US4564392A
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Heat resistant martensitic stainless steel containing 12 percent chromium
Assignee: Japan Steel Works Ltd
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Filing: 1984-07-19
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Granted: 1986-01-14
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Expires: 2004-07-19
Abstract
Abstract A heat resistant martensitic stainless steel having an improved creep rupture strength is described. This steel consists of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, and, if desired, at least one of 0.02 to 0.50% columbium, 0.02 to 0.5% tantalum, 0.5 to 2.0% tungsten, and 0.0003 to 0.0100% boron, with the balance being iron and incidental or inevitable impurities, and wherein the weight ratio of carbon to nitrogen (C/N) is not more than 3:1.
Inventors
- 👤 Tateo Ohhashi
- 👤 Hideyuki Kawamoto
- 👤 Yutaka Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:57
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/24; C22C38/22
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
69 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, and 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium and not more than 0.15% nitrogen, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 2
Dependent Claim
69 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, and 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium and not more than 0.15% nitrogen, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 3
Dependent Claim
71 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.02 to 0.50% columbium, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 4
Dependent Claim
71 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.02 to 0.50% columbium, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 5
Dependent Claim
71 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.0003 to 0.0100% boron, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 6
Dependent Claim
71 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.0003 to 0.0100% boron, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 7
Dependent Claim
71 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.5 to 2.0% tungsten, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 8
Dependent Claim
71 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.5 to 2.0% tungsten, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 9
Dependent Claim
87 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.02 to 0.5% tantalum and one of 0.02 to 0.50% columbium, 0.5 to 2.0% tungsten and 0.0003 to 0.0100% boron, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 10
Dependent Claim
87 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.02 to 0.5% tantalum and one of 0.02 to 0.50% columbium, 0.5 to 2.0% tungsten and 0.0003 to 0.0100% boron, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 11
Dependent Claim
83 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.0003 to 0.0100% boron and one of 0.02 to 0.50% columbium, and 0.5 to 2.0% tungsten, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 12
Dependent Claim
83 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, 0.0003 to 0.0100% boron and one of 0.02 to 0.50% columbium, and 0.5 to 2.0% tungsten, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 13
Dependent Claim
89 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, at least three of 0.02 to 0.50% columbium, 0.02 to 0.5% tantalum, and 0.5 to 2.0% tungsten and 0.0003 to 0.0100% boron, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
Claim 14
Dependent Claim
89 words
A heat resistant martensitic stainless steel consisting of, in weight percent, 0.05% to 0.12% carbon, not more than 0.5% silicon, not more than 1.5% manganese, not more than 1.5% nickel, 9.0 to 13.0% chromium, 0.5 to 2.0% molybdenum, 0.05 to 0.50% vanadium, not more than 0.15% nitrogen, at least three of 0.02 to 0.50% columbium, 0.02 to 0.5% tantalum, and 0.5 to 2.0% tungsten and 0.0003 to 0.0100% boron, the balance being iron and impurities, and the weight ratio of carbon to nitrogen (C/N) being not more than 3:1.
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) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |