ELECTROLYTIC CHROMATE TREATED GALVANIZED STEEL SHEET EXCELLENT IN BLACKENING RESISTANCE AND SURFACE APPEARANCE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To produce an electrolytic chromate treated galvanized steel sheet excellent in blackening resistance and having a uniform and beautiful surface appearance and to provide a method for producing the same. ;SOLUTION: This electrolytic chromate treated galvanized steel sheet excellent in blackening resistance and surface appearance is the one in which the surface of galvanizing coating of a galvanized steel sheet in which the galvanizing coating has been formed is applied with an oxide layer contg. Al oxide by 5 to 40mg/m² as metallic Al, and the surface of the oxide layer is applied with chromate coating contg. Co and/or Ni by 0.5 to 25mg/m² expressed in terms of metals and chromate by 5 to 80mg/m² expressed in terms of metallic chromium.;COPYRIGHT: (C)1998,JPO