Chromium(VI)-free, aqueous acidic chromium(III) conversion solutions

摘要

An essentially chromium(VI)-free, chromium(III)-containing corrosion resistant conversion solution, or layer thereof for treating metals such as zinc, zinc alloy, aluminum, or aluminum alloy substrates. The conversion solution, is substantially free of chromium(III)-chelates, is capable of producing thick conversion films even at low temperatures, has good corrosion resistance, and is self healing with regard to scratches and the like.