US1277543A - Hollow ingot and method of making same. - Google Patents

Description

F. D. CARNEY.

HoLLow INGor AND METHOD oF MAKINGYSAME.

1.9%?7543 APPLICATION yFILED MAR. 23|` |918. 3, 3 SHEETS-SHEET l- N @W w no Q W65 l? @3 2 QH 5 Q f $7 @I 1k w f@ m N i is Q @l fr i r 'T W@ x l Q N QN Q5 9i W w Q l* w s (J1/mudo@ @im @www vo i i 5% @3 M l (mouw,

F. D; CARNEY. n -HOLLDW INGOT AND METHOD 0F MAKING SAME.

Patented Se pt. 3,1918 3 SHEETS-SHEET 2.

APPLICATION FILED MAR. 23. I98.

Gufotue F`. D. CARNEY.

HOLLOW INGOT AND METHOD 0F MAKING SAME. APPLICATION FILED MAfLvzs. |918.

LQ7'543@ v PatentedSept.3,1918.

' tion.

naaien' n. canning, or nncmnnnnn, rnnnsrnvnnra To all 'whom t may concern.'

Be it known that FRANK D. a citizen of the United States, and a resident of Bethlehem, in the countyof Northampton and State of Pennsylvania, U. S. A.

have invented certain new-.and useful Img provements in Hollow Ingots and Methods of Making Same; and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled n the art to which it appertains to make and use the same, being had to the accompanying drawings, and to letters or figures of reference marked thereon,

Heretofore, in the production of the ingots cast in the customary vertical method, it has been dicult to avoid pipe, segregation, surface cracks and other defects; slag inclusions resultingA from reactions in the mold revolving at a high speed on its' hori- A tio'n in the cooling molten metal during solidification and inclusions from accidental additions of foreign matter. llt is also an impossibility to obtain a uniform uniaxis crystalline condition in the ingots, due to the great variarate from the outside surface to the center.

To avoid the above trouble when casting ingots which areto be used for objects with hollow centers; I have cast cylindrical and conical ingots with a uniform cylindrical bore, by pouring the molten steel into the zontal axis, producing, thereby, a centrifugal force inl excessl of the force of gravity.

j l found, for example, in the case of steel when poured or cast directly on the iron or steel surface of an ordinary ingot mold revolving on its horizontal aXis at a speed sufiicient to produce centrifugal force, that it was impossible to make an ingot free from surface defects, strains and cracks. `While the method of horizontal centrifugalcasting is known in general, I believe that I am `the iirstto cast cylindrical and conical ingots of variable dimensions and weight.; in a practical way which are free romtje above enumerated defects. j

My ig. ention overcomes sald defects, and

`is a mfethod of casting hollow, cylindrical and conical ingots free from pipe, internal strains, surface cracks and' the customary internal defects due to segregation and slag inclusions, in a practical way, by casting rapidly under the action of centrifugal speemmion of Letters raam. i

CARNEY, A

reference which form a part of this specifica-l nonnow meorai'tn nmrngon or nanntesans.

force in a suitable machine, one or a plurality of ingots from a single ladle of molten steel; controlling the relative rate of cooling of the interior and exterior surfaces of the ingot; controlling the crystalline structure of the ingot, vand rapidly removing the ingot with the mold from the revolving container thereo In' order to clearly define the mode of procedure, reference will be made to the accompanying drawings, in which like parts are similarly designated, and in which- Figure l is a vertical longitudinal section of a machine such as I usevto produce the ingots referred to.

Fig. -2 is a diagrammatic plan view, and

AFig. 3 an elevation of a plant for centrifugally casting the hollow ingots.

Fig. t is a cross section, and

Fig. 5 is a longitudinal section, partly 4in elevation, of a moditication of the apparatus.

Fig. 6 is an elevation nal section, and

Fig. 7 an end view of a modiiied form of ingot mold, and

Fig. 8 is an elevation, partlygin section, of another form of such mold.

Figs. 9 and 10 are diagrammatic views of the manner of simultaneously casting a plurality of Vhollow ingots.

ln the apparatus 1 is the carrier` or drum of cast metal provided between its ends with a pair 'of tires or the equivalent, 2. Contained within the drum is the ingot mold 3 of sheet metal. This sheet metal mold 3 is held within the carrier or drum l by clamps, andv in the structure shown the clamps 4 at the right hand end, Fig. 1, directly engage one end of the sheet metal mold 3,'while at the other end thereof is an annular, trough shaped spill way 5, of brick, Figs. 1 and 9, or of sheet metal 5, Fig. 10, fitting into the end of the drum 1 and engaged by the clamps 6. f

These clamps are-of well known construction, of angle shape 'and are adjustable longitudinally of the drum in slots therein.

The sheet metal molds 3 are not to make continuous surface contact with the drum 1, and for this purpose they may have any desired projections, either longitudinal corrugations 3a, as in Figs. 4 and 5, or quincunXially arranged rounded bulges or projections 3", Figs. 6 and 7, or more pointed Droiections. as 3, Fig. 8.

partly in longitudi- Patented Sept.. 3, iljl. Y Applicatiton tiled March 23, 1918. Serial No. 224,184.'

n for the insertion of a pulverulent or sandlike insulation of fireproof material between the two concentric membersz "when 1t is desirable to employ such material. i The dimensions of this interspace, as well as the nature of the material included insaid space, whether air, or sand, dolomlte, 89o., controls the rate of solidificatlon, as with some steels it is desirable that solidicationtakes place' quicker than with others.

Several such carrlers or drums 1 with their contained sheet metal molds 3 are stored.

on an inclined track 7, and are temporarily l held by a chock 8.

At the end of the track 7 is located the,

centrifugal casting machine C, shown in detail in Fig. 1, and after the casting of the ingot has been completed in this machine the carrier or drum with the ingot therein is delivered to a second inclined track 8 'having a depression 9 or equivalent means for arresting the travel of the carrier or l drum at a required point, where a suitable plunger dev-ice ,10 removes the ingot fromthe drum.

The carrier 1 with its contained ingot mold rolls down into the centrifugal casting machine, Fig. 1, with its rails or flanges 2 resting between the flanges of four rollers 11. There is sufficient play between the flanges of these rollers 11 and the sides of the flanges 2 on the drum 1 to permit longitudinal reciprocation of the carrier during the rapid rotation of the drum.

The carriers are also provided with auxiliary rails-13,- one near each end of the carrier. Each of these rails 13 is engaged by a pair of holdingldown rollers 14 for holding the drum on t e rollers lland preventing the drum from jumping out of the machine durin the rapid rotation.

Eac air of holding down rollers is mounted 1n a yoke 15 pivoted at 16 and connected at 4'17 to an eccentric rod 18 operatedP by an eccentric 1-9 on a shaft 20. This shaft,

carries both eccentrics 19, set 180. apart for actuating the two yokes 15, one for each end of the drum, as illustrated.

On the shaft 20 is a worm wheel 21 driven by a worm 22 on the shaft 23 of a reversible electric motor 24.

'.On the drum 1, between the two main fianges 2- thereof, is a machined surface 25,

which is capable of being engaged 'by one or theother of twocurved arms 26. .These curved arms 26 are capable of alternate engagement with the surface 25 and are operimams ated by a` reversible electric motor`27. The arms 26 serve a double purpose, to brake the drum, and to lift the drum Jand lts contained ingot out `of the machine onto the second track 8 after the metal has been cast. v One end of the drum is rovided with a series of recesses 28 into w ich engage the pins 29 of the hollow clutch member 30, moved into and out of engagement with the drum by a shifting yoke or ring 31, of any suit-able construction. The shaft 32 of the clutch 30 is hollow and carries a spur gear 33 driven by a driving pinion 34. At the end of the shaft is a rotary blower 35 driven by a belt pulley 36.

After the'drum is in position in the machine, a spout or runner 37 is inserted through one end. The runner is provided with the customary trap 38 into which the ladle discharges the metal. As soon -as the drum has been brought upto speed the metal is poured.

The detailed procedure will be as follows The ingot is made by, first preparing an ingot mold 3 of thin sheet metalywhich may or may not be of the composition o'f the ingot to be formed. Usually it is not of the composition of an ingot, but of a cheaper metal. By using such a mold supported in a mold carrier or drum it is possible to withdraw the ingot, with its weld connected mold immediately after solidification, from the mold carrier. Thisis important, in that not only is the ycarrier released for re-use at 100 once, but also the ingot can be transferred as 4 hot as possible toa furnace, soaking pit, or the equivalent, for controlling the rate of cooling. The ingot molds that I have used are about one-sixteenth of an inch in thickness for hollow ingots of 18 diameter and 3 thickness of wall. The thickness of the wall of the ingot 'mold will vary directly with the size of the ingot, but is preferably very thin, so that in subsequent manipula- 110 tion of the metal the entire ingot mold will be oxidized away.

The ingots with which I have yhad experience are of cylindrical and slightly conical shape, and are rotated at the high speed of about 3500 peripheral feet per minute,

. more or less; the object being that the speed should be high enough to attain a heavy centrifugal force on the metal, sufficient to cause the elimination' ofMsegregation and 120 the slag, gasinclusions, and accidental foreign matter, and to carry them to the surface of the hollow of the ingot.

The ends a of the ingot molds are constructed of the same material as the body of 125 the molds, and are annular for forming the annular. end walls of the ingots; the thickness of the ingot being controlled and meas1 ured by the difference between the external and internal ldiameter of the annulus.v

and carrier to edectually prevent vide between the mold and space to permit thel insertion between the p carrier may be These molds may be cylindrical, but, whatever their general' shape, I prefer to have` them corrugated as'at 3a cal, as in Figs. 4 and 5. The corrugations may be of any desired shape, and may run longitudinally or otherwise of the mold. The mold may also be so' constructed as to provide projections on its outer surface, with the object of having the mold spaced at irregular distances from its carrier, (such carrier being a metal speed drum, with its interior cylindrical or conical, in which the mold is supported and rotated).

'The mold is centrally spaced from the inner surface of this drum, and the intervening space may or may not be lled with an insulating material. rial is preferably ine and of a sand-like character; the object being that the material should have a flow similar to that of sand, in order to facilitate the withdrawal of the ingot and its adhering mold from the carrier, to allow freedom of shrinkage both lon` gitudinally .and transversely,- and at the same time maintain and accommodate insulation between the mold and carrier. At

the fsame time this insulating material will produce sucient friction between the mold any slip between the two during .casting operations;l

While l have described the mold as being spaced from the carrier, there is no objection to having corrugations, indentations or other protruding surfaces on the mold contacting with the carrier -at intervals, as shown at 3b and 3, Figs. (38. Y

'ln lieu of thecstructure just described, the

provided with internal projections or corrugations, or ll may, in some cases, use both corrugationsand projections; or the 4:mold may be provided with longitudinal corrugations 3, and the carrier may be provided with internal circumferential corrugations l", Figs. i and 5, so that the corrugations of the one will cross the corrugations of the other; the object being to procarrier suiiicient mold and carrier of some insulation material, to prevent to'o rapid chilling of the mold and ingot. p

One of the great. .objects attained by such a structure with a thin sheet metal mold (this mold being spaced and insulated with an insulating material) is that the liquid metal never comes into contact with the insulating material; if it did, a slag might be v formed, or impurities due to or contamed inthe insulating material might become incprpprated in the metal, so that the resulting metal obtained in the ingot would not be .absolutely ofthe same purity as the metal introduced therein. For high grade steel, this is a very important consideration.

ln order to facilitate the withdrawal of and slightly-coni-- This insulating matethe ingot and mold from the carrier, especially when very heavy ingots are cast, it is of advantage to make the ingot mold or the carrier, or both, conical, Figs. 4.- Vand 5; that is to say, have an easy drawing taper. The fine sand, having a iiow like sand, greatly facilitates the withdrawal of the ingot when either cylindrical or conical shapes are used.

The ingot mold is held in position in the carrier by, means of adjustable clamps 6; the clamps being adjusted lengthwise of the carrier, so that it is possible with a single carrier to cast ingots any length, less than the length of the carrier.

he carrier is provided at one end, preferably at thev pouring end, with a second annular head 5, spaced so as to provide a metal trough or spill-way for excess metal; the object being that sufficient metal is poured until the operator sees it iiow into the spill-way, by which he determines that `the mold is filled. This metal in the spillway is cropped or removed from the ingot before rolling or forging; or, in lieu of the spill-way formingl a part of the mold itself, I insert right next to the end of the mold a refractory spill-Way 5, Fig. 9, so that when the ingot'is removed from the mold the spill-way metal will separate from it.

When casting several ingots in a single mold` there is provided at distances apart equal to the length of the ingots, annular 'l walls of frangible, refractory material, as of lire brick, Fig. 9; or I insert in the carrier short mold sections 113 spaced apart by lire brick Fig. 10. The fir placed within the mold, as .may be placed in the carrier molds 113.

in operation, the molten metal must be poured into the rapidly rotating mold at a much faster rate than when casting solid ingots; the rate being so great as to prevent solidification starting to any appreciable enteint efore the pouring of the ingot is comu ete p The practice that lf have followed, and which l find especially successful isto pour molten steel into the ingot mold at the rapid rate of four to five thousand pounds per minute. For the same grade of steel in a solid ingot the rate would be from one to two thousand pounds per minute; it being understood that the rates of pouring for different grades of steel vary according to their composition, the temperature and the size and shape ofthe ingot mold. After pouring the metal into the mold and solidiication .is completed, l immediately remove the carrier and its contained ingot and mold from the centrifugal machine, strip the carrier at once from the mold and ingot, and place the' ingot and mold in an insulating materialv soaking pit, or heating furnace, in

in Fig. 9, or it separating short e brick may be izo' Y llt@ titi

With 18 diameter ingots made by'me,`

the peripheral speed is so great that the 'pressure on the metal at the external surface of the ingot is in the neighborhood of 30 pounds per square inch, and the pressure at the internal surface of such an ingot is in the neighborhood of 20 pounds per square inch, the thickness of the ingot walls being about three and `one-half inches. These pressures can be accurately determined from the known speed and diameter of the mold and container. As the diameter of the ingot increases, the peripheral pressure will increase and the speed of rotation may then be appreciably decreased. These pressures are suiiiciently great to force. toward the central inner surface any impurities, slags or gases, that may be in the metal.

Inaddition to the centrifugal' force due to rapid rotation of the ingot, I impart a longitudinal reciprocation, and this longitudinal reciprocation or agitation' assists in rapidly flowing the metal over the entire surface of the mold and prevents the formationof coarse columnar crystals, normal to the surface, as ordinarily found in vertically cast solid ingots.

In order to facilitate rapid solidification,

I inject, by means of blower 35, through the center of the hollow ingot immediately after pouring, a current of air, to aid the solidication of the metal throughout its thickness as rapidly as possible, and also to control the rate of cooling of the ingot, in proportion to the thickness; the rate of cooling being controlled by the volume and pressure of the air supply.

rIhe'rate of solidifioation of the ingot is also controlled by increasing or decreasingy the space between the mold and the carrier, thereby varying the thickness of the insulating material vbetween the mold and the carrier, and, where no solid insulating material is contained between the mold and its carrier, the air trapped between the mold and carrier acts in the-same manner.

The solidification is controlled so as to arrest segregation under the casting conditions and according to the nature ofthe metal being cast.

I claim- 1. The method of casting hollow steel inof the metal throughout' the mold.

2. 'Ihe method of casting hollow ingots, which comprises pouring molten metal into a mold maintained in rotation and longitul dinal reciprocation.

3. The method of casting hollow ingots, which comprises pouringmolten metal into an insulated metal container maintained in rotation sufficient to impart centrifugal action to the metal, and cause said container to become part of the ingot, and immediately removing the ingot with its adherin oontainer. from the rotating device, an then retarding its rate of cooling.

4. The method of casting hollow ingots, which comprises pouring molten metal into a sheet metal container having annular heads that determine the thickness of the ingot while supported on insulating material and maintained in rotation sucient to impart centrifugal action to the metal, whereby said container becomes welded to the ingot.

5. The method of casting hollow ingots, which comprises casting molten metal into a rotating sheet metal container at a temperature welding the metal. and container,

said container being of a thickness suiiicientl Ato oxidize 0H during subsequent manipulation of the metal, and maintaining its speed of rotation sucient to overcome segregation.

6. The method of casting hollow ingots, which comprises casting molten steel into a horizontal rotating thin metal mold hav# ing annular heads, and continuing the pour ing of the metalfuntil the metal in the mold spills through the central orifice at one end. l

`7. The method of casting hollow ingots, which comprises pouring molten steel into a horizontal rotating thin metal mold having annular heads, and continuing the pourin of the metal until said metal spills through the central orifice at one end, and retaining the spilled metal in a compartment ad]acent the end of the mold.

8. The method of casting hollow ingots, which comprises pouring molten steel into a horizontal rotatin thin sheet metal mold having annular hea s; and continuing the pouring of the metal until said metal spills through the central orifice in one of said heads, and retaining the spilled metal in a separate separable -compartment adjacent the end of the ingot.

9. The method of casting hollow ingots, which comprisesy pouring the'molten metal into a horizontal rotating thin metal mold while supporting said mold within a drum,

maratea' and withdrawing the integral ingot and mold as soon as solidied.

10. The method .of casting hollow ingots, which comprises pouring the molten metal into a horizontal, rotating thin metal mold while supporting the mold within a drumi and immediately distributin the metal in the mold, said mold being su 'ciently thin to be'oxidized 0H during subsequentvmanipulation of the hot metal.

11. The-method of casting hollow ingots, which comprises pouring the'molten metal into a rapidly rotating thin sheet metalmold supported within a drum havin heat insulation between it and the said drum, and controlling the rate of solidification of the metal under centrifugal action by the thickness of the said insulating material.

12. The method of casting hollow ingots, which comprises pouring .the molten metal into a horizontal, rapidly rotating, thin sheet metal mold in non-continuous surface contact with a s eed drum, said mold being of sucient thic ess to be oxidized olf in subsequent manipulation of the metal.

13. The method of casting hollow ingots, which comprises pouring the molten metal into a horizontal, rapidly rotating, thin metal mold in non-continuous surface contact with a speed drum; the interior space between said mold and drum containing a heat insulating material.

14. The method of casting hollow ingots, which comprises rapidly pouring the molten metal into rotating thin sheet metal molds in non-continuous surface contact with a speed drum, the interior space between said drum and molds containing a dry, pulverulent, highly refractory, insulating material.

15. The method of casting hollow ingots, which comprises rapidly pouring the molten steel into thin corrugated sheet metal molds supported within a heavy metal drum heat insulated therefrom, and maintained in rapid rotation, removing the hot ingot immediately after solidication with its adhering mold, and controlling the rate of cooling of the ingot.

16. The method of casting hollow ingots, which comprises pouring molten steel into corrugated thin sheet metal ingot moldsA supported within a heavy metal drum heat insulated therefrom and maintained in rapid rotation, removing the hot ingot and its adhering mold immediately after solidification, andL controlling the cooling of the ingot by covering it up with insulating material.

17. The method of casting hollow steel\ ingots, which comprises rapidly pouring.;

molten steel into a sheet metal mold sufficiently thin to oxidize oill in the subsequent treatment of the steel ingot, said mold being rotated at a speed suiiicient to instantly distribute the steel throughout the mold and ,rapid rotation,

Iby external insulation and controlling the character of the steel by controlling the rate of soliditication by a current of air through the Vinterior of the mold and ingot.

18. The method of casting hollow steel ingots, which comprises rapidly pouring molten steel into a sheet metal mold while in controlling the character of the steel by controlling the rate of solidication of the ingot both from the exterior and from the interior.

19. The method of casting hollow steel ingots, which comprises pouring molten steel into a sheet metal mold while in rapidrotation at aspeed suicient to cause an instantaneous distribution of the metal throughout the mold, and controlling the characterof the metal by external insulation of the mold and the pesage of a gaseous medium through the ingot and mold.

2 0. 'lhe method of casting hollow ingots, which comprises pouring molten metal into a rapidly rotating sheet metal mold and controlling the rate of solidification of the ingot internal current of gaseous medium, the temperature of the metal being sufficient to weld to said mold.

21. rlhe method of casting hollow ingots, which comprises pouring molten-metal into a rapidly rotating horizontal ingot mold and imparting a longitudinal reciprocation to said mold while directing a cooling medium into the interior of the ingot.

22. A sheet metal -ingot mold whose exterior surface has elevations and depressions and is in welded-connection with the ingot.

23. rlhe method ingots, which comprises pouring steel into a rotating ingot mold in excess of the quantity required to lill the mold, thereby imparting centrifugal pressure to the metal during' solidication and washing from the of casting hollow steel.

interior of the hollow ingot any impurities V forced to the interior surface by centrifugal action, by the excess pouring operation. v

24.4. rlhe method of making hollow steel ingots, which comprises pouring molten Steel into direct contact'with a rapidly rotating sheet metal mold having transversely arranged annular partitions, and separating the ingots at the partitions.

25. The methd of making hollow ingots, which comprises pouring molten metal into a rapidly rotating sheet metal mold having transversely arranged friable annular partitions, and separating the ingots at the partitions. y

26. The method of making hollow 4steel ingots which comprises pouring molten steel into direct contact with the interior of a sheet metal mold rotating ata speed suitlcient to impart centrifugal force to the steel when poured, separating the metal into ingots by annular partitions, the character of metal' at the end of the the steel being controlled by controlling the time of solidification of the metal by a dry comminuted insulating material.

27. The method of making hollow ingots, Which comprises supporting a corrugated sheet metal mold having annular" heads Within an interiorly corrugated speed drum, corrugations of the mold and drum crossing one another, the interspace between the mold and drum containing a loose insulating material capable of yielding to expansion of the mold, rotating said mold and drum at a Lemme speed .suflicient to impart centrifugaly force to the contents of the mold, and simultaneously longitudinally reciprocating the drum, pouring molten metal into direct v'contact with the interior of the drum until some of the metal spills from the mold, and collecting the spilled metal in a Se arate compartment in the drum adjacent t e mold.

In testimony that I claim the foregoing as my invention I have-signed my name hereto.

FRANK D. ,CARNE

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