Notch size influence on fatigue limit of steels pertinent to grain size

Abstract Fatigue limit of notched specimens is influenced by notch geometries and material microstructure. In this paper, seven groups of fatigue measurements on different steels with average grain size (G) from 8 to 64 μm were analyzed, and an explicit model was proposed to describe notch geometry effect on fatigue limit and its relation to G. Additionally, normal distribution theory was incorporated to consider the inevitable scatter of fatigue limit caused by material heterogeneity and machining/measurement errors. The result shows that the proposed model can predict fatigue limits of both notched and cracked specimens of various steels.