US2978761A

US2978761A - Continuous casting apparatus

Info

Publication number: US2978761A
Application number: US656872A
Authority: US
Inventors: John J Foye; William O Stauffer
Original assignee: Kaiser Aluminum and Chemical Corp
Current assignee: Kaiser Aluminum and Chemical Corp
Priority date: 1957-05-03
Filing date: 1957-05-03
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11

Description

APrll 1961 J. J. FOYE EI'AL CONTINUOUS CASTING APPARATUS 6 Sheets-Sheet 1 Filed May 3, 1957 INVENTORS JOHN J. FOYE WILLIAM O. STAUFFER BY ;

m

2, 5

ATTORNEY April 11, 1961 J. J. FOYE ETAL CONTINUOUS CASTING APPARATUS INVENTORS JOHN J. FOYE 6 Sheets-Sheet 2 Filed May 3, 1957 WILLIAM O.STAUFFER ATTORNEY April 11, 1961 J. J. FOYE ETAL 2,978,761

CONTINUOUS CASTING APPARATUS Filed May 3, 1957 6 Sheets-Sheet 5 INVENTORS JOHN J. FOYE WILLIAM O. STAUFFER ATTORNEY April 11, .1961 J FQYE ETAL 2,978,761

CONTINUOUS CASTING APPARATUS Filed May 3, 1957 6 Sheets-Sheet 4 IN VENTORS JOHN J. F OYE WILLIAM 0.8TAUFFER ATTORNEY April 11, J J, FOYE ETAL CONTINUOUS CASTING APPARATUS Filed May 3, 1957 6 Sheets-Sheet 5 IN VENTORS JOHN J. FOYE WILLIAM O.STAUFFEH TTORNEY April 11, 1961 FQYE HAL 2,978,761

CONTINUOUS CASTING APPARATUS Filed May 3, 1957 6 Sheets-Sheet 6 D OOOOOOOOOO INVENTORS JOHN J. FOYE WILLIAM O. STAUFFER BY w 3 Q A ORNEY United States Patent 2,978,761 CONTINUOUS CASTING APPARATUS John J. Foye and William 0. Stautfer, New Orleans, La.,

assignors to Kaiser Aluminum & Chemical Corporation, Oakland, Calif., a corporation ofDelaware Filed May 3, 1957, Ser. No. 656,872 8 Claims. (Cl. 2 257.2)

This invention relates generally 'to an improved method and apparatus for the continuous casting of metal. More particularly, the invention relates to an improved method vand apparatus for substantially horizontal casting of metal shapes directly from molten metal.

Continuous casting of metals by means of endless members, e.g. mold blocks mounted on continuous chains or endless bands with moving side dams disposed between said bands, has been known for a number of years. The endless members which are disposed horizontally or slanted at a small angle from the horizontal serve as the mold for the metal shape, e.g. billet, slab, plate or strip, being cast. The endless members, moving in non-circular paths, come together to form a casting mold and stay together long enough so the resultant billet or slab can support itself after which the endless members separate and are carried back to the casting point. This method of casting has proved efficient and economical particularly in the casting of shapes, such as slab, plate or strip, which may be used as the finished product. If desired, the shape may be subjected to reduction rolling as it emerges from the horizontally disposed casting machine.

Heretofore, serious difliculty has been experienced in obtaining the proper flow of molten metal to the mold zone, that is, the zone where the endless members come together. In the normally used feeding device, the molt'en metal is fed or distributed to the mold or cavity formed by the top and bottom endless members by means of an open overflow trough. This has proved unsatisfactory for the complete filling of the mold cavity, particularly in the casting of slabs of substantial width, thereby resulting in internal shrinkage cavities. Also, with the open overflow trough feeding means the molten metal is in contact with the bottom endless member for a substantial distance prior to contacting the upper endless member thereby resulting in unequal cooling between the top and bottom of the slab. A further disadvantage of the overflow trough feeding means is that oxide film and skim is entrapped on the top surface of the slab, thereby resulting in impaired surface quality of the cast slab.

Therefore, it is a primary object of this invention to provide a method and apparatus for the continuous casting of metal shapes in a substantially horizontal manner wherein improved mold filling characteristics and substantial reduction or elimination of defects due to entrapment of oxide film are realized.

It is a further object of this invention to provide an improved feeding apparatus for a substantially horizontally disposed continuous casting machine which effects a feeding of molten metal under pressure to the mold cavity thereby increasing the rate of heat abstraction by the upper endless member and substantially reducing or eliminating surface defects and internal shrinkage cavities of the casting and permitting casting at a higher unit rate.

These and other objects and advantages of the invention will be apparent from the ensuing description with 2,978,761 Patented Apr. 11, 1961 reference being had to the accompanying drawings wherein: I

Figure 1 is aside elevation view partially broken away of a horizontal casting machine embodying the principles of this invention as applied to the casting of a shape of substantially rectangular cross-section and showing the relationship of the novel distribution or feeding means and the endless members, which form the traveling mold of the machine; 7

Figure 2 is a rear elevational view of the machine of Figure 1;

Figure 3 is an enlarged sectional view showing the details of the back-up rolls taken along the line 3-3 of Figure 1;

Figure 4; is a perspective view of a distributor or feeding apparatus of the invention;

Figure 5 is a perspective view of the bottom member of the distributor or feeding apparatus shown in Figure 4;

Figure 6 is a perspective view of the top plate of the distributor or feeding apparatus shown in Figure 4;

Figure 7 is a perspective view of an alternative dis- 'tributor or feeding mechanism which may be used in the practice of the invention Figure 8 isa side elevational view of the distributor bowl and distributor shown partially in section and with the container for molten metal feed and transfer trough and endless bands shown partially in phantom lines.

Figure 9 shows various configurations of distributor prifics which may be employed in the practice of the invention. 7

Referring now to Figures 1 and 2 the reference numeral 1 designates a continuous casting machine for casting metal shapes in a substantially horizontal manner. The machine generally comprises a pair of

endless metal bands

3 and 5, and moving dams 7 whieh when moved in non-circular paths form a traveling mold of substantially rectangular cross-section in which metal shapes may be cast continuously. The

bands

3 and 5 are preferably formed of light weight metal e.g., steel or other suitable flexible and heat resistant metal. Molten metal is fed to the moldby distributor 9 which is connected to dis:- tributor bowl 11. During the operation of the casting machine the supply of molten metal to the distributor bowl 11 is furnished by a suitable container, such as a furnace or a crucible 13 as shown in Figure 8. The molten metal is transferred from crucible 13 to the dis; tributor bowl 11 by means of a transfer trough 15 and downspout 17. I p

, Lower metal band 3 is supported by band assembly 19. Lower band assembly 19 is generally comprised of drive pulley 21 and idler pulley 23 which are supported by two rectangular frames 25 positioned at opposite ends of

pulleys

21 and 23. Each frame 25 is comprised of horizontally disposed frame members 27 and 29 and vertical members '31 and 33 which join together frame members 27 and 29 at their extremities. Frames 25 are supported by I

beams

34, 35, 36 and 37 which extend transversely beneath the frame members 27 and to the rear of the lower band assembly 19 where they are secured to cross-beams 3'9 and 41. Cross beams 39 and 4 1, turn, are supported by a framework which includes vertical frame members 43 and 45. Members 31 support the end bearings 47 of drive pulley 21 while members 33 support the end bearings 49 of idler pulley 23. The band 3 passes'over drive pulley 21 and over idler pulley 23, and the tension of the belt 3 may be regulated by a suitable device such as a hydraulically actuated band tensioning mechanism shown in Figure 1 comprised of roller 51 pivotally attached to frame member -27-ar1'd adapted to be pivoted by hydraulic cylinder 52. P

Upper band assembly 53 supports the :endless bahd 5 and is constructed, as will be hereafter described, to be are supported by two rectangular frames 59 positioned at opposite ends of

pulleys

55 and 57. Each frame 59 is comprised of horizontally disposed frame members 61 and 63 and vertical members 65 and 67 which join togetherframe members 61 and 63 at their extremities. Members 65 support the end bearings 69 of drive pulley 55 while members 67 support the end bearings 71 of idler pulley 57. A roller 58 is supported by horizontal frame members 61, said roller 58 being positioned at themtrance to the casting region so that the portion of band which forms a part of the traveling mold is maintained parallel with the adjacent portion of band 3. Roller 58 is provided with lands similar'to the lands 99 and 103 described below in connection with back-uprolls 97 and 101. Band 5 passes over drive pulley 55, idler pulley 57, and roller 58, and the tension of the band 5 may be regulated by a suitable device, such as a hydraulically actuated band tensioning mechanism comprised of roller 73 pivotally attached to frame member 63 and adapte 75 to drive

pulleys

21 and 55 by means of sprocket 77 mounted on the armature of electric motor 75,

sprockets

79 and 81 mounted on

drive pulleys

21 and 55, respectively, sprocket 83 mounted on bracket 85 which in turn is supported by horizontal beam member 42, and a suitable endless chain 87 which engages

sprockets

77, 79, 81 and 83.

During the casting of metal the lower band 3 and the upper band 5 form the lower and upper walls, respectively, of a traveling mold. In order to retain the molten metal between

bands

3 and 5, two moving side dams 7 are provided and are each composed of a plurality of blocks 89, said blocks 89 being suitably mounted on an endless cable, wire or band. The height of blocks 89 is equal to the thickness of the metal shape to be cast, and the dams 7 are greater in length than band 3 and are arranged to 'ride on the upper surface of band 5 through the casting zone. The dams 7 pass continually through the casting zone in close engagement with lower band 3 and upper band 5 to provide side seals which confine the metal to the width of casting desired. These dams may be constructed either of a porous refractory material or of a heat conducting material, such as aluminum. In order to prevent lateral shifting of the dams, guide bars 91 and transverse guide bar clamp 93 connecting guide bars 91 are provided. During the casting operation, blocks 89 may be cooled, if desired, by passing them after emergence from the casting zone through troughs containing water. Before the blocks 46 have rotated back to the position of casting they may be dried off by a suitable means, such as by air nozzles 95. V

Back-up rolls 97 which are supported by horizontal frame members 27 of the lower band assembly 19 and back-up rolls 101 which are supported by horizontal frame members 61 of upper band assembly 53 hold

hands

3 and 5, respectively, against the metal shape during the casting operation. The structure of rolls 97 and 101, which are identical, is shown in Figure 3. Rolls 97 and 101 have a plurality of lands 99 and 103, respectively, across their longitudinal dimensions. The lands 99 and 103 contact the

bands

3 and 5, respectively, during the casting operation without substantially interfering with cooling medium applied thereto. The structure as shown in Figure 3 wherein the lands are individual circular flanges spaced apart along the longitudinal dimension of the back-up rolls insures minimum interference of the t garage: 7

lands with liquid coolant which is placed on the metal bands.

In order to rapidly chill the cast shape, water spray conduits 105 and 109 are disposed in

band assemblies

19 and 53, respectively, said conduits 105 and 109 being mounted on

horizontal frame members

27 and 61, respectively. Conduits 105 and 109 are provided with orifices 107 and 111, respectively, through which coolant is sprayed on the

endless bands

3 and 5 while said bands are in the casting region. The water spray conduits are adjustable in order thatthe proper angle of impingement formedwith the endless bands can be used. It has been found that an angle of impingement relative to the endless bands of six to eight degrees is satisfactory for cooling said bands. Upper band assembly is also provided with nip nozzle 113 which is provided to supply coolant to the band 5 at the region where molten metal first enters the traveling mold. The water emerging from nip nozzle 113 passes between the lands of roller 58 and is thereby supplied to band 5 at the region where the molten metal enters the traveling mold. V

The coolant water applied to the under side. of lower metal band 3 in the casting region will, after impingement on the band surface, fall by gravity into a trough (not shown) and thence into tank 117. The water which is sprayed on the upper surface of upper endless band 5 in the casting region is removed by suitable means such as scoops 119, which are mounted on horizontal frame member 61 of upper band assembly 53, and dropped into ,tank 117. Scoops 119 have blade portions 121, shown in Figure 1 which is positioned near the upper surface of band 5 and is curved in a direction opposite to the flow of water so that water which impinges on blade portions 121 of scoops 119 is thrown upwardly into scoops 119 and thence into tank 117 by means of suitable troughs in scoops 119. The water from tank 117 is recirculated to conduits 105 and 109 and nip nozzle 113 by means of centrifugal pump 123 which is operated by electric motor 125. The water is pumped from tank 117 into a manifold 127 which is connected to conduits 105 and 109 and nip nozzle 113 by means of flexible hoses 129 as is shown in Figure 2. i

As the cast shape emerges from the casting machine 1, it is supported by suitable'means, such as a run-out table comprised of a series of rollers (not shown). Water sprays (not shown) directly spraying on the surfaces of the emerging cast shape may be suitably mounted on the run-out table.

Water from the direct water sprays will also strike the surface of bands 3 and '5 as they emerge from the casting region. The band surfaces may be dried olf by any suitable means, such as

air nozzles

128 and 132 which are shown in Figure 1 and which are for drying off

bands

3 and 5, respectively. After being dried olf the

bands

3 and 5 are preferably oiled with a suitable lubricant, such as rape seed oil, cooking oil, or a light motor oil. Suitable apparatus for oiling the bands is shown in Figure 1 wherein devices and 134, for

bands

3 and 5 respectively,are comprised of a felt blade in communication with a trough for containing the oil.

As was hereinbefore mentioned, upper band assembly 53 is adapted to be raised and lowered with respect to lower band assembly 19 in order that the placement of the distributor or feeding apparatus may be readily made and also repair and maintenance of the casting machine may be easily undertaken. The lever assembly, as shown in Figure 2, is comprised of lever arms 133 which are pivotally supported in brackets 135, which are attached to cross-beam 42, and a cross-member 137 which connects lever arms 133. The extremities of lever arms 133 which are'shown in Figure '2 as extending into upper band assembly 53 are pivotally connected by links (as shown in Figure 1) to cross members 139 which are supported by horizontal frame members 63. Tosupply the motivating force to raise and lower the upper band assembly 53, a hydraulic ram 141 is attached to crossbeam 41. Piston rod 143 of ram 141 is joined to cross member 137. Any suitable means, not shown, may be provided for supplying hydraulic or pneumatic pressure to ram 141.

A feeding apparatus or distributor 9 which may be used in practice of the invention is shown in Figures 4, 5, 6 and 8. The distributor 9 which is an elongated member has an inlet portion for communication with a source of molten metal, an outlet portion for feeding molten metal to the traveling mold, and a body portion connecting said inlet and outlet portions, said body portion being tubular in order to prevent exposure of the molten metal to the atmosphere. The distributor may be fabricated as shown in Figures 4, 5 and 6 wherein distributor 9 is comprised of bottom member 147 and top plate 149. Bottom member 147 and top plate 149 are fabricated from a suitable refractory material which has high strength, good insulating properties and low specific heat. An example of such material is Marinite #36, a product of the Johns-Manville Company, which is an insulating sheet material composed of asbestos fiber, diatomaceous silica and an inorganic binder. As shown in Figure 5 member 147 has a channel 151 which fans out at its outlet portion. The outlet portion is provided at its exit end with orifices 153, said orifices extending substantially across said exit end. In channel 151 are provided a plurality of deflectors 155, which are integral with bottom member 147, in order to insure uniform spreading out of the molten metal flowing through channel 151 so that a uniform amount of metal is fed to orifices 153. In order to ensure proper mold filing, the orifices 153 have axes which are parallel to each other and parallel to the longitudinal axis of channel 151. Consequently, the axes of orifices 153 will be parallel to the longitudinal axis of the traveling mold when the distributor 9 is placed in operative relation with the traveling mold defined by the

bands

3 and 5 and dams 7. In addition, the axes of orifices 153 lie preferably in the same horizontal plane. The orifices 153 are shown as circular in the figures, however, it is within the scope of the invention to have the orifices of other configurations, for example, as rectangular slots. Also, only one orifice in the nature of a rectangular slot is within the scope of the invention.

Bottom member 147 and top plate 149 are positioned together, as shown in Figure 4, in operative position by suitable clamping and bolting means, such as clamp 157 and plates 159 which are bolted together and which sandwhich bottom member 147 and top plate 149.

At the extremity of distributor 9 which is farthest re moved from the orifices 153 is a plate 161 which engages flanges on plates 159 and which enables the distributor 9 to be bolted onto distributor bowl 11, as is shown in Figure 8. Also, there is shown in Figure 8 in phantom lines crucible 13 which supplies metal to refractory lined distributor bowl 11 by means of a refractory lined transfer trough 15 and a downspout 17 having a control pin 18 for controlling the flow of molten metal into bowl 11. The lower end of downspout 17 is submerged below the surface of the molten metal in distributor bowl 11 during casting in order to prevent undue exposure of the molten metal to the atmosphere. The molten metal flows from distributor bowl 11 into the distributor 9 through outlet 12 located at one end near the bottom of distributor bowl 11. In operation, due to the head of molten metal in distributor bowl 11, the distributor 9 feeds metal under pressure to the traveling mold formed by the endless bands 3 and 5 (shown in phantom in Figure 8) and the moving side dams 7.

Distributor 9 is shown in Figures 4, 5, and 6 as having a V-shape face at its outlet portion. This V-shape prevents freezing of the molten metal as it enters the casting region, however, other substantially concave shapes for 6 example, a C-shape, of this face at the outlet portion can be used and are within the scope of the invention.

In preparation for casting a continuous metal shape, the upper band assembly 53 is raised by means heretofore described and the distributor 9, bolted to distributor bowl 11, is placed in its operative position within the traveling mold. The front or outlet portion of the distributor 9 has on its outer surfaces a gasketos sealing material 163 such as Fiberfrax (alumina-silica fiber, ap proximately 70% alumina and 30% silica) paper and which in turn is covered'with shim stock 165, e.g. brass strip. The shim stock protects the member 163 from abrasion and wear from the

bands

3 and 5 during the casting operation. The transverse dam guide bar clamp 93 is adjusted so that the dam guide bars 91 and blocks 89 are in a substantial sealed relationship with member 163 and shim stock 165 surrounding the front portion of distributor 9. Upper band assembly 53 is then lowered thereby placing upper band 5 in contiguous relationship with the gasket on the top surface of the distributor. The member 163 and the shim stock 165 on the front portion of distributor 9 are, when distributor 9 is in operative position, in substantial sealed engagement with the traveling mold formed by

bands

3 and 5 and dams 7 and in molten metal flow relationship therewith. When upper band assembly 53 is lowered into operative position, horizontal frame members 61 rest on spacers 167 and 169 which are mounted on horizontal frame members 27 of lower band assembly 19. Spacers 167 which are positioned near the casting region and spacers 169 which are downstream from the casting region are adjustable and are adjusted to give a small clearance between the

bands

3 and 5 and the side dams 7.

After the upper band assembly 53 is lowered, suitable screw type clamps, such as carpenters clamps, are placed on each side of the casting machine clamping the

rectangular frames

25 and 59 of

band assemblies

19 and 53, respectively, together.

Figure 7 depicts an alternative distributor or feeding apparatus 171 which may be used in the practice of the invention. Distributor 171 has an inlet portion 172 and a detachable tip or outlet portion 173 which contains orifices 175. The tubular body portion 177 of distributor 171 has a passageway 179 for supplying molten metal, when the inlet portion 172 is attached to molten metal container, such as a distributor bowl, to the orifices 175. The body portion comprises metal frames 181, side strips 183, layers of asbestos cloth 185, layers of Fiberfrax paper, and layers of aluminum foil 189. The tip 173 is preferably fabricated from a suitable refractory material, such as Marinite #36, discussed above. The orifices has axes which are parallel to each other and parallel to the longitudinal axis of passageway 179. Consequently, the axes of orifices 175 will be parallel to the longitudinal axis of the traveling mold when distributor 171 is placed in operative position.

In the body portion 177, as shown in Figure 7, which is a sandwich type structure, the side strips 183 may be of a suitable refractory material, such as Marinite #36 or metal strips covered with asbestos cloth. The asbestos cloth layers 185 and side strips 183 form the walls of passageway 179. The Fiberfrax layers 187 give further insulation to the distributor and the layers of aluminum foil 189 function as a vapor barrier substantially reducing the absorption of moisture by the asbestos cloth layers 185. Similar to the front or outlet portion of distributor 9, the detachable tip 173 of distributor 171 should preferably have (not shown) on its outer surfaces a gasket or sealing material, such as Fiberfrax paper and which is covered with shim stock in order to give a substantially sealed relationship with the

bands

3 and 5 and the side dams 7.

It is contemplated in the invention that the distributor or feeding device can be made in plural sections such as shown by the distributors in Figures 4 and 7. The distributor depicted in Figure 5 is comprised generally of a top plate 149 and a bottom member 147. The distributor of Figure 7 is comprised of inlet portion 172, detachable tip 173 and body portion 177. It is within the scope of the invention that the distributor for use in the invention may be comprised of various other schemes of plural sections than those shown in Figures 4 and 7. Also, it is within the scope of the invention to have a distributor fabricated in one piece, for example, a distributor which has been molded in one piece from material such as Marinite #36.

Various configurations of the feeding orifices of the distributor are within the contemplation of the invention. Figure 9 shows various arrangements and configurations of orifices that may be employed. The various views in Figure 9 are of the exit end of the outlet of the distributor. Figure 9A depicts the orifices as circular openings of equal size, said openings extending substantially across the exit end while Figure 9B shows the orifices as plural elongated slots of equal configuration and extending substantially across the exit end of the outlet of the distributor.- Figure 9C shows a single elongated slot extending substantially across the exit end and being of substantially equal dimensions; that is, the opening dimension, along the length of the slot. If it is desired to feed metal to the outer portions of the casting at a higher rate than to the central portion, then configurations of orifices such as shown in Figures 9D, E, F or G may be employed. Figure 9D shows circular orifices extending substantially across the exit end with the orifices at the central portion of the face being of smaller diameter than the diameter of the orifices removed from the central portion. Figure 9E shows an arrangement of plural elongated slots wherein the slot located at the central portion of the exit end is of smaller size than the slots located at the end portions of the exit end. Figures 9F and 9G depict single elongated slots which extend substantially across the exit end and wherein each slot is of smaller cross sectional dimension near the central portion of the exit end than the cross sectional dimensions removed from said central portion.

During the casting operation (described in conjunction with the distributor or feeding apparatus shown in Figures 4, 5, 6 and 8) the molten metal level in distributor bowl 11 is maintained at such a height as to give the proper pressure at the orifices 153 in order to ensure proper mold filling characteristics. For example, in the continuous casting of aluminous metal, such as aluminum and aluminum alloys, the molten metal level in bowl 11 should be maintained at a height to give a pressure of greater than 0.25 p.s.i., preferably 0.5 p.s.i. or greater, at orifices 153. This molten metal pressure keeps the frozen shell of the shape being cast pushed against the

endless band

3 and 5 for maximum heat removal. When the flow of molten metal is reduced by the lowering of the molten metal level-in bowl 11 the frozen shell will shrink away from the

endless bands

3 and 5 with subsequent reduction of heat removal. This is undesirable because the casting would have increased porosity and cold folding on the surface. Care should be exercised to avoid too high a metal level because use of a metal pressure substantially in excess of that necessary to have proper mold filling will cause spillouts of molten metal in the vicinity of the gaskets or seals on the front portion of distributor 9. In order to start the cast, a plug, or bait such as a steel rod or bar with a bolt therein is placed in the traveling mold at a position in front of distributor 9. When the molten metal solidifies around the plug, the movement of

bands

3 and 5 is started. After the casting emerges from the machine, the plug can then be sawed off. The optimum casting speed is attained when the distribution of the molten metal is uniform across the width of the metal shape being cast and contact of the frozen metal 0.5 pound per square inches.

shell with

bands

3 and 5 is good. Under these conditions it has been found that suificient heat is removed from the casting by the endless band to at least form a shell of strength adequate to stand the force of direct water sprays, even when casting at relatively high speeds and to produce a cast shape possessing good surface appearance. 7

As a specific example of practice of the instant invention, approximately 1000 feet of electrical conductor grade aluminum alloy (99.45% aluminum minimum) material of the cross-sectional dimensions one and one-quarter inches by ten inches was cast continuously at rates ranging from six and one-quarter to nine feet per minute. The distributor used in this cast was the same as that shown in Figure 4 with the exception that, of the ten circular orifices, the four orifices in the central portion of the face were of inch diameter while the six orifices (three on each side of the orifices at the central portion) at the end portions of the face had diameters-of 95 inch making a total orifice area of approximately 1.34 square inches. The temperature of the metal in the crucible was 1350 F. while the temperature of the metal in the distributor bowl varied from 1274 F. to 1350 F. during the casting run. The molten metal in the crucible was fluxed therein just prior to casting by stirring AlCl pellets into the molten metal (5 pounds of AlCl per 16,000 pounds of metal). The level of the molten metal in the distributor bowl was maintained at approximately three inches giving a pressure atthe orifices of about The metal casting as it emerged from the casting machine was subjected to direct water sprays and was sawed into length as the casting proceeded.

From examination of the casting it was found that the greastest variation in thickness across the width of the casting was 0.06 inch. Bend tests were made on sections of the casting wherein the sections subjected to bends on a 2 /2 inch radius without failure occurring indicating the freedom or substantial freedom from longitudinal shrinkage pipes and surface defects, such as cold folds. The mechanical properties of the cast metal averaged approximately 10,000 p.s.i. for ultimate tensilf strength, 4,300 p.s.i. for yield strength and 45% elongation in 2 inches. These values compare very favorably with typical values for electrical conductor grade aluminum alloy fabricated by rolling and in the annealed temper which are 12,000 p.s.i. ultimate tensile strength, 4,000 p.s.i. yield strength and 23% elongation in 10 inches. Electrical conductivity tests showed that the metal had a conductivity in the range of 60 to 61% IACS (International Annealed Copper Standard); It will be seen that such cast metal is eminently suited for use in bus bar applications for electrical installations, for example, in aluminum reduction plants. Other casts of electrical conductor grade aluminum metal have been made wherein the cast material has cross-sectional dimensions of one and one-quarter by fifteen inches. Also, casting rates greater than 9 feet per minute have been used, e.g. 12 feet per minute. I

Employing the method and apparatus herein disclosed a metal casting free or substantially free from shrinkage cavities and surface defects, such as cold folds, can be cast continuously at high rates in a substantially horizontal manner. Although certain specific embodiments of the invention have been illustrated and described, it is 'to be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. For example, shapes having cross-sectional configurations other thanrectangular can be cast, e.g., square, round, etc., and the method and apparatus with slight modification can be made to cast plural slabs simultaneously. It is also to be understood that, although the casting of electrical conductor grade aluminum alloy is given specifically in the example, the teachings of the invention are applicable to the casting of other aluminum 9 alloys as well as other metals, such as copper, brass and steel.

We claim:

1. A continuous casting apparatus comprising an upper endless band, a lower endless band adjacent to said upper band, moving side dams, means for moving said bands and said side dams in non-circular paths, said side dams surrounding and moving in the same direction as said lower endless band, said endless bands and said side dams adapted during movement thereof to form a substantially horizontally traveling mold, means for cooling said mold, means for cooling a cast shape as it emerges from said traveling mold, a molten metal distributor, said distributor being of a refractory material having high strength, good insulating properties and low specific heat and comprising a tubular body portion on one end of which is an inlet portion and at the other end of which is an outlet portion, said inlet portion and said outlet portion being connected by a channel, said channel fanning out at said outlet portion and having a plurality of deflectors disposed therein, said inlet portion being in communication with a source of molten metal, said outlet portion having on its outer surfaces gasket material, said gasket material being covered with shim stock, said gasket and said shim stock effecting a substantially sealed relationship between said outlet portion of said distributor and said traveling mold and being in molten metal flow relationship therewith, said outlet portion being provided at its exit end with a plurality. or orifices extending substantially across said exit end, the axes of said orifices being parallel to each other and parallel to the axis of said traveling mold.

2. A continuous casting apparatus according to claim 1 wherein the axes of said orifices are in the same horizontal plane.

3. A continuous casting apparatus according to claim 1 wherein the orifices near the central portion of the exit end of the outlet portion of the distributor are of smaller size than the orifices removed from said central portions.

4. A distributor for feeding molten metal to a substantially horizontally traveling mold, said distributor being of a refractory material which has high strength, good insulating properties and low specific heat and comprising a tubular body portion on one end of which is an inlet portion and at the other end of which is an outlet portion, said inlet portion andsaid outlet portion being connected by a channel in said body portion, said channel fanning out at said outlet portion and having a plurality of deflectors disposed therein, gasket material provided on the outer surfaces of said outlet portion, said gasket material 10 being covered with shim stock, said outlet portion being provided at its exit end with a plurality of orifices extending substantially across the exit end, the axes of said orifices being parallel to each other and parallel to the longitudinal axis of said traveling mold when said outlet is disposed therein.

5. A distributor according to claim 4 wherein the axes of said orifices lie in the same plane.

6. A distributor according to claim 4 wherein the orifices are of equal size.

7. A distributor according to claim 4 wherein the orifices near the central portion of the exit end of the outlet of the distributor are of smaller size than the orifices removed from said central portion.

8. A continuous casting apparatus including endless members, means for moving said members to form a substantially horizontally traveling mold, a molten metal distributor comprising a tubular body portion on one end I of which is an inlet portion and at the other end of which is an outlet portion, said inlet portion and said outlet portion being connected by a channel, said channel fanning out at said outlet portion and having a plurality of deflectors disposed therein, said inlet portion being in communication with a source of molten metal, said outlet portion having on its outer surfaces gasket material, said gasket material being covered with shim stock, said gasket and said shim stock effecting a substantially sealed relationship between said outlet portion of said distributor and said traveling mold and being in molten metal flow relationship therewith, said outlet portion being provided at its exit end with a plurality of orifices extending substantially across said exit end, the axes of said orifices being parallel to each other and parallel to the axis of said traveling mold.

References Cited in the file of this patent UNITED STATES PATENTS 594,583 Wood Nov. 30, 1897 767,304 Meadows Aug. 9, 1904 1,139,885 Mellen May 18, 1915 1,342,127 ,Mellen June 1, 1920 2,056,233 Stroup Jan. 10, 1935 2,058,448 Hazelett Oct. 27, 1936 2,103,995 Willis Dec. 28, 1937 2,127,515 Hazelett Aug. 23, 1938 2,560,639 Giesler July 17, 1951 2,631,343 Hunter Mar. 17, 1953 2,640,235 Hazelett June 2, 1953 2,772,517 Bowes Dec. 4, 1956 UNITED STATES FATENT OFFICE CERTIFiCATE CORRECTION Patent No, 2,978,761 April 11, 1961 John J'Q'QFoye et a]..,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent. should read as corrected below.

Column 2, line 3, for "elevation" read elevetional column 5, line 38, for "filing" read iilling column 6, line 8, for "0s" read or line 52 for "has" read have column 9, line 30 for "or" read oi Signed and sealed t his,17th day of'October' 1961.

(SEA L) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer 1 Commissioner of Patents USCOMM-DC