Characterization and the improved Arrhenius model of 0Cr11Ni₂MoVNb steel during hot deformation process

True stress versus true strain curves of 0Cr11Ni₂MoVNb alloy steel were obtained from isothermal compression tests on Gleeble-1500 tester over a wide temperature range from 1223K to 1433K and a strain rate range from 0.01s^-1 to 10s^-1. Considering the compensation of strain, the improved Arrhenius model based on Zener-Holloman parameter was evaluated by regression analysis and modified by optimizing parameters of strain hardening exponent as well as the deformation activation energy with a method of five-order polynomial fitting. Then constitutive equation of the flow stress was verified by comparing both the correlation coefficient R and the average absolute relative error (AARE). The main result shows that: (1) the deformation activation energy is insensitive to strain rate under a lower temperature range from 1223K to 1373K; (2) maximum values of the deformation activation energy under various strain degree are concentrated with the temperature over 1373K and the strain rate nearby 0.1s^-1. (3) the improved Arrhenius model has a low value level of its parameters R(<0.977%) and AARE (<5.031%), which has a good agreement with the experimental values to predict the flow stress at different temperatures and strain rates.