Research on micro-arc oxidation method based on passivation layer on non-valve metal low-carbon steel surface

In this study, a method for preparing micro-arc oxidation (MAO) coatings on the surface of non-valve metal low-carbon steel based on a passivation layer is proposed. Microstructure and elemental composition of the surface and cross-section were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS). Micro-scratch tests, tribological tests and electrochemical corrosion tests were conducted. Compared to MAO coatings, coatings obtained by pre-passivation treatment exhibit fewer surface micropores with smaller pore sizes, and both wear resistance and corrosion resistance are enhanced. In summary, the method for preparing MAO coatings based on the passivation layer on the surface of low-carbon steel provides feasible approach to improving the drawbacks of low-carbon steel.