US4108641A
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Oxidation-resisting austenitic stainless steel
Assignee: Nippon Steel Nisshin Co Ltd
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Filing: 1977-07-11
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Granted: 1978-08-22
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Expires: 1997-07-11
Abstract
Abstract An austenitic stainless steel substantially comprising not more than 0.15% by weight of C, 2.56 - 4.0% by weight of Si, not more than 2.0% by weight of Mn, 8 - 22% by weight of Ni, 16 - 25% by weight of Cr, 0.001 - 0.05% by weight of at least one alkaline earth metal, 0 - 2.5% by weight of Al, 0 - 0.1% by weight of at least one rare earth metal, 0 - 1.0% by weight of at least one of Nb, Ta, Ti, Zr and Hf, 0 - 2.0% by weight of Cu and balance Fe is disclosed. This class of steels are superior to the known high Si oxidation-resisting austenitic stainless steels in oxidation resistance especially in resistance to scaling, are of the same level in high temperature strength, and are much less expensive.
Inventors
- 👤 Tokio Fujioka
- 👤 Masayuki Kinugasa
- 👤 Shozo Iizumi
- 👤 Shizuhiro Teshima
- 👤 Isamu Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:27
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
73 words
An oxidation-resisting austenitic stainless steel consisting essentially of not more than 0.15% by weight of C, 2.56 - 4.0% by weight of Si, not more than 2.0% by weight of Mn, 8 - 22% by weight of Ni, 16 - 25% by weight of Cr, 0.001 - 0.05% by weight of at least one alkaline earth metal, 0.001 - 0.1% by weight of at least one rare earth metal and the balance Fe.
Claim 2
Dependent Claim
73 words
An oxidation-resisting austenitic stainless steel consisting essentially of not more than 0.15% by weight of C, 2.56 - 4.0% by weight of Si, not more than 2.0% by weight of Mn, 8 - 22% by weight of Ni, 16 - 25% by weight of Cr, 0.001 - 0.05% by weight of at least one alkaline earth metal, 0.001 - 0.1% by weight of at least one rare earth metal and the balance Fe.
Claim 3
Dependent Claim
86 words
The oxidation resisting austenitic stainless steel as set forth in claim 1, wherein the C content is not more than 0.12% by weight, the Si content is 3.0 - 4.0% by weight, the Mn content is not more than 1.5% by weight, the Ni content is 10 - 22% by weight, the Cr content is 16 - 23% by weight, the alkaline earth metal is Ca and its content is 0.001 - 0.035% by weight, the rare earth metal content is 0.005 - 0.1% by weight.
Claim 4
Dependent Claim
80 words
The oxidation-resisting austenitic stainless steel as set forth in claim 2, wherein the C content is not more than 0.1% by weight, the Si content is 3.4 - 4.0% by weight, the Mn content is not more than 1.0% by weight, the Ni content is 12 - 20% by weight, the Cr content is 16 - 22% by weight, the Ca content is 0.001 - 0.02% by weight and the rare earth metal content is 0.005 - 0.08% by weight.
Claim 5
Dependent Claim
30 words
The oxidation-resisting austenitic stainless steel as set forth in claim 1, which further contains 0.05 - 1.0% by weight of at least one of Ti, Zr, Hf, Nb and Ta.
Claim 6
Dependent Claim
102 words
The oxidation-resisting austenitic stainless steel as set forth in claim 4, wherein the C content is not more than 0.12% by weight, the Si content is 3.0 - 4.0% by weight, the Mn content is not more than 1.5% by weight, the Ni content is 10 - 22% by weight, the Cr content is 16 - 23% by weight, the alkaline earth metal is Ca and its content is 0.001 - 0.035% by weight, the rare earth content is 0.005 - 0.1% by weight and the content of any of Ti, Zr, Hf, Nb and Ta is 0.05 - 0.7% by weight.
Claim 7
Dependent Claim
97 words
The oxidation-resisting austenitic stainless steel as set forth in claim 5, wherein the C content is not more than 0.1% by weight, the Si content is 3.4 - 4.0% by weight, the Mn content is not more than 1.0% by weight, the Ni content is 12 - 20% by weight, the Cr content is 16 - 22% by weight, the Ca content is 0.001 - 0.02% by weight, the rare earth metal content is 0.005 - 0.08% by weight and the content of any of Ti, Zr, Hf, Nb and Ta is 0.05 - 0.5% by weight.
Claim 8
Dependent Claim
21 words
The oxidation-resisting austenitic stainless steel as set forth in claim 1, which further contains 0.1 - 2.5% by weight of Al.
Claim 9
Dependent Claim
84 words
The oxidation-resisting austenitic stainless steel as set forth in claim 7, wherein the C content is not more than 0.12% by weight, the Si content is 3.0 - 4.0% by weight, the Mn content is not more than 1.5% by weight, the Ni content is 10 - 22% by weight, the Cr content is 16 - 23% by weight, the alkaline earth metal is Ca and its content is 0.001 - 0.035% by weight, and the Al content is 0.3 - 2.0% by weight.
Claim 10
Dependent Claim
78 words
The oxidation-resisting austenitic stainless steel as set forth in claim 8, wherein the C content is not more than 0.1% by weight, the Si content is 3.4 - 4.0% by weight, the Mn content is not more than 1.0% by weight, the Ni content is 12 - 20% by weight, the Cr content is 16 - 22% by weight, the Ca content is 0.001 - 0.02% by weight, and the Al content is 0.3 - 1.5% by weight.
Claim 11
Dependent Claim
26 words
The oxidation-resisting austenitic stainless steel as set forth in claim 7, which further contains 0.001 - 0.1% by weight of at least one rare earth metal.
Claim 12
Dependent Claim
95 words
The oxidation-resisting austenitic stainless steel as set forth in claim 10, wherein the C content is not more than 0.12% by weight, the Si content is 3.0 - 4.0% by weight, the Mn content is not more than 1.5% by weight, the Ni content is 10 - 22% by weight, the Cr content is 16 - 23% by weight, the alkaline earth metal is Ca and its content is 0.001 - 0.035% by weight, the Al content is 0.3 - 2.0% by weight, and the rare earth metal content is 0.005 - 0.1% by weight.
Claim 13
Dependent Claim
89 words
The oxidation-resisting austenitic stainless steel as set forth in claim 11, wherein the C content is not more than 0.1% by weight, the Si content is 3.0 - 4.0% by weight, the Mn content is not more than 1.0% by weight, the Ni content is 12 - 20% by weight, the Cr content is 16 - 22% by weight, the Ca content is 0.001 - 0.02% by weight, the Al content is 0.3 - 1.5% by weight, and the rare earth metal content is 0.005 - 0.08% by weight.
Claim 14
Dependent Claim
30 words
The oxidation-resisting austenitic stainless steel as set forth in claim 10, which further contains 0.05 - 1.0% by weight of at least one of Ti, Zr. Hf, Nb and Ta.
Claim 15
Dependent Claim
110 words
The oxidation-resisting austenitic stainless steel as set forth in claim 13, wherein the C content is not more than 0.12% by weight, the Si content is 3.0 - 4.0% by weight, the Mn content is not more than 1.5% by weight, the Ni content is 10 - 22% by weight, the Cr content is 16 - 23% by weight, the alkaline earth metal is Ca and its content is 0.001 - 0.035% by weight, the Al content is 0.3 - 2.0% by weight, the rare earth metal content is 0.005 - 0.1% by weight, and the content of any of Ti, Zr, Hf, Nb and Ta is 0.05 - 0.7%.
Claim 16
Dependent Claim
105 words
The oxidation-resisting austenitic stainless steel as set forth in claim 14, wherein the C content is not more than 0.1% by weight, the Si content is 3.4 - 4.0% by weight, the Mn content is not more than 1.0% by weight, the Ni content is 12 - 20% by weight, the Cr content is 16 - 22% by weight, the Ca content is 0.001 - 0.02% by weight, the Al content is 0.3 - 1.5% by weight, the rare earth content is 0.005 - 0.08% by weight and the content of any of Ti, Zr, Hf, Nb and Ta is 0.05 - 0.5% by weight.
Claim 17
Dependent Claim
21 words
The oxidation-resisting austenitic stainless steel as set forth in claim 1, which further contains up to 2.0% by weight of Cu.
Claim 18
Dependent Claim
21 words
The oxidation-resisting austenitic stainless steel as set forth in claim 7, which further contains up to 2.0% by weight of Cu.
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) | 1981-08-21 | 1982-02-20 | 1982-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-21 | 1986-02-20 | 1986-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-21 | 1990-02-20 | 1990-08-22 | $7700.00 | Window Closed / Lapsed |