ISSN: 1546-962X
CODEN: JAIOAD
Published Online: 12 November 2009
Page Count: 14

Interrelationship between True Stress–True Strain Behavior and Deformation Microstructure in the Plastic Deformation of Neutron-Irradiated or Work-Hardened Austenitic Stainless Steel

Kondo, K.
Research Group for Corrosion Damage Mechanism, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2–4 Shirakata-Shirane, Tokai-mura, Ibaraki-ken

Miwa, Y.
Research Group for Corrosion Damage Mechanism, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2–4 Shirakata-Shirane, Tokai-mura, Ibaraki-ken

Tsukada, T.
Research Group for Corrosion Damage Mechanism, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2–4 Shirakata-Shirane, Tokai-mura, Ibaraki-ken

Yamashita, S.
Materials Monitoring Section, Fuels and Materials Department, Oarai Research and Development Center, Japan Atomic Energy Agency, 2–4 Shirakata-Shirane, Tokai-mura, Ibaraki-ken

Nishinoiri, K.
Materials Monitoring Section, Fuels and Materials Department, Oarai Research and Development Center, Japan Atomic Energy Agency, 2–4 Shirakata-Shirane, Tokai-mura, Ibaraki-ken

(Received 2 February 2009; accepted 1 October 2009)

Abstract

True stress–true strain relation and deformation microstructure have been examined for high purity Fe-18Cr-12Ni alloy and its alloys doped with 0.7 wt % Si or 0.09 wt % C. In high purity alloy and C-doped alloy irradiated at 240°C up to 3 dpa, the work hardening rate is equivalent to that in unirradiated alloys. These alloys show dislocation channel structure after irradiation and deformation. In irradiated Si-doped alloy, however, the work hardening rate is different from that in unirradiated alloys. This alloy shows fully developed dislocation cell structure after deformation, as seen in unirradiated deformed stainless steels. The cell structure in irradiated Si-doped alloy was much smaller than that in unirradiated Si-doped alloy and in type 316L stainless steel. One of the factors affecting the change in the work hardening rate of irradiated austenitic stainless steel at 240°C is strong obstacles such as γ precipitate that acts as dislocation pining and dislocation loops such as Frank loops that do not act as obstacles.

Keywords:
austenitic stainless steel, neutron irradiation, plastic deformation, dislocation channel, dislocation cell, true stress–true strain relation, work hardening rate

Paper ID: JAI102358
DOI: 10.1520/JAI102358
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