Dépouillements

A corrosion study of nickel–copper and nickel–copper–palladium welding filler metals / D. Liang in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 909–919 Titre : A corrosion study of nickel–copper and nickel–copper–palladium welding filler metals Type de document : texte imprimé Auteurs : D. Liang, Auteur ; J. W. Sowards, Auteur ; G. S. Frankel, Auteur Année de publication : 2011 Article en page(s) : pp. 909–919 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Nickel;  stainless  steel;  welding Résumé : In an effort to reduce the release of fumes containing carcinogenic Cr6+ during arc welding of stainless steel, Cr-free filler metals for welding of SS304 have been developed. Corrosion studies were carried out on 304L stainless steel samples welded with these Cr-free consumables. The corrosion properties of gas tungsten arc (GTA) and shielded metal arc (SMA) welds fabricated with Ni-Cu and Ni-Cu-Pd consumables were found to be comparable to those of welds fabricated with SS308L, the standard filler metal used with SS304. Although the breakdown potentials of the welds made using both welding processes were lower than that of the SS308L GTA weld, the repassivation potentials of these welds were much higher. Generally, the repassivation potential is a more conservative measure of susceptibility to localized corrosion. Accordingly, the Ni-Cu and Ni-Cu-Pd welds were more resistant to crevice corrosion than SS308L welds. The addition of a small amount of Pd improved the corrosion resistance relative to Ni-Cu welds, which is consistent with previous studies from specially-prepared button samples and bead-on-plate samples. Other corrosion studies such as creviced and uncreviced long time immersion, atmospheric exposure, and slow strain rate testing suggest that Ni-Cu-Pd filler metal can be a potential replacement for the conventional SS308L filler metal for joining SS304. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905583/abstract [article] A corrosion study of nickel–copper and nickel–copper–palladium welding filler metals [texte imprimé] / D. Liang, Auteur ; J. W. Sowards, Auteur ; G. S. Frankel, Auteur . - 2011 . - pp. 909–919. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 909–919 Mots-clés : Nickel;  stainless  steel;  welding Résumé : In an effort to reduce the release of fumes containing carcinogenic Cr6+ during arc welding of stainless steel, Cr-free filler metals for welding of SS304 have been developed. Corrosion studies were carried out on 304L stainless steel samples welded with these Cr-free consumables. The corrosion properties of gas tungsten arc (GTA) and shielded metal arc (SMA) welds fabricated with Ni-Cu and Ni-Cu-Pd consumables were found to be comparable to those of welds fabricated with SS308L, the standard filler metal used with SS304. Although the breakdown potentials of the welds made using both welding processes were lower than that of the SS308L GTA weld, the repassivation potentials of these welds were much higher. Generally, the repassivation potential is a more conservative measure of susceptibility to localized corrosion. Accordingly, the Ni-Cu and Ni-Cu-Pd welds were more resistant to crevice corrosion than SS308L welds. The addition of a small amount of Pd improved the corrosion resistance relative to Ni-Cu welds, which is consistent with previous studies from specially-prepared button samples and bead-on-plate samples. Other corrosion studies such as creviced and uncreviced long time immersion, atmospheric exposure, and slow strain rate testing suggest that Ni-Cu-Pd filler metal can be a potential replacement for the conventional SS308L filler metal for joining SS304. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905583/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

