US3897279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the production of high strength notch tough steel
Assignee: Algoma Steel Inc
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Filing: 1973-05-11
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Granted: 1975-07-29
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Expires: 1993-05-11
Abstract
Abstract A fully killed steel having a high yield strength and high notch toughness below 0*F. and containing by weight up to 0.20 percent carbon, at least 0.015 percent columbium and at least 0.75 percent manganese, said steel having a substantially uniform, fine grain, essentially ferritic grain structure with an average grain size of finer than 9.0 as determined by ASTM Test No. E 112, said steel preferably having a longitudinal Charpy Impact of at least 60, as well as a method of producing said steel which essentially involves continuously rolling the steel in the temperature interval 1700* to 1900*F.
Inventors
- 👤 Reginald N Shaughnessy
- 👤 Robert W Witty
- 👤 Robert J Ackert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:16
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/0221; C21D8/0226; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49988; Y10T29/49991
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
29 words
A METHOD OF MAKING A HIGH STRENGTH STEEL OF IMPROVED NOTCH TOUGHNESS BELOW 0*F WHICH COMPRISES SUBJECTING A FULLY KILLED STEEL CONSISTING ESSENTIALLY OF THE FOLLOWING COMPOSITION BY WEIGHT:
Claim 2
Independent Claim
29 words
A METHOD OF MAKING A HIGH STRENGTH STEEL OF IMPROVED NOTCH TOUGHNESS BELOW 0*F WHICH COMPRISES SUBJECTING A FULLY KILLED STEEL CONSISTING ESSENTIALLY OF THE FOLLOWING COMPOSITION BY WEIGHT:
Claim 3
Dependent Claim
25 words
A method as claimed in claim 1 in which the rolling is continuous throughout the temperature range about 1950*F to about 1700*F of the steel.
Claim 4
Dependent Claim
51 words
A method as claimed in claim 1 in which the reducing rolling is effected in both a roughing mill and subsequently in a finishing mill, the transfer of the steel from the roughing mill to the finishing mill being above or below the temperature range 1900*F to 1700*F of the steel.
Claim 5
Dependent Claim
20 words
A method as claimed in claim 1 in which the initial temperature of the ingot is at least about 2250*F.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 1 in which the rolling is continuous throughout the temperature range about 1900*F to about 1650*F of the steel.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1 in which the rolling is continuous throughout the temperature range about 1950*F to about 1650*F of the steel.
References Cited (Backward Citations)
US2158651A
Cited
US3102831A
Cited
US3010822A
Cited
US3386862A
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US3539404A
Cited
US3619303A
Cited
US3681057A
Cited
US3721587A
Cited
US3738874A
Cited
US3834949A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |