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.