The effect of alloying element partitioning on the interface velocity during the isothermal bainite formation

Following a previous study on the effect of alloying elements on the isothermal bainitic ferrite formation in quaternary steels with the mean field approximation, the Gibbs Energy Balance (GEB) model is further developed to incorporate the effect of partioning of alloying element in both austenite and ferrite domains. In the new model, distributions of alloying elements are updated according to their initial profiles, progresses of the interface and corresponding local equilibrium condition at each time step. The dissipation of carbon (interstitial) diffusion inside and across the interface is calculated and added to the contributions of substitutional alloying elements, e.g. Mn, Si, Ni and Mo. The new model enables a detailed analysis of the effect of alloying element partitioning on the interface velocity during the entire transformation. The results are compared to previous simulations and the metallurgical insights are discussed.