US2857637A

US2857637A - Casting apparatus

Info

Publication number: US2857637A
Application number: US512192A
Authority: US
Inventors: Robert W Winters
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 1955-05-31
Filing date: 1955-05-31
Publication date: 1958-10-28
Anticipated expiration: 1975-10-28

Description

Oct. 28, 1958 v R. w. WIIINTE'RS 2,857,637

' CASTING APPARATUS Filed May 31, 1955 I 2 Sheets-Sheet 1 FIG. l'

7 Filed May 31, 1955 Oct. 28, 1958 R w, wlNTERS 2,857,637

CASTING APPARATUS 2 Sheets-Sheet 2 FIG.2

/4 I I $2 n 8 4 5 2?;iI(Ill/113717511111!IIIIlIIIIIIlIIi/I4 H 'I//// W4 l2 44w A 1 l3 III/ I'IIIIIIIIiI/IIII07171111111111111114 INVENTOR. ROBERT W. WINTERS 2 ATTORNEYS 'CASTIN G APPARATUS Robert W. Winters, Branforil, 'Conn., assignor to Olin 'Mathieson Chemical Corporation, East Alton, 111., a corporation of Virginia Application MaySl, 1955, Serial No. 512,192

8 Claims. (Cl. 2257.4)

This invention'relates to the casting :of metal and more specifically to an improved mold structure especially adapted for the continuous casting of metal.

One known method'of continuous casting of metal ina shape having a width far in excessof the thickness of the casting involves pouring and solidification of the molten metal between two broad moving metal belts. In aption has resulted largely because of the frictional resistance presented by this type of side wall to the metal being shaped. To overcome this problem moving side walls of various types including laminated walls have also been tried; but penetration by the molten metal and undesired welding between the side belts and the metal being cast have prevented the successful adoption ofsuch structures and any worthwhile realization of the potential advantages of endless belt casting machines. -;prior: types of side wall structures have been .furtherchar- Most of these acterized by inability to adjust to variation in belt spacing and by disadvantageous heat conductivity for the successful casting of metal in the shape of a thin slab or strip. Specifically a disadvantage of these priorart .moldside walls has been the difficulty of obtaining an operable fit at the edges of the broad moving casting belts adjacent the side walls and especially the type of fit necessary to prevent the escape of molten metal between the belt and side wall and to avoid the resultant inferiorperformance whenever excessive flash, for example, is formed by the escaping metal.

Therefore one object of this invention is to overcome the aforementioned difficulties by provision of a mold .side wall of a novel construction. Another object is to provide an improved moving belt type of continuous casting apparatus especially suitable for the production of metal strip and the like. A still further object is to provide a novel laminated but sturdy side wall structure suitable for the casting of relatively high melting ,point or refractory metals and alloys. Other objects and advantages of this invention will be apparent from the follow- .ing description and the accompanying drawing in which:

Figure 1 is a semi-diagrammatic elevational view showing a typical moving belt type of continuous casting machine having side walls in accordance with this invention;

Figure 2 is a cross-sectional view taken on line II.II of Figure l; and

Figure 3 is a perspective view of a part of a preferred embodiment of the side wall of this invention with an end shown in cross section.

Inaccordance with this invention there is provided a relatively compressible mold wall or a continuous casting edge dam made up of a bundle of refractory strands or wires and more specifically of strands of metal such as steel or the like. The flexibility and the compressibility States Patent regularities. I a cable so as to extend straight along the length of the 'o'f the mold wall accomplish an improved seal with the adjacent mold faces which in operation have surface i'r- The strands may be laid down together as cable or maybe twisted as they are put together to form a twisted strand cable. To form the side wall or edge 'dam of a continuous casting mold, it is preferred that the strands of the cable or wire rope be convolutedly wound together to form an endless belt or cable. It is further preferred that the strands be so assembled as to lustrated but not limited by a reference to the rather diagrammatic representation of Figures 1 and 2 of a continuous casting machine in which 1 and 2 each refers'to an endless side wall or edge dam belt of this invention which is adapted'to be sandwiched in operative position between endless broad metal mold face belts or bands 3 and 4 at the lateral edges of the face belts to form therewith a casting region or cavity. Side walls 1 and -2 are carried along on and adjacent the lateral edges of belt 3, which in turn is supported on and passes around end rolls 5 and 6. The other main casting or mold face belt 4, which like belt 3 is made of a strip of suitable metal such'as stainless steel, is carried over another pair of end rolls 7 and 8. As shown in Figure 2, belt 4 overlies belt 3 and in the casting area or region of the machine belts 3 and 4 pass in closely spaced parallel relationship. Side wall belt 1is carried about belt 3 at one side of the rolls :5 and 6 while side wall belt 2 is carried at the other side of rolls 5 and 6 about belt 3. In this casting area, the lower mold face belt 3 is backed up by a series of rolls 9 and upper mold face'belt 4 is in turn backed up by a series of rolls 10. As assembled in operative relationship in the casting area of the machine, side belt 1 forms the edge dam 11 and belt 2 forms the edge dam 12 of the casting cavity 13 of rectangular cross section defined by the mold face belts 3 and 4 and the edge dams 11 and 12. At the casting cavity 13 the lateral edges of face belts 3 and 4 are pressed at intervals against the edge dams 11 and 12 by any suitable instrumentalities such as the series of support rolls 9 and 10 the ends of which are'forced against the back side of the lateral edges of the face belts 3 and 4 so as to squeeze belts 3 and 4 against the compressible'edge dams 11 and 12, which are backed up by guide bars 14 and 15, respectively. Side belts 1 and 2 and face belts 3 and 4 are driven by any suitable mechanism to move with the casting 18 as it forms in andtraverses the mold cavity 13.

In operation molten metal from a reservoir or crucible 16 is supplied to the tundish 17 which feeds a stream "of metal at a desirable flow rate into the cavity 13 in which solidification of the metal occurs to produce the relatively broad thin slab 18. To aid in solidifying the metal, the faces of belts 3 and 4 exterior to cavity 13 may be subjected to a stream of coolant.

The side wall or continuous casting edge dam structure of this invention, as illustrated in greater detail in Figure 3, is formed of a plurality of metallic strands or wire which are wound and twisted to produce an endless cable 19 or loop having a length such as to permit the cable to pass between the main or mold face belts 3 -and-4 of the casting machine hereinbefore described and to also pass over and extend between the end rolls of the machine on the return side of those rolls. A sufficient number of the metallic strands are laid together or plied up so as to form a cable of a cross section large enough to fill the lateral edge portions of the gap between the parallel spaced mold face parts 3 and 4 at the casting cavity or chamber 13, Figure 2. In the specific embodiment illustrated in Figure 3, the edge dam structure 19 consists of a composite cable composed of six smaller cables 20 each of which in turn consist of 19 twisted steel wires 21. It will be understood that a greater or lesser number of component cables may be used and that a greater or lesser number of strands of either uniform or different sizes may form each com ponent cable. At least part of the strands are of rounded or of such polygonal cross-sectional shape as will permit a degree of mobility to the metallic strands and also contribute to compressibility of the structure. Preferably the component members of the edge dam cable are assembled or formed in such a manner so as to make a cable or side wall 19 of at least an approximately quadrangular shape as shown. When installed in the casting apparatus, one of the surfaces 22 of the endless side wall belt 19, after application of a suitable mold dressing is presented to the metal being cast in cavity 13, Figure 2.

The endless side wall or edge dam structure formed in this manner of strands of steel provides a laminated mold wall characterized by high flexibility, almost any desired degree of compressibility as determined by numher and type of strands and their manner of assembly, high refractoriness and by suitable heat conductivity which is adaptable to modification by the application of mold dressing or coating compound at least to the surface of the cable which is to be exposed to the molten metal undergoing casting. The flexible, compressible mold wall structure of this invention is especially adaptable to carrying a mold dressing because of the presence of interstices between the steel strands which constitute the cable. The mold structure provided is capable of carrying almost any type of mold dressing material which is needed to facilitate the parting of the casting metal from the mold wall and to prevent welding or mechanically interlocking the metal casting and the mold side wall. Any suitable refractory parting or mold dressing compound can be applied such as graphite in a suitable vehicle, or a silicone, silca gel, graphite compound or the like. A suitable silicone is dimethylpolysiloxane.

By means of this invention there is provided a sturdy mold side wall or continuous casting edge dam structure of metal which is sutficiently compressible to enable it to adapt itself when under proper clamping pressure to the desired spacing between mold face plates or face plate belts of a casting apparatus and especially of a continuous casting machine where a continuous and positive seal is made with the face plates or belts. The side wall is adapted to carry any suitable mold dressing applied to it. Furthermore, the multistrand mold wall is capable of withstanding the temperatures encountered in the casting of most metals including the more refractory metals and alloys without distorting or developing fractures and without loss of the continuous and positive seal.

While the invention has outstanding utility in the art of continuous casting with respect to which it has been described herein, it will be understood that it has utility with any metal casting apparatus such as the permanent metallic type of two-part book mold.

Since many other embodiments may occur to those skilled in the art, it is to be understood that the foregoing is intended by way of illustration and not as a limitation of the scope of the present invention except as set forth in the appended claims. I

What is claimed is:

1. In apparatus for continuously casting wide thin shapes such as strip from molten metal, a pair of endless elongated moving broad metal bands at least a portion of each of which is traveling in the same direction in spaced face-toface relationship and a mold side wall belt of rectangular cross sectional contour moving with and clamped between said bands at each of the opposing lateral edge portions of said bands, each of said side wall belts comprising an endless wound multi-strand twisted steel cable compressible in the direction of its thickness and defining a rectangular casting cavity together with said bands, said strands of said cable being contiguous and of substantially polygonal cross sectional shape having limited mobility with respect to each other and having interstitial spaces therebetween for reception of a mold dressing medium and a mold dressing medium being received in said spaces and coating at least the outer layer of strands facing said cavity.

2. In apparatus for the casting of metals, a molten metal pressure retaining mold wall comprising a transversely compressible bundle consisting essentially of wound metallic strands each stacked up so as to be substantially continuously contiguous with neighboring strands adjacent to each other both in the direction of mold wall width and thickness and running continuously in the longitudinal direction in said mold wall and at least part of said strands being of such substantially rounded cross sectional configuration and thinness permitting a degree of transverse mobility with respect to each other under the forces of said compression and the pressure of said molten metal, said bundle consisting of a plurality of rows and layers of said strands having interstitial spaces therebetween adapted for reception of a mold dressing medium said bundle including an outer layer of strands at least a part of which is adapted to form at least a side wall part facing said molten metal.

3. In an apparatus for the casting of metals, the combination of a pair of solid mold face plate members disposed in spaced apart face-to-face relationship and at each of the opposed lateral edge portions thereof at least one mold side wall member clamped between said opposing edge portions and each comprising a longitudinally extending bundle consisting of metallic strands at least a substantial part of which are so shaped cross sectionally as to render substantially all of them relatively mobile transversely with respect to the length of said bundle, said strands being wound in a row and columnar arrangement with respect to the width and height of said bundle measuring in a transverse direction, each of said strands being contiguous with adjacent strands substantially completely along the length thereof, said bundle having interstitial spaces between the strands and a mold dressing medium received in said spaces and coating at least the outer layer of strands facing said molten metal, said face plate and side wall members together defining a substantially rectangular casting cavity for retention of said molten metal.

4. The apparatus of claim 3 wherein said side wall member is a metal cable consisting of a relatively large number of twisted refractory strands each in linear contiguity with an adjacent strand and of a round cross sectional shape and size facilitating limited transverse mobility and compressibility.

5. The apparatus of claim 3 wherein said side wall member is a compressible bundle of quadrilateral cross sectional contour.

6. The apparatus of claim 3 wherein the strands consist of refractory metal and wherein the dressing is a refractory compound.

7. Apparatus for continuously casting wide thin shapes such as strip from molten metal comprising a pair of endless elongated moving broad metal bands at least a portion of each of which is traveling in the same direction in spaced face-to-face relationship and a mold side wall belt moving in unison with and clamped between each of the opposing lateral edge portions of said bands, said side wall belt comprising an endless convolutely wound multi-strand metal cable, the individual strands of which run continuously in the direction of belt length and are stacked up in a transversely compressible bundle so as to be substantially continuously contiguous with adjacent neighboring strands in the directions of belt width and thickness, said strands being of such substantially rounded cross sectional configuration and thinness as to have interstitial spaces therebetween and to permit a degree of transverse mobility with respect to each other for obtainment of said transverse compressibility under the forces of transverse compression between said edge portions and the outward force of said molten metal, said bundle having at least a partially compressed thicknecess between said lateral edge portions not less than that of the edge portion spacing.

8. In an apparatus for the casting of metals, the combination of a pair of solid mold face plate members disposed in spaced apart face-to-face relationship and at each of the opposed lateral edge portions thereof at least one mold side wall member clamped between said opposing edge portions and each comprising a longitudinally extending bundle consisting of metallic strands relatively mobile transversely with respect to the length of said bundle, said strands being arrayed in a row and columnar arrangement with respect to the width and height of said bundle measuring in a transverse direction, each of said strands being contiguous with adjacent strands substantially completely along the length thereof, said bundle having interstitial spaces between the strands and a mold dressing medium received in said spaces and coating at least the outer layer of strands facing said molten metal, said face plate and side wall members together defining a substantially rectangular casting cavity for retention of said molten metal, said mold side wall comprising a flexible cable of rectangular cross sectional contour formed of a plurality of twisted strands of refractory metal.

References Cited in the file of this patent UNITED STATES PATENTS 2,285,740 Merle June 9, 1942 2,554,356 Beare May 22, 1951 2,640,235 Hazelett June 2, 1953 2,668,987 Harris et a1. Feb. 16, 1954 FOREIGN PATENTS 383,313 Italy Oct. 2, 1940