In the present work, initial stage carbonization of γ-Fe(100) surface in C2H2 from 1000 K to 1600 K has been investigated by a molecular dynamic (MD) simulation, based on which the atomic mechanism of initial stage carbonization was provided. The absorption of C and H atoms during the carbonization process under different temperatures was analyzed. The related distributions of C and H atoms in carbonized layer were provided. The results manifested that higher temperature enhanced the inward diffusion of C and H, meanwhile caused the desorption of H atom. Furthermore, the effect of preset polycrystal γ-Fe on the carbonization process has been discussed, indicating a promoting role to the absorption and inner diffusion of C and H atom. The results of this study may support the optimal design of high-performance steel to some extent.
Keywords: austenite; carbonization; microstructure; molecular dynamics.