Mechanical behavior of oxide dispersion strengthened steels irradiated in JOYO

Yamashita, Shinichiro   ; Yoshitake, Tsunemitsu ; Akasaka, Naoaki; Ukai, Shigeharu  ; Kimura, Akihiko*

Oxide dispersion strengthened (ODS) steels, which are candidate materials for water-cooled solid breeder blankets, were fabricated with several manufacturing parameters, and then irradiated in JOYO to evaluate their irradiation behavior. Engineering stress strain curve of ODS steels irradiated at 673 K exhibited superior material response, i.e., increased tensile strength due to irradiation hardening and no loss of total elongation. Also, their temperature dependence on tensile property indicated that degradation of the tensile property at elevated temperature, which is closely related to phase stability during irradiation, could be avoided due to optimal combination of manufacturing parameters, such as chemical composition, type of inert gas during mechanical alloying, heat-treatment temperature and initial phase of the matrix.