Micro-Crack Initiation, Propagation and Threshold in Elevated Temperature Inelastic Fatigue

Abstract

Micro-crack initiation, propagation and threshold behavior in plain, short crack, weld defect and notch specimens of 304 stainless steel are observed under elevated temperature strain-controlled inelastic fatigue conditions. The effects of temperature, strain rate, wave shape and strain gradient are analyzed and methods for estimating fatigue life and fatigue limit are postulated on the basis of the behavior of the micro-cracks.