| 摘要 |
The present invention relates to a low iron loss high strength non-oriented electromagnetic steel sheet and to a method for manufacturing the same. The method for manufacturing a low iron loss high strength non-oriented electromagnetic steel sheet comprises hot-rolling a slab comprising 0.005 weight % or less of C, 4.0 weight % or less of Si, 0.1 weight % or less of P, 0.03 weight % or less of S, 0.1 to 2.0 weight % of Mn, 0.3 to 2.0 weight % of Al, 0.003 weight % or less of N, 0.005 weight % or less of Ti, the remainder being Fe and unavoidable impurities, cold-rolling the slab, and finally annealing the slab such that the fractional area of the non-recrystallization tissue at the cross sectional surface of the steel sheet is 50% or lower (not including 0%). According to the present invention, the fractional area of the non-recrystallization tissue at the cross sectional surface of the steel sheet is maintained at an appropriate level and the average grain size of recrystallized grains is controlled so as to manufacture low iron loss non-oriented electromagnetic steel wheel having superior strength. The final annealing process is performed in a temperature area in which a variation in yield strength caused by a temperature variation in the final annealing process is low to thereby prevent degradation of elongation and reduce variations in magnetic property and strength, thus stably ensuring low iron loss and high strength characteristics. |
