US1828200A - Ingot mold and method of making same - Google Patents

Description

GM. 20, 1931. J PERRY 1,828,200

INGOT MOLD AND METHOD OF MAKING SAME Original Filed June 18, 1926 INVENTOR /Zn 1;. Perry M ATTORNEY the kish and spon Pace-ted 0a. 20, 1931 UNITED STATES PATENT? OFFICE JOHN IBDIUND PERRY, OF SHARON, PENNSYLVANIA, ASSIGNOR T0 VALLEY MOULD AND IRON CORPORATION, OF SHARI'SVILLE, PENNSYLVANIA, A CORPORATION 0}! new roan meow 1:01.10 AND moi) or MAKING SAME Original application filed June 18, 1926,-Seria1 No. 116,793. "Divided and this application filed December 16, 1926. Serial No. 155,138.

The present invention relates to metallurgy and more particularly to ingot molds. This is a division of my pending application, Serial No, 116,793, filed June 18, 1926, which eventuated into Patent 1,643,419, granted September 27, 1927, in which is claimed a set-up and core bar structure. The present invention relates more especiall to ingot molds of the closed bottom type. ig-end-up ingot m'olds adapted for use without stools and being provlded in the bottom with a stripping opening usually closed with a plug are known in the art as closed bottom ingot molds.

, Heretofore in the art, it has been customary to' cast a closed bottom ingot mold inverted over an inverted sand core; that is, with the bottom of the mold uppermost and with the mouth of the ingot mold being in the bottom of the casting set-up. This results in .the impurities rising during casting and leaves metal in that part of the finished mold whlch is sub'ected to greatest strain when the in t mol is being used to cast steel ingots. urthermore, this prior method necessitated machining the bottom of the finished ingot mold inorder to provide a base surface on'which the mold could be set.

The ingot mold comprising the present invention'isone' wherein the base of the mold isa substantially plane surfabeadapted to set' on a suitable support so that the mold sets with the axis ofthe matrix substantially vertical. Preferabl the surface on the bottom ofthe base is a ard skin referred tom the claims as mold skin, and is produced by contact of the molten metal with the casting moldwall, as distin uished from a surface produced by machining. Machined surfaces add-to the cost of the production of the mold and; furthermore, usually cut away the surfaceskin so that the metal'exposed' is not as hard; as, that produced where the hot metal comes into direct contactwith the cold wall of the casting mold. More especially, the

particular preferred form of the present invention is one wherein this base surface is a chilled surface. The

mechanical usage.

, roduces hardness conducive to long life of t e mold under hard The metal in the mold is of the most dense structure adjacent the base of the mold and is of lesser dense structure toward the top of the mold, while the most spongy part of the is best adapted to receive the direct and full force of. the stream of molten steel which in-.

itially enters the mold,-without being liable to the cut away under the action of this stream of'hot metal.

In the method of manufacturing this-new mold, in its-preferred form, the mold is cast with the bottom downward.

This places the best metal, when cold, in the bottom of the ingot mold and completely obviates machining the base, because the mold seat is automatically formed during the casting operation. The area comprising the bottom of the matrix is chilled either during casting or later. The area com rising the base of the mold is also prefera ly chilled.

The chilling of the bottom of the matrix is of the specific form herewith disclosed, which is a complete disclosure of the invention as required b the patent statutes. However, realizing t at the invention may be utilized and practiced in other forms, it is to be understood that the disclosure herewith is illustrative and not to be considered in the limitin sense. v S The gure of the-drawin is a vertical sectional view through a mol made in accordance with the present method and invention. Referrin now more specifically to the of the matrix likewise comprises a chill dense drawing w ich illustrates a section through metal as at 28. The most compact, solid and firm metal in the mold is in the bottom por-- tion or zone arbitrarily indicated on the figure in the drawing by means of the lower bracket 29. The next best metal is in the zone arbitrarily indicated by the middle bracket 30; and the metal containing the greatest amount of impurities is in the zone arbitrarily indicated by the upper bracket It is to be understood, of course, that there is no distinct line of demarcation between the zones indicated by the brackets 29, 30 and 31., but that these arbitrary divisions are merely conveniences of ea: ression to set forth the conditions of the metal. in the mold having a structure in accordance with the present invention.

