Computer simulation of the austenitizing process in cast iron with pearlitic matrix

摘要

In computations of the kinetics of austenitizing, a one-dimensional model of austenite growth assuming a diffusion-related mechanism acting between the lamellae of ferrite and cementite was used. The diffusion-related mechanism of transformation was coupled with the transient field of temperature, resulting from preheating of the casting (sample) in a salt bath. The results of modeling were compared with the values of temperature measured in the preheated sample. For comparison, the Kolmogorov equation was also used to determine volume of the transformed phase, where the kinetics of the austenite grains nucleation and growth was related to overheating above the A_1 temperature in the Fe-C system (allowing for an effect of Si and Mn) and to the kinetics of sample preheating. The Kolmogorov equation was compared with the Johnson-Mehl-Avrami equation (for constant coefficients).