在620 ℃, 对In783合金进行不同应力水平下的单轴拉伸蠕变试验, 获得了该合金的Norton-Bailey本构参数; 研究了应力水平对合金蠕变性能和蠕变机制的影响, 并观察了合金在典型应力水平下的位错特征。结果表明: 在不同应力水平下, 合金的本构参数并不相同, 高应力区的应力指数比低应力区的大; Norton-Bailey本构方程能较好地描述低应力区的蠕变曲线, 但不能很好地描述高应力区的蠕变曲线; 不同应力水平下本构参数不同的本质原因是蠕变机制不同, 高应力区的蠕变机制以位错绕越第二相粒子为主, 低应力区的蠕变机制以位错热激活攀移为主。

Creep experiments for In783 alloy uniaxial tensile samples were carried out at 620 ℃ and different stress levels, and Norton-Bailey constitutive parameters of the alloy were obtained. The effects of stress levels on creep property and creep mechanism were studied, and the dislocation features of the alloy at typical stress levels were observed. The results show that the Norton constitutive parameters of the alloy at different stress levels were not same. Norton stress index at low stress area was lower than that at high stress area. The creep curves could be well described by Norton-Bailey constitutive equation at low stress area, but can not be accurately described at high stress area. The essential reason for the variation of constitutive parameters was the different creep mechanism in these two stress areas. Creep mechanism was mainly dislocation around the second phase particles at high stress area, and might be dislocation thermal activation climb at low stress area.