难变形镍基高温合金GH710的高温变形特性

Hot Deformation Characteristics of Ni-Based Superalloy GH710 with Hard Deformation

利用热模拟试验机研究了GH710合金在变形温度为1 110～1150℃,应变速率为0.01～1 s^(-1)条件下的高温变形特性及变形后的组织特征。结果表明:在1150℃以下热变形时合金发生了亚固溶态的再结晶,且γ相在1 130℃时已部分回溶;通过Arrhenius双曲正弦函数模型构建了合金的本构关系,得到了合金热变形激活能为693.46 kJ·mol^(-1);合金动态再结晶临界应变随着应变速率的增大及变形温度的降低而增加,且临界应变和峰值应变之间满足ε_c=0.61_(εp);合金热加工过程中的软化机制为动态再结晶,根据热变形后的组织特征确定合金合理的热变形温度范围为1 110～1130℃,应变速率为0.01 s^(-1)。

The hot deformation and microstructure characteristics of GH710 alloy were investigated by thermal simulated test at the strain rates of 0. 01--1 s 1 and temperatures of 1 ll0--1 150 ℃. The results show that metastable solid solution stare recrystallization occurred below 1 150 ℃, and phase partly dissolved into the matrix at 1 130 ℃. A hyperbolic sine function of Arrhenius was used to describe the constitutive relation for GH710 alloy with good fit accuracy, giving the hot deformation activation energy of 693.46 kJ ~ mo1-1, The critical strain of dynamic recrystalliztion, which met a linear relationship with peak strain as ec =0. 61~p, increased with increasing the strain rate and decreasing the deformation temperature. The soften mechanism of GHT10 alloy was dynamic recrystallization during hot working process. According to the microstructure after hot deformation, it was proposed for GH710 alloy that proper deformation temperature range was 1 110-1 130 ℃ and proper strain rate was 0. 01 s-1.