330Cb alloy (Fe-35Ni-18Cr-1Nb-2Si) oxidation study between 800 and 1000 °C / C. Issartel in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 929–938 Titre : 330Cb alloy (Fe-35Ni-18Cr-1Nb-2Si) oxidation study between 800 and 1000 °C Type de document : texte imprimé Auteurs : C. Issartel, Auteur ; H. Buscail, Auteur ; C. T. Nguyen, Auteur Année de publication : 2011 Article en page(s) : pp. 929–938 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : 330Cb;  conveyor  units;Fe-35Ni-18Cr-1Nb-2Si;  high  temperatures;  in  situ  XRD;  Niobium;  oxidation;  silicon Résumé : The 330Cb alloy (Fe-35Ni-18Cr-1Nb-2Si) has been oxidized, in air, in the 800–1000 °C temperature range. Results show the formation of a chromia layer acting as a good diffusion barrier under isothermal conditions. Nevertheless, some oxide scale spallation is generally observed after cooling to room temperature. A fine and adherent chromia scale is only obtained after short-term oxidation at 800 °C. In this case, the scale is probably too fine to expect a protection against carburization. At 900 °C we have observed that the scale spalled off on the niobium rich alloy areas. At 1000 °C the scale adherence is very bad. This study shows that the oxide scale adherence is decreased when the 330Cb alloy oxidation duration is increased. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905442/abstract [article] 330Cb alloy (Fe-35Ni-18Cr-1Nb-2Si) oxidation study between 800 and 1000 °C [texte imprimé] / C. Issartel, Auteur ; H. Buscail, Auteur ; C. T. Nguyen, Auteur . - 2011 . - pp. 929–938. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 929–938 Mots-clés : 330Cb;  conveyor  units;Fe-35Ni-18Cr-1Nb-2Si;  high  temperatures;  in  situ  XRD;  Niobium;  oxidation;  silicon Résumé : The 330Cb alloy (Fe-35Ni-18Cr-1Nb-2Si) has been oxidized, in air, in the 800–1000 °C temperature range. Results show the formation of a chromia layer acting as a good diffusion barrier under isothermal conditions. Nevertheless, some oxide scale spallation is generally observed after cooling to room temperature. A fine and adherent chromia scale is only obtained after short-term oxidation at 800 °C. In this case, the scale is probably too fine to expect a protection against carburization. At 900 °C we have observed that the scale spalled off on the niobium rich alloy areas. At 1000 °C the scale adherence is very bad. This study shows that the oxide scale adherence is decreased when the 330Cb alloy oxidation duration is increased. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905442/abstract

Short-term oxidation and hot corrosion resistance of a gradient CrN/Cr1−xAlxN coating / M. Zhu in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 939–946 Titre : Short-term oxidation and hot corrosion resistance of a gradient CrN/Cr1−xAlxN coating Type de document : texte imprimé Auteurs : M. Zhu, Auteur ; J. J. Xu, Auteur Année de publication : 2011 Article en page(s) : pp. 939–946 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Gradient  CrN/Cr1−xAlxN  coating;  hot-corrosion;  magnetron  sputtering;  oxidation Résumé : A CrN/Cr1−xAlxN coating comprised of an inner layer of CrN and an outer layer of Cr1−xAlxN with a gradient distribution of Al was deposited on two different alloys by a reactive sputtering method. Oxidation and hot-corrosion tests of the gradient CrN/Cr1−xAlxN coating were performed at different temperatures. The phase compositions and morphologies of the as-deposited coating and the corrosion products were investigated by using XRD and SEM/EDS. The results showed that the gradient CrN/Cr1−xAlxN coating exhibited good oxidation resistance at temperatures above 1000 °C owing to the formation of an α-Al2O3-rich oxide scale. The coating possessed good hot-corrosion resistance in molten sulfate because the inner CrN layer could supply enough Cr to form a relatively protective Cr2O3 after the Al2O3-enriched scale failed due to its dissolution in the molten sulfate. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905376/abstract [article] Short-term oxidation and hot corrosion resistance of a gradient CrN/Cr1−xAlxN coating [texte imprimé] / M. Zhu, Auteur ; J. J. Xu, Auteur . - 2011 . - pp. 939–946. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 939–946 Mots-clés : Gradient  CrN/Cr1−xAlxN  coating;  hot-corrosion;  magnetron  sputtering;  oxidation Résumé : A CrN/Cr1−xAlxN coating comprised of an inner layer of CrN and an outer layer of Cr1−xAlxN with a gradient distribution of Al was deposited on two different alloys by a reactive sputtering method. Oxidation and hot-corrosion tests of the gradient CrN/Cr1−xAlxN coating were performed at different temperatures. The phase compositions and morphologies of the as-deposited coating and the corrosion products were investigated by using XRD and SEM/EDS. The results showed that the gradient CrN/Cr1−xAlxN coating exhibited good oxidation resistance at temperatures above 1000 °C owing to the formation of an α-Al2O3-rich oxide scale. The coating possessed good hot-corrosion resistance in molten sulfate because the inner CrN layer could supply enough Cr to form a relatively protective Cr2O3 after the Al2O3-enriched scale failed due to its dissolution in the molten sulfate. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905376/abstract

