纯镍与GH3625合金热压缩行为研究及本构解析

利用Gleeble-3500热模拟试验机对铸态纯镍及GH3625合金在变形温度900~1 200 ℃、应变速率0.1~10 s^－1、应变量60%条件下,进行了热压缩实验.研究分析了纯镍以及GH3625合金的热塑性变形规律,并构建了本构方程,绘制了2种材料不同变形参数下的热加工图,分析了热加工图稳定与失稳区所对应的组织特征.研究发现纯镍在热压缩变形时,失稳区组织出现晶粒层级分化现象.通过对热加工图分析研究,确定纯镍最优热变形温度为1 050 ℃,最优应变速率为0.1 s^－1;GH3625合金最优变形温度为1 170 ℃,最优应变速率为0.1 s^－1.

Investigated on hot compression behavior and constitutive analysis of pure nickel and GH3625 alloy

Hot compression deformation experiment of pure nickle and GH3625 alloy were conducted on a Gleeble-3500 thermomechanical simulator at a 900 to 1 200 ℃, a deformation rate range of 0.1~10 s^－1 and a deformation of 60%. The constitutive equation of pure nickel and GH3625 alloy were constructed. The processing map which under different deformation parameters were drawn and the microstructure characteristics of the stable and unstable regions of the processing map were analyzed. During the hot compression deformation of pure nickel, it was found that the grain appears to hierarchical differentiation. According to the analysis of the process map, the optimum hot deformation temperature of pure nickel is1 050 ℃, the strain rate is 0.1 s^－1, the optimum deformation temperature of Inconel alloy is about 1 170 ℃, the strain rate is 0.1 s^－1.