High-Temperature Behavior and Constitutive Modeling of MS1180 High-Strength Steel

The flow behavior analysis of MS1180 steel at high-temperature was carried out by the stress-strain data which were obtained through isothermal uniaxial tensile tests with Gleeble-3800 thermal simulator. The temperature range is 600 degrees C similar to 900 degrees C and the strain rate is varied from 0.005 s(-1) to 0.02 s(-1). A modified Johnson-Cook (JC) constitutive model of MS1180 steel considering the mutual effect of deformation parameters was proposed applying multiple nonlinear regression method. The calculated stress values obtained by the modified constitutive equations and the experimental ones were compared with each other. The average relative error is less than 5% and correlation coefficient is greater than 0.95. The results verified that the modified constitutive equations has good prediction accuracy for the flow stress of MS1180.