In the regime of Very-High-Cycle Fatigue (VHCF) for high strength steels, crack initiation and early growth dominate the fatigue life. The process of crack initiation and early growth of high strength steels at VHCF regime almost originates from the interior of the material with fish-eye embracing FGA or ODA. In this paper, fatigue tests on two high strength steels, i.e. a high carbon chromium steel and a medium carbon chromium steel, were performed with rotating bending and ultrasonic fatigue testing machines. The results show the dimensions of FGA and fish-eye as a function of inclusion size and reveal the correlation of the dimensions for FGA and fish-eye with fatigue failure cycles. The results also show the values of stress intensity factor ranges for FGA and fish-eye keep constant with fatigue failure cycles, which was used to estimate the fatigue life of high cycle and VHCF for high strength steels.
Hong YS,Zhao AG,Sun CQ. On Crack Initiation and Early Growth of Very-High-Cycle Fatigue for High Strength Steels[C]Fatigue and Corrosion Damage in Metallic Materials: Fundamentals, Modeling and Prevention,2012.