Pub Date : 2001-02-01DOI: 10.1179/000705901101501596
E. Garcia, J. Uruchurtu, Juan Genesca
Abstract The electrochemical behaviour of copper in sea water includes the formation of passive products on the surface and their breakdown by pit nucleation and growth. The aim of the present paper is to report this behaviour, paying particular attention to the electrochemical current noise response. On the basis of this information a possible pitting mechanism is proposed.
{"title":"Electrochemical ac and dc response of copper in sea water at different anodic potentials","authors":"E. Garcia, J. Uruchurtu, Juan Genesca","doi":"10.1179/000705901101501596","DOIUrl":"https://doi.org/10.1179/000705901101501596","url":null,"abstract":"Abstract The electrochemical behaviour of copper in sea water includes the formation of passive products on the surface and their breakdown by pit nucleation and growth. The aim of the present paper is to report this behaviour, paying particular attention to the electrochemical current noise response. On the basis of this information a possible pitting mechanism is proposed.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"19 1","pages":"151 - 156"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81795661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501433
D. Law, S. Millard, J. Bungey
Abstract This paper reports the results of galvanostatic pulse transient response experiments to determine the corrosion parameters associated with actively corroding reinforcing steel in concrete. Galvanostatic pulse measurements have been conducted on a number of short 100 mm sections of steel reinforcing bar embedded in chloride contaminated concrete. The duration of the applied galvanostatic pulse was 90 s and the lateral distance of the point of measurement from the bar varied from zero to 400 mm. All of the bars monitored were conditioned so that they were actively corroding at different rates. Analysis of the galvanostatic pulse transient response has enabled the separate components that make up the measured transients to be isolated and evaluated. These components display a range of resistivities and capacitances, dependent on the corrosion condition of the reinforcing steel, which may be attributed to the corrosion process, to effects within the concrete cover, or to film effects on the surface of the concrete. Other investigators using this technique have evaluated the corrosion rate by summation of the separate corrosion components, i.e. simply summing all of the resistance values to obtain an aggregated corrosion resistance. However, it is possible that not all resistances identified are associated with the loss of steel from the surface of the reinforcement. Significant variations in corrosion rates have been observed dependent on the assignment of the separate components to either corrosion or to other processes. The data indicate that it is not feasible to assign the component based solely on the capacitance. An inappropriate selection of measurement time or equilibrium time may result in part of the resistance associated with the corrosion process being left out or an additional resistance not controlling the rate of corrosion being included.
{"title":"Use of galvanostatic pulse measurements on active reinforcing steel in concrete to assess corrosion rates","authors":"D. Law, S. Millard, J. Bungey","doi":"10.1179/000705901101501433","DOIUrl":"https://doi.org/10.1179/000705901101501433","url":null,"abstract":"Abstract This paper reports the results of galvanostatic pulse transient response experiments to determine the corrosion parameters associated with actively corroding reinforcing steel in concrete. Galvanostatic pulse measurements have been conducted on a number of short 100 mm sections of steel reinforcing bar embedded in chloride contaminated concrete. The duration of the applied galvanostatic pulse was 90 s and the lateral distance of the point of measurement from the bar varied from zero to 400 mm. All of the bars monitored were conditioned so that they were actively corroding at different rates. Analysis of the galvanostatic pulse transient response has enabled the separate components that make up the measured transients to be isolated and evaluated. These components display a range of resistivities and capacitances, dependent on the corrosion condition of the reinforcing steel, which may be attributed to the corrosion process, to effects within the concrete cover, or to film effects on the surface of the concrete. Other investigators using this technique have evaluated the corrosion rate by summation of the separate corrosion components, i.e. simply summing all of the resistance values to obtain an aggregated corrosion resistance. However, it is possible that not all resistances identified are associated with the loss of steel from the surface of the reinforcement. Significant variations in corrosion rates have been observed dependent on the assignment of the separate components to either corrosion or to other processes. The data indicate that it is not feasible to assign the component based solely on the capacitance. An inappropriate selection of measurement time or equilibrium time may result in part of the resistance associated with the corrosion process being left out or an additional resistance not controlling the rate of corrosion being included.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"5 1","pages":"75 - 80"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87370744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501424
H. Da, K. Gowers, W. Dongwei, L. Dawang, Z. Zhuo, S. Millard
Abstract Techniques have been assessed for estimating corrosion in reinforced concrete structures in chemical environments, and measurements have been carried out in the laboratory at the University of Liverpool and at several different chemical factory sites in China and the UK. If it is possible to make a direct contact to the steel reinforcement, then linear polarisation resistance (LPR) measurement is the most suitable technique to employ. Where it is not possible to make contact with the reinforcement, it has been found that concrete resistivity measurement is a better technique in chemical environments for estimating corrosion than potential measurement or mapping.
{"title":"Corrosion assessment of reinforced concrete structures in corrosive environments in Chinese chemical industry","authors":"H. Da, K. Gowers, W. Dongwei, L. Dawang, Z. Zhuo, S. Millard","doi":"10.1179/000705901101501424","DOIUrl":"https://doi.org/10.1179/000705901101501424","url":null,"abstract":"Abstract Techniques have been assessed for estimating corrosion in reinforced concrete structures in chemical environments, and measurements have been carried out in the laboratory at the University of Liverpool and at several different chemical factory sites in China and the UK. If it is possible to make a direct contact to the steel reinforcement, then linear polarisation resistance (LPR) measurement is the most suitable technique to employ. Where it is not possible to make contact with the reinforcement, it has been found that concrete resistivity measurement is a better technique in chemical environments for estimating corrosion than potential measurement or mapping.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"23 1","pages":"70 - 74"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76031919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501488
B. Bozzini, P. Cavallotti, G. Parisi
Abstract The present paper reports on electrodeposition, characterisation, corrosion, and erosion–corrosion of Ni–P and Ni–P/B4 C layers on a brass substrate. Alloys with 5%P and 8 vol.-% micrometric B4 C were prepared from a lactate bath at pH 4 containing H3 PO3 . The following deposit properties were measured and related to corrosion behaviour: composition (EDS, XPS), crystalline structure (XRD), morphology (inplane and cross-sectional SEM), and mechanical properties. The immersion and anodic behaviour of pure matrix and composite samples was studied in slightly acidic, aerated chloride solutions. The presence of B4 C particles is correlated with higher crystallinity of the matrix at a given P content. Anodic linear sweep voltammograms show more noble breakdown potentials and lower plateau current densities for the composites. The pit-arresting effect of particle addition was assessed. More noble corrosion potentials and much lower mass losses, pitting, and crevice formation were observed under erosion–corrosion conditions with normal impact of a sand containing slurry.
{"title":"Corrosion and erosion-corrosion of electrodeposited Ni–P/B4 C composites","authors":"B. Bozzini, P. Cavallotti, G. Parisi","doi":"10.1179/000705901101501488","DOIUrl":"https://doi.org/10.1179/000705901101501488","url":null,"abstract":"Abstract The present paper reports on electrodeposition, characterisation, corrosion, and erosion–corrosion of Ni–P and Ni–P/B4 C layers on a brass substrate. Alloys with 5%P and 8 vol.-% micrometric B4 C were prepared from a lactate bath at pH 4 containing H3 PO3 . The following deposit properties were measured and related to corrosion behaviour: composition (EDS, XPS), crystalline structure (XRD), morphology (inplane and cross-sectional SEM), and mechanical properties. The immersion and anodic behaviour of pure matrix and composite samples was studied in slightly acidic, aerated chloride solutions. The presence of B4 C particles is correlated with higher crystallinity of the matrix at a given P content. Anodic linear sweep voltammograms show more noble breakdown potentials and lower plateau current densities for the composites. The pit-arresting effect of particle addition was assessed. More noble corrosion potentials and much lower mass losses, pitting, and crevice formation were observed under erosion–corrosion conditions with normal impact of a sand containing slurry.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"20 1","pages":"49 - 55"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89745532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501505
A. Zaky
Abstract The electrochemical behaviour of Cu–20 wt-%Ag and Cu–80 wt-%Ag alloys was studied in aerated Na2 CO3 solutions using cyclic voltammetry, potentiodynamic anodic polarisation, and current transient techniques. The microstructure of the compounds formed on the surface of the alloy during the anodic potential sweep was obtained using XRD analysis. The dissolution behaviour of either of the two constituents from the alloys resembles that of the pure state. The galvanic coupling effect enhances the dissolution of the less noble metal, copper, on alloying with silver. The anodic sweep potential exhibited seven anodic peaks A1 , A2 , A3 , A4 , A5 , A6 , and A7 prior to the oxygen evolution reaction. These peaks are assigned to the formation of Cu2O, Cu(OH)2 , CuO, Ag2O, Ag2 CO3 , and Ag2O2 respectively. Potentiostatic current/time transients showed that the formation of Cu2O, CuO, Ag2O, and Ag2 CO3 layers involves a nucleation and growth mechanism under diffusion control.
