Growth Mechanism and Corrosion Resistance of Replacement Copper Coating on Carbon Steel Surface

Copper coating was prepared on surface of the 20^# carbon steel by self-developed displacement copper plating solution. The effect of replacement copper plating time on the corrosion resistance of copper coating was studied by electrochemical test, and the growth regulation of copper coating was analyzed. The results show that with the increase of replacement copper plating time, the free corrosion potential of the coating shifted positively, the free corrosion current density decreased, and the charge transfer resistance (R_ct) increased significantly. When the replacement copper plating time was 16 h, R_ct value was the largest, and the corrosion resistance of copper coating was the best. The growth of the replacement copper coating was divided into three stages. In the early stage, a barrier layer and a porous layer were formed. In the middle stage, a barrier layer, a dense layer and a porous layer were formed. In the later stage, a barrier layer and a dense layer were formed.