Patent US4839140A successfully refreshed from Google Patents.
US4839140A
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Chromium modified nickel-iron aluminide useful in sulfur bearing environments
Assignee: Lockheed Martin Energy Systems Inc
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Filing: 1987-08-31
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Granted: 1989-06-13
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Expires: 2007-08-31
Abstract
Abstract An improved nickel-iron aluminide containing chromium and molybdenum additions to improve resistance to sulfur attack.
Inventors
- 👤 John V. Cathcart
- 👤 Chain T. Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:41
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/007
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
47 words
A composition of matter consisting essentially of 18 to 19 at. % aluminum, 10 to 11.5 at. % iron, 6.5 to 8.0 at. % chromium, 0.4 to 0.8 at. % molybdenum, 0.1 to 0.3 at. % zirconium, 0.05 to 0.2 at. % boron and the balance nickel.
Claim 2
Dependent Claim
47 words
A composition of matter consisting essentially of 18 to 19 at. % aluminum, 10 to 11.5 at. % iron, 6.5 to 8.0 at. % chromium, 0.4 to 0.8 at. % molybdenum, 0.1 to 0.3 at. % zirconium, 0.05 to 0.2 at. % boron and the balance nickel.
References Cited (Backward Citations)
US4731221A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |