US4173502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing silicon-iron sheet material with boron addition, and product
Assignee: General Electric Co
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Filing: 1978-02-27
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Granted: 1979-11-06
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Expires: 1998-02-27
Abstract
Abstract Addition of as little as six parts per million boron to the magnesia final anneal coating on silicon-iron strip containing only about 1.5 ppm insures secondary recrystallization while the addition of 70 ppm boron to the coating on a strip containing 10 to 15 ppm boron results in substantial reduction in losses without affecting permeability of the final product when the nitrogen content of the alloy is in the 80 to 90 ppm range.
Inventors
- 👤 Howard C. Fiedler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:07
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/14766; H01F1/14775; H01F1/14783; C; C21; C21D; C21D8/00; C21D8/12; C21D8/1277; C21D8/1283; C22; C22C; C22C38/00; C22C38/02; C23; C23D; C23D5/00; C23D5/10; C21D8/1244; C21D8/1272
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
141 words
The method of producing grain-oriented silicon-iron sheet which comprises the steps of providing a fine-grained, primary-recrystallized, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about 1.5 and 7.5 parts per million boron, amounts of manganese and sulfur within a ratio of manganese to sulfur less than 2.5, and between about 30 and 90 parts per million nitrogen in the ratio to boron of one to 15 parts per part of boron, covering the sheet with an electrically-insulating adherent coating containing about 15 parts per million boron on the basis of the silicon-iron sheet, the total amount of boron in the sheet and boron in the coating available to the sheet being between about 16.5 and about 22.5 parts per million, and subjecting the coated sheet to a final heat treatment to develop (110) secondary recrystallization texture in the silicon-iron sheet.
Claim 2
Independent Claim
141 words
The method of producing grain-oriented silicon-iron sheet which comprises the steps of providing a fine-grained, primary-recrystallized, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about 1.5 and 7.5 parts per million boron, amounts of manganese and sulfur within a ratio of manganese to sulfur less than 2.5, and between about 30 and 90 parts per million nitrogen in the ratio to boron of one to 15 parts per part of boron, covering the sheet with an electrically-insulating adherent coating containing about 15 parts per million boron on the basis of the silicon-iron sheet, the total amount of boron in the sheet and boron in the coating available to the sheet being between about 16.5 and about 22.5 parts per million, and subjecting the coated sheet to a final heat treatment to develop (110) secondary recrystallization texture in the silicon-iron sheet.
Claim 3
Dependent Claim
49 words
The method of claim 1 in which the boron content of the silicon-iron sheet is about 1.5 parts per million, the nitrogen content of the sheet is about 50 parts per million, and the coating contains about 15 parts per million boron on the basis of the silicon-iron sheet.
Claim 4
Dependent Claim
49 words
The method of claim 1 in which the boron content of the silicon-iron sheet is about 6.9 parts per million, the nitrogen content of the sheet is about 50 parts per million, and the coating contains about 15 parts per million boron on the basis of the silicon-iron sheet.
Claim 5
Dependent Claim
129 words
An electrically-insulating magnetic sheet material comprising a fine-grained, primary-recrystallized, magnetic, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about 1.5 and 7.5 parts per million boron, amounts of manganese and sulfur within a ratio of manganese to sulfur less than 2.5, and between about 30 and 90 parts per million nitrogen and having thereon a coating of a water-insoluble hydroxide of a metal selected from the group consisting of calcium, magnesium, manganese and aluminum, said coating containing about 15 parts per million boron on the basis of the silicon-iron sheet and so proportioned to the boron content of the said sheet that the total amount of boron in the sheet and boron in the coating available to the sheet is between about 16.5 and 22.5 parts per million.
Claim 6
Dependent Claim
129 words
An electrically-insulating magnetic sheet material comprising a fine-grained, primary-recrystallized, magnetic, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about 1.5 and 7.5 parts per million boron, amounts of manganese and sulfur within a ratio of manganese to sulfur less than 2.5, and between about 30 and 90 parts per million nitrogen and having thereon a coating of a water-insoluble hydroxide of a metal selected from the group consisting of calcium, magnesium, manganese and aluminum, said coating containing about 15 parts per million boron on the basis of the silicon-iron sheet and so proportioned to the boron content of the said sheet that the total amount of boron in the sheet and boron in the coating available to the sheet is between about 16.5 and 22.5 parts per million.
Claim 7
Independent Claim
125 words
The method of producing grain-oriented silicon-iron sheet which comprises the steps of providing a fine-grained, primary-recrystallized, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about six and 50 parts per million boron, between about 0.010 and 0.018 percent sulfur and between about 40 and 90 parts per million nitrogen in the ratio to boron of one to 15 parts per part of boron, covering the sheet with an electrically-insulating adherent coating containing boron in quantity such that the total amount of boron in the sheet and boron in the coating available to the sheet is between about 15 and about 75 parts per million, and subjecting the coated sheet to a final heat treatment to develop (110) secondary recrystallization texture in the silicon-iron sheet.
Claim 8
Independent Claim
125 words
The method of producing grain-oriented silicon-iron sheet which comprises the steps of providing a fine-grained, primary-recrystallized, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about six and 50 parts per million boron, between about 0.010 and 0.018 percent sulfur and between about 40 and 90 parts per million nitrogen in the ratio to boron of one to 15 parts per part of boron, covering the sheet with an electrically-insulating adherent coating containing boron in quantity such that the total amount of boron in the sheet and boron in the coating available to the sheet is between about 15 and about 75 parts per million, and subjecting the coated sheet to a final heat treatment to develop (110) secondary recrystallization texture in the silicon-iron sheet.
Claim 9
Dependent Claim
38 words
The method of claim 5 in which the sulfur content of the silicon-iron sheet is about 0.010 percent and the boron and nitrogen contents of the silicon-iron sheet are about nine and about 84 parts per million, respectively.
Claim 10
Dependent Claim
37 words
The method of claim 5 in which the sulfur content of the silicon-iron sheet is about 0.018 percent and the boron and nitrogen content of the silicon-iron sheet are about 6.5 and 90 parts per million, respectively.
Claim 11
Dependent Claim
104 words
An electrically-insulating magnetic sheet material comprisng a fine-grained, primary-recrystallized, magnetic, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about six and 90 parts per million boron, between about 0.010 and 0.018 percent sulfur, and between about 40 and 90 parts per million nitrogen and having thereon a coating of a water-insoluble hydroxide of a metal selected from the group consisting of calcium, magnesium, manganese and aluminum, said coating containing boron in quantity such that the total amount of boron in the sheet and boron in the coating is between about 15 and 75 parts per million on the basis of the said sheet.
Claim 12
Dependent Claim
104 words
An electrically-insulating magnetic sheet material comprisng a fine-grained, primary-recrystallized, magnetic, silicon-iron sheet containing 2.2 to 4.5 percent silicon, between about six and 90 parts per million boron, between about 0.010 and 0.018 percent sulfur, and between about 40 and 90 parts per million nitrogen and having thereon a coating of a water-insoluble hydroxide of a metal selected from the group consisting of calcium, magnesium, manganese and aluminum, said coating containing boron in quantity such that the total amount of boron in the sheet and boron in the coating is between about 15 and 75 parts per million on the basis of the said sheet.
Claim 13
Dependent Claim
64 words
The sheet material of claim 8 in which the sulfur content of the silicon-iron sheet is about 0.010 percent and the boron and nitrogen contents of the said sheet are about nine and about 84 parts per million, respectively, and the total amount of boron in the sheet and in the coating is about 30 parts per million on the basis of the sheet.
Claim 14
Dependent Claim
63 words
The sheet material of claim 8 in which the sulfur content of the silicon-iron sheet is about 0.014 percent and the boron and nitrogen contents of the sheet are about seven and about 55 parts per million, respectively, and the total amount of boron in the coating and in the sheet is about 15 parts per million on the basis of the sheet.
References Cited (Backward Citations)
US3054732A
Cited
US3540948A
Cited
US3676227A
Cited
US3700506A
Cited
US3583887A
Cited
US3681152A
Cited
US3905843A
Cited
US3905842A
Cited
US3957546A
Cited
US4097343A
Cited
US4116730A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |