Claims
- 1. A process for manufacturing a double oriented electrical steel sheet having a high magnetic flux density B.sub.8 (T) of at least 1.89, which comprises providing a silicon steel slab comprising 1.8-4.8% by weight of Si, 0.008-0.048% by weight of acid soluble Al, 0.0028-0.0100% by weight of total N, 0.0010 to 0.016% by weight of S and the balance being Fe and unavoidable impurities, heating the silicon steel slab to about 1000.degree. to 1270.degree. C., hot-rolling the silicon steel slab into a hot-rolled sheet, subjecting the sheet to cold-rolling at a reduction rate of 40-80%, subsequently subjecting the sheet to another cold-rolling at a reduction rate of 30-70% in a direction crossing perpendicularly to a direction of said cold-rolling, annealing the sheet at 750.degree.-950.degree. C. in a wet hydrogen atmosphere for decarburization, and carrying out final finishing annealing of the sheet which comprises a stage for completing secondary recrystallization at a temperature of 920.degree.-1100.degree. C. followed by a stage for purification.
- 2. A process for manufacturing a double oriented magnetic steel sheet having a high magnetic flux density B.sub.8 (T) of at least 1.89, which comprises providing a silicon steel slab comprising 1.8-4.8% by weight of Si, 0.008-0.048% by weight of acid soluble Al, 0.0010to 0.016% by weight of S and the balance being Fe and unavoidable impurities, heating the silicon steel slab to about 1000.degree. to 1270.degree. C., hot-rolling the silicon steel slab into a hot-rolled sheet, subjecting the sheet to cold-rolling at a reduction rate of 40-80%, subsequently subjecting the sheet to another cold-rolling at a reduction rate of 30-70% in a direction crossing perpendicularly to a direction of said cold-rolling, annealing the sheet at 750.degree.-950.degree. C. in a wet hydrogen atmosphere for decarburization, subsequently nitriding the sheet so that the total N content in the raw material is 0.002-0.060% by weight at any time during the annealing stage for decarburization, during an additional annealing stage thereafter, or during a heating stage in a final finishing annealing stage by the time of the start of secondary recrystallization, and carrying out final finishing annealing which comprises a stage for completing secondary recrystallization at a temperature of 920.degree.-1100.degree. C. followed by a stage for purification.
- 3. The process of claim 1, wherein the hot-rolled sheet is annealed at a temperature of 750.degree.-1200.degree. C. for 30 seconds to 30 minutes prior to the first cold-rolling.
- 4. The process of claim 2, wherein the hot-rolled sheet is annealed at a temperature of 750.degree.-1200.degree. C. for 30 seconds to 30 minutes prior to the first cold-rolling.
Priority Claims (1)
Number |
Date |
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Kind |
2-103182 |
Apr 1990 |
JPX |
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Parent Case Info
This application is a continuation of now abandoned application Ser. No. 07/685,893 filed Apr. 16, 1991, now abandoned.
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Name |
Date |
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3640780 |
Stanley |
Feb 1972 |
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4997493 |
Ushigami et al. |
Mar 1991 |
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Continuations (1)
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Number |
Date |
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Parent |
685893 |
Apr 1991 |
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