US4417720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous heat treatment plant for steel sheet
Assignee: Centre de Recherches Metallurgiques CRM ASBL
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Filing: 1980-12-04
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Granted: 1983-11-29
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Expires: 2000-12-04
Abstract
Abstract The continuous steel-sheet heat-treatment plant comprises, in sequence, a zone in which the sheet is heated to a temperature above the recrystallization temperature, a zone in which the sheet is held at this temperature for more than 30 seconds, a rapid cooling zone, an optional overaging zone, and a final cooling zone. The rapid cooling zone has devices for spraying a cooling fluid and a tank containing an aqueous bath at above 75° C.
Inventors
- 👤 Philippe Paulus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:10
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/52; C21D9/54; C21D9/56; C21D9/573
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
142 words
A continuous heat treatment plant for steel sheet, comprising in sequence: (a) means for heating the steel sheet to a temperature higher than the recrystallization temperature of the steel; (b) means for holding the steel sheet at this temperature for more than 30 seconds; and (c) a rapid cooling zone comprising (i) means for spraying a cooling fluid onto the steel sheet, and (ii) a tank for containing an aqueous bath, means for maintaining the aqueous bath at a temperature greater than 75° C., (1) means for varying the level of the aqueous bath in the tank, and (2) a roller contained within the tank around which the steel sheet passes and means for displacing said roller--so that the length of the path of the sheet through the aqueous bath can be modified by employing either or both of (1) and (2).
Claim 2
Dependent Claim
142 words
A continuous heat treatment plant for steel sheet, comprising in sequence: (a) means for heating the steel sheet to a temperature higher than the recrystallization temperature of the steel; (b) means for holding the steel sheet at this temperature for more than 30 seconds; and (c) a rapid cooling zone comprising (i) means for spraying a cooling fluid onto the steel sheet, and (ii) a tank for containing an aqueous bath, means for maintaining the aqueous bath at a temperature greater than 75° C., (1) means for varying the level of the aqueous bath in the tank, and (2) a roller contained within the tank around which the steel sheet passes and means for displacing said roller--so that the length of the path of the sheet through the aqueous bath can be modified by employing either or both of (1) and (2).
Claim 3
Dependent Claim
21 words
The plant of claim 1, further comprising, after the rapid cooling zone, an overaging zone followed by a final cooling zone.
Claim 4
Dependent Claim
35 words
The plant of claim 1, in which the rapid cooling zone comprises means for modifying the action of the spraying means so as to adjust the temperature of the strip on discharge from this zone.
Claim 5
Dependent Claim
16 words
The plant of claim 1, in which the spraying means comprises means for spraying a liquid.
Claim 6
Dependent Claim
12 words
The plant of claim 1, in which the spraying means comprises atomizers.
Claim 7
Dependent Claim
17 words
The plant of claim 1, in which the spraying means comprises means for blasting a gaseous agent.
Claim 8
Dependent Claim
14 words
The plant of claim 6, in which the gaseous agent is a reducing agent.
Claim 9
Dependent Claim
22 words
The plant of claim 6, in which the blasting means comprise means for atomizing a liquid, by means of the gaseous agent.
Claim 10
Dependent Claim
24 words
The plant of claim 1, further comprising means for conducting the cooling fluid to the tank after it has been sprayed onto the sheet.
Claim 11
Dependent Claim
16 words
The plant of claim 6, further comprising means for recovering, purifying, and re-utilizing the gaseous agent.
Claim 12
Dependent Claim
18 words
The plant of claim 1, in which the rapid cooling zone is preceded by a slow cooling zone.
Claim 13
Dependent Claim
83 words
The plant of claim 1, further comprising a final cooling zone comprising three successive units: the first unit comprising means for blasting atmospheric gas in order to cool the sheet to a temperature lower than 350° C., the second unit comprising means for immersing the sheet in an aqueous bath at a temperature greater than 75° C., this bath having a composition designed to treat the surface of the steel, and the third unit comprising means for cooling the sheet in cold water.
Claim 14
Dependent Claim
19 words
The plant of claim 1, further comprising a non-oxidising naked-flame furnace arranged to heat the sheet to be treated.
Claim 15
Dependent Claim
19 words
The plant of claim 1, further comprising means for recovering the energy contained in vapor produced in the plant.
Claim 16
Dependent Claim
20 words
The plant of claim 1, further comprising means for modifying the temperature of the cooling fluid sprayed onto the sheet.
References Cited (Backward Citations)
US3358980A
Cited
US4052234A
Cited
BE835666A
Cited
GB1514270A
Cited
GB1497502A
Cited
GB1516611A
Cited
GB1571150A
Cited
GB1568483A
Cited
US4191600A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-28 | 1987-05-30 | 1987-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-28 | 1991-05-30 | 1991-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-28 | 1995-05-30 | 1995-11-29 | $7700.00 | Window Closed / Lapsed |