| 摘要 |
PROBLEM TO BE SOLVED: To provide a pretreatment method for pickling, which improves efficiency in a subsequent pickling step and provides a stainless steel strip free from flaw. SOLUTION: This pretreatment method is characterized by immersing the stainless steel strip into a molten alkaline salt bath, which includes NaNO3 , KOH, Na2 SO4 , and NaCl, and the balance NaOH with inevitable impurities such as Na2 CO3 as secondary products, satisfies (NaOH+KOH)/NaNO3 =3.5-8.0, and Na2 SO4 +NaCl+NaNO3 -Na2 CO3 =15-30%, by mass%, and has a temperature of a melting point or higher but 550 deg.C or lower, through a roll immersed in the bath; and removing foreign matters adhering to the surface of the roll, by using a deposit removal material fixed to a holder connected with a drive mechanism, which is installed in a state of having a peripheral temperature of 100 deg.C or lower and of not being affected by dispersion of the bath fume.
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