| 摘要 |
PROBLEM TO BE SOLVED: To provide a method where, in a pickling stage after annealing for a stainless steel, its descaling properties are improved; the generation of nitrogen oxide from a pickling tank composed of a nitric acid and hydrofluoric acid is suppressed, and the amount of the nitric acid to be used is reduced. SOLUTION: Regarding the method for pickling a stainless steel sheet, in the pickling after annealing for a stainless steel sheet, the surface of the stainless steel sheet is subjected to descaling with a pickling solution essentially consisting of nitric acid-hydrofluoric acid-Fe<SP>3+</SP>-hydrogen peroxide, and the descaling is performed by continuous addition to set the pickling solution to comprise nitric acid of 1.0 to 2.5 mol/L, hydrofluoric acid of 0.3 to 1.5 mol/L, Fe<SP>3+</SP>of 10 to 50 g/L and hydrogen peroxide of 0.003 to 0.30 mol/L, respectively. COPYRIGHT: (C)2007,JPO&INPIT
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