Patent US4330574A successfully refreshed from Google Patents.
US4330574A
Expired / Lapsed
US
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Finishing method for conventional hot dip coating of a ferrous base metal strip with a molten coating metal
Assignee: Armco Steel Co LP
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Filing: 1980-09-29
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Granted: 1982-05-18
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Expires: 2000-09-29
Abstract
Abstract A finishing method and apparatus for conventional continuous hot-dip coating of the type wherein a ferrous base metal strip is caused to pass beneath the surface of a coating bath of molten coating metal and is thereafter subjected to jet finishing, the ferrous base metal strip having been appropriately pretreated so as to be at the proper coating temperature and so as to have its surfaces oxide-free when passing through the bath of molten coating metal. The method comprises the steps of providing an enclosure for the two-side coated strip as it exits the coating bath, locating a finishing jet nozzle to either side of the coated strip within the enclosure, jet finishing the coated strip with a non-oxidizing or inert gas. The apparatus comprises the above mentioned enclosure with the jet finishing nozzles located therein and an appropriate system to provide a non-oxidizing or inert atmosphere within the enclosure.
Inventors
- 👤 Marvin B. Pierson
- 👤 Charles Flinchum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:25
CPC Classifications
C; C23; C23C; C23C2/00; C23C2/14; C23C2/16; C23C2/18; C23C2/20; C23C2/34; C23C2/36; C23C2/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
207 words
A finishing process for conventional continuous hot-dip, two-side coating of a ferrous base metal strip with a molten coating metal of the type wherein said ferrous base metal strip is caused to enter a bath of said molten coating metal contained in a coating pot, said ferrous base metal strip having been treated to bring it to a coating temperature sufficiently high to prevent casting of said coating metal thereon and low enough to prevent excess coating metal-base metal alloying and to render the surfaces of said strip clean and free of oxide as it passes through said molten coating metal bath, said finishing process comprising the steps of providing an enclosure in sealed relationship with said bath for said two-side coated ferrous base metal strip as it exits said bath and an exit in said enclosure for said coated strip, maintaining a non-oxidizing atmosphere within said enclosure, locating a jet finishing nozzle to either side of said coated strip within said enclosure, jet finishing said coated strip with a non-oxidizing gas and maintaining said jet finishing gas and said atmosphere within said enclosure at an oxygen level of less than about 1000 ppm, whereby to render said two-side coated strip uniform in appearance and coating thickness.
Claim 2
Dependent Claim
207 words
A finishing process for conventional continuous hot-dip, two-side coating of a ferrous base metal strip with a molten coating metal of the type wherein said ferrous base metal strip is caused to enter a bath of said molten coating metal contained in a coating pot, said ferrous base metal strip having been treated to bring it to a coating temperature sufficiently high to prevent casting of said coating metal thereon and low enough to prevent excess coating metal-base metal alloying and to render the surfaces of said strip clean and free of oxide as it passes through said molten coating metal bath, said finishing process comprising the steps of providing an enclosure in sealed relationship with said bath for said two-side coated ferrous base metal strip as it exits said bath and an exit in said enclosure for said coated strip, maintaining a non-oxidizing atmosphere within said enclosure, locating a jet finishing nozzle to either side of said coated strip within said enclosure, jet finishing said coated strip with a non-oxidizing gas and maintaining said jet finishing gas and said atmosphere within said enclosure at an oxygen level of less than about 1000 ppm, whereby to render said two-side coated strip uniform in appearance and coating thickness.
Claim 3
Dependent Claim
27 words
The process claimed in claim 1 wherein said molten coating metal is chosen from the class consisting of zinc, zinc alloys, aluminum, aluminum alloys, terne and lead.
Claim 4
Dependent Claim
31 words
The process claimed in claim 1 including the step of maintaining said jet finishing gas and said atmosphere within said enclosure at an oxygen level of less than about 200 ppm.
Claim 5
Dependent Claim
31 words
The process claimed in claim 1 including the step of maintaining said jet finishing gas and said atmosphere within said enclosure at an oxygen level of less than about 100 ppm.
Claim 6
Dependent Claim
20 words
The process claimed in claim 1 wherein said non-oxidizing jet finishing gas and said atmosphere within said enclosure comprise nitrogen.
Claim 7
Dependent Claim
22 words
The process claimed in claim 1 wherein said non-oxidizing jet finishing gas and said atmosphere within said enclosure comprise an inert gas.
Claim 8
Dependent Claim
21 words
The process claimed in claim 1 including the step of vertically staggering said jet finishing nozzle with respect to each other.
Claim 9
Dependent Claim
33 words
The process claimed in claim 1 wherein each of said jet finishing nozzles has a rectangular nozzle opening of uniform width throughout its length and equidistant from said coated strip throughout its length.
Claim 10
Dependent Claim
25 words
The process claimed in claim 1 including the step of recirculating a portion of said non-oxidizing gas from said enclosure through said jet finishing nozzles.
Claim 11
Dependent Claim
42 words
The process claimed in claim 1 wherein said molten coating metal is chosen from the class consisting of zinc and zinc alloys and including the step subjecting said two-side coated strip to a spangle minimizing treatment after said strip exits said enclosure.
Claim 12
Dependent Claim
24 words
The process claimed in claim 5 including the step of recirculating a portion of said nitrogen from said enclosure through said jet finishing nozzles.
Claim 13
Dependent Claim
21 words
The process claimed in claim 5 including the step of vertically staggering said jet finishing nozzles with respect to each other.
Claim 14
Dependent Claim
33 words
The process claimed in claim 12 wherein each of said jet finishing nozzles has a rectangular nozzle opening of uniform width throughout its length and equidistant from said coated strip throughout its length.
Claim 15
Dependent Claim
23 words
The process claimed in claim 13 including the step of maintaining said nitrogen at an oxygen level of less than about 100 ppm.
Claim 16
Dependent Claim
26 words
The process claimed in claim 14 including the step of subjecting said two-side coated strip to a spangle minimizing treatment after said strip exits said enclosure.
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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) | 1985-05-17 | 1985-11-16 | 1986-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-17 | 1989-11-16 | 1990-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-17 | 1993-11-16 | 1994-05-18 | $7700.00 | Window Closed / Lapsed |