Modelling of microstructural evolution in multipass hot rolling

Mechanism-based unified viscoplastic constitutive equations are developed to model the evolution of grain size, recovery, dynamic and static recrystallisation and their effects on viscoplastic flow of materials. This set of constitutive equations are determined for a C–Mn steel using a GA-based optimisation technique and implemented into the commercial FE solver ABAQUS for process simulations. Numerical procedures to simulate multipass rolling are developed. FE analysis is carried out to rationalise the evolution of grain size, dynamic/static recrystallisation and recovery, viscoplastic flow and stress relaxation in a multipass hot rolling process.