Deformation Structure in Highly Irradiated Stainless Steels

• Published in: Journal of nuclear science and technology Vol. 45; no. 4; pp. 274 - 287
• Main Authors: NISHIOKA, Hiromasa, FUKUYA, Koji, FUJJI, Katsuhiko, KITSUNAI, Yuji
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis Group 01.04.2008; Atomic Energy Society of Japan
• Subjects: Applied sciences; deformation; dislocation channeling; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; grain boundary; Installations for energy generation and conversion: thermal and electrical energy; irradiation-assisted stress corrosion cracking; neutron irradiation; stainless steel; twin; Spacing; Stress corrosion cracking; Stress strain; Light water reactor; Nuclear reactor; Heterogeneity; dislocation channeling; irradiation-assisted stress corrosion cracking; Stainless steel; grain boundary; Neutron irradiation; deformation; Microstructure; twin
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.2008.9711437

Surface steps and deformation microstructure in cold-worked SUS316 stainless steels irradiated to 4 and 35 dpa (displacements per atom) were examined after being deformed by uniaxial tensile stress at 320°C at a slow or fast strain rate. Dislocation channeling was the predominant mode of deformation near the surface at the slow strain rate. Twinning was dominant at the fast strain rate whereas twinning and nanotwin formation occurred in the locally stressed area at the slow strain rate. Deformation heterogeneity measured using the spacing of coarse surface steps induced by dislocation channels increased with increasing dose from 4 to 35 dpa. Grain boundary separation occurred when dislocation pileups and high normal stress on the grain boundary plane coexisted, which likely was a precursor of intergranular cracking without any environmental factor.