METHODS FOR PRODUCING A PRE-LACQUERED METAL SHEET HAVING ZN-AL-MG COATINGS, AND CORRESPONDING METAL SHEET

摘要

The method comprises the following steps: providing a steel substrate (3) having two faces (5) that are coated by quenching the substrate (3) in a bath, altering the magnesium hydroxide or magnesium oxide layers formed on the outer surfaces (15) of the metal coatings (7) by applying an acid solution, optionally a conversion solution, having a pH of between 1 and 2 and/or mechanical stress, and painting the outer surfaces (15) of the metal coatings (7).