ISO 3613:2021
Issue date: 2021 05 10
Metallic and other inorganic coatings — Chromate conversion coatings on zinc, cadmium, aluminium-zinc alloys and zinc-aluminium alloys — Test methods
This document specifies methods for the determination of
— the presence of colourless chromate conversion coatings,
— the presence of hexavalent chromium in colourless and coloured coatings on zinc or cadmium or aluminium-zinc (mass fraction of aluminium: 55 %, within a range of 54 % to 56 % mass fraction) and zinc-aluminium (mass fraction of aluminium: 5 %) alloys,
— the total chromium content per unit area on zinc and cadmium,
— the mass per unit area of both colourless and coloured coatings,
— the satisfactory adhesion of chromate conversion coatings, and
— the quality of chromate coatings.
These methods are applicable to
— colourless and coloured chromate conversion coatings containing trivalent and hexavalent chromium in varying proportions and produced by either chemical or electrochemical processes, and
— chromate coatings that are free from any supplementary coatings, such as oil, water or solvent-based polymers or wax.
