High temperature fatigue creep life prediction of 316L stainless steel under 2-step load

摘要

Pressurized equipment often experiences the state that force or temperature is changed inevitably in operation under high temperature condition,namely undergoes 2-step or multi-step load. To investigate the fatigue creep behavior and life of material and structure which may be influenced under different step load,the 3 i 6L stainless steel fatigue creep experiment under 2-step load at high temperature was conducted,and the damage evolution and life were analyzed. The result showed an obvious load history effect on the fatigue creep behavior and life of 316L steel under high temperature condition. A modified failure rule coupled with load history effect induced by dynamic strain aging (DSA) was presented in the paper. The 316L steel fatigue creep life under 2-step load at high temperature was predicted well by the rule.