Simulation of coarsening of inter-lath cementite in a Q&T steel during tempering

A mathematical model, using the finite difference approach, was established to consider tempering in a low carbon low alloy quenched and tempered steel based on experimental observations, treating the coarsening of a larger particle and dissolution of a smaller particle as a continuous and simultaneous process for coupled inter-lath cementite systems. The diffusion of Mn was simplified as a 1D diffusion and occurred between the interface elements and their adjacent elements in the model. The mathematical model predicted the shortest dissolution times for smaller particles in coupled inter-lath cementite systems, which agreed well with experimental observations on tempering from 2 to 4 h. However, the larger particle coarsening was under predicted due to the simplification of considering two particle arrangements.