US3705058A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Soft-nitriding procedure for steel and cast iron
Assignee: FABRICA DE UTILAJE SI PIESE DE SCHIMB METALOTEHNICA
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Filing: 1971-07-07
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Granted: 1972-12-05
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Expires: 1991-07-07
Abstract
Abstract A METHOD OF INCREASING THE NITROGEN CONTENT OF STEEL AND CAST IRON WHEREIN THE BODY IS MAINTAINED IN AN ATMOSPHERE OF AMMONIA, METHANE AND OXYGEN IN A MOLAR RATIO OF CH4:NH3=1 AND (CH4+NH3):O2=25-30 WHILE MAINTAINING THE DISSOCIATION RATE OF THE AMMONIA BETWEEN 38 AND 40%. THE TREATMENT TIME IS 1 TO 10 HOURS AT A TEMPERATURE OF 570* C.+ 10* C.
Inventors
- 👤 Zoltan Kolozsvari
- 👤 Endre Gal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:22
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/24; C23C8/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |