Constitutive Modeling During Simultaneous Forming and Quenching of a Boron Bearing Steel at High Temperatures

Abstract

Simulation of hot stamping process needs reliable material data, especially at high temperatures where plastic deformation takes place in austenitic microstructure. In the current study, high-temperature non-isothermal compression tests (NICT) at different ranges of temperature, strain and strain rate as well as constitutive modeling of the flow curves were carried out. The Johnson-Cook and the Nemat-Nasser phenomenological models for isothermal deformation conditions were revised and applied to fit the flow curves during high-temperature NICT. It was shown that the models can satisfactorily predict the material flow stress at the mentioned conditions. Furthermore, the models were employed in order to describe the work-hardening behavior of the material. The results indicated that the fitted work-hardening rate can successfully follow the experimental data during deformation till no strain-induced phase transformation is initiated.