A phenomenological model utilizing Voce’s strain-hardening model describing high strain rate behavior of alloy 800H during hot working

In this study, a simple mathematical model is introduced to predict the stress–strain curves under the occurrence of minor dynamic recrystallization. In this regard, first, with the assumption of nonlinear variation of strain-hardening rate versus strain, a mathematical equation was derived to obtain the strain-hardening rate. Then, using the Voce’s equation, a new mathematical model was developed to predict the hot deformation behavior of metallic alloys at high strain rates. The most important feature of the proposed model is its simplicity so that the only constant of the stress–strain equation can easily be interpolated at different temperatures and strain rates. Accordingly, it was found that the defined material constant varies linearly and exponentially with strain rate and temperature, respectively. The high correlation factors (average correlation factor, r² = 0.85) obtained from regression analysis showed that the model can provide a precise estimation of flow stress curves for the defined deformation conditions.