Constitutive equation for thermal deformation of OTMnNiMoDR plate in rolling

On the basis of isothermal thermal compression test of 07MnNiMoDR steel in a Gleeble-3500 thermal simulator, the high temperature rheological behavior of 07MnNiMoDR steel at the forming temperature of 900 - 1100 °C, the strain rate of 0. 01 - 10 s^-1 and the strain of 4 5 % was discussed. The results show that the flow stress is significantly affected by deformation temperature and strain rate. By analyzing of Arrhenius hyperbolic sine equation and Zener-HoUomon parameter, the peak rheological stress constitutive model was established, and the thermal deformation activation energy Q was calculated. Based on the stress-dislocation relationship and dynamic recrystallization kinetics, the mechanism-type constitutive models of the two stages of work hardening-dynamic recovery and dynamic recrystallization were established, and the equation concerned with dynamic recovery coefficient, Zener-HoUomon parameter and the dynamic recrystallization volume fraction were obtained. The change rule of rheological stress according to the established constitutive equation is agreed with that of the test. The experimental value is in good agreement with the prediction of the established constitutive equation for the correlation coefficient r of 0. 99.