US2591858A - Double walled mold for casting long ingots - Google Patents

Description

April 8, 1952 P. OSTENDORF DOUBLE WALLED MOLD FOR CASTING LONG INGOTS Filed April 19, 1949 3 Sheets-Sheet l INVENTOR. 7') 7e April 3, 1952 P. OSTENDORF DOUBLE WALLED MOLD F OR CASTING LONG INGOTS Filed April 19, 1949 3 Sheets-Sheet 2 Fig.

llllll ll 7 INVENTOR EW D P. OSTENDORF DOUBLE WALLED MOLD FOR CASTING LONG INGOTS Filed April 19, 1949 April 8, 1952 3 Sheets-Sheet 3 INVENTOR.

Patented Apr. 8, 1952 'oF'Fic g;

DOUBLE WALLED MoLn FOR CASTING LONG INGOTS Peter Ostendorf, Godesberg, Germany 'Application April 19, 1949, Serial No. 88,356 In Austria May' 3, 1948 a Claims. (Cl. 22- 144) This invention relates to molds forand methods of casting long stringed ingots of light and heavy metals and particularly of steel and steel alloys.

In the production of ingots having any length and consisting of light metals, comparatively ;low moldsareusedwhich are open at the lowerrend. Inefiectingthe known casting process with these molds. .the ingot is immediately lowered into water.

i The use of molds which are provided with water jackets for cooling water are also known for the casting of long stringed light metal ingots.

'When long stringed ingots of steel and other heavymetals are cast, the cooling must be effected to a large extent in the mold itself because thelowering of the ingot into water would, due to its high temperature, cause an explosivelike evaporation of the water. The ordinary molds and the molds provided with cooling jackets which are customarily used for the casting of light metals cannotbe used for the casting of heavy metals due to the relatively high temperatures of up to 1500" C. used. This is due to the fact that these molds are made in one piece and could not stand the extremely high heat stresses which would occurdue to the great difierence existing between the temperature of the mold walls and cooling chamber walls..

One-object 01f this invention is a mold provided with a cooling jacket which may be used for the casting-of long stringed ingots of both light and heavy metals without the foregoing disadvantages. This and still further objects will become apparent from the following description read in conjunction with the drawings in which:

Fig. 1 is a horizontal section of a cast iron mold in accordance with the invention for th casting g1 long stringed ingots having a square cross secion:

Fig. 2 is a section of a part of a cast iron mold in accordance with the invention used for casting ingots having a rectangular cross section:

is a horizontal section of a long stringed ir'igjotflcasting mold in accordance with the invention;1which allows the lowering of the side walls with the casting of the ingot:

Fig. 3:

Fig. 4 is a vertical section of the mold shown in Fig. 5 is a horizontal section of another embodiment of a mold in accordance with the inven tion, and v Figs. 6 and 'l are vertical sections of the mold shown in Fig. 5.

In accordance with the invention,'a mold for the casting of long stringed ingots is constructed with a number of longitudinal walls forminga mold having a polygonal cross section such as a square or rectangular cross section orthe like. A cooling jacket is provided around the mold walls in spaced relation thereto. The mold walls instead of being rigidly connected to the cooling jacket are connected and held in the cooling jacket by means of mating inclined surfaces defined by positioning'guide projections or positioning means positioned on the cooling jacket and on the mold walls. These mating inclinedsurfaces are inclined in a direction toward the) center of the mold'and each inclined surface should be parallel to the resultant of the lateral heat expansion of its nearest adjacent mold walls. These inclined surfaces are'mated in slidingcontact with each other. Thus, each of these projections having the mating inclined surfaces will form a continuing sealing Joint in any position or; the sliding contact, and the walls of the mold will be allowed to expand or contract within the water jacket freely without placing undue stresses on themselves or the jacket. These molds may beused for casting light or heavy long stringed in-" gots, cooling the same by means of acooling jacket and yet avoiding thedetrimental and pro-' hibitive effects of the heat stresses encountered. According to a further embodiment of the invention, the molds in accordance with the invention may be constructed in order to allow a special method of casting long stringed ingots particularly plated ingots. According to this embodiment. the molds are constructed of a substantially rectangular cross section with two opposingwalls slidably moveable together with the bottom in their plane. The mating surfaces of the projec tions are mounted in slidable engagement throughout the entire range of'movement of the walls. This embodiment allows the lowering of the walls while the ingot is being cast with cool-' ing medium flowing through the cooling jacket of the new mold. These moveable walls may be constructed 01' any plating material which will remain combined with the cast ingot.

According to another feature of the new mold. the guide projections or positioning means are provided with one or more channels so that water which penetrates through the sliding jointsjw'ill be collected therein.

When the ingot is cast in the mold in accord assists the plates being lowered. In order to prevent this separation, the walls of the mold to be lowered may be provided with dove-tailed grooves near their edge into which the molten cast metal will enter and hold fast.

In order to effect cooling of the ingot in zones, the cooling chamber may be wholly or partially subdivided by horizontaldividing or guide walls or by several frame'lilre :molds :relatively low in height which can be put one upon another. In the latter case, however, the lateral cover plates and the guide projections or positioning .means should extend over the whole height of the mold. The mold so constructed may have the guide bars or positioning means of the nonemoveable side walls extended beyond the mold.

If the walls of the mold become excessively heated due to cooling water failure or when the metal level is higher than the cooling water level, the difference in expansion of the inner and outer wall-.layers will :have tendency .to .cause the .walls to warp. This is especially true when the mating .surfacesof the guide projections .or positioning means .do not lie close together .so thatgt-hey can follow the warping of the walls. In order to overcome this drawback, the cooling chambers adjacentto the walls may 'he provided with reinforcements running ,parallel to the walls and .at .a small distance therefrom. These reinforcementsashould have the shape .of bars, perforated walls-or the like and should consist preferably of ametal having .a relatively high eoe'fiicient of .expansionsuch as strong .life metal alloys .and the like.

fllnordertdobtain acompletely closed mold .in accordance with the invention, the plates which constitute the side walls of the mold should be firmly and tightly connected to the walls defining .the frontsides ofthemold. Within this mold a piston head is arranged in a known manner so that .a long stringed ingot can be lowered. According to another feature of the invention, the expansion joints between the outward extending walls of the mold-bottom, and .the ad-J'acentcooling chamber walls maybe subdivided as in a steplike fashion in order to form stops and/or vertical outlet channels. The .wallsof the mold bottom and the .outer cooling chamber walls should engage each other in an angular direction extending toward the center of the mold.

Theclosedmold may be used in either .a vertical, inclined .or horizontal position provided that the ifeedinghead is correspondingly built.

In accordance with anotherembodimentoi the inventiomthe joints which run horizontally hetween-the mold proper and the cooling jacket. are defined'by mating adjacent surfaces whichare inclined in the direction of the resultant .of the longitudinal and lateral expansion .of the inner mold. The long stringed ingot .casting mold should have sealing joints defined by the inclined surfaces of the inclined positioning means or guide projections at the 'four vertical edges, the

planes of the surfaces of which will meet :at a.

common perpendicular imaginary line. If the four upper and four lower horizontal surfaces forming the sealingjoints had their planes .extended, .a pyramid would be formed the top of which would lie on the aforementioned perpendicular line.

The invention will be more fully readily un Referring to Fig. 1 of the drawing the inner mold isiormed'by comparatively thin plates I, I

4 which are welded together or are tightly connected by some other means at the vertical inner edges at 2. The outer mold body 3 consists of two parts surrounding the mold I, I and forming cooling chambers 4 through which a cooling medium, preferably water is flowed. The casing 3 has guide projections or positioning means 5 projecting towards the inside; the Zfront edges of the projections defining the sliding surfaces 1 for guide projections 6 which are attached to projecting parts of the two opposite walls I. The plane of the surfaces faces I of the projections '5 and 8 lie parallel to the resultant of the lateral expansion of the casting mold l and I' at its corners. Thus if the mold has a square cross section the .plane of the surfaces 1 and the -wa'lls I or I' have an inclination to each other of about 45. Compressive stresses are thereby completely avoided at the guide surfaces which displace themselves by sliding along one another while exerting a small, more or less constant, surface pressure therebetween.

