ISO 3613:2021

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.