Hastelloy G-3合金热变形特性研究

Research on Hot Deformation Behavior of Hastelloy G-3 Alloy

摘要:

利用变形温度为1050~1200 ℃、应变速率为0.1~10 s-1的恒温热压缩试验系统分析了Hastelloy G-3合金的高温变形特性及变形后的组织特征。对高应变速率下的流动应力进行变形热效应修正，建立了G-3合金热变形过程中峰值应力与变形温度、应变速率关系的本构模型。结果表明：所建立的本构模型在预测G-3合金热变形峰值应力时具有良好的精确度，能够满足工程应用的要求。G-3合金热加工过程的软化机制为动态再结晶，根据热变形后的组织特征确定G-3合金合理的热变形温度为1180~1200 ℃，应变速率为5~10 s-1。

Abstract:

The hot deformation behavior and the subsequent microstructure characteristics of Hastelloy G-3 alloy were studied by isothermal compression tests at the strain rates of 0.1-10 s-1 and the temperatures of 1050-1200 oC. The flow-stress at high strain rates were corrected considering the effect of deformation heating, and a new constitutive relationship between peak stress and deformation temperature as well as strain rate for G-3 alloy at high temperature was established. The results show that the built material model has good fitting accuracy to satisfy the engineering need. The softening mechanism of G-3 alloy is dynamic recrystalization during hot working process. According to the microstructures after deformation, for G-3 alloy the proper deformation temperature is 1180-1200 oC and the proper strain rate is 5-10 s-1.