Dépouillements

Corrosion resistance of Ni-50Cr HVOF coatings on 310S alloy substrates in a metal dusting atmosphere / J. Saaedi in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 823–835 Titre : Corrosion resistance of Ni-50Cr HVOF coatings on 310S alloy substrates in a metal dusting atmosphere Type de document : texte imprimé Auteurs : J. Saaedi, Auteur ; H. Arabi, Auteur ; T. W. Coyle, Auteur Année de publication : 2011 Article en page(s) : pp. 823–835 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Carburization  HVOF  Metal  dusting  Ni-Cr  coatings  Pores Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Metal dusting attack has been examined after three 168 h cycles on two Ni-50Cr coatings with different microstructures deposited on 310S alloy substrates by the high velocity oxy-fuel (HVOF) thermal-spray process. Metal dusting in uncoated 310S alloy specimens was found to be still in the initiation stage after 504 h of exposure in the 50H2:50CO gas environment at 620 °C. Dense Ni-50Cr coatings offered suitable resistance to metal dusting. Metal dusting was observed in the 310S substrates adjacent to pores at the interface between the substrate and a porous Ni-50Cr coating. The porosity present in the as-deposited coatings was shown to introduce a large variability into coating performance. Carbon formed by decomposition of the gaseous species accumulated in the surface pores and resulted in the dislodgement of surface splats due to stresses generated by the volume changes. When the corrosive gas atmosphere was able to penetrate through the interconnected pores and reach the coating–substrate interface, the 310S substrate was carburized, metal dusting attack occurred, and the resulting formation of coke in the pores led to local failure of the coating. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905536/abstract [article] Corrosion resistance of Ni-50Cr HVOF coatings on 310S alloy substrates in a metal dusting atmosphere [texte imprimé] / J. Saaedi, Auteur ; H. Arabi, Auteur ; T. W. Coyle, Auteur . - 2011 . - pp. 823–835. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 823–835 Mots-clés : Carburization  HVOF  Metal  dusting  Ni-Cr  coatings  Pores Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Metal dusting attack has been examined after three 168 h cycles on two Ni-50Cr coatings with different microstructures deposited on 310S alloy substrates by the high velocity oxy-fuel (HVOF) thermal-spray process. Metal dusting in uncoated 310S alloy specimens was found to be still in the initiation stage after 504 h of exposure in the 50H2:50CO gas environment at 620 °C. Dense Ni-50Cr coatings offered suitable resistance to metal dusting. Metal dusting was observed in the 310S substrates adjacent to pores at the interface between the substrate and a porous Ni-50Cr coating. The porosity present in the as-deposited coatings was shown to introduce a large variability into coating performance. Carbon formed by decomposition of the gaseous species accumulated in the surface pores and resulted in the dislodgement of surface splats due to stresses generated by the volume changes. When the corrosive gas atmosphere was able to penetrate through the interconnected pores and reach the coating–substrate interface, the 310S substrate was carburized, metal dusting attack occurred, and the resulting formation of coke in the pores led to local failure of the coating. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905536/abstract

Chromate replacement in coatings for corrosion protection of aerospace aluminium alloys / T. A. Markley in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 836–840 Titre : Chromate replacement in coatings for corrosion protection of aerospace aluminium alloys Type de document : texte imprimé Auteurs : T. A. Markley, Auteur ; J. I. Mardel, Auteur ; A. E. Hughes, Auteur Année de publication : 2011 Article en page(s) : pp. 836–840 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aluminium  alloys  Coatings  Filiform  corrosion  Inhibition Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Mixed rare earth organophosphates have been investigated as potential corrosion inhibitors for AA2024-T3 with the aim of replacing chromate-based technologies. Cerium diphenyl phosphate (Ce(dpp)3) and mischmetal diphenyl phosphate (Mm(dpp)3) were added to epoxy coatings applied to AA2024-T3 panels and they were effective in reducing the amount and rate of filiform corrosion in high humidity conditions. Ce(dpp)3 was the most effective and characterisation of the coating formulations showed approximately a factor of 5 reduction in both the number of corrosion filaments initiated as well as the length of these. Mm(dpp)3 appeared to reduce the corrosion growth rate by a factor of 2 although it was the more effective inhibitor in solution studies. Spectroscopic characterisation of the coatings indicated that the cerium based inhibitor may disrupt network formation in the epoxy thus resulting in a coating that absorbed more water and allowed greater solubilisation of the corrosion inhibiting compound. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905597/abstract [article] Chromate replacement in coatings for corrosion protection of aerospace aluminium alloys [texte imprimé] / T. A. Markley, Auteur ; J. I. Mardel, Auteur ; A. E. Hughes, Auteur . - 2011 . - pp. 836–840. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 836–840 Mots-clés : Aluminium  alloys  Coatings  Filiform  corrosion  Inhibition Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Mixed rare earth organophosphates have been investigated as potential corrosion inhibitors for AA2024-T3 with the aim of replacing chromate-based technologies. Cerium diphenyl phosphate (Ce(dpp)3) and mischmetal diphenyl phosphate (Mm(dpp)3) were added to epoxy coatings applied to AA2024-T3 panels and they were effective in reducing the amount and rate of filiform corrosion in high humidity conditions. Ce(dpp)3 was the most effective and characterisation of the coating formulations showed approximately a factor of 5 reduction in both the number of corrosion filaments initiated as well as the length of these. Mm(dpp)3 appeared to reduce the corrosion growth rate by a factor of 2 although it was the more effective inhibitor in solution studies. Spectroscopic characterisation of the coatings indicated that the cerium based inhibitor may disrupt network formation in the epoxy thus resulting in a coating that absorbed more water and allowed greater solubilisation of the corrosion inhibiting compound. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905597/abstract

Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment / S. Y. Zhang in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 841–847 Titre : Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment Type de document : texte imprimé Auteurs : S. Y. Zhang, Auteur ; Q. Li, Auteur ; X. K. Yang, Auteur Année de publication : 2011 Article en page(s) : pp. 841–847 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : AZ91D  magnesium  alloy  Corrosion  protection  Electrochemical  impedance  spectroscopy  Potentiodynamic  polarization Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, a protective coating scheme was applied for the corrosion protection of AZ91D magnesium alloy. Electroless Ni coating (EN coating) as bottom layer, electrodeposited Ni coating (ENN coating), and silane-based coating (ENS coating) as top layer, respectively, were successfully prepared on AZ91D magnesium alloy by combination techniques. Scanning electron microscopy and X-ray diffraction were employed to investigate the surface and phase structure of coatings, respectively. The electrochemical corrosion behaviors of coatings in neutral 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion testing showed that the three kinds of coatings all could provide corrosion protection for AZ91D magnesium alloy to a certain extent, and the corrosion resistance of ENN and ENS was superior to EN. In order to further study the corrosion protection properties of ENN and ENS, a comparative investigation on the evolution of EIS of ENN and ENS was carried out by dint of immersion test in neutral 3.5 wt% NaCl solution. The results indicated that, compared with ENN, the ENS could provide longer corrosion protection for AZ91D magnesium alloy. It is significant to determine the barrier effect of each coating, which could provide reference for industry applications. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005958/abstract [article] Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment [texte imprimé] / S. Y. Zhang, Auteur ; Q. Li, Auteur ; X. K. Yang, Auteur . - 2011 . - pp. 841–847. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 841–847 Mots-clés : AZ91D  magnesium  alloy  Corrosion  protection  Electrochemical  impedance  spectroscopy  Potentiodynamic  polarization Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, a protective coating scheme was applied for the corrosion protection of AZ91D magnesium alloy. Electroless Ni coating (EN coating) as bottom layer, electrodeposited Ni coating (ENN coating), and silane-based coating (ENS coating) as top layer, respectively, were successfully prepared on AZ91D magnesium alloy by combination techniques. Scanning electron microscopy and X-ray diffraction were employed to investigate the surface and phase structure of coatings, respectively. The electrochemical corrosion behaviors of coatings in neutral 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion testing showed that the three kinds of coatings all could provide corrosion protection for AZ91D magnesium alloy to a certain extent, and the corrosion resistance of ENN and ENS was superior to EN. In order to further study the corrosion protection properties of ENN and ENS, a comparative investigation on the evolution of EIS of ENN and ENS was carried out by dint of immersion test in neutral 3.5 wt% NaCl solution. The results indicated that, compared with ENN, the ENS could provide longer corrosion protection for AZ91D magnesium alloy. It is significant to determine the barrier effect of each coating, which could provide reference for industry applications. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005958/abstract

Improving corrosion resistance of Al-11mass%Si alloy through a large number of ECAP passes / J.-H. Jiang in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 848–852 Titre : Improving corrosion resistance of Al-11mass%Si alloy through a large number of ECAP passes Type de document : texte imprimé Auteurs : J.-H. Jiang, Auteur ; A.-B. Ma, Auteur ; F.-M. Lu, Auteur Année de publication : 2011 Article en page(s) : pp. 848–852 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aluminum  alloy  Corrosion  Equal-channel  angular  pressing  (ECAP)Ultrafine-grained  (UFG) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Ultrafine-grained (UFG) Al-11mass%Si alloy, processed by multi-pass equal-channel angular pressing (ECAP) at 573 K, was investigated on corrosion behavior in 0.6 M NaCl solution. Potentiodynamic polarization tests and scanning electron microscopy observation showed that a large number of ECAP passes resulted in lower corrosion current density, more positive corrosion potential, and rather smooth corroded surface with shallow corrosion pits. The uniform distribution of fine secondary-phase particles on UFG Al matrix weakened the susceptibility to pitting corrosion while inhibited general microgalvanic reactions. The present results indicate that grain refinement of aluminum matrix to the UFG state and uniform redistribution of broken particles (including eutectic silicon and secondary phases), via severe plastic deformation at elevated temperature undergoing dynamic recrystallization, can significantly improve the corrosion resistance of Al alloys, besides the known exceptional mechanical advantages. The simple and effective ECAP procedure makes UFG Al alloys more attractive for high strength structural application in corrosive environment. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905521/abstract [article] Improving corrosion resistance of Al-11mass%Si alloy through a large number of ECAP passes [texte imprimé] / J.-H. Jiang, Auteur ; A.-B. Ma, Auteur ; F.-M. Lu, Auteur . - 2011 . - pp. 848–852. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 848–852 Mots-clés : Aluminum  alloy  Corrosion  Equal-channel  angular  pressing  (ECAP)Ultrafine-grained  (UFG) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Ultrafine-grained (UFG) Al-11mass%Si alloy, processed by multi-pass equal-channel angular pressing (ECAP) at 573 K, was investigated on corrosion behavior in 0.6 M NaCl solution. Potentiodynamic polarization tests and scanning electron microscopy observation showed that a large number of ECAP passes resulted in lower corrosion current density, more positive corrosion potential, and rather smooth corroded surface with shallow corrosion pits. The uniform distribution of fine secondary-phase particles on UFG Al matrix weakened the susceptibility to pitting corrosion while inhibited general microgalvanic reactions. The present results indicate that grain refinement of aluminum matrix to the UFG state and uniform redistribution of broken particles (including eutectic silicon and secondary phases), via severe plastic deformation at elevated temperature undergoing dynamic recrystallization, can significantly improve the corrosion resistance of Al alloys, besides the known exceptional mechanical advantages. The simple and effective ECAP procedure makes UFG Al alloys more attractive for high strength structural application in corrosive environment. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905521/abstract

Effect of porosity of phosphate coating on corrosion resistance of galvanized and phosphated steels. Part II, Evaluation of corrosion resistance / C. H. S. B. Teixeira in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 853–860 Titre : Effect of porosity of phosphate coating on corrosion resistance of galvanized and phosphated steels. Part II, Evaluation of corrosion resistance Type de document : texte imprimé Auteurs : C. H. S. B. Teixeira, Auteur ; E. A. Alvarenga, Auteur ; W. L. Vasconcelos, Auteur Année de publication : 2011 Article en page(s) : pp. 853–860 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Accelerated  corrosion  test  Galvanized  steel  Phosphate  coating  Porosity Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The effect of porosity of phosphate coatings on the corrosion resistance of ungalvanized (UG), electrogalvanized, and hot dip galvanized steels is evaluated in this study. The corrosion resistance of phosphatized and painted steel is related to the integrity and continuity of phosphate and paint layers, and pores in the phosphate layer affect the corrosion resistance of material. The porosity of the phosphate coating was evaluated by using the cathodic polarization electrochemical test. To evaluate the corrosion resistance of the phosphatized and painted steels, they were submitted to accelerated corrosion tests. As was expected, the creepback from the scribe increased with the increase in porosity. This behavior was evident for UG steel, but less evident for galvanized steels due to cathodic protection and/or barrier effect of the zinc coating. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905504/abstract [article] Effect of porosity of phosphate coating on corrosion resistance of galvanized and phosphated steels. Part II, Evaluation of corrosion resistance [texte imprimé] / C. H. S. B. Teixeira, Auteur ; E. A. Alvarenga, Auteur ; W. L. Vasconcelos, Auteur . - 2011 . - pp. 853–860. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 853–860 Mots-clés : Accelerated  corrosion  test  Galvanized  steel  Phosphate  coating  Porosity Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The effect of porosity of phosphate coatings on the corrosion resistance of ungalvanized (UG), electrogalvanized, and hot dip galvanized steels is evaluated in this study. The corrosion resistance of phosphatized and painted steel is related to the integrity and continuity of phosphate and paint layers, and pores in the phosphate layer affect the corrosion resistance of material. The porosity of the phosphate coating was evaluated by using the cathodic polarization electrochemical test. To evaluate the corrosion resistance of the phosphatized and painted steels, they were submitted to accelerated corrosion tests. As was expected, the creepback from the scribe increased with the increase in porosity. This behavior was evident for UG steel, but less evident for galvanized steels due to cathodic protection and/or barrier effect of the zinc coating. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905504/abstract

Morphology of corrosion products of steel in concrete under macro-cell and self-corrosion conditions / D. Neff in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 861–871 Titre : Morphology of corrosion products of steel in concrete under macro-cell and self-corrosion conditions Type de document : texte imprimé Auteurs : D. Neff, Auteur ; J. Harnisch, Auteur ; M. Beck, Auteur Année de publication : 2011 Article en page(s) : pp. 861–871 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Corrosion  Concrete  Chlorides  Iron  hydroxychloride  X-ray  tomography  Raman  spectroscopy Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper investigations into the formation of specific corrosion products during the process of chloride induced corrosion of steel in concrete are presented. The extension of corrosion products within concrete was established by means of X-ray tomography analyses. Then a detailed analysis of the nature of corrosion products has been conducted by means of Raman micro-spectroscopy and energy dispersive spectroscopy. Results emphasize two different corrosion patterns. The first one is composed of shallow cavities, where mostly magnetite and goethite were identified, traducing aerated to moderate aerated conditions in these media. The second pattern was identified as deep, needle-like pits, where chlorinated-iron-oxides phases were present associated with more or less important chloride enrichments. The presence of these particular species is indicating low redox and low pH conditions within these pits. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005861/abstract [article] Morphology of corrosion products of steel in concrete under macro-cell and self-corrosion conditions [texte imprimé] / D. Neff, Auteur ; J. Harnisch, Auteur ; M. Beck, Auteur . - 2011 . - pp. 861–871. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 861–871 Mots-clés : Corrosion  Concrete  Chlorides  Iron  hydroxychloride  X-ray  tomography  Raman  spectroscopy Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper investigations into the formation of specific corrosion products during the process of chloride induced corrosion of steel in concrete are presented. The extension of corrosion products within concrete was established by means of X-ray tomography analyses. Then a detailed analysis of the nature of corrosion products has been conducted by means of Raman micro-spectroscopy and energy dispersive spectroscopy. Results emphasize two different corrosion patterns. The first one is composed of shallow cavities, where mostly magnetite and goethite were identified, traducing aerated to moderate aerated conditions in these media. The second pattern was identified as deep, needle-like pits, where chlorinated-iron-oxides phases were present associated with more or less important chloride enrichments. The presence of these particular species is indicating low redox and low pH conditions within these pits. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005861/abstract

Effect of the molecular structure of some quinones on their corrosion inhibiting action / A. Stoyanova in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 872–877 Titre : Effect of the molecular structure of some quinones on their corrosion inhibiting action Type de document : texte imprimé Auteurs : A. Stoyanova, Auteur ; E. Slavcheva, Auteur Année de publication : 2011 Article en page(s) : pp. 872–877 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Dipole  moment  Geometrical  and  molecular  structure  Inhibiting  effect  Ionization  potential  Quinones  SCF  calculations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The molecular characteristics obtained by quantum chemical self-consistent field (SCF) calculations of a series of quinones are correlated with the experimentally determined inhibitor efficiency for mild steel corrosion in neutral aqueous medium. It was established that the decrease of the ionization potential and the increase of the dipole moment of the quinone molecules favor the higher protective effect. The electron density and the geometric molecular structure have also been computed and are discussed in view of the corrosion inhibition. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905579/abstract [article] Effect of the molecular structure of some quinones on their corrosion inhibiting action [texte imprimé] / A. Stoyanova, Auteur ; E. Slavcheva, Auteur . - 2011 . - pp. 872–877. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 872–877 Mots-clés : Dipole  moment  Geometrical  and  molecular  structure  Inhibiting  effect  Ionization  potential  Quinones  SCF  calculations Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The molecular characteristics obtained by quantum chemical self-consistent field (SCF) calculations of a series of quinones are correlated with the experimentally determined inhibitor efficiency for mild steel corrosion in neutral aqueous medium. It was established that the decrease of the ionization potential and the increase of the dipole moment of the quinone molecules favor the higher protective effect. The electron density and the geometric molecular structure have also been computed and are discussed in view of the corrosion inhibition. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905579/abstract

Corrosion of API XL 52 steel in presence of Clostridium celerecrescens / O. A. Ramos Monroy in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 878–883 Titre : Corrosion of API XL 52 steel in presence of Clostridium celerecrescens Type de document : texte imprimé Auteurs : O. A. Ramos Monroy, Auteur ; M. J. Hernandez Gayosso, Auteur ; N. Ruiz Ordaz, Auteur Année de publication : 2011 Article en page(s) : pp. 878–883 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Clostridium  celerecrescens  Electrochemical  impedance  spectroscopy  microbiologically  induced  corrosion  Polarization  resistance Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : During the characterization of sediments formed in pipelines transporting hydrocarbons, the knowledge of the microbiological diversity becomes very interesting, especially when it is related to microbiologically influenced corrosion (MIC). The presence of microorganisms is considered as one of the factors that affect the corrosion processes occurring at the pipeline; therefore, their corrosiveness must be determined. In this way, the identification of new species affecting the MIC processes is still considered relevant. In this work, the effect of Clostridium celerecrescens upon the corrosion of API KL 52 steel was evaluated. This microorganism was isolated and identified from the sediments collected during the inner cleaning procedures of a gas pipeline. The polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) techniques were considered to estimate the microorganism behavior during the corrosion process. The results were complemented with a metal surface analysis, using a scanning electron microscope (SEM). The resistance values induced by the presence of the microorganisms clearly indicated that C. celerecrescens has an effect on the corrosion process occurring at the API XL 52 steel surface. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905582/abstract [article] Corrosion of API XL 52 steel in presence of Clostridium celerecrescens [texte imprimé] / O. A. Ramos Monroy, Auteur ; M. J. Hernandez Gayosso, Auteur ; N. Ruiz Ordaz, Auteur . - 2011 . - pp. 878–883. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 878–883 Mots-clés : Clostridium  celerecrescens  Electrochemical  impedance  spectroscopy  microbiologically  induced  corrosion  Polarization  resistance Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : During the characterization of sediments formed in pipelines transporting hydrocarbons, the knowledge of the microbiological diversity becomes very interesting, especially when it is related to microbiologically influenced corrosion (MIC). The presence of microorganisms is considered as one of the factors that affect the corrosion processes occurring at the pipeline; therefore, their corrosiveness must be determined. In this way, the identification of new species affecting the MIC processes is still considered relevant. In this work, the effect of Clostridium celerecrescens upon the corrosion of API KL 52 steel was evaluated. This microorganism was isolated and identified from the sediments collected during the inner cleaning procedures of a gas pipeline. The polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) techniques were considered to estimate the microorganism behavior during the corrosion process. The results were complemented with a metal surface analysis, using a scanning electron microscope (SEM). The resistance values induced by the presence of the microorganisms clearly indicated that C. celerecrescens has an effect on the corrosion process occurring at the API XL 52 steel surface. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905582/abstract

Stress corrosion cracking for 316 stainless steel clips in a condensate stabilizer / A. Al Awar in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 884–889 Titre : Stress corrosion cracking for 316 stainless steel clips in a condensate stabilizer Type de document : texte imprimé Auteurs : A. Al Awar, Auteur ; S. Aldajah, Auteur ; A. Harhara, Auteur Année de publication : 2011 Article en page(s) : pp. 884–889 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Inconel  Stress  corrosion  cracking  316  stainless  steel Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In one of the gas processing facilities in Abu Dhabi, UAE; a case of 316L stainless steel material failure occurred in the fractionating column due to stress cracking corrosion twice in a cycle of less than 2 years. This paper studies the stress corrosion cracking behavior of the 316L stainless steel in an accelerated corrosion environment and compares it with a higher corrosion resistant nickel alloy (Inconel 625). The experimental work was designed according to ASTM G36 standard, the samples were immersed in a boiling magnesium chloride medium which provided the accelerated corrosion environment and the tested samples were shaped into U-bend specimens as they underwent both plastic and elastic stresses. The specimens were then tested to determine the time required for cracks to initiate. The results of the experimental work showed that the main mode of failure was stress corrosion cracking initiated by the proven presence of chlorides, hydrogen sulfide, and water at elevated temperatures. Inconel 625 samples placed in the controlled environment showed better corrosion resistance as it took them an average of 56 days to initiate cracks, whereas it took an average of 24 days to initiate cracks in the stainless steel 316L samples. The scanning electron microscopy (SEM) micrographs showed that the cracks in the stainless steel 316L samples were longer, wider, and deeper compared to the cracks of Inconel 625. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905589/abstract [article] Stress corrosion cracking for 316 stainless steel clips in a condensate stabilizer [texte imprimé] / A. Al Awar, Auteur ; S. Aldajah, Auteur ; A. Harhara, Auteur . - 2011 . - pp. 884–889. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 884–889 Mots-clés : Inconel  Stress  corrosion  cracking  316  stainless  steel Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In one of the gas processing facilities in Abu Dhabi, UAE; a case of 316L stainless steel material failure occurred in the fractionating column due to stress cracking corrosion twice in a cycle of less than 2 years. This paper studies the stress corrosion cracking behavior of the 316L stainless steel in an accelerated corrosion environment and compares it with a higher corrosion resistant nickel alloy (Inconel 625). The experimental work was designed according to ASTM G36 standard, the samples were immersed in a boiling magnesium chloride medium which provided the accelerated corrosion environment and the tested samples were shaped into U-bend specimens as they underwent both plastic and elastic stresses. The specimens were then tested to determine the time required for cracks to initiate. The results of the experimental work showed that the main mode of failure was stress corrosion cracking initiated by the proven presence of chlorides, hydrogen sulfide, and water at elevated temperatures. Inconel 625 samples placed in the controlled environment showed better corrosion resistance as it took them an average of 56 days to initiate cracks, whereas it took an average of 24 days to initiate cracks in the stainless steel 316L samples. The scanning electron microscopy (SEM) micrographs showed that the cracks in the stainless steel 316L samples were longer, wider, and deeper compared to the cracks of Inconel 625. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905589/abstract

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