Constitutive relationship and microstructure for 20CrMnTiH steel during warm deformation

The hot flow behaviors of 20CrMnTiH steel are studied using isothermal compression tests corresponding to the temperature range from 973 to 1123 K and the strain rates range from 0.01 to 10 s−1. The flow behaviors of 20CrMnTiH steel are represented, which are based on the analysis of true stress-true strain curves. The results show that there exist typical dynamic recovery (DRV) and dynamic recrystallization (DRX) during hot deformation. The effect of hot deformation on microstructure is investigated. There exists a dual phase feature within the deformation temperature. A modified Zerilli-Armstrong (ZA) model, based upon the original ZA model and Johnson-Cook model, is proposed to describe the flow stress under different deformation conditions. Compared with experimental data, the modified ZA model has a good accuracy in describing the constitutive relation of the material.