Post-treatment for metal coated substrates

摘要

An aqueous composition for post-treating metal coated substrates such as cadmium-plated steel or zinc-nickel coated substrates and the process for using said composition to improve the corrosion-resistance, abrasion, and adhesion bonding properties of the metal coatings. The composition comprising an acidic aqueous solution having a pH ranging from about 2.5 to 4.5 containing effective amounts of trivalent chromium salts, an alkali metal hexafluorozirconate, at least one alkali metal fluoro-compound, and effective amounts of water soluble thickeners and/or surfactants.