“…However, the process of subsurface crack initiation and propagation is still not clear and there are few theoretical models developed to analyze the different crack initiation process [8,9,13,20]. Additionally, although there have been many studies on the factors those may affect VHCF propensity of high strength steels, such as environmental medium [14][15][16], loading frequency [17,18], microstructure state [19][20][21], etc. [5,8,12], the influence of notch effect has not been fully understood.…”