CHROMATE SOLUTION FOR ZINC ELECTROPLATING OF A STEEL SHEET

摘要

The chromate treating solution for improving the corrosion resistance of a Zn-electroplated steel strip is composed of hexavalent chromium ions with 0.03-0.2 mole/l concentration, sulfate ions having 3-5 times concentration of hexavalent chromium, and hydro ions having 1-3 times concentration of hexavalent chromium. The chromate treated layer with coating amount of max. 200 mg/m2 is similar to the Zn-electroplated steel strip in brightness, and is tinged with a light yellow.