| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing a surface-treated steel plate which enables thickening of a film of a metal-oxygen compound formed on a metal substrate while preventing occurrence of appearance defects, e.g. arc spots, in the metal substrate.SOLUTION: A plurality of rolls provided in each of a plurality of electrolytic treatment tanks 30 and 40, including a roll for transferring a steel plate to the electrolytic treatment tank and a roll for pulling up the steel plate from the electrolytic treatment tank, consist of a conduction roll 65 connected electrically to a power source for electrifying a DC current to the steel plate and non-conduction rolls 61, 63, 67, 69 and 71 not connected to the power source. The conduction roll is arranged so that, after formation of a metal-oxygen compound on a surface of the steel plate in contact with the roll by an electrolytic treatment, the metal-oxygen compound does not come in contact with the conduction roll, leading to elimination of the possibility of occurrence of arc spots. |
