METHOD FOR ELECTROLYTICALLY DESCALING COLD-ROLLED STAINLESS STEEL

PURPOSE:To control the consumption of an anode and to electrolytically descale a cold-rolled stainless steel in an aq. neutral salt soln. over a long period by using the Ti coated with the oxide of a platinum-group element for the anode. CONSTITUTION:The oxide scales on a cold-rolled stainless steel sheet 3 are electrolytically removed. In this case, the sheet 3 is passed through an inlet-side chamber 5A contg. a 20% soln. 4 of the neutral salt of Na2SO4 and in which plural sets of anodes 1 are arranged above and below the sheet in the traveling direction and passed through an outlet-side chamber 5B contg. the same soln. 4 and in which plural sets of cathodes 2 are arranged above and below the sheet 3 in its traveling direction, and a current is applied to the cathode and anode to electrolytically remove the oxide scales on the surface of the sheet. In this case, an electrode of the Ti coated with the oxide of a platinum-family element such as IrO2 is used as the cathode, high-silicon cast iron is used for the cathode, the anode current density is controlled to 2-12A/dm , the anode potential is adjusted to 2.1V based on a silver-silver chloride electrode, and electrolytic descaling is carried out.