Effects of Pressurized Water Reactor Environment and Cyclic Loading Parameters on the Low Cycle Fatigue Behavior of 316L Stainless Steel

Austenitic stainless steels used in light water reactor coolant environments can be susceptible to environmentally assisted fatigue due to non-monotonic loading conditions. Effects of a pressurized water reactor (PWR) environment containing hydrogen and cyclic loading parameters on the low cycle fatigue (LCF) behavior of 316L stainless steel were investigated by comprehensive striation spacing evaluation. The exposure to a PWR environment results in a decreased LCF lifetime, an enhanced fatigue crack initiation, and an accelerated fatigue crack growth rate of 316L austenitic stainless steel. The effect of the loading waveform (periodic underload PUL, periodic overload POL, and constant amplitude sawtooth CA) was also evaluated. PUL reduces the low cycle fatigue lifetime, accelerates the fatigue crack growth rate, and advances the cycle where initiation of fatigue crack occurs compared to CA loading.