Correlation Between Tensile Property and Micro-Hardness Irradiated RAF/M Steel

Irradiation hardening and embrittlement due to high-dose neutron irradiation around 573 K are important issues on RAF/M steels. The purpose of this study is to examine a correlation between tensile property and micro-hardness in F82H steel using neutron and ion-irradiation. Neutron irradiation was performed in HFIR up to 8 dpa at 573 K. Ion irradiation experiment at ~573 K was carried out at the TIARA facility of JAEA. Relationship between the micro-hardness (Hm) and Vickers hardness (Hv) in F82H and its heat treatment variants was calculated by Hv≒60×Hm. The yield stress (σy) was evaluated by σy=3.2~3.4×Hv×(0.1)n (n: work hardening exponent) from this study. Following these equations, it can be estimated that the yield stress of irradiated F82H up to ~100 dpa at 573 K is about 1000 MPa.