A METHOD FOR PRODUCING HIGH PERMEABILITY GRAIN-ORIENTED SILICON STEEL SHEET

摘要

The invention, by contrast to that, the secondary recrystallization during the final high temperature annealing is performed for the development of tissue first with a constant temperature maintained annealing atmosphere in a final high temperature annealing in accordance with the average size of recrystallized grains temperature relates to a method for producing a grain-oriented electrical steel sheet excellent to to provide a method for manufacturing a grain-oriented electrical steel to obtain the magnetic flux density, it is an object.; The present invention, Si in weight%: 1.0 ~ 4.8%, C: 0.02 ~ 0.1%, and containing Al and B alone or in compound, the balance Fe and other a steel slab consisting of unavoidable impurities, the temperature of 1050 ~ 1250 ℃ after re-heating in the range after applying the hot-rolled and hot-rolled and annealed, and then once with a final thickness cold rolling subjected to decarburization and nitriding remove or at the same time the annealing separator to the next, the surface of the steel sheet by causing a primary recrystallization the final high temperature in the method of annealing grain-oriented electrical steel sheet,; Measure the average size of the primary recrystallized grains, and from the measured first using the recrystallized grains size obtained for the secondary recrystallization starting temperature in the final high temperature annealing step (T _a), and then, the final high temperature annealing step, and an atmosphere with a nitrogen-containing atmosphere at 25 to 50%, and the temperature was raised and when T -b _a constant temperature maintaining magnetic flux density grain-oriented electrical superior to a constant temperature for 1 to 10 hours at a holding temperature (where, 5 ℃ ≤b≤20 ℃) the method of manufacturing the steel sheet as the base.