US3512957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steelmaking processes
Assignee: Dortmund Hoerder Huettenunion AG
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Filing: 1964-06-19
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Granted: 1970-05-19
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Expires: 1984-06-19
Abstract
No abstract record available.
Inventors
- 👤 Karl Brotzmann
- 👤 Eric R Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:05
CPC Classifications
C; C21; C21C; C21C7/00; C21C7/10; C22; C22C; C22C38/00; C22C38/06
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
84 words
THE METHOD OF PRODUCING NON-AGING STEELS COMPRISING THE STEPS OF SUBJECTING A MOLTEN STEEL BATH TO A VACUUM SUFFICIENT TO CAUSE REMOVAL OF OXYGEN FROM THE BATH, MAINTAINING THE BATH UNDER VACUUM UNTIL THE OXYGEN LEVEL IN THE BATH IS REDUCED TO ABOUT 0.005% TO ABOUT 0.01%, ADDING ALUMINUM TO THE STEEL IN AN AMOUNT SUFFICIENT TO REACT WITH THE REMAINING OXYGEN TO REDUCE THE OXYGEN LEVEL BELOW ABOUT 0.003% AND ADDING 0.005% TO 0.010% BORON TO THE MOLTEN BATH FOLLOWING THE ALUMINUM ADDITION.
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) | 1973-05-18 | 1973-11-17 | 1974-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-05-18 | 1977-11-17 | 1978-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-05-18 | 1981-11-17 | 1982-05-19 | $7700.00 | Window Closed / Lapsed |