| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing non-oriented silicon steel sheet providing both of excellent mechanical properties and magnetic properties, needed as a rotor in a motor rotated at high speed. <P>SOLUTION: There is prepared a steel ingot or a steel slab composed by mass% of ≤0.06% C, ≤3.5% Si, 0.05-3.0% Mn, ≤2.5% Al, ≤0.30% P, ≤0.04% S, ≤0.02% N, >0.02% Nb and at least one kind selected from the group of Nb, Ti, Zr and V in the range of expression (1): 0<Nb/93+Zr/91+Ti/48+V/51-(C/12+N/14)<5×10<SP>-3</SP>, and the balance substantially Fe with impurities. The production method comprises a hot-rolling process, a cold-rolling process for producing a cold-rolled steel sheet having 0.15-0.80mm thickness and ≥850MPa tensile strength by applying one time cold-rolling or ≥two times cold-rolling including an intermediate annealing to a hot-rolled steel plate, and a soaking treatment process for soaking the cold-rolled steel sheet at ≤820°C. <P>COPYRIGHT: (C)2007,JPO&INPIT |
