A two-dimensional diffusion model for the prediction of phase transformations: Application to austenitization and homogenization of hypoeutectoid Fe-C steels

摘要: A two-dimensional (2D) model has been developed for the prediction of diffusive phase transformations (e.g. α to γ). For that purpose, diffusion equations are solved within each (α and γ) using an explicit finite volume technique formulated a regular hexagonal grid. The discrete α/γ interface is represented by special elements α/γ. An element undergoes transition state before becoming γ. This procedure allows us handle displacement while respecting flux condition at interface. applied austenitization hypoeutectoid plain carbon steel during heating. Simulated microstructures showing dissolution ferrite particles in austenite matrix presented different stages transformation. Specifically, influence microstructure scale heating rate on transformation kinetics investigated. Reverse TTT-diagrams calculated with this 2D compared experimental results from literature predictions simpler one-dimensional (1D) front-tracking calculation. Finally, it shown instabilities leading formation dendrites can also be reproduced such model.