The method of manufacturing the preferred form' of the present mold comprises casting the mold with the bottom matrix 28 downward so that the initial molten metal poured into the casting set-up forms the bottom portion of the ingot mold. Then, as the molten metal rises to form the sides of the mold, the impurities in the molten metal will rise with the molten metal and certain proportions of these impurities will be trapped in the side walls of the mold as the molten metal freezes. However, the greater the amountof molten metal. used in the casting, the greater the percentage of impurities which are floated upwardly through the molten metal and consequently, the upper part of the finished mold will contain the greatest amount of impurities. In the manufacture of the mold in the preferred form, the bottom portion of the matrix preferably is chilled. This chill may be brought about by the introduction of chilling means either during the casting operation or so shortly thereafter as to chill the metal surface at the bottom of the matrix as at 28. Preferably, the base surface of the mold is cast against a forming surface to form a seat for said mold, and preferably, though not necessarily, is chilled by any commonly known method in the art, either during casting or so shortly thereafter that the rapid cooling of the metal will result in chilled metal adjacent this surface when the mold has cooled.

A closed bottom mold in accordance with the present invention has chilled surfaces where the mold is subjected to greatest wear and since these chilled surfaces are adjacent the heaviest mold wall, the strains set up in the ingot mold by the chilling operation are supported by sufficient metal to prevent any tendency of the chilled portions to break down during the use of the mold because of the varying heat conditions to which the mold is subjected while being used to cast steel ingots.

Having thus described my invention, what I claim is:

1. An article of manufacture comprising a cast iron ingot mold having a closed bottom and with the most dense cast iron in the lower portion of the mold adjacent the bottom of the matrix face wall, and with the density of the cast iron decreasing upwardly in such manner that the least dense iron is adjacent the mouth of the mold.

2. An artii'le of manufacture comprising a ca i rcn ingot mold having a closed bottom and with the most dense cast iron in the lower portion of the mold adjacent the bottom of the matrix, the metal adjacent the bottom of the matrix face wall being chilled, and with the density of the cast iron decreasing upwardly in such manner that the least dense iron is adjacent the mouth of the mold.

3. As an article of manufacture, a cast iron ingot mold having a closed bottom and with the metal comprising the bottom of the matrix being chilled cast iron.

A. As an article of manufacture, a closed bottom ingot mold having a smooth chilled base portion, and a smooth chilled surface comprising the face of the bottom of the matrix portion of the mold.

5. As an article of manufacture, a cast iron closed bottom ingot mold having a smooth chilled base portion, and a smooth chilled surface comprising the bottom of the matrix portion of the mold, and with the metal of least solidity and density being adjacent the mouth of the mold.

6. As an article of manufacture, an ingot mold comprising a cast iron body having a substantially closed bottom matrix, the bottom portion of said matrix comprising chilled metal having a close fine grain, and thebase of said mold comprising a smooth portion of chilled mold skin metal.

7. As an article of manufacture, an ingot mold comprising a cast iron body having a substantially closed bottom matrix, the bottom portion of said matrix comprising chilled metal having a close fine grain, and the base of said mold comprising a smooth portion of chilled mold skin metal, the most dense metal being in the bottom portion of said mold.

8. The method of manufacturing a. cast iron closed bottom ingot mold comprising casting the mold with the bottom downward and chilling the cast iron adjacent the bottom of the matrix of the ingot mold.

9. The method of manufacturing a cast iron ingot mold having a closed bottom which method comprises chilling the metal adjacent the bottom walls of the matrix and also chilling the metal adjacent the surface comprising the base of the mold.

10. A method of manufacturing a cast iron closed bottom ingot mold comprising chilling the metal of the walls adjacent the bottom of v the matrix.

11. The method of manufacturing a cast iron closed bottom mold having a stripping opening in the bottom of the mold, comprising casting the mold with the closed bottom downward! matrix wal s rounding the and chillin the bottom of the and also chllling the metal surstripping opening.

JOHN EDMUNDPERRY.

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