In order to promote the research in the field of microstructure prediction technology

and to extend the applications of the technology in hot forming field

the mathematical models of the change process for Austenite grain including dynamic recrystallization

static recrystallization

crystal grain growth and the temperature compensating equivalent time

are systemically studied.Results show that the successful application of microstructure forecast by finite element technology to production process not only can improve product quality

but also can decrease product cost.