Mean stress effects on fatigue life of a stainless steel in air and boiling water reactor (BWR) environments were evaluated by load-controlled tests. In stress-life, non-zero mean stresses increase life in low cycle fatigue regime in both environments and in high cycle regime in air. In high cycle fatigue regime in BWR environment, higher fatigue life was observed with negative mean stress while a decrease of the fatigue limit was found for positive one. In strain-life, the mean stress effects are insignificant. All data are well correlated with a Smith-Watson-Topper parameter showing no interaction between mean stress and BWR environment.

通过负荷控制试验评估了平均应力对不锈钢在空气和沸水反应堆（BWR）环境中疲劳寿命的影响。在应力寿命中，非零平均应力会增加两种环境下低循环疲劳状态下的寿命以及空气中高循环状态下的寿命。在BWR环境下的高周疲劳状态下，平均应力为负值时，疲劳寿命更长，而正应力值则疲劳极限降低。在应变寿命中，平均应力影响不明显。所有数据均与Smith-Watson-Topper参数良好相关，表明平均应力与BWR环境之间没有相互作用。