Environmental effect of PWR primary water on fatigue life of stainless steel (influence of loading rate on fatigue life reduction)

Abstract

Fatigue tests on Type 316 stainless steel specimens were conducted for various combinations of rise time and strain range in simulated pressurized water reactor (PWR) water. It was demonstrated that crack growth rate estimated from test results correlated well with the strain intensity factor range. An equation for predicting F en was obtained as a function of rise time and strain range. It was found that, although F en depends on strain range, the magnitude of the change in F en due to the strain range is negligibly small compared with the scatter in the test results.

Environmental effect on fatigue strength of stainless steel in PWR primary water: Relation between fatigue life in air and environment

“…The smaller strain range resulted in larger N f(air) / N f(env) for the strain range larger than 0.5%. The strain range dependency on N f(air) / N f(env) has been discussed in two previous papers by the author 24,28 . In them, it was shown that strain range dependency can be explained by assuming the environmental effect depends not on strain rate but on rise time.…”

“…The strain range dependency on N f (air) /N f (env) has been discussed in two previous papers by the author. 24,28 In them, it was shown that strain range dependency can be explained by assuming the environmental effect depends not on strain rate but on rise time. Since the rise time corresponds to Δε/(dε/dt), it varies depending on the strain range for the same strain rate.…”