The coating of chromium plating material has the advantages of high hardness, good wear resistance and corrosion resistance. However, the hardness of chromium plating layer decreases at high temperature, and crack structure occurs when the thickness of chromium plating layer is greater than 0.7 micron. At this time, the protective effect of chromium plating material on the substrate will be weakened. Chromium alloy coating is more wear resistant, corrosion resistant and high temperature resistant than chromium coating. Metals that can be co-deposited with chromium are iron, cobalt, nickel, molybdenum, tungsten, vanadium and manganese. The electroplating of early chromium alloys was usually carried out in chromate or chromium sulphate solutions. Later, there was a process of electroplating chromium alloys with trivalent chromium as the main salt.
The properties of electroplated chromium-nickel alloys are almost the same as those of cast and forged chromium-nickel alloys. It has the characteristics of wear resistance, corrosion resistance, high temperature resistance and high resistance.
An alloy coating similar to stainless steel can be obtained by electroplating Fe-Cr-Ni ternary alloy, which has the properties of stainless steel and is naturally widely used in practical applications.
The chromium-molybdenum alloy coating has compact structure, excellent corrosion resistance and wear resistance.
