Surface coating process where the workpiece through an anode-cathode reaction is coated with hexavalent chromium. Beskrivning The process Before processing can begin the work should have been pre-treated to achieve a clean surface, which is usually done through electrolytic cleaning followed by pickling and rinsing. The workpiece acts as a cathode and the surface coating agent acts as the anode when connected to a power source and immersed in a solution. The solution used in this method is a mixture of chromic acid and a catalyst that is dependent on the substrate to be coated. The solution is usually heated to about 60 degrees Celsius. An anode-cathode reaction occurs that drives the ions to the workpiece and create a layer of hexavalent chromium on the surface of the workpiece and increases its wear resistance and corrosion protection. The main difference between hard chrome plating and decorative chromium plating is that hard chrome is intended to create a much thicker surface of the workpiece. The workpiece can thus in some cases having subsequent grinding or lapping to refine the relatively rough surface created. Hexavalent hard chromium
