抄録
In the structures or the components used at the high temperature, the ratchet deformation and the creep fatigue by the cyclic thermal stress are important breakage style. The influence of the ratchet deformation on fatigue strength at the high temperature is not necessarily clear, therefore it is demanded to clarify the tolerance. In this study, a new fatigue testing method of attention to two parameters like the accumulative strain and ratchet expired cycle was designed to understand the influence of the ratchet transformation on fatigue life under the fast reactor component condition, and the influence that the ratchet deformation exerted on the decrease in the fatigue life was examined.