USE OF A SOLUTION CONTAINING SULPHATE IONS FOR REDUCING THE BLACKENING OR TARNISHING OF A METAL SHEET DURING THE STORAGE THEREOF AND METAL SHEET TREATED WITH SUCH A SOLUTION

摘要

The present invention provides an aqueous treatment solution containing sulfate ions SO42− in a concentration greater than or equal to 0.01 mol/l, to treat sheet metal including a steel substrate coated on at least one face with a coating including at least zinc and magnesium to reduce blackening or tarnishing of the sheet metal during storage. The present invention also provides a sheet metal treated with a solution of this type.