| 摘要 |
PROBLEM TO BE SOLVED: To produce a steel sheet having excellent anisotropy and good earing properties and suitable for a thin DI formed can for a battery. SOLUTION: A slab having a composition containing, by weight, 0.015 to 0.06% C, <=0.03% Si, 0.1 to 0.6% Mn, <=0.02% P, <=0.04% S, 0.03 to 0.10% Cr, 0.03 to 0.12% Al, <=0.0030% N, B: 5 ppm <=B-(11/14)×N<=30 ppm, and the balance Fe with inevitable impurities is subjected to hot rolling in such a manner that hot finish rolling is performed at the Ar3 point or higher, and coiling temperature is controlled to 540 to 680 deg.C, is pickled, is thereafter cold- rolled at a rolling ratio of 60 to 93% and is subsequently subjected to continuous annealing at the recrystallization temperature or higher or box annealing at 580 to 680 deg.C, and in the case of the continuous annealing, further, precipitating treatment of solid solution C is performed in a box annealing furnace, and after skinpass rolling, Ni plating is applied thereon, and next, after diffusing treatment of Ni, skinpass rolling is performed to control the surface average roughness Ra of the sheet to 0.02 to 0.06μm. |
