US1024722A - Process and apparatus for casting ingots. - Google Patents

Description

J. ENSSLEN.

PROCESS AND APPARATUS FOB. CASTING INGOTS.

APPLICATION FILED BEPT.16, 1911.

1,024,722. Patented Apr. 30, 1912.

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f%gW B "7" WM M JACOB ENSSLEN, 0F PITTSBURGH, PENNSYLVANIA.

PROCESS AND APPARATUS FOR CASTTNG INGOTS.

Specification of Letters Patent.

Patented Apr. 30, 1912.

Application filed September 16, 1911. Serial No. 649,677.

To all whom it may concern:

Be it known that LJnoon ENssLnN, a subject of the Czar of Russia, and the city of Pittsburgh, in the, county of Allegheny and State of Pennsylvania, have invented or discovered new and useful Improvements in Processes and Apparatus for Casting lngots, of which the followmg is a specification.

My invention consists of a new and improved process for casting ingots of steel or other metal.

In the present practice the metal is ordinarily oured into the top of the mold directly rom the ladle in a stream, the gases being retained in the metal and the process of solidification proceeding upward from the bottom of the mold. The metal poured at a high temperature, is subjected to excessive shrinkage in the mold during solidification, thus forming pipes and other dc fects in the ingot. The higher temperature in the upper portion of the ingot retards the solidification of that portion thereof which permits the gases to rise thcicin and the metalloids, such as carbon, sultur,pl1osphorus, manganese, etc., to segregate in that portion of the ingot, resulting also in numerous blow holes. As a result, the upper portion of the ingot must be out off and scrapped, while the body of the ingot must be hammered, pressed or rolled to reduce the pipes and other defects.

The segregation of the metalloids is not as is generally believed, the result of the lower specific gravity of the alloys higher in said constituents, but is due to their lower melting or solidifying temperature. The alloys lower in carbon, sulfur, phosphorus and manganese are solidified first at the lower part of the ingot and around the walls. On the other hand, the alloys of a higher content of metalloids with their lower melting or solidifying temperature, are still in a liquid state when the alloys lower in. carbon, sulfur, phosphorus, and manganese have reached their temperature of solidification. In ordinary top pouring. the metal in the upper portion of the mold is hotter than that in the lower portion of the mold when the mold is filled and the solidification progresses upwardly from the bottom and inwardly from the walls of the mold toward the center. As a result the nlloys higher in carbon, sulfup, phosphorus and manganese are continuously squeezed or residing in of the alloys higher forced upwardly by the building up of the crystals of the alloys lower in said metallOldS, which alloys, as explained, solidity first owing to their higher temperature of solidification. Thus in the solidified ingot the percentage of carbon, sulfur, phosphorus and manganese increases from the bottom upwardly and from the walls toward the center, the richest zone being at the upper part of the ingot.

During the process of solidification of the ingot, as above described, the gases included in the metal, tending to rise into the upper part of the mold, facilitate the segregation in carbon, sulfur, phosphorus and manganese in the upper part of the ingot. It is evident that such segrega tion is less when, first, the gases are eliminated from the metal; second, the metal throughout theniold has the same temperature when the pouring operation is completed, and, third, the contents of the mold are cooled quickly, that is the time elapsing between the completion of the pouring operation and the solidification oi the whole ingot is reduced.

By the use of my process and apparatus the gases are removed from the metal in its passage from the ladle to the ingot mold, and the metal is introduced into the mold in such a merrier that the temperature throughout the casting is substantially uni form, thus preventing the segregation of the metalloids and the formation of blow holes or other defects. The metal is cast at a lower temperature, than when contained in the ladle, and means are employed for cooling the walls of the ingot mold. I thus greatly expedite the operation of solidification, reduce shrinkage to a minimum, avoid the formation of pipes. blow holes and other defects, and prevent the segregation of the metalloids.

I eliminate the gases from the metal by passing the latter over a surface in a relatively shallow flow or stream prior to its introduction into the mold, and 1 introduce the metal into the mold through a pouring pipe placed inside the mold and extending downwardly in the interior thereof and discharging the metal in such a manner that it flows upwardly to fill the mold. The pouring pipe is retained in its lowered po' sition during the pouring operation, until the mold is almost filled, when it is raised to permit the space previously occupiedb} gas eliminator and the solidification is exthe d pedited bythe low temperature at which the metal enters the mold and by the cooling means applied to the exterior walls of the niold, a minimum of shrinkage and segregation occurs and the formation of pipes and blow holes is avoided. so that practically the entire ingot is available for use.

In the accompanying drawings, which are merely illustrative of the principles of my invention and not intended to limit the scope of the same to what is therein shown, Figure 1 is a side elevation of a pouring ladle from which is suspended my gas eliminator and pouring pipe, both shown in section, the ingotmold in,place to receive the metal being also shown in section. and Fig. 2 is a vertical section of a modified form of my gas eliminator;

The following is a detailed description of rawings.

1 is a ladle of the ordinary type suspended in the usual manner from a crane, not shown: 2, is the pouring port of ladle 1 and 3 is the stopper device controlling said port 2. v

4 is the gas eliminator suspended by links 5 5 from the ladle 1. The eliminator 4 is a hollow receptacle and 6 is a spiral trough extending around the interior wall of said receptacle 4 from top to bottom. The interior Wall of receptaclc 4 and trough 6 is lined with suitable refractory material 7. The bottom of the receptacle 4 is provided with a discharge .port 8 under which is suspended by links 9-9 depending from the receptacle 4 a pouring pipe 10, preferably provided with a funnel shaped upper end to facilitate the passage of the metal into said pipe 10. It is evident that inasmuch as the gas eliminator and pouring pipe are suspended from the ladle. they are raised, lowered and transferred from place to place in unison with the latter.

11 is the ingot mold, open at top and bot tom and standing upon bottom plate 12 on car 13. Themetal is introduced into the ladle 1 from the converter or other furnace and the ladle and its depending devices swung over the mold 11 and lowered until the pipe 10 extends down into the mold 11 as shown in Fig. 1. The stopper is now removed from port 2 and the inetal escapes gradually fIOIIlIi hG ladle 1 to the top of trough 6 down which it flows to the bottom of receptacle 4 into the top of pipe 10. As the metal passes from pipe 10, the level of the former rises in the mold 11 until said mold is almost filled, whereupon the ladle 1 is raised, elevating the pipe 10 above the metal in mold 11, thus permitting the space previously occupied by the said pipe and the upper portion of the mold to be tilled.

When the proper amount of metal has throughout the mold,which temperature is further reduced by artificially cooling means, such as a perforated annular pipe 14, connected to a water supply not shown and placed upon the neck of the mold before the pouring operation is begun. Instead of retaining the pipe 10 in its lowered position during the pouring operation, 1 may gradually elevate said ipc-as the level of the metal rises in the m0 (1.

In Fig. 2 I show a modified form of gas eliminator which consists of a receptacle 15 removably mounted on a platform 16 which may be rotated by means of its gear wheel 17 meshing with power driven gear 18. The top of receptacle 15 is provided with a horizontal ilange 19 which extends over the edge of the annular trough 20 of the stationary hood 21. The trough 20 and receptacle 15 are lined with refractory material 22. The hood 21 is secured to the pouring pipe 23 whose funnel sha ed upper end receives the metal from t e port 2 of the ladle 1. The trough 20 is provided with a port 24 which communicates by means of a trough 25, provided with a refractory lining .26, with the pouring pipe 10. The metal entering the receptacle 15 through the pipe 23 is thrown by the centrifugal force of the rotation of the receptacle 15 in a shallow flow up the walls of the receptacle 15, thus permitting the escape of v the gases from the metal into the trough 20, whence it passes through port 24., trough 25 and pipe 10 into the ingot mold.

What I desire to claim is 1. The process of casting ingots which consists in introducing the metal downwardly through the top of the ingot mold and discharging the same at a point near the bottom of said mold and causing the metal to flow upwardly from the bottom to fill the mold, for the purpose described. 2. The process of casting ingots, which consists in first eliminating or liberating the gases 'from'the fluid metal by passing the latter in a shallow flow over an extended surface, and then discharging the metal into the mold.

3. The process of casting ingots which through the top of consists in first passing the fluid metal in a relatively shallow flow over an extended surface, and, second, introducing the metal the mold and discharg ing said metal into the interior of at a point adjacent to the bottom thereof. and causing the metal to flow upwardly from the bottom to fill the mold.

a. The process of casting ingots which consists in admitting the metal downwardly through the top of the mold through-- the metal accumulated in said mold and discharging the newly admitted metal beneath the accumulated metal, whereby the metal flows upwardly from the bottom to fill the mold, thus maintaining a substantially uniform temperature in the mold during the operation of pouring.

5. In apparatus for casting ingots, a gas eliminator adapted to be interposed between the ladle and the ingot mold and consisting of a receptacle adapted to receive the metal from the ladle and means for passing said metal in the form of a shallow stream over the side wallof said receptacle, for the purpose described. i p

6. In apparatus for casting ingots, a gas eliminator adapted to beinterposed between the ladle and the ingot sisting of a receptacle adapted to receive the mold mold and con the metal from the ladle and means for passing; said metal in the form of a shallow flow alongthe interior side wall of said receptadle, for the purpose. described.

7. In apparatus for casting ingots, a gas eliminator adapted to be interposed be tween the ladle and the ingot mold and consisting of a receptacle adapted to receive the metal from the ladle land a trough spirally arranged on the interior of said re ceptaele for the passage of the metal through said receptalile in the form of a shallow flow. for the purpose described.

8. In apparatus for casting ingots, in combination with an ingot mold, of a pouring ladle, eliminator supported heneath said ladle and adapted to receive the metal therefrom, and a pouring pipe adapted to receive metal from said gas eliminator and suspended therefrom and means for lowering said pipe down into the interior of said ingot mold, whereby the metal is caused to flow upwardly to fill the mold.

Signed at Pittsburgh, Penna, this 15th day of September 1911.

J ACOB ENssLEN.

Htncsses 1 W. S. WALSH, E. A. Lawnnucn.

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