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US4450006A
Expired / Lapsed
US
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Martensitic stainless steel
Assignee: Daido Steel Co Ltd
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Filing: 1981-10-21
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Granted: 1984-05-22
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Expires: 2001-10-21
Abstract
Abstract Disclosed is an improved martensitic stainless steel, which essentially consisting of 0.15 to 0.50% of C, 0.01 to 0.50% of Si, 0.30 to 2.0% of Mn, 1.0 to 3.0% of Cu, up to 0.20% of Ni, 13.0 to 17.0% of Cr and 0.02 to 0.10% of N, and the balance being Fe and inevitable impurities. The stainless steel can be easily cold pressed as annealed and acquires a high strength when heat treated. Corrosion resistance of the steel is equal to or better than that of a conventional martensitic steel.
Inventors
- 👤 Norioki Uyehara
- 👤 Susumu Abe
- 👤 Yasuhiro Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:23
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/001; C22C38/18; C22C38/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
A martensitic stainless steel of high mechanical strength and suitable for processing by cold pressing, which steel consist of 0.20 to 0.50% of C, 0.01 to 0.50% of Si, 0.30 to 2.0% of Mn, 1.0 to 3.0% of Cu, up to 0.20% of Ni, 13.0 to 17.0% of Cr and 0.02 to 0.10% of N, and the balance being Fe and inevitable impurities.
Claim 2
Dependent Claim
63 words
A martensitic stainless steel of high mechanical strength and suitable for processing by cold pressing, which steel consist of 0.20 to 0.50% of C, 0.01 to 0.50% of Si, 0.30 to 2.0% of Mn, 1.0 to 3.0% of Cu, up to 0.20% of Ni, 13.0 to 17.0% of Cr and 0.02 to 0.10% of N, and the balance being Fe and inevitable impurities.
Claim 3
Dependent Claim
17 words
A martensitic stainless steel of claim 1, wherein the steel further contains 0.50 to 3.0% of Mo.
Claim 4
Dependent Claim
26 words
A martensitic stainless steel of claim 1, wherein the steel further contains 0.01 to 0.10% of at least one member of Ta, Nb, Ti and Zr.
Claim 5
Dependent Claim
22 words
A martensitic stainless steel of claim 1, wherein the steel further contains 0.001 to 0.10% of a rare earth metal or metals.
Claim 6
Dependent Claim
17 words
A martensitic stainless steel of claim 1, wherein the steel further contains 0.001 to 0.01% of Ca.
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) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |