WorldWideScience

Sample records for surface corrosion products

  1. Development of Copper Corrosion Products and Relation between Surface Appearance and Corrosion Rate

    International Nuclear Information System (INIS)

    Lan, Tran Thi Ngoc; Binh, Nguyen Thi Thanh; Tru, Nguyen Nhi; Yoshino, Tsujino; Yasuki, Maeda

    2008-01-01

    Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time

  2. Experimental Study of Removing Surface Corrosion Products from Archaeological Iron Objects and Alternating Iron Corrosion Products by Nd:YAG Laser Cleaning System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hye Youn; Cho, Nam Chul [Kongju National University, Daejeon (Korea, Republic of); Lee, Jong Myoung [IMT co. Ltd, Suwon (Korea, Republic of); Yu, Jae Eun [National Research Institute of Cultural Heritage, Daejeon (Korea, Republic of)

    2012-05-15

    The corrosion product of archaeological iron objects is supposed to be removed because it causes re-corrosion. So far it is removed by scapel and sand blaster but they depend on the skill and experience of a conservator and the glass-dust of the sand blaster is harmful to humans. Therefore this study applies a laser cleaning system which is used in various industrial cleaning processes, to remove corrosion product from archaeological iron objects. In addition, this work studies the alternation of corrosion product after laser irradiation, which evaluates the reliability of the laser cleaning system. Optical microscopy, SEM-EDS, XRD, Raman have been used to observe and analyse the surface of the objects. The results show the capacity of laser cleaning some corrosion product, but blackening appears with increasing pulses and laser energy, and some corrosion products, goethite and hematite, are partially altered to magnetite. These problems, blackening and alternation of corrosion product, should be solved by further studies which find the optimal laser irradiation condition and use a wetting agent.

  3. Deposition of corrosion products from dowels on human dental root surfaces measured with proton microprobe technique

    Science.gov (United States)

    Brune, D.; Brunell, G.; Lindh, U.

    1982-06-01

    Distribution of copper, mercury and zinc on human teeth root surfaces adjacent to dowels of gold alloy or brass as well as dowels of brass in conjunction with an amalgam crown has been measured with a proton microprobe using PIXE techniques. Upper limits of the contents of gold and silver on the root surfaces were established. Pronounced concentration profiles of copper and zinc were observed on the root surfaces of teeth prepared with dowels of brass. The dowel of gold alloy revealed only zinc deposition. The major part of copper on the root surfaces is assumed to arise from corrosion of the dowels, and has been transported to the surface by diffusion through the dential tubuli. Zinc in the volume analysed is a constituent of dentin tissue as well as a corrosion product of the brass dowel. Part of the zinc level could also be ascribed to erosion of the zinc phosphate cement matrix. The volumes analysed were (25×25×25)μm 3. The levels of copper, mercury and zinc on the tooth root surfaces attained values up to about 200, 20 and 600 ppm, respectively.

  4. Corrosion-resistant metal surfaces

    Science.gov (United States)

    Sugama, Toshifumi [Wading River, NY

    2009-03-24

    The present invention relates to metal surfaces having thereon an ultrathin (e.g., less than ten nanometer thickness) corrosion-resistant film, thereby rendering the metal surfaces corrosion-resistant. The corrosion-resistant film includes an at least partially crosslinked amido-functionalized silanol component in combination with rare-earth metal oxide nanoparticles. The invention also relates to methods for producing such corrosion-resistant films.

  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. 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.)

  7. 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

  8. Study on corrosion products from ear piercing studs

    International Nuclear Information System (INIS)

    Rogero, Sizue O.; Costa, Isolda; Saiki, Mitiko

    2000-01-01

    In this work instrumental neutron activation analysis was applied to analyse elemental composition of commercial gold coated ear piercing substrate and metals present in their corrosion products. The cytotoxic effect was also verified in these corrosion product extracts, probably, due to the lixiviation of Ni present in high quantity in their substrates. The analysis of gold coated ear piercing surfaces by scanning electron microscopy before and after the corrosion test showed coating defects and the occurrence of corrosion process. (author)

  9. Influence of dissolved oxygen, dissolved hydrogen and surface film on the corrosion products release from stainless steel in high purity water at room temperature

    International Nuclear Information System (INIS)

    Iwahori, Toru; Kato, Shunji; Wada, Kunihisa; Kanbe, Hiromi; Mizuno, Takayuki

    1983-01-01

    The influence of dissolved oxygen, dissolved hydrogen and surface film on corrosion products release from SUS 304 stainless steel was studied in high purity water at room temperature. The determination of corrosion products released was performed by using millipore filter (0.45μm), cation-exchange resins and anion-exchange resins. The selective release of Fe component from stainless steel occurred in deoxygenated water containing saturated hydrogen or below 120 ppb oxygen, while the selective release of Co and Ni occurred in oxygenated water containing above 8 ppm oxygen. In the case of preautoclaved stainless steel coated with R 3 O 4 (spinel type oxides) film, the selective release of Co and Ni occurred in any high purity water, regardless of dissolved oxygen or dissolved hydrogen. Similar selective dissolution of Co from cobalt ferrite occurred in any high purity water, regardless of dissolved oxygen or dissolved hydrogen. Relation between corrosion potential and release was discussed. (author)

  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 Formation, presence and deposition of corrosion product radionuclides (such as 60Co, 51Cr, 54Mn, 59Fe and/or 110mAg) in the primary circuits of water-cooled nuclear reactors (PWRs) throw many obstacles in the way of normal operation. During...

  11. Corrosion Protection of Electrically Conductive Surfaces

    Directory of Open Access Journals (Sweden)

    Jian Song

    2012-11-01

    Full Text Available The basic function of the electrically conductive surface of electrical contacts is electrical conduction. The electrical conductivity of contact materials can be largely reduced by corrosion and in order to avoid corrosion, protective coatings must be used. Another phenomenon that leads to increasing contact resistance is fretting corrosion. Fretting corrosion is the degradation mechanism of surface material, which causes increasing contact resistance. Fretting corrosion occurs when there is a relative movement between electrical contacts with surfaces of ignoble metal. Avoiding fretting corrosion is therefore extremely challenging in electronic devices with pluggable electrical connections. Gold is one of the most commonly used noble plating materials for high performance electrical contacts because of its high corrosion resistance and its good and stable electrical behavior. The authors have investigated different ways to minimize the consumption of gold for electrical contacts and to improve the performance of gold plating. Other plating materials often used for corrosion protection of electrically conductive surfaces are tin, nickel, silver and palladium. This paper will deal with properties and new research results of different plating materials in addition to other means used for corrosion protection of electrically conductive surfaces and the testing of corrosion resistance of electrically conductive surfaces.

  12. Capturing device for radioactive corrosion products

    International Nuclear Information System (INIS)

    Ono, Kiyoshi.

    1987-01-01

    Purpose: To render the flow channel area uniform for each of coolants over the entire capturing device and reduce the corrosion of capturing materials due to coolants. Constitution: Most of radioactivity caused by radioactive corrosion products are due to Mn-54 radioactive nuclides and it has been known that the nuclides are readily deposited to the surface of nickel material in sodium at high temperature. It is difficult in a conventional capturing device constituted by winding a nickel plate fabricated with protrusions in a multiple-coaxial configuration, that the flow channel area is reduced in a portion of the flow channel and it is difficult to make the flow of the coolants uniform. In view of the above, by winding a nickel plate having a plurality of protrusions at the surface formed integrally by way of an electrolytic process into a multiple-coaxial or spiral shape, those having high resistance to the coolant corrosion can be obtained. (Takahashi, M.)

  13. Corrosion Product Film-Induced Stress Facilitates Stress Corrosion Cracking.

    Science.gov (United States)

    Wang, Wenwen; Zhang, Zhiliang; Ren, Xuechong; Guan, Yongjun; Su, Yanjing

    2015-06-11

    Finite element analyses were conducted to clarify the role of corrosion product films (CPFs) in stress corrosion cracking (SCC). Flat and U-shaped edge-notched specimens were investigated in terms of the CPF-induced stress in the metallic substrate and the stress in the CPF. For a U-shaped edge-notched specimen, the stress field in front of the notch tip is affected by the Young's modulus of the CPF and the CPF thickness and notch geometry. The CPF-induced tensile stress in the metallic substrate is superimposed on the applied load to increase the crack tip strain and facilitate localized plasticity deformation. In addition, the stress in the CPF surface contributes to the rupture of the CPFs. The results provide physical insights into the role of CPFs in SCC.

  14. 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

    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...... 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...... 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....

  15. Drying characteristics of thorium fuel corrosion products

    Science.gov (United States)

    Smith, R.-E. Lords

    2004-07-01

    The open literature and accessible US Department of Energy-sponsored reports were reviewed for the dehydration and rehydration characteristics of potential corrosion products from thorium metal and thorium oxide nuclear fuels. Mixed oxides were not specifically examined unless data were given for performance of mixed thorium-uranium fuels. Thorium metal generally corrodes to thorium oxide. Physisorbed water is readily removed by heating to approximately 200 °C. Complete removal of chemisorbed water requires heating above 1000 °C. Thorium oxide adsorbs water well in excess of the amount needed to cover the oxide surface by chemisorption. The adsorption of water appears to be a surface phenomenon; it does not lead to bulk conversion of the solid oxide to the hydroxide. Adsorptive capacity depends on both the specific surface area and the porosity of the thorium oxide. Heat treatment by calcination or sintering reduces the adsorption capacity substantially from the thorium oxide produced by metal corrosion.

  16. Surface engineering for corrosion and wear resistance

    National Research Council Canada - National Science Library

    Davis, J. R

    2001-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Pitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Crevice Corrosion . . . . . . . . ....

  17. 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).

  18. Chemical treatment of zinc surface and its corrosion inhibition studies

    Indian Academy of Sciences (India)

    WINTEC

    elements are capable of forming thin film or molecular layers on the metal surface (Abdel Aal et al 1983; Lakhan. Jha et al 1991; Maja et al 1993; Rajappa and .... solution at 298 K. The surface contained small cavities, which are distributed over the entire surface and a needle- like deposit (corrosion product) was observed.

  19. Identification of Corrosion Products Due to Seawater and Fresh Water

    Science.gov (United States)

    Gismelseed, A.; Elzain, M.; Yousif, A.; Al Rawas, A.; Al-Omari, I. A.; Widatallah, H.; Rais, A.

    2004-12-01

    Mössbauer and X-ray diffraction (XRD) measurements were performed on corrosion products extracted from the inner surface of two different metal tubes used in a desalination plant in Oman. One of the tubes corroded due to the seawater while the second was corroded due to fresh water. The corrosion products thus resulted due to seawater were scrapped off in to two layers, the easily removable rust from the top is termed outer surface corrosion product and the strongly adhered rust as internal corrosion product. The Mössbauer spectra together with the XRD pattern of the outer surface showed the presence of magnetite (Fe3O4), akaganeite (β-FeOOH), lepidocrocite (γ-FeOOH), goethite (α-FeOOH) and hematite (Fe2O3). The inner surface however showed the presence of akaganite, goethite, and magnetite. On the other hand, the corrosion products due to the fresh water showed only the presence of goethite and magnetite. The mechanism of the corrosion process will be discussed based on the significant differences between the formation of the iron components of the corrosion products due to seawater and the fresh water.

  20. Corrosion in systems for storage and transportation of petroleum products and biofuels identification, monitoring and solutions

    CERN Document Server

    Groysman, Alec

    2014-01-01

    This book treats corrosion as it occurs and affects processes in real-world situations, and thus points the way to practical solutions. Topics described include the conditions in which petroleum products are corrosive to metals; corrosion mechanisms of petroleum products; which parts of storage tanks containing crude oils and petroleum products undergo corrosion; dependence of corrosion in tanks on type of petroleum products; aggressiveness of petroleum products to polymeric material; how microorganisms take part in corrosion of tanks and pipes containing petroleum products; which corrosion monitoring methods are used in systems for storage and transportation of petroleum products; what corrosion control measures should be chosen; how to choose coatings for inner and outer surfaces of tanks containing petroleum products; and how different additives (oxygenates, aromatic solvents) to petroleum products and biofuels influence metallic and polymeric materials. The book is of interest to corrosion engineers, mat...

  1. Corrosion behaviors and effects of corrosion products of plasma electrolytic oxidation coated AZ31 magnesium alloy under the salt spray corrosion test

    Science.gov (United States)

    Wang, Yan; Huang, Zhiquan; Yan, Qin; Liu, Chen; Liu, Peng; Zhang, Yi; Guo, Changhong; Jiang, Guirong; Shen, Dejiu

    2016-08-01

    The effects of corrosion products on corrosion behaviors of AZ31 magnesium alloy with a plasma electrolytic oxidation (PEO) coating were investigated under the salt spray corrosion test (SSCT). The surface morphology, cross-sectional microstructure, chemical and phase compositions of the PEO coating were determined using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD), respectively. Further, the corrosion process of the samples under the SSCT was examined in a non-aqueous electrolyte (methanol) using electrochemical impedance spectroscopy (EIS) coupled with equivalent circuit. The results show that the inner layer of the coating was destroyed firstly and the corrosion products have significant effects on the corrosion behaviors of the coating. The results above are discussed and an electrochemical corrosion model is proposed in the paper.

  2. Corrosion product film-induced stress facilitates stress corrosion cracking

    OpenAIRE

    Wang, Wenwen; Zhang, Zhiliang; Ren, Xuechong; Guan, Yongjun; Su, Yanjing

    2015-01-01

    Finite element analyses were conducted to clarify the role of corrosion product films (CPFs) in stress corrosion cracking (SCC). Flat and U-shaped edge-notched specimens were investigated in terms of the CPF-induced stress in the metallic substrate and the stress in the CPF. For a U-shaped edge-notched specimen, the stress field in front of the notch tip is affected by the Young’s modulus of the CPF and the CPF thickness and notch geometry. The CPF-induced tensile stress in the metallic subst...

  3. Corrosion mechanisms of containment glasses for fission products

    International Nuclear Information System (INIS)

    Nogues, J.L.

    1984-01-01

    After a review of nuclear energy production and waste vitrification principles, the aqueous corrosion mechanisms of the containment glasses and the various parameters affecting the corrosion are studied: effects of glass composition, temperature, lixiviation agent pH, lixiviation duration and mode. Conventional mass loss measurement and solution analyses are coupled to sophisticated surface analysis techniques. The hydrolyzed layer formation and the solubility limits are discussed. 87 figs., 30 tabs., 144 refs

  4. Surface films and corrosion of copper

    International Nuclear Information System (INIS)

    Hilden, J.; Laitinen, T.; Maekelae, K.; Saario, T.; Bojinov, M.

    1999-03-01

    In Sweden and Finland the spent nuclear fuel is planned to be encapsulated in cast iron canisters that have an outer shield made of copper. The copper shield is responsible for the corrosion protection of the canister construction. General corrosion of the copper is not expected to be the limiting factor in the waste repository environment when estimating the life-time of the canister construction. However, different forms of localised corrosion, i.e. pitting, stress corrosion cracking, or environmentally assisted creep fracture may cause premature failure of the copper shield. Of the probable constituents in the groundwater, nitrites, chlorides, sulphides and carbonates have been suggested to promote localised corrosion of copper. The main assumption made in planning this research program is that the surface films forming on copper in the repository environment largely determine the susceptibility of copper to the different forms of localised corrosion. The availability of reactants, which also may become corrosion rate limiting, is investigated in several other research programs. This research program consists of a set of successive projects targeted at characterising the properties of surface films on copper in repository environment containing different detrimental anions. A further aim was to assess the significance of the anion-induced changes in the stability of the oxide films with regard to localised corrosion of copper. This report summarises the results from a series of investigations on properties of surface films forming on copper in water of pH = 8.9 at temperature of 80 deg C and pressure of 2 MPa. The main results gained so far in this research program are as follows: The surface films forming on copper in the thermodynamic stability region of monovalent copper at 80 deg C consist of a bulk part (about 1 mm thick) which is a good ionic and electronic conductor, and an outer, interfacial layer (0.001 - 0.005 mm thick) which shows p-type semiconductor

  5. Surface morphology and corrosion resistance of electrodeposited ...

    Indian Academy of Sciences (India)

    Administrator

    Surface morphology and corrosion resistance of electrodeposited composite coatings containing polyethylene or polythiophene in. Ni–Mo base. J NIEDBAŁA. Institute of Materials Science, University of Silesia, 40-007 Katowice, ul. Bankowa 12, Poland. MS received 11 December 2009; revised 30 April 2010. Abstract.

  6. 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)

  7. The Impact of Road Maintenance Substances on Metals Surface Corrosion

    Directory of Open Access Journals (Sweden)

    Jolita Petkuvienė

    2011-04-01

    Full Text Available The purpose of research is to assess changes in the visual metal surface due to the exposure of road maintenance salts and molasses (‘Safecote’. Chlorides of deicing salts (NaCl, CaCl2 are the main agents affecting soil and water resources as well as causing the corrosion of roadside metallic elements. Molasses (‘Safecote’ is offered as an alternative to deice road pavement by minimizing the corrosion of metal elements near the road. A laboratory experiment was carried out to immerse and spray metals with NaCl, CaCl2, NaCl:CaCl2 and NaCl:Safecote solutions. The obtained results showed that NaCl:Safecote solution had the lowest coating with corrosion products (the average 17±4 % of the surface. The solutions of NaCl, CaCl2 and NaCl:CaCl2 had the highest percentage rate of the corrosion product on the metal surface reaching an average of 33±5 %. Article in English

  8. 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.

  9. Specific corrosion product on interior surface of a bronze wine vessel with loop-handle and its growth mechanism, Shang Dynasty, China

    Energy Technology Data Exchange (ETDEWEB)

    Li Yang; Bao Zhirong; Wu Taotao [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072 (China); Jiang, Junchun [Xiaogan Museum, Xiaogan 432000 (China); Chen Guantao [Center for Archaeometry, Wuhan University, Wuhan 430072 (China); Pan Chunxu, E-mail: cxpan@whu.edu.cn [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072 (China); Center for Archaeometry, Wuhan University, Wuhan 430072 (China)

    2012-06-15

    In this paper, a kind of specific stalactitic product was found on the interior surface of a covered bronze wine vessel with loop-handle (Chinese name is you), which was fabricated in Shang Dynasty (1700 B.C.-1100 B.C.) and now is collected in Xiaogan Museum, Hubei province of China. The microstructures of the product were characterized systematically by using optical microscopy, scanning electron microscope, transmission electron microscope, X-ray diffraction, and Raman microscopy. The experimental results revealed that the product belonged to a kind of malachite with high purity and high crystallinity. The growth of the product was considered to be a possible reason that the vessel was overly airtight within a museum display cabinet besides a lid of the vessel, which made the excess of H{sub 2}O and CO{sub 2} gas concentrations inside the vessel during long-term storage. This corrosion product is very harmful to bronze cultural relics, because of a large amount of copper consumption from the matrix which will reduce its life. The growth mechanism of the specific stalactitic product and the suggestions for preservation of the similar bronze relics in museum were proposed. - Highlights: Black-Right-Pointing-Pointer The stalactitic product was the high purity and good crystallinity malachite. Black-Right-Pointing-Pointer Its growth was related to the excess of H{sub 2}O and CO{sub 2} gas concentrations in museum. Black-Right-Pointing-Pointer It is harmful to the bronzes, because copper will be consumed from the matrix. Black-Right-Pointing-Pointer The suggestions for preservation of the similar bronzes in museum were proposed.

  10. 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.

  11. Surface layer effects on waste glass corrosion

    International Nuclear Information System (INIS)

    Feng, X.

    1993-01-01

    Water contact subjects waste glass to chemical attack that results in the formation of surface alteration layers. Two principal hypotheses have been advanced concerning the effect of surface alteration layers on continued glass corrosion: (1) they act as a mass transport barrier and (2) they influence the chemical affinity of the glass reaction. In general, transport barrier effects have been found to be less important than affinity effects in the corrosion of most high-level nuclear waste glasses. However, they can be important under some circumstances, for example, in a very alkaline solution, in leachants containing Mg ions, or under conditions where the matrix dissolution rate is very low. The latter suggests that physical barrier effect may affect the long-term glass dissolution rate. Surface layers influence glass reaction affinity through the effects of the altered glass and secondary phases on the solution chemistry. The reaction affinity may be controlled by various precipitates and crystalline phases, amorphous silica phases, gel layer, or all the components of the glass. The surface alteration layers influence radionuclide release mainly through colloid formation, crystalline phase incorporation, and gel layer retention. This paper reviews current understanding and uncertainties

  12. Application of response surface methodology method in designing corrosion inhibitor

    Science.gov (United States)

    Asmara, Y. P.; Athirah; Siregar, J. P.; Kurniawan, T.; Bachtiar, D.

    2017-10-01

    In oil and gas pipelines and offshore structure, inhibitors have been considered to be the first choice to reduce corrosion rate. There are many corrosion inhibitor compositions available in the market. To produce the best corrosion inhibitor requires many experimental data which is not efficient. These experiments used response surface methodology (RSM) to select corrosion inhibitor compositions. The experiments investigated effects of corrosion inhibition on corrosion rate of low carbon steel in 3% NaCl solution with different concentrations of selected main inhibitor compositions which are ethyl acetate (EA), ethylene glycol (EG) and sodium benzoate (SB). Corrosion rate were calculated using linear polarization resistance (LPR). All of the experiments were set in natural conditions at pH 7. MINITAB® version 15 was used for data analysis. It is shown that a quadratic model is a representative model can predict best corrosion inhibitor composition comprehensibly.

  13. Corrosion products in the coolant circuits of PWR nuclear power plants

    International Nuclear Information System (INIS)

    Darras, R.

    1984-01-01

    The characteristics of corrosion products formed in the primary and secondary circuits of pressurized light water nuclear power plants are first briefly recalled. The problem set by the pollution of coolants and metallic surfaces is then examined. Finally, the measures of precaution to take and the possible solutions to minimize the disturbing effects of this pollution by corrosion products are presented [fr

  14. The corrosion products in the coolant circuits of pressurized water nuclear power plants

    International Nuclear Information System (INIS)

    Darras, R.

    1983-01-01

    The characteristics of the corrosion products formed in the primary and secondary coolant circuits of light-water pressurized reactors are reviewed. The problem induced by the pollution of coolants and metallic surface are examined. Then, the recommendations to follow to minimize the disturbing effects of this pollution by the corrosion products are indicated [fr

  15. [Corrosion resistant properties of different anodized microtopographies on titanium surfaces].

    Science.gov (United States)

    Fangjun, Huo; Li, Xie; Xingye, Tong; Yueting, Wang; Weihua, Guo; Weidong, Tian

    2015-12-01

    To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies. Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid. Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr. Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.

  16. 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.

  17. 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

    -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...

  18. High Temperature Corrosion under Laboratory Conditions Simulating Biomass-Firing: A Comprehensive Characterization of Corrosion Products

    DEFF Research Database (Denmark)

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

    2014-01-01

    characterization of the corrosion products. The corrosion products consisted of three layers: i) the outermost layer consisting of a mixed layer of K2SO4 and FexOy on a partly molten layer of the initial deposit, ii) the middle layer consists of spinel (FeCr2O4) and Fe2O3, and iii) the innermost layer is a sponge......-like Ni3S2 containing layer. At the corrosion front, Cl-rich protrusions were observed. Results indicate that selective corrosion of Fe and Cr by Cl, active oxidation and sulphidation attack of Ni are possible corrosion mechanisms....

  19. Nuclear reactor structural material forming less radioactive corrosion product

    International Nuclear Information System (INIS)

    Nakazawa, Hiroshi.

    1988-01-01

    Purpose: To provide nuclear reactor structural materials forming less radioactive corrosion products. Constitution: Ni-based alloys such as inconel alloy 718, 600 or inconel alloy 750 and 690 having excellent corrosion resistance and mechanical property even in coolants at high temperature and high pressure have generally been used as nuclear reactor structural materials. However, even such materials yield corrosion products being attacked by coolants circulating in the nuclear reactor, which produce by neutron irradiation radioactive corrosion products, that are deposited in primary circuit pipeways to constitute exposure sources. The present invention dissolves dissolves this problems by providing less activating nuclear reactor structural materials. That is, taking notice on the fact that Ni-58 contained generally by 68 % in Ni changes into Co-58 under irradiation of neutron thereby causing activation, the surface of nuclear reactor structural materials is applied with Ni plating by using Ni with a reduced content of Ni-58 isotopes. Accordingly, increase in the radiation level of the nuclear reactor structural materials can be inhibited. (K.M.)

  20. Tracing correlations of corrosion products and microclimate data on outdoor bronze monuments by Principal Component Analysis

    International Nuclear Information System (INIS)

    Polikreti, Kyriaki; Argyropoulos, Vassilike; Charalambous, Demetres; Vossou, Aggelina; Perdikatsis, Vassilis; Apostolaki, Chryssa

    2009-01-01

    Although the corrosion of outdoor bronzes has been extensively studied for the last decades, there is no quantitative correlation of corrosion products to microclimatic factors. The present work aims to demonstrate how Principal Component Analysis (PCA) can serve this purpose. Thirty corrosion product samples were collected from the bronze monument of Theodoros Kolokotronis (Nafplio, Greece) and analysed using X-Ray Diffractometry (XRD). The quantitative XRD data together with data on surface orientation and exposure to rain or wind were treated by PCA and three distinct groups were found. Each group includes samples of similar composition and microclimate characteristics showing that PCA may give useful information on corrosion mechanisms.

  1. Effect of surface morphology on atmospheric corrosion behaviour of ...

    Indian Academy of Sciences (India)

    Wintec

    adverse effect of quenched-in defects on the corrosion resistance of Fe34Ni36Cr10P14B6 amorphous alloy has been reported by some investigators (Gravano et al 1992). The inferior corrosion resistance of the wheel side surface has been attributed to higher concentration of quenched- in defects due to higher cooling rate ...

  2. 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.

  3. Surface morphology and corrosion resistance of electrodeposited ...

    Indian Academy of Sciences (India)

    Electrochemical corrosion resistance investigations were carried out in 5 M KOH, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the basis of these investigations it was found, that the composite coatings containing thiophene are more corrosion resistant in alkaline solution than the ...

  4. Corrosion Resistance and Durability of Superhydrophobic Copper Surface in Corrosive NaCl Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Chun-Wei Yao

    2018-02-01

    Full Text Available Artificial superhydrophobic copper surfaces play an important role in modern applications such as self-cleaning and dropwise condensation; however, corrosion resistance and durability often present as major concerns in such applications. In this study, the anti-corrosion properties and mechanical durability of superhydrophobic copper surface have been investigated. The superhydrophobic copper surfaces were achieved with wet chemical etching and an immersion method to reduce the complexity of the fabrication process. The surface structures and materials were characterized using scanning electron microscope (SEM, energy dispersive X-ray spectroscopy (EDX, and Fourier transform infrared spectrometer (FTIR. The corrosion resistance and mechanical properties of the superhydrophobic copper surface were characterized after immersing surfaces in a 3.5 wt % NaCl solution. The chemical stability of the superhydrophobic copper surface in the NaCl solution for a short period of time was also evaluated. An abrasion test and an ultrasound oscillation were conducted to confirm that the copper surface contained durable superhydrophobic properties. In addition, an atomic force microscope was employed to study the surface mechanical property in the corrosion conditions. The present study shows that the resulting superhydrophobic copper surface exhibit enhanced corrosion resistance and durability.

  5. 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

  6. Corrosion and surface modification on biocompatible metals: A review.

    Science.gov (United States)

    Asri, R I M; Harun, W S W; Samykano, M; Lah, N A C; Ghani, S A C; Tarlochan, F; Raza, M R

    2017-08-01

    Corrosion prevention in biomaterials has become crucial particularly to overcome inflammation and allergic reactions caused by the biomaterials' implants towards the human body. When these metal implants contacted with fluidic environments such as bloodstream and tissue of the body, most of them became mutually highly antagonistic and subsequently promotes corrosion. Biocompatible implants are typically made up of metallic, ceramic, composite and polymers. The present paper specifically focuses on biocompatible metals which favorably used as implants such as 316L stainless steel, cobalt-chromium-molybdenum, pure titanium and titanium-based alloys. This article also takes a close look at the effect of corrosion towards the implant and human body and the mechanism to improve it. Due to this corrosion delinquent, several surface modification techniques have been used to improve the corrosion behavior of biocompatible metals such as deposition of the coating, development of passivation oxide layer and ion beam surface modification. Apart from that, surface texturing methods such as plasma spraying, chemical etching, blasting, electropolishing, and laser treatment which used to improve corrosion behavior are also discussed in detail. Introduction of surface modifications to biocompatible metals is considered as a "best solution" so far to enhanced corrosion resistance performance; besides achieving superior biocompatibility and promoting osseointegration of biocompatible metals and alloys. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Theme day: corrosion and surface treatments in nuclear facilities. Proceedings

    International Nuclear Information System (INIS)

    2012-02-01

    This document brings together the available presentations given at the theme day organized by the Bourgogne Nuclear Pole on the topic of corrosion and surface treatments in nuclear facilities. Eleven presentations (slides) are compiled in this document: 1 - Introduction - PNB centre of competitiveness and R and D activities (A. Mantovan, PNB); 2 - Corrosion damage (M. Foucault, Areva NP - Centre Technique Le Creusot); 3 - Corrosion mechanisms (R. Oltra, UB-ICB); 4 - Examples of expertise management (C. Duret-Thual, Institut de la corrosion/Corrosion Institute); 5 - General framework of surface treatments (C. Nouveau, ENSAM Cluny Paris Tech); 6 - Surfaces et interfaces characterisation - Part A (C. Langlade, Y. Gachon, UTBM and HEF); 7 - Surfaces et interfaces characterisation - Part B (C. Langlade, Y. Gachon, UTBM and HEF); 8 - Ion beam surface treatment (Y. Le Guellec, Quertech Ingenierie); 9 - Impact surface treatment (G. Saout, Sonats); 10 - Metal oxides Characterisation by US laser (R. Oltra, UB-ICB); 11 - Detection and Characterisation of intergranular corrosion (Y. Kernin, Stephane Bourgois, Areva Intercontrole)

  8. 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)

  9. Laser Surface Alloying of Aluminum for Improving Acid Corrosion Resistance

    Science.gov (United States)

    Jiru, Woldetinsay Gutu; Sankar, Mamilla Ravi; Dixit, Uday Shanker

    2018-04-01

    In the present study, laser surface alloying of aluminum with magnesium, manganese, titanium and zinc, respectively, was carried out to improve acid corrosion resistance. Laser surface alloying was conducted using 1600 and 1800 W power source using CO2 laser. Acid corrosion resistance was tested by dipping the samples in a solution of 2.5% H2SO4 for 200 h. The weight loss due to acid corrosion was reduced by 55% for AlTi, 41% for AlMg alloy, 36% for AlZn and 22% for AlMn alloy. Laser surface alloyed samples offered greater corrosion resistance than the aluminum substrate. It was observed that localized pitting corrosion was the major factor to damage the surface when exposed for a long time. The hardness after laser surface alloying was increased by a factor of 8.7, 3.4, 2.7 and 2 by alloying with Mn, Mg, Ti and Zn, respectively. After corrosion test, hardness was reduced by 51% for AlTi sample, 40% for AlMg sample, 41.4% for AlMn sample and 33% for AlZn sample.

  10. Study on influence of native oxide and corrosion products on atmospheric corrosion of pure Al

    International Nuclear Information System (INIS)

    Liu, Yanjie; Wang, Zhenyao; Ke, Wei

    2014-01-01

    Highlights: •Corrosion products layer is only formed in coastal atmosphere. •In coastal atmosphere, rate controlling step is diffusion process. •In rural atmosphere, rate controlling step is charge transfer process. •Pitting area increases greatly in coastal site, but slightly in rural site. -- Abstract: Effects of native oxide and corrosion products on atmospheric corrosion of aluminium in rural and coastal sites were studied by electrochemical impedance spectroscopy (EIS), open-circuit potential (OCP) and scanning electron microscope (SEM) techniques after outdoor exposure. In the rural atmosphere, only the compact, adhesive native oxide layer exists, and the rate controlling step is diffusion process, while in the coastal atmosphere, another loose, inadhesive corrosion products layer exists, and a charge transfer process controls the corrosion process. The pitting area in the coastal atmosphere increases over time more obviously than that in the rural atmosphere

  11. TEM characterization of corrosion products formed on a SS-15ZR alloy

    International Nuclear Information System (INIS)

    Luo, J. S.; Abraham, D. P.

    2000-01-01

    The corrosion products formed on a stainless steel-15Zr (SS-15Zr) alloy have been characterized by transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS). Examination of alloy particles that were immersed in 90 C deionized water for two years revealed that different corrosion products were formed on the stainless steel and intermetallic phases. Two corrosion products were identified on an austenite particle: trevorite (NiFe 2 O 4 ) in the layer close to the metal and maghemite (Fe 2 O 3 ) in the outer layer. The corrosion layer formed on the intermetallic was uniform, adherent, and amorphous. The EDS analysis indicated that the layer was enriched in zirconium when compared with the intermetallic composition. High-resolution TEM images of the intermetallic-corrosion layer interface show an interlocking metal-oxide interface which may explain the relatively strong adherence of the corrosion layer to the intermetallic surface. These results will be used to evaluate corrosion mechanisms and predict long-term corrosion behavior of the alloy waste form

  12. Corrosion products study of alcohol by Mossbauer spectroscopy

    International Nuclear Information System (INIS)

    Velazquez, R.; Gil de Larre, M.

    1995-01-01

    Simulated corrosion essays in alcohol is presented and corrosion products of storage tanks (CAPASA) were analyzed. The analysis by Mossbauer absortion and transmission spectroscopy shows the formation of hematite substratum in the rust of the storage tanks of carburetant and burning alcohol. In the sample of corrosion with strong rum shows the formation of lepidocrocite and with destilled water besides of lepidocrocite, magnetite (Fe3 O4) is detected

  13. Oxidation kinetics of reaction products formed in uranium metal corrosion

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    1998-01-01

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O 2 and Ar-20%O 2 were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates

  14. FeS Corrosion Products Formation and Hydrogen Uptake in a Sour Environment for Quenched & Tempered Steel

    Directory of Open Access Journals (Sweden)

    Elien Wallaert

    2018-01-01

    Full Text Available Surface corrosion product formation is one of the important factors affecting the corrosion rate and hydrogen uptake in a H2S environment. However, it is still unclear how the base material composition will affect the corrosion products that are generated, and consequently their impact on the corrosion rate. In this paper, corrosion product formation and the impact of the Mo content of the base material on the composition of the corrosion products and hydrogen absorption in a sour environment was investigated. The corrosion layer was composed of a double layered mackinawite (FeS1−x structure, which was enriched with molybdenum and chromium. The layers were formed via two different mechanisms, i.e., the inner layer was created via a general oxide film formation corrosion mechanism, whereas the upper layer was formed by a precipitation mechanism. The presence of this double corrosion layer had a large influence on the amount of diffusible hydrogen in the materials. This amount decreased as a function of contact time with the H2S saturated solution, while the corrosion rate of the materials shows no significant reduction. Therefore, the corrosion products are assumed to act as a physical barrier against hydrogen uptake. Mo addition caused a decrease in the maximal amount of diffusible hydrogen.

  15. 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

  16. Corrosion resistance of surface modified nickel titanium archwires.

    Science.gov (United States)

    Krishnan, Manu; Seema, Saraswathy; Kumar, A Vinod; Varthini, N Parvatha; Sukumaran, Kalathil; Pawar, Vasant R; Arora, Vimal

    2014-03-01

    To compare the corrosion behavior of commercially available surface modified nickel titanium (NiTi) arch wires with respect to a conventional NiTi and to evaluate its association with surface characteristics. Five types of surface modified arch wires and a conventional NiTi arch wire, all from different manufacturers, were evaluated for their corrosion resistance from breakdown potential in an anodic polarization scan in Ringer's solution. Surface characteristics were determined from scanning electron microscopy, atomic force microscopy, and energy dispersive analysis. One-way analysis of variance and post hoc Duncan's multiple range tests were used to evaluate statistical significance. Surface modified NiTi wires showed significant improvement in corrosion resistance and reduction in surface roughness values. Breakdown potentials increased in the order of group 6 (conventional; 204 mV) corrosion resistance and decreasing surface roughness. However, neither factor could maintain a direct, one-to-one relationship. It meant that the type and nature of coating material can effectively influence the anticorrosive features of NiTi wires, compared with its surface roughness values.

  17. Pitting corrosion

    International Nuclear Information System (INIS)

    Allgaier, W.

    1985-01-01

    Pitting corrosion is a kind of electrolytic corrosion by which the surface of a material is locally affected owing to inhomogeneities on the part of the material or medium. The paper deals briefly with questions relating to the importance, to parameters medium or materialwise, influence on production and construction, as well as the general conditions for pitting corrosion. In particular oxygen corrosion in unalloyed and low-alloy steel, and pitting corrosion in ferritic chromium-steel and austenitic chromium-nickel (molybdenum) steel is described. (DG) [de

  18. Corrosion protection of aluminum by silane-based surface treatment

    Science.gov (United States)

    Song, Jun

    The possibility of using silane coupling agents as replacements for chromate treatments was investigated for aluminum substrates. In order to understand the influence of deposition parameters on silane film formation, pure Al substrates were used to study the interaction between silane coupling agents and aluminum surfaces. The silane films formed on pure A1 substrates from aqueous solutions were characterized by ellipsometry, contact angle measurements, reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and Time-of Flight Secondary Ion Mass Spectrometry. 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 in aqueous solution. It has been found that the silane film thickness obtained depends primarily on the solution concentration and is independent of the solution dipping time. The molecular orientation of the applied silane film is determined by the pH value of the applied silane solution and the isoelectic point of the metal substrates. The deposition window in terms of pH value for A1 substrates is between 4 and 7. The total surface energy of silane-coated A1 substrate decreases with film aging time, the decreased rate, however, is determined by the nature of silane coupling agents. Based on the results obtained above, a pretreatment, which involved two-step bis-(triethoxysilyl) ethane and gamma-aminopropyltriethoxysilane, was developed for Al substrates with commercial polyester and polyurethane paints. The results of salt spray testing, cyclic corrosion testing, and electrochemical impedance spectroscopy showed that this treatment provided the same level of corrosion performance as the treatment of phosphating plus a final chromate rinse. The likely reasons for excellent performance are discussed in terms of the physical and chemical characteristics of the

  19. DETECTING GLASS SURFACE CORROSION WITH IMAGE PROCESSING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Rafet AKDENİZ

    2012-12-01

    Full Text Available Glass is a kind of amorphous materials that exhibits a transition from rigid to viscous state and finally liquid state when heated. For daily usage, it is desirable to have different forms and differenttransparencies for different purposes. Most widely used one is the one with high transparency and flat surface.One of the detrimental effects that glass is undergone during the storage or usage periods is corrosion. In this work, a way for detecting corrosion on the glass surface by image processing methodis presented.

  20. Method of separation of fission and corrosion products and of corresponding isotopes from liquid waste

    International Nuclear Information System (INIS)

    Prochazka, H.; Stamberg, K.; Jilek, R.; Hulak, P.; Katzer, J.

    1976-01-01

    A method of separating fission and corrosion products and corresponding stable isotopes from liquid waste is described. Mycelia of fungi are used as sorbents for retaining these products on their surface and within their pores. Methods of activation or regeneration of the sorbent are outlined. 11 claims

  1. Simulations of corrosion product transfer with the OSCAR V1.2 code

    International Nuclear Information System (INIS)

    Dacquait, F.; Francescatto, J.; Broutin, F.; Genin, J.B.; Benier, G.; Girard, M.; You, D.; Ranchoux, G.; Bonnefon, J.; Bachet, M.; Riot, G.

    2012-09-01

    Activated Corrosion Products (ACPs) generate a radiation field in PWRs, which is the major contributor to the dose absorbed by nuclear power plant staff working during shutdown operations and maintenance. Therefore, a thorough understanding of the mechanisms that control the corrosion product transfer is of the highest importance. Since the 1970's, the R and D strategy in France has been based on experiments in test loops representative of PWR conditions, on in-situ gamma spectrometry measurements of the PWR primary system contamination and on simulation code development. The simulation of corrosion product transfers in PWR primary circuits is a major challenge since it involves many physical and chemical phenomena including: corrosion, dissolution, precipitation, erosion, deposition, convection, activation... In addition to the intrinsic difficulty of multi-physics modelling, the primary systems present severe operating conditions (300 deg. C, 150 bar, neutron flux, fluid velocity up to 15 m.s -1 and very low corrosion product concentrations). The purpose of the OSCAR code, developed by the CEA in cooperation with EDF and AREVA NP, is to predict the PWR primary system contamination by corrosion and fission products. The OSCAR code is considered to be not only a tool for numerical simulations and predictions (operational practices improvements and new-built PWRs design) but also one that might combine and organise all new knowledge useful to progress on contamination. The OSCAR code for Products of Corrosion, OSCAR PC, allows researchers to analyse the corrosion product behaviour and to calculate the ACP volume and surface activities of the primary and auxiliary systems. In the new version, OSCAR PC V1.2, the corrosion product transfer in the particulate form is enhanced and a new feature is the possibility to simulate cold shutdowns. In order to validate this version, the contamination transfer has been simulated in 5 French PWRs with different operating and

  2. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

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

  3. SNF Interim Storage Canister Corrosion and Surface Environment Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Enos, David G. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    This progress report describes work being done at Sandia National Laboratories (SNL) to assess the localized corrosion performance of container/cask materials used in the interim storage of spent nuclear fuel (SNF). Of particular concern is stress corrosion cracking (SCC), by which a through-wall crack could potentially form in a canister outer wall over time intervals that are shorter than possible dry storage times. In order for SCC to occur, three criteria must be met. A corrosive environment must be present on the canister surface, the metal must susceptible to SCC, and sufficient tensile stress to support SCC must be present through the entire thickness of the canister wall. SNL is currently evaluating the potential for each of these criteria to be met.

  4. [The effect of epigallocatechin gallate (EGCG) on the surface properties of nickel-chromium dental casting alloys after electrochemical corrosion].

    Science.gov (United States)

    Qiao, Guang-yan; Zhang, Li-xia; Wang, Jue; Shen, Qing-ping; Su, Jian-sheng

    2014-08-01

    To investigate the effect of epigallocatechin gallate (EGCG) on the surface properties of nickel-chromium dental alloys after electrochemical corrosion. The surface morphology and surface structure of nickel-chromium dental alloys were examined by stereomicroscope and scanning electron microscopy before and after electrochemical tests in 0 g/L and 1.0 g/L EGCG artificial saliva. The surface element component and chemical states of nickel-chromium dental alloys were analyzed by X-ray photoelectron spectrograph after electrochemical tests in 0 g/L and 1.0 g/L EGCG artificial saliva. More serious corrosion happened on the surface of nickel-chromium alloy in 1.0 g/L EGCG artificial saliva than in 0 g/L EGCG. The diameters of corrosion pits were smaller, and the dendrite structure of the alloy surface was not affected in 0 g/L EGCG. While the diameters of corrosion pits were larger, the dendritic interval of the alloy surface began to merge, and the dendrite structure was fuzzy in 1.0 g/L EGCG. In addition, the O, Ni, Cr, Be, C and Mo elements were detected on the surface of nickel-chromium alloys after sputtered for 120 s in 0 g/L EGCG and 1.0 g/L EGCG artificial saliva after electrochemical corrosion, and the surface oxides were mainly NiO and Cr(2)O(3). Compared with 0 g/L EGCG artificial saliva, the content of O, NiO and Cr(2)O(3) were lower in 1.0 g/L EGCG. The results of surface morphology and the corrosion products both show that the corrosion resistance of nickel-chromium alloys become worse and the oxide content of corrosion products on the surface reduce in 1.0 g/L EGCG artificial saliva.

  5. Corrosive inorganic contamination on wafer surfaces after nickel-iron electroplating formation mechanisms and prevention

    Energy Technology Data Exchange (ETDEWEB)

    Kritzer, P. [Freudenberg Nonwovens KG, Technical Nonwovens Div., Weinheim (Germany); Diel, W.; Barber, P.H. [IBM Speichersysteme Deutschland GmbH, Mainz (Germany); Romankiw, L.T. [IBM Watson Research Center, Yorktown Heights, NY (United States)

    2001-11-01

    Electroplating of Nickel-Iron alloys is widely used in the production of magnetic heads for storage systems. Usually, the plating process is performed in acidic, salt-containing solutions. After the plating step, a complete removal of the plating salts is necessary to receive a clean surface. In disadvantageous cases, a precipitation of sticky particles is observed that cannot be removed from the plated surface without damaging the surface. Some of these substances (esp. nickel sulfates) might lead to severe local corrosion and thus might act as ''time-bomb'' in the later product. Non-corrosive precipitations (i.e. nickel hydroxides) strongly hinder or even prevent the following production steps. In the present paper, the mechanisms of the origin of the different kinds of precipitation are described and the principle actions for their prevention are given. An outlook is given for other possible technical applications. (orig.)

  6. Evaluation of the susceptibility to pitting corrosion of structural steels, including steels with modified surface

    International Nuclear Information System (INIS)

    Lunarska, E.; Nikiforow, K.

    2001-01-01

    Although the low alloy ferrite-perlite and bainite-martensite steels mostly undergo the general corrosion, pitting corrosion occurring under certain conditions jeopardizes the safety of installations, causing perforation of walls or initiation of crack. On the basis of electrochemical, corrosion and microscopic examinations, the conditions simulating typical industrial corrosion environments, containing Cl - ions have been selected, to which the parts of machines, devices and installation are subjected. The test parameters provide the preferential pitting corrosion without prevailing general corrosion, and provide the similar type of corrosion of different kinds of ferrite-perlite and bainite-martensite steels, including steels with modified surface layer. The proposed express method allows to evaluate the susceptibility to pitting corrosion and to evaluate the effect of surface modification on susceptibility to pitting corrosion in environments containing Cl - ions. The method may be applied for the proper selection of materials exploited under pitting corrosion conditions and for preparation of precorroded samples for mechanical testing. (author)

  7. Modelling and numerical simulation of the corrosion product transport in the pressurised water reactor primary circuit

    International Nuclear Information System (INIS)

    Marchetto, C.

    2002-05-01

    During operation of pressurised water reactor, corrosion of the primary circuit alloys leads to the release of metallic species such as iron, nickel and cobalt in the primary fluid. These corrosion products are implicated in different transport phenomena and are activated in the reactor core where they are submitted to neutron flux. The radioactive corrosion products are afterwards present in the out of flux parts of primary circuit where they generate a radiation field. The first part of this study deals with the modelling of the corrosion: product transport phenomena. In particular, considering the current state of the art, corrosion and release mechanisms are described empirically, which allows to take into account the material surface properties. New mass balance equations describing the corrosion product behaviour are thus obtained. The numerical resolution of these equations is implemented in the second part of this work. In order to obtain large time steps, we choose an implicit time scheme. The associated system is linearized from the Newton method and is solved by a preconditioned GMRES method. Moreover, a time step auto-adaptive management based on Newton iterations is performed. Consequently, an efficient resolution has been implemented, allowing to describe not only the quasi-steady evolutions but also the fast transients. In a last step, numerical simulations are carried out in order to validate the new corrosion product transport modelling and to illustrate the capabilities of this modelling. Notably, the numerical results obtained indicate that the code allows to restore the on-site observations underlining the influence of material surface properties on reactor contamination. (author)

  8. 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

  9. The Influence of Pseudomonas fluorescens on Corrosion Products of Archaeological Tin-Bronze Analogues

    Science.gov (United States)

    Ghiara, G.; Grande, C.; Ferrando, S.; Piccardo, P.

    2018-01-01

    In this study, tin-bronze analogues of archaeological objects were investigated in the presence of an aerobic Pseudomonas fluorescens strain in a solution, containing chlorides, sulfates, carbonates and nitrates according to a previous archaeological characterization. Classical fixation protocols were employed in order to verify the attachment capacity of such bacteria. In addition, classical metallurgical analytical techniques were used to detect the effect of bacteria on the formation of uncommon corrosion products in such an environment. Results indicate quite a good attachment capacity of the bacteria to the metallic surface and the formation of the uncommon corrosion products sulfates and sulfides is probably connected to the bacterial metabolism.

  10. Influence of impurities and ion surface alloying on the corrosion resistance of E110 alloy

    International Nuclear Information System (INIS)

    Kalin, B. A.; Volkov, N. V.; Valikov, R. A.; Novikov, V. V.; Markelov, V. A.; Pimenov, Yu. V.

    2013-01-01

    The corrosion resistance of zirconium alloys depends on their structural-phase state, the type of core coolant and operating factors. The formation of a protective oxide film on the zirconium alloys is sensitive to the content of impurity atoms present in the charge base of alloys and accumulating in them in the manufacture of products. The impurity composition of the initial zirconium is determined by the method of its manufacture and generally remains unchanged in the products, deter-mining their properties, including their corrosion resistance. An increased content of impurities (C, N, Al, Mo, Fe) both individually and in their combination negatively affects the corrosion resistance of zirconium and its alloys. One of the potentially effective methods to increase the protective properties of oxide films on zirconium alloys is a surface alloying using the regime of mixing the atoms of a film, preliminarily coated on the surface, and the atoms of a target. This method makes it possible to form a given structural-phase state in the thin surface layer with unique physicochemical properties and thus to in-crease the corrosion resistance and wear resistance of fuel claddings. In this context, the object of investigation was samples of cladding tubes from alloy E110 with various content of impurity elements (nitrogen, aluminum, and carbon) with the aim to reduce the negative influence of impurities on the corrosion resistance by changing the structural-phase state of the surface layer of fuel claddings and fuel assembly components with alloying in the regime of ion mixing of atoms

  11. The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W.L. [Argonne National Lab., IL (United States). Chemical Technology Div.

    1995-03-01

    This report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume (SA/V) ratio on the corrosion behavior of borosilicate waste glasses. The SA/V ratio affects the rate of glass corrosion through the extent of dilution of corrosion products released from the glass into the leachate solution: glass corrosion products are diluted more in tests conducted at low SA/V ratios than they are in tests conducted at high SA/V ratios. Differences in the solution chemistries generated in tests conducted at different SA/V ratios then affect the observed glass corrosion behavior. Therefore, any testing parameter that affects the solution chemistry will also affect the glass corrosion rate. The results of static leach tests conducted to assess the effects of the SA/V are discussed with regard to the effects of SA/V on the solution chemistry. Test results show several remaining issues with regard to the long-term glass corrosion behavior: can the SA/V ratio be used as an accelerating parameter to characterize the advanced stages of glass corrosion relevant to long disposal times; is the alteration of the glass surface the same in tests conducted at different SA/V, and in tests conducted with monolithic and crushed glass samples; what are the effects of the SA/V and the extent of glass corrosion on the disposition of released radionuclides? These issues will bear on the prediction of the long-term performance of waste glasses during storage. The results of an experimental program conducted at ANL to address these and other remaining issues regarding the effects of SA/V on glass corrosion are described. 288 refs., 59 figs., 16 tabs.

  12. 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

  13. 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.

  14. Influence of surface liquid segregation on corrosion behavior of semi-solid metal high pressure die cast aluminium alloys

    CSIR Research Space (South Africa)

    Masuku, EP

    2010-09-01

    Full Text Available of the major advantages of SSM processing is that high strength wrought alloys such as 7075 and 2024 can be used to produce near-net shape products. Corrosion is a surface phenomenon, and since the surface compositions of the SSM-processed components...

  15. 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

  16. A Moessbauer and Electrochemical Characterization of the Corrosion Products Formed from Marine and Marine-Antartic Environments

    International Nuclear Information System (INIS)

    Ohanian, M.; Caraballo, R.; Dalchiele, E. A.; Quagliata, E.

    2003-01-01

    Corrosion products formed on low alloy steel under two marine environments are characterised. Both environments are classified as C4 according to the ISO 9223 Standard. The corrosion products are identified and their relative proportion is determined by Moessbauer spectroscopy (transmission geometry). Free potentials of corrosion are measured to evaluate the activity of their surfaces. Structural characterisation by XRD were performed on selected samples. It is concluded that the principal phases are goethite, lepidocrocite, ferrihidrite and maghemite. The relative amount of each of them changes with time and with the atmospheric dynamics of each environment.

  17. Corrosion behaviour of laser surface melted magnesium alloy AZ91D

    International Nuclear Information System (INIS)

    Taltavull, C.; Torres, B.; Lopez, A.J.; Rodrigo, P.; Otero, E.; Atrens, A.; Rams, J.

    2014-01-01

    A high power diode laser (HPDL) was used to produce laser surface melting (LSM) treatments on the surface of the Mg alloy AZ91D. Different treatments with different microstructures were produced by varying the laser-beam power and laser-scanning speed. Corrosion evaluation, using hydrogen evolution and electrochemical measurements, led to a relationship between microstructure and corrosion. Most corrosion rates for LSM treated specimens were within the scatter of the as-received AZ91D, whereas some treatments gave higher corrosion rates and some of the samples had corrosion rates lower than the average of the corrosion rate for AZ91D. There were differences in corroded surface morphology. Nevertheless laser treatments introduced surface discontinuities, which masked the effect of the microstructure. Removing these surface defects decreased the corrosion rate for the laser-treated samples. - Highlights: • Corrosion behavior of AZ91D Mg alloys is intimately related with its microstructure. • Laser surface melting treatments allows surface modification of the microstructure. • Different laser parameters can achieve different microstructures. • Controlling laser parameters can produce different corrosion rates and morphologies. • Increase of surface roughness due to laser treatment is relevant to the corrosion rate

  18. Analysis of Steam Generators Corrosion Products from Slovak NPP Bohunice

    Directory of Open Access Journals (Sweden)

    Jarmila Degmová

    2012-01-01

    Full Text Available One of the main goals of the nuclear industry is to increase the nuclear safety and reliability of nuclear power plants (NPPs. As the steam generator (SG is the most corrosion sensitive component of NPPs, it is important to analyze the corrosion process and optimize its construction materials to avoid damages like corrosion cracking. For this purpose two different kinds of SGs and its feed water distributing systems from the NPP Jaslovske Bohunice were studied by nondestructive Mössbauer spectroscopy. The samples were scraped from the surface and analyzed in transmission geometry. Magnetite and hematite were found to be the main components in the corrosion layers of both SGs. Dependant of the material the SG consisted of, and the location in the system where the samples were taken, the ratios between magnetite and hematite and the paramagnetic components were different. The obtained results can be used to improve corrosion safety of the VVER-440 secondary circuit as well as to optimize its water chemistry regime.

  19. Temperature Effect on the Corrosion Behaviour of Alloy 31 in polluted H3PO4 and Analysis of the Corrosion Products by Laser Raman Microscope

    OpenAIRE

    Escrivá Cerdán, Clara; Blasco-Tamarit, E.; García-García, D.M.; Garcia-Anton, Jose; Ben-Bachir, A.

    2012-01-01

    Electrochemical behaviour of Alloy 31, a highly alloyed austenitic stainless steel (UNS N08031), in a 40 wt.% H3PO4 solution polluted with 2 wt.% H2SO4, 0.06 wt.% KCl and 0.6 wt.% HF was evaluated by cyclic potentiodinamic curves at different temperatures (20, 40, 60 and 80 degrees C). Temperature was found to favour both cathodic and anodic reactions. The corrosion products forming on the surface of Alloy 31 were indentified in situ by Laser Raman microscope. Corrosion products were mainly i...

  20. 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...biological role of strontium’. Bone , 35, (2004): p. 583. 10. P. Watts and P. Howe: ’Strontium and Strontium Compounds’, Concise International Chemical

  1. Computational technique for estimating corrosion product release in an LMFBR

    International Nuclear Information System (INIS)

    Kuhn, W.L.

    1976-01-01

    A model is developed to predict the release of activated corrosion products in an LMFBR. Model parameters are obtained from literature correlations and from fitting the model to release rates observed in experimental sodium loops. The model is simplified to consider only two cases: release controlled by corrosion only or controlled by simultaneous corrosion and diffusion only. The release rates, radionuclide inventories, and resulting radiation fields near primary system components are predicted for the Fast Flux Test Facility as a function of operating temperature, oxygen concentration in the sodium, and time of operation. Saturation inventories are reported for 54 Mn, 60 Co, 58 Co, 51 Cr, and 59 Fe. The resulting radiation fields are due mainly to 54 Mn, and are found to reach the 5 R/hr range for operation at a core outlet temperature of 593 0 C

  2. 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

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

    Science.gov (United States)

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

    2016-08-01

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

  4. Electrochemical corrosion behaviours of pulsed bias MSIP aluminum coating on depleted uranium surface

    International Nuclear Information System (INIS)

    Wang Qingfu; Zhang Pengcheng; Chen Lin; Liu Qinghe; Lang Dingmu; Wang Xiaohong

    2009-01-01

    Aluminum coating was prepared by magnetron sputtering ion plating (MSIP) with pulsed bias on depleted uranium surface. Its electrochemical corrosion behaviours were studied by electrochemical technology, scanning electron microscope (SEM) and X-ray energy dispersive spectroscope (EDS). The corrosion potential of aluminum coating (-534.8 mV) is higher than that of depleted uranium (-641.2 mV). The aluminum coating is a cathodic deposit to depleted uranium. Depleted uranium coated aluminum has much higher polarization resistance,greater magnitude of electrochemical impedance and much lower corrosion current than that of depleted uranium. The aluminum coating has a good corrosion resistance to depleted uranium. Corrosion characteristic of depleted uranium coated aluminum is a typical local corrosion. Meanwhile,the aluminum coating cracks and flakes off from depleted uranium substrate, which deteriorates its anti-corrosion property. Pseudo-diffusion layer on interface between aluminum coating and uranium substrate has some degree of anti-corrosion effect. (authors)

  5. Corrosion Resistance of Steel 45 Subjected to Electromechanical Treatment and Surface Plastic Deformation

    Science.gov (United States)

    Dudkina, N. G.

    2018-01-01

    The corrosion properties of normalized steel 45 are studied after a combined hardening of its surface layer, which consists of electromechanical treatment and surface plastic deformation (EMT + SPD). The effect of different aggressive environments on the structure, microhardness and corrosion rate of the hardened surface layer is determined.

  6. OSCAR-Na: A New Code for Simulating Corrosion Product Contamination in SFR

    Science.gov (United States)

    Génin, J.-B.; Brissonneau, L.; Gilardi, T.

    2016-12-01

    A code named OSCAR-Na has been developed to calculate the mass transfer of corrosion products in the primary circuit of sodium fast reactors (SFR). It is based on a solution/precipitation model, including diffusion in the steel (enhanced under irradiation), diffusion through the sodium boundary layer, equilibrium concentration of each element, and velocity of the interface (bulk corrosion or deposition). The code uses a numerical method for solving the diffusion equation in the steel and the complete mass balance in sodium for all elements. Corrosion and deposition rates are mainly determined by the iron equilibrium concentration in sodium and its oxygen-enhanced dissolution rate. All parameters of the model have been assessed from a literature review, but iron solubility had to be adjusted. A simplified primary system description of PHENIX French SFR was able to assess the correct amounts and profiles of contamination on heat exchanger surfaces for the main radionuclides.

  7. Chemical and mechanical control of corrosion product transport

    Energy Technology Data Exchange (ETDEWEB)

    Hede Larsen, O.; Blum, R. [I/S Fynsvaerket, Faelleskemikerne, Odense (Denmark); Daucik, K. [I/S Skaerbaekvaerket, Faelleskemikerne, Fredericia (Denmark)

    1996-12-01

    The corrosion products formed in the condensate and feedwater system of once-through boilers are precipitated and deposited inside the evaporator tubes mainly in the burner zone at the highest heat flux. Depositions lead to increased oxidation rate and increased metal temperature of the evaporator tubes, hereby decreasing tube lifetime. This effect is more important in the new high efficiency USC boilers due to increased feedwater temperature and hence higher thermal load on the evaporator tubes. The only way to reduce the load on the evaporator tubes is to minimise corrosion product transport to the boiler. Two general methods for minimising corrosion product transport to the boiler have been evaluated through measurement campaigns for Fe in the water/steam cycle in supercritical boilers within the ELSAM area. One method is to reduce corrosion in the low temperature condensate system by changing conditioning mode from alkaline volatile treatment (AVT) to oxygenated treatment (OT). The other method is to filtrate part of the condensate with a mechanical filter at the deaerator. The results show, that both methods are effective at minimising Fe-transport to the boiler, but changing to OT has the highest effect and should always be used, whenever high purity condensate is maintained. Whether mechanical filtration also is required, depends on the boiler, specifically the load on the evaporator. A simplified calculation model for lifetime evaluation of evaporator tubes has been developed. This model has been used for evaluating the effect of corrosion product transport to the boiler on evaporator tube lifetime. Conventional supercritical boilers generally can achieve sufficient lifetime by AVT and even better by OT, whereas all measures to reduce Fe-content of feedwater, including OT and mechanical filtration, should be taken, to ensure sufficient lifetime for the new boilers with advanced steam data - 290 bar/580 deg. C and above. (au)

  8. Positive aspects issued from bio corrosion studies: from hydrogen production to biofuel cells

    International Nuclear Information System (INIS)

    Silva Munoz, L. de

    2007-12-01

    Microbially influenced corrosion or bio corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio-films could play a major role in steel bio corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild pH conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase/glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

  9. Positive aspects issued from bio-corrosion studies: from hydrogen production to biofuel cells

    International Nuclear Information System (INIS)

    De Silva Munoz, Leonardo

    2007-01-01

    Microbially influenced corrosion or bio-corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio-corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio films could play a major role in steel bio-corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild ph conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase / glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author) [fr

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

    Science.gov (United States)

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

    2013-11-01

    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.

  11. 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

    This paper introduces a non-destructive test method to monitor the development of corrosion products as well as the corrosion-induced formation and propagation of cracks in cementitious materials. A parametric experimental investigation (utilizing x-ray attenuation measurement technique...

  12. Surface Treatment to Improve Corrosion Resistance in Lead-Alloy Coolants

    International Nuclear Information System (INIS)

    Todd R. Allen; Kumar Sridharan; McLean T. Machut; Lizhen Tan

    2007-01-01

    One of the six proposed advanced reactor designs of the Generation IV Initiative, the Lead-cooled Fast Reactor (LFR) possesses many characteristics that make it a desirable candidate for future nuclear energy production and responsible actinide management. These characteristics include favorable heat transfer, fluid dynamics, and neutronic performance compared to other candidate coolants. However, the use of a heavy liquid metal coolant presents a challenge for reactor designers in regards to reliable structural and fuel cladding materials in both a highly corrosive high temperature liquid metal and an intense radiation field. Flow corrosion studies at the University of Wisconsin have examined the corrosion performance of candidate materials for application in the LFR concept as well as the viability of various surface treatments to improve the materials compatibility. To date this research has included several focus areas, which include the formulation of an understanding of corrosion mechanisms and the examination of the effects of chemical and mechanical surface modifications on the materials performance in liquid lead-bismuth by experimental testing in Los Alamos National Laboratory's DELTA Loop, as well as comparison of experimental findings to numerical and physical models for long term corrosion prediction. This report will first review the literature and introduce the experiments and data that will be used to benchmark theoretical calculations. The experimental results will be followed by a brief review of the underlying theory and methodology for the physical and theoretical models. Finally, the results of theoretical calculations as well as experimentally obtained benchmarks and comparisons to the literature are presented

  13. Surface Treatment to Improve Corrosion Resistance in Lead-Alloy Coolants

    Energy Technology Data Exchange (ETDEWEB)

    Todd R. Allen; Kumar Sridharan; McLean T. Machut; Lizhen Tan

    2007-08-29

    One of the six proposed advanced reactor designs of the Generation IV Initiative, the Leadcooled Fast Reactor (LFR) possesses many characteristics that make it a desirable candidate for future nuclear energy production and responsible actinide management. These characteristics include favorable heat transfer, fluid dynamics, and neutronic performance compared to other candidate coolants. However, the use of a heavy liquid metal coolant presents a challenge for reactor designers in regards to reliable structural and fuel cladding materials in both a highly corrosive high temperature liquid metal and an intense radiation fieldi. Flow corrosion studies at the University of Wisconsin have examined the corrosion performance of candidate materials for application in the LFR concept as well as the viability of various surface treatments to improve the materials’ compatibility. To date this research has included several focus areas, which include the formulation of an understanding of corrosion mechanisms and the examination of the effects of chemical and mechanical surface modifications on the materials’ performance in liquid lead-bismuth by experimental testing in Los Alamos National Laboratory’s DELTA Loop, as well as comparison of experimental findings to numerical and physical models for long term corrosion prediction. This report will first review the literature and introduce the experiments and data that will be used to benchmark theoretical calculations. The experimental results will be followed by a brief review of the underlying theory and methodology for the physical and theoretical models. Finally, the results of theoretical calculations as well as experimentally obtained benchmarks and comparisons to the literature are presented.

  14. Method of neutralizing the corrosive surface of amine-cured epoxy resins

    Science.gov (United States)

    Lee, S. Y. (Inventor)

    1982-01-01

    The corrosive alkaline surface layer of an epoxy resin product formed by the curing of the epoxy with an aliphatic amine is eliminated by first applying a non-solvent to remove most or all of the free unreacted amine and then applying a layer of a chemical reagent to neutralize the unused amine or amine functional groups by forming a substituted urea. The surface then may be rinsed with acetone and then with alcohol. The non-solvent may be an alcohol. The neutralizing chemical reagent is a mono-isocyanate or a mono-isothiocyanate. Preferred is an aromatic mono-isocyanate such as phenyl isocyanate, nitrophenyl isocyanate and naplthyl isocyanate.

  15. Corrosion resistance of the welded AISI 316L after various surface treatments

    Directory of Open Access Journals (Sweden)

    Tatiana Liptáková

    2014-01-01

    Full Text Available The main aim of this work is to monitor the surface treatment impact on the corrosion resistance of the welded stainless steel AISI 316L to local corrosion forms. The excellent corrosion resistance of austenitic stainless steel is caused by the existence of stable, thin and well adhering passive layer which quality is strongly influenced by welding. Therefore surface treatment of stainless steel is very important with regard to its local corrosion susceptibility Surfaces of welded stainless steel were treated by various mechanical methods (grinding, garnet blasting. Surface properties were studied by SEM, corrosion resistance was evaluated after exposition tests in chlorides environment using weight and metalographic analysis. The experimental outcomes confirmed that the mechanical finishing has a significant effect on the corrosion behavior of welded stainless steel AISI 316L.

  16. Corrosion prevention of magnesium surfaces via surface conversion treatments using ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun; Luo, Huimin

    2016-09-06

    A method for conversion coating a magnesium-containing surface, the method comprising contacting the magnesium-containing surface with an ionic liquid compound under conditions that result in decomposition of the ionic liquid compound to produce a conversion coated magnesium-containing surface having a substantially improved corrosion resistance relative to the magnesium-containing surface before said conversion coating. Also described are the resulting conversion-coated magnesium-containing surface, as well as mechanical components and devices containing the conversion-coated magnesium-containing surface.

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

    Energy Technology Data Exchange (ETDEWEB)

    Videla, H.A.; Mele, M.F.L. de [Univ. of La Plata (Argentina). Dept. of Chemistry; Swords, C. [Univ. of Leeds (United Kingdom). School of Materials; Edyvean, R.G.J. [Univ. of Sheffield (United Kingdom). Dept. of Chemical and Processing Engineering; Beech, I.B. [Univ. of Portsmouth (United Kingdom). Dept. of Chemistry

    1999-11-01

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

  18. Comparison of surface fractal dimensions of chromizing coating and P110 steel for corrosion resistance estimation

    International Nuclear Information System (INIS)

    Lin, Naiming; Guo, Junwen; Xie, Faqin; Zou, Jiaojuan; Tian, Wei; Yao, Xiaofei; Zhang, Hongyan; Tang, Bin

    2014-01-01

    Highlights: • Continuous chromizing coating was synthesized on P110 steel by pack cementation. • The chromizing coating showed better corrosion resistance. • Comparison of surface fractal dimensions can estimate corrosion resistance. - Abstract: In the field of corrosion research, mass gain/loss, electrochemical tests and comparing the surface elemental distributions, phase constitutions as well as surface morphologies before and after corrosion are extensively applied to investigate the corrosion behavior or estimate the corrosion resistance of materials that operated in various environments. Most of the above methods are problem oriented, complex and longer-period time-consuming. However from an object oriented point of view, the corroded surfaces of materials often have self-similar characterization: fractal property which can be employed to efficiently achieve damaged surface analysis. The present work describes a strategy of comparison of the surface fractal dimensions for corrosion resistance estimation: chromizing coating was synthesized on P110 steel surface to improve its performance via pack cementation. Scanning electron microscope (SEM) was used to investigate the surface morphologies of the original and corroded samples. Surface fractal dimensions of the detected samples were calculated by binary images related to SEM images of surface morphologies with box counting algorithm method. The results showed that both surface morphologies and surface fractal dimensions of P110 steel varied greatly before and after corrosion test, but the chromizing coating changed slightly. The chromizing coating indicated better corrosion resistance than P110 steel. Comparison of surface fractal dimensions of original and corroded samples can rapidly and exactly realize the estimation of corrosion resistance

  19. Investigating longevity of corrosion inhibitors and performance of deicer products under storage or after pavement application.

    Science.gov (United States)

    2011-06-01

    This study evaluated the longevity of corrosion inhibitors and the performance of inhibited deicer products under storage or after pavement application. No significant degradation of corrosion inhibitor or loss of chlorides was seen during the months...

  20. Kinetics of corrosion products release from nickel-base alloys corroding in primary water conditions. A new modeling of release

    International Nuclear Information System (INIS)

    Carrette, F.; Guinard, L.; Pieraggi, B.

    2002-01-01

    The radioactivity in the primary circuit arises mainly from the activation of corrosion products in the core of pressurised water reactors; corrosion products dissolve from the oxide scales developed on steam generator tubes of alloy 690. The controlling and modelling of this process require a detailed knowledge of the microstructure and chemical composition of oxide scales as well as the kinetics of their corrosion and dissolution. Alloy 690 was studied as tubes and sheets, with three various surface states (as-received, cold-worked, electropolished). Corrosion tests were performed at 325 C and 155 bar in primary water conditions (B/Li - 1000/2 ppm, [H 2 ] 30 cm 3 .kg -1 TPN, [O 2 ] < 5 ppb); test durations ranged between 24 and 2160 hours. Corrosion tests in the TITANE loop provided mainly corrosion and oxidation kinetics, and tests in the BOREAL loop yielded release kinetics. This study revealed asymptotic type kinetics. Characterisation of the oxide scales grown in representative conditions of the primary circuit was performed by several techniques (SEM, TEM, SIMS, XPS, GIXRD). These analyses revealed the essential role of the fine grained cold-worked scale present on as-received and cold-worked materials. This scale controls the corrosion and release phenomena. The kinetic study and the characterisation of the oxide scales contributed to the modelling of the corrosion/release process. A growth/dissolution model was proposed for corrosion product scales grown in non-saturated dynamic fluid. This model provided the temporal evolution of oxide scales and release kinetics for different species (Fe, Ni, Cr). The model was validated for several surface states and several alloys. (authors)

  1. Complementary Methods for the Characterization of Corrosion Products on a Plant-Exposed Superheater Tube

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Nießen, Frank; Villa, Matteo

    2017-01-01

    In this work, complex corrosion products on a superheater tube exposed to biomass firing were characterized by the complementary use of energy-dispersive synchrotron diffraction, electron microscopy, and energy-dispersive X-ray spectroscopy. Non-destructive synchrotron diffraction in transmission......-rich austenite phase to selective removal of Fe and Cr from the alloy, via a KCl-induced corrosion mechanism. Compositional variations were related to diffraction results and revealed a qualitative influence of the spinel cation concentration on the observed diffraction lines.......In this work, complex corrosion products on a superheater tube exposed to biomass firing were characterized by the complementary use of energy-dispersive synchrotron diffraction, electron microscopy, and energy-dispersive X-ray spectroscopy. Non-destructive synchrotron diffraction in transmission...... geometry measuring with a small gauge volume from the sample surface through the corrosion product allowed depth-resolved phase identification and revealed the presence of (Fe,Cr)2O3 and FeCr2O4. This was supplemented by microstructural and elemental analysis correlating the additional presence of a Ni...

  2. Theme day: corrosion and surface treatments in nuclear facilities. Proceedings; Journee Thematique: Corrosion et Traitements de surface dans les Installations Nucleaires. Recueil des presentations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-02-15

    This document brings together the available presentations given at the theme day organized by the Bourgogne Nuclear Pole on the topic of corrosion and surface treatments in nuclear facilities. Eleven presentations (slides) are compiled in this document: 1 - Introduction - PNB centre of competitiveness and R and D activities (A. Mantovan, PNB); 2 - Corrosion damage (M. Foucault, Areva NP - Centre Technique Le Creusot); 3 - Corrosion mechanisms (R. Oltra, UB-ICB); 4 - Examples of expertise management (C. Duret-Thual, Institut de la corrosion/Corrosion Institute); 5 - General framework of surface treatments (C. Nouveau, ENSAM Cluny Paris Tech); 6 - Surfaces et interfaces characterisation - Part A (C. Langlade, Y. Gachon, UTBM and HEF); 7 - Surfaces et interfaces characterisation - Part B (C. Langlade, Y. Gachon, UTBM and HEF); 8 - Ion beam surface treatment (Y. Le Guellec, Quertech Ingenierie); 9 - Impact surface treatment (G. Saout, Sonats); 10 - Metal oxides Characterisation by US laser (R. Oltra, UB-ICB); 11 - Detection and Characterisation of intergranular corrosion (Y. Kernin, Stephane Bourgois, Areva Intercontrole)

  3. The effects of corrosion product colloids on actinide transport

    International Nuclear Information System (INIS)

    Gardiner, M.P.; Smith, A.J.; Williams, S.J.

    1991-11-01

    This report assesses the possible effects of colloidal corrosion products on the transport of actinides from the near field of radioactive waste repositories. The desorption of plutonium and americium from colloidal corrosion products of iron and zirconium was studied under conditions simulating a transition from near-field to far-field environmental conditions. Desorption of actinides occurred slowly from the colloids under far-field conditions. Measurements of particle stability showed all the colloids to be unstable in the near field. Stability increased under far-field conditions or as a result of the evolution of the near field. Migration of colloids from the near field is unlikely except in the presence of organic materials. (Author)

  4. Corrosive characteristics of surface-modified stainless steel bipolar plate in solid polymer fuel cell

    Science.gov (United States)

    Zhang, Xiaowen; Wang, Lixia; Sun, Juncai

    2015-03-01

    In this paper, corrosion behavior of an AISI 304 stainless steel modified by niobium or niobium nitride (denoted as niobized 304 SS and Nb-N 304 SS, respectively) is investigated in simulated solid polymer fuel cell (SPFC) operating conditions. Potentiodynamic polarizations show that the corrosion potentials of surface modified 304 SS shift to positive direction while the corrosion current densities decrease greatly comparing with the bare 304 SS in simulated anodic SPFC environments. The order of corrosive resistance in corrosive potential, corrosive current density and pitting potential is: Nb-N 304 SS > niobized 304 SS > bare 304 SS. In the methanol-fueled SPFC operating conditions, the results show that the corrosion resistance of bare and niobized 304 SS increases with the methanol concentration increasing in the test solutions.

  5. Solubility of corrosion products in high temperature water

    International Nuclear Information System (INIS)

    Srinivasan, M.P.; Narasimhan, S.V.

    1995-01-01

    A short review of solubility of corrosion products at high temperature in either neutral or alkaline water as encountered in BWR, PHWR and PWR primary coolant reactor circuits is presented in this report. Based on the available literature, various experimental techniques involved in the study of the solubility, theory for fitting the solubility data to the thermodynamic model and discussion of the published results with a scope for future work have been brought out. (author). 17 refs., 7 figs

  6. Surface aspects of pitting and stress corrosion cracking

    Science.gov (United States)

    Truhan, J. S., Jr.; Hehemann, R. F.

    1977-01-01

    The pitting and stress corrosion cracking of a stable austenitic stainless steel in aqueous chloride environments were investigated using a secondary ion mass spectrometer as the primary experimental technique. The surface concentration of hydrogen, oxygen, the hydroxide, and chloride ion, magnesium or sodium, chromium and nickel were measured as a function of potential in both aqueous sodium chloride and magnesium chloride environments at room temperature and boiling temperatures. It was found that, under anodic conditions, a sharp increase in the chloride concentration was observed to occur for all environmental conditions. The increase may be associated with the formation of an iron chloride complex. Higher localized chloride concentrations at pits and cracks were also detected with an electron microprobe.

  7. Allowing for surface preparation in stress corrosion cracking modelling

    International Nuclear Information System (INIS)

    Berge, P.; Buisine, D.; Gelpi, A.

    1997-01-01

    When a 600 alloy component is significantly deformed during installation, by welding, rolling, bending, its stress corrosion cracking in Pressurized Water Nuclear Reactor's primary coolant, is significantly changed by the initial surface treatment. Therefore, the crack initiated time may be reduced by several orders of magnitude for certain surfaces preparations. Allowing for cold working of the surface, for which modelling is proposed, depends less on the degree of cold work then on the depths of the hardened layers. Honing hardens the metal over depths of about one micron for vessel head penetrations, for example, and has little influence on subsequent behaviour after the part deforms. On the other hand, coarser turning treatment produces cold worked layers which can reach several tens of microns and can very significantly reduce the initiation time compared to fine honing. So evaluation after depths of hardening is vital on test pieces for interpreting laboratory results as well as on service components for estimating their service life. Suppression by mechanical or chemical treatment of these layers, after deformation, seems to be the most appropriate solution for reducing over-stressing connected with surface treatment carried out before deformation. (author)

  8. Corrosion products formed from marine environments: structural variables and corrosion potential vinculation

    International Nuclear Information System (INIS)

    Ohanian, M.; Caraballo, R.; Dalchiele, E. a.; Guineo-Cobs, G.; Martinez-Luaces, V.; Qauagliata, E.

    2005-01-01

    Structural and electrochemical analysis of rust formed from low alloy steel was performed. The samples, generated in the framework of MICAT project, were exposed in two marine environments: subtropical and sub polar Antarctic. the results suggested for formation of oxides and oxihidroxides of low crystallinity and poor protective properties. The evolution of the results is analyzed tacking to account the different environments. The electrochemical activity and phases concentration of corrosion products are analyzed by cluster diagrams with the objective of adjusting qualitative models. (Author)

  9. Electrochemical properties of corrosion products formed on Zn-Mg, Zn-Al and Zn-Al-Mg coatings in model atmospheric conditions

    Czech Academy of Sciences Publication Activity Database

    Stoulil, J.; Prošek, T.; Nazarov, A.; Oswald, Jiří; Kříž, P.; Thierry, D.

    2015-01-01

    Roč. 66, č. 8 (2015), s. 777-782 ISSN 0947-5117 Institutional support: RVO:68378271 Keywords : corrosion products * electrochemical properties * zinc coating Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.450, year: 2015

  10. Self-Assembled Films as Corrosion Protective Coatings for Metal Surfaces

    National Research Council Canada - National Science Library

    Robinson, Gary

    1996-01-01

    .... Monolayers of stearic acid on aluminum surfaces were found to profoundly affect the wettability of Al surfaces by concentrated sulfuric acid, but not to act as a significant barrier to corrosion...

  11. Influence of surface treatments on corrosion resistance of stainless steels. Residual stresses in metals

    International Nuclear Information System (INIS)

    Berge, J. Philippe

    1968-05-01

    In a first part, this research thesis proposes presentation of the definition of a surface condition: chemical characteristics such as passivity and contamination, physical characteristics (obtained through micrographic methods, X ray diffusion, magnetic methods), and micro-geometrical characteristics. The author notably discusses the measurement of characteristics either by appropriate conventional methods or by an original method in the case of passivity. In a second part, the author reports the study of the influence of surface condition on different types of corrosion of stainless steels in chemical environments (corrosion in sulphuric acid, intergranular corrosion, stress corrosion cracking in magnesium chloride, pitting corrosion) and of high temperature oxidation (corrosion in pressurized water, oxidation in dry vapour or in carbon dioxide)

  12. Biodegradable magnesium alloys for orthopaedic applications: A review on corrosion, biocompatibility and surface modifications

    International Nuclear Information System (INIS)

    Agarwal, Sankalp; Curtin, James; Duffy, Brendan; Jaiswal, Swarna

    2016-01-01

    Magnesium (Mg) and its alloys have been extensively explored as potential biodegradable implant materials for orthopaedic applications (e.g. Fracture fixation). However, the rapid corrosion of Mg based alloys in physiological conditions has delayed their introduction for therapeutic applications to date. The present review focuses on corrosion, biocompatibility and surface modifications of biodegradable Mg alloys for orthopaedic applications. Initially, the corrosion behaviour of Mg alloys and the effect of alloying elements on corrosion and biocompatibility is discussed. Furthermore, the influence of polymeric deposit coatings, namely sol-gel, synthetic aliphatic polyesters and natural polymers on corrosion and biological performance of Mg and its alloy for orthopaedic applications are presented. It was found that inclusion of alloying elements such as Al, Mn, Ca, Zn and rare earth elements provides improved corrosion resistance to Mg alloys. It has been also observed that sol-gel and synthetic aliphatic polyesters based coatings exhibit improved corrosion resistance as compared to natural polymers, which has higher biocompatibility due to their biomimetic nature. It is concluded that, surface modification is a promising approach to improve the performance of Mg-based biomaterials for orthopaedic applications. - Highlights: • The Mg based alloys are promising candidates for orthopaedic applications. • The rapid corrosion of Mg can affect human cells, and causes infection and implant failure. • The various physiological factors and Mg alloying elements affect the corrosion and mechanical properties of implants. • The polymeric deposit coatings enhance the corrosion resistance and biocompatibility.

  13. Influence of surface roughness of stainless steel on microbial adhesion and corrosion resistance

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Bagge-Ravn, Dorthe; Kold, John

    2003-01-01

    was evaluated in a commercial disinfectant and in 1 M NaCl. Electropolished and grit 4000 polished steel proved more corrosion resistant as opposed to grit 80 and 120 polished surfaces. In conclusion, the surface finish did not influence bacterial attachment, colonisation, or removal, but is an important...... was not affected by surface roughness (Ra) ranging from grit 4000 polished stainless steel (Ra resistance...... parameter for the corrosion resistance of the surface....

  14. Assessment of caffeine adsorption onto mild steel surface as an eco-friendly corrosion inhibitor

    OpenAIRE

    Souza, Fernando S. de; Gonçalves, Reinaldo S.; Spinelli, Almir

    2014-01-01

    The adsorption and corrosion-inhibition properties of caffeine as an eco-friendly corrosion inhibitor for mild steel in acid medium were investigated by electrochemical and spectroscopic techniques. Polarization experiments indicated that caffeine behaves as a cathodic-type inhibitor. Impedance data showed that surface coverage increased with caffeine concentration in the range of 1.0 to 10.0 mmol L-1. The maximum inhibition efficiency obtained was 92.4%. The adsorption of the corrosion inhib...

  15. Surface modification to improve fireside corrosion resistance of Fe-Cr ferritic steels

    Science.gov (United States)

    Park, Jong-Hee; Natesan, Krishnamurti; Rink, David L.

    2010-03-16

    An article of manufacture and a method for providing an Fe--Cr ferritic steel article of manufacture having a surface layer modification for corrosion resistance. Fe--Cr ferritic steels can be modified to enhance their corrosion resistance to liquid coal ash and other chemical environments, which have chlorides or sulfates containing active species. The steel is modified to form an aluminide/silicide passivating layer to reduce such corrosion.

  16. Influence of the surface finishing on the corrosion behaviour of AISI 316L stainless steel

    Czech Academy of Sciences Publication Activity Database

    Dundeková, S.; Zatkalíková, V.; Fintová, Stanislava; Hadzima, B.; Škorík, Viktor

    2015-01-01

    Roč. 22, č. 1 (2015), s. 48-53 ISSN 1335-0803 R&D Projects: GA MŠk(CZ) EE2.3.30.0063 Institutional support: RVO:68081723 Keywords : AISI 316L stainless steel * Corrosion * Immersion test * Corrosion rate Subject RIV: JK - Corrosion ; Surface Treatment of Materials http://ojs.mateng.sk/index.php/Mateng/article/view/166/251

  17. Influence of pipe material and surfaces on sulfide related odor and corrosion in sewers.

    Science.gov (United States)

    Nielsen, Asbjørn Haaning; Vollertsen, Jes; Jensen, Henriette Stokbro; Wium-Andersen, Tove; Hvitved-Jacobsen, Thorkild

    2008-09-01

    Hydrogen sulfide oxidation on sewer pipe surfaces was investigated in a pilot scale experimental setup. The experiments were aimed at replicating conditions in a gravity sewer located immediately downstream of a force main where sulfide related concrete corrosion and odor is often observed. During the experiments, hydrogen sulfide gas was injected intermittently into the headspace of partially filled concrete and plastic (PVC and HDPE) sewer pipes in concentrations of approximately 1,000 ppm(v). Between each injection, the hydrogen sulfide concentration was monitored while it decreased because of adsorption and subsequent oxidation on the pipe surfaces. The experiments showed that the rate of hydrogen sulfide oxidation was approximately two orders of magnitude faster on the concrete pipe surfaces than on the plastic pipe surfaces. Removal of the layer of reaction (corrosion) products from the concrete pipes was found to reduce the rate of hydrogen sulfide oxidation significantly. However, the rate of sulfide oxidation was restored to its background level within 10-20 days. A similar treatment had no observable effect on hydrogen sulfide removal in the plastic pipe reactors. The experimental results were used to model hydrogen sulfide oxidation under field conditions. This showed that the gas-phase hydrogen sulfide concentration in concrete sewers would typically amount to a few percent of the equilibrium concentration calculated from Henry's law. In the plastic pipe sewers, significantly higher concentrations were predicted because of the slower adsorption and oxidation kinetics on such surfaces.

  18. 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)

  19. Biodegradation of corrosion inhibitors and their influence on petroleum product pipeline.

    Science.gov (United States)

    Rajasekar, Aruliah; Maruthamuthu, Sundaram; Palaniswamy, Narayanan; Rajendran, Annamalai

    2007-01-01

    The present study enlightens the role of Bacillus cereus ACE4 on biodegradation of commercial corrosion inhibitors (CCI) and the corrosion process on API 5LX steel. Bacillus cereus ACE4, a dominant facultative aerobic species was identified by 16S rDNA sequence analysis, which was isolated from the corrosion products of refined diesel-transporting pipeline in North West India. The effect of CCI on the growth of bacterium and its corrosion inhibition efficiency were investigated. Corrosion inhibition efficiency was studied by rotating cage test and the nature of biodegradation of corrosion inhibitors was also analyzed. This isolate has the capacity to degrade the aromatic and aliphatic hydrocarbon present in the corrosion inhibitors. The degraded products of corrosion inhibitors and bacterial activity determine the electrochemical behavior of API 5LX steel.

  20. Fission and corrosion products behavior in primary circuits of LMFBR's

    International Nuclear Information System (INIS)

    Feuerstein, H.; Thorley, A.W.

    1987-08-01

    Most of the 20 presented papers report items belonging to more than one session. The equipment results of primary circuits of LMFBR's relative to corrosion and fission products, release and chemistry of fuel, measurement techniques and analytical procedures of sodium sampling, difficulties with radionuclides and particles, reactor experiences with EBR-II, FFTF, BR10, BOR60, BN350, BN600, JOYO, and KNK-II, DFR, PFR, RAPSODIE, PHENIX, and SUPERPHENIX, and at least the verification of codes for calculation models of radioactive products accumulation and distribution are described. All 20 papers presented at the meeting are separately indexed in the database. (DG)

  1. Effect of La surface treatments on corrosion resistance of A3xx.x/SiCp composites in salt fog

    International Nuclear Information System (INIS)

    Pardo, A.; Merino, M.C.; Arrabal, R.; Merino, S.; Viejo, F.; Coy, A.E.

    2006-01-01

    The influence of the SiC p proportion and the matrix concentration of four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) modified by lanthanum-based conversion or electrolysis coating was evaluated in neutral salt fog according to ASTM B 117. Lanthanum-based conversion coatings were obtained by immersion in 50 deg. C solution of La(III) salt and lanthanum electrolysis treatments were performed in ethylene glycol mono-butyl ether solution. These treatments preferentially covered cathodic areas such as intermetallic compounds, Si eutectic and SiC p . The kinetic of the corrosion process was studied on the basis of gravimetric tests. Both coating microstructure and nature of corrosion products were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDS) and low angle X-ray diffraction (XRD) before and after accelerated testing to determine the influence of microstructural changes on corrosion behaviour during exposure to the corrosive environment. The corrosion process was more influenced by the concentration of alloy elements in the matrix than by the proportion of SiC p reinforcement. Both conversion and electrolysis surface treatments improved the behaviour to salt fog corrosion in comparison with original composites without treatment. Additionally, electrolysis provided a higher degree of protection than the conversion treatment because the coating was more extensive

  2. 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......-induced damage of concrete, typically by monitoring and quantifying the formation of cracks in concrete surrounding corroding reinforcement. Based on the type of experimental data numerous corrosion-induced damage models have been developed. One common conclusion from these models is that a certain amount...... 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...

  3. Corrosion resistance of the AISI 304, 316 and 321 stainless steel surfaces modified by laser

    Science.gov (United States)

    Szubzda, B.; Antończak, A.; Kozioł, P.; Łazarek, Ł.; Stępak, B.; Łęcka, K.; Szmaja, A.; Ozimek, M.

    2016-02-01

    The article presents the analysis results of the influence of laser fluence on physical and chemical structure and corrosion resistance of stainless steel surfaces modified by irradiating with nanosecond-pulsed laser. The study was carried out for AISI 304, AISI 316 and AISI 321 substrates using Yb:glass fiber laser. All measurements were made for samples irradiated in a broad range of accumulated fluence (10÷400 J/cm2). The electrochemical composition (by EDX) and surface morphology (by SEM) of the prepared surfaces were carried out. Finally, corrosion resistance was analyzed by a potentiodynamic electrochemical test. The obtained results showed very high corrosion resistance for samples made by fluency of values lower than 100 J/cm2. In this case, higher values of corrosion potentials and breakdown potentials were observed. A correlation between corrosion phenomena, the range of laser power (fluence) and the results of chemical and structural tests were also found.

  4. Influence of the surface finishing on electrochemical corrosion characteristics of AISI 316L stainless steel

    Czech Academy of Sciences Publication Activity Database

    Dundeková, S.; Hadzima, B.; Fintová, Stanislava

    2015-01-01

    Roč. 22, č. 2 (2015), s. 77-84 ISSN 1335-0803 Institutional support: RVO:68081723 Keywords : AISI 316L stainless steel * EIS * Corrosion Subject RIV: JK - Corrosion ; Surface Treatment of Materials http://ojs.mateng.sk/index.php/Mateng/article/view/167/278

  5. Surface Modelling of Nanostructured Copper Subjected to Erosion-Corrosion

    Directory of Open Access Journals (Sweden)

    Osama M. Irfan

    2017-04-01

    Full Text Available The last decade has witnessed considerable advancements in nanostructured material synthesis and property characterization. However, there still exists some deficiency in the mechanical and surface property characterization of these materials. In this paper, the erosion corrosion (E-C behavior of nanostructured copper was studied. The nanostructured copper was produced through severe plastic deformation (SPD by applying four passes of equal channel angular pressing (ECAP. The combined effects of the testing time, impact velocity, and concentration of erosive solid particles (i.e., sand concentration on the E-C behavior of nanostructured copper were then examined. Based on a defined domain for the testing time, impact velocity, and sand concentration, E-C tests were performed for numerous combinations of test points via the slurry pot method. The test points were selected using the face-centered center composite design of experiments to enable visualization of the test results through surface plots. The extent of E-C on the test specimens was determined by measuring the mass loss. Polynomial regression and Kriging were used to fit surfaces to the experimental data, which were subsequently used to generate surface plots. The results showed that the E-C of nanostructured copper is best described by a quadratic function of testing time, velocity, and erosive solid particle concentration. The results also revealed that E-C increases with an increasing testing time, impact velocity, and erosive solid particle concentration. In addition, it was observed that the effect of the erosive solid particles on E-C is further intensified by an increased impact velocity.

  6. Characterization of uranium corrosion products involved in the March 13, 1998 fuel manufacturing facility pyrophoric event

    International Nuclear Information System (INIS)

    Totemeier, T.C.

    1999-01-01

    Uranium metal corrosion products from ZPPR fuel plates involved in the March 13, 1998 pyrophoric event in the Fuel Manufacturing Facility at Argonne National Laboratory-West were characterized using thermo-gravimetric analysis, X-ray diffraction, and BET gas sorption techniques. Characterization was performed on corrosion products in several different conditions: immediately after separation from the source metal, after low-temperature passivation, after passivation and extended vault storage, and after burning in the pyrophoric event. The ignition temperatures and hydride fractions of the corrosion product were strongly dependent on corrosion extent. Corrosion products from plates with corrosion extents less than 0.7% did not ignite in TGA testing, while products from plates with corrosion extents greater than 1.2% consistently ignited. Corrosion extent is defined as mass of corrosion products divided by the total mass of uranium. The hydride fraction increased with corrosion extent. There was little change in corrosion product properties after low-temperature passivation or vault storage. The burned products were not reactive and contained no hydride; the principal constituents were UO 2 and U 3 O 7 . The source of the event was a considerable quantity of reactive hydride present in the corrosion products. No specific ignition mechanism could be conclusively identified. The most likely initiator was a static discharge in the corrosion product from the 14th can as it was poured into the consolidation can. The available evidence does not support scenarios in which the powder in the consolidation can slowly self-heated to the ignition point, or in which the powder in the 14th can was improperly passivated

  7. Characterization of uranium corrosion products involved in the March 13, 1998 fuel manufacturing facility pyrophoric event.

    Energy Technology Data Exchange (ETDEWEB)

    Totemeier, T.C.

    1999-04-26

    Uranium metal corrosion products from ZPPR fuel plates involved in the March 13, 1998 pyrophoric event in the Fuel Manufacturing Facility at Argonne National Laboratory-West were characterized using thermo-gravimetric analysis, X-ray diffraction, and BET gas sorption techniques. Characterization was performed on corrosion products in several different conditions: immediately after separation from the source metal, after low-temperature passivation, after passivation and extended vault storage, and after burning in the pyrophoric event. The ignition temperatures and hydride fractions of the corrosion product were strongly dependent on corrosion extent. Corrosion products from plates with corrosion extents less than 0.7% did not ignite in TGA testing, while products from plates with corrosion extents greater than 1.2% consistently ignited. Corrosion extent is defined as mass of corrosion products divided by the total mass of uranium. The hydride fraction increased with corrosion extent. There was little change in corrosion product properties after low-temperature passivation or vault storage. The burned products were not reactive and contained no hydride; the principal constituents were UO{sub 2} and U{sub 3}O{sub 7}. The source of the event was a considerable quantity of reactive hydride present in the corrosion products. No specific ignition mechanism could be conclusively identified. The most likely initiator was a static discharge in the corrosion product from the 14th can as it was poured into the consolidation can. The available evidence does not support scenarios in which the powder in the consolidation can slowly self-heated to the ignition point, or in which the powder in the 14th can was improperly passivated.

  8. Contribution to the Study of Effects of Surface State of Welded Joints in Stainless Steel Upon Resistance Towards Pitting Corrosion

    Directory of Open Access Journals (Sweden)

    Juraga, I.

    2007-01-01

    Full Text Available Successful corrosion resistance of stainless steels is based on their natural ability of passivation, i.e. formation of film of chromium oxides that prevents corrosion in many environments. Any nonuniformity of surface layers may be initial spot for corrosion processes and damages. In this contribution, beside real corrosion damages occurred in practice, results of testing of pitting corrosion resistance of weld beads made applying TIG process on AISI 316L steel grade are presented. SEM and EDX testing, as well as electrochemical corrosion testing confirmed adverse effects of heat tints zones upon corrosion resistance of stainless steels.

  9. The mechanisms underlying corrosion product formation and deposition in nuclear power plant circuits through the action of galvanic and thermal electromotive forces

    International Nuclear Information System (INIS)

    Brusakov, V.P.; Sedov, V.M.; Khitrov, Yu.A.; Brusov, K.N.; Razmashkin, N.V.; Versin, V.V.; Rybalchenko, I.L.

    1983-01-01

    From a theoretical standpoint, the processes of formation of corrosion products in nuclear power plant circuits, deposition of corrosion products on the circuit surfaces, formation of an equilibrium concentration of corrosion products in the coolant, and distribution of radionuclides resulting from corrosion in different parts of the circuit are considered. It is shown that the main driving forces for the mass-transfer processes in the circuits are the thermal and galvanic electromotive forces (EMF) of the microcouples. On the basis of the theoretical concepts developed the authors have obtained analytical dependences for calculating the individual stages of the process of corrosion product transfer in the circuits. The mechanisms underlying the processes which occur as a result of thermal and galvanic EMFs are considered, together with the factors influencing these processes. The results of verification of the dependences by computational methods are given and they are compared with operational data from nuclear and conventional thermal power plants and with experimental data. (author)

  10. Experimental Investigation of the Corrosion Behavior of Friction Stir Welded AZ61A Magnesium Alloy Welds under Salt Spray Corrosion Test and Galvanic Corrosion Test Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    A. Dhanapal

    2013-01-01

    Full Text Available Extruded Mg alloy plates of 6 mm thick of AZ61A grade were butt welded using advanced welding process and friction stir welding (FSW processes. The specimens were exposed to salt spray conditions and immersion conditions to characterize their corrosion rates on the effect of pH value, chloride ion concentration, and corrosion time. In addition, an attempt was made to develop an empirical relationship to predict the corrosion rate of FSW welds in salt spray corrosion test and galvanic corrosion test using design of experiments. The corrosion morphology and the pit morphology were analyzed by optical microscopy, and the corrosion products were examined using scanning electron microscope and X-ray diffraction analysis. From this research work, it is found that, in both corrosion tests, the corrosion rate decreases with the increase in pH value, the decrease in chloride ion concentration, and a higher corrosion time. The results show the usage of the magnesium alloy for best environments and suitable applications from the aforementioned conditions. Also, it is found that AZ61A magnesium alloy welds possess low-corrosion rate and higher-corrosion resistance in the galvanic corrosion test than in the salt spray corrosion test.

  11. Technical investigation of a pyrophoric event involving corrosion products from HEU ZPPR fuel plates

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    2000-01-01

    A pyrophoric event recently occurred which involved corrosion products collected from highly-enriched uranium (HEU) fuel plates used in the Zero Power Physics Reactor (ZPPR). This paper summarizes the event and its background, and presents the results of an investigation into its source and mechanism. The investigation focused on characterization of corrosion product samples similar to those involved in the event using thermo-gravimetric analysis (TGA). Burning curve TGA tests were performed to measure the ignition temperature and hydride fractions of corrosion products in several different conditions to assess the effects of passivation treatment and long-term storage on chemical reactivity. The hydride fraction and ignition temperature of the corrosion products were found to be strongly dependent on the corrosion extent of the source metal. The results indicate that the energy source for the event was a considerable quantity of uranium hydride present in the corrosion products, but the specific ignition mechanism could not be identified

  12. Emeraldine base as corrosion protective layer on aluminium alloy AA5182, effect of the surface microstructure

    DEFF Research Database (Denmark)

    Cecchetto, L; Ambat, Rajan; Davenport, A.J.

    2007-01-01

    AA5182 aluminium alloy cold rolled samples were coated by thin Wlms of emeraldine base (EB) obtained from a 5% solution in N-methylpyrrolidinone. Accelerated corrosion tests prove this coating very eVective for corrosion protection of aluminium alloys in neutral environment. This study underlines...... the prominent role of surface cathodic intermetallic particles in pit initiation and coating break down in enhanced corrosion conditions and suggest that, beside the EB barrier properties, the enhanced corrosion resistance observed on the EB coated samples could partly arise from two other mains factors......: • a weak redox activity of the polymer which passivate the metal, • a proton involving self-healing process taking place at the polymer–metal interface, which contributes to delay local acidiWcation in Wrst steps of corrosion on EB coated aluminium surfaces....

  13. Corrosion properties of sealing surface material for RPV under abnormal working conditions

    International Nuclear Information System (INIS)

    Liu Jinhua; Wen Yan; Zhang Xuemei; Hou Songmin; Gong Bin; He Yanchun

    2012-01-01

    Based on the corrosion issue of sealing surface material for RPV in some nuclear projects, the corrosion properties of sealing surface material for RPV under abnormal working conditions were investigated. The corrosion behavior of 308L stainless steel were studied by using autoclave in different contents of Cl - solutions, and these samples were observed and analyzed by means of the metalloscope and Scanning electron microscope (SEM). Results show that no pitting, crevice and stress corrosion occurred, when the content of Cl - was lower than 1 mg/L at the temperatures of 270℃ and the pressure of 5.5 MPa. However, with the increase of the content of Cl - , the susceptibility to pitting, crevice and stress corrosion of 308L was enhanced remarkably. (authors)

  14. Emeraldine base as corrosion protective layer on aluminium alloy AA5182, effect of the surface microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Cecchetto, L. [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, CNRS-UJF-INP-Grenoble (UMR 5631), ENSEEG, BP 75, 38402 St. Martin d' Heres (France); Ambat, R. [School of Engineering Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Davenport, A.J. [School of Engineering Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Delabouglise, D. [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, CNRS-UJF-INP-Grenoble (UMR 5631), ENSEEG, BP 75, 38402 St. Martin d' Heres (France)]. E-mail: Didier.Delabouglise@lepmi.inpg.fr; Petit, J.-P. [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, CNRS-UJF-INP-Grenoble (UMR 5631), ENSEEG, BP 75, 38402 St. Martin d' Heres (France); Neel, O. [Centre de Recherche de Voreppe, Pechiney, Parc economique Centr' Alp, 38340 Voreppe (France)

    2007-02-15

    AA5182 aluminium alloy cold rolled samples were coated by thin films of emeraldine base (EB) obtained from a 5% solution in N-methylpyrrolidinone. Accelerated corrosion tests prove this coating very effective for corrosion protection of aluminium alloys in neutral environment. This study underlines the prominent role of surface cathodic intermetallic particles in pit initiation and coating break down in enhanced corrosion conditions and suggest that, beside the EB barrier properties, the enhanced corrosion resistance observed on the EB coated samples could partly arise from two other mains factors:- a weak redox activity of the polymer which passivate the metal, - a proton involving self-healing process taking place at the polymer-metal interface, which contributes to delay local acidification in first steps of corrosion on EB coated aluminium surfaces.

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

    Science.gov (United States)

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

    2013-05-21

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

  16. Effect of Rare Earth on Corrosion Products and Impedance Behavior of AZ91 Magnesium Alloy Under Dry-wet Cycles

    Directory of Open Access Journals (Sweden)

    ZHAO Xi

    2017-04-01

    Full Text Available The effect of mischmetal of lanthanum and cerium on the composition and structure of the corrosion products on the surface of AZ91 Mg alloy in deicing salt solution under dry-wet cycles was investigated by scanning electron microscopy (SEM, X-ray diffraction (XRD and energy dispersive spectrometer (EDS. The results show that the corrosion products of AZ91 Mg alloy without mischmetal addition (La,Ce are mainly composed of Mg(OH2, MgO, CaCO3 and Mg6Al2CO3(OH16·4H2O; and (La,CeAlO3 can be found in the products of AZ91 with mischmetal addition, meanwhile dense layer occurs in the corrosion products. Electrochemical impedance spectroscopy (EIS measurements show that the charge transfer resistance of AZ91 alloy with mischmetal addition tested in the same dry-wet cycles is much higher than that of AZ91 alloy, the addition of mischmetal helps to reduce the dispersing effect of impedance spectroscopy, indicating that the corrosion resistance of AZ91 Mg alloy and the stability of corrosion product films can be improved by mischmetal of La and Ce.

  17. The transition of corrosion pitting to surface fatigue cracks in 2024-T3 aluminum alloy

    Science.gov (United States)

    Clark, Paul Nolan

    Pitting corrosion experiments were executed to characterize the dynamics. of accelerated corrosion for the combination of 2024-T3 aluminum and a 3.5% NaCl solution at room temperature. Platinum was used as a counter electrode and a silver-silver chloride electrode was used as a reference. A corrosion protocol was developed to accelerate pitting corrosion on 2024-T3 aluminum. The developed protocol allowed for the relative control of pitting depth on fatigue dog-bone specimens. A pitting damage threshold was encountered for depths beyond an average value of approximately 135mum. Corrosion fatigue experiments were performed on specimens that had been prior corroded using the developed corrosion protocol. Pitting depths from approximately 40mum-200mum were examined for fatigue characterization. Corrosion pitting to surface fatigue crack transition was captured and fatigue crack growth behavior was documented. As well as the pit to crack transition, the short crack behavior to long crack behavior transition was captured and analyzed. Fractographic analysis of corrosion fatigue specimens revealed cracks nucleating, propagating and causing subsequent failure from accelerated prior pitting corrosion damage.

  18. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    International Nuclear Information System (INIS)

    Totemeier, T.C.; Pahl, R.G.; Frank, S.M.

    1998-01-01

    The oxidation behavior of hydride-bearing uranium metal corrosion products from zero power physics reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2 , Ar-9%O 2 , and Ar-20%O 2 . Ignition of corrosion product samples from two moderately corroded plates was observed between 125 C and 150 C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride. (orig.)

  19. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    Science.gov (United States)

    Totemeier, Terry C.; Pahl, Robert G.; Frank, Steven M.

    The oxidation behavior of hydride-bearing uranium metal corrosion products from Zero Power Physics Reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2, Ar-9%O 2, and Ar-20%O 2. Ignition of corrosion product samples from two moderately corroded plates was observed between 125°C and 150°C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride.

  20. The effect of corrosion product colloids on actinide transport

    International Nuclear Information System (INIS)

    Gardiner, M.P.; Smith, A.J.; Williams, S.J.

    1992-01-01

    The near field of the proposed UK repository for ILW/LLW will contain containers of conditioned waste in contact with a cementious backfill. It will contain significant quantities of iron and steel, Magnox and Zircaloy. Colloids deriving from their corrosion products may possess significant sorption capacity for radioelements. If the colloids are mobile in the groundwater flow, they could act as a significant vector for activity transport into the far field. The desorption of plutonium and americium from colloidal corrosion products of iron and zirconium has been studied under chemical conditions representing the transition from the near field to the far field. Desorption R d values of ≥ 5 x 10 6 ml g -1 were measured for both actinides on these oxides and hydroxides when actinide sorption took place under the near-field conditions and desorption took place under the far-field conditions. Desorption of the actinides occurred slowly from the colloids under far-field conditions when the colloids had low loadings of actinide and more quickly at high loadings of actinide. Desorbed actinide was lost to the walls of the experimental vessel. (author)

  1. Influence of surface treatment on the crevice corrosion of super duplex stainless steel

    International Nuclear Information System (INIS)

    Malik, H.

    1997-01-01

    The aim of this work was to try and discover if changes i surface condition, derived through various methods could influence the resistance to crevice corrosion of super duplex stainless teel (SDS). Such data could then be employed to elucidate the main factors controlling crevice corrosion. Through the manipulation of these parameters it was envisaged that the crevice corrosion temperature of this material may be further advanced and to increase its application within harsher industrial environments. For this reason a series of crevice tests were performed on SDSS heat exchanger tubing both in the as received condition and after various surface treatments. Such modification was carried out by; shot blasting, passivation, pickling and combinations of annealing, shot blasting, pickling and passivation. Results have indicated that the main factor controlling the resistance to crevice corrosion is the level of Cr depletion within a few microns of the steel surface. Although various treatments such as shot blasting and pickling reduce Cr depletion by removal of surface material, the nature of the surface finish itself was not found to affect the corrosion resistance. An increase in Cr content from 20 to 25% within 2 microns of the surface of the tubing was able to increase the crevice corrosion temperature by 20 sub deg. C. (author)

  2. Effect of Surface Modification on Corrosion Resistance of Uncoated and DLC Coated Stainless Steel Surface

    Science.gov (United States)

    Scendo, Mieczyslaw; Staszewska-Samson, Katarzyna

    2017-08-01

    Corrosion resistance of 4H13 stainless steel (EN-X46Cr13) surface uncoated and coated with an amorphous hydrogenated carbon (a-C:H) film [diamond-like carbon (DLC)] in acidic chloride solution was investigated. The DLC films were deposited on steel surface by a plasma deposition, direct current discharge (PDCD) method. The Fourier transform infrared (FTIR) was used to determine the chemical groups existing on DLC films. The surface of the specimens was observed by a scanning electron microscope (SEM). The tribological properties of the both materials were examined using a ball-on disk tribometer. The microhardness (HV) of diamond-like carbon film increased over five times in relation to the 4H13 stainless steel without of DLC coating. Oxidation kinetic parameters were determined by gravimetric and electrochemical methods. The high value of polarization resistance indicates that the DLC film on substrate was characterized by low electrical conductivity. The corrosion rate of 4H13 stainless steel with of DLC film decreased about eight times in relation to uncoated surface of 4H13 stainless steel.

  3. The effect of surface treatment and position of the dental restoration on amalgam corrosion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Mortazavi, V. [Isfahan Univ. of Medical Sciences, Faculty of Dentistry, Isfahan (Iran, Islamic Republic of); Fathi, M.H. [Isfahan Univ. of Technology, Materials Engineering Dept., Isfahan (Iran, Islamic Republic of)

    2003-07-01

    The aim of this research was to evaluate the effect of surface treatment, clinical operations and the condition and position of the dental restoration on amalgam corrosion behavior. Commercial amalgam alloy namely Oralloy was selected. Twenty-one amalgam samples were prepared. After triturating and condensation, the samples were divided into three groups and each group was finished by using one of three surface clinical procedures; carving, carving-burnishing, carving-burnishing-polishing. A special cylindrical mold was used in order to simulation of the interproximal areas and proximal surfaces of the dental restorations. Stainless steel matrix band was laid on the internal mold surfaces and amalgam paste was compacted in the mold. Electrochemical potentiodynamic tests were performed at a temperature of 37{+-}1 {sup o}C in physiological solution in order to determine and compare the corrosion behavior of dental amalgam samples, as an indication of biocompatibility. The results showed statistically significant differences between the mean corrosion current density values of three different groups of dental amalgam (P<0.05). The polished group possesses the lowest and the carved group shows the highest corrosion current density. The carved group shows more corrosion resistance in compare with the sample near the matrix band as an index of the proximal surfaces of restorations. It was concluded that even a simple clinical operation could effect on dental amalgam corrosion resistance. The proximal surfaces of the class II restorations are not only susceptible to concentration cell corrosion but also possess less corrosion resistance because dentist could perform no clinical surface treatment. (author)

  4. Electrochemical Characterisation of Filiform Corrosion on Aluminium Rolled Products

    NARCIS (Netherlands)

    Huisert, M.

    2001-01-01

    When aluminium is protected by an organic coating a special form of corrosion can occur underneath the organic coating; filiform corrosion. This form of corrosion manifests itself as threadlike filaments under the coating, it causes local delamination of the coating and the coating cannot protect

  5. Corrosion and anticorrosion. Industrial practice

    International Nuclear Information System (INIS)

    Beranger, G.; Mazille, H.

    2002-01-01

    This book comprises 14 chapters written with the collaboration of about 50 French experts of corrosion. It is complementary to another volume entitled 'corrosion of metals and alloys' and published by the same editor. This volume comprises two parts: part 1 presents the basic notions of corrosion phenomena, the properties of surfaces, the electrochemical properties of corrosion etc.. Part 2 describes the most frequent forms of corrosion encountered in industrial environments and corresponding to specific problems of protection: marine environment, atmospheric corrosion, galvanic corrosion, tribo-corrosion, stress corrosion etc.. The first 8 chapters (part 1) treat of the corrosion problems encountered in different industries and processes: oil and gas production, chemical industry, phosphoric acid industry, PWR-type power plants, corrosion of automobile vehicles, civil engineering and buildings, corrosion of biomaterials, non-destructive testing for the monitoring of corrosion. The other chapters (part 2) deal with anticorrosion and protective coatings and means: choice of materials, coatings and surface treatments, thick organic coatings and enamels, paints, corrosion inhibitors and cathodic protection. (J.S.)

  6. 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...... deformations were compared to a numerical corrosion model that considers electrochemical, transport, and mechanical processes, including penetration of corrosion products into a ‘corrosion-accommodating region,’ provided by the mortar’s capillary porosity, directly surrounding the steel. Comparing model...

  7. Plasma surface tantalum alloying on titanium and its corrosion behavior in sulfuric acid and hydrochloric acid

    Science.gov (United States)

    Wei, D. B.; Chen, X. H.; Zhang, P. Z.; Ding, F.; Li, F. K.; Yao, Z. J.

    2018-05-01

    An anti-corrosion Ti-Ta alloy coating was prepared on pure titanium surface by double glow plasma surface alloying technology. Electrochemical corrosion test was applied to test the anti-corrosion property of Ti-Ta alloy layer. The microstructure and the phase composition of Ti-Ta alloy coating were detected before and after corrosion process by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The results showed that the Ta-Ti alloy layer has a thickness of about 13-15 μm, which is very dense without obvious defects such as pores or cracks. The alloy layer is composed mainly of β-Ta and α-Ti. The Ta alloy layer improves the anti-corrosion property of pure titanium. A denser and more durable TiO2 formed on the surface Ta-Ti alloy layer after immersing in strong corrosive media may account for the excellent corrosion resistant.

  8. Development of corrosion resistant surfaces via friction stir processing for bio implant applications

    Science.gov (United States)

    Pal Singh Sodhi, Gurvinder; Singh, Harpreet

    2018-01-01

    Current investigation presents the use of Friction Stir Processing (FSP) to improve the corrosion resistance of pure magnesium for biomedical applications. FSP has been used to incorporate hydroxyapetite (HAP) into Mg-surface so as to modify the chemical composition. FSP was done within a matrix of different parameters and conditions. Influence of various parameters on microstructure was also clearly observed. XRD analysis confirmed the presence of HAP, whereas SEM images revealed a uniform distribution of the imbedded phase. Microhardness and in-vitro corrosion studies were also performed. Influence of grain size on hardness was validated by Hall-Petch relationship. Corrosion behavior was explained on the basis of texture, which indicated better corrosion resistance in comparison to the pure Mg. Therefore, the study reveals that the proposed FSP methodology can be useful tool to improve mechanical and corrosion properties of pure Mg for biomedical applications.

  9. Influence of surface roughness on the corrosion behaviour of magnesium alloy

    International Nuclear Information System (INIS)

    Walter, R.; Kannan, M. Bobby

    2011-01-01

    Research highlights: → Surface roughness of AZ91 magnesium alloy plays a critical role in the passivation behaviour of the alloy. → The passivation behaviour of the alloy influences the pitting tendency. → Increase in surface roughness of AZ91 magnesium alloy increases the pitting tendency of the alloy. -- Abstract: In this study, the influence of surface roughness on the passivation and pitting corrosion behaviour of AZ91 magnesium alloy in chloride-containing environment was examined using electrochemical techniques. Potentiodynamic polarisation and electrochemical impedance spectroscopy tests suggested that the passivation behaviour of the alloy was affected by increasing the surface roughness. Consequently, the corrosion current and the pitting tendency of the alloy also increased with increase in the surface roughness. Scanning electron micrographs of 24 h immersion test samples clearly revealed pitting corrosion in the highest surface roughness (Sa 430) alloy, whereas in the lowest surface roughness (Sa 80) alloy no evidence of pitting corrosion was observed. Interestingly, when the passivity of the alloy was disturbed by galvanostatically holding the sample at anodic current for 1 h, the alloy underwent high pitting corrosion irrespective of their surface roughness. Thus the study suggests that the surface roughness plays a critical role in the passivation behaviour of the alloy and hence the pitting tendency.

  10. 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...

  11. 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

  12. INFLUENCE OF AISI 316Ti STAINLESS STELL SURFACE TREATMENT ON PITTING CORROSION IN VARIOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Pavol Fajnor

    2010-12-01

    Full Text Available Investigation of the surface treatment effect on the resistance of AISI 316Ti stainless steel to pitting corrosion is presented in this paper. The grinded surfaces without additional chemical treatment, grinded and pickled, grinded, pickled and passivated surfaces are tested. The corrosion tests are carried out by exposition in solution which evoke pitting and by electrochemical cyclic potential - sweep method. According to the results the surface treatment has a great influence on the resistance of the tested material to pitting. It is not possible to estimate the best surface treatment because behavior of AISI 316Ti stainless steel with different surface state depends on the mechanism of corrosion processes which vary in the used experimental methods.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, Maria-Dolores [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, C/ Doctor Fleming s/n, Campus Muralla del Mar, 30202 Cartagena (Spain)]. E-mail: mdolores.bermudez@upct.es; Jimenez, Ana-Eva [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, C/ Doctor Fleming s/n, Campus Muralla del Mar, 30202 Cartagena (Spain); Martinez-Nicolas, Gines [Grupo de Ciencia de Materiales e Ingenieria Metalurgica, Departamento de Ingenieria de Materiales y Fabricacion, Universidad Politecnica de Cartagena, C/ Doctor Fleming s/n, Campus Muralla del Mar, 30202 Cartagena (Spain)

    2007-06-30

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

  14. Properties of colloidal corrosion products and their effects on nuclear plants. Volume 1. Executive summary. Final report

    International Nuclear Information System (INIS)

    Matijevic, E.

    1982-10-01

    The properties of aqueous dispersions of finely divided oxides of iron, nickel, cobalt, chromium, and copper are described in overview fashion. More detailed aspects of this work will be found in a separate, larger report, NP-2606, Volume 2. The properties of these oxide corrosion products of importance to nuclear reactor water system technology are emphasized: adhesion, desorption, dissolution, transformation, and adsorption of dissolved species such as Co 60 ions. The work is fundamental to many LWR problems - radiation transport to piping surfaces, avoidance of crud buildup on nuclear fuel rods, decontamination and chemical cleaning of heat exchangers, and control of corrosion of piping

  15. Biodegradable magnesium alloys for orthopaedic applications: A review on corrosion, biocompatibility and surface modifications.

    Science.gov (United States)

    Agarwal, Sankalp; Curtin, James; Duffy, Brendan; Jaiswal, Swarna

    2016-11-01

    Magnesium (Mg) and its alloys have been extensively explored as potential biodegradable implant materials for orthopaedic applications (e.g. Fracture fixation). However, the rapid corrosion of Mg based alloys in physiological conditions has delayed their introduction for therapeutic applications to date. The present review focuses on corrosion, biocompatibility and surface modifications of biodegradable Mg alloys for orthopaedic applications. Initially, the corrosion behaviour of Mg alloys and the effect of alloying elements on corrosion and biocompatibility is discussed. Furthermore, the influence of polymeric deposit coatings, namely sol-gel, synthetic aliphatic polyesters and natural polymers on corrosion and biological performance of Mg and its alloy for orthopaedic applications are presented. It was found that inclusion of alloying elements such as Al, Mn, Ca, Zn and rare earth elements provides improved corrosion resistance to Mg alloys. It has been also observed that sol-gel and synthetic aliphatic polyesters based coatings exhibit improved corrosion resistance as compared to natural polymers, which has higher biocompatibility due to their biomimetic nature. It is concluded that, surface modification is a promising approach to improve the performance of Mg-based biomaterials for orthopaedic applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Model tests for corrosion influence of electrode surface on electroosmosis in marine sludge

    Science.gov (United States)

    Zheng, Lingwei; Li, Jinzhu; Shi, Hanru

    2017-11-01

    The corrosion of metal electrodes is inevitable on electroosmosis in soil. Surface corrosion of electrodes is also one of the reasons for increasing energy consumption in electroosmosis treatment. A series of laboratory tests were conducted employing three kinds of materials, aluminium, steel, and brass. To explore the impact of surface corrosion degree on electroosmosis, metal electrodes were pretreated with durations 0 h, 12 h, 24 h, and 36 h. After the pretreatment, corroded electrodes are used as anodes on electroosmosis. Water discharge, current, voltage potential were measured during the tests; water content was also tested at three points after the electroosmosis. The results showed that aluminium was better than steel in electroosmotic drainage while brass provided the worst dewatering performance. Surface corrosion did not influence the aluminium and steel on electroosmosis in marine sludge, but brass did. In the pretreatment of brass electrodes, corrosion rate had started to slow down at later periods, with the deterioration rate of dewatering reduced afterwards. As the results showed, it is not recommended to employ those easily deteriorated electrode materials from surface corrosion in practical engineering, such as brass; electrode material with higher electroosmosis exchange rate is recommended, such as aluminium.

  17. Surface preparation for residual stress measurement of an accelerated corrosion tested welded marine steel

    International Nuclear Information System (INIS)

    Ahmad, Bilal; Fitzpatrick, Michael E.

    2015-01-01

    Residual stress measurement is often required for the assessment of structural integrity of components. Measurement of residual stress in corrosion tested specimens is challenging owing to the difficulty of accessing the surface because of the rust layer. This study explored the potential methods for the surface preparation of an ultrasonically-peened and accelerated corrosion tested DH36 marine steel fillet welded specimen to ease the way for subsequent residual stress measurement using neutron diffraction and the contour method. We find that hydroblasting introduces compressive residual stress at the surface that will alter the surface stress to be measured

  18. Corrosion mechanism of a Ni-based alloy in supercritical water: Impact of surface plastic deformation

    International Nuclear Information System (INIS)

    Payet, Mickaël; Marchetti, Loïc; Tabarant, Michel; Chevalier, Jean-Pierre

    2015-01-01

    Highlights: • The dissolution of Ni and Fe cations occurs during corrosion of Ni-based alloys in SCW. • The nature of the oxide layer depends locally on the alloy microstructure. • The corrosion mechanism changes when cold-work increases leading to internal oxidation. - Abstract: Ni–Fe–Cr alloys are expected to be a candidate material for the generation IV nuclear reactors that use supercritical water at temperatures up to 600 °C and pressures of 25 MPa. The corrosion resistance of Alloy 690 in these extreme conditions was studied considering the surface finish of the alloy. The oxide scale could suffer from dissolution or from internal oxidation. The presence of a work-hardened zone reveals the competition between the selective oxidation of chromium with respect to the oxidation of nickel and iron. Finally, corrosion mechanisms for Ni based alloys are proposed considering the effects of plastically deformed surfaces and the dissolution.

  19. Corrosion protection application of slippery liquid-infused porous surface based on aluminum foil

    Science.gov (United States)

    Tuo, Yanjing; Zhang, Haifeng; Chen, Weiping; Liu, Xiaowei

    2017-11-01

    Corrosion is a major problem for metal in marine systems. In this research, we fabricated a slippery liquid-infused porous surface (SLIPS) on the aluminum foil to protect the underneath metal. The as-fabricated samples were characterized with EDS, XRD, SEM, and contact angle meter. And the anti-corrosion property was evaluated by electrochemical measurements. The corrosion current density of SLIPS is ca.2 orders of magnitude lower than that of the untreated aluminum and superhydrophobic surface. And the impedance spectra of the SLIPS shows a large impedance semicircle with a diameter of several hundred kΩ.cm2. The SLIPS exhibits an outstanding corrosion protection capability, thus it has a broad application prospect in marine.

  20. Radiochemical studies on corrosion products of oral biomaterials

    International Nuclear Information System (INIS)

    Madbouly, H.A.Abdallah

    1998-01-01

    The work given in this thesis deals with a radioactive tracer study of the sorption of the corrosion products of dental amalgams and antimony on human teeth, porcelain and acrylic materials, used as dental restorative material. Sorption was investigated in presence of water and liquids commonly intaken by man; namely tea with or without sugar, soluble coffee ( Nescaffee) with or without sugar and/or milk, red tea (karkadeh or hibiscus) with or without sugar and chicken soup. The radioactive isotopes of Ag, Sn, Zn (amalgam components) and antimony were prepared by their irradiation in the nuclear reactor; 110m Ag, 113 Sn, 65 Zn and 124 Sb were thereby produced. The percent uptake of each studied element was evaluated from the depletion of radioactivity of the corresponding radioactive tracer in the given medium containing a tooth (human or artificial)

  1. Super-hydrophobic surface treatment as corrosion protection for aluminum in seawater

    Energy Technology Data Exchange (ETDEWEB)

    He Tian; Wang Yuanchao; Zhang Yijian; Lv Qun; Xu Tugen [College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Liu Tao [Institute of Ocean Materials and Engineering, Shanghai Maritime University, Shanghai 200135 (China)], E-mail: yys2003ouc@163.com

    2009-08-15

    'Underwater super-hydrophobic' surface applied in the corrosion protection was prepared by melting myristic acid (CH{sub 3}(CH{sub 2}){sub 12}COOH) adsorbed onto the anodized aluminum. The static contact angle for seawater on the surface was measured to be 154{sup o}. The surface structure and composition were then characterized by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectrum (EDS) and atomic force microscope (AFM). The electrochemical measurements showed that the super-hydrophobic surface significantly improved the corrosion resistance of aluminum in sterile seawater. In addition, the mechanism of the underwater super-hydrophobic surface applied in the corrosion resistance was discussed using a schematic.

  2. Analysis of Short-Term Steel Corrosion Products Formed in Tropical Marine Environments of Panama

    Directory of Open Access Journals (Sweden)

    Juan A. Jaén

    2012-01-01

    Full Text Available A low-carbon steel A-36 and two conventional weathering steels A-588 and COR-420 exposed at four atmospheric test stations located in (i Tocumen, an urban site near the Pacific Ocean, (ii Sherman-Open, (iii Sherman-Coastal, and (iv Sherman-Breakwater on the Caribbean coast of Panama. Kinetics of the short-term atmospheric corrosion process and the relationship with exposure time and environmental characteristics of each site were investigated. The atmospheric exposure conditions, particularly the time of wetness, deposition of chloride, and the washing effect of contaminants on the metal surface by rain are of upmost importance in determining the corrosion behaviour and composition of rust. The corrosion products were mainly identified using room temperature and low temperature (80 K Mössbauer spectroscopy, FTIR, and X-ray powder diffraction. In all samples, γ-FeOOH and α-FeOOH were the main constituents. Maghemite (γ-Fe2O3, magnetite (Fe3O4, and Akaganeite (β-FeOOH were also identified.

  3. Laser surface melting of 304 stainless steel for pitting corrosion resistance improvement

    CSIR Research Space (South Africa)

    Seleka, TS

    2006-11-01

    Full Text Available are prone to pitting corrosion when exposed to halide ions, particularly chloride ions. This is in fact reducing their applicability in variety of engineering industries. The corrosion properties of steels depend primarily on the microstructure, surface... processing parameters. Argon gas was applied into the melt pool to minimize oxidation. Samples of interest were subjected for further studies. After laser treatment, the samples were sectioned, polished and electrochemically etched with oxalic acid...

  4. Benzotriazole a Corrosion Inhibitor for Antiques: Some Practical Surface Chemistry.

    Science.gov (United States)

    Walker, Robert

    1980-01-01

    Describes the structure and inhibitive properties of Benzotriazole. The chemical may be employed as an inhibitor to reduce corrosion of articles during storage or display. It may be applied to copper and copper-based antiques as well as to silver and other metals. (Author/JN)

  5. Surface properties and corrosion behavior of Co-Cr alloy fabricated with selective laser melting technique.

    Science.gov (United States)

    Xin, Xian-zhen; Chen, Jie; Xiang, Nan; Wei, Bin

    2013-01-01

    We sought to study the corrosion behavior and surface properties of a commercial cobalt-chromium (Co-Cr) alloy which was fabricated with selective laser melting (SLM) technique. For this purpose, specimens were fabricated using different techniques, such as SLM system and casting methods. Surface hardness testing, microstructure observation, surface analysis using X-ray photoelectron spectroscopy (XPS) and electrochemical corrosion test were carried out to evaluate the corrosion properties and surface properties of the specimens. We found that microstructure of SLM specimens was more homogeneous than that of cast specimens. The mean surface hardness values of SLM and cast specimens were 458.3 and 384.8, respectively; SLM specimens showed higher values than cast ones in hardness. Both specimens exhibited no differences in their electrochemical corrosion properties in the artificial saliva through potentiodynamic curves and EIS, and no significant difference via XPS. Therefore, we concluded that within the scope of this study, SLM-fabricated restorations revealed good surface properties, such as proper hardness, homogeneous microstructure, and also showed sufficient corrosion resistance which could meet the needs of dental clinics.

  6. Microbiologically influenced corrosion in petroleum product pipelines--a review.

    Science.gov (United States)

    Muthukumar, N; Rajasekar, A; Ponmariappan, S; Mohanan, S; Maruthamuthu, S; Muralidharan, S; Subramanian, P; Palaniswamy, N; Raghavan, M

    2003-09-01

    Microbiologically influenced corrosion is responsible for most of the internal corrosion problems in oil transportation pipelines and storage tanks. One problematic area in treating gas lines is the occurrence of the stratification of water in the line. Under these conditions, corrosion inhibitors do not come into contact properly and oil and inhibitors undergo degradation. The role of bacteria on oil degradation, the consequences of oil degradation in fuel systems and its influence on corrosion have been explained in detail. Besides, factors influencing on degradation of oil and corrosion inhibitors have also been discussed. Mechanism of microbiologically influenced corrosion in oil pipeline has been explained. Many of the misapplication of biocides/inhibitors occur mainly because the characteristics of biocides/inhibitors are not considered before use in pipeline industry. List of biocides and monitoring programme have been collected from literature and presented.

  7. Corrosion and corrosion control

    International Nuclear Information System (INIS)

    Khanna, A.S.; Totlani, M.K.

    1995-01-01

    Corrosion has always been associated with structures, plants, installations and equipment exposed to aggressive environments. It effects economy, safety and product reliability. Monitoring of component corrosion has thus become an essential requirement for the plant health and safety. Protection methods such as appropriate coatings, cathodic protection and use of inhibitors have become essential design parameters. High temperature corrosion, especially hot corrosion, is still a difficult concept to accommodate in corrosion allowance; there is a lack of harmonized system of performance testing of materials at high temperatures. In order to discuss and deliberate on these aspects, National Association for Corrosion Engineers International organised a National Conference on Corrosion and its Control in Bombay during November 28-30, 1995. This volume contains papers presented at the symposium. Paper relevant to INIS is indexed separately. refs., figs., tabs

  8. 77 FR 24221 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission...

    Science.gov (United States)

    2012-04-23

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

  9. 77 FR 301 - Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year...

    Science.gov (United States)

    2012-01-04

    ...)] Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea: Institution of Five-Year Reviews Concerning the Countervailing Duty Order on Corrosion-Resistant Carbon Steel Flat Products From Korea and the Antidumping Duty Orders on Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea AGENCY...

  10. Simulation study on insoluble granular corrosion products deposited in PWR core

    International Nuclear Information System (INIS)

    Yang Xu; Zhou Tao; Ru Xiaolong; Lin Daping; Fang Xiaolu

    2014-01-01

    In the operation of reactor, such as fuel rods, reactor vessel internals etc. will be affected by corrosion erosion of high pressure coolant. It will produce many insoluble corrosion products. The FLUENT software is adopted to simulate insoluble granular corrosion products deposit distribution in the reactor core. The fluid phase uses the standard model to predict the flow field in the channel and forecast turbulence variation in the near-wall region. The insoluble granular corrosion products use DPM (Discrete Phase Model) to track the trajectory of the particles. The discrete phase model in FLUENT follows the Euler-Lagrange approach. The fluid phase is treated as a continuum by solving the Navier-Stokes equations, while the dispersed phase is solved by tracking a large number of particles through the calculated flow field. Through the study found, Corrosion products particles form high concentration area near the symmetry, and the entrance section of the corrosion products particles concentration is higher than export section. Corrosion products particles deposition attached on large area for the entrance of the cladding, this will change the core neutron flux distribution and the thermal conductivity of cladding material, and cause core axial offset anomaly (AOA). Corrosion products particles dot deposit in the outlet of cladding, which can lead to pitting phenomenon in a sheath. Pitting area will cause deterioration of heat transfer, destroy the cladding integrity. In view of the law of corrosion products deposition and corrosion characteristics of components in the reactor core. this paper proposes regular targeted local cleanup and other mitigation measures. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ambrish, E-mail: ambrish.16752@ipu.co.in [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Department of Chemistry, LFTS, Lovely Professional University, Phagwara, Punjab 144402 (India); Lin, Yuanhua, E-mail: yhlin28@163.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Ansari, K.R.; Quraishi, M.A. [Department of Applied Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi, U.P. (India); Ebenso, Eno. E. [Department of Chemistry, School of Mathematical & Physical Sciences, North-West University(Mafikeng Campus), Private Bag X2046, Mmabatho 2735 (South Africa); Chen, Songsong; Liu, Wanying [CNPC Key Lab for Tubular Goods Engineering (Southwest Petroleum University), Chengdu, Sichuan 610500 (China)

    2015-12-30

    Graphical abstract: Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO2 by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO2 by Porphines. • Weight loss and impedance results are in good agreement. • The adsorption of Porphines obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. • Examination of surface morphology by AFM. - Abstract: Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO{sub 2} by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), Contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). Adsorption of such Porphines on the J55 steel surface obeyed to the Langmuir adsorption isotherm. Atomic force microscopy (AFM), SECM, and Contact angle results confirm the formation of inhibitor film on J55 steel surface thereby mitigating corrosion.

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

    Science.gov (United States)

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

    2002-01-01

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

  13. Effect of Surface Pretreatment on the Corrosion Resistance of Epoxy-Coated Carbon Steel

    International Nuclear Information System (INIS)

    Lee, Dongho; Park, Jinhwan; Shon, Minyoung

    2012-01-01

    The corrosion resistance of epoxy-coated carbon steel was evaluated. The carbon steel surface was subjected to different treatment methods such as steel grit blasting with different size, steel shot ball blasting and power tool treatment. To study the effect of the treatments, the topology of the treated surface was observed by optical 3D microscopy and a pull-off adhesion test was conducted. The corrosion resistance of the epoxy-coated carbon steel was further examined by electrochemical impedance spectroscopy (EIS) combined with hygrothermal cyclic testing. The results of EIS indicated that the epoxy-coated carbon steel treated with steel grit blasting showed an improved corrosion resistance compared to untreated epoxy-coated surfaces or surfaces subjected to shot ball blasting and power tool treatments

  14. corrosion of a carbon steel covered by treated bentonites in ...

    African Journals Online (AJOL)

    F. Arbaoui

    2017-09-01

    Sep 1, 2017 ... Keywords: Corrosion inhibitor, Carbon steel, Electrochemical Impedances Spectroscopy;. Algerian bentonites; Tungstate. ... layer of corrosion products formed on the steel surface remains thinner than in aqueous solutions [11]. ..... chloride-induced crevice corrosion of Alloy 22. Corrosion Science, 2013, 68, ...

  15. Concrete Cracking Prediction Including the Filling Proportion of Strand Corrosion Products

    Science.gov (United States)

    Wang, Lei; Dai, Lizhao; Zhang, Xuhui; Zhang, Jianren

    2016-01-01

    The filling of strand corrosion products during concrete crack propagation is investigated experimentally in the present paper. The effects of stirrups on the filling of corrosion products and concrete cracking are clarified. A prediction model of crack width is developed incorporating the filling proportion of corrosion products and the twisting shape of the strand. Experimental data on cracking angle, crack width, and corrosion loss obtained from accelerated corrosion tests of concrete beams are presented. The proposed model is verified by experimental data. Results show that the filling extent of corrosion products varies with crack propagation. The rust filling extent increases with the propagating crack until a critical width. Beyond the critical width, the rust-filling extent remains stable. Using stirrups can decrease the critical crack width. Stirrups can restrict crack propagation and reduce the rust filling. The tangent of the cracking angle increases with increasing corrosion loss. The prediction of corrosion-induced crack is sensitive to the rust-filling extent. PMID:28772367

  16. Quantitative assessment of the effect of corrosion product buildup on occupational exposure

    International Nuclear Information System (INIS)

    Divine, J.R.

    1982-10-01

    The program was developed to provide a method for predicting occupational exposures caused by the deposition of radioactive corrosion products outside the core of the primary system of an operating power reactor. This predictive capability will be useful in forecasting total occupational doses during maintenance, inspection, decontamination, waste treatment, and disposal. In developing a reliable predictive model, a better understanding of the parameters important to corrosion product film formation, corrosion product transport, and corrosion product film removal will be developed. This understanding can lead to new concepts in reactor design to minimize the buildup and transport of radioactive corrosion products or to improve methods of operation. To achieve this goal, three objectives were established to provide: (1) criteria for acceptable coolant sampling procedures and sampling equipment that will provide data which will be used in the model development; (2) a quantitative assessment of the effect of corrosion product deposits on occupational exposure; and (3) a model which describes the influence of flow, temperature, coolant chemistry, construction materials, radiation, and other operating parameters on the transport and buildup of corrosion products

  17. Influence of surface preparation on the corrosion performance of epoxy coatings for ship ballast tank

    NARCIS (Netherlands)

    Zhang, X.; Buter, S.J.; Ferrari, G.M.

    2011-01-01

    The surface preparation has influence on the adhesion for coatings and consequently affect the corrosion performance of the coatings. The international Maritime Organization (IMO) has adopted a Performance Standard for Protective Coatings (PSPC) on the surface preparation for ballast tanks. However,

  18. Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

    International Nuclear Information System (INIS)

    Rotaru, Ileana; Varvara, Simona; Gaina, Luiza; Muresan, Liana Maria

    2014-01-01

    Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E HOMO and E LUMO and HOMO–LUMO energy gap were used for correlation with the corrosion data

  19. Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rotaru, Ileana [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Varvara, Simona, E-mail: svarvara@uab.ro [Department of Exact Sciences and Engineering, “1 Decembrie 1918” University, 11-13 Nicolae Iorga St., 510009 Alba Iulia (Romania); Gaina, Luiza [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Muresan, Liana Maria, E-mail: limur@chem.ubbcluj.ro [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania)

    2014-12-01

    Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E{sub HOMO} and E{sub LUMO} and HOMO–LUMO energy gap were used for correlation with the corrosion data.

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

    Science.gov (United States)

    1978-11-01

    Aluminum Zinc Galvanized Steel (New) Aluminum Alloy 5052 Alclad Aluminum (X7002) Aluminum Alloy 3003 Aluminum Alloy 6061-T6 Aluminum ... Alloy 7079-T6 Aluminum Alloy 2024 Ca.•mium Cadmium Coated Steel (New) Mild Steel Wrought Iron Alloy Steel Cast Iron Ni-Resist Cast Iron Monel Alloy 400... aluminum alloys . Even very small amcunts of copper from the corrosion of copper-

  1. Chapter 23: Corrosion of Metals in Wood Products

    Science.gov (United States)

    Samuel L. Zelinka

    2014-01-01

    The corrosion of metals in contact with wood has been studied for over 80 years, and in most situations wood is not corrosive [1]. Recently, however, the durability of fasteners in preservative--treated wood has become a concern. Changes in legislation and certification in the United States, the European Union, and Australasia have restricted the use of chromated...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-06

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

  3. Surface characterization and corrosion behavior of micro-arc oxidized Ti surface modified with hydrothermal treatment and chitosan coating

    International Nuclear Information System (INIS)

    Neupane, Madhav Prasad; Park, Il Song; Lee, Min Ho

    2014-01-01

    In the present work, we describe the surface modification of commercially pure titanium (CP-Ti) by a composite/multilayer coating approach for biomedical applications. CP-Ti samples were treated by micro-arc oxidation (MAO) and subsequently some of the samples were coated with chitosan (Chi) by dip coating method, while others were subjected to hydrothermal treatment (HT) followed by chitosan coating. The MAO, MAO/Chi, and MAO/HT/Chi coated Ti were characterized and their characteristics were compared with CP-Ti. X-ray diffraction and scanning electron microscopy were used to assess the structural and morphological characteristics. The average surface roughness was determined using a surface profilometer. The corrosion resistance of untreated and surface modified Ti in commercial saline at 298 K was evaluated by potentiodynamic polarization test. The results indicated that the chitosan coating is very well integrated with the MAO and MAO/HT coating by physically interlocking itself with the coated layer and almost sealed all the pores. The surface roughness of hydrothermally treated and chitosan coated MAO film was superior evidently to that with other sample groups. The corrosion studies demonstrated that the MAO, hydrothermally treated and chitosan coated sample enhanced the corrosion resistance of titanium. The result indicates that fabrication of hydrothermally treated MAO surface coatings with chitosan is a significant approach to protect the titanium from corrosion, hence enhancing the potential use of titanium as bio-implants. - Highlights: • Micro-arc oxidized (MAO) and hydrothermally treated (HT) Ti surfaces are coated with chitosan (Chi). • The MAO/HT/Chi surface exhibits pores sealing and enhanced the surface roughness. • The MAO/HT/Chi surface significantly increase the corrosion resistance. • The MAO/HT/Chi can be a potential surface of titanium for bio-implants

  4. Emerging surface characterization techniques for carbon steel corrosion: a critical brief review.

    Science.gov (United States)

    Dwivedi, D; Lepkova, K; Becker, T

    2017-03-01

    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 reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.

  5. Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

    Science.gov (United States)

    Dwivedi, D.; Lepkova, K.; Becker, T.

    2017-03-01

    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 reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.

  6. Monitoring Microbially Influenced Corrosion

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    Abstract Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria (SRB). The applicability and reliability of a number of corrosion monitoring techniques for monitoring MIC has been evaluated in experiments...... and diffusional effects and unreliable corrosion rates, when biofilm and ferrous sulphide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 by electrochemical techniques. Weight loss coupons and ER are recommended as necessary basic monitoring techniques....... EIS might be used for detection of MIC as the appearance of very large capacitances can be attributed to the combined ferrous sulphide and biofilm formation. Capacitance correlates directly with sulphide concentration in sterile sulphide media. Keywords: Corrosion monitoring, carbon steel, MIC, SRB...

  7. SRB seawater corrosion project

    Science.gov (United States)

    Bozack, M. J.

    1991-01-01

    The corrosion behavior of 2219 aluminum when exposed to seawater was characterized. Controlled corrosion experiments at three different temperatures (30, 60 and 100 C) and two different environments (seawater and 3.5 percent salt solution) were designed to elucidate the initial stages in the corrosion process. It was found that 2219 aluminum is an active catalytic surface for growth of Al2O3, NaCl, and MgO. Formation of Al2O3 is favored at lower temperatures, while MgO is favored at higher temperatures. Visible corrosion products are formed within 30 minutes after seawater exposure. Corrosion characteristics in 3.5 percent salt solution are different than corrosion in seawater. Techniques utilized were: (1) scanning electron microscopy, (2) energy dispersive x-ray spectroscopy, and (3) Auger electron spectroscopy.

  8. Surface and corrosion characteristics of carbon plasma implanted and deposited nickel-titanium alloy

    International Nuclear Information System (INIS)

    Poon, R.W.Y.; Liu, X.Y.; Chung, C.Y.; Chu, P.K.; Yeung, K.W.K.; Lu, W.W.; Cheung, K.M.C.

    2005-01-01

    Nickel-titanium shape memory alloys (NiTi) are potentially useful in orthopedic implants on account of their super-elastic and shape memory properties. However, the materials are prone to surface corrosion and the most common problem is out-diffusion of harmful Ni ions from the substrate into body tissues and fluids. In order to improve the corrosion resistance and related surface properties, we used the technique of plasma immersion ion implantation and deposition to deposit an amorphous hydrogenated carbon coating onto NiTi and implant carbon into NiTi. Both the deposited amorphous carbon film and carbon plasma implanted samples exhibit much improved corrosion resistances and surface mechanical properties and possible mechanisms are suggested

  9. Solubility of simulated PWR primary circuit corrosion products

    International Nuclear Information System (INIS)

    Kunig, R.H.; Sandler, Y.L.

    1986-08-01

    The solubility behavior of non-stoichiometric nickel ferrites, nickel-cobalt ferrites, and magnetite, as model substances for the corrosion products (''crud'') formed in nuclear pressurized water reactors, was studied in a flow system in aqueous solutions of lithium hydroxide, boric acid, and hydrogen with pH, temperature, and hydrogen concentrations as parameters. Below the temperature region of 300 to 330 0 C, at hydrogen concentrations of 25 to 40 cm 3 /kg H 2 O as used during reactor operation, the solubility of nickel-cobalt ferrite is the same as that of Ni and Co/sub x/Fe/sub 3-x/O 4 (x 3 /kg of hydrogen, the equilibrium iron and nickel solubilities increase congruently down to about 100 0 C, in a manner consistent with the solubility of Fe 3 O 4 , but sharply decline at lower temperatures, apparently due to formation of a borated layer. A cooldown experiment on a time scale of a typical Westinghouse reactor shutdown, as well as static experiments carried out on various ferrite samples at 60 0 C show that after addition of oxygen or peroxide evolution of nickel (and possibly cobalt) above the equilibrium solubility in hydrogen depends on the presence of dissociation products prior to oxidation. Thermodynamic calculations of various reduction and oxidative decomposition reactions for stoichiometric and non-stoichiometric nickel ferrite and cobalt ferrite are presented. Their significance to evolutions of nickel and cobalt on reactor shutdown is discussed. 30 refs., 38 figs., 34 tabs

  10. On iron radionuclide interactions and in situ measurement of iron corrosion products

    International Nuclear Information System (INIS)

    Puranen, A.; Jonsson, M.; Cui, D.; Scheidegger, A.M.; Wersin, P.; Spahiu, K.

    2005-01-01

    Full text of publication follows: In performance assessments of hard rock repositories, it is conservatively assumed that waste canisters are breached and that the spent fuel will get into contact with groundwater after 1000 years. When the canister eventually fails to protect HLW from groundwater, dissolved radionuclides from HLW will react with iron canister materials. The reactivity will depend on the conditions in solution and at the iron-water interface. To improve our understanding on the redox chemistry at near field conditions, batch experiments are conducted by contacting polished iron foils with a synthetic groundwater solution containing 10 mM NaCl, 2 mM NaHCO 3 and 5 ppm Se(IV), Se(VI), Tc(VII) and U(VI) in a glove box filled with Ar + 0.03% CO 2 gas mixture. The reaction rates are measured by analysing Se, Tc and U concentrations by ICP-MS. Iron corrosion products formed during the reaction(s) is monitored in-situ by a Layer Raman spectrometer through an optical window. The corrosion potential of the iron foil as well as the Eh and pH values of the bulk solution are recorded continuously during the experiment. The reacted iron foil is embedded with EPOXY resin, and the cross section will be analysed by SEM-EDS and XAS. The preliminary experimental results shows that with the formation of iron green rust FeII 4 FeIII 2 (OH) 12 CO 3 on iron foil, the rates of redox reactions between iron and the negatively charged radionuclides species are increased. The observation is explained by the fact that radionuclide anionic species can be first adsorbed then reduced on the positively charged outer surface of iron green rust. The positive charge is a result of the electrical balance of the negative charges of carbonate contained between the layered iron hydroxides in the green rust. Reduced forms of radionuclides are identified in the iron corrosion products. The results suggest that the formation of iron green rust as a corrosion product on the surface of iron

  11. 77 FR 14501 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2012-03-12

    ... International Trade Administration Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of... antidumping duty administrative review for certain corrosion-resistant carbon steel flat products (CORE) from... (POR) is August 1, 2009, through, July 31, 2010. \\1\\ See Certain Corrosion-Resistant Carbon Steel Flat...

  12. 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...

  13. Long-term reactive transport simulations of the interactions of corrosion products and compacted bentonite in a HLW repository

    International Nuclear Information System (INIS)

    Samper, J.; Naves, A.; Montenegro, L.; Mon, A.; Pisani, B.

    2012-01-01

    Document available in extended abstract form only. Carbon steel and compacted bentonite are considered as candidate materials for the overpack and buffer of a nuclear waste in deep geological high level waste (HLW) repositories. Canister corrosion and the chemical interactions of corrosion products with bentonite are key reactions for the long term performance of a repository in granite. Samper et al. (2008a) presented 1-D and 2-D axisymmetric models for the long-term hydrochemical evolution of the porewater composition in the near-field bentonite barrier of a spent-fuel, carbon-steel canister, bentonite and granite repository (ENRESA, 2005). The model accounted for mineral dissolution/precipitation, single-site proton surface complexation and cation exchange of Ca 2+ , Mg 2+ , Na + , K + and Fe 2+ . Canister corrosion was modelled with a constant corrosion rate. The 2-D axisymmetric model accounted for flow in the granite. Lu et al. (2011) extended the model by considering a 1-D axisymmetric model with Fe sorption via surface complexation, three-sites proton surface complexation in the bentonite, constant and kinetically-controlled canister corrosion and magnetite precipitation, the competition effect of Ni 2+ for sorption sites and no water flow through the granite. Here we take a step beyond their models and present an updated version of both reactive transport models. The improved model includes at the same time: 1) Flow through the granite; 2) A three-sites surface complexation model in bentonite; 3) Fe sorption complexation; 4) Kinetically-controlled mineral precipitation; and 5) A dual porosity model for bentonite based on the model developed by Samper et al. (2008b) from laboratory experiments. The model accounts for revised estimates of the initial chemical composition of the bentonite and granite pore waters and assumes corrosion rates based on recent experimental corrosion data collected for carbon steel in contact with compacted bentonite (King, 2008

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

    Energy Technology Data Exchange (ETDEWEB)

    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 /sup 60/Co and /sup 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.

  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. 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

  17. The effects of surface processing on in-vivo corrosion of Nitinol stents in a porcine model.

    Science.gov (United States)

    Sullivan, Stacey J L; Madamba, Daniel; Sivan, Shiril; Miyashiro, Katie; Dreher, Maureen L; Trépanier, Christine; Nagaraja, Srinidhi

    2017-10-15

    A major limitation with current assessments of corrosion in metallic medical devices is the lack of correlation between in-vitro and in-vivo corrosion performance. Therefore, the objective of this study was to elucidate the relationship between pitting corrosion measured by breakdown potentials (E b ) in ASTM F2129 testing and corrosion resistance in-vivo. Four groups of Nitinol stents were manufactured using different processing methods to create unique surface properties. The stents were implanted into iliac arteries of minipigs for six months and explanted for corrosion analysis. Scanning electron microscopy and energy dispersive X-ray spectrometry analyses indicated that stents with a thick complex thermal oxide (420nm) and high corrosion resistance in-vitro (E b =975±94mV) were free from detectable corrosion in-vivo and exhibited no changes in Ni/Ti ratio when compared to non-implanted controls. This result was also found in mechanically polished stents with a thin native oxide (4nm; E b =767±226mV). In contrast, stents with a moderately thick thermal oxide (130nm) and low corrosion resistance in-vitro (E b =111±63mV) possessed corrosion with associated surface microcracks in-vivo. In addition, Ni/Ti ratios in corroded regions were significantly lower compared to non-corroded adjacent areas on explanted stents. When stents were minimally processed (i.e. retained native tube oxide from the drawing process), a thick thermal oxide was present (399nm) with low in-vitro corrosion resistance (E b =68±29mV) resulting in extensive in-vivo pitting. These findings demonstrate that functional corrosion testing combined with a detailed understanding of the surface characteristics of a Nitinol medical device can provide insight into in-vivo corrosion resistance. Nitinol is a commonly used material in the medical device industry. However, correlations between surface processing of nitinol and in-vivo corrosion has yet to be established. Elucidating the link between in

  18. Surface microstructures and corrosion resistance of Ni-Ti-Nb shape memory thin films

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kun [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology, Beihang University, Beijing 100191 (China); Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST (United Kingdom); Li, Yan, E-mail: liyan@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology, Beihang University, Beijing 100191 (China); Huang, Xu [Memry Corporation, Bethel, CT 06801 (United States); Gibson, Des [Institute of Thin Films, Sensors & Imaging, Scottish Universities Physics Alliance, University of the West of Scotland, Paisley PA1 2BE (United Kingdom); Zheng, Yang; Liu, Jiao; Sun, Lu [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology, Beihang University, Beijing 100191 (China); Fu, Yong Qing, E-mail: richard.fu@northumbria.ac.uk [Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST (United Kingdom)

    2017-08-31

    Highlights: • The corrosion resistance of Ni-Ti-Nb shape memory thin films is investigated. • Modified surface oxide layers improve the corrosion resistance of Ni-Ti-Nb films. • Further Nb additions reduce the potential corrosion tendency of the films. - Abstract: Ni-Ti-Nb and Ni-Ti shape memory thin films were sputter-deposited onto silicon substrates and annealed at 600 °C for crystallization. X-ray diffraction (XRD) measurements indicated that all of the annealed Ni-Ti-Nb films were composed of crystalline Ni-Ti (Nb) and Nb-rich grains. X-ray photoelectron spectroscopy (XPS) tests showed that the surfaces of Ni-Ti-Nb films were covered with Ti oxides, NiO and Nb{sub 2}O{sub 5}. The corrosion resistance of the Ni-Ti-Nb films in 3.5 wt.% NaCl solution was investigated using electrochemical tests such as open-circuit potential (OCP) and potentio-dynamic polarization tests. Ni-Ti-Nb films showed higher OCPs, higher corrosion potentials (E{sub corr}) and lower corrosion current densities (i{sub corr}) than the binary Ni-Ti film, which indicated a better corrosion resistance. The reason may be that Nb additions modified the passive layer on the film surface. The OCPs of Ni-Ti-Nb films increased with further Nb additions, whereas no apparent difference of E{sub corr} and i{sub corr} was found among the Ni-Ti-Nb films.

  19. Super-hydrophobic surfaces improve corrosion resistance of copper in seawater

    International Nuclear Information System (INIS)

    Liu, Tao; Yin, Yansheng; Chen, Shougang; Chang, Xueting; Cheng, Sha

    2007-01-01

    Pretreated by a n-tetradecanoic acid (CH 3 (CH 2 ) 12 COOH) etch, the super-hydrophobic film was formed on the fresh copper surface. The film structure was probed with contact angle measurement and scanning electron microscopy (SEM). The results suggest that the structure of the film is similar to haulm or flower and the seawater contact angle is larger than 150 o . Moreover, the corrosion resistance of bare and modified samples in seawater were investigated by cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS). Experimental results show that the corrosion rate of Cu with super-hydrophobic surface decreases dramatically because of its special microstructure

  20. Facile fabrication of iron-based superhydrophobic surfaces via electric corrosion without bath

    International Nuclear Information System (INIS)

    Sun, Qinghe; Liu, Hongtao; Chen, Tianchi; Wei, Yan; Wei, Zhu

    2016-01-01

    Graphical abstract: - Highlights: • This paper investigates the fabrication techniques towards superhydrophobic surface on carbon steel substrate via electric corrosion without a bath. • It has a vital significance to the industrialization of the fabrication of superhydrophobic surface on hard metal due to the advantages such as low cost, high efficiency, can be prepared in a large area, easy to construct in the field. • The preparation approach is so facile and time-saving that it delivers an opportunity to construct a superhydrophobic surface on carbon steel substrate and provides the feasibility for industrial application of superhydrophobic surface. • The as-prepared surface has many excellent properties, like low adhesive property, anti-corrosion ability, mechanical durability and anti-icing performance. - Abstract: Superhydrophobic surface is of wide application in the field of catalysis, lubrication, waterproof, biomedical materials, etc. The superhydrophobic surface based on hard metal is worth further study due to its advantages of high strength and wear resistance. This paper investigates the fabrication techniques towards superhydrophobic surface on carbon steel substrate via electric corrosion and studies the properties of as-prepared superhydrophobic surface. The hydrophobic properties were characterized by a water sliding angle (SA) and a water contact angle (CA) measured by the Surface tension instrument. A Scanning electron microscope was used to analyze the structure of the corrosion surface. The surface compositions were characterized by an Energy Dispersive Spectrum. The Electrochemical workstation was used to measure its anti-corrosion property. The anti-icing performance was characterized by a steam-freezing test in Environmental testing chamber. The SiC sandpaper and 500 g weight were used to test the friction property. The research result shows that the superhydrophobic surface can be successfully fabricated by electrocorrosion on

  1. Surface modification techniques for increased corrosion tolerance of zirconium fuel cladding

    Science.gov (United States)

    Carr, James Patrick, IV

    Corrosion is a major issue in applications involving materials in normal and severe environments, especially when it involves corrosive fluids, high temperatures, and radiation. Left unaddressed, corrosion can lead to catastrophic failures, resulting in economic and environmental liabilities. In nuclear applications, where metals and alloys, such as steel and zirconium, are extensively employed inside and outside of the nuclear reactor, corrosion accelerated by high temperatures, neutron radiation, and corrosive atmospheres, corrosion becomes even more concerning. The objectives of this research are to study and develop surface modification techniques to protect zirconium cladding by the incorporation of a specific barrier coating, and to understand the issues related to the compatibility of the coatings examined in this work. The final goal of this study is to recommend a coating and process that can be scaled-up for the consideration of manufacturing and economic limits. This dissertation study builds on previous accident tolerant fuel cladding research, but is unique in that advanced corrosion methods are tested and considerations for implementation by industry are practiced and discussed. This work will introduce unique studies involving the materials and methods for accident tolerant fuel cladding research by developing, demonstrating, and considering materials and processes for modifying the surface of zircaloy fuel cladding. This innovative research suggests that improvements in the technique to modify the surface of zirconium fuel cladding are likely. Three elements selected for the investigation of their compatibility on zircaloy fuel cladding are aluminum, silicon, and chromium. These materials are also currently being investigated at other labs as alternate alloys and coatings for accident tolerant fuel cladding. This dissertation also investigates the compatibility of these three elements as surface modifiers, by comparing their microstructural and

  2. Improvement of in vitro corrosion and cytocompatibility of biodegradable Fe surface modified by Zn ion implantation

    Science.gov (United States)

    Wang, Henan; Zheng, Yang; Li, Yan; Jiang, Chengbao

    2017-05-01

    Pure Fe was surface-modified by Zn ion implantation to improve the biodegradable behavior and cytocompatibility. Surface topography, chemical composition, corrosion resistance and cytocompatibility were investigated. Atomic force microscopy, auger electron spectroscopy and X-ray photoelectron spectroscopy results showed that Zn was implanted into the surface of pure Fe in the depth of 40-60 nm and Fe2O3/ZnO oxides were formed on the outmost surface. Electrochemical measurements and immersion tests revealed an improved degradable behavior for the Zn-implanted Fe samples. An approximately 12% reduction in the corrosion potential (Ecorr) and a 10-fold increase in the corrosion current density (icorr) were obtained after Zn ion implantation with a moderate incident ion dose, which was attributed to the enhanced pitting corrosion. The surface free energy of pure Fe was decreased by Zn ion implantation. The results of direct cell culture indicated that the short-term (4 h) cytocompatibility of MC3T3-E1 cells was promoted by the implanted Zn on the surface.

  3. Influence of surface layer on mechanical and corrosion properties of nickel-titanium orthodontic wires.

    Science.gov (United States)

    Katić, Višnja; Curković, Helena Otmačić; Semenski, Damir; Baršić, Gorana; Marušić, Katarina; Spalj, Stjepan

    2014-11-01

    To analyze the effect of various coating formulations on the mechanical and corrosion properties of nickel-titanium (NiTi) orthodontic wires. Uncoated, rhodium-coated, and nitrified NiTi wires were observed with a three-point-bend test, surface roughness (Ra) measurement, scanning electron microscopy, energy dispersive spectroscopy, and electrochemical testing (open circuit potential, electrochemical impedance spectroscopy, and cyclic polarization scan). Differences in the properties of tested wire types were analyzed with analysis of variance and Tukey post hoc test. Uncoated and nitrified NiTi wires showed similar mechanical and anticorrosive properties, while rhodium-coated NiTi wires showed the highest Ra and significantly higher modulus of elasticity, yield strength, and delivery of forces during loading but not in unloading. Rhodium-coated NiTi wires also had the highest corrosion current density and corrosion potential, lowest impedance modulus, and two time constants on Bode plot, one related to the Rh/Au coating and the other to underlying NiTi. Working properties of NiTi wires were unaffected by various coatings in unloading. Nitrification improved corrosion resistance. Rhodium coating reduced corrosion resistance and pronounced susceptibility to pitting corrosion in artificial saliva because of galvanic coupling between the noble coating and the base alloy.

  4. Modeling of corrosion product migration in the secondary circuit of nuclear power plants with WWER-1200

    Science.gov (United States)

    Kritskii, V. G.; Berezina, I. G.; Gavrilov, A. V.; Motkova, E. A.; Zelenina, E. V.; Prokhorov, N. A.; Gorbatenko, S. P.; Tsitser, A. A.

    2016-04-01

    Models of corrosion and mass transfer of corrosion products in the pipes of the condensate-feeding and steam paths of the secondary circuit of NPPs with WWER-1200 are presented. The mass transfer and distribution of corrosion products over the currents of the working medium of the secondary circuit were calculated using the physicochemical model of mass transfer of corrosion products in which the secondary circuit is regarded as a cyclic system consisting of a number of interrelated elements. The circuit was divided into calculated regions in which the change in the parameters (flow rate, temperature, and pressure) was traced and the rates of corrosion and corrosion products entrainment, high-temperature pH, and iron concentration were calculated. The models were verified according to the results of chemical analyses at Kalinin NPP and iron corrosion product concentrations in the feed water at different NPPs depending on pH at 25°C (pH25) for service times τ ≥ 5000 h. The calculated pH values at a coolant temperature t (pH t ) in the secondary circuit of NPPs with WWER-1200 were presented. The calculation of the distribution of pH t and ethanolamine and ammonia concentrations over the condensate feed (CFC) and steam circuits is given. The models are designed for developing the calculation codes. The project solutions of ATOMPROEKT satisfy the safety and reliability requirements for power plants with WWER-1200. The calculated corrosion and corrosion product mass transfer parameters showed that the model allows the designer to choose between the increase of the correcting reagent concentration, the use of steel with higher chromium contents, and intermittent washing of the steam generator from sediments as the best solution for definite regions of the circuit.

  5. Stable Titania Nanostructures on Stainless Steel Coronary Stent Surface for Enhanced Corrosion Resistance and Endothelialization.

    Science.gov (United States)

    Mohan, Chandini C; Cherian, Aleena Mary; Kurup, Sujish; Joseph, John; Nair, Manitha B; Vijayakumar, Maniyal; Nair, Shantikumar V; Menon, Deepthy

    2017-06-01

    Stainless steel (SS) coronary stents continue to present risk of in-stent restenosis that impact its long term safety and efficacy. The present work focuses on developing a drug-free and polymer-less surface on coronary stents by utilizing a titania (TiO 2 ) nanotexturing approach through hydrothermal processing, that will offer improved stent performance in vivo. Mechanically stable and durable nanotextured coatings are obtained on SS stents that also offer good corrosion resistance. In vitro vascular cell (endothelial and smooth muscle cells) studies on surface modified SS show preferential rapid endothelialization with enhanced nitric oxide production and reduce smooth muscle cell proliferation, in comparison to unmodified SS. In vivo evaluation of the nanotextured stents after subcutaneous implantation in rabbits show reduced irritability and minimal localized inflammatory response. These beneficial effects suggest that the stable, easily scalable titania nanosurface modification strategy on coronary stent surfaces can be a much cheaper alternative to drug eluting stents in addressing in-stent restenosis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Effect of Surface Contaminants Remained on the Blasted Surface on Epoxy Coating Performance and Corrosion Resistance

    International Nuclear Information System (INIS)

    Baek, Kwang Ki; Park, Chung Seo; Kim, Ki Hong; Chung, Mong Kyu; Park, Jin Hwan

    2006-01-01

    One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities

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

    Science.gov (United States)

    Paul, Subir; Yadav, Kasturi

    2011-04-01

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

  8. Mössbauer effect study of corrosion products from a Brazilian oil refinery

    Science.gov (United States)

    da Costa, M. I.; Kunrath, J. I.; Moro, J. T.; da Cunha, J. B. M.; Englert, G.; Comparsi, L. U.; Muller, I. L.

    1993-04-01

    Corrosion of an oil refining plant in southern Brazil is controlled by placing metallic coupons in strategic places of the unit. The amount of the corrosion products formed after two months of exposure of the coupons is then obtained by weight loss measurements. To have a better insight of these products an analysis by Conversion Electron and transmission Mössbauer spectroscopies was done on some of the coupons. This paper reports some of the findings.

  9. A mini-catalogue of metal corrosion products studied by Raman microscopy

    International Nuclear Information System (INIS)

    Bouchard, M.; Smith, D.C.

    2000-01-01

    Full text.The extensive development of physical methods of analysis since the beginning of this century has revolutionised the classical observation techniques most frequently used by the archaeologist. Raman Microscopy (RM) appears to be one of the most promising tools due to the many advantages that it offers: e.g. non-destructive, in situ, micro-analysis. RM is being applied to many archaeological fields as well as to industrial or environmental sectors. In relation with parallel studies made on the identification of corrosion products on archaeological materials, and according to the principal condition for the RM characterisation of an unknown product being the comparison of its Raman spectrum with known standard spectra, the essential aim of this study is to build a mini-catalogue of standard corrosion products susceptible to be found on metallic objects; these could be from archaeological as well as from modern contexts. However, it is noted that the identification of a corrosion product may suggest either an urgent intervention from the restoration team (in the case of active corrosion products), or a stabilisation of the corrosion layer if this is considered to be a protective layer. All the standard samples are natural minerals coming from the Museum National d'Histoire Naturelle in Paris (France) and correspond to the corrosion products most frequently found on metals such copper, zinc, lead or tin. These samples have been analyzed by RM and also confirmed by powder x-ray diffraction analysis. This catalogue, including more than 30 standard species corresponding to the most common metal corrosion products, is very useful for the different studies in progress in collaboration with different archaeological metal restoration teams. The near future will probably see a mobile Raman Microprobe (MRM) equipped with many different mini-catalogues on the site of a corroded mettalic bridge, a corroded canalisation or under the sea to rapidly identify the different

  10. Influence of Surface Pretreatment on the Corrosion Resistance of Cold-Sprayed Nickel Coatings in Acidic Chloride Solution

    Science.gov (United States)

    Scendo, Mieczyslaw; Zorawski, Wojciech; Staszewska-Samson, Katarzyna; Makrenek, Medard; Goral, Anna

    2018-03-01

    Corrosion resistance of the cold-sprayed nickel coatings deposited on the Ni surface (substrate) without and with abrasive grit-blasting treatment of the substrate was investigated. The corundum powder with different grain sizes was used. The corrosive environment contained an acidic chloride solution. The mechanism of the corrosion of nickel was suggested and discussed. Corrosion electrochemical parameters were determined by electrochemical methods. The corrosion effect of a nickel coating depends on the grain size used to prepare the substrate. The nickel coating after the medium grit-blasting treatment of the substrate was found to be the most corrosion resistant. However, the smallest resistance on the corrosion effect should be attributed to the nickel coating on the substrate after the coarse grit-blasting treatment.

  11. Surface monitoring for pitting evolution into uniform corrosion on Cu-Ni-Zn ternary alloy in alkaline chloride solution: ex-situ LCM and in-situ SECM

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Zheng, Zhaoran; Mao, Feixiong; Xu, Aoni; Ni, Xiaoqing; Man, Cheng; Yao, Jizheng; Xiao, Kui; Li, Xiaogang

    2018-05-01

    The evolution of the corrosion process on Cu-Ni-Zn alloy in alkaline chloride solution was investigated by in-situ scanning electrochemical microscopy, X-ray photoelectron spectroscopy, and ex-situ laser confocal microscopy, and the effects of ambient temperature and polarization time were also discussed. The results demonstrated a higher pitting nucleation rate and lower pit growth rate at low temperature. The ratio of pit depth to mouth diameter decreased with increasing pit volume and temperature, indicating that pits preferentially propagate in the horizontal direction rather than the vertical direction owing to the presence of corrosion products and deposited copper. The surface current was uniform and stabilized at approximately 2.2 nA during the passive stage, whereas the current increased after the pits were formed with the maximum approaching 3 nA. Increasing the temperature led to an increase in porous corrosion products (CuO, Zn(OH)2, and Ni(OH)2) and significantly increased the rate of transition from pitting to uniform corrosion. Dezincification corrosion was detected by energy dispersive spectrometry, and a mechanism for pitting transition into uniform corrosion induced by dezincification at the grain boundaries is proposed.

  12. Research and development on is process components for hydrogen production. (2) Corrosion resistance of glass lining in high temperature sulfuric acid

    International Nuclear Information System (INIS)

    Tanaka, Nobuyuki; Iwatsuki, Jin; Kubo, Shinji; Terada, Atsuhiko; Onuki, Kaoru

    2009-01-01

    Japan Atomic Energy Agency has been conducting a research and development on hydrogen production system using High Temperature Gas-Cooled Reactor. As a part of this effort, thermochemical water-splitting cycle featuring iodine- and sulfur-compounds (IS process) is under development considering its potential of large-scale economical hydrogen production. The IS process constitutes very severe environments on the materials of construction because of the corrosive nature of process chemicals, especially of the high temperature acidic solution of sulfuric acid and hydriodic acid dissolving iodine. Therefore, selection of the corrosion-resistant materials and development of the components has been studied as a crucial subject of the process development. This paper discusses corrosion resistance of commercially available glass-lining material in high temperature sulfuric acid. Corrosion resistance of a soda glass used for glass-lining was examined by immersion tests. The experiments were performed in 47-90wt% sulfuric acids at temperatures of up to 400degC and for the maximum immersion time of 100 hours using an autoclave designed for the concerned tests. In every condition tested, no indication of localized corrosion such as defect formation or pitting corrosion was observed. Also, the corrosion rates decreased with the progress of immersion, and were low enough (≅0.1 mm/year) after 60-90 hours of immersion probably due to formation of a silica rich surface. (author)

  13. Corrosion in Supercritical carbon Dioxide: Materials, Environmental Purity, Surface Treatments, and Flow Issues

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Anderson, Mark

    2013-12-10

    separately to high purity CO{sub 2}. Task 3: Evaluation of surface treatments on the corrosion performance of alloys in supercritical CO{sub 2}: Surface treatments can be very beneficial in improving corrosion resistance. Shot peening and yttrium and aluminum surface treatments will be investigated. Shot peening refines the surface grain sizes and promotes protective Cr-oxide layer formation. Both yttrium and aluminum form highly stable oxide layers (Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), which can get incorporated in the growing Fe-oxide layer to form an impervious complex oxide to enhance corrosion resistance. Task 4: Study of flow-assisted corrosion of select alloys in supercritical CO{sub 2} under a selected set of test conditions: To study the effects of flow-assisted corrosion, tests will be conducted in a supercritical CO{sub 2} flow loop. An existing facility used for supercritical water flow studies at the proposing university will be modified for use in this task. The system is capable of flow velocities up to 10 m/s and can operate at temperatures and pressures of up to 650°C and 20 MPa, respectively. All above tasks will be performed in conjunction with detailed materials characterization and analysis using scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS), x-ray diffraction (XRD), Auger electron spectroscopy (AES) techniques, and weight change measurements. Inlet and outlet gas compositions will be monitored using gas chromatography-mass spectrometry (GCMS).

  14. Laser gas assisted treatment of steel 309: Corrosion and scratch resistance of treated surface

    Science.gov (United States)

    Toor, Ihsan-ul-Haq; Yilbas, B. S.; Ahmed, Junaid; Karatas, C.

    2017-10-01

    Laser gas assisted surface treatment of steel 309 is carried out and the characteristics of the resulting surface are analyzed using the analytical tools. Scanning electron and 3-D optical microscopes are used to assess the morphological and metallurgical changes in the laser treated layer. Energy spectroscopy and X-ray diffraction are carried out to determine the elemental composition and compounds formed on the laser treated surface. The friction coefficient of the laser treated surface is measured using the micro-tribometer and compared to that of the as received surface. The corrosion resistance of the laser treated and as received surfaces is measured incorporating the electrochemical tests. It is found that laser treatment results in a dense layer and formation of nitride compounds at the surface. This enhances the microhardness at the laser treated surface. The friction coefficient attains lower values at the laser treated surface than that corresponding to the as received surface. The corrosion rate of the surface reduces significantly after the laser treatment process, which can be attributed to the passive layer at the surface via formation of a dense layer and nitride compounds in the surface vicinity. In addition, the number of pit sites decreased for the laser treated surface than that of as received surface.

  15. 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...

  16. The characteristics of surface oxidation and corrosion resistance of nitrogen implanted zircaloy-4

    International Nuclear Information System (INIS)

    Tang, G.; Choi, B.H.; Kim, W.; Jung, K.S.; Kwon, H.S.; Lee, S.J.; Lee, J.H.; Song, T.Y.; Shon, D.H.; Han, J.G.

    1997-01-01

    This work is concerned with the development and application of ion implantation techniques for improving the corrosion resistance of zircaloy-4. The corrosion resistance in nitrogen implanted zircaloy-4 under a 120 keV nitrogen ion beam at an ion dose of 3 x 10 17 cm -2 depends on the implantation temperature. The characteristics of surface oxidation and corrosion resistance were analyzed with the change of implantation temperature. It is shown that as implantation temperature rises from 100 to 724 C, the colour of specimen surface changes from its original colour to light yellow at 100 C, golden at 175 C, pink at 300 C, blue at 440 C and dark blue at 550 C. As the implantation temperature goes above 640 C, the colour of surface changes to light black, and the surface becomes a little rough. The corrosion resistance of zircaloy-4 implanted with nitrogen is sensitive to the implantation temperature. The pitting potential of specimens increases from 176 to 900 mV (SCE) as the implantation temperature increases from 100 to 300 C, and decreases from 900 to 90 mV(SCE) as the implantation temperature increases from 300 to 640 C. The microstructure, the distribution of oxygen, nitrogen and carbon elements, the oxide grain size and the feature of the precipitation in the implanted surface were investigated by optical microscope, TEM, EDS, XRD and AES. The experimental results reveal that the ZrO 2 is distributed mainly on the outer surface. The ZrN is distributed under the ZrO 2 layer. The characteristics of the distribution of ZrO 2 and ZrN in the nitrogen-implanted zircaloy-4 is influenced by the implantation temperature of the sample, and in turn the corrosion resistance is influenced. (orig.)

  17. Influence of the surface finishing on electrochemical corrosion characteristics of AISI 316L stainless steel

    Directory of Open Access Journals (Sweden)

    Sylvia Dundeková

    2015-05-01

    Full Text Available Stainless steels from 316 group are very often and successfully uses for medical applications where the good mechanical and chemical properties in combination with non-toxicity of the material assure its safe and long term usage. Corrosion properties of AISI 361L stainless steel are strongly influenced by surface roughness and treatment of the engineering parts (specimens and testing temperature. Electrochemical characteristics of ground, mechanically polished and passivated AISI 316L stainless steel specimens were examined with the aim to identify the polarization resistance evolution due to the surface roughness decrease. Results obtained on mechanically prepared specimens where only natural oxide layer created due to the exposure of the material to the corrosion environment was protecting the materials were compared to the passivated specimens with artificial oxide layer. Also the influence of temperature and stabilization time before measurement were taken into account when discussing the obtained results. Positive influence of decreasing surface roughness was obtained as well as increase of polarization resistance due to the chemical passivation of the surface. Increase of the testing temperature and short stabilization time of the specimen in the corrosion environment were observed negatively influencing corrosion resistance of AISI 316L stainless steel.

  18. Effects of surface topography and vibrations on wetting: Superhydrophobicity, icephobicity and corrosion resistance

    Science.gov (United States)

    Ramachandran, Rahul

    Concrete and metallic materials are widely used in construction and water industry. The interaction of both these materials with water and ice (or snow) produces undesirable results and is therefore of interest. Water that gets absorbed into the pores of dry concrete expands on freezing and can lead to crack formation. Also, the ice accretion on concrete surfaces such as roadways can have disastrous consequence. Metallic components used in the water industry undergo corrosion due to contact with aqueous corrosive solutions. Therefore, it is desirable to make concrete water/ice-repellent, and to make metallic surfaces corrosion-resistant. Recent advances in micro/nanotechnology have made it possible to design functional micro/nanostructured surfaces with micro/nanotopography providing low adhesion. Some examples of such surfaces are superhydrophobic surfaces, which are extremely water repellent, and icephobic surfaces, which have low ice adhesion, repel incoming water droplets before freezing, or delay ice nucleation. This dissertation investigates the effects of surface micro/nanotopography and small amplitude fast vibrations on the wetting and adhesion of concrete with the goal of producing hydrophobic and icephobic concrete, and on the wetting of metallic surfaces to prevent corrosion. The relationship between surface micro/nanotopography and small fast vibrations is established using the method of separation of motions. Both these small scale effects can be substituted by an effective force or energy. The structure-property relationships in materials and surfaces are established. Both vibrations as well as surface micro/nanopatterns can affect wetting properties such as contact angle and surface free energy. Hydrophobic engineered cementitious composite samples are produced by controlling their surface topography and surface free energy. The surface topography is controlled by varying the concrete mixture composition. The surface free energy of concrete is

  19. Studies on dissolution characteristics of simulated corrosion products on pressurized water reactor primary coolant loops. Pt.2: Cobalt simulated corrosion product

    International Nuclear Information System (INIS)

    Li Shan; Zhou Xianyu

    1997-01-01

    The studies on the dissolution characteristics of simulated corrosion product of cobalt on pressurized water reactor primary coolant loops in aqueous solution of citric acid, hydrogen peroxide and citric acid-hydrogen peroxide have been performed. The results show that the portion of the dissolved simulated corrosion product of cobalt in citric acid aqueous solution clearly increases with a rise in citric acid concentration and is ten times above the corresponding value of iron. The portion of the products that dissolve is the largest at pH 3.00 in the pH range of 2.33∼4.50 and at 70 degree C in the range of 60∼80 degree C. It is shown that the portion of the dissolved simulated corrosion product of cobalt in hydrogen peroxide aqueous solution is smaller than the corresponding value in citric acid, and that the portion of the dissolved simulated corrosion product of cobalt in aqueous solution of hydrogen peroxide-citric acid is larger than the corresponding value in single citric acid aqueous solution

  20. Identification of microorganisms associated with corrosion of offshore oil production systems

    Science.gov (United States)

    Sørensen, Ketil; Grigoryan, Aleksandr; Holmkvist, Lars; Skovhus, Torben; Thomsen, Uffe; Lundgaard, Thomas

    2010-05-01

    Microbiologically influenced corrosion (MIC) poses a major challenge to oil producers and distributors. The annual cost associated with MIC-related pipeline failures and general maintenance and surveillance of installations amounts to several billion dollar in the oil production sector alone. Hence, large efforts are undertaken by some producers to control and monitor microbial growth in pipelines and other installations, and extensive surveillance programs are carried out in order to detect and quantify potential MIC-promoting microorganisms. Traditionally, efforts to mitigate and survey microbial growth in oil production systems have focused on sulfate-reducing Bacteria (SRB), and microorganisms have usually been enumerated by the culture-dependent MPN (most probable number) -technique. Culture-independent molecular tools yielding much more detailed information about the microbial communities have now been implemented as a reliable tool for routine surveillance of oil production systems in the North Sea. This has resulted in new and hitherto unattainable information regarding the distribution of different microorganisms in hot reservoirs and associated oil production systems. This presentation will provide a review of recent insights regarding thermophilic microbial communities and their implication for steel corrosion in offshore oil production systems. Data collected from solids and biofilms in different corroded pipelines and tubes indicate that in addition to SRB, other groups such as methanogens and sulfate-reducing Archaea (SRA) are also involved in MIC. In the hot parts of the system where the temperature approaches 80 ⁰C, SRA closely related to Archaeoglobus fulgidus outnumber SRB by several orders of magnitude. Methanogens affiliated with the genus Methanothermococcus were shown to completely dominate the microbial community at the metal surface in a sample of highly corroded piping. Thus, the microbial communities associated with MIC appear to be more

  1. Slippery liquid-infused porous surfaces fabricated on aluminum as a barrier to corrosion induced by sulfate reducing bacteria

    International Nuclear Information System (INIS)

    Wang, Peng; Lu, Zhou; Zhang, Dun

    2015-01-01

    Highlights: • Slippery liquid-infused porous surfaces (SLIPS) were fabricated over aluminum. • SLIPS depress the adherence of sulfate reducing bacteria in static seawater. • SLIPS inhibit the microbiological corrosion of aluminum in static seawater. • The possible microbiological corrosion protection mechanism of SLIPS is proposed. - Abstract: Microbiological corrosion induced by sulfate reducing bacteria (SRB) is one of the main threatens to the safety of marine structure. To reduce microbiological corrosion, slippery liquid infused porous surfaces (SLIPS) were designed and fabricated on aluminum substrate by constructing rough aluminum oxide layer, followed by fluorination of the rough layer and infiltration with lubricant. The as-fabricated SLIPS were characterized with wettability measurement, SEM and XPS. Their resistances to microbiological corrosion induced by SRB were evaluated with fluorescence microscopy and electrochemical measurement. It was demonstrated that they present high resistance to bacteria adherence and the resultant microbiological corrosion in static seawater

  2. 77 FR 27438 - Certain Corrosion-Resistant Carbon Steel Flat Products From Korea: Final Results of Expedited...

    Science.gov (United States)

    2012-05-10

    ... International Trade Administration Certain Corrosion-Resistant Carbon Steel Flat Products From Korea: Final... third five-year sunset review of the countervailing duty order on certain corrosion-resistant carbon..., plated, or coated with corrosion-resistant metals such as zinc, aluminum, or zinc-, aluminum-, nickel- or...

  3. 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..., 2010, the Department published the preliminary results of this review. See Certain Corrosion-Resistant...

  4. 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.... See Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Preliminary Results of...

  5. 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..., 2011, the Department published the preliminary results of this review. See Certain Corrosion-Resistant...

  6. 78 FR 19210 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2013-03-29

    ... 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... subsidies that result in de minimis net subsidy rates. \\1\\ See Corrosion-Resistant Carbon Steel Flat...

  7. 76 FR 3613 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Final Results of...

    Science.gov (United States)

    2011-01-20

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea) for the period of review (POR) January 1, 2008, through December 31, 2008. See Corrosion-Resistant Carbon Steel Flat...

  8. 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... partial revocation of the countervailing duty order on corrosion-resistant carbon steel flat products from...

  9. PITTING CORROSION OF AISI 316Ti STAINLESS STEEL WITH POLISHED SURFACE

    Directory of Open Access Journals (Sweden)

    Viera Zatkalíková

    2010-05-01

    Full Text Available AISI 316Ti is Cr–Ni–Mo austenitic stainless steel with the high Pitting Resistance Equivalent Number (PREN. The effect of the surface finishing by polishing on the pitting corrosion resistance was tested in aggressive 5% FeCl3 solution. The immersion tests were curried out at the temperature 30, 50, 80 °C. The electrochemical cyclic potentiodynamic tests were carried out in the same solution at temperature 30 and 50 °C. The evaluation of the corrosion resistance arose from the comparison of the results of the immersion and the cyclic potentiodynamic tests.

  10. Colorimetric visualization of tin corrosion: A method for early stage corrosion detection on printed circuit boards

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2017-01-01

    A majority of printed circuit board surfaces are covered with tin, therefore tin corrosion under humid conditions and movement of tin ions under the influence of an electric field plays an important role in the corrosion failure development. Tracking tin corrosion products spread on the printed...

  11. The nature of the surface film on steel treated with cerium and lanthanum cinnamate based corrosion inhibitors

    International Nuclear Information System (INIS)

    Blin, Frederic; Leary, Stuart G.; Deacon, Glen B.; Junk, Peter C.; Forsyth, Maria

    2006-01-01

    The corrosion inhibition mechanisms of new cerium and lanthanum cinnamate based compounds have been investigated through the surface characterisation of the steel exposed to NaCl solution of neutral pH. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to identify the nature of the deposits on the metal surface and demonstrated that after accelerated tests the corrosion product commonly observed on steel (i.e. lepidocrocite, γ-FeOOH) is absent. The cinnamate species were clearly present on the steel surface upon exposure to NaCl solution for short periods and appeared to coordinate through the iron. At longer times the Rare Earth Metal (REM) oxyhydroxide species are proposed to form as identified through the bands in the 1400-1500 cm -1 region. These latter bands have been previously assigned to carbonate species adsorbed onto REM oxyhydroxide surfaces. The protection mechanism appears to involve the adsorption of the REM-cinnamate complex followed by the hydrolysis of the REM to form a barrier oxide on the steel surface

  12. Improving the corrosion resistance of proton exchange membrane fuel cell carbon supports by pentafluorophenyl surface functionalization

    Science.gov (United States)

    Forouzandeh, Farisa; Li, Xiaoan; Banham, Dustin W.; Feng, Fangxia; Joseph Kakanat, Abraham; Ye, Siyu; Birss, Viola

    2018-02-01

    In this study, the effect of surface functionalization on the electrochemical corrosion resistance of a high surface area, mesoporous colloid imprinted carbon powder (CIC), as well as microporous Vulcan carbon (VC, serving as the benchmark), was demonstrated, primarily for PEM fuel cell applications. CIC-22, which is highly hydrophilic and was synthesized with 22 nm silica colloid templates, and as-received, mildly hydrophobic, VC powders, were functionalized with 2,3,4,5,6-pentafluorophenyl (-PhF5) surface groups using a straightforward diazonium reduction reaction. These carbons were then subjected to corrosion testing, involving a potential cycling-step sequence in room temperature 0.5 M H2SO4. Using cyclic voltammetry and charge/time analysis, the double layer and pseudo-capacitive gravimetric charges of the carbons, prior to and after the application of these potential steps, were tracked in order to obtain information about surface area changes and the extent of carbon oxidation, respectively. It is shown that the corrosion resistance was improved by ca. 50-80% by surface functionalization, likely due to a combination of surface passivation (loss of carbon active sites) and increased surface hydrophobicity.

  13. Corrosion resistance, chemistry, and mechanical aspects of Nitinol surfaces formed in hydrogen peroxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Shabalovskay, Svetlana A.; Anderegg, James W.; Undisz, Andreas; Rettenmayr, Markus; Rondelli, Gianni C.

    2012-06-12

    Ti oxides formed naturally on Nitinol surfaces are only a few nanometers thick. To increase their thickness, heat treatments are explored. The resulting surfaces exhibit poor resistance to pitting corrosion. As an alternative approach to accelerate surface oxidation and grow thicker oxides, the exposure of Nitinol to strong oxidizing H2O2 aqueous solutions (3 and 30%) for various periods of time was used. Using X-Ray Photoelectron Spectroscopy (XPS) and Auger spectroscopy, it was found that the surface layers with variable Ti (6–15 at %) and Ni (5–13 at %) contents and the thickness up to 100 nm without Ni-enriched interfaces could be formed. The response of the surface oxides to stress in superelastic regime of deformations depended on oxide thickness. In the corrosion studies performed in both strained and strain-free states using potentiodynamic and potentiostatic polarizations, the surfaces treated in H2O2 showed no pitting in corrosive solution that was assigned to higher chemical homogeneity of the surfaces free of secondary phases and inclusions that assist better biocompatibility of Nitinol medical devices. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 1490–1499, 2012

  14. Superhydrophobic copper surfaces fabricated by fatty acid soaps in aqueous solution for excellent corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wenlong; Hu, Yuanyuan; Bao, Wenda; Xie, Xiaoyu; Liu, Yiran; Song, Aixin, E-mail: songaixin@sdu.edu.cn; Hao, Jingcheng

    2017-03-31

    Highlights: • The superhydrophobic property can be realized in a much quicker process (7.5 min) in aqueous solution than in ethanol. • The fabrication process of superhydrophobic metal surfaces greatly increases the safety in industrial manufacture in commercial scale. • The superhydrophobic copper surfaces show excellent corrosion resistance. - Abstract: A simple and safe one-step immersion method was developed to obtain the stable superhydrophobic copper surfaces with excellent corrosion resistance ability using fatty acids in water-medium instead of ethanol. An organic alkali, N,N-dimethylcyclohexylamine (DMCHA), was chosen to solve the poor solubility of fatty acids in water and the high Krafft point of carboxylate salts with inorganic counterions. The superhydrophobic property can be realized in a much quicker process (7.5 min) in aqueous solution than in ethanol (more than 2 d), which is universally feasible for the fabrication of superhydrophobic metal surfaces in industry scale, thereby greatly increasing the safety in industrial manufacture.

  15. The effect of different surface treatments on the molten salt hot corrosion of IN-657 superalloy

    International Nuclear Information System (INIS)

    Otero, E.; Utrilla, M.V.

    1996-01-01

    The influence of different surface treatments (laser surface treatment, silicon nitride, and 25 wt.% Al 2 (OH) 4 Si 2 O 5 -75 wt.% Na 2 SiO 3 ), on the hot corrosion behaviour of IN-657 superalloy has been studied. The corrosion tests were performed in an oxidizing atmosphere in contact with a molten mixture of 82% K 2 S 2 O 7 -18% V 2 O 5 . The effects of operation temperature and carbon residues as component of the molten mixture were also analyzed. The best results were obtained for the kaolin and methasilicate mixture coating. Laser surface treatment and the CVD-silicon nitride are not recommended for surface modification of the IN-657 superalloy. Taking into account the results obtained, the authors suggest the average temperature and molten salt compositions where the above coating can work satisfactorily. (orig.)

  16. INFLUENCE OF PHOSPHATIZED SURFACE LAYER ON CORROSION RESISTANCE OF Mg-Al-RE ALLOY

    Directory of Open Access Journals (Sweden)

    Katarína Miková

    2015-09-01

    Full Text Available This contribution deals with evaluation of the corrosion resistance of extruded Mg-2Al-1RE (AE21 magnesium alloy in the state before and after treatment of ground surface by selected phosphatizing procedure. Specimens were exposed to 0.1M NaCl solution for several time periods starting from 5 minutes up-to 168 hours at room temperature of 22 ± 1 °C. Afterwards electrochemical impedance spectroscopy was carried out on the exposed specimens. Based on the results obtained from the electrochemical tests and visual observation of corrosion attack progress, positive or negative impact of selected phosphating process on the corrosion resistance of Mg-2Al-1RE magnesium alloy under given conditions was assessed.

  17. Electrochemical Impedance and Polarization Corrosion Studies of Tantalum Surface Modified by DC Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Maciej Sowa

    2018-04-01

    Full Text Available Tantalum has recently become an actively researched biomaterial for the bone reconstruction applications because of its excellent corrosion resistance and successful clinical records. However, a bare Ta surface is not capable of directly bonding to the bone upon implantation and requires some method of bioactivation. In this study, this was realized by direct current (DC plasma electrolytic oxidation (PEO. Susceptibility to corrosion is a major factor determining the service-life of an implant. Therefore, herein, the corrosion resistance of the PEO coatings on Ta was investigated in Ringer’s solution. The coatings were formed by galvanostatic anodization up to 200, 300 and 400 V, after which the treatment was conducted potentiostatically until the total process time amounted to 5 min. Three solutions containing Ca(H2PO22, Ca(HCOO2 and Mg(CH3COO2 were used in the treatment. For the corrosion characterization, electrochemical impedance spectroscopy and potentiodynamic polarization techniques were chosen. The coatings showed the best corrosion resistance at voltages low enough so that the intensive sparking was absent, which resulted in the formation of thin films. The impedance data were fitted to the equivalent electrical circuits with two time constants, namely R(Q[R(QR] and R(Q[R(Q[RW

  18. Superhydrophobic surface fabricated on iron substrate by black chromium electrodeposition and its corrosion resistance property

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resource, Chinese Academy of Science, Xining 810008, Qinghai (China); Feng, Haitao [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resource, Chinese Academy of Science, Xining 810008, Qinghai (China); Lin, Feng [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Yabin [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resource, Chinese Academy of Science, Xining 810008, Qinghai (China); Wang, Liping [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Dong, Yaping [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resource, Chinese Academy of Science, Xining 810008, Qinghai (China); Li, Wu, E-mail: liwu2016@126.com [Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai (China); Key Lab of Comprehensive and Highly Efficient Utilization of Salt Lake Resource, Chinese Academy of Science, Xining 810008, Qinghai (China)

    2016-08-15

    Highlights: • Superhydrophobic surface was fabricated by black chromium electrodeposition and stearic acid modification. • The reaction process is simple, and of low cost, and no special instrument or environment is needed. • The obtained superhydrophobic surface presents good water repellency, and performs well at corrosion resistance. - Abstract: The fabrication of superhydrophobic surface on iron substrate is carried out through 20 min black chromium electrodeposition, followed by immersing in 0.05 M ethanolic stearic acid solution for 12 h. The resultant superhydrophobic complex film is characterized by scanning electron microscope (SEM), disperse Spectrometer (EDS), atomic force microscope (AFM), water contact angle (CA), sliding angle (SA) and X-ray photoelectron spectroscope (XPS), and its corrosion resistance property is measured with cyclic voltammetry (CV), linear polarization and electrochemical impedance spectroscopy (EIS). The results show that the fabricated superhydrophobic film has excellent water repellency (CA, 158.8°; SA, 2.1°) and significantly high corrosion resistance (1.31 × 10{sup 6} Ω cm{sup −2}) and excellent corrosion protection efficiency (99.94%).

  19. An Evaluation of the Corrosion and Mechanical Performance of Interstitially Surface Hardened Stainless Steel

    Science.gov (United States)

    2013-05-10

    pitting corrosion and is present in stainless steels due to the chromium concentration in the microstructure . As the potential increases, the...carbon and nitrogen as the interstitial atom. The hardness and thickness of the surface hardened layer is characterized and compared using...hardened using available commercial techniques, using both carbon and nitrogen as the interstitial atom. The hardness and thickness of the surface

  20. Impact of β- radiolysis and transient products on irradiation-enhanced corrosion of zirconium alloys

    International Nuclear Information System (INIS)

    Lemaignan, C.

    1992-01-01

    An analysis has been undertaken of the various cases of local enhancement of the corrosion rate of zirconium alloys under irradiation. It is observed that in most cases a strong emission of energetic β - is present leading to a local energy desorption rate higher than the core average. This suggests that the local transient radiolytic oxidising species produced in the coolant by the β - particles could contribute to corrosion enhancement, by increasing the local corrosion potential. This process is applicable to the local enhanced corrosion found in front of stainless steels structural parts, due to the contribution of Mn, in front of Pt inserts and Cu-rich cruds. It explains also the irradiation corrosion enhancement of Cu-rich Zr alloys. Enhanced corrosion around neutron absorbing material is explained similarly by pair production from conversion of high energy capture photons in the cladding, leading to energetic electrons. The same process was found to be active with other highly ionising species like α in Ni-rich alloys and fission products in homogeneous reactors. This mechanism, applicable for an explanation of localised irradiation-enhanced corrosion, is proposed to be extended to the reactor core, where the general enhancement of Zr-alloy corrosion under irradiation would be due to the general radiolysis. It suggests that care should be taken to avoid any source of β - emission or other ionising species in the reactor core that could give an increase of energy deposition rate for radiolysis. Also the corrosion testing conditions for the materials to be used in reactors have to be relevant to the radiolytic environments found in the reactor cores. (orig.)

  1. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants.

    Science.gov (United States)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-10-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes-conversion and deposition coatings-while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches are

  2. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

    International Nuclear Information System (INIS)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-01-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

  3. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

    Science.gov (United States)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-01-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

  4. Atmospheric corrosion in subtropical areas: XRD and electrochemical study of zinc atmospheric corrosion products in the province of Santa Cruz de Tenerife (Canary Islands, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Morales, J. [Departamento de Quimica Fisica, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain)]. E-mail: jmorales@ull.es; Diaz, F. [Departamento de Quimica Fisica, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain); Hernandez-Borges, J. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain); Gonzalez, S. [Departamento de Quimica Fisica, Universidad de La Laguna, 38071 La Laguna, Tenerife (Spain)

    2006-02-15

    In the present paper, zinc sheets have been exposed for 4 years to the action of different atmospheres in 35 test sites located in the province of Santa Cruz de Tenerife, Canary Islands, Spain. Corrosion products formed on the surface of the samples have been identified by means of X-ray diffraction (XRD) for the first and second year of exposure. Zincite, hydrozincite, simonkolleite, zinc chlorohydroxysulphate, zinc oxysulphate and zinc hydroxysulphate have been identified in the test sheets. Preliminary results of an electrochemical study of the breakdown potential of zinc samples are also presented in order to test the protective effect of the film formed on the surface of the samples. It was found that the protective effect of this film increases linearly with exposure time.

  5. 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

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

    International Nuclear Information System (INIS)

    Taniguchi, N.

    2003-01-01

    The mechanism of the acceleration of the corrosion of carbon steel due to the presence of magnetite was studied. Immersion tests of carbon steel in the presence of magnetite powder were performed using sealed glass ampoules. Hydrogen gas enclosed in the ampoule was analysed by gas chromatography, and the material balance of hydrogen gas and reduced Fe(III) in the magnetite against the weight loss of the specimens was analysed. The analysis showed that the main cathodic reaction in the presence of magnetite powder was the reduction of Fe(III). The effect of magnetite on the lifetime of carbon steel overpacks is also discussed in this paper. (author)

  7. Evaluation of effect of surface treatment on corrosion resistance of Nd-Fe-B magnets

    International Nuclear Information System (INIS)

    Martins, Emerson Alves

    2009-01-01

    Nd-Fe-B magnets produced by powder metallurgy are highly susceptible to corrosion due to their complex microstructure and intrinsic porosity due to their fabrication process. Moreover, these magnets have excellent magnetic properties and find many applications. In the nuclear area, permanent magnets based on rare earth transition-iron-boron (Ne-Fe-B) are used in the manufacture of magnetic media (magnetic levitation) for ultra-centrifuges used for isotopic enrichment of uranium employed in nuclear reactors. In dentistry these types of magnets are used to fix total and partial prostheses on implants; in orthodontics to correct dental malocclusion and make moves; in buco-maxillo-facial surgery for setting facial prostheses of large defects of the face. In electronic equipment, they are used in scales, locks, electric motors and particularly in the manufacturing of hard drives of computers. The objective of this study is to evaluate the corrosion resistance of the magnet tested and surface treatments that could replace chromating that generates toxic residues and present high cost of processing waste with treatments that are environmentally friendly. The evaluation of the corrosion resistance was carried out through the analysis potentiodynamic polarization curves, electrochemical impedance spectroscopy, monitoring of corrosion potential as a function of test time and scanning electron microscopy to try to correlate the magnet microstructure with its corrosion resistance. The results show that these magnets are highly susceptible to corrosion that occurs preferentially in the Nd-rich phase, located in the boundaries of the magnetic matrix phase (ψ). Treatment with silane, cerium, sam, Cr 6 + , tricationic phosphate followed by bath of chromium trioxide and in NaH 2 PO 4 solution for 24 hours followed by bath of zinc sulphate did not improve the corrosion resistance of the magnet. Among the treatments used, immersion in NaH 2 PO 4 solution for 24 hours pH=3.8 was the

  8. Effect of surface morphology on atmospheric corrosion behaviour of ...

    Indian Academy of Sciences (India)

    Co18Si1B14 ribbon, was evaluated. The wheel side surface of the ribbon was more corroded than the air side surface, due to the higher density of air pockets present. The phases present in atmospheric rust were analysed by X-ray diffraction ...

  9. Surface modifications of steels to improve corrosion resistance in sulfidizing-oxidizing environments

    Science.gov (United States)

    Behrani, Vikas

    Industrial and power generation processes employ units like boilers and gasifiers to burn sulfur containing fuels to produce steam and syn gas (H 2 and CO), which can generate electricity using turbines and fuel cells. These units often operate under environments containing gases such as H 2S, SO2, O2 etc, which can attack the metallic structure and impose serious problems of corrosion. Corrosion control in high temperature sulfur bearing environments is a challenging problem requiring information on local gaseous species at the surface of alloy and mechanisms of degradation in these environments. Coatings have proved to be a better alternative for improving corrosion resistance without compromising the bulk mechanical properties. Changes in process conditions may result in thermal and/or environment cycling between oxidizing and sulfidizing environments at the alloy surface, which can damage the protective scale formed on the alloy surface, leading to increase in corrosion rates. Objective of this study was to understand the effect of fluctuating environments on corrosion kinetics of carbon steels and develop diffusion based coatings to mitigate the high temperatures corrosion under these conditions. More specifically, the focus was: (1) to characterize the local gaseous environments at the surface of alloys in boilers; (2) optimizing diffusion coatings parameters for carbon steel; (3) understand the underlying failure mechanisms in cyclic environments; (4) to improve aluminide coating behavior by co-deposition of reactive elements such as Yttrium and Hafnium; (5) to formulate a plausible mechanism of coating growth and effects of alloying elements on corrosion; and (6) to understand the spallation behavior of scale by measuring stresses in the scales. The understanding of coating mechanism and effects of fluctuating gaseous environments provides information for designing materials with more reliable performance. The study also investigates the mechanism behind

  10. Corrosion behavior of super-hydrophobic surface on copper in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tao; Chen Shougang; Cheng Sha; Tian Jintao; Chang Xueting [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Yin Yansheng [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)], E-mail: yys2003@ouc.edu.cn

    2007-11-01

    A novel super-hydrophobic film was prepared by myristic acid (n-tetradecanoic) chemically adsorbed onto the copper wafer. The film formation and its structure were characterized by means of water contact angle measurement, Fourier transformation infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The static contact angle for water on the surface of this organic film was measured to be as high as 158{sup o}. The formation of a composite interface composed of the flower-like surface nanostructures, water droplet and air trapped in the crevices was suggested to be responsible for the superior water-repellent property. The corrosion behavior of the super-hydrophobic surface was investigated with potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Due to the 'air valleys' and 'capillarity' effects, the corrosion resistance of the material was improved remarkably.

  11. Corrosion behavior of super-hydrophobic surface on copper in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tao; Chen, Shougang; Cheng, Sha; Tian, Jintao; Chang, Xueting; Yin, Yansheng [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2007-11-01

    A novel super-hydrophobic film was prepared by myristic acid (n-tetradecanoic) chemically adsorbed onto the copper wafer. The film formation and its structure were characterized by means of water contact angle measurement, Fourier transformation infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The static contact angle for water on the surface of this organic film was measured to be as high as 158 . The formation of a composite interface composed of the flower-like surface nanostructures, water droplet and air trapped in the crevices was suggested to be responsible for the superior water-repellent property. The corrosion behavior of the super-hydrophobic surface was investigated with potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Due to the 'air valleys' and 'capillarity' effects, the corrosion resistance of the material was improved remarkably. (author)

  12. Effect of Surface Pretreatment on Quality and Electrochemical Corrosion Properties of Manganese Phosphate on S355J2 HSLA Steel

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

    Roč. 6, č. 4 (2016), s. 1-9 ISSN 2079-6412 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : corrosion * steel * sandblasting * manganese phosphate Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 2.175, year: 2016 http://www.mdpi.com/2079-6412/6/4/46

  13. Exposing the sub-surface of historical daguerreotypes and the effects of sulfur-induced corrosion

    International Nuclear Information System (INIS)

    Marquis, Emmanuelle A.; Chen, Yimeng; Kohanek, Julia; Dong, Yan; Centeno, Silvia A.

    2015-01-01

    Highlights: • Ungilded and gilded daguerreotypes were prepared in the laboratory. • Processing conditions were correlated to microstructures and behavior to S exposure. • The observations revealed key structural consequences of the gilding process. • Corrosion of the Ag layer was confirmed on a 19th century gilded daguerreotype. • Cu and Ag sulfide particles accumulated on the plate surfaces during corrosion. - Abstract: Preventing the loss of image detail and resolution in historical photographs is a crucial topic, yet the properties of the image particles and mechanisms of deterioration are not fully understood. Through detailed surface and cross sectional analyzes, ungilded and gilded daguerreotypes prepared in the laboratory were analyzed before and after exposure to high sulfur-concentration environments revealing important structural consequences of the gilding process. Comparisons with the surface and sub-surface structures found on a 19th century gilded daguerreotype confirmed the slow corrosion of the underlying Ag and the accumulation of Cu and Ag sulfide particles on the surfaces of the plates

  14. Effects of Ultrasonic Nanocrystal Surface Modification on the Residual Stress, Microstructure, and Corrosion Resistance of 304 Stainless Steel Welds

    Science.gov (United States)

    Ye, Chang; Telang, Abhishek; Gill, Amrinder; Wen, Xingshuo; Mannava, Seetha R.; Qian, Dong; Vasudevan, Vijay K.

    2018-01-01

    In this study, ultrasonic nanocrystal surface modification (UNSM) of 304 stainless steel welds was carried out. UNSM effectively eliminates the tensile stress generated during welding and imparts beneficial compressive residual stresses. In addition, UNSM can effectively refine the grains and increase hardness in the near-surface region. Corrosion tests in boiling MgCl2 solution demonstrate that UNSM can significantly improve the corrosion resistance due to the compressive residual stresses and changes in the near-surface microstructure.

  15. Effects of Ultrasonic Nanocrystal Surface Modification on the Residual Stress, Microstructure, and Corrosion Resistance of 304 Stainless Steel Welds

    Science.gov (United States)

    Ye, Chang; Telang, Abhishek; Gill, Amrinder; Wen, Xingshuo; Mannava, Seetha R.; Qian, Dong; Vasudevan, Vijay K.

    2018-03-01

    In this study, ultrasonic nanocrystal surface modification (UNSM) of 304 stainless steel welds was carried out. UNSM effectively eliminates the tensile stress generated during welding and imparts beneficial compressive residual stresses. In addition, UNSM can effectively refine the grains and increase hardness in the near-surface region. Corrosion tests in boiling MgCl2 solution demonstrate that UNSM can significantly improve the corrosion resistance due to the compressive residual stresses and changes in the near-surface microstructure.

  16. 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.

  17. Analysis of corrosion product transport in PWR primary system under non-convective condition

    International Nuclear Information System (INIS)

    Han, Byoung Sub

    1992-02-01

    The increase of occupational radiation exposure (ORE) due to the increase of the operational period at existing nuclear power plant and also the publication of the new version of ICRP recommendation (ICRP publication No. 60) for radiological protection require much more strict reduction of radiation buildup in the nuclear power plant. The major sources of the radiation, i.e. the radioactive corrosion-products, are generated by the neutron activation of the corrosion products at the reactor core, and then the radioactive corrosion products are transported to the outside of the core, and accumulated near the steam generator side at PWR. Major radioactive corrosion-products of interest in PWR are Cr 51 ,: Mn 54 ,: Co 58 ,: Fe 59 and Co 60 . Among them Co 58 and Co 60 are known to contribute approximately more than 70% of the total ORE. Thus our main concerns are focused on predicting the transport and deposition of the Co radionuclides and suggesting the optimizing method which can minimize and control the ORE of the nuclear power plant. It is well known that Co-source is most effectively controlled by pH-solubility radiation control, and also some complex computer codes such as CORA and PACTOLE have been developed and revised to predict the corrosion product behavior. However these codes still imply some intrisic problems in simulating the real behavior of corrosion products in the reactor because of 1) the lack of important experimental data, coefficients and parameters of the transport and reactions under actual high temperature and pressure conditions, 2) no general theoretical modelling which can describe such many different mechanisms involved in the corrosion product movements, 3) the newly developed and measured behavior of the corrosion product transport mechanism. Since no sufficient and detailed information is available from the above-mentioned codes (also due to propriority problems), we concentrate on developing a new computer code, CP-TRAN (Corrosion

  18. Nanostructure Formations and Improvement in Corrosion Resistance of Steels by Means of Pulsed Electron Beam Surface Treatment

    Directory of Open Access Journals (Sweden)

    K. M. Zhang

    2013-01-01

    Full Text Available The corrosion of steels has long been the topic for materials scientists. It is established that surface treatment is an efficient way to improve the corrosion resistance of steels without changing the bulk properties and with low costs. In the present paper, different kinds of surface treatment techniques for steels are briefly reviewed. In particular, the surface modification involving nanostructure formations of steels by using a low energy high pulsed electron beam (LEHCPEB treatment is lightened in the case of an AISI 316L stainless steel and D2 steel. The overall results demonstrate the high potential of the LEHCPEB technique for improving the corrosion performance of steels.

  19. Anti-corrosion treatment of metal surfaces based on photonics methods

    Science.gov (United States)

    Ruzankina, J. S.; Vasiliev, O. S.; Parfenov, V. A.

    2017-11-01

    Metal corrosion protection is the main problem of all metal structures. Estimated to NASA, the loss of metal around the world is about of 2.5 trillion dollars, equivalent to 3.4% of global GDP. In our work we used a CW fiber laser with the wavelength of 1064 nm and a power up to 18, 4 W for laser irradiation of metal surfaces. We report on the optimal treatment of the metal corrosion with laser power density in the range from 7*104 to 9*104 W/cm2. After the process of laser treatment of steel surface we observe decreased roughness of steel and a small change in its chemical composition.

  20. Thermodynamic study of preventing the corrosion of plutonium surface with CO and H2 system

    International Nuclear Information System (INIS)

    Li Quan; Gao Tao; Wang Hongyan; Jiang Gang; Zhu Zhenghe

    1999-08-01

    The calculated results of the temperature dependence of standard Gibbs free energy change ΔG 0 of the reactions of CO and H 2 with Pu, PuO, Pu 2 O 3 , PuO 2 , respectively, show that the CO-H 2 system enables a passive surface film to be formed on the compact and stable crystal surface of Pu 2 O 3 to prevent the metallic plutonium from further corrosion by the inward diffusive CO and H 2 gas. It is presumably like the protecting aluminum surface with its oxidized layer

  1. Corrosion protection

    Science.gov (United States)

    Brown, Donald W.; Wagh, Arun S.

    2003-05-27

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

  2. Analysis of corrosion layers in ancient Roman silver coins with high resolution surface spectroscopic techniques

    International Nuclear Information System (INIS)

    Keturakis, Christopher J.; Notis, Ben; Blenheim, Alex; Miller, Alfred C.; Pafchek, Rob; Notis, Michael R.; Wachs, Israel E.

    2016-01-01

    Highlights: • Five ancient silver alloy coins (225 BCE–244 CE) were analyzed using surface characterization techniques. • Both destructive and non-destructive surface characterization methods were developed. • Alloying with copper, even in small amounts, leads to the formation of an outer Cu 2 O corrosion layer. - Abstract: Determination of the microchemistry of surface corrosion layers on ancient silver alloy coins is important both in terms of understanding the nature of archaeological environmental conditions to which these ancient coins were exposed and also to help in their conservation. In this present study, five ancient silver alloy coins (225 BCE–244 CE) were used as test vehicles to measure their immediate surface microchemistry and evaluate the appropriateness and limitations of High Sensitivity-Low Energy Ion Scattering Spectroscopy (HS-LEIS, 0.3 nm depth analysis), High Resolution-X-ray Photoelectron Spectroscopy (HR-XPS, 1–3 nm depth analysis) and High Resolution-Raman Spectroscopy (HR-Raman, ∼1000 nm depth analysis). Additional information about the deeper corrosion layers, up to ∼300–1000 nm, was provided by dynamic HS-LEIS and HR-Raman spectroscopy. While not archeologically significant, the use of these coins of small commercial value provides data that is more representative of the weaker signals typically obtained from ancient corroded objects, which can be in stark contrast to pristine data often obtained from carefully prepared alloys of known composition. The oldest coins, from 225 to 214 BCE, possessed an outermost surface layer containing Cu 2 O, Na, Al, Pb, and adsorbed hydrocarbons, while the more recent coins, from 98 to 244 CE, contained Cu 2 O, Ag, N, F, Na, Al, S, Cl, and adsorbed hydrocarbons in similar corresponding surface layers. It thus appears that alloying with copper, even in small amounts, leads to the formation of an outer Cu 2 O layer. Depth profiling revealed the presence of K, Na, Cl, and S as key

  3. Corrosion products, activity transport and deposition in boiling water reactor recirculation systems

    International Nuclear Information System (INIS)

    Alder, H.P.; Buckley, D.; Grauer, R.; Wiedemann, K.H.

    1992-01-01

    The deposition of activated corrosion products in the recirculation loops of Boiling Water Reactors produces increased radiation levels which lead to a corresponding increase in personnel radiation dose during shut down and maintenance. The major part of this dose rate is due to cobalt-60. Based on a comprehensive literature study concerning this theme, it has been attempted to identify the individual stages of the activity build-up and to classify their importance. The following areas are discussed in detail: The origins of the corrosion products and of cobalt-59 in the reactor feedwaters; the consolidation of the cobalt in the fuel pins deposits (activation); the release and transport of cobalt-60; the build-up of cobalt-60 in the corrosion products in the recirculation loops. Existing models of the build-up of circuit radioactivity are discussed and the operating experiences from selected reactors are summarized. 90 refs, figs and tabs

  4. Surface Analytical Techniques for Microbiologically Influenced Corrosion. A Review

    Science.gov (United States)

    1994-01-01

    natural waters and colonize surfaces to produce biofilms. The biofilms are varied in composition but usually include bacteria, algae, and fungi, in...potential and dissolved oxgen oicitlauios associated ivith ate Anain, sp.ference andd tentation l biofili ptiuder a 61h light/dark regime. Ligtht ...depositing bacteria. and (c) crosssco thilrough pie 1%ed %en natural waters! has re Ited i areas conducive t acteri: should be known TING WAGNER AND RAY ON

  5. Oxidation of ZPPR fuel corrosion products : National Spent Nuclear Fuel program FY 1999 final report

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    1999-01-01

    The oxidation behavior of hydride-bearing corrosion products from uranium metal ZPPR fuel plates was studied in Ar-O 2 , Ar-H 2 O, Ar-O 2 -H 2 O, dry air, and moist air environments. Both isothermal and burning curve tests in the different environments were performed using a thermo-gravimetric analyzer. The effect of pre-oxidation in each environment on subsequent ignition temperature was investigated by performing burning curve tests on samples after isothermal oxidation. Low-temperature oxidation rates in Ar-O 2 and dry air environments were identical. Oxidation rates in moist environments were slightly higher, but the difference was not statistically significant at 95% confidence. Oxygen contamination was suspected to have lowered rates measured in the Ar-H 2 O environment. ignition temperatures measured in air were 10-15 C higher than those measured in Ar-20% O 2 ; the ignition temperatures of samples pre-oxidized in moist gas environments appeared to be slightly lower than those of unreacted samples at equivalent hydride fractions. Burning rates in all environments were linearly dependent on hydride surface area for surface areas less than 200 cm 2 . Burning rates were constant at higher surface areas

  6. 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...

  7. Corrosion Behavior and Surface Modification of Mg-Zn Implant Alloys

    Science.gov (United States)

    Ghayad, I. M.; Maamoun, M. A.; Metwally, W. A.; El-Baradie, Z. M.; Abdel-Azim, A. N.

    2016-10-01

    In this study, Mg-Zn alloys (1-4 wt.% Zn) were fabricated with high-purity raw materials using a clean melting process (fluxless method) and a protective atmosphere of CO2 + 0.4 SF6. The as-cast microstructures of the investigated alloys were characterized by optical and scanning electron microscopes, EDS and XRD. Corrosion properties of the prepared alloys were examined in simulated body fluid by electrochemical techniques and immersion test (hydrogen evolution method). Surface modification of the prepared alloys was performed using micro-arc oxidation (MAO) treatment and hydroxyapatite (HA) coating. Microstructure observation revealed that Zn was completely dissolved in the α-Mg matrix up to 2 wt.%. Higher Zn content led to a reduction in the grain size and the development of a second phase (MgZn2). Corrosion testing results revealed that Mg-1,2,3 wt.% Zn have almost the same degradation rate, whereas Mg-4Zn has the highest degradation rate. HA coating on MAO-treated magnesium alloys formed a dense and compact layer on the alloy surface, which had largely improved surface properties and enhanced corrosion resistance of the prepared alloys.

  8. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  9. A systematic approach to Bronze corrosion products and the methods of treatment , applied on three bronze anklets from Dhamar museum , Yemen

    Directory of Open Access Journals (Sweden)

    Hazem Mohamed

    2014-04-01

    Full Text Available Three bronze anklets were found during the archaeological excavation of Yemeni mission 2002 A.D, in Gabal al- lawd , Jawf area , Yemen , they dated back to Minaean period in Yemen [sixth century B.C – 24 B.C] , and now they are situated in Dhamar regional museum .They were suffered from the deterioration aspects , two of these anklets had a thick corrosion products of pale green / brown , the third anklet had a rust-colored Black and Brown with the presence of small parts and scattered pale green. The aim of this paper is to examine, in detail, the corrosion of the selected objects that was grown during the long-term burial and identify its products that will help us to understand the corrosive factors and the degradation mechanisms , as well as their constituting metals in order to carry out scientific treatment and conservation .For this purpose ,samples from the objects were examined by Metallographic Microscope (ME , Scanning Electron Microscope (SEM, the corrosion products were analyzed by X-ray diffraction (XRD and X-ray fluorescence( XRF was used to determine the objects metallic constituents . XRD data showed that the corrosion products constitute of cuprite , atacamite , and paratacamite , whereas XRF analysis declared that the anklets compose of bronze alloy . Microscopic examination reveals that the three anklets were suffered from the deterioration spots , which dispersed on the metal surface . Chemical cleaning was chosen for treating the objects , finally they were isolated to preserve them against further attack.

  10. Corrosion protection of zirconium surface based on Heusler alloy

    Czech Academy of Sciences Publication Activity Database

    Horáková, Kateřina; Cichoň, Stanislav; Lančok, Ján; Kratochvílová, Irena; Fekete, Ladislav; Sajdl, P.; Krausová, A.; Macák, J.; Cháb, Vladimír

    2017-01-01

    Roč. 89, č. 4 (2017), s. 553-563 ISSN 0033-4545 R&D Projects: GA MŠk LO1409; GA ČR(CZ) GA16-03085S; GA ČR GJ17-19910Y; GA ČR(CZ) GA15-05095S Institutional support: RVO:68378271 ; RVO:67985858 Keywords : electrochemistry * silicon * spectroscopy * SSC-2016 * surface chemistry * wate * zirconium Subject RIV: JI - Composite Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 2.626, year: 2016

  11. XPS response in the corrosion products analysis for copper exposed at clean air environment

    International Nuclear Information System (INIS)

    Mariaca, L.; Morcillo, M.; Feliu Jr, S.; Gonzalez, J.A.

    1998-01-01

    In this work is presented the obtained response for superficial analysis technique by X-ray photoelectron spectroscopy (XPS or ESCA), to determine the corrosion products formed during the copper exposure at environment without pollutants (clean air) at 50, 70 and 90 % of relative humidity at 35 Centigrade. One of the copper corrosion products most knew is Cu 2 O. This oxide is formed instantly to be exposed the copper at air. However in function of the exposure time and the relative humidity at it is exposed, the Cu 2 O oxide is transformed at Cu O and Cu(OH) 2 (Author)

  12. Nanotechnology based surface treatments for corrosion protection and deposit control of power plant equipment. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-05-15

    Nanotechnology can provide possibilities for obtaining new valuable information regarding performance and corrosion protection in power plants. In general the desired performance of the contact surfaces is an easy-to-release effect. This is in order to prolong the time interval between cleaning periods or make the cleaning procedures easier and less expensive. Corrosion protection is also desired in order to extend the life time of various parts in the power plants and thus optimize the energy output and overall efficiency of the plant. Functional sol-gel coating based on nanotechnology is tested in a variety of conditions. Applications of functional sol-gel coatings were performed in the condenser and on seven air preheaters at Fynsvaerket, Odense, with corrosion protection as the main issue. Coatings with easy-to-clean effects were tested in the Flue Gas Desulphurization plant at Nordjyllandsvaerket, Aalborg, with the aim of reducing gipsum deposit. Thermo stabilized coatings were tested on tube bundles between in the passage from the 1st to 2end pass and on the wall between 1st and 2end pass at Amagervaerket, Copenhagen, and in the boiler at Haderslev CHP plant. The objective of this test were reducing deposits and increasing corrosion protection. The tested coatings were commercial available coatings and coatings developed in this project. Visual inspections have been performed of all applications except at Nordjyllandsvaerket. Corrosion assessment has been done at DTU - Mechanical Engineering. The results range from no difference between coated and uncoated areas to some improvements. At Amagervaerket the visual assessment showed in general a positive effect with a sol-gel hybrid system and a commercial system regarding removal of deposits. The visual assessment of the air preheaters at Fynsvaerket indicates reduced deposits on a sol-gel nanocomposite coated air preheater compared to an uncoated air preheater. (Author)

  13. Corrosion/95 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

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

  14. Corrosion Testing in Support of the Accelerator Production of Tritium Program

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, G.

    2000-11-07

    The Accelerator Production of Tritium Project is part of the United States Department of Energy strategy to meet the nation's tritium needs. The project involves the design of a proton beam accelerator, which will produce tritium through neutron/proton interaction with helium-3. Design, construction and operation of this one-of-a-kind facility will involve the utilization of a wide variety of materials exposed to unique conditions, including elevated temperature and high-energy mixed-proton and -neutron spectra. A comprehensive materials test program was established by the APT project which includes the irradiation of structural materials by exposure to high-energy protons and neutrons at the Los Alamos Neutron Science Center at the Los Alamos National Laboratory. Real-time corrosion measurements were performed on specially designed corrosion probes in water irradiated by an 800 MeV proton beam. The water test system provided a means for measuring water chemistry, dissolved hydroge n concentration, and the effects of water radiolysis and water quality on corrosion rate. The corrosion probes were constructed of candidate APT materials alloy 718, 316L stainless steel, 304L stainless steel, and 6061 Aluminum (T6 heat treatment), and alternate materials 5052 aluminum alloy, alloy 625, and C276. Real-time corrosion rates during proton irradiation increased with proton beam current. Efforts are continuing to determine the effect of proton beam characteristics and mixed-particle flux on the corrosion rate of materials located directly in the proton beam. This paper focuses on the real-time corrosion measurements of materials located in the supply stream and return stream of the water flow line to evaluate effects of long-lived radiolysis products and water chemistry on the corrosion rates of materials. In general, the corrosion rates for the out-of-beam probes were low and were affected mainly by water conductivity. The data indicate a water conductivity threshold e

  15. 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

  16. Surface Corrosion and Microstructure Degradation of Calcium Sulfoaluminate Cement Subjected to Wet-Dry Cycles in Sulfate Solution

    Directory of Open Access Journals (Sweden)

    Wuman Zhang

    2017-01-01

    Full Text Available The hydration products of calcium sulfoaluminate (CSA cement are different from those of Portland cement. The degradation of CSA cement subjected to wet-dry cycles in sulfate solution was studied in this paper. The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM. The results show that SO42-, Na+, Mg2+, and Cl− have an effect on the stability of ettringite. In the initial period of sulfate attack, salt crystallization is the main factor leading to the degradation of CSA cement specimens. The decomposition and the carbonation of ettringite will cause long-term degradation of CSA cement specimens under wet-dry cycles in sulfate solution. The surface spalling and microstructure degradation increase significantly with the increase of wet-dry cycles, sulfate concentration, and water to cement ratio. Magnesium sulfate and sodium chloride reduce the degradation when the concentration of sulfate ions is a constant value.

  17. Surfaces: processing, coating, decontamination, pollution, etc. Surface mastering to prevent component corrosion; Surfaces: traitement, revetements, decontamination, pollution, etc. Maitrise de la surface pour prevenir la corrosion des composants

    Energy Technology Data Exchange (ETDEWEB)

    Foucault, M. [Departement Corrosion Chimie, AREVA Centre Technique, BP 181, 71205 Le Creusot (France)

    2012-07-01

    In the primary and secondary circuits of nuclear Pressurized Water Reactors, AREVA uses several nickel-based alloys or austenitic stainless steels for the manufacture of safety components. The experience feedback of the last twenty years allows us to point out the major role hold by the component surface state in their life duration. In this paper, we present four examples of problem encountered and solved by a surface study and the definition and implementation of processes for the surface control of the repaired components. Then, we propose some ideas about the present needs in term of analysis means to improve the surface knowledge and control of the manufactured components. (author)

  18. Simulation of corrosion product activity in ion- exchanger of PWR under acceleration of corrosion and flow rate perturbations

    International Nuclear Information System (INIS)

    Mirza, N.M.; Mirza, S.M.; Rafique, M.

    2005-01-01

    In this paper computer code developed earlier by the authors (CPAIR-P) has been employed to compute corrosion product activity in PWRs for flow rate perturbations. The values of radioactivity in ion exchanger of Pressurized Water Reactor (PWR) under normal and flow rate perturbation conditions have been calculated. For linearly accelerating corrosion rates, activity saturates for removal rate of 600 cm/sup 3// s in primary coolant of PWR. A higher removal rate of 750 cm/sup 3// s was selected for which the saturation value is sufficiently low (0. 28 micro Ci/cm/sup 3/). Simulation results shows that the Fe/sup 59/ Na/sup 24/, Mo/sup 99/, Mn/sup 56/ reaches saturation values with in about 700 hours of reactor operation. However, Co/sup 58/ and Co/sup 60/ keep on accumulating and do not saturate with in 2000 hours of these simulation time. When flow rate is decreased by 10% of rated flow rate after 500 hours of reactor operation, a dip in activity is seen, which reaches to the value of 0.00138 micro Ci cm/sup -3/ then again it begins to rise and reaches saturation value of 0.00147 cm/sup 3//s. (author)

  19. 77 FR 25405 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2012-04-30

    ... 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... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering...

  20. 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...

  1. 75 FR 25841 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2010-05-10

    ... 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... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering...

  2. 76 FR 21332 - Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time...

    Science.gov (United States)

    2011-04-15

    ... 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... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering...

  3. 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...

  4. 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...

  5. Corrosion resistance and surface characterization of electrolyzed Ti-Ni alloy.

    Science.gov (United States)

    Fukushima, Osamu; Yoneyama, Takayuki; Doi, Hisashi; Hanawa, Takao

    2006-03-01

    Ti-Ni alloy has been increasingly applied to medical and dental devices, such as coronary stents and orthodontic wires. This alloy contains nickel, which is known to give rise to cytotoxicity, metal allergy, and carcinogenicity. Therefore, the purpose of this study was to improve the corrosion resistance of Ti-Ni alloy by electrolytic treatment, whereby investigation was carried out using different acidic electrolyte compositions. As a result, specimens electrolyzed with lactic acid, water, and glycerol were found to show higher corrosion potential and release lower amount of titanium and nickel ions than mechanical-polished specimens (pnickel concentration in the surface oxide layer of Ti-Ni alloy decreased, and the thickness of the surface oxide layer increased. Based on the results of this study, it was shown that electrolytic treatment with suitable electrolyte could improve the corrosion resistance of Ti-Ni alloy, which is effective to produce medical and dental devices that utilize shape memory effect or superelasticity with better biocompatibility.

  6. Intergranular Corrosion of 316L Stainless Steel by Aging and UNSM (Ultrasonic Nano-crystal Surface Modification) treatment

    International Nuclear Information System (INIS)

    Lee, J. H.; Kim, Y. S.

    2015-01-01

    Austenitic stainless steels have been widely used in many engineering fields because of their high corrosion resistance and good mechanical properties. However, welding or aging treatment may induce intergranular corrosion, stress corrosion cracking, pitting, etc. Since these types of corrosion are closely related to the formation of chromium carbide in grain boundaries, the alloys are controlled using methods such as lowering the carbon content, solution heat treatment, alloying of stabilization elements, and grain boundary engineering. This work focused on the effects of aging and UNSM (Ultrasonic Nano-crystal Surface Modification) on the intergranular corrosion of commercial 316L stainless steel and the results are discussed on the basis of the sensitization by chromium carbide formation and carbon segregation, residual stress, grain refinement, and grain boundary engineering

  7. Thermodynamic study of preventing the corrosion of uranium surface with CO and H2 system

    International Nuclear Information System (INIS)

    Wang Hongyan; Tan Mingliang; Zhu Zhenghe

    1997-11-01

    The present calculational results of the temperature dependence of standard Gibbs free energy change ΔG 0 for the reactions of CO and H 2 with U, UO 2 , UO 3 and U 3 O 8 , respectively, instructively show that the uranium polyoxides surface will tend to a compact and stable coated with nearly UO 2 crystal so-called 'the bluntly thin skin' preventing further corrosion. It is presumably like the protecting aluminum surface with its oxidized layer. This conceptional model explored for the first-time has been confirmed by the latest works

  8. Corrosion control of aluminum surfaces by polypyrrole films: influence of electrolyte

    Directory of Open Access Journals (Sweden)

    Andréa Santos Liu

    2007-06-01

    Full Text Available Polypyrrole (PPy films were galvanostatically deposited on 99.9 wt. (% aluminum electrodes from aqueous solutions containing each carboxylic acid: tartaric, oxalic or citric. Scanning Electron Microscopy (SEM was used to analyze the morphology of the aluminum surfaces coated with the polymeric films. It was observed that the films deposited from tartaric acid medium presented higher homogeneity than those deposited from oxalic and citric acid. Furthermore, the corrosion protection of aluminum surfaces by PPy films was also investigated by potentiodynamic polarization experiments.

  9. Detection of stress corrosion cracking on the surface of stainless steel plate by DC-PDM

    International Nuclear Information System (INIS)

    Maeda, Hiroki; Tada, Naoya; Uchida, Makoto

    2010-01-01

    In order to examine the applicability of the direct-current potential difference method to detection of stress corrosion cracking, the potential difference was measured on the surface of stainless steel plates with simulated cracking. Potential difference was measured near the cracking and at the points distant from the crack to evaluate the degree of increase in the potential difference by the crack. The potential difference near the cracking area was higher than that in the other area. The normalized potential difference, which is the ratio of potential difference near the cracking to that far from the area, was 1.03 to 1.50. The result suggests that stress corrosion cracking was able to be detected by direct-current potential difference method. (author)

  10. Electrochemical impedance spectroscopy and Surface Studies of Steel Corrosion by Sulphate-Reducing Bacteria

    International Nuclear Information System (INIS)

    Fathul Karim Sahrani; Zaharah Ibrahim; Madzlan Aziz; Adibah Yahya

    2009-01-01

    Sulphate-reducing bacteria (SRB), implicated in microbiologically influenced corrosion were isolated from the deep subsurface at the vicinity of Pasir Gudang, Johor, Malaysia. Electrochemical impedance spectroscopic (EIS) study was carried out to determine the polarization resistance in various types of culturing solutions, with SRB1, SRB2, combination of SRB1 and SRB2 and without SRBs inoculated (control). EIS results showed that in the presence of SRB1, SRB2 and mixed culture SRB1 and SRB2, polarisation resistance values were 7170, 6370 and 7190 ohms respectively compared to that of control, 92400 ohm. X-ray analysis (EDS) of the specimens indicated high sulphur content in the medium containing SRBs. Localized corrosion was observed on the metal surface which was associated with the SRB activity. (author)

  11. Study on corrosion simulation device for marine structural steel

    Indian Academy of Sciences (India)

    Unknown

    Abstract. A corrosion simulation device was studied using offshore long scale hanging specimens. An Ni–. Cu–P steel specimen was studied by analysing its corrosion products and corrosion types. The appearance of the samples and the surface of the metallic substrate after the removal of the rust layer produced by these ...

  12. Study on corrosion simulation device for marine structural steel

    Indian Academy of Sciences (India)

    A corrosion simulation device was studied using offshore long scale hanging specimens. An Ni–Cu–P steel specimen was studied by analysing its corrosion products and corrosion types. The appearance of the samples and the surface of the metallic substrate after the removal of the rust layer produced by these two ...

  13. Moessbauer study of corrosion products formed on Fe80B20 and Fe40Ni40 (MoB)20 amorphous alloys in an SO2-polluted atmosphere

    International Nuclear Information System (INIS)

    Davalos, J.; Marco, J.F.; Gracia, M.; Gancedo, J.R.; Greneche, J.M.

    1990-01-01

    ICEMS, XPS, XRD, and AES have been used to study the corrosion layers formed on two metallic glasses, Fe 80 B 20 and Fe 40 Ni 40 (MoB) 20 (2605 and 2826 MB, Allied Company), exposed to an SO 2 -polluted humid atmosphere. The iron-containing corrosion products are the same found for pure iron in the same environment, but different relative concentrations were clearly evidenced by ICEMS results. Elemental sulphur, Ni(OH) 2 , and B(OH) 3 , the latter enriched at the surface, were found by XPS, XRD and AES. (orig.)

  14. Allowing for surface preparation in stress corrosion cracking modelling; Prise en compte de l`etat de surface dans la modelisation de la fissuration par corrosion sous contrainte

    Energy Technology Data Exchange (ETDEWEB)

    Berge, P.; Buisine, D. [Electricite de France (EDF), 92 - Clamart (France); Gelpi, A. [FRAMATOME, 92 - Paris-La-Defence (France)

    1997-12-31

    When a 600 alloy component is significantly deformed during installation, by welding, rolling, bending, its stress corrosion cracking in Pressurized Water Nuclear Reactor`s primary coolant, is significantly changed by the initial surface treatment. Therefore, the crack initiated time may be reduced by several orders of magnitude for certain surfaces preparations. Allowing for cold working of the surface, for which modelling is proposed, depends less on the degree of cold work then on the depths of the hardened layers. Honing hardens the metal over depths of about one micron for vessel head penetrations, for example, and has little influence on subsequent behaviour after the part deforms. On the other hand, coarser turning treatment produces cold worked layers which can reach several tens of microns and can very significantly reduce the initiation time compared to fine honing. So evaluation after depths of hardening is vital on test pieces for interpreting laboratory results as well as on service components for estimating their service life. Suppression by mechanical or chemical treatment of these layers, after deformation, seems to be the most appropriate solution for reducing over-stressing connected with surface treatment carried out before deformation. (author). 14 refs.

  15. Surface characteristics, corrosion and bioactivity of chemically treated biomedical grade NiTi alloy.

    Science.gov (United States)

    Chembath, Manju; Balaraju, J N; Sujata, M

    2015-11-01

    The surface of NiTi alloy was chemically modified using acidified ferric chloride solution and the characteristics of the alloy surface were studied from the view point of application as a bioimplant. Chemically treated NiTi was also subjected to post treatments by annealing at 400°C and passivation in nitric acid. The surface of NiTi alloy after chemical treatment developed a nanogrid structure with a combination of one dimensional channel and two dimensional network-like patterns. From SEM studies, it was found that the undulations formed after chemical treatment remained unaffected after annealing, while after passivation process the undulated surface was filled with oxides of titanium. XPS analysis revealed that the surface of passivated sample was enriched with oxides of titanium, predominantly TiO2. The influence of post treatment on the corrosion resistance of chemically treated NiTi alloy was monitored using Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) in Phosphate Buffered Saline (PBS) solution. In the chemically treated condition, NiTi alloy exhibited poor corrosion resistance due to the instability of the surface. On the other hand, the breakdown potential (0.8V) obtained was highest for the passivated samples compared to other surface treated samples. During anodic polarization, chemically treated samples displayed dissolution phenomenon which was predominantly activation controlled. But after annealing and passivation processes, the behavior of anodic polarization was typical of a diffusion controlled process which confirmed the enhanced passivity of the post treated surfaces. The total resistance, including the porous and barrier layer, was in the range of mega ohms for passivated surfaces, which could be attributed to the decrease in surface nickel content and formation of compact titanium oxide. The passivated sample displayed good bioactivity in terms of hydroxyapatite growth, noticed after 14days immersion in

  16. High temperature corrosion in the thermochemical hydrogen production from nuclear heat

    International Nuclear Information System (INIS)

    Coen-Porisini, F.; Imarisio, G.

    1976-01-01

    In the production of hydrogen by water decomposition utilizing nuclear heat, a multistep process has to be employed. Water and the intermediate chemical products reach in chemical cycles giving hydrogen and oxygen with regeneration of the primary products used. Three cycles are examined, characterized by the presence of halide compounds and particularly hydracids at temperatures up to 800 0 C. Corrosion tests were carried out in hydrobromic acid, hydrochloric acid, ferric chloride solutions, and hydriodic acid

  17. The role of surface preparation in corrosion protection of copper with nanometer-thick ALD alumina coatings

    Energy Technology Data Exchange (ETDEWEB)

    Mirhashemihaghighi, Shadi; Światowska, Jolanta [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France); Maurice, Vincent, E-mail: vincent.maurice@chimie-paristech.fr [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France); Seyeux, Antoine; Klein, Lorena H. [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France); Salmi, Emma; Ritala, Mikko [Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland); Marcus, Philippe [PSL Research University, CNRS – Chimie ParisTech, Institut de Recherche de Chimie Paris (IRCP), 11 rue Pierre et Marie Curie, 75005 Paris (France)

    2016-11-30

    Highlights: • 10–50 nm thick alumina coatings were grown on copper by atomic layer deposition. • Surface smoothening by substrate annealing was studied as pre-deposition treatment. • Corrosion protection is promoted by pre-treatment for 10 nm but not for thicker films. • Local adhesion failure is assigned to the stresses accumulated in the thicker films. • Surface smoothening decreases the interfacial strength bearing the film stresses. - Abstract: Surface smoothening by substrate annealing was studied as a pre-treatment for improving the corrosion protection provided to copper by 10, 20 and 50 nm thick alumina coatings deposited by atomic layer deposition. The interplay between substrate surface state and deposited film thickness for controlling the corrosion protection provided by ultrathin barrier films is demonstrated. Pre-annealing at 750 °C heals out the dispersed surface heterogeneities left by electropolishing and reduces the surface roughness to less than 2 nm independently of the deposited film thickness. For 10 nm coatings, substrate surface smoothening promotes the corrosion resistance. However, for 20 and 50 nm coatings, it is detrimental to the corrosion protection due to local detachment of the deposited films. The weaker adherence of the thicker coatings is assigned to the stresses accumulated in the films with increasing deposited thickness. Healing out the local heterogeneities on the substrate surface diminishes the interfacial strength that is bearing the stresses of the deposited films, thereby increasing adhesion failure for the thicker films. Pitting corrosion occurs at the local sites of adhesion failure. Intergranular corrosion occurs at the initially well coated substrate grain boundaries because of the growth of a more defective and permeable coating at grain boundaries.

  18. Aluminum surface corrosion and the mechanism of inhibitors using pH and metal ion selective imaging fiber bundles.

    Science.gov (United States)

    Szunerits, Sabine; Walt, David R

    2002-02-15

    The localized corrosion behavior of a galvanic aluminum copper couple was investigated by in situ fluorescence imaging with a fiber-optic imaging sensor. Three different, but complementary methods were used for visualizing remote corrosion sites, mapping the topography of the metal surface, and measuring local chemical concentrations of H+, OH-, and Al3+. The first method is based on a pH-sensitive imaging fiber, where the fluorescent dye SNAFL was covalently attached to the fiber's distal end. Fluorescence images were acquired as a function of time at different areas of the galvanic couple. In a second method, the fluorescent dye morin was immobilized on the fiber-optic imaging sensor, which allowed the in situ localization of corrosion processes on pure aluminum to be visualized over time by monitoring the release of Al3+. The development of fluorescence on the aluminum surface defined the areas associated with the anodic dissolution of aluminum. We also investigated the inhibition of corrosion of pure aluminum by CeCl3 and 8-hydroxyquinoline. The decrease in current, the decrease in the number of active sites on the aluminum surface, and the faster surface passivation are all consistent indications that cerium chloride and 8-hydroxyquinoline inhibit corrosion effectively. From the number and extent of corrosion sites and the release of aluminum ions monitored with the fiber, it was shown that 8-hydroxyquinoline is a more effective inhibitor than cerium chloride.

  19. Synergistic Effect of Superhydrophobicity and Oxidized Layers on Corrosion Resistance of Aluminum Alloy Surface Textured by Nanosecond Laser Treatment.

    Science.gov (United States)

    Boinovich, Ludmila B; Emelyanenko, Alexandre M; Modestov, Alexander D; Domantovsky, Alexandr G; Emelyanenko, Kirill A

    2015-09-02

    We report a new efficient method for fabricating a superhydrophobic oxidized surface of aluminum alloys with enhanced resistance to pitting corrosion in sodium chloride solutions. The developed coatings are considered very prospective materials for the automotive industry, shipbuilding, aviation, construction, and medicine. The method is based on nanosecond laser treatment of the surface followed by chemisorption of a hydrophobic agent to achieve the superhydrophobic state of the alloy surface. We have shown that the surface texturing used to fabricate multimodal roughness of the surface may be simultaneously used for modifying the physicochemical properties of the thick surface layer of the substrate itself. Electrochemical and wetting experiments demonstrated that the superhydrophobic state of the metal surface inhibits corrosion processes in chloride solutions for a few days. However, during long-term contact of a superhydrophobic coating with a solution, the wetted area of the coating is subjected to corrosion processes due to the formation of defects. In contrast, the combination of an oxide layer with good barrier properties and the superhydrophobic state of the coating provides remarkable corrosion resistance. The mechanisms for enhancing corrosion protective properties are discussed.

  20. 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

  1. Corrosion behaviour of alloy 31 - UNS N08031 - under conditions of oil and gas production

    Energy Technology Data Exchange (ETDEWEB)

    Kloewer, J. [ThyssenKrupp VDM France SARL, Rueil-Malmaison (France); Schlerkmann, H.; Poepperling, R. [Mannesmann Forschungsinstitut, Duisburg (Germany)

    2002-10-01

    The corrosion behaviour of alloy 31 (UNS N08031-31Ni-27Cr-6.5Mo-1.2Cu-0.2N-bal.Fe) was tested in laboratory and field tests in seawater with and without additions of CO{sub 2} and/or H{sub 2}S in slow strain rate tests, and in SSC (Sulphide Stress Corrosion) tests according to NACE MR0175. The results demonstrate a high resistance of alloy 31 to localised corrosion. Due to the high chromium and molybdenum concentration, its resistance to pitting and crevice corrosion in chloride-contaminated seawater is significantly higher than that of alloy 28 and alloy 825 and it equals that of typical nickel base alloys like alloy 625. Alloy 31 is not sensitive to chloride-induced stress corrosion cracking, either with or without H{sub 2}S, or sulphide stress cracking. Alloy 31 is approved for sour gas applications up to LEVEL VI in NACE MR0175. The combination of properties makes alloy 31 an attractive choice for components in oil and gas production including wirelines, umbilicals, tubing, piping and topside application. (orig.)

  2. Surface corrosion analysis of machine elements using thin layer activation technique with the proton beam from national medical cyclotron

    International Nuclear Information System (INIS)

    Mukherjee, B.

    1996-01-01

    The surface of metallic objects becomes activated when irradiated with a narrow energetic charged particle (eg. proton) beam. The depth of the activated region and the yield of the induced radioactivity depend on the charged particle energy and beam intensity respectively. The surface radioactivity of the irradiated object is depleted when the activated surface undergo wear or corrosion processes. Therefore, the quantitative assay of the remaining surface radioactivity could be used as a very effective method for monitoring wear or corrosion processes. This poster highlights some interesting results of the Thin Layer Activation (TLA) study currently undertaken at the Health Physics laboratory of the National Medical Cyclotron

  3. Moessbauer Studies of Corrosion Products Developed in Prohesion Test over Galvanized Steel Sheets

    International Nuclear Information System (INIS)

    Zapponi, M.; Perez, T.; Ramos, C.; Saragovi, C.

    2003-01-01

    Precoated galvanized steel sheets were submitted to Prohesion test (PT) and to outdoor marine exposure test (OT). The corrosion products were different in both cases. Goethite, lepidocrocite, pyrite and magnetite were found in the Prohesion test samples; the presence of akaganeite cannot be discarded. Surprisingly greigite was detected in these samples, suggesting in addition a located microbiological corrosion process. On the other hand, goethite, lepidocrocite, magnetite, akaganeite and silicates were found in outdoor exposure samples. This study allows the conclusion that in the Prohesion G-85 test the corrosion mechanism is different from that in the marine atmosphere for the analyzed samples and could not be used to predict the performance of this type of outdoor exposed materials.

  4. Characterization and corrosion study of NiTi laser surface alloyed with Nb or Co

    Science.gov (United States)

    Ng, K. W.; Man, H. C.; Yue, T. M.

    2011-02-01

    The interest in NiTi alloys for medical applications has been steadily growing in recent years because of its biocompatibility, superelasticity and shape memory characteristics. However, the high Ni content in NiTi alloys is still a concern for its long-term applications in the human body. The release of Ni ion into the human body might cause serious problems, as Ni is capable of eliciting toxic and allergic responses. In view of this, surface modification to reduce the surface content of Ni and to improve the corrosion resistance, both of which would reduce Ni release, is an important step in the development of NiTi implants. In the present study, NiTi was surface alloyed with Nb or Co by laser processing. The fine dendritic structure characteristic of laser processing has been described in terms of rapid solidification. The amount of surface elemental Ni was reduced to 10% and 35% for the Nb-alloyed and Co-alloyed layer, respectively. The corrosion resistance in Hanks' solution (a simulated body fluid) was increased as evidenced by a reduced passive current density and a higher pitting potential for both the Nb- and Co-alloyed specimens. The composition and hardness profiles along the depth of the modified layer were correlated with the distribution of the dendrites. The microhardness of the alloyed layers was around 700-800 Hv, which was about four times that of the untreated NiTi specimens.

  5. Plasma Sprayed Bondable Stainless Surface (BOSS) Coatings for Corrosion Protection and Adhesion Treatments

    Science.gov (United States)

    Davis, G. D.; Groff, G. B.; Rooney, M.; Cooke, A. V.; Boothe, R.

    1995-01-01

    Plasma-sprayed Bondable Stainless Surface (BOSS) coatings are being developed under the Solid Propulsion Integrity Program's (SPIP) Bondlines Package. These coatings are designed as a steel case preparation treatment prior to insulation lay-up. Other uses include the exterior of steel cases and bonding surfaces of nozzle components. They provide excellent bondability - rubber insulation and epoxy bonds fail cohesively within the polymer - for both fresh surfaces and surfaces having undergone natural and accelerated environmental aging. They have passed the MSFC requirements for protection of inland and sea coast environment. Because BOSS coatings are inherently corrosion resistant, they do not require preservation by greases or oils. The reduction/elimination of greases and oils, known bondline degraders, can increase SRM reliability, decrease costs by reducing the number of process steps, and decrease environmental pollution by reducing the amount of methyl chloroform used for degreasing and thus reduce release of the ozone-depleting chemical in accordance with the Clean Air Act and the Montreal Protocol. The coatings can potential extend the life of RSRM case segments and nozzle components by eliminating erosion due to multiple grit blasting during each use cycle and corrosion damage during marine recovery. Concurrent work for the Air Force show that other BOSS coatings give excellent bondline strength and durability for high-performance structures of aluminum and titanium.

  6. Influence of steam generator surface state on corrosion and oxide formation

    International Nuclear Information System (INIS)

    Mazenc, Arnaud; Leclercq, Stephanie; Seyeux, Antoine; Galtayries, Anouk; Marcus, Philippe

    2012-09-01

    The corrosion and release of nickel-based alloy Steam Generator tubes are partly due to their surface state. Among the most important parameters influencing the corrosion, the effect of grain size and the effect of grain crystallographic orientation have been chosen to be studied. The aim of this study is to determine how these parameters have an impact on the corrosion of Steam Generator tubes. Thermal treatments (700 deg. C and 1050 deg. C) have been performed on several samples in Alloy 690 to obtain homogeneous grain sizes, varying from 25 μm to 110 μm. Two samples have been oxidised for four days in a recirculating autoclave, reproducing primary conditions. The changes of oxide composition and thickness were examined by ToF-SIMS on samples exposed to primary water conditions. The intensity profiles versus thicknesses of characteristic oxide anions, such as CrO - , NiO - or FeO - enable us to evaluate the effect of grain size and crystallographic orientation on the formation of an enriched inner chromium layer. As regards to the grain size, there was no effect on the growth, but smaller grains led to a chromium-rich oxide layer. The effect of crystallographic orientation was observed on the oxidation kinetics and the composition of oxide scales. (authors)

  7. Brief description of out-of-pile test facilities for study in corrosion and fission product behaviour in flowing sodium

    International Nuclear Information System (INIS)

    Iizawa, K.; Sekiguchi, N.; Atsumo, H.

    1976-01-01

    The experimental methods to perform tests for study in corrosion and fission products behaviour in flowing sodium are outlined. Flow diagrams for the activated materials and fission products behaviour test loop are given

  8. Enhanced osteoblast proliferation and corrosion resistance of commercially pure titanium through surface nanostructuring by ultrasonic shot peening and stress relieving.

    Science.gov (United States)

    Jindal, Shitu; Bansal, Rajesh; Singh, Bijay P; Pandey, Rajiv; Narayanan, Shankar; Wani, Mohan R; Singh, Vakil

    2014-07-01

    This investigation was carried out to study the effect of a novel process of surface modification, surface nanostructuring by ultrasonic shot peening, on osteoblast proliferation and corrosion behavior of commercially pure titanium (c p-Ti) in simulated body fluid. A mechanically polished disc of c p-Ti was subjected to ultrasonic shot peening with stainless steel balls to create nanostructure at the surface. A nanostructure (corrosion resistance. Corrosion rate was increased by 327% in the shot peened condition. In order to examine the role of residual stresses associated with the shot peened surface on these aspects, a part of the shot peened specimen was annealed at 400°C for 1 hour. A marked influence of annealing treatment was observed on surface structure, cell proliferation, and corrosion resistance. Surface nanostructure was much more prominent, with increased number density and sharper grain boundaries; cell proliferation was enhanced to approximately 50% and corrosion rate was reduced by 86.2% and 41% as compared with that of the shot peened and the as received conditions, respectively. The highly significant improvement in cell proliferation, resulting from annealing of the shot peened specimen, was attributed to increased volume fraction of stabilized nanostructure, stress recovery, and crystallization of the oxide film. Increase in corrosion resistance from annealing of shot peened material was related to more effective passivation. Thus, the surface of c p-Ti, modified by this novel process, possessed a unique quality of enhancing cell proliferation as well as the corrosion resistance and could be highly effective in reducing treatment time of patients adopting dental and orthopedic implants of titanium and its alloys.

  9. Optical-fiber-based chemical sensors for detection of corrosion precursors and by-products

    Science.gov (United States)

    Elster, Jennifer L.; Greene, Jonathan A.; Jones, Mark E.; Bailey, Timothy A.; Lenahan, Shannon M.; Velander, William H.; VanTassell, Roger; Hodges, William; Perez, Ignacio M.

    1999-02-01

    Optical fiber sensors are a novel and ideal approach for making chemical and physical measurements in a variety of harsh environments. They do not corrode, are resistant to most chemicals, immune to electromagnetic interference, light weight, inherently small and have a flexible geometry. This paper presents recent test results using optical fiber long-period grating (LPG) sensors to monitor corrosion precursors and by-products. With the appropriate coating, the LPG sensor can be designed to identify a variety of environmental target molecules, such as moisture, pH, sulfates, chlorates, nitrates and metal-ions in otherwise inaccessible regions of metallic structures. Detection of these chemicals can be used to determine if the environment within a particular area of an airplane or infrastructure is becoming conducive to corrosion or whether the corrosion process is active. The LPG sensors offer a clear advantage over similar electrochemical sensors since they can be rendered immune to temperature cross-sensitivity, multiplexed along a single fiber, and can be demodulated using a simple, low-cost spectrum analyzer. By coating the LPG sensor with specially designed affinity coatings that selectively absorb target molecules, selective, real-time monitoring of environmental conditions is possible. This sensing platform shows great promise for corrosion by- product detection in pipe networks, civil infrastructure, process control, and petroleum production operations and can be applied as biological sensors for in-vitro detection of pathogens, and chemical sensors for environmental and industrial process monitoring.

  10. A Facile Method to Modify the Characteristics and Corrosion Behavior of 304 Stainless Steel by Surface Nanostructuring toward Biomedical Applications.

    Science.gov (United States)

    Thangaraj, Balusamy; Nellaiappan, Sankara Narayanan T S; Kulandaivelu, Ravichandran; Lee, Min Ho; Nishimura, Toshiyasu

    2015-08-19

    The study addresses how surface nanostructuring of AISI 304 stainless steel (SS) by surface mechanical attrition treatment (SMAT) influences its characteristic properties and corrosion behavior in Ringer's solution. SMAT of 304 SS induced plastic deformation, enabled surface nanocrystallization, refined the grain size, transformed the austenite phase to strain induced α'-martensite phase, increased the surface roughness, induced defects/dislocations, imparted compressive residual stresses at the surface, decreased the contact angle, and increased surface energy. The change in properties of 304 SS following treatment using 5 and 8 mm ⌀ balls for 15, 30, 45, and 60 min has caused a deleterious influence on its corrosion resistance in Ringer's solution, while an improvement in corrosion behavior is observed for those treated using 2 mm ⌀ balls. The increase in surface roughness, transformation of the austenite to α'-martensite phase, a higher extent of deformation, and the presence of larger number of defects/dislocations are main factors responsible for the lower corrosion resistance observed for 304 SS treated using 5 and 8 mm ⌀ balls in Ringer's solution. In spite of having these attributes with a relatively lower extent, 304 SS treated using 2 mm ⌀ balls offered a better corrosion resistance and exhibits a better passivity. For those treated using 2 mm ⌀ balls, the ability of the nanocrystalline surface to promote passivation outweighs the deleterious influences caused by the limited amount of deformation and defects/dislocations. Based on the findings of this study, it is recommend that SMAT of 304 SS using 2 mm ⌀ balls for 15-30 min is the optimum condition to achieve the suitable surface profile, surface characteristics with better corrosion resistance.

  11. The Influence of Chemical Surface Treatment on the Corrosion Resistance of Titanium Castings Used in Dental Prosthetics

    Directory of Open Access Journals (Sweden)

    Burnat B.

    2014-08-01

    Full Text Available Air abrasion process is used for cleaning casting surface of prosthetic components, and to prepare the surface of these elements for the application of veneering items. Its side effect, however, is that abrasive particles are embedded in the treated surface, which can be up to 30% of the surface and it constitutes the side effect of this procedure. Such a significant participation of foreign material can not be indifferent to the properties of the surface. Embedded particles can be the place of stress concentration causing cracking of ceramics, and may deteriorate corrosion resistance by forming corrosive microlinks. In the latter cases, it would be advisable to remove elements embedded into the surface. The simplest method is chemical etching or electrochemical one. Nevertheless, these procedures should not significantly change the parameters of the surface. Among many possible reagents only a few fulfills all the above conditions. In addition, processing should not impair corrosion resistance of titanium, which is one of the most important factors determining its use as a prosthetic restoration in the mouth. The study presented results of corrosion resistance of titanium used to make prosthetic components by means of casting method, which were subjected to chemical processing designed to remove the embedded abrasive particles. The aim of the study was to investigate whether etching with selected reagents affects the corrosion resistance of titanium castings. For etching the following reagents were used: 30% HNO3 + 3% HF + H2O, HNO3+ HF+ glycerol (1:2:3, 4% HF in H2O2, 4% HF in H2O, with a control sandblasted sample, not subjected to etching. Tests demonstrated that the etching affected corrosion properties of test samples, in each case the reduction of the corrosion potential occurred - possibly due to the removal of particles of Al2O3 from the surface and activation of the surface. None of the samples underwent pitting corrosion as a result

  12. Superhydrophobic and superoleophobic surface by electrodeposition on magnesium alloy substrate: Wettability and corrosion inhibition.

    Science.gov (United States)

    Liu, Yan; Li, Shuyi; Wang, Yaming; Wang, Huiyuan; Gao, Ke; Han, Zhiwu; Ren, Luquan

    2016-09-15

    Superamphiphobic (both superhydrophobic and superoleophobic) surfaces have attracted great interests in the fundamental research and practical application. This research successfully fabricated the superamphiphobic surfaces by combining the nickel plating process and modification with perfluorocaprylic acid. The cooperation of hierarchical micro-nano structures and perfluorocaprylic acid with low surface energy plays an important role in the formation of superamphiphobic surfaces. The contact angles of water/oil have reached up to 160.2±1°/152.4±1°, respectively. Contrast with bare substrate, the electrochemical measurements of superamphiphobic surfaces, not only the EIS measurement, but also potentiodynamic polarization curves, all revealed that, the surface corrosion inhibition was improved significantly. Moreover, superamphiphobic surfaces exhibited superior stability in the solutions with a large pH range, also could maintain excellent performance after storing for a long time in the air. This method is easy, feasible and effective, and could be used to fabricate large-area mutli-functional surface. Such a technique will develop a new approach to fabricate superamphiphobic surfaces on different engineering materials. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Effect of water chemistry on the dissolution rate of the lead corrosion product hydrocerussite.

    Science.gov (United States)

    Noel, James D; Wang, Yin; Giammar, Daniel E

    2014-05-01

    Hydrocerussite (Pb3(CO3)2(OH)2) is widely observed as a corrosion product in drinking water distribution systems. Its equilibrium solubility and dissolution rate can control lead concentrations in drinking water. The dissolution rate of hydrocerussite was investigated as a function of pH, dissolved inorganic carbon (DIC), and orthophosphate concentrations at conditions relevant to drinking water distribution using continuously stirred tank reactors (CSTRs). In the absence of DIC and orthophosphate, the dissolution rate decreased with increasing pH. Addition of DIC inhibited the dissolution of hydrocerussite. The addition of orthophosphate significantly decreased the dissolution rate of hydrocerussite. At conditions with orthophosphate and without DIC, a lead(II) phosphate solid hydroxylpyromorphite (Pb5(PO4)3OH) was observed after reaction, and orthophosphate's inhibitory effect can be attributed to the formation of this low-solubility lead(II) phosphate solid. In the presence of both orthophosphate and DIC, no lead(II) phosphate solid was observed, but the rate was still lowered by the presence of orthophosphate, which might be due to the adsorption of orthophosphate to block reactive sites on the hydrocerussite surface. For systems in which hydroxylpyromorphite was present, the steady-state effluent lead concentrations from the CSTRs were close to the predicted equilibrium solubility of hydroxylpyromorphite. In the absence of orthophosphate rapid equilibration of hydrocerussite was observed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The external beam facility used to characterize corrosion products in metallic statuettes

    International Nuclear Information System (INIS)

    Rizzutto, M.A.; Tabacniks, M.H.; Added, N.; Barbosa, M.D.L.; Curado, J.F.; Santos, W.A.; Lima, S.C.; Melo, H.G.; Neiva, A.C.

    2005-01-01

    To open new possibilities in nuclear applied physics research, mainly for the analysis of art objects in air, an external beam facility was installed at LAMFI (Laboratorio de Analise de Materiais por Feixes Ionicos) of University of Sao Paulo. PIXE measurements were made using an XR-100CR (Si-PIN) X-ray detector pointed to the sample mounted after an approximate 11 mm air path, hence with effective beam energy of 0.9 MeV. This setup was used to characterize the corrosion products of two ethnological metallic statuettes from the African collection of the Museum of Archaeology and Etnology. PIXE analysis of the corrosion free base of one statuette showed that Cu and Zn are the main components of the alloy, while Pb is present in smaller amount. The analysis of some corrosion products showed a Zn:Cu relationship higher than that of the base, evidencing selective corrosion. The main components of the other statuette were Cu and Pb, while S and Zn were found in smaller amounts

  15. The external beam facility used to characterize corrosion products in metallic statuettes

    Science.gov (United States)

    Rizzutto, M. A.; Tabacniks, M. H.; Added, N.; Barbosa, M. D. L.; Curado, J. F.; Santos, W. A.; Lima, S. C.; Melo, H. G.; Neiva, A. C.

    2005-10-01

    To open new possibilities in nuclear applied physics research, mainly for the analysis of art objects in air, an external beam facility was installed at LAMFI (Laboratório de Análise de Materiais por Feixes Iônicos) of University of São Paulo. PIXE measurements were made using an XR-100CR (Si-PIN) X-ray detector pointed to the sample mounted after an approximate 11 mm air path, hence with effective beam energy of 0.9 MeV. This setup was used to characterize the corrosion products of two ethnological metallic statuettes from the African collection of the Museum of Archaeology and Etnology. PIXE analysis of the corrosion free base of one statuette showed that Cu and Zn are the main components of the alloy, while Pb is present in smaller amount. The analysis of some corrosion products showed a Zn:Cu relationship higher than that of the base, evidencing selective corrosion. The main components of the other statuette were Cu and Pb, while S and Zn were found in smaller amounts.

  16. A computer code PACTOLE to predict activation and transport of corrosion products in a PWR

    International Nuclear Information System (INIS)

    Beslu, P.; Frejaville, G.; Lalet, A.

    1978-01-01

    Theoretical studies on activation and transport of corrosion products in a PWR primary circuit have been concentrated, at CEA on the development of a computer code : PACTOLE. This code takes into account the major phenomena which govern corrosion products transport: 1. Ion solubility is obtained by usual thermodynamics laws in function of water chemistry: pH at operating temperature is calculated by the code. 2. Release rates of base metals, dissolution rates of deposits, precipitation rates of soluble products are derived from solubility variations. 3. Deposition of solid particles is treated by a model taking into account particle size, brownian and turbulent diffusion and inertial effect. Erosion of deposits is accounted for by a semi-empirical model. After a review of calculational models, an application of PACTOLE is presented in view of analyzing the distribution of in core. (author)

  17. Mussel-inspired superhydrophobic surfaces with enhanced corrosion resistance and dual-action antibacterial properties.

    Science.gov (United States)

    Qian, Hongchang; Li, Minglu; Li, Zhong; Lou, Yuntian; Huang, Luyao; Zhang, Dawei; Xu, Dake; Du, Cuiwei; Lu, Lin; Gao, Jin

    2017-11-01

    In this study, a multilayer antibacterial film was assembled onto 316L stainless steel via mussel-inspired depositions of polydopamine (PDA) and silver (Ag) nanoparticles followed by post-modification with 1H, 1H, 2H, 2H-perfluorodecanethiol. The resulting surface exhibited excellent superhydrophobicity with hierarchical micro/nanostructures that were constructed by both PDA and Ag nanoparticles. The crystal structure and chemical composition of these surfaces were investigated using X-ray photoelectron spectroscopy (XPS) analysis. Potentiodynamic polarization measurements revealed that the corrosion resistance of the as-prepared surfaces were sequentially increased after each step of the fabrication process. Compared with the surface covered with only Ag nanoparticles, the superhydrophobic surfaces exhibited substantially enhanced antibacterial activity against the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, resulting from the synergistic antibacterial actions of the superhydrophobic surface and Ag nanoparticles. The superhydrophobic surface exhibited lower cytotoxicity, compared to the surface covered with Ag nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Oxidative Corrosion of the UO 2 (001) Surface by Nonclassical Diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Stubbs, Joanne E.; Biwer, Craig A.; Chaka, Anne M. [Pacific Northwest; Ilton, Eugene S. [Pacific Northwest; Du, Yingge [Pacific Northwest; Bargar, John R. [Stanford Synchrotron; Eng, Peter J.

    2017-11-07

    Uranium oxide is central to every stage of the nuclear fuel cycle, from mining through fuel fabrication and use, to waste disposal and environmental cleanup. Its chemical and mechanical stability are intricately linked to the concentration of interstitial O atoms within the structure and the oxidation state of U. We have previously shown that during corrosion of the UO2 (111) surface under either 1 atm O2 gas or oxygenated water at room temperature, oxygen interstitials diffuse into the substrate to form a superlattice with three-layer periodicity. In the current study, we present results from surface x-ray scattering that reveal the structure of the oxygen diffusion profile beneath the (001) surface. The first few layers below the surface oscillate strongly in their surface-normal lattice parameters, suggesting preferential interstitial occupation of every other layer below the surface, which is geometrically consistent with the interstitial network that forms below the oxidized (111) surface. Deeper layers are heavily contracted and indicate that the oxidation front penetrates ~52 Å below the (001) surface after 21 days of dry O2 gas exposure at ambient pressure and temperature. X-ray photoelectron spectroscopy indicates U is present as U(IV), U(V), and U(VI).

  19. The effect of surface treatment and topography on corrosion behavior of EN 1.4404 stainless steel

    DEFF Research Database (Denmark)

    Lage, R.; Møller, Per; Fallesen, Henrik Ebbe

    2015-01-01

    Corrosion properties of EN 1.4404 (316L) stainless steel with different applied surface treatment, were studied in NaCl solution using cyclic polarization. Observed properties were related to the specific topography of each surface by scanning electron microcopy and cross-section analysis. Average...

  20. 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

  1. Electrosynthesis of Polyaniline-TiO2 Nanocomposite Films on Aluminum Alloy 3004 Surface and its Corrosion Protection Performance

    Directory of Open Access Journals (Sweden)

    M. Shabani-Nooshabadi

    2013-03-01

    Full Text Available The direct synthesis of polyaniline-TiO2 nanocomposite coatings on aluminum alloy 3004 (AA3004 surface has been investigated by using the galvanostatic method. The synthesized coatings were characterized by FT-IR, SEM-EDX, SEM and AFM. Optical absorption spectroscopy reveals the formation of the emeraldine oxidation state form of polyaniline-TiO2 nanocomposite. The corrosion performances of polyaniline-TiO2 nanocomposite coatings were investigated in 3.5% NaCl solution by Tafel polarization and Electrochemical Impedance Spectroscopy (EIS methods. The corrosion rate of polyaniline-TiO2 nanocomposite coating on AA3004 was found ∼260 times lower than bare AA3004 and corrosion potentials of these coatings have shifted to more positive potentials (105 mV. The results of this study clearly ascertain that the polyaniline-TiO2 nanocomposite coating has outstanding potential to protect the AA3004 against corrosion in a chloride environment.

  2. Surface Layers of Zr-18%Nb Alloy Modified by Ultrasonic Impact Treatment: Microstructure, Hardness and Corrosion

    Science.gov (United States)

    Khripta, N. I.; Karasevska, O. P.; Mordyuk, B. N.

    2017-11-01

    Near-surface layers in Zr-18%Nb alloy were modified using ultrasonic impact treatment (UIT). The effects of the UIT processing time on a microstructural formation, omega/alpha precipitations, microhardness and corrosion are analyzed. XRD analysis, TEM and SEM observations and EDX characterization allow establishing the links between the microstructure, microhardness and corrosion behavior of the surface layers formed. At the strain extent up to e ≈ 0.3, structural formation occurs under influence of deformation induced heating, which facilitates omega precipitation in beta phase and mechanically induced oxygen transport and oxide formation. XRD analysis reveals moderate compressive residual stresses (- 160 MPa) and pronounced {110} texture after the UIT process. Generation of dislocations and hindering of their movement by nanoscale omega precipitates manifest themselves as the broadening of diffraction peaks occurred mainly owing to the lattice microstrains, and they provide marked strain hardening. The enhanced anticorrosion properties of Zr-18%Nb alloy in saline solution were concluded to be a result of the formation of a protective oxide film, {110} texture and compressive stresses.

  3. Prediction of Outside Surface Aluminium Tank Corrosion on TRIGA Mark - IIResearch Reactor Bandung

    International Nuclear Information System (INIS)

    Soedardjo

    2000-01-01

    The prediction of outside surface aluminium tank corrosion on researchreactor design which coated by epoxy paint, has been assessed. The new TRIGAMark - II Bandung research reactor tank design separated by 3 section arebottom, middle and upper section then inserted into the existing old reactor.The separation carried out caused by the space constraint on top of old tank,so that the novel tank impossible inserted into old tank all at once. Thespace between novel and old tank is 10 mm. After bottom and middle section oftank welded then followed by epoxy painting and inserted partially into oldtank. From then on the middle and upper section welded and followed by epoxypainting then inserted into old tank. Based on prediction result, that theroot cause of corrosion would be took place on welding and on imperfectlyepoxy painting area. The outside surface novel tank would be generated by thereaction between imperfectly epoxy painting area and the highly basecondition on cement grout that available on novel and old tank gap. (author)

  4. Surface Morphology and Corrosion Behavior of Hydroxyapatite-Coated Co-Cr Implant: Effect of Sintering Conditions

    Science.gov (United States)

    Shirdar, Mostafa Rezazadeh; Taheri, Mohammad Mahdi

    2017-12-01

    The surface morphology and corrosion behavior of a hydroxyapatite (HA)-coated cobalt-chromium (Co-Cr) implant after sintering posttreatment using different times and temperatures were investigated. The substrates were electrophoretically coated with calcium phosphate in solution of Ca(NO3)·4H2O and NH4H2PO4. Sintering at four different conditions was then performed on the as-deposited samples. Scanning electron microscopy, contact angle measurement, and potentiodynamic polarization studies were employed to investigate the surface morphology, porosity, wettability, and corrosion behavior of the coated samples. The results revealed that the HA-coated substrate sintered at temperature of 600°C for 20 min showed fairly uniform microstructure with the highest density and corrosion resistance compared with the other conditions. Moreover, the highest wettability was exhibited by the HA surface sintered at temperature of 500°C for 60 min.

  5. Mechanically robust superhydrophobic steel surface with anti-icing, UV-durability, and corrosion resistance properties.

    Science.gov (United States)

    Wang, Nan; Xiong, Dangsheng; Deng, Yaling; Shi, Yan; Wang, Kun

    2015-03-25

    A superhydrophobic steel surface was prepared through a facile method: combining hydrogen peroxide and an acid (hydrochloric acid or nitric acid) to obtain hierarchical structures on steel, followed by a surface modification treatment. Empirical grid maps based on different volumes of H2O2/acid were presented, revealing a wettability gradient from "hydrophobic" to "rose effect" and finally to "lotus effect". Surface grafting has been demonstrated to be realized only on the oxidized area. As-prepared superhydrophobic surfaces exhibited excellent anti-icing properties according to the water-dripping test under overcooled conditions and the artificial "steam-freezing" (from 50 °C with 90% humidity to the -20 °C condition) test. In addition, the surfaces could withstand peeling with 3M adhesive tape at least 70 times with an applied pressure of 31.2 kPa, abrasion by 400 grid SiC sandpaper for 110 cm under 16 kPa, or water impacting for 3 h without losing superhydrophobicity, suggesting superior mechanical durability. Moreover, outstanding corrosion resistance and UV-durability were obtained on the prepared surface. This successful fabrication of a robust, anti-icing, UV-durable, and anticorrosion superhydrophobic surface could yield a prospective candidate for various practical applications.

  6. Rapid fabrication of large-area, corrosion-resistant superhydrophobic Mg alloy surfaces.

    Science.gov (United States)

    Xu, Wenji; Song, Jinlong; Sun, Jing; Lu, Yao; Yu, Ziyuan

    2011-11-01

    A superhydrophobic magnesium (Mg) alloy surface was successfully fabricated via a facile electrochemical machining process, and subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphologies and chemical compositions were investigated using a scanning electron microscope (SEM) equipped with an energy-dispersive spectroscopy (EDS) and a Fourier-transform infrared spectrophotometer (FTIR). The results show hierarchal rough structures and an FAS film with a low surface energy on the Mg alloy surfaces, which confers good superhydrophobicity with a water contact angle of 165.2° and a water tilting angle of approximately 2°. The processing conditions, such as the processing time and removal rate per unit area at a constant removal mass per unit area, were investigated to determine their effects on the superhydrophobicity. Interestingly, when the removal mass per unit area is constant at approximately 11.10 mg/cm(2), the superhydrophobicity does not change with the removal rate per unit area. Therefore, a superhydrophobic Mg alloy surface can be rapidly fabricated based on this property. A large-area superhydrophobic Mg alloy surface was also fabricated for the first time using a small-area moving cathode. The corrosion resistance and durability of the superhydrophobic surfaces were also examined.

  7. One-step electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on magnesium alloy.

    Science.gov (United States)

    Liu, Qin; Chen, Dexin; Kang, Zhixin

    2015-01-28

    A simple, one-step method has been developed to construct a superhydrophobic surface by electrodepositing Mg-Mn-Ce magnesium plate in an ethanol solution containing cerium nitrate hexahydrate and myristic acid. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were employed to characterize the surfaces. The shortest electrodeposition time to obtain a superhydrophobic surface was about 1 min, and the as-prepared superhydrophobic surfaces had a maximum contact angle of 159.8° and a sliding angle of less than 2°. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements demonstrated that the superhydrophobic surface greatly improved the corrosion properties of magnesium alloy in 3.5 wt % aqueous solutions of NaCl, Na2SO4, NaClO3, and NaNO3. Besides, the chemical stability and mechanical durability of the as-prepared superhydrophobic surface were also examined. The presented method is rapid, low-cost, and environmentally friendly and thus should be of significant value for the industrial fabrication of anticorrosive superhydrophobic surfaces and should have a promising future in expanding the applications of magnesium alloys.

  8. On the properties of two binary NiTi shape memory alloys. Effects of surface finish on the corrosion behaviour and in vitro biocompatibility.

    Science.gov (United States)

    Es-Souni, Mohammed; Es-Souni, Martha; Fischer-Brandies, Helge

    2002-07-01

    The present paper compares the transformation behaviour and mechanical properties of two orthodontic wires of close chemical compositions. The effects of surface topography and surface finish residues on the potentiodynamic corrosion behaviour and biocompatibility are also reported. The cytotoxicity tests were performed on both alloys in fibroblast cell cultures from human gingiva using the MTT test. It is shown that the surface finish and the amounts of surface finish residues affect dramatically the corrosion resistance. Bad surface finish results in lower corrosion resistance. The in vitro biocompatibility, though not affected to the extent of corrosion resistance, is also reduced as the surface roughness and the amounts of residues increase. This is thought to be due to surface effects on corrosion and metallic ions release.

  9. Mass transfer of corrosion products in high temperature, high pressure water circuits

    International Nuclear Information System (INIS)

    Rodd, J.T.; Nicholson, F.D.

    1976-01-01

    The CWL-3 loop is used to study the mass transfer of corrosion products in water at 270 0 C for pressures up to 6.9 MPa. Two parallel Zircaloy-2 test sections are heated directly by a low voltage a.c. electrical current to give a heat flux up to 500 W cm -2 and a heat rating up to 1500 W cm -1 . Coolant flow rates can be varied up to 0.4 kg cm -2 s -1 with or without boiling. A tracer technique has been developed to monitor continuously the deposition of corrosion products in the test sections during operation of the loop. Magnetite deposits 2.6 nm thick can be readily detected. (author)

  10. Analysis of corrosion-product transport using nondestructive XRF and MS techniques

    International Nuclear Information System (INIS)

    Sawicka, B.D.; Sawicki, J.A.

    1998-01-01

    This paper describes the application of X-ray fluorescence (XRF) and Moessbauer spectroscopy (MS) techniques to monitor corrosion-product transport (CPT) in water circuits of nuclear reactors. The combination of XRF and MS techniques was applied in studies of CPT crud filters from both primary- and secondary-side water circuits (i.e., radioactive and nonradioactive specimens) of CANDU reactors. The XRF-MS method allows nondestructive analysis of species collected on filters and provides more complete information about corrosion products than commonly used digestive methods of chemical analysis. Recent analyses of CPT specimens from the Darlington Nuclear Generating Station (NGS) primary side and the Bruce B NGS feedwater system are shown as examples. Some characteristics of primary and secondary water circuits are discussed using these new data. (author)

  11. Surface chemistry and corrosion behavior of Inconel 625 and 718 in subcritical, supercritical, and ultrasupercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, David; Merwin, Augustus; Karmiol, Zachary; Chidambaram, Dev, E-mail: dcc@unr.edu

    2017-05-15

    Highlights: • Mixtures of oxides containing Ni, Fe, Cr and Nb formed on the surface. • Short term exposure tests observed breakdown of native film. • Formation of a Fe rich oxide layer on Inconel 718 prevents mass loss. - Abstract: Corrosion behavior of Inconel 625 and 718 in subcritical, supercritical and ultrasupercritical water was studied as a function of temperature and time. The change in the chemistry of the as-received surface film on Inconel 625 and 718 after exposure to subcritical water at 325 °C and supercritical water at 425 °C and 527.5 °C for 2 h was studied. After exposure to 325 °C subcritical water, the CrO{sub 4}{sup 2−} based film formed; however minor quantities of NiFe{sub x}Cr{sub 2-x}O{sub 4} spinel compounds were observed. The oxide film formed on both alloys when exposed to supercritical water at 425 °C consisted of NiFe{sub x}Cr{sub 2-x}O{sub 4} spinel. The surface films on both alloys were identified as NiFe{sub 2}O{sub 4} when exposed to supercritical water at 527.5 °C. To characterize the fully developed oxide layer, studies were conducted at test solution temperatures of 527.5 and 600 °C. Samples were exposed to these temperatures for 24, 96, and 200 h. Surface chemistry was analyzed using X-ray diffraction, as well as Raman and X-ray photoelectron spectroscopies. Inconel 718 exhibited greater mass gain than Inconel 625 for all temperatures and exposure times. The differences in corrosion behavior of the two alloys are attributed to the lower content of chromium and increased iron content of Inconel 718 as compared to Inconel 625.

  12. Uniform and pitting corrosion events induced by SCN- anions on Al alloys surfaces and the effect of UV light

    International Nuclear Information System (INIS)

    Amin, Mohammed A.

    2011-01-01

    The influence of the alloying elements on the uniform and pitting corrosion processes of Al-6061, Al-4.5%Cu, Al-7.5%Cu, Al-6%Si and Al-12%Si alloys was studied in 0.50 M KSCN solution at 25 o C. Open-circuit potential, Tafel polarization, linear polarization resistance (LPR) and ICP-AES measurements were used to study the uniform corrosion process on the surfaces of the tested alloys. Cyclic polarization, potentiostatic current-time transients and impedance techniques were employed for pitting corrosion studies. Obtained results were compared with pure Al. Passivation kinetics of the tested Al samples were also studied as a function of applied potential, [SCN - ] and sample composition by means of potentiostatic current transients. The induction time, after which the growth of stable pits occurs, decreased with increasing applied potential and [SCN - ]. Regarding to uniform corrosion, alloyed Cu was found to enhance the corrosion rate, while alloyed Si suppressed it. Alloying elements of the tested samples diminished pitting attack to an extent depending on the percentage of the alloying element in the sample. Among the investigated materials, Al-Si alloys exhibited the highest corrosion resistance towards uniform and pitting corrosion processes in KSCN solutions. The passive and dissolution behaviour of Al was also studied under the conditions of continuous illumination (300-450 nm) based on cyclic polarization and potentiostatic techniques. The incident photons had a little influence on pit initiation and a marked effect on pit growth. These explained in terms of a photo-induced modification of the passive film formed on the anode surface, which render it more resistant to pitting. The effects of UV photons energy and period of illumination on the morphology of the pitted surfaces were also studied.

  13. An overview of the activated corrosion product reduction program for US power reactors

    International Nuclear Information System (INIS)

    Murphy, T.D.

    1977-01-01

    Recent studies have shown that radiation levels associated with reactor coolant components are increasing at US nuclear power plants. Recent experience also shows that occupational radiation exposure to personnel is also increasing. This paper discusses one aspect of reducing exposure to personnel, that is, recent developments in the reduction of existing corrosion product radioactivity in reactor coolant systems and the minimization of the formation and buildup of such activity.(orig.) [de

  14. Influence of laser surface treated on the characterization and corrosion behavior of Al–Fe aerospace alloys

    Energy Technology Data Exchange (ETDEWEB)

    Pariona, Moisés Meza, E-mail: mmpariona@uepg.br [Graduate Program in Engineering and Materials Science, State University of Ponta Grossa (UEPG), Ponta Grossa 84010-919, PR (Brazil); Teleginski, Viviane; Santos, Kelly dos; Lima, Angela A.O.C. de; Zara, Alfredo J.; Micene, Katieli Tives [Graduate Program in Engineering and Materials Science, State University of Ponta Grossa (UEPG), Ponta Grossa 84010-919, PR (Brazil); Riva, Rudimar [Department of Aerospace Science and Technology, Institute for Advanced Studies (IEAv), São José dos Campos 12227-000, SP (Brazil)

    2013-07-01

    In this research laser surface remelting without protective coating with a 2 kW Yb-fiber laser (IPG YLR-2000S) was applied in the Al–1.5 wt.%Fe alloy in order to investigate the layer treated with different techniques of superficial characterization, thereby, the technique of optical microscopy, atomic force microscopy and low-angle X-ray diffraction were used. The present work mainly focuses on the corrosion study by diverse techniques in aggressive environment of the laser-treated area and the substrate material was carried out, thereby, at open circuit potential testing, the results have shown a displacement to more anodic values in the corrosion potential for the laser-treated specimen when compared to the untreated specimen; in potentiodynamic polarization tests have shown that as a result of the laser treatment, the corrosion current can be reduced by as much as ten times, and a passive region was obtained, which served as an effective barrier for reducing anodic dissolution and finally, the result in cyclic polarization curves of the untreated sample there was a greater area of the hysteresis loop, implying that it is more susceptible to corrosion. This study was complemented by other techniques mentioned above in order to elucidate this study. Laser surface remelting process has definitely modified the surface film, which results in higher corrosion resistance, a large range of passivation and a lower area of the hysteresis loop.

  15. Influence of laser surface treated on the characterization and corrosion behavior of Al–Fe aerospace alloys

    International Nuclear Information System (INIS)

    Pariona, Moisés Meza; Teleginski, Viviane; Santos, Kelly dos; Lima, Angela A.O.C. de; Zara, Alfredo J.; Micene, Katieli Tives; Riva, Rudimar

    2013-01-01

    In this research laser surface remelting without protective coating with a 2 kW Yb-fiber laser (IPG YLR-2000S) was applied in the Al–1.5 wt.%Fe alloy in order to investigate the layer treated with different techniques of superficial characterization, thereby, the technique of optical microscopy, atomic force microscopy and low-angle X-ray diffraction were used. The present work mainly focuses on the corrosion study by diverse techniques in aggressive environment of the laser-treated area and the substrate material was carried out, thereby, at open circuit potential testing, the results have shown a displacement to more anodic values in the corrosion potential for the laser-treated specimen when compared to the untreated specimen; in potentiodynamic polarization tests have shown that as a result of the laser treatment, the corrosion current can be reduced by as much as ten times, and a passive region was obtained, which served as an effective barrier for reducing anodic dissolution and finally, the result in cyclic polarization curves of the untreated sample there was a greater area of the hysteresis loop, implying that it is more susceptible to corrosion. This study was complemented by other techniques mentioned above in order to elucidate this study. Laser surface remelting process has definitely modified the surface film, which results in higher corrosion resistance, a large range of passivation and a lower area of the hysteresis loop.

  16. Development of stress corrosion cracking resistant welds of 321 stainless steel by simple surface engineering

    Science.gov (United States)

    Mankari, Kamal; Acharyya, Swati Ghosh

    2017-12-01

    We hereby report a simple surface engineering technique to make AISI grade 321 stainless steel (SS) welds resistant to stress corrosion cracking (SCC) in chloride environment. Heat exchanger tubes of AISI 321 SS, welded either by (a) laser beam welding (LBW) or by (b) metal inert gas welding (MIG) were used for the study. The welds had high magnitude of tensile residual stresses and had undergone SCC in chloride environment while in service. The welds were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Subsequently, the welded surfaces were subjected to buffing operation followed by determination of residual stress distribution and surface roughness by XRD and surface profilometer measurements respectively. The susceptibility of the welds to SCC was tested in buffed and un-buffed condition as per ASTM G-36 in boiling MgCl2 for 5 h and 10 h, followed by microstructural characterization by using optical microscope and FESEM. The results showed that the buffed surfaces (both welds and base material) were resistant to SCC even after 10 h of exposure to boiling MgCl2 whereas the un-buffed surfaces underwent severe SCC for the same exposure time. Buffing imparted high magnitude of compressive stresses on the surface of stainless steel together with reduction in its surface roughness and reduction in plastic strain on the surface which made the welded surface, resistant to chloride assisted SCC. Buffing being a very simple, portable and economic technique can be easily adapted by the designers as the last step of component fabrication to make 321 stainless steel welds resistant to chloride assisted SCC.

  17. Effects of surface chromium depletion on localized corrosion of alloy 825 as a high-level nuclear waste container material

    International Nuclear Information System (INIS)

    Dunn, D.S.; Sridhar, N.; Cragnolino, G.A.

    1995-01-01

    Effects of the chromium-depleted, mill-finished surface on the localized corrosion resistance of alloy 825 (UNS N08825) were investigated. Tests were conducted in solutions based on the ground water at Yucca mountain, Nevada, but with a higher concentration of chloride. Results indicated that breakdown (E p ) and repassivation (E rp ) potentials for mill-finished surfaces were more active than those for polished surfaces. Potentiodynamic polarization tests indicated pits could be initiated on the chromium-depleted surface at potentials of 220 mV SCE in a solution containing 1,000 ppm Cl - at 95 C. Potentiostatic tests identified a similar pit initiation potential for the mill-finished surface. However, under longterm potentiostatic tests, a higher potential of 300 mV SCE was needed to sustain stable pit growth beyond the chromium-depleted layer. An increase in surface roughness also was observed to decrease localized corrosion resistance of the material

  18. Surface chemistry and corrosion behavior of Inconel 625 and 718 in subcritical, supercritical, and ultrasupercritical water

    Science.gov (United States)

    Rodriguez, David; Merwin, Augustus; Karmiol, Zachary; Chidambaram, Dev

    2017-05-01

    Corrosion behavior of Inconel 625 and 718 in subcritical, supercritical and ultrasupercritical water was studied as a function of temperature and time. The change in the chemistry of the as-received surface film on Inconel 625 and 718 after exposure to subcritical water at 325 °C and supercritical water at 425 °C and 527.5 °C for 2 h was studied. After exposure to 325 °C subcritical water, the CrO42- based film formed; however minor quantities of NiFexCr2-xO4 spinel compounds were observed. The oxide film formed on both alloys when exposed to supercritical water at 425 °C consisted of NiFexCr2-xO4 spinel. The surface films on both alloys were identified as NiFe2O4 when exposed to supercritical water at 527.5 °C. To characterize the fully developed oxide layer, studies were conducted at test solution temperatures of 527.5 and 600 °C. Samples were exposed to these temperatures for 24, 96, and 200 h. Surface chemistry was analyzed using X-ray diffraction, as well as Raman and X-ray photoelectron spectroscopies. Inconel 718 exhibited greater mass gain than Inconel 625 for all temperatures and exposure times. The differences in corrosion behavior of the two alloys are attributed to the lower content of chromium and increased iron content of Inconel 718 as compared to Inconel 625.

  19. Testing and prediction of erosion-corrosion for corrosion resistant alloys used in the oil and gas production industry

    Science.gov (United States)

    Rincon, Hernan E.

    The corrosion behavior of CRAs has been thoroughly investigated and documented in the public literature by many researchers; however, little work has been done to investigate erosion-corrosion of such alloys. When sand particles are entrained in the flow, the degradation mechanism is different from that observed for sand-free corrosive environment. There is a need in the oil and gas industry to define safe service limits for utilization of such materials. The effects of flow conditions, sand rate, pH and temperature on the erosion-corrosion of CRAs were widely studied. An extensive experimental work was conducted using scratch tests and flow loop tests using several experimental techniques. At high erosivity conditions, a synergistic effect between erosion and corrosion was observed. Under the high sand rate conditions tested, erosivity is severe enough to damage the passive layer protecting the CRA thereby enhancing the corrosion rate. In most cases there is likely a competition between the rates of protective film removal due to mechanical erosion and protective film healing. Synergism occurs for each of the three alloys examined (13Cr and Super13Cr and 22Cr); however, the degree of synergism is quite different for the three alloys and may not be significant for 22Cr for field conditions where erosivities are typically much lower that those occurring in the small bore loop used in this research. Predictions of the corrosion component of erosion-corrosion based on scratch test data compared reasonably well to test results from flow loops for the three CRAs at high erosivity conditions. Second order behavior appears to be an appropriate and useful model for representing the repassivation process of CRAs. A framework for a procedure to predict penetration rates for erosion-corrosion conditions was developed based on the second order model behavior observed for the re-healing process of the passive film of CRAs and on computational fluid dynamics (CFD) simulations

  20. Constructing superhydrophobic WO3@TiO2 nanoflake surface beyond amorphous alloy against electrochemical corrosion on iron steel

    Science.gov (United States)

    Yu, S. Q.; Ling, Y. H.; Wang, R. G.; Zhang, J.; Qin, F.; Zhang, Z. J.

    2018-04-01

    To eliminate harmful localized corrosion, a new approach by constructing superhydrophobic WO3@TiO2 hierarchical nanoflake surface beyond FeW amorphous alloy formed on stainless steel was proposed. Facile dealloying and liquid deposition was employed at low temperature to form a nanostructured layer composing inner WO3 nanoflakes coated with TiO2 nanoparticles (NPs) layer. After further deposition of PFDS on nanoflakes, the contact angle reached 162° while the corrosion potential showed a negative shift of 230 mV under illumination, resulting in high corrosion resistance in 3.5 wt% NaCl solution. The tradeoff between superhydrophobic surface and photo-electro response was investigated. It was found that this surface feature makes 316 SS be immune to localized corrosion and a pronounced photo-induced process of electron storage/release as well as the stability of the functional layer were detected with or without illumination, and the mechanism behind this may be related to the increase of surface potential due to water repellence and the delayed cathodic protection of semiconducting coating derived mainly from the valence state changes of WO3. This study demonstrates a simple and low-cost electrochemical approach for protection of steel and novel means to produce superhydrophobic surface and cathodic protection with controllable electron storage/release on engineering scale.

  1. Numerical simulation of the detection of crack in reinforced concrete structures of NPP due to expansion of reinforcing corrosive products using Impact-Echo method

    Directory of Open Access Journals (Sweden)

    Morávka Š.

    2008-12-01

    Full Text Available Nuclear energy boom is starting nowadays. But also current nuclear power plants (NPP are duty to certify their security for regular renewal of their operating licenses. NPP security can be significantly affected by defects of large amount of ageing reinforced concrete structures. Advanced Impact-Echo method seams to be very hopeful to cooperate at performing in-service inspections such structures. Just these in-service inspections are included in the first priority group of specific technical issues according to the recommendations of OECD-Nuclear Energy Agency, Commission on Safety of Nuclear Installation in the field of ageing management.This paper continues of extensive project dealing with Impact-Echo method application. It will present method description and main results of numerical modeling of detection and localization of crack caused by corrosive product expansion. Steel reinforcing rods are subjected to corrosion due to diffusion of corrosive agents from structure surface. Corrosive products have up to 7-times larger volume than pure steel. Raised strain can cad lead up to concrete failure and crack development. We investigate whether it is possible to detect these growing cracks by Impact-Echo method in time.Experimental verification of our numerical predictions is prepared on Civil Faculty in Brno.

  2. Composition of the corrosion product oxide phases in the gaps of three LMFBR-type mixed oxide fuel pins

    International Nuclear Information System (INIS)

    Walker, C.T.

    1978-01-01

    Identification of the corrosion product oxide phases in the gaps of mixed oxide fuel pins clad with austenitic stainless steel is an important step in understanding the mechanisms of corrosion. Once the oxide is identified the reaction paths by which it is formed can be established. The corrosion product oxide will also be a reliable indication of the oxygen potential in the gap. A grey oxide phase which is recognised to contain the products of cladding corrosion is often observed in the gaps of mixed oxide fuel pins. Its main constituents are known to be chromium, caesium and oxygen, and recently the composition of the grey oxide phase in the gaps of three fuel pins was shown to be broadly similar, and it was proposed that the phase was essentially chromium oxide. (Auth.)

  3. Corrosion product characterisation by fibre optic raman spectroscopy

    International Nuclear Information System (INIS)

    Guzonas, D.A.; Rochefort, P.A.; Turner, C.W.

    1998-01-01

    Fibre optic Raman spectroscopy has been used to characterise secondary-side deposits removed from CANDU steam generators. The deposits examined were in the form of powders, millimetre-sized flakes, and deposits on the surfaces of pulled steam generator tubes. The compositions of the deposits obtained using Raman spectroscopy are similar to the compositions obtained using other ex-situ analytical techniques. A semi-quantitative estimate of amounts of the major components can be obtained from the spectra. It was noted that the signal-to-noise ratio of the Raman spectra decreased as the amount of magnetite in the deposit increased, as a result of absorption of the laser light by the magnetite. The conversion of magnetite to hematite by the laser beam was observed when high laser powers were used. The Raman spectra of larger flake samples clearly illustrate the inhomogeneous nature of the deposits. (author)

  4. Siderite as a Corrosion Product on Archaeological Iron from a Waterlogged Environment

    DEFF Research Database (Denmark)

    Matthiesen, H.; Hilbert, Lisbeth Rischel; Gregory, D.J.

    2003-01-01

    microscopy with energy-dispersive spectrometry (SEM-EDS), which showed only minor contents of other minerals in the corrosion scales. The implications of the formation of siderite as a corrosion product are discussed in terms of its possible passivating properties and thermodynamic stability in situ......This paper discusses the occurrence of siderite (FeCO3) on iron artifacts excavated from the waterlogged peat and gyttja sediment of the Danish Iron Age site Nydam Mose. Siderite was identified by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron....... A Pourbaix diagram adjusted to the actual conditions in Nydam is presented and discussed. Different mechanisms for the formation of siderite in this environment are proposed, based on the results of environmental monitoring in the area....

  5. Modeling of Corrosion-induced Concrete Damage

    DEFF Research Database (Denmark)

    Thybo, Anna Emilie A.; Michel, Alexander; Stang, Henrik

    2013-01-01

    In the present paper a finite element model is introduced to simulate corrosion-induced damage in concrete. The model takes into account the penetration of corrosion products into the concrete as well as non-uniform formation of corrosion products around the reinforcement. To ac-count for the non......-uniform formation of corrosion products at the concrete/reinforcement interface, a deterministic approach is used. The model gives good estimates of both deformations in the con-crete/reinforcement interface and crack width when compared to experimental data. Further, it is shown that non-uniform deposition...... of corrosion products affects both the time-to cover cracking and the crack width at the concrete surface....

  6. In situ monitoring of corrosion mechanisms and phosphate inhibitor surface deposition during corrosion of zinc-magnesium-aluminium (ZMA) alloys using novel time-lapse microscopy.

    Science.gov (United States)

    Sullivan, James; Cooze, Nathan; Gallagher, Callum; Lewis, Tom; Prosek, Tomas; Thierry, Dominique

    2015-01-01

    In situ time-lapse optical microscopy was used to examine the microstructural corrosion mechanisms in three zinc-magnesium-aluminium (ZMA) alloy coated steels immersed in 1% NaCl pH 7. Preferential corrosion of MgZn(2) lamellae within the eutectic phases was observed in all the ZMA alloys followed by subsequent dissolution of Zn rich phases. The total extent and rate of corrosion, measured using time-lapse image analysis and scanning vibrating electrode technique (SVET) estimated mass loss, decreased as Mg and Al alloying additions were increased up to a level of 3 wt% Mg and 3.7 wt% Al. This was probably due to the increased presence of MgO and Al(2)O(3) at the alloy surface retarding the kinetics of cathodic oxygen reduction. The addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to 1% NaCl pH 7 had a dramatic influence on the corrosion mechanism for a ZMA with passivation of anodic sites through phosphate precipitation observed using time-lapse image analysis. Intriguing rapid precipitation of filamentous phosphate was also observed and it is postulated that these filaments nucleate and grow due to super saturation effects. Polarisation experiments showed that the addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to the 1% NaCl electrolyte promoted an anodic shift of 50 mV in open circuit potential for the ZMA alloy with a reduction in anodic current of 2.5 orders of magnitude suggesting that it was acting primarily as an anodic inhibitor supporting the inferences from the time-lapse investigations. These phosphate additions resulted in a 98% reduction in estimated mass loss as measured by SVET demonstrating the effectiveness of phosphate inhibitors for this alloy system.

  7. Understanding Passive Layer Formation for Further Corrosion Management in Gas Production Pipes

    Science.gov (United States)

    Santoso, R. K.; Rahmawati, S. D.; Gadesa, A.; Wahyuningrum, D.

    2017-07-01

    Corrosion is a critical issue during the development of a gas field, especially wet gas or retrograde gas field. Corrosion affects the management system of a field and further impacts the amount of investment. Therefore, accurate prediction of corrosion rate is needed to plan an effective preventive action before going further to the development phase. One of the important parameters that should be noticed to create an accurate prediction is the formation of the passive layer. In CO2-H2S environment, there will be three possibilities of passive layer: FeS, FeCO3 or no passive layer. In this study, we create mathematical models to determine the formed passive layer in each segment of the gas production tubing and pipeline. The model is built using Faraday’s Law and Thermodynamic approach to account the passive layer formation at different temperature, pH, corrosion rate and partial pressure of CO2 and H2S. From the simulation, it was found that there were three boundary conditions: no scale-FeS boundary, no scale-FeCO3 boundary and FeS-FeCO3 boundary. The first two boundaries evolved over a time as the concentration of Fe2+ ions was increasing. However, FeS-FeCO3 boundary remained steady as it was not affected by the addition of Fe2+ ions. Using sample case study, few variations were noticed at production pipeline and tubing. It was caused by the gas composition, which contained high CO2 and very low H2S. Boundary conditions only changed slightly over two days period.

  8. Surfaces: processing, coating, decontamination, pollution, etc. Surface mastering to prevent component corrosion

    International Nuclear Information System (INIS)

    Foucault, M.

    2012-01-01

    In the primary and secondary circuits of nuclear Pressurized Water Reactors, AREVA uses several nickel-based alloys or austenitic stainless steels for the manufacture of safety components. The experience feedback of the last twenty years allows us to point out the major role hold by the component surface state in their life duration. In this paper, we present four examples of problem encountered and solved by a surface study and the definition and implementation of processes for the surface control of the repaired components. Then, we propose some ideas about the present needs in term of analysis means to improve the surface knowledge and control of the manufactured components. (author)

  9. Positive aspects issued from bio corrosion studies: from hydrogen production to biofuel cells; Des aspects positifs issus des recherches en biocorrosion: de la production d'hydrogene aux biopiles a combustible

    Energy Technology Data Exchange (ETDEWEB)

    Silva Munoz, L. de

    2007-12-15

    Microbially influenced corrosion or bio corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio-films could play a major role in steel bio corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild pH conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase/glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

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

    Directory of Open Access Journals (Sweden)

    Maurizio Muniz-Miranda

    2014-12-01

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

  11. Effect of fibre laser marking on surface properties and corrosion resistance of a Fe-Ni-Cr alloy

    Science.gov (United States)

    Astarita, Antonello; Mandolfino, Chiara; Lertora, Enrico; Gambaro, Carla; Squillace, Antonino; Scherillo, Fabio

    2017-10-01

    Fiber laser techniques are increasing their use in many applications, including modification of material surface properties. In particular they are often used for materials' marking as a non-contact processing. In spite of this, the impact of the laser beam on the surface causes metallurgical and morphological changes. The developments during the laser-material interaction can also affect other surface properties, especially corrosion properties which are crucial in the case of Iron-Nickel alloys. Effect of laser marking on a Fe-Cr-Ni alloy using a Tm-fibre laser (IPG Photonics TRL1904; maximum power: 50W, wavelength: 1904 nm), is described in this paper. In order to evaluate the effect of the laser on corrosion properties a specific ageing test in salt spray has been performed. Moreover, superficial morphology analyses have been performed on samples before and after corrosion tests. Possibilities and limitations of laser marking on these alloys have been discussed, in particular from the point of view of the marked surface corrosion resistance preservation.

  12. Dual-action smart coatings with a self-healing superhydrophobic surface and anti-corrosion properties

    NARCIS (Netherlands)

    Qian, Hongchang; Xu, Dake; Du, Cuiwei; Zhang, Dawei; Li, Xiaogang; Huang, Luyao; Deng, Leping; Tu, Yunchao; Mol, J.M.C.; Terryn, H.A.

    2017-01-01

    This work introduces a new self-healing superhydrophobic coating based on dual actions by the corrosion inhibitor benzotriazole (BTA) and an epoxy-based shape memory polymer (SMP). Damage to the surface morphology (e.g., crushed areas and scratches) and the corresponding superhydrophobicity are

  13. Reduction of corrosion products in water coolant - basic way of increase in efficiency and improvement of ecological safety of NPU

    International Nuclear Information System (INIS)

    Prozorov, V.V.

    2004-01-01

    Corrosion of oxidated steel in water with additives of inhibitors or oxygen was considered. It is shown that preliminary oxidation of steel makes possible declining concentration of inhibitors or oxygen. Experiments demonstrate possibilities of the neutral-oxygen water regime for supply of the effective protection. Corrosion resistance of steel may be increased in many times through correct aqua-chemical regimes. Also concentration of corrosion products may be decreased in many times in coolant and their activation in neutron flux of nuclear reactor, amount of radioisotopes [ru

  14. Predicting corrosion product transport in nuclear power stations using a solubility-based model for flow-accelerated corrosion

    International Nuclear Information System (INIS)

    Burrill, K.A.; Cheluget, E.L.

    1995-01-01

    A general model of solubility-driven flow-accelerated corrosion of carbon steel was derived based on the assumption that the solubilities of ferric oxyhydroxide and magnetite control the rate of film dissolution. This process involves the dissolution of an oxide film due to fast-flowing coolant unsaturated in iron. The soluble iron is produced by (i) the corrosion of base metal under a porous oxide film and (ii) the dissolution of the oxide film at the fluid-oxide film interface. The iron released at the pipe wall is transferred into the bulk flow by turbulent mass transfer. The model is suitable for calculating concentrations of dissolved iron in feedtrain lines. These iron levels were used to calculate sludge transport rates around the feedtrain. The model was used to predict sludge transport rates due to flow accelerated corrosion of major feedtrain piping in a CANDU reactor. The predictions of the model compare well with plant measurements

  15. Metallurgical, surface, and corrosion analysis of Ni-Cr dental casting alloys before and after porcelain firing.

    Science.gov (United States)

    Lin, Hsin-Yi; Bowers, Bonnie; Wolan, John T; Cai, Zhuo; Bumgardner, Joel D

    2008-03-01

    A porcelain veneer is often fired on nickel-chromium casting alloys used in dental restorations for aesthetic purposes. The porcelain-fused-to-metal (PFM) process brings the temperature to over 950 degrees C and may change the alloy's corrosion properties. In this study, the metallurgical, surface, and corrosion properties of two Ni-Cr alloys were examined, before and after PFM firing. Two types of alloy were tested-a high Cr, Mo alloy without Be and a low Cr, Mo alloy with Be. Before the PFM firing, specimens from both alloys were examined for their microstructures, hardness, electrochemical corrosion properties, surface composition, and metal ion release. After the PFM firing, the same specimens were again examined for the same properties. Neither of the alloys showed any differences in their electrochemical corrosion properties after the PFM firing. However, both alloys exhibited new phases in their microstructure and significant changes in hardness after firing. In addition, there was a slight increase in CrO(x) on the surface of the Be-free alloy and increased Mo-Ni was observed on the surface of both alloys via X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). This might be one of the reasons why both alloys had increased Ni and Mo ion release after firing. The PFM firing process changed the alloys' hardness, microstructure, and surface composition. No significant changes in the alloys' corrosion behavior were observed, however, the significant increase in metal ion release over a month may need to be further investigated for its clinical effects.

  16. Effect of the Parameters of Gas-Powder Laser Surfacing on the Structural Characteristics of Reconditioned Surface Layer of Corrosion-Resistant Steels

    Science.gov (United States)

    Krylova, S. E.; Oplesnin, S. P.; Manakov, N. A.; Yasakov, A. S.; Strizhov, A. O.

    2018-01-01

    Results of the developed commercial process for reconditioning the surface of corrosion-resistant steels by the method of laser surfacing are presented. A comparative analysis of the microstructures of the deposited wear-resistant layer, of the zone of fusion with the matrix material and of the diffusion zone after different variants of surfacing is performed. The hardness of the deposited layer is measured and a nondestructive inspection of the latter for the presence of flaws is performed.

  17. Microstructure and corrosion behavior of laser surface-treated AZ31B Mg bio-implant material.

    Science.gov (United States)

    Wu, Tso-Chang; Ho, Yee-Hsien; Joshi, Sameehan S; Rajamure, Ravi S; Dahotre, Narendra B

    2017-05-01

    Although magnesium and magnesium alloys are considered biocompatible and biodegradable, they suffer from poor corrosion performance in the human body environment. In light of this, surface modification via rapid surface melting of AZ31B Mg alloy using a continuous-wave Nd:YAG laser was conducted. Laser processing was performed with laser energy ranging from 1.06 to 3.18 J/mm 2 . The corrosion behavior in simulated body fluid of laser surface-treated and untreated AZ31B Mg alloy samples was evaluated using electrochemical technique. The effect of laser surface treatment on phase and microstructure evolution was evaluated using X-ray diffraction and scanning electron microscopy. Microstructure examination revealed grain refinement as well as formation and uniform distribution of Mg 17 Al 12 phase along the grain boundary for laser surface-treated samples. Evolution of such unique microstructure during laser surface treatment indicated enhancement in the corrosion resistance of laser surface-treated samples compared to untreated alloy.

  18. 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)

  19. Corrosion of copper containers prior to saturation of a nuclear fuel waste disposal vault

    International Nuclear Information System (INIS)

    King, F.; Kolar, M.

    1997-12-01

    The buffer material surrounding the containers in a Canadian nuclear fuel waste disposal vault will partially desiccate as a result of the elevated temperature at the container surface. This will lead to a period of corrosion in a moist air atmosphere. Corrosion will either take the form of slow oxidation if the container surface remains dry or aqueous electrochemical corrosion if the surface is wetted by a thin liquid film. The relevant literature is reviewed, from which it is concluded that corrosion should be uniform in nature, except if the surface is wetted, in which case localized corrosion is a possibility. A quantitative analysis of the extent and rate of uniform corrosion during the unsaturated period is presented. Two bounding cases are considered: first, the case of slow oxidation in moist air following either logarithmic or parabolic oxide-growth kinetics and, second, the case of electrochemically based corrosion occurring in a thin liquid film uninhibited by the growth of corrosion products. (author)

  20. One-step fabrication of biomimetic superhydrophobic surface by electrodeposition on magnesium alloy and its corrosion inhibition.

    Science.gov (United States)

    Liu, Yan; Xue, Jingze; Luo, Dan; Wang, Huiyuan; Gong, Xu; Han, Zhiwu; Ren, Luquan

    2017-04-01

    A facile, rapid and one-step electrodeposition process has been employed to construct a superhydrophobic surface with micro/nano scale structure on a Mg-Sn-Zn (TZ51) alloy, which is expected to be applied as a biodegradable biomedical implant materials. By changing the electrodeposition time, the maximum contact angle of the droplet was observed as high as 160.4°±0.7°. The characteristics of the as-prepared surface were conducted by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). Besides, the anti-corrosion performance of the coatings in stimulated body fluid (SBF) solution were investigated by electrochemical measurement. The results demonstrated that the anti-corrosion property of superhydrophobic surface was greatly improved. This method show beneficial effects on the wettability and corrosion behavior, and therefore provides a efficient route to mitigate the undesirable rapid corrosion of magnesium alloy in favor of application for clinical field. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Effect of air humidity on microstructure and phase composition of lithium deuteride corrosion products

    International Nuclear Information System (INIS)

    Liu, Xiaobo; Liu, Jiping

    2017-01-01

    Highlights: • Lithium deuteride samples are corroded by air with different relative humidity. • Show the structure and composition of fracture surface of corrosion particle. • The lithium carbonate formation is related to air humidity. • The lithium carbonate only exists in the surface of lithium hydroxide layer. • There is a concentration gradient of H 2 O across the lithium hydroxide layer. - Abstract: Lithium deuteride (LiD) was exposed to air for 600 min to determine the effect of air humidity on its microstructure and phase composition. XRD and XPS results revealed that LiOH and Li 2 CO 3 formed at relative humidity values of >30%, whereas only LiOH formed at values <20%. SEM and EDS images showed a clear LiOH layer; Li 2 CO 3 was confined to the surface of this layer. The schematic illustration revealed that the concentration gradient of H 2 O across the LiOH layer resulted in little Li 2 CO 3 formed in the layer. This work will contribute to increase understanding of LiD corrosion in air.

  2. Effect of Surface Precipitate on the Crevice Corrosion in HYBRID and Oxalic Acid Solution

    International Nuclear Information System (INIS)

    Park, S. Y.; Jung, J. Y.; Won, H. J.; Kim, S. B.; Choi, W. K.; Moon, J. K.; Park, S. J.

    2015-01-01

    In this study, we investigated the characteristics of the crevice corrosion for Inconel-600 and 304SS in OA solution according to the change in pH. The evaluation of the crevice corrosion with the chemical thermodynamic analysis identified the effect of the residual chemicals such as iron-oxalate and nickeloxalate to the crevice corrosion behavior. Test results were compared with those of HYBRID (HYdrizine Base Reductive metal Ion Decontamination). The crevice corrosion properties of 304 SS and Inconel-600 in HYBRID and oxalic acid solution were evaluated. In case of oxalic acid solution, the corrosion rate on 304SS was rapidly increased with a pH decrease of around 2, but there was no increase in the corrosion rate on Inconel-600

  3. High temperature and stress corrosion cracking of 310S austenitic stainless steel in wet chloride corrosive environment

    Directory of Open Access Journals (Sweden)

    T. Pornpibunsompop

    2018-01-01

    Full Text Available High temperature corrosion and stress corrosion cracking of 310S austenitic stainless steel in wet chloride environment at a high temperature was investigated. The result showed that high temperature corrosion products mostly consisted of ferrous oxides and chromium oxides. Chloride ions attacked a chromium passive film and strongly reacted with iron and chromium. As a result of metal chlorides being volatized, tunnel of pores inside corrosion layer existed. Intergranular stress corrosion cracking was observed. The oxide originated on surface could act as a crack initiator and a crack propagation would progress along grain boundaries and particularly along tunnel of pores.

  4. ANALYSIS OF CORROSION PRODUCT RETRIEVED FROM THE PRIMARY TANK WALL IN THE ANNULUS OF TANK 241-AY-102

    International Nuclear Information System (INIS)

    ANANTATMULA, R.P.

    2003-01-01

    Corrosion product from the annulus side of the double-shell tank 241-AY-102 primary wall was retrieved and analyzed. The analyses indicated that the tank wall was wetted with water leading to corrosion. The water source was quite likely the ingress of water from an external source and condensation of moisture during the long annulus ventilation system shutdowns. Corrosion of the primary tank wall in the annulus of double-shell tank (DST) 241-AY-102 was observed during the review of annulus videos of the tank in year 2001. This resulted in the issuance of an occurrence report, RP-CHG-TANKFARM-2001-0106. The occurrence report required collection and evaluation of the corrosion product to determine the cause of such corrosion. Therefore, a corrosion product sample was collected from the annulus side of the primary wall through Riser 80 in February 2003. The sample was scanned by Operational Health Physics and found to contain no radioactivity. The sample was then released and transmitted to ChemMet, Ltd , PC, for analyses. The present report discusses the types of analyses performed and the results of these analyses from ChemMet, Ltd , PC (Divine 2003) along with conclusions and recommendations. The letter report from ChemMet, Ltd, PC is attached

  5. Grain boundary defects initiation at the outer surface of dissimilar welds: corrosion mechanism studies

    International Nuclear Information System (INIS)

    De Bouvier, O.; Yrieix, B.

    1995-11-01

    Dissimilar welds located on the primary coolant system of the French PWR I plants exhibit grain boundary defects in the true austenitic zones of the first buttering layer. If grain boundaries reach the interface, they can extend to the martensitic band. Those defects are filled with compact oxides. In addition, the ferritic base metal presents some pits along the interface. Nowadays, three mechanisms are proposed to explain the initiation of those defects: stress corrosion cracking, intergranular corrosion and high temperature intergranular oxidation. This paper is dealing with the study of the mechanisms involved in the corrosion phenomenon. Intergranular corrosion tests performed on different materials show that only the first buttering layer, even with some δ ferrite, is sensitized. The results of stress corrosion cracking tests in water solutions show that intergranular cracking is possible on a bulk material representative of the first buttering layer. It is unlikely on actual dissimilar welds where the ferritic base metal protects the first austenitic layer by galvanic coupling. Therefore, the stress corrosion cracking assumption cannot explain the initiation of the defects in aqueous environment. The results of the investigations and of the corrosion studies led to the conclusion that the atmosphere could be the only possible aggressive environment. This conclusion is based on natural atmospheric exposure and accelerated corrosion tests carried out with SO 2 additions in controlled atmosphere. They both induce a severe intergranular corrosion on true sensitized austenitic materials. This corrosion studies cannot conclude definitively on the causes of the defect initiation on field, but they show that the atmospheric corrosion could produce intergranular attacks in the pure austenitic zones of the first buttering layer of the dissimilar welds and that this corrosion is stress assisted. (author). 1 ref., 6 figs., 4 tabs

  6. Steamgenerators corrosion monitoring and chemical cleanings

    International Nuclear Information System (INIS)

    Otchenashev, G.

    2001-01-01

    One of the most important secondary side water chemistry objectives is optimization of chemistry conditions to reduce materials corrosion and their products transport into steam generators. Corrosion products (mainly iron and copper oxides) can form deposits on the SG's tubes and essentially decrease their operating resource. The transport of corrosion products by the constant flowrate of feed and blowdown water depends only on their content in these streams. All the internal surfaces (walls, collectors, tubes) were covered with the tough deposit firmly connected with the surface. Corrosion under this deposit was not detected. In some places sludge unconnected with the surface was detected. The lower tubes are located the more unconnected sludge was detected. On SG bottom near the hatch the sludge thickness was about 3 cm. (R.P.)

  7. Material problems in high temperature corrosive environments and their solution by surface technologies

    International Nuclear Information System (INIS)

    Anzai, Toshio; Shibata, Keiichi

    1992-01-01

    The materials for high temperature facilities are usually determined by the heat resistant strength except special corrosive environment. High temperature corrosion has been considered in the case of using low quality fuel which is avoided recently. Even though fuel is clean, high temperature corrosion occurs due to the rise of design temperature and the intake of sea salt particles. There is also one more high temperature corrosion problem on process side that consumes heat energy. The research on high temperature corrosion is important for realizing new energy system such as molten carbonate type fuel cell, pulverized coal-firing supercritical power generation and high temperature gas-cooled nuclear reactor. In this report, the examples experienced actually in a chemical plant are examined, and the possibility of material technology against high temperature corrosion is reviewed. Corrosion phenomena in high temperature environment, the examples of corrosion in the high temperature facilities in a chemical plant and the material technology as the countermeasures for corrosion prevention are reported. (K.I.)

  8. Comprehensive investigation of the corrosion and surface chemical effects of the decontamination technologies

    International Nuclear Information System (INIS)

    Szabo-Nagy, Andrea; Varga, Kalman; Deak-Horvath, Emese; Nemeth, Zoltan; Horvath, David; Schunk, Janos; Patek, Gabor

    2012-09-01

    Decontamination technologies are mainly developed to reduce the collective dose of the maintenance personnel at NPPs. The highest efficiency (i.e., the highest DF values) available without detrimental modification of the treated surface of structural material is the most important goal in the course of the application of a decontamination technology. A so-called 'soft' chemical decontamination technology has been developed - supported by the Paks Nuclear Power Plant - at the Institute of Radiochemistry and Radioecology of the University of Pannonia. The novel base technology can be effectively applied for the decontamination of the heat exchanger tubes of steam generators. In addition, by optimizing the main technological parameters (temperature, concentration of the liquid chemicals, flow rates, contact time, etc.) it can be utilized for specific applications such as decontamination of some dismountable devices and separable equipment or the total decontamination prior to plant dismantling (decommissioning) in the future. The aim of this work is to compare the efficiency, corrosion and surface chemical effects of some improved versions of the novel base-technology elaborated for decontamination of austenitic stainless steel surfaces. The experiments have been performed at laboratory conditions in decontamination model systems. The applied methods: γ-spectrometry, ICP-OES, voltammetry and SEM-EDX. The experimental results revealed that the efficiency of the base-technology mainly depends on the surface features of the stainless steel samples such as the chemical composition and thickness of the oxide layer, the nature (quantity, morphology and chemical composition) of the crystalline deposits. It has been documented that the improved version of the base-technology are suitable for the decontamination of both steel surfaces covered by chemically resistant large Cr-content crystals and that having compact oxide-layers (up to a thickness of 10

  9. Vibrational Spectroscopy in Studies of Atmospheric Corrosion.

    Science.gov (United States)

    Hosseinpour, Saman; Johnson, Magnus

    2017-04-18

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

  10. Vibrational Spectroscopy in Studies of Atmospheric Corrosion

    Directory of Open Access Journals (Sweden)

    Saman Hosseinpour

    2017-04-01

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

  11. Corrosion in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Brondel, D. (Sedco Forex, Montrouge (France)); Edwards, R. (Schlumberger Well Services, Columbus, OH (United States)); Hayman, A. (Etudes et Productions Schlumberger, Clamart (France)); Hill, D. (Schlumberger Dowell, Tulsa, OK (United States)); Mehta, S. (Schlumberger Dowell, St. Austell (United Kingdom)); Semerad, T. (Mobil Oil Indonesia, Inc., Sumatra (Indonesia))

    1994-04-01

    Corrosion costs the oil industry billions of dollars a year, a fact that makes the role of the corrosion engineer an increasingly important one. Attention is paid to how corrosion affects every aspect of exploration and production, from offshore rigs to casing. Also the role of corrosion agents such as drilling and production fluids is reviewed. Methods of control and techniques to monitor corrosion are discussed, along with an explanation of the chemical causes of corrosion. 21 figs., 32 refs.

  12. Preliminary study of radionuclide corrosion products in primary cooling water at RSG-GAS

    International Nuclear Information System (INIS)

    Lestari, D.E.; Pudjojanto, M.S.; Subiharto; Budi, S.

    1998-01-01

    Analysis of radionuclides emitting gamma rays at the primary cooling water at RSG-GAS has been carried out. The water coolant samples was performed using a low level background gamma spectrometer unit, including of high resolution of gamma detector HP-Ge Tennelec and Multichannel Analyzer (MCA) ADCAM 100 ORTEC. The result indicated Na-24 and Mn-56 radionuclides that may be as corrosion product and should studied deeply in the future. The expected activity concentration radionuclide for Mn-56 is lower than those written in the Safety Analysis Report (SAR), while for Na-24 is in agreement

  13. Corrosion protection products as a source of bisphenol A and toxicity to the aquatic environment.

    Science.gov (United States)

    Vermeirssen, Etiënne L M; Dietschweiler, Conrad; Werner, Inge; Burkhardt, Michael

    2017-10-15

    Steel components are typically treated with anti-corrosion coatings like epoxy or polyurethane resins to protect the integrity and functioning of steel. Such resins may contain substances, such as bisphenol A (BPA), that have caused concern in a human and environmental toxicological context. We investigated the release of toxicity from four anti-corrosion coatings used in hydraulic and civil engineering. Resins were applied onto glass plates and leachate samples produced by horizontally shaking the plates in water for 7 days. Two experiments were conducted, one with a 1 day and one with a 7 day curing period. Using a suite of bioassays, we tested samples for: agonistic and antagonistic effects on various mammalian nuclear receptors; inhibition of photosynthesis and growth in algae; inhibition of bacterial bioluminescence; and inhibition of water flea reproduction. Concentrations of BPA, bisphenol F and various BPA transformation products were determined by chemical analysis (LC-MS/MS). Bioassay results were evaluated using a scheme developed by DIBt (Centre of Competence for Construction, Berlin, Germany). Three products induced responses in one or more of the measured endpoints and toxicity profiles varied markedly in intensity across products. One product released high amounts of BPA which was associated with effects on nuclear receptor transactivation, requiring a more than 700-fold dilution for effect induction to fall below 20%. The same product was also the most toxic to water flea reproduction, requiring ca. 70-fold dilution for effects to fall below 20%. Another product was highly toxic in terms of bacterial bioluminescence, particularly after a shorter curing time, requiring a ca. 1'300-fold dilution for effects to fall below 20%. The third product required a 22-fold dilution for inhibition of water flea reproduction to drop below 20%. Results show that anti-corrosion coatings based on epoxy resins can be a source of toxicity to the aquatic environment

  14. Influence of hardening and surface modification of endourological wires on corrosion resistance.

    Science.gov (United States)

    Walke, Witold; Przondziono, Joanna

    2012-01-01

    Guide wires with suitable functional characteristics are of crucial importance for proper urological treatment. This study presents an analysis of the effect of work hardening taking place in the process of wire cold drawing and the effect of surface modification by means of electrochemical polishing and chemical passivation on the resistance of wires made of X10CrNi18-8 steel used in urology. Corrosion resistance was evaluated on the grounds of the registered anodic polarisation curves by means of potentiodynamic method. The tests were made in solution simulating human urine. Anodic polarisation curves were presented for selected wire diameters. Mechanical properties were tested in a static uniaxial tensile test. The course of flow curve as well as mathematical form of flow stress function were determined. Curves presenting the relation of polarisation resistance as a function of strain applied in the drawing process are given. The tests carried out show that surface modification by means of electrochemical polishing and then chemical passivation of wires used in endourological treatment is fundamental.

  15. Monte Carlo simulation of stress corrosion cracking on smooth surface under non-uniform stress condition

    International Nuclear Information System (INIS)

    Suzuki, Hiromitsu; Tohgo, Keiichiro; Shimamura, Yoshinobu; Nakayama, Guen; Hirano, Takashi

    2008-01-01

    A Monte Carlo simulation model for the process of stress corrosion cracking (SCC) in structural metal materials under non-uniform stress condition has been proposed. The possible number of crack initiations is set for given space and initiation times for all cracks are assigned random numbers based on exponential distributions depending on stress level. Sites and lengths of the cracks are assigned by random numbers based on uniform distribution and normal distribution, respectively. Coalescence of cracks and subcritical crack growth are determined based on the fracture mechanics concept. Through the SCC process in the model, the influence of semi-elliptical surface cracks is taken into consideration. SCC simulations were carried out on a smooth surface under two kinds of non-uniform stress conditions such as residual stress distribution around a weld line. Multiple parallel cracks and multiple cracks along narrow high stress region were obtained depending on the stress distributions, respectively. Simulation results exhibit the applicability of the model to describe the SCC behavior observed in real structures. (author)

  16. CORROSION AND SURFACE PROTECTION IN MACHINE MATERIALS FRICTION HAVE DIFFERENT SURFACE PAIRS EXPERIMENTAL INVESTIGATION OF FACTORS

    Directory of Open Access Journals (Sweden)

    Senai YALCINKAYA

    2017-05-01

    Full Text Available Friction force, normal force, linear change. The normal force varies with the loads on the friction object. In order to determine the friction force and the friction coefficient, the friction object and the friction speed are used. The experimental work was carried out in three stages. In the first stage, the effect of normal force on the friction force was studied. In the second step, the friction force of the friction surface area is influenced. The effect of the change of the shear rate in step 3 on the friction force was investigated. At the last stage, the experimental study of the effect of the material selection on the friction force was made and it was seen that the aluminum / brass surface pair had the smallest friction coefficient as a result of the opening. The greatest coefficient of friction is found in the pair of glass / felt objects.

  17. CORROSION AND SURFACE PROTECTION IN MACHINE MATERIALS FRICTION HAVE DIFFERENT SURFACE PAIRS EXPERIMENTAL INVESTIGATION OF FACTORS

    OpenAIRE

    Senai YALCINKAYA

    2017-01-01

    Friction force, normal force, linear change. The normal force varies with the loads on the friction object. In order to determine the friction force and the friction coefficient, the friction object and the friction speed are used. The experimental work was carried out in three stages. In the first stage, the effect of normal force on the friction force was studied. In the second step, the friction force of the friction surface area is influenced. The effect of the change of the s...

  18. Corrosion of alloy 800H and the effect of surface-applied CeO2 in a sulphidizing/oxidizing/carburizing environment at 700°C

    NARCIS (Netherlands)

    Stroosnijder, M.F.; Guttmann, V.; Fransen, T.; de Wit, J.H.W.

    The corrosion behavior of a wrought austenitic Fe-20Cr-32Ni steel, Alloy 800H, was studied in a simulated coal-gasification atmosphere at 700°C for exposure times up to 2500 hr. The influence of preoxidation and CeO2-surface application followed by preoxidation on the corrosion resistance of this

  19. The effect of laser surface melting on microstructure and corrosion behavior of friction stir welded aluminum alloy 2219

    Science.gov (United States)

    Ma, Shengchong; Zhao, Yong; Zou, Jiasheng; Yan, Keng; Liu, Chuan

    2017-11-01

    This study aimed to explore the electrochemical properties and microstructure of friction stir welds to understand the correlation between their properties and processing. Friction stir welding is a promising solid-state joining process for high-strength aluminum alloys (AA). Although friction stir welding (FSW) eliminates the problems of fusion welding due to the fact that it is performed below Tm, it causes severe plastic deformation in the material. Some AA welded by FSW exhibit relatively poor corrosion resistance. In this research, the corrosion resistance of such welds was enhanced through laser surface melting. A friction stir weld of AA 2219 was laser melted. The melt depth and microstructure were observed using optical and scanning electron microscopy. The melt zone exhibited epitaxially grown columnar grains. The redistribution of elemental composition was analyzed using energy-dispersive spectroscopy. The anticorrosion properties of both laser-melted and original welds were studied in aqueous 3.5% NaCl solution using cyclic potentiodynamic polarization. The results indicated a noticeable increase in the pitting corrosion resistance after the laser treatment on the surface. The repassivation potential was nobler than the corrosion potential after the laser treatment, confirming that the resistance to pitting growth improved.

  20. Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

    Energy Technology Data Exchange (ETDEWEB)

    Rajeswari, Velayutham [Department of Chemistry, Periyar University, Salem 636011 (India); Kesavan, Devarayan [Department of Chemistry, Dhirajlal Gandhi College of Technology, Salem 636309 (India); Gopiraman, Mayakrishnan [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India); Viswanathamurthi, Periasamy, E-mail: viswanathamurthi72@gmail.com [Department of Chemistry, Periyar University, Salem 636011 (India); Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan [Department of Bio-Chemistry, Periyar University, Salem 636011 (India)

    2014-09-30

    Graphical abstract: - Highlights: • Eleusine aegyptiaca and Croton rottleri are commonly available, less-toxic and eco-friendly inhibitors for cast iron corrosion. • The active constituents present in extracts adsorbed on the iron surface to inhibit the acidic corrosion. • The higher values of E{sub a} and ΔH{sup *} point out the higher inhibition efficiency noticed for the inhibitors. • Weight loss methods at various temperature and spectral data provides evidence for adsorption mechanism of inhibitors. - Abstract: The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV–vis, Wide-angle X-ray diffraction and SEM methods.

  1. Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

    International Nuclear Information System (INIS)

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy; Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan

    2014-01-01

    Graphical abstract: - Highlights: • Eleusine aegyptiaca and Croton rottleri are commonly available, less-toxic and eco-friendly inhibitors for cast iron corrosion. • The active constituents present in extracts adsorbed on the iron surface to inhibit the acidic corrosion. • The higher values of E a and ΔH * point out the higher inhibition efficiency noticed for the inhibitors. • Weight loss methods at various temperature and spectral data provides evidence for adsorption mechanism of inhibitors. - Abstract: The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV–vis, Wide-angle X-ray diffraction and SEM methods

  2. Nanoparticle coating on the silane-modified surface of magnesium for local drug delivery and controlled corrosion.

    Science.gov (United States)

    Lee, Won Seok; Park, Min; Kim, Myung Hun; Park, Chun Gwon; Huh, Beom Kang; Seok, Hyun Kwang; Choy, Young Bin

    2016-01-01

    In this study, we proposed a potential method for the preparation of a magnesium-based medical device for local drug delivery and controlled corrosion. A magnesium surface was modified with 3-aminopropyltrimethoxy silane, and the resulting surface was then coated with drug-loaded nanoparticles made of poly (lactic-co-glycolic acid) via electrophoretic deposition. The drug-loaded nanoparticles (i.e., Tr_NP) exhibited a size of 250 ± 67 nm and a negative zeta potential of -20.9 ± 2.75 mV. The drug was released from the nanoparticles in a sustained manner for 21 days, and this did not change after their coating on the silane-modified magnesium. The silane-modified surface suppressed magnesium corrosion. When immersed in phosphate buffered saline at pH 7.4, the average rate of hydrogen gas generation was 0.41-0.45 ml/cm(2)/day, compared to 0.58-0.6 ml/cm(2)/day from a bare magnesium surface. This corrosion profile was not significantly changed after nanoparticle coating under the conditions employed in this work. The in vitro cell test revealed that the drug released from the coating was effective during the whole release period of 21 days, and both the silane-modified surface and carrier nanoparticles herein were not cytotoxic. © The Author(s) 2015.

  3. 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

  4. Corrosion Inhibition on SAE 1010 Steel by Nanoscale Exopolysaccharides Coatings Determined by Electrochemical and Surface Characterization

    Science.gov (United States)

    Plating, painting and the application of enamel are the most common anti-corrosion treatments. They are effective by providing a barrier of corrosion resistant material between the damaging environment and the structural material. Coatings start failing rapidly if scratched or damaged because a co...

  5. 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.

  6. Corrosion product identification and relative rates of corrosion of candidate metals in an irradiated air-steam environment

    International Nuclear Information System (INIS)

    Reed, D.T.; Swayambunathan, V.; Tani, B.S.; Van Konynenburg, R.A.

    1989-01-01

    Previously reported work by others indicates that dicopper trihydroxide nitrate, Cu 2 NO 3 (OH) 3 , forms on copper and copper alloys subjected to irradiated moist air near room temperature. We have performed experiments over a range of temperature and humidity, and have found that this species is formed at temperatures up to at least 150 degree C if low to intermediate relative humidities are present. At 150 degree C and 100% relative humidity, only Cu 2 O and CuO were observed. The relative general corrosion rates of the copper materials tested in 1-month experiments at dose rates of 0.7 and 2.0 kGy/h were Cu > 70/30 Cu--Ni > Al-bronze. High-nickel alloy 825 showed no observable corrosion. 29 refs., 4 tabs

  7. Surface modification, organometallic and polyaryl polymer coatings, and flame spray technologies for preventing corrosion of metals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T.

    1995-07-01

    To improve adherent properties of electrogalvanized steel (EGS) to polymeric topcoats, the surfaces of EGS were modified by polyelectrolyte-modified zinc phosphating solution. The electrochemical reaction between phosphating solution and EGS led to the complete coverage with fully grown hopeite crystals after only 5 sec treatment, thereby improving adhesion to topcoating and providing protection of EGS against corrosion. To evaluate the ability of polyphenylene sulfide (PPS) polyaryl thermoplastic coatings to protect zinc phosphate (Zn{center_dot}Ph)treated steels from corrosion in a wet, harsh environment ( 1.0 wt % H{sub 2}SO{sub 4}, 3.0 wt % NaCl and 96.0 wt % water at temperatures from 25{degrees} to 200{degree}C), we exposed them in an autoclave to attempt heating-cooling cyclic fatigue tests (1 cycle = 12 hr at 200{degrees}C + 12 hr at 25{degrees}C) up to 90 times. The major chemical reaction at the interface between the PPS and Zn in the Zn-Ph layer during cycling led to the formation of ZnS reaction product, which enhanced the Zn-Ph-to-PPS adhesive bond; correspondingly, there were no signs of peeling and separation of the coating after 90 cycles. organometallosiloxane polymer (OMSP) was synthesized through the hydrolysis-condensation reaction of the mixed precursor solutions of the N-[3-(triethoxysily)propyl]-4,5,-dihydroimidazole and {Beta}-trimethoxysilylethyl-2-pyridine sols in liquor medium and the metal alkoxides and metallocene dichloride dissolved in water or tetrahydrofurane. The OMSP films (thickness, 0. 5 to 1. 0 {mu}m) deposited by simple dip-withdrawing coating methods to aluminum alloys displayed the impedance of > 10{sup 6} ohm-cm {sup 2} after exposure for 40 days in 0.5 N NaCl solution at 25{degrees}C and the 3000 hr-salt spray resistance. Using a flame spray coating process, the methacrylic acid-modified polyethylene copolymer was overlaid onto cold rolled steel surfaces.

  8. Impact of surface condition on sulphide stress corrosion cracking of 316L stainless steel

    International Nuclear Information System (INIS)

    Hinds, G.; Wickström, L.; Mingard, K.; Turnbull, A.

    2013-01-01

    Highlights: ► Heat tinting renders 316L stainless steel more susceptible to sulphide stress corrosion cracking. ► Pitting more likely at physical defects generated from specimen preparation than at inclusions. ► Cracks developed after 90 days that were not evident after the standard test duration of 30 days. ► Only shallow pitting observed due to constrained access of H 2 S to the pit recesses. ► Determination of near surface residual stress in austenitic stainless steels by XRD is unreliable. -- Abstract: The effect of surface condition on crack initiation in 316L stainless steel during laboratory testing in sour (H 2 S) environments for oil and gas applications has been investigated using the four-point bend test method. The main focus was on the effect of the degree of surface damage introduced during specimen machining and the influence of heat tinting to simulate the welding process. Detailed mapping of the surface of the four-point bend specimens before and after the tests revealed a greater tendency for pits to form at pre-existing mechanical defects than at inclusions. Perhaps surprisingly, pitting was initiated more readily on the finer ground surface. The effect of heat tinting was (i) to increase the pit density and (ii) to facilitate cracking, shifting the material from the pass to the failure domain. In all cases cracks initiated at pitting sites. A clear time dependence was observed in both the evolution of pitting and the transition from pit to crack during the four-point bend test, implying that the standard 30 day test duration may not always be sufficiently conservative. Characterisation of pitting and cracking in the specimens using electron back-scatter diffraction (EBSD) and focused ion beam (FIB) milling revealed evidence of de-alloying local to the crack. The origin of the cracks could not be identified precisely but initiation in the thinned region of the metal caused by undercutting or intense localised dissolution along slip

  9. Biodegradable Mg/HA/TiO2 Nanocomposites Coated with MgO and Si/MgO for Orthopedic Applications: A Study on the Corrosion, Surface Characterization, and Biocompatability

    Directory of Open Access Journals (Sweden)

    Shahrouz Zamani Khalajabadi

    2017-09-01

    Full Text Available In the field of orthopedics, magnesium (Mg and magnesium-based composites as biodegradable materials have attracted fundamental research. However, the medical applications of magnesium implants have been restricted owing to their poor corrosion resistance, especially in the physiological environment. To improve the corrosion resistance of Mg/HA/TiO2 nanocomposites, monolayer MgO and double-layer Si/MgO coatings were fabricated layer-by-layer on the surface of a nanocomposite using a powder metallurgy route. Then, coating thickness, surface morphology, and chemical composition were determined, and the corrosion behavior of the uncoated and coated samples was evaluated. Field-emission scanning electron microscopy (FE-SEM micrographs show that an inner MgO layer with a porous microstructure and thickness of around 34 μm is generated on the Mg/HA/TiO2 nanocomposite substrate, and that the outer Si layer thickness is obtained at around 23 μm for the double-layered coated sample. Electrochemical corrosion tests and immersion corrosion tests were carried out on the uncoated and coated samples and the Si/MgO-coated nanocomposite showed significantly improved corrosion resistance compared with uncoated Mg/HA/TiO2 in simulated body fluid (SBF. Corrosion products comprising Mg(OH2, HA, Ca3(PO42, and amorphous CaP components were precipitated on the immersed samples. Improved cytocompatibility was observed with coating as the cell viability ranged from 73% in uncoated to 88% for Si/MgO-coated Mg/HA/TiO2 nanocomposite after nine days of incubation.

  10. Greener Approach towards Corrosion Inhibition

    Directory of Open Access Journals (Sweden)

    Neha Patni

    2013-01-01

    Full Text Available Corrosion control of metals is technically, economically, environmentally, and aesthetically important. The best option is to use inhibitors for protecting metals and alloys against corrosion. As organic corrosion inhibitors are toxic in nature, so green inhibitors which are biodegradable, without any heavy metals and other toxic compounds, are promoted. Also plant products are inexpensive, renewable, and readily available. Tannins, organic amino acids, alkaloids, and organic dyes of plant origin have good corrosion-inhibiting abilities. Plant extracts contain many organic compounds, having polar atoms such as O, P, S, and N. These are adsorbed on the metal surface by these polar atoms, and protective films are formed, and various adsorption isotherms are obeyed. Various types of green inhibitors and their effect on different metals are mentioned in the paper.

  11. New approach to the elucidation of corrosion mechanism of ceramics by the ion implantation

    International Nuclear Information System (INIS)

    Saito, J.; Hayashi, K.; Tachi, Y.; Kano, S.

    1998-08-01

    Ceramics possessing high temperature strength are promising materials for the structural application in severe environment. The development of ceramics has been carried out in order to use them in FBR environment such as liquid sodium. In particular, corrosion behavior of ceramics has been investigated to improve the corrosion resistance in liquid sodium. However, the corrosion mechanism of ceramics was not comprehended in detail even now. Because corrosion products which were deposited on the surface of test pieces during corrosion test and played an important role in corrosion behavior, were not detected distinctly after thr corrosion test. In this study, an ion implantation technique was applied to understand the corrosion mechanism of ceramics in stead of the conventional corrosion test. Sodium ions were implanted in ceramics (100 keV, 1.9 x 10 17 ions/cm 2 ) and then heat treatment was performed at either 923 K or 823 K for 36 ks in argon atmosphere. After that, products on the surface were analyzed using SEM and TEM observation and X-ray diffraction. Consequently, the corrosion products were not identified exactly, but their presence was confirmed on the surface. It was caused by the minute amount of corrosion products. In future, it is necessary to carry systematically out the implantation and heat treatment under various conditions. Therefore, it seems that the beneficial information will be obtained to understand the corrosion mechanism of ceramics. (author)

  12. Effect of steel surface conditions on reinforcing steel corrosion in concrete exposed to marine environments

    Directory of Open Access Journals (Sweden)

    Anzola, E.

    2005-09-01

    Full Text Available Laboratory methods and experimental tests were deployed in the present study to evaluate corrosion in reinforced concrete exposed to marine environments. Reinforcing steel exhibiting two different surface conditions prior to embedment in concrete were studied, one the one hand to assess the electrochemical behaviour of the bars during exposure of the concrete specimens to a simulated marine environment, and on the other to determine the strength of the steel/concrete bond. The reinforced concrete specimens prepared were adapted as required for electrochemical potential and corrosion rate testing. A total of 56 7x15-cm cylindrical specimens containing 3/8" steel rods anchored at a depth of 11.5 cm were made to evaluate the steel / concrete bond and exposed to a natural marine environment for 28 or 190 days prior to testing. All the specimens were made with ready-mixed concrete. It may be concluded from the results of the corrosion tests on reinforcing steel with different surface conditions that the oxide initially covering the bars was dissolved and the steel passivated by the alkalinity in the concrete. The chief finding of the bonding study was that the layer of oxide formed in pre-embedment steel deterioration contributed to establishing a better bond.

    En el contexto de esta investigación, se tomaron en consideración métodos y ensayos experimentales de laboratorio, que permiten hacer una evaluación de la corrosión del hormigón armado expuesto en ambientes marinos. Por una parte se evaluó el comportamiento electroquímico de dos condiciones de estados superficiales del acero embebido en el hormigón, exponiéndolo en un ambiente marino simulado y, por otra parte, se estudió la adherencia entre el acero y el hormigón, con los mismos estados superficiales usados para la evaluación electroquímica. Las probetas se fabricaron de hormigón con acero de refuerzo en su interior, adecuándolas para realizar los ensayos de potenciales

  13. Investigations of the corrosion behaviour of the Si-containing stainless steel 1.4361 with combined surface analysis, electrochemistry and radionuclide technique

    International Nuclear Information System (INIS)

    Maar-Stumm, M.

    1990-03-01

    The present work aimed at detailed information on the corrosion behaviour and particularly the corrosion mechanism of the steel 1.4361 in concentrated nitric acid by use of a combination of electrochemical methods, radionuclide technique and surface analysis. For comparison steel samples corroded by other methods were investigated by surface analysis, too. At the beginning of the corrosion in nitric acid Fe and Ni are dissolved preferentially. Cr and Si are enriched in the surface region. A primary corrosion layer is formed which is equivalent to the oxidic overlayer of atmospherically oxidized samples. It consists of the oxides of chromium and iron mixed up with glass-like SiO 2 . Ni does not contribute to the formation of the oxidic overlayer. On top of this primary corrosion layer there is an isolating gel-like SiO 2 -layer with a thickness depending on strength and duration of the corrosive attack. Its mechanical stability decreases with increasing layer thickness. At the boundary to the primary corrosion layer this gel-like SiO 2 -layer is closed, mechanically stable and conducting. Samples corroded under the standardized conditions of the Huey-test show a similar structure of the overlayer with the exception that the primary corrosion layer consists only of glass-like SiO 2 . The combination of several methods revealed detailed information about mass loss and structure of the overlayer at different electrode potentials. (orig./MM) [de

  14. 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...

  15. Detection of boron in simulated corrosion products by using a laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Song, K.; Yeon, J-W.; Jung, S-H.; Hwang, J.; Jung, E-C.

    2010-01-01

    In nuclear power plants, many methods for detection of coolant leakage have been developed and employed for the safe operation. However, these methods have many limitations for analyzing and dealing with the corrosion products due to the high radioactivity. LIBS (Laser-induced breakdown spectroscopy) offer a remote and on-site elemental analysis including the boron in the corrosion products with no sample preparation. In this study, we investigated the feasibility of detecting boron and analyzing an elemental composition of boron-containing iron oxides with the LIBS, in order to develop a coolant leakage detection system. First, we prepared five different boron-containing iron oxides and the element ratios were determined by using ICP-AES (inductive coupled plasma-atomic emission spectrometer). After this, the laser induced emission spectra of these iron oxides were obtained by using a 266 nm Nd:YAG laser. The B/Fe ratios of the oxides were determined by comparing the intensities of the B emission peak at 249.844 nm with those of the Fe peak at 250.217 nm as an internal reference. It was confirmed that the B contents in the oxides could be analyzed over 0.1 wt% by the laser induced breakdown spectroscopic technique. (author)

  16. The development of an adsorbent for corrosion products in high-temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Ik; Sung, Ki Woung; Kim, Kwang Rag; Kim, Yu Hwan; Koo, Jae Hyoo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-08-01

    In order to use as adsorbent for removal of the soluble corrosion products, mainly Co{sup 60} under PWR reactor coolant conditions (300 deg C, 160 kg/cm{sup 2}), stable ZrO{sub 2} adsorbent was prepared using sol-gel process from zirconyl nitrate, AlO adsorbent was prepared by hydrolysis of aluminum isopropoxide, and titanium tetraisopropoxide, respectively. The prepared adsorbents were calcined at various temperature and analyzed by physical properties and the Co{sup 2+} adsorption capacity. And it was shown that the Co{sup 2+} adsorption capacity of the TiO{sub 2}-Al{sub 2}O{sub 3} adsorbents were found to have larger than that of ZrO{sub 2} and Al{sub 2}O{sub 3} adsorbents in high-temperature water. ZrO{sub 2}, Al{sub 2}O{sub 3} and TiO{sub 2}-Al{sub 2}O{sub 3} adsorbents were found to be suitable high-temperature adsorbents for the removal of dissolved corrosion products, mainly Co in PWR reactor coolant conditions. 15 tabs., 51 figs., 55 refs. (Author).

  17. The development of an adsorbent for corrosion products in high-temperature water

    International Nuclear Information System (INIS)

    Kim, Yong Ik; Sung, Ki Woung; Kim, Kwang Rag; Kim, Yu Hwan; Koo, Jae Hyoo

    1996-08-01

    In order to use as adsorbent for removal of the soluble corrosion products, mainly Co 60 under PWR reactor coolant conditions (300 deg C, 160 kg/cm 2 ), stable ZrO 2 adsorbent was prepared using sol-gel process from zirconyl nitrate, AlO adsorbent was prepared by hydrolysis of aluminum isopropoxide, and titanium tetraisopropoxide, respectively. The prepared adsorbents were calcined at various temperature and analyzed by physical properties and the Co 2+ adsorption capacity. And it was shown that the Co 2+ adsorption capacity of the TiO 2 -Al 2 O 3 adsorbents were found to have larger than that of ZrO 2 and Al 2 O 3 adsorbents in high-temperature water. ZrO 2 , Al 2 O 3 and TiO 2 -Al 2 O 3 adsorbents were found to be suitable high-temperature adsorbents for the removal of dissolved corrosion products, mainly Co in PWR reactor coolant conditions. 15 tabs., 51 figs., 55 refs. (Author)

  18. Chemistry - Toward efficient hydrogen production at surfaces

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet; Christensen, Claus H.

    2006-01-01

    Calculations are providing a molecular picture of hydrogen production on catalytic surfaces and within enzymes, knowledge that may guide the design of new, more efficient catalysts for the hydrogen economy.......Calculations are providing a molecular picture of hydrogen production on catalytic surfaces and within enzymes, knowledge that may guide the design of new, more efficient catalysts for the hydrogen economy....

  19. The corrosion of steam generator surfaces under typical secondary coolant conditions: effects of pH excusions on the alloy surface composition

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, N.S.; Davidson, R.D.; Walzak, T.L. [University of Western Ontario, London, ON (Canada); Brennenstuhl, A.M.; Gonzalez, F.; Corazza, S. [Ontario Hydro, Toronto, ON (Canada)

    1995-07-01

    Specimens of Inconel 600 (I-600), Inconel 690 (I-690), Incoloy 800 (I-800) and Monel 400 (M-400) were exposed to high temperature steam generator water conditions typical of those which might be found when the secondary coolant pH is allowed to fall into the acid regime. The specimens were analysed by surface and electrochemical techniques, either directly following exposure in the acid medium steam generator coolant or after adjusting the coolant pH and chemistry to near-normal steam generator conditions. The initial acid exposure resulted in the growth of a chromium-rich surface corrosion product film on all alloys (except M-400) and the precipitation of nickel-rich sulphates. Following the return to a high pH, the alloy again had chromium-rich surface oxides but also exhibited sulphide crystallites adhering to the base oxide, particularly for I-600. The tendency to retain these sulphides is attributed to the porosity of the protective oxide through which nickel is transported to the solution. The conversion of sulphate-sulphide is believed to occur as the pH is raised to normal alkaline conditions. In the case of M-400, a chromium oxide layer is not available to restrict the transport of nickel to the solution. As a result, a thick layer of sulphide crystals grows on the surface of the M-400 alloy even when subjected to a mild acid pH excursion. Even trace concentrations of sulphide/sulphate under normal pH control are shown to react with alloys whose oxide films appear permeable to nickel transport. (Author).

  20. Corrosion behaviour of the welded steel sheets used in automotive industry

    OpenAIRE

    D. Katundi; A. Tosun-Bayraktar; E. Bayraktar; D. Toueix

    2010-01-01

    Purpose: of this paper is to characterise the corrosion resistance in the steel sheets (Hot dip galvanizing of steel sheets) used in automotive industry. In fact, corrosion of automotive components by road salt is a widely known problem. The different parts under the car body and the interior surface of body panels suffer easily from the corrosive products deposited on roads and used mainly to melt snow. A comparison in a chemical investigation of the corrosion rate for base metals (without w...

  1. THE PRODUCT DESIGN PROCESS USING STYLISTIC SURFACES

    Directory of Open Access Journals (Sweden)

    Arkadiusz Gita

    2017-06-01

    Full Text Available The increasing consumer requirements for the way what everyday use products look like, forces manufacturers to put more emphasis on product design. Constructors, apart from the functional aspects of the parts created, are forced to pay attention to the aesthetic aspects. Software for designing A-class surfaces is very helpful in this case. Extensive quality analysis modules facilitate the work and allow getting models with specific visual features. The authors present a design process of the product using stylistic surfaces based on the front panel of the moped casing. In addition, methods of analysis of the design surface and product technology are presented.

  2. Design of containment system of nuclear fuel attacked by corrosion with leaking fission products

    International Nuclear Information System (INIS)

    Poblete Maturana, Tomas

    2015-01-01

    The following report presents the design of an innovative confinement system for the nuclear fuel attacked by corrosion, with leakage of fission products to be used in the RECH-1 nuclear experimental reactor of the Chilean Nuclear Energy Commission, is currently within the framework of the international nuclear waste management program developed by the member countries of the IAEA, including Chile. The main objective of this project is the development of a system that is capable of containing, in the smallest possible volume, the fission products that are released to the reactor coolant medium from the nuclear fuel that are attacked by corrosion. Among the tasks carried out for the development of the project are: the compilation of the necessary bibliography for the selection of the most suitable technology for the retention of the fission products, the calculation of the most important parameters to ensure that the system will operate within ranges that do not compromise the radiological safety, and the design of the hydraulic circuit of the system. The results obtained from the calculations showed that the fuel element confinement system is stable from a thermal point of view since the refrigerant does not under any circumstances reach the saturation temperature and, in addition, from a hydraulic point of view, since the rate at which the refrigerant flows through the hydraulic circuit is low enough so that the deformation of the fuel plates forming the nuclear fuel does not occur. The most appropriate technology for the extraction of fission products according to the literature consulted is by ion exchange. The calculations developed showed that with a very small volume of resins, it is possible to capture all of the non-volatile fission products of a nuclear fuel

  3. Effect of surface passivation on corrosion resistance and antibacterial properties of Cu-bearing 316L stainless steel

    Science.gov (United States)

    Zhao, Jinlong; Xu, Dake; Shahzad, M. Babar; Kang, Qiang; Sun, Ying; Sun, Ziqing; Zhang, Shuyuan; Ren, Ling; Yang, Chunguang; Yang, Ke

    2016-11-01

    The resistance for pitting corrosion, passive film stability and antibacterial performance of 316L-Cu SS passivated by nitric acid solution containing certain concentration of copper sulfate, were studied by electrochemical cyclic polarization, electrochemical impedance spectroscopy (EIS) and co-culture with bacteria. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Cu2+ ions release from 316L-Cu SS surface. XPS analysis proved that the enrichment of CuO, Cr2O3 and Cr(OH)3 on the surface of specimen could simultaneously guarantee a better corrosion resistance and stable antibacterial properties. The biocompatibility evaluation determined by RTCA assay also indicated that the 316L-Cu SS after antibacterial passivation was completely biocompatible.

  4. Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors

    International Nuclear Information System (INIS)

    Louthan, M.R. Jr.; West, S.L.; Nelson, D.Z.

    1991-01-01

    Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking in weld heat-affected zones and that the overall weld quality was excellent. The evaluation also revealed weld fusion zone discontinuities such as incomplete penetration, incomplete fusion, inclusions, underfill at weld roots and hot cracks. Service induced extension of these discontinuities was generally not significant although stress corrosion cracking in one weld fusion zone was noted. One set of UT indications was caused by metallurgical discontinuities at the fusion boundary of an extra weld. This extra weld, not apparent on the outer pipe surface, was slightly overlapping and approximately parallel to the weld being inspected. This extra weld was made during a pipe repair, probably associated with initial construction processes. The two nearly parallel welds made accurate assessment of the UT signal difficult. The implications of these observations to the inspection and repair of process water systems of nuclear reactors is discussed

  5. Influence of yttria surface modification on high temperature corrosion of porous Ni22Cr alloy

    DEFF Research Database (Denmark)

    Karczewski, Jakub; Dunst, Katarzyna; Jasinski, Piotr

    2017-01-01

    Protective coatings for porous alloys for high temperature use are relatively new materials. Their main drawback is high temperature corrosion. In this work protective coatings based the on Y-precursor infiltrated into the sintered Ni22Cr alloys are studied at 700°C. Effects of the amount...... of the protective phase on the resulting corrosion properties are evaluated in air and humidified hydrogen. Weight gain of the samples, their open porosities and microstructures are analyzed and compared. Results show, that by the addition of even a minor amount of the Y-precursor corrosion rates can be decreased...

  6. Contribution to surface physicochemical factors to stress corrosion resistance in stainless steels

    International Nuclear Information System (INIS)

    Gras, Jean-Marie

    1974-01-01

    The author of this research thesis first presents and discusses the various aspects of stress corrosion cracking of Fe-Cr-Ni alloys of high purity: experimental conditions (alloy elaboration, sample preparation), corrosion results (Schaeffer diagram, crack morphology, intergranular corrosion), influence of addition elements in ferritic alloys. He reports an electrochemical study of stainless steels in magnesium chloride (experimental conditions, influence of metallurgic and environmental parameters on polarization resistance, current-voltage curves), and an analytical study of layers formed in the magnesium chloride

  7. Printed Circuit Board Surface Finish and Effects of Chloride Contamination, Electric Field, and Humidity on Corrosion Reliability

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2017-01-01

    Corrosion reliability is a serious issue today for electronic devices, components, and printed circuit boards (PCBs) due to factors such as miniaturization, globalized manufacturing practices which can lead to process-related residues, and global usage effects such as bias voltage and unpredictable...... probability under condensing conditions. Leakage currents were measured on interdigitated comb test patterns with three different types of surface finish typically used in the electronics industry, namely gold, copper, and tin. Susceptibility to electrochemical migration was studied under droplet conditions...

  8. The effects of RE and Si on the microstructure and corrosion resistance of Zn–6Al–3Mg hot dip coating

    International Nuclear Information System (INIS)

    Li, Shiwei; Gao, Bo; Yin, Shaohua; Tu, Ganfeng; Zhu, Guanglin; Sun, Shuchen; Zhu, Xiaoping

    2015-01-01

    Highlights: • ZAM coating has been prepared by using an experimental hot-dip galvanizing simulator. • The corrosion resistance of ZAM coating can be improved by additions of Si and RE. • Zn–6Al–3Mg–Si–RE coating forms a dense and stabilized corrosion product layer. • Zn–6Al–3Mg–Si–RE coating shows uniform corrosion. - Abstract: The effects of Si and RE on the microstructure and corrosion resistance of Zn–6Al–3Mg coating (ZAM) have been investigated. Surface morphology observations of the coating and corrosion products reveal that the additions of Si and rare earth metals (RES) improve the microstructural homogeneity of ZAMSR coating and stability of corrosion products formed on ZAMSR coating. Moreover, only uniform corrosion occurs in ZAMSR coating during the corrosion test, while intergranular corrosion and pitting occur in ZAM. As a result, the corrosion resistance of ZAM coating is improved by the additions of Si and RES.

  9. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    International Nuclear Information System (INIS)

    Feliu, S.; Pardo, A.; Merino, M.C.; Coy, A.E.; Viejo, F.; Arrabal, R.

    2009-01-01

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 deg. C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH) 2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH) 2 . A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

  10. Ti-O-N/Ti composite coating on Ti-6Al-4V: surface characteristics, corrosion properties and cellular responses.

    Science.gov (United States)

    Cao, Xiao-Lin; Sun, Tao; Yu, Yonghao

    2015-03-01

    To enhance the corrosion resistance of Ti-6Al-4V and extend its lifetime in medical applications, Ti-O-N/Ti composite coating was synthesized on the surface via plasma immersion ion implantation and deposition (PIIID). Surface morphology and cross sectional morphology of the composite coating were characterized using atomic force microscopy and scanning electron microscopy, respectively. Although X-ray photoelectron spectroscopic analysis revealed that the Ti-O-N/Ti composite coating was composed of non-stoichiometric titanium oxide, titanium nitride and titanium oxynitride, no obvious characteristic peak corresponding to the crystalline phases of them was detected in the X-ray diffraction pattern. In accordance with Owens-Wendt equation, surface free energy of the uncoated and coated samples was calculated and compared. Moreover, the corrosion behavior of uncoated and coated samples was evaluated by means of electrochemical impedance spectroscopy measurement, and an equivalent circuit deriving from Randles model was used to fit Bode plots and describe the electrochemical processes occurring at the sample/electrolyte interface. On the basis of the equivalent circuit model, the resistance of the composite coating was 4.7 times higher than that of the passive layer on uncoated samples, indicating the enhanced corrosion resistance after PIIID treatment. Compared to uncoated Ti-6Al-V, Ti-O-N/Ti-coated samples facilitated ostoblast proliferation within 7 days of cell culture, while there was no statistically significant difference in alkaline phosphate activity between uncoated and coated samples during 21 days of cell culture.

  11. Microstructural and aqueous corrosion aspects of laser-surface-melted type 304 SS plasma-coated mild steel

    Science.gov (United States)

    Pujar, M. G.; Dayal, R. K.; Singh Raman, R. K.

    1994-06-01

    Plasma spray deposition of metals, ceramics, or plastics onto base metals to produce wear- and corrosion-resistant surfaces is a promising technique whereby base metal performance can be considerably im-proved. Because these coatings invariably contain pores, voids, and cracks, laser surface melting may be employed to improve their homogeneity. This study focuses on the corrosion performance of laser- sur-face- melted type 304 SS plasma- coated mild steel specimens. Mild steel strips were plasma coated with an approximately 100 to 200 μm thick layer of type 304 by transferred plasma jet. These specimens were sub-sequently laser irradiated using a 3 kW continuous- wave CO2 gas laser. Eight different sets of specimens were selected based on different laser beam travel speeds. Scanning electron microscopic studies of the plasma- coated specimens revealed both pancake and flowery types of deposited particles. Optical micro-scopic studies followed by anodic polarization experiments were carried out on these specimens in IN H2SO4 medium. It was observed that specimens with laser beam interaction times ranging from 30 to 120 ms showed relatively better general corrosion performance than specimens with interaction times of from 15 to 24 ms.

  12. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

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

  13. Microorganisms as potential corrosion inhibitors of metallic materials

    Directory of Open Access Journals (Sweden)

    Tasić Žaklina Z.

    2016-01-01

    Full Text Available Corrosion presents the destruction of materials through chemical or electrochemical interactions with their environment. Interactions between the metal surface and bacterial cells or products of their metabolic activities can lead to microbially-influenced corrosion. Also, it is known that certain microorganisms can contribute to corrosion inhibition. In accordance to that, the literature dealing with the application of different microorganisms as a potentialy corrosion inhibitors of metals is investigated. Different bacterial strains as a corrosion inhibitor of a metalic materials are examined. Further, the role of extracellular polymeric substances in corrosion behavior of metals is emphasized. Based on the data presented in this work, it can be said that inhibition efficiency depends on microorganism as well as type of metal. Also, it is presented that some bacterial species can be used as a good corrosion inhibitor instead of toxic organic compounds.

  14. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    Abstract Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria, e.g. on pipelines buried in soil and on marine structures. MIC...... of carbon steel must be monitored on-line in order to provide an efficient protection and control the corrosion. A number of monitoring techniques is industrially used today, and the applicability and reliability of these for monitoring MIC is evaluated. Coupons and ER are recommended as necessary basic...... 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...

  15. Corrosion of metallic materials. Dry corrosion, aqueous corrosion and corrosion by liquid metal, methods of protection

    International Nuclear Information System (INIS)

    Helie, Max

    2015-01-01

    This book is based on a course on materials given in an engineering school. The author first gives an overview of metallurgy issues: metallic materials (pure metals, metallic alloys), defects of crystal lattices (point defects, linear defects or dislocations), equilibrium diagrams, steels and cast, thermal processing of steels, stainless steels, aluminium and its alloys, copper and its alloys. The second part addresses the properties and characterization of surfaces and interfaces: singularity of a metal surface, surface energy of a metal, energy of grain boundaries, adsorption at a material surface, metal-electrolyte interface, surface oxide-electrolyte interface, techniques of surface analysis. The third chapter addresses the electrochemical aspects of corrosion: description of the corrosion phenomenon, free enthalpy of a compound and free enthalpy of a reaction, case of dry corrosion (thermodynamic aspect, Ellingham diagram, oxidation mechanisms, experimental study, macroscopic modelling), case of aqueous corrosion (electrochemical thermodynamics and kinetics, experimental determination of corrosion rate). The fourth part addresses the different forms of aqueous corrosion: generalized corrosion (atmospheric corrosion, mechanisms and tests), localized corrosion (galvanic, pitting, cracking, intergranular, erosion and cavitation), particular cases of stress cracking (stress corrosion, fatigue-corrosion, embrittlement by hydrogen), and bi-corrosion (of non alloyed steels, of stainless steels, and of aluminium and copper alloys). The sixth chapter addresses the struggle and the protection against aqueous corrosion: methods of prevention, scope of use of main alloys, geometry-based protection of pieces, use of corrosion inhibitors, use of organic or metallic coatings, electrochemical protection. The last chapter proposes an overview of corrosion types in industrial practices: in the automotive industry, in the oil industry, in the aircraft industry, and in the

  16. Self-Assembled Films as Corrosion Protective Coatings for Metal Surfaces

    National Research Council Canada - National Science Library

    Robinson, Gary

    1996-01-01

    ...) of stearic acid and 10,12-pentacosadiynoic acid (10,12-PDA) on aluminum. Infrared (IR) and X-ray photoelectron spectroscopy, in addition to wetting measurements, were employed to study the corrosion process...

  17. Evaluation of two corrosion inhibitors using two surface application methods for reinforced concrete structures.

    Science.gov (United States)

    2004-01-01

    This study investigated the use of penetrating corrosion inhibitors to extend the life of existing reinforced concrete bridge decks. The use of assisted (vacuum/pressure injection) and unassisted (diffusion) treatment methods and two inhibitors were ...

  18. Growth and Breakdown of Surface Films and Localized Corrosion of Aluminum in Concentrated Chloride Media

    National Research Council Canada - National Science Library

    Lee, Jiajing

    1994-01-01

    ...) and mechanical stress for aluminum and titanium alloys in aggressive corrosion environments. This report presents results of some very preliminary experiments on aluminum alloys and titanium during anodic dissolution in chloride media...

  19. Corrosion/96 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

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

  20. 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

  1. 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.

  2. Increased bioclogging and corrosion risk by sulfate addition during iodine recovery at a natural gas production plant.

    Science.gov (United States)

    Lim, Choon-Ping; Zhao, Dan; Takase, Yuta; Miyanaga, Kazuhiko; Watanabe, Tomoko; Tomoe, Yasuyoshi; Tanji, Yasunori

    2011-02-01

    Iodine recovery at a natural gas production plant in Japan involved the addition of sulfuric acid for pH adjustment, resulting in an additional about 200 mg/L of sulfate in the waste brine after iodine recovery. Bioclogging occurred at the waste brine injection well, causing a decrease in well injectivity. To examine the factors that contribute to bioclogging, an on-site experiment was conducted by amending 10 L of brine with different conditions and then incubating the brine for 5 months under open air. The control case was exposed to open air but did not receive additional chemicals. When sulfate addition was coupled with low iodine, there was a drastic increase in the total amount of accumulated biomass (and subsequently the risk of bioclogging) that was nearly six times higher than the control. The bioclogging-associated corrosion rate of carbon steel was 84.5 μm/year, which is four times higher than that observed under other conditions. Analysis of the microbial communities by denaturing gradient gel electrophoresis revealed that the additional sulfate established a sulfur cycle and induced the growth of phototrophic bacteria, including cyanobacteria and purple bacteria. In the presence of sulfate and low iodine levels, cyanobacteria and purple bacteria bloomed, and the accumulation of abundant biomass may have created a more conducive environment for anaerobic sulfate-reducing bacteria. It is believed that the higher corrosion rate was caused by a differential aeration cell that was established by the heterogeneous distribution of the biomass that covered the surface of the test coupons.

  3. Investigation of the corrosion resistance of Ti-13Nb-13Zr alloy by electrochemical techniques and surface analysis

    International Nuclear Information System (INIS)

    Assis, Sergio Luiz de

    2006-01-01

    In this work, the in vitro corrosion resistance of the Ti-13Nb-13Zr alloy, manufactured at a national laboratory, and used for orthopedic applications, has been investigated in solutions that simulate the body fluids. The electrolytes used were 0.9 % (mass) NaCl, Hanks' solution, a culture medium (MEM), and the two last electrolytes, without and with addition of hydrogen peroxide. The aim of peroxide addition was to simulate the conditions found when inflammatory reactions occur due to surgical procedures. The corrosion resistance of alloys commercially in use as biomaterials, Ti-6Al-7Nb and Ti-6Al-4V, as well as of the pure titanium (Ti-cp), was also studied for comparison with the Ti-13Nb-13Zr alloy. The corrosion resistance characterization was carried out by electrochemical and surface analysis techniques. The electrochemical tests used were: open circuit potential measurements as a function of tim; potentiodynamic polarization; and electrochemical impedance spectroscopy (EIE). The impedance experimental diagrams were interpreted using equivalent electric circuits that simulate an oxide film with a duplex structure composed of an internal and compact, barrier type layer, and an external porous layer. The results showed that the corrosion resistance is due mainly to the barrier type layer. The titanium alloys and the Ti-cp showed high corrosion resistance in all electrolytes used. The oxides formed on the Ti-13Nb-13Zr, either naturally or during immersion in MEM ar Hank's solution was characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (MEV). The results showed that the presence of hydrogen peroxide in MEM promotes the growth of the porous layer and incorporation of mineral ions, besides favouring hydroxyapatite formation. The cytotoxicity of the Ti-13Nb-13Zr alloy was also evaluated and it was shown to be non-toxic. (author)

  4. Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

    Energy Technology Data Exchange (ETDEWEB)

    R. P. Martukanitz and S. Babu

    2007-05-03

    Laser surfacing in the form of cladding, alloying, and modifications are gaining widespread use because of its ability to provide high deposition rates, low thermal distortion, and refined microstructure due to high solidification rates. Because of these advantages, laser surface alloying is considered a prime candidate for producing ultra-hard coatings through the establishment or in situ formation of composite structures. Therefore, a program was conducted by the Applied Research Laboratory, Pennsylvania State University and Oak Ridge National Laboratory to develop the scientific and engineering basis for performing laser-based surface modifications involving the addition of hard particles, such as carbides, borides, and nitrides, within a metallic matrix for improved wear, fatigue, creep, and corrosion resistance. This has involved the development of advanced laser processing and simulation techniques, along with the refinement and application of these techniques for predicting and selecting materials and processing parameters for the creation of new surfaces having improved properties over current coating technologies. This program has also resulted in the formulation of process and material simulation tools capable of examining the potential for the formation and retention of composite coatings and deposits produced using laser processing techniques, as well as positive laboratory demonstrations in producing these coatings. In conjunction with the process simulation techniques, the application of computational thermodynamic and kinetic models to design laser surface alloying materials was demonstrated and resulted in a vast improvement in the formulation of materials used for producing composite coatings. The methodology was used to identify materials and to selectively modify microstructures for increasing hardness of deposits produced by the laser surface alloying process. Computational thermodynamic calculations indicated that it was possible to induce the

  5. Study of the corrosion products in the primary system of PWR plants as the source of radiation fields build-up

    International Nuclear Information System (INIS)

    Brabant, R. van; Regge, P. de.

    1982-01-01

    In the first part the behaviour of the corrosion products in the primary system of PWR plants is depicted on the basis of a literature review of the field. Water chemistry, corrosion processes and activation of corrosion products are the main topics. In the second part the results of the characterization of corrosion particles in the primary coolant circuit of the Doel 1 and 2 reactors are described, during steady state operation and transient phases. In the third part the possibilities for radiation control at nuclear power plants are outlined. The filtration possibilities for the reactor coolant are explored in detail. (author)

  6. Effects of AISI 316L corrosion products in in vitro bone formation.

    Science.gov (United States)

    Morais, S; Sousa, J P; Fernandes, M H; Carvalho, G S; de Bruijn, J D; van Blitterswijk, C A

    1998-06-01

    Rat bone marrow cells were cultured in experimental conditions that favour the proliferation and differentiation of osteoblastic cells (i.e., 2.52 x 10(-4) mol l(-1) ascorbic acid, 10(-2) mol l(-1) beta-glycerophosphate and 10(-8) mol l(-1) dexamethasone) in the absence and in the presence of stainless-steel corrosion products, for a period of 18 days. An AISI 316L stainless-steel slurry (SS) was obtained by electrochemical means and the concentrations of the major metal ions, determined by atomic absorption spectrometry, were 8.78 x 10(-3) mol l(-1) of Fe, 4.31 x 10(-3) mol l(-1) of Cr and 2.56 x 10(-3) mol l(-1) of Ni. Bone marrow cells were exposed to 0.01, 0.1 and 1% of the SS and at the end of the incubation period, control and treated cultures were evaluated by histochemical assays for the identification of the presence of alkaline phosphatase and also calcium and phosphate deposition. Cultures were further observed by scanning electron microscopy. Levels of total and ionised calcium and phosphorus in the culture media collected from control and metal exposed cell cultures were also quantified. Histochemical staining showed that control cultures presented a strong reaction for the presence of alkaline phosphatase and exhibited formation of calcium and phosphates deposits. The presence of 0.01% SS caused no detectable biological effects in these cultures, 0.1% SS impaired osteoblastic behaviour and, 1% SS resulted in cell death. In the absence of bone cells, levels of total and ionised calcium and phosphorus in the control and metal added culture medium were similar throughout the incubation period. A significant decrease in the levels of ionised calcium and phosphorus were observed in the culture medium of control cultures and also in cultures exposed to 0.01% SS after two weeks of incubation, an event related with the formation of mineral calcium phosphate deposits in these cultures. In cultures grown in the presence of 0.1 and 1% SS corrosion products

  7. Influence of Direct Current Electric Field on Corrosion Behavior of Tin Under a Thin Electrolyte Layer

    Science.gov (United States)

    Huang, H. L.; Bu, F. R.; Tian, J.; Liu, D.

    2017-12-01

    The influence of a direct current electric field (DCEF) on corrosion behavior of tin under a thin electrolyte layer was investigated based on an array electrode technology by polarization, electrochemical impedance spectroscopy and surface analysis. The experimental results indicate that the corrosion rate of tin near the positive plate of DCEF increases with increased electric field intensity, which could be attributed to the acceleration of the migration of ions, the removal of corrosion products under DCEF and the damage of tin surface oxide film. Furthermore, tin at different positions in a DCEF exhibits different corrosion behavior, which could be ascribed to the difference of the local corrosion environment caused by the DCEF.

  8. Study on improvement of durability for reinforced concrete by surface-painting migrating corrosion inhibitor and engineering application

    Science.gov (United States)

    Song, Ning; WANG, Zixiao; LIU, Zhiyong; Zhou, Jiyuan; Zheng, Duo

    2017-01-01

    The corrosion currents of steel bar in concrete with three W/B and four chloride contents after surface-painting two migrating corrosion inhibitors (PCI-2015 and MCI-A) 14d to 150d in atmospheric condition were measured. The results showed that the corrosion current density (I corr) of steel bar reduced to 0.1 μA.cm-2 from the initial highest 3.833 μA.cm-2 (W/B=0.65, NaCl-1%) after surface-painting PCI-2015 14 d, and the I corr was still lower than 0.1 μA.cm-2 until 150d. The compressive strength and chloride migration coefficient of concrete specimens were tested. The possible reasons of the mechanisms of durability improvement for reinforced concrete by applying PCI-2015 inhibitor were PCI-2015 may be reacted with calcium hydroxide in cement concrete and lots of inhibitor particles may be adsorbed on the active sites first and then a stable protective layer may be formed. The I corr of steel bars in a hydraulic aqueduct concrete structure after painting PCI-2015, MCI-A (the United States) and MCI-B (Europe) during 6 months was monitored by Gecor 8 tester. The results showed that the average values of I corr of steel bars after painting the PCI-2015 150d fulfilled the specification requirements in “Design code for concrete structure strengthening (E.3) ”(GB 50367-2013).

  9. Reduction of initial corrosion rate and improvement of cell adhesion through surface modification of biodegradable Mg alloy

    Science.gov (United States)

    Han, Hyung-Seop; Lee, Sun Hee; Kim, Won-Joo; Jeon, Hojeong; Seok, Hyun-Kwang; Ahn, Jae-Pyung; Kim, Yu-Chan

    2015-01-01

    In this study, the surface modification of biodegradable pure Magnesium and Mg-5wt%Ca-1wt%Zn alloy was performed through immersion in HBSS, inorganic salt solution and cell media to reduce initial hydrogen evolution and improve cell adhesion. The formation of different CaP-like coatings from immersion of pure Mg and Mg alloy were observed using Cryo FIB analysis and their performances were measured through cell adhesion, quantification of released Mg ions, and cell cytotoxicity assays. The coating layers displayed significant reduction of initial corrosion rate, and cell adhesion for both pure Mg and Mg alloy appeared to be influenced by the amino acids and proteins in the cell media. In general, Mg alloy showed a denser coating layer with higher Ca contents, resulting in greater reduction of initial corrosion rate and improved cell adhesion, when compared to pure Mg. This is due to saturation of Ca around the corrosion site that provided much favorable environmental condition to produce denser calcium phosphate coating mixture. The result from this study suggests that the surface modification of biodegradable Mg alloy by immersion in alkaline solutions can be utilized to obtain ideal biodegradable orthopedic implant material with reduced initial hydrogen evolution rate and improved cell adhesion.

  10. Monte Carlo simulation taking account of surface crack effect for stress corrosion cracking in a stainless steel SUS 304

    International Nuclear Information System (INIS)

    Tohgo, Keiichiro; Suzuki, Hiromitsu; Shimamura, Yoshinobu; Nakayama, Guen; Hirano, Takashi

    2008-01-01

    Stress corrosion cracking (SCC) in structural metal materials occurs by initiation and coalescence of micro cracks, subcritical crack propagation and multiple large crack formation or final failure under the combination of materials, stress and corrosive environment. In this paper, a Monte Carlo simulation for the process of SCC has been proposed based on the stochastic properties of micro crack initiation and fracture mechanics concept for crack coalescence and propagation. The emphasis in the model is put on the influence of semi-elliptical surface cracks. Numerical simulations are carried out based on CBB (creviced bent beam) test results of a sensitized stainless steel SUS 304 and the influence of micro crack initiation rate and coalescence condition on the simulation results is discussed. The numerical examples indicate the applicability of the present model to a prediction of the SCC behavior in real structures. (author)

  11. Corrosion of copper in oxygen-deficient groundwater with and without deep bedrock micro-organisms: Characterisation of microbial communities and surface processes

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen-Saarivirta, E., E-mail: elina.huttunen-saarivirta@vtt.fi [VTT Technical Research Centre of Finland, Materials Performance, Kemistintie 3, FI-02044 VTT (Finland); Rajala, P. [VTT Technical Research Centre of Finland, Materials Performance, Kemistintie 3, FI-02044 VTT (Finland); Bomberg, M. [VTT Technical Research Centre of Finland, Geobiotechnology, Tietotie 2, FI-02044 VTT (Finland); Carpén, L. [VTT Technical Research Centre of Finland, Materials Performance, Kemistintie 3, FI-02044 VTT (Finland)

    2017-02-28

    Highlights: • Copper was exposed to groundwater with and without deep bedrock micro-organisms. • Biofilm composition was determined and correlated with the behaviour of copper. • Under biotic conditions, the film of Cu{sub 2}S formed on copper surfaces. • Bacterial pool was in a key role for the morphology and properties of Cu{sub 2}S film. • Under abiotic conditions, Cu{sub 2}O systematically developed on copper surfaces. - Abstract: Copper specimens were exposed to oxygen-deficient artificial groundwater in the presence and absence of micro-organisms enriched from the deep bedrock of the planned nuclear waste repository site at Olkiluoto island on the western coast of Finland. During the exposure periods of 4 and 10 months, the copper specimens were subjected to electrochemical measurements. The biofilm developed on the specimens and the water used in the exposures were subjected to microbiological analyses. Changes in the water chemistry were also determined and surfaces of the copper specimens were characterized with respect to the morphology and composition of the formed corrosion products. The results showed that under biotic conditions, redox of the water and open circuit potential (OCP) of the copper specimens were generally negative and resulted in the build-up of a copper sulphide, Cu{sub 2}S, layer due to the activity of sulphate-reducing bacteria (SRB) that were included in the system. In the 4-month test, the electrochemical behaviour of the specimens changed during the exposure and alphaproteobactria Rhizobiales were the dominant bacterial group in the biofilm where the highest corrosion rate was observed. In the 10-month test, however, deltaproteobacteria SRB flourished and the initial electrochemical behaviour and the low corrosion rate of the copper were retained until the end of the test period. Under abiotic conditions, the positive water redox potential and specimen OCP correlated with the formation of copper oxide, Cu{sub 2}O

  12. 76 FR 17381 - Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of...

    Science.gov (United States)

    2011-03-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Certain Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Notice of Final Results of the Sixteenth Administrative Review Correction In notice document 2011...

  13. A process for the production of a scale-proof and corrosion-resistant coating on graphite and carbon bodies

    Science.gov (United States)

    Fitzer, E.

    1981-01-01

    A process for the production of a corrosion resistant coating on graphite and carbon bodies is described. The carbon or graphite body is coated or impregnated with titanium silicide under the addition of a metal containing wetting agent in a nitrogen free atmosphere, so that a tight coating is formed.

  14. 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...

  15. Synchrotron based x-ray fluorescence microscopy confirms copper in the corrosion products of metals in contact with treated wood

    Science.gov (United States)

    Samuel L. Zelinka; Joseph E. Jakes; Grant T. Kirker; David Vine; Stefan Vogt

    2017-01-01

    Copper based waterborne wood preservatives are frequently used to extend the service life of wood products when subjected to frequent moisture exposure. While these copper based treatments protect the wood from fungal decay and insect attack, they increase the corrosion of metals embedded or in contact with the treated wood. Previous research has shown the most...

  16. Effect of surface cold work on corrosion of Alloy 690TT in high temperature high pressure water

    International Nuclear Information System (INIS)

    Wang, J.; Zhang, Z.; Han, E.-H.; Ke, W.

    2009-01-01

    This paper aims to investigate the effect of surface cold work on corrosion of Alloy 690TT. The Alloy 690TT was mechanical ground and electro polished respectively and immersed in primary water at DO = 2 ppm and DH = 2.5ppm respectively. The microstructure of surface and the compositions and morphology of the surface film on Alloy 690TT after immersion test were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Auger electron spectroscopy (AES) and focused ion beam (FIB). The results showed that feather-like oxide with decorated polyhedral oxide formed on ground surface and needle-like oxide with decorated polyhedral oxide formed on electro-polished surface. (author)

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

    Directory of Open Access Journals (Sweden)

    Jaspreet eMand

    2016-01-01

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

  18. Impact of surface integrity on machining productivity

    International Nuclear Information System (INIS)

    Koster, W.P.

    1975-01-01

    Surface integrity data developed in recent years have brought into critical focus many situations where component performance is dependent upon the characteristics of machined surfaces. The surface integrity behavior of important structural materials--steel, nickel, and titanium base alloys--described. Surfaces characteristically produced by milling, grinding, electrical discharge machining, and electrochemical machining are illustrated. These same surfaces are characterized in terms of residual stress profiles and fatigue behavior. Specific instances where surface integrity information has been used to overcome production problems or to enhance the reliability of components are cited. Examples of situations where relative insensitivity to metal removal variables has permitted significant reductions in machining costs are also discussed. Finally, manufacturing methods necessary to achieve adequate surface integrity are described, along with suggestions for the control of processing through adequate specifications and inspection procedures. 14 figures

  19. A shape-recovery polymer coating for the corrosion protection of metallic surfaces.

    Science.gov (United States)

    Lutz, Alexander; van den Berg, Otto; Van Damme, Jonas; Verheyen, Karen; Bauters, Erwin; De Graeve, Iris; Du Prez, Filip E; Terryn, Herman

    2015-01-14

    Self-healing polymer coatings are a type of smart material aimed for advanced corrosion protection of metals. This paper presents the synthesis and characterization of two new UV-cure self-healing coatings based on acrylated polycaprolactone polyurethanes. On a macroscopic scale, the cured films all show outstanding mechanical properties, combining relatively high Young's modulus of up to 270 MPa with a strain at break above 350%. After thermal activation the strained films recover up to 97% of their original length. Optical and electron microscopy reveals the self-healing properties of these coatings on hot dip galvanized steel with scratches and microindentations. The temperature-induced closing of such defects restores the corrosion protection and barrier properties of the coating as shown by electrochemical impedance spectroscopy and scanning vibrating electrode technique. Therefore, such coatings are a complementary option for encapsulation-based autonomous corrosion protection systems.

  20. Corrosion inhibition of magnesium heated in wet air, by surface fluoridation

    International Nuclear Information System (INIS)

    Caillat, R.; Darras, R.; Leclercq, D.

    1960-01-01

    The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [fr

  1. 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.

  2. In situ regulating of surface morphologies, anti-corrosion and tribological properties of epoxy resin coatings by heat treatment

    Science.gov (United States)

    Liu, Dan; Zhao, Wenjie; Liu, Shuan; Cen, Qihong; Xue, Qunji

    2017-06-01

    A simple and in situ formation method through controlling curing temperature was used to regulate the surface morphology of epoxy resin (EP) coating. Multi-functional tribology test equipment and an electrochemistry workstation were used to evaluate the tribological and anti-corrosion properties of the EP coating cured with diethylenetriamine at room temperature, 80 °C, 100 °C and 120 °C, respectively. The results indicated that the diameter and depth of pores or pits existing on the surface of EP coatings decreased significantly with the increase of curing temperature. The EP coating cured at 120 °C exhibited the best tribological performance, the friction coefficient and wear trace area were 0.56 and 0.003 02 mm2 under dry conditions, 0.18 and 1.873  ×  10-5 mm2 under seawater conditions, respectively. The excellent tribological performance could be attributed to the surface morphologies and high hardness of EP coatings. The EP coating cured at 80 °C exhibited the best anti-corrosion performance that the impedance modulus at 0.01 Hz was close to 5.0 KΩ cm2 even after being immersed in 3.5 wt% NaCl solution for 24 h, which was closely related to its hydrophobic behavior and surface morphology.

  3. One-step hydrothermal process to fabricate superhydrophobic surface on magnesium alloy with enhanced corrosion resistance and self-cleaning performance

    Science.gov (United States)

    Feng, Libang; Zhu, Yali; Wang, Jing; Shi, Xueting

    2017-11-01

    Superhydrophobic surfaces can exhibit anti-corrosion, anti-fogging, and self-cleaning performance due to their high water repellence. It is significant for industrial fabricating of superhydrophobic surface with a simple and environment-friendly method. Herein, a facile, environment-friendly, and cost-effective one-step hydrothermal route is proposed to fabricate the superhydrophobic surface on magnesium alloy. The as-prepared superhydrophobic magnesium alloy surface presents the rough and hierarchical micro/nano- structure grafted with long hydrophobic alkyl chains via covalent bonds. Both electrochemical corrosion test and long term immersion in 3.5 wt.% of NaCl solution demonstrate that the superhydrophobic surface greatly improves the corrosion resistance of magnesium alloy. Meanwhile, the superhydrophobic magnesium alloy exhibits excellent self-cleaning performance. It is supposed that this facile method and remarkable properties of resultant superhydrophobic magnesium alloys have a promising future in expanding the application of magnesium alloys.

  4. Corrosion in Electronics

    DEFF Research Database (Denmark)

    Ambat, Rajan; Gudla, Helene Virginie Conseil; Verdingovas, Vadimas

    2017-01-01

    and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in the presence of water film formed due to humidity exposure and bias conditions on the PCBA surface. This article provides a short review of the corrosion reliability issues of electronics due...... to the use of electronics under varying humidity conditions. Important PCBA aspects, which are fundamental to the corrosion cell formation under humid conditions, are discussed. Effect of hygroscopic residues from the process and service and their role in assisting water film build up and corrosion...... is presented. Various failure modes resulting from the corrosion and influence factors are discussed including humid and gaseous conditions....

  5. Corrosion inhibition properties of pyrazolylindolenine compounds on copper surface in acidic media

    Directory of Open Access Journals (Sweden)

    Ebadi Mehdi

    2012-12-01

    Full Text Available Abstract Background The corrosion inhibition performance of pyrazolylindolenine compounds, namely 4-(3,3-dimethyl-3H-indol-2-yl-pyrazole-1-carbothioamide (InPzTAm, 4-(3,3-dimethyl-3H-indol-2-yl-1H-pyrazole-1-carbothiohydrazide (InPzTH and 3,3-dimethyl-2-(1-phenyl-1H-pyrazol-4-yl-3H-indole (InPzPh, on copper in 1M HCl solution is investigated by electrochemical impedance spectroscopy (EIS, open circuit potential (OCP and linear scan voltammetry (LSV techniques. Results The results show that the corrosion rate of copper is diminished by the compounds with the inhibition strength in the order of: InPzTAm> InPzTH > InPzPh. The corrosion inhibition efficiencies for the three inhibitors are 94.0, 91.4 and 79.3, for InPzTAm, InPzTH and InPzPh respectively with the same inhibitor concentration (2 mM. Conclusion From the EIS, OCP and LSV results it was concluded that pyrazolylindolenine compounds with S-atom (with an amine group have illustrated better corrosion inhibition performance compared to hydrazine and phenyl group.

  6. CORROSION AND WEAR PROPERTIES OF MATERIALS USED FOR MINCED MEAT PRODUCTION

    DEFF Research Database (Denmark)

    Jellesen, Morten Stendahl; Hansen, Martin Otto Laver; Hilbert, Lisbeth Rischel

    2009-01-01

    The risk of material degradation is present in minced-meat processing equipment. Corrosion, wear and tribocorrosion properties of commonly used steel materials for such processing equipment are therefore studied in detail. Corrosiveness of minced meat has been evaluated by potentiodynamic...

  7. Evaluation of corrosion resistance and surface characteristics of orthodontic wires immersed in different mouthwashes.

    Science.gov (United States)

    Nalbantgil, Didem; Ulkur, Feyza; Kardas, Gulfeza; Culha, Mustafa

    2016-11-25

    Patients use mouthwashes in addition to mechanical cleaning during orthodontic treatment. The effects of mouthwashes on the archwires have not been examined yet. To compare the corrosion resistance of four different arch wires and corrosion effects of different mouthwashes to formulate a biocompatible and mechanically useful arch wire and mouthwash combination. Each group comprised of 4 wire samples of 2 cm 0.016 × 0.022 inch. 1st group: ion implanted nickel titanium (INT), 2nd group: nickel titanium, without ion implantation (NT), 3rd group: micro layered esthetic nickel titanium (ENT), 4th group: stainless steel (SS) wires. They were immersed inside 2 ml of artificial saliva solutions (AS) for the control, or AS (9%) combined with 1 of the 3 mouthwashes (91%) for study groups, for 24 hours. These mouthwashes were essential oil (EO), chlorhexidine (CHX), sodium-fluoride (NaF). An electrochemical analyzer was used for electrochemical impedance spectroscopy measurements. High corrosion resistance was obtained for ENT than the other wires. The corrosion potentials are 0.007, -0.042, 0.074 and -0.015 V (Ag/AgCl) for ENT, INT, SS and NT in the artificial salivary, respectively. In NaF containing mouthwash Rp value of ENT is significantly high in comparison to others. The impedance responses of all materials increased significantly in the presence of NaF mouthwash as well as in the CHX mouthwash. Low frequencies are seen at all materials in EO mouthwash. Diameters of loops are 22, 5.9, 5.9 and 3.7 MΩ at ENT, INT, SS and NT. In this study, micro layered esthetic nickel titanium wires are found biocompatible among other wires and NaF and CHX mouthwashes can be recommend for their good corrosion resistance during fixed orthodontic therapy.

  8. Effect of perfluorodecyltrichlorosilane on the surface properties and anti-corrosion behavior of poly(dimethylsiloxane)-ZnO coatings

    Science.gov (United States)

    Arukalam, Innocent O.; Meng, Meijiang; Xiao, Haigang; Ma, Yuantai; Oguzie, Emeka E.; Li, Ying

    2018-03-01

    Poly(dimethylsiloxane)-ZnO coatings modified with different amounts of perfluorodecyltrichlorosilane (FDTS) were prepared using sol-gel technique. The results of field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) examinations showed that the surface structures and roughness of the coatings were respectively influenced by the increasing addition of FDTS. The water contact angle measurements showed maximum value of 130.52° with the 0.10 g FDTS-modified coating sample. The X-ray photoelectron spectroscopy (XPS) results indicated the coatings' hydrophobicity was also influenced by surface chemistry. The FTIR-ATR characterization results showed there was remarkable increase in the crystallinity of 0.10 g FDTS-modified coating after modification, and was confirmed by differential scanning calorimetry (DSC) analysis of crystallization temperature and the X-ray diffraction (XRD) results with an estimation of 71.29% percent crystallinity. The mechanical properties of the coatings were also conducted. The EIS measurements for anti-corrosion behavior showed that 0.10 g FDTS-modified coating had the highest barrier performance and lowest rate of degradation. Indeed, the obtained data have demonstrated that 0.10 g (≈ 0.18%) FDTS produced the most significantly effect on the surface and barrier properties of the coatings and thus, can effectively be used for anti-corrosion application in the marine environments.

  9. The roles of Al2Cu and of dendritic refinement on surface corrosion resistance of hypoeutectic Al-Cu alloys immersed in H2SO4

    International Nuclear Information System (INIS)

    Osorio, Wislei R.; Spinelli, Jose E.; Freire, Celia M.A.; Cardona, Margarita B.; Garcia, Amauri

    2007-01-01

    Al-Cu alloys castings can exhibit different corrosion responses at different locations due to copper content and to the resulting differences on microstructural features and on Al 2 Cu fractions. The aim of this study was to investigate the influence of Al 2 Cu intermetallic particles associated to the dendritic arm spacings on the general corrosion resistance of three different hypoeutectic Al-Cu alloys samples in sulfuric acid solution. The cast samples were produced using a non-consumable tungsten electrode furnace with a water-cooled copper hearth under argon atmosphere. The typical microstructural pattern was examined by using electronic microscopy techniques. In order to evaluate the surface corrosion behavior of such Al-Cu alloys, corrosion tests were performed in a 0.5 M sulfuric acid solution at 25 deg. C by using an electrochemical impedance spectroscopy (EIS) technique and potentiodynamic polarization curves. An equivalent circuit was also used to provide quantitative support for the discussions and understanding of the corrosion behavior. It was found that Al 2 Cu has a less noble corrosion potential than that of the Al-rich phase. Despite that, dendrite fineness has proved to be more influent on corrosion resistance than the increase on alloy copper content with the consequent increase on Al 2 Cu fraction

  10. Study of corrosion behaviour in saturated bentonite barrier Corroben

    International Nuclear Information System (INIS)

    Azkarate, I.; Insausti, M.; Medina, V.

    2004-01-01

    tested samples. Finally, Cu30Ni and Cu-ETP cooper alloys have shown some degree of surface corrosion, with rates under 1/year in the 100C and 18 months test. Because some corrosion products rich in sulfur have been found in Cu30Ni alloy, the effect of microbiological corrosion should be further studied for this alloy. (Author) 16 refs

  11. The growing rate and the type of corrosion products of aluminium alloy AA 5052 in deionized water at temperature up to 3000C

    International Nuclear Information System (INIS)

    Ferreira, E.G.

    1980-01-01

    The process of corrosion concerning the aluminum alloy AA5052 in deionized water at temperatures of 40 0 C, 80 0 C, 90 0 C, 140 0 C, 200 0 C and 280 0 C is studied. The following methods are used: periodic weighting of the test samples; analysis by neutronic activation of the corrosion products dissolved in water; thermogravimetric and thermodiferential analysis; analysis through X-ray diffraction and from metalografic observations of the crystals produced in the corrosion process; an optical microscope using polarized and normal light and a scanning electronic microscope. The activation energies are calculated for the corrosion film formation, and for the dissolution of the corrosion products in the deionized water. (ARHC) [pt

  12. Piecewise Loglinear Estimation of Efficient Production Surfaces

    OpenAIRE

    Rajiv D. Banker; Ajay Maindiratta

    1986-01-01

    Linear programming formulations for piecewise loglinear estimation of efficient production surfaces are derived from a set of basic properties postulated for the underlying production possibility sets. Unlike the piecewise linear model of Banker, Charnes, and Cooper (Banker R. D., A. Charnes, W. W. Cooper. 1984. Models for the estimation of technical and scale inefficiencies in data envelopment analysis. Management Sci. 30 (September) 1078--1092.), this approach permits the identification of ...

  13. Long Term Corrosion/Degradation Test Six Year Results

    Energy Technology Data Exchange (ETDEWEB)

    M. K. Adler Flitton; C. W. Bishop; M. E. Delwiche; T. S. Yoder

    2004-09-01

    the performance assessment for the SDA. The corrosion on the carbon steel, beryllium, and aluminum were more evident with a clear difference in corrosion performance between the 4-ft and 10-ft levels. Notable surface corrosion products were evident as well as numerous pit initiation sites. Since the corrosion of the beryllium and aluminum is characterized by pitting, the geometrical character of the corrosion becomes more significant than the general corrosion rate. Both pitting factor and weight loss data should be used together. For six-year exposure, the maximum carbon steel corrosion rate was 0.3643 MPY while the maximum beryllium corrosion rate was 0.3282 MPY and the maximum aluminum corrosion rate was 0.0030 MPY.

  14. Corrosion and wear resistant metallic layers produced by electrochemical methods

    DEFF Research Database (Denmark)

    Christoffersen, Lasse; Maahn, Ernst Emanuel

    1999-01-01

    Corrosion and wear-corrosion properties of novel nickel alloy coatings with promising production characteristics have been compared with conventional bulk materials and hard platings. Corrosion properties in neutral and acidic environments have been investigated with electrochemical methods....... Determination of polarisation resistance during 100 hours followed by stepwise anodic polarisation seems to be a promising technique to obtain steady state data on slowly corroding coatings with transient kinetics. A slurry test enables determination of simultaneous corrosion and abrasive wear. Comparison...... of AISI 316, hard chromium and hardened Ni-P shows that there is no universal correlation between surface hardness and wear-corrosion loss. The possible relation between questionable passivity of Ni-P coatings and their high wear-corrosion loss rate compared to hard chromium is discussed....

  15. Technological Aspects of Corrosion-Resistant Steels Surfacing by Intense Relativistic Electron Beams

    Science.gov (United States)

    Belozerov, V. V.; Donets, S. E.; Klepikov, V. F.; Kivshik, V. F.; Lytvynenko, V. V.; Lonin, Yu. F.; Ponomarev, A. G.; Uvarov, V. T.

    Intense tubular relativistic electron beams are a promising tool for a number of practical applications, such as obtaining nanodispersed powder materials, surface properties modification of products, remote surfacing, etc. In current technologies for obtaining of nanopowder materials, one of the leading techniques is one based on the materials handling concentrated flows of energy. Using the various technological equipment (pulse current generators, accelerators), energy is inputted into the material in the form of intense impulse current, the plasma flows of charged particle beams. Each of the specified types of impact is characterized by a certain decomposition mechanism of processed materials to micro- and nano-sized state. Thus, the action of intense pulsed currents based on the thermal evaporation of a melt conductor with its subsequent condensation in liquid, the use of plasma flows and charged particle beams also involves evaporation and condensation of a material in a vacuum or in a special atmosphere.

  16. Facile fabrication of superhydrophobic surface with excellent mechanical abrasion and corrosion resistance on copper substrate by a novel method.

    Science.gov (United States)

    Su, Fenghua; Yao, Kai

    2014-06-11

    A novel method for controllable fabrication of a superhydrophobic surface with a water contact angle of 162 ± 1° and a sliding angle of 3 ± 0.5° on copper substrate is reported in this Research Article. The facile and low-cost fabrication process is composed from the electrodeposition in traditional Watts bath and the heat-treatment in the presence of (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane (AC-FAS). The superhydrophobicity of the fabricated surface results from its pine-cone-like hierarchical micro-nanostructure and the assembly of low-surface-energy fluorinated components on it. The superhydrophobic surface exhibits high microhardness and excellent mechanical abrasion resistance because it maintains superhydrophobicity after mechanical abrasion against 800 grit SiC sandpaper for 1.0 m at the applied pressure of 4.80 kPa. Moreover, the superhydrophobic surface has good chemical stability in both acidic and alkaline environments. The potentiodynamic polarization and electrochemical impedance spectroscopy test shows that the as-prepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Cu substrate. In addition, the as-prepared superhydrophobic surface has self-cleaning ability. It is believed that the facile and low-cost method offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on various metallic materials.

  17. Study of ferrous corrosion products on iron archaeological objects by electron backscattered diffraction (EBSD)

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, Ilanith; Conforto, Egle; Refait, Philippe; Remazeilles, Celine [FRE 3474 CNRS - Universite de La Rochelle, Laboratoire des Sciences de l' Ingenieur pour l' Environnement, La Rochelle cedex 01 (France)

    2013-02-15

    The corrosion of iron-based archaeomaterials in anoxic environments leads mainly to Fe(II) compounds, like the hydroxychloride {beta}-Fe{sub 2}(OH){sub 3}Cl, chukanovite Fe{sub 2}(OH){sub 2}CO{sub 3} or siderite FeCO{sub 3}. The understanding of the mechanisms then necessarily implies a thorough investigation of the chemical, mechanical and morphological characteristics of the Fe(II)-based layer that develops between the metal surface and the environment. In the peculiar case of Fe(II) compounds, generally very reactive towards O{sub 2}, the main concern is to prevent any transformation by air during the analysis. The EBSD technique is adapted on a scanning electron microscope (SEM) where the samples are analysed under vacuum and consequently sheltered from air. Different options offered by EBSD for phase characterisation and microstructural study were tested for the first time on the rust layers of two archaeological iron nails. Results were confronted to those obtained by micro-Raman spectroscopy, which was used as reference method. Magnetite, Fe(II) hydroxychloride {beta}-Fe{sub 2}(OH){sub 3}Cl and siderite were analysed successfully but improvements have to be brought for the study of other compounds such as iron oxyhydroxides and chukanovite. The choice of experimental parameters in our approach as well as the potentialities and limits of the technique for this kind of application are discussed. (orig.)

  18. 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)

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

    Science.gov (United States)

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

    2002-01-01

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

  20. Corrosion inhibitors for concrete bridges.

    Science.gov (United States)

    2004-12-01

    Deicing salts and salt-water spray can cause serious corrosion problems for reinforced concrete bridge structures. : These problems can lead to costly and labor-intensive repair and even replacement of the structure. Surface applied : corrosion inhib...

  1. Investigation of surface oxide morphology in SG feedwater pipes and study of its influence on flow accelerated corrosion rate

    International Nuclear Information System (INIS)

    Qiu, G.; Alos-Ramos, O.; Monchecourt, D.; Mansour, C.; Delaunay, S.; Trevin, S.

    2015-01-01

    Flow accelerated corrosion (FAC) affects carbon steel components in the secondary circuits of PWR plants. The mandatory use of the prediction tool BRT-CICERO in all its PWR plants enables EDF to perform efficient inspections programs and minimize the number of leaks in the secondary circuits. Due to the operating conditions, SG feedwater flow regulation (ARE) circuits can be affected by FAC phenomenon. Thickness loss has been reported by several plants during the last 10 years, although significant damage by FAC remains very rare. This paper describes the surface features observed on an ARE straight tube that has orange peel pattern with thickness loss on the one half of its inner surface and a thick fouling layer without much thickness loss on the other. An analysis of the oxide porosity and structure by SEM investigation has been carried out. The origin of fouling layer and its behavior in the ARE circuits environment (oxide solubility, flow stability/turbulence) have been discussed. Finally by comparing with the classic FAC models, an attempt of correlation between the presence of the fouling layer and the lower corrosion rate is proposed. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    El Hamdani, Naoual; Fdil, Rabiaa [Laboratoire de Chimie Bioorganique, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Tourabi, Mustapha [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Jama, Charafeddine [UMET-PSI, CNRS UMR 8207, ENSCL, Université Lille 1, CS 90108, F-59652 Villeneuve d’Ascq Cedex (France); Bentiss, Fouad, E-mail: fbentiss@enscl.fr [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); UMET-PSI, CNRS UMR 8207, ENSCL, Université Lille 1, CS 90108, F-59652 Villeneuve d’Ascq Cedex (France)

    2015-12-01

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

  3. Corrosion behaviour and surface analysis of a Co-Cr and two Ni-Cr dental alloys before and after simulated porcelain firing.

    Science.gov (United States)

    Qiu, Jing; Yu, Wei-Qiang; Zhang, Fu-Qiang; Smales, Roger J; Zhang, Yi-Lin; Lu, Chun-Hui

    2011-02-01

    This study evaluated the corrosion behaviour and surface properties of a commercial cobalt-chromium (Co-Cr) alloy and two nickel-chromium (Ni-Cr) alloys [beryllium (Be)-free and Be-containing] before and after a simulated porcelain-firing process. Before porcelain firing, the microstructure, surface composition and hardness, electrochemical corrosion properties, and metal-ion release of as-cast alloy specimens were examined. After firing, similar alloy specimens were examined for the same properties. In both as-cast and fired conditions, the Co-Cr alloy (Wirobond C) showed significantly more resistance to corrosion than the two Ni-Cr alloys. After firing, the corrosion rate of the Be-free Ni-Cr alloy (Stellite N9) increased significantly, which corresponded to a reduction in the levels of Cr, molybdenum (Mo), and Ni in the surface oxides and to a reduction in the thickness of the surface oxide film. The corrosion properties of the Co-Cr alloy and the Be-containing Ni-Cr alloy (ChangPing) were not significantly affected by the firing process. Porcelain firing also changed the microstructure and microhardness values of the alloys, and there were increases in the release of Co and Ni ions, especially for Ni from the Be-free Ni-Cr alloy. Thus, the corrosion rate of the Be-free Ni-Cr alloy increased significantly after porcelain firing, whereas the firing process had little effect on the corrosion susceptibility of the Co-Cr alloy and the Be-containing Ni-Cr alloy. © 2011 Eur J Oral Sci.

  4. Moessbauer spectroscopy and FTIR spectroscopy of corrosion products obtained beneath mild steel coated with different phosphate primers

    International Nuclear Information System (INIS)

    Ramesh Kumar, A.V.; Nigam, R.K.; Monga, S.S.; Srivastava, A.K.

    1999-01-01

    In the present study corrosion products obtained on mild steel beneath coating of five different alkyd base phosphate primers (i) zinc phosphate (ii) manganese phosphate (iii) calcium phosphate (iv) barium phosphate and (v) aluminium phosphate and exposed under; (i) immersed conditions in 3% NaCl and (ii) salt spray by 3% NaCl for one month have been discussed. The Moessbauer and FTIR spectroscopic analysis show the corrosion products mainly consist of γ-FeOOH, β-FeOOH and δ-FeOOH. However, under salt spray conditions the downward bend in Moessbauer spectra may be due to FeO x (OH) 3-2x which is generally precipitated as a precursor for α-FeOOH under alternate wet and dry conditions. The ferrous/ferric phosphate was absent under immersed conditions, however, the asymmetry of central doublet of Moessbauer spectrum under salt sprayed condition could be due to ferric hydrogen phosphate. (author)

  5. Pitting corrosion resistance and bond strength of stainless steel overlay by friction surfacing on high strength low alloy steel

    OpenAIRE

    Amit Kumar Singh; G. Madhusudhan Reddy; K. Srinivas Rao

    2015-01-01

    Surface modification is essential for improving the service properties of components. Cladding is one of the most widely employed methods of surface modification. Friction surfacing is a candidate process for depositing the corrosion resistant coatings. Being a solid state process, it offers several advantages over conventional fusion based surfacing process. The aim of this work is to identify the relationship between the input variables and the process response and develop the predictive mo...

  6. Surface Water Protection by Productive Buffers

    DEFF Research Database (Denmark)

    Christen, Benjamin

    Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates...... on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU study landscapes, model tentative N-loss mitigation, calculate biomass production potential and economic...... scenarios are developed and visualized using maps, photography and artwork. The potential effects on the landscape N-cycle are discussed. Nitrogen removal by biomass production using forage or energy grasses, short rotation coppice willow/poplar or short rotation forestry with other tree species in buffers...

  7. On the fundamentals of electrochemical corrosion of X65 steel in CO{sub 2}-containing formation water in the presence of acetic acid in petroleum production

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.A. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4 (Canada); Department of Materials Science and Engineering, China University of Petroleum-Beijing, Beijing 102249 (China); Cheng, Y.F. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4 (Canada)], E-mail: fcheng@ucalgary.ca

    2009-01-15

    Electrochemical corrosion behavior of X65 steel in CO{sub 2}-containing oilfield formation water in the presence of acetic acid (HAc) was investigated by various electrochemical measurements and analyses as well as thermodynamic calculations of ionic concentrations, reaction rate constants and equilibrium electrode potentials. A conceptual model was developed to illustrate corrosion processes of steel in oilfield formation water system. The anodic reactions of the steel contain a direct dissolution of Fe, Fe {yields} Fe{sup 2+} + 2e, and the formation of corrosion scale, FeCO{sub 3}, by Fe + HCO{sub 3}{sup -} {yields} FeCO{sub 3} + H{sup +} + 2e. The cathodic processes contain the reduction of H{sup +}, HCO{sub 3}{sup -}, H{sub 2}O and HAc, where reduction of HAc has the least negative equilibrium potential and thus dominates the cathodic process. With addition of HAc in the solution, both cathodic and anodic reaction rates increase remarkably. It is attributed to the fact that HAc inhibits or degrades the formation of protective scales due to the decrease of solution pH. Upon electrode rotation, the measured impedance decreases with the increase in HAc concentration. The FeCO{sub 3} scale will not form on electrode surface. When HAc concentration is less than 1000 ppm, the adsorbed intermediate product is not significant, resulting in generation of a low-frequency inductive loop in EIS plots. When HAc concentration is more than 3000 ppm, the adsorption of intermediate product is significant, generating overlapped capacitive semicircles in EIS measurements.

  8. Analysis on the gamma dose distribution by major corrosion products during preventive maintenance period in nuclear power plant

    International Nuclear Information System (INIS)

    Ha, Wi Ho

    2006-02-01

    The information on dose distribution inside the containment building is an essential requirement to make a reduction of radiation exposure as well as effective operation and design of nuclear power plant. After reactor shutdown, radiation exposure to workers mainly occurs during preventive maintenance period due to inspection or repair works of major components. During that period, gamma doses are induced by major corrosion products in the primary coolant system. The radiation exposure to workers has been assessed by using the measurements. The measurements are, of course, a basic and reliable assessment. But the measurement has defect such as limitation of detecting area. In order to improve the defect of the measurements, system for assessment of gamma dose distribution during preventive maintenance period by using computational code was suggested in this study. First, activity of major corrosion products was calculated by using modified CRUDSIM code. Original CRUDSIM code was modified to add evaluation of other major corrosion products besides cobalt isotopes. Modeling of containment building for YGN Unit 3 was then performed. Gamma dose distribution by major corrosion products inside the containment building was calculated by using MCNPX code. Finally, the calculations were mapped for whole space inside the containment building and were compared with the measurements. As a result of this study, the defect of the measurement are supplemented by using computational calculation system, and it is expected that workers can make an effective work plan through providing dose distribution inside the containment building in advance. In addition, this study can be applied to technology development to make an effective containment shielding design of the next generation reactor as well as an improvement of the safety for workers in nuclear power plant

  9. Technical note 4. Corrosion of copper canister

    International Nuclear Information System (INIS)

    Szakalos, Peter; Seetharaman, Seshadri

    2012-06-01

    Objectives of the project: In this review assignment, SKB's treatment of copper corrosion processes or mechanisms in SR-Site shall be reviewed both for the anticipated oxic and anoxic repository environments. The reviewer(s) shall consider if corrosion and corrosion mechanisms of the copper canisters in different possible evolutionary repository environments have been properly described. The objectives of this initial review phase in the area of copper corrosion is to achieve a broad coverage of SR-Site and its supporting references and in particular identify the need for complementary information and clarifications to be delivered by SKB. Summary by the authors: It is expected that the inflow of ground water to the deposition holes and tunnels in the Forsmark repository will be very slow. Thus, it might take some few hundred years up to thousand years before the deposition holes are filled with ground water and it might take 6000 years or more before the bentonite buffer is fully water saturated and pressurized. The copper canisters will therefore meet to two completely different environments: 1. An initial period of several hundreds of years when copper is exposed to gaseous corrosion. 2. And then to aqueous corrosion. From a corrosion point of view the first 1000 years are the most critical for the copper canister since pure, or phosphorus alloyed copper, is not designed to cope with corrosion at elevated temperatures. The outer copper surface temperature is expected to reach 100 deg C within some decades after closure of the repository and then slowly cool down to around 50 deg C after 1000 years. The gaseous corrosion is treated in SKB's safety assessment as being only dependent on oxygen gas and thus easily estimated by an oxygen mass-balance calculation. This simple model has no scientific support since several corrosive trace gases, such as sulphurous and nitrous compounds, operates together with water molecules (moisture) and the corrosion product consists

  10. Cytotoxicity of corrosion products of degradable Fe-based stents: relevance of pH and insoluble products.

    Science.gov (United States)

    Fagali, Natalia S; Grillo, Claudia A; Puntarulo, Susana; Fernández Lorenzo de Mele, Mónica A

    2015-04-01

    Fe-based biodegradable metallic materials (Fe-BMMs) have been proposed for cardiovascular applications and are expected to disappear via corrosion after an appropriate period. However, in vivo studies showed that Fe ions release leads to accumulation of orange and brownish insoluble products at the biomaterial/cell interface. As an additional consequence, sharp changes in pH may affect the biocompatibility of these materials. In the present work, the experimental protocols were designed with the aim of evaluating the relative importance that these factors have on biocompatibility evaluation of BMMs. Mitochondrial activity (MTT assay) and thiobarbituric acid reactive substances (TBARS) assay on mammalian cells, exposed to 1-5 mM of added Fe3+ salt, were assessed and compared with results linked exclusively to pH effects. Soluble Fe concentration in culture medium and intracellular Fe content were also determined. The results showed that: (i) mitochondrial activity was affected by pH changes over the entire range of concentrations of added Fe3+ assayed, (ii) at the highest added Fe3+ concentrations (≥3 mM), precipitation was detected and the cells were able to incorporate the precipitate, that seems to be linked to cell damage, (iii) the extent of precipitation depends on the Fe/protein concentration ratio; and (iv) lipid peroxidation products were detected over the entire range of concentrations of added Fe3+. Hence, a new approach opens in the biocompatibility evaluation of Fe-based BMMs, since the cytotoxicity would not be solely a function of released (and soluble) ions but of the insoluble degradation product amount and the pH falling at the biomaterial/cell interface. The concentration of Fe-containing products at the interface depends on diffusional conditions in a very complex way that should be carefully analyzed in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Effects of Dextrose and Lipopolysaccharide on the Corrosion Behavior of a Ti-6Al-4V Alloy with a Smooth Surface or Treated with Double-Acid-Etching

    Science.gov (United States)

    Faverani, Leonardo P.; Assunção, Wirley G.; de Carvalho, Paulo Sérgio P.; Yuan, Judy Chia-Chun; Sukotjo, Cortino; Mathew, Mathew T.; Barao, Valentim A.

    2014-01-01

    Diabetes and infections are associated with a high risk of implant failure. However, the effects of such conditions on the electrochemical stability of titanium materials remain unclear. This study evaluated the corrosion behavior of a Ti-6Al-4V alloy, with a smooth surface or conditioned by double-acid-etching, in simulated body fluid with different concentrations of dextrose and lipopolysaccharide. For the electrochemical assay, the open-circuit-potential, electrochemical impedance spectroscopy, and potentiodynamic test were used. The disc surfaces were characterized by scanning electron microscopy and atomic force microscopy. Their surface roughness and Vickers microhardness were also tested. The quantitative data were analyzed by Pearson's correlation and independent t-tests (α = 0.05). In the corrosion parameters, there was a strong lipopolysaccharide correlation with the Ipass (passivation current density), Cdl (double-layer capacitance), and Rp (polarization resistance) values (pTi-6Al-4V alloy with surface treatment by double-acid-etching. The combination of dextrose and lipopolysaccharide was correlated with the Icorr (corrosion current density) and Ipass (pTi-6Al-4V alloy decreased (pTi-6Al-4V alloy increased (pTi-6Al-4V alloy by increasing the surface thickness mainly in the group associated with dextrose and lipopolysaccharide. The combination of dextrose and lipopolysaccharide affected the corrosion behavior of the Ti-6Al-4V alloy surface treated with double-acid-etching. However, no dose-response corrosion behavior could be observed. These results suggest a greater susceptibility to corrosion of titanium implants in diabetic patients with associated infections. PMID:24671257

  12. Stainless steel surface alloying process with molybdenum or ruthenium by high-energy excimer laser: structural, electrochemical, and corrosion properties

    Science.gov (United States)

    Beaunier, Luc; Pasquier, Christian; Pillier, Francoise; Laurens, Patricia

    1997-08-01

    Chemical transformations on stainless steel surfaces (304 AISI) are obtained by melting with an excimer laser. The very high quenching rate allows to create a thin continuous metastable gradient in composition and structure by opposition to other melting techniques which promote multiphase layer. The mechanical properties of the bulk are maintained and the external layer is chemically modified for a better resistance to environmental aggressivity. Molybdenum is used for corrosion protection and ruthenium for cathodic and anodic properties. The composition is analyzed on cross-sections obtained by ultramicrotomy. A continuous gradient approximately 500 nm (nanometer) of Mo or Ru with decreasing grain size (304 AISI) is observed. Mo and Ru surface alloys show an important beneficial effect from cathodic and transpassive potential range.

  13. Basic aspects of the carbon dioxide corrosion in oil and gas production; Aspectos basicos de la corrosion por dioxido de carbono en la produccion de petroleo y gas

    Energy Technology Data Exchange (ETDEWEB)

    Angulo Macias, J.

    2010-07-01

    Carbon dioxide (CO{sub 2}) is a non-corrosive gas within the driven conditions in the oil and gas industry, but the presence of water converts it, maybe, in the most important component in the corrosive processes in this industry. Corrosion has an important impact inside the oil and gas companies, no only in economics but also in safety, environmental and social aspects. After several decades of investigation of these corrosion processes, there are still several mechanisms not fully understood. (Author) 19 refs.

  14. Formation of a nano-pattering NiTi surface with Ni-depleted superficial layer to promote corrosion resistance and endothelial cell-material interaction.

    Science.gov (United States)

    Zhao, Tingting; Li, Yan; Xia, Yun; Venkatraman, Subbu S; Xiang, Yan; Zhao, Xinqing

    2013-01-01

    Zirconium ion implantation was performed on NiTi alloy to suppress Ni ion release as well as to improve corrosion resistance and cell-material interaction. A thicker Ni-depleted nano-scale composite layer formed after Zr implantation and the corrosion resistance was evidently increased in aspects of increased E(br) - E(corr) (difference between corrosion potential and breakdown potential) and decreased corrosion current density. 2.5/2 NiTi sample possessed the highest E(br) - E(corr), more than 500 mV higher than that of untreated NiTi, suggesting a significant improvement on pitting corrosion resistance. Ni ion release rate of Zr-NiTi was decreased due to the depletion of Ni in the superficial surface layer and the diffusion resistance effect of the ZrO(2)/TiO(2) nano-film. Increased surface wettability induced by increased surface roughness was obtained after Zr implantation. Zr-NiTi samples were found to be favorable to endothelial cells (ECs) proliferation, especially after 5 and 7 days culture.

  15. Corrosion surface protection by using titanium carbon nitride/titanium-niobium carbon nitride multilayered system

    Energy Technology Data Exchange (ETDEWEB)

    Caicedo, J.C., E-mail: jcesarca@calima.univalle.edu.co [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Amaya, C. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Laboratorio de Recubrimientos Duros, CDT-ASTIN SENA, Cali (Colombia); Cabrera, G. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Esteve, J. [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain); Aperador, W. [Universidad Militar Nueva Granada Bogota D.C (Colombia); Gomez, M.E. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Prieto, P. [Grupo de Peliculas Delgadas, Universidad del Valle, Cali (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Calle 13 100-00 Edificio 320, espacio 1026, Cali (Colombia)

    2011-07-29

    The aim of this work is the improvement of the electrochemical behavior of 4140 steel substrate using TiCN/TiNbCN multilayered system as a protective coating. We have grown [TiCN/TiNbCN]{sub n} multilayered via reactive r.f. magnetron sputtering technique in which was varied systematically the bilayer period ({Lambda}), and the bilayer number (n), maintaining constant the total thickness of the coatings ({approx} 3 {mu}m). The coatings were characterized by X-ray diffraction (XRD), optical microscopy, electron microscopy and transmission electron microscopy assisted with selected area electron diffraction. The electrochemical properties were studied by Electrochemical Impedance Spectroscopy and Tafel curves. XRD results showed a preferential growth in the face-centered cubic (111) crystal structure for [TiCN/TiNbCN]{sub n} multilayered coatings [1]. In this work was obtained the maximum corrosion resistance for the coating with ({Lambda}) equal to 15 nm, corresponding to n = 200 bilayered. The polarization resistance and corrosion rate were around 8.6 kOhm cm{sup 2} and 7.59 . 10{sup -4} mm/year, these values were 8.6 and 0.001 times better than those showed by the uncoated 4140 steel substrate (1.0 kOhm and 0.57 mm/year), respectively. The improvement of the electrochemical behavior of the 4140 coated with this TiCN/TiNbCN multilayered system can be attributed to the presence of several interfaces that act as obstacles for the inward and outward diffusions of Cl{sup -} ion species, generating an increment in the energy or potential required for translating the corrosive ions across the coating/substrate interface. Moreover, the interface systems affect the means free path on the ions toward the metallic substrate, due to the decreasing of the defects presented in the multilayered coatings.

  16. Corrosion surface protection by using titanium carbon nitride/titanium-niobium carbon nitride multilayered system

    International Nuclear Information System (INIS)

    Caicedo, J.C.; Amaya, C.; Cabrera, G.; Esteve, J.; Aperador, W.; Gomez, M.E.; Prieto, P.

    2011-01-01

    The aim of this work is the improvement of the electrochemical behavior of 4140 steel substrate using TiCN/TiNbCN multilayered system as a protective coating. We have grown [TiCN/TiNbCN] n multilayered via reactive r.f. magnetron sputtering technique in which was varied systematically the bilayer period (Λ), and the bilayer number (n), maintaining constant the total thickness of the coatings (∼ 3 μm). The coatings were characterized by X-ray diffraction (XRD), optical microscopy, electron microscopy and transmission electron microscopy assisted with selected area electron diffraction. The electrochemical properties were studied by Electrochemical Impedance Spectroscopy and Tafel curves. XRD results showed a preferential growth in the face-centered cubic (111) crystal structure for [TiCN/TiNbCN] n multilayered coatings [1]. In this work was obtained the maximum corrosion resistance for the coating with (Λ) equal to 15 nm, corresponding to n = 200 bilayered. The polarization resistance and corrosion rate were around 8.6 kOhm cm 2 and 7.59 . 10 -4 mm/year, these values were 8.6 and 0.001 times better than those showed by the uncoated 4140 steel substrate (1.0 kOhm and 0.57 mm/year), respectively. The improvement of the electrochemical behavior of the 4140 coated with this TiCN/TiNbCN multilayered system can be attributed to the presence of several interfaces that act as obstacles for the inward and outward diffusions of Cl - ion species, generating an increment in the energy or potential required for translating the corrosive ions across the coating/substrate interface. Moreover, the interface systems affect the means free path on the ions toward the metallic substrate, due to the decreasing of the defects presented in the multilayered coatings.

  17. 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)

  18. Mechanisms and energetics of surface reactions at the copper-water interface. A critical literature review with implications for the debate on corrosion of copper in anoxic water

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Adam Johannes; Brinck, Tore [Applied Physical Chemistry, KTH Royal Inst. of Technology, Stockholm (Sweden)

    2012-06-15

    In order to make a critical analysis of the discussion of corrosion of copper in pure anoxic water it is necessary to understand the chemical reactivity at the copper-water interface. Even though the most fundamental issue, i.e. the nature and existence of a hypothetical product that is thermodynamically stable, is still under debate, it is clear that if anoxic corrosion really exists, it must be initiated through oxidative surface reactions at the copper-water interface. This report presents a survey of the peer reviewed literature on the reactivity of copper surfaces in water. Reactions discussed involve molecular adsorption of water, dissociation of the OH-bonds in adsorbed water molecules and hydroxyl groups, the disproportionation/synproportionation equilibrium between hydroxyl groups/hydroxide ions, water molecules and atomic oxygen, the surface diffusion of adsorbed species, and the formation of hydrogen gas (molecular hydrogen). Experimental, as well as theoretical (quantum chemical) studies are reviewed. It is concluded that a limited amount of hydrogen gas (H{sub 2}) should be formed as the result of dissociative water adsorption at certain copper surfaces. Quantitative estimates of the amounts of H2 that could form at the copper-water interface are made. Assuming that the water-cleavage/hydrogen-formation reaction proceeds on an ideal [110] or [100] surface until a hydroxyl monolayer (ML) is reached, the amount of H{sub 2} formed is {approx} 2.4 ng cm{sup -2} copper surface. Based on the literature cited, this is most likely possible, thermodynamically as well as kinetically. Although not proven, it is not unlikely that the reaction can proceed until an oxide ML is formed, which would give 4.8 ng cm{sup -2}. If the formation of an oxide ML is thermodynamically feasible the surface will probably react further, since Cu{sub 2}O(s) is known to activate and cleave the water molecule when it adsorbs at the Cu{sub 2}O(s) surface. Assuming the formation of a

  19. LITERATURE REVIEW ON THE SORPTION OF PLUTONIUM, URANIUM, NEPTUNIUM, AMERICIUM AND TECHNETIUM TO CORROSION PRODUCTS ON WASTE TANK LINERS

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Kaplan, D.

    2012-02-29

    The Savannah River Site (SRS) has conducted performance assessment (PA) calculations to determine the risk associated with closing liquid waste tanks. The PA estimates the risk associated with a number of scenarios, making various assumptions. Throughout all of these scenarios, it is assumed that the carbon-steel tank liners holding the liquid waste do not sorb the radionuclides. Tank liners have been shown to form corrosion products, such as Fe-oxyhydroxides (Wiersma and Subramanian 2002). Many corrosion products, including Fe-oxyhydroxides, at the high pH values of tank effluent, take on a very strong negative charge. Given that many radionuclides may have net positive charges, either as free ions or complexed species, it is expected that many radionuclides will sorb to corrosion products associated with tank liners. The objective of this report was to conduct a literature review to investigate whether Pu, U, Np, Am and Tc would sorb to corrosion products on tank liners after they were filled with reducing grout (cementitious material containing slag to promote reducing conditions). The approach was to evaluate radionuclides sorption literature with iron oxyhydroxide phases, such as hematite ({alpha}-Fe{sub 2}O{sub 3}), magnetite (Fe{sub 3}O{sub 4}), goethite ({alpha}-FeOOH) and ferrihydrite (Fe{sub 2}O{sub 3} {center_dot} 0.5H{sub 2}O). The primary interest was the sorption behavior under tank closure conditions where the tanks will be filled with reducing cementitious materials. Because there were no laboratory studies conducted using site specific experimental conditions, (e.g., high pH and HLW tank aqueous and solid phase chemical conditions), it was necessary to extend the literature review to lower pH studies and noncementitious conditions. Consequently, this report relied on existing lower pH trends, existing geochemical modeling, and experimental spectroscopic evidence conducted at lower pH levels. The scope did not include evaluating the appropriateness

  20. High temperature corrosion of superheater materials for power production through biomass

    Energy Technology Data Exchange (ETDEWEB)

    Gotthjaelp, K.; Broendsted, P. [Forskningscenter Risoe (Denmark); Jansen, P. [FORCE Institute (Denmark); Montgomery, M.; Nielsen, K.; Maahn, E. [Technical Univ. of Denmark, Corrosion and Surface Techn. Inst. of Manufacturing Engineering (Denmark)

    1996-08-01

    The aim of the present study has been to establish a fundamental knowledge of the corrosion mechanisms acting on materials for use in biomass fired power plants. The knowledge is created based on laboratory exposures of selected materials in well-defined corrosive gas environments. The experiments using this facility includes corrosion studies of two types of high temperature resistant steels, Sanvik 8LR30 (18Cr 10Ni Ti) and Sanicro 28 (27Cr 31Ni 4Mo), investigated at 600 deg. C in time intervals up to 300 hours. The influence of HCl (200 ppm) and of SO{sub 2} (300 ppm) on the corrosion progress has been investigated. In addition the corrosion behaviour of the same materials was investigated after having been exposed under a cover of ash in air in a furnace at temperatures of 525 deg. C, 600 deg. C, and 700 deg. C. The ashes utilised are from a straw fired power plant and a synthetic ash composed of potassium chloride (KCl) and potassium sulphate (K{sub 2}SO{sub 4}). Different analysis techniques to characterise the composition of the ash coatings have been investigated in order to judge the reliability and accuracy of the SEM-EDX method. The results are considered as an important step towards a better understanding of the high temperature corrosion under the conditions found in biomass fired power plants. One of the problems to solve in a suggested subsequent project is to combine the effect of the aggressive gases (SO{sub 2} and HCl) and the active ash coatings on high temperature corrosion of materials. (EG) 20 refs.

  1. Surface Characterization, Corrosion Resistance and in Vitro Biocompatibility of a New Ti-Hf-Mo-Sn Alloy

    Science.gov (United States)

    Ion, Raluca; Drob, Silviu Iulian; Ijaz, Muhammad Farzik; Vasilescu, Cora; Osiceanu, Petre; Gordin, Doina-Margareta; Cimpean, Anisoara; Gloriant, Thierry

    2016-01-01

    A new superelastic Ti-23Hf-3Mo-4Sn biomedical alloy displaying a particularly large recovery strain was synthesized and characterized in this study. Its native passive film is very thick (18 nm) and contains very protective TiO2, Ti2O3, HfO2, MoO2, and SnO2 oxides (XPS analysis). This alloy revealed nobler electrochemical behavior, more favorable values of the corrosion parameters and open circuit potentials in simulated body fluid in comparison with commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy taken as reference biomaterials in this study. This is due to the favorable influence of the alloying elements Hf, Sn, Mo, which enhance the protective properties of the native passive film on alloy surface. Impedance spectra showed a passive film with two layers, an inner, capacitive, barrier, dense layer and an outer, less insulating, porous layer that confer both high corrosion resistance and bioactivity to the alloy. In vitro tests were carried out in order to evaluate the response of Human Umbilical Vein Endothelial Cells (HUVECs) to Ti-23Hf-3Mo-4Sn alloy in terms of cell viability, cell proliferation, phenotypic marker expression and nitric oxide release. The results indicate a similar level of cytocompatibility with HUVEC cells cultured on Ti-23Hf-3Mo-4Sn substrate and those cultured on the conventional CP-Ti and Ti-6Al-4V metallic materials. PMID:28773939

  2. Effect of Laser Surface Melting on the Microstructure and Pitting Corrosion Resistance of 304L SS Weldment

    Science.gov (United States)

    Suresh, Girija; Dasgupta, Arup; Kishor, P. S. V. R. A.; Upadhyay, B. N.; Saravanan, T.; Mallika, C.; Mudali, U. Kamachi

    2017-10-01

    The manuscript presents the effect of laser surface melting (LSM) on the microstructural variations and pitting corrosion resistance of 304L SS weldment fabricated by gas tungsten arc welding of 304L SS plates using 308L SS filler wire. The weld region was examined by X-ray radiography for defect detection. LSM of 304L SS weldment was performed using Nd:YAG pulsed laser. Microstructural evaluation was carried out using optical and electron back scatter diffraction techniques. The microstructure of 304L SS base was found to be austenitic, while the weld region of 304L SS weldment contained delta ferrite distributed in austenite matrix. The microstructure of LSM 304L SS weldment was found to be homogeneous austenite matrix with sparsely distributed ferrite. Ferrite measurements showed a decrease in the percentage ferrite in the fusion zone of 304L SS weldment after LSM. A profound enhancement in the pitting corrosion resistance was observed after LSM, which could be attributed to the homogeneous microstructure and decrease in the ferrite content. Pit density was found to be higher in the heat-affected zone of the weldment. Very few pits were observed in the LSM 304L SS weldment compared to the as-weldment.

  3. Standard test method for determining susceptibility to stress-corrosion cracking of 2XXX and 7XXX Aluminum alloy products

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1998-01-01

    1.1 This test method covers a uniform procedure for characterizing the resistance to stress-corrosion cracking (SCC) of high-strength aluminum alloy wrought products for the guidance of those who perform stress-corrosion tests, for those who prepare stress-corrosion specifications, and for materials engineers. 1.2 This test method covers method of sampling, type of specimen, specimen preparation, test environment, and method of exposure for determining the susceptibility to SCC of 2XXX (with 1.8 to 7.0 % copper) and 7XXX (with 0.4 to 2.8 % copper) aluminum alloy products, particularly when stressed in the short-transverse direction relative to the grain structure. 1.3 The values stated in SI units are to be regarded as standard. The inch-pound units in parentheses are provided for information. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and de...

  4. A microwave sensor for zinc corrosion detection

    Science.gov (United States)

    Rammal, Jamal; Salameh, Farah; Tantot, Olivier; Delhote, Nicolas; Verdeyme, Serge; Rioual, Stéphane; Gallée, François; Lescop, Benoit

    2017-09-01

    This article presents a sensor based on zinc wires of different widths deposited on the surface of the ceramic resonator capable of detecting and following the evolution of the corrosion of the zinc material. Electromagnetic studies show that due to the evolution of the corrosion, the progressive degradation of the conductivity of the formed zinc grid (from 6 S/μm to 0.015 S/μm) causes a degradation of the quality factor (from Q0 = 50 to Q0 transmission of the TE101 mode of the resonator (from -8 dB to transmission coefficient, and a degradation of the unloaded quality factor. Confirmed by electronic microscopy and X-Ray analysis, these variations are due to the evolution in the corrosion of zinc wires over time, leading to a creation of corrosion products in these wires.

  5. 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)

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

    Science.gov (United States)

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

    2015-06-01

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

  7. Pitting corrosion resistance and bond strength of stainless steel overlay by friction surfacing on high strength low alloy steel

    Directory of Open Access Journals (Sweden)

    Amit Kumar Singh

    2015-09-01

    Full Text Available Surface modification is essential for improving the service properties of components. Cladding is one of the most widely employed methods of surface modification. Friction surfacing is a candidate process for depositing the corrosion resistant coatings. Being a solid state process, it offers several advantages over conventional fusion based surfacing process. The aim of this work is to identify the relationship between the input variables and the process response and develop the predictive models that can be used in the design of new friction surfacing applications. In the current work, austenitic stainless steel AISI 304 was friction surfaced on high strength low alloy steel substrate. Friction surfacing parameters, such as mechtrode rotational speed, feed rate of substrate and axial force on mechtrode, play a major role in determining the pitting corrosion resistance and bond strength of friction surfaced coatings. Friction surfaced coating and base metal were tested for pitting corrosion by potentio-dynamic polarization technique. Coating microstructure was characterized using optical microscopy, scanning electron microscopy and X-ray diffraction. Coatings in the as deposited condition exhibited strain-induced martensite in austenitic matrix. Pitting resistance of surfaced coatings was found to be much lower than that of mechtrode material and superior to that of substrate. A central composite design with three factors (mechtrode rotational speed, substrate traverse speed, axial load on mechtrode and five levels was chosen to minimize the number of experimental conditions. Response surface methodology was used to develop the model. In the present work, an attempt has been made to develop a mathematical model to predict the pitting corrosion resistance and bond strength by incorporating the friction surfacing process parameters.

  8. High Temperature Corrosion of Superheater Materials for Power Production through Biomass

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Maahn, Ernst emanuel; Nielsen, Karsten agersted

    plant boiler. The experiments using this facility includes corrosion studies of two types of high temperature resistant steels, Sandvik 8LR30 (18Cr 10Ni Ti) and Sanicro 28 (27Cr 31Ni 4Mo)investigated at 600Cin time intervals up to 300 hours. The influence of HCl (200ppm) and of SO2 (300 ppm......The aim of the present study has been to establish a fundamental knowledge of the corrosion mechanisms acting on materials for use in biomass fired power plants. The knowledge is created based on laboratory exposures on selected materials in well-defined corrosive gas environments. An experimental......) on the corrosion progress has been investigated.In addition the corrosion behaviour of the same materials was investigated after having been exposed under a cover of ash in air in a furnace at temperatures of 525C, 600C and 700C. The ashes utilised are from a straw-fired power plant and a synthetic ash composed...

  9. Alternating current techniques for corrosion monitoring in water reactor systems

    International Nuclear Information System (INIS)

    Isaacs, H.S.; Weeks, J.R.

    1977-01-01

    Corrosion in both nuclear and fossil fueled steam generators is generally a consequence of the presence of aggressive impurities introduced into the coolant system through condenser leakage. The impurities concentrate in regions of the steam generator protected from coolant flow, in crevices or under deposited corrosion products and adjacent to heat transfer surfaces. These three factors, the aggressive impurity, crevice type areas and heat transfer surfaces appear to be the requirements for the onset of rapid corrosion. Under conditions where coolant impurities do not concentrate the corrosion rates are low, easily measured and can be accounted for by allowances in the design of the steam generator. Rapid corrosion conditions cannot be designed for and must be suppressed. The condition of the surfaces when rapid corrosion develops must be markedly different from those during normal operation and these changes should be observable using electrochemical techniques. This background formed the basis of a design of a corrosion monitoring device, work on which was initiated at BNL. The basic principles of the technique are described. The object of the work is to develop a corrosion monitoring device which can be operated with PWR steam generator secondary coolant feed water

  10. Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vittorio, Luca; Drabarek, Elizabeth; Chronis, Harriet; Griffith, Christopher S

    2004-07-01

    It has previously been demonstrated that immobilization of Cs{sup +} and/or Sr{sup 2+} sorbed on hexagonal tungsten oxide bronze (HTB) adsorbent materials can be achieved by heating the materials in air at temperatures in the range 500 - 1300 deg C. Highly crystalline powdered HTB materials formed by heating at 800 deg C show leach characteristics comparable to Cs-containing hot-pressed hollandites in the pH range from 0 to 12. As a very harsh leaching test, and also to model in a basic manner, leaching in the presence of canister corrosion products in oxidising environments, leaching of the bronzoid phases has been undertaken in Fe(NO{sub 3}){sub 3} solutions of increasing concentration. This is done in comparison with Cs -hollandite materials in order to compare the leaching characteristics of these two materials under such conditions. Both the Cs-loaded bronze and hollandite materials leach severely in Fe(NO{sub 3}){sub 3} losing virtually all of the immobilized Cs in a period of four days at 150 deg C. Total release of Cs and conversion of hollandite to titanium and iron titanium oxides begins to be observed at relatively low concentrations and is virtually complete after four days reaction in 0.5 mol/L Fe(NO{sub 3}){sub 3}. In the case of the bronze, all of the Cs is also extracted but the HTB structure is preserved. The reaction presumably involves an ion-exchange mechanism and iron oxide with a spinel structure is also observed at high Fe concentrations. (authors)

  11. Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions

    International Nuclear Information System (INIS)

    Vittorio, Luca; Drabarek, Elizabeth; Chronis, Harriet; Griffith, Christopher S.

    2004-01-01

    It has previously been demonstrated that immobilization of Cs + and/or Sr 2+ sorbed on hexagonal tungsten oxide bronze (HTB) adsorbent materials can be achieved by heating the materials in air at temperatures in the range 500 - 1300 deg C. Highly crystalline powdered HTB materials formed by heating at 800 deg C show leach characteristics comparable to Cs-containing hot-pressed hollandites in the pH range from 0 to 12. As a very harsh leaching test, and also to model in a basic manner, leaching in the presence of canister corrosion products in oxidising environments, leaching of the bronzoid phases has been undertaken in Fe(NO 3 ) 3 solutions of increasing concentration. This is done in comparison with Cs -hollandite materials in order to compare the leaching characteristics of these two materials under such conditions. Both the Cs-loaded bronze and hollandite materials leach severely in Fe(NO 3 ) 3 losing virtually all of the immobilized Cs in a period of four days at 150 deg C. Total release of Cs and conversion of hollandite to titanium and iron titanium oxides begins to be observed at relatively low concentrations and is virtually complete after four days reaction in 0.5 mol/L Fe(NO 3 ) 3 . In the case of the bronze, all of the Cs is also extracted but the HTB structure is preserved. The reaction presumably involves an ion-exchange mechanism and iron oxide with a spinel structure is also observed at high Fe concentrations. (authors)

  12. RESEARCH OF FRUIT CONSERVES’ CORROSIVE AGGRESSIVENESS

    Directory of Open Access Journals (Sweden)

    I. Kuznecova

    2017-10-01

    Full Text Available Corrosion of metal canning containers is one of the obstacles in spreading its application for packing of food. Particularly aggressive to the metal container is fruit canned medium, containing organic acids.The basic material for the production of metal canning container is white tinplate. The main advantage of white tinplate is the tin compounds are harmless to human organism. For this reason, a white badge is used widely, usually used for production of canning containers, packaging beverages. Despite the fact that recently often used containers made of aluminum badge (foil, the basic material for manufacturing metal canning containers is steel white tinplate.Now applied for coating paints and varnishes do not provide anti-corrosion protection of inner surface of metal containers during storage. Preserving of canned fruit quality in metal containers is largely defined corrosion resistance of the containers. This is due to the fact that the metal transition to canned fruit in due courses of corrosion processes is lowering the nutritional value and deterioration taste of the product, and while allocation of hydrogen is accompanied by swelling and destruction of metal containers.We have investigated a number of anti-corrosion coatings based on Fe-Cr and Fe-Sn-Ti of their behavior in aggressive mediums canned fruit. For the purpose of modeling such mediums the solutions of most widespread organic acids were used. The research allowed conclude, that in surface solid solutions Fe-Sn-Ti increase the corrosion resistance of carbon steel in aqueous solutions of malic, citric and tartaric acids. This implies that the surface solid solutions’ formation can significantly improve corrosion resistance in aggressive canning mediums.

  13. Development of corrosion models to ensure reliable performance of nuclear power plants

    International Nuclear Information System (INIS)

    Kritzky, V.G.; Stjazhkin, P.S.

    1993-01-01

    The safety and reliability of the coolant circuits in nuclear power plants depend much on corrosion and corrosion products transfer processes. Various empirical models have been developed which are applicable to particular sets of operational conditions. In our laboratory a corrosion model has been worked out, which is based on the thermodynamic properties of the compounds, participating in corrosion process and on the assumption, that the corrosion process is controlled by the solubilities of the corrosion products forming the surface oxide layer. The validity of the model has been verified by use of retrospective experimental data, which have been obtained for a series of structural materials such as e.g., carbon and stainless steels, Cu-, Al-, and Zr alloys. With regard for hydriding the model satisfactorily describes stress corrosion cracking process in water-salt environments. This report describes a model based on the thermodynamic properties of the compounds participating in the corrosion process, and on the assumption that the corrosion process is controlled by the solubilities of the corrosion products forming the surface oxide layer

  14. Corrosion of AA2024-T3 Part II: Co-operative corrosion

    International Nuclear Information System (INIS)

    Hughes, A.E.; Boag, A.; Glenn, A.M.; McCulloch, D.; Muster, T.H.; Ryan, C.; Luo, C.; Zhou, X.; Thompson, G.E.

    2011-01-01

    Research highlights: → Corrosion of AA2024 in 0.1 M NaCl was examined for immersion times up to 120 min. → Rings of corrosion products with H 2 evolution developed as early as 5 min after immersion. → The rings were distinct from corrosion around isolated intermetallics elsewhere on the surface. → Analyses of chloride containing sites (red) showed a significant level of IM particle clustering. → The number of neighbors was much higher at these sites than the average particle number density. - Abstract: Polished specimens of AA2024-T3 alloy were immersed for up to 120 min in 0.1 M NaCl. The development of corrosion was monitored using scanning electron microscopy with energy dispersive X-ray spectroscopy (EDXS) and particle induced X-ray emission spectroscopy (PIXE). Both techniques revealed the intermetallic (IM) particle distributions and attack sites as distinguished by detection of chloride species. The earliest stages of attack involved localized attack around isolated IM particles as reported in Part I. Additionally attack occurred on a larger scale developing rapidly with rings of corrosion product surrounding clusters of IM particles. There were significantly higher numbers of IM particles within the corrosion rings, indicating that local clustering played an important role in co-operative corrosion.

  15. The corrosion of depleted uranium in terrestrial and marine environments.

    Science.gov (United States)

    Toque, C; Milodowski, A E; Baker, A C

    2014-02-01

    Depleted Uranium alloyed with titanium is used in armour penetrating munitions that have been fired in a number of conflict zones and testing ranges including the UK ranges at Kirkcudbright and Eskmeals. The study presented here evaluates the corrosion of DU alloy cylinders in soil on these two UK ranges and in the adjacent marine environment of the Solway Firth. The estimated mean initial corrosion rates and times for complete corrosion range from 0.13 to 1.9 g cm(-2) y(-1) and 2.5-48 years respectively depending on the particular physical and geochemical environment. The marine environment at the experimental site was very turbulent. This may have caused the scouring of corrosion products and given rise to a different geochemical environment from that which could be easily duplicated in laboratory experiments. The rate of mass loss was found to vary through time in one soil environment and this is hypothesised to be due to pitting increasing the surface area, followed by a build up of corrosion products inhibiting further corrosion. This indicates that early time measurements of mass loss or corrosion rate may be poor indicators of late time corrosion behaviour, potentially giving rise to incorrect estimates of time to complete corrosion. The DU alloy placed in apparently the same geochemical environment, for the same period of time, can experience very different amounts of corrosion and mass loss, indicating that even small variations in the corrosion environment can have a significant effect. These effects are more significant than other experimental errors and variations in initial surface area. Copyright © 2013. Published by Elsevier Ltd.

  16. EFFECT OF THE HEAT AND SURFACE LASER TREATMENT ON THE CORROSION DEGRADATION OF THE Mg-Al ALLOYS

    Directory of Open Access Journals (Sweden)

    Leszek A. Dobrzański

    2011-09-01

    Full Text Available In this paper there is presented the corrosion behavior of the cast magnesium alloys as cast state, after heat and laser treatment. Pitting corrosion resistance of the analyzed alloys was carried out using the potentiodynamic electrochemical method (direct current, based on a anodic polarization curve. On the basis of the achieved anodic polarization curves, using the Tefel extrapolation method near to the corrosion potential, the quantitative data were determined, which describe the electrochemical corrosion process of the investigated alloys: value of the corrosion potential Ecorr (mV, polarization resistance RP (kohm.cm2, corrosion current density icorr (10-6A/cm2, corrosion rate Vcorr (mm/year as well the mass loss Vc (g/m2<.

  17. A countermeasure for external stress corrosion cracking in piping components by means of residual stress improvement on the outer surface

    International Nuclear Information System (INIS)

    Tanaka, Yasuhiro; Umemoto, Tadahiro

    1988-01-01

    Many techniques have been proposed as countermeasures for the External Stress Corrosion Cracking (ESCC) on austenitic stainless steel piping caused by sea salt particles. However, not one seems perfect. The method proposed here is an expansion of IHSI (Induction Heating Stress Improvement) which has been successfully implemented in many nuclear power plants as a remedy for Intergranular Stress Corrossion Cracking. The proposed method named EIHSI (External IHSI) can make the residual stress compressive on the outer surface of the piping components. In order to confirm the effectiveness of EIHSI, one series of tests were conducted on a weld joint between the pipe flange and the straight pipe. The measured residual stresses and also the results of the cracking test revealed that EIHSI is a superior method to suppress the ESCC. The outline of EIHSI and the verification tests are presented in this paper. (author)

  18. Corrosion behaviour and structure of the surface layer formed on austempered ductile iron in concentrated sulphuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Krawiec, H. [AGH University of Science and Technology, Department of Foundry Engineering, ul. Reymonta 23, 30-059 Cracow (Poland)]. E-mail: krawiec@uci.agh.edu.pl; Stypula, B. [AGH University of Science and Technology, Department of Foundry Engineering, ul. Reymonta 23, 30-059 Cracow (Poland); Stoch, J. [Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences (PAS), ul. Niezapominajek 8, 30-239 Cracow (Poland); Mikolajczyk, M. [Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences (PAS), ul. Niezapominajek 8, 30-239 Cracow (Poland)

    2006-03-15

    The aim of this paper is to investigate the structure of the surface layer formed on austempered ductile iron (ADI) after exposure to hot concentrated sulphuric acid at the open circuit potential value (OCP). The results derived from polarization measurements carried out in sulphuric acid at a temperature of 90 deg. C show that anodic dissolution of ADI is divided into three stages (corresponding to three anodic dissolution peaks). The structure of the layer formed on alloys at 90 deg. C at OCP was investigated using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). SEM analysis shows that the main elements of the surface layer are iron, silicon, oxygen, sulphur, and carbon. The binding energy recorded in individual bands indicates that the surface layer includes mainly SiO{sub 2} and FeOOH. The presence of sulphur at the lower oxidation state (S{sup 2-}) indicates that sulphuric acid undergoes reduction during this process. The corrosion resistance of these alloys is connected with the presence of SiO{sub 2} in the surface layer.

  19. Low Temperature Curing of Hydrogen Silsesquioxane Surface Coatings for Corrosion Protection of Aluminum

    DEFF Research Database (Denmark)

    Lampert, Felix; Jensen, Annemette Hindhede; Møller, Per

    2016-01-01

    Hydrogen Silsesquioxane (HSQ) has shown to be a promising precursor for corrosion protective glass coatings for metallic substrates due to the excellent barrier properties of the films, especially in the application of protective coatings for aluminum in the automotive industry where high chemical...... stability in alkaline environments is required. The coatings have been successfully applied to stainless steel substrates. However the traditional thermal curing of HSQ involves heating to elevated temperatures, which are beyond those applicable for most industrial applications of aluminum. In this study...... low temperature processes are tested and evaluated as possible alternatives to the traditional high temperature cure. Thin HSQ films are deposited onsilicon wafers to model the degree of curing induced by the low temperature methods in comparison to thermal curing.Furthermore, the coatings are applied...

  20. Novel Schiff-base molecules as efficient corrosion inhibitors for mild steel surface in 1 M HCl medium: experimental and theoretical approach.

    Science.gov (United States)

    Saha, Sourav Kr; Dutta, Alokdut; Ghosh, Pritam; Sukul, Dipankar; Banerjee, Priyabrata

    2016-07-21

    In order to evaluate the effect of the functional group present in the ligand backbone towards corrosion inhibition performances, three Schiff-base molecules namely, (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)pyridine (L(1)), (E)-4-(2-(pyridin-4-ylmethylene)hydrazinyl)benzonitrile (L(2)) and (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)phenol (L(3)) were synthesized and used as corrosion inhibitors on mild steel in 1 M HCl medium. The corrosion inhibition effectiveness of the studied inhibitors was investigated by weight loss and several sophisticated analytical tools such as potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Experimentally obtained results revealed that corrosion inhibition efficiencies followed the sequence: L(3) > L(1) > L(2). Electrochemical findings showed that inhibitors impart high resistance towards charge transfer across the metal-electrolyte interface and behaved as mixed type inhibitors. Scanning electron microscopy (SEM) was also employed to examine the protective film formed on the mild steel surface. The adsorption as well as inhibition ability of the inhibitor molecules on the mild steel surface was investigated by quantum chemical calculation and molecular dynamic (MD) simulation. In quantum chemical calculations, geometry optimized structures of the Schiff-base inhibitors, electron density distribution in HOMO and LUMO and Fukui indices of each atom were employed for their possible mode of interaction with the mild steel surfaces. MD simulations revealed that all the inhibitors molecules adsorbed in parallel orientation with respect to the Fe(110) surface.

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