Corrosion resistance of the new Ti-25Ta-25Nb alloy in severe functional conditions / E. Vasilescu in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 947–954 Titre : Corrosion resistance of the new Ti-25Ta-25Nb alloy in severe functional conditions Type de document : texte imprimé Auteurs : E. Vasilescu, Auteur ; P. Drob, Auteur ; C. Vasilescu, Auteur Année de publication : 2011 Article en page(s) : pp. 947–954 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Corrosion  tests;  EIS;  microstructure;  SEM;  titanium  alloy Résumé : In this study, a new Ti-25Ta-25Nb (mass%) β alloy was synthesised by cold crucible semi-levitation melting. After melting, each ingot was solution treated in the β-phase domain and water quenched in order to obtain a fully recrystallised homogeneous β-phase microstructure. To evaluate the bio-corrosion property of this new alloy, corrosion tests (cyclic potentiodynamic and linear polarisation, EIS) and surface analysis (SEM) were carried out in Ringer solution at different pH values (acid, neutral and basic). The results indicated that the corrosion resistance of the Ti-25Ta-25Nb alloy is quite higher than that of the commercially pure CP Ti alloy. These results show that this new alloy possesses all the characteristics necessary for its long-term use as medical implants. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005740/abstract [article] Corrosion resistance of the new Ti-25Ta-25Nb alloy in severe functional conditions [texte imprimé] / E. Vasilescu, Auteur ; P. Drob, Auteur ; C. Vasilescu, Auteur . - 2011 . - pp. 947–954. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 947–954 Mots-clés : Corrosion  tests;  EIS;  microstructure;  SEM;  titanium  alloy Résumé : In this study, a new Ti-25Ta-25Nb (mass%) β alloy was synthesised by cold crucible semi-levitation melting. After melting, each ingot was solution treated in the β-phase domain and water quenched in order to obtain a fully recrystallised homogeneous β-phase microstructure. To evaluate the bio-corrosion property of this new alloy, corrosion tests (cyclic potentiodynamic and linear polarisation, EIS) and surface analysis (SEM) were carried out in Ringer solution at different pH values (acid, neutral and basic). The results indicated that the corrosion resistance of the Ti-25Ta-25Nb alloy is quite higher than that of the commercially pure CP Ti alloy. These results show that this new alloy possesses all the characteristics necessary for its long-term use as medical implants. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005740/abstract

Crude unit overhead corrosion — pH profile and corrosion rate of carbon steel under controlled condensation / D. L. N. Cypriano in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 955–960 Titre : Crude unit overhead corrosion — pH profile and corrosion rate of carbon steel under controlled condensation Type de document : texte imprimé Auteurs : D. L. N. Cypriano, Auteur ; J. A. C. Ponciano, Auteur ; H. C. M. Jambo, Auteur Année de publication : 2011 Article en page(s) : pp. 955–960 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Hydrochloric  acid;  inhibitor;  integrity  program;  neutralizers;  overhead  corrosion Résumé : For this paper a laboratory simulation of the crude unit overhead corrosion was conducted. The main variable that impacts the corrosion rates for pipes, heat exchangers, and drums that compound the overhead system is pH. To control this pH many companies use different kinds of neutralizers, trying to keep in an optimum range, determined for each unit, according to their own characteristics. For this study an apparatus that simulate the evaporation and subsequent condensation of a solution with hydrochloric acid and other with neutralizer, with five carbon steel coupons analyzed by metal mass-loss was used. To compare to field practices, three kinds of neutralizer solutions were used. It was possible to observe differences between the pH profiles along condensation, which certainly influences the corrosion rate from the first condensed solution until the last one. It can be compared with the process at the atmospheric tower, from the overhead pipe, passing by the condenser until the drum that accumulates sour water at the end. In this last one the pH is usually measured, but it cannot represent what we could observe with this laboratory apparatus, that the first solution condensed is the worst for corrosion, and that there is a direct relationship between them. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905509/abstract [article] Crude unit overhead corrosion — pH profile and corrosion rate of carbon steel under controlled condensation [texte imprimé] / D. L. N. Cypriano, Auteur ; J. A. C. Ponciano, Auteur ; H. C. M. Jambo, Auteur . - 2011 . - pp. 955–960. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 955–960 Mots-clés : Hydrochloric  acid;  inhibitor;  integrity  program;  neutralizers;  overhead  corrosion Résumé : For this paper a laboratory simulation of the crude unit overhead corrosion was conducted. The main variable that impacts the corrosion rates for pipes, heat exchangers, and drums that compound the overhead system is pH. To control this pH many companies use different kinds of neutralizers, trying to keep in an optimum range, determined for each unit, according to their own characteristics. For this study an apparatus that simulate the evaporation and subsequent condensation of a solution with hydrochloric acid and other with neutralizer, with five carbon steel coupons analyzed by metal mass-loss was used. To compare to field practices, three kinds of neutralizer solutions were used. It was possible to observe differences between the pH profiles along condensation, which certainly influences the corrosion rate from the first condensed solution until the last one. It can be compared with the process at the atmospheric tower, from the overhead pipe, passing by the condenser until the drum that accumulates sour water at the end. In this last one the pH is usually measured, but it cannot represent what we could observe with this laboratory apparatus, that the first solution condensed is the worst for corrosion, and that there is a direct relationship between them. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905509/abstract

The use of infrared thermography in the corrosion science area / M. Jönsson in Materials and corrosion, Vol. 61 N° 11 (Novembre 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 961–965 Titre : The use of infrared thermography in the corrosion science area Type de document : texte imprimé Auteurs : M. Jönsson, Auteur ; B. Rendahl, Auteur ; I. Annergren, Auteur Année de publication : 2011 Article en page(s) : pp. 961–965 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Thermography;  delamination;  NDT Résumé : The use of infrared (IR) cameras has in recent years gained interest as a non-destructive testing (NDT) technique in a number of different research fields. All objects with a temperature above absolute zero emits IR radiation, and the amount of radiation increases with temperature. Infrared thermography is a non-contact technique with high speed which allows inspection of large areas in a relatively short time. In the present work different aspects of IR thermography are described and discussed. Further, corrosion panels with defects, i.e. blisters and filiform corrosion, have been investigated with pulsed thermography. The area of the blisters and filaments, measured with pulsed thermography, have been evaluated, the result obtained have been compared with results from surface profile measurements of the same area. The differences between the results and the limitations of the pulsed thermography are discussed. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905525/abstract [article] The use of infrared thermography in the corrosion science area [texte imprimé] / M. Jönsson, Auteur ; B. Rendahl, Auteur ; I. Annergren, Auteur . - 2011 . - pp. 961–965. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 11 (Novembre 2010) . - pp. 961–965 Mots-clés : Thermography;  delamination;  NDT Résumé : The use of infrared (IR) cameras has in recent years gained interest as a non-destructive testing (NDT) technique in a number of different research fields. All objects with a temperature above absolute zero emits IR radiation, and the amount of radiation increases with temperature. Infrared thermography is a non-contact technique with high speed which allows inspection of large areas in a relatively short time. In the present work different aspects of IR thermography are described and discussed. Further, corrosion panels with defects, i.e. blisters and filiform corrosion, have been investigated with pulsed thermography. The area of the blisters and filaments, measured with pulsed thermography, have been evaluated, the result obtained have been compared with results from surface profile measurements of the same area. The differences between the results and the limitations of the pulsed thermography are discussed. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905525/abstract

Exemplaires

Bibliothèque Ecole Nationale Polytechnique d'Alger

Accueil

Se connecter

Météo

Adresse