US3465810A - Apparatus for casting metal - Google Patents

Description

p 9, 1969 E. Q. SYLVESTER 3,465,810

APPARATUS FOR CASTING METAL Filed Dec. 4. 1967 have 1102" Edyuuud Sy/zesi Q I v Z/WJAAZ%ZQ United States Patent U.S. Cl. 164259 2 Claims ABSTRACT OF THE DISCLOSURE Molten metal is poured into a mold and during solidification of the metal within the mold an inert gas, such as argon, is bubbled upwardly through the metal.

It has been the practice to cast metal by pressure pouring and by continuous casting. If a rimming grade steel is desired, it has been the practice to vacuum degas the melt in order to control the oxygen content of the melt to reduce the rimming action during cooling of the molten metal in a pressure casting mold. Vacuum degassing of the melt has also been used to reduce the oxygen content for ingot casting as well as continuous casting. Vacuum degassing of the molten metal requires expensive equipment with the result that rimmed steel, produced by such a process is expensive.

It is, therefore, an object of this invention to provide a method and apparatus for casting metal.

A further object of this invention is to provide a method and apparatus for the casting of rimmed steel.

It is a further object of this invention to provide a method and apparatus for the casting of rimmed steel slabs, billets, blooms and other similar articles without the attendant increase in cost of the prior art process.

These and other advantages and objects of this invention will become apparent from a reading of the following detailed description of this invention, when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of the apparatus of this invention; and

FIGURE 2 is a perspective view of a portion of the apparatus of this invention, which portion is capable of introducing an inert gas into the mold cavity.

Referring now to the drawings, reference numeral denotes the pouring tube of a conventional pressure pouring apparatus (not shown). The pouring tube 10 is open at its upper end 12 for communication with an ingate assembly 14. The ingate assembly is secured to the cast iron bottom block 16 of a vertical slab mold 18. The ingate assembly 14 is provided with a central aperture 20 having inserted therein a ceramic sleeve 22, the bore 24 of which is in open communication with the bore 26 of the pouring tube 10. Also positioned in and forming a part of the ingate assembly 14 is a slide cut-off plate 28 having a bore 30 which plate 28 slides in a recess 29 in the ingate assembly 14. A ceramic insert 32 is positioned within the bore 30 of the slide cut-ofi plate 28 and is provided with a bore 34 of the same internal diameter as the internal diameter of the sleeve 22.

The mold 18 consists of a pair of graphite side blocks 36, a pair of cast iron end blocks 38, the bottom block 16 and a cast iron riser 40. Only one side block 36 has been shown, it being understood that the other side block 36 is of identical construction. The side blocks 36, end blocks 38, bottom block 16 and riser 40 form therebetween a slab molding cavity 42. The bottom block 16 is provided with a central aperture '44 of the same internal diameter as the internal diameter of the insert 32 and is in open communication therewith. Preferably, the bottom block 16 is provided with a frustoconical cavity 46 communicating with the mold cavity 42.

Referring now to FIGURE 2 for a more complete showing of the slide cut-off plate 28 and associated structure, wherein the plate 28 is provided with a second aperture or bore 48. A ceramic sleeve 50 is positioned snugly within the bore 48 and retains a porous plug 52 of suitable refractory material such as a spinel. Means such as a pipe 54 are provided to supply inert gas such as boron to the porous plug 52.

The slide plate is moved from its position wherein sleeve 32 is aligned as shown in FIGURE 2 to its position wherein the porous plug 52 is aligned with the aperture 44 by a piston rod 56 operatively connected to an air or hydraulic cylinder 58.

In operation, the mold 18 is positioned over the pouring tube 10 of a conventional pressure pouring apparatus (not shown). The slide cut-01f plate 28 is positioned with the ceramic sleeve 32 in alignment with the bore 26 of the pouring tube and the aperture 44 of the bottom block 16. Molten metal is forced upwardly by the conventional pressure pouring method through the pouring tube into the mold cavity 42 until the cavity has been filled. The piston 58 is actuated to move the slide cutoif plate from its position in FIGURE 1 to its position wherein the porous plug is aligned with the aperture 44 of the bottom block 16. The air pressure is shut off and the inert gas supply is started which forces the inert gas through line 54, and the porous plug 52 upwardly into the still molten central portion of the casting. The inert gas bubbles upwardly through the casting thereby removing deleterious substances such as hydrogen from the melt. It also deoxidizes the melt.

Since the inert gas bubbles in from the bottom, rimming action is obtained throughout the slab rather than only in a portion of the slab in ingot pouring. This process will result in interanl cooling of the melt which will reduce the shrinkage and the solidification time.

In the preferred embodiment of this invention, the top 60 of the mold 18 is covered with a light refractory brick or asbestos to prevent the introduction of oxygen into the mold during the inert gas introduction.

It can be seen from the foregoing that this method and apparatus will produce an improved product. It should be understood that various modifications may be made in the invention without departing from the spirit and scope of the following claims.

I claim:

1. An apparatus for casting metal articles comprising a mold having a cavity of the configuration of the article to be formed, means for forcing molten metal upwardly into the mold, an ingate assembly having a passageway to provide communication between said means and said mold, a slide plate forming a part of said ingate assembly, said slide plate being provided with an aperture and a porous plug alignable with said passageway, said porous plug being in open communication with inert gas supply means, and means for aligning said aperture With said passageway during filling of the mold and for aligning said plug during solidification of said article.

2. An apparatus according to claim 1 wherein said mold is a vertical mold comprising a pair of cast iron end blocks, a cast iron bottom block, a cast iron riser and a pair of graphite side blocks.

References Cited UNITED STATES PATENTS Burkhardt 164-66 X Sylvester l64-66 Goedecke et a1. 164-56 X Sylvester 164-66 Bonis et al. 164-55 10/1967 Buehl et a1 164-66 X 11/1967 Wentzell 164-68 X 2/1968 Bonis et a1 164-259 X 12/1958 Dunn 164-259 3/ 1895 Casgrain 164-306 FOREIGN PATENTS 6/ 1961 Italy.

2/1963 Japan.

U.S. Cl. X.R.

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