应变速率对IC10合金1100℃低周疲劳性能的影响

Strain Rate Effects on Low Cycle Fatigue Performance of Superalloy IC10 in 1100 ℃

研究了不同应变速率(1×10-2s-1,1×10-3s-1,1.6×10-4s-1)下IC10合金1100℃下的低周疲劳性能、弹性模量、屈服强度和循环应力响应行为。研究结果表明:随应变速率的增加,材料的弹性模量没有变化,而材料的屈服强度明显增大,材料的屈服强度与应变速率的对数符合线性关系;材料在3种应变速率下都表现为明显的循环软化,随着应变水平的降低,该材料的循环软化行为逐渐地变弱。应变速率对低周疲劳寿命的影响规律与应变水平的大小有关:当总应变范围大于1.2%时,应变速率为1.6×10-4s-1的低周疲劳寿命最长,应变速率为1×10-3s-1的疲劳寿命最短,而应变速率为1×10-2s-1的疲劳寿命界于二者之间;当总应变范围为0.8%时,随着应变速率的减小,疲劳寿命明显缩短。

Low-cycle fatigue （LCF） performance, elastic modulus, yield strength and cyclic stress response of superalloy IC10 have been evaluated at 1 100℃ under different strain rates （1×10^-2s^-1 , 1×10^-3s^-1 , and 1.6×10^-4s^-1 ）. The results show that with the increase of the strain rate, the yield strength increases obviously but the elastic modulus keeps stable. The yield strength is linearly related to the logarithm of the strain rate. Under the three different strain rates, cyclical softening behavior is always obvious, and the degree of cyclic softening behavior and low-cycle fatigue life both depend on strain level. Under the total strain range of 0.8%, low-cycle fatigue life decreases obviously with the decline of the strain rate. Under the total strain range greater than 1.2%, the low-cycle fatigue life is longest under the strain rate of 1.6×10^-4s^-1 and is shortest under the strain rate of 1×10^-3s^-1.