Constitutive Relationship of TRIP780 Steel in Quenching Process

To characterize the mechanical behavior of TRIP780 steel in quenching process, Uniaxial tensile tests are performed on Gleeble-3500 thermo-simulation machine at temperature 323K~1073K and corresponding stress-strain curves are obtained. The results show that flow stress is affected by deformation temperature significantly and declines with increasing temperature. Based on simplified and modified Zerrilli-Armstrong model, the impact factor of temperature with quadratic polynomial fitting is introduced and the constitutive relationships with temperature dependent are established. The accuracy of the constitutive equations is verified and the flow stress predicted by the proposed model is consistent with experimental results. Therefore, the constitutive model can be applied for numerical simulation of quenching process.