Aqueous reaction solution and method of passivating workpieces having zinc or zinc alloy surfaces and use of a heteroaromatic compound

摘要

For producing corrosion resistant yellow passivate layers on zinc and zinc alloy surfaces, an aqueous reaction solution is utilized that contains trivalent chromium ions, at least one acid as well as at least one heteroaromatic compound selected from the group comprising nicotinic acid, the salts and derivatives thereof.