| 摘要 |
PROBLEM TO BE SOLVED: To produce a nonoriented silicon steel sheet having high magnetic flux density and low core loss. SOLUTION: In the method of producing a nonoriented silicon steel sheet in which a steel slab containing, by weight, 0.1 to 7% Si, 0.1 to 1.5% Mn, <=0.005% C, <=0.005% N, <=0.005% S and, suitably, 0.1 to 2.5% Al, and the balance Fe with inevitable impurities is made into a hot rolled sheet, which is subjected to cold rolling for one time and is next subjected to finish annealing or is thereafter subjected to skinpass rolling as well, after the finish hot rolling, the sheet is coiled at 750 to 1,050 deg.C, is held for 30 sec to 90 min, is thereafter subjected to tempering cooling and is again coiled at <=550 deg.C. At this time, the friction coefficient between a hot rolling roll and the steel sheet at least in one pass is controlled to <=0.25, the strain rate in the final pass is controlled to >=150s-1, the tension between final two stands is controlled to >=1.5 kgf/mm2, and the tension σ (kgf/mm2) between the final stand and a proximity coil is controlled to >=2-T0.3+InT (T denotes hot rolling finishing temperature). |
