US4010049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Columbium-stabilized high chromium ferritic stainless steels containing zirconium
Assignee: J&L Specialty Steel Inc
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Filing: 1975-10-06
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Granted: 1977-03-01
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Expires: 1995-10-06
Abstract
Abstract The inclusion of small interrelated amounts of zirconium and columbium to ferritic stainless steels results in a stabilized steel having good pitting corrosion resistance and good ductility.
Inventors
- 👤 Charles R. Rarey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:04
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/28; C22C38/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
94 words
A stabilized fully ferritic stainless steel in the wrought condition having good ductility, and characterized by a minimal amount of surface streaking, consisting essentially of: Carbon, 0.10% maximum; Chromium, from 11% to 30%; Molybdenum, up to 3.0%; Nitrogen, residual quantities: Columbium, from about 0.1% total to 0.3% in solid solution, and in no event less than (7.7 × % carbon - % zirconium in excess of 6.5 × % nitrogen); Zirconium, from 6.5 × % nitrogen to 0.25% in excess of (6.5 × % nitrogen × 7.6% carbon); and balance iron and residual impurities.
Claim 2
Dependent Claim
94 words
A stabilized fully ferritic stainless steel in the wrought condition having good ductility, and characterized by a minimal amount of surface streaking, consisting essentially of: Carbon, 0.10% maximum; Chromium, from 11% to 30%; Molybdenum, up to 3.0%; Nitrogen, residual quantities: Columbium, from about 0.1% total to 0.3% in solid solution, and in no event less than (7.7 × % carbon - % zirconium in excess of 6.5 × % nitrogen); Zirconium, from 6.5 × % nitrogen to 0.25% in excess of (6.5 × % nitrogen × 7.6% carbon); and balance iron and residual impurities.
Claim 3
Dependent Claim
21 words
A stabilized fully ferritic stainless steel having good ductility according to claim 1, wherein said molybdenum is from 0.5 to 2.0%.
Claim 4
Dependent Claim
19 words
A stabilized fully ferritic stainless steel having good ductility according to claim 1, wherein said carbon is 0.05% maximum.
References Cited (Backward Citations)
CA884806A
Cited
US2793113A
Cited
DE2124391A1
Cited
US3852063A
Cited
US3926624A
Cited
US3890143A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |