Mechanical behavior of oxide dispersion strengthened steels irradiated in JOYO

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 the experimental fast reactor JOYO to evaluate their irradiation behavior. Engineering stress strain curves 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 of tensile properties indicated that degradation of the tensile properties 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, types of inert gas during mechanical alloying, heat-treatment temperature and initial phases of the matrix. (author)