Diffusion-controlled peritectic reaction process in carbon steel analyzed by quantitative phase-field simulation

The peritectic reaction process in carbon steel, L + δ → γ, has been analyzed by a quantitative phase-field simulation. The calculated moving velocities of the γ–L and γ–δ planar interfaces in the isothermal peritectic transformation precisely agree with the corresponding experimental data, which strongly supports the accuracy of the present simulation. The diffusion-controlled peritectic reaction rate and the growth velocity of the γ phase along the δ–L interface obtained by the present simulation were fairly consistent with the experimentally measured values. This indicates that recent experimental findings can be explained by a diffusion-controlled mechanism. This is in marked contrast to the claims made on the basis of the experimental data and an analytical model that the peritectic reaction is not controlled by the diffusion of carbon.