{"title":"Electrochemical behaviour of copper–silver alloys in sodium carbonate aqueous solution","authors":"A. Zaky","doi":"10.1179/000705901101501505","DOIUrl":"https://doi.org/10.1179/000705901101501505","url":null,"abstract":"Abstract The electrochemical behaviour of Cu–20 wt-%Ag and Cu–80 wt-%Ag alloys was studied in aerated Na2 CO3 solutions using cyclic voltammetry, potentiodynamic anodic polarisation, and current transient techniques. The microstructure of the compounds formed on the surface of the alloy during the anodic potential sweep was obtained using XRD analysis. The dissolution behaviour of either of the two constituents from the alloys resembles that of the pure state. The galvanic coupling effect enhances the dissolution of the less noble metal, copper, on alloying with silver. The anodic sweep potential exhibited seven anodic peaks A1 , A2 , A3 , A4 , A5 , A6 , and A7 prior to the oxygen evolution reaction. These peaks are assigned to the formation of Cu2O, Cu(OH)2 , CuO, Ag2O, Ag2 CO3 , and Ag2O2 respectively. Potentiostatic current/time transients showed that the formation of Cu2O, CuO, Ag2O, and Ag2 CO3 layers involves a nucleation and growth mechanism under diffusion control.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"03 1","pages":"59 - 64"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88333592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501460
S. Ningshen, U. Mudali, R. Dayal
Abstract The influence of electrolyte composition and temperature on the pitting corrosion resistance of nitrogen bearing (0·015, 0·198, and 0·56%N) type 316L stainless steels has been investi gated. Anodic polarisation curves were determined in neutral chloride solution at room temperature and at elevated temperatures of 308, 318, and 333 K. Similar polarisation studies were also conducted at room temperature in 1N H2 SO4 and in an acidic chloride solution containing 1N H2 SO4 and 0·5M NaCl. The results show that the critical pitting potential Epp in neutral chloride and acidic chloride media increases as the nitrogen content of the alloy increases, indicating that resistance to pitting increases with the addition of nitrogen. However, in 1N H2 SO4 solution, the transpassive potential was almost independent of the nitrogen content. As the temperature of the neutral chloride medium was increased, the Epp values decreased, irrespective of nitrogen content. The decrease in Epp is attributed not only to the temperature induced modification of the passive oxide film but also to chloride induced activity at the passive film/solution interface. Nevertheless, the alloy con taining 0·56% nitrogen showed better resistance to pitting at 333 K than did the alloy with 0·015% nitrogen at room temperature. SEM examination of the pitted specimens showed clear evidence of pitting for the alloy with 0·015% nitrogen, but insignificant pitting attack for the alloy with 0·56%N. However, the alloy with 0·56%N displayed some pitting attack when the experiments were conducted at 333 K.
