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

摘要

A method is provided. The method includes providing a steel substrate having two faces coated by dipping the substrate in a bath, altering layers of magnesium oxide or magnesium hydroxide formed on the outer surfaces of the metal coatings by applying an acid solution, optionally a conversion solution with a pH between 1 and 2, and/or mechanical forces, and painting the outer surfaces of the metal coatings. Additional methods and a metal sheet are also provided.