Mathematical modelling of hot rolling of steel strip with microstructure analysis

A three-dimensional mathematical model has been developed to predict the variation of austenite grain size during hot strip rolling process. In the rolling analysis, Eulerian visco-plastic FEM and up-winding FEM were incorporated to solve the deformation and temperature distribution in the roll-bite and also elastic deformation of rolling roll was considered. In the thermal analysis of the strip rolling, pressure dependant heat transfer coefficient was introduced to calculate the heat flux between rolling roll and strip surface. Subsequent to the rolling analysis, two dimensional transient FEM was employed for the thermal analysis during interstand and the evolution of microstructure was analyzed with the information of strain, strain rate and temperature.