An Integrated Model for Predicting Hierarchical Microstructure Evolution of Steel during Hot Rolling

Abstract

A robust model for calculating the necessary process variables such as strain, strain rate and temperature in hot rolling of a steel plate or strip is presented in this paper. The applied approach includes a well-constructed velocity function in the deformation model that is validated using a commercial finite element solver. The developed microstructure model is then integrated into the process model and includes the most essential descriptions of restoration and austenite grain structure evolution phenomena during hot rolling. Furthermore, the concept of hierarchical grain structure evolution is described as a method track the evolution of un-recrystallized and recrystallized features of the microstructure throughout a given pass schedule. The most important outcome of this approach is that each grain size component is modelled separately based on its prior thermomechanical history. A computer implementation of these models called MICDEL is used together with a simulation example to demonstrate its capability of predicting process variables and austenite grain structure evolution in hot strip rolling of steel.