| 摘要 |
PURPOSE: To remove surface defects such as band mark and scratch by electroplating an electrogalvanized steel sheet in a chloride bath again. CONSTITUTION: The method is characterized in that an electroplated steel sheet is again plated in a chloride bath containing 45 to 150 g/L of Zn¬2+, 80 to 380 g/L of Cl¬- and 0.1 to 20 g/L of NH4¬+ under condition that pH of plating solution is 2.0 to 6.0, the temperature of plating solution is 40 to 70 deg.C, electric current is 10 to 200 A/dm¬2, relative flow rate of plating solution against anodic plate is 0.5 to 3.0 m/sec, wherein the plating amount is 1.0 to 10.0 g/m¬2, and relative concentration of chloride ion to zinc ion is kept within 1.5 and 2.5.
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