| 摘要 |
1. A magnetic steel sheet consisting of, expressed in wt. %: C <= 0.005; 1.20 <= Si <= 1.40; 0.18 <= Al <= 0.22; 0.25 <= Mn <= 0.35; 0.10 <= P <= 0.14; 0.09 <= Sn <= 0.12; 0.005 <= S <= 0.015; N <= 0.01; O <= 0.01; the rest of the composition consisting of iron and impurities resulting from production. 2. A method for preparing steel plates having said composition according to claim 1, wherein comprises the steps of: making steel and forming slabs; slab hot rolling for fabricating steel plates, said rolling is finished at a temperature between temperature point Ar3 minus 80 degree C to Ar3 point; rolling the steel plates on a coil at a temperature higher than 680 degree C; cold rolling followed by thermal treatment of steel plates. 3. The method according to claim 2, wherein the temperature of steel plates rolling is higher than 700 degree C. 4. The method according to claim 2 or 3, wherein said thermal treatment is annealing carried out at a temperature higher than 900 degree . 5. The method according to claim 2, wherein the annealing of steel plates is carried out in a furnace for less than or equal to 50 seconds. 6. The method according to claim 4 or 5, wherein said cold rolling is continued until the final thickness is obtained and said annealing is a final annealing. 7. A magnetic steel sheet with non-oriented grains having a composition according to claim 1. 8. The A magnetic steel sheet with non-oriented grains obtained by the method according to any one of claims 2-6. 9. The magnetic steel sheet with non-oriented grains according to claim 7 or 8, wherein at the thickness of 0.50 mm the total magnetic losses are below 4W/kg and the induction higher than 1.72 Tl when applying the field of 5000 A/m. 10. The magnetic steel sheet with non-oriented grains according to claim 9, wherein the total magnetic losses are below 3.5W/kg. 11. The magnetic steel sheet with non-oriented grains according to claim 10, wherein the total magnetic losses are below 3.3W/kg. 12. The magnetic steel sheet with non-oriented grains according to claim 7 or 8, wherein at the thickness of 0.65 mm the total magnetic losses are below 5.30W/kg and the induction higher than 1.72 Tl when applying the field of 5000 A/m. 13. The magnetic steel sheet with non-oriented grains according to claim 12, wherein the total magnetic losses are below 4.70W/kg. 14. The magnetic steel sheet with non-oriented grains according to any one of claims 7-13, wherein the thermal conductivity is equal or higher than 35 W/mK and the elasticity limit equal or higher than 300 Mpa. 15. The magnetic steel sheet with non-oriented grains according to any one of claims 7-14, wherein further comprises with a layer of insulation coating provided on each of its sides.
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