US4016740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and an apparatus for the manufacture of a steel sheet
Assignee: Nippon Steel Corp
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Filing: 1975-08-22
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Granted: 1977-04-12
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Expires: 1995-08-22
Abstract
Abstract A steel sheet, especially a thin one, can be manufactured from a hot rolled coil through heat treating steps by means of positively applying stress to the material. The product has excellent shape and mechanical properties such as drawability and toughness.
Inventors
- 👤 Hisashi Gondo
- 👤 Hiroshi Takechi
- 👤 Tsuyoshi Kawano
- 👤 Hiroaki Masui
- 👤 Kazuo Kovama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:44
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D9/00; C21D9/52; C21D8/04; C21D8/0421; C21D8/0431; C21D8/0447; C21D8/0452; C21D8/0463; C21D8/0473; C21D8/0221; C21D8/0226; C21D8/0231; C21D8/0236; C21D8/0247; C21D8/0263; C21D8/0426; C21D8/0436
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
93 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil, said sheet having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip at temperatures below 1300° C., subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., and positively imparting a stress upon said strip during the heat treatment.
Claim 2
Independent Claim
93 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil, said sheet having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip at temperatures below 1300° C., subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., and positively imparting a stress upon said strip during the heat treatment.
Claim 3
Independent Claim
130 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix (structure) of the strip uniform and strong by utilizing the phase deformation of matrix of the strip, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., and positively imparting a stress upon said strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 4
Independent Claim
130 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix (structure) of the strip uniform and strong by utilizing the phase deformation of matrix of the strip, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., and positively imparting a stress upon said strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 5
Independent Claim
138 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix of the strip uniform and strong by utilizng the phase deformation of the matrix of the strip, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., reheating the strip at temperatures below 1000° C, and positively imparting a stress upon the strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 6
Independent Claim
138 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix of the strip uniform and strong by utilizng the phase deformation of the matrix of the strip, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., reheating the strip at temperatures below 1000° C, and positively imparting a stress upon the strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 7
Independent Claim
143 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix of the strip uniform and strong by utilizing the phase deformation of matrix of the strip, rolling the strip at temperatures above the A 1 point at a reduction of at least 3% to make the steel strong, tough and ductile, subjecting the same to a forced cooling rate of at least 20° C/min., and positively imparting a stress upon the strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 8
Independent Claim
143 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix of the strip uniform and strong by utilizing the phase deformation of matrix of the strip, rolling the strip at temperatures above the A 1 point at a reduction of at least 3% to make the steel strong, tough and ductile, subjecting the same to a forced cooling rate of at least 20° C/min., and positively imparting a stress upon the strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 9
Independent Claim
127 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip at a temperature below the A 3 point, rolling the strip at temperatures between 200° C and 750° C at a reduction of at least 3% to produce precipitation suitable for obtaining good deep-drawability after cold rolling and annealing, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., and positively imparting a stress upon the strip during the heat treatment to promote deep-drawability.
Claim 10
Independent Claim
127 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip at a temperature below the A 3 point, rolling the strip at temperatures between 200° C and 750° C at a reduction of at least 3% to produce precipitation suitable for obtaining good deep-drawability after cold rolling and annealing, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., and positively imparting a stress upon the strip during the heat treatment to promote deep-drawability.
Claim 11
Independent Claim
163 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling and the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix of the strip uniform and strong by utilizing the phase deformation of matrix of the strip, rolling the strip at temperatures above the A 1 point at a reduction of at least 3% to make the steel strong, tough and ductile, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., reheating the strip at temperatures below 1000° C, and positively imparting a stress upon said strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 12
Independent Claim
163 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling and the hot rolled coil, heating said uncoiled strip from a temperature of the A 1 point to temperatures below 1300° C to make the matrix of the strip uniform and strong by utilizing the phase deformation of matrix of the strip, rolling the strip at temperatures above the A 1 point at a reduction of at least 3% to make the steel strong, tough and ductile, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., reheating the strip at temperatures below 1000° C, and positively imparting a stress upon said strip during the heat treatment to make the matrix of the strip fine and uniform.
Claim 13
Independent Claim
132 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip at temperatures below the A 3 point, rolling the strip at temperatures between 200° C and 750° C at a reduction of at least 15% to produce a desirable recrystallization texture for deep-drawability, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., reheating the strip at temperatures below the A 3 point, and positively imparting a stress upon the strip during the heat treatment to promote deep-drawability.
Claim 14
Independent Claim
132 words
A method for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil having a thickness of as low as 1.2 mm and as high as 12.7 mm which comprises uncoiling the hot rolled coil, heating said uncoiled strip at temperatures below the A 3 point, rolling the strip at temperatures between 200° C and 750° C at a reduction of at least 15% to produce a desirable recrystallization texture for deep-drawability, subjecting the same to a forced cooling down to temperatures below the A 1 point at a cooling rate of at least 20° C/min., reheating the strip at temperatures below the A 3 point, and positively imparting a stress upon the strip during the heat treatment to promote deep-drawability.
Claim 15
Dependent Claim
17 words
A method according to claim 1 in which the stress imparted is at least 1.0Kg/mm 2 .
Claim 16
Dependent Claim
17 words
A method according to claim 2 in which the stress imparted is at least 1.0Kg/mm 2 .
Claim 17
Dependent Claim
17 words
A method according to claim 3 in which the stress imparted is at least 1.0Kg/mm 2 .
Claim 18
Dependent Claim
15 words
A method according to claim 4 in which the stress imparted is 1.0Kg/mm 2 .
Claim 19
Dependent Claim
17 words
A method according to claim 5 in which the stress imparted is at least 1.0Kg/mm 2 .
Claim 20
Dependent Claim
17 words
A method according to claim 6 in which the stress imparted is at least 1.0Kg/mm 2 .
Claim 21
Dependent Claim
17 words
A method according to claim 7 in which the stress imparted is at least 1.0Kg/mm 2 .
Claim 22
Independent Claim
92 words
An apparatus for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil which comprises an uncoiler, a non-oxidizing heating furnace, steel strip transport roll means, forced cooling means for directing a cooling medium against said steel strip at locations between succeeding transport roll means, a second heating furnace, and a stress-imparting means, said stress-imparting means being selectively positioned at a location between said uncoiler and the outlet of the second heating furnace, all the aforementioned elements being arranged in line.
Claim 23
Independent Claim
92 words
An apparatus for the manufacture of a steel sheet, steel strip and the like subjected to a heat treatment from a hot rolled coil which comprises an uncoiler, a non-oxidizing heating furnace, steel strip transport roll means, forced cooling means for directing a cooling medium against said steel strip at locations between succeeding transport roll means, a second heating furnace, and a stress-imparting means, said stress-imparting means being selectively positioned at a location between said uncoiler and the outlet of the second heating furnace, all the aforementioned elements being arranged in line.
Claim 24
Dependent Claim
25 words
An apparatus according to claim 15 in which at least one rolling stand is arranged between the non-oxidizing heating furnace and the forced cooling means.
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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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |