.

  19. Understanding corrosion via corrosion product characterization: II. Role of alloying elements in improving the corrosion resistance of Zn-Al-Mg coatings on steel

    International Nuclear Information System (INIS)

    Volovitch, P.; Vu, T.N.; Allely, C.; Abdel Aal, A.; Ogle, K.

    2011-01-01

    Highlights: → Origins of better corrosion resistance of ZnAlMg coatings than galvanized steel. → Comparative study of corrosion products formed on ZnAlMg, ZnMg and Zn coatings. → Modeling of dissolution and precipitation stages of corrosion. → At early stages Mg stabilizes protective zinc basic salts during dry-wet cycling. → At later stages Al dissolves at high pH forming protective layered double hydroxides. - Abstract: Corrosion products are identified on Zn, ZnMg and ZnAlMg coatings in cyclic corrosion tests with NaCl or Na 2 SO 4 containing atmospheres. For Mg-containing alloys the improved corrosion resistance is achieved by stabilization of protective simonkolleite and zinc hydroxysulfate. At later stages, the formation of layered double hydroxides (LDH) is observed for ZnAlMg. According to thermodynamic modeling, Mg 2+ ions bind the excess of carbonate or sulfate anions preventing the formation of soluble or less-protective products. A preferential dissolution of Zn and Mg at initial stages of corrosion is confirmed by in situ dissolution measurement. The physicochemical properties of different corrosion products are compared.

  20. Investigations of the diverse corrosion products on steel in a hydrogen sulfide environment

    International Nuclear Information System (INIS)

    Bai, Pengpeng; Zheng, Shuqi; Zhao, Hui; Ding, Yu; Wu, Jian; Chen, Changfeng

    2014-01-01

    Highlights: • Diverse corrosion products on steel are investigated in H 2 S environment. • The sequence of the main corrosion products is mackinawite + cubic FeS → troilite. • The large single beam-shaped troilite has a growth pattern along the c axis. • The flower-like troilite develops from beam- or hexagonal wire-shaped grains. • The corresponding crystal structure and morphology of the products are provided. - Abstract: The corrosion products of carbon steel in aqueous H 2 S environment are investigated. The products, which include mackinawite, cubic FeS, troilite, and pyrite, are characterized through their shapes, chemical compositions and crystal structures. Mackinawite appears with a flake shape. Cubic FeS has a perfect/truncated octahedral shape, and pyrite is framboid-shaped. Flower-shaped troilite is developed from beam- or hexagonal wire-shaped grains by electrostatic interactions along a certain lattice plane. The large single beam-shaped troilite has a growth pattern along the c axis. The corresponding crystal structure and micro-morphology of the corrosion products are provided, and the three-dimensional models of them are generated

  1. In situ Raman identification of corrosion products on galvanized steel sheets

    International Nuclear Information System (INIS)

    Bernard, M.C.; Hugot le Goff, A.; Massinon, D.; Phillips, N.; Thierry, D.

    1992-01-01

    In situ Raman spectroscopy was used to identify corrosion products on zinc immersed in chloride solutions. In aerated 0,03 M NaCl solution, zinc carbonate was identified as the main corrosion product. Even with higher chloride concentrations, for which zinc hydroxychloride was also detected, the carbon dioxide concentration is likely to be the rate controlling factor of the corrosion process. In a confinement experiment, Raman analysis revealed that the upper face of the sample was covered with zinc carbonate, whereas hydroxychlorides were identified on the confined face. This result confirmed the hypothesis of a differential aeration mechanism responsible for the formation of zinc hydroxychloride. This is in good agreement with Raman spectroscopy results obtained in the case of painted galvanized steel

  2. 77 FR 25141 - Corrosion-Resistant Carbon Steel Flat Products From Germany and South Korea: Extension of Time...

    Science.gov (United States)

    2012-04-27

    ...-Resistant Carbon Steel Flat Products From Germany and South Korea: Extension of Time Limits for Preliminary...) orders on corrosion-resistant carbon steel flat products (CORE) from Germany and South Korea (Korea... from Germany and South Korea: Adequacy Redetermination Memorandum,'' (April 20, 2012). The preliminary...

  3. The study of the corrosion protection of the low-carbon steel using film-products

    International Nuclear Information System (INIS)

    Aiancului, L.; Millet, Jean-Pierre

    2001-01-01

    The paper reports studies on the efficiency of the film-inhibitors that covered low-carbon steel placed in a humid medium, and also, the optimization of the working conditions to improve the resistance to corrosion. The analyzes were done in the Industrial Physical - Chemical Laboratories of INSA - Lyon by electrochemical stationary techniques. The experimental device was a potentiometer of type EGG PAR (Princeton Applied Research). It was connected with a computer and three potential electrodes introduced in a cell with NaCl 30 g/l solution to acquire the data and to process the information. The film-products used were organic hydrosoluble polymers with diphosphonic 'heads' that permit a very good absorption at the metallic surface. This research is used to protect the installations of low-carbon steel against the atmospheric and high temperature corrosion. (authors)

  4. 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.

  5. 75 FR 55769 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2010-09-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant...) is conducting the sixteenth administrative review of the antidumping order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea).\\1\\ This review covers eight...

  6. 78 FR 59652 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2013-09-27

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant... corrosion-resistant carbon steel flat products (``CORE'') from the Republic of Korea (``Korea''), pursuant... administrative review of the antidumping duty order on CORE from Korea covering the period of review (``POR'') of...

  7. 78 FR 55057 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary Results of...

    Science.gov (United States)

    2013-09-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon... Department) is conducting an administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea), covering the period [[Page 55058...

  8. 78 FR 16247 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea; Final Results of...

    Science.gov (United States)

    2013-03-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon... preliminary results of the administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea).\\1\\ This review covers seven manufacturers...

  9. 76 FR 69703 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Extension of...

    Science.gov (United States)

    2011-11-09

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon... administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products from Korea, covering the period August 1, 2009, to July 31, 2010. See Initiation of Antidumping and Countervailing Duty...

  10. 77 FR 14501 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2012-03-12

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant... the preliminary results of the antidumping duty administrative review for certain corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea).\\1\\ This review covers eight...

  11. 76 FR 77775 - Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-12-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... results of the administrative review of the countervailing duty order on corrosion-resistant carbon steel flat products from the Republic of Korea covering the period January 1, 2009, through December 31, 2009...

  12. 77 FR 54891 - Certain Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Preliminary...

    Science.gov (United States)

    2012-09-06

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant...) is conducting the 18th administrative review of the antidumping order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea \\1\\ (Korea). This review covers seven...

  13. 76 FR 4291 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Partial Rescission of...

    Science.gov (United States)

    2011-01-25

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... Commerce (the Department) initiated an administrative review of the countervailing duty order on corrosion- resistant carbon steel flat products from the Republic of Korea covering the period January 1, 2009, through...

  14. 78 FR 59651 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2013-09-27

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant... duty order on certain corrosion-resistant carbon steel flat products (``CORE'') from the Republic of... covering the period of review (``POR'') of August 1, 2006 through July 31, 2007, with respect to the...

  15. 76 FR 55004 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary...

    Science.gov (United States)

    2011-09-06

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant...) is conducting the seventeenth administrative review of the antidumping order on corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea \\1\\ (Korea). This review covers eight...

  16. 75 FR 77615 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Extension of...

    Science.gov (United States)

    2010-12-13

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon... administrative review of the antidumping duty order on corrosion-resistant carbon steel flat products from Korea, covering the period August 1, 2008, to July 31, 2009. See Initiation of Antidumping and Countervailing Duty...

  17. Enhanced corrosion resistance of stainless steel type 316 in sulphuric acid solution using eco-friendly waste product

    Science.gov (United States)

    Sanni, O.; Popoola, A. P. I.; Fayomi, O. S. I.

    2018-06-01

    Literature has shown that different organic compounds are effective corrosion inhibitors for metal in acidic environments. Such compounds usually contain oxygen, nitrogen or sulphur and function through adsorption on the metal surface, thereby creating a barrier for corrosion attack. Unfortunately, these organic compounds are toxic, scarce and expensive. Therefore, plants, natural product and natural oils have been posed as cheap, environmentally acceptable, abundant, readily available and effective molecules having low environmental impact. The corrosion resistance of austenitic stainless steel Type 316 in the presence of eco-friendly waste product was studied using weight loss and potentiodynamic polarization techniques in 0.5 M H2SO4. The corrosion rate and corrosion potential of the steel was significantly altered by the studied inhibitor. Results show that increase in concentration of the inhibitor hinders the formation of the passive film. Experimental observation shows that its pitting potential depends on the concentration of the inhibitor in the acid solution due to adsorption of anions at the metal film interface. The presence of egg shell powder had a strong influence on the corrosion resistance of stainless steel Type 316 with highest inhibition efficiency of 94.74% from weight loss analysis, this is as a result of electrochemical action and inhibition of the steel by the ionized molecules of the inhibiting compound which influenced the mechanism of the redox reactions responsible for corrosion and surface deterioration. Inhibitor adsorption fits the Langmuir isotherm model. The two methods employed for the corrosion assessment were in good agreement.

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

    International Nuclear Information System (INIS)

    Karas, A.; Cihal, V. Jr.; Vanek, V.; Herzan, J.; Protiva, K.; Cihal, V.

    1987-01-01

    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

  19. Phase analysis of corrosion products of carbon steel in sea water

    International Nuclear Information System (INIS)

    Garcia R, J.; Yee M, H.; Maldonado M, H.; Nunez, L.; Reguera, E.

    1998-01-01

    Nowadays carbon steel continues being the most widely used metallic material in marine and coastal buildings. The economic losses, due to corrosion processes, of those countries with important industrial and social activities in coastal regions are highly significant. In this sense the evaluation of the corrosion process of carbon steel and other materials in seawater or in coastal zones is a primary task for protection methods or to predict the hfe of an specific installation. In this communication we present the phases analysis, using XRD and Moessbauer techniques, of corrosion products of a carbon steel (CT3, equivalent to AISI C1020) exposed in two natural corrosion stations in the Caribbean sea (Cuba). The exposition time run from days to 36 months and the evaluated rust are characteristic of samples totally immersed in seawater, from the splash zone and form coastal zones at different distance from the shoreline. Quantitative phase analysis shown presence of magnetite (Fe 3 O 4 ), maghemite (y-Fe 2 O 3 ), akaganeite (B-FeOOH), lepidocrocite (y-FeOOH) and goethite (a-FeOOH) as iron bearing phases, and CaCO 3 (Calcite and aragonite), these last ones mainly in the immersed samples. Quantitative phase analysis by XRD was implemented as a linear combination of the patterns characteristic of all the detected phases and an appropriate model for the background. The quantitative results were used in kinetic models to understand the phase transformation between the iron oxides and oxy hydroxides in the studied conditions. The XRD qualitative and quantitative results were corroborated by Moessbauer spectroscopy in the temperature range of 20 to 300 K. (Author)

  20. Effect of water chemistry on corrosion of stainless steel and deposition of corrosion products in high temperature pressurised water

    International Nuclear Information System (INIS)

    Morrison, Jonathan; Cooper, Christopher; Ponton, Clive; Connolly, Brian; Banks, Andrew

    2012-09-01

    In any water-cooled nuclear reactor, the corrosion of the structural materials in contact with the coolant and the deposition of the resulting oxidised species has long been an operational concern within the power generation industry. Corrosion of the structural materials at all points in the reactor leads to low concentrations of oxidised metal species in the coolant water. The oxidised metal species can subsequently be deposited out as CRUD deposits at various points around the reactor's primary and secondary loops. The deposition of soluble oxidised material at any location in the reactor cooling system is undesirable due to several effects; deposits have a porous structure, capable of incorporating radiologically active material (forming out of core radiation fields) and concentrating aggressively corrosive chemicals, which exacerbate environmental degradation of structural and fuel-cladding materials. Deposits on heat transfer surfaces also limit efficiency of the system as a whole. The work in this programme is an attempt to determine and understand the fundamental corrosion and deposition behaviour under controlled, simulated reactor conditions. The rates of corrosion of structural materials within pressurised water reactors are heavily dependent on the condition of the exposed surface. The effect of mechanical grinding and of electropolishing on the corrosion rate and structure of the resultant oxide film formed on grade 316L stainless steel exposed to high purity water, modified to pH 9.5 and 10.5 at temperatures between 200 and 300 deg. C and pressures of up to 100 bar will be investigated. The corrosion of stainless steel in water via electrochemical oxidation leads to the formation of surface iron, nickel and chromium based spinels. Low concentrations of these spinels can be found dissolved in the coolant water. The solubility of magnetite, stainless steels' major corrosion product, in high purity water will be studied at pH 9.5 to 10.5 at

  1. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    Daniel, B.

    1988-09-01

    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. Filterability of corrosion products formed between carbon steel and water. Influence of temperature and oxygen content

    International Nuclear Information System (INIS)

    Kelen, T.; Falk, I.

    1975-09-01

    A laboratory investigation has been made for the purpose of studying the influence of temperature and oxygen content on the filterability of corrosion products formed between carbon-steel and water. The experiments were performed in a high temperature loop where the water is initially heated in a pre-heater, then cooled and finally filtered. The corrosion products were transferred to thewater from a carbon-steel surface that had previously been neutron activated and the amount of iron present was determined from measurements of the γ-radiation emitted by Fe-59. Filterability was then computed as the ratio between the total amount of iron in the water phase and the amount of iron retained on the filter. The investigation covers a series of experiments at filtering temperatures of 20, 90 and 160 dec G, pre-heater temperatures up to 300 deg C and oxygen contents of 10 and 300 ppb O 2 . In addition the extent of iron deposition in the pre-heater and heat regulator has been determined after each series of experiments. Filterability exhibited a pronounced dependence upon both the filter and pre-heater temperatures and also upon the oxygen content. Among the conclusions to which the results lead is the observation that a strict comparison of filterability values for the fraction of corrosion products in cooled water samples is impossible when these are taken from 1) different sections of a high temperature system 2) a single sampling point while the system is being run up 3) two separate systems (e.g. steam boilers) operated at different temperatures 4) two separate systems operated at different oxygen contents. It accordingly appears advizable to restrict the use of cold-filtered samples from conventional steam-raising plants to the comparison of values relating to a single sampling point under constant operating conditions. (author)

  3. Behaviour of steel corrosion products under neutral-oxidizing water conditions

    International Nuclear Information System (INIS)

    Martynova, O.I.; Petrova, T.I.; Samojlov, Yu.F.; Kharitonova, N.L.

    1985-01-01

    Results of laboratory experiments on studying the solubility of iron and cobalt corrosion products are given. It is established that oxygen dosage doesn't influence practically on the iron corrosion product solubility but cobalt corrosion product solubility decreases, the presence of hydrogen peroxide in an initial solution leads to increase of the iron corrosion product solubility especially at 125 deg C. It is shown that hydrogen peroxide affects unambiguously the cobalt corrosion product solubility: at hydrogen peroxide concentration of about 400 μg/l at 50-275 deg C temperature their solubility is minimum

  4. 77 FR 67395 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Revised Schedule for the...

    Science.gov (United States)

    2012-11-09

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-350 and 731-TA-616 and 618 (Third Review)] Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Revised Schedule for the Subject Reviews AGENCY: United States International Trade Commission. ACTION: Notice. DATES: Effective Date...

  5. Spectroscopic study of the final protective corrosion product on weathering steel

    International Nuclear Information System (INIS)

    Yamashita, M.; Misawa, T.

    1998-01-01

    Recent progress in understanding the structure and properties of final protective rust layer on weathering steel and its application for structural steels is shown based on the data obtained mainly by spectroscopic characterization. The main constituent of the weathering steel rust layer is changed with exposure period from γ- FeOOH (less than a few years) via, amorphous substance (several years), to α-FeOOH goethite phase (decades). The corrosion rate of the weathering steel decreased with this phase transformation. The final protective rust layer possesses the structure of α- (Fe 1 - X p Cr x)O OH, Cr substitute goethite; the crystal size decreases with its Cr-content. It is shown that the Cr content in the Cr-substituted goethite increases gradiently with reaching the rust/steel interface. This increase in the Cr content and resultant aggregation of fine crystals lead a densely packed Cr-substituted goethite rust layers which provides higher protective ability for atmospheric corrosives. It is found that the Cr-substituted goethite possesses the cation selective ability at the vicinity of the rust/steel interface where the Cr content can be estimated approximately 5-10 mass %. Thus, the final protective rust layer of the Cr-substituted goethite impedes the penetration of aggressive corrosive anions such as Cl - and SO 4 2- , besides the physically prevention effect of its densely aggregated structure for corrosive penetration. It is found that Cr 2 (SO 4 ) 3 is effective for obtaining the final protective rust layer in a short period. SO 4 2 accelerates rust formation and Cr 3- substitutes goethite crystal lattice point at the initial stage of corrosion; resultantly the rust layer formed suppresses dissolution of the steel even in the severe environment. (Author)

  6. 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.

  7. Electrochemical corrosion studies on a selected carbon steel for application in nuclear waste disposal containers: Influence of radiolytic products on corrosion in brines

    International Nuclear Information System (INIS)

    Farvaque-Bera, A.M.; Smailos, E.

    1994-07-01

    In previous corrosion studies, carbon steels were identified as promising materials for the manufacturing of long-lived high-level waste containers that could act as a radionuclide barrier in a rock-salt repository. In the present work, the influence of some important oxidizing radiolytic products generated in gamma irradiated brines on the electrochemical corrosion behaviour of the preselected fine-grained steel TStE 355 was studied. The steel was examined by potentiodynamic and potentiostatic polarization methods at 90 C in a disposal relevant NaCl-rich brine containing radiolytic products such as H 2 O 2 , ClO - , ClO 3 - and ClO 4 - at concentrations between 10 -4 and 10 -2 M/l. The significance of the radiolytic products to steel corrosion depends on their concentration at the metal-brine interface, which in turn, depends on many factors such as the dose rate, the amount of water present in the disposal area, the escape of gases (e.g. H 2 )

  8. 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)

  9. Responses of Microbial Community Composition to Temperature Gradient and Carbon Steel Corrosion in Production Water of Petroleum Reservoir

    Directory of Open Access Journals (Sweden)

    Xiao-Xiao Li

    2017-12-01

    Full Text Available Oil reservoir production systems are usually associated with a temperature gradient and oil production facilities frequently suffer from pipeline corrosion failures. Both bacteria and archaea potentially contribute to biocorrosion of the oil production equipment. Here the response of microbial populations from the petroleum reservoir to temperature gradient and corrosion of carbon steel coupons were investigated under laboratory condition. Carbon steel coupons were exposed to production water from a depth of 1809 m of Jiangsu petroleum reservoir (China and incubated for periods of 160 and 300 days. The incubation temperatures were set at 37, 55, and 65°C to monitoring mesophilic, thermophilic and hyperthermophilic microorganisms associated with anaerobic carbon steel corrosion. The results showed that corrosion rate at 55°C (0.162 ± 0.013 mm year-1 and 37°C (0.138 ± 0.008 mm year-1 were higher than that at 65°C (0.105 ± 0.007 mm year-1, and a dense biofilm was observed on the surface of coupons under all biotic incubations. The microbial community analysis suggests a high frequency of bacterial taxa associated with families Porphyromonadaceae, Enterobacteriaceae, and Spirochaetaceae at all three temperatures. While the majority of known sulfate-reducing bacteria, in particular Desulfotignum, Desulfobulbus and Desulfovibrio spp., were predominantly observed at 37°C; Desulfotomaculum spp., Thermotoga spp. and Thermanaeromonas spp. as well as archaeal members closely related to Thermococcus and Archaeoglobus spp. were substantially enriched at 65°C. Hydrogenotrophic methanogens of the family Methanobacteriaceae were dominant at both 37 and 55°C; acetoclastic Methanosaeta spp. and methyltrophic Methanolobus spp. were enriched at 37°C. These observations show that temperature changes significantly alter the microbial community structure in production fluids and also affected the biocorrosion of carbon steel under anaerobic conditions.

  10. Electrochemical formation of carbonated corrosion products on carbon steel in deaerated solutions

    International Nuclear Information System (INIS)

    Refait, Ph.; Bourdoiseau, J.A.; Jeannin, M.; Nguyen, D.D.

    2012-01-01

    Highlights: ► Green rust is electro-generated at low NaHCO 3 concentration (0.003 mol dm −3 ). ► Chukanovite and carbonated green rust are obtained in NaHCO 3 + Na 2 SO 4 deaerated electrolytes. ► The mechanisms of formation of carbonated corrosion products of carbon steel are specified. - Abstract: To investigate the nature and properties of carbonated rust layers, carbon steel electrodes were polarised anodically at a potential ∼100–200 mV higher than the open circuit potential in NaHCO 3 solutions (0.003, 0.1 and 1 mol dm −3 ) continuously deaerated by an argon flow. X-ray diffraction and μ-Raman spectroscopy were used to identify the electro-generated compounds. GR(CO 3 2− ) (=Fe II 4 Fe III 2 (OH) 12 CO 3 ·4H 2 O) is observed at 0.003 and 0.1 mol dm −3 NaHCO 3 whereas FeCO 3 is obtained at the largest concentration (1 mol dm −3 ). GR(CO 3 2− ) is accompanied by magnetite Fe 3 O 4 at the lowest NaHCO 3 concentration. The current density decreases to negligible values in each case, indicating that a passive film also forms independently of the nature of the carbonated compound. Experiments were performed similarly in solutions of NaHCO 3 and Na 2 SO 4 . Chukanovite Fe 2 (OH) 2 CO 3 could be obtained in solutions containing 0.03 mol dm −3 of each salt. In contrast with the results obtained in the solutions free of sulphate, the current density remains important during the formation of the rust layer

  11. A mechanism for corrosion product deposition on the carbon steel piping in the residual heat removal system of BWRs

    International Nuclear Information System (INIS)

    Aizawa, Motohiro; Chiba, Yoshinori; Hosokawa, Hideyuki; Ohsumi, Katsumi; Uchida, Shunsuke; Ishizawa, Noboru

    2002-01-01

    The dose rate of the residual heat removal (RHR) piping has been considered to be caused by accumulation of insoluble (crud) radioactive corrosion products on carbon steel surfaces. Soft shutdown procedures (i.e., plant shutdown with moderate coolant temperature reduction rate) used to be applied to reduce crud radioactivity release from the fuel surface, but these are no longer used because of the need for shorter plant shutdown times. In order to apply other suitable countermeasures to reduce RHR dose rate, assessment of plant data, experiments on deposition of crud and ion species on carbon steel, and mass balance evaluation of radioactive corrosion products based on plant and laboratory data were carried out and the following findings were made. (1) Deposits of ion species on carbon steel surfaces of the RHR piping was much more numerous than for crud. (2) Ion species accumulation behavior on RHR piping, which is temperature dependent, can be evaluated with the calculation model used for the dehydration reaction of corrosion products generated during the wet lay-up period. (3) Deposition amounts could be reduced to 1/2.5 when the starting RHR system operation temperature was lowered from 155degC to 120degC. (author)

  12. Corrosion behavior of stainless steel in bio diesel production; Comportamento quanto a corrosao de acos inoxidaveis na producao do biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, E.F. de [ArcelorMittal Sao Paulo Servicos, SP (Brazil); Moreira, M.C.; Lebrao, S.M.G. [Centro Universitario do Instituto Maua de Tecnologia, Sao Paulo, SP (Brazil)], e-mail: susana.lebrao@maua.br

    2010-07-01

    Biodiesel has become more attractive due to the benefits to the environment, mainly because it is a renewable resource. However, the main barrier to biodiesel is it cost. One factor which is charged to marketing is the use of stainless steel throughout the production line, the most used is AISI 304. To evaluate more economical stainless steels, weight loss and stress corrosion tests were performed on samples of AISI 304 and 439 in methanol PS X30% sodium methylate solution, crude soybean oil, glycerol and biodiesel for about two hundred and fifty days. The mass loss was negligible, and there was complete absence of pitting and stress corrosion cracking in all media studied, showing that both alloys are suitable for the manufacture of such equipment. (author)

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

    International Nuclear Information System (INIS)

    Itty, Pierre-Adrien; Serdar, Marijana; Meral, Cagla; Parkinson, Dula; MacDowell, Alastair A.; Bjegović, Dubravka; Monteiro, Paulo J.M.

    2014-01-01

    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. Corrosion of ferritic steels by molten lithium: Influence of competing thermal gradient mass transfer and surface product reactions

    International Nuclear Information System (INIS)

    Tortorelli, P.F.

    1987-10-01

    An Fe-12Cr-1MoVW steel was exposed to thermally convective lithium for 6962 h. Results showed that the weight change profile of Fe-12Cr-1MoVW steel changed substantially as the maximum loop temperature was raised from 500 to 600 0 C. Furthermore, for a particular loop experiment, changes in the structure and composition of the exposed surfaces did not reflect typical thermal gradient mass transfer effects for all elements: the surface concentration of chromium was often a maximum at intermediate temperatures, while nickel (present at low concentrations in the starting material) tended to be transported to the coldest part of the loop. Such data were interpreted in terms of a qualitative model in which there are different dominant reactions or the various constituents of the ferritic steels (surface product formation involving nitrogen and/or carbon and solubility-driven elemental transport). This competition among different reactions is important in evaluating overall corrosion behavior and the effects of temperature. The overall corrosion rate of the 12Cr-1MoVW steel was relatively low when compared to that for austenitic stainless steel exposed under similar conditions

  15. Composition and Morphology of Product Layers in the Steel/Cement Paste Interface in Conditions of Corrosion and Cathodic Protection in Reinforced Concrete

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.; De Wit, J.H.W.; Fraaij, A.L.A.; Boshkov, N.

    2007-01-01

    The present study explores the formation of corrosion products on the steel surface in reinforced concrete in conditions of corrosion and subsequent transformation of these layers in conditions of cathodic protection (CP). Of particular interest was to investigate if the introduced pulse CP (as

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

    KAUST Repository

    Itty, Pierre-Adrien; Serdar, Marijana; Meral, Cagla; Parkinson, Dula; MacDowell, Alastair A.; Bjegović, Dubravka; Monteiro, Paulo J.M.

    2014-01-01

    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.

  17. 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.

  18. Corrosion fatigue of steels

    International Nuclear Information System (INIS)

    Spaehn, H.; Wagner, G.H.

    1976-01-01

    Corrosion fatigue phenomena can be classified into two main groups according to the electrochemical state of the metal surface in the presence of electrolytes: the active and the passive state with an important sub-group of corrosion fatigue in the unstable passive state. The allowable stress for structures exposed to the conjoint action of corrosion and fatigue is influenced by many factors: kind of media, number of cycles, frequency, mean stress, size, notches, loading mode, alloy composition and mechanical strength. A critical literature review shows contradictory results if a classification by the electrochemical surface state is not applied. Case histories and counter measures illustrate the practical importance of corrosion fatigue in many branches of industry as well as the urgent need for a better knowledge about the mutual influence of the phenomena to get rules by which the engineer can appraise the risk of corrosion fatigue. (orig.) [de

  19. Steel corrosion products solubility under conditions simulating various water chemistry parameters in power plants

    International Nuclear Information System (INIS)

    Slobodov, A.A.; Kritskij, V.G.; Zarembo, V.I.; Puchkov, L.V.

    1988-01-01

    To simulate construction material corrosion product mass transfer model in power plant circuits calculation of iron oxide and hydroxide solubility, depending on water chemistry parameters: temperature, pH-value, content of dissolved in water hydrogen and oxygen, is carried out

  20. BWR steel containment corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.P.; Bagchi, G.

    1996-04-01

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

  1. Corrosion of austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M C.M. [Instituto Nacional de Tecnologia, Rio de Janeiro (Brazil)

    1977-01-01

    Types of corrosion observed in a heat exchanger pipe and on a support of still of molasses fermented wort, both in austenitic stainless steel, are focused. Not only are the causes which might have had any kind of influence on them examined, but also the measures adopted in order to avoid and lessen its occurence.

  2. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    corrosion rates, when biofilm and corrosion products cover the steel surface. However, EIS might be used for detection of MIC. EN is a suitable technique to characterise the type of corrosion attack, but is unsuitable for corrosion rate estimation. The concentric electrodes galvanic probe arrangement......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...

  3. Effect of corrosion product layer on SCC susceptibility of copper containing type 304 stainless steel in 1 M H2SO4

    International Nuclear Information System (INIS)

    Asawa, M.; Devasenapathi, A.; Fujisawa, M.

    2004-01-01

    The effect of surface corrosion product layer on the stress corrosion cracking (SCC) susceptibility of type 304 stainless steel with Cu was studied in 1 kmol/m 3 (1 M) sulfuric acid at 353 K temperature. Studies based on the intermittent removal of surface corrosion product layer indicated that the surface film governs the SCC behavior of the alloy by accelerating both the crack initiation and propagation stages. The electrochemical impedance and polarization studies showed the surface layer to be promoting SCC initiation by lowering the uniform corrosion rate and the propagation by shifting the surface corrosion potential to a more noble direction. The elemental analysis of the corrosion product both by the energy dispersive X-ray (EDX) spectroscopy and by X-ray diffraction (XRD) analysis along with the thermodynamic calculations showed the layer to be constituted mainly of metallic copper (Cu) and the mono-hydrated iron sulfate which acts as cathode promoting SCC

  4. Corrosion of steel in concrete

    International Nuclear Information System (INIS)

    Preece, C.M.

    1982-10-01

    A comparative study has been made of those properties of Massiv and Standard cements which are considered to determine their ability to protect steel reinforcement from corroding. Saturated Massiv cement has a higher evaporabel water content, but a significantly finer pore structure than has saturated Standard cement. This fine structure resulted in an electrical resistivity ten times higher and chloride diffusivity ten times lower than those of Standard cement. Electrochemical measurements have shown that the passive current density of steel in Massiv mortar is higher than that of steel in Standard mortar, but the higher current should lead to a more rapid decrease in potential to a level at which neither chloride attack of hydrogen evolution will occur. Whereas steel in Standard mortar was found to be highly susceptible to crevice corrosion, no such attack has been observed in Massiv mortar. Moreover, the initiation of chloride induced corrosion and the subsequent rates of corrosion were both lower in Massiv mortar than in Standard mortar. Thus, it may be predicted that Massiv cement would provide greater protection for steel reinforcement in underground structures exposed to chloride containing ground water than would Standard cement. (author)

  5. Mechanical properties of layers of corrosion products at steel / concrete interface

    International Nuclear Information System (INIS)

    Dehoux, Anita

    2012-01-01

    To take account of the development of corrosion products layers in residual lifetime calculations of reinforced concrete structures requires a good knowledge of the mechanical properties of these products. Our study aims to determine the mechanical properties of layers of corrosion products. The approach consists of an identification of the microstructure properties complemented by homogenization calculations to calculate a mesoscopic behavior in linear elasticity of layers of corrosion products. The study includes a series of experimental campaigns at the microscopic scale. Vickers micro indentation tests analyzed by a Gaussian mixture model approach allowed the acquisition of hardness and elastic moduli at the microscale. An identification of the microstructure products is performed by Raman microspectrometry. The microstructure's characterization brings valuable information for homogenization calculations. The first approach has consisted of calculations of random media homogenization by self-consistent and generalized self-consistent schemes. In the second approach, effective modulus calculations were performed using numerical microstructures resulting from 2D images taken with an optical microscope. The corpus is composed of samples of different ages and origins, their microstructures were compared. (author) [fr

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

    Science.gov (United States)

    Saeidi, Sheida

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

  7. 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.

  8. Atmospheric corrosion of mild steel in Oman

    International Nuclear Information System (INIS)

    Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

    2006-01-01

    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.

  9. The anaerobic corrosion of carbon steel in concrete

    International Nuclear Information System (INIS)

    Naish, C.C.; Balkwill, P.H.; O'Brien, T.M.; Taylor, K.J.; Marsh, G.P.

    1991-01-01

    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 20-30 0 C, ie ambient conditions. 4 refs.; 19 figs.; 6 tabs

  10. 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).

  11. Microstructural characterisation and corrosion performance of old railway girder bridge steel and modern weathering structural steel

    International Nuclear Information System (INIS)

    Tewary, N.K.; Kundu, A.; Nandi, R.; Saha, J.K.; Ghosh, S.K.

    2016-01-01

    Highlights: • Microstructure and corrosion performance are compared for two structural steels. • Microstructure evolution shows primarily ferrite-pearlite in both the steels. • Steels show higher corrosion rate in 1% HCl solution than in 3.5% NaCl solution. • The corrosion products show the presence of oxide, hydroxide and oxy-hydroxides. • The corroded surface reveals morphologies like flowery, cotton balls and rosette. - Abstract: A comparison on microstructure and corrosion performance has been made between the two structural steels used in old railway girder bridge (Sample A) and modern grades of weathering structural steel (Sample B). The microstructures, viewed under optical microscope and scanning electron microscope (SEM), show mainly ferrite-pearlite phase constituents in both the steels, A and B. The phase fraction analysis shows higher amount of pearlite in steel A compared to that of steel B. The grain size of steel A is larger than that of steel B under identical processing condition. The immersion corrosion test in 3.5% NaCl shows that the corrosion rate of steel A increases with time, while the same for steel B decreases with time. On the other hand, corrosion test in 1% HCl shows that the corrosion rate of both steel A and B is higher as compared to that of NaCl which always decreases with time. The XRD analysis of corrosion products show the presence of many oxides, hydroxide and oxy-hydroxide like Lepidocrocite (γ-FeOOH), Goethite (α-FeOOH), Akaganeite (β-FeOOH), Magnetite (Fe_3O_4) and Maghemite (γ-Fe_2O_3) in both the steels. The SEM images of corroded surfaces reveal different morphologies like flowery, cotton balls and rosette etc. which indicate that the corrosion products primarily contain Lepidocrocite (γ-FeOOH), Goethite (α-FeOOH) and Akaganeite (β-FeOOH).

  12. Evaluation of steel corrosion by numerical analysis

    OpenAIRE

    Kawahigashi, Tatsuo

    2017-01-01

    Recently, various non-destructive and numerical methods have been used and many cases of steel corrosion are examined. For example, methods of evaluating corrosion through various numerical methods and evaluating macrocell corrosion and micro-cell corrosion using measurements have been proposed. However, there are few reports on estimating of corrosion loss with distinguishing the macro-cell and micro-cell corrosion and with resembling an actuality phenomenon. In this study, for distinguishin...

  13. Corrosion of carbon steel in contact with bentonite

    International Nuclear Information System (INIS)

    Dobrev, D.; Vokal, A.; Bruha, P.

    2010-01-01

    Document available in extended abstract form only. Carbon steel canisters were chosen in a number of disposal concepts as reference material for disposal canisters. The corrosion rates of carbon steels in water solution both in aerobic and anaerobic conditions are well known, but only scarce data are available for corrosion behaviour of carbon steels in contact with bentonite. A special apparatus, which enables to measure corrosion rate of carbon steels under conditions simulating conditions in a repository, namely in contact with bentonite under high pressure and elevated temperatures was therefore prepared to study: - Corrosion rate of carbon steels in direct contact with bentonite in comparison with corrosion rate of carbon steels in synthetic bentonite pore water. - Influence of corrosion products on bentonite. The apparatus is composed of corrosion chamber containing a carbon steel disc in direct contact with compacted bentonite. Synthetic granitic water is above compacted bentonite under high pressure (50 - 100 bar) to simulate hydrostatic pressure in a repository. The experiments can be carried out under various temperatures. Bentonites used for experiments were Na-type of bentonite Volclay KWK 80 - 20 and Ca-Mg Czech bentonite from deposit Rokle. Before adding water into corrosion system the corrosion chamber was purged by nitrogen gas. The saturation of bentonite and corrosion rate were monitored by measuring consumption of water, pressure increase caused by swelling pressure of bentonite and by generation of hydrogen. Corrosion rate was also determined after corrosion experiments from weight loss of samples. The results of experiments show that the corrosion behaviour of carbon steels in contact with bentonite is very different from corrosion of carbon steels in water simulating bentonite pore water solution. The corrosion rates of carbon steel in contact with bentonite reached after 30 days of corrosion the values approaching 40 mm/yr contrary to values

  14. Analysis of the corrosion products on galvanized steels by FTIR spectroscopy

    International Nuclear Information System (INIS)

    Kasperek, J.

    1998-01-01

    FTIR reflectance spectroscopy has been used for the characterization of products formed by an accelerated wet ageing test on industrial hot-dip galvanized steel. Several aluminium contents are selected. Various products have been detected in this study. The kind and amount vary with the substrate, the type of ageing test used, the relative humidity level and the temperature. The galvanized coatings studied show a mixed zinc-aluminium compound, Zn 6 Al 2 (OH) 16 CO 3 .4H 2O. This phase is observed from the first exposure time on all coatings regardless of the amount of aluminium. Contrary to zinc, no basic aluminium compound has been detected. (orig.)

  15. Importance of temperature, pH, and boric acid concentration on rates of hydrogen production from galvanized steel corrosion

    International Nuclear Information System (INIS)

    Loyola, V.M.

    1982-01-01

    One of the known sources of hydrogen gas within a nuclear plant containment building during a LOCA is the high temperature corrosion of galvanized steel yielding hydrogen gas. The importance of this source of hydrogen will vary depending on the severity of the accident. In an accident which resulted in core degradation, for example, the major source of hydrogen would probably be the metal-water reaction of the zircaloy cladding, and the corrosion of galvanized steel would then become a relatively minor source of hydrogen. However, in an accident in which core degradation is avoided or limited to minor damage, the corrosion of galvanized steel, and presumably of other materials as well, would then become a major contributor to the buildup of hydrogen within containment. The purpose of this paper is to present the overall effects of temperature, pH, and boric acid concentration on the rate of hydrogen generation over a broad range of each parameter

  16. Corrosion Behavior and Durability of Low-Alloy Steel Rebars in Marine Environment

    Science.gov (United States)

    Liu, Ming; Cheng, Xuequn; Li, Xiaogang; Yue, Pan; Li, Jun

    2016-11-01

    The corrosion resistance of Cr-modified low-alloy steels and HRB400 carbon steel was estimated using the open-circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopic, and weight loss methods in simulated concrete pore solution. Results show that Cr-modified steels exhibit a higher corrosion resistance with a higher critical chloride level (CTL), lower corrosion current density, and higher impedance than carbon steel. The CTL of the steels significantly reduces with increasing temperature. Weight loss measurement shows that the Cr-modified steels exhibit low corrosion rates and small corrosion pitting. The primary constituents of the corrosion scales are Fe2O3, Fe3O4, β-FeOOH, γ-FeOOH, and α-FeOOH. A large amount of α-FeOOH could be detected in the Cr-modified steel corrosion products. Moreover, the Cr-modified steels demonstrate a higher durability than HRB400 carbon steel.

  17. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 4: Hatteras abyssal red clay

    International Nuclear Information System (INIS)

    Schmidt, R.L.

    1982-07-01

    A study in which neutron-activated 347 stainless steel was exposed to surficial sediment from a site in the Hatteras Abyssal Plain of the Northwest Atlantic Ocean is described. This sediment consists of approx. 20% CaCO 3 , which could lead to the formation of calcareous scale on the metal surface and reduce the corrosion rate. The distribution of indigenous metals among different chemical fractions shows that extractable Cr, Mn, Fe, Co, and Zn were associated with amorphous Mn and Fe oxides. Most of the remaining extractable Cr, and about a third of the extractable Cu appear to have been weakly complexed. Major fractions (25 to 36%) of extractable Mn, Co and Ni were present as adsorbed cations. Organic complexation appears to account for a large amount of extractable Fe, Ni, Cu and Zn. Neutron-activated 347 stainless steel specimens were exposed to sediment slurry under aerobic and non-oxygenated conditions for a period of 94 days. The redox potential measurements for air-sparged and N 2 , CO 2 -sparged sediment slurries were +410 and +60 mv, respectively. The presence of 0 2 produced increased amounts of corrosion products. Chemical extraction showed that relatively labile substances constituted about 84% of the 60 Co activity released in aerated sediment. Relatively labile substances constitute about 82% of the total 60 Co activity released under non-oxygenated conditions. A large fraction of 60 Co which was in the soluble or easily dissolved forms under non-oxygenated conditions appears to have been more strongly adsorbed to the sediment under aerated conditions

  18. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 4: Hatteras abyssal red clay

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.L.

    1982-07-01

    A study in which neutron-activated 347 stainless steel was exposed to surficial sediment from a site in the Hatteras Abyssal Plain of the Northwest Atlantic Ocean is described. This sediment consists of approx. 20% CaCO/sub 3/, which could lead to the formation of calcareous scale on the metal surface and reduce the corrosion rate. The distribution of indigenous metals among different chemical fractions shows that extractable Cr, Mn, Fe, Co, and Zn were associated with amorphous Mn and Fe oxides. Most of the remaining extractable Cr, and about a third of the extractable Cu appear to have been weakly complexed. Major fractions (25 to 36%) of extractable Mn, Co and Ni were present as adsorbed cations. Organic complexation appears to account for a large amount of extractable Fe, Ni, Cu and Zn. Neutron-activated 347 stainless steel specimens were exposed to sediment slurry under aerobic and non-oxygenated conditions for a period of 94 days. The redox potential measurements for air-sparged and N/sub 2/, CO/sub 2/-sparged sediment slurries were +410 and +60 mv, respectively. The presence of 0/sub 2/ produced increased amounts of corrosion products. Chemical extraction showed that relatively labile substances constituted about 84% of the /sup 60/Co activity released in aerated sediment. Relatively labile substances constitute about 82% of the total /sup 60/Co activity released under non-oxygenated conditions. A large fraction of /sup 60/Co which was in the soluble or easily dissolved forms under non-oxygenated conditions appears to have been more strongly adsorbed to the sediment under aerated conditions.

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

    International Nuclear Information System (INIS)

    BOOMER, K.D.

    2007-01-01

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

  20. Corrosion of Galvanized Steel Under Different Soil Moisture Contents

    OpenAIRE

    Pereira,Roseana Florentino da Costa; Oliveira,Edkarlla Sousa Dantas de; Lima,Maria Alice Gomes de Andrade; Brasil,Simone Louise Delarue Cezar

    2015-01-01

    Galvanized steel has been widely applied in different applications and the industry significantly increased its production in recent years. Some galvanized structures can be completely or partially buried, such as transmission tower footings. The corrosion of these metallic structures is related to the soil chemical and physicochemical properties, which define the aggressiveness of the environment. To assess the effect of the soil moisture on galvanized steel corrosion, a comparative study wa...

  1. Microbial Corrosion and Cracking in Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    1998-01-01

    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 recommendati......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...... 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...

  2. Characterization of corrosion products of Zn and Zn–Mg–Al coated steel in a marine atmosphere

    International Nuclear Information System (INIS)

    Diler, E.; Rouvellou, B.; Rioual, S.; Lescop, B.; Nguyen Vien, G.; Thierry, D.

    2014-01-01

    Highlights: • The corrosion behaviour of Zn–Mg–Al alloy in marine environment is characterized. • Zn–Mg–Al alloy shows a better corrosion resistance than Zn. • Strong enhancement of NaZn 4 Cl(OH) 6 SO 4 ·6H 2 O in the corrosion products is observed. • Al 3+ and Mg 2+ induced quenching effects in corrosion activity are described. - Abstract: The corrosion behaviour of pure zinc and zinc–magnesium–aluminium alloy (ZMA) has been studied during 6 months of exposure in marine environment (Brest, France). The composition of corrosion products is analysed using infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). An improved corrosion resistance of ZMA is observed. This improvement is found to be connected to Mg 2+ and Al 3+ induced quenching of corrosion activity and to the enhancement of NaZn 4 Cl(OH) 6 SO 4 ·6H 2 O in the formed corrosion product

  3. Corrosion of steel structures in sea-bed sediment

    Indian Academy of Sciences (India)

    Unknown

    corrosion mechanism, measurement of metal corrosion rate, corrosion ... cables, steel rigs, pipelines and other marine facilities, is ..... make high strength steel material to crack with stress ... of SBS has yet been very limited, and selection of.

  4. Corrosion Protection of Steels by Conducting Polymer Coating

    Directory of Open Access Journals (Sweden)

    Toshiaki Ohtsuka

    2012-01-01

    Full Text Available The corrosion protection of steels by conducting polymer coating is reviewed. The conducting polymer such as polyaniline, polypyrrole, and polythiophen works as a strong oxidant to the steel, inducing the potential shift to the noble direction. The strongly oxidative conducting polymer facilitates the steel to be passivated. A bilayered PPy film was designed for the effective corrosion protection. It consisted of the inner layer in which phosphomolybdate ion, PMo12O3−40 (PMo, was doped and the outer layer in which dodecylsulfate ion (DoS was doped. The inner layer stabilized the passive oxide and the outer possessed anionic perm-selectivity to inhibit the aggressive anions such as chloride from penetrating through the PPy film to the substrate steel. By the bilayered PPy film, the steel was kept passive for about 200 h in 3.5% sodium chloride solution without formation of corrosion products.

  5. IN DRIFT CORROSION PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Jolley

    1999-12-02

    As directed by a written development plan (CRWMS M&O 1999a), a conceptual model for steel and corrosion products in the engineered barrier system (EBS) is to be developed. The purpose of this conceptual model is to assist Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift, thus allowing PAO to provide a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE) Revision 2 (NRC 1999). This document provides the conceptual framework for the in-drift corrosion products sub-model to be used in subsequent PAO analyses including the EBS physical and chemical model abstraction effort. This model has been developed to serve as a basis for the in-drift geochemical analyses performed by PAO. However, the concepts discussed within this report may also apply to some near and far-field geochemical processes and may have conceptual application within the unsaturated zone (UZ) and saturated zone (SZ) transport modeling efforts.

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

    Science.gov (United States)

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

    2017-09-01

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

  7. Corrosion behaviour of laser clad stainless steels

    International Nuclear Information System (INIS)

    Damborenea, J.J. de; Weerasinghe, V.M.; West, D.R.F.

    1993-01-01

    The present paper is focussed in the study of the properties of a clad layer of stainless steel on a mild steel. By blowing powder of the alloy into a melt pool generated by a laser of 2 KW, an homogeneous layer of 316 stainless steel can be obtained. Structure, composition and corrosion behaviour are similar to those of a stainless steel in as-received condition. (Author)

  8. LongerLife products increase the sustainability. Is corrosion protection ecologically useful for steel components?; LongerLife-Produkte erhoehen die Nachhaltigkeit. Ist Korrosionsschutz von Stahlbauteilen oekologisch sinnvoll?

    Energy Technology Data Exchange (ETDEWEB)

    Rogall, Armin Dietmar [Fachhochschule Dortmund (Germany). Fachbereich Architektur

    2011-07-01

    The installation of hot-dip galvanized construction units means sustainable acting. Since corrosion protection by hot-dip galvanizing can be particularly named sustainable due to its longevity, its environmental careful production, its recycling ability and life extension of steel components. Particularly the reduction of the maintenance cycles and utilization costs accompanying with a slightly higher initial investment makes the hot-dip galvanizing a sustainable system. Steel components which are treated with galvanization and colour coating, have a maintenance-free life span of more than 80 years.

  9. 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.

  10. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 2. Sequim Bay clayey silt

    International Nuclear Information System (INIS)

    Schmidt, R.L.

    1982-04-01

    This report describes laboratory experiments in which neutron-activated 347 stainless steel specimens were exposed to clayey silt from Sequim Bay, Washington. The properties and trace metal geochemistry of the sediment and the amounts of corrosion products that were released under oxic and reduced conditions and their distribution among different chemical fractions of the sediment are discussed. The distributions of Cr, Mn, Fe, Ni and Cu among different chemical forms in the Sequim Bay sediment show that DTPA removed <10% of extractable Cr, Fe and Mn, approx. 20% of extractable Ni and approx. 30% of extractable Cu. The inorganic fraction (material soluble in 2.5% acetic acid) accounted for approx. 30% of total extractable Mn and approx. 10% or less of Cr, Fe, Ni and Cu. Major portions of Cr and Cu, and a large amount of Fe were in the organic fraction. Extractable Mn, Fe and Ni were associated with hydrous oxides likely as coatings on the mineral substrate of the sediment. No Co was detectable in any of the extracts

  11. A technique for predicting steel corrosion resistance

    Science.gov (United States)

    Novikov, V. F.; Sokolov, R. A.; Neradovskiy, D. F.; Muratov, K. R.

    2018-01-01

    Research works were carried out to develop a technique with the aim to increase the lifetime of steel items used in corrosive media. The possibility to monitor corrosion parameters of steel samples is analyzed on the basis of magnetic properties obtained by means of a magnetic structuroscope DIUS-1.15M designed by the Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences (IMP UB RAS).

  12. 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...... temperature (CPT) test as corrosion test. The following welding parameters are varied: Welding speed, lsser power, focus point position and laser operation mode (CW or pulsed)....

  13. Ferritic stainless steels: corrosion resistance + economy

    International Nuclear Information System (INIS)

    Remus, A.L.

    1976-01-01

    Ferritic stainless steels provide corrosion resistance at lower cost. They include Type 409, Type 439, 18SR, 20-Mo (1.6 Mo), 18-2 (2 Mo), 26-1S, E-Brite 26-1, 29 Cr-4 Mo, and 29 Cr-4 Mo-2 Ni. Their corrosion and mechanical properties are examined. Resistance to stress-corrosion cracking is an advantage compared to austenitic types

  14. Neutrophilic Iron-Oxidizing Zetaproteobacteria and Mild Steel Corrosion in Nearshore Marine Environments

    Science.gov (United States)

    2011-02-16

    sample harvested at 14 days, and 316L stainless steel controls did not show evidence of corrosion product formation at any of the time points. A...direct or indirect enzymatic reduction or oxidation of corrosion products, formation of biofilms that create corrosive microen- vironments, or...sampler prior to deployment. Cold-finish 1018 mild steel coupons and 3161. stainless steel control coupons (13 by 15 by 3 mm) were polished with a

  15. 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

  16. Corrosion of carbon steel in neutral water

    International Nuclear Information System (INIS)

    Kawai, Noboru; Iwahori, Toru; Kurosawa, Tatsuo

    1983-01-01

    The initial corrosion behavior of materials used in the construction of heat exchanger and piping system of BWR nuclear power plants and thermal power plants have been examined in neutral water at 30, 50, 100, 160, 200, and 285 deg C with two concentrations of dissolved oxygen in the water. In air-saturated water, the corrosion rate of carbon steel was so higher than those in deaerated conditions and the maximum corrosion rate was observed at 200 deg C. The corrosion rate in deaerated water gradually increased with increasing the water temperature. Low alloy steel (2.25 Cr, 1Mo) exhibited good corrosion resistance compared with the corrosion of carbon steel under similar testing conditions. Oxide films grown on carbon steel in deaerated water at 50, 100, 160, 200, and 285 deg C for 48 and 240 hrs were attacked by dissolved oxygen in room temperature water respectively. However the oxide films formed higher than about 160 deg C showed more protective. The electrochemical behavior of carbon steel with oxide films was also similar to the effect of temperature on the stability of oxide films. (author)

  17. Stress corrosion of low alloy steel forgings

    International Nuclear Information System (INIS)

    Thornton, D.V.; Mould, P.B.; Patrick, E.C.

    1976-01-01

    The catastrophic failure of a steam turbine rotor disc at Hinkley Point 'A' Power station was shown to have been caused by the growth of a stress corrosion crack to critical dimensions. This failure has promoted great interest in the stress corrosion susceptibility of medium strength low alloy steel forgings in steam environments. Consequently, initiation and growth of stress corrosion cracks of typical disc steels have been investigated in steam and also in water at 95 0 C. Cracking has been shown to occur, predominantly in an intergranular manner, with growth rates of between 10 -9 and 10 -7 mm sec. -1 . It is observed that corrosion pitting and oxide penetration prior to the establishment of a stress corrosion crack in the plain samples. (author)

  18. Kinetics of steel corrosion in water

    International Nuclear Information System (INIS)

    Vettegren', V.I.; Bashkarev, A.Ya.; Danchukov, K.G.; Morozov, G.I.

    2003-01-01

    Kinetics of corrosion damage accumulation in steels of different composition (Cr-Ni-Mo-Ti, Cr-Ni-Mn-N-V, Cr-Ni-N-Mn-Mo, Cr-Ni-Nb, Cr-Ni-Ti, Cr-Mn-Ni, Mn-Al-Nb-Si, Mn-Cr-Al-Si and Mn-Al-Si) in NaCl solution and in sea water was studied. It is shown that degree of corrosion damage relates to time according to the first order reaction expression. The values of corrosion activation energy and of parameter characterizing protection properties of corrosion film are determined [ru

  19. Corrosion of carbon steel under waste disposal conditions

    International Nuclear Information System (INIS)

    Marsh, G.

    1990-01-01

    The corrosion of carbon steel has been studied in the United Kingdom under granitic groundwater conditions, with pH between 5 and 10 and possibly substantial amounts of Cl - , SO 4 2- and HCO 3 - /CO 3 2- . Corrosion modes considered include uniform corrosion under both aerobic and anaerobic conditions; passive corrosion; localized attack in the form of pitting or crevice corrosion; and environmentally assisted cracking - hydrogen embrittlement or stress corrosion cracking. Studies of these processes are being carried out in order to predict the metal thicknesses required to give container lifetimes of 500 to 1000 years. A simple uniform corrosion model predicts a corrosion rate of around 13.4 μm/a at 20C, rising to 69 μm/a at 50C and 208 μm/a at 90C. A radiation dose of 10 5 rad/h and a G-value of 2.8 for the production of oxidizing species would account for an increase in corrosion rate of 7 μm/a. This model overestimates slightly the results actually achieved for experimental samples exposed for two years, the difference being due to a protective film formed on the samples. These corrosion rates predict that the container must be 227 mm thick to withstand uniform corrosion; however, they predict very high levels of hydrogen production. Conditions will be favourable for localized or pitting corrosion for about 125 years, leading to a maximum penetration of 160 mm. Since the exposure environment cannot be predicted precisely, one cannot state that stress corrosion cracking is impossible. Thus the container must be stress relieved. Other corrosion mechanisms such as microbial corrosion and hydrogen embrittlement are not considered significant

  20. Corrosion behavior of 321 stainless steel in low-acidity uranium nitrate solution

    International Nuclear Information System (INIS)

    Liao Junsheng; Sun Ying; Zhang Wanglin; Ding Ping; Yang Jiangrong; Wu Lunqiang

    2003-01-01

    Weighing and electrochemical methods have been used to investigate the high-temperature uniform corrosion and electrochemical corrosion behavior of lCr18Ni9Ti (321) stainless steel in uranium nitrate solution at different concentrations and pH values. The uniform corrosion results showed that the corrosion rate of 321 stainless steel was less than 0.04 g/m 2 .h, and the visible change of surface smoothness was not observed through 960 h. It was perfect corrosion-resisting in obtained conditions. The electro-chemical corrosion behavior study has been performed to investigate 321 stainless steel in uranium nitrate solutions of the dissolved and saturated oxygen. The corrosion potential and corrosion current density were obtained. Auger photoelectron spectroscopy for measurement of uranium in specimen was used to indicate that uranium is in corrosion product. The corrosion film was measured by Ar ion gun sputter, and the thickness is 10-15 nm. (authors)

  1. Marine Atmospheric Corrosion of Carbon Steel: A Review

    OpenAIRE

    Alc?ntara, Jenifer; de la Fuente, Daniel; Chico, Bel?n; Simancas, Joaqu?n; D?az, Iv?n; Morcillo, Manuel

    2017-01-01

    The atmospheric corrosion of carbon steel is an extensive topic that has been studied over the years by many researchers. However, until relatively recently, surprisingly little attention has been paid to the action of marine chlorides. Corrosion in coastal regions is a particularly relevant issue due the latter’s great importance to human society. About half of the world’s population lives in coastal regions and the industrialisation of developing countries tends to concentrate production pl...

  2. Water vapor effects on the corrosion of steel

    International Nuclear Information System (INIS)

    Estill, J.C.; Gdowski, G.E.

    1995-01-01

    Critical relative humidity for AISI 1020 carbon steel is 75-85% RH at 65 C. Aggressive electrochemical corrosion occurs above 85% RH, while dry oxidation occurs below 75% RH. The reddish-brown product is probably Fe2O3 or its hydrate; the black oxide layer, Fe3O4. The face surfaces had little or no corrosion, while the mill-machined edges were corroded with nonuniform reddish-brown areas

  3. 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)

    Bourdoiseau, Jacques-Andre

    2011-01-01

    mackinawite and greigite. Secondly, to investigate the nature and properties of carbonated rust layers, carbon steel electrodes were polarised anodically in NaHCO 3 electrolytes continuously de-aerated by an argon flow. The experiments were performed at room temperature. The carbonated green rust was observed to form at 0.003 and 0.1 mol L -1 NaHCO 3 whereas FeCO 3 was obtained at the largest concentrations (0.5 and 1 mol L -1 ). Additional experiments were performed similarly in solutions of NaHCO 3 and Na 2 SO 4 . Chukanovite, the Fe(II) hydroxycarbonate with formula Fe 2 (OH) 2 CO 3 , could be obtained in solutions containing 0.03 mol L -1 of each salt. Finally, interactions between sulphide species and corrosion products were studied. Siderite, goethite and lepidocrocite proved to be reactive towards sulphide. So, it seems clear that sulphide species produced by SRB should interact with the rust layer before to reach the metal underneath. Tests were performed with ferrous archaeological artefacts immersed 2 months in anoxic sulphide-containing electrolytes to demonstrate it. The main effect of the immersion was the formation of iron sulphide at the interface between the dense corrosion products layer, mainly constitute of siderite, and the transformed medium, where minerals of the soil are mixed with corrosion products. Sulphide species were not detected at the vicinity of the iron surface. (author)

  4. Corrosion resistance of zinc-magnesium coated steel

    International Nuclear Information System (INIS)

    Hosking, N.C.; Stroem, M.A.; Shipway, P.H.; Rudd, C.D.

    2007-01-01

    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 (Zn 5 Cl 2 (OH) 8 . H 2 O), 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

  5. Electrochemical and weight-loss study of carbon steel corrosion

    International Nuclear Information System (INIS)

    Thomas, V.J.; Olive, R.P.

    2007-01-01

    The Point Lepreau Generating Station (PLGS) will undergo an 18 month refurbishment project beginning in April, 2008. During this time, most of the carbon steel piping in the primary loop will be drained of water and dried. However, some water will remain during the shutdown due to the lack of drains in some lower points in the piping system. As a result, it is necessary to examine the effect of corrosion during the refurbishment. This study examined the effect of several variables on the corrosion rate of clean carbon steel. Specifically, the effect of oxygen in the system and the presence of chloride ions were evaluated. Corrosion rates were determined using both a weight-loss technique and electrochemical methods. The experiment was conducted at room temperature. The corrosion products from the experiment were analyzed using a Raman microscope. The results of the weight-loss measurements show that the corrosion rate of polished carbon steel is independent of both the presence of oxygen and chloride ions. The electrochemical method failed to yield meaningful results due to the lack of clearly interpretable data and the inherent subjectivity in the analysis. Lepidocricite was found to be the main corrosion product using the Raman microscope. (author)

  6. corrosion response of low carbon steel in tropical road mud

    African Journals Online (AJOL)

    Dr Obe

    Corrosion Mitigation efforts using readily available anti- corrosion coatings to protect low carbon steel test coupons against the ... The following protective coating devices were effective: ..... 2 West, J.M (1986): Basic Corrosion and Oxidation,.

  7. The anaerobic corrosion of carbon steel in concrete

    International Nuclear Information System (INIS)

    Naish, C.C.; Balkwill, P.H.; O'Brien, T.M.; Taylor, K.J.; Marsh, G.P.

    1990-11-01

    The report describes the work of a two year programme investigating the anaerobic corrosion of carbon steel embedded in a range of candidate repository cements and concretes at laboratory temperatures. The factors investigated in the study were the rate of the anaerobic corrosion reaction, the effect of hydrogen overpressure on the reaction rate and the form of the corrosion product. Both electrochemical and sample weight loss corrosion rate measurements were used. The cements and concretes used were prepared both with and without small additions of chloride (2% by weight of mix water). The results indicate that the corrosion rate is low, < 1 μm/year, the effect of hydrogen overpressure is not significant over the range of pressures investigated, 1-100 atmospheres, and that the corrosion product is dependent on the cement used to cast the samples. Magnetite was identified in the case of blast furnace slag replacement cements but for pulverised fuel ash and ordinary Portland cements no corrosion product was evident either from X-ray diffraction or laser Raman measurements. Further work is presently underway to investigate the effects of elevated temperatures and chloride levels on the anaerobic corrosion reaction and the rate of hydrogen gas production. (author)

  8. Initiation and developmental stages of steel corrosion in wet H2S environments

    International Nuclear Information System (INIS)

    Bai, Pengpeng; Zhao, Hui; Zheng, Shuqi; Chen, Changfeng

    2015-01-01

    Highlights: • The initiation and development stages of steel corrosion in wet H 2 S environment were investigated. • Preferential dissolution at the grain boundaries of steel allowed corrosion products to form and accumulate. • The shapes and crystal types of corrosion products at various steel layers differed. • With increasing duration time, the S 2− peak with a binding energy of 161.2 eV gradually decreased. • A model of the formation process of corrosion product films was proposed. - Abstract: The initiation and various developmental stages of steel corrosion in H 2 S environments were investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Results revealed that grain boundaries corrode at the initiation stage and that corrosion products initially form on both sides of the grain boundary and then accumulate. Corrosion products grew at the interface between the steel and corrosion product layer at the developmental stage. XPS analyses showed the composition and valence states of the corrosion products, and a model of the formation process of corrosion product films was proposed

  9. Corrosion resistance testing of high-boron-content stainless steels

    International Nuclear Information System (INIS)

    Petrman, I.; Safek, V.

    1994-01-01

    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

  10. Ultrasonic guided wave for monitoring corrosion of steel bar

    Science.gov (United States)

    Liu, Xi; Qin, Lei; Huang, Bosheng

    2018-01-01

    Steel corrosion of reinforced concrete structures has become a serious problem all over the word. In this paper, the work aims at monitoring steel corrosion using ultrasonic guided wave (UGW). Ultrasonic guided wave monitoring is a dynamic and non-destructive testing technology. The advantages of ultrasonic guided wave monitoring for reinforcement corrosion are real-time, online and continuous. In addition, it can judge the different stages of steel bar corrosion, which achieved non-destructive detection.

  11. Corrosion behaviour of carbon steel in the Tournemire clay

    International Nuclear Information System (INIS)

    Foct, F.; Dridi, W.; Cabrera, J.; Savoye, S.

    2004-01-01

    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)

  12. Removal of corrosion products of construction materials in heat carrier

    International Nuclear Information System (INIS)

    1975-01-01

    A review of reported data has been made on the removal of structural material corrosion products into the heat-carrying agent of power reactors. The corrosion rate, and at the same time, removal of corrosion products into the heat-carrying agent (water) decreases with time. Thus, for example, the corrosion rate of carbon steel in boiling water at 250 deg C and O 2 concentration of 0.1 mg/1 after 3000 hr is 0.083 g/m 2 . day; after 9000 hr the corrosion rate has been reduced 2.5 times. Under static conditions the transfer rate of corrosion products into water has been smaller than in the stream and also depends on time. The corrosion rate of carbon steel under nuclear plant operating conditions is almost an order higher over that of steel Kh18N10T

  13. 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.

  14. Steel corrosion in radioactive waste storage tanks

    International Nuclear Information System (INIS)

    Carranza, Ricardo M.; Giordano, Celia M.; Saenz, E.; Weier, Dennis R.

    2004-01-01

    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) [es

  15. The corrosion behaviour of carbon steel in Portland cement

    International Nuclear Information System (INIS)

    Grauer, R.

    1988-01-01

    The production of hydrogen can cause problems in a repository for low- and intermediate-level waste. Since gas production is mainly due to the corrosion of carbon steel, it is important to have as reliable data as possible on the corrosion rate of steel in anaerobic cement. A review of the literature shows that the corrosion current densities lie in the range 0.01 to 0.1 μA/cm 2 (corresponding to corrosion rates between 0.1 and 1.2 μm/a). This implies hydrogen production rates between 0.022 and 0.22 mol/(m 2 .a). Corrosion rates of this order of magnitude are technically irrelevant, with the result that there is very little interest in determining them accurately. Furthermore, their determination entails problems of measurement technique. Given the current situation, it would appear somewhat risky to accept the lower value for hydrogen production as proven. Proposals are made for experiments which would reduce this element of uncertainty. (author) 10 figs., 35 refs

  16. The anaerobic corrosion of carbon steel in concrete

    International Nuclear Information System (INIS)

    Naish, C.C.; Balkwill, P.H.; O'Brien, T.M.; Taylor, K.J.; Marsh, G.P.

    1990-11-01

    The report describes the work of a two year programme investigating the anaerobic corrosion of carbon steel embedded in a range of candidate repository cements and concretes at laboratory ambient temperatures. The factors investigated in the study were the rate of the anaerobic corrosion reaction, the effect of hydrogen overpressure on the reaction rate and the form of the corrosion product. Both electrochemical and sample weight loss corrosion rate measurements were used. The cements and concretes used were prepared both with and without small additions of chloride (2% by weight of mix water). The results indicate that the corrosion rate is low, <1 μm/year, the effect of hydrogen overpressure is not significant over the range of pressures investigated, 1-100 atmospheres, and that the corrosion product is dependent on the cement used to cast the samples. Magnetite was identified in the case of blast furnace slag replacement cements but for pulverised fuel ash and ordinary Portland cements no corrosion product was evident either from X-ray diffraction or laser Raman measurements. (Author)

  17. Corrosion of mild steel and stainless steel by marine Vibrio sp.

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Wagh, A.B.

    Microbially induced corrosion (MIC) of stainless steel and mild steel coupons exposed to media with and without a bacterial culture Vibrio sp. was studied using Scanning Electron Microscope (SEM). Pitting type of corrosion was noticed which was more...

  18. Marine Atmospheric Corrosion of Carbon Steel: A Review.

    Science.gov (United States)

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

    2017-04-13

    The atmospheric corrosion of carbon steel is an extensive topic that has been studied over the years by many researchers. However, until relatively recently, surprisingly little attention has been paid to the action of marine chlorides. Corrosion in coastal regions is a particularly relevant issue due the latter's great importance to human society. About half of the world's population lives in coastal regions and the industrialisation of developing countries tends to concentrate production plants close to the sea. Until the start of the 21st century, research on the basic mechanisms of rust formation in Cl - -rich atmospheres was limited to just a small number of studies. However, in recent years, scientific understanding of marine atmospheric corrosion has advanced greatly, and in the authors' opinion a sufficient body of knowledge has been built up in published scientific papers to warrant an up-to-date review of the current state-of-the-art and to assess what issues still need to be addressed. That is the purpose of the present review. After a preliminary section devoted to basic concepts on atmospheric corrosion, the marine atmosphere, and experimentation on marine atmospheric corrosion, the paper addresses key aspects such as the most significant corrosion products, the characteristics of the rust layers formed, and the mechanisms of steel corrosion in marine atmospheres. Special attention is then paid to important matters such as coastal-industrial atmospheres and long-term behaviour of carbon steel exposed to marine atmospheres. The work ends with a section dedicated to issues pending, noting a series of questions in relation with which greater research efforts would seem to be necessary.

  19. Marine Atmospheric Corrosion of Carbon Steel: A Review

    Science.gov (United States)

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

    2017-01-01

    The atmospheric corrosion of carbon steel is an extensive topic that has been studied over the years by many researchers. However, until relatively recently, surprisingly little attention has been paid to the action of marine chlorides. Corrosion in coastal regions is a particularly relevant issue due the latter’s great importance to human society. About half of the world’s population lives in coastal regions and the industrialisation of developing countries tends to concentrate production plants close to the sea. Until the start of the 21st century, research on the basic mechanisms of rust formation in Cl−-rich atmospheres was limited to just a small number of studies. However, in recent years, scientific understanding of marine atmospheric corrosion has advanced greatly, and in the authors’ opinion a sufficient body of knowledge has been built up in published scientific papers to warrant an up-to-date review of the current state-of-the-art and to assess what issues still need to be addressed. That is the purpose of the present review. After a preliminary section devoted to basic concepts on atmospheric corrosion, the marine atmosphere, and experimentation on marine atmospheric corrosion, the paper addresses key aspects such as the most significant corrosion products, the characteristics of the rust layers formed, and the mechanisms of steel corrosion in marine atmospheres. Special attention is then paid to important matters such as coastal-industrial atmospheres and long-term behaviour of carbon steel exposed to marine atmospheres. The work ends with a section dedicated to issues pending, noting a series of questions in relation with which greater research efforts would seem to be necessary. PMID:28772766

  20. Corrosion processes of alloyed steels in salt solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kienzler, Bernhard [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Institut fuer Nukleare Entsorgung

    2018-02-15

    A summary is given of the corrosion experiments with alloyed Cr-Ni steels in salt solutions performed at Research Centre Karlsruhe (today KIT), Institute for Nuclear Waste Disposal (INE) in the period between 1980 and 2004. Alloyed steels show significantly lower general corrosion in comparison to carbon steels. However, especially in salt brines the protective Cr oxide layers on the surfaces of these steels are disturbed and localized corrosion takes place. Data on general corrosion rates, and findings of pitting, crevice and stress corrosion cracking are presented.

  1. Statistical evaluation of unobserved nonuniform corrosion in A216 steel

    International Nuclear Information System (INIS)

    Pulsipher, B.A.

    1988-07-01

    Tests designed to promote nonuniform corrosion have been conducted at PNL on A216 steel. In all of the tests performed to date, there have been no manifestations of significant nonuniform corrosion. Although this may suggest that nonuniform corrosion in A216 steel may not be a significant problem in the nuclear waste repository, a question arises as to whether enough tests have been conducted for a sufficient length of time to rule out nonuniform corrosion of A216 steel. In this report, a method for determining the required number of tests is examined for two of the mechanisms of nonuniform corrosion: pitting and crevice corrosion

  2. A Study on the Characteristics of Corrosion in Cold Worked Flexible STS 304 Stainless Steel Pipes

    International Nuclear Information System (INIS)

    Kim, In Soo; Kim, Sung Jin

    1993-01-01

    Effects of cold working on the corrosion resistance of austenitic STS 304 stainless steel pipes were investigated using anodic polarization method, EDX analysis and SEM technique. Corrosion products had a lots of S and Cl - ion. Generally, corrosion patterns as a result of STS 304 stainless steel to concrete environment were proceeded in the order of the pitting to intergranular corrosion. In the case of the flexible pipes were covered tightly with other polymer materials, crevice corrosion occurred to a much greater extent on austenitic than on martensitic region

  3. Effect Mo Addition on Corrosion Property and Sulfide Stress Cracking Susceptibility of High Strength Low Alloy Steels

    International Nuclear Information System (INIS)

    Lee, Woo Yong; Koh, Seong Ung; Kim, Kyoo Young

    2005-01-01

    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

  4. Atmospheric Corrosion Behavior and Mechanism of a Ni-Advanced Weathering Steel in Simulated Tropical Marine Environment

    Science.gov (United States)

    Wu, Wei; Zeng, Zhongping; Cheng, Xuequn; Li, Xiaogang; Liu, Bo

    2017-12-01

    Corrosion behavior of Ni-advanced weathering steel, as well as carbon steel and conventional weathering steel, in a simulated tropical marine atmosphere was studied by field exposure and indoor simulation tests. Meanwhile, morphology and composition of corrosion products formed on the exposed steels were surveyed through scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction. Results indicated that the additive Ni in weathering steel played an important role during the corrosion process, which took part in the formation of corrosion products, enriched in the inner rust layer and promoted the transformation from loose γ-FeOOH to dense α-FeOOH. As a result, the main aggressive ion, i.e., Cl-, was effectively separated in the outer rust layer which leads to the lowest corrosion rate among these tested steels. Thus, the resistance of Ni-advanced weathering steel to atmospheric corrosion was significantly improved in a simulated tropical marine environment.

  5. The Corrosion of High Performance Steel in Adverse Environments

    International Nuclear Information System (INIS)

    Cook, Desmond C.

    2005-01-01

    The corrosion products that have formed on weathering steel bridges exposed to different weather conditions in the United States have been evaluated. They have been analyzed by spectroscopic techniques to determine the relationship between protective and non-protective rust coatings, and their relationship to the exposure conditions. Bridges constructed recently using High Performance Steel, as well as older bridges built with Type A588B weathering steel, were evaluated for corrosion performance of the rust coatings. In locations where the steel is subjected to regular wet-dry cycling, where the surface is wet for less than about 20% of the time, a protective patina starts to form after a few months exposure, and continues to an adherent, impervious coating after a decade. The protective patina is characterized by the formation of only goethite and lepidocrocite. The goethite makes up about 80% of the rust, and itself consists of a nanophase component, 40%, or infrequent drying cycles (regions close to waterways, fog or having high humidity), the weathering steel forms a rust coating that consists of a large amount of maghemite, and goethite that contains very little of the nanophase component. The rust coating ex-foliates from the steel and is not protective. Under exposure conditions in which chlorides are deposited onto the weathering steel surface (marine or de-icing salt locations), the protective patina also does not form. Instead, the rust coating consists of a large fraction of akaganeite that forms at the expense of the lepidocrocite and nanophase goethite. The bridges exposed to high chloride concentrations, 1.5 wt%, and therefore having no protective patina, have corrosion rates measured to be 6 times larger than expected for weathering steel with the protective patina

  6. Electrochemical study of corrosion inhibition of stainless steel in phosphoric medium

    Energy Technology Data Exchange (ETDEWEB)

    Hnini, K.; Chtaini, A. [Laboratoire d' Electrochimie et de Bio Corrosion, Faculte des Sciences et Techniques, Beni-Mellal (Morocco); Khouili, M.; Elbouadili, A. [Laboratoire de Chimie Organique et Analytique, Faculte des Sciences et Techniques, Beni-Mellal (Morocco)

    2004-07-01

    The corrosion of metals represents a terrible waste of both natural resources and money, the failure of some stainless steel resulting from pitting corrosion is some times considered a technological problem, consequently, much effort has been expended in attempting to understand and overcome the corrosion therefore, many stainless steel/ environment combinations have been studied. The use of heterocyclic compounds as inhibitors is one of the most practical methods for protection against corrosion in acidic media. In continuation of our work on development of macrocyclic compounds as corrosion inhibitors we report in our study the corrosion inhibiting behaviour of organic compound Methoxy-2-Allyl-4 Phenol (MAP) containing coordinating and conjugation groups, at three forms (natural, polymerized and chemically treated) on the corrosion of stainless steel in phosphoric acid. This study focused on the comparison for corrosion inhibition proprieties of these different applications using potentiodynamic polarization, electrochemical impedance spectroscopy and SEM. The specimen was evaluated to determine change in his corrosion potential and resistance polarization; These MAP products have exhibited corrosion inhibition by maintaining a high resistance polarization (low corrosion rate) in each application. These results reveal that this compound is efficient inhibitor in all forms; the most inhibition efficiency is obtained with polymerized form. To further evaluate the test data, the steel surfaces were analyzed using scanning electron microscopy, SEM observations of surface treated concrete confirmed presence of inhibitor on the steel surfaces. (authors)

  7. 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.

  8. To the corrosion of austenitic steels in sodium loops

    International Nuclear Information System (INIS)

    Schad, M.

    1978-03-01

    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.) [de

  9. Corrosion aspects of steel radioactive waste containers in cementitious materials

    International Nuclear Information System (INIS)

    Smart, Nick

    2012-01-01

    Nick Smart from Serco, UK, gave an overview of the effects of cementitious materials on the corrosion of steel during storage and disposal of various low- and intermediate-level radioactive wastes. Steel containers are often used as an overpack for the containment of radioactive wastes and are routinely stored in an open atmosphere. Since this is an aerobic and typically humid environment, the steel containers can start to corrode whilst in storage. Steel containers often come into contact with cementitious materials (e.g. grout encapsulants, backfill). An extensive account of different steel container designs and of steel corrosion mechanisms was provided. Steel corrosion rates under conditions buffered by cementitious materials have been evaluated experimentally. The main conclusion was that the cementitious environment generally facilitates the passivation of steel materials. Several general and localised corrosion mechanisms need to be considered when evaluating the performance of steel containers in cementitious environments, and environmental thresholds can be defined and used with this aim. In addition, the consequences of the generation of gaseous hydrogen by the corrosion of carbon steel under anoxic conditions must be taken into account. Discussion of the paper included: Is crevice corrosion really significant in cementitious systems? Crevice corrosion is unlikely in the cementitious backfill considered because it will tend to neutralise any acidic conditions in the crevice. What is the role of microbially-induced corrosion (MIC) in cementitious systems? Microbes are likely to be present in a disposal facility but their effect on corrosion is uncertain

  10. Stress corrosion cracking evaluation of precipitation-hardening stainless steel

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1970-01-01

    Accelerated test program results show which precipitation hardening stainless steels are resistant to stress corrosion cracking. In certain cases stress corrosion susceptibility was found to be associated with the process procedure.

  11. Corrosion performance tests for reinforcing steel in concrete : technical report.

    Science.gov (United States)

    2009-10-01

    The existing test method used to assess the corrosion performance of reinforcing steel embedded in : concrete, mainly ASTM G 109, is labor intensive, time consuming, slow to provide comparative results, : and can be expensive. However, with corrosion...

  12. Corrosion performance tests for reinforcing steel in concrete : test procedures.

    Science.gov (United States)

    2009-09-01

    The existing test method to assess the corrosion performance of reinforcing steel embedded in concrete, mainly : ASTM G109, is labor intensive, time consuming, slow to provide comparative results, and often expensive. : However, corrosion of reinforc...

  13. Long-term atmospheric corrosion of mild steel

    International Nuclear Information System (INIS)

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

    2011-01-01

    Research highlights: → Atmospheric corrosion rate stabilises after the first 4-6 years of exposure. → Great compaction of the rust layers in rural and urban atmospheres. → Corrosion (in rural and urban) deviates from common behaviour of bilogarithmic law. → Typical structures of lepidocrocite, goethite and akaganeite are identified. → Formation of hematite (industrial atmosphere) and ferrihydrite (marine atmosphere). - Abstract: A great deal of information is available on the atmospheric corrosion of mild steel in the short, mid and even long term, but studies of the structure and morphology of corrosion layers are less abundant and generally deal with those formed in just a few years. The present study assesses the structure and morphology of corrosion product layers formed on mild steel after 13 years of exposure in five Spanish atmospheres of different types: rural, urban, industrial and marine (mild and severe). The corrosion layers have been characterised by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Long-term corrosion is seen to be more severe in the industrial and marine atmospheres, and less so in the rural and urban atmospheres. In all cases the corrosion rate is seen to decrease with exposure time, stabilising after the first 4-6 years of exposure. The most relevant aspects to be noted are (a) the great compaction of the rust layers formed in the rural and urban atmospheres, (b) the formation of hematite and ferrihydrite phases (not commonly found) in the industrial and marine atmospheres, respectively and (c) identification of the typical morphological structures of lepidocrocite (sandy crystals and flowery plates), goethite (cotton balls structures) and akaganeite (cotton balls structures and cigar-shaped crystals).

  14. Comparison of Corrosion Behavior of Low-Alloy Steel Containing Copper and Antimony with 409L Stainless Steel for a Flue Gas Desulfurization System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun-Ah; Shin, Su-Bin; Kim, Jung-Gu [Sungkyunkwan University, Suwon (Korea, Republic of)

    2016-07-15

    The corrosion behavior of low alloy steel containing Cu, Sb and 409L stainless steel was investigated for application in the low-temperature section of a flue gas desulfurization (FGD) system. The electrochemical properties were evaluated by potentiodynamic polarization testing and electrochemical impedance spectroscopy (EIS) in 16.9 vol% H{sub 2}SO{sub 4} + 0.35 vol% HCl at 60 ℃. The inclusions in these steels ere identified by electron probe microanalyzer (EPMA). The corrosion products of the steels were analyzed using scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The corrosion rate of the low alloy steel containing Cu, Sb was about 100 times lower than that of 409L stainless steel. For stainless steel without passivation, active corrosion behavior was shown. In contrast, in the low alloy steel, the Cu, Sb compounds accumulated on the surface improved the corrosion resistance by suppressing the anodic dissolution reaction.

  15. Effect of Biodiesel Concentration on Corrosion of Carbon Steel by Serratia marcescens

    Directory of Open Access Journals (Sweden)

    Pusparizkita Yustina M

    2018-01-01

    Full Text Available Biodiesel come into being used as an alternative source of energy as the diminishing of petroleum reserves. This fuel is typically stored in tanks that are commonly made from carbon steel, which is easily corroded by microorganisms. Recent studies have shown that bacteria aside from SRB may also be involved in corrosion. Therefore, this research was aimed to evaluate the effect of biodiesel concentration (15%, 20% and 30% v/v mixed in diesel oil on the corrosion of carbon steel by S. marcescens that dominate biocorrosion on hydrocarbon products. In this study, the corrosion process was investigated by evaluation of biofilm morphology and composition, the rate of corrosion and the corrosion product of carbon steel which was exposed in the mixture of hydrocarbons and the presence of S. marcescens. It can be concluded that higher concentration of biodiesel in diesel oil leads to higher growth of bacteria in the biofilm and higher corrosion rate.

  16. Study on corrosion of carbon steel in DEA aqueous solutions

    Science.gov (United States)

    Yang, Jun Han; Xie, Jia Lin; Zhang, Li

    2018-02-01

    Corrosion of carbon steel in the CO2 capture process using diethanolamine (DEA) aqueous solutions was investigated. The effects of the mass concentrations of DEA, solution temperature and CO2 loading on the corrosion rate of carbon steel were demonstrated. The experimental results provided comprehensive information on the appropriate concentration range of DEA aqueous solutions under which low corrosion of carbon steel can be achieved.

  17. The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.

    Science.gov (United States)

    Minnoş, Bihter; Ilhan-Sungur, Esra; Çotuk, Ayşın; Güngör, Nihal Doğruöz; Cansever, Nurhan

    2013-01-01

    The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01).

  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 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...... initiation and propagation of corrosion of steel in concrete are outlined....

  19. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    NICOLAAS

    2014-06-23

    Jun 23, 2014 ... allows for extensive use as the material of construction in petro- leum industries .... steel specimens was investigated after mass-loss analysis ..... Ogbuliec, Inhibition of pseudo-anaerobic corrosion of oil pipeline steel in ...

  20. Corrosion behavior of low-alloy steel in the presence of Desulfotomaculum sp

    International Nuclear Information System (INIS)

    Cetin, Demet; Aksu, Mehmet Levent

    2009-01-01

    The objective of this study was to determine the effect of sulfate-reducing Desulfotomaculum sp. bacteria isolated from a crude oil field on the corrosion of low-alloy steel. The corrosion rate and mechanism were determined with the use of Tafel slopes, mass loss method and electrochemical impedance spectroscopy (EIS). The formation of the biofilm and the corrosion products on the steel surface was determined with scanning electron microscopy (SEM) micrographs and energy dispersive X-ray spectra (EDS) analysis. It was observed from the Tafel plots that the corrosion potential exhibited a cathodic shift that verifies an increase in the corrosion rates. The semicircles tended to open at lower frequencies in the Nyquist plots which indicates the rupture of the protective film. The corrosion current density reached its maximum value at the 14th hour after the inoculation and decreased afterwards. This was attributed to the accumulation of corrosion products on the surface.

  1. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  2. Exposure testing of fasteners in preservative treated wood: Gravimetric corrosion rates and corrosion product analyses

    Energy Technology Data Exchange (ETDEWEB)

    Zelinka, Samuel L., E-mail: szelinka@fs.fed.u [USDA Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726 (United States); Sichel, Rebecca J. [College of Engineering, University of Wisconsin, Madison, WI 53706 (United States); Stone, Donald S. [Department of Materials Science and Engineering, College of Engineering, University of Wisconsin, Madison, WI 53706 (United States)

    2010-12-15

    Research highlights: {yields} The composition of the corrosion products was similar for the nail head and shank. {yields} Reduced copper was not detected on any of the fasteners. {yields} Measured corrosion rates were between 1 and 35 {mu}m year{sup -1}. - Abstract: Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27 {sup o}C at 100% relative humidity for 1 year. The corrosion rate was determined gravimetrically and the corrosion products were analyzed with scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. Although the accepted mechanism of corrosion in treated wood involves the reduction of cupric ions from the wood preservative, no reduced copper was found on the corrosion surfaces. The galvanized corrosion products contained sulfates, whereas the steel corrosion products consisted of iron oxides and hydroxides. The possible implications and limitations of this research on fasteners used in building applications are discussed.

  3. Corrosion processes on weathering steel railway bridge in Prague

    OpenAIRE

    Urban, Viktor; Křivý, Vít; Buchta, Vojtěch

    2016-01-01

    This contribution deals with experimental corrosion tests carried out on the weathering steel railway bridge in Prague. The basic specific property of the weathering steel is an ability to create in favourable environment a protective patina layer on its surface. Since 1968 weathering steel is used under the name “Atmofix” in the Czech Republic and can be used as a standard structural material without any corrosion protection. The weathering steel Atmofix is mostly used for bridge structures ...

  4. Accelerated corrosion of stainless steel in thiocyanate-containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Pistorius, P Chris; Li, Wen

    2012-09-19

    (visible as a black corrosion product) forms during anodic dissolution. The sulfide is electronically conductive, and gives an increase of several orders of magnitude in the electrode capacitance; the sulfide also causes anodic activation to persist after the pure metals and steels were removed from the thiocyanate-containing electrolyte and transferred to a thiocyanate-free electrolyte. The main practical implications of this work are that low concentrations of reduced sulfur compounds strongly affect anodic dissolution of stainless steels, and that selecting steels with elevated concentrations of chromium, nickel or molybdenum would serve to limit the anodic dissolution rate in the presence of reduced sulfur compounds.

  5. Mechanism and degree of chemical elements effect on atmosphere corrosion resistance of steels

    International Nuclear Information System (INIS)

    Vu Din' Vuj

    1991-01-01

    It follows from the proposed regression equations that falourable effect of chemical elements on steel resistance to atmospheric corrosion is determined by their ability to increase interatom bond stability in iron crystal lattice and form corrosion products with high protection properties. Element positive influence on steel corrosion resistance decreases in the following order: S, P, Si, Mn, Cu, Cr, Ni, C in semiurban tropical atmosphere and S, Mn, Sr, Cu, Ni, Cr in coastal atmosphere. In the latter case C increases corrosion in a greater degree as compared to P. Small ammounts of Mo decrease steel resistance in semiurban atmosphere and almost do not influence it in the coastal one. Possible mechanisms of individual element influence on steel corrosion resistance are considered

  6. 77 FR 72827 - Corrosion-Resistant Carbon Steel Flat Products From Germany and the Republic of Korea: Final...

    Science.gov (United States)

    2012-12-06

    ... States Steel Corporation (``U.S. Steel''); ArcelorMittal USA LLC (``AMUSA''); and Nucor Corporation (``Nucor''), within the deadline specified in 19 CFR 351.218(d)(1)(i). The domestic interested parties...

  7. Boric acid corrosion of low alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.; White, G.; Collin, J.; Marks, C. [Dominion Engineering, Inc., Reston, Virginia (United States); Reid, R.; Crooker, P. [Electric Power Research Inst., Palo Alto, California (United States)

    2010-07-01

    In the last decade, the industry has been aware of a potential loss of coolant accident (LOCA) per the following scenario: primary water stress corrosion cracking (PWSCC) of a primary system component or weld leads to a coolant leak, the coolant corrodes a low alloy steel structural component (e.g., the reactor vessel (RV) or the reactor vessel head (RVH)), and corrosion degrades the pressure boundary leading to a loss of coolant accident. The industry has taken several steps to address this concern, including replacement of the most susceptible components (RVH replacement), enhanced inspection (both NDE of components and visual inspections for boric acid deposits), and safety analyses to determine appropriate inspection intervals. Although these measures are generally thought to have adequately addressed this issue, there have been some uncertainties in the safety analyses which the industry has sought to address in order to quantify the extent of conservatism in the safety analyses. Specifically, there has been some uncertainty regarding the rate of boric acid corrosion under various conditions which might arise due to a PWSCC leak and the extent to which boric acid deposits are retained near the leak under various geometries. This paper reviews the results of the Electric Power Research Institute (EPRI) Materials Reliability Program (MRP) boric acid corrosion (BAC) test programs conducted over the last 8 years, focusing on the most recent results of full-scale mockup testing of CRDM nozzle and bottom mounted nozzle (BMN) configurations. The main purpose of this presentation is to provide an overview of the latest understanding of the risk of boric acid corrosion as it is informed by the results of the testing conducted over the last eight years. The rate of boric acid corrosion has been found to be a function of many factors, including initial chemistry, the extent of concentration due to boiling, the temperature at which concentration takes place, the velocity

  8. Marine corrosion of mild steel at Lumut, Perak

    Science.gov (United States)

    Ting, Ong Shiou; Potty, Narayanan Sambu; Liew, Mohd. Shahir

    2012-09-01

    The corrosion rate of structural steels in the adverse marine and offshore environments affects the economic interest of offshore structures since the loss of steel may have significant impact on structural safety and performance. With more emphasis to maintain existing structures in service for longer time and hence to defer replacement costs, there is increasing interest in predicting corrosion rate at a given location for a given period of exposure once the protection coating or cathodic protection is lost. The immersion depth, salinity, steel composition and water pollution will be taken into account. Various corrosion allowances are prescribed for structural members by different standards. There are no studies to determine the appropriate corrosion allowance for steel structures in marine environment in Malaysia. The objectives of the research are to determine the nature and rate of corrosion in mm/year for steel structures in marine environment. It also tries to identify whether the corrosion rate is affected by differences in the chemical composition of the steels, and microalgae. Two sets of corrosion coupons of Type 3 Steel consisting of mild steel were fabricated and immersed in seawater using steel frames. The corrosion rate of the coupon in mm/ per year is estimated based on the material weight loss with time in service. The results are compared with recommendations of the code.

  9. Corrosion behaviour of unalloyed steel in Portland cement

    International Nuclear Information System (INIS)

    Grauer, R.

    1988-04-01

    The production of hydrogen can cause problems in a repository for low and intermediate level waste. Since the production of gas is mainly due to the corrosion of unalloyed steel, it is important to have as reliable data as possible for the corrosion rate in anaerobic cement. A review of the literature shows that the corrosion current densities are in the range of 0.01 to 0.1 μA/cm 2 (corresponding to corrosion rates between 0.1 and 1.2 μm/a). This implies hydrogen production rates between 0.022 and 0.22 mol/(m 2 a). Corrosion rates of the abovementioned order of magnitude are technically irrelevant, so that there is little interest in determining them accurately. Furthermore, their determination entails problems of measurement technique. In the present situation it would therefore appear risky to accept the lower value as proven. Experiments are proposed to reduce the present uncertainty. (author) 35 refs., 10 figs

  10. Corrosion behaviour of unalloyed steel in Portland cement

    International Nuclear Information System (INIS)

    Grauer, R.

    1988-01-01

    The production of hydrogen can cause problems in a repository for low and intermediate level waste. Since the production of gas is mainly due to the corrosion of unalloyed steel, it is important to have as reliable data as possible for the corrosion rate in anaerobic cement. A review of the literature shows that the corrosion current densities are in the range of 0.01 to 0.1 μA/cm 2 (corresponding to corrosion rates between 0.1 and 1.2 μm/a). This implies hydrogen production rates between 0.022 and 0.22 mol/(m 2 xa). Corrosion rates of the abovementioned order of magnitude are technically irrelevant, so that there is little interest in determining them accurately. Furthermore, their determination entails problems of measurement technique. In the present situation it would therefore appear risky to accept the lower value as proven. Experiments are proposed to reduce the present uncertainty. (author) 35 refs., 10 figs

  11. Investigating the Crevice Corrosion Behavior of Coated Stainless Steel in Seawater

    National Research Council Canada - National Science Library

    Kain, Robert

    2000-01-01

    .... austenitic stainless steel. Testing in natural seawater has demonstrated that coatings can protect susceptible stainless steel from barnacle related crevice corrosion and localized corrosion at weldments...

  12. Zinc Addition Effects on General Corrosion of Austenitic Stainless Steels in PWR Primary Conditions

    International Nuclear Information System (INIS)

    Qiao Peipeng; Zhang Lefu; Liu Ruiqin; Jiang Suqing; Zhu Fawen

    2010-01-01

    Zinc addition effects on general corrosion of austenitic stainless steel 316 and 304 were investigated in simulated PWR primary coolant without zinc or with 50 ppb zinc addition at 315 degree C for 500 h. The results show that with the addition of zinc, the corrosion rate of austenitic stainless steel is effectively reduced, the surface oxide film is thinner, the morphology and chemical composition of surface oxide scales are evidently different from those without zinc. There are needle-like corrosion products on the surface of stainless steel 304. (authors)

  13. 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.

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

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Kim, Hong Pyo; Kim, Joung Soo; Machonald, Digby D.

    2005-01-01

    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

  15. Corrosion of low alloy steels in natural seawater. Influence of alloying elements and bacteria

    International Nuclear Information System (INIS)

    Dajoux Malard, Emilie

    2006-01-01

    Metallic infrastructures immersed in natural seawater are exposed to important corrosion phenomena, sometimes characterised as microbiologically influenced corrosion. The presence of alloying elements in low alloy steels could present a corrosion resistance improvement of the structures. In this context, tests are performed with commercial steel grades, from 0,05 wt pc Cr to 11,5 wt pc Cr. They consist in 'on site' immersion in natural seawater on the one hand, and in laboratory tests with immersion in media enriched with marine sulphide-producing bacteria on the other hand. Gravimetric, microbiological, electrochemical measurements and corrosion product analyses are carried out and show that corrosion phenomenon is composed of several stages. A preliminary step is the reduction of the corrosion kinetics and is correlated with the presence of sessile sulphide-producing bacteria and an important formation of sulphur-containing species. This phase is shorter when the alloying element content of the steel increases. This phase is probably followed by an increase of corrosion, appearing clearly after an 8-month immersion in natural seawater for some of the grade steels. Chromium and molybdenum show at the same time a beneficial influence to generalised corrosion resistance and a toxic effect on sulphide-producing bacteria. This multidisciplinary study reflects the complexity of the interactions between bacteria and steels; sulphide-producing bacteria seem to be involved in corrosion processes in natural seawater and complementary studies would have to clarify occurring mechanisms. (author) [fr

  16. Properties of corrosion resistance in C + Mo multi implanted steel

    International Nuclear Information System (INIS)

    Zhang Tonghe; Wu Yuguang; Wang Xiaoyan

    2001-01-01

    The influence of multi-implantation on the corrosion resistance of H13 steel was studied using multi-sweep cyclic voltammetry. The formation conditions of phases and its effects on corrosion resistance were studied. The mechanism of improvement in corrosion resistance was discussed. The experimental results show that the increase of Mo dose can improve corrosion resistance, however the increase of C dose can enhance pitting corrosion potential. Both effects were obtained using dual-and multi-implantation. The passivation layer consists of the phases of Fe 2 Mo, FeMo, MoC, Fe 5 C 3 and Fe 7 C 3 in dual implantation surface of steel. It can improve corrosion resistance and increase pitting corrosion potential. Multi-implantation can further improve corrosion and pitting corrosion resistance compared with dual implantation

  17. 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.

  18. Corrosion protection of steel in ammonia/water heat pumps

    Science.gov (United States)

    Mansfeld, Florian B.; Sun, Zhaoli

    2003-10-14

    Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

  19. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    NICOLAAS

    2014-06-23

    Jun 23, 2014 ... The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium ... the formation of a complex precipitate of protective film, which ... silicon carbide abrasive papers of 80, 120, 220, 800 and 1000 grit ...... ions in sulphuric acid on the corrosion behaviour of stainless steel,.

  20. Water corrosion test of oxide dispersion strengthened (ODS) steel claddings

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    As a part of feasibility study of ODS steel cladding, its water corrosion resistance was examined under water pool condition. Although addition of Cr is effective for preventing water corrosion, excessive Cr addition leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, water corrosion test was conducted for these ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) Corrosion rate of 9Cr-ODS martensitic and 12Cr-ODS ferritic steel are significantly small and no pitting was observed. Thus, these ODS steels have superior resistance for water corrosion under the condition of 60degC and pH8-12. (2) It was showed that 9Cr-ODS martensitic steel and 12Cr-ODS ferritic steel have comparable water corrosion resistance to that of PNC316 and PNC-FMS at 60degC for 1,000h under varying pH of 8, 10. Water corrosion resistance of these alloys is slightly larger than that of PNC316 and PNC-FMS at pH12 without significant difference of appearance and uneven condition. (author)

  1. A new steel with good low-temperature sulfuric acid dew point corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, X.Q.; Li, X.G. [Corrosion and Protection Center, University of Science and Technology Beijing (China); Key Laboratory of Corrosion and Protection (Ministry of Education), Beijing (China); Sun, F.L. [Corrosion and Protection Center, University of Science and Technology Beijing (China); Lv, S.J. [Corrosion and Protection Center, University of Science and Technology Beijing (China); Equipment and Power Department, Shijiazhuang Refine and Chemical Company Limited, SINOPEC, Shijiazhuang (China)

    2012-07-15

    In this work, new steels (1, 2, and 3) were developed for low-temperature sulfuric acid dew point corrosion. The mass loss rate, macro- and micro-morphologies and compositions of corrosion products of new steels in 10, 30, and 50% H{sub 2}SO{sub 4} solutions at its corresponding dew points were investigated by immersion test, scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). The results indicated that mass loss rate of all the tested steels first strongly increased and then decreased as H{sub 2}SO{sub 4} concentration increased, which reached maximum at 30%. Corrosion resistance of 2 steel is the best among all specimens due to its fine and homogeneous morphologies of corrosion products. The electrochemical corrosion properties of new steels in 10 and 30% H{sub 2}SO{sub 4} solutions at its corresponding dew points were studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results demonstrated that corrosion resistance of 2 steel is the best among all the experimental samples due to its lowest corrosion current density and highest charge transfer resistance, which is consistent with the results obtained from immersion tests. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Corrosion of Steel in Concrete – Thermodynamical Aspects

    DEFF Research Database (Denmark)

    Küter, Andre; Møller, Per; Geiker, Mette Rica

    2004-01-01

    The present understanding of selected corrosion phenomena in reinforced concrete is reviewed. Special emphasis is given to chloride induced corrosion. There is a general acceptance of the basic corrosion mechanism for steel in concrete. However different anodic reactions governing the subsequent...

  3. Inhibition of Bio corrosion of steel coupon by sulphate reducing ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Inhibition of Bio corrosion of steel coupon by sulphate reducing bacteria and Iron oxidizing bacteria using .... Ethanol for 24 h. The extract was ... with distilled water to get a zero reading from the meter before .... Ethanol extract of musa species peels as a green corrosion ... Eco friendly extract of banana peel as corrosion ...

  4. Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

    OpenAIRE

    M. Yadav; Debasis Behera; Usha Sharma

    2016-01-01

    The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl)-2-oleylimidazoline (AEOI) and 1-(2-oleylamidoethyl)-2-oleylimidazoline (OAEOI) as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl) and the corrosion inhibition of N80 steel in hydroch...

  5. Corrosion behaviour of sintered duplex stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Utrilla, M. Victoria; Urena, Alejandro; Otero, Enrique; Munez, Claudio Jose [Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2004-07-01

    Duplex austenite-ferrite stainless steels were prepared by mixing austenitic (316L) and ferritic (434L) atomized powders. Although different 316L/434L ratios were prepared, present work centred its study on 50% ferrite - 50% austenite sintered steel. The powders were mixed and pressed at 700 MPa and sintered at 1250 deg. C for 30 min in vacuum. The cooling rate was 5 deg. C/min. Solution treatment was carried out to homogenize the microstructure at 1100 deg. C during 20 min. A microstructural study of the material in solution was performed, evaluating the microstructure, proportion and shape of porosity, and ferrite percentage. This last was measured by two methods, quantitative metallography and Fischer ferrito-metry. The materials were heat treated in the range of 700 to 1000 deg. C, for 10, 30 and 60 min and water quenched, to study the microstructural changes and the influence on the intergranular corrosion resistance. The method used to evaluate the sensitization to the intergranular corrosion was the electrochemical potentio-kinetic reactivation procedure (EPR). The test solution was 0.5 M H{sub 2}SO{sub 4} + 0,01 M KSCN at 30 deg. C. The criterion used to evaluate the sensitization was the ratio between the maximum reactivation density (Ir) and the maximum activation density (Ia). The results of the electrochemical tests were discussed in relation with the microstructures observed at the different heat treatments. (authors)

  6. Irradiated accelerated corrosion of stainless steel

    International Nuclear Information System (INIS)

    Raiman, S.S.; Wang, P.; Was, G.S.

    2015-01-01

    Type 316L stainless steel was exposed to a simulated PWR environment with in-situ proton irradiation to investigate the effect of simultaneous irradiation and corrosion. To enable these experiments, a dedicated beamline was constructed to transport a 3.2 MeV proton beam from a tandem accelerator, through the sample that also acts as the window between the beamline vacuum and a corrosion cell designed to flow primary water at 320 C. degrees and 13.1 MPa. Experiments were conducted on 316L stainless steel samples which were irradiated for 24 hours in 320 C. degrees water with 3 ppm H 2 , at dose rates of 7*10 -6 dpa/s and 7*10 -7 dpa/s, for 4, 24, and 72 hours. A dual-layer oxide formed on the samples, with an inner layer rich in Cr with Fe and Ni content, and an outer layer of Fe oxides. Samples were characterized with TEM (Transmission Electron Microscopy), EDS, and Raman spectroscopy to determine the effect of irradiation. Irradiated samples were found to have a thinner and more porous inner oxide which was deficient in chromium. The outer oxide was found to have significant hematite content, suggesting that irradiation led to an increase in ECP (Electro-Chemical Potential) at the oxide-solution interface, causing accelerated dissolution of the oxide under irradiation. (authors)

  7. Steel fibre corrosion in cracks:durability of sprayed concrete

    OpenAIRE

    Nordström, Erik

    2000-01-01

    Steel fibre reinforced sprayed concrete is common practice for permanent linings in underground construction. Today there is a demand on "expected technical service life" of 120 years. Thin steel fibres could be expected to discontinue carrying load fast with a decrease of fibre diameter caused by corrosion, especially in cracks. The thesis contains results from inspections on existing sprayed concrete structures and a literature review on corrosion of steel fibres in cracked concrete. To stu...

  8. AC-Induced Bias Potential Effect on Corrosion of Steels

    Science.gov (United States)

    2009-02-05

    induction, variable conduction Experimental Setup Super- martensitic stainless steel composition Analysis: C Mn Si Cr Ni Mo Cu N Typical 13 Cr ɘ.01 0.6... stainless steel used in pipelines. •Low carbon (ɘ.01): allows the formation of a “soft” martensite that is more resistant than standard martensitic ...Proposed AC Corrosion Models  AC Simulated Corrosion testing  Stainless steel pipe and coating  Cathodic protection  Experimental Setup  Preliminary

  9. Chromium steel corrosion rates and mechanisms in aqueous nickel chloride at 300C

    International Nuclear Information System (INIS)

    Forrest, J.E.; Broomfield, J.P.; Mitra, P.K.

    1985-01-01

    Rapid corrosion of PWR steam generator carbon steel support structures and consequential denting of steam generator tubes led to investigation of alternative support designs and materials. In recent designs of steam generators the carbon steel drilled hole tube support plate has been replaced by one of quatrefoil or trefoil shape to minimize the contact area. These plates are now made of more corrosion resistant chromium steel (approx. 12%Cr) to ensure that they are less vulnerable to attack in the event of adverse boiler water chemistry. This study was initiated to examine the corrosion behavior of a range of chromium steels in the acid chloride environments characteristic of tube/support plate crevices under adverse boiler water conditions. Objectives of the study were to: 1) determine the relative susceptibility of candidate tube support plate steels to acid chloride corrosion; 2) investigate the corrosion product morphology and its relationship to the corrosion mechanism; 3) determine the effect of environment aggressiveness on 12%Cr (A405) steel corrosion rates and mechanisms; and 4) investigate the effect of restraint stress/environment on denting potential of A405. Experimental method and results are discussed

  10. Stainless Steel Corrosion Studies Final Report: FY17 End of-Year

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Milenski, Helen Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Destiny [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-08

    Two materials are being considered in applications requiring their contact against stainless steel surfaces. These materials include the solvent methyl ethyl ketone (MEK), and the polymer neoprene (polychloroprene). There is concern that contact of these materials with stainless steel substrates may lead to corrosion. To address these concerns we have undertaken corrosion studies under conditions expected to be more aggressive than in intended applications. These conditions include elevated temperature and humidity, and submersion and suspension in solvent vapors, in an attempt to accelerate any potential deleterious interactions. Corrosion rates below 0.1 mpy have historically been deemed INSIGNIFICANT from a WR Production standpoint; corresponding guidelines for non-production applications are lacking.

  11. Corrosion Inhibitor of Carbon Steel from Onion Peel Extract

    Directory of Open Access Journals (Sweden)

    Muhammad Samsudin Asep

    2018-01-01

    Full Text Available Carbon steels composed by two main elements, they are iron (Fe and carbon (C elements which widely used in industrial because of its resistance and more affordable than stainless steel, but their weakness is they have low corrosion resistance. One way to modify carbon steel is by coating them with antioxidant compounds that can delay, slow down, and prevent lipid oxidation process, which obtained from onion peel extract. Several studies on corrosion inhibitors have been performed. However, the efficiency was not reach the optimum. This study aims to examine the effect of onion peel extract concentration on the efficiency of corrosion inhibitor and characterization of the green corrosion inhibitor from onion peel extract. This research method begins by extracting onion peel to 200 ml solvent which we use aquadest and methanol and mixed with 5 grams of crushed onion peel, then let them be extracted for 60 minutes with room temperature. Once it was filtered and the solution obtained, followed by evaporating process with rotary evaporator to decrease the content of solvent. The product is ready to be used as a green corrosion inhibitor of carbon steel in 1 mol/L HCl. While the analysis used is HPLC qualitative analysis, and electroplatting process. The impedance is measured at a frequency of 100 kHz to 4 mHz with an AC current of 10mV. Inhibitor concentrations are vary between 2 ml and 4 ml of onion peel extract. Electroplatting is done within 30 minutes with 10 minutes each checking time. Furthermore, quantitative analysis was done for the analysis of corrosion rate and weight loss. Based on HPLC analysis, it is known that the extract of onion peel contains 1mg/L of quercetin, which is belong to flavonoid group as green inhibitor. While electroplatting process, aquadest solvent having average efficiency of 99,57% for 2 ml of extract, and 99,60% for 4 ml of extract. Methanol solvent having average efficiency of 99,52% for 2 ml of extract and 99

  12. On the corrosion resistance of 01Kh25 ferritic steel

    International Nuclear Information System (INIS)

    Eremeeva, R.A.; Koval', E.K.

    1989-01-01

    Effect of non-ferrous metal ions on corrosion behaviour of 01Kh25 specific low carbon steel as compared to austenitic 12Kh18N10T and 06KhN28MDT steels in boiling solutions of sulfuric and nitric acids and their mixture is studied. Compositions initating commercial ones are chosen the media. It is shown that trough corrosion resistance of 01Kh25 steel in 10% H 2 SO 4 is two order below 06KhN28MDT austenitic steel in presence of Cu 2+ ions as a result of the surface passivation corrosion resistance of ferritic steel is an order higher the austenitic ones. Ferrite steel resistance in the nitric acid and its mixture with sulfuric acid is five timesas much as in 12Kh18N10T austenitic steel

  13. Corrosion of reinforcement bars in steel ibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Solgaard, Anders Ole Stubbe

    and the influence of steel fibres on initiation and propagation of cracks in concrete. Moreover, the impact of fibres on corrosion-induced cover cracking was covered. The impact of steel fibres on propagation of reinforcement corrosion was investigated through studies of their impact on the electrical resistivity...... of concrete, which is known to affect the corrosion process of embedded reinforcement. The work concerning the impact of steel fibres on initiation and propagation of cracks was linked to corrosion initiation and propagation of embedded reinforcement bars via additional studies. Cracks in the concrete cover...... are known to alter the ingress rate of depassivating substances and thereby influence the corrosion process. The Ph.D. study covered numerical as well as experimental studies. Electrochemically passive steel fibres are electrically isolating thus not changing the electrical resistivity of concrete, whereas...

  14. Corrosion susceptibility of steel drums to be used as containers for intermediate level nuclear waste

    Science.gov (United States)

    Farina, S.; Schulz Rodriguez, F.; Duffó, G.

    2013-07-01

    The present work is a study of the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins contaminated with different types and concentrations of aggressive species. A special type of specimen was manufactured to simulate the cemented ion-exchange resins in the drum. The evolution of the corrosion potential and the corrosion rate of the steel, as well as the electrical resistivity of the matrix were monitored over a time period of 900 days. The aggressive species studied were chloride ions (the main ionic species of concern) and sulphate ions (produced during radiolysis of the cationic exchange-resins after cementation). The work was complemented with an analysis of the corrosion products formed on the steel in each condition, as well as the morphology of the corrosion products. When applying the results obtained in the present work to estimate the corrosion depth of the steel drumscontaining the cemented radioactive waste after a period of 300 years (foreseen durability of the Intermediate Level Radioactive Waste facility in Argentina) , it is found that in the most unfavourable case (high chloride contamination), the corrosion penetration will be considerably lower than the thickness of the wall of the steel drums.

  15. Corrosion susceptibility of steel drums to be used as containers for intermediate level nuclear waste

    International Nuclear Information System (INIS)

    Farina, S.; Schulz Rodriguez, F.; Duffo, G.

    2013-01-01

    The present work is a study of the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins contaminated with different types and concentrations of aggressive species. A special type of specimen was manufactured to simulate the cemented ion-exchange resins in the drum. The evolution of the corrosion potential and the corrosion rate of the steel, as well as the electrical resistivity of the matrix were monitored over a time period of 900 days. The aggressive species studied were chloride ions (the main ionic species of concern) and sulphate ions (produced during radiolysis of the cationic exchange-resins after cementation). The work was complemented with an analysis of the corrosion products formed on the steel in each condition, as well as the morphology of the corrosion products. When applying the results obtained in the present work to estimate the corrosion depth of the steel drums containing the cemented radioactive waste after a period of 300 years (foreseen durability of the Intermediate Level Radioactive Waste facility in Argentina), it is found that in the most unfavourable case (high chloride contamination), the corrosion penetration will be considerably lower than the thickness of the wall of the steel drums. (authors)

  16. Influence of heat treatment on corrosive resistance of concrete steels

    International Nuclear Information System (INIS)

    Woldan, A.; Suliga, I.; Kusinski, J.; Jazowy, R.

    1998-01-01

    The reinforcing bars are essential elements of ferro-concrete structures. During the building structure service the reinforcing bars should co-operate with surrounding concrete. Any bonding defects as well as corrosion induced strength reduction may result in construction failure. The reinforcing steel working environment is determined by concrete chemical and phase composition and surrounding environmental properties. The aggressive corrosive activity of the letter implies necessity of effective ways development to protect elements against corrosion. The effect of heat treatment, increased Si content in steel on corrosion resistance of reinforcing steel in concrete was studied in the current work. Corrosion tests and metallographic examinations proved a positive influence of hardening and Si enrichment on corrosion resistance of reinforcing bars in ferro-concrete structures. (author)

  17. Effect of Additional Sulfide and Thiosulfate on Corrosion of Q235 Carbon Steel in Alkaline Solutions

    Directory of Open Access Journals (Sweden)

    Bian Li Quan

    2016-01-01

    Full Text Available This paper investigated the effect of additional sulfide and thiosulfate on Q235 carbon steel corrosion in alkaline solutions. Weight loss method, scanning electron microscopy (SEM equipped with EDS, X-ray photoelectron spectroscopy (XPS, and electrochemical measurements were used in this study to show the corrosion behavior and electrochemistry of Q235 carbon steel. Results indicate that the synergistic corrosion rate of Q235 carbon steel in alkaline solution containing sulfide and thiosulfate is larger than that of sulfide and thiosulfate alone, which could be due to redox reaction of sulfide and thiosulfate. The surface cracks and pitting characteristics of the specimens after corrosion were carefully examined and the corrosion products film is flake grains and defective. The main corrosion products of specimen induced by S2− and S2O32- are FeS, FeS2, Fe3O4, and FeOOH. The present study shows that the corrosion mechanism of S2− and S2O32- is different for the corrosion of Q235 carbon steel.

  18. High temperature corrosion during biomass firing: improved understanding by depth resolved characterisation of corrosion products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2015-01-01

    changes within the near surface region (covering both the deposit and the steel surface). Such cross-section analysis was further complemented by plan view investigations (additionally involving X-ray diffraction) combined with removal of the corrosion products. Improved insights into the nature......The high temperature corrosion of an austenitic stainless steel (TP 347H FG), widely utilised as a superheater tube material in Danish power stations, was investigated to verify the corrosion mechanisms related to biomass firing. KCl coated samples were exposed isothermally to 560 degrees C...... of the corrosion products as a function of distance from the deposit surface were revealed through this comprehensive characterisation. Corrosion attack during simulated straw-firing conditions was observed to occur through both active oxidation and sulphidation mechanisms....

  19. Factors and mechanisms affecting corrosion of steel in concrete

    International Nuclear Information System (INIS)

    Dehqanian, Ch.

    1986-01-01

    Atomic power plants possess reinforced concrete structures which are exposed to sea water or sea atmosphere. Sea water or its surrounding environment contain very corrosive species which cause corrosion of metal in concrete. It should be mentioned that corrosion of steel in concrete is a complex problem that is not completely understood. Some of the factors which influence the corrosion mechanism and can be related to the pore solution composition is discussed. Chloride ion caused problems are the main source of the corrosion damage seen on the reinforced concrete structures. Corrosion rate in concrete varies and depends on the way chloride ion diffuses into concrete. In addition, the associated cations can influence diffusion of chloride into concrete. The type of portland cement and also the concrete mix design all affect the corrosion behaviour of steel in concrete

  20. CORROSION RATE OF STEELS DX51D AND S220GD IN DIFFERENT CORROSION ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Alina Crina CIUBOTARIU

    2016-06-01

    Full Text Available Corrosion in the marine environment is an important issue because the costs causes by marine corrosion increased year upon year. It is necessary a correctly approach to materials selection, protection and corrosion control to reduce this burden of wasted materials, wasted energy and wasted money. Many different types of corrosion attack can be observed to structures, ships and other equipment used in sea water service. Shipping containers are exposed to various corrosive mediums like as airborne salt, industrial pollutants, rain and saltwater. Transport damage during loading onto and unloading off trucks, train beds and ships breaches the paint coating which further contributes to corrosion. The result is shortened container life and high costs for container repair or replacement. The paper intends to evaluate, by gravimetric method, the corrosion rate and corrosion penetration rate of two types of carbon steel DX51D and S220GD. Carbon steel DX51D and hot-dip galvanized steel S220GD are used in marine and industrial applications for buildings cargo vessels, container ships and oil tankers. For testing it was used different corrosive environments: 5% NaOH solution; 5% HCL solution and 0.5M NaCl solution. The samples were immersed in 400mL of testing solution for exposure period of 28 days. Periodically at 3 days, 7 days, 14 days, 21 days and 28 days was measured de mass loss and evaluate the corrosion rate and corrosion stability coefficient. The steel DX51D was stable in 5% NaOH solution for 28 days, the values of corrosion stability coefficient was 7 after 3 days and 6 after 28 days of immersion in corrosive medium. In 5% HCL solution steels DX51D and S220GD was completely corroded in 21 days with a corrosion stability coefficient equal with 9 for 7 days and 8 for 21 days of immersion in corrosive solution. It was observed a good resistance for 3 days in 0.5M NaCl solution with a corrosion stability coefficient equal with 5, but after that

  1. Corrosion of vessel steel during its interaction with molten corium

    International Nuclear Information System (INIS)

    Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Granovsky, V.S.; Lopukh, D.B.; Gusarov, V.V.; Martinov, A.P.; Martinov, V.V.; Fieg, G.; Tromm, W.; Bottomley, D.; Tuomisto, H.

    2006-01-01

    An experimental examination of the cooled vessel steel corrosion during the interaction with molten corium is presented. The experiments have been conducted on 'Rasplav-2' test facility and followed up with physico-chemical and metallographic analyses of melt samples and corium-specimen ingots. The results discussed in the first part of the paper have revealed specific corrosion mechanisms for air and inert atmosphere above the melt. Models have been proposed based on this information and approximate curves constructed for the estimation of the corrosion rate or corrosion depth of vessel steel in conditions simulated by the experiments

  2. Corrosion of vessel steel during its interaction with molten corium

    Energy Technology Data Exchange (ETDEWEB)

    Bechta, S.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation)]. E-mail: bechta@sbor.spb.su; Khabensky, V.B. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Vitol, S.A. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Krushinov, E.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Granovsky, V.S. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Lopukh, D.B. [SPb Electrotechnical University (SpbGETU), Professor Popov str., b.5/3, 197376 St. Petersburg (Russian Federation); Gusarov, V.V. [Institute of Silicate Chemistry of Russian Academy of Science (ISC of RAS), Odoevsky str., b. 24/2, 199155 St. Petersburg (Russian Federation); Martinov, A.P. [SPb Electrotechnical University (SpbGETU), Professor Popov str., b.5/3, 197376 St. Petersburg (Russian Federation); Martinov, V.V. [Scientific Research Technological Institute (NITI), Sosnovy Bor of Leningrad Oblast 188540 (Russian Federation); Fieg, G. [Forshungszentrum Karlsruhe (FZK), Institut fur Neutronenphysik and Reaktortechnik, Postfach 3640, D-78021 Karlsruhe (Germany); Tromm, W. [Forshungszentrum Karlsruhe (FZK), Institut fur Neutronenphysik and Reaktortechnik, Postfach 3640, D-78021 Karlsruhe (Germany); Bottomley, D. [Europaeische Kommission, General Direktion GFS, Institut fuer Transurane (ITU), Postfach 2340, 76125 Karlsruhe (Germany); Tuomisto, H. [Fortum Engineering Ltd. 00048 FORTUM, Rajatorpantie 8, Vantaa (Finland)

    2006-07-15

    An experimental examination of the cooled vessel steel corrosion during the interaction with molten corium is presented. The experiments have been conducted on 'Rasplav-2' test facility and followed up with physico-chemical and metallographic analyses of melt samples and corium-specimen ingots. The results discussed in the first part of the paper have revealed specific corrosion mechanisms for air and inert atmosphere above the melt. Models have been proposed based on this information and approximate curves constructed for the estimation of the corrosion rate or corrosion depth of vessel steel in conditions simulated by the experiments.

  3. Cathodic corrosion protection of steel pipes; Kathodischer Korrosionsschutz von Rohrleitungsstaehlen

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, Markus [SGK Schweizerische Gesellschaft fuer Korrosionsschutz, Zuerich (Switzerland); Schoeneich, Hanns-Georg [Open Grid Europe, Essen (Germany)

    2011-07-01

    The cathodic corrosion protection has been proven excellently in the practical use for buried steel pipelines. This is evidenced statistically by a significantly less frequency of loss compared to non-cathodically protected pipelines. Based on thermodynamic considerations, the authors of the contribution under consideration describe the operation of the cathodic corrosion protection and regular adjustment of the electrochemical potential at the interface steel / soil in practical use. Subsequently, the corrosion scenarios are discussed that may occur when an incorrect setting of the potential results from an operation over several decades. This incorrect setting also can be caused by the failure of individual components of the corrosion protection.

  4. Corrosion of vessel steel during its interaction with molten corium

    International Nuclear Information System (INIS)

    Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Granovsky, V.S.; Lopukh, D.B.; Gusarov, V.V.; Martinov, A.P.; Martinov, V.V.; Fieg, G.; Tromm, W.; Bottomley, D.; Tuomisto, H.

    2006-01-01

    This paper is concerned with corrosion of a cooled vessel steel structure interacting with molten corium in air and neutral (nitrogen) atmospheres during an in-vessel retention scenario. The data on corrosion kinetics at different temperatures on the heated steel surface, heat flux densities and oxygen potential in the system are presented. The post-test physico-chemical and metallographic analyses of melt samples and the corium-specimen ingot have clarified certain mechanisms of steel corrosion taking place during the in-vessel melt interaction

  5. Steel Bar corrosion monitoring based on encapsulated piezoelectric sensors

    Science.gov (United States)

    Xu, Ying; Tang, Tianyou

    2018-05-01

    The durability of reinforced concrete has a great impact on the structural bearing capacity, while the corrosion of steel bars is the main reason for the degradation of structural durability. In this paper, a new type of encapsulated cement based piezoelectric sensor is developed and its working performance is verified. The consistency of the finite element simulation and the experimental results shows the feasibility of monitoring the corrosion of steel bars using encapsulated piezoelectric sensors. The research results show that the corrosion conditions of the steel bars can be determined by the relative amplitude of the measured signal through the encapsulated piezoelectric sensor.

  6. The role of molybdenum in corrosion resistance of stainless steel

    International Nuclear Information System (INIS)

    Abdul Razak bin Daud

    1989-01-01

    The effect of Mo on corrosion properties of stainless steels in 1M MgCl 2 solution was studied using an electrochemical polarization method. Procedure for the preparation of electrochemically polarized samples for surface analysis is described. The samples surface were analyzed using X-ray Photoelectron Spectroscopy (XPS). The stainless steel which has high Mo content has a better resistance to corrosion in Cl containing media. Cr and Mo are enriched in the surface of Mo-bearing stainless steels which have undergone high anodic-metal dissolution. Mo may exist as MoO 2 which is responsible in slowing down the rate of corrosion attack. (author)

  7. Corrosion inhibition of mild steel by Capsicum annuum fruit paste

    Directory of Open Access Journals (Sweden)

    Chandan M. Reddy

    2016-09-01

    Full Text Available The anti-corrosive property of Capsicum annuum fruit paste (CFP on mild steel was investigated. Weight loss and SEM analysis showed that the aqueous and ethanolic solutions of CFP exhibits excellent corrosion inhibition in 2 M HCl. Contact angle, surface atomic composition and FTIR studies verified the presence of an organic film on the mild steel surface. The FTIR spectra also indicated the formation of active compound-Fe complex. CFP thus shows potential as an inexpensive environment friendly corrosion inhibitor for mild steel.

  8. Prediction of external corrosion for steel cylinders

    International Nuclear Information System (INIS)

    Lyon, B.F.

    1997-02-01

    The US Department of Energy (DOE) currently manages the UF 6 Cylinder Program (the program). The program was formed to address the depleted-uranium hexafluoride (UF 6 ) 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 UF 6 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

  9. Effect of noble metals on the corrosion of AISI 316L stainless steel in nitric acid

    International Nuclear Information System (INIS)

    Robin, R.; Andreoletti, G.; Fauvet, P.; Terlain, A.

    2004-01-01

    In the spent fuel treatment, the solutions of fission products contain dissolution fines, in particular platinoids. These solutions are stored into AISI 316L stainless steel tanks, and the contact of noble metallic particles such as platinoids with austenitic stainless steels may induce a shift of the steel corrosion potential towards the trans-passive domain by galvanic coupling. In that case, the steel may be polarized up to a potential value above the range of passive domain, that induces an increase of the corrosion current. The galvanic corrosion of AISI 316L stainless steel in contact with different platinoids has been investigated by electrochemical and gravimetric techniques. Two types of tests were conducted in 1 mol/L nitric acid media at 80 deg C: (1) polarization curves and (2) immersion tests with either platinoid powders (Ru, Rh, Pd) or true insoluble dissolution fines (radioactive laboratory test). The results of the study have shown that even if galvanic coupling enhances the corrosion rate by about a factor 10 in these conditions, the corrosion behavior of AISI 316L remains low (a corrosion rate below 6 μm/year, few small intergranular indentations). No specific effect of irradiation and of elements contained in radioactive fines (other than Ru, Rh and Pd) was observed on corrosion behavior. A platinoids-ranking has also been established according to their coupling potential: Ru > Pd > Rh. (authors)

  10. Accumulation of radioactive corrosion products on steel surfaces of VVER type nuclear reactors. I. 110mAg

    CSIR Research Space (South Africa)

    Hirschberg, G

    1999-03-01

    Full Text Available contaminants in the passive layer formed on austenitic stainless steel. In the first part of the series the accumulation of 110mAg has been investigated. Potential dependent sorption of Ag+. ions (cementation) is found to be the predominant process...

  11. Corrosion behaviour of the welded steel 1.4313/CA6-NM

    OpenAIRE

    Lovíšek, Martin; Liptáková, Tatiana; Pešlová, Františka

    2014-01-01

    The stainless steel 1.4313/CA6-NM (EN X3CrNiMo13-4) is used for turbine production. The weld joints are therefore very sensitive localities from mechanical and corrosion point of view. The subject of the work is corrosion studying of the steel welded by TIG method with consequent heat treatment. Corrosion resistance of the weld joints and base material are evaluated through potentiodynamic polarization test measured on the surface after heat treatment and on the surface cleaned by grinding an...

  12. Effect of Plasma Nitriding Process Conditions on Corrosion Resistance of 440B Martensitic Stainless Steel

    Directory of Open Access Journals (Sweden)

    Łępicka Magdalena

    2014-09-01

    Full Text Available Martensitic stainless steels are used in a large number of various industrial applications, e.g. molds for plastic injections and glass moldings, automotive components, cutting tools, surgical and dental instruments. The improvement of their tribological and corrosion properties is a problem of high interest especially in medical applications, where patient safety becomes a priority. The paper covers findings from plasma nitrided AISI 440B (PN-EN or DIN X90CrMoV18 stainless steel corrosion resistance studies. Conventionally heat treated and plasma nitrided in N2:H2 reaction gas mixture (50:50, 65:35 and 80:20, respectively in two different temperature ranges (380 or 450°C specimens groups were examined. Microscopic observations and electrochemical corrosion tests were performed using a variety of analytical techniques. As obtained findings show, plasma nitriding of AISI 440B stainless steel, regardless of the process temperature, results in reduction of corrosion current density. Nevertheless, applying thermo-chemical process which requires exceeding temperature of about 400°C is not recommended due to increased risk of steel sensitization to intergranular and stress corrosion. According to the results, material ion nitrided in 450°C underwent leaching corrosion processes, which led to significant disproportion in chemical composition of the corroded and corrosion-free areas. The authors suggest further research into corrosion process of plasma nitrided materials and its degradation products.

  13. Corrosion of steel drums containing simulated radioactive waste of low and intermediate level

    International Nuclear Information System (INIS)

    Farina, S.B.; Schulz Rodríguez, F.; Duffó, G.S.

    2013-01-01

    Ion-exchange resins are frequently used during the operation of nuclear power plants and constitute radioactive waste of low and intermediate level. For the final disposal inside the repository the resins are immobilized by cementation and placed inside steel drums. The eventful contamination of the resins with aggressive species may cause corrosion problems to the drums. In order to assess the incidence of this phenomenon and to estimate the lifespan of the steel drums, in the present work, the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins contaminated with different aggressive species was studied. The aggressive species studied were chloride ions (main ionic species of concern) and sulphate ions (produced during radiolysis of the cationic exchange-resins after cementation). The corrosion rate of the steel was monitored over a time period of 900 days and a chemical and morphological analysis of the corrosion products formed on the steel in each condition was performed. When applying the results obtained in the present work to estimate the corrosion depth of the drums containing the cemented radioactive waste after a period of 300 years (foreseen durability of the Low and Intermediate Level Radioactive Waste facility in Argentina), it was found that in the most unfavourable case (high chloride contamination), the corrosion penetration will be considerably lower than the thickness of the wall of the steel drums. (author)

  14. Corrosion characteristics of DMR-1700 steel and comparison with different steels in marine environment

    International Nuclear Information System (INIS)

    Gurrappa, I.; Malakondaiah, G.

    2005-01-01

    In the present paper, a systematic corrosion study has been carried out on DMR-1700 steel to understand the protective nature of oxide scale that forms on its surface under marine environmental conditions. Further, the studies related to oxide scales as well as pitting and crevice corrosion resistance of both stainless steels and widely used low alloy steel EN24 in marine environment have been studied for comparison purpose. The surface morphologies of corroded steels have been observed under scanning electron microscope (SEM) in order to understand the nature of corrosion. A high performance protective coating that has been developed for protection of low alloy steels DMR-1700 and EN24 against corrosion is presented after stressing the importance of surface engineering in enhancing the life of steels. Based on the studies with different techniques, DMR-1700 steel has been recommended for manufacture of components used in aerospace systems in association with appropriate protective coating for improving their efficiency

  15. Corrosion fatigue behaviour of ion nitrided AISI 4140 steel

    Energy Technology Data Exchange (ETDEWEB)

    Genel, K. [Sakarya Univ., Adapazari (Turkey). Mech. Eng. Dept.; Demirkol, M.; Guelmez, T. [Faculty of Mechanical Engineering, Istanbul Technical University, Guemuessuyu, 80191, Istanbul (Turkey)

    2000-08-31

    Machine components suffer from corrosion degradation of fatigue characteristics and improvement can be attained by the application of a nitriding treatment, particularly to low alloy steels. In the present study, the effect of ion nitriding on corrosion fatigue performance of AISI 4140 steel has been investigated by conducting a series of rotary bending corrosion fatigue tests at 95 Hz, in 3% NaCl aqueous solution. Hourglass shaped, 4 mm diameter fatigue specimens were ion nitrided at 748 K for 1, 3, 8 and 16 h prior to the tests. It was observed that distinct fatigue limit behaviour of ion nitrided steel in air completely disappeared in corrosive environment besides severe degradation in fatigue characteristics. An improvement reaching to 60% in corrosion fatigue strength can be attained by successive ion nitriding practice based on a fatigue life of 10{sup 7} cycles. An attempt was made to establish an empirical relationship between corrosion fatigue strength and relative case depth, which considers the size of the ion nitrided specimen. It was also determined that a power relationship holds between corrosion fatigue strength and fatigue life of ion nitrided steel. The presence of white layer has resulted in additional improvement in corrosion fatigue resistance, and it was observed that corrosion fatigue cracks were initiated dominantly under the white layer by pit formation mechanism. (orig.)

  16. Corrosion fatigue behaviour of ion nitrided AISI 4140 steel

    International Nuclear Information System (INIS)

    Genel, K.

    2000-01-01

    Machine components suffer from corrosion degradation of fatigue characteristics and improvement can be attained by the application of a nitriding treatment, particularly to low alloy steels. In the present study, the effect of ion nitriding on corrosion fatigue performance of AISI 4140 steel has been investigated by conducting a series of rotary bending corrosion fatigue tests at 95 Hz, in 3% NaCl aqueous solution. Hourglass shaped, 4 mm diameter fatigue specimens were ion nitrided at 748 K for 1, 3, 8 and 16 h prior to the tests. It was observed that distinct fatigue limit behaviour of ion nitrided steel in air completely disappeared in corrosive environment besides severe degradation in fatigue characteristics. An improvement reaching to 60% in corrosion fatigue strength can be attained by successive ion nitriding practice based on a fatigue life of 10 7 cycles. An attempt was made to establish an empirical relationship between corrosion fatigue strength and relative case depth, which considers the size of the ion nitrided specimen. It was also determined that a power relationship holds between corrosion fatigue strength and fatigue life of ion nitrided steel. The presence of white layer has resulted in additional improvement in corrosion fatigue resistance, and it was observed that corrosion fatigue cracks were initiated dominantly under the white layer by pit formation mechanism. (orig.)

  17. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-01-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. The efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness, and as a monitor of system corrosion effects. The discussion is based mostly on the results and observations from Ontario Hydro plants, and their comparisons with PWRs. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of lay-up and various start-up conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on corrosion-product transport on the primary side of steam generators are also discussed. (author)

  18. Image-based corrosion recognition for ship steel structures

    Science.gov (United States)

    Ma, Yucong; Yang, Yang; Yao, Yuan; Li, Shengyuan; Zhao, Xuefeng

    2018-03-01

    Ship structures are subjected to corrosion inevitably in service. Existed image-based methods are influenced by the noises in images because they recognize corrosion by extracting features. In this paper, a novel method of image-based corrosion recognition for ship steel structures is proposed. The method utilizes convolutional neural networks (CNN) and will not be affected by noises in images. A CNN used to recognize corrosion was designed through fine-turning an existing CNN architecture and trained by datasets built using lots of images. Combining the trained CNN classifier with a sliding window technique, the corrosion zone in an image can be recognized.

  19. Monitoring Corrosion of Steel Bars in Reinforced Concrete Structures

    Science.gov (United States)

    Verma, Sanjeev Kumar; Bhadauria, Sudhir Singh; Akhtar, Saleem

    2014-01-01

    Corrosion of steel bars embedded in reinforced concrete (RC) structures reduces the service life and durability of structures causing early failure of structure, which costs significantly for inspection and maintenance of deteriorating structures. Hence, monitoring of reinforcement corrosion is of significant importance for preventing premature failure of structures. This paper attempts to present the importance of monitoring reinforcement corrosion and describes the different methods for evaluating the corrosion state of RC structures, especially hal-cell potential (HCP) method. This paper also presents few techniques to protect concrete from corrosion. PMID:24558346

  20. Monitoring corrosion of steel bars in reinforced concrete structures.

    Science.gov (United States)

    Verma, Sanjeev Kumar; Bhadauria, Sudhir Singh; Akhtar, Saleem

    2014-01-01

    Corrosion of steel bars embedded in reinforced concrete (RC) structures reduces the service life and durability of structures causing early failure of structure, which costs significantly for inspection and maintenance of deteriorating structures. Hence, monitoring of reinforcement corrosion is of significant importance for preventing premature failure of structures. This paper attempts to present the importance of monitoring reinforcement corrosion and describes the different methods for evaluating the corrosion state of RC structures, especially hal-cell potential (HCP) method. This paper also presents few techniques to protect concrete from corrosion.

  1. Monitoring Corrosion of Steel Bars in Reinforced Concrete Structures

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar Verma

    2014-01-01

    Full Text Available Corrosion of steel bars embedded in reinforced concrete (RC structures reduces the service life and durability of structures causing early failure of structure, which costs significantly for inspection and maintenance of deteriorating structures. Hence, monitoring of reinforcement corrosion is of significant importance for preventing premature failure of structures. This paper attempts to present the importance of monitoring reinforcement corrosion and describes the different methods for evaluating the corrosion state of RC structures, especially hal-cell potential (HCP method. This paper also presents few techniques to protect concrete from corrosion.

  2. Effects of Si as alloying element on corrosion resistance of weathering steel

    International Nuclear Information System (INIS)

    Mejía Gómez, J.A.; Antonissen, J.; Palacio, C.A.; De Grave, E.

    2012-01-01

    Highlights: ► Weathering steels with different concentrations of Si as alloying element were exposed to laboratory atmospheric conditions. ► The iron oxides formed as corrosion products were characterized and analyzed by XRD, TEM and Mössbauer spectroscopy. ► Silicon affects the corrosion resistance of weathering steels. ► Silicon promotes the formation of goethite as corrosion product with small particle size. - Abstract: The corrosion resistance in saline conditions of weathering steel with different concentrations of Si (1, 2 and 3 wt.%) exposed to dip dry tests (simulating wet/dry cycles of atmospheric corrosion) was studied by weight loss, X-ray diffraction, Mössbauer spectroscopy and transmission electron microscopy. The results showed that the steels exhibit better corrosion performance with increasing Si concentration. The formation of Fe-oxides such as goethite, lepidocrocite and magnetite was observed. Superparamagnetic goethite is the dominant phase in the rust developed on the Si steels, indicating that Si favors the formation of goethite with small particle size.

  3. Stress-Corrosion Cracking in Martensitic PH Stainless Steels

    Science.gov (United States)

    Humphries, T.; Nelson, E.

    1984-01-01

    Precipitation-hardening alloys evaluated in marine environment tests. Report describes marine-environment stress-corrosion cracking (SCC) tests of three martensitic precipitation hardening (PH) stainless-steel alloys.

  4. Corrosion resistance of chromium-nickel steel containing rare earths

    International Nuclear Information System (INIS)

    Asatiani, G.N.; Mandzhgaladze, S.N.; Tavadze, L.F.; Chuvatina, S.N.; Saginadze, D.I.

    1983-01-01

    Effect of additional out-of-furnace treatment with complex alloy (foundry alloy) calcite-silicon-magnesium-rare earth metal on corrosion resistance of the 03Kh18N20M3D3C3B steel has been studied. It is shown that introduction of low additions of rare earths improves its corrosion resistance improves its corrosion resistance in agressive media (in 70% - sulfuric acid) in the range of transition from active to passive state. Effect of additional introduction of rare earth metals is not considerable, if potential of steel corrosion is in the range of stable passive state (32% - sulfuric acid). Additional out-of-furnace treatment with complex foundry alloy, containing rare earth metals, provides a possibility to use a steel with a lower content of Cr, Ni, Mo, than in conventional acid-resistant steels in highly agressive media

  5. An Evaluation of Carbon Steel Corrosion Under Stagnant Seawater Conditions

    National Research Council Canada - National Science Library

    Lee, Jason

    2004-01-01

    Corrosion, of 1020 carbon steel coupons in, natural seawater over a six-month period was more aggressive under stagnant anaerobic conditions than stagnant aerobic conditions as measured by weight loss...

  6. Stress Corrosion Cracking of Type 304 Stainless Steel

    National Research Council Canada - National Science Library

    Louthan, M

    1964-01-01

    Stress corrosion cracking of type 304 stainless steel exposed in dilute chloride solutions is being investigated at the Savannah River Laboratory in attempts to develop a fundamental understanding of the phenomenon...

  7. Structure, mechanical and corrosion properties of powdered stainless steel Kh13

    International Nuclear Information System (INIS)

    Radomysel'skij, I.D.; Napara-Volgina, S.G.; Orlova, L.N.; Apininskaya, L.M.

    1982-01-01

    Structure, mechanical and corrosion properties are studied for compact powdered stainless steel, Grade Kh13, produced from prealloyed powder and a mixture of chromium and iron powders by hot vacuum pressing (HVP) following four schemes: HVP of unsintered billets; HVP of presintered billets; HVP of unsintered billets followed by diffusion annealing; HVP of sintered billets followed by diffusion annealing. Analysis of the structure, mechanical and corrosion properties of Kh13 steel produced according to the four schemes confirmed that production of this steel by the HVP method without presintering of porous billets and diffusion annealing of compact stampings is possible only when prealloyed powder of particular composition is used as a starting material

  8. Super-Hydrophobic Green Corrosion Inhibitor On Carbon Steel

    Science.gov (United States)

    Hassan, H.; Ismail, A.; Ahmad, S.; Soon, C. F.

    2017-06-01

    There are many examples of organic coatings used for corrosion protection. In particular, hydrophobic and super-hydrophobic coatings are shown to give good protection because of their enhanced ability to slow down transport of water and ions through the coating. The purpose of this research is to develop water repellent coating to avoid direct contact between metal and environment corrosive and mitigate corrosion attack at pipeline system. This water repellent characteristic on super-hydrophobic coating was coated by electrodeposition method. Wettability of carbon steel with super-hydrophobic coating (cerium chloride and myristic acid) and oxidized surface was investigated through contact angle and inhibitor performance test. The inhibitor performance was studied in 25% tannin acid corrosion test at 30°C and 3.5% sodium chloride (NaCl). The water contact angle test was determined by placing a 4-μL water droplet of distilled water. It shows that the wettability of contact angle super-hydrophobic with an angle of 151.60° at zero minute can be classified as super-hydrophobic characteristic. By added tannin acid as inhibitor the corrosion protection on carbon steel becomes more consistent. This reveals that the ability of the coating to withstand with the corrosion attack in the seawater at different period of immersions. The results elucidate that the weight loss increased as the time of exposure increased. However, the corrosion rates for uncoated carbon steel is high compared to coated carbon steel. As a conclusion, from both samples it can be seen that the coated carbon steel has less corrosion rated compared to uncoated carbon steel and addition of inhibitor to the seawater provides more protection to resist corrosion attack on carbon steel.

  9. Hot Corrosion Behavior of Stainless Steel with Al-Si/Al-Si-Cr Coating

    Science.gov (United States)

    Fu, Guangyan; Wu, Yongzhao; Liu, Qun; Li, Rongguang; Su, Yong

    2017-03-01

    The 1Cr18Ni9Ti stainless steel with Al-Si/Al-Si-Cr coatings is prepared by slurry process and vacuum diffusion, and the hot corrosion behavior of the stainless steel with/without the coatings is studied under the condition of Na2SO4 film at 950 °C in air. Results show that the corrosion kinetics of stainless steel, the stainless steel with Al-Si coating and the stainless steel with Al-Si-Cr coating follow parabolic laws in several segments. After 24 h corrosion, the sequence of the mass gain for the three alloys is the stainless steel with Al-Si-Cr coating coating coating. The corrosion products of the three alloys are layered. Thereinto, the corrosion products of stainless steel without coating are divided into two layers, where the outside layer contains a composite of Fe2O3 and FeO, and the inner layer is Cr2O3. The corrosion products of the stainless steel with Al-Si coating are also divided into two layers, of which the outside layer mainly consists of Cr2O3, and the inner layer is mainly SiO2. The corrosion film of the stainless steel with Al-Si-Cr coating is thin and dense, which combines well with substrate. Thereinto, the outside layer is mainly Cr2O3, and the inside layer is Al2O3. In the matrix of all of the three alloys, there exist small amount of sulfides. Continuous and protective films of Cr2O3, SiO2 and Al2O3 form on the surface of the stainless steel with Al-Si and Al-Si-Cr coatings, which prevent further oxidation or sulfide corrosion of matrix metals, and this is the main reason for the much smaller mass gain of the two alloys than that of the stainless steel without any coatings in the 24 h hot corrosion process.

  10. Local corrosion of high alloy steels under biodeposits

    International Nuclear Information System (INIS)

    Korovyakova, M.D.; Nikitin, V.M.; Speshneva, N.V.

    1999-01-01

    Impact of the bacteriozenosis different structural-functional state under biodeposits on corrosion resistance of the 12Kh18N10T and Kh18N10T high-alloy steels in the natural seawater is studied. It is shown that saturation of natural micro communities by separate aerobic and facultative-anaerobic bacterial monocultures increases corrosion resistance of these steels by their overgrow with biodeposits [ru

  11. Corrosion under stress of AISI 304 steel in thiocyanate solutions

    International Nuclear Information System (INIS)

    Perillo, P.M.; Duffo, G.S.

    1989-01-01

    Corrosion susceptibility under stress of AISI 304 steel sensitized in a sodium thiocyanate solution has been studied and results were compared with those obtained with solutions of thiosulfate and tetrathionate. Sensitized steel type 304 is highly susceptible to corrosion when under intergranular stress (IGSCC) in thiocyanate solutions but the aggressiveness of this anion is less than that of the other sulphur anions studied (thiosulfate and tetrathionate). This work has been partly carried out in the Chemistry Department. (Author) [es

  12. On the use of triazines as inhibitors of steel corrosion

    International Nuclear Information System (INIS)

    Sizaya, O.I.; Andrushko, A.P.

    2004-01-01

    A possibility of using substandard pesticides as a raw materials for synthesis of a set of triazines and also using them as a inhibitors of acidic corrosion of steel 20, as well as additions to epoxy powder coatings is considered. It is shown that triazines studied are inhibitors of acidic corrosion of steel 20. 2,4-di(ethylamino)-6-phenylhydrazono-1,3,5-triazine (In 4) has a maximum inhibiting effect among the studied compounds [ru

  13. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

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

    Directory of Open Access Journals (Sweden)

    Oluleke OLUWOLE

    2010-12-01

    Full Text Available 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 determined at intervals of 5 days for the duration of the exposure period. The result showed corrosion attack on the nickel- plated steel, the severity decreasing with the increasing weight of nickel coating on substrate. The result showed that thinly plated low carbon steel generally did not have any advantage over unplated steel. The pH of the tomato solution which initially was acidic was observed to progress to neutrality after 4 days and then became alkaline at the end of the thirty days test (because of corrosion product contamination of the tomatocontributing to the reduced corrosion rates in the plated samples after 10 days. Un-plated steel was found to be unsuitable for the fabrication of tomato processing machinery without some form of surface treatment - thick nickel plating is suitable as a protective coating in this environment.

  15. Pitting corrosion in austenitic stainless steel water tanks of hotel trains

    International Nuclear Information System (INIS)

    Moreno, D. A.; Garcia, A. M.; Ranninger, C.; Molina, B.

    2011-01-01

    The water storage tanks of hotel trains suffered pitting corrosion. To identify the cause, the tanks were subjected to a detailed metallographic study and the chemical composition of the austenitic stainless steels used in their construction was determined. Both the tank water and the corrosion products were further examined by physicochemical and microbiological testing. Corrosion was shown to be related to an incompatibility between the chloride content of the water and the base and filler metals of the tanks. These findings formed the basis of recommendations aimed at the prevention and control of corrosion in such tanks. (Author) 18 refs.

  16. Effects of chloride ions on corrosion of ductile iron and carbon steel in soil environments.

    Science.gov (United States)

    Song, Yarong; Jiang, Guangming; Chen, Ying; Zhao, Peng; Tian, Yimei

    2017-07-31

    Chloride is reported to play a significant role in corrosion reactions, products and kinetics of ferrous metals. To enhance the understanding of the effects of soil environments, especially the saline soils with high levels of chloride, on the corrosion of ductile iron and carbon steel, a 3-month corrosion test was carried out by exposing ferrous metals to soils of six chloride concentrations. The surface morphology, rust compositions and corrosion kinetics were comprehensively studied by visual observation, scanning electron microscopy (SEM), X-Ray diffraction (XRD), weight loss, pit depth measurement, linear polarization and electrochemical impedance spectroscopy (EIS) measurements. It showed that chloride ions influenced the characteristics and compositions of rust layers by diverting and participating in corrosion reactions. α-FeOOH, γ-FeOOH and iron oxides were major corrosion products, while β-Fe 8 O 8 (OH) 8 Cl 1.35 rather than β-FeOOH was formed when high chloride concentrations were provided. Chloride also suppressed the decreasing of corrosion rates, whereas increased the difficulty in the diffusion process by thickening the rust layers and transforming the rust compositions. Carbon steel is more susceptible to chloride attacks than ductile iron. The corrosion kinetics of ductile iron and carbon steel corresponded with the probabilistic and bilinear model respectively.

  17. The Effects of Corrosive Chemicals on Corrosion Rate of Steel Reinforcement Bars: II. Swamp Sludges

    Directory of Open Access Journals (Sweden)

    Henki Ashadi

    2010-10-01

    Full Text Available A polluted environment will influence the building age. The objective of this research was to find out the influence of corrosive chemicals within the sludge swamp area with the corrosion rate of steel concrete. Corrosion in steel concrete usually occur in acid area which contain of SO42-, Cl- and NO3-. The research treatment used by emerging ST 37 andST 60 within 60 days in 'polluted' sludge swamp area. Three variation of 'polluted' swamp sludge were made by increasing the concentration a corrosive unsure up to 1X, 5X and 10X. The corrosion rate measured by using an Immersion Method. The result of Immersion test showed that sulphate had a greatest influence to corrosion rate of ST 37 and ST 60 and followed by chloride and nitrate. Corrosion rate value for ST 37 was 17.58 mpy and for ST 60 was 12.47 mpy.

  18. Corrosion of steel structures in sea-bed sediment

    Indian Academy of Sciences (India)

    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 ...

  19. Effect of Pseudomonas fluorescens on Buried Steel Pipeline Corrosion.

    Science.gov (United States)

    Spark, Amy J; Law, David W; Ward, Liam P; Cole, Ivan S; Best, Adam S

    2017-08-01

    Buried steel infrastructure can be a source of iron ions for bacterial species, leading to microbiologically influenced corrosion (MIC). Localized corrosion of pipelines due to MIC is one of the key failure mechanisms of buried steel pipelines. In order to better understand the mechanisms of localized corrosion in soil, semisolid agar has been developed as an analogue for soil. Here, Pseudomonas fluorescens has been introduced to the system to understand how bacteria interact with steel. Through electrochemical testing including open circuit potentials, potentiodynamic scans, anodic potential holds, and electrochemical impedance spectroscopy it has been shown that P. fluorescens increases the rate of corrosion. Time for oxide and biofilms to develop was shown to not impact on the rate of corrosion but did alter the consistency of biofilm present and the viability of P. fluorescens following electrochemical testing. The proposed mechanism for increased corrosion rates of carbon steel involves the interactions of pyoverdine with the steel, preventing the formation of a cohesive passive layer, after initial cell attachment, followed by the formation of a metal concentration gradient on the steel surface.

  20. Corrosion and hydrogen permeation of A216 Grade WCA steel in hydrothermal magnesium-containing brines

    International Nuclear Information System (INIS)

    Haberman, J.H.; Frydrych, D.J.; Westerman, R.E.

    1988-03-01

    Corrosion rates determined at 1 month in 150/degree/C brine increased with magnesium concentration. The structure of the corrosion product, as determined by x-ray diffraction, depended upon the magnesium concentration. In brines with less than 10,000 ppM magnesium, the primary corrosion product had a spinel structure characteristic of magnetite or magnesioferrite. In brines containing magnesium concentrations greater than 20,000 ppM, the primary corrosion product had the amakinite structure characteristic of a complex iron-magnesium hydroxide. The high corrosion rates observed in brines containing high magnesium concentrations suggest that the corrosion products having the amakinite structure is less protective than corrosion products having the spinel structure. Corrosion rates in high-magnesium (inclusion) brine determined over a 6-month test duration were essentially constant. Hydrogen permeation rates observed in exposing mild steel to high-Mg/sup 2/plus// brine at 150/degree/C could be potentially damaging to a mild steel waste package container. The rate of hydrogen permeation was proportional to the brine flow rate in the autoclave. Thiourea additions to the brine increased the hydrogen permeation rate; sulfate and bromide ion additions did not. The maximum gaseous hydrogen pressure attainable is not known (based on 3Fe /plus/ 4H 2 O /plus/ Fe(sub 3)O /plus/ 4H 2 , would be /approximately/900 atmospheres), and the dependence of permeation rate on temperature is not known. 8 refs., 13 figs., 3 tabs

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

    International Nuclear Information System (INIS)

    Smart, N.R.; Blackwood, D.J.; Werme, L.

    2001-07-01

    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

  2. Natural Corrosion Inhibitors for Steel Reinforcement in Concrete — a Review

    Science.gov (United States)

    Raja, Pandian Bothi; Ghoreishiamiri, Seyedmojtaba; Ismail, Mohammad

    2015-04-01

    Reinforced concrete is one of the widely used construction materials for bridges, buildings, platforms and tunnels. Though reinforced concrete is capable of withstanding a large range of severe environments including marine, industrial and alpine conditions, there are still a large number of failures in concrete structures for many reasons. Either carbonation or chloride attack is the main culprit which is due to depassivation of reinforced steel and subsequently leads to rapid steel corrosion. Among many corrosion prevention measures, application of corrosion inhibitors play a vital role in metal protection. Numerous range of corrosion inhibitors were reported for concrete protection that were also used commercially in industries. This review summarizes the application of natural products as corrosion inhibitors for concrete protection and also scrutinizes various factors influencing its applicability.

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

    Energy Technology Data Exchange (ETDEWEB)

    Smart, N.R. [AEA Technology plc, Culham Science Centre (United Kingdom); Blackwood, D.J. [National Univ. of Singapore (Singapore); Werme, L. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2001-07-01

    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.

  4. Microbiologically influenced corrosion of galvanized steel by Desulfovibrio sp. and Desulfosporosinus sp. in the presence of Ag–Cu ions

    Energy Technology Data Exchange (ETDEWEB)

    Ilhan-Sungur, Esra, E-mail: esungur@istanbul.edu.tr [Istanbul University, Faculty of Science, Department of Biology, 34134 Vezneciler, Istanbul (Turkey); Unsal-Istek, Tuba [Istanbul University, Faculty of Science, Department of Biology, 34134 Vezneciler, Istanbul (Turkey); Cansever, Nurhan [Yıldız Technical University, Faculty of Chemistry-Metallurgy, Metallurgical and Materials Engineering Department, 34210 Esenler, Istanbul (Turkey)

    2015-07-15

    The effects of Ag–Cu ions on the microbiologically induced corrosion of galvanized steel in the presence of Desulfovibrio sp. and Desulfosporosinus sp. were investigated. The corrosion behavior of galvanized steel was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy. The biofilm, corrosion products and Ag–Cu ions on the surfaces were investigated by using scanning electron microscopy, energy dispersive X-ray spectrometry and elemental mapping. The biofilm layer formed by the Desulfovibrio sp. was stable covering the all surface of galvanized steel coupons, while that by Desulfosporosinus sp. was intermittent, highly porous and heterogeneous. It was found that both of the sulfate reducing bacteria species accelerated corrosion of the galvanized steel. However, it was detected that Desulfosporosinus sp. was more corrosive for galvanized steel than Desulfovibrio sp. Scanning electron microscopy images showed that Desulfovibrio sp. and Desulfosporosinus sp. in biofilm clustered into patches on the galvanized steel surface when the culture contained toxic Ag–Cu ions. The ions affected the growth of the sulfate reducing bacteria strains in different ways and hence the corrosion behaviors. It was observed that the Ag–Cu ions affected negatively growth of Desulfosporosinus sp. especially after 24 h of exposure leading to a decrease in the corrosion rate of galvanized steel. However, Desulfovibrio sp. showed more corrosive effect in the presence of the ions according to the ions-free culture. Energy dispersive X-ray spectrometry analysis showed that corrosion products on the surfaces were mainly composed of Zn, S, Na, O and P. - Highlights: • Galvanized steel was corroded by Desulfosporosinus sp. and Desulfovibrio sp. • Desulfosporosinus sp. is more corrosive than Desulfovibrio sp. • The Ag–Cu ions affected corrosion behavior of Desulfosporosinus sp. and Desulfovibrio sp. on galvanized steel.

  5. Microbiologically influenced corrosion of galvanized steel by Desulfovibrio sp. and Desulfosporosinus sp. in the presence of Ag–Cu ions

    International Nuclear Information System (INIS)

    Ilhan-Sungur, Esra; Unsal-Istek, Tuba; Cansever, Nurhan

    2015-01-01

    The effects of Ag–Cu ions on the microbiologically induced corrosion of galvanized steel in the presence of Desulfovibrio sp. and Desulfosporosinus sp. were investigated. The corrosion behavior of galvanized steel was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy. The biofilm, corrosion products and Ag–Cu ions on the surfaces were investigated by using scanning electron microscopy, energy dispersive X-ray spectrometry and elemental mapping. The biofilm layer formed by the Desulfovibrio sp. was stable covering the all surface of galvanized steel coupons, while that by Desulfosporosinus sp. was intermittent, highly porous and heterogeneous. It was found that both of the sulfate reducing bacteria species accelerated corrosion of the galvanized steel. However, it was detected that Desulfosporosinus sp. was more corrosive for galvanized steel than Desulfovibrio sp. Scanning electron microscopy images showed that Desulfovibrio sp. and Desulfosporosinus sp. in biofilm clustered into patches on the galvanized steel surface when the culture contained toxic Ag–Cu ions. The ions affected the growth of the sulfate reducing bacteria strains in different ways and hence the corrosion behaviors. It was observed that the Ag–Cu ions affected negatively growth of Desulfosporosinus sp. especially after 24 h of exposure leading to a decrease in the corrosion rate of galvanized steel. However, Desulfovibrio sp. showed more corrosive effect in the presence of the ions according to the ions-free culture. Energy dispersive X-ray spectrometry analysis showed that corrosion products on the surfaces were mainly composed of Zn, S, Na, O and P. - Highlights: • Galvanized steel was corroded by Desulfosporosinus sp. and Desulfovibrio sp. • Desulfosporosinus sp. is more corrosive than Desulfovibrio sp. • The Ag–Cu ions affected corrosion behavior of Desulfosporosinus sp. and Desulfovibrio sp. on galvanized steel

  6. The corrosion behavior of steel exposed to a DC electric field in the simulated wet-dry cyclic environment

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Nianwei [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090 (China); Department of Materials Science, Fudan University, Shanghai 200433 (China); Chen, Qimeng [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Junxi, E-mail: zhangjunxi@shiep.edu.cn [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Xin; Ni, Qingzhao [Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090 (China); Jiang, Yiming; Li, Jin [Department of Materials Science, Fudan University, Shanghai 200433 (China)

    2017-05-01

    The corrosion of steel exposed under a direct current (DC) electric field during simulated wet-dry cycles was investigated using weight gain, electrochemical tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results show that the steel exposed to a DC electric field exhibits a higher corrosion rate than those exposed under no DC electric field. The higher the DC electric field intensity, the higher the corrosion rate of steel. The XRD and SEM analyses indicate that more γ-FeOOH and cracks appear in the rust formed on steel exposed to the DC electric field. The porous γ-FeOOH, formation and expansion of cracks enhance the transfer of oxygen and corrosion products, thereby accelerating corrosion of steel exposed to DC electric field. - Highlights: • Effect of DC electric field on the corrosion of steel in wet/dry cycles was studied. • DC electric field accelerates the steel corrosion in wet/dry cyclic processes. • More γ-FeOOH is generated on the surface of steel exposed under a DC electric field. • More cracks appear in the rust formed on the steel exposed under a DC electric filed.

  7. The corrosion behavior of steel exposed to a DC electric field in the simulated wet-dry cyclic environment

    International Nuclear Information System (INIS)

    Dai, Nianwei; Chen, Qimeng; Zhang, Junxi; Zhang, Xin; Ni, Qingzhao; Jiang, Yiming; Li, Jin

    2017-01-01

    The corrosion of steel exposed under a direct current (DC) electric field during simulated wet-dry cycles was investigated using weight gain, electrochemical tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results show that the steel exposed to a DC electric field exhibits a higher corrosion rate than those exposed under no DC electric field. The higher the DC electric field intensity, the higher the corrosion rate of steel. The XRD and SEM analyses indicate that more γ-FeOOH and cracks appear in the rust formed on steel exposed to the DC electric field. The porous γ-FeOOH, formation and expansion of cracks enhance the transfer of oxygen and corrosion products, thereby accelerating corrosion of steel exposed to DC electric field. - Highlights: • Effect of DC electric field on the corrosion of steel in wet/dry cycles was studied. • DC electric field accelerates the steel corrosion in wet/dry cyclic processes. • More γ-FeOOH is generated on the surface of steel exposed under a DC electric field. • More cracks appear in the rust formed on the steel exposed under a DC electric filed.

  8. Corrosion of X65 Pipeline Steel Under Deposit and Effect of Corrosion Inhibitor

    Directory of Open Access Journals (Sweden)

    XU Yun-ze

    2016-10-01

    Full Text Available Effect of the deposit on the electrochemical parameters of X65 pipeline steel in oxygen contained sodium chloride solution was studied by EIS and PDS methods. The galvanic corrosion behavior under deposit and effect of different concentration of corrosion inhibitor PBTCA were studied by electrical resistance (ER method combined with ZRA. The results show that the corrosion potential of X65 steel shifts negatively as SiO2 covering its surface and the corrosion rate becomes lower. When the galvanic couple specimen with deposit is electrically connected with the specimen without deposit, anodic polarization occurs on X65 steel under deposit and the galvanic current density decreases from 120μA/cm2 to 50μA/cm2 and keeps stable. As 5×10-5, 8×10-5 and 3×10-4 PBTCA were introduced into the solution, the galvanic current density reaches the highest 1300μA/cm2 and then decreases to 610μA/cm2 keeping stable around 610μA/cm2, corrosion rate of X65 steel under deposit reaches 6.11mm/a. PBTCA accelerates the corrosion of X65 steel under deposit in oxygen contained solution. Through the investigation on the surface of the specimens, serious local corrosion occurs on the X65 steel surface under deposit.

  9. 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.

  10. Corrosion resistance of steel fibre reinforced concrete – a literature review

    DEFF Research Database (Denmark)

    Marcos Meson, Victor; Michel, Alexander; Solgaard, Anders

    2016-01-01

    Steel fibre reinforced concrete (SFRC) is increasingly being used in the construction of prefabricated segmental linings for bored tunnels, since it entails simplified production processes and higher quality standards. However, international standards and guidelines are not consistent regarding...... the consideration of steel fibres for the structural verification of SFRC elements exposed to corrosive environments, hampering the development of civil infrastructure built of SFRC. In particular, the long-term effect of exposure to chlorides is in focus and under discussion. This paper reviews the existing...... the existence of a critical crack width, below 0.20 mm, where corrosion of carbon-steel fibres is not critical and the structural integrity of the exposed SFRC can be ensured over the long-term. A doctoral project investigating chloride-induced corrosion of steel fibres on cracked SFRC has been initiated...

  11. The effect of magnetite on corrosion of stainless steel (SUS309S) in deaerated synthetic sea water

    International Nuclear Information System (INIS)

    Taniguchi, N.; Honda, A.

    1999-10-01

    The assessment of lifetime of carbon steel overpack needs to clear the effects of corrosion products on the corrosion rate of carbon steel. It is reported that the corrosion of carbon steel was accelerated under the presence of magnetite as simulated corrosion products. Therefore, it is important to clear the mechanism of the acceleration of corrosion under the presence of magnetite. If carbon steel overpack will not be able to avoid the acceleration of corrosion under repository condition, some countermeasures have to be taken. One of the countermeasures against the effect of magnetite is considered to be the addition of alloying elements to a steel. The immersion test of stainless steel (SUS309S) as the extreme case of alloying was conducted under the presence of magnetite on the metal surface in synthetic sea water. As the result of this test, the corrosion of stainless steel (SUS309S) was not accelerated by the presence of magnetite. Therefore, it is expected that the susceptibility to the effect of magnetite is able to be reduced by addition of alloying elements to a steel. (author)

  12. Stress corrosion cracking properties of 15-5PH steel

    Science.gov (United States)

    Rosa, Ferdinand

    1993-01-01

    Unexpected occurrence of failures, due to stress corrosion cracking (SCC) of structural components, indicate a need for improved characterization of materials and more advanced analytical procedures for reliably predicting structures performance. Accordingly, the purpose of this study was to determine the stress corrosion susceptibility of 15-5PH steel over a wide range of applied strain rates in a highly corrosive environment. The selected environment for this investigation was a highly acidified sodium chloride (NaCl) aqueous solution. The selected alloy for the study was a 15-5PH steel in the H900 condition. The slow strain rate technique was selected to test the metals specimens.

  13. Mechanistic studies of carbon steel corrosion inhibition by cashew ...

    African Journals Online (AJOL)

    The phenoxide, R-Ar-O- ions from the CNSL inhibitor were found to be responsible for the reduction of the corrosion rate of the carbon steel. Also, it was observed that the surface charge of the carbon steel electrodes was positive with respect to the solutions containing CNSL inhibitor. It is likely that the mechanism of the ...

  14. Anticorrosion potential of hydralazine for corrosion of mild steel in ...

    African Journals Online (AJOL)

    Anticorrosion potential of mild steel by Hydralazine as corrosion inhibitor for mild steel in 1M hydrochloric acid was investigated by chemical and electrochemical measurements at 303-333 K temperature. The maximum inhibition efficiency of inhibitor by Weight loss method is around 90%, Tafel polarization method is ...

  15. General corrosion of carbon steels in high temperature water

    International Nuclear Information System (INIS)

    Gras, J.M.

    1994-04-01

    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

  16. Properties of Douglas Point Generating Station heat transport corrosion products

    International Nuclear Information System (INIS)

    Montford, B.; Rummery, T.E.

    1975-09-01

    Chemical, radiochemical and structural properties of circulating and fixed corrosion products from the Douglas Point Generating Station are documented. Interaction of Monel-400 and carbon steel corrosion products is described, and the mechanisms of Monel-400 surface deposit release, and activity buildup in the coolant system, are briefly discussed. Efficiencies of filters and ion-exchangers for the removal of released radionuclides are given. (author)

  17. A non-destructive test method to monitor corrosion products and corrosion-induced cracking in reinforced cement based materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Pease, Bradley Justin; Peterova, Adela

    2011-01-01

    ) was conducted to describe the impact of water-to-cement ratio and corrosion current density (i.e., corrosion rate) on the reinforcement corrosion process. Focus was placed, in particular on the determination of the corrosion accommodating region (CAR) and time to corrosion-induced cracking. Experimental results...... showed that x-ray attenuation measurements allow determination of the actual concentrations of corrosion products averaged through the specimen thickness. The total mass loss of steel measured by x-ray attenuation was found to be in very good agreement with the calculated mass loss obtained by Faraday......’s law. Furthermore, experimental results demonstrated that the depth of penetration of corrosion products as well as time to corrosion-induced cracking is varying for the different water-to-cement ratios and applied corrosion current densities....

  18. All-Optical Photoacoustic Sensors for Steel Rebar Corrosion Monitoring

    Directory of Open Access Journals (Sweden)

    Cong Du

    2018-04-01

    Full Text Available This article presents an application of an active all-optical photoacoustic sensing system with four elements for steel rebar corrosion monitoring. The sensor utilized a photoacoustic mechanism of gold nanocomposites to generate 8 MHz broadband ultrasound pulses in 0.4 mm compact space. A nanosecond 532 nm pulsed laser and 400 μm multimode fiber were employed to incite an ultrasound reaction. The fiber Bragg gratings were used as distributed ultrasound detectors. Accelerated corrosion testing was applied to four sections of a single steel rebar with four different corrosion degrees. Our results demonstrated that the mass loss of steel rebar displayed an exponential growth with ultrasound frequency shifts. The sensitivity of the sensing system was such that 0.175 MHz central frequency reduction corresponded to 0.02 g mass loss of steel rebar corrosion. It was proved that the all-optical photoacoustic sensing system can actively evaluate the corrosion of steel rebar via ultrasound spectrum. This multipoint all-optical photoacoustic method is promising for embedment into a concrete structure for distributed corrosion monitoring.

  19. Microbially influenced corrosion of stainless steels in nuclear power plants

    International Nuclear Information System (INIS)

    Sinha, U.P.; Wolfram, J.H.; Rogers, R.D.

    1990-01-01

    This paper reviews the components, causative agents, corrosion sites, and potential failure modes of stainless steel components susceptible to microbially influenced corrosion (MIC). The stainless steel components susceptible to MIC are located in the reactor coolant, emergency, and reactor auxiliary systems, and in many plants, in the feedwater train and condenser. The authors assessed the areas of most high occurrence of corrosion and found the sites most susceptible to MIC to the heat-affected zones in the weldments of sensitized stainless steel. Pitting is the predominant MIC corrosion mechanisms, caused by sulfur reducing bacteria (SRB). Also discussed is the current status of the diagnostic, preventive, and mitigation techniques, including use of improved water chemistry, alternate materials, and improved thermomechanical treatments. 37 refs., 3 figs

  20. Influence of inclusions on the local corrosion in steels

    International Nuclear Information System (INIS)

    Grall, L.; Mahieu, C.

    1978-01-01

    A synthesis of the work relating to the influence of inclusions on the pitting corrosion of steels, shows that pitting mainly occurs preferentially at precipitate levels, particularly sulfur precipitates. However oxidized inclusions can also cause this condition which is found on austenitic steels as well as on slightly alloyed or non alloyed steels. The method of refining as well as the morphology of inclusions can also play a part in this [fr

  1. Corrosion resistance of steel fibre reinforced concrete - A literature review

    DEFF Research Database (Denmark)

    Marcos Meson, Victor; Michel, Alexander; Solgaard, Anders

    2017-01-01

    Steel fibre reinforced concrete (SFRC) is increasingly being used in the construction of civil infrastructure. However, there are inconsistencies among international standards and guidelines regarding the consideration of carbon-steel fibres for the structural verification of SFRC exposed...... of the mechanisms governing the corrosion of carbon-steel fibres in cracks and its effects on the fracture behaviour of SFRC are not fully understood....

  2. Corrosion of radioactive waste containers, case of a container made of low allow steel

    International Nuclear Information System (INIS)

    Bataillon, C.; Musy, C.; Roy, M.

    2001-01-01

    The following topics were dealt with: radioactive waste concept ANDRA, low alloy steel (XC38) container corrosion under representative storage conditions, corrosion rate and passivation effects, micrographic investigations

  3. PITTING CORROSION OF STAINLESS STEEL AT THE VARIOUS SURFACE TREATMENT

    Directory of Open Access Journals (Sweden)

    Viera Zatkalíková

    2011-09-01

    Full Text Available The stainless steel surface treatment is very important with regard to its pitting corrosion susceptibility. An effect of various types surfacing on pitting corrosion resistance of AISI 304stainless steel is investigated in this work. The samples of the tested material are turned, blasted, peened, grinded and a half of them are pickled to achieve higher purity of surfaces and better quality of passive film. Eight types of different finished surfaces are tested by electrochemical and immersion tests to determine corrosion behaviour in conditions where pitting is evoked by controlled potential and second by solution with high redox potential. By this way the effect of mechanical and chemical surface treatment on the resistance to pitting corrosion, character, size and shape of pits are compared in the conditions of different mechanisms of corrosion process.

  4. Water corrosion resistance of ODS ferritic-martensitic steel tubes

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasuji

    2008-01-01

    Oxide dispersion strengthened (ODS) ferritic-martensitic steels have superior radiation resistance; it is possible to achieve a service temperature of up to around 973 K because of their superior creep strength. These advantages of ODS steels facilities their application to long-life cladding tubes in advanced fast reactor fuel elements. In addition to neutron radiation resistance, sufficient general corrosion resistance to maintain the strength of the cladding, and the stress corrosion cracking (SCC) resistance for spent-fuel-pool cooling systems and high-temperature oxidation for the fuel-clad chemical interaction (FCCI) of ODS ferritic steel are required. Although the addition of Cr to ODS is effective in preventing water corrosion and high-temperature oxidation, an excessively high amount of Cr leads to embrittlement due to the formation of a Cr-rich α' precipitate. The Cr content in 9Cr-ODS martensite and 12Cr-ODS ferrite, the ODS steels developed by the Japan Atomic Energy Agency (JAEA), is controlled. In a previous paper, it has been demonstrated that the resistances of 9Cr- and 12Cr-ODS ferritic-martensitic steels for high-temperature oxidation are superior to those of conventional 12Cr ferritic steel. However, the water corrosion data of ODS ferritic-martensitic steels are very limited. In this study, a water corrosion test was conducted on ODS steels in consideration of the spent-fuel-pool cooling condition, and the results were compared with those of conventional austenitic stainless steel and ferritic-martensitic stainless steel. (author)

  5. 77 FR 301 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year...

    Science.gov (United States)

    2012-01-04

    ... information is required if a currently valid Office of Management and Budget (OMB) number is not displayed... production of the product. In its original investigations and its full first and second five-year review... revised Commission's Handbook on E-Filing, available on the Commission's Web site at http://edis.usitc.gov...

  6. The electrochemical corrosion of maraging steel in various media

    International Nuclear Information System (INIS)

    Iqbal, A.; Hussain, S.W.; Qamar, I.; Salam, I.

    1993-01-01

    Electrochemical corrosion behavior of maraging steel in various media has been studied using electrode kinetic measurements. The media used included IN H/sub 2/SO/sub 4/, IN HCl and artificial sea water, all at room temperature. The steel used was 350 grade of maraging steel and its corrosion behavior was studied in annealed as well as aged condition. In addition to the general behavior observed using potentiodynamic polarization, the corrosion rates were also evaluated using our own method known as Z TCorr . This method has been proved to be robust and accurate as compared to any other known method. The surfaces of corroded specimens were examined in an scanning electron microscope. The pitting observed in samples corroded by sea water was found to be associated with the inclusion present in the steel. Passive behavior was noted in IN H/sub 2/SO/sub 4/ but not IN HCl or artificial sea water. (author)

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  8. Corrosion Resistance of Some Stainless Steels in Chloride Solutions

    Directory of Open Access Journals (Sweden)

    Kasprzyk D.

    2017-06-01

    Full Text Available The present work compares corrosion behaviour of four types of S30403, S31603, S32615 austenitic and S32404 austenitic-ferritic stainless steels in chloride solutions (1%, 3% NaCl and in Ringer solution, at 37°C temperature. Corrosion resistance was determined by potentiodynamic polarization measurements and a thirty day immersion test conducted in Ringer solution. The immersion test was performed in term of biomedical application. These alloy were spontaneously passivated in all electrolytes, wherein S30403, S31603 and S32404 undergo pitting corrosion. Only S32615 containing 5.5% Si shows resistance to pitting corrosion.

  9. Carbon steel corrosion induced by sulphate-reducing bacteria in artificial seawater: electrochemical and morphological characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Mariana Silva de; Goncalves, Marcia Monteiro Machado; Rola, Monick Alves da Cruz; Maciel, Diana Jose; Senna, Lilian Ferreira de; Lago, Dalva Cristina Baptista do, E-mail: sdp.mari@gmail.com, E-mail: marciamg@uerj.br, E-mail: monickcruz@yahoo.com.br, E-mail: dijmaciel@gmail.com, E-mail: lsenna@uerj.br, E-mail: dalva@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Instituto de Quimica

    2016-10-15

    In this work, the corrosion behavior of carbon steel AISI 1020 was evaluated in artificial seawater in the presence of mixed sulfate-reducing bacteria (SRB) culture isolated from the rust of a pipeline. The corrosion evaluation was performed by electrochemical techniques (open circuit potential (E{sub ocp}), polarization curves and electrochemical impedance spectroscopy (EIS)), while the formation of a biofilm and corrosion products were observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The presence of SRB in the medium shifted the open circuit potential to more positive values and increased the corrosion rate of the steel. Electrochemical and morphological techniques confirmed the presence of a biofilm on the steel surface. EDS spectra data showed the presence of sulfur in the corrosion products. After removing the biofilm, localized corrosion was observed on the surface, confirming that localized corrosion had occurred. The biogenic sulfide may lead to the formation of galvanic cells and contributes to cathodic depolarization. (author)

  10. Carbon steel corrosion induced by sulphate-reducing bacteria in artificial seawater: electrochemical and morphological characterizations

    International Nuclear Information System (INIS)

    Paula, Mariana Silva de; Goncalves, Marcia Monteiro Machado; Rola, Monick Alves da Cruz; Maciel, Diana Jose; Senna, Lilian Ferreira de; Lago, Dalva Cristina Baptista do

    2016-01-01

    In this work, the corrosion behavior of carbon steel AISI 1020 was evaluated in artificial seawater in the presence of mixed sulfate-reducing bacteria (SRB) culture isolated from the rust of a pipeline. The corrosion evaluation was performed by electrochemical techniques (open circuit potential (E_o_c_p), polarization curves and electrochemical impedance spectroscopy (EIS)), while the formation of a biofilm and corrosion products were observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The presence of SRB in the medium shifted the open circuit potential to more positive values and increased the corrosion rate of the steel. Electrochemical and morphological techniques confirmed the presence of a biofilm on the steel surface. EDS spectra data showed the presence of sulfur in the corrosion products. After removing the biofilm, localized corrosion was observed on the surface, confirming that localized corrosion had occurred. The biogenic sulfide may lead to the formation of galvanic cells and contributes to cathodic depolarization. (author)

  11. Combined geochemical and electrochemical methodology to quantify corrosion of carbon steel by bacterial activity

    International Nuclear Information System (INIS)

    Schutz, Marta K.; Moreira, Rebeca; Tribollet, Bernard; Vivier, Vincent; Bildstein, Olivier; Lartigue, Jean-Eric; Libert, Marie; Schlegel, Michel L.

    2014-01-01

    The availability of respiratory substrates, such as H 2 and Fe(II,III) solid corrosion products within nuclear waste repository, will sustain the activities of hydrogen-oxidizing bacteria (HOB) and iron-reducing bacteria (IRB). This may have a direct effect on the rate of carbon steel corrosion. This study investigates the effects of Shewanella oneidensis (an HOB and IRB model organism) on the corrosion rate by looking at carbon steel dissolution in the presence of H 2 as the sole electron donor. Bacterial effect is evaluated by means of geochemical and electrochemical techniques. Both showed that the corrosion rate is enhanced by a factor of 2-3 in the presence of bacteria. The geochemical experiments indicated that the composition and crystallinity of the solid corrosion products (magnetite and vivianite) are modified by bacteria. Moreover, the electrochemical experiments evidenced that the bacterial activity can be stimulated when H 2 is generated in a small confinement volume. In this case, a higher corrosion rate and mineralization (vivianite) on the carbon steel surface were observed. The results suggest that the mechanism likely to influence the corrosion rate is the bioreduction of Fe(III) from magnetite coupled to the H 2 oxidation. (authors)

  12. Effects of simulated inflammation on the corrosion of 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Emily K.; Brooks, Richard P. [Department of Biomedical Engineering, State University of New York at Buffalo (United States); Ehrensberger, Mark T., E-mail: mte@buffalo.edu [Department of Biomedical Engineering, State University of New York at Buffalo (United States); Department of Orthopaedics, State University of New York at Buffalo (United States)

    2017-02-01

    Stainless steel alloys, including 316L, find use in orthopaedics, commonly as fracture fixation devices. Invasive procedures involved in the placement of these devices will provoke a local inflammatory response that produces hydrogen peroxide (H{sub 2}O{sub 2}) and an acidic environment surrounding the implant. This study assessed the influence of a simulated inflammatory response on the corrosion of 316L stainless steel. Samples were immersed in an electrolyte representing either normal or inflammatory physiological conditions. After 24 h of exposure, electrochemical impedance spectroscopy (EIS) and inductively coupled plasma mass spectroscopy (ICPMS) were used to evaluate differences in corrosion behavior and ion release induced by the inflammatory conditions. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) were used to evaluate surface morphology and corrosion products formed on the sample surface. Inflammatory conditions, involving the presence of H{sub 2}O{sub 2} and an acidic pH, significantly alter the corrosion processes of 316L stainless steel, promoting aggressive and localized corrosion. It is demonstrated that particular consideration should be given to 316L stainless steel implants with crevice susceptible areas (ex. screw-head/plate interface), as those areas may have an increased probability of rapid and aggressive corrosion when exposed to inflammatory conditions. - Highlights: • The corrosion of 316L exposed to simulated inflammation is examined. • Inflammation is replicated with an acidic electrolyte containing hydrogen peroxide. • Inflammatory conditions increase 316L corrosion compared to normal conditions. • Accelerated corrosion under inflammation is likely due to crevice corrosion. • Care should be taken using 316L in devices with crevice susceptible areas.

  13. Effect of chlorides on the corrosion behaviour of mild steel

    International Nuclear Information System (INIS)

    Harada, Kazuyuki; Shimada, Minoru

    1980-01-01

    In PWR's steam generators, ''denting'' resulted from corrosion of support plate material, carbon steel is an important problem. The role of chlorides in corrosion acceleration of mild steel was studied. Corrosion tests were conducted at temperature from 100 0 C to 280 0 C in deaerated solutions of NaCl and MgCl 2 which are main content of sea water. 1) Solution of MgCl 2 was more corrosive than that of NaCl. The more increased in concentration of each chloride solution, the more corrosive in MgCl 2 soln. but the less corrosive in NaCl soln. 2) The rate of corrosion in the mixed solution of NaCl and MgCl 2 was governed by the concentration of MgCl 2 soln. The corrosion behaviour in sea water was suggested to be not controlled by NaCl but by MgCl 2 . 3) Acidification of MgCl 2 soln. could be evaluated by experiment at 100 0 C, the degree of acidification increased with increasing the concentration. However, the value of pH during corrosion was kept constant by the concentration of dissolved Fe 2+ ions. 4) The corrosion acceleration by MgCl 2 soln. was arised not only from acidification by the solution itself but from continuous supplementation of H + ions with the hydrolysis of dissolved Fe 2+ ions. This autocatalytic corrosion process not exhausting acid was characterized with the corrosion in closed system such as in crevice. In addition to acidification of MgCl 2 soln., the formation of non-protective magnetite film by Mg 2+ ion was estimated to be a reason of accelerated corrosion. (author)

  14. Corrosion of an austenite and ferrite stainless steel weld

    Directory of Open Access Journals (Sweden)

    BRANIMIR N. GRGUR

    2011-07-01

    Full Text Available Dissimilar metal connections are prone to frequent failures. These failures are attributed to the difference in the mechanical properties across the weld, the coefficients of thermal expansion of the two types of steels and the resulting creep at the interface. For the weld analyzed in this research, it was shown that corrosion measurements can be used for a proper evaluation of the quality of weld material and for the prediction of whether or not the material, after the applied welding process, can be in service without failures. It was found that the corrosion of the weld analyzed in this research resulted from the simultaneous activity of different types of corrosion. In this study, electrochemical techniques including polarization and metallographic analysis were used to analyze the corrosion of a weld material of ferrite and austenitic stainless steels. Based on surface, chemical and electrochemical analyses, it was concluded that corrosion occurrence was the result of the simultaneous activity of contact corrosion (ferrite and austenitic material conjuction, stress corrosion (originating from deformed ferrite structure and inter-granular corrosion (due to chromium carbide precipitation. The value of corrosion potential of –0.53 V shows that this weld, after the thermal treatment, is not able to repassivate a protective oxide film.

  15. Corrosion Behavior of Low-C Medium-Mn Steel in Simulated Marine Immersion and Splash Zone Environment

    Science.gov (United States)

    Zhang, Dazheng; Gao, Xiuhua; Su, Guanqiao; Du, Linxiu; Liu, Zhenguang; Hu, Jun

    2017-05-01

    The corrosion behavior of low-C medium-Mn steel in simulated marine immersion and splash zone environment was studied by static immersion corrosion experiment and wet-dry cyclic corrosion experiment, respectively. Corrosion rate, corrosion products, surface morphology, cross-sectional morphology, elemental distribution, potentiodynamic polarization curves and electrochemical impedance spectra were used to elucidate the corrosion behavior of low-C medium-Mn steel. The results show that corrosion rate in immersion zone is much less than that in splash zone owing to its relatively mild environment. Manganese compounds are detected in the corrosion products and only appeared in splash zone environment, which can deteriorate the protective effect of rust layer. With the extension of exposure time, corrosion products are gradually transformed into dense and thick corrosion rust from the loose and porous one in these two environments. But in splash zone environment, alloying elements of Mn appear significant enrichment in the rust layer, which decrease the corrosion resistance of the steel.

  16. Atmospheric corrosion performance of different steels in early exposure in the coastal area region West Java, Indonesia

    Science.gov (United States)

    Nuraini, Lutviasari; Prifiharni, Siska; Priyotomo, Gadang; Sundjono, Gunawan, Hadi; Purawiardi, Ibrahim

    2018-05-01

    The performance of carbon steel, galvanized steel and aluminium after one month exposed in the atmospheric coastal area, which is in Limbangan and Karangsong Beach, West Java, Indonesia was evaluated. The corrosion rate was determined by weight loss method and the morphology of the steel after exposed was observed by Scanning Electron Microscopy(SEM)/Energy Dispersive X-Ray Analysis(EDX). The site was monitored to determine the chloride content in the marine atmosphere. Then, the corrosion products formed at carbon steel were characterized by X-Ray diffraction (XRD). The result showed the aggressively corrosion in Karangsong beach, indicated from the corrosion rate of carbon steel, galvanized steel and aluminium were 38.514 mpy; 4.7860 mpy and 0.5181 mpy, respectively. While in Limbangan Beach the corrosion rate of specimen carbon steel, galvanized steel and aluminium were 3.339; 0.219 and 0.166 mpy, respectively. The chloride content was found to be the main factor that influences in the atmospheric corrosion process in this area. Chloride content accumulated in Karangsong and Limbangan was 497 mg/m2.day and 117 mg/m2.day, respectively. The XRD Analysis on each carbon steel led to the characterization of a complex mixture of iron oxides phases.

  17. Corrosion behaviour of high chromium ferritic stainless steels

    International Nuclear Information System (INIS)

    Kiesheyer, H.; Lennartz, G.; Brandis, H.

    1976-01-01

    Ferritic steels developed for seawater desalination and containing 20 to 28% chromium, up to 5% Mo and additions of nickel and copper have been tested with respect to their corrosion behaviour, in particular in chloride containing media. The materials in the sensibilized state were tested for intercrystalline corrosion susceptibility in the Strauss-, Streicher-, nitric acid hydrofluoric acid- and Huey-Tests. No intercrystalline corrosion was encountered in the case of the steels with 28% Cr and 2% Mo. The resistance to pitting was assessed on the basis of rupture potentials determined by potentiokinetic tests. The resistance of the steels with 20% Cr and 5% Mo or 28% Cr and 2% Mo is superior to that of the molybdenum containing austenitic types. Addition of nickel yields a significant increase in crevice corrosion resistance; the same applies to resistance in sulfuric acid. In boiling seawater all the materials tested are resistant to stress corrosion cracking. No sign of any type of corrosion was found on nickel containing steels after about 6,000 hours exposure to boiling 50% seawater brine even under salt deposits. (orig.) [de

  18. Influence of stainless steel Internals on Corrosion of tower wall materials

    Science.gov (United States)

    Chen, Bing; Ren, Ke

    2017-12-01

    In view of the galvanic corrosion of the tower wall material in the tower of a refinery atmospheric vacuum distillation unit, the electrochemical behavior of Q345R steel, stainless steel (201, 304 cold-rolled plate, 304 hot rolled plate and 316L) in 3.5%NaCl solution was studied by electrochemical method. The results show that the corrosion potential of Q345R is much lower than that of stainless steel, and the corrosion rate of Q345R is higher than that of stainless steel. As the anode is etched as the anode corrosion, the anode polarizability of stainless steel shows strong polarization ability, which is anodic polarization control, and Q345R is anode Active polarization control; Q345R / 201 galvanic pair may be the most serious corrosion, and Q345R/316L galvanic couple may be relatively slight. Therefore, in the actual production of tower equipment, material design or tower to upgrade the replacement, it are recommended to use the preferred anode and cathode potential difference with the use of materials.

  19. Corrosion of steel tanks in liquid nuclear wastes

    International Nuclear Information System (INIS)

    Carranza, Ricardo M.; Giordano, Celia M.; Saenz, Eduardo

    2005-01-01

    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) [es

  20. Improving by postoxidation of corrosion resistance of plasma nitrocarburized AISI 316 stainless steels

    Science.gov (United States)

    Yenilmez, A.; Karakan, M.; Çelik, İ.

    2017-01-01

    Austenitic stainless steels are widely used in several industries such as chemistry, food, health and space due to their perfect corrosion resistance. However, in addition to corrosion resistance, the mechanic and tribological features such as wear resistance and friction are required to be good in the production and engineering of this type of machines, equipment and mechanic parts. In this study, ferritic (FNC) and austenitic (ANC) nitrocarburizing were applied on AISI 316 stainless steel specimens with perfect corrosion resistance in the plasma environment at the definite time (4 h) and constant gas mixture atmosphere. In order to recover corrosion resistance which was deteriorated after nitrocarburizing again, plasma postoxidation process (45 min) was applied. After the duplex treatment, the specimens' structural analyses with XRD and SEM methods, corrosion analysis with polarization method and surface hardness with microhardness method were examined. At the end of the studies, AISI 316 surface hardness of stainless steel increased with nitrocarburizing process, but the corrosion resistance was deteriorated with FNC (570 °C) and ANC (670 °C) nitrocarburizing. With the following of the postoxidation treatment, it was detected that the corrosion resistance became better and it approached its value before the process.

  1. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-10-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. Efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness and as a monitor of system corrosion effects. The discussion is based mostly on the results of observations from Ontario Hydro plants, and their comparisons with pressurized-water reactors. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of layup and various startup conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on CPT on the primary side of SGs are also discussed. (author)

  2. Corrosion of mild steel, copper and brass in crude oil / seawater mixture

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi, S.; Sawant, S.S.; Wagh, A.B.

    Mild steel, copper and brass coupons were introduced in natural seawater containing varying amount of crude oil. Mild steel showed higher rate of corrosion in seawater containing oil and lower corrosion rate in natural as well as artificial seawater...

  3. Initiation and inhibition of pitting corrosion on reinforcing steel under natural corrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Abd El Wanees, S., E-mail: s_wanees@yahoo.com [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bahgat Radwan, A. [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Alsharif, M.A. [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Abd El Haleem, S.M. [Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt)

    2017-04-01

    Initiation and inhibition of pitting corrosion on reinforcing steel in saturated, naturally aerated Ca(OH){sub 2} solutions, under natural corrosion conditions, are followed through measurements of corrosion current, electrochemical impedance spectroscopy and SEM investigation. Induction period for pit initiation and limiting corrosion current for pit propagation are found to depend on aggressive salt anion and cation-types, as well as, concentration. Ammonium chlorides and sulfates are more corrosive than the corresponding sodium salts. Benzotriazole and two of its derivatives are found to be good inhibitors for pitting corrosion of reinforcing steel. Adsorption of these compounds follows a Langmuir adsorption isotherm. The thermodynamic functions ΔE{sup ∗}, ΔH{sup ∗} and ΔS{sup ∗} for pitting corrosion processes in the absence and presence of inhibitor are calculated and discussed. - Highlights: • Cl{sup −} and SO{sub 4} {sup 2-} induce pitting corrosion on passive reinforcing steel. • Initiation and propagation of pitting depend on cation and anion types. • Inhibition is based on adsorption according to Langmuir isotherm.

  4. 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

    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 accelerates......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...... 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...

  5. 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

    if the 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......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 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...

  6. Characterizing the effect of carbon steel exposure in sulfide containing solutions to microbially induced corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Sherar, B.W.A. [Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7 (Canada); Power, I.M. [Department of Earth Sciences, University of Western Ontario, London, ON, N6A 5B7 (Canada); Keech, P.G.; Mitlin, S. [Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7 (Canada); Southam, G. [Department of Earth Sciences, University of Western Ontario, London, ON, N6A 5B7 (Canada); Shoesmith, D.W., E-mail: dwshoesm@uwo.c [Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7 (Canada)

    2011-03-15

    Research highlights: Compares inorganic sulfide and sulfate reducing bacteria (SRB) on steel corrosion. Mackinawite was the dominant iron sulfide phase. SRBs can form nanowires, presumably grown to acquire energy. - Abstract: This article compares the electrochemical effects induced by inorganic sulfide and sulfate reducing bacteria on the corrosion of carbon steel - a subject of concern for pipelines. Biological microcosms, containing varying concentrations of bioorganic content, were studied to investigate changes to the morphology of biofilms and corrosion product deposits. Raman analysis indicated mackinawite (FeS{sub 1-x}) was the dominant iron sulfide phase grown both abiotically and biotically. A fascinating feature of biological media, void of an organic electron donor, was the formation of putative nanowires that may be grown to acquire energy from carbon steel by promoting the measured cathodic reaction.

  7. Penetration of corrosion products and corrosion-induced cracking in reinforced cementitious materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Pease, Brad J.; Peterova, Adela

    2014-01-01

    This paper describes experimental investigations on corrosion-induced deterioration in reinforced cementitious materials and the subsequent development and implementation of a novel conceptual model. Rejnforced mortar specimens of varying water-to-cement ratios were subjected to current-induced c......This paper describes experimental investigations on corrosion-induced deterioration in reinforced cementitious materials and the subsequent development and implementation of a novel conceptual model. Rejnforced mortar specimens of varying water-to-cement ratios were subjected to current......-dependent concentrations of corrosion products averaged through the specimen thickness. Digital image correlation (DIC) was used to measure corrosion-induced deformations including deformations between steel and cementitious matrix as well as formation and propagation of corrosion-induced cracks. Based on experimental...... observations, a conceptual model was developed to describe the penetration of solid corrosion products into capillary pores of the cementitious matrix. Only capillary pores within a corrosion accommodating region (CAR), i.e. in close proximity of the steel reinforcement, were considered accessible...

  8. Coated steel rebar for enhanced concrete-steel bond strength and corrosion resistance.

    Science.gov (United States)

    2010-10-01

    This report summarizes the findings and recommendations on the use of enamel coating in reinforced concrete structures both for bond strength and : corrosion resistance of steel rebar. Extensive laboratory tests were conducted to characterize the pro...

  9. Electrochemical noise measurements of steel corrosion in the molten NaCl-K2SO4 system

    DEFF Research Database (Denmark)

    Cappeln, Frederik Vilhelm; Bjerrum, Niels; Petrushina, Irina

    2005-01-01

    -called active corrosion (i.e., the corrosion proceeds with no passivation due to the influence of chlorine), characterized by the formation of volatile metal chlorides as a primary corrosion product. It was found possible to obtain an empirical separation of general and intergranular corrosion using kurtosis (a......Electrochemical noise measurements have been carried out on AISI347, 10CrMo910, 15Mo3, and X20CrMoV121 steels in molten NaCl-K2SO4 at 630 degrees C. Different types of current noise have been identified for pitting, intergranular and peeling corrosion. The corrosion mechanism was the so...... statistical parameter calculated from the electrochemical noise data). It was found that average kurtosis values above 6 indicated intergranular corrosion and average values below 6 indicated general corrosion. The response time for localized corrosion detection in in-plant monitoring was approximately 90 min...

  10. Inorganic coatings on stainless steel for protection against crevice corrosion

    International Nuclear Information System (INIS)

    Henrikson, Sture

    1989-12-01

    In order to create protection against crevice corrosion stainless steel test specimens of type 316 steel with various inorganic coatings applied on crevice surfaces were tested for 3-50 months at 25 and 30 degree C in natural seawater containing 0.2-1.5 ppm free chlorine. Various metallic coatings, Ni base alloys with Cr and Mo, Ni with W, pure Ag and pure Mo, as well as ceramic coatings - Cr 2 O 3 , TiO 2 and Al 2 O 3 - were studied. All the coatings tested, except pure Molybdenum applied by plasma spraying in a max 0.1 mm thick layer were found to promote crevice corrosion of the stainless steel. A significant reduction of the crevice corrosion susceptibility was obtained with Molybdenum. The result is considered promising enough to justify full scale tests in seawater on flange joints of pipes, valves or pumps. (author)

  11. Corrosion of carbon steel in clay environments relevant to radioactive waste geological disposals, Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Necib, S. [Agence Nationale pour la Gestion des Déchets Radioactifs ANDRA, Meuse Haute-Marne, Center RD 960, Bure (France); Diomidis, N. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Keech, P. [Nuclear Waste Management Organisation NWMO, Toronto (Canada); Nakayama, M. [Japan Atomic Energy Agency JAEA, Horonobe-Cho (Japan)

    2017-04-15

    Carbon steel is widely considered as a candidate material for the construction of spent fuel and high-level waste disposal canisters. In order to investigate corrosion processes representative of the long term evolution of deep geological repositories, two in situ experiments are being conducted in the Mont Terri rock laboratory. The iron corrosion (IC) experiment, aims to measure the evolution of the instantaneous corrosion rate of carbon steel in contact with Opalinus Clay as a function of time, by using electrochemical impedance spectroscopy measurements. The Iron Corrosion in Bentonite (IC-A) experiment intends to determine the evolution of the average corrosion rate of carbon steel in contact with bentonite of different densities, by using gravimetric and surface analysis measurements, post exposure. Both experiments investigate the effect of microbial activity on corrosion. In the IC experiment, carbon steel showed a gradual decrease of the corrosion rate over a period of 7 years, which is consistent with the ongoing formation of protective corrosion products. Corrosion product layers composed of magnetite, mackinawite, hydroxychloride and siderite with some traces of oxidising species such as goethite were identified on the steel surface. Microbial investigations revealed thermophilic bacteria (sulphate and thiosulphate reducing bacteria) at the metal surface in low concentrations. In the IC-A experiment, carbon steel samples in direct contact with bentonite exhibited corrosion rates in the range of 2 µm/year after 20 months of exposure, in agreement with measurements in absence of microbes. Microstructural and chemical characterisation of the samples identified a complex corrosion product consisting mainly of magnetite. Microbial investigations confirmed the limited viability of microbes in highly compacted bentonite. (authors)

  12. Corrosivity Index Copper and Steel at Two Locations in Villahermosa, Tabasco

    Directory of Open Access Journals (Sweden)

    Tejero-Rivas María Candelaria

    2015-03-01

    Full Text Available This paper presents a study of the atmospheric corrosion of copper and carbon steel made ​​in two environments Villahermosa, Tabasco for six months. The test site of the industrial zone started Villahermosa Institute of Technology (ITVH and rural-urban site at the Technological University of Tabasco (UTTAB. Aluminum in combination with a screw carbon steel provided the index marine corrosivity (MA, the brass screw gives the index of industrial corrosivity (IA; wire method of screw according to ASTM G116-93 was used and the plastic screw nylon gives the rate of rural-urban corrosivity (RUA. The determination of air pollutants (sulfur dioxide and chlorides, was with the methods of wet candle and sulfation plates according to ISO 9225. Morphology studies were performed on the corrosion products formed on the specimens screw, using scanning electron microscopy coupled with energy dispersive. The corrosion products that formed on the surface of copper and carbon steel, having a bulb-shaped morphology characteristic of the addition of soluble salts, particularly sulphates and chlorides, were identified in the two stations.

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

    Science.gov (United States)

    Delaunois, F; Tosar, F; Vitry, V

    2014-06-01

    Galvanized steel tubes are a popular mean for water distribution systems but suffer from corrosion despite their zinc or zinc alloy coatings. First, the quality of hot-dip galvanized (HDG) coatings was studied. Their microstructure, defects, and common types of corrosion were observed. It was shown that many manufactured tubes do not reach European standard (NBN EN 10240), which is the cause of several corrosion problems. The average thickness of zinc layer was found at 41μm against 55μm prescribed by the European standard. However, lack of quality, together with the usual corrosion types known for HDG steel tubes was not sufficient to explain the high corrosion rate (reaching 20μm per year versus 10μm/y for common corrosion types). Electrochemical tests were also performed to understand the corrosion behaviours occurring in galvanized steel tubes. Results have shown that the limiting step was oxygen diffusion, favouring the growth of anaerobic bacteria in steel tubes. EDS analysis was carried out on corroded coatings and has shown the presence of sulphur inside deposits, suggesting the likely bacterial activity. Therefore biocorrosion effects have been investigated. Actually sulphate reducing bacteria (SRB) can reduce sulphate contained in water to hydrogen sulphide (H2S), causing the formation of metal sulphides. Although microbial corrosion is well-known in sea water, it is less investigated in supply water. Thus, an experimental water main was kept in operation for 6months. SRB were detected by BART tests in the test water main. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Wire-Arc-Sprayed Aluminum Protects Steel Against Corrosion

    Science.gov (United States)

    Zimmerman, Frank R.; Poorman, Richard; Sanders, Heather L.; Mckechnie, Timothy N.; Bonds, James W., Jr.; Daniel, Ronald L., Jr.

    1995-01-01

    Aluminum coatings wire-arc sprayed onto steel substrates found effective in protecting substrates against corrosion. Coatings also satisfy stringent requirements for adhesion and flexibility, both at room temperature and at temperatures as low as liquid hydrogen. Developed as alternatives to corrosion-inhibiting primers and paints required by law to be phased out because they contain and emit such toxic substances as chromium and volatile organic compounds.

  15. Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2016-11-01

    Full Text Available The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl-2-oleylimidazoline (AEOI and 1-(2-oleylamidoethyl-2-oleylimidazoline (OAEOI as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl and the corrosion inhibition of N80 steel in hydrochloric acid medium containing inhibitors was tested by weight loss, potentiodynamic polarization and AC impedance measurements. Influence of temperature (298–323 K on the inhibition behavior was studied. Surface studies were performed by using FTIR spectra and SEM. Both the inhibitors, AEOI and OAEOI at 150 ppm concentration show maximum efficiency 90.26% and 96.23%, respectively at 298 K in 15% HCl solution. Both the inhibitors act as mixed corrosion inhibitors. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.

  16. Corrosion behaviour of some conventional stainless steels in electrolyzing process

    Directory of Open Access Journals (Sweden)

    Amal NASSAR

    2015-12-01

    Full Text Available In this study, attempts were made to increase the amount of hydrogen generated from the water electrolysis process. Some conventional stainless steels (316; 409; 410 and 430 were used as anode and cathode in electrolysis process. Further study was carried out on the corrosion trend in all the investigated metals. It is observed that the electrode material can effect on the amount of hydrogen generate by electrolyzing process and metal composition of the stainless steels effects on the rate of corrosion.

  17. Threshold Corrosion Fatigue of Welded Shipbuilding Steels.

    Science.gov (United States)

    1992-01-01

    8. J. C. Walter, E. Olbjorn, 0. Allstad and G. Elde, "Safety Against Corrosion Fatigue Offshore," Publication No. 94, Det Norske Ventas , Horik...Offshore. Publication No;. 94;, Det Norske Ventas , Horik, Norway, April 1976. 18. C. E. Jaske, D. Broek, J. E. Slater, W. E. Anderson. Corrosion Fatigue

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

    International Nuclear Information System (INIS)

    Saenz Gonzalez, Eduardo

    2005-01-01

    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 (NaNO 3 , NaCl, NaF, NaNO 2 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

  19. Hot corrosion of pack cementation aluminized carbon steel

    International Nuclear Information System (INIS)

    Waheed, A.F.; Mohamed, K.E.; Abd El-Azim, M.E.; Soliman, H.M.

    1998-01-01

    Low carbon steel was aluminized by the pack cementation technique at various aluminizing temperatures and times in or der to have different aluminide coatings. The aluminized specimens were sprayed at the beginning of the hot corrosion experiments with Na C 1+Na 2 SO 4 solution. The hot corrosion tests were carried out by thermal cycling at 850 degree C in air. The results were evaluated by, corrosion kinetics based on weight change measurements, scanning electron microscopy and energy dispersive X-ray analysis. It was found that the maximum corrosion resistance to this corrosive environment is achieved by aluminizing at 900 degree C for 19 h or 950 degree C for >4 h. These aliminizing conditions lead to formation of thick aluminide coatings with sufficient aluminium concentration (>15 wt%) at their outer surface necessary for continuous formation of protective Al 2 O 3 scale. The tested materials are used in protection of some components used in electric power stations (conventional or nuclear)

  20. Composition and corrosion properties of high-temperature oxide films on steel type 18-10

    International Nuclear Information System (INIS)

    Vakulenko, B.F.; Morozov, O.N.; Chernysheva, M.V.

    1985-01-01

    The composition and propeties of oxide films, formed in the process of tube production of steel type 18-10, as well as the behaviour of the steels coated with oxide films under operating conditions of NPP heat-exchange equipment at the 20-300 deg C temperatures are determined. It is found, that the films have a good adhesion to the steel surface and repeat the metal structure without interfering with, the surface defect determination. Introduction of the NaNO 2 corrosion inhibitor decreases the film destruction rate to the level of the base metal corrosion. It is found acceptable to use tubes of steel 18-10 coated with dense oxide films in the heat-exchange and water supply systems of NPP

  1. 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.

  2. Pitting Corrosion Susceptibility of AISI 301 Stainless Steel in ...

    African Journals Online (AJOL)

    The susceptibility of austenitic (AISI 301) stainless steel to pitting corrosion was evaluated in sodium chloride (NaCl) solutions - 0.1M, 0.2M, 0.3M, 0.5M and 0.7M and 1.0M. Tensile tests and microscopic examinations were performed on samples prepared from the steel after exposure in the various environments.

  3. The efficiency of a corrosion inhibitor on steel in a simulated concrete environment

    Energy Technology Data Exchange (ETDEWEB)

    Gartner, Nina; Kosec, Tadeja, E-mail: tadeja.kosec@zag.si; Legat, Andraž

    2016-12-01

    The aim of the present work was to characterize the efficiency of a corrosion inhibitor on steel in a simulated concrete pore solution. Laboratory measurements were performed at various chloride and inhibitor concentrations in order to simulate different applications of the inhibitor when used for the protection or rehabilitation of steel reinforcement in concrete. Two electrochemical techniques, i.e. potentiodynamic polarization scans and electrochemical impedance spectroscopy, were used for this study. The exposed surfaces of the steel specimens were subsequently investigated by Raman spectroscopy and scanning electron microscopy. It was found that the inhibitor can efficiently retard the corrosion of steel in a simulated concrete pore solution at concentrations of the inhibitor >2.0% and of chlorides <0.3% at a pH 10.5. On the other hand, when these conditions are not fulfilled, localized corrosion was observed. The results of the Raman and SEM/EDS analysis showed various morphologies of corrosion products and different types of corrosion attack depending on the pH of the pore solution, and the applied concentrations of the chlorides and the inhibitor. - Highlights: • Electrochemical studies performed at various Cl{sup −} and inhibitor concentrations. • Exposed steel surfaces investigated by Raman spectroscopy and SEM. • Cl{sup −}/inhibitor ratio is important parameter for the inhibitor's efficiency. • The corrosion can re-occur if the concentration of the inhibitor is reduced. • Different corrosion behaviour and oxides in the presence of inhibitor and/or Cl{sup −}.

  4. Characterisation of the steel concrete interface submitted to chloride-induced corrosion

    International Nuclear Information System (INIS)

    L'Hostis, V.; Amblard, E.; Guillot, W.; Paris, C.; Bellot-Gurlet, L.

    2013-01-01

    This paper deals with the characterisation by means of electrochemical, gravimetric and analytical methods of chloride-induced-corrosion behaviour of steel coupons embedded in chloride-containing-cement pastes. Corrosion rates were estimated from electrochemical measurements as well as gravimetric ones. They vary from 2.6 to 5.7μm/year for 5 and 10 g/L chloride-containing cement pastes. Analytical characterisations (including optical and electron microscopy and Raman micro-spectroscopy) showed that corrosion patterns are not depending on the chloride content of the cement paste (5 and 10 g/L chloride in the interstitial solution). A localised corrosion pattern composed of pits growing inside the metallic substratum, a corrosion products layer (CPL) and a transformed medium (TM) was pointed out. CPL can be divided into two sub-layers (CPL1 and CPL2), characterised by the presence or absence of calcium coming from the cement matrix. (authors)

  5. Quantifying movements of corrosion products in reinforced concrete using x-ray attenuation measurements

    DEFF Research Database (Denmark)

    Pease, Bradley Justin; Michel, Alexander; Stang, Henrik

    2011-01-01

    Corrosion of steel reinforcement, embedded in concrete, may substantially degrade concrete structures due to the expansive nature of corrosion products. Expansion of corrosion products cause tensile stresses to develop and cracks to form in concrete. Extensive research has focused on corrosion...... of corrosion products move into the concrete without generating tensile stresses and cracks in the concrete. Typically, corrosion products are thought to occupy pores, interfacial defects, and/or air voids located near the concrete-steel interface and stresses develop only after filling of these pores. Further....... X-ray attenuation measurements are also capable of detecting cracks. Therefore, this approach provides a direct measurement of the amount and location of reinforcement corrosion products required to induce cracking. Results of a parametric investigation on the impact of water-to-cement ratio (0...

  6. Effect of Chromium on Corrosion Behavior of P110 Steels in CO2-H2S Environment with High Pressure and High Temperature

    Science.gov (United States)

    Sun, Jianbo; Sun, Chong; Lin, Xueqiang; Cheng, Xiangkun; Liu, Huifeng

    2016-01-01

    The novel Cr-containing low alloy steels have exhibited good corrosion resistance in CO2 environment, mainly owing to the formation of Cr-enriched corrosion film. In order to evaluate whether it is applicable to the CO2 and H2S coexistence conditions, the corrosion behavior of low-chromium steels in CO2-H2S environment with high pressure and high temperature was investigated using weight loss measurement and surface characterization. The results showed that P110 steel suffered localized corrosion and both 3Cr-P110 and 5Cr-P110 steels exhibited general corrosion. However, the corrosion rate of 5Cr-P110 was the highest among them. The corrosion process of the steels was simultaneously governed by CO2 and H2S. The outer scales on the three steels mainly consisted of FeS1−x crystals, whereas the inner scales on Cr-containing steels comprised of amorphous FeS1−x, Cr(OH)3 and FeCO3, in contrast with the amorphous FeS1−x and FeCO3 mixture film of P110 steel. The more chromium the steel contains, the more chromium compounds the corrosion products contain. The addition of chromium in steels increases the uniformity of the Cr-enriched corrosion scales, eliminates the localized corrosion, but cannot decrease the general corrosion rates. The formation of FeS1−x may interfere with Cr-enriched corrosion scales and lowering the corrosion performance of 3Cr-P110 and 5Cr-P110 steels. PMID:28773328

  7. Effect of Chromium on Corrosion Behavior of P110 Steels in CO2-H2S Environment with High Pressure and High Temperature

    Directory of Open Access Journals (Sweden)

    Jianbo Sun

    2016-03-01

    Full Text Available The novel Cr-containing low alloy steels have exhibited good corrosion resistance in CO2 environment, mainly owing to the formation of Cr-enriched corrosion film. In order to evaluate whether it is applicable to the CO2 and H2S coexistence conditions, the corrosion behavior of low-chromium steels in CO2-H2S environment with high pressure and high temperature was investigated using weight loss measurement and surface characterization. The results showed that P110 steel suffered localized corrosion and both 3Cr-P110 and 5Cr-P110 steels exhibited general corrosion. However, the corrosion rate of 5Cr-P110 was the highest among them. The corrosion process of the steels was simultaneously governed by CO2 and H2S. The outer scales on the three steels mainly consisted of FeS1−x crystals, whereas the inner scales on Cr-containing steels comprised of amorphous FeS1−x, Cr(OH3 and FeCO3, in contrast with the amorphous FeS1−x and FeCO3 mixture film of P110 steel. The more chromium the steel contains, the more chromium compounds the corrosion products contain. The addition of chromium in steels increases the uniformity of the Cr-enriched corrosion scales, eliminates the localized corrosion, but cannot decrease the general corrosion rates. The formation of FeS1−x may interfere with Cr-enriched corrosion scales and lowering the corrosion performance of 3Cr-P110 and 5Cr-P110 steels.

  8. Corrosion Behavior of Steels in Supercritical CO2 for Power Cycle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Repukaiti, Richard [National Energy Technology Lab. (NETL), Albany, OR (United States); Oregon State Univ., Corvallis, OR (United States); Teeter, Lucas [National Energy Technology Lab. (NETL), Albany, OR (United States); Oregon State Univ., Corvallis, OR (United States); Ziomek-Moroz, Margaret [National Energy Technology Lab. (NETL), Albany, OR (United States); Dogan, Omer [National Energy Technology Lab. (NETL), Albany, OR (United States); Tucker, Julie [Oregon State Univ., Corvallis, OR (United States)

    2017-07-07

    In order to understand issues with corrosion of heat exchanger materials in direct supercritical carbon dioxide (sCO2) power cycles, a series of autoclave exposure experiments and electrochemical experiments have been conducted. Corrosion behaviors of 347H stainless steel and P91 martensitic-ferrtic steel in sCO2 environment have been compared. In autoclave exposure tests performed at 50°C- 245°C and 80 bar. Mass change measurements, surface characterization, and corrosion product analysis have been conducted to understand the corrosion behavior of steels in sCO2 containing H2O and O2. Electrochemical tests performed at room temperature and 50°C, a simulation environment of water condensation phase with dissolved CO2 was prepared to evaluate the corrosion resistance of materials. From both types of experiments, generally 347H showed higher corrosion resistance than P91.

  9. Effects of gaseous nitriding AISI4140 alloy steel on corrosion and hardness properties

    Science.gov (United States)

    Tamil Moli, L.; Wahab, N.; Gopinathan, M.; Karmegam, K.; Maniyarasi, M.

    2016-10-01

    Corrosion is one of the major problems in the industry especially on machinery since it weakens the structure of the machinery part and causes the mechanical failure. This will stop the production and increase the maintenance cost. In this study, the corrosion behaviour of gas nitriding on a screw press machine shaft made from AISI 4140 steel was investigated. Pitting corrosion was identified as a major cause of the shaft failure and this study was conducted to improve the corrosion resistance on the AISI 4140 alloy steel shaft by gas nitriding as a surface hardening treatment. Gas nitriding was performed with composition of 15% ammonia and 85% nitrogen at temperatures of 525 °C, 550 °C and 575 °C and with the soaking time of 30, 45 and 60 minutes, respectively. The samples were prepared as rectangular sized of 30mm x 12mm x 3mm for immersion testing. The results showed that corrosion rate of untreated samples was 77% higher compared to the nitrided samples. It was also found that hardness of the nitrided samples was higher than untreated sample. All in all, it can be concluded that gaseous nitriding can significantly improve the surface hardness and the corrosion resistance of the shaft made of AISI 4140 alloy steel, hence reduces the pitting that is the root cause of failure.

  10. The corrosion of steels by hot sodium melts

    International Nuclear Information System (INIS)

    Currie, R.

    1996-01-01

    Considerable research has been performed by AEA Technology on the corrosion of steels by hot sodium melts containing sodium hydroxide and sodium oxide. This research has principally been in support of understanding the effects of sodium-water reactions on the internals of fast reactor steam generators. The results however have relevance to sodium fires. It has been determined that the rate of corrosion of steels by melts of pure NaOH can be significantly increased by the addition of Na 2 O. In the case of a sodium-water reaction jet created by a leak of steam into sodium, the composition of the jet varies from 100% sodium through to 100% steam, with a full range of concentrations of NaOH and Na 2 O, depending on axial and radial position. The temperature in the jet also varies with position, ranging from bulk sodium temperature on one boundary to expanded steam temperature on the other boundary, with internal temperatures ranging up to 1300 deg. C, depending on the local pre-reaction mole ratio of steam to sodium. In the case of sodium-water reaction jets, it has been possible to develop a model which predicts the composition of the reaction jet and then, using the data generated on the corrosivity of sodium melts, predict the rate of corrosion of a steel target in the path of the jet. In the case of a spray sodium fire, the sodium will initially contain a concentration of NaOH and the combustion process will generate Na 2 O. If there is sufficient humidity, conversion of some of the Na 2 O to NaOH will also occur. There is therefore the potential for aggressive mixtures of NaOH and Na 2 O to exist on the surface of the sodium droplets. It is therefore possible that the rate of corrosion of steels in the path of the spray may be higher than expected on the basis of assuming that only Na and Na 2 O were present. In the case of a pool sodium fire, potentially corrosive mixtures of NaOH and Na 2 O may be formed at some locations on the surface. This could lead to

  11. A liquid aluminum corrosion resistance surface on steel substrate

    International Nuclear Information System (INIS)

    Wang Deqing; Shi Ziyuan; Zou Longjiang

    2003-01-01

    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-Al 2 O 3 , followed by a thinner layer of FeAl 3 , and then a much thicker one of Fe 2 Al 5 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

  12. Effects of iron-reducing bacteria and nitrate-reducing bacteria on the transformations of iron corrosion products, magnetite and siderite, formed at the surface of non-alloy steel

    International Nuclear Information System (INIS)

    Etique, Marjorie

    2014-01-01

    Radioactive waste is one of the major problems facing the nuclear industry. To circumvent this issue France plans to store vitrified high-level nuclear waste in a stainless steel container, placed into a non-alloy steel overpack, at a depth of 500 m in an argillaceous formation. The main iron corrosion products formed at the surface of the non-alloy steel are siderite (Fe II CO 3 ) and magnetite (Fe II Fe III 2 O 4 ). These compounds are formed in the anoxic conditions present in the nuclear waste repository and play a protective role against corrosion as a passive layer. This work aims to investigate the activity of nitrate-reducing bacteria (NRB, Klebsiella mobilis) and iron-reducing bacteria (IRB, Shewanella putrefaciens) during the transformation of siderite and magnetite, especially those involved in anoxic iron biogeochemical cycle. Klebsiella mobilis and Shewanella putrefaciens were first incubated with siderite or magnetite suspensions (high surface specific area) in order to exacerbate the microbial iron transformation, subsequently incubated with a magnetite/siderite film synthesized by anodic polarization at applied current density. The transformation of siderite and magnetite by direct or indirect microbial processes led to the formation of carbonated green rust (Fe II 4 Fe III 2 (OH) 12 CO 3 ). As a transient phase shared by several bacterial reactions involving Fe II and Fe III , this compound is the cornerstone of the anoxic iron biogeochemical cycle. The novelty of this thesis is the consideration of bacterial metabolisms of NRB and IRB often overlooked in bio-corrosion processes. (author) [fr

  13. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    International Nuclear Information System (INIS)

    Liu, Yan; Xu, Lining; Lu, Minxu; Meng, Yao; Zhu, Jinyang; Zhang, Lei

    2014-01-01

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH − ligand generates and adsorbs in a certain scale because of abundant OH − on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs

  14. Iron Drinking Water Pipe Corrosion Products: Concentrators of Toxic Metals

    Science.gov (United States)

    2013-01-01

    health risk. In addition Pb corrosion products may be sinks for other metals such as chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn). These...Vanadium K-Edge X-ray Absorption Near-Edge Structure Interpretation: Application to the Speciation of Vanadium in Oxide Phases from Steel Slag ’, Journal

  15. Flow accelerated corrosion and erosion-corrosion of RAFM steel in liquid breeders

    International Nuclear Information System (INIS)

    Kondo, Masatoshi; Muroga, Takeo; Sagara, Akio

    2010-11-01

    Corrosion experiments for RAFM, JLF-1 steel (Fe-9Cr-2w-0.1C) in 3types of flowing liquid breeders (i.e. Li, Pb-17Li and Flinak) were performed at the same conditions, and the compatibility was compared with each other. The weight loss of the specimens in the fluids was evaluated by the corrosion model based on mass transfer. The model can be applied to different test systems with different quantity of liquid breeders and different surface area of the systems. The flow enhanced the dissolution of element of the steel in the fluids. The mechanism of an erosion-corrosion in the liquid breeders was the peeling off of the corroded steel surface by the flow. (author)

  16. austenitic steel corrosion by oxygen-containing liquid sodium

    International Nuclear Information System (INIS)

    Rivollier, Matthieu

    2017-01-01

    France is planning to construct the 4. generation of nuclear reactors. They will use liquid sodium as heat transfer fluid and will be made of 316L(N) austenitic steel as structural materials. To guarantee optimal operation on the long term, the behavior of this steel must be verified. This is why corrosion phenomena of 316L(N) steel by liquid sodium have to be well-understood. Literature points out that several corrosion phenomena are possible. Dissolved oxygen in sodium definitely influences each of the corrosion phenomenon. Therefore, the austenitic steel corrosion in oxygen-containing sodium is proposed in this study. Thermodynamics data point out that sodium chromite formation on 316L(N) steel is possible in sodium containing roughly 10 μg.g -1 of oxygen for temperature lower than 650 C (reactor operating conditions).The experimental study shows that sodium chromite is formed at 650 C in the sodium containing 200 μg.g -1 of oxygen. At the same concentration and at 550 C, sodium chromite is clearly observed only for long immersion time (≥ 5000 h). Results at 450 C are more difficult to interpret. Furthermore, the steel is depleted in chromium in all cases.The results suggest the sodium chromite is dissolved in the sodium at the same time it is formed. Modelling of sodium chromite formation - approached by chromium diffusion in steel (in grain and grain boundaries -, and dissolution - assessed by transport in liquid metal - show that simultaneous formation and dissolution of sodium chromite is a possible mechanism able to explain our results. (author) [fr

  17. Study of the Corrosion Resistance of Austenitic Stainless Steels during Conversion of Waste to Biofuel

    Science.gov (United States)

    Cabrini, Marina; Lorenzi, Sergio; Pastore, Tommaso; Pellegrini, Simone; Burattini, Mauro; Miglio, Roberta

    2017-01-01

    The paper deals with the corrosion behavior of stainless steels as candidate materials for biofuel production plants by liquefaction process of the sorted organic fraction of municipal solid waste. Corrosion tests were carried out on AISI 316L and AISI 304L stainless steels at 250 °C in a batch reactor during conversion of raw material to bio-oil (biofuel precursor), by exposing specimens either to water/oil phase or humid gas phase. General corrosion rate was measured by weight loss tests. The susceptibility to stress corrosion cracking was evaluated by means of U-bend specimens and slow stress rate tests at 10−6 or 10−5 s−1 strain rate. After tests, scanning electron microscope analysis was carried out to detect cracks and localized attacks. The results are discussed in relation with exposure conditions. They show very low corrosion rates strictly dependent upon time and temperature. No stress corrosion cracking was observed on U-bend specimens, under constant loading. Small cracks confined in the necking cone of specimens prove that stress corrosion cracking only occurred during slow strain rate tests at stresses exceeding the yield strength. PMID:28772682

  18. Corrosion Inhibition of Cold-rolled Low Carbon Steel with Pulse Fiber Laser Ablation in Water

    Science.gov (United States)

    Chan, Sze Ney; Wong, Wai Yin; Walvekar, Rashmi; Kadhum, Abdul Amir H.; Khalid, Mohammad; Lim, Kean Long

    2018-04-01

    This study aims at the use of a fiber laser for modifying the surface properties of cold-rolled low carbon steel via a pulse laser ablation technique in water. The effect on the corrosion behavior of the fiber laser-treated metal surface was investigated in NaCl and HCl environments. Electrochemical tests showed significant improvement in the corrosion resistance of the laser-treated sample in NaCl, with an increase in open-circuit potential (OCP) from - 0.65 to - 0.60 V and an inhibition efficiency of 89.22% as obtained from the impedance study. Such improvement was less significant in an acidic environment. Lower corrosion rates of 20.9 mpy and 5.819 × 103 mpy were obtained for the laser-treated samples in neutral and acidic electrolytes, respectively, than the corrosion rates obtained for the as-received samples (33.2 mpy and 11.98 × 103 mpy). Morphological analysis indicated a passive film built by spherical grains of regular size on the metal surface after laser treatment. The corrosion inhibition effects in NaCl were evident by the nonexistence of the common corrosion products of lepidocrocite and crystalline structures that were seen on as-received samples; only polyhedral crystals with micrograins grown on them were seen covering the laser-treated surface. Therefore, the laser treatment using a fiber laser source improved the corrosion resistance of cold-rolled low carbon steel.

  19. Corrosion investigations of high-alloyed steels carried out in different marine area organized by European Federation of Corrosion

    International Nuclear Information System (INIS)

    Birn, J.; Skalski, I.

    1999-01-01

    Research works arranged by EFC Working Party on Marine Corrosion are described. The research was performed in sea areas of Norway, Finland, Sweden, France, Italy, Poland and Netherlands. Subjected to test were three corrosion resistant steel grades; 316, 904 and UNS S 31524. Two corrosion tests were carried out in the years 1993 and 1994 each of min. 6 month duration. The results show that chemical composition of water at salinity level of more than 0.7% has not great effect on corrosion aggressivity in relation to corrosion resistant steels. On the other hand temperature of sea water has great influence on corrosion process. (author)

  20. Corrosion of steel tendons used in prestressed concrete pressure vessels

    International Nuclear Information System (INIS)

    Griess, J.C.; Naus, D.J.

    The purpose of this investigation was to determine the corrosion behavior of a high strength steel (ASTM A416-74 grade 270), typical of those used as tensioning tendons in prestressed concrete pressure vessels, in several corrosive environments and to demonstrate the protection afforded by coating the steel with either of two commercial petroleum-base greases or Portland Cement grout. In addition, the few reported incidents of prestressing steel failures in concrete pressure vessels used for containment of nuclear reactors are reviewed. The susceptibility of the steel to stress corrosion cracking and hydrogen embrittlement and its general corrosion rate were determined in several salt solutions. Wires coated with the greases and grout were soaked for long periods in the same solutions and changes in their mechanical properties were subsequently determined. All three coatings appeared to give essentially complete protection but small flaws in the grease coatings were detrimental; flaws or cracks less than 1 mm wide in the grout were without effect

  1. Electrochemical corrosion behavior of carbon steel with bulk coating holidays

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With epoxy coal tar as the coating material, the electrochemical corrosion behavior of Q235 with different kinds of bulk coating holidays has been investigated with EIS (Electrochemical Impedance Spectroscopy) in a 3.5vol% NaCl aqueous solution.The area ratio of bulk coating holiday to total coating area of steel is 4.91%. The experimental results showed that at free corrosionpotential, the corrosion of carbon steel with disbonded coating holiday is heavier than that with broken holiday and disbonded & broken holiday with time; Moreover, the effectiveness of Cathodic Protection (CP) of carbon steel with broken holiday is better than that with disbonded holiday and disbonded & broken holiday on CP potential -850 mV (vs CSE). Further analysis indicated that the two main reasons for corrosion are electrolyte solution slowly penetrating the coating, and crevice corrosion at steel/coating interface near holidays. The ratio of impedance amplitude (Z) of different frequency to minimum frequency is defined as K value. The change rate of K with frequency is related to the type of coating holiday.

  2. Corrosion properties of plasma deposited high-alloy steel

    Czech Academy of Sciences Publication Activity Database

    Voleník, Karel; Pražák, M.; Kalabisová, E.; Kreislová, K.; Neufuss, Karel

    2002-01-01

    Roč. 47, - (2002), s. 243-254 ISSN 0001-7043 R&D Projects: GA ČR GA106/99/0298 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma deposits, high-alloy steel, polarization curves, corrosion test Subject RIV: BL - Plasma and Gas Discharge Physics

  3. Structural Characterization of Highly Corrosion-resistant Steel

    Czech Academy of Sciences Publication Activity Database

    Lančok, Adriana; Kmječ, T.; Štefánik, M.; Sklenka, L.; Miglierini, M.

    2015-01-01

    Roč. 88, č. 4 (2015), s. 355-361 ISSN 0011-1643 R&D Projects: GA ČR(CZ) GA14-12449S Institutional support: RVO:61388980 Keywords : Mossbauer spectroscopy * corrosion-resistant steel * LC200 * CEMS Subject RIV: CA - Inorganic Chemistry Impact factor: 0.732, year: 2015

  4. Investigations on the corrosion of constructional steels in different ...

    African Journals Online (AJOL)

    The corrosion behavior of three constructional steels used in Senegal, S235, S275 and S355, was studied in simulated atmospheric conditions in an exposure chamber above distilled water and above 3% NaCl solution representing marine atmosphere by comparing the ratio of rusted to unrusted area. Electrochemical test ...

  5. Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

    African Journals Online (AJOL)

    The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium chloride addition was studied by means of mass-loss, potentiodynamic polarization, electrode potential monitoring, scanning electron microscopy and statistical analysis. Results show that deanol performed excellently with ...

  6. Crude Oil Corrosion Fatigue of L485MB Pipeline Steel

    Czech Academy of Sciences Publication Activity Database

    Gajdoš, Lubomír; Šperl, Martin; Bystrianský, J.

    2015-01-01

    Roč. 137, č. 5 (2015), 051401 ISSN 0094-9930 R&D Projects: GA TA ČR(CZ) TE02000162 Institutional support: RVO:68378297 Keywords : corrosion fatigue * crude oil * pipeline steel * S–N curve * separated water Subject RIV: JI - Composite Materials Impact factor: 0.476, year: 2015 http://pressurevesseltech.asmedigitalcollection.asme.org/article.aspx?articleID=2107675

  7. Corrosion of N80 carbon steel in oil field formation water containing CO2 in the absence and presence of acetic acid

    International Nuclear Information System (INIS)

    Zhu, S.D.; Fu, A.Q.; Miao, J.; Yin, Z.F.; Zhou, G.S.; Wei, J.F.

    2011-01-01

    Highlights: → Effects of temperature and HAc concentration on N80 carbon steel were investigated. → Temperature increased corrosion rate of N80 and precipitation rate of FeCO 3 . → HAc increased corrosion rate of N80 and enhanced the local corrosion attack (pitting). → FeCO 3 was still the main composition of corrosion products in the presence of HAc. → There was a transition region between CO 2 corrosion control and HAc corrosion control. - Abstract: Corrosion behaviour of N80 carbon steel in formation water containing CO 2 was studied by polarization curve technique, electrochemical impedance spectroscopy, weight loss test, scanning electron microscope, and X-ray diffraction. Effects of temperature and acetic acid concentration on the corrosion behaviour of N80 carbon steel were discussed. The results showed that increasing temperature not only enhanced the dissolution of steel substrate, but also promoted the precipitation of FeCO 3 , the addition of acetic acid enhanced localized corrosion attack on N80 carbon steel. FeCO 3 was the main corrosion product. And there was a transition region between CO 2 corrosion control and HAc corrosion control.

  8. Corrosion of steels in sour gas environments

    International Nuclear Information System (INIS)

    Twigg, R.J.

    1984-03-01

    This report presents a study on the effects of sour gas environments on steels. Emphasis is placed on alloys commonly used in the heavy water, sour gas and refining industries. In addition, 'high strength, low alloy' steels, known as 'oil country tubular goods', are included. Reference is made to the effects of hydrogen sulphide environments on austenitic steels and on certain specialty steels. Theories of hydrogen-related cracking mechanisms are outlined with emphasis placed on sulphide stress cracking and hydrogen induced cracking in carbon and low alloy steels. Methods of controlling sulphide stress cracking and hydrogen induced cracking are addressed separately. Case histories from the heavy water, refining, and sour gas industries are used to illustrate operating experience and failure mechanisms. Finally, recommendations, based largely on the author's industrial experience, are made with respect to quality assurance and inspection requirements for sour service components. Only published literature was surveyed. Abstracts were made of all references, reviewing the major sources in detail

  9. Effect of Ni on the corrosion resistance of bridge steel in a simulated hot and humid coastal-industrial atmosphere

    Science.gov (United States)

    Li, Dong-liang; Fu, Gui-qin; Zhu, Miao-yong; Li, Qing; Yin, Cheng-xiang

    2018-03-01

    The corrosion resistance of weathering bridge steels containing conventional contents of Ni (0.20wt%, 0.42wt%, 1.50wt%) and a higher content of Ni (3.55wt%) in a simulated hot and humid coastal-industrial atmosphere was investigated by corrosion depth loss, scanning electron microscopy-energy-dispersive X-ray spectroscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical methods. The results showed that, with increasing Ni content, the mechanical properties of the bridge steel were markedly improved, the welding parameters were satisfactory at room temperature, and the corrosion resistance was enhanced. When the Ni content was low (≤0.42wt%), the crystallization process of the corrosion products was substantially promoted, enhancing the stability of the rust layer. When the Ni content was higher ( 3.55wt%), the corrosion reaction of the steel quickly reached a balance, because the initial rapid corrosion induced the formation of a protective rust layer in the early stage. Simultaneously, NiO and NiFe2O2 were generated in large quantities; they not only formed a stable, compact, and continuous oxide protective layer, but also strongly inhibited the transformation process of the corrosion products. This inhibition reduced the structural changes in the rust layer, thereby enhancing the protection. However, when the Ni content ranged from 0.42wt% to 1.50wt%, the corrosion resistance of the bridge steel increased only slightly.

  10. Influence of Changes in Water-to-Cement Ratio, Alkalinity, Concrete Fluidity, Voids, and Type of Reinforcing Steel on the Corrosion Potential of Steel in Concrete.

    Science.gov (United States)

    2014-04-01

    "Research on steel corrosion has demonstrated that the concentrations of chloride and hydroxide ion at the concrete/steel : interface influence the susceptibility of the steel to corrosive attack. This study used electrochemical means and changes in ...

  11. Corrosion of Ferritic-Martensitic steels in high temperature water: A literature Review

    International Nuclear Information System (INIS)

    Fernandez, P.; Lapena, J.; Blazquez, F.

    2001-01-01

    Available literature concerning corrosion of high-chromium ferritic/martensitic steel in high temperature water as reviewed. The subjects considered are general corrosion, effect of irradiation on corrosion, environmentally assisted cracking (EAC) including stress corrosion cracking (SCC), corrosion fatigue and irradiation-assisted stress corrosion cracking (IASCC). In addition some investigations about radiation induced segregation (RIS). Are shown in order to know the compositional changes at grain boundaries of these alloys and their influence on corrosion properties. (Author)

  12. Corrosion by concentrated sulfuric acid in carbon steel pipes and tanks: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Panossian, Zehbour; Almeida, Neusvaldo Lira de; Sousa, Raquel Maria Ferreira de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Pimenta, Gutemberg de Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento (CENPES); Marques, Leandro Bordalo Schmidt [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    PETROBRAS, allied to the policy of reduction of emission of pollutants, has been adjusting the processes of the new refineries to obtain products with lower sulfur content. Thus, the sulfur dioxide, extracted from the process gases of a new refinery to be built in the Northeast, will be used to produce sulfuric acid with concentration between (94-96) %. This acid will be stored in carbon steel tanks and transported through a buried 8-km carbon steel pipe from the refinery to a pier, where it will be loaded onto ships and sent to the consumer markets. Therefore, the corrosion resistance of carbon steel by concentrated acid will become a great concern for the mentioned storage and transportation. When the carbon steel comes into contact with concentrated sulfuric acid, there is an immediate acid attack with the formation of hydrogen gas and ferrous ions which, in turn, forms a protective layer of FeSO{sub 4} on the metallic surface. The durability of the tanks and pipes made of carbon steel will depend on the preservation of this protective layer. This work presents a review of the carbon steel corrosion in concentrated sulfuric acid and discusses the preventive methods against this corrosion, including anodic protection. (author)

  13. The Moessbauer spectroscopy in the characterization of atmospheric corrosion products

    International Nuclear Information System (INIS)

    Hernandez Torres, D.; Leiva Ronda, P.; Gomez, J.; Ronda, M.

    1996-01-01

    A study of corrosion products on mild steel formed after 1 and 5 years exposure in two industrial coastal weathering stations in the Bay from Matanzas City, Cuba, has been carried out. Structural analysis was conducted using mainly transmission Moessbauer Spectroscopy and the X-ray diffraction as complementary technique. The main phases found in the specimen exposed to high chloride containing environment were: lepidocrocite (γ- FeOOH), goethite (α- FeOOH) and magnetite concentration was the lowest, the phases found were γ- FeOOH and α- FeOOH, and the phase transformation proposed was γ- FeOOh -> α- Fe-OOH. In this station were found also amorphous corrosion products. There amorphous phases could be responsible for the lowest levels of corrosion on steel in this station

  14. Pitting and stress corrosion cracking of stainless steel

    Science.gov (United States)

    Saithala, Janardhan R.

    An investigation has been performed to determine the pitting resistance of stainless steels and stress corrosion cracking of super duplex stainless steels in water containing chloride ions from 25 - 170°C. The steels studied are 12% Cr, FV520B, FV566, 304L, Uranus65, 2205, Ferallium Alloy 255, and Zeron 100. All these commercial materials used in very significant industrial applications and suffer from pitting and stress corrosion failures. The design of a new experimental setup using an autoclave enabled potentiodynamic polarisation experiments and slow strain rate tests in dilute environments to be conducted at elevated temperatures. The corrosion potentials were controlled using a three electrode cell with computer controlled potentiostat.The experimental programme to determine pitting potentials was designed to simulate the service conditions experienced in most industrial plants and develop mathematical model equations to help a design engineer in material selection decision. Stress corrosion resistance of recently developed Zeron100 was evaluated in dilute environments to propose a mechanism in chloride solutions at high' temperatures useful for the nuclear and power generation industry. Results have shown the significance of the composition of alloying elements across a wide range of stainless steels and its influence on pitting. Nitrogen and molybdenum added to modern duplex stainless steels was found to be unstable at higher temperatures. The fractographic results obtained using the scanning electron microscope (SEM) has given insight in the initiation of pitting in modem duplex and super duplex stainless steels. A mathematical model has been proposed to predict pitting in stainless steels based on the effect of environmental factors (temperature, chloride concentration, and chemical composition). An attempt has been made to identify the mechanism of SCC in Zeron100 super duplex stainless steel.The proposed empirical models have shown good correlation

  15. 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.

  16. Microbiologically induced corrosion of carbon steel under continuous flow conditions

    International Nuclear Information System (INIS)

    Tunaru, Mariana; Dragomir, Maria; Voicu, Anca

    2008-01-01

    Microbiologically induced corrosion is the label generally applied to corrosion involving the action of bacteria on metal surfaces. While different combinations of bacterial species, materials and chemical constituents are interrelated factors, stagnant water is the factor most often mentioned in reported cases. This paper presents the results obtained regarding the testing of microbiologically induced corrosion of carbon steel under continuous flow conditions in the presence of iron-oxidizing bacteria. The tests were performed on coupons of SA106gr.B exposed both in stagnant conditions and in flow conditions. The surfaces of these coupons were studied by metallographic technique, while the developed biofilms were analysed using microbiological technique. The correlation of all the results which were obtained emphasized that the minimizing the occurrence of stagnant or low-flow conditions can prove effective in reducing the risk of microbiologically induced corrosion in plant cooling-water systems. (authors)

  17. Polyaspartic acid as a green corrosion inhibitor for carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Cui, R. [Department of Chemistry, Hebei Normal University, Shijiazhuang 050016 (China); Department of Chemistry and Materials Engineering, Changshu Institute of Technology, Changshu 215500 (China); Gu, N.; Li, C. [Department of Chemistry, Hebei Normal University, Shijiazhuang 050016 (China)

    2011-04-15

    The inhibitor effect of the environmentally friendly corrosion inhibitor polyaspartic acid (PASP) on the corrosion of carbon steel in 0.5 M H{sub 2}SO{sub 4} was investigated by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Polarization curve results clearly reveal the fact that PASP is a good anode-type inhibitor. EIS results confirm its corrosion inhibition ability. The inhibition efficiency increases with increasing PASP concentration, and the maximum inhibition efficiency was 80.33% at 10 C. SEM reveals that a protective film forms on the surface of the inhibited sample. The adsorption of this inhibitor is found to follow the Freundlich adsorption isotherm. A mechanism is proposed to explain the inhibitory action of the corrosion inhibitor. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Aluminum corrosion product release kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Matt, E-mail: Matthew.Edwards@cnl.ca; Semmler, Jaleh; Guzonas, Dave; Chen, Hui Qun; Toor, Arshad; Hoendermis, Seanna

    2015-07-15

    Highlights: • Release of Al corrosion product was measured in simulated post-LOCA sump solutions. • Increased boron was found to enhance Al release kinetics at similar pH. • Models of Al release as functions of time, temperature, and pH were developed. - Abstract: The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable)

  19. Effects of chemistry on corrosion-erosion of steels in water and wet steam

    International Nuclear Information System (INIS)

    Berge, P.; Ducreux, J.; Saint-Paul, P.

    1981-01-01

    In steam production plants, numerous cases of degradation of steels occur when in contact with water or wet steam circulating at high velocity: in feed or discharge pumps, water reheaters, etc. When the phenomenon occurs without any mechanical wear of the metal or the oxide from the impact of solid particles (abrasion) or droplets (erosion), it is called corrosion-erosion. The phenomenon usually occurs between 100 and 250 0 C, as has been confirmed by an empirical study of the thermal and hydraulic factors which govern it. Corrosion rates can reach 1 to 2 mm/year, for a carbon steel pipe where water treated with ammonia circulates at about pH 9, at 200 0 C, and at a velocity of 5 to 10 m/s. This study evaluates the part played by the factors solely connected to the chemistry of water, with respect to the kinetics of the corrosion-erosion phenomenon. (author)

  20. Corrosion behavior of stainless steel and zirconium in nitric acid containing highly oxidizing species

    International Nuclear Information System (INIS)

    Mayuzumi, Masami; Fujita, Tomonari

    1994-01-01

    Corrosion behavior of 304ELC, 310Nb stainless steels and Zirconium was investigated in the simulated dissolver solution of a reprocessing plant to obtain fundamental data for life prediction. Corrosion of heat transfer surface was also investigated in nitric acid solutions containing Ce ion. The results obtained are as follows: (1) Stainless steels showed intergranular corrosion in the simulated dissolver solution. The corrosion rate increased with time and reached to a constant value after several hundred hours of immersing time. The constant corrosion rate changed depending on potential suggesting that corrosion potential dominates the corrosion process. 310Nb showed superior corrosion resistance to 304ELC. (2) Corrosion rate of stainless steels increased in the heat transfer condition. The causes of corrosion enhancement are estimated to be higher corrosion potential and higher temperature of heat transfer surface. (3) Zirconium showed perfect passivity in all the test conditions employed. (author)

  1. The Effects of Corrosive Chemicals on Corrosion Rate of Steel Reinforcement Bars: I. Swamp Water

    Directory of Open Access Journals (Sweden)

    Sulistyoweni Widanarko

    2010-10-01

    Full Text Available Most of infrastructures using steel concrete to reinforce the strength of concrete. Steel concrete is so vulnerable to chemical compounds that can cause corrosion. It can happen due to the presence of chemical compounds in acid environment in low pH level. These chemical compounds are SO42-, Cl-, NO3-. There are many swamp area in Indonesia. The acid contents and the concentration of ion sulphate, chlorides, and nitrate are higher in the swamp water than in the ground water .The objective of this research was to find out the influence of corrosive chemicals in the swamp water to the steel concrete corrosion rate. There were two treatment used: (1 emerging ST 37 and ST 60 within 60 days in the 'polluted' swamp water, (2 moving the ST 37 up and down periodically in the ' polluted' swamp water. Three variation of 'polluted' swamp water were made by increasing the concentration of corrosive chemical up to 1X, 5X and 10X respectively. The corrosion rate was measured by using an Immersion Method. The result of Immersion test showed that chloride had the greatest influence to corrosion rate of ST 37 and ST 60 and followed by sulphate and Nitrate. Corrosion rate value for ST 37 is 24.29 mpy and for ST 60 is 22.76 mpy. By moving the sample up and down, the corrosion rate of ST 37 increase up to 37.59 mpy, and chloride still having the greatest influence, followed by sulphate and nitrate.

  2. Influence of chemical bonding of chlorides with aluminates in cement hidratation process on corrosion steel bars in concrete

    Directory of Open Access Journals (Sweden)

    Bikić Farzet H.

    2010-01-01

    Full Text Available The presence of chlorides in concrete is a permanent subject of research because they cause corrosion of steel bars. Chlorides added to the concrete during preparation, as accelerators of the bonding of cement minerals process, enter into reaction with aluminates, creating a phase known as chloroaluminate hydrates. In everyday conditions the product of chemical bonding between chlorides and aluminates is usually monochloridealuminate C3A·CaCl2·Hx, better known as Friedel's salt. In this paper, the influence of chemical bonding of chlorides with aluminates during the process of cement hydration on corrosion of steel bars in concrete was investigated. The process of chlorides bonding with aluminates yielding monochloride aluminate is monitored by XRD analyses. It was found that the amount of chlorides bonding with aluminates increases with an increase of temperature, and as a result, reduces the amount of 'free' chlorides in concrete. Potentiodynamic measurements have shown that increase in temperature of the heat treatment of working electrodes by chlorides leads to a reduction of steel bars corrosion as a result of either the increase of the monochloride-aluminate content or the decrease of free chlorides amount. Chlorides bound in chloroaluminate hydrates do not cause activation of steel bars corrosion in concrete. It was also proven that the increase of free chlorides concentration in the concrete leads to intensification of steel bars corrosion. This additionally approves that free chlorides are only the activators of process of steel bars corrosion in the concrete.

  3. Stress corrosion cracking evaluation of martensitic precipitation hardening stainless steels

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1980-01-01

    The resistance of the martensitic precipitation hardening stainless steels PH13-8Mo, 15-5PH, and 17-4PH to stress corrosion cracking was investigated. Round tensile and c-ring type specimens taken from several heats of the three alloys were stressed up to 100 percent of their yield strengths and exposed to alternate immersion in salt water, to salt spray, and to a seacoast environment. The results indicate that 15-5PH is highly resistant to stress corrosion cracking in conditions H1000 and H1050 and is moderately resistant in condition H900. The stress corrosion cracking resistance of PH13-8Mo and 17-4PH stainless steels in conditions H1000 and H1050 was sensitive to mill heats and ranged from low to high among the several heats included in the tests. Based on a comparison with data from seacoast environmental tests, it is apparent that alternate immersion in 3.5 percent salt water is not a suitable medium for accelerated stress corrosion testing of these pH stainless steels.

  4. Stress corrosion cracking of duplex stainless steels in caustic solutions

    Science.gov (United States)

    Bhattacharya, Ananya

    Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion cracking of duplex stainless steels in chloride solution has been investigated and well documented in the literature but the SCC mechanisms for DSS in caustic solutions were not known. Microstructural changes during fabrication processes affect the overall SCC susceptibility of these steels in caustic solutions. Other environmental factors, like pH of the solution, temperature, and resulting electrochemical potential also influence the SCC susceptibility of duplex stainless steels. In this study, the role of material and environmental parameters on corrosion and stress corrosion cracking of duplex stainless steels in caustic solutions were investigated. Changes in the DSS microstructure by different annealing and aging treatments were characterized in terms of changes in the ratio of austenite and ferrite phases, phase morphology and intermetallic precipitation using optical micrography, SEM, EDS, XRD, nano-indentation and microhardness methods. These samples were then tested for general and localized corrosion susceptibility and SCC to understand the underlying mechanisms of crack initiation and propagation in DSS in the above-mentioned environments. Results showed that the austenite phase in the DSS is more susceptible to crack initiation and propagation in caustic solutions, which is different from that in the low pH chloride environment where the ferrite phase is the more susceptible phase. This study also showed that microstructural changes in duplex stainless steels due to different heat treatments could affect their SCC

  5. Chemistry of the aqueous medium - Determining factor of corrosion in carbon steel components of secondary circuit

    International Nuclear Information System (INIS)

    Radulescu, M.; Pirvan, I.; Dinu, A.; Velciu, L.

    2003-01-01

    The interplay of chemistry of aqueous medium and corrosion processes followed by deposition and/or release of corrosion products determines both formation and growth of superficial films as well as the kinetics of ion release from materials into the aqueous medium. Material corrosion in the secondary circuit of a NPP can be minimized by choosing the materials of the components and by a rigorous inspection of the chemistry of aqueous agent. The chemical inspection helps in minimizing: - the corrosion of the components immersed in feedwater and vapor and of Steam Generator components; - 'dirtying' of the systems particularly of the surfaces implied in heat transfer; - the amount of insoluble chemical species resulting in corrosion process and carried along the circuit; - the corrosion of secondary circuit components during revisions or outages. An important role among the chemical parameters of the fluids circulated in NPP tubing appears to be the pH. In CANDU reactors it must be kept within the range of 8.7 to 9.4 by treating the medium with volatile amines (morpholine and cyclohexylamine). A plot is presented giving the corrosion rate of carbon steels as a function of the pH of the medium. Besides, the oxygen concentration dissolved in the aqueous medium must be maintained under 5 μg per water kg. Other factors determining the corrosion rates are also discussed. The paper gives the results of the experiments done with various materials, solutions and analysis methods

  6. Research on atmospheric corrosion of steel using synchrotron radiation

    International Nuclear Information System (INIS)

    Yamashita, M.; Uchida, H.; Konishi, H.; Mizuki, J.

    2004-01-01

    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 CrO x 3-2X complex anions. This CrO x 3-2X 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)

  7. Anaerobic Corrosion of 304 Stainless Steel Caused by the Pseudomonas aeruginosa Biofilm

    Directory of Open Access Journals (Sweden)

    Ru Jia

    2017-11-01

    Full Text Available Pseudomonas aeruginosa is a ubiquitous bacterium capable of forming problematic biofilms in many environments. They cause biocorrosion of medical implants and industrial equipment and infrastructure. Aerobic corrosion of P. aeruginosa against stainless steels has been reported by some researchers while there is a lack of reports on anaerobic P. aeruginosa corrosion in the literature. In this work, the corrosion by a wild-type P. aeruginosa (strain PAO1 biofilm against 304 stainless steel (304 SS was investigated under strictly anaerobic condition for up to 14 days. The anaerobic corrosion of 304 SS by P. aeruginosa was reported for the first time. Results showed that the average sessile cell counts on 304 SS coupons after 7- and 14-day incubations were 4.8 × 107 and 6.2 × 107 cells/cm2, respectively. Scanning electron microscopy and confocal laser scanning microscopy corroborated the sessile cell counts. The X-ray diffraction analysis identified the corrosion product as iron nitride, confirming that the corrosion was caused by the nitrate reducing biofilm. The largest pit depths on 304 SS surfaces after the 7- and 14-day incubations with P. aeruginosa were 3.9 and 7.4 μm, respectively. Electrochemical tests corroborated the pitting data.

  8. Investigation of Eh, pH and corrosion potential of steel in anoxic groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Peat, R.; Brabon, S.; Fennell, P.A.H.; Rance, A.P.; Smart, N.R. [AEA Technology (United Kingdom)

    2001-01-01

    calibrations and the results of the electrochemical monitoring are presented. The volume of gas produced by corrosion was also measured. The results showed that the Eh value fell rapidly to approximately -400 mV vs NHE when steel wires were added to the test solution and oxygen was gettered from the artificial groundwater. The pH started at a value of approximately 10.4 but stabilised at a value of 9.7. The reasons for the fall in pH need further investigation. The corrosion potential of steel was approximately -620 mV vs NHE in cell 1, but more positive in cell 2. Anaerobic corrosion of steel wires in both cells produced hydrogen. The main conclusions from this work are: It is possible to make measurements of Eh, pH and corrosion potential in the presence of anaerobically corroding steel in artificial Bentonite equilibrated groundwater at 30 C. The presence of corroding steel leads to the rapid local deoxygenation of groundwater and a fall in the redox potential. Calomel electrodes appears to be more reliable than silver-silver chloride reference electrodes for long-term electrochemical measurements in artificial groundwaters. The methods developed during the course of this work could be used to make similar measurements in the presence of dissolved uranium and other actinides.It would then be possible to monitor the environmental conditions while studying the effect of iron corrosion products on the oxidation state and solubility of actinides.

  9. Stainless steel corrosion in conditions simulating WWER-1000 primary coolant. Corrosion behaviour in mixed core

    International Nuclear Information System (INIS)

    Krasnorutskij, V.S.; Petel'guzov, I.A.; Gritsina, V.M.; Zuek, V.A.; Tret'yakov, M.V.; Rud', R.A.; Svichkar', N.V.; Slabospitskaya, E.A.; Ishchenko, N.I.

    2011-01-01

    Research into corrosion kinetics of austenitic stainless steels (06Cr18Ni10Ti, 08Cr18Ni10Ti, 12Cr18Ni10Ti) in medium which corresponds to composition and parameters of WWER-1000 primary coolant with different pH values in autoclave out-pile conditions during 14000 hours is given. Surface of oxide films on stainless steels is investigated. Visual inspection of Westinghouse and TVEL fuel was carried out after 4 cycles in WWER-1000 primary water chemistry conditions at South Ukraine NPP. Westinghouse and TVEL fuel cladding materials possess high corrosion resistance. Blushing of weldments was observed. No visual corrosion defects or deposits were observed on fuel rods.

  10. Corrosion behaviour of mooring chain steel in seawater

    NARCIS (Netherlands)

    Zhang, X.; Noel, N.; Ferrari, G.; Hoogland, M.G.

    2016-01-01

    Failures of mooring lines on floating production, storage and offloading systems (FPSOs) raise concern to the offshore industry. Localized corrosion of mooring chain is regarded as one of main failure mechanisms. The project of Localized Mooring Chain Corrosion (LMCC) is aiming at studying the

  11. Corrosion cracking of rotor steels of steam turbines

    International Nuclear Information System (INIS)

    Melekhov, R.K.; Litvintseva, E.N.

    1994-01-01

    Results of investigation of stress corrosion cracking of steam turbine materials in nuclear, fossil and geothermal power plants have been analysed. The role of factors that cause damage to rotor discs, mono block and welding rotors of steam turbines has been shown. These are yield stress and steel composition, stress intensity coefficient and crack growth rate, composition and temperature of the condensed steam and water, electrochemical conditions. The conclusion has been made about the state of stress corrosion cracking of the rotors materials, and main investigation trends which are necessary to solve this problem have been listed

  12. Electrochemical and corrosion properties of carbon steel in simulated geological disposal environments

    International Nuclear Information System (INIS)

    Sugimoto, Katsuhisa

    2011-01-01

    This paper reviews electrochemical and corrosion studies on the application of carbon steel to an overpack container, which is used for the geological disposal of radioactive wastes. Deaerated alkaline Na 2 SO 4 -NaHCO 3 - NaCl solutions and bentonite soaked with the solutions are used as simulated geological disposal environments. Electrochemical studies show the corrosion of the steel in an early stage is the activation control. Corrosion rates are controlled by the composition of the solutions, alloying elements, and the structure of the steel. The rates decrease with time due to the formation of FeCO 3 (siderite) film on the steel. Immersion corrosion tests show general corrosion morphology. Average corrosion rates of long duration have been evaluated. Clear proofs of the initiation of localized corrosion, such as pitting, crevice corrosion, hydrogen embrittlement and stress-corrosion cracking, have not been reported. (author)

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

    Directory of Open Access Journals (Sweden)

    Ikhlas Basheer

    2015-02-01

    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

  14. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    International Nuclear Information System (INIS)

    Subramanian, Ananth Kumar; Arumugam, Sankar; Mallaiya, Kumaravel; Subramaniam, Rameshkumar

    2013-01-01

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H 2 SO 4 was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H 2 SO 4 medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface

  15. 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.

  16. Corrosion resistance of stainless steel pipes in soil

    Energy Technology Data Exchange (ETDEWEB)

    Sjoegren, L.; Camitz, G. [Swerea KIMAB AB, Box 55970, SE-102 16 Stockholm (Sweden); Peultier, J.; Jacques, S.; Baudu, V.; Barrau, F.; Chareyre, B. [Industeel and ArcelorMittal R and D, 56 rue Clemenceau, BP19, FR-71201 le Creusot, Cedex (France); Bergquist, A. [Outokumpu Stainless AB, P.O. Box 74, SE-774 22 Avesta (Sweden); Pourbaix, A.; Carpentiers, P. [Belgian Centre for Corrosion Study, Avenue des Petits-Champs 4A, BE 1410 Waterloo (Belgium)

    2011-04-15

    To be able to give safe recommendations concerning the choice of suitable stainless steel grades for pipelines to be buried in various soil environments, a large research programme, including field exposures of test specimens buried in soil in Sweden and in France, has been performed. Resistance against external corrosion of austenitic, super austenitic, lean duplex, duplex and super duplex steel grades in soil has been investigated by laboratory tests and field exposures. The grades included have been screened according to their critical pitting-corrosion temperature and according to their time-to-re-passivation after the passive layer has been destroyed locally by scratching. The field exposures programme, being the core of the investigation, uses large specimens: 2 m pipes and plates, of different grades. The exposure has been performed to reveal effects of aeration cells, deposits or confined areas, welds and burial depth. Additionally, investigations of the tendency of stainless steel to corrode under the influence of alternating current (AC) have been performed, both in the laboratory and in the field. Recommendations for use of stainless steels under different soil conditions are given based on experimental results and on operating experiences of existing stainless steel pipelines in soil. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

    International Nuclear Information System (INIS)

    Park, Tae Jun; Lee, Eun Hee; Kim, Kyung Mo; Kim, Hong Pyo

    2012-01-01

    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

  18. Study on Increasing High Temperature pH(t) to Reduce Iron Corrosion Products

    International Nuclear Information System (INIS)

    Shin, Dong Man; Hur, Nam Yong; Kim, Waang Bae

    2011-01-01

    The transportation and deposition of iron corrosion products are important elements that affect both the steam generator (SG) integrity and secondary system in pressurized water reactor (PWR) nuclear power plants. Most of iron corrosion products are generated on carbon steel materials due to flow accelerated corrosion (FAC). The several parameters like water chemistry, temperature, hydrodynamic, and steel composition affect FAC. It is well established that the at-temperature pH of the deaerated water system has a first order effect on the FAC rate of carbon steels through nuclear industry researches. In order to reduce transportation and deposition of iron corrosion products, increasing pH(t) tests were applied on secondary system of A, B units. Increasing pH(t) successfully reduced flow accelerated corrosion. The effect of increasing pH(t) to inhibit FAC was identified through the experiment and pH(t) evaluation in this paper

  19. Specification for corrosion-resisting chromium and chromium-nickel steel covered welding electrodes

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    This specification prescribes requirements for covered corrosion-resisting chromium and chromium-nickel steel electrodes. These electrodes normally are used for shielded metal arc welding, and include those alloy steels designated as corrosion or heat-resisting chromium-nickel steels in which chromium exceeds 4.0 percent and nickel does not exceed 50.0 percent

  20. Specification for corrosion-resisting chromium and chromium-nickel steel covered welding electrodes

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This specification prescribes requirements for covered corrosion-resisting chromium and chromium-nickel steel electrodes. These electrodes are normally used for shielded metal arc welding, and include those alloy steels designated as corrosion or heat-resisting chromium and chromium-nickel steels, in which chromium exceeds 4.0% and nickel does not exceed 50.0%

  1. Specification for corrosion-resisting chromium and chromium-nickel steel covered welding electrodes

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    This specification prescribes requirements for covered corrosion-resisting chromium and chromium-nickel steel electrodes. These electrodes are normally used for shielded metal arc welding, and include those alloy steels designated as corrosion or heat-resisting chromium and chromium-nickel steels, in which chromium exceeds 4.0 percent and nickel does not exceed 50.0 percent

  2. The corrosion and protection of less carbon containing steel in subsoil

    International Nuclear Information System (INIS)

    Kazimov, A. M; Mamedyarova, I. F; Selimkhanova, G. G; Bskhishova, D. A; Ibragimova, S. G.

    2007-01-01

    Full text: The protection and corrosion resistance of steel in subsoil waters of Baku subway were investigated. Kinetic curves were drawn. The results obtained from the experiment coincide with calculated results. There have been revealed and proposed hudron and fuel oil mixture protecting steel from corrosion in subsoil waters (97.8%) for the internal surface of steel pipes

  3. Bacillus sp. Acting as Dual Role for Corrosion Induction and Corrosion Inhibition with Carbon Steel (CS

    Directory of Open Access Journals (Sweden)

    Santosh K. Karn

    2017-10-01

    Full Text Available Present work investigated the role of five different bacteria species as a corrosion inducer as well as corrosion inhibitor with carbon steel (CS. We observed the ability of different bacteria species on the metal surface attachment, biofilm formation, and determined Peroxidase, Catalase enzyme activity in the detached biofilm from the CS surface. We found that each strain has diverse conduct for surface attachment like DS1 3.3, DS2 2.5, DS3 4.3, DS4 4.0, and DS5 4.71 log cfu/cm2 and for biofilm 8.3 log cfu/cm2. The enzyme Peroxidase, Catalase was found in huge concentration inside the biofilm Peroxidase was maximum for DS4 36.0 U/ml and least for DS3 19.54 U/ml. Whereas, Catalase was highest for DS4, DS5 70.14 U/ml and least 57.2 U/ml for DS2. Scanning electron microscopy (SEM was conducted to examine the biofilm and electrochemical impedance spectroscopy (EIS were utilized to observe corrosion in the presence of bacteria. The electrochemical results confirmed that DS1, DS3, DS4, and DS5 strains have statistically significant MIC-factors (Microbially Influenced Corrosion of 5.46, 8.51, 2.36, and 1.04, while DS2 protective effect factor of 0.89. Weight reduction results with carbon steel likewise supports that corrosion was initiated by DS1 and DS3, while DS2 and DS5 have no any impact though with DS4 we watched less weight reduction however assumed no role in the corrosion. We established the relation of Peroxidase enzyme activity of the isolates. DS1, DS3 and having Peroxidase in the range 22.18, 19.54 U/ml which induce the corrosion whereas DS2 and DS5 having 28.57 and 27.0 U/ml has no any effect and DS4 36 U/ml has inhibitory effect, increasing concentration inhibiting the corrosion. For Catalase DS1, DS3 have 67.28, 61.57 U/ml which induce corrosion while DS2 and DS5 57.71 and 59.14 U/ml also has no effect whereas DS4 70.14 U/ml can inhibit corrosion. Results clearly express that in a specific range both enzymes can induce the corrosion

  4. Corrosion of steels in liquid sodium

    International Nuclear Information System (INIS)

    Clement, C.F.; Hawtin, P.

    1976-01-01

    Proposed expressions for the corrosion and deposition rates and other relevant data are examined theoretically using models which treat both particle and molecular transport and the coupling between particle and molecular concentrations. It is difficult to reconcile some properties of the observed rates, including sodium velocity dependence, with currently accepted best values for the equilibrium iron concentration in sodium. To overcome this difficulty a new model is proposed which contains two iron solubilities, one with and one without association with oxygen, which can also explain some existing anomalies in solubility measurements. The models also give a qualitative understanding of some properties of particles in circuits including the observed size distribution

  5. Corrosion Behavior of Titanium Based Ceramic Coatings Deposited on Steels

    OpenAIRE

    Ali, Rania

    2016-01-01

    Titanium based ceramic films are increasingly used as coating materials because of their high hardness, excellent wear resistance and superior corrosion resistance. Using electrochemical and spectroscopic techniques, the electrochemical properties of different coatings deposited on different steels under different conditions were examined in this study. Thin films of titanium nitride (TiN), titanium diboride (TiB2), and titanium boronitride with different boron concentrations (TiBN-1&2) w...

  6. Corrosion studies on casing steel in CO2 storage environments

    NARCIS (Netherlands)

    Zhang, X.; Zevenbergen, J.F.; Benedictus, T.

    2013-01-01

    The corrosion behavior of casing steel N80 in brine plus CO2 was studied in autoclave to simulate the CO2 storage environment. The brine solution used in the study contained 130 g/l NaCl, 22.2 g/l CaCl2 and 4 g/l MgCl2. The CO2 was charged in the autoclave at different pressures (60, 80 and 100 bar)

  7. Bilayers Polypyrrole Coatings for Corrosion Protection of SAE 4140 Steel

    OpenAIRE

    Lehr, I.L.; Saidman, S.B.

    2014-01-01

    In this study polypyrrole (PPy) bilayers films were electrodeposited onto SAE 4140 steel. The inner layer was electropolymerized in the presence of molibdate and nitrate and the outer layer in a solution containing sodium bis (2-ethylhexyl) sulfosuccinate (AOT). The electrosynthesis was done under potentiostatic conditions. The corrosion protection properties of the films were examined in sodium chloride solution by open circuit measurements, linear polarization and electrochemical impedance ...

  8. Corrosion Protection of Steel by Epoxy-Organoclay Nanocomposite Coatings

    OpenAIRE

    Domna Merachtsaki; Panagiotis Xidas; Panagiotis Giannakoudakis; Konstantinos Triantafyllidis; Panagiotis Spathis

    2017-01-01

    The purpose of the present work was to study the corrosion behavior of steel coated with epoxy-(organo) clay nanocomposite films. The investigation was carried out using salt spray exposures, optical and scanning electron microscopy examination, open circuit potential, and electrochemical impedance measurements. The mechanical, thermomechanical, and barrier properties of pristine glassy epoxy polymer and epoxy-clay nanocomposites were examined. The degree of intercalation/exfoliation of clay ...

  9. Corrosion fatigue behaviors of steel wires used in coalmine

    International Nuclear Information System (INIS)

    Wang, Songquan; Zhang, Dekun; Chen, Kai; Xu, Linmin; Ge, Shirong

    2014-01-01

    Highlights: • The CF life of steel wire in acid solution is the shortest. • The fatigue source zone showed dimple morphology when coupled with anode potential. • The area of dimple increases with the increase of the applied anode potential. • The strong cathode potential cannot reduce the CF life of the smooth steel wire. • The hydrogen impacted mainly on the plastic deformation of the wire surface. - Abstract: The corrosion fatigue (CF) behaviors of the mining steel wire in different solutions at different applied polarization potentials were investigated in this paper. The surfaces and fracture morphologies of the steel wire at different applied potentials were observed by scanning electron microscope (SEM). The results showed that the CF life of steel wire in acid solution is the shortest. Moreover, the strong anodic polarization potential greatly reduced the CF life of steel wire, while the strong cathode potential did not reduce the CF life. For the smooth steel wire, the hydrogen impacted mainly on the plastic deformation of the wire surface. There was obvious dimple in the fatigue source zone of the wire when coupled with anode potential, and the area of the dimple increased with the increase of the applied anode potential. Conversely, the fatigue source zone of the fracture was relatively smooth at cathode polarization potential, which indicated that the crack propagation followed the mechanism of hydrogen induced cracking

  10. Stress corrosion in low alloy steels

    International Nuclear Information System (INIS)

    Scott, P.M.; Tice, D.R.

    1988-01-01

    The main variables affecting environmentally induced crack initiation and growth in low alloy pressure vessel steels exposed to high temperature aqueous environments are reviewed. Considerable background knowledge is available on many of the important factors such as stress, crack tip stress intensity, strain rate, steel composition and microstructure, environmental temperature, chemistry, oxidising capacity and flowrate. This information is also compared with known plant incidents of environmentally induced or assisted cracking. Certain gaps in these data and their interpretation are judged to remain particularly in the case where oxygenated water is present. These arise predominantly in the definition of margins available on plant water chemistry specifications before risk of environmentally induced cracking becomes unacceptable and in quantifying the beneficial effect of high water flowrates. (orig.)

  11. Stress corrosion in low alloy steels

    International Nuclear Information System (INIS)

    Scott, P.M.; Tice, D.R.

    1990-01-01

    The main variables affecting environmentally induced crack initiation and growth in low alloy pressure vessel steels exposed to high temperature aqueous environments are reviewed. Considerable background knowledge is available on many of the important factors such as stress, crack tip stress intensity, strain rate, steel composition and microstructure, environmental temperature, chemistry, oxidising capacity and flowrate. This information is also compared with known plant incidents of environmentally induced or assisted cracking. Certain gaps in these data and their interpretation are judged to remain particularly in the case where oxygenated water is present. These arise predominantly in the definition of margins available on plant water chemistry specifications before risk of environmentally incuced cracking becomes unacceptable and in quantifying the beneficial effect of high water flowrates. (orig.)

  12. Resistance to corrosion fatigue fracture in heat resistant steels and their welded joints

    International Nuclear Information System (INIS)

    Timofeev, B.T.; Fedorova, V.A.; Zvezdin, Yu.I.; Vajner, L.A.; Filatov, V.M.

    1987-01-01

    Experimental data on cyclic crack resistance of heat-resistant steels and their welded joints employed for production of the reactor bodies are for the first time generalized and systematized. The formula is suggested accounting for surface and inner defects to calculate the fatigue crack growth in the process of operation. This formula for surface defects regards also the effect of the corrosion factor. Mechanisms of the reactor water effect on the fatigue crack growth rate are considered as well as a combined effect of radiation and corrosive medium on this characteristic

  13. Studies on corrosion of mild steel by water using Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Nigam, A.N.; Tripathi, R.P.; Jangid, M.L.

    1987-01-01

    The corrosion of mild steel as a result of interaction with various types of local natural water samples and distilled water is studied with the help of Moessbauer spectroscopy. The data are supplemented with the studies on IR and magnetic properties as and when required. Distilled water and potable water behave in almost similar fashion wherein ferrihydrite and FeOOH are observed to be the precursors of magnetite, the end corrosion product. In case of brakish water, the additional species, viz., FeCl 2 , βFeOOH and an intermediate possibly FeOCl are accounted, and possible mechanisms are suggested. (author)

  14. Influence of remanent magnetization on pitting corrosion in pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J. H. [ESIME Zacatenco, SEPI Electronica Instituto Politecnico Nacional Mexico, D. F. (Mexico); Caleyo, F.; Hallen, J. M. [DIM-ESIQIE, Instituto Politecnico Nacional Mexico D. F. (Mexico); Lopez-Montenegro, A.; Perez-Baruch, E. [Pemex Exploracion y Produccion, Region Sur Villahermosa, Tabasco (Mexico)

    2010-07-01

    Statistical studies performed in Mexico indicate that leakage due to external pitting corrosion is the most likely cause of failure of buried pipelines. When pipelines are inspected with the magnetic flux leakage (MFL) technology, which is routinely used, the magnetization level of every part of the pipeline changes as the MFL tool travels through it. Remanent magnetization stays in the pipeline wall after inspection, at levels that may differ from a point to the next. This paper studies the influence of the magnetic field on pitting corrosion. Experiments were carried out on grade 52 steel under a level of remanent magnetization and other laboratory conditions that imitated the conditions of a pipeline after an MLF inspection. Non-magnetized control samples and magnetized samples were subjected to pitting by immersion in a solution containing chlorine and sulfide ions for seven days, and then inspected with optical microscopy. Results show that the magnetic field in the pipeline wall significantly increases pitting corrosion.

  15. Alternatives to reduce corrosion of carbon steel storage drums

    International Nuclear Information System (INIS)

    Zirker, L.R.; Beitel, G.A.

    1995-11-01

    The major tasks of this research were (a) pollution prevention opportunity assessments on the overpacking operations for failed or corroded drums, (b) research on existing container corrosion data, (c) investigation of the storage environment of the new Resource Conservation and Recovery Act Type II storage modules, (d) identification of waste streams that demonstrate deleterious corrosion affects on drum storage life, and (e) corrosion test cell program development. Twenty-one waste streams from five US Department of Energy (DOE) sites within the DOE Complex were identified to demonstrate a deleterious effect to steel storage drums. The major components of these waste streams include acids, salts, and solvent liquids, sludges, and still bottoms. The solvent-based waste streams typically had the shortest time to failure: 0.5 to 2 years. The results of this research support the position that pollution prevention evaluations at the front end of a project or process will reduce pollution on the back end

  16. Corrosion behavior of stainless steel weldments in physiological solutions

    Science.gov (United States)

    Farooq, A.; Azam, M.; Deen, K. M.

    2018-01-01

    In this study corrosion behavior of TIG welded 316L stainless steel plates in simulated biological solutions is investigated. The mechanical testing results showed slight decrease in ductility after welding and the fracture surface represented mixed cleavage and inclusions containing dimple structure. The heat affected and weld zone (WZ) demonstrated higher corrosion potential and relatively large pitting tendency than base metal (BM) in both Hank’s and Ringer’s solution. The formation of delta (δ) ferrite in the heat affected and WZ decreased the corrosion resistance as confirmed from potentiodynamic Tafel scans. The decrease in pitting resistance and lower protection tendency of the WZ compared to BM and heat affected zone was also quantified from the cyclic polarization trends.

  17. Corrosion behaviour of stainless steels by internal friction method

    International Nuclear Information System (INIS)

    Postnikov, V.S.; Kovalevskij, V.I.

    1987-01-01

    Corrosion of austenite chromium-nickel stainless steels 12 Kh18N9, 12Kh18N9T, 12Kh18N10 and 12Kh18N10T is investigated. Wire samples 0.7...0.8 mm in diameter before tests were subjected to quenching in water from the temperature of 1050...1100 deg C and part of them - to tempering at 650 deg C for 2 h. Pitting corrosion was brought about by different concentration of iron chloride solutions (C FeCl 3 ). Total corrosion has a slight effect on the character of IF (internal friction) variation that increases without the whole test period up to the moment when mechanical strength of the sample

  18. Analysis of corrosion data for carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures

    International Nuclear Information System (INIS)

    Diercks, D.R.; Hull, A.B.; Kassner, T.F.

    1988-03-01

    Carbon steel is currently the leading candidate material for fabrication of a container for isolation of high level nuclear waste in a salt repository. Since brine entrapped in the bedded salt can migrate to the container by several transport processes, corrosion is an important consideration in the long-term performance of the waste package. A detailed literature search was performed to compile relevant corrosion data for carbon steels in anoxic acid chloride solutions, and simulated salt repository brines at temperatures between ∼ 20 and 400 0 C. The hydrolysis of Mg 2+ ions in simulated repository brines containing high magnesium concentrations causes acidification at temperatures above 25 0 C, which, in turn, influences the protective nature of the magnetite corrosion product layer on carbon steel. The corrosion data for the steels were analyzed, and an analytical model for general corrosion was developed to calculate the amount of penetration (i.e., wall thinning) as a function of time, temperature, and the pressure of corrosion product hydrogen than can build up during exposure in a closed system (e.g., a sealed capsule). Both the temperature and pressure dependence of the corrosion rate of steels in anoxic acid chloride solutions indicate that the rate-controlling partial reaction is the cathodic reduction of water to form hydrogen. Variations in the composition and microstructure of the steels or the concentration of the ionic species in the chloride solutions (provided that they do not change the pH significantly) do not appear to strongly influence the corrosion rate

  19. Modification of corrosion resistances of steels by rare earths ion implantation

    International Nuclear Information System (INIS)

    Hu Zhaomin; Zhang Weiguo; Liu Fengying; Shao Tongyi; Xiang Xuyang; Gao Fengqin; Li Gongpan

    1987-01-01

    Five kinds of rare earth RE elements have been implanted into steel No.45 and GCr15 bearing steel respectively. The corrosion resistances of the specimens have been examined using electrochemical dynamic potential method, in a NaAc/HAc solution for steel No.45 specimens and in a NaAc/HAc solution containing 0.1 mol/lNaCl for GCr15 bearing steel specimens. It has been found that the aqueous solution corrosion resistances of steel No.45 are obviously modified by implantation of RE element, and the pitting corrosion properties of GCr15 bearing steel are significantly improved due to heavy RE element implantation

  20. Localized corrosion of high alloyed austenitic stainless steels

    International Nuclear Information System (INIS)

    Morach, R.; Schmuki, P.; Boehni, H.

    1992-01-01

    The susceptibility of several high alloyed stainless steels against localized corrosion was investigated by traditional potentiostatic and -kinetic methods and the current transient technique. Different test cells, proposed in literature, were evaluated for use in testing of plate materials. The AVESTA-cell showed to be not useful for potentiokinetic current density potential curves, but useable for pitting experiments. After pickling and prepassivation epoxy embedded materials proved to be resistant to crevice corrosion at the metal-resin interface. The electrode in form of a wire was the most reliable crevice free cell design. The grinding of the samples in the pretreatment procedure was found to have a large effect on the pitting corrosion behaviour. Using different paper types with varying grit, a drop in pitting potential for rougher surfaces and an increase in metastable pitting activity was found. Increasing surface roughness led also to changes in the electronic structure of the passive film reflected by a lower bandgap energy. High alloyed stainless steels showed no breakdown potential within the examined potential range. Compared to 18/8 type stainless steels significantly less transients were found. The number of transients decreases with increasing molybdenum and chromium content

  1. Mechanical Suppression of SCC and Corrosion Fatigue Failures in 300M Steel Landing Gear

    National Research Council Canada - National Science Library

    Prevey, Paul; Jayaraman, N; Ontko, Neal; Shepard, Mike; Ware, Robert; Coate, Jack

    2004-01-01

    300M steel is widely used in landing gear because of its ultra high strength with high fracture toughness, but is vulnerable to both corrosion fatigue and stress corrosion cracking, with potentially...

  2. Corrosion resistance of hsla steel after various surface treatments in chloride environment

    Czech Academy of Sciences Publication Activity Database

    Borko, K.; Pastorek, F.; Fintová, Stanislava; Hadzima, B.

    2016-01-01

    Roč. 18, č. 4 (2016), s. 99-102 ISSN 1335-4205 Institutional support: RVO:68081723 Keywords : Corrosion properties * Iron phosphating * S355J steel Subject RIV: JK - Corrosion ; Surface Treatment of Materials

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

    International Nuclear Information System (INIS)

    Yeon, Jae-Won; Ha, Young-Kyoung; Choi, In-Kyu; Chun, Kwan-Sik

    1996-01-01

    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)

  4. Prevention of Crevice Corrosion of STS 304 Stainless Steel by a Mg-alloy Galvanic Anode

    International Nuclear Information System (INIS)

    Lim, U. J.; Yun, B. D.; Kim, J. J.

    2006-01-01

    Prevention of crevice corrosion was studied for STS 304 stainless steel using a Mg-alloy galvanic anode in solutions with various specific resistivity. The crevice corrosion and corrosion protection characteristics of the steel was investigated by the electrochemical polarization and galvanic corrosion tests. Experimental results show that the crevice corrosion of STS 304 stainless steel does not occur in solutions of high specific resistivity, but it occurs in solutions of low specific resistivity like in solutions with resistivities of 30, 60 and 115 Ω · m. With decreasing specific resistivity of the solution, the electrode potential of STS 304 stainless steel in the crevice is lowered. The potential of STS 304 stainless steel in the crevice after coupling is cathodically polarized more by decreasing specific resistivity indicating that the crevice corrosion of STS 304 stainless steel is prevented by the Mg-alloy galvanic anode

  5. Evaluation of properties of low activation Mn-Cr steel. 3. Evaluation of corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Shigeru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Fukaya, Kiyoshi [Nihon Advanced Technology Co., Ltd., Tokai, Ibaraki (Japan); Ishiyama, Shintaro [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sato, Ikuo; Kusuhashi, Mikio; Hatakeyama, Takeshi [Japan Steel Works Ltd., Muroran, Hokkaido (Japan). Muroran Plant; Takahashi, Heishichiro [Hokkaido Univ., Sapporo, Hokkaido (Japan); Kikuchi, Mitsuru [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2002-05-01

    JAERI and the Japan Steel Works LTD. (JSW) have developed new Mn-Cr steels as low induced activation material. Until now, chemical composition and metallurgical processes were optimized and some steels named VC-series were selected. The properties of the steels have been evaluated and reported elsewhere. In this study, corrosion resistance of VC-series was studied. Corrosion tests for stainless steels were performed to investigate a relationship between corrosion rate and chemical composition or sensitization. Furthermore, corrosion tests under actual environment for the vacuum vessel of the reinforced JT-60 were done for non-magnetic steels. As a result, almost no weight change was observed for uniform and gap corrosion tests, No crack was shown for double U-bend corrosion tests. (author)

  6. Corrosion behavior of a superduplex stainless steel in chloride aqueous solution

    Science.gov (United States)

    Dabalà, Manuele; Calliari, Irene; Variola, Alessandra

    2004-04-01

    Super duplex stainless steels (SDSS) have been widely used as structural materials for chemical plants (especially in those engaged in phosphoric acid production), in the hydrometallurgy industries, and as materials for offshore applications due to their excellent corrosion resistance in chloride environments, compared with other commercial types of ferritic stainless steels. These alloys also possess superior weldability and better mechanical properties than austenitic stainless steels. However, due to their two-phase structure, the nature of which is very dependent on their composition and thermal history, the behavior of SDSS regarding localized corrosion appears difficult to predict, especially in chloride environments. To improve their final properties, the effect of the partition of the alloying elements between the two phases, and the composition and microstructure of each phase are the key to understanding the localized corrosion phenomena of SDSS. This paper concerns the effects of the SDSS microstructure and heat treatment on the SDSS corrosion resistance in aqueous solutions, containing different amounts of NaCl at room temperature.

  7. Stress corrosion of very high purity stainless steels in alkaline media

    International Nuclear Information System (INIS)

    Hechmat-Dehcordi, Ebrahim

    1981-01-01

    This research thesis reports the study of stress corrosion resistance of stainless steels in caustic environments. It notably concerns the electronuclear industrial sector, the production of soda by electrolysis, and the preparation of hydrogen as energy vector. After a presentation of the experimental conditions, the author highlights the influence of purity on stress corrosion cracking of 20Cr-25Ni-type austenitic alloys. The specific action of a high number of addition metallic and non-metallic elements has been studied. Stress corrosion tests have been also performed in autoclave on austeno-ferritic (21 to 25 pc Cr - 6 to 10 pc Ni) as well as ferritic (26 pc Cr) grades. The author reports the study of electrochemical properties of stainless steel in soda by means of potentiostatic techniques with an application of Pourbaix thermodynamic equilibrium diagrams, and the study of the chemical composition of passivation thin layers by Auger spectroscopy. He more particularly studies the influence of electrode potential and of some addition elements on the chemical characteristics of oxides developed at the surface of austenite. Then, the author tries to establish correlations between strain hardening microstructure of the various steels and their sensitivity to stress corrosion [fr

  8. Development of Custom 465® Corrosion-Resisting Steel for Landing Gear Applications

    Science.gov (United States)

    Daymond, Benjamin T.; Binot, Nicolas; Schmidt, Michael L.; Preston, Steve; Collins, Richard; Shepherd, Alan

    2016-04-01

    Existing high-strength low-alloy steels have been in place on landing gear for many years owing to their superior strength and cost performance. However, there have been major advances in improving the strength of high-performance corrosion-resisting steels. These materials have superior environmental robustness and remove the need for harmful protective coatings such as chromates and cadmium now on the list for removal under REACH legislation. A UK government-funded collaborative project is underway targeting a refined specification Custom 465® precipitation hardened stainless steel to replace the current material on Airbus A320 family aircraft main landing gear, a main fitting component developed by Messier-Bugatti-Dowty. This is a collaborative project between Airbus, Messier-Bugatti-Dowty, and Carpenter Technology Corporation. An extensive series of coupon tests on four production Heats of the material have been conducted, to obtain a full range of mechanical, fatigue, and corrosion properties. Custom 465® is an excellent replacement to the current material, with comparable tensile strength and fracture toughness, better ductility, and very good general corrosion and stress corrosion cracking resistance. Fatigue performance is the only significant area of deficit with respect to incumbent materials, fatigue initiation being often related to carbo-titanium-nitride particles and cleavage zones.

  9. Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

    OpenAIRE

    Dwivedi, D.; Lepkova, K.; Becker, T.

    2017-01-01

    Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The rev...

  10. Influence of cold worked layer on susceptibility to stress corrosion of duplex stainless steel

    International Nuclear Information System (INIS)

    Labanowski, J.; Ossowska, A.; Cwiek, J.

    2001-01-01

    Stress corrosion cracking resistance of cold worked layers on duplex stainless steel was investigated. The surface layers were performed through burnishing treatment. Corrosion tests were performed with the use of Slow Strain Rate Test technique in boiling 35% MgCl 2 solution. It has been shown that burnishing treatment increases corrosion resistance of steel. The factor that improves stress corrosion cracking resistance is crack incubation time. (author)

  11. High temperature chlorosilane corrosion of iron and AISI 316L stainless steel

    Science.gov (United States)

    Aller, Joshua Loren

    Chlorosilane gas streams are used at high temperatures (>500°C) throughout the semiconductor, polycrystalline silicon, and fumed silica industries, primarily as a way to refine, deposit, and produce silicon and silicon containing materials. The presence of both chlorine and silicon in chlorosilane species creates unique corrosion environments due to the ability of many metals to form both metal-chlorides and metal-silicides, and it is further complicated by the fact that many metal-chlorides are volatile at high-temperatures while metal-silicides are generally stable. To withstand the uniquely corrosive environments, expensive alloys are often utilized, which increases the cost of final products. This work focuses on the corrosion behavior of iron, the primary component of low-cost alloys, and AISI 316L, a common low-cost stainless steel, in environments representative of industrial processes. The experiments were conducted using a customized high temperature chlorosilane corrosion system that exposed samples to an atmospheric pressure, high temperature, chlorosilane environment with variable input amounts of hydrogen, silicon tetrachloride, and hydrogen chloride plus the option of embedding samples in silicon during the exposure. Pre and post exposure sample analysis including scanning electron microscopy, x-ray diffraction, energy dispersive x-ray spectroscopy, and gravimetric analysis showed the surface corrosion products varied depending on the time, temperature, and environment that the samples were exposed to. Most commonly, a volatile chloride product formed first, followed by a stratified metal silicide layer. The chlorine and silicon activities in the corrosion environment were changed independently and were found to significantly alter the corrosion behavior; a phenomenon supported by computational thermodynamic equilibrium simulations. It was found that in comparable environments, the stainless steel corroded significantly less than the pure iron. This

  12. Oxidation and stress corrosion cracking of stainless steels in SCWRs

    International Nuclear Information System (INIS)

    Gomez Briceno, D.; Castro, L.; Blazquez, F.

    2008-01-01

    SCWRs are high-temperature, high-pressure, water-cooled reactors that operate above the thermodynamic critical point of water (374 deg C, 22.1 MPa). The SCWR offers many advantages compared to state-of- the-art LWRs including the use of a single phase coolant with high enthalpy, the elimination of components such as steam generators and steam separators and dryers, a low coolant mass inventory resulting in smaller components, and a much higher efficiency ∼ 44% vs. 33% in current LWRs). In these systems high pressure (25 MPa) coolant enters the vessel at 280 deg C which is heated to about 500 deg C and delivered to a power conversion cycle. Supercritical water (SCW) exhibits properties significantly different from those of liquid water below the critical point. Supercritical water acting essentially as a non-polar dense gas with solvation properties approaching those of a low-polarity organic. In this conditions, can dissolve gases like oxygen to complete miscibility. Depending upon what species are present and how much oxygen is present in the solution can becomes a very aggressive oxidising environment. Most of the data on corrosion in supercritical water are from fossil plant or oxidation waste disposal systems. However there is very limited data on corrosion in low conductivity de-aerated SCW and less on stress corrosion cracking behaviour under operating conditions foreseen for SCWR. Candidate materials for structural components are materials for high temperatures and include ferritic-martensitic alloys; oxide dispersion strengthened (ODS) ferritic/martensitic steels and strengthened steels by precipitation and for lower temperatures the austenitic stainless steels, such as 304 and 316, used in the LWR. Low swelling austenitic steels are also of high interest for areas with high dpa and high temperature. A review of the available information on corrosion and stress corrosion behaviour of different types of stainless steels in supercritical water at high

  13. Evolution of carbon steel corrosion in feedwater conditions reproduce by the Fortrand loop

    International Nuclear Information System (INIS)

    Delaunay, Sophie; Bescond, Aurelien; Mansour, Carine; Bretelle, Jean-Luc

    2012-09-01

    Fouling and tubes support plate blockage of steam generators (SG) are major problems in the secondary circuit of pressurized water reactor (PWR) plants. Corrosion products (CP) responsible of these phenomena are mainly constituted of magnetite. Limit the amount of these CP, generated in the feedwater system and transported to SG, constitutes one way to limit fouling and blockage of SGs. This work requires the understanding of CP behaviour in the feedwater system conditions. A specific experimental circulating water loop, FORTRAND, was built at EDF to follow the formation, the transport and the deposition of iron oxides in representative conditions of the secondary circuit feedwater system. The test section operating at high temperature (up to 250 deg. C) is made in carbon steel and includes three removable segments while all the other parts of the loop are made in stainless steel. First results confirm the formation of iron oxides on carbon steel and stainless steel surface in the conditions of PWR secondary circuits. The surface characterizations show that magnetite is the corrosion product formed on carbon steel and stainless steel at 220 deg. C and goethite is formed at room temperature on stainless steel. The aim of the most recent tests performed in FORTRAND loop was to follow the evolution of corrosion in the feedwater conditions. Tests were performed in one-phase flow conditions at 150 L.h -1 with a linear velocity of 0.82 m/s at 220 deg. C in morpholine/ammonia/hydrazine medium, at pH 25C equal to 9.2. To conduct this study, a removable segment constituted by ten tubes was added to the loop. Several tests were performed to follow the deposit thickness, the iron lost in solution and the oxide morphology with time from two to nine hundred sixty hours. Chemical conditions were controlled and the reproducibility of the results was confirmed by the observation of three tubes at each test. SEM pictures present kinetics with three steps: after the first hours the

  14. Methods to Evaluate Corrosion in Buried Steel Structures: A Review

    Directory of Open Access Journals (Sweden)

    Lorena-de Arriba-Rodriguez

    2018-05-01

    Full Text Available Around the world, there are thousands of metal structures completely or partially buried in the soil. The main concern in their design is corrosion. Corrosion is a mechanism that degrades materials and causes structural failures in infrastructures, which can lead to severe effects on the environment and have direct impact on the population health. In addition, corrosion is extremely complex in the underground environment due to the variability of the local conditions. The problem is that there are many methods to its evaluation but none have been clearly established. In order to ensure the useful life of such structures, engineers usually consider an excess thickness that increases the economic cost of manufacturing and does not satisfy the principles of efficiency in the use of resources. In this paper, an extended revision of the existing methods to evaluate corrosion is carried out to optimize the design of buried steel structures according to their service life. Thus, they are classified into two categories depending on the information they provide: qualitative and quantitative methods. As a result, it is concluded that the most exhaustive methodologies for estimating soil corrosion are quantitative methods fed by non-electrochemical data based on experimental studies that measure the mass loss of structures.

  15. Study of sulphate-reducing bacteria corrosion in the weld joint for API X-70 steel

    Energy Technology Data Exchange (ETDEWEB)

    Flores, J. E.; Patino-Carachure, C.; Alfonso, I.; Rodriguez, J. A.; Rosas, G.

    2012-11-01

    The corrosion behavior originated by sulfate-reducing bacteria (SRB) was studied in two regions of welded API X-70 steel pipeline. The studies were focused on base material (BM) and heat affected zone (HAZ), from the internal region of the pipe. SRB were extracted from oil and grown in a Postgate medium. Corrosion was evaluated at 60 degree centigrade for times between 5 and 64 days. Potentiodynamic polarization curves, obtained by electrochemical techniques, indicated surface activation at short times. Structural and morphological characterizations were carried out by scanning electron microscopy (SEM) and optical microscopy (OM). H{sub 2}S concentration and pH were also measured. Results showed an important increase in the corrosion damage up to 20 days, influenced by the SRB activity, which lead to a maximum of H{sub 2}S (pH minimum). It was found a localized corrosion attack in the HAZ in a higher quantity compared to BM; and the formation of a thin film on the steel surface, originated by corrosion products and bacterial activity. (Author) 15 refs.

  16. Characterization of organic-inorganic hybrid coatings for corrosion protection of galvanized steel and electroplated ZnFe steel

    Directory of Open Access Journals (Sweden)

    Maria Eliziane Pires de Souza

    2006-03-01

    Full Text Available The development of hybrids materials has been extensively investigated in recent years. The combination of a wide variety of compositions and production processes had permitted the use of these materials in different applications like coatings for corrosion protection of metals. In this work organic-inorganic hybrid materials have been prepared from the hydrolysis of tetraethylorthosilicate and silanol-terminated polidymetilmetoxysilane using a sol-gel process. These materials have been applied on galvanized steel and on steel electroplated with a ZnFe. In order to evaluate the degradation behavior of these coatings, electrochemical techniques (Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization were used. EIS data was fitted to an equivalent circuit from which the electrochemical parameters were obtained. Results show a good protective character of the hybrid films, when compared with uncovered specimens. The overall performance of the coating systems appears to be highly dependent on the kind of metallic coating applied to the steel.

  17. Corrosion of steel drums containing immobilized ion exchange-resins and incineration ashes

    International Nuclear Information System (INIS)

    Marotta, F.; Schulz Rodriguez, F.M.; Farina, Silvia B.; Duffo, Gustavo S.

    2009-01-01

    The Argentine Atomic Energy Commission (CNEA) is responsible for developing the management nuclear waste disposal programme. This programme contemplates the design and construction of a facility for the final disposal of intermediate-level radioactive wastes. The proposed model is a near-surface monolithic repository similar to those in operation in El Cabril, Spain. The design of this type of repository is based on the use of multiple, independent and redundant barriers. The intermediate radioactive waste consists mostly in spent ionic exchange resins and filters from the nuclear power plants, research reactors and radioisotopes production facilities. The spent resins, as well as the incineration ashes, have to be immobilized before being stored to improve leach resistance of waste matrix and to maintain mechanical stability for safety requirements. Generally, cementation processes have been used as immobilization techniques for economical reasons as well as for being a simple operation. The immobilized resins and incineration ashes are thus contained in steel drums that, in turn, can undergo corrosion depending on the ionic content of the matrix. This work is a part of a systematic study of the corrosion susceptibility of steel drums in contact with immobilized cemented exchange-resins with different types and contents of aggressive species and incineration ashes. To this purpose, a special type of specimen was manufactured to simulate the cemented waste in the drum. The evolution of the corrosion potential and the corrosion current density of the steel, as well as the electrical resistivity of the matrix are being monitored along time. The aggressive species studied were chloride ions (the main ionic species present in nature) and sulphate ions (produced during the radiolysis process of the cationic exchange-resins after cementation). Preliminary results show the strong effect of chloride on the corrosion susceptibility of the steel. Monitoring will continue for

  18. Mössbauer investigation of the influence of the sea atmosphere on the corrosion of steel constructions in Sochi

    International Nuclear Information System (INIS)

    Filippov, V. P.; Lauer, D. E.; Lauer, Yu. A.; Kargin, N. I.; Goloborodko, P. G.; Goloborodko, I. V.; Poliakov, A. M.

    2013-01-01

    A study of the sea atmosphere influence on the corrosion products of steel constructions near Sochi at difference distances from the sea has been made. The phases and compositions of the corrosion products formed on different sides of steel construction elements were examined by using Mössbauer spectroscopy (at 298 and 78 K). The results show that phases and composition distributions in oxide films are different on different parts of the constructions. The differences depend not only on the distance from the sea, but from their relative orientation to the sea also. The phase structure of the oxide films on different positions is identified.

  19. Numerical Simulation of Galvanic Corrosion Caused by Shaft Grounding Systems in Steel Ship Hulls

    National Research Council Canada - National Science Library

    Wang, Y

    2005-01-01

    .... This led to the accelerated corrosion of the exposed steel ship hull on paint holidays because of the substantial difference of the electric potentials between the steel ship hull and the nickel...

  20. An AFM and XPS study of corrosion caused by micro-liquid of dilute sulfuric acid on stainless steel

    International Nuclear Information System (INIS)

    Wang Rongguang

    2004-01-01

    Micro-liquid of dilute sulfuric acid deposited on SUS304 steel surface were observed with the ac non-contact mode of an atomic force microscopy (AFM), and the detail of the corrosion process caused by them was investigated with the contact mode of the AFM, X-ray photoelectron spectroscopy (XPS) and wavelength dispersive X-ray spectroscopy (WDXS). As a result, even not applying bias voltages between the tip of the cantilever and the specimen, micro-liquid of sulfuric acid can be successfully imaged using the ac non-contact mode of AFM. Two shapes of micro-acid, i.e., micro-droplets and micro-films, were found to co-exist on the specimen surface. On areas covered by micro-films of acid, only small corrosion product particles appeared and no corrosion pits were found. Beneath micro-droplets, corrosion reaction continue to produce pits until they were all consumed to form a corrosion product (mainly iron oxides) with almost the same shape with the droplet. The total corrosion reaction time was speculated to be between 690 and 1500 ks. The corrosion product formed from micro-droplets was believed to be a process of accumulating small corrosion product particles from the liquid/substrate interface to the surface of the formerly produced corrosion product. The XPS and WDXS analysis also supports the above results

  1. The effect of zinc thickness on corrosion film breakdown of Colombian galvanized steel

    Science.gov (United States)

    Sandoval-Amador, A.; E Torres Ramirez, J.; Cabrales-Villamizar, P. A.; Laverde Cataño, D.; Y Peña-Ballesteros, D.

    2017-12-01

    This work studies the corrosion behaviour of Colombian galvanized steel in solutions of chloride and sulphate ions. The effect of the thickness and exposure time on the film’s breakdown susceptibility and protectiveness of the corrosion products were studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The corrosion products were analysed using SEM-EDS and XRD. The samples with a higher thickness level in the zinc film (Z180) have the lowest corrosion rate. In this case, one of the products that was formed by the chemical reactions that occurred was Zinc hydroxide, which exhibits a passive behaviour as observed in the Pourbaix curves of the obtained potentials and in how the different Ph levels of the solutions worked. The sheets with the highest thickness (Z180) had the best performance, since at the end of the study they showed the least amount of damage on the surface of the zinc layer. This is because the thickness of the zinc layer favours the formation of simonkolleite, which is the corrosion product that protects the material under the conditions of the study.

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

    International Nuclear Information System (INIS)

    Sherar, B.W.A.; Keech, P.G.; Shoesmith, D.W.

    2013-01-01

    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. Progress in the Research of Fatigue of Weathering Steel after Corrosion

    Science.gov (United States)

    Jianyu, Liang; Jian, Yao; Youwu, Xu

    2017-12-01

    Weathering steel has a good corrosion resistance in the atmosphere, and the application of weathering steel in civil structure also reduces the cost of painting and maintenance. It is also possible for the bare weathering steel to bear the fatigue load with a rust layer. This paper summarizes the fatigue researches after corrosion of weathering steel, including the shape of specimens, failure modes of fatigue and the conclusions obtained through experimental investigations. It is also introduced the fatigue model of weathering steel after corrosion, which can be useful for the engineering application or further researches.

  4. Irradiation Assisted Stress Corrosion Cracking of austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Irradiation Assisted Stress Corrosion Cracking (IASCC) of austenitic stainless steels in oxygenated high temperature water was studied. The IASCC failure has been considered as a degradation phenomenon potential not only in the present light water reactors but rather common in systems where the materials are exposed simultaneously to radiation and water environments. In this study, effects of the material and environmental factors on the IASCC of austenitic stainless steels were investigated in order to understand the underlying mechanism. The following three types of materials were examined: a series of model alloys irradiated at normal water-cooled research reactors (JRR-3M and JMTR), the material irradiated at a spectrally tailored mixed-spectrum research reactor (ORR), and the material sampled from a duct tube of a fuel assembly used in the experimental LMFBR (JOYO). Post-irradiation stress corrosion cracking tests in a high-temperature water, electrochemical corrosion tests, etc., were performed at hot laboratories. Based on the results obtained, analyses were made on the effects of alloying/impurity elements, irradiation/testing temperatures and material processing, (i.e., post-irradiation annealing and cold working) on the cracking behavior. On the basis of the analyses, possible remedies against IASCC in the core internals were discussed from viewpoints of complex combined effects among materials, environment and processing factors. (author). 156 refs.

  5. Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion

    Directory of Open Access Journals (Sweden)

    Christopher Neil Lyles

    2014-04-01

    Full Text Available The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11 or a methanogen (M. hungatei. The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons.

  6. Anaerobic hydrocarbon and fatty acid metabolism by syntrophic bacteria and their impact on carbon steel corrosion.

    Science.gov (United States)

    Lyles, Christopher N; Le, Huynh M; Beasley, William Howard; McInerney, Michael J; Suflita, Joseph M

    2014-01-01

    The microbial metabolism of hydrocarbons is increasingly associated with the corrosion of carbon steel in sulfate-rich marine waters. However, how such transformations influence metal biocorrosion in the absence of an electron acceptor is not fully recognized. We grew a marine alkane-utilizing, sulfate-reducing bacterium, Desulfoglaeba alkanexedens, with either sulfate or Methanospirillum hungatei as electron acceptors, and tested the ability of the cultures to catalyze metal corrosion. Axenically, D. alkanexedens had a higher instantaneous corrosion rate and produced more pits in carbon steel coupons than when the same organism was grown in syntrophic co-culture with the methanogen. Since anaerobic hydrocarbon biodegradation pathways converge on fatty acid intermediates, the corrosive ability of a known fatty acid-oxidizing syntrophic bacterium, Syntrophus aciditrophicus was compared when grown in pure culture or in co-culture with a H2-utilizing sulfate-reducing bacterium (Desulfovibrio sp., strain G11) or a methanogen (M. hungatei). The instantaneous corrosion rates in the cultures were not substantially different, but the syntrophic, sulfate-reducing co-culture produced more pits in coupons than other combinations of microorganisms. Lactate-grown cultures of strain G11 had higher instantaneous corrosion rates and coupon pitting compared to the same organism cultured with hydrogen as an electron donor. Thus, if sulfate is available as an electron acceptor, the same microbial assemblages produce sulfide and low molecular weight organic acids that exacerbated biocorrosion. Despite these trends, a surprisingly high degree of variation was encountered with the corrosion assessments. Differences in biomass, initial substrate concentration, rates of microbial activity or the degree of end product formation did not account for the variations. We are forced to ascribe such differences to the metallurgical properties of the coupons.

  7. Effect of free Cr content on corrosion behavior of 3Cr steels in a CO2 environment

    Science.gov (United States)

    Li, Wei; Xu, Lining; Qiao, Lijie; Li, Jinxu

    2017-12-01

    The corrosion behavior of 3Cr steels with three microstructures (martensite, bainite, combined ferrite and pearlite) in simulated oil field formation water with a CO2 partial pressure of 0.8 MPa was investigated. The relationships between Cr concentrations in corrosion scales and corrosion rates were studied. The precipitated phases that contained Cr were observed in steels of different microstructures, and free Cr content levels were compared. The results showed that steel with the martensite microstructure had the highest free Cr content, and thus had the highest corrosion resistance. The free Cr content of bainite steel was lower than that of martensite steel, and the corrosion rate of bainite steel was higher than that of martensite steel. Because large masses of Cr were combined in ferrite and pearlite steel, the corrosion rates of ferrite and pearlite steel were the highest. Free Cr content in steel affects its corrosion behavior greatly.

  8. The use of different techniques for determination of pitting corrosion potential of austenitic stainless steel

    International Nuclear Information System (INIS)

    Eskelinen, P.; Forsen, O.; Onnela, J.; Ylaesaari, S.; Haenninen, H.

    1992-01-01

    Three different techniques for pitting corrosion potential measurement on austenitic stainless steel (Fe18Cr10Ni) were compared: conventional polarization method, a new Avesta electrochemical corrosion measurement cell and a scratch technique. Special attention was paid to the effects of crevice corrosion during pitting corrosion potential measurement and to their elimination. Development of a rapid test technique for reliable pitting corrosion potential determination was aimed at and resulted from comparison of the different techniques

  9. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Corrosion behavior of carbon steel for overpack in groundwater containing bicarbonate ions

    International Nuclear Information System (INIS)

    Nishimura, Toshiyasu; Dong, Junpha

    2009-01-01

    Carbon steel is considered in Japan the candidate material for overpacks in high-level radioactive waste disposal. Effects of bicarbonate solutions on the corrosion behavior and corrosion products of carbon steel were investigated by electrochemical measurements, FT-IR and XRD analyses. The anodic polarization measurements showed that bicarbonate ions (HCO 3 - ) accelerated the anodic dissolution and the outer layer film formation of carbon steel in the case of high concentrations, on the other hand, it inhibited these processes in the case of low concentrations. The FT-IR and XRD analyses of the anodized film showed that siderite (FeCO 3 ) was formed in 0.5 to 1.0 mol/L bicarbonate solution, and Fe 2 (OH) 2 CO 3 in 0.1 to 0.2 mol/L bicarbonate solution, while Fe 6 (OH) 12 CO 3 was formed in 0.02 to 0.05 mol/L bicarbonate solutions. The stability of these corrosion products was able to be explained by using the actual potential-pH diagrams for the Fe-H 2 O-CO 2 system. (author)

  11. Corrosion fatigue in nitrocarburized quenched and tempered steels

    Science.gov (United States)

    Khani, M. Karim; Dengel, D.

    1996-05-01

    In order to investigate the fatigue strength and fracture mechanism of salt bath nitrocarburized steels, specimens of the steels SAE 4135 and SAE 4140, in a quenched and tempered state, and additionally in a salt bath nitrocarburized and oxidizing cooled state as well as in a polished (after the oxidizing cooling) and renewed oxidized state, were subjected to comparative rotating bending fatigue tests in inert oil and 5 pct NaCl solution. In addition, some of the quenched and tempered specimens of SAE 4135 material were provided with an approximately 50-μm-thick electroless Ni-P layer, in order to compare corrosion fatigue behavior between the Ni-P layer and the nitride layers. Long-life corrosion fatigue tests of SAE 4135 material were carried out under small stresses in the long-life range up to 108 cycles with a test frequency of 100 Hz. Fatigue tests of SAE 4140 material were carried out in the range of finite life (low-cycle range) with a test frequency of 13 Hz. The results show that the 5 pct NaCl environment drastically reduced fatigue life, but nitrocarburizing plus oxidation treatment was found to improve the corrosion fatigue life over that of untreated and Ni-P coated specimens. The beneficial effect of nitrocarburizing followed by oxidation treatment on cor-rosion fatigue life results from the protection rendered by the compound layer by means of a well-sealed oxide layer, whereby the pores present in the compound layer fill up with oxides. The role of inclusions in initiating fatigue cracks was investigated. It was found that under corrosion fatigue conditions, the fatigue cracks started at cavities along the interfaces of MnS inclusions and matrix in the case of quenched and tempered specimens. The nitrocarburized specimens, however, showed a superposition of pitting corrosion and corrosion fatigue in which pores and nonmetallic inclusions in the compound layer play a predominant role concerning the formation of pits in the substrate.

  12. Exposure testing of fasteners in preservative treated wood : gravimetric corrosion rates and corrosion product analyses

    Science.gov (United States)

    Samuel L. Zelinka; Rebecca J. Sichel; Donald S. Stone

    2010-01-01

    Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27oC at 100% relative humidity for 1 year. The...

  13. Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

    Directory of Open Access Journals (Sweden)

    OLORUNFEMI MICHAEL AJAYI

    2014-05-01

    Full Text Available Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions.

  14. Stainless steel welding method with excellent nitric acid corrosion resistance

    International Nuclear Information System (INIS)

    Matsushita, Yukinobu; Inazumi, Toru; Hyakubo, Tamako; Masamura, Katsumi.

    1996-01-01

    The present invention concerns a welding method for a stainless steel used in a circumstance being in contact with a highly oxidizing nitric acid solution such as nuclear fuel reprocessing facilities, upon welding 316 type austenite steel containing Mo while giving excellent nitric acid resistance. A method of TIG welding using a filler metal having a composition of C, Si, Mn, P, S, Ni, Cr, Mo and Cu somewhat different from a stainless steel mother material in which C, Si, Mn, P, S, Ni, Cr and Mo are specified comprises a step of TIG-welding the surface of the mother material and a step of TIG-welding the rear face of the mother material, in which the welding conditions for the rear face of the mother material are such that the distance between the surface of the outermost welding metal layer on the side of the surface of the mother material and the bottom of the groove is not less than 5mm, and an amount of welding heat is made constant. As a result, even if the method is used in a circumstance being in contact with a highly corrosive solution such as nitric acid, corrosion resistance is not degraded. (N.H.)

  15. Improved Application of Local Models to Steel Corrosion in Lead-Bismuth Loops

    International Nuclear Information System (INIS)

    Zhang Jinsuo; Li Ning

    2003-01-01

    The corrosion of steels exposed to flowing liquid metals is influenced by local and global conditions of flow systems. The present study improves the previous local models when applied to closed loops by incorporating some global condition effects. In particular the bulk corrosion product concentration is calculated based on balancing the dissolution and precipitation in the entire closed loop. Mass transfer expressions developed in aqueous medium and an analytical expression are tested in the liquid-metal environments. The improved model is applied to a pure lead loop and produces results closer to the experimental data than the previous local models do. The model is also applied to a lead-bismuth eutectic (LBE) test loop. Systematic studies illustrate the effects of the flow rate, the oxygen concentration in LBE, and the temperature profile on the corrosion rate

  16. Corrosion of steels in saline mediums with CO2, efficiency of inhibitors as a function of the degree of pre-corrosion and microstructure

    International Nuclear Information System (INIS)

    Paolinelli, LD; Perez, T; Simison, S.N

    2004-01-01

    Despite the big influence of the microstructure and chemical composition of plain carbon steels and low alloy steels on corrosion in saline mediums with CO 2 , the results found in the literature are contradictory. An aspect that is less studied is the effect of these variables on the formation and characteristics of the films as products of corrosion and on the efficiency of the inhibitors used in oil production. Previous works have shown that the efficiency of the inhibitors is affected by the microstructure and that this effect depends on the inhibitor's molecular structure. This work aims to further define the relationship between the films of corrosion products, the steel microstructure and the efficiency of the inhibitors. A plain carbon steel was studied with two different microstructures in a 5% NaCl deoxygenated solution at 40 o C, pH 6, saturated with CO 2 under laminar flow conditions. The efficiency of an imidazoline-based commercial inhibitor commonly used in oil production was characterized. The inhibitor was added after different periods of pre-corrosion: 24, 48 and 72 hours. The characteristics of the surface films were analyzed by SEM. Electrochemical tests were carried out (electrochemical impedance, resistance to lineal polarization every 24 h.) and the corrosion potentials were also recorded. The results show that the properties of the surface films and the inhibitor's efficiency depend on the microstructure with higher values for the quenched and tempered samples than for the annealed samples. While the inhibitor's efficiency diminishes in all cases along with the degree of pre-corrosion, the amount of this decrease is different for each microstructural condition (CW)

  17. The Effect of Low-Quantity Cr Addition on the Corrosion Behaviour of Dual-Phase High Carbon Steel

    Directory of Open Access Journals (Sweden)

    Wilson Handoko

    2018-03-01

    Full Text Available Industrial application of high carbon low alloy steel with the dual-phase structure of martensite and austenite has increased drastically in recent years. Due to its excellent compression strength and its high abrasion resistance, this grade of steel has used as a high performance cutting tool and in press machinery applications. By increasing the usage of more corrosive media in industrial practice and increasing the demand for reducing the production cost, it is crucial to understand the effect of the small addition of Cr on the corrosion behaviour of this grade of steel. In this study, this effect was investigated using Secondary Electron Microscopy (SEM and in-situ Atomic Force Microscopy (AFM in the sodium chloride solution. Also, the corrosion rate was measured using the Tafel polarisation curve. It has been found that the small addition of Cr increased the stability of retained austenite, thus improving its corrosion resistance and reducing its corrosion rate. This effect has been acquired through in-situ high resolution topography images in which the samples were submerged in a corrosive solution. It has been demonstrated that the corrosion rate was reduced when the stability of austenite enhanced.

  18. Carbon steel corrosion prevention during chemical cleaning of steam generator secondary side components

    International Nuclear Information System (INIS)

    Fulger, M.; Lucan, D.; Velciu, L.

    2009-01-01

    During operation of a nuclear power plant, many contaminants, such as solid particles or dissolved species are formed in the secondary circuit, go into steam generator and deposit as scales on heat transfer tubing, support plate or as sludge on tube sheet. By accumulation of these impurities, heat transfer is reduced and the integrity of the steam generator tubing is influenced. Chemical cleaning is a qualified, efficient measure to improve steam generator corrosion performance. The corrosion mechanism can be counteracted by the chemical cleaning of the deposits on the tube sheet and the scales on the heat transfer tubing. The major component of the scales is magnetite, which can be dissolved using an organic chelating agent (ethylenediaminetetraacetic acid, EDTA) in combination with a complexing agent such as citric acid in an alkaline reducing environment. As the secondary side of SG is a conglomerate of alloys it is necessary to choose an optimal chemical cleaning solution for an efficient cleaning properties and at the same time with capability of corrosion prevention of carbon steel components during the process. The paper presents laboratory tests initiated to confirm the ability of this process to clean the SG components. The experiments followed two paths: - first, carbon steel samples have been autoclavized in specific secondary circuit solutions of steam generator to simulate the deposits constituted during operation of this equipment; - secondly, autoclavized samples have been cleaned with a solvent composed of EDTA citric acid, hydrazine of pH = 5 and temperature of 85 deg. C. Before chemical cleaning, the oxide films were characterized by surface analysis techniques including optical microscopy, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Applied to dissolve corrosion products formed in a steam generator, the solvents based on chelating agents are aggressive toward carbon steels and corrosion inhibitors are

  19. Corrosion resistance and protection mechanism of hot-dip Zn-Al-Mg alloy coated steel sheet under accelerated corrosion environment; Yoyu Zn-Al-Mg kei gokin mekki koban no sokushin fushoku kankyoka ni okeru taishokusei toi boshoku kiko

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, A.; Izutani, H.; Tsujimura, T.; Ando, A.; Kittaka, T. [NKK Corp., Tokyo (Japan)

    2000-08-01

    Corrosion behavior of hot-dip Zn-6%Al 0-3%Mg alloy coated steel sheets in cyclic corrosion test (CCT) has been investigated. The corrosion resistance was improved with increasing Mg content in the coating layer, and the highest corrosion resistance was observed at 3% Mg. In Zn-6%Al-3%Mg alloy coated steel sheet, the formations of zinc carbonate hydroxide and zinc oxide were suppressed for longer duration compared with Zn-0.2%Al and Zn-4.5%Al-0.l%Mg alloy coated steel sheets. As a result, zinc chloride hydroxide existed stable on the surface of the coating layer. From the polarization behaviors in 5% NaCl aqueous solution after CCT, it was found that the corrosion current density of Zn-6%At-3%Mg alloy coated steel sheet was much smaller than those of Zn-0.2%Al and Zn-4.5%Al-0.1%Mg alloy coated steel sheets. As zinc carbonate hydroxide and zinc oxide had poor adhesion to the coating layer and had porous structures, these corrosion products were considered to have little protective action for the coating layer. Therefore, it was concluded that Mg suppressed the formation of such nonprotective corrosion products. resulting in the remarkable improvement of corrosion resistance. (author)

  20. Some Clarifications Regarding Literature on Atmospheric Corrosion of Weathering Steels

    Directory of Open Access Journals (Sweden)

    I. Díaz

    2012-01-01

    Full Text Available Extensive research work has thrown light on the requisites for a protective rust layer to form on weathering steels (WSs in the atmosphere, one of the most important is the existence of wet/dry cycling. However, the abundant literature on WS behaviour in different atmospheres can sometimes be confusing and lacks clear criteria regarding certain aspects that are addressed in the present paper. What corrosion models best fit the obtained data? How long does it take for the rust layer to stabilize? What is the morphology and structure of the protective rust layer? What is an acceptable corrosion rate for unpainted WS? What are the guideline environmental conditions, time of wetness (TOW, SO2, and Cl−, for unpainted WS? The paper makes a review of the bibliography on this issue.

  1. Interaction between corrosion crack width and steel loss in RC beams corroded under load

    International Nuclear Information System (INIS)

    Malumbela, Goitseone; Alexander, Mark; Moyo, Pilate

    2010-01-01

    This paper presents results and discussions on an experimental study conducted to relate the rate of widening of corrosion cracks with the pattern of corrosion cracks as well as the level of steel corrosion for RC beams (153 x 254 x 3000 mm) that were corroded whilst subjected to varying levels of sustained loads. Steel corrosion was limited to the tensile reinforcement and to a length of 700 mm at the centre of the beams. The rate of widening of corrosion cracks as well as strains on uncracked faces of RC beams was constantly monitored during the corrosion process, along the corrosion region and along other potential cracking faces of beams using a demec gauge. The distribution of the gravimetric mass loss of steel along the corrosion region was measured at the end of the corrosion process. The results obtained showed that: the rate of widening of each corrosion crack is dependent on the overall pattern of the cracks whilst the rate of corrosion is independent of the pattern of corrosion cracks. A mass loss of steel of 1% was found to induce a corrosion crack width of about 0.04 mm.

  2. Corrosion products behaviour under VVER primary coolant conditions

    International Nuclear Information System (INIS)

    Grygar, T.; Zmitko, M.

    2002-01-01

    The aim of this work was to collect data on thermodynamic stability of Cr, Fe, and Ni oxides, mechanisms of hydrothermal corrosion of stainless steels and to compare the real observation with the theory. We found that the electrochemical potential and pH in PWR and VVER are close to the thermodynamic boundary between two fields of stable spinel type oxides. The ways of degradation of the passivating layers due to changes in water chemistry were considered and PWR and VVER systems were found to be potentially endangered by reductive attack. In certain VVER systems the characteristics of the passivating layer on steels and also concentration of soluble corrosion products seem to be in contradiction with the theoretical expectations. (author)

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

    International Nuclear Information System (INIS)

    Nasser, A.

    2010-01-01

    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)

  4. Resistance to Corrosion of Zirconia Coatings Deposited by Spray Pyrolysis in Nitrided Steel

    Science.gov (United States)

    Cubillos, G. I.; Olaya, J. J.; Bethencourt, M.; Cifredo, G.; Blanco, G.

    2013-10-01

    Coatings of zirconium oxide were deposited onto three types of stainless steel, AISI 316L, 2205, and tool steel AISI D2, using the ultrasonic spray pyrolysis method. The effect of the flux ratio on the process and its influence on the structure and morphology of the coatings were investigated. The coatings obtained, 600 nm thick, were characterized using x-ray diffraction, scanning electron microscopy, confocal microscopy, and atomic force microscopy. The resistance to corrosion of the coatings deposited over steel (not nitrided) and stainless steel nitrided (for 2 h at 823 K) in an ammonia atmosphere was evaluated. The zirconia coating enhances the stainless steel's resistance to corrosion, with the greatest increase in corrosion resistance being observed for tool steel. When the deposition is performed on previously nitrided stainless steel, the morphology of the surface improves and the coating is more homogeneous, which leads to an improved corrosion resistance.

  5. Corrosion of construction steel in pore simulated solution

    International Nuclear Information System (INIS)

    Valdes, Matias; Vasquez, Marcela

    2004-01-01

    The corrosion of steel for reinforcing reinforced cement structures is a common problem particularly in structures that are exposed to a marine environment. Loosened masonry originating by the diametrical stress that iron oxides place on the cement is not unusual. These situations involve risk to people and goods and make it necessary to repair the structure to prolong its useful service life. Some preliminary results are presented from the reproduction of the corrosive process with the use of a solution that simulates the chemical surroundings in the concrete pores. These results will help to evaluate the incidence of contaminants (CO 2 , chloride ions), inhibitors and coatings, among others, in the following stages by conveniently adjusting the solution's composition. The composition of the chosen solution is: 0.01 mol NaOH - 0.002 mol/l Ca(OH) 2 . The effect was evaluated of a passive film generated on the surface of the steel of the reinforcements at 100 mV for 14 minutes and for 12 hours. This potential corresponds to the passive region, as determined by recording tests with cyclic volt amperometry and in accordance with the Pourbaix diagram for steel. The corrosion current was defined by recording the resistance to polarization using different electrochemical methods: potential sweep, potentiostatic jump and sweep electrochemical impedance. The results show that neither of the two times selected are enough to generate the metal's passive state and that the potential of 100 mV used to generate the passive film may be too low to produce a compact and long lasting layer, considering that the passive zone interval comes to 700 mV, according to the volt amperometry readings (CW)

  6. An Industrial Perspective on Environmentally Assisted Cracking of Some Commercially Used Carbon Steels and Corrosion-Resistant Alloys

    Science.gov (United States)

    Ashida, Yugo; Daigo, Yuzo; Sugahara, Katsuo

    2017-08-01

    Commercial metals and alloys like carbon steels, stainless steels, and nickel-based super alloys frequently encounter the problem of environmentally assisted cracking (EAC) and resulting failure in engineering components. This article aims to provide a perspective on three critical industrial applications having EAC issues: (1) corrosion and cracking of carbon steels in automotive applications, (2) EAC of iron- and nickel-based alloys in salt production and processing, and (3) EAC of iron- and nickel-based alloys in supercritical water. The review focuses on current industrial-level understanding with respect to corrosion fatigue, hydrogen-assisted cracking, or stress corrosion cracking, as well as the dominant factors affecting crack initiation and propagation. Furthermore, some ongoing industrial studies and directions of future research are also discussed.

  7. Corrosion of steel drums containing cemented ion-exchange resins as intermediate level nuclear waste

    Science.gov (United States)

    Duffó, G. S.; Farina, S. B.; Schulz, F. M.

    2013-07-01

    Exhausted ion-exchange resins used in nuclear reactors are immobilized by cementation before being stored. They are contained in steel drums that may undergo internal corrosion depending on the presence of certain contaminants. The objective of this work is to evaluate the corrosion susceptibility of steel drums in contact with cemented ion-exchange resins with different aggressive species. The corrosion potential and the corrosion rate of the steel, and the electrical resistivity of the matrix were monitored for 900 days. Results show that the cementation of ion-exchange resins seems not to pose special risks regarding the corrosion of the steel drums. The corrosion rate of the steel in contact with cemented ion-exchange resins in the absence of contaminants or in the presence of 2.3 wt.% sulphate content remains low (less than 0.1 μm/year) during the whole period of the study (900 days). The presence of chloride ions increases the corrosion rate of the steel at the beginning of the exposure but, after 1 year, the corrosion rate drops abruptly reaching a value close to 0.1 μm/year. This is probably due to the lack of water to sustain the corrosion process. When applying the results obtained in the present work to estimate the corrosion depth of the steel drums containing the cemented radioactive waste after a period of 300 years, it is found that in the most unfavourable case (high chloride contamination), the corrosion penetration will be considerably lower than the thickness of the wall of the steel drums. Cementation of ion-exchange resins does not seem to pose special risks regarding the corrosion of the steel drums that contained them; even in the case the matrix is highly contaminated with chloride ions.

  8. Corrosion protection of galvanized steels by silane-based treatments

    Science.gov (United States)

    Yuan, Wei

    The possibility of using silane coupling agents as replacements for chromate treatments was investigated on galvanized steel substrates. In order to understand the influence of deposition parameters on silane film formation, pure zinc substrates were first used as a model for galvanized steel to study the interaction between silane coupling agents and zinc surfaces. The silane films formed on pure zinc substrates from aqueous solutions were characterized by ellipsometry, contact angle measurements, reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscopy. The deposition parameters studied include solution concentration, solution dipping time and pH value of the applied solution. It appears that silane film formation involved a true equilibrium of hydrolysis and condensation reactions in aqueous solutions. It has been found that the silane film thickness obtained depends primarily on the solution concentration and is almost independent of the solution dipping time. The molecular orientation of applied silane films is determined by the pH value of applied silane solutions and the isoelectric point of metal substrates. The deposition window in terms of pH value for zinc substrates is between 6.0 and 9.0. The total surface energy of the silane-coated pure zinc substrates decreases with film aging time, the decrease rate, however, is determined by the nature of silane coupling agents. Selected silane coupling agents were applied as prepaint or passivation treatments onto galvanized steel substrates. The corrosion protection provided by these silane-based treatments were evaluated by salt spray test, cyclic corrosion test, electrochemical impedance spectroscopy, and stack test. The results showed that silane coupling agents can possibly be used to replace chromates for corrosion control of galvanized steel substrates. Silane coatings provided by these silane treatments serve mainly as physical barriers. Factors that

  9. Intergranular corrosion susceptibility in supermartensitic stainless steel weldments

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, J.M. [Sao Carlos Federal University (UFSCar), Materials Engineering Department, Rodovia Washington Luis, km 235, CEP 13565-905, Sao Carlos, SP (Brazil)], E-mail: dsek@power.ufscar.br; Della Rovere, C.A.; Kuri, S.E. [Sao Carlos Federal University (UFSCar), Materials Engineering Department, Rodovia Washington Luis, km 235, CEP 13565-905, Sao Carlos, SP (Brazil)

    2009-10-15

    The intergranular corrosion susceptibility in supermartensitic stainless steel (SMSS) weldments was investigated by the double loop - electrochemical potentiokinetic reactivation (DL-EPR) technique through the degree of sensitization (DOS). The results showed that the DOS decreased from the base metal (BM) to the weld metal (WM). The heat affected zone (HAZ) presented lower levels of DOS, despite of its complex precipitation mechanism along the HAZ length. Chromium carbide precipitate redissolution is likely to occur due to the attained temperature at certain regions of the HAZ during the electron beam welding (EBW). Scanning electron microscopy (SEM) images showed preferential oxidation sites in the BM microstructure.

  10. Material selection and corrosion control practices in petroleum production

    International Nuclear Information System (INIS)

    Tuttle, R.N.

    1980-01-01

    The intent of this paper is to review briefly the current state of the art and to discuss some of the anticipated future oil and gas drilling and production activities which may challenge the materials selection and corrosion technologies. The current state of art discussions in this paper have been augmented by providing a list of references so that interested engineers may delve into each subject in more detail as desired. The technological areas which appear to require additional input to meet future needs include high strength tubular goods for sour gas service, corrosion resistant high strength alloys, definition of the effects of pressure, temperature, and fluid composition on corrosion behavior, and fatigue properties of various steels in seawater

  11. Estimation of elastic modulus of reinforcement corrosion products using inverse analysis of digital image correlation measurements for input in corrosion-induced cracking model

    DEFF Research Database (Denmark)

    Pease, Bradley Justin; Michel, Alexander; Thybo, Anna Emilie A.

    2012-01-01

    A combined experimental and numerical approach for estimating the elastic modulus of reinforcement corrosion products is presented. Deformations between steel and mortar were measured using digital image correlation during accelerated corrosion testing at 100 μA/cm2 (~1.16 mm/year). Measured defo...

  12. Pitting corrosion and crevice corrosion of an advanced chromium-based stainless steel

    International Nuclear Information System (INIS)

    Kohler, M.

    1999-01-01

    Alloy 33 is a (wt. %) 33 Cr-32Fe-31Ni-1.6Mo-0.6CU-0.4N austenitic stainless steel combining high yield strength of min. 380 N/mm 2 (55 KSI) with high resistance to local corrosion and superior resistance to stress corrosion cracking. Ranking the material according to its PRE (pitting resistance equivalent) value, the new alloy fits in between the advanced 6% Mo superaustenitics and the nickel-base Alloy 625 but due to the balanced chemical composition the alloy shows a lot less sensitivity to segregation in the base material as well as in welded structures. It is recommended to weld the material with matching filler. The critical pitting temperature of such joints in the 10% FeCl 3 · 6H 2 O solution is reduced by only 10 C in comparison to the base material. Corrosion tests in artificial seawater (20 g/l Cl - ) with additions of chloride up to 37 g/l as well as in a NaCl-CaCl 2 , solution with 62 g/l Cl - --revealed that the critical pitting temperature does not differentiate from the 6% Mo austenitic steel Alloy 926. With respect to crevice corrosion the depassivation pH value has been determined in 1 M NaCl solution according to Crolet and again there was no difference between Alloy 33 and Alloy 926. SCC tests performed on Alloy 33 in the solution annealed condition as well as after heavy cold work up to R PO,2 ∼ 1,100--1,200 N/mm 2 (160--174 KSI) indicate the high resistance to stress corrosion cracking in hot sodium chloride solutions

  13. Electropotential measurements of passivation and corrosion of steel coupons

    International Nuclear Information System (INIS)

    Petit, G.S.; Wright, R.R.

    1977-02-01

    There is considerable interest at the Oak Ridge Gaseous Diffusion Plant (ORGDP) in the preparation of mild steel to resist corrosion (passivation) both in moist air and uranium hexafluoride (UF 6 ) environments. Steel prepared by the usual procedures to prevent rusting, such as oiling, plastic coating, painting, or phosphating, cannot be used in the presence of UF 6 . Tests have shown that a chromate treatment or an ammoniacal citrate treatment for passivation are effective. The electropotential behavior of these two passivation treatments is described. The initial electropotential measurement, when compared to that of an unpassivated coupon, gives the electropotential degree in volts of passivation. Continual exposure in the test, when compared to the unpassivated coupon, gives a profile of the durability of the passivation film. The chromate passivation treatment was slightly superior to the citrate passivation

  14. Corrosion of AISI 304 stainless steel in polluted seawater

    International Nuclear Information System (INIS)

    Brankevich, G.; Guiamet, P.; Videla, H.A.

    1987-01-01

    The sequence of microbiofouling settlement on AISI 304 stain steel samples exposed to polluted harbor sea water of a power cooling water intake is studied. The firts sates of bacterial colonization are followed by means of scanning electron microscopy during two weeks of exposure. The relation between microbiofouling and corrosion is also followed by scanning electron microscopy and evaluated through electrochemical polarization experiments. The results obtained show that microbial colonization and extracellular polimeric substances forming the biofilms have a marked influence on the electrochemical behaviour of stainless steel in sea water. Laboratory experiments using inorganic chloride solutions or artificial sea water show a considerably lesser attack of the metal than those performed 'in situ' with natural sea water. Passivity breadown is highly facilitated when complex biological and inorganic deposits (fouling) have settled on the metal surface. (Author) [pt

  15. Corrosion of high Ni-Cr alloys and Type 304L stainless steel in HNO3-HF

    International Nuclear Information System (INIS)

    Ondrejcin, R.S.; McLaughlin, B.D.

    1980-04-01

    Nineteen alloys were evaluated as possible materials of construction for steam heating coils, the dissolver vessel, and the off-gas system of proposed facilities to process thorium and uranium fuels. Commercially available alloys were found that are satisfactory for all applications. With thorium fuel, which requires HNO 3 -HF for dissolution, the best alloy for service at 130 0 C when complexing agents for fluoride are used is Inconel 690; with no complexing agents at 130 0 C, Inconel 671 is best. At 95 0 C, six other alloys tested would be adequate: Haynes 25, Ferralium, Inconel 625, Type 304L stainless steel, Incoloy 825, and Haynes 20 (in order of decreasing preference); based on composition, six untested alloys would also be adequate. The ions most effective in reducing fluoride corrosion were the complexing agents Zr 4+ and Th 4+ ; Al 3+ was less effective. With uranium fuel, modestly priced Type 304L stainless steel is adequate. Corrosion will be most severe in HNO 3 -HF used occasionally for flushing and in solutions of HNO 3 and corrosion products (ferric and dichromate ions). HF corrosion can be minimized by complexing the fluoride ion and by passivation of the steel with strong nitric acid. Corrosion caused by corrosion products can be minimized by operating at lower temperatures

  16. Velocities and mechanisms of AISI 304 steel corrosion in heated acid solutions

    International Nuclear Information System (INIS)

    Silva, B.M.; Guedes, C.D.

    1984-01-01

    The corrosion resistance of stainless steel on H 2 SO 4 at temperature higher than 60 0 C is studied. The weight loss technique and the analysis of the different components in solution are used. A proposition is made about the reason for the loss of resistance to corrosion of the stainless steel at this high temperature. (C.L.B.) [pt

  17. Corrosion of pipe steel in CO2 containing impurities and possible solutions

    NARCIS (Netherlands)

    Zhang, X.; Zevenbergen, J.F.; Spruijt, M.P.N.; Borys, M.

    2013-01-01

    CO2 flue gases acquired from different sources contain a significant amount of impurities and water, which are corrosive to the pipeline steel. To design the pipelines for large scale of CO2 flue gas transport, the corrosion of pipeline steels has to be investigated in the realistic conditions. In

  18. Effect of radiolysis on long-term corrosion system formed on low-alloy steels

    International Nuclear Information System (INIS)

    Badet, H.

    2013-01-01

    In France, for nuclear waste management, it is planned to build a storage device with a barrier system composed of steel container. Corrosion is evaluated for the safety of anoxic storage over the long term. With radiation, water radiolysis generates oxidizing and reducing species that can change the corrosion. Three aspects are developed in this thesis. The first concerns iron coupon samples experimented in carbonate deaerated water and subjected to gamma irradiation. It is shown that irradiation can increase corrosion rates within the parameters of dose. Identified crystalline phases are little changed with irradiation. Solution chemistry shows a decrease in pH with dose related to iron. Organic species are identified. The second axis is archaeological analogues irradiation with an old corrosion products layer. Structural analysis verified the phase stability with radiolysis, only the newly formed products changes. The third axis is a kinetic simulation approach. It checks the pH drop under irradiation. Taken together, these results allow us to provide new data for the anoxic corrosion under irradiation. (author) [fr

  19. The Corrosion Behavior of Stainless Steel 316L in Novel Quaternary Eutectic Molten Salt System

    Science.gov (United States)

    Wang, Tao; Mantha, Divakar; Reddy, Ramana G.

    2017-03-01

    In this article, the corrosion behavior of stainless steel 316L in a low melting point novel LiNO3-NaNO3-KNO3-NaNO2 eutectic salt mixture was investigated at 695 K which is considered as thermally stable temperature using electrochemical and isothermal dipping methods. The passive region in the anodic polarization curve indicates the formation of protective oxides layer on the sample surface. After isothermal dipping corrosion experiments, samples were analyzed using SEM and XRD to determine the topography, corrosion products, and scale growth mechanisms. It was found that after long-term immersion in the LiNO3-NaNO3-KNO3-NaNO2 molten salt, LiFeO2, LiFe5O8, Fe3O4, (Fe, Cr)3O4 and (Fe, Ni)3O4 oxides were formed. Among these corrosion products, LiFeO2 formed a dense and protective layer which prevents the SS 316L from severe corrosion.

  20. Corrosion of High Chromium Ferritic/Martensitic Steels in High Temperature Water. a Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, P.; Lapena, J.; Blazquez, F. [Ciemat, Madrid (Spain)

    2000-07-01

    Available literature concerning corrosion of high-chromium ferritic/martensitic steels in high temperature water has been reviewed. The subjects considered are general corrosion, effect of irradiation on corrosion, stress corrosion cracking (SCC) and irradiation-assisted stress corrosion cracking (IASCC). In addition some investigations about radiation induced segregation (RIS) are shown in order to know the compositional changes at grain boundaries of these alloys and their influence on corrosion properties. The data on general corrosion indicate moderate corrosion rates in high temperature water up to 350 degree centigree. Considerably larger corrosion rates were observed under neutron irradiation. The works concerning to the behaviour of these alloys to stress corrosion cracking seem to conclude that in these materials is necessary to optimize the temper temperature and to carry out the post-weld heat treatments properly in order to avoid stress corrosion cracking. (Author) 40 refs.

  1. Corrosion of High Chromium Ferritic/Martensitic Steels in High Temperature Water. a Literature Review

    International Nuclear Information System (INIS)

    Fernandez, P.; Lapena, J.; Blazquez, F.

    2000-01-01

    Available literature concerning corrosion of high-chromium ferritic/martensitic steels in high temperature water has been reviewed. The subjects considered are general corrosion, effect of irradiation on corrosion, stress corrosion cracking (SCC) and irradiation-assisted stress corrosion cracking (IASCC). In addition some investigations about radiation induced segregation (RIS) are shown in order to know the compositional changes at grain boundaries of these alloys and their influence on corrosion properties. The data on general corrosion indicate moderate corrosion rates in high temperature water up to 350 degree centigrade. Considerably larger corrosion rates were observed under neutron irradiation. The works concerning to the behaviour of these alloys to stress corrosion cracking seem to conclude that in these materials is necessary to optimize the temper temperature and to carry out the post-weld heat treatments properly in order to avoid stress corrosion cracking. (Author) 40 refs

  2. Effect of nitrogen alloying of stainless steels on their corrosion stability

    International Nuclear Information System (INIS)

    Chigal, V.; Knyazheva, V.M.; Pitter, Ya.; Babich, S.G.; Bogolyubskij, S.D.

    1986-01-01

    Results of corrosion tests and structural investigations of 03Cr18Ni10 and 03Cr18Ni10Mo3 steels without nitrogen and with nitrogen content of 0.15-0.3% are presented. Corrosion-electrochemical behaviour of Cr20Ni20 steel with ultralow carbon content (0.004-0.006%) and nitrogen content with 0-0.5% as well as Cr 2 N nitride behaviour are investigated. A conclusion is made on nitrogen and excessive nitride phase effect on corrosion stability of steel in corrosive media with different reduction-oxidation properties

  3. CORROSION AND CHEMICAL WASTE IN SAWBLADES STEEL USED IN WOOD

    Directory of Open Access Journals (Sweden)

    Paulo Fernando Trugilho

    2002-01-01

    Full Text Available The objective this work was to evaluate the chemical waste provoked by the wood on the sheets of steel used in the making of the mountains and cut tools. It was certain the correlationbetween the chemical waste and the extractive soluble in cold water, hot water and in the sequencetoluene and ethanol content. Two types of steel and twenty-seven species different from wood wereused. The corrosive agent, constituted of 50 g of fresh sawdust (moist mixed to 50 ml of distilledwater, it was prepared and placed inside of the plastic box, hermetically closed, on the samples ofsteel, which were totally immersed. The box was placed in a water bath pre-heated to 75°C, that themedium temperature of reaction is considered, that affects the sheet of the sawblade in operation. Thisgroup was operated to 80 rotations per minute (rpm. The time of reaction was of four hours. Afterthat time the corrosive agent was discarded and the samples were washed, dried and weighed. At theend, each sample was processed by a total period of forty hours. The chemical waste was evaluated by the weight difference suffered from beginning at the end of the experiment. For theresults it was observed that the Eucalyptus tradryphloia and the Eucalyptus phaeotricha the speciesthat provoked were, respectively, the largest and smaller chemical waste for the two types of steelappraised. Great variation exists in the chemical waste due to the effect of the species. The corrosionand chemical waste are especially related with the quality of the material solved in ethanol. The 1070steel were more attached than the 6170 steel.

  4. The effect of sulphide and moisture content on steel corrosion during transport of fine wet coal

    International Nuclear Information System (INIS)

    Waanders, F. B.; Vorster, S. W.

    2013-01-01

    In the present investigation the influence of compaction pressure (stress) on the corrosivity of wet coal was investigated. Two coal samples, one high in sulphur content (3 %) and the other low in sulphur content (0.6 %) were used to determine the influence of compaction stress on the corrosion rates of steel samples in contact with compacted coal. It was found that the pressure exerted on finely divided wet coal is an important factor in determining its water content and corrosivity towards mild steel. Corrosion of the steel was typically in the form of pitting and the sulphur content of the coal was an important factor in determining the corrosivity of the coal. The corrosion rate of the high sulphur content coal was higher than that of the low sulphur coal. Mössbauer spectroscopy showed that a FeS species developed on the steel surface.

  5. Fracture-tough, corrosion-resistant bearing steels

    Science.gov (United States)

    Olson, Gregory B.

    1990-01-01

    The fundamental principles allowing design of stainless bearing steels with enhanced toughness and stress corrosion resistance has involved both investigation of basic phenomena in model alloys and evaluation of a prototype bearing steel based on a conceptual design exercise. Progress in model studies has included a scanning Auger microprobe (SAM) study of the kinetics of interfacial segregation of embrittling impurities which compete with the kinetics of alloy carbide precipitation in secondary hardening steels. These results can define minimum allowable carbide precipitation rates and/or maximum allowable free impurity contents in these ultrahigh strength steels. Characterization of the prototype bearing steel designed to combine precipitated austenite transformation toughening with secondary hardening shows good agreement between predicted and observed solution treatment response including the nature of the high temperature carbides. An approximate equilibrium constraint applied in the preliminary design calculations to maintain a high martensitic temperature proved inadequate, and the solution treated alloy remained fully austenitic down to liquid nitrogen temperature rather than transforming above 200 C. The alloy can be martensitically transformed by cryogenic deformation, and material so processed will be studied further to test predicted carbide and austenite precipitation behavior. A mechanistically-based martensitic kinetic model was developed and parameters are being evaluated from available kinetic data to allow precise control of martensitic temperatures of high alloy steels in future designs. Preliminary calculations incorporating the prototype stability results suggest that the transformation-toughened secondary-hardening martensitic-stainless design concept is still viable, but may require lowering Cr content to 9 wt. pct. and adding 0.5 to 1.0 wt. pct. Al. An alternative design approach based on strain-induced martensitic transformation during

  6. Effect of Cl on the corrosive wear of AISI 321 stainless steel in ...

    Indian Academy of Sciences (India)

    Unknown

    2002-07-25

    Jul 25, 2002 ... The passivation current oscillates tremendously due to the coexistence of passive and active ions in the solution with 0⋅2 mol/l Cl–. 3.2 Corrosive wear behaviour of 321 stainless steel in Cl– + H2SO4 solution at free corrosion and passive potentials. The relationship between corrosive wear rate and Cl–.

  7. 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...

  8. A study on the corrosion characteristics of gear steel by shot peening

    International Nuclear Information System (INIS)

    Kang, Jin Shik; Kim, Tae Hyung; Cheong, Seong Kyun; Yoon, Jong Ku; Lee, Seung Ho

    2001-01-01

    The surface treatment technique to increase corrosion resistance is very important in mechanical components of structures. Therefore, this paper investigates the effects of shot peening on the corrosion resistance of SCM 420steel. The results show that the surface compressive residual stress largely increases, which cause the increase of corrosion resistance

  9. Study on electrochemical corrosion mechanism of steel foot of insulators for HVDC lines

    Science.gov (United States)

    Zheng, Weihua; Sun, Xiaoyu; Fan, Youping

    2017-09-01

    The main content of this paper is the mechanism of electrochemical corrosion of insulator steel foot in HVDC transmission line, and summarizes five commonly used artificial electrochemical corrosion accelerated test methods in the world. Various methods are analyzed and compared, and the simulation test of electrochemical corrosion of insulator steel feet is carried out by water jet method. The experimental results show that the experimental environment simulated by water jet method is close to the real environment. And the three suspension modes of insulators in the actual operation, the most serious corrosion of the V type suspension hardware, followed by the tension string suspension, and the linear string corrosion rate is the slowest.

  10. Corrosion at system chimneys made of CrNi-steels

    Energy Technology Data Exchange (ETDEWEB)

    Pajonk, Gunther [Institute of Materials Testing of Northrhine-Westfalia, D-44285 Dortmund (Germany)

    2004-07-01

    Names like 'chimney' und 'funnel' usually identify flue gas devices made of bricks. Much less known is the fact that chimney elements are still manufactured from alloys. The following article describes the particular demands ruled by legislation on building pro-ducts, just as the consequences resulting from corrosion loads by flue gas condensates. Difficulties caused by manufacturing and construction are primarily discussed. Furthermore a test procedure is introduced that allows to catch and correlate corrosion loads and technical designs systematically to corrosion behaviour and service life of flue gas devices. For the first time a tool for active quality assurance has been given by this test rig allowing to recognize construction errors systematically. This way, manufacturers of system chimneys and flue liners are enabled to optimize their products applications going ahead to the respective requests of the market. (authors)

  11. Corrosion studies of austenitic and duplex stainless steels in aqueous lithium bromide solution at different temperatures

    International Nuclear Information System (INIS)

    Igual Munoz, A.; Garcia Anton, J.; Lopez Nuevalos, S.; Guinon, J.L.; Perez Herranz, V.

