P91钢的蠕变-疲劳交互作用研究现状

摘要

The tests of creep -fatigue for P91 steel in domestic and abroad was summaried. Based on the data from creep - fatigue tests, the research on creep - fatigue interaction and life prediction models had been carried out,which were also summaried. Some results were made from the researches. For the tests loading controlled by strain, the holding time will be changed during the experiments. Creep and fatigue were negative interaction for the tests loading controlled by stress, while creep and fatigue were positive interaction for the tests loading controlled by strain. Modified ductility exhaustion model was a suitable method to predict the creep -fatigue life for P91 steel. Under the same experiment conditions,creep -fatigue life was less than relaxation fatigue life. The ASME criterion tends to give overly conservative life prediction,whereas the RCC -MR/DDS criterion exhibits a non -conservative tendency.%综述了国内外关于P91钢的蠕变-疲劳试验，以及前人在试验数据基础上开展的蠕变-疲劳交互作用研究和蠕变-疲劳寿命预测模型研究。综述前人的研究成果，得到了以下结论：应变控制的蠕变-疲劳试验，试验过程中保载时间会发生变化；应变控制的蠕变-疲劳试验认为蠕变与疲劳互相促进作用，应力控制的蠕变-疲劳试验认为疲劳抑制了蠕变；修正的延性耗损模型较适用于预测P91钢的蠕变-疲劳寿命；试验条件相同的情况下，对于CF(Creep-fatigue)试验与RF(Re1axation Fatigue)试验，CF寿命明显小于RF寿命；利用ASME规范预测的寿命偏于保守，利用RCC-MR/DDS规范预测的寿命稍高于试验值。