Nippon Steel Corporation

Yasukazu Mori

Yoshiaki Shimoyama

Shozaburo Nakashima

Jirou Harase

Hisanobu Nakayama

Shouzaburo Nakashima

Method for the production of a single oriented silicon steel sheet having excellent magnetic property which comprises providing a silicon steel slab containing 0.010.about.0.10% C, 2.5.about.4.5% Si, 0.02.about.0.15% Mn, and a total of 0.008.about.0.080% of one or two of S and Se, hot rolling the silicon steel slabing to sheet, and subjecting the hot rolled sheet to a two-step annealing procedure wherein the first half is at a temperature of 1000.degree..about.1200.degree. C. and the latter half at 750.degree..about.980.degree. C., and to at least two cold rolling steps.

Method for the production of oriented silicon steel sheet having

A grain oriented electrical silicon steel sheet containing aluminium and having an extremely high magnetic flux density, for example, a B8 of 1.90 or more, is produced by a secondary recrystallization annealing operation in which, during the period of elevating the temperature of a reducing atmosphere to a level within a range of from 850.degree. to 950.degree. C., the partial pressure of nitrogen in the reducing atmosphere is limited to 20% or less based on the entire pressure of the reducing atmosphere, and during the period of elevating the temperature of the reducing atmosphere in which the secondary recrystallization is in progress, the partial pressure of nitrogen is maintained at a level of at least 3%.

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Kitakyushu, Japan

Yasukazu Mori