Effect of current density on micro‐arc oxidation of Q235 steel and corrosion resistance in liquid Pb‐Bi

Abstract

An attempt has been made to improve the corrosion resistance in liquid Pb-Bi by micro-arc oxidation (MAO), and the effects under different current densities on the corrosion resistance of the coatings were discussed. Scanning electron microscope, energy dispersive spectrometer, and X-ray diffraction were used to analyze the surface morphology and phase constituents of the MAO coatings produced under different current densities. The corrosion resistance of the coatings was evaluated by studying the element changes and morphology evolution. The results show that the compactness of the ceramic coating decreases with the current density increasing. In contrast to the performance of matrix metal, the ceramic coating exhibited a much better corrosion resistance in liquid Pb-Bi. Moreover, the ceramic coating produced under current density of 10 A/dm 2 shows the best corrosion resistance. K E Y W O R D S current density, fusion-brazing, liquid Pb-Bi corrosion, micro-arc oxidation