Documents disponibles écrits par cet auteur

Effect of different thermochemical treatments on the electrochemical behaviour of a hot working steel / F. Rosalbino in Materials and corrosion, Vol. 62 N° 4 (Avril 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 4 (Avril 2011) . - pp. 357–361 Titre : Effect of different thermochemical treatments on the electrochemical behaviour of a hot working steel Type de document : texte imprimé Auteurs : F. Rosalbino, Auteur ; G. Scavino, Auteur ; E. Angelini, Auteur Année de publication : 2011 Article en page(s) : pp. 357–361 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Hot  working  steel  Nitriding  Nitrocarburising  Overcarburising  Polarisation  curves Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The X 37CrMoV5 1 KU hot working steel has been quenched and tempered, overcarburised, nitrided and nitrocarburised. The surface layers constituted after the thermochemical treatments were characterised by means of X-ray diffraction (XRD) analyses, optical and scanning electron microscope (SEM) observations, micro- and macrohardness indentations. The electrochemical behaviour was evaluated in two different aggressive environments: 0.1 M Na2SO4 and 0.1 M NaCl solutions. While the overcarburised and the nitrocarburised samples exhibit a poor electrochemical behaviour, the presence of a nitrided surface layer enhances the corrosion resistance. This is attributable to the protective action of the nitrided layer that hinders the anodic dissolution reaction of the matrix, whereas the presence of complex carbides in the overcarburised or nitrocarburised samples causes the preferential dissolution of the ferritic matrix due to galvanic coupling phenomena. Finally, the poor corrosion resistance exhibited by the nitrocarburised sample can be ascribed to the presence of a large amount of ferrite together with little ε solid solution in the surface layer. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905530/abstract [article] Effect of different thermochemical treatments on the electrochemical behaviour of a hot working steel [texte imprimé] / F. Rosalbino, Auteur ; G. Scavino, Auteur ; E. Angelini, Auteur . - 2011 . - pp. 357–361. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 4 (Avril 2011) . - pp. 357–361 Mots-clés : Hot  working  steel  Nitriding  Nitrocarburising  Overcarburising  Polarisation  curves Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The X 37CrMoV5 1 KU hot working steel has been quenched and tempered, overcarburised, nitrided and nitrocarburised. The surface layers constituted after the thermochemical treatments were characterised by means of X-ray diffraction (XRD) analyses, optical and scanning electron microscope (SEM) observations, micro- and macrohardness indentations. The electrochemical behaviour was evaluated in two different aggressive environments: 0.1 M Na2SO4 and 0.1 M NaCl solutions. While the overcarburised and the nitrocarburised samples exhibit a poor electrochemical behaviour, the presence of a nitrided surface layer enhances the corrosion resistance. This is attributable to the protective action of the nitrided layer that hinders the anodic dissolution reaction of the matrix, whereas the presence of complex carbides in the overcarburised or nitrocarburised samples causes the preferential dissolution of the ferritic matrix due to galvanic coupling phenomena. Finally, the poor corrosion resistance exhibited by the nitrocarburised sample can be ascribed to the presence of a large amount of ferrite together with little ε solid solution in the surface layer. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905530/abstract

Electrochemical corrosion behaviour of innovative mould steels in a chloride-containing environment / F. Rosalbino in Materials and corrosion, Vol. 63 N° 2 (Fevrier 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 2 (Fevrier 2012) . - pp. 105–110 Titre : Electrochemical corrosion behaviour of innovative mould steels in a chloride-containing environment Type de document : texte imprimé Auteurs : F. Rosalbino, Auteur ; G. Scavino, Auteur ; G. Mortarino, Auteur Année de publication : 2012 Article en page(s) : pp. 105–110 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : bainitic  microstructure;  corrosion  behaviour;  electrochemical  impedance  spectroscopy  (EIS);  mould  steels;  polarization  curves Résumé : Investigations concerning the electrochemical corrosion behaviour of mould steels are scarce and limited. In the present study the corrosion resistance of an innovative mould steel (a microalloyed steel, steel 2), devoted to the fabrication of large size moulds, and a steel having the same composition without microalloying elements (B, Zr, Nb, steel 3), proposed for small size moulds, was assessed in a chloride-containing environment and compared with that of the traditional 1.2738 steel. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements were carried out on the investigated steel samples in a 0.1 M NaCl solution at 25 °C. Scanning electron microscopy and electron probe microanalysis were used to characterize the specimens surface after the electrochemical tests. Despite having a bainitic microstructure, the electrochemical corrosion behaviour of the investigated steels is quite different. Results showed that the steel 3 and the 1.2738 steel samples exhibit the best and the worst electrochemical corrosion behaviours compared to the steel 2 sample. The presence of pearlite is considered as the main reason for the poor corrosion behaviour showed by the 1.2738 steel sample, due to galvanic coupling phenomena between this phase and the bainitic matrix which experiences preferential dissolution. The coarse bainitic microstructure characterizing the steel 2 sample is responsible for its lower corrosion resistance as compared with the steel 3 sample exhibiting a finer bainitic microstructure. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005794/abstract [article] Electrochemical corrosion behaviour of innovative mould steels in a chloride-containing environment [texte imprimé] / F. Rosalbino, Auteur ; G. Scavino, Auteur ; G. Mortarino, Auteur . - 2012 . - pp. 105–110. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 2 (Fevrier 2012) . - pp. 105–110 Mots-clés : bainitic  microstructure;  corrosion  behaviour;  electrochemical  impedance  spectroscopy  (EIS);  mould  steels;  polarization  curves Résumé : Investigations concerning the electrochemical corrosion behaviour of mould steels are scarce and limited. In the present study the corrosion resistance of an innovative mould steel (a microalloyed steel, steel 2), devoted to the fabrication of large size moulds, and a steel having the same composition without microalloying elements (B, Zr, Nb, steel 3), proposed for small size moulds, was assessed in a chloride-containing environment and compared with that of the traditional 1.2738 steel. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements were carried out on the investigated steel samples in a 0.1 M NaCl solution at 25 °C. Scanning electron microscopy and electron probe microanalysis were used to characterize the specimens surface after the electrochemical tests. Despite having a bainitic microstructure, the electrochemical corrosion behaviour of the investigated steels is quite different. Results showed that the steel 3 and the 1.2738 steel samples exhibit the best and the worst electrochemical corrosion behaviours compared to the steel 2 sample. The presence of pearlite is considered as the main reason for the poor corrosion behaviour showed by the 1.2738 steel sample, due to galvanic coupling phenomena between this phase and the bainitic matrix which experiences preferential dissolution. The coarse bainitic microstructure characterizing the steel 2 sample is responsible for its lower corrosion resistance as compared with the steel 3 sample exhibiting a finer bainitic microstructure. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005794/abstract

