Corrosion resistance behaviour of hard chromium coatings with Zinc undercoat

Hard chromium plating is being used for a number of industrial applications especially to resist wear and tear with a view to increase the life of the component. When the life of the component increases the hard chromium coating is also expected to withstand corrosion for increased life. But some of the hard chromium coated components fail because of low corrosion resistance. A suitable undercoat can improve the corrosion resistance behaviour of hard chromium coating. In this paper the authors discuss the effect of zinc undercoat in improving the corrosion resistance behaviour of hard chromium coatings. Mild steel plates with different thick chromium deposits and with an undercoat of zinc were subjected to salt spray and the results are presented