US1888604A - Casting ingots - Google Patents

Description

Nov. 22, 1932. L; N. MCDONALD CASTING INGOT Filed June 5. 1930 jawenfor:

Patented Nov. 22, 1932 UNITED STATES LOUIS N. MCDONALD, 0F YOUNGSTOWN, OHIO CASTING INGOTS Application filed June 5, 1930. Serial No. 459,270.

This invention relates to a method of casting ingots and has for one of its objects the revision of a novel method of casting wherey the heat of the molten metal is retained in the upper end of the ingot and scams and holes in the upper end of the ingot known as piping are prevented. V Heretofore specially formed refractory hot tops have generally been used to retain the heat of the molten metal in the upper ends of ingots, and such articles while maintaining the heat in the top of the ingot are subject to many disadvantages.

The refractory hot tops are very fragile which leads to much breakage in shipment and handling. When refractory hot tops come in contact with the metal during the pouring operation they are apt to crumble, slag, crack or spall, and this results in particles of the hot top being included in the ingot. It is also the general practice to break the refractory hot tops off of the ingot so that they are used but once, making their cost quite a problem.

The present invention provides a novel method whereby all of the above objections are overcome and the expense of using hot tops is materially reduced.

In the drawing:

Figure 1 is a side elevation, partly in section, of the upper end of an ingot mold having the apparatus for carrying out this method applied thereto.

Figure 2 is a top plan view thereof.

Figure 3 is a view similar to Figure 1 but taken at right angles thereto.

Figure 4 is a sectional view showing the form-removed and the filling of granulated refractory in place.

The apparatus for carrying out the novel I method of this invention consists of the ordinary ingot mold 2 in the upper end of which an open ended metal form member 3 is suspended.

The member 3 is of materially less transverse dimensions than the interior dimensions of the ingot mold 2 so as to leave a space 4 surrounding the member when it is centered in the mold. The member 3 is provided with upwardly extending side wall extensions 5 whichhave ears or lugs 6 extending outwardly therefrom and adapted to engage the top edge of the ingot mold 2 to support the member 3 in position within the mold. The side wall extensions 5 are provided with aper 1 tures or openings 7 to receive a crane hook or other lifting element ,to withdraw the member 2 after the ingot is cast.

The inside face or wall of the member 3 I is tapered upwardly and inwardly from its lower to its upper end to facilitate the withdrawal of the member from the upper endor neck of the ingot after the metal has solidified within the form 3.

The outside face or wall-of the member 3 is tapered outwardly and upwardly from its lower end for a very short distance, as at 9, and then is tapered upwardly and inwardly similar to the inside face or wall.

In carrying out the method of this lnven 7 tion the member 3 will be positioned as shown in the upper end of the ingot mold 2 and the molten metalwill be poured into sald mold until it reaches the lower end of the form 3 or to a level slightly above the lower end of, the form 3 but below the upper end of the tapered portion 9. -At this point the pouring of the molten metal will be interrupted for a sufficient length of time for the molten metal to chill or harden around so the lower end of the form 3 to prevent any additional flow ,of metal upwardly between the outside face of the form 3 and the inside face of the mold 2.

After the molten metal has chilled or hardened around the lower'end of the form 3 the pouring of the molten metal will be continued until the form 3 is filled to the desired point. \Vhen the form 3 has been filled the metal will be permitted to chill, harden or set until a shell is formed around the interior of the form 3 of sufiicient thickness to supportthe molten interior of thesink-head or upper end of the ingot. After this shell hasformed, the form 3 will be removed and the space he tween the sink-head or neck A of the ingot B and the .inside of the mold 2 will be filled vitha quantity of granulated refractory 10 whichwill serve to retain the heat in the up- 1 0 per end or neck of the ingot. 0

- top of the sink-head when found necessary Refractory material also will be put on top tween the portion of said ingot cast in saic of the neck or sink-head A in the manner form and the sides of the lngot mold Wlth shown in Figure 4, to further insulate the granulatedrefractory material to prevent the top of the ingot. Obviously, however, the rerapid coohng of the upper portlon of the fractory material may be omitted from on ingot.

or desirable. my hand.

Ordinarily the ingots will be poured short in the way shown in Figure 4. It frequently is found necessary or desirable to increase' the weight of the ingot B to prevent waste when blooms or slabs of definite Weight are to be cut from the rolled ingot.

The increased weight is obtained by adjusting the member 3 vertically within the mold 2 to vary the distance it projects downwardly within the mold.

A convenient way of doing this is by employing blocks 11 between the lower faces of LOUIS N; MoDONALD.

the lugs 6 and upper end of the mold. The thickness of the blocks 11 will vary, as-required, to change the distance the form member extends into the mold and in this way produce an ingot of the desired length and weight.

The refractory material may consist of any standard refractory material, however, good results have been obtained by using waste refractories, such as old fire-brick and other refractory furnace parts which have been crushed to the necessary granular form.

By practicing this method the interior of the upper end of the ingot is maintained in a molten condition a suflicient length of time to prevent the formation of holes (piping) e in the main body of the ingot, which is t function of the prior art hot tops. The prior art hot tops in generabuse, however,

are in the form of prepared refractory forms which are quite expensive and in the ma- I jority of cases are usable with only one cast.

While I have shown and described one specific form of apparatus and a method consisting of a certain sequence of steps as comprising my invention, I. do not wish to be limited thereto since various modifications may be .made without departin from the scope of my invention, as define in the appended claim.

I claim:

The method of casting ingots which includes mserting an upwardly tapering open ended metal form member centrally in the upper end of the ingot mold and spaced from the sides of the mold, pouring the molten metal'through said form and into the mold, stopping the supply of-molten metal when the mold is filled up to a oint slightly above the lower end of said orm to permit the metal to solidify between said form and the mold thencontinuing the pouring of the molten metal until said form is filled, permitting the metal to chill until a skin is formed around the interior of said form, then withdrawing said form and filling the space be- 0 In testimony whereof, I have hereunto set 7

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