Modeling of austenite decomposition in plain carbon steels during hot rolling

The prediction of the mechanical properties of plain carbon steels depends on an accurate calculation of the volume fraction of the phases and the ferrite grain size. This present work proposed a phase transformation model and a ferrite grain size model during hot rolling. The phase transformation model is based on Avrami equation and Scheil's additivity rule. In this model, a wide range of composition, cooling rate, austenite grain size and retained strain can be considered. The volume fraction of phase formed during cooling, and the ferrite grain size during cooling and coiling can be simulated using the present phase transformation model. In order to predict the volume fraction of ferrite and final ferrite grain size, the transformation start temperature and finish temperature were also calculated. The calculated volume fraction of ferrite and final ferrite grain size agreed well with the log data from hot strip mill.