PROCESS FOR REMOVING A CHROMIUM PASSIVATION FILM FROM AN ALUMINUM-ZINC COATED STEEL SURFACE

摘要

Processes for chemically modifying without abrasive treatment a chromium passivation film from a passivated aluminum-zinc coated steel surface. The cleaner compositions employ at least one chelant, at least one surfactant and an alkaline source compound in an aqueous solution. The processes employ spraying the cleaner composition onto the passivated steel.