| 摘要 |
PURPOSE:To prevent generation of dissolution and staining on the plated surface of a one-side galvanized steel sheet in the stage of pickling electrolytically the nonplated surface of said sheet by sealing the plated surface with an endless belt having an electrical insulating characteristic. CONSTITUTION:The nonplated surface of the steel sheet 1 of which one side is plated with Zn, etc. is electrolytically pickled by which the Zn spread to the non-plated surface and the oxide of the steel sheet are removed to prevent deterioration of chemical convertibility for formation of a phosphate film, etc. The endless belt 6 having the electrically insulating characteristic is brought into tight contact with the plated surface (the bottom surface in the first time) of the sheet 1 for the above-mentioned purpose and the non-plated surface of the sheet 1 as an anode is electrolytically pickled while said sheet is moved in a way as to face cathode 8 in an electrolytic cell contg. a pickling sonl. 16 such as sulfuric acid, hydrochloric acid or phosphoric acid as an electrolyte in synchronization with the moving speed of the sheet 1 by supporting rolls 5. Since the belt 6 is held in tight contact with the plated surface, only the non-plated surface is electrolytically pickled and cleaned. The one-side galvanized steel sheet having the nonplating surface which has excellent chemical convertibility is thus obtd.
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