Internal Crack Initiation and Propagation Behaviors in High Cycle Fatigue of HSP-treated SUS 316 L Steel.

Abstract

In our previous paper, as the results of the high cycle rotating fatigue tests of HSP-treated SUS 316 L steel, the fatigue crack initiation was observed on inside of the specimen by fractographical investigation using the scanning electron microscope (SEM). In this paper, in order to investigate the mechanism of the internal crack initiation and propagation behaviors, elastic-plastic finite element method (FEM) analysis was carried out. For the FEM analysis, the residual stress and the yield stress distributions models of the HSP-treated specimen were established based on the residual stress by X-ray diffraction measurement. As the results of analysis, the depth of maximum stress of the specimen by FEM agreed well with the depth of the crack origin by SEM. Also internal crack propagation behaviors could be satisfactorily explained by the FEM analysis.