US3897280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing a steel sheet and product obtained thereby
Assignee: Nippon Steel Corp
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Filing: 1973-12-11
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Granted: 1975-07-29
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Expires: 1993-12-11
Abstract
Abstract A killed steel having a particular composition is heated, subjected to hot rolling such that the finishing temperature is 750*C or less, and subjected to recrystallization treatment. A steel sheet thus obtained has excellent press formability.
Inventors
- 👤 Hisashi Gondo
- 👤 Hiroshi Takechi
- 👤 Tsuyoshi Kawanc
- 👤 Hiroaki Masui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:43
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/04; C21D8/0421; C21D8/0426; C22; C22C; C22C38/00; C22C38/06; C22C38/12; C22C38/14; C21D8/0447; C21D8/0463
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
90 words
A METHOD FOR MANUFACTURING A STEEL SHEET HAVING AN EXCELLENT PRESS FORMABILITY WHICH COMPRISES HEATING A KILLED STEEL COMPOSED OF NOT MORE THAN 0.10% C, 0.05% TO 1.0% MN, 0.005% TO 0.15% AL, AT LEAST ONE MEMBER OF THE GRUP CONSISTING OF TI, NB AND ZR, AND THE REST FE AND UNAVOIDABLE IMPURITIES, THE TI%/4 + NB%/7.8 + ZR%/7.6 BEING MORE THAN THE C % IN THE STEEL, SUBJECTING THE SAME TO HOT ROLLING SUCH THAT THE FINISHING TEMPERATURE IS 750*C OR LESS, AND THEREAFTER EFFECTING A TREATMENT FOR RECRYSTALLIZATION.
Claim 2
Independent Claim
90 words
A METHOD FOR MANUFACTURING A STEEL SHEET HAVING AN EXCELLENT PRESS FORMABILITY WHICH COMPRISES HEATING A KILLED STEEL COMPOSED OF NOT MORE THAN 0.10% C, 0.05% TO 1.0% MN, 0.005% TO 0.15% AL, AT LEAST ONE MEMBER OF THE GRUP CONSISTING OF TI, NB AND ZR, AND THE REST FE AND UNAVOIDABLE IMPURITIES, THE TI%/4 + NB%/7.8 + ZR%/7.6 BEING MORE THAN THE C % IN THE STEEL, SUBJECTING THE SAME TO HOT ROLLING SUCH THAT THE FINISHING TEMPERATURE IS 750*C OR LESS, AND THEREAFTER EFFECTING A TREATMENT FOR RECRYSTALLIZATION.
Claim 3
Dependent Claim
54 words
A method according to claim 1 in which said killed steel further contains at least one member selected from the group consisting of not more than 0.15% P, not more than 0.10% W, not more than 0.10% Mo, not more than 0.3% Cr, not more than 0.3% Cu and not more than 0.4% Si.
Claim 4
Dependent Claim
26 words
A method according to claim 1 in which the total reduction rate below 800*C is at least 40% of the thickness of the material at 800*C.
Claim 5
Dependent Claim
25 words
A method according to claim 1 in which C is no greater than 0.03%; Mn is 0.1% to 0.5%; and Al is 0.01% to 0.15%.
Claim 6
Dependent Claim
15 words
A method according to claim 1 in which the finishing temperature is 400*C to 750*C.
Claim 7
Dependent Claim
26 words
A method according to claim 1 in which the recrystallization treatment is conducted by heating at temperatures ranging from the recrystallization temperature up to A3 point.
Claim 8
Dependent Claim
22 words
A method according to claim 1 in which the recrystallization treatment is conducted by box annealing, open coil annealing or continuous annealing.
Claim 9
Dependent Claim
26 words
A method according to claim 2 in which the total reduction rate below 800*C is at least 40% of the thickness of the material at 800*C.
Claim 10
Dependent Claim
25 words
A method according to claim 2 in which C is no greater than 0.03%; Mn is 0.1% to 0.5%, and Al is 0.01% to 0.15%.
Claim 11
Dependent Claim
15 words
A method according to claim 2 in which the finishing temperature is 400*C to 750*C.
Claim 12
Dependent Claim
26 words
A method according to claim 2 in which the recrystallization treatment is conducted by heating at temperatures ranging from the recrystallization temperature up to A3 point.
Claim 13
Dependent Claim
22 words
A method according to claim 2 in which the recrystallization treatment is conducted by box annealing, open coil annealing or continuous annealing.
Claim 14
Dependent Claim
27 words
A method according to claim 1 in which the ratio of (111) axial density (100) axial density is within the range from about 2.0/1.3 to about 7.8/1.0.
Claim 15
Dependent Claim
27 words
A method according to claim 2 in which the ratio of (111) axial density (100) axial density is within the range from about 2.0/1.3 to about 7.8/1.0.
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) | 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 |