中文摘要：

采用Gleeble-3500热模拟试验机研究了Hastelloy C-276镍基合金在0．01～10s^-1、1000—1250℃、应变量0．7条件下的高温恒温压缩变形行为，对热压缩后的组织进行了金相显微分析。结果表明：C-276合金热变形流变应力随着应变速率的增大和变形温度的降低而增大。热变形过程中发生了动态再结晶，当温度r≥1200℃时，发生了完全动态再结晶，T〈1200℃时，发生部分动态再结晶。热变形流变应力可用Zener-Hollomon参数来描述，根据修正后的流变应力曲线建立了HasteltoyC-276合金峰值应力下的高温变形本构方程，热变形材料常数为：激活能Q=446．51kJ·mol^-1，a=0．0037346，n=4．42851，A=1．11×10^16。

英文摘要：

The hot deformation behavior of nickel base alloy Hastelloy C-276 was investigated by compression test under isothermal hot working conditions of varying temperature （between 1000 and 1250 ℃ ） and strain rates（between 0.01 and 10 s ^-1 ） up to a true strain of 0.7 on Gleeble 3500 simulator. The deformed microstructures of vertical sections were observed by using optical microscope. The results showed that the flow stress of C-276 decreased with the increase of strain rate and with the increase of deformation tempera- ture. Dynamic recrystallization（DRX） occurred during hot deformation; there was a complete dynamic recrystallization when tempera- ture was not less than 1200 ℃, and part of dynamic recrystallization when temperature was less than 1200 ℃. The flow stress of the al- loy during thermal deformation can be described by a Zener-Hollomon parameter to described. The constitutive equation under peak stress was established based on the corrected flow stress. The material constants of thermal deformation were as follows ： activation ener- gy Q of 446.51 kJ.mol-1, α of 0.0037346, n of 4.42851, and A of 1.11 × 1016.