Irradiation hardening and mechanical behavior of K-RAFM steels subjected to Fe ion irradiation at doses up to 20 dpa

Abstract

This study explores the irradiation hardening behavior of K-RAFM steel and Reference steel through micropillar compression tests. Fe ion irradiation at 300 degrees C was conducted to achieve a dose of 20 dpa. The irradiated specimens exhibited increased yield strength and reduced strain bursts, which are attributed to the formation of radiation-induced defects. K-RAFM steel exhibited superior resistance to irradiation hardening compared to Reference steel across all irradiation conditions. This improved performance is attributed to the addition of Ti, which enhances the fraction of MX precipitates that serve as efficient traps for radiation-induced defects. Additionally, the yield strength changes observed for K-RAFM steel at 2 dpa and 20 dpa are consistent with trends reported for other RAFM steels in the literature, highlighting its promise as a structural material for fusion reactor applications.