304不锈钢在室温和高温下的蠕变－棘轮－疲劳交互作用的实验研究

he creep, ratcheting behaviour and fatigue failure, as well as their interaction were investigated by uniaxial cyclic stressing tests for SS304 stainless steel at room temperature, 100oC and 300oC. The effects of mean stress, stress amplitude, stress rate and the peak stress holds on the ratcheting strain and final failure life were discussed. Simultaneously, the variations of responded strain amplitude with the number of cycles were illustrated to discuss the interaction of creep, ratcheting behaviour and fatigue failure. The experimental results show that the creep and ratcheting behaviour for SS304 stainless steel at different temperatures are different. The fatigue life of the material at room and high temperatures all depend greatly on mean stress, stress amplitude, stress rate and the peak stress holds of uniaxial cyclic stressing. And the material show different kind of failure modes: ratcheting failure due to large ratcheting strain and fatigue failure due to low-cycle fatigue with nearly constant responded strain amplitude.