Computer simulation of steel quenching process using a multi-phase transformation model

A phenomenological kinetic model has been developed for the description of diffusional austenite transformations in low-alloy hypoeutectoid steels during cooling after austenitization. A fundamental property of the model consisting of coupled differential equations is that by taking into account the rate of austenite grain growth, it permits the prediction of the progress of ferrite, pearlite, upper bainite and lower bainite transformations simultaneously. To demonstrate the applicability of the model, experiments have been performed on the DIN 34 Cr 4 steel. Investigations based on computer simulation verified that the coupled multi-phase model can be applicable to predicting the CCT diagrams of low-alloy steels and calculating the microstructure and hardness distribution after quenching.