Discussion of Miner’s Rule on Type 304 Austenitic Stainless Steel at 288 C in Air Free

The surface worked type 304 stainless steel exhibits an extraordinary behavior when subjected random fatigue load. In this study the effect of load history on the cumulative damage was examined. The random loads are 1) two step increasing stresses, 2) two step decreasing stresses, 3) repeated high and low step stresses, 4) repeated low and high step stresses, and 5) gradually increasing stresses. In any cases the cumulative damage calculated according to Miner’s rule remarkably exceeded 1.0, especialy for the gradually increasing stresses. In order to survey the mechanism, the elastic and plastic strain behaviors were studied. The extraordinal cumulative fatigue damage could be explained by the remarkable fatigue hardening behavir of austenitic stainless steel.