Growth Retardation of Fatigue Crack by Cold Expanded with Ring Indented Method for AISI 304 Stainless Steel

Abstract

Drilled, cold expanded with ring indented method was employed for crack-tip on the both sides and front side of the specimens, thus build up the residual compressive stresses, strain hardening and plasticity induced closure, and lead toward crack growth retardation. The compact tension specimens of AISI 304 stainless steel were used drilled, cold expanded with ring indented in the fatigue test. The experimental methods were drilled (Φ=2mm ) and cold expanded (Φ=2.074mm) and both sides at 2mm and 1mm position of the crack-tip in the specimen, then apply 0kN, 6KN, and 9kN test loads, respectively. The experimental results showed that, for the same test position, the number of delay cycles result from cold expanded than that of drilled and the number of delay cycles are 220798. For the same position, the stronger test load is, the greater crack growth retardation effect is. And, This study proposed some useful information on utilizing cold expanded with ring indented method for AISI 304 Stainless Steel crack growth retardation.