Mechanism of Texture Formation in Iron Boride Coatings on Low-Carbon Steel

In this paper, the boriding of low-carbon steel was studied. We found that FeB phase forms on the surface of low-carbon steel at the initial stage, and then Fe2B nucleates on the FeB, with a crystallographic relation between the two phases. In the third stage, Fe2B further grows on the FeB phase, and FeB starts to diminish. A model is proposed to explain the formation of the textured FeB and Fe2B phases. It is found that the strong anisotropy of the FeB lattice structure and the lattice matching between FeB and Fe2B are the reasons for the preferred crystallographic development in the boride coating.