Comparative Study of the Electrochemical Performance of Cyanide/Non-Cyanide Cadmium Plating Coating on 30CrMnSiA Surface

Abstract

In order to analyze and compare the difference in the corrosion resistance of cadmium plating processes with and without cyanide，these two cadmium plating processes were used to treat the 30CrMnSiA alloy steel，which was commonly used in aviation field.The bath composition，process flow and plating parameters of the two processes were introduced respectively.After the same passivation treatment，the electrochemical properties of the two samples in seawater and sweat with different pH were analyzed using electrochemical workstation，and the two samples were subjected to neutral salt spray corrosion in salt spray test chamber.Moreover，the microscopic surface morphology was observed by optical microscope and SEM，and the components of corrosion products were analyzed by EDS and XRD.Results showed that the corrosion resistance of the two samples in alkaline solution was better than that in acidic solution，and the corrosion resistance of the noncyanide cadmium plating sample was better than that of the cyanide cadmium plating sample.The salt spray test results exhibited that white rust and red rust did not appear on the two samples，indicating that the two processes could meet the corrosion resistance standard.However，the micro morphology of the cyanide cadmium plating sample changed obviously，while that of the non-cyanide cadmium plating sample only changed a little，signifying that the non-cyanide cadmium plating process was better than the cyanide cadmium plating process.

Keywords

• cyanide cadmium plating|non-cyanide cadmium plating|passivation|electrochemical performance|neutral salt spray test