Numerical prediction and experimental research of microstructure development during hot rolling

For the thermomechanical coupled large deformation problems, a thermal-elastic-plastic variational principle and corresponding finite element method are developed. Integrating the method with mathematical model of microstructure evolution, a numerical method to predict the microstructure during hot deformation is proposed. In regard to the highly non-linearity of the equations for recrystallization fraction and grain growth, an effective time compensated by temperature is defined, by which the time additivity is reasonable and suitable for temperature-varying conditions. As an application, the microstructure evolutions of H-team during hot rolling are simulated, and corresponding experimental research are performed. The coincidence of the predicted grain sizes with measured ones shows that the method is able to successfully predict the microstructure of metals after hot deformation.