US2779697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of nitriding metallic surfaces
Assignee: United States Steel Corp
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Filing: 1955-09-26
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Granted: 1957-01-29
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Expires: 1975-09-26
Abstract
No abstract record available.
Inventors
- 👤 Roy L Chenault
- 👤 Gerald E Mohnkern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:19
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/24; C23C8/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
A METHOD OF NITRIDING SURFACES OF METALLIC ARTICLES AND CONTROLLING THE FORMATION OF WHITE LAYER THEREON COMPRISING PLACING THE SURFACES TO BE NITRIDED WITHIN A CHAMBER, CONNECTING SAID CHAMBER TO A SOURCE OF AMMONIA LOCATED EXTERNALLY THEREOF, HEATING THE CHAMBER TO A TEMPERATURE ABOVE THAT OF THE AMMONIA SOURCE, CHARGING A REGULATED MASS OF AMMONIA PER UNIT AREA OF SURFACE REACTIVE TO NITROGEN FROM SAID SOURCE INTO SAID CHAMBER AND INTO DIRECT CONTACT WITH SAID SURFACES, SAID MASS BEING EQUIVALENT TO AT LEAST ONE GRAM OF AMMONIA PER SQUARE FOOT OF REACTIVE SURFACE BUT BELOW THE MASS WHICH PRODUCES APPRECIABLE WHITE LAYER, SEALING SAID CHAMBER WITH SAID SURFACES AND SAID AMMONIA IN CONTACT AND CONFINED THEREIN, AND HEATING SAID CHAMBER TO A TEMPERATURE APPROXIMATELY BETWEEN 800 AND 1200F. FOR A PROLONGED PERIOD.
Claim 2
Independent Claim
132 words
A METHOD OF NITRIDING SURFACES OF METALLIC ARTICLES AND CONTROLLING THE FORMATION OF WHITE LAYER THEREON COMPRISING PLACING THE SURFACES TO BE NITRIDED WITHIN A CHAMBER, CONNECTING SAID CHAMBER TO A SOURCE OF AMMONIA LOCATED EXTERNALLY THEREOF, HEATING THE CHAMBER TO A TEMPERATURE ABOVE THAT OF THE AMMONIA SOURCE, CHARGING A REGULATED MASS OF AMMONIA PER UNIT AREA OF SURFACE REACTIVE TO NITROGEN FROM SAID SOURCE INTO SAID CHAMBER AND INTO DIRECT CONTACT WITH SAID SURFACES, SAID MASS BEING EQUIVALENT TO AT LEAST ONE GRAM OF AMMONIA PER SQUARE FOOT OF REACTIVE SURFACE BUT BELOW THE MASS WHICH PRODUCES APPRECIABLE WHITE LAYER, SEALING SAID CHAMBER WITH SAID SURFACES AND SAID AMMONIA IN CONTACT AND CONFINED THEREIN, AND HEATING SAID CHAMBER TO A TEMPERATURE APPROXIMATELY BETWEEN 800 AND 1200F. FOR A PROLONGED PERIOD.
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) | 1960-01-29 | 1960-07-30 | 1961-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-01-29 | 1964-07-30 | 1965-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-01-29 | 1968-07-30 | 1969-01-29 | $7700.00 | Window Closed / Lapsed |