高温高圧水中におけるステンレス鋼の疲労寿命に及ぼすひずみ速度の影響

（ひずみ速度不感帯に関する一考察）

抄録

In hot water simulating LWR coolants, the fatigue life of stainless steel depends strongly on temperature and strain rate and decreases with decreasing strain rate. On the other hand, it has been experimentally confirmed that a certain strain range on the compression side does not contribute to the reduction of fatigue life and has been reported as the insensitive strain region. Although the evaluation method of environmental effects is prescribed in the JSME Standard Environmental Fatigue Evaluation Method, it is expected that the amount of reduction in fatigue life can be predicted more rationally by considering this region.

In the Fatigue Evaluation Subcommittee and the Fatigue Evaluation Techniques Working Group of the JSME, we are studying a method to estimate the value of this region easily and safely, and also incorporate it into fatigue assessment. This paper describes the outline of this activities.