US3989514A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-resisting austenitic stainless steel
Assignee: Nippon Steel Nisshin Co Ltd
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Filing: 1975-03-25
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Granted: 1976-11-02
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Expires: 1995-03-25
Abstract
Abstract An austenitic stainless steel comprising not more than 0.15% by weight of C, 1.5 - 4.0% by weight of Si, not more than 2% by weight of Mn, 17.0 - 30.0% by weight of Ni, 24.0 - 32.0% by weight of Cr, 0.5 - 2.5% by weight of Al, 0.001 - 0.100% by weight of Ca, 0.001 - 0.100% by weight of at least one rare earth metal, 0 - 1.0% by weight of at least one of Ti, Zr, Hf, Nb and Ta, and balance Fe and incidental impurities is disclosed. Steels of this class are superior to the known high Si oxidation-resisting austenitic stainless steels in scaling and nitriding resistance and with stand prolonged use under the circumstances where the steels undergo cyclic heating to high temperatures.
Inventors
- 👤 Tokio Fujioka
- 👤 Masayuki Kinugasa
- 👤 Shozo Iizumi
- 👤 Shizuhiro Teshima
- 👤 Isamu Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:12
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
93 words
A heat-resisting austenitic stainless steel consisting essentially of not more than 0.15% by weight of C, 1.5 - 4.0% by weight of Si, not more than 2% by weight of Mn, 17.0 - 30.0% by weight of Ni, 24.0 - 32.0% by weight of Cr, 0.5 - 2.5% by weight of Al, 0.001 - 0.100% by weight of Ca, 0.001 - 0.100% by weight of at least one rare earth metal, 0 - 1.0% by weight of at least one of Ti, Zr, Hf, Nb and Ta and balance Fe and incidental impurities.
Claim 2
Dependent Claim
93 words
A heat-resisting austenitic stainless steel consisting essentially of not more than 0.15% by weight of C, 1.5 - 4.0% by weight of Si, not more than 2% by weight of Mn, 17.0 - 30.0% by weight of Ni, 24.0 - 32.0% by weight of Cr, 0.5 - 2.5% by weight of Al, 0.001 - 0.100% by weight of Ca, 0.001 - 0.100% by weight of at least one rare earth metal, 0 - 1.0% by weight of at least one of Ti, Zr, Hf, Nb and Ta and balance Fe and incidental impurities.
Claim 3
Dependent Claim
98 words
The heat-resisting austenitic stainless steel as claimed in claim 1, consisting essentially of not more than 0.12% by weight of C, 1.5 - 3.5% by weight of Si, not more than 1.5% by weight of Mn, 19 - 27% by weight of Ni, 25 - 30% by weight of Cr, 0.5 - 2.3% by weight of Al, 0.001 - 0.06% by weight of Ca, 0.005 - 0.1% by weight of at least one rare earth metal, 0.05 - 0.7% by weight of at least one of Ti, Zr, Hf, Nb and Ta and balance Fe and incidental impurities.
Claim 4
Dependent Claim
98 words
The heat-resisting austenitic stainless steel as claimed in claim 2, consisting essentially of not more than 0.1% by weight of C, 1.5 - 3.0% by weight of Si, not more than 1.0% by weight of Mn, 21 - 25% by weight of Ni, 25 - 27% by weight of Cr, 0.5 - 2.3% by weight of Al, 0.001 - 0.03% by weight of Ca, 0.005 - 0.08% by weight of at least one rare earth metal, 0.05 - 0.5% by weight of at least one of Ti, Zr, Hf, Nb and Ta and balance Fe and incidental impurities.
References Cited (Backward Citations)
US2553330A
Cited
US3754898A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |