TY - JOUR
T1 - In situ and ex situ characterisation of oxide films formed on strained stainless steel surfaces in high-temperature water
AU - Takeda, Yoichi
AU - Shoji, Tetsuo
AU - Bojinov, Martin
AU - Kinnunen, Petri
AU - Saario, Timo
N1 - Funding Information:
This work has been conducted within the integrity and Life Time of Reactor Circuits (INTELI) project as a part of SAFIR (Safety of nuclear power plants—Finnish national research programme 2003–2006) funded by the Finish Ministry of Trade and Industry (KTM) and coordinated by the Finnish Nuclear Safety Authority (STUK). This work has been supported by the grand-in aid for the 21st Century COE Program, “The Exploration of the Frontiers of Mechanical Science Based on Nanotechnology”, The Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT).
PY - 2006/10/15
Y1 - 2006/10/15
N2 - A possible approach in describing the role of the environment in the phenomena behind initiation and propagation of a stress corrosion crack is to assume that the transport of matter and charge through the oxide film on the material is one of the rate-controlling factors. Straining of the bulk material may affect the transport rates of ionic defects, such as vacancies and interstitials, through the oxide film. The aim of the present work has been to verify the applicability of combined slow strain rate tests (SSRT) and contact electric resistance (CER) measurements to assess the influence of strain on the electric properties of oxide films on AISI 316L stainless steel with or without prior cold work in simulated boiling water reactor (BWR) coolant conditions. The SSRT-CER measurements have been combined with ex situ characterisation of the oxide films after experiments using electron spectroscopy for chemical analysis (ESCA) and scanning electron microscopy (SEM). The results suggest that the effect of strain on the resistance of the oxide films seems to correlate with the effect of the same parameter on the Cr(III) concentration in the inner layer of the oxide. In addition, important differences between the concentration of Ni and Fe in the outer layer formed on stressed and unstressed surface have been observed. Based on the mixed-conduction model for oxide films, an attempt is made to evaluate the effect of straining on the electric properties of the oxide films and to correlate these effects with the changes in film composition and structure.
AB - A possible approach in describing the role of the environment in the phenomena behind initiation and propagation of a stress corrosion crack is to assume that the transport of matter and charge through the oxide film on the material is one of the rate-controlling factors. Straining of the bulk material may affect the transport rates of ionic defects, such as vacancies and interstitials, through the oxide film. The aim of the present work has been to verify the applicability of combined slow strain rate tests (SSRT) and contact electric resistance (CER) measurements to assess the influence of strain on the electric properties of oxide films on AISI 316L stainless steel with or without prior cold work in simulated boiling water reactor (BWR) coolant conditions. The SSRT-CER measurements have been combined with ex situ characterisation of the oxide films after experiments using electron spectroscopy for chemical analysis (ESCA) and scanning electron microscopy (SEM). The results suggest that the effect of strain on the resistance of the oxide films seems to correlate with the effect of the same parameter on the Cr(III) concentration in the inner layer of the oxide. In addition, important differences between the concentration of Ni and Fe in the outer layer formed on stressed and unstressed surface have been observed. Based on the mixed-conduction model for oxide films, an attempt is made to evaluate the effect of straining on the electric properties of the oxide films and to correlate these effects with the changes in film composition and structure.
KW - Contact electric resistance
KW - Kinetic model
KW - Oxide film
KW - Simulated nuclear reactor coolant
KW - Slow strain rate test
KW - Stainless steel
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U2 - 10.1016/j.apsusc.2005.11.073
DO - 10.1016/j.apsusc.2005.11.073
M3 - Article
AN - SCOPUS:33749137789
SN - 0169-4332
VL - 252
SP - 8580
EP - 8588
JO - Applied Surface Science
JF - Applied Surface Science
IS - 24
ER -