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Publication numberUS3576207 A
Publication typeGrant
Publication dateApr 27, 1971
Filing dateApr 22, 1969
Priority dateApr 23, 1968
Also published asDE1919416A1, DE1919416B2, DE6915297U
Publication numberUS 3576207 A, US 3576207A, US-A-3576207, US3576207 A, US3576207A
InventorsGrenfell Hugh Willmott
Original AssigneeSteel Co Of Wales Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Formation of steel strip
US 3576207 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

United States Patent Inventor llugh Wilhnott Grent'ell Morriston, Swansea, Glamorgan, Wales Appl. No. 818,299 Filed Apr. 22, 1969 Patented Apr. 27, 1971 Assignee The Steel Company of Wales Limited Priority Apr. 23, 1968 Great Britain 3594/68 FORMATION OF STEEL STRIP 15 Claims, 1 Drawing Fig.

[1.8. CI. 164/48, 117/934, 117/9343, 164/46, 164/87, 164/278, 164/281 Int. Cl. B22d 27/02 Field of Search 164/48, 46,

278, 281, 87; l17/93.4 (Inquired)93.44

[56] References Cited UNITED STATES PATENTS 2,699,415 l/l955 Nachtman 154/91 3,010,009 11/1961 Ducati 1l7/93.4X 2,239,642 4/1941 Burkhardt et al. 204/192 3,075,066 1/1963 Yenni et a]. 219/76 Primary Examiner-J. Spencer Overholser Assistant Examiner-V. K. Rising Attorneyl3uell, Blenko & Ziesenheim ABSTRACT: The present disclosure :relates to a process for the continuous casting of metal strip, which process comprises imparting an electrostatic charge of at least 80,000 volts to a stream of molten metal, passing the stream of metal through a nozzle into an inert atmosphere and allowing the stream leaving the nozzle to atomize to a fine spray, collecting the spray droplets on a cool receiving surface to form a layer of metal on said surface and continuously stripping the layer of metal from said surface.

FORMATION OF STEEL STRIP The present invention relates to the formation of steel strip.

At the present time steel strip is formed from ingots by slabbing and hot rolling. The present process is to some extent wasteful since in the formation of slabs from ingots, a certain amount of wastage results due to cropping of the ends of the ingot after it is rolled into a slab. These cropped ends have to be severed from the slab and are scrapped. There is also a large loss in yield due to scaling of the ingot and slab in the various stages of the known process.

According to the present invention there is provided a process for the continuous casting of metal strip, which process comprises imparting an electrostatic charge of at least 80,000 volts to a stream of molten metal, passing the stream of metal through a nozzle into an inert atmosphere and allowing the stream leaving the nozzle to atomize to a fine spray, collecting the spray droplets on a cool receiving surface to form a layer of metal on said surface and continuously stripping the layer of metal from said surface.

The receiving surface may be the cylindrical surface of a water-cooled roll and the receiving surface may be earthed. The inert atmosphere may be any gas which will not react with or dissolve to an appreciable extent in steel under the particular process conditions and which does not adversely afiect the quality of the steel but is preferably argon, krypton or other inert gas.

The stream of molten steel may be tapped from a ladle or tundish which is insulated from its surroundings, the melt contained therein contacting with an electrode charged to a potential of at least 80,000 volts and preferably 100,000 to 200,000 volts to impart a charge to the contents of the tundish and to a stream of molten steel leaving the same.

The layer of steel stripped from the collecting surface may subsequently be rolled to form strip of the desired thickness.

Following is a description by way of example and with reference to the accompanying drawing of one method of carrying the invention into effect.

The accompanying drawing is a diagrammatic side view partially in section of apparatus for use in the process of the present invention.

A tundish 10 is provided with a discharge opening including a downwardly extending nozzle 13. A tapping rod 11 is vertically disposed with respect to the bottom 12 of the tundish l and extending therethrough to terminate at a lower end which is adapted to close the discharge opening. The tapping rod is provided with control means for controlling the flow of molten steel passing from the tundish and through the nozzle 13. The nozzle end 13 of the tapping rod 11 is disposed within a collecting chamber 15 having an inert atmosphere of, for instance, argon which is maintained in the collecting chamber under a pressure slightly greater than atmospheric. Immediately below the nozzle 13 is disposed a rotatable watencooled roll 16 which is disposed within the bottom surface l7 of the collecting chamber 15 glands 18 being provided to permit rotation of the roll 16 about its axis 19 with respect to the chamber 15 and without substantial loss of argon.

In operation, the tundish is periodically charged with molten steel and an electrode 20 is inserted in the molten steel and maintained at a potential of 100,000 volts. The tundish l0 and collecting chamber 15 are substantially insulated from their surroundings and the tapping rod 11 is operated to allow a continuous controlled stream of molten steel charged at a potential of 100,000 volts to pass down the tapping rod and out of the bottom end of the nozzle 13 into the collecting chamber 15. Free of the constraint provided by the walls of the conduit 21 in the tapping rod 11, the stream of molten steel debouching from the lower end of the nozzle 13 separates into a finely atomized spray 22 of steel droplets, the atomization being caused by the electrostatic charge on the stream which causes the stream to split into a number of small droplets each containing a lower electrostatic charge.

The roller 16 disposed below the nozzle 13 is earthed by means of conductor 23 and the droplets and the spray are attracted towards the surface 24 of the roll 16 and are deposited thereon to form a thin layer 25 of steel. The droplets coalesce on the cooled surface of the ml] to form an uniform layer. The roll 16 is slowly rotated and is continually cooled by water passing through the inner structure of the roll.

The layer 25 of steel so formed is carried by the surface 24 of the roll 16 out of the collecting chamber 15 through the gland 18 between the wall 17 of the collecting chamber 15 and the surface 24 of the roll 16 and at a point externally of the collecting chamber, is stripped from the surface 24 of the roll 16 by suitable stripper means 27. The steel strip 28 so produced is then passed between one or more stands of rollers to a coiler 29 in the usual way. The strip obtained on the coil may be suitably reduced in a reduction mill to a desired thickness.

The sealing glands 18 between the roll 16 and wall 17 may comprise elongate conduits disposed adjacent the roller surface along which a nitrogen or mixture of nitrogen or argon is blown under pressure in an endeavor to prevent or restrict the escape of argon from the collecting chamber.

It will be appreciated that the process described above can effectively replace the stages of the present process for forming steel strip, from the ladle of steel obtained from the converter, through the ingot stage, soaking pit, slabbing furnaces, and coarse rolls on the hot reduction mill.

I claim:

1. A process for the continuous casting of metal strip, which process comprises imparting an electrostatic'charge of at least 80,000 volts to a stream of molten metal, passing the stream of metal through a nozzle into an inert atmosphere and allowing the stream leaving the nozzle to atomize to a fine spray, collecting the spray droplets on a cool receiving surface to form a layer of metal on said surface and continuously stripping the layer of metal from said surface.

2. A process as claimed in claim 1 wherein the metal is steel.

. 3. A process as claimed in claim 1 wherein the receiving surface is the cylindrical surface of a water cooled roll.

4. A process as claimed in claim 1 wherein the receiving surface is earthed.

5. A process as claimed in any one of the preceding claims wherein the inert atmosphere is a gas which will not react with or dissolve to an appreciable amount, in the metal.

6. A process as claimed in claim 5 wherein the inert atmosphere is argon, krypton or other inert gas.

7. A process as claimed in claim 1 wherein the stream of molten metal is tapped from a ladle or tundish which is insulated from its surrounding.

8. A process as claimed in claim 7 wherein the melt contained therein is contacted with an electrode charged to a potential of at least 80,000 volts.

9. A process as claimed in claim 8 wherein the magnitude of the electrostatic charge is within the range 100,000 to 200,000 volts.

10. A process as claimed in claim 1 wherein the metal strip from the collecting surface is subsequently rolled to form a strip of the desired thickness.

11. A process as claimed in claim 1 for the production of steel strip wherein a tundish is provided with a tapping rod vertically disposed with respect to the bottom of the tundish and extending therethrough to terminate at a lower end in a downwardly extending nozzle.

12. A process as claimed in claim 11 wherein the tapping rod is provided with control means for controlling the flow of molten steel passing from the tundish and through the nozzle.

13. A process as claimed in claim 12 wherein the nozzle end of the tapping rod is disposed within a collecting chamber having an inert atmosphere of argon which is maintained in the collecting chamber under a pressure slightly greater than atmospheric.

14. A process as claimed in claim i3 wherein immediately below the nozzle there is disposed a rotatable water-cooled 15. A process as claimed in claim 14 wherein the tundish is periodically charged with molten steel and an electrode is inserted in the molten steel and maintained at a potential of 120,000 volts.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2239642 *May 21, 1937Apr 22, 1941Bernhard BerghausCoating of articles by means of cathode disintegration
US2699415 *Feb 25, 1953Jan 11, 1955Owens Corning Fiberglass CorpMethod of producing refractory fiber laminate
US3010009 *Sep 29, 1958Nov 21, 1961Plasmadyne CorpMethod and apparatus for uniting materials in a controlled medium
US3075066 *Dec 3, 1957Jan 22, 1963Union Carbide CorpArticle of manufacture and method of making same
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3775193 *Oct 8, 1971Nov 27, 1973British Steel CorpMethod for passivating a zinc surface
US4339508 *Jul 21, 1980Jul 13, 1982Shiro MaedaMethod for manufacturing a thin and flexible ribbon of superconductor material
US5040592 *Jun 22, 1990Aug 20, 1991Armco Inc.Method and apparatus for separating continuous cast strip from a rotating substrate
US5343926 *Dec 3, 1992Sep 6, 1994Olin CorporationMetal spray forming using multiple nozzles
US7374598Aug 9, 2004May 20, 2008Ati Properties, Inc.Methods and apparatus for spray forming, atomization and heat transfer
US7578960Sep 22, 2005Aug 25, 2009Ati Properties, Inc.Apparatus and method for clean, rapidly solidified alloys
US7798199Dec 4, 2007Sep 21, 2010Ati Properties, Inc.Casting apparatus and method
US7803211Mar 21, 2008Sep 28, 2010Ati Properties, Inc.Method and apparatus for producing large diameter superalloy ingots
US7803212Mar 21, 2008Sep 28, 2010Ati Properties, Inc.Apparatus and method for clean, rapidly solidified alloys
US7963314Aug 23, 2010Jun 21, 2011Ati Properties, Inc.Casting apparatus and method
US8156996May 16, 2011Apr 17, 2012Ati Properties, Inc.Casting apparatus and method
US8216339Jul 14, 2009Jul 10, 2012Ati Properties, Inc.Apparatus and method for clean, rapidly solidified alloys
US8221676Jul 7, 2010Jul 17, 2012Ati Properties, Inc.Apparatus and method for clean, rapidly solidified alloys
US8226884Jun 23, 2010Jul 24, 2012Ati Properties, Inc.Method and apparatus for producing large diameter superalloy ingots
US8302661Mar 15, 2012Nov 6, 2012Ati Properties, Inc.Casting apparatus and method
US8642916Mar 26, 2008Feb 4, 2014Ati Properties, Inc.Melting furnace including wire-discharge ion plasma electron emitter
US8747956Aug 11, 2011Jun 10, 2014Ati Properties, Inc.Processes, systems, and apparatus for forming products from atomized metals and alloys
US8748773Aug 25, 2009Jun 10, 2014Ati Properties, Inc.Ion plasma electron emitters for a melting furnace
US8891583Oct 30, 2007Nov 18, 2014Ati Properties, Inc.Refining and casting apparatus and method
US9008148Nov 28, 2006Apr 14, 2015Ati Properties, Inc.Refining and casting apparatus and method
EP1296772A1 *Jun 18, 2001Apr 2, 2003Ati Properties, Inc.Methods and apparatus for spray forming, atomization and heat transfer
Classifications
U.S. Classification164/48, 164/46, 164/479, 164/415, 427/483
International ClassificationB22D11/06, C23C4/12
Cooperative ClassificationC23C4/121, B22D11/0611
European ClassificationC23C4/12A, B22D11/06D