US3000731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fine-grained steels
Assignee: Research Institute for Iron Steel and Other Metals of Tohoku University
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Filing: 1958-06-10
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Granted: 1961-09-19
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Expires: 1978-06-10
Abstract
No abstract record available.
Inventors
- 👤 Ototani Tohei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:18
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/0006
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
A METHOD OF MANUFACTURING A FINE-GRAINED STEEL, WHICH COMPRISES ADDING TO A MOLTEN BATH OF STEEL CONTAINING LESS THAN ABOUT 1.7% OF CARBON, AN IRON-CALCIUMSILICON-MANGANESE ALLOY CONSISTING ESSENTIALLY OF AT LEAST 10% OF IRON, 5 TO 40% OF CALCIUM AND 5 TO 55% OF MANGANESE AND SILICON RESPECTIVELY SO AS TO RETAIN 0.001 TO 0.05% OF CALCIUM IN THE CASTING, AND THEN CASTING THE MOLTEN STEEL INTO A MOLD.
Claim 2
Independent Claim
69 words
A METHOD OF MANUFACTURING A FINE-GRAINED STEEL, WHICH COMPRISES ADDING TO A MOLTEN BATH OF STEEL CONTAINING LESS THAN ABOUT 1.7% OF CARBON, AN IRON-CALCIUMSILICON-MANGANESE ALLOY CONSISTING ESSENTIALLY OF AT LEAST 10% OF IRON, 5 TO 40% OF CALCIUM AND 5 TO 55% OF MANGANESE AND SILICON RESPECTIVELY SO AS TO RETAIN 0.001 TO 0.05% OF CALCIUM IN THE CASTING, AND THEN CASTING THE MOLTEN STEEL INTO A MOLD.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-09-18 | 1965-03-20 | 1965-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-09-18 | 1969-03-20 | 1969-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-09-18 | 1973-03-20 | 1973-09-19 | $7700.00 | Window Closed / Lapsed |