XPS study of the corrosion resisting composite alloying layer obtained by double glow plasma with the brush plating Ni interlayer

The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brush plating Ni interlayer on the low carbon steel substrate has been investigated. By the electrochemical method in 3.5% (mass fraction) NaCl solution, the corrosion resistance of the composite alloying layer and single alloying layer is determined. The experimental results show that the corrosion resistance of the composite alloying layer is obviously better than that of the single alloying layer. The structure and composition of passive films formed on the two kinds of alloyed layers after electrochemical tests in 3.5% NaCl solution have been studied using X-ray photoelectron spectroscopy (XPS). It is concluded that the double glow plasma surface alloying of low carbon steel with the electric brush plating Ni interlayer is an appropriate technique to enhance the corrosion resistance compared with the single double glow surface alloying.