Effect of Surface Roughness on Fatigue Strength in Hot-rolled Sheet Steel with High Tensile Strength : Part 2 : Effect of Mean Stress

Abstract

The reliability of fatigue strength is one of the most important properties on the light-weight car components using high tensile steels. In this study, the effect of mean stress on fatigue strength of hot-rolled sheet steel under two surface conditions was discussed. As a result, Haigh diagram used actual rupture stress was well predicted fatigue limit under the conditions of that maximum stress was not beyond yield stress. When Haigh diagrams will be used a design of components, it is important to select adequate line for prediction of fatigue limit.