| 摘要 |
PURPOSE:To avert the formation of mixed linear fine grains and economically heat the titled slab by heating then hot rolling a continuously cast slab contg. Si as its essential component thence cold rolling and annealing the same. CONSTITUTION:In heating a continuously cast slab contg. 2.5-4.0% Si at its essential component, the slab center temp. is set at <=1,350 deg.C, and the heating time when the center temp. of the slab thickness is >=1,300 deg.C is set in the time range defined by Table I, whereby the temp. is controlled. This heated continuously cast slab is then hot rolled by one time of hot rolling process, thence it is cold rolled and annealed, whereby the undirectional electrical steel sheet is produced. If the heating time defined by the table is taken, the rates of crystal growth are about 15% or about 95% with both group A and group B, and the formation of mixed linear fine grains (imperfect parts showing linear fine grains) in the product is sufficiently prevented and the magnetic characteristics are made good. |
