[2L08-12] Structural Materials for Nuclear Fusion Reactors 1

[2L11] Ion irradiation effects on the 12Cr ODS steel after a novel recrystallization process

*Jingjie Shen¹, Takeo Muroga¹, Kiyohiro Yabuuchi², Sho Kano³, Hiroaki Abe³ (1. NIFS, 2. Kyoto Univ., 3. UTokyo)

Keywords:ODS steel, Ion irradiation, irradiation defects, Hardening

A multi-directional thermomechanical process was applied to get recrystallization and thus improve the ductility of oxide dispersion strengthened (ODS) ferritic steel. In this study, it is to investigate the microstructural evolution and hardness changes of the recrystallized 12Cr ODS steel upon ion irradiation. Ion irradiation experiments were carried out at 973 K using single beam (6.4 MeV Fe³⁺) and dual beam (6.4 MeV Fe³⁺ and 1 MeV He⁺). Irradiation dose was estimated at about 10.5 dpa at the peak damage. After irradiation, the nanoindentation harness tests were conducted, and microstructure was characterized by TEM. Results showed that irradiation defects such as helium bubbles were observed, however, the irradiation hardening was not obvious, suggesting helium bubbles did not evidently induce hardening.