US2195613A - Means for producing composite metal products - Google Patents

Description

P r T. B. CHACE I 2,195,613

IEANS FOR PRODUCING COIPOSITE METAL IRODUGI'S Filed lay 13, 1937 1 2 Sheets-Sheet 1 7/; Jig/@587?- 0/7262? we.

P 0- v r. B. CHACE I ,5 3

IBANS FOR PRODUCING COIPOSITE IB'I'AL PRODUC'IS rma lay 13, 1937 2 Sheets-Sheet 2 Patented 'Apr. 2, 1940 MEANS m raonncnvc COMPOSITE METAL rnonoc'rs Thomas B. Chace, Winnetka, Ill., assignor to Clad Metals Industries, Inc., Chicago, 111., a. corporation of Illinois Application May 13, 1937, Serial N0.'142,387

1 Claim.

My invention relates, generally, to mould constructions and it has particular relation to the construction of moulds used in the production of composite slabs which may be rolled into various shapes and sizes. This application is a division,

in part, of my copending applications, Serial No.

6,497, filed February 14, 1935, now Patent No.

2,145,248, and Serial No. 64,280, filed February '17, 1936.

In the bonding and rolling of some high corrosion resistant alloys to steel, the design and type of mould'is very essential in making the process commercial and the product-usable. Some of the copper alloys, such as silicon copper are particularly fluid in the molten state and are very difficult to hold, in the molten state, on the surface of'the steel backing slab. Some of'the other non-corrosive alloys, such as the high nickel coppers of from to 40% nickel content, having melting temperatures up to 2400 F., or .Monel metal or stainless steel having melting temperatures similar to the steel backing slab,

are difiicult to hold in the molten state because.

of the extremely high casting temperatures involved. The mould must be liquid-tight after 'havingbeen preheated to temperatures of around Large slabs having a thickness of 10" to 12" must be preheated fo'r five or six hours at this temperature and the mould forming a part thereof must be such that it will not burn out and will remain liquid-tight as a container for the molten fiux during the preheating, as well asa container for the non-corroding metal which is cast in the mould after preheating. This casting operation differs from ordinary casting in that the mould, in some cases, is preheated to a temperature above the melting point of the casting alloy and; since the base of the mould or backing member is made up of a relatively thick steel slab, the heat is maintained .for a considerable period and the cast metal remains moltenmuch longer than ordinary cast metal remains molten in' a cold mould, in which case the cast metal solidifies quickly. In fact, for the cladding of some combinations, such for, example as my silicon-copper alloys, it is necessary to prolong the molten state of the casting alloy to perfect a bond between the two.

In viw'of the foregoing, an object of my inverition is the provision of a mould which can" be rolled as a'part' of a composite slab either diiiiiiim hot rolling temperature.

rectl'y'from the bonding heat or as soon as the.

Another object of my invention is to provide an open-faced mould on which the depth can be readily regulated as the measuring means for determining the required alloy in proportion to the steel backing metal.

'A further object of my invention is to provide an open-faced mould construction that can be readily adapted to fit any size of slab or backing thickness of the cast steel backing metal when the former is softer than the latter.-

A still further object of my invention is to so construct an open-faced mould that spreading of the castmetal over the sides of the wrought base metal is prevented when the former is softer than the latter.

Other objects of -my invention will, in part, be obvious and in part appear hereinafter.

Accordingly, my invention is disclosed in the embodiments hereof shown in the accompanying drawings, and it comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the description hereinafter set forth and the scope of the application of which will be indicated in the appended claim.

For a more complete understanding of the nature and scope of my invention, reference may be had to the following detailed description, taken in connection with the accompanying drawings,

in which:

Figure 1 is a perspective view of one form of mould construction;

Figure 2 is a perspective view of a mould construction showing another embodiment of the ing how relative spreading takes place between the slab of base metal and the layer of cladding metal unless special precautions are taken to prevent the same when the cladding metal is relatively soft as compared to the slab metal; and

Figure 9 is a view, similar to Figure 8, showing that no spreading of the layer of cladding metal takes place relative tothe slab of base metal when the mould constructions shown in Figures 3, 4, 5 and 6 of the drawings are employed.

The utility and construction of my type of mould for the purpose of cladding by casting one metal on the upper surface of the other, or on this surface in combination with other surfaces, are of great importance. For instance, any size of slab or backing member may be chosen with I respect to starting and finish size which best fits the requirements of a particular order or specification with a minimum of scrap loss. This permits using regular bloom sections requiring a minimum of processing before cladding. Generally stated, the mould is formedby welding to the backing slab steel stripsor plates of proper height or thickness to govern the mould depth. If the clad slab is to be rolled into plates, for instance, and if the facing or casting alloy has similar compression resistance to the steel backing material, so that they roll evenly, the steel strips are welded to the sides and ends, leaving the full area of the slab for cladding and making a minimum of scrap loss. If the bloom has irregular edges and ends, so'that welding along the edges and ends is not practical, the mould strips can be located on the upper surface of the bloom, leaving the irregular ends and edges tial that this layer of cladding metal be integrally bonded to the top surface 2| of the backing slab so that the composite slab thus formed may be worked into various shapes and sections. In order to provide this integral bond the cladding metal must be heated to such a temperature that it will become molten. In accordance with the present invention, various embodiments of mould construction may be employed to retain the cladding metal in the molten state so that, on cooling. the composite slab will be formed. It is for this purpose that relatively thin metal side members 22 and relatively thin metal end members 23 are provided around the top surface 2| of the slab 20, are welded together as indicated at 24, and welded to the sides of the slab 20 as indicated at 25.

The cladding metal may be introduced into the mould formed by the side and end members 22 and 23 and the top surface 2|, either in the form of a flat plate, or, in the molten state, by pour' I ing. As disclosed in my copending applications, referred to hereinbefore, a suitable flux is provided for excluding air from the bonding surfaces so that no oxidation will take place.

If the composite slab is to be rolledpinto bars for re-rolling into strip material on which good edges are required for continuous strip rolling; the mould construction shown in Figure 2 may .the layer of cladding metal.

be employed. As there shown, a layer of cladding metal is to be bonded to the top surface of a slab 5| and a mould is provided therefor by the side members 52 and end members 53. It will be noted that therelatively thin metal side members 52 are located on the upper surface 50 along opposite edges and that they are welded on the outside as indicated at 54. If the slab 5| is from 4" to 5" thick, the side and end members 52 and 53 should be approximately' in thickness to withstand the preheating. With this thickness/of side and end members, the. side members 52 elongate with the composite slab and, instead of breaking up, finish with a good rolled edge. It will be noted that the end members 53 extend below the top surface 50 of the slab 5| and that they are'suitably welded in position." The side and end members 52 Mid, can be welded on the inside of the mould formed by them with the top surface 50 but the weld metal from the arc spatters over thetopsurface 5|! and must -be removed before=s-receiving I When the members 52 and 53 are weldedon theoutside, as shown, they protect .the'top surface 50 of the slab 5| from oxidizing from the heat of the arc.

When the cladding metal is softer than the steel backing member or'slab, it 'is difiicult to roll the resulting composite slab. particularly for the first few passes, until the cladding metal or alloy has work-hardened to some extent. As

shown in Figure 8 of the drawings, when'the composite slab 55 is worked between rolls 56 of a blooming mill, or'the like, the softer layer 550 I of cladding metal elongates faster and further than does the backing metal 55b. This causes the composite slab to curl badly, as shown, and to follow around one of the rolls 55. With a view to correcting thiscondition the mould constructions shown'in Figures 3, 4,5 and 6 may be employed.

in I

In Figure 3 the top surface 51 of the slab 58 is to be provided with a layerv of cladding metal that is appreciably softer than the metal of the base 58. Side members 59, formed of relatively thin metal, are provided along the opposite edges of the top surface 51 and welded thereto as shown at 60. Relatively thick and wide end members 5| are provided at the ends of the top I surface 51, between the ends ofthe side members 59, and are welded in position as shown at 62.

On the first pass'throughthe 'rolls, such as the; rolls 56, the relativelythick and wide end members 5| weld to the'endsof thetop surface 51 so that the end of the compositeslab rollsin the same manner as does a solid steel slab, thereby preventing the faster elongation of'thecladding metal and the curling of the composite slab, as

shown in Figure 8. 5 0n a'slab 58 approximately 6' long, the end members, Qj mately 4"in idt 3 I I In Figure '4 of thedrawin'gs the mould -construction is similar to that shown in Figure 3 except that the-side members 59 do not extend the full length of the slab 58. In-Figure 5 of the drawings the side members 59 extend-below the top surface 51 of theslab- 58. Otherwise the construction is as shown in Figure '3. I In Figure 6 of the drawings another form of mould construction is shown in which a slab 65, having a-top surface. 65 tobe clad with a relatively soft cladding metal, is provided with inmembers 88 are positioned in the ends of the channel section and welded as indicated at 6!.

In Figure!) of the drawings the reference character 12 represents a composite slab that has.

been formed by the use of one of the mould constructions shown in Figures 3, 4, 5 and 6 of the drawings. It will he observed that no relative spreading or lengthening of the cladding layer 120 with reference to the backing slab 12b takes place. There is, then, no curling, as shown in Figure 8, and a fiat rolled section results.

It the cladding metal has substantially the same compression resistance as the backing metal the relatively thick and wide end members 68 may be dispensed with, as shown in Figure 7, while still retaining the channel shaped top section of the backing member 65. Relatively thin metal end members 13 may be welded across the ends of the channel section to form a mould for receiving the cladding metal. A composite slab formed in this manner is particularly well adapted for strip roiling, since the edges. roll down evenly with the slab. From the original composite slab rolled into a strip bar, the edges from this type of mouldremain square enough for pushing through a pusher furnace and the edges are. suitable for a continuous strip mill.

Since certain further'changes may be made in the foregoing mould constructions, and diflerent embodiments of the invention may be made without departing from the scope thereof, it is intended that all mattershown in the accompanying drawings or described hereinbefore' shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

Means for bonding a relatively thin facing of cuprous metal to a thick heavy backing slab of steel adapted to be reduced by a series of rolling passes according to steel rolling mill practice, which comprises a thick heavy backing slab of steel having a relatively thin steel retaining wall formed of strip steelwelded to the slab about the margin of the race to be bonded, said (ace and said retaining wall forming a fluid tight basin, said face being cleaned and 'fluxed to facilitate the formation of a bond, the slab with retaining wall and flux being adapted to be preheated to approximately 2200" .F. to receive and retain molten cuprous metal tor bonding to said face.

/ THOMAS B. CHACE.

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