US3708280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High temperature low alloy steel
Assignee: JFE Engineering Corp
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Filing: 1970-10-26
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Granted: 1973-01-02
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Expires: 1990-10-26
Abstract
Abstract A high temperature low alloy steel having a chemical composition consisting essentially of between about (i) 0.05 - 0.25% C, (ii) 0.05 - 0.80% Si, (iii) 0.40 - 1.30% Mn, (iv) 0.30 - 0.20% Mo, (v) 0.002 - 0.015% N in solid solution, (vi) less than 0.010% Sol. Al, (vii) 0 - 0.70% Cr, (viii) 0 - 0.10% V, and (ix) the balance being Fe + incidental impurities. The steel is preferably subjected to a normalizing heat treatment to obtain a high strength steel useful for extended service at temperatures between 400* and 500*C.
Inventors
- 👤 T Mimino
- 👤 K Kinoshita
- 👤 K Hattori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:51
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/001; C22C38/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
47 words
The steel of claim 1 which after being subjected to a normalizing heat treatment at a temperature of 800* - 950*C retains said nitrogen in solid solution and has a microstructure of (i) ferrite and pearlite, or (ii) ferrite and pearlite containing a small amount of bainite.
Claim 2
Dependent Claim
48 words
The high temperature low alloy steel of claim 1 consisting of C 0.05 - 0.25% Si 0.05 - 0.80% Mn 0.40 - 1.30% Cr 0.20 - 0.70% Mo 0.03 - 0.20% N 0.002 - 0.015% in solid solution Sol. Al less than 0.010% Fe + incidental impurities balance
Claim 3
Dependent Claim
47 words
The steel of claim 3 which after being subjected to a normalizing heat treatment at a temperature of 800* - 950*C retains said nitrogen in solid solution and has a microstructure of (i) ferrite and pearlite, or (ii) ferrite and pearlite containing a small amount of bainite.
Claim 4
Dependent Claim
52 words
The high temperature low alloy steel of claim 1 consisting of C 0.05 - 0.25% Si 0.05 - 0.80% Mn 0.40 - 1.30% Cr 0.20 - 0.70% Mo 0.03 - 0.20% N 0.002 - 0.015% in solid solution Sol. Al less than 0.010% V 0.01 - 0.10% Fe + incidental impurities balance
Claim 5
Dependent Claim
47 words
The steel of claim 5 which after being subjected to a normalizing heat treatment at a temperature of 800*C - 950*C retains said nitrogen in solid solution and has a microstructure of (i) ferrite and pearlite, or (ii) ferrite and pearlite containing a small amount of bainite.
Claim 6
Dependent Claim
45 words
The high temperature low alloy steel of claim 1 consisting of C 0.05 - 0.25% Si 0.05 - 0.80% Mn 0.40 - 1.30% Mo 0.03 - 0.20% N 0.002 - 0.015% in solid solution Sol. Al less than 0.010%V0.01 -0.10% Fe + incidental impurities balance
Claim 7
Dependent Claim
47 words
The steel of claim 7 which after being subjected to a normalizing heat treatment at a temperature of 800*C - 950*C retains said nitrogen in solid solution and has a microstructure of (i) ferrite and pearlite, or (ii) ferrite and pearlite containing a small amount of bainite.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |