| 摘要 |
PURPOSE: To stabilize the productivity of a highly corrosion resistant steels strip by annealing a cold rolled low-carbon ferritic chromium stainless steel sheet in a reducing atmosphere controlled in dew point and mechanically grinding the surface layers thereof under the specified conditions corresponding to the dew point thereof, then subjecting the steel sheet to an electrolytic treatment. CONSTITUTION: The cold rolled stainless steel sheet having a steel compsn. contg., by weight, <=0.02% e, 0.3 to 3.0% Si, <=1.0% Mn, <=0.05% P, <=0.02% S, 10 to 25% Cr, <=0.02% N, <=0.008% O and <=0.5% Al and consisting of the balance Fe and inevitable impurities is annealed in a reducing atmosphere which consists of an inert gas contg. 20vol.% H2 and is kept at the dew point -10 deg.C or below. The surface layers of the thickness satisfying equation I are then mechanically ground according to the dew point of the inert gas. The steel sheet is thereafter subjected to an electrolytic treatment under conditions of a temp. of 38 to 65 deg.C and current density of 1 to 30A/dm<2> in a nitric acid soln. having a liquid compsn. of a nitric acid concn. of 10 to 300g/l and nitric acid concn. of 1 to 30g/l. |
