US3945858A
Expired / Lapsed
US
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Method of manufacturing steel for low temperature services
Assignee: JFE Engineering Corp
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Filing: 1974-03-18
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Granted: 1976-03-23
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Expires: 1994-03-18
Abstract
Abstract A low alloy steel substantially consisting of Ni-Cr-Cu-Nb system and further adding 0.01 to 0.10% rare earth metals or their alloy thereto, and then being as only hot-rolled by 30 to 80% rolling rate at a temperature of less than 950 DEG C. The steel exhibits absorption energy of at least 10kg-m at -20 DEG C and a DTC transition temperature of lower than -40 DEG C, if necessary, may be tempered at a temperature of 500 DEG to 680 DEG C to improve the properties.
Inventors
- 👤 Hiroyoshi Matsubara
- 👤 Tatsumi Osuka
- 👤 Tadao Sugiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:14
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/58
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
107 words
A method of manufacturing steel for low temperature services consisting of the following chemical composition, 0.02 to 0.10% C, 0.10 to 0.50% Si,
1.20 to 1.80% Mn, up to 0.030% P,
up to 0.015% S, 0.05 to 0.50% Ni,
0.05 to 0.50% Cr, 0.05 to 0.50% Cu,
0.01 to 0.10% Nb, unavoidable impurities
and the balance being Fe, further adding rare earth metal or an alloy thereof of 0.01 to 0.20% to the above steel at the stage of vacuum degassing or of pouring into a mold, and then, being as only hot-rolled at a rolling rate of from 30 to 80% at a temperature below 950°C.
Claim 2
Independent Claim
107 words
A method of manufacturing steel for low temperature services consisting of the following chemical composition, 0.02 to 0.10% C, 0.10 to 0.50% Si,
1.20 to 1.80% Mn, up to 0.030% P,
up to 0.015% S, 0.05 to 0.50% Ni,
0.05 to 0.50% Cr, 0.05 to 0.50% Cu,
0.01 to 0.10% Nb, unavoidable impurities
and the balance being Fe, further adding rare earth metal or an alloy thereof of 0.01 to 0.20% to the above steel at the stage of vacuum degassing or of pouring into a mold, and then, being as only hot-rolled at a rolling rate of from 30 to 80% at a temperature below 950°C.
Claim 3
Dependent Claim
27 words
A method of manufacturing steel for low temperature services as set forth in claim 1 wherein the hot-rolled steel is further tempered at from 500° to 680°C.
References Cited (Backward Citations)
US2823992A
Cited
US3666570A
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US3666452A
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US3671336A
Cited
US3711340A
Cited
US3806378A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |