Quantitative evaluation of effects of non-metallic inclusions on fatigue strength of high strength steels. I: Basic fatigue mechanism and evaluation of correlation between the fatigue fracture stress and the size and location of non-metallic inclusions

摘要: Abstract The effects of non-metallic inclusions on the fatigue strength metals are reviewed and major factors involved discussed. It is emphasized that must be analysed from viewpoint small defects or cracks, because threshold condition at limit not for crack initiation but non-propagation a emanating inclusions. To accommodate this point equations prediction stress intensity factor range, ΔK th , limit, σ w cracks were extended to predict those contained in high steels. demonstrated square root projected area Vickers hardness, Hv matrix crucial parameters containing predictions given by proposed very good agreement with experimental results obtained fracture surface showing fish-eye patterns. reasons why steels does increase linearly increasing reason scatters so large, clarified.