US2804410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for nitriding titanium surfaces
Assignee: NL Industries Inc
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Filing: 1953-10-27
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Granted: 1957-08-27
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Expires: 1973-10-27
Abstract
No abstract record available.
Inventors
- 👤 James L Wyatt
- 👤 Nicholas J Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:09
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A PROCESS FOR NITRIDING A REFRACTORY METAL SURFACE WHICH COMPRISES: HEATING THE SURFACE OF A REFRACTORY METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM TO A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 1400*F. TO ABOUT 1700*F. IN AN OXYGEN FREE ATMOSPHERE OR PARTIALLY DISSOCICATED AMMONIA GAS INCLUDING UNDISSOCIATED AMMONIA IN AN AMOUNT FROM 0.05 TO 2% BY VOLUME OF THE GAS INTRODUCTION INTO SAID ATMOSPHERE; AND CONTINUING SAID HEATING FOR A PERIOD OF TIME WHICH BEARS AN INVERSE RELATIONSHIP TO THE TEMPERATURE OF SAID HEATED ATMOSPHERE TO FORM A HIGH HARDNESS CASE ON SAID REFRACTORY METAL.
Claim 2
Dependent Claim
99 words
A PROCESS FOR NITRIDING A REFRACTORY METAL SURFACE WHICH COMPRISES: HEATING THE SURFACE OF A REFRACTORY METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM TO A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 1400*F. TO ABOUT 1700*F. IN AN OXYGEN FREE ATMOSPHERE OR PARTIALLY DISSOCICATED AMMONIA GAS INCLUDING UNDISSOCIATED AMMONIA IN AN AMOUNT FROM 0.05 TO 2% BY VOLUME OF THE GAS INTRODUCTION INTO SAID ATMOSPHERE; AND CONTINUING SAID HEATING FOR A PERIOD OF TIME WHICH BEARS AN INVERSE RELATIONSHIP TO THE TEMPERATURE OF SAID HEATED ATMOSPHERE TO FORM A HIGH HARDNESS CASE ON SAID REFRACTORY METAL.
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) | 1960-08-26 | 1961-02-25 | 1961-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-26 | 1965-02-25 | 1965-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-26 | 1969-02-25 | 1969-08-27 | $7700.00 | Window Closed / Lapsed |