The standard "GB/T 39495-2020 Metal and Miscellaneous Inorganic Coatings, Chromium-Free Chemical Conversion Films for Aluminum and Aluminum Alloys" specifies the classification, requirements, test methods and sampling inspection procedures of chromium-free chemical conversion films for washed and leave-in chromium-free chemical conversion films for aluminum and aluminum alloy parts. The standard applies to chromium-free chemical conversion films for extruded aluminum, aluminum alloy parts, profiles, coils, plates and cast aluminum alloy parts. The chromium-free chemical conversion film can not only be used as a separate anti-corrosion layer, but also as a bottom layer for organic coatings (such as Coatings, Rubber, Adhesive). The standard includes testing requirements for the anti-corrosion performance, abrasion resistance and Miscellaneous-related performance of the conversion film.