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Corrosion–erosion wear of N80 carbon steel and 316L stainless steel in saline–quartz slurry / H. Li in Materials and corrosion, Vol. 62 N° 11 (Novembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 11 (Novembre 2011) . - pp. 1051–1060 Titre : Corrosion–erosion wear of N80 carbon steel and 316L stainless steel in saline–quartz slurry Type de document : texte imprimé Auteurs : H. Li, Auteur ; Y. H. Liu, Auteur ; Y. Z. Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 1051–1060 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : 3D  ultra-deep  microscopy  316lL  N80  SEM Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The corrosion–erosion behavior of carbon steel N80 and austenitic stainless 316L are investigated both in water–quartz slurry and saline–quartz slurry. The sample mass losses after each test and the roughness of sample surfaces are measured and a potentiostat is used to gain the polarization curves. The worn surfaces and the corrosion–erosion wear mechanism are analyzed using scanning electron microscopy (SEM) and 3D ultra-deep microscopy. Results show that the Ra for N80 is much larger than 316L under the same experimental condition, and the weight losses of the two materials show a similar trend except for tests with higher impact angles. The lowest Rsm for 316L matches along with the highest Rsm for N80 at the 45 min testing time. According to the obtained results of the corrosion–erosion mechanism of the N80 and 316L based on the SEM and 3D ultra-deep microscopy, the conclusion is drawn that the ploughing and crashing are the major mechanisms for the forming of surface morphologies and the mass removal. Different impact angles and materials affect the corrosion–erosion process to some extent. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106086/abstract [article] Corrosion–erosion wear of N80 carbon steel and 316L stainless steel in saline–quartz slurry [texte imprimé] / H. Li, Auteur ; Y. H. Liu, Auteur ; Y. Z. Wang, Auteur . - 2012 . - pp. 1051–1060. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 11 (Novembre 2011) . - pp. 1051–1060 Mots-clés : 3D  ultra-deep  microscopy  316lL  N80  SEM Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The corrosion–erosion behavior of carbon steel N80 and austenitic stainless 316L are investigated both in water–quartz slurry and saline–quartz slurry. The sample mass losses after each test and the roughness of sample surfaces are measured and a potentiostat is used to gain the polarization curves. The worn surfaces and the corrosion–erosion wear mechanism are analyzed using scanning electron microscopy (SEM) and 3D ultra-deep microscopy. Results show that the Ra for N80 is much larger than 316L under the same experimental condition, and the weight losses of the two materials show a similar trend except for tests with higher impact angles. The lowest Rsm for 316L matches along with the highest Rsm for N80 at the 45 min testing time. According to the obtained results of the corrosion–erosion mechanism of the N80 and 316L based on the SEM and 3D ultra-deep microscopy, the conclusion is drawn that the ploughing and crashing are the major mechanisms for the forming of surface morphologies and the mass removal. Different impact angles and materials affect the corrosion–erosion process to some extent. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106086/abstract

Effect of TiO2 nanoparticles on the microstructure and corrosion behavior of MAO coatings on magnesium alloy / Y. L. Song in Materials and corrosion, Vol. 63 N° 9 (Septembre 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 9 (Septembre 2012) . - pp. 813–818 Titre : Effect of TiO2 nanoparticles on the microstructure and corrosion behavior of MAO coatings on magnesium alloy Type de document : texte imprimé Auteurs : Y. L. Song, Auteur ; X. Y. Sun, Auteur ; Y. H. Liu, Auteur Année de publication : 2013 Article en page(s) : pp. 813–818 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Corrosion  behavior;  micro-arc  oxidation;  microstructure;  TiO2  nanoparticles Résumé : The microstructure and corrosion behavior of the micro-arc oxidation (MAO) coatings modified by TiO2 on AZ91 magnesium alloys were investigated by SEM, EDS, XRD, electrochemical analysis and drop test, respectively. The modified MAO coatings were consisted of not only MgAl2O4 and MgO, which usually could be found in MAO coatings on the AZ91 alloys, but also a small quantity of Ti. With increasing the contents of TiO2 nanoparticles from 0 to 4.8 g/L in the electrolyte, the coatings thickness increased from 19 to 24 µm, and the color of the MAO coating changed from light gray to dark. The addition of TiO2 could effectively decrease the number of the pores and improve the density of the coatings. The corrosion potential of the modified coatings positively shifted about 180 mV and the corrosion current density declined and the drop time increased. The mechanism of the corrosion resistances of the modified coatings lay in the fact that TiO2 nanoparticles could increase the thickness and the density of the coatings on the AZ91 magnesium alloys. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106251/abstract [article] Effect of TiO2 nanoparticles on the microstructure and corrosion behavior of MAO coatings on magnesium alloy [texte imprimé] / Y. L. Song, Auteur ; X. Y. Sun, Auteur ; Y. H. Liu, Auteur . - 2013 . - pp. 813–818. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 9 (Septembre 2012) . - pp. 813–818 Mots-clés : Corrosion  behavior;  micro-arc  oxidation;  microstructure;  TiO2  nanoparticles Résumé : The microstructure and corrosion behavior of the micro-arc oxidation (MAO) coatings modified by TiO2 on AZ91 magnesium alloys were investigated by SEM, EDS, XRD, electrochemical analysis and drop test, respectively. The modified MAO coatings were consisted of not only MgAl2O4 and MgO, which usually could be found in MAO coatings on the AZ91 alloys, but also a small quantity of Ti. With increasing the contents of TiO2 nanoparticles from 0 to 4.8 g/L in the electrolyte, the coatings thickness increased from 19 to 24 µm, and the color of the MAO coating changed from light gray to dark. The addition of TiO2 could effectively decrease the number of the pores and improve the density of the coatings. The corrosion potential of the modified coatings positively shifted about 180 mV and the corrosion current density declined and the drop time increased. The mechanism of the corrosion resistances of the modified coatings lay in the fact that TiO2 nanoparticles could increase the thickness and the density of the coatings on the AZ91 magnesium alloys. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106251/abstract

A mathematical model for prediction of time from corrosion initiation to corrosion cracking in RC structures / G. Lin in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 920–928 Titre : A mathematical model for prediction of time from corrosion initiation to corrosion cracking in RC structures Type de document : texte imprimé Auteurs : G. Lin, Auteur ; Y. H. Liu, Auteur ; Z. H. Xiang, Auteur Année de publication : 2011 Article en page(s) : pp. 920–928 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Dynamic  corrosion  rate  model;  parametric  analysis;  reinforcement  corrosion;  rust  expansion;  time  to  cover  cracking Résumé : Prediction of time from corrosion initiation to corrosion cracking is a crucial factor in evaluating concrete structures' durability and integrity deteriorated by reinforcement corrosion. This paper presents a mathematical model to predict the time from corrosion initiation to corrosion cracking. A dynamic corrosion rate model based on Bulter–Volmer kinetics and a rust expansion model based on Faraday's law are developed. An analytical model is developed to demonstrate the mechanical consequences of rust buildup around the rebar. The time to corrosion cracking is found to be a function of surrounding concrete material properties, chemical composition of rust, ratio of concrete cover thickness to rebar diameter, and corrosion current density. Comparisons with available experimental results are conducted to show the accuracy and reliability of the present model. Further parametric analysis is carried out to show the influences of various parameters included in the model on the time to corrosion cracking. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905438/abstract [article] A mathematical model for prediction of time from corrosion initiation to corrosion cracking in RC structures [texte imprimé] / G. Lin, Auteur ; Y. H. Liu, Auteur ; Z. H. Xiang, Auteur . - 2011 . - pp. 920–928. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 920–928 Mots-clés : Dynamic  corrosion  rate  model;  parametric  analysis;  reinforcement  corrosion;  rust  expansion;  time  to  cover  cracking Résumé : Prediction of time from corrosion initiation to corrosion cracking is a crucial factor in evaluating concrete structures' durability and integrity deteriorated by reinforcement corrosion. This paper presents a mathematical model to predict the time from corrosion initiation to corrosion cracking. A dynamic corrosion rate model based on Bulter–Volmer kinetics and a rust expansion model based on Faraday's law are developed. An analytical model is developed to demonstrate the mechanical consequences of rust buildup around the rebar. The time to corrosion cracking is found to be a function of surrounding concrete material properties, chemical composition of rust, ratio of concrete cover thickness to rebar diameter, and corrosion current density. Comparisons with available experimental results are conducted to show the accuracy and reliability of the present model. Further parametric analysis is carried out to show the influences of various parameters included in the model on the time to corrosion cracking. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905438/abstract

Study on the effect of corrosion on the tensile behavior of an AZ91 alloy / Q. Wang in Materials and corrosion, Vol. 61 N° 3 (Mars 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 3 (Mars 2010) . - pp. 222–228 Titre : Study on the effect of corrosion on the tensile behavior of an AZ91 alloy Type de document : texte imprimé Auteurs : Q. Wang, Auteur ; Y. H. Liu, Auteur ; L. N. Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 222–228 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : AZ91  magnesium  alloy;  corrosion  residual  strength;  estimation;  fracture Résumé : The effect of corrosion on the tensile behavior of an as-cast AZ91 alloy was investigated via systematical experiments. The corrosion residual strength of the AZ91 magnesium alloy is approximately negative linear dependent on the extreme depth of corrosion pit, which was quantitatively obtained by the corrosion morphology analysis and the statistic analysis. Experimental results reveal that the corrosion residual strength of the AZ91 magnesium alloy dropped quickly in the first 40 h due to the initiation and development of the corrosion pit and subsequently decreased slowly as a result of the development of the corrosion pit encountered the β phase. The β phase at the grain boundary of the primary α phase acts as an effective barrier to prevent the development of the corrosion pit into the alloy matrix and thus remarkably prevents the drop of the corrosion residual strength. In general, the variation of the corrosion residual strength exhibits an exponential decay regulation within the testing time. Consequently, the empirical prediction of the corrosion residual strength was given with regard to the variation of the corrosion residual strength varied with the immersion time. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905317/abstract [article] Study on the effect of corrosion on the tensile behavior of an AZ91 alloy [texte imprimé] / Q. Wang, Auteur ; Y. H. Liu, Auteur ; L. N. Zhang, Auteur . - 2010 . - pp. 222–228. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 3 (Mars 2010) . - pp. 222–228 Mots-clés : AZ91  magnesium  alloy;  corrosion  residual  strength;  estimation;  fracture Résumé : The effect of corrosion on the tensile behavior of an as-cast AZ91 alloy was investigated via systematical experiments. The corrosion residual strength of the AZ91 magnesium alloy is approximately negative linear dependent on the extreme depth of corrosion pit, which was quantitatively obtained by the corrosion morphology analysis and the statistic analysis. Experimental results reveal that the corrosion residual strength of the AZ91 magnesium alloy dropped quickly in the first 40 h due to the initiation and development of the corrosion pit and subsequently decreased slowly as a result of the development of the corrosion pit encountered the β phase. The β phase at the grain boundary of the primary α phase acts as an effective barrier to prevent the development of the corrosion pit into the alloy matrix and thus remarkably prevents the drop of the corrosion residual strength. In general, the variation of the corrosion residual strength exhibits an exponential decay regulation within the testing time. Consequently, the empirical prediction of the corrosion residual strength was given with regard to the variation of the corrosion residual strength varied with the immersion time. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905317/abstract

Susceptibility of 316L stainless steel to crevice corrosion in submersible solenoid valve / B. P. Cai in Materials and corrosion, Vol. 62 N° 8 (Août 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 8 (Août 2011) . - pp. 753-759 Titre : Susceptibility of 316L stainless steel to crevice corrosion in submersible solenoid valve Type de document : texte imprimé Auteurs : B. P. Cai, Auteur ; Y. H. Liu, Auteur ; X. J. Tian, Auteur Année de publication : 2011 Article en page(s) : pp. 753-759 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : AFM  Crevice  corrosion  SEM  Stainless  steel Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The susceptibility of 316L stainless steel to crevice corrosion was investigated by using immersion test and electrochemical test. Three kinds of crevices including 316L-to-polytetrafluoroethylene (PTFE) crevice, 316L-to-fluoroelastomeric (FKM) crevice and 316L-to-316L crevice were tested in artificial seawater at 50°C. The results indicate that 316L stainless steel specimen is the most susceptible to crevice corrosion when it is coupled to 316L stainless steel crevice former, while it is the least susceptible when it is coupled to FKM crevice former. It suggests that during submersible solenoid valve design, the crevice of metal-to-metal should be moderately large so that crevice corrosion can not initiate and propagate, and FKM O-ring rather than PTFE O-ring should be selected as obturating ring. The corroded surface morphology was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Three regions including passive region, active region and variable region can be observed on crevice corrosion sites. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005917/abstract [article] Susceptibility of 316L stainless steel to crevice corrosion in submersible solenoid valve [texte imprimé] / B. P. Cai, Auteur ; Y. H. Liu, Auteur ; X. J. Tian, Auteur . - 2011 . - pp. 753-759. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 8 (Août 2011) . - pp. 753-759 Mots-clés : AFM  Crevice  corrosion  SEM  Stainless  steel Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The susceptibility of 316L stainless steel to crevice corrosion was investigated by using immersion test and electrochemical test. Three kinds of crevices including 316L-to-polytetrafluoroethylene (PTFE) crevice, 316L-to-fluoroelastomeric (FKM) crevice and 316L-to-316L crevice were tested in artificial seawater at 50°C. The results indicate that 316L stainless steel specimen is the most susceptible to crevice corrosion when it is coupled to 316L stainless steel crevice former, while it is the least susceptible when it is coupled to FKM crevice former. It suggests that during submersible solenoid valve design, the crevice of metal-to-metal should be moderately large so that crevice corrosion can not initiate and propagate, and FKM O-ring rather than PTFE O-ring should be selected as obturating ring. The corroded surface morphology was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Three regions including passive region, active region and variable region can be observed on crevice corrosion sites. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005917/abstract