US3645801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing rolled steel having high-strength and low-impact transition temperature
Assignee: Bethlehem Steel Corp
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Filing: 1968-12-20
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Granted: 1972-02-29
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Expires: 1988-12-20
Abstract
Abstract Rolled steels characterized in their as-rolled condition by an unexpected combination of high-strength and low-impact transition temperature. The product is produced by rolling a steel workpiece containing both austenite and ferrite, preventing complete recrystallization at any time thereafter, and continuing the rolling of said workpiece as it is cooling in the temperature range between the Ar1 temperature and 600* F.
Inventors
- 👤 George F Melloy
- 👤 Joseph D Dennison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:12
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/0221; C21D8/0231; C21D8/0226
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
151 words
Method of rolling a steel workpiece containing not more than 0.35 percent carbon and not more than a total of 3 percent of other elements other than iron comprising: a. rolling said workpiece in one or more passes as it is cooling from a temperature at which it is austenitic but while its temperature is still above the Ar3 temperature, b. continuing the rolling of said workpiece in one or more passes including at least one reduction pass as it is cooling in the temperature range between the Ar3 and the Ar1 temperatures, c. continuing the rolling of said workpiece in one or more passes including at least one reduction pass as it is cooling in the temperature range between the Ar1 temperature and 600* F., and d. maintaining conditions such that the percentage recrystallization does not exceed 60 percent at any time after the last reduction pass in step (b).
Claim 2
Dependent Claim
129 words
Method of rolling a steel workpiece containing not more than 0.35 percent carbon and not more than a total of 3 percent of other elements other than iron comprising: a. providing said workpiece at a temperature at which it is essentially completely austenitic, b. rolling said workpiece in one or more passes including at least one reduction pass as it is cooling in the temperature range between the Ar3 and the Ar1 temperatures, c. continuing the rolling of said workpiece in one or more passes including at least one reduction pass as it is cooling in the temperature range between the Ar1 temperature and 600* F., and d. maintaining conditions such that complete recrystallization does not take place at any time after the last reduction pass in step (b).
Claim 3
Dependent Claim
131 words
Method of rolling a steel workpiece containing not more than 0.35 percent carbon and not more than a total of 3 percent of other elements other than iron comprising: a. providing said workpiece at a temperature at which it is essentially completely austenitic, b, rolling said workpiece in one or more passes including at least one reduction pass as it is cooling in the temperature range between the Ar3 and the Ar1 temperatures, c. continuing the rolling of said workpiece in one or more passes including at least one reduction pass as it is cooling in the temperature range between the Ar1 temperature and 600* F., and d. maintaining conditions such that the percentage recrystallization does not exceed 60 percent at any time after the last reduction pass in step (b).
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |