Constitutive Model for F45V Microalloyed Forging Steel at High Temperature

 Isothermal hot compression experiments of F45V, a microalloyed steel, were performed on a Gleeble-1500 thermo-mechanical simulator at temperatures of 950-1200 ℃ and strain rate of 0. 01-10 s-1. Based on the experimental flow stress curves, a constitutive model that was expressed by the hyperbolic laws in an Arrhenius-type equation was established, and the material parameters of the model were expressed as 6th order polynomial form of strain. Standard statistical parameters such as correlation coefficient and average absolute relative error were employed to quantify the predictability of the model. They were found to be 0. 995 and 4. 34% respectively. The results show that the established constitutive model can predict the magnitude and tendency of flow stress with the increase of deformation accurately, and can be used for the numerical simulation of hot forging process of the F45V steel.