Abstract: | Based on the concept of the equivalent crack and theories of crack growth, a fatigue-creep life prediction model is presented. The influence of time independent fatigue , time dependent static creep and cyclic creep on the equation of micro crack growth speed is considered. Tomkins micro crack growth model is applied to time independent crack propagation while C* parameter is applied to time dependent crack propagation.1.25Cr0.5Mo steel fatigue creep life with stress control at 540°C is predicted by the model. The predicted results are correlated well with the experimental ones. |