800H合金热变形行为研究

通过高温单道次压缩实验,研究800H合金在变形温度850～1 050℃和应变速率0.01～10 s-1条件下的热变形行为和微观组织变化.根据单道次压缩实验数据,绘制了不同变形条件下的800H合金真应力-真应变曲线,通过非线性回归建立了流变应力数学模型;通过线性回归建立了不同温度区间内热变形本构方程.分析了热变形条件对合金微观组织的影响,结果表明:动态再结晶更有可能发生在低应变速率和高变形温度的变形条件下;当变形温度低于950℃时,沿晶界析出的Cr23C6粒子对动态再结晶的发生有一定的抑制作用.

Hot Deformation Behavior of Alloy 800H

The hot deformation behavior and microstructure evolution of alloy 800H were investigated by high temperature single-pass compression tests at the temperatures ranging from 850 to 1 050 ℃ and the strain rates ranging from 0.01 to 10 s-1.Based on the data of single-pass compression tests,the flow stress curves of alloy 800H under different deformation conditions were plotted,and the mathematical model of flow stress was established through nonlinear regression.The hot deformation constitutive equations at different temperature intervals were established through linear regression.The effects of hot deformation conditions on the microstructure were analyzed.The results showed that the dynamic recrystallization is more likely to occur at a low strain rate and high deformation temperature.When deformation temperature is below 950 ℃,the dynamic recrystallization is inhibited by Cr23C6 carbide precipitated at grain boundaries.