Coatings of zinc and cadmium are chromate treated in order to retard the formation of corrosion
products on the surfaces of coatings exposed in corrosive atmospheres. Chromate treatment is particularly effective in retarding the formation of white corrosion products which form on zinc and cadmium coatings under certain conditions.
BS 6338 is an International Standard that specifies requirements relating to chromate conversion coatings on zinc and cadmium intended to give protection against corrosion. Finishes for giving particular colours only or specifically to improve paint adhesion are not covered by BS 6338.
Thicknesses of electroplated coatings suitable for chromate treatment are covered by the relevant International Standards, i.e. BS EN ISO 2081 and BS EN ISO 2082.
BS 6338 on chromate conversion coatings on zinc and cadmium is useful for:
Chromate conversion coating or alodine coating is a type of conversion coating used to passivate steel, aluminium, zinc, cadmium, copper, silver, titanium, magnesium, and tin alloys.
BS 6338 provides you with a method of application of chromate conversion coatings, classification, and requirements of the chromate conversion coatings to be applied on zinc and cadmium.
BS 6338 provides you guidance on chromate conversion coating which can be useful for to impart brightness and improving the corrosion resistance of bare metal and as a substrate to provide improved paint adherence on nonferrous surface.
By adopting BS 6338 best industry requirements, you can to protect electroplated zinc and cadmium coated components from corrosion and deteriorating.