疲労き裂の発生・成長挙動に与える炉水環境中での温度の影響について
概要
The fatigue tests were conducted under different temperature (325℃ and 200℃) in simulated PWR reactor coolant condition with interrupting tests and replica-observation. By observing fatigue crack on the specimen surface, the effect of temperature on crack initiation and growth were studied. From the results of the fatigue tests, the followings were confirmed; ・The number of cycles that fatigue cracks initiate is almost the same in different temperature. On the other hand, the number of cracks that initiate on the specimen increase in high temperature. ・The crack growth rate is accelerated and the number of cracks coalescence increase in high temperature condition. ・The increase of temperature decreases fatigue life and the decrease of fatigue life is mainly caused by the increase of crack coalescence.
