US4537643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for thermomechanically rolling hot strip product to a controlled microstructure
Assignee: SMS Demag Tippins LLC
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Filing: 1984-07-11
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Granted: 1985-08-27
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Expires: 2004-07-11
Abstract
Abstract A hot strip mill having a final reducing stand and runout cooling means downstream of the reducing stand includes an incubator capable of coiling and decoiling the hot strip. The incubator is located intermediate the runout cooling means. In a preferred form the final reducing stand is a hot reversing mill. A second incubator and/or a temper mill and/or a slitter may be positioned downstream of the first incubator. The method of rolling includes isothermally treating the strip within a predetermined time and temperature range in the incubator prior to subsequent processing. The subsequent processing may include any one or more of the following: further deformation by cold rolling, temper rolling or cooling at a desired heat loss rate.
Inventors
- 👤 John E. Thomas
- 👤 Ronald D. Gretz
- 👤 George W. Tippins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:49
CPC Classifications
B; B21; B21B; B21B1/00; B21B1/22; B21B1/24; B21B1/26; B21B1/30; B21B1/32; C; C21; C21D; C21D8/00; C21D8/02; C21D8/0221; C21D8/0226; B21B1/34; B21B1/38; B21B2001/228; B21B45/00; B21B45/004; B21B2045/006; B21B2201/00; B21B2201/04; B21B2201/06; C21D8/0231; C21D8/0247; C21D8/0263; C21D9/00; C21D9/52; C21D9/54; C21D9/68
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
133 words
A method of thermomechanically rolling a steel hot strip product to a controlled microstructure on a hot strip mill including a final reducing stand and an incubator positioned along a runout table intermediate first and second cooling means comprising in sequence: A. causing the strip to leave the final reducing stand at a temperature above the A 3 ; B. cooling said strip below the A 3 by the first cooling means; C. coiling the strip in the incubator; D. holding the strip in the incubator between the A 1 and A 3 temperatures to cause nucleation and growth of ferrite particles in austenite; E. decoiling the strip out of the incubator; and F. cooling said strip out of the incubator by the second cooling means to minimize grain growth and carbide coarsening.
Claim 2
Independent Claim
133 words
A method of thermomechanically rolling a steel hot strip product to a controlled microstructure on a hot strip mill including a final reducing stand and an incubator positioned along a runout table intermediate first and second cooling means comprising in sequence: A. causing the strip to leave the final reducing stand at a temperature above the A 3 ; B. cooling said strip below the A 3 by the first cooling means; C. coiling the strip in the incubator; D. holding the strip in the incubator between the A 1 and A 3 temperatures to cause nucleation and growth of ferrite particles in austenite; E. decoiling the strip out of the incubator; and F. cooling said strip out of the incubator by the second cooling means to minimize grain growth and carbide coarsening.
Claim 3
Dependent Claim
32 words
The method of claim 1, including fast cooling the strip of step F to on the order of 300° F. (149° C.) or less and temper rolling said fast cooled strip in-line.
Claim 4
Independent Claim
118 words
A method of thermomechanically rolling a steel hot strip product to a controlled microstructure on a hot strip mill including a hot reversing mill with coilers on either side thereof as the last reducing stand and an incubator positioned along a runout table comprising in sequence: A. reducing the product in a hot reversing mode on the reversing mill at a standard deformation schedule through the penultimate pass and substantially above the A 3 ; B. cooling the strip on a runout table to about 50° F. (10° C.) above the A 3 ; C. coiling the strip in the incubator to equalize temperature; D. finally reducing the strip; and E. cooling the strip on the runout table.
Claim 5
Independent Claim
118 words
A method of thermomechanically rolling a steel hot strip product to a controlled microstructure on a hot strip mill including a hot reversing mill with coilers on either side thereof as the last reducing stand and an incubator positioned along a runout table comprising in sequence: A. reducing the product in a hot reversing mode on the reversing mill at a standard deformation schedule through the penultimate pass and substantially above the A 3 ; B. cooling the strip on a runout table to about 50° F. (10° C.) above the A 3 ; C. coiling the strip in the incubator to equalize temperature; D. finally reducing the strip; and E. cooling the strip on the runout table.
Claim 6
Dependent Claim
45 words
The method of claim 3 including cooling the strip after final deformation to approximately 1100° F. (593° C.) on the runout table, coiling the strip in the incubator and equalizing temperature by holding the strip in the incubator prior to cooling on the runout table.
Claim 7
Dependent Claim
29 words
The method of claim 3 including holding the strip after final deformation in one of the hot reversing mill coilers and fast cooling the strip on the runout table.
Claim 8
Dependent Claim
22 words
The method of claim 5 including fast cooling the strip to about 300° F. (149° C.) and temper rolling the strip in-line.
Claim 9
Dependent Claim
24 words
The method of claim 3 including finally reducing the strip through a substantial deformation and holding the strip in the incubator to promote recrystallization.
Claim 10
Dependent Claim
23 words
The method of claim 7 including rapid cooling of the strip to about 300° F. (149° C.) and temper rolling the strip in-line.
Claim 11
Independent Claim
126 words
A method of thermomechanically rolling a steel hot strip product to a controlled acicular ferrite microstructure on a hot strip mill including a hot reversing mill with coilers on either side thereof as the last reducing stand and an incubator positioned along a runout table comprising in sequence: A. rolling the product in the austenite range; B. cooling the product to a temperature in the A 1 -A 3 range; C. coiling and holding the product in the incubator to equalize temperature and nucleate ferrite; D. finish rolling with a final substantial deformation pass; E. runout cooling to a bainite reaction temperature range; F. coiling the product and holding it in an incubator to equalize temperature and effect bainite reaction; and G. air cooling the product.
Claim 12
Independent Claim
126 words
A method of thermomechanically rolling a steel hot strip product to a controlled acicular ferrite microstructure on a hot strip mill including a hot reversing mill with coilers on either side thereof as the last reducing stand and an incubator positioned along a runout table comprising in sequence: A. rolling the product in the austenite range; B. cooling the product to a temperature in the A 1 -A 3 range; C. coiling and holding the product in the incubator to equalize temperature and nucleate ferrite; D. finish rolling with a final substantial deformation pass; E. runout cooling to a bainite reaction temperature range; F. coiling the product and holding it in an incubator to equalize temperature and effect bainite reaction; and G. air cooling the product.
Claim 13
Independent Claim
104 words
A method of thermomechanically rolling a hot strip product to a controlled microstructure on a hot strip mill including a final reducing stand and an incubator positioned along a runout table intermediate first and second cooling means comprising in sequence: A. reducing the strip on the final reducing stand to a predetermined thickness; B. cooling said strip by the first cooling means to a given temperature; C. coiling the strip in the incubator; D. holding the strip in the incubator for a given time and temperature; E. decoiling the strip out of the incubator; and F. cooling the strip by the second cooling means.
Claim 14
Independent Claim
104 words
A method of thermomechanically rolling a hot strip product to a controlled microstructure on a hot strip mill including a final reducing stand and an incubator positioned along a runout table intermediate first and second cooling means comprising in sequence: A. reducing the strip on the final reducing stand to a predetermined thickness; B. cooling said strip by the first cooling means to a given temperature; C. coiling the strip in the incubator; D. holding the strip in the incubator for a given time and temperature; E. decoiling the strip out of the incubator; and F. cooling the strip by the second cooling means.
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) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |