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AssigneeNippon Steel Corporation
InventorsHiroyasu Fujii, Yoshiyuki Ushigami, Shuichi Nakamura, Kenichi Murakami, Norihiro Yamamoto, Kiyoshi Sawano, Shuichi Yamazaki
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The present invention provides a method for producing a grain-oriented silicon steel sheet not having inorganic mineral films by using an annealing separator capable of preventing the inorganic mineral films composed of forsterite (Mg2SiO4), and so on, from forming during final annealing, comprising the steps of decarburization annealing followed by coating of annealing separator and final annealing, wherein alumina powder calcined at a calcination temperature of 900 to 1,400° C., or further having a BET specific surface area of 1 to 100 m2/g, an oil absorption of 1 to 70 ml/100 g, and/or having a gamma ratio of 0.001 to 2.0, is used as the annealing separator. Magnesia having a BET specific surface area of 0.5 to 5 m2/g may be added to said alumina powder.
A method for producing a grain-oriented silicon steel sheet not having inorganic mineral films, comprising the steps of decarburization annealing followed by coating of annealing separator and final annealing, wherein alumina powder calcined at a calcination temperature of 900 to 1,400° C. is used as an annealing separator.
Dependencies are inferred from the claim text.