US3917494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous annealing process of steels exhibiting low yield point retarded of aging properties and good drawability
Assignee: Individual
•
Filing: 1973-10-26
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Granted: 1975-11-04
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Expires: 1993-10-26
Abstract
Abstract In a continuous annealing process for rimmed steels having < OR = 0.06% carbon content, the coiling temperature of said steel while in a strip form, hot and rolling is more than 630*C to form massive carbides in said steel strip then after known coil reducing, is given a rapid cooling rate from a holding temperature during a continuous annealing stage of more than 50*C/sec, subesequent shelf treating temperature of said traveling strip is within the range of 300*C to 500*C for at least 10 seconds, and then said strip is coiled after cooling to room temperature, consequently low yield point of less than about 23kg/mm2, and retarded aging property and good drawability are exhibited.
Inventors
- 👤 Haruo Kubotera
- 👤 Kazuhide Nakaoka
- 👤 Kaoru Watanabe
- 👤 Akihiko Nishimoto
- 👤 Nobuo Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:38
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/04; C21D8/0447; C21D8/0473; C21D8/041; C21D8/0421; C21D8/0426
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
IN A CONTINUOUS ANNEALING PROCESS FOR PRODUCING STEEL HAVING A YEILD STRENGTH OF LESS THAN 23 KG/MM2, A RETARDED AGING PROPERTY AND GOOD DRAWABILITY, COMPRISING PASSING A LOW CARBON AND STEEL OF $ 0.06% CARBON SERIALLY THROUGH A HEATING ZONE, RAPID COOLING ZONE, SHELF TREATING ZONE AND COOLING ZONE, THE IMPROVEMENT WHICH INCLUDES COILING A HOT ROLLED STEEL STRIP AT A TEMPERATURE OF MORE THAN 630*C.AND THEN QUENCHING THE STRIP FRON THE RECRYSTALLIZATION TEMPERATURE TO A TEMPERATURE BETWEEN ROOM TEMPERATUE AND 500*C AT A RATE OF MORE THAN 50*C/SEC IN SAID RAPID COOLING ZONE.
Claim 2
Dependent Claim
94 words
IN A CONTINUOUS ANNEALING PROCESS FOR PRODUCING STEEL HAVING A YEILD STRENGTH OF LESS THAN 23 KG/MM2, A RETARDED AGING PROPERTY AND GOOD DRAWABILITY, COMPRISING PASSING A LOW CARBON AND STEEL OF $ 0.06% CARBON SERIALLY THROUGH A HEATING ZONE, RAPID COOLING ZONE, SHELF TREATING ZONE AND COOLING ZONE, THE IMPROVEMENT WHICH INCLUDES COILING A HOT ROLLED STEEL STRIP AT A TEMPERATURE OF MORE THAN 630*C.AND THEN QUENCHING THE STRIP FRON THE RECRYSTALLIZATION TEMPERATURE TO A TEMPERATURE BETWEEN ROOM TEMPERATUE AND 500*C AT A RATE OF MORE THAN 50*C/SEC IN SAID RAPID COOLING ZONE.
Claim 3
Dependent Claim
23 words
A complete continuous annealing process as set forth in claim 1 wherein said carbon content is within the range of 0.03 to 0.06%.
Claim 4
Dependent Claim
22 words
A complete continuous annealing process as set forth in claim 1 wherein said coiling temperature at hot rolling stage is about 700*C.
Claim 5
Dependent Claim
26 words
A complete continuous annealing process set forth in claim 1 wherein said holding temperature of the steel strip is within the range of 710*C to 750*C.
Claim 6
Dependent Claim
28 words
A complete continuous annealing process set forth in claim 1 wherein said shelf treating of the steel strip is carried out within the range of 350*C to 450*C.
References Cited (Backward Citations)
US2381435A
Cited
US3412781A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |