Patent US3681152A successfully refreshed from Google Patents.
US3681152A
Expired / Lapsed
US
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Method of siliconizing
Assignee: Allegheny Ludlum Corp
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Filing: 1971-03-25
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Granted: 1972-08-01
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Expires: 1991-03-25
Abstract
Abstract A METHOD OF TREATING GRAIN ORINETED SILICON STEEL, WHICH COMPRISES THE STEPS OF: HEATING GRAIN ORIENTED SILICON STEEL AT A TEMPERATURE OF FROM ABOUT 1900*F. TO ABOUT 2300* F., SUBJECTING THE STEEL TO AN ACIDIC ATMOSPHERE WHICH PREFERENTIALLY REMOVES IRON, THUS ENRICHING THE MEMBER WITH SILICON, FOR A PERIOD OF TIME SUFFICIENT TO INCREASE THE TOTAL PROPORTION OF SILICON IN THE STEEL BY ABOUT 0.4 TO 4 WT. PERCENT; AND HOMOGENIZING THE STEEL AT A TEMPERATURE AND FOR A TIME SUFFICIENT FOR THE SILICON TO DISPERSE ITSELF SUBSTANTIALLY UNIFORMLY THEREIN.
Inventors
- 👤 William E Staley
- 👤 Stuart L Ames
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:06
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/02; C21; C21D; C21D3/00; C23; C23F; C23F1/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |