Computer Modelling of Phase Transformation from Work-hardened Austenite

To make quantitative prediction of microstructure in HSLA steels produced by isothermal or continuous cooling transformation, transformation kinetics of various phases were modeled thermodynamically. Five kinds of phases, i.e. polygonal ferrite, Widmanstatten ferrite, pearlite, bainite and martensite, and 10 alloying elements were taken into account. A program was developed on the basis of this model. Out line of the involved transformation kinetics are presented in this paper. The effects of work-hardening of austenite on the nucleation and growth rates of various phases are discussed and a mathematical model of transformation kinetics from work-hardened austenite is also presented.