The microstrucure of wear-induced transfer layer on cast iron surface was investigated using scanning electron microscopy, transmission electron
microscopy and X-ray diffraction. The results indicate that a novel face-centred cubic Fe–C ordered phase with the lattice parameter a = 0.38 nm
was formed in the microstructure. The experimental results show that the microhardness of wear-transfer layer is higher than that of the substrate
due to presenting of the Fe–C ordered phase and Fe3O4 nanocrystalline phase.