| 摘要 |
PURPOSE:To manufacture nonoriented electromagnetic steel strip having high magnetic flux density and less iron loss by subjecting a low-carbon steel slab containing 1.5% or less Si or Si and Al to the so-called one-time skin pass in which the slab is hot-rolled at a specific temperature, washed with an acid, cold-rolled, and then annealed. CONSTITUTION:A steel slab containing <0.05% C, 1.5% or less Si or Si+Al, 0.1-1% Mn, and <0.2% P is hot-rolled at a specific temperature and then coiled up at least 680 deg.C. In this case, the hot roll-ending temperature is set up to a temperature between the central value of the transformation point Ar3 and Ar1, represensed by the formulas I and II, in connected with the chemical composition of the steel, and 750 deg.C. After washing the coil with an acid, it is cold-rolled to a thickness of 0.50mm. and then bright-annealed at 750 deg.C for two minutes in a continuous annealing furnace, followed by one-time cold rolling skin pass at a draft of 15% or less. Thereby, nonoriented process electromagnetic steel strip can be manufactured by one-time cold rolling method. |
