Patent ID: 8038806

Claim:
Method for producing grain oriented magnetic steel strip using a continuous casting process for thin slabs, comprising the following steps: a) Melting of a steel, which beside iron and unavoidable impurities contains (in wt %) Si: 2.5-4.0%, C: 0.01-0.10%, Mn: 0.02-0.50% S and Se with contents whose total amounts to 0.005-0.04%, and optionally: up to 0.07% Al, up to 0.015% N, up to 0.035% Ti, up to 0.3% P, one or more elements from the group of As, Sn, Sb, Te, Bi each with a content of up to 0.2%, one or more elements from the group of Cu, Ni, Cr, Co, Mo each with a content of up to 0.3%, one or more elements from the group of B, V, Nb each with a content of up to 0.012%, b) secondary metallurgical treatment of the molten metal in a vacuum facility and in a ladle furnace, c) continuous casting of the molten metal into a strand, d) dividing of the strand into thin slabs, e) heating of the thin slabs in a heating facility standing in a line to a temperature ranging between 1050 and 1300° C., the dwell time in the facility being 60 minutes maximum, f) continuous hot rolling of the thin slabs in a multi-stand hot rolling mill standing in a line into a hot strip having a thickness of 0.5-4.0 mm, during this hot rolling stage a first forming run being carried out at a temperature of 900-1200° C. with a deformation strain of more than 40%, the reduction per pass in a second forming run being more than 30% and the reduction per pass in a final hot rolling run being 30% maximum, g) cooling of the hot strip, h) reeling of the hot strip into a coil, i) cold rolling of the hot strip into cold strip having a final thickness of 0.15-0.50 mm, j) recrystallization and decarburization annealing of the cold strip, k) application of an annealing separator onto the cold strip surface, and n) final annealing of the recrystallization and decarburization annealed cold strip in order to form a Goss texture.