    2004-01-01

    The corrosion behavior of three stainless steels EN 14311, EN 14429 (austenitic stainless steels) and EN 14462 (duplex stainless steel) was studied in a commercial LiBr solution (850 g/l LiBr solution containing chromate as inhibitor) at different temperatures (25, 50, 75 and 85 deg C) by electrochemical methods. Open circuit potentials shifted towards more active values as temperature increased, while corrosion potentials presented the opposite tendency. The most resistant alloys to general corrosion were EN 14429 and EN 14462 because they had the lowest corrosion current for all temperatures. In all the cases corrosion current increases with temperature. Pitting corrosion resistance is improved by the EN 14462, which presented the highest pitting potential, and the lowest passivation current for the whole range of temperatures studied. The duplex alloy also presents the worst repassivation behavior (in terms of the narrowest difference between corrosion potential and pitting potential); it does not repassivate from 50 deg C

  12. Wrought stainless steel butt-welding fittings: including reference to other corrosion resistant materials - approved 1971

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    ANSI B16.9 is the American Standard for steel butt-welding fittings and although not so stated, it is implied that its scope deals primarily with the schedules of wall thicknesses which are common to carbon steel and the grades of alloy steel piping that are selected for pressure and temperature considerations. The purpose of this standard is to provide industry with a set of dimensional standards for butt-welding fittings that can be used with these light wall pipes of corrosion resisting materials. The center-to-end dimensions of all fittings are identical with those in ANSI B16.9 which give to industry the advantage of uniform design room practice and a maximum utilization of existing die equipment. The only departure from this is in the lap-joint stub end where for purposes of economy the face-to-end of the product has been reduced for use with thin wall piping

  13. V and Nb Influence on the Austenitic Stainless Steel Corrosion in 0.1 M HCl

    Directory of Open Access Journals (Sweden)

    Amel GHARBI

    2014-05-01

    Full Text Available Vanadium and niobium were added in AISI309 austenitic stainless steel composition to modify their structure and pitting corrosion resistance in 0.1 M HCl. The structural characterization was carried out by X-rays diffraction and optical microscopy. Corrosion behavior was investigated using potentiodynamic tests and electrochemical impedance measurements (EIS .Results showed that vanadium and niobium addition precipitated stable carbides (VC, NbC to chromium carbides’ detriment and improved austenitic stainless steel corrosion resistance.

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

    International Nuclear Information System (INIS)

    Arnau, G.; Gimenez, E.; Rubio, M.V.; Saura, J.J.; Suay, J.J.

    1998-01-01

    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

  15. Influence of alloying elements and density on aqueous corrosion behaviour of some sintered low alloy steels

    International Nuclear Information System (INIS)

    Kandavel, T.K.; Chandramouli, R.; Karthikeyan, P.

    2012-01-01

    Highlights: ► Corrosion of low alloy P/M steels under HCl acid pickling environment has been studied. ► Influence of density, strain and alloying elements on the rate of corrosion of the steels has been investigated. ► Residual porosity has significant effect on acid corrosion. ► Addition of the alloying elements Cu, Mo and Ti reduces the corrosion rate significantly. ► Carbide forming elements Mo and Ti improve further the resistance of the steels to aqueous corrosion. -- Abstract: Low alloy steels produced through powder metallurgy route of sintering followed by forging are promising candidate materials for high strength small components. Porosity in such steels poses a real challenge during acid pickling treatment, which is one of the processing steps during manufacturing. The present research work attempts to investigate the mechanism underlying the acid corrosion behaviour of some sintered low alloy steels under induced acid pickling conditions. Sintered-forged low alloy steel samples containing molybdenum (Mo), copper (Cu) and titanium (Ti) were subjected to aqueous corrosion attack by immersing the samples in 18% HCl (Hydrochloric acid) solution for 25 h. Sample weight loss and Fe (Iron) loss were estimated for the corroded samples. The morphology of the corroded surfaces was studied through metallography and scanning electron microscopy. Higher porosity alloys underwent enhanced corrosion rates. Both corrosion rate and iron loss are found to decrease linearly with reduction in porosity in all cases of the alloys. The alloying elements Mo, Ti and Cu, when added in combination, have played a complementary role in the reduction of corrosion rate by almost one order of magnitude compared to unalloyed steel. Presence of carbides of the carbide forming elements Mo and Ti played a positive role on the corrosion behaviour of the low alloy steels.

  16. Investigation of corrosion of welded joints of austenitic and duplex stainless steels

    Science.gov (United States)

    Topolska, S.

    2016-08-01

    Investigation of corrosion resistance of materials is one of the most important tests that allow determining their functional properties. Among these tests the special group consist electrochemical investigations, which let to accelerate the course of the process. These investigations allow rapidly estimating corrosion processes occurring in metal elements under the influence of the analysed environment. In the paper are presented results of investigations of the resistance to pitting corrosion of the steel of next grades: austenitic 316L and duplex 2205. It was also analysed the corrosion resistance of welded joints of these grades of steel. The investigations were conducted in two different corrosion environments: in the neutral one (3.5 % sodium chloride) and in the aggressive one (0.1 M sulphuric acid VI). The obtained results indicate different resistance of analysed grades of steel and their welded joints in relation to the corrosion environment. The austenitic 316L steel characterizes by the higher resistance to the pitting corrosion in the aggressive environment then the duplex 2205 steel. In the paper are presented results of potentiodynamic tests. They showed that all the specimens are less resistant to pitting corrosion in the environment of sulphuric acid (VI) than in the sodium chloride one. The 2205 steel has higher corrosion resistance than the 316L stainless steel in 3.5% NaCl. On the other hand, in 0.1 M H2SO4, the 316L steel has a higher corrosion resistance than the 2205 one. The weld has a similar, very good resistance to pitting corrosion like both steels.

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

    International Nuclear Information System (INIS)

    Zapp, P.E.; Zee, J. van.

    1998-01-01

    '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.'

  18. 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

  19. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Ananth Kumar; Arumugam, Sankar [Kandaswami Kandar' s College, Namakkal (India); Mallaiya, Kumaravel; Subramaniam, Rameshkumar [PSG College of Technology Peelamedu, Coimbatore (India)

    2013-12-15

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H{sub 2}SO{sub 4} was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H{sub 2}SO{sub 4} medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface.

  20. Stress corrosion cracking of highly irradiated 316 stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Morihito; Fukuya, Koji; Fujii, Katsuhiko; Nakajima, Nobuo; Furutani, Gen [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2001-09-01

    Mechanical property tests, grain boundary (GB) composition analysis and slow strain rate test (SSRT) in simulated PWR primary water changing dissolved hydrogen (DH) and dissolved oxygen (DO) content were carried out on cold-worked (CW) 316 stainless steels which were irradiated to 1-8x10{sup 26} n/m{sup 2} (E>0.1 MeV) in a Japanese PWR in order to evaluate irradiation-assisted stress corrosion cracking (IASCC) susceptibility. Highly irradiated stainless steels were susceptible to intergranular stress corrosion cracking (IGSCC) in both hydrogenated water and oxygenated water and to intergranular cracking in inert gas atmosphere. IASCC susceptibility increased with increasing DH content (0-45 ccH{sub 2}/kgH{sub 2}O). Hydrogen content of the section containing fracture surface was higher than that of the section far from fracture surface. These results suggest that hydrogen would have an important role for IASCC. While mechanical property was saturated, GB segregation and IASCC susceptibility increased with an increase in fluence, suggesting that GB segregation would have a dominant role for an increase in IASCC susceptibility at this high fluence region. (author)

  1. Corrosion of martensitic steels in flowing 17Li83Pb alloy

    International Nuclear Information System (INIS)

    Flament, T.; Fauvet, P.; Hocde, B.; Sannier, J.

    1988-01-01

    Corrosion of three martensitic steels - 1.4914, HT9 and T91 - in the presence of flowing 17Li83Pb is investigated in thermal convection loops Tulip entirely made of 1.4914 steel. Two 3000-hour tests were performed at maximal temperatures of respectively 450 and 475 0 C with a δT of 60 0 C and an alloy velocity of about 0.08 m.s -1 . In both tests, corrosion is characterized by an homogeneous dissolution of the steel without formation of a corrosion layer. Corrosion rate is constant and very temperature dependent: the sound-metal loss of 1.4914 steel is 22 μm. year -1 at 450 0 C and 40 μm.year -1 at 475 0 C. Behaviours of 1.4914 and HT9 steels are very similar whereas T91 steel is about 20% less corroded

  2. A wireless embedded passive sensor for monitoring the corrosion potential of reinforcing steel

    International Nuclear Information System (INIS)

    Bhadra, Sharmistha; Thomson, Douglas J; Bridges, Greg E

    2013-01-01

    Corrosion of reinforcing steel, which results in premature deterioration of reinforced concrete structures, is a worldwide problem. Most corrosion sensing techniques require some type of wired connection between the sensor and monitoring electronics. This causes significant problems in their installation and long-term use. In this paper we describe a new type of passive embeddable wireless sensor that is based on an LC coil resonator where the resonant frequency is changed by the corrosion potential of the reinforcing steel. The resonant frequency can be monitored remotely by an interrogator coil inductively coupled to the sensor coil. The sensor unit comprises an inductive coil connected in parallel with a voltage dependent capacitor (varactor) and a pair of corrosion electrodes consisting of a reinforcing steel sensing electrode and a stainless steel reference electrode. Change of potential difference between the electrodes due to variation of the corrosion potential of the reinforcing steel changes the capacitance of the varactor and shifts the resonant frequency of the sensor. A time-domain gating method was used for the interrogation of the inductively coupled corrosion sensor. Results of an accelerated corrosion test using the sensor indicate that the corrosion potential can be monitored with a resolution of less than 10 mV. The sensor is simple in design and requires no power source, making it an inexpensive option for long-term remote monitoring of the corrosion state of reinforcing steel. (paper)

  3. Mechanical Behavior of Stainless Steel Fiber-Reinforced Composites Exposed to Accelerated Corrosion

    Science.gov (United States)

    O’Brien, Caitlin; McBride, Amanda; E. Zaghi, Arash; Burke, Kelly A.; Hill, Alex

    2017-01-01

    Recent advancements in metal fibers have introduced a promising new type of stainless steel fiber with high stiffness, high failure strain, and a thickness corrosion. The main goal of this study is to compare the impact of corrosion on the mechanical properties of steel fiber-reinforced composites with those of conventional types of stainless steel. By providing experimental evidences, this study may promote the application of steel fiber-reinforced composite as a viable alternative to conventional metals. Samples of steel fiber-reinforced polymer and four different types of stainless steel were subjected to 144 and 288 h of corrosion in ferric chloride solution to simulate accelerated corrosion conditions. The weight losses due to corrosion were recorded. The corroded and control samples were tested under monotonic tensile loading to measure the ultimate stresses and strains. The effect of corrosion on the mechanical properties of the different materials was evaluated. The digital image correlation (DIC) technique was used to investigate the failure mechanism of the corrosion-damaged specimens. Overall, steel fiber-reinforced composites had the greatest corrosion resistance. PMID:28773132

  4. Corrosion Inhibition of Mild Steel in Seawater using Jatropha Stem

    Directory of Open Access Journals (Sweden)

    Olawale Olamide

    2016-10-01

    Full Text Available The present work investigate the inhibition of Jatropha Stem Extract (JSE in sea water using mild steel coupons of dimension 5 × 5 × 0.5 cm. The cupons were immersed in test solutions of sea water and varied concentrations of extracts of 0.1g/l to 0.9g/l was used. The functional groups of the compounds was analyzed using an FTIR. The results showed that as the concentration of the extract increases, there was a reduction in the corrosion rates. Furthermore, as the extract concentrations increased from 0.1g/l to 0.4g/l at 48hrs exposure time, the weight loss decreased by 14.3% in the medium. However, the Jatropha Stem Extract was absorbed on the substrate surface to inhibit corrosion, the morphology of phases formed from the scanning Electron Microscopy examination confirmed this trend. Hence, JSE is a good and safe inhibitor in sea water solution. The FT-IR results also indicates the presence of active corrosion inhibitor present in the Jatropha Stem.

  5. Device of capturing for radioactive corrosion products

    International Nuclear Information System (INIS)

    Ohara, Atsushi; Fukushima, Kimichika.

    1984-01-01

    Purpose: To increase the area of contact between the capturing materials for the radioactive corrosion products contained in the coolants and the coolants by producing stirred turbulent flows in the coolant flow channel of LMFBR type reactors. Constitution: Constituent materials for the nuclear fuel elements or the reactor core structures are activated under the neutron irradiation, corroded and transferred into the coolants. While capturing devices made of pure metal nickel are used for the elimination of the corrosion products, since the coolants form laminar flows due to the viscosity thereof near the surface of the capturing materials, the probability that the corrosion products in the coolants flowing through the middle portion of the channel contact the capturing materials is reduced. In this invention, rotating rolls and flow channels in which the balls are rotated are disposed at the upstream of the capturing device to forcively disturb the flow of the liquid sodium, whereby the radioactive corrosion products can effectively be captured. (Kamimura, M.)

  6. Techniques for the identification of corrosion products

    International Nuclear Information System (INIS)

    Ramanathan, L.V.

    1988-12-01

    This paper presents the different techniques that can be used to identify corrosion/oxidation products through determination of either their composition or their structure, chemical analysis and spectrochemical analysis are commonly used to determine the composition of gross corrosion products. Surface anaLysis techniques such as electron microprobe, AES, ESCA, SIMS, ISS, neutron activation analysis, etc., can be used not only to detect the concentration of the various elements present, but also to obtain the concentration profiles of these elements through the corrosion products. The structure of corrosion products is normally determined with the aid of either X-ray or electron diffraction techniques. This paper describes the basic principles, typical characteristics, limitations and the types of information that can be obtained from each of the techniques along with some typical examples. (author) [pt

  7. Inhibition of salt precipitation, corrosion and corrosion fatigue of steel in neutral environments

    International Nuclear Information System (INIS)

    Mikhajlovskij, V.Ya.; Slobodyan, Z.V.; Soprunyuk, N.G.; Ivanov, A.M.

    1983-01-01

    Processes of salt precipitation, corrosion under dynamic and static conditions, are studied as well as corrosion fatigue of 20 and 40Kh steels in neutral aqueous media without and with the addition of compounds of several classes. The solution of calcium bicarbonate with the initial concentration [Ca(HCO 3 ) 2 ]=1.3 g/l and 3% NaCl solution in distilled water are used for investigation. The effectiveness index of salt precipitation inhibitor is determined by the change in the rate of calcium bicarbonate transformation into carbonate. The combination of results obtained permits to make the conclusion that tripolyphosphate and pyrophosphoric acid are rather perspective inhibitors of complex effect with low protective concentrations

  8. Corrosion products in power generating systems

    International Nuclear Information System (INIS)

    Lister, D.H.

    1980-06-01

    The important mechanisms of corrosion and corrosion product movement and fouling in the heat transport systems of thermal electric generating stations are reviewed. Oil- and coal-fired boilers are considered, along with nuclear power systems - both direct and indirect cycle. Thus, the fireside and waterside in conventional plants, and the primary coolant and steam-raising circuits in water-cooled reactors, are discussed. Corrosion products in organic- and liquid-metal-cooled reactors also are shown to cause problems if not controlled, while their beneficial effects on the cooling water side of condensers are described. (auth)

  9. The Sensitivity Of Carbon Steels' Susceptibility To Localized Corrosion To The pH Of Nitrate Based Nuclear Wastes

    International Nuclear Information System (INIS)

    Boomer, K.D.

    2010-01-01

    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. Corrosive Metabolic Activity of Desulfovibrio sp. on 316L Stainless Steel

    Science.gov (United States)

    Arkan, Simge; Ilhan-Sungur, Esra; Cansever, Nurhan

    2016-12-01

    The present study investigated the effects of chemical parameters (SO4 2-, PO4 3-, Cl-, pH) and the contents of extracellular polymeric substances (EPS) regarding the growth of Desulfovibrio sp. on the microbiologically induced corrosion of 316L stainless steel (SS). The experiments were carried out in laboratory-scaled test and control systems. 316L SS coupons were exposed to Desulfovibrio sp. culture over 720 h. The test coupons were removed at specific sampling times for enumeration of Desulfovibrio sp., determination of the corrosion rate by the weight loss measurement method and also for analysis of carbohydrate and protein in the EPS. The chemical parameters of the culture were also established. Biofilm/film formation and corrosion products on the 316L SS surfaces were investigated by scanning electron microscopy and energy-dispersive x-ray spectrometry analyses in the laboratory-scaled systems. It was found that Desulfovibrio sp. led to the corrosion of 316L SS. Both the amount of extracellular protein and chemical parameters (SO4 2- and PO4 3-) of the culture caused an increase in the corrosion of metal. There was a significantly positive relationship between the sessile and planktonic Desulfovibrio sp. counts ( p < 0.01). It was detected that the growth phases of the sessile and planktonic Desulfovibrio sp. were different from each other and the growth phases of the sessile Desulfovibrio sp. vary depending on the subspecies of Desulfovibrio sp. and the type of metal when compared with the other published studies.

  11. Effect of boron control of environment on corrosion and resistance to low-cycle corrosion fatigue in structural steels

    International Nuclear Information System (INIS)

    Babej, Yu.I.; Zhitkov, V.V.; Zvezdin, Yu.I.; Liskevich, I.Yu.; Nazarov, A.A.

    1982-01-01

    Tests of the specimens on total, contact and crevice corrosion, corrosion cracking and low-cycle fatigue are conducted for determination of corrosion and corrosion-fatigue characteristics in the 15Kh3NMFA, 10N3MFA, 10Kh16N4B, 05Kh13N6M2 structural steels, used in energetics. The environment is subjected to boron control and contacting with atmosphere for simulation of stop and operation modes of the facility. The experiments are carried out in the distilled water with 12g/l H 3 BO 3 and 10 mg/l Cl' at 25, 60, 100 deg C under contacting with atmosphere. It is established, that the pearlitic steels 15Kh3NMFA, 10N3MFA, as well as transition and martensitic 05Kh13N6M2 and 10Kh16N4B steels are highly stable to total, crevice and contact corrosion at the high parameters of aqueous boron-containing medium. Steel resistance to low-cycle fracture decreases slightly under the conditions similar to the operation ones, in the water with 12 g/l H 3 BO 3 . Durability of the pearlitic steels at the simulation of stop conditions decreases more noticeably, crack formation as a rule, initiating from corrosion spots

  12. Corrosion-resistant coating technique for oxide-dispersion-strengthened ferritic/martensitic steel

    International Nuclear Information System (INIS)

    Sakasegawa, Hideo; Tanigawa, Hiroyasu; Ando, Masami

    2014-01-01

    Oxide-dispersion-strengthened (ODS) steels are attractive materials for application as fuel cladding in fast reactors and first-wall material of fusion blanket. Recent studies have focused more on high-chromium ferritic (12-18 wt% Cr) ODS steels with attractive corrosion resistance properties. However, they have poor material workability, require complicated heat treatments for recrystallization, and possess anisotropic microstructures and mechanical properties. On the other hand, low-chromium ferritic/martensitic (8-9 wt% Cr) ODS steels have no such limitations; nonetheless, they have poor corrosion resistance properties. In our work, we developed a corrosion-resistant coating technique for a low-chromium ferritic/martensitic ODS steel. The ODS steel was coated with the 304 or 430 stainless steel, which has better corrosion resistances than the low-chromium ferritic/martensitic ODS steels. The 304 or 430 stainless steel was coated by changing the canning material from mild steel to stainless steel in the conventional material processing procedure for ODS steels. Microstructural observations and micro-hardness tests proved that the stainless steels were successfully coated without causing a deterioration in the mechanical property of the low-chromium ferritic/martensitic ODS steel. (author)

  13. Investigation of Microstructure and Corrosion Propagation Behaviour of Nitrided Martensitic Stainless Steel Plates

    OpenAIRE

    Abidin Kamal Ariff Zainal; Ismail Elya Atikah; Zainuddin Azman; Hussain Patthi

    2014-01-01

    Martensitic stainless steels are commonly used for fabricating components. For many applications, an increase in surface hardness and wear resistance can be beneficial to improve performance and extend service life. However, the improvement in hardness of martensitic steels is usually accompanied by a reduction in corrosion strength. The objective of this study is to investigate the effects of nitriding on AISI 420 martensitic stainless steel, in terms of microstructure and corrosion propagat...

  14. Corrosion products of reinforcement in concrete in marine and industrial environments

    International Nuclear Information System (INIS)

    Vera, R.; Villarroel, M.; Carvajal, A.M.; Vera, E.; Ortiz, C.

    2009-01-01

    The corrosion products formed on embedded steel in concrete under simulated marine and industrial conditions and natural marine environment were studied. A 0.50 water/cement ratio concrete was used and 3.5% NaCl and 180 g L -1 of H 2 SO 4 with 70 ppm of chloride ions solutions were used to simulate the synthetic medium. The initial electrochemical variables of the steel and pH, chlorides and sulfates profiles were measured according to the concrete depth. The morphology of the corrosive attack was determined via scanning electron microscopy (SEM), and the composition of the corrosion products was determined using an X-ray analyzer and an X-ray diffractometer (XRD). The protective power of the corrosion products was evaluated through anodic polarization curves in a saturated Ca(OH) 2 solution. The results from XRD and SEM show that all the resulting corrosion products correspond to lepidocrocite, goethite and magnetite mixtures; moreover, akaganeite was also identified under natural and simulated marine environments. Siderite was only detected in samples exposed to a natural marine environment. Concerning the protective nature of the corrosion products, these show lower performance in a simulated industrial environment, where the corrosion rate of the steel is up to 1.48 μm year -1

  15. Corrosion products of reinforcement in concrete in marine and industrial environments

    Energy Technology Data Exchange (ETDEWEB)

    Vera, R. [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Avenida Brasil 2950, Casilla 4059, Valparaiso (Chile)], E-mail: rvera@ucv.cl; Villarroel, M. [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Avenida Brasil 2950, Casilla 4059, Valparaiso (Chile); Carvajal, A.M. [Facultad de Ingenieria, Escuela de Construccion Civil, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, Macul, Santiago (Chile); Vera, E.; Ortiz, C. [Universidad Pedagogica y Tecnologica de Colombia, Avenida Central Norte, Km 2, Tunja (Colombia)

    2009-03-15

    The corrosion products formed on embedded steel in concrete under simulated marine and industrial conditions and natural marine environment were studied. A 0.50 water/cement ratio concrete was used and 3.5% NaCl and 180 g L{sup -1} of H{sub 2}SO{sub 4} with 70 ppm of chloride ions solutions were used to simulate the synthetic medium. The initial electrochemical variables of the steel and pH, chlorides and sulfates profiles were measured according to the concrete depth. The morphology of the corrosive attack was determined via scanning electron microscopy (SEM), and the composition of the corrosion products was determined using an X-ray analyzer and an X-ray diffractometer (XRD). The protective power of the corrosion products was evaluated through anodic polarization curves in a saturated Ca(OH){sub 2} solution. The results from XRD and SEM show that all the resulting corrosion products correspond to lepidocrocite, goethite and magnetite mixtures; moreover, akaganeite was also identified under natural and simulated marine environments. Siderite was only detected in samples exposed to a natural marine environment. Concerning the protective nature of the corrosion products, these show lower performance in a simulated industrial environment, where the corrosion rate of the steel is up to 1.48 {mu}m year{sup -1}.

  16. Hydrogen assisted cracking and CO2 corrosion behaviors of low-alloy steel with high strength used for armor layer of flexible pipe

    Science.gov (United States)

    Liu, Zhenguang; Gao, Xiuhua; Du, Linxiu; Li, Jianping; Zhou, Xiaowei; Wang, Xiaonan; Wang, Yuxin; Liu, Chuan; Xu, Guoxiang; Misra, R. D. K.

    2018-05-01

    In this study, hydrogen induced cracking (HIC), sulfide stress corrosion cracking (SSCC) and hydrogen embrittlement (HE) were carried out to study hydrogen assisted cracking behavior (HIC, SSCC and HE) of high strength pipeline steel used for armor layer of flexible pipe in ocean. The CO2 corrosion behavior of designed steel with high strength was studied by using immersion experiment. The experimental results demonstrate that the corrosion resistance of designed steel with tempered martensite to HIC, SSCC and HE is excellent according to specific standards, which contributes to the low concentration of dislocation and vacancies previously formed in cold rolling process. The corrosion mechanism of hydrogen induced cracking of designed steel, which involves in producing process, microstructure and cracking behavior, is proposed. The designed steel with tempered martensite shows excellent corrosion resistance to CO2 corrosion. Cr-rich compound was first formed on the coupon surface exposed to CO2-saturated brine condition and chlorine, one of the corrosion ions in solution, was rich in the inner layer of corrosion products.

  17. Corrosive effect of oil's accompanying water polluted with H2S over steel (API 5L X-52)

    International Nuclear Information System (INIS)

    Cueli Corugedo, Alexander; Adames Montero, Yosmari; Rivera Beltran, Yischy; Davis Harriet, Juan

    2013-01-01

    The corrosion from the steel to the carbon in the sale oil pipage conduction, is a serious problem, due to the material and economical looses they cause, damaging even in some cases the productive field. The purpose of this study is to determine the aggressiveness of the oil's water layer, polluted with H 2 S ( g) , over the steel of pipelines' construction (API 5L X-52), taking into account the temperature variations which take place during the transportation of the oil, using the electrochemical techniques of polarisation resistance (LPR) and electrochemical noise. It is pretended to determine the velocity of steel corrosion in the oil's water layer polluted with H 2 S through electrochemical techniques. It was shown that the temperature increases and the concentration of H 2 S to 500 ppm in the oil's accompanying water emphasizes the corrosion phenomenon experienced by the steel (9, 188 0 mm/year to 70℃).The results of the electrochemical noise spectrums and the values of the localisation ?s index calculated, shown the presence of corrosion on the steel surface (API 5L X-52).This result was complemented through optic Microscopy which permits to corroborate the poor adherence of the sulphur layers deposited on the metal that increase the appearance of events found with the temperature increase and the concentration of H 2 S in the environment studied

  18. Effect of Thermomechanical Processing and Crystallographic Orientation on the Corrosion Behavior of API 5L X70 Pipeline Steel

    Science.gov (United States)

    Ohaeri, Enyinnaya; Omale, Joseph; Eduok, Ubong; Szpunar, Jerzy

    2018-04-01

    This work presents the electrochemical response of X70 pipeline steel substrates thermomechanically processed at different conditions. The WE sample was hot rolled at a temperature range of 850 °C to 805 °C and cooled at a rate of 42.75 °C/s. Another sample WD was hot rolled from 880 °C to 815 °C and cooled at a faster rate of 51.5 °C/s. Corrosion tests were conducted electrochemically by potentiodynamic polarization in hydrogen-charged and non-hydrogen-charged environments. A lower corrosion rate was measured with hydrogen charging due to the rapid formation of corrosion product film on pipeline substrate, but WE specimen emerged as the most susceptible to corrosion with and without hydrogen charging. Variations in thermomechanical rolling conditions influenced grain orientation, protective film properties, corrosion, and cracking behavior on both specimens. Cracks were seen in both specimens after hydrogen charging, but specimen WE experienced a more intense deterioration of protective corrosion product film and subsequent cracking. A large part of specimen WD retained its protective corrosion product film after the polarization test, and sites where spalling occurred resulted in pitting with less cracking. Despite weak crystallographic texture noticed in both specimens, WD showed a higher intensity of corrosion-resistant 111||ND-oriented grains, while WE showed a more random distribution of 111||ND-, 011||ND-, and 001||ND-oriented grains with a lower intensity.

  19. Effect of Thermomechanical Processing and Crystallographic Orientation on the Corrosion Behavior of API 5L X70 Pipeline Steel

    Science.gov (United States)

    Ohaeri, Enyinnaya; Omale, Joseph; Eduok, Ubong; Szpunar, Jerzy

    2018-06-01

    This work presents the electrochemical response of X70 pipeline steel substrates thermomechanically processed at different conditions. The WE sample was hot rolled at a temperature range of 850 °C to 805 °C and cooled at a rate of 42.75 °C/s. Another sample WD was hot rolled from 880 °C to 815 °C and cooled at a faster rate of 51.5 °C/s. Corrosion tests were conducted electrochemically by potentiodynamic polarization in hydrogen-charged and non-hydrogen-charged environments. A lower corrosion rate was measured with hydrogen charging due to the rapid formation of corrosion product film on pipeline substrate, but WE specimen emerged as the most susceptible to corrosion with and without hydrogen charging. Variations in thermomechanical rolling conditions influenced grain orientation, protective film properties, corrosion, and cracking behavior on both specimens. Cracks were seen in both specimens after hydrogen charging, but specimen WE experienced a more intense deterioration of protective corrosion product film and subsequent cracking. A large part of specimen WD retained its protective corrosion product film after the polarization test, and sites where spalling occurred resulted in pitting with less cracking. Despite weak crystallographic texture noticed in both specimens, WD showed a higher intensity of corrosion-resistant 111|| ND-oriented grains, while WE showed a more random distribution of 111|| ND-, 011|| ND-, and 001|| ND-oriented grains with a lower intensity.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (paper)

  1. EFFECT OF INTERMETALLIC PHASES ON CORROSION BEHAVIOR AND MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL AND SUPER-DUPLEX STAINLESS STEEL

    OpenAIRE

    Prabhu Paulraj; Rajnish Garg

    2015-01-01

    Duplex Stainless Steels (DSS) and Super Duplex Stainless Steel (SDSS) have excellent integration of mechanical and corrosion properties. However, the formation of intermetallic phases is a major problem in their usage. The mechanical and corrosion properties are deteriorated due to the presence of intermetallic phases. These phases are induced during welding, prolonged exposure to high temperatures, and improper heat treatments. The main emphasis of this review article is on intermetallic pha...

  2. Image analysis of corrosion pit initiation on ASTM type A240 stainless steel and ASTM type A 1008 carbon steel

    Science.gov (United States)

    Nine, H. M. Zulker

    The adversity of metallic corrosion is of growing concern to industrial engineers and scientists. Corrosion attacks metal surface and causes structural as well as direct and indirect economic losses. Multiple corrosion monitoring tools are available although those are time-consuming and costly. Due to the availability of image capturing devices in today's world, image based corrosion control technique is a unique innovation. By setting up stainless steel SS 304 and low carbon steel QD 1008 panels in distilled water, half-saturated sodium chloride and saturated sodium chloride solutions and subsequent RGB image analysis in Matlab, in this research, a simple and cost-effective corrosion measurement tool has identified and investigated. Additionally, the open circuit potential and electrochemical impedance spectroscopy results have been compared with RGB analysis to gratify the corrosion. Additionally, to understand the importance of ambiguity in crisis communication, the communication process between Union Carbide and Indian Government regarding the Bhopal incident in 1984 was analyzed.

  3. Properties, microstructure and resistance to metal corrosion from pure runoff of supermartensitic stainless steel

    International Nuclear Information System (INIS)

    Zappa, S; Burgueno, A; Svoboda, H. G; Ramini de Rissone, M; Surian, E. S

    2008-01-01

    Supermartensitic stainless steels (AISM) are characterized by their very low carbon content, providing good tenacity and weldability. They also contain Ni as a stabilizing agent of the austenite and Mo to improve corrosion resistance. The weldability of these materials is fundamentally important for their applications, mainly in the gas and oil industries. The presence of CO 2 , H 2 S, water with a high solids content and condensed water in the production of hydrocarbons together with the large amounts of Cl in these aqueous phases make localized corrosion one of the mechanisms for the degradation of these steels while in service. The protective gases used in the semiautomatic welding process with heavy or tubular wires (GMAW, FCAW) affect the chemical composition of the deposits, particularly the contents of C, O and N, generating variations in their properties. The mechanical properties of these steels are usually optimized after a post-welding heat treatment (PWHT), which may also significantly affect the corrosion resistance of the welding deposits. This work studied the influence of the welding procedure (protective gas and PWHT) on corrosion resistance from pitting of the unalloyed AISM metal. Two test pieces of unalloyed metal were welded according to ANSI/AWS A5.22-95 with a GMAW process using a 1.2 mm diameter tubular wire with metal filling that deposits a supermartensitic stainless steel. The effect of the gas protection was evaluated, welding one of the test pieces with Ar- 5%He and the other with Ar-18%CO 2 . The effect of the PWHT was analyzed, for which samples were extracted from each welded test piece, which were thermally treated at 650 o C for 15 minutes, producing as-welded (AW) samples and with PWHT. The chemical composition for both welding conditions was determined. Microstructural characterization was carried out for the four conditions , using optic and scanning electron microscopy and X-ray diffraction, and the Vickers microhardness was

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

    Science.gov (United States)

    Hou, Hua; Yang, Ruifeng

    2009-01-01

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

  5. Detection of localized and general corrosion of mild steel in simulated defense nuclear waste solutions using electrochemical noise analysis

    International Nuclear Information System (INIS)

    Edgemon, G.L.; Ohl, P.C.; Bell, G.E.C.; Wilson, D.F.

    1995-12-01

    Underground waste tanks fabricated from mild steel store more than 60 million gallons of radioactive waste from 50 years of weapons production. Leaks are suspected in a significant number of tanks. The probable modes of corrosion failures are reported to be localized corrosion (e.g. nitrate stress corrosion cracking and pitting). The use of electrochemical noise (EN) for the monitoring and detection of localized corrosion processes has received considerable attention and application over the last several years. Proof of principle laboratory tests were conducted to verify the capability of EN evaluation to detect localized corrosion and to compare the predictions of general corrosion obtained from EN with those derived from other sources. Simple, pre-fabricated flat and U-bend specimens of steel alloys A516-Grade 60 (UNS K02100) and A537-CL 1 (UNS K02400) were immersed in temperature controlled simulated waste solutions. The simulated waste solution was either 5M NaNO 3 with 0.3M NaOH at 90 C or 11M NaNO 3 with 0.15M NaOH at 95 C. The electrochemical noise activity from the specimens was monitored and recorded for periods ranging between 140 and 240 hours. At the end of each test period, the specimens were metallographically examined to correlated EN data with corrosion damage

  6. The Evaluation of Crevice Corrosion of Inconel-600 and 304 Stainless Steel in Reductive Decontamination Solutions

    International Nuclear Information System (INIS)

    Jung, Junyoung; Park, Sangyoon; Won, Huijun; Choi, Wangkyu; Moon, Jeikwon; Park, Sojin

    2014-01-01

    In this sturdy, we investigated the characteristics of corrosion to Inconel-600 and type 304 stainless steel which are mainly used for the steam generator and primary system of PWR reactor respectively. We conducted the corrosion test for the HYBRID (HYdrazine Based metal Ion Reductive decontamination) which was developed in KAERI, Citrox and Oxalic acid solutions used in reductive decontamination of the inner surface of PWR. Since Citrox and oxalic acid solution were well-known conventional decontamination solutions, it is meaningful to compare the corrosion result of HYBRID with those solutions to confirm the corrosion compatibility. In order to obtain visible results in a limited time, we conducted the crevice corrosion tests under harsh condition. According to the results of crevice corrosion tests, we can conclude that metals such as type 304 stainless steel and Inconel-600 in HYBRID are very stable against crevice corrosion. On the other hand, those metals in Citrox and oxalic acid solutions were very susceptible to the crevice corrosion. Especially when using the oxalic acid solution, severe corrosion was observed not only Inconel-600 but also 304 stainless steel. The degree of corrosion can be expressed as; HYBRID << Citrox < OA. Conclusively, our results support that the HYBRID is more stable to the corrosion of structural materials in primary system than other Citrox and oxalic acid solutions. This finding will appoint the HYBRID solution as a candidate to solve the corrosion problem which is often issued by existing chemical decontamination processes

  7. The influence of heat treatment and process parameters optimization on hardness and corrosion properties of laser alloyed X12CrNiMo steel

    CSIR Research Space (South Africa)

    Popoola, API

    2016-10-01

    Full Text Available Martensitic stainless steels are used in the production of steam turbine blades but their application is limited due to low hardness and poor corrosion resistance. Laser surface alloying and heat treatment of X12CrNiMo Martensitic stainless steel...

  8. Sliding Wear Characteristics and Corrosion Behaviour of Selective Laser Melted 316L Stainless Steel

    Science.gov (United States)

    Sun, Y.; Moroz, A.; Alrbaey, K.

    2014-02-01

    Stainless steel is one of the most popular materials used for selective laser melting (SLM) processing to produce nearly fully dense components from 3D CAD models. The tribological and corrosion properties of stainless steel components are important in many engineering applications. In this work, the wear behaviour of SLM 316L stainless steel was investigated under dry sliding conditions, and the corrosion properties were measured electrochemically in a chloride containing solution. The results show that as compared to the standard bulk 316L steel, the SLM 316L steel exhibits deteriorated dry sliding wear resistance. The wear rate of SLM steel is dependent on the vol.% porosity in the steel and by obtaining full density it is possible achieve wear resistance similar to that of the standard bulk 316L steel. In the tested chloride containing solution, the general corrosion behaviour of the SLM steel is similar to that of the standard bulk 316L steel, but the SLM steel suffers from a reduced breakdown potential and is more susceptible to pitting corrosion. Efforts have been made to correlate the obtained results with porosity in the SLM steel.

  9. Investigation of intergranular corrosion resistance of Cr16Ni25NMo6 steel

    International Nuclear Information System (INIS)

    Kamenev, Yu.B.; Nazarov, A.A.; Kuusk, L.V.; Majdeburova, T.F.

    1990-01-01

    The effect of 08Kh16N25AM6 steel susceptibility to intergranular corrosion on its intergranular cracking resistance in high-temperature water is investigated. In addition, the performed tests point to the susceptibility of sensibilized Kh16N25AM6 steel to intergranular corrosion in media simulating an agressive environment of power generation equipment; the latter requires a strict control over the resistance of weld joints of the above steel to intergranular corrosion. It is shown that Kh16N25AM6 type steel in sensibilized state is susceptible to intercrystalline corrosion cracking in high-temperature water which correlates with its susceptibility to intergranular corrosion established by AM GOST 6032-84 and potentiodynamic reactivation methods

  10. Corrosion Inhibition of AISI/SAE Steel in a Marine Environment

    Directory of Open Access Journals (Sweden)

    Fatai Olufemi ARAMIDE

    2009-12-01

    Full Text Available Effect of Sodium nitrite as a corrosion inhibitor of mild steel in sea water wasinvestigated, using the conventional weight loss method. Differentpercentages of sodium nitrite were used from 0% to 10% in sea water.Samples of mild steel were exposed to these corrosive media and the weightloss was calculated at intervals of 120 hours, 168 hours, 208 hours, 256 hours,304 hours and 352 hours. It was observed that corrosion rate increases withtime of exposure to the corrosive medium (inhibited or non-inhibited and thatsodium nitrite can be used to retards the corrosion rate of mild steel if theappropriate concentration is used in sea water. It was concluded that theoptimum percentage of sodium nitrate in sea water that gives the optimumcorrosion inhibition of mild steel is 4%.

  11. The optimization of CNT-PVA nanocomposite for mild steel coating: Effect of CNTs concentration on the corrosion rate of mild steel

    Science.gov (United States)

    Maryam, M.; Ibrahim, N. M. A. A.; Eswar, K. A.; Guliling, M.; Suhaimi, M. H. F.; Khusaimi, Z.; Abdullah, S.; Rusop, M.

    2018-05-01

    Carbon Nanotubes (CNTs) are molecular-scale tubes of graphitic carbon which have outstanding mechanical and magnetic properties with extraordinary strength. It can be said that CNTs can be used in coating application to prevent corrosion and lower the rate of corrosion on steel. However, CNT alone cannot be used for coating purposes. Therefore, by combining it with polymer to produce a nanocomposite thin film, it can be used for nanocoating on mild steel substrate. Polyvinyl alcohol (PVA) was chosen due to its high strength and high modulus polymer fibers and has the possibilities of improving the physicochemical properties of carbon nanotubes. Carbon nanotubes and polyvinyl alcohol (CNT-PVA) nanocomposite were prepared by using sol-gel method and coated as thin film on mild steel substrate by using spin coating. Sol-gel is a convenient technique used for the production of nanocomposite aqueous solution. Five samples were prepared at the different concentration of CNTs-PVA to verify the corrosion rate application. The samples were then characterized by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) obtaining the structural properties, surface morphology and topography of samples. Raman spectroscopy was used to determine the microraman spectra of CNTs which showed the quality and purity of samples. Finally, corrosion test was done to measure the corrosion rate of samples at the different concentration of CNTs/PVA nanocomposite.

  12. Corrosion behaviour of Fe-Mn-Si based shape memory steels trained by cold rolling

    International Nuclear Information System (INIS)

    Soederberg, O.; Liu, X.W.; Ullakko, K.; Lindroos, V.K.

    1999-01-01

    Fe-Mn-Si based high nitrogen steels have been studied in recent years for potential industrial applications. These steels show good shape memory properties, high strength and excellent ductility. In the present study, the effects of training history on the corrosion properties of Fe-Mn-Si-Cr-Ni based high nitrogen steels were investigated. The corrosion behaviour of shape memory alloys was analyzed by implementing anodic polarisation measurements and immersion tests. The shape memory steels in annealed, deformed and recovered conditions were studied to examine the training effect on their corrosion behaviour. The features of the anodic polarisation curves indicated a general corrosion type of these steels. The experimental results showed that Cr and Mn had a marked influence on the corrosion behaviour of the steels, followed by Ni, N and V. It was also apparent that the deformation during the shape memory training by cold rolling decreased the corrosion stability, and the recovery heating reduced further their corrosion resistance. However, further studies are needed in order to better understand the corrosion behaviour of the investigated alloys. (orig.)

  13. Corrosion of steel tendons in concrete pressure vessels: review of recent literature and experimental investigations

    International Nuclear Information System (INIS)

    Griess, J.C.

    1978-01-01

    The fundamentals of localized corrosion are briefly discussed, and the literature concerning corrosion of carbon steel in aqueous environments, in particular the stress-corrosion cracking of carbon steels, is reviewed. The behavior of high strength steels in specific environments, including concrete and organic substances, is also summarized. The available information indicates that the corrosion of steels in correctly formulated concrete is minimal. Even appreciable concentrations of chloride, sulfate, sulfide, and nitrate salts can be tolerated in the concrete or grout without detrimental effects. Adherence to established standards in the preparation and application of grouts in tendon-bearing conduits should guarantee very long tendon lifetimes. Little is reported about the behavior of tendons in proprietary organic greases or waxes, but very good corrosion resistance is expected if the organic material remains intact. Stress-corrosion cracking tests performed with AISI 1080 steel tendon wires, using the constant-strain-rate method, produced results expected from data in the literature. Cracking was observed only in neutral or acid solutions containing hydrogen sulfide, in ammonium nitrate solutions, and possibly in a dilute solution of sodium bisulfite. General corrosion tests in water and in dilute solutions of sodium nitrate, chloride, or sulfate showed that oxygen was an important factor; corrosion was substantially greater when oxygen had free access to the solution than when access to oxygen was restricted. In the tests with oxygen the heaviest attack on the steel tendons was at the waterline of the solution

  14. Investigation of models to predict the corrosion of steels in flowing liquid lead alloys

    International Nuclear Information System (INIS)

    Balbaud-Celerier, F.; Barbier, F.

    2001-01-01

    Corrosion of steels exposed to flowing liquid lead alloys can be affected by hydrodynamic parameters. The rotating cylinder system is of interest for the practical evaluation of the fluid velocity effect on corrosion and for the prediction of the corrosion behavior in other geometries. Models developed in aqueous medium are tested in the case of liquid metal environments. It is shown that equations established for the rotating cylinder and the pipe flow geometry can be used effectively in liquid lead alloys (Pb-17Li) assuming the corrosion process is mass transfer controlled and the diffusion coefficient of dissolved species is known. The corrosion rate of martensitic steels in Pb-17Li is shown to be independent of the geometry when plotted as a function of the mass transfer coefficient. Predictions about the corrosion of steel in liquid Pb-Bi are performed but experiments are needed to validate the results obtained by modeling

  15. Corrosion of type 304L stainless steel in boiling dilute neptunium nitrate solution

    International Nuclear Information System (INIS)

    Motooka, Takafumi; Kiuchi, Kiyoshi

    2003-01-01

    Corrosion of type 304L stainless steel in nitric acid solution containing neptunium was studied under immersion and heat-transfer condition. Corrosion rates of stainless steel were obtained by the weight loss measurement and the quantitative analysis of metallic ions dissolved in solution. The surface morphology was observed by scanning electron microscopy. The corrosion acceleration mechanism was investigated by polarization measurement and spectrophotometry. The corrosion rate in boiling 9M nitric acid was accelerated by addition of neptunium. The corrosion of stainless steel was promoted under heat-transfer condition compared to immersion condition. In polarization measurements, the cathodic current was increased by addition of neptunium. Spectrophotometric measurements showed the oxidization of neptunium in boiling nitric acid. It was suggested that the accelerated corrosion in nitric acid solution containing neptunium was caused by re-oxidation of neptunium. (author)

  16. Unexpected corrosion of stainless steel in low chloride waters – microbial aspects

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Carpén, Leena; Møller, Per

    2009-01-01

    conditions or periods of low water consumption have occurred prior to the failure. Typically the corrosion attacks appear within 2-3 years in weld nuggets, heat affected zones or in crevices like e.g. press fitting pipe connections. The failure mode is pitting and crevice corrosion leading to leaks and rust......Abstract Stainless steels EN 1.4301 and 1.4401/1.4404 are normally considered corrosion resistant in low chloride natural waters like drinking water. However, a number of corrosion failures have been observed in e.g. fire extinguisher systems and drinking water installations, where stagnant...... stains on the outside of the installation. Corrosion may occur in water qualities with rather low chloride contents and fairly low conductivity, which would usually not be considered especially corrosive towards stainless steel. One key parameter is the ennoblement documented on stainless steel...

  17. On the corrosion behaviour of stainless steel, nickel-chromium and zirconium-alloys in pore water of Portland cement

    International Nuclear Information System (INIS)

    Heitz, E.; Graefen, H.

    1991-12-01

    On the basis of an extensive review of literature and available experience, an evaluation was made of the corrosion of a metallic matrix for radioactive nuclides embedded in porous, water containing Portland cement. As a metallic matrix, austenitic high-alloy steel, nickel-base alloys and zirconium alloys are discussed. Pore waters in Portland cement have low aggressivity. However, through contact with formation water, chloride and sulphate enrichment can occur. Although corrosion is principally possible on the basis of purely thermodynamic considerations, it can be assumed that local corrosion (pitting, stress corrosion cracking, intergranular corrosion) is highly improbable under the given boundary conditions. This is valid for all three groups of alloys and means that only low release rates of corrosion products are to be expected. As a result of the discussion on radiolysis-induced corrosion, additional corrosion activity can be excluded. Final conclusions concerning the stimulation of corrosion processes by microbial action cannot be drawn and, therefore, additional experiments are proposed. The release rates of radioactive products are controlled by a very low dissolution rate of the materials in the passive state. All three groups of alloys show this type of general dissolution. From a survey of literature data it can be concluded that release rates greater than 250 mg/m 2 per day are not exceeded. Since these data were mainly obtained by electrochemical methods, it is proposed that quantitative analytical investigations of the corrosion products in pore water be made. On the whole the release rates determined are far below corrosion rates which are generally technically relevant. (author) 13 figs., 9 tabs., 61 refs

  18. 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.

  19. Research on A3 steel corrosion behavior of basic magnesium sulfate cement

    Science.gov (United States)

    Xing, Sainan; Wu, Chengyou; Yu, Hongfa; Jiang, Ningshan; Zhang, Wuyu

    2017-11-01

    In this paper, Tafel polarization technique is used to study the corrosion behavior of A3 steel basic magnesium sulfate, and then analyzing the ratio of raw materials cement, nitrites rust inhibitor and wet-dry cycle of basic magnesium sulfate corrosion of reinforced influence, and the steel corrosion behavior of basic magnesium sulfate compared with magnesium oxychloride cement and Portland cement. The results show that: the higher MgO/MgSO4 mole ratio will reduce the corrosion rate of steel; Too high and too low H2O/MgSO4 mole ratio may speed up the reinforcement corrosion effect; Adding a small amount of nitrite rust and corrosion inhibitor, not only can obviously reduce the alkali type magnesium sulfate in the early hydration of cement steel bar corrosion rate, but also can significantly reduce dry-wet circulation under the action of alkali type magnesium sulfate cement corrosion of reinforcement effect. Basic magnesium sulfate cement has excellent ability to protect reinforced, its long-term corrosion of reinforcement effect and was equal to that of Portland cement. Basic magnesium sulfate corrosion of reinforced is far below the level in the MOC in the case.

  20. Nanostructure and Properties of Corrosion Resistance in C+Ti Multi-Ion-Implanted Steel

    Institute of Scientific and Technical Information of China (English)

    张通和; 吴瑜光; 刘安东; 张旭; 王晓妍

    2003-01-01

    The corrosion and pitting corrosion resistance of C+ Ti dual and C+Ti+C ternary implanted H13 steel were studied by using a multi-sweep cyclic voltammetry and a scanning electron microscope. The effects of phase formation on corrosion and pitting corrosion resistance were explored. The x-ray diffraction analysis shows that the nanometer-sized precipitate phases consist of compounds of Fe2 Ti, TiC, Fe2C and Fe3 C in dual implanted layer and even in ternary implanted layer. The passivation layer consists of these nanometer phases. It has been found that the corrosion and pitting corrosion resistance of dual and ternary implanted H13 steel are improved extremely. The corrosion resistance of ternary implanted layer is better than that of dual implantations and is enhanced with the increasing ion dose. When the ion dose of Ti is 6 × 1017/cm2 in the ternary implantation sample, the anodic peak current density is 95 times less than that of the H13 steel. The pitting corrosion potential of dual and ternary implantation samples is in the range from 55mV to 160mV which is much higher than that of the H13 steel. The phases against the corrosion and pitting corrosion are nanometer silkiness phases.