This International Standard specifies methods for the determination of the
- presence of colourless *) chromate conversion coatings;
- presence and quantity of hexavalent chromium in colourless and coloured coatings on zinc, cadmium, aluminium (55 % mass fraction)-zinc and zinc-aluminium (5 % mass fraction) alloys;
- total chromium content per unit area on zinc and cadmium;
- mass per unit area of both colourless and coloured coatings;
- satisfactory adhesion of chromate conversion coatings;
- quality of chromate coating.
These methods are applicable
- to colourless and coloured chromate conversion coatings containing tri- and hexavalent chromium in varying proportions and produced by either chemical or electrochemical processes;
- only to chromate coatings that are free from any supplementary coatings such as oil, water or solvent-based polymers or wax.
*) The application of very thin, colourless, practically invisible chromate conversion coatings is frequently called "passivation", while the application of thicker, coloured chromate conversion coatings is often called "chromating". The term passivation is not correct and is, therefore, not recommended.