Non-Oriented Silicon Steel and Manufacturing Process Thereof

摘要

The present invention provides a non-oriented silicon steel with excellent magnetic properties and a manufacturing process therefor. During the manufacturing process of the present invention, the temperature T of the molten steel of steel tapped from a converter during steelmaking and the carbon content [C] and the free oxygen content [O] comply with the following formula: 7.27×103≦[O][C]e(−5000/T)≦2.99×104, and the final annealing step uses tension annealing at a low temperature for a short time. A non-oriented silicon steel with a low iron loss, and excellent anisotropy of iron loss can be obtained by means of the manufacturing process of the present invention.

主权项

1. A method for producing non-oriented silicon steel, comprising the following steps in sequence: a) steel making, b) hot rolling, c) normalizing, d) cold rolling, and e) annealing, wherein,
a casting slab containing the following composition by weight percentage is obtained by said steel making step a): C 0.001˜0.004%, Si 2.5˜4.0%, Al 0.5˜1.5%, Mn 0.10˜1.50%, P≦0.02%, S≦0.002%, N≦0.003%, B≦0.005%, where Mn/S≧300, Al/N≧300, and the balance being Fe and unavoidable impurities; wherein, said steel making step a) includes converter steel making, in which the temperature T of molten steel during tapping on converter, the carbon content [C] and the free oxygen content [O] satisfy the following formula: 7.27×103≦[O][C]e(−5,000/T)≦2.99×104, and in said annealing step e), the cold-rolled steel strip is heated to 900˜1,050° C., and then is subject to thermal insulation under a tension σ of 0.5˜1.5 MPa for a period of time t of 8˜60 sec.