{"title":"Electrolyte and temperature effects on pitting corrosion of type 316LN stainless steels","authors":"S. Ningshen, U. Mudali, R. Dayal","doi":"10.1179/000705901101501460","DOIUrl":"https://doi.org/10.1179/000705901101501460","url":null,"abstract":"Abstract The influence of electrolyte composition and temperature on the pitting corrosion resistance of nitrogen bearing (0·015, 0·198, and 0·56%N) type 316L stainless steels has been investi gated. Anodic polarisation curves were determined in neutral chloride solution at room temperature and at elevated temperatures of 308, 318, and 333 K. Similar polarisation studies were also conducted at room temperature in 1N H2 SO4 and in an acidic chloride solution containing 1N H2 SO4 and 0·5M NaCl. The results show that the critical pitting potential Epp in neutral chloride and acidic chloride media increases as the nitrogen content of the alloy increases, indicating that resistance to pitting increases with the addition of nitrogen. However, in 1N H2 SO4 solution, the transpassive potential was almost independent of the nitrogen content. As the temperature of the neutral chloride medium was increased, the Epp values decreased, irrespective of nitrogen content. The decrease in Epp is attributed not only to the temperature induced modification of the passive oxide film but also to chloride induced activity at the passive film/solution interface. Nevertheless, the alloy con taining 0·56% nitrogen showed better resistance to pitting at 333 K than did the alloy with 0·015% nitrogen at room temperature. SEM examination of the pitted specimens showed clear evidence of pitting for the alloy with 0·015% nitrogen, but insignificant pitting attack for the alloy with 0·56%N. However, the alloy with 0·56%N displayed some pitting attack when the experiments were conducted at 333 K.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"100 1","pages":"36 - 41"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75092370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501479
H. McMurray, S. Powell, D. Worsley
Abstract Corrosion at the exposed cut edges of organically coated galvanised steel (OCS) used for construction is one of the primary failure mechanisms. The scanning vibrating electrode technique (SVET) has shown that corrosion is driven by differential aeration when materials are coated with organic over-layers of widely differing thickness and primer layers are pigmented with strontium chromate (SrCrO4 ). In such materials anodic activity is localised on the zinc layer proximal to the thicker organic coating with cathodic activity focused on the steel and zinc proximal to the thinner organic coating. To overcome the localisation of anodic and cathodic activity we have prepared novel OCS panels in which cathodic inhibitor primer systems based on rare earth metal cation exchanged pigments have been employed beneath the thinner organic coating and conventional strontium chromate anodic inhibitor systems beneath the thicker organic coating. The differential inhibitor loading overrides the effects of differential aeration and leads to significant passivation within the 24 h immersion period.
{"title":"Mechanistic changes in cut edge corrosion induced by variation of inhibitor pigmentation in organically coated galvanised steel","authors":"H. McMurray, S. Powell, D. Worsley","doi":"10.1179/000705901101501479","DOIUrl":"https://doi.org/10.1179/000705901101501479","url":null,"abstract":"Abstract Corrosion at the exposed cut edges of organically coated galvanised steel (OCS) used for construction is one of the primary failure mechanisms. The scanning vibrating electrode technique (SVET) has shown that corrosion is driven by differential aeration when materials are coated with organic over-layers of widely differing thickness and primer layers are pigmented with strontium chromate (SrCrO4 ). In such materials anodic activity is localised on the zinc layer proximal to the thicker organic coating with cathodic activity focused on the steel and zinc proximal to the thinner organic coating. To overcome the localisation of anodic and cathodic activity we have prepared novel OCS panels in which cathodic inhibitor primer systems based on rare earth metal cation exchanged pigments have been employed beneath the thinner organic coating and conventional strontium chromate anodic inhibitor systems beneath the thicker organic coating. The differential inhibitor loading overrides the effects of differential aeration and leads to significant passivation within the 24 h immersion period.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"3 1","pages":"42 - 48"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77470260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501415
G. Gabetta, S. Di Liberto, A. Bennardo, N. Mancini
Abstract Transgranular stress corrosion cracking (TGSCC) has been observed in buried pipelines where the metal is in contact with a dilute solution under a disbonded coating. It is already known that such cracking involves the evolution and permeation of hydrogen at the crack tip, as previously observed in nuclear pressure vessel steels and other low alloy steels under variable loading. This cracking mechanism is much more influenced by loading conditions (crack tip strain rate) than by the solution chemistry. With reference to pipeline steels, several authors claim that it is difficult to reproduce in the laboratory the actual cracking morphology observed in the field. The present paper presents and discusses the results of tests where the fracture surface appearance observed in pipes taken from service has been reproduced. In this work, attention has been focused on mechanical factors rather than chemical parameters. It is proposed that the term low pH stress corrosion cracking, normally used to define the cracking phenomenon, is inappropriate and can be misleading. If greater attention is paid to strain rate and loading parameters, TGSCC in buried pipelines can be reproduced in laboratory tests (with no major influence of solution pH) and the phenomenon can be better described. Through a comparison with data in the literature data describing the behaviour of landslides, the hypothesis that crack growth occurs only during short intervals, followed by long periods where only generalised corrosion takes place, is proposed. This is consistent with features observed on the fracture surfaces of pipelines that failed in service.
{"title":"Strain rate induced stress corrosion cracking in buried pipelines","authors":"G. Gabetta, S. Di Liberto, A. Bennardo, N. Mancini","doi":"10.1179/000705901101501415","DOIUrl":"https://doi.org/10.1179/000705901101501415","url":null,"abstract":"Abstract Transgranular stress corrosion cracking (TGSCC) has been observed in buried pipelines where the metal is in contact with a dilute solution under a disbonded coating. It is already known that such cracking involves the evolution and permeation of hydrogen at the crack tip, as previously observed in nuclear pressure vessel steels and other low alloy steels under variable loading. This cracking mechanism is much more influenced by loading conditions (crack tip strain rate) than by the solution chemistry. With reference to pipeline steels, several authors claim that it is difficult to reproduce in the laboratory the actual cracking morphology observed in the field. The present paper presents and discusses the results of tests where the fracture surface appearance observed in pipes taken from service has been reproduced. In this work, attention has been focused on mechanical factors rather than chemical parameters. It is proposed that the term low pH stress corrosion cracking, normally used to define the cracking phenomenon, is inappropriate and can be misleading. If greater attention is paid to strain rate and loading parameters, TGSCC in buried pipelines can be reproduced in laboratory tests (with no major influence of solution pH) and the phenomenon can be better described. Through a comparison with data in the literature data describing the behaviour of landslides, the hypothesis that crack growth occurs only during short intervals, followed by long periods where only generalised corrosion takes place, is proposed. This is consistent with features observed on the fracture surfaces of pipelines that failed in service.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"30 1","pages":"24 - 28"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88588562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501451
Z. Qin, P. Norton, J. Luo
Abstract The amount of oxide and the thickness of passive films on AISI 310 stainless steel pre-charged with hydrogen were found to be smaller than those on the uncharged samples. It is believed that one of the causes of the higher susceptibility to corrosion of stainless steels containing hydrogen is that the dissolved hydrogen degrades the passive film formed on the stainless steel. Evidence has also been obtained that passivity is associated with the oxides at the inner region of the passive film.
{"title":"Effects of hydrogen on formation of passive films on AISI 310 stainless steel","authors":"Z. Qin, P. Norton, J. Luo","doi":"10.1179/000705901101501451","DOIUrl":"https://doi.org/10.1179/000705901101501451","url":null,"abstract":"Abstract The amount of oxide and the thickness of passive films on AISI 310 stainless steel pre-charged with hydrogen were found to be smaller than those on the uncharged samples. It is believed that one of the causes of the higher susceptibility to corrosion of stainless steels containing hydrogen is that the dissolved hydrogen degrades the passive film formed on the stainless steel. Evidence has also been obtained that passivity is associated with the oxides at the inner region of the passive film.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"18 1","pages":"33 - 35"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87612278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1179/000705901101501497
Y. Li, H. Wang, B. Hou, F. Feng, X. Wei
Abstract A low concentration chromate passivation treatment has been successfully applied to a new type of hot dipped Zn2 5Al alloy coating, and the corrosion resistance of the chromate passive film has been assessed using the copper accelerated acetic salt spray (CASS) test, electrochemical measurements, and sea water immersion testing. The results showed that the corrosion resistance of the Zn2 5Al alloy coating was significantly better after the chromate passivation treatment. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) analyses showed that the composition (at.-%) of the low concentration chromate passive film was: 5·5S–3·4Na–11·8C–7·9Ti–41·6O–1 3·7Cr–16·0Zn. Aluminium was not found in the film, which is attributed to the dissolution behaviour of the Zn2 5Al alloy coating in acidic chromate solution.
{"title":"Chromate passivation of hot dipped Zn25Al alloy coatings","authors":"Y. Li, H. Wang, B. Hou, F. Feng, X. Wei","doi":"10.1179/000705901101501497","DOIUrl":"https://doi.org/10.1179/000705901101501497","url":null,"abstract":"Abstract A low concentration chromate passivation treatment has been successfully applied to a new type of hot dipped Zn2 5Al alloy coating, and the corrosion resistance of the chromate passive film has been assessed using the copper accelerated acetic salt spray (CASS) test, electrochemical measurements, and sea water immersion testing. The results showed that the corrosion resistance of the Zn2 5Al alloy coating was significantly better after the chromate passivation treatment. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) analyses showed that the composition (at.-%) of the low concentration chromate passive film was: 5·5S–3·4Na–11·8C–7·9Ti–41·6O–1 3·7Cr–16·0Zn. Aluminium was not found in the film, which is attributed to the dissolution behaviour of the Zn2 5Al alloy coating in acidic chromate solution.","PeriodicalId":9349,"journal":{"name":"British Corrosion Journal","volume":"20 1-2 1","pages":"56 - 58"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78168471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：