US 5,855,694 AGranted

Method for producing grain-oriented silicon steel sheet

AssigneeKawasaki Steel Corporation

InventorsTetsuo Toge, Atsuhito Honda, Mineo Muraki, Kenichi Sadahiro, Minoru Takashima

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Abstract

Production of grain-oriented silicon steel sheet, in which the heating temperature of slabs is as low as that in common steels and good magnetic properties are maintained, without applying a nitriding process. The contents of Al, Se and S substantially satisfy formulae (1) and (2), and both or either of formulae (3) and (4): Al (wt %)!+(5/9){Se (wt %)!+2.47S(wt %)!}.ltoreq.0.027 (1) Se (wt %)!+2.47S (wt %)!.ltoreq.0.025 (2) 0.016.ltoreq.Al (wt %)!+(5/9){Se (wt %)!+2.47 S (wt %)!}(3) 0.010.ltoreq.Al (wt %)! (4) Annealing of the hot rolling sheet is applied at a temperature of about 800.degree. C. or more, and about 1000.degree. C. or below; preferably, cold rolling is applied at about 100.degree. C. or more, using a tandem mill.

Claims8

Dependent claims

In a method for producing a grain-oriented silicon steel sheet wherein a silicon steel slab is subjected to heating and then hot rolling, and wherein the resulting hot-rolled steel sheet is annealed, followed by single or multiple cold rolling to adjust the annealed sheet to final thickness, and said sheet is treated by decarbonization annealing, coating the sheet with an annealing separator followed by finish annealing,

the novel steps wherein the contents of Al, Se and S (Al!, Se! and S!, each in wt %) substantially satisfy both of the following formulae (1) and (2) as well as both or either of the following formulae (3) and (4):
Al (wt %)!+(5/9){Se (wt %)!+2.47S(wt %)!}.ltoreq.0.027 (1)
Se (wt %)!+2.47S (wt %)!.ltoreq.0.025 (2)
0.016.ltoreq.Al (wt %)!+(5/9){Se (wt %)!+2.47 S (wt %)!}(3)
0.010.ltoreq.Al (wt %)! (4)
wherein said step of heating said slab is conducted at about 1260.degree. C. or less, and wherein said step of annealing said hot-rolled sheet prior to cold rolling is conducted at about 800.degree. C.-1000.degree. C.

3 more elements

Dependencies are inferred from the claim text.