镍铜合金NCu30-4-2-1电渣熔铸件的热变形行为

Hot deformation behavior of nickel-copper alloy NCu30-4-2-1 electroslag castings

在Gleeble-3800热模拟机上对电渣熔铸态镍铜合金NCu30-4-2-1进行高温热压缩实验,研究该合金在900～1 100℃和应变速率为0.01～10 s-1条件下的流变应力行为。结果表明:在变形初期,随着应变的增加,流变应力增大,出现峰值后逐渐趋于平稳;随着温度的升高,峰值应力减小,而随着应变速率的增大,峰值应力增大,求得镍铜合金NCu30-4-2-1的热变形激活能Q为416.5 kJ/mol,Zener-Hollomon参数的对数和峰值应力的对数较好地满足线性关系,建立了镍铜合金NCu30-4-2-1的流变应力方程;合金的显微组织受变形温度和显微组织的影响,变形温度越高,应变速率越低,越有利于动态再结晶的发生。

The flow stress behavior of nickel-copper alloy NCu30-4-2-1 electroslag castings during hot compression was studied by thermal simulation test at the deformation condition of 900-1 100 ℃ and 0.01-10 s^-1 on the Gleeble-3800 thermal-mechanical simulator. The results show that the flow stress increases with increasing strain and tends to be constant after a peak value. The peak stress increases with increasing strain rate, and decreases with increasing deformation temperature. The calculated hot deformation activation energy is 416.5 kJ/mol. The logarithm of Zener-Hollomon parameter has a good linear relationship with the logarithm of peak stress, and the flow stress equation of nickel-copper alloy NCu30-4-2-1 was established. The microstructure strongly depends on the deformation temperature and strain rate, and lower strain rate promotes the dynamic recrystallization.