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 is mainly for treating a steel sheet comprising a steel substrate covered with at least one of the sides with a coating comprising at least zinc and magnesium, in order to reduce blackening or discoloration of the steel sheet during storage of the steel sheet, 0.01 It relates to the use of an aqueous treatment solution containing _{sulfate ions (SO 4}^2- ) in a concentration of mol/l or more. Further, the present invention relates to a metal sheet treated with the solution.