温度对2CrMo转子钢低周疲劳性能的影响

摘要

在室温和高温(450,500,566℃)下对2CrMo转子钢进行了应变控制的低周疲劳试验,得到了该钢应变-寿命关系式及循环稳定应力-应变曲线,研究了温度对低周疲劳性能的影响,并观察了疲劳断口形貌。结果表明：在试验温度下,试验钢均出现了循环软化现象；随着温度的升高,试验钢的疲劳循环强度系数及循环应变硬化指数下降,同一应变下的低周疲劳寿命缩短；其疲劳断口中疲劳辉纹的间距随温度的升高而增大,塑性变形增大。%The strain controlled low cycle fatigue test was conducted on 2CrMo rotor steel at room temperature and high temperatures (450,500,566 ℃)and the strain-life relation and cyclically stable stress-strain curves of the steel were obtained.The effect of temperature on the low cycle fatigue property was studied and the fatigue fracture surface was observed.The results show that the cyclic softening phenomena appeared in the tested steel at the experimental temperatures.With the increase of the temperature,the cyclic strength coefficient and cyclic strain hardening exponent of the tested steel decreased;the low cycle fatigue life at the same strain decreased;the distance between the fatigue striations increased and more plastic transformation appeared.