Kawasaki Steel Corporation

Masataka Yamada

Yasuyuki Hayakawa

Michiro Komatsubara

Ujihiro Nishiike

Bunjiro Fukuda

Yoshiaki Iida

Yoh Shimizu

Shigeru Yoshida

Fumihiko Takeuchi

Humihiko Takeuchi

Tetsuya Oishi

A method of manufacturing a grain-oriented silicon steel sheet having excellent and uniform magnetic characteristics by improving the magnetic flux density of a silicon coil cold rolled to a thin thickness without increasing a Si content. The method comprises controlling steel sheet temperature along the rolling direction of a coil immediately downstream of the outlet roll bites of one or more rolling paths to about 15.degree. C. or less, and controlling the temperature of one or more of the rolling paths between about 150.degree. C. to about 350.degree. C.

Method of cold rolling grain-oriented silicon steel sheet having

A method of producing a grain oriented silicon steel sheet is adapted to lower the iron loss. A silicon steel slab, containing about 2.0 to 4.0 weight % of Si and an inhibitor-forming amount of S, or Se, or both, is hot rolled. After the hot rolled steel sheet is annealed when necessary, the steel sheet is cold rolled into a cold rolled steel sheet having a final thickness by performing cold rolling either one time or a plurality of times with intermediate annealing therebetween, the cold rolled steel sheet then being subjected to decarburization, coating of the surface of the steel sheet with an annealing separation agent mainly comprising MgO, secondary recrystallization annealing, and purification annealing. In the cold rolling step, an oxide layer exists on the surface of the steel sheet. Specifically, in the cold rolling step, rolling oil is supplied only at the entrance of the rolling mill used, and an oxide layer having a thickness of about 0.05 to 5 .mu.m is generated. Or, an outer oxide layer of an oxide layer structure generated on the surface of the steel sheet after hot rolling or intermediate annealing, is removed, and an inner oxide layer of a thickness of about 0.05 to 5 .mu.m is maintained on the surface, the resultant steel sheet then being subjected to cold rolling.

Method of producing grain oriented silicon steel sheet having low iron

Method of manufacturing a grain oriented silicon steel sheet. An annealing separating agent mainly composed of MgO is coated on a surface of a decarburized silicon steel sheet. The silicon steel sheet is subjected to secondary recrystallization annealing and then purification annealing. The annealing separating agent contains Ti oxide or a Ti compound which can be oxidized by heating. The purification annealing is conducted in steps. A non-oxidizing atmosphere having a high nitrogen concentration is present in one step. A hydrogen atmosphere having a low nitrogen concentration is present in a subsequent step.

Method of manufacturing grain oriented silicon steel sheets

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Kobe, Japan

Masataka Yamada