Small fatigue crack initiation mechanisms and growth behavior of 304 stainless steel at room temperature

Abstract

The aim of this paper was to clarify the initiation and small fatigue crack growth mechanisms of 304 austenitic stainless steel at room temperature. The two-part silicon based replica method, repliset, was employed for measuring surface small crack growth in this research. Results showed that grain boundaries were the crack initiation sites and played an important role on the propagation of small cracks. Once the surface small crack length reached the critical crack size of 0.2mm, rapid growth of this crack occurred. Stress intensity factor range is not an appropriate parameter to correlate the small crack growth rate.