Thermal fatigue strength of type 304 stainless steel in simulated BWR environment

Abstract

Thermal fatigue tests of type 304 stainless steel were performed using thermal fatigue testing apparatus developed in order to clarify thermal fatigue behavior in a BWR environment. Pressurized high and low temperature pure waters were alternately supplied to an autoclave containing a thin-walled cylindrical specimen. The fatigue specimen was then subjected to homogeneous thermal stress through the wall thickness. The thermal fatigue strengths were compared with the mechanical fatigue strength performed in air and in high temperature water. It was found that the thermal fatigue strength of type 304 stainless steels almost agreed with the mechanical fatigue strength when the nominal stress amplitude was converted to a fictitious stress amplitude by using the mean value of strain amplitudes for room temperature and 288°C.