Documents disponibles écrits par cet auteur

Microstructural investigation of the oxide formed on TP 347H FG during long-term steam oxidation / A. N. Hansson in Materials and corrosion, Vol. 61 N° 8 (Août 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 8 (Août 2010) . - pp. 665–675 Titre : Microstructural investigation of the oxide formed on TP 347H FG during long-term steam oxidation Type de document : texte imprimé Auteurs : A. N. Hansson, Auteur ; H. Danielsen, Auteur ; F. B. Grumsen, Auteur Année de publication : 2010 Article en page(s) : pp. 665–675 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Austenitic  18–12  stainless  steel;  Cr  diffusion;  internal  oxidation;  steam  oxidation Résumé : The long-term oxidation behaviour of TP347H FG in ultra supercritical steam conditions was assessed by exposing the steel in test superheater loops in a Danish coal-fired power plant and characterising the oxide layer with reflective light and electron microscopy. Double layered oxide scales formed during steam oxidation. TEM investigations reveal that the inner oxide layer consists of particles of metallic Ni/Fe and FeCr spinel in the interior of the former alloy grains and a compact layer of FeCr spinel and Cr2O3 along the former alloy grain boundaries. The morphology suggests that the inner layer grows by internal oxidation of the interior of the alloy grains. The thickness of the inner oxide layer did not change significantly with oxidation time and temperature for exposure times up to 30 000 h. Faster Cr diffusion within the fine-grained alloy at higher temperatures is held responsible for this observation. This hypothesis is supported by kinetic data. The oxide thickness at low and high temperatures after 58 000 h exposure was higher than expected. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905439/abstract [article] Microstructural investigation of the oxide formed on TP 347H FG during long-term steam oxidation [texte imprimé] / A. N. Hansson, Auteur ; H. Danielsen, Auteur ; F. B. Grumsen, Auteur . - 2010 . - pp. 665–675. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 8 (Août 2010) . - pp. 665–675 Mots-clés : Austenitic  18–12  stainless  steel;  Cr  diffusion;  internal  oxidation;  steam  oxidation Résumé : The long-term oxidation behaviour of TP347H FG in ultra supercritical steam conditions was assessed by exposing the steel in test superheater loops in a Danish coal-fired power plant and characterising the oxide layer with reflective light and electron microscopy. Double layered oxide scales formed during steam oxidation. TEM investigations reveal that the inner oxide layer consists of particles of metallic Ni/Fe and FeCr spinel in the interior of the former alloy grains and a compact layer of FeCr spinel and Cr2O3 along the former alloy grain boundaries. The morphology suggests that the inner layer grows by internal oxidation of the interior of the alloy grains. The thickness of the inner oxide layer did not change significantly with oxidation time and temperature for exposure times up to 30 000 h. Faster Cr diffusion within the fine-grained alloy at higher temperatures is held responsible for this observation. This hypothesis is supported by kinetic data. The oxide thickness at low and high temperatures after 58 000 h exposure was higher than expected. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905439/abstract

Steam oxidation of X20CrMoV121 / M. Montgomery in Materials and corrosion, Vol. 63 N° 8 (Août 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 8 (Août 2012) . - pp. 674–684 Titre : Steam oxidation of X20CrMoV121 : comparison of laboratory exposures and in situ exposure in power plants Type de document : texte imprimé Auteurs : M. Montgomery, Auteur ; A. N. Hansson, Auteur ; T. Vilhelmsen, Auteur Année de publication : 2013 Article en page(s) : pp. 674–684 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Cr  diffusion;  power  plants;  steam  oxidation;  X20 Résumé : X20CrMoV121 is a 12% Cr martensitic steel which has been used in power plants in Europe for many decades. Specimens have been removed from superheater tubes to investigate long-term exposure with respect to steam oxidation. These tubes have been exposed for various durations up to 135 000 h in power plants in Denmark at steam temperatures varying from 450–565 °C. This paper collates the data, compares oxide morphologies and assesses to what extent parabolic kinetics can be used to describe the oxidation rate. The steam oxidation behaviour has been investigated in the laboratory in an Ar-46%H2O mixture at 500, 600 and 700 °C for 336 h. It was observed that the morphology of the oxide layers was strongly influenced by temperature, and some of the same morphologies are also observed for power plant specimens. However, the temperatures at which they occur were different for plant and laboratory specimens, e.g. the presence of Cr rich bands within the oxide occurred at a lower temperature in the plant than in the laboratory. In addition there is a greater variety of oxide morphologies for long-term plant specimens compared to laboratory specimens. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106063/abstract [article] Steam oxidation of X20CrMoV121 : comparison of laboratory exposures and in situ exposure in power plants [texte imprimé] / M. Montgomery, Auteur ; A. N. Hansson, Auteur ; T. Vilhelmsen, Auteur . - 2013 . - pp. 674–684. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 8 (Août 2012) . - pp. 674–684 Mots-clés : Cr  diffusion;  power  plants;  steam  oxidation;  X20 Résumé : X20CrMoV121 is a 12% Cr martensitic steel which has been used in power plants in Europe for many decades. Specimens have been removed from superheater tubes to investigate long-term exposure with respect to steam oxidation. These tubes have been exposed for various durations up to 135 000 h in power plants in Denmark at steam temperatures varying from 450–565 °C. This paper collates the data, compares oxide morphologies and assesses to what extent parabolic kinetics can be used to describe the oxidation rate. The steam oxidation behaviour has been investigated in the laboratory in an Ar-46%H2O mixture at 500, 600 and 700 °C for 336 h. It was observed that the morphology of the oxide layers was strongly influenced by temperature, and some of the same morphologies are also observed for power plant specimens. However, the temperatures at which they occur were different for plant and laboratory specimens, e.g. the presence of Cr rich bands within the oxide occurred at a lower temperature in the plant than in the laboratory. In addition there is a greater variety of oxide morphologies for long-term plant specimens compared to laboratory specimens. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106063/abstract