Radiation Hardening and Swelling in Ti-bearing Reduced Activation Ferritic-Martensitic Steels

In this study, we investigated the radiation-induced hardening and swelling in ion irradiated Ti-bearing RAFM steels. Ti is added as an alloying element in order to induce the precipitation of (Ti,W)C nano-particles. The radiation-induced hardening was characterized by compressing micro-pillars fabricated on the cross-sections of the self-ion irradiated sample. The blanket of DEMO nuclear fusion reactor is exposed to harsh environments such as high temperature and high neutron flux. Resistance to radiation damage as well as high temperature is required for the materials used as the blanket. RAFM (Reduced Activation Ferritic / Martensitic) steel is a strong candidate material for the structural materials of a fusion reactor, and the radiation damage of RAFM steel has been an interest for recent studies. In this study, we investigated the radiation-induced hardening and swelling in ion irradiated Ti-bearing RAFM steels. The radiation-induced hardening was characterized by compressing micro-pillars fabricated on the cross-sections of the self-ion irradiated sample. Swelling was experimentally measured by implanting He ions on the polished surface at nominal room temperature, and annealing the irradiated specimens at 700 K. The radiation damages of Ti-bearing RAFM steel are compared with other RAFM steels such as Eurofer97 and F82H.