Physically based constitutive analysis to predict flow stress of medium carbon and vanadium microalloyed steels

Two medium carbon steel grades were used in the present investigation. One of them was microalloyed with vanadium. Both steel grades were subjected to hot compression tests on the Gleeble-1500 thermo-mechanical simulator in the temperature range of 900-1100 °C and strain rate range of 0.01-10 s−1. Constitutive relationships of both steels were investigated by the physically based approach incorporating the strain effect, which accounts for the dependence of Young׳s modulus and the self-diffusion coefficient of austenite on temperature. The accuracy and reliability of the equations was quantified by employing statistical parameters such as the correlation coefficient and absolute average error. The results showed that the proposed equations can predict the flow stress of the experimental steels with acceptable accuracy, thus may be an alternative method for predicting the flow stress in hot working.