US929688A - Process of casting metal ingots. - Google Patents

Description

J. F. MONNOT.

PROCESS OF GASTING METAL INGOTS.

APPLICATION FILED SEPT. 6, 1907. RENEWED DEC. 17, 190B.

Patented Aug. 3, 1909.

+ W Attys UNITED STATES PATENT OFFICE.

JOHN FERREOL MONNOT, OF NEW YORK, N. "Y., ASSIGNOR -TO MONNOT-METALLURGICAL ing Metal Ingots; and I hereby declare COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF NEW YORK.

rnocn ss or cAsTING ETAL INeors.

Patented Aug. ,3, 1909.

Application filed September 6, 1907, serial No. 391,674. Renewed December 17, 1908. Serial No. 468,055.

To all whom it may concern:

Be it known that I, J OHN FERREOL MON- ,NOT, a citizen of the United States, and a resident of the city, county, and State of N ew, York, have invented certain new and useful Improvements in Processes of Caste the following to be a full, clear, and exact description thereof, such as will enable others skilled in the art to which the invention pertains to make and practice the same. ,.v

This inventionrelates to the art of casting metals and consists in a method of casting moltenmetal into 'molds in the presenceof. a wiping liquid all as more fully hereinafter set forth and as. claimed.

As has been known for many years, all 2 common objects exposed to atmospheric eondltlons are covered with a relat velydense adherlng layer of v condensed vaporizable matter; this layer being probably partly moisture and partly condensed gases. Glass and. solid metals, as wellas most other materials, after. exposure to air have a condensed adhering .layer of moisture and gases which they refuse to part with, even at relatively elevated temperatures. Glass surfaces, for

instanc'e,.refuse to part with all .their moisture even at 500 C though losing it' at still higher temperatures, and they cannot be, absolutely dried even by contact with air dried with powerful chemical hygroscopic agents.- lVith this moisture occur ga'ses also; glass; for instance, alSoretaining much absorbed carbon dioxid as'well as, probably ,.other at;

mospheric, gases. The connection or relation of these condensed bodies, and moisture, to each other is unknown; their practically invariableoccurrence on all mineral matters, metals and vitreous substances is a matter. of fact.

In the ordina y methods of casting molten metals into'mo ds, theinterior of the mold is always ,covered ,with the described layer and in the art, beyond perhaps some warin-.. ing of the mold, no efforts are customarily made to obviate its, p,1esence. This layer under the influence ofthe great; heat of the match metal. is vapprized after somelittle time, generally after a body of metal has accumulated above .it, and in its ,expan sion. and in its accumulation interning its yvay upward through 5 the flsolidifying metal 1 1t forms ,the familiar pit holes on the surfaces of the bodiesof cast metal- Thelmold walls being generallycolder than the molten metal do not releasethe condensed vaporizable ,niatt'er until after such metalbegins to be- ,come thick or pasty as a rule, metals being brdinarily cast at a temperature not much above their melting points.

The ,molten metal in pouring through the .air; into .the mold also accumulatesmore, or

less of a similar superficial layer, though .by.

reason of the high temperature of such metal this layer is .notusually very great in amount. B ut it carries. with it entrained air; frequently in considerable amounts with .careless casting; ,Entrained. air is also of coursle responsi le for blowholes and porous meta ;to do away with the described phenomena 'It is the purpose of the present invention and make metal castings under conditions which will enable the molten metal to come 'in contact with mold walls free of vaporizable matter and which will prevent accumulationot' gases and vapors, whether entrained or absorbed, to form pitholes, blebs, blowholes and unsound castings. To this end, ;the metal to-becast is poured into the mold through, a body of a non-metallic wipin iliquidcontained in the mold. .This; liqui should be of such nature asto readily wet .the molten metal flowing through it. .Sodium' silicate, or ordinary commercial ,water-glass, forms a suitable wiping liquid for this purpose, since it is readily .tused at the .,temperature of most molten metals to form a comparatively viscous liquid which :wets metals, coming into actual contact with :their surfaces, and which is well'adapted to wipe otf clinging layers of condensed gases and the like, while entrained air will of course not descend through it. Being lighter than the metal, the metal descends through .it, so that a comparatively small {amount of .such wiping fluid will suflice for a comparatively large ingot.

face, enabling them to unite tov form a homo@ genousflawless .body of metal. And if;the gwiping. liquid be contained in the-mold, it

steadily rises upward as the molten metal- ;accumulates in the base of. the. mold, wiping before it as it goes any condensed or abthe exact form of the mold walls without sorbed layer of vaporizable material on the mold walls and enabling the metal to take formation of bubbles, blebs, pitholes or flaws.

N o'entrained air will go through the wiping liquid with the poured metal. Advanta geously, thewiping liquid is contained for the most part in a receptacle separate from dry types of apparatus of the many ada ted to perform the described process and fa ling within the limits of my invention. I

In this illustration, Figure 1- shows in vertical cross-section an ordinary type of mold provided with a special non-conduct ve crown piece; Fig. 2 shows a vertical section of a similar mold and of a portion of a pouring table and runner arranged to pour the mold from the bottom. Fig. 3 shows a vertical section of a mold and of a floatable retainer for wiping fluid therein; and Fig. 4

' is a view similar to Fig. 3, illustrating the counterbalancing of such retainer to assist ffluid and 8 a non-conductive head. The' mold is filled upwardly from conduit 9 by same .in rising.

In Fig.1, 1 designates the 'mold body;-2 an ingot of metal contained therein; 3 a layer of wiping fluid floating on the metal; and 4 is a non-conductive crown piece or head. v

In Fig. 2, 5 is an ingot mold; 6 a body of metal therein; 7 a floating layer of wiping pouring molten metal into the runner 10 in. communication with said conduit, according to the, method common in makin steel ingots. Whether the mold be poured from the top, as in Fig. 1, or from the bottom, as in Fig. 2, the first portion of the molten metal entering the mold melts the wiping material,

if the latter has been placed in the mold in a solid condition; and the molten wiping material covers the surface of the molten metal, protecting the same from oxidation, and also as it rises wiping the sides of the mold free from the absorbed layer of moisture and gases above mentioned-which said wiping material is able to do because of its high temperature, the result of contactwith the molten metal.

When carrying on the process as illustrated in Fig. 1, the moltenmetal is caused to pass through the floating layer of wiping material 3, and is thereby wiped clean of en trained air andgases. When carrying on the process as illustrated in Fig 2, the same resu t is accomplished by maintaining in the runner 10, as well as inthe mold, a layer of wiping material, designated in the runner of Fig. 2 by reference numeral 11. As the molten metal nears the top of the-mold, the

wiping material is lifted up into the bore of the crown-piece or head,4 or 8; and commonly so much molten metal is run into the.

mold that said molten metal rises up into such crown-piece. a reater or less distance,

also. This crown-piece being of refractory non-conductive material, and the upper surface of the metal being'protected to reat extent against radiation to the outside air by the coating of wiping material, 3 or 7, now of considerable depth owing to the upwardlytapering form of the bore of .the crown piece,

the-metal in such bore solidifies relatively slowly, as com ared with the metal in the" mold itself, an thus such metal in the bore of the crown piece forms a reservoir from which molten metal is drawn automatically to fill the pipe commonly formed in the central portion of an ingot by contraction of the metal from the inside outward as the required; and owing to the e cient protection against surface oxidation and absorption 0 gases afforded by the wiping material and the consequent freedom of the metal from contained oxid (which usually makes the upper portion of an ingot bad when the ingot is cast without protection by a layer of'wiping material) cropping will often not be required at all. My invention therefore makes available for working a much greater portion of the ingot than has been available heretofore.

- Heretofore, in casting steel ingots, it has been considered substantially necessary .to fill the molds from the bottom, as in Fig. 2, to avoid, so far as possible, oxidation of the main body of the metal and to keep the bulk ofthe oxid formed near the top of the ingot, and to give as much opportunity as possible for the escape of entrained air and gases; but according to the methods of pouring commonly use heretofore it has not been possible to avoid contact of air with the stream of molten metal flowing into the riser, and thus a considerable quantity of oxid has been formed and carried into and mixed with the main'body of molten metal, distributing oxid to some extent throughout the ingot. The wiping layer used in my process wipes the stream of molten metal clear of such oxid. For this reason there is not so much reason in my process for pouring molds from the bottom (as in Fig. 2) and in general it will be permissible to pour them from the'top, as in Fig.1.

The wi ing material may be contained within a oatable ring 12 (Fig. 3) located whatever is within the mold; said ring having a central space, open at the bottom, for containing such wiping material; there being also some space between the outer surface of such ring and the inner surface of the mold. In such case, the stream of molten metal is poured into the mold through ring 12; and while the major ortion of the wiping material will remain in said ring, a certain proportion of it will be carried mechanically by the molten metal beneath the ring to the outside thereof and will flow up into the annular space between the ring and the side of the mold, thereby covering the metal in such annular space, and wiping the sides of the mold as above described. This ring 12 may be made of crucible mixture, carborundum, or other suitable refractory material.

If desired, the ring may be counterweighted, as shown in, Fig. 4, being connected by flexible cables 13 to counterweights 14, said cables passing over pulleys 15 carried by a ring 16 resting removably on top of the mold, and adapted to be moved from mold to mold as the pouring goes on.

Other fusible materials may be used as the wiping material; for example, potassium silicate, amixture of potassium and sodium silicate, glass, or neutralized borax, or in general and readily fusible mineral substance which will not unite or-mix with the molten metal.

What I claim is:-

1. In the art of casting metals, the process of making homogeneous ingots which consists in-casting molten metal into an in ot mold down through a wiping layer 0 a fused inorganic body.

'2. In the art of casting metals, the process of making homogeneous ingots which consists in casting molten metal into an ingot mold through a confined wiping layer of a fused inorganic body.

3. In the art of casting metals, the process of making homogeneous steelingots which consists in casting molten steel into an in ct mold: down through a wiping layer 0 a fused inorganic body.

4-. In the art of casting metals, the process of making homogeneous steel ingots which consists in casting molten steel into an ingot mold through a confined wiping layer of a fused inorganic body.

5. In the art of casting metals,the process of making homogeneous ingots which consists in casting molten metal into an ingot mold down through a wiping layer of fused alkali silicate.

6. In the art of casting metals, the process of making homogeneous ingots which consists in casting molten metal into an ingot mold. through a confined wiping layer of fused alkali silicate.

7. In the art of casting metals, the process of making homogeneous steel ingots which consists in casting molten steel into an ingot mold down through a wiping layer of a fused alkali silicate.

8. In the art of casting metals, the process of making homogeneous steel ingots which consists in casting molten steel into an ingot mold through a confined Wiping layer of a fused alkali silicate.

9. In the art of casting metals, the process of making homogeneous ingots which consists in providing a suitable ingot mold internally with a floatable container holding a fusible mineral body and having an open bottom, and casting molten metal into said mold through said container and through the fusible mineral matter therein contained.

10. In the art of casting metals, the process of making homogeneous steel ingots which consists in providing a suitable ingot mold internally with a floatable container holding a fusible mineral body and having an open bottom, and casting molten steel into said mold through said container and through the fusible mineral matter therein contained.

11. In the art of casting metals, the proccess of making homogeneous ingots which consists in providing a suitable ingot mold internally with a floatable container holding alkali siiicate and having an open bottom, and casting molten metal into said mold through sald container and through the al-

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