Simulation of Austenitization Processes in Fe-C Steels by Coupled Cellular Automaton and Finite Difference Methods

摘要

The aim of the simulation was to calculate the austenitization processes in plain carbon steels with different carbon concentrations. As the first step of simulation, an initial structure was generated where the diameters of pearlite colonies, the thickness and orientation of cementite lamellae, and the thickness of pro-eutectoid ferrite or even secondary cementite were changed. By this method, similar structures to the real ones were obtained. To solve the nucleation problem, a free enthalpy model was used, which makes difference between the places of nuclei. The diffusion equation (Fick II.) in case of the grain growth of austenite was solved by the Finite Differential Method. Nuclei can be formed at the boundary of pearlite colonies, at the boundary of the pro-eutectoid ferrite and cementite, or rarely at the boundary of cementite and ferrite lamellae too. The grain growth model calculates the carbon diffusion through both ferrite and austenite phases. The simulation runs as a coupled Cellular Automaton and Finite Difference Methods.