Estimation of fatigue strain-life curves for austenitic stainless steels in light water reactor environments

摘要

The ASME Boiler and Pressure Vessel Code design fatigue curves for structural materials do not explicitly address the effects o freactor coolant environmetns on fatigue life. Recent test data indicate a significant decrease in fatigue lives of austenitic stainless steels (SSs) in light wate reactor (LWR) environments. Unlike those of carbon and low-alloy steels, environmental effects on fatigue lives of SSs are more pronounced in low-dissolved-oxygen (low-DO) water than in high-DO water. This paper summarizes available fatigue strain vs. life data on the effects of various material and loading variables such as steel type. DO level, strain range, and strain rate on the fatigue lives of wrought and cast austenitic SSs. Statisticall models for estimating the fatigue lives of these steels in LWR environmetns have been updated with a larger data base. The significance of the effect of environment on the current Code design curve has bene evaluated.