Constitutive modeling of the viscoplastic deformation in high temperature forging of titanium alloy IMI834

The experimental observation reveals that the deformation mechanisms in high temperature forging of titanium alloy IMI834 are primarily attributed to deformation-induced recrystallization, which results in a decrease in flow stress after its peak value has been obtained. In this paper, evolution of mean grain size is formulated and internal variables are used to characterize the resulting flow softening. An automated procedure for the determination of the material constants is also developed. The model has been successfully applied to predict the true stress–strain behavior of IMI834 at the isothermal forging conditions.