Grain oriented electrical steel sheet having specular surface

摘要

PCT No. PCT/JP93/00136 Sec. 371 Date Jan. 7, 1994 Sec. 102(e) Date Jan. 7, 1994 PCT Filed Feb. 4, 1993 PCT Pub. No. WO93/23577 PCT Pub. Date Nov. 25, 1993In order to provide a very low iron loss, it is necessary to render the surface of a steel sheet smooth (specular). In the present invention, this is effected in a finish annealing furnace to simultaneously attain a high magnetic flux density and a specular surface. Specifically, after the completion of decarburization annealing, a steel material is pickled to remove an oxide layer present on the surface of the steel sheet, coated with an annealing separator comprising a substance nonreactive or less reactive with SiO2 and then subjected to finish annealing to provide a grain oriented electrical steel sheet having a specular surface. Magnetic domain division and tension coating of the steel sheet can provide a low iron loss value. In the finish annealing, since no time is required for dehydration, the annealing time can be shortened.