Electrochemical corrosion response of a precipitation hardening moulds steel in a NaCl solution / F. Rosalbino in Materials and corrosion, Vol. 63 N° 3 (Mars 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 3 (Mars 2012) . - pp. 247–253 Titre : Electrochemical corrosion response of a precipitation hardening moulds steel in a NaCl solution Type de document : texte imprimé Auteurs : F. Rosalbino, Auteur ; G. Scavino, Auteur ; G. Mortarino, Auteur Année de publication : 2012 Article en page(s) : pp. 247–253 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Corrosion  behavior;  electrochemical  impedance  spectroscopy;  polarization  curves;  precipitation  hardening  moulds  steel Résumé : Investigations concerning the electrochemical corrosion behavior of mould steels are scarce and limited. In the present study, the corrosion resistance of a precipitation hardening moulds steel submitted to aging treatments has been assessed in a 0.1 M NaCl aqueous solution by means of potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The electrochemical characterization of the steel not submitted to hardening treatments was also examined and a comparative study was made between the different specimens. Scanning electron microscopy and electron probe microanalysis were used to obtain information about the morphology and chemical composition of the steels surface after the electrochemical tests. Increasing the aging temperature an increase of secondary hardness is observed, attributable to an increase of secondary phases (re-precipitated carbides and metastable GP zones) amount, positively reflecting on the mechanical properties. However, the electrochemical results show a progressive worsening of the corrosion behavior, the as-received steel sample exhibiting the best corrosion resistance. The observed decrease of corrosion resistance with increasing the aging temperature is ascribed to enhanced galvanic coupling phenomena between the secondary phases, acting as cathodes, and the surrounding matrix which, consequently, experiences preferential dissolution. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005820/abstract [article] Electrochemical corrosion response of a precipitation hardening moulds steel in a NaCl solution [texte imprimé] / F. Rosalbino, Auteur ; G. Scavino, Auteur ; G. Mortarino, Auteur . - 2012 . - pp. 247–253. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 3 (Mars 2012) . - pp. 247–253 Mots-clés : Corrosion  behavior;  electrochemical  impedance  spectroscopy;  polarization  curves;  precipitation  hardening  moulds  steel Résumé : Investigations concerning the electrochemical corrosion behavior of mould steels are scarce and limited. In the present study, the corrosion resistance of a precipitation hardening moulds steel submitted to aging treatments has been assessed in a 0.1 M NaCl aqueous solution by means of potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The electrochemical characterization of the steel not submitted to hardening treatments was also examined and a comparative study was made between the different specimens. Scanning electron microscopy and electron probe microanalysis were used to obtain information about the morphology and chemical composition of the steels surface after the electrochemical tests. Increasing the aging temperature an increase of secondary hardness is observed, attributable to an increase of secondary phases (re-precipitated carbides and metastable GP zones) amount, positively reflecting on the mechanical properties. However, the electrochemical results show a progressive worsening of the corrosion behavior, the as-received steel sample exhibiting the best corrosion resistance. The observed decrease of corrosion resistance with increasing the aging temperature is ascribed to enhanced galvanic coupling phenomena between the secondary phases, acting as cathodes, and the surrounding matrix which, consequently, experiences preferential dissolution. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005820/abstract