According .toFigure 2 of the drawing, theinner mold consists of the. plates I and U-sha'pedmlate I which are welded together .at 2. The :outer mold 13 is'closed'at its front .by thecoverifnthe sidesurfaces of which are, according ;to therprinciple already mentioned, :placed .in thedirection of the resultant of the longitudinal and lateral expansion .of :the mold walls. These. surfaces are stepped at .8. The guide projections 6 :are .connected with theprojecting edges "ofthe walls I and the legs of the U-shaped walls TI". In the end walls :of the outer mold 3 :there are.zprovided channels 9 through which cooling water which may enter throughthe sl-idings'urfaces' will run downwards.

The walls I of the mold, a cross section of which is shown in Fig. 3, consist preferably f plating material, and are lowered together with the ingot as it is cast. The plates I andthe guide projections 6 arefastened together with bolts by means of angles II or the like. The projections B are also lowered. 'In order to prevent the plates I from being completely lifted from the ingot, they are provided with dove-tailed groovesl 0. In case plated ingots are to be produced, the plates I may, as already mentioned, consist'of any plating material such as copper, nickel, a high alloyed stainless steel orthe like.

'Fig. 4 illustrates the plates I together-with the guide bars 6 projecting beyond the other parts "of the mold. The mold body 3 is arranged on a corresponding frame 3". The'inner mold, ji. 6.. the mold proper, is closed at its bottom by means of the bottom piece I2 fitting the 'interioriolf the mold, and-which can be lowered by means of the piston rod I3 and the hydraulic piston I4 moving in the cylinder I5. The bottom piece I2 may, however, also be loweredby purely mechanical means, e. -g., by means of a screw spindle, .raicks. fluted roller, or .thelike. The bottom piece 42 carries the "plates I to be loweredjand supporting means It extending downwards, said supporting means having at their lower ends crossflplates I?! to which the guide projections 6 are attached.

When casting is started, the bottom piece is high up in the mold and the wall .plates .I as

well .as the guide bars 6 project from the mold.

at its top. As the casting of the'ingot proceeds. the bottom piece I2 is lowered together with the wall'plates I and the guide bars 6. Whenthe full size of the ingot is attained, the guide me- .jections 6 .are taken off whereas the plates I will remain attached tothe ingot when plated ingots are to be produced.

In case no cooling water is present, the inner I molding walls are liable to warp and in consequence thereof the guide projections 6 will be distorted out of position. In order to prevent this from occurring, the projections 6 are, as shown by way of example in Fig. 1, propped by bars I8, perforated walls, or the like. These bars stiffen the walls and consist preferably of a meta1 which has a relatively high coefficient of expansion (light metal). These bars are placed at a small distance from the walls I. The guide projections can also be made broader and reinforced around the mold I, I' by additional supports I8.

In Figs. 5-7 of the drawings similar parts have the same references as in Figs. 1-4. The projections 5 are so inclined that all planes of surfaces I intersect in a common line AA (Fig. 6 and7) There is no need that this line go through the center of gravity of the whole system and can even lie outside of one of the plates I. In the latter case, one pair of the surfaces I are inclined on an angle whereas the other pair may have a correspondingly greater inclination.

In order to keep the upper and lower. closure of the cooling water chamber 4 tight as shown in Figs. 6 and 7, the planes of sealing surfaces I are inclined so an extension thereof willform the planes P of a pyramid having an apex O which lies on the line AA. In this case, though not necessary, it is advisable that the line AA be the central axis of the whole system in order to attain the same inclination of all the surfaces I'. In ascertaining the inclination of the surfaces I the fact has to be taken into consideration that the projections 6' are heated less than the plates I and I respectively and that they have therefore a relatively smaller expansion. This fact, however, need not be considered to any great extent due to the great height of the surfaces I and I as compared to the height of the projections.

What I claim is:

1. In ingot casting the improvement in molds comprising means defining a number of mold walls defining an inner longitudinally extending mold of polygonal cross section, a cooling jacket around said mold in spaced relation thereto, first positioned means carried by said mold for pcsitioning the same within said cooling jacket and defining a first surface inclined in a direction toward the center of the mold and substantially parallel to the resultant of the lateral heat expansion of the nearest adjacent walls of the mold, second positioning means carried by said jacket and defining a second surface in substantially slidable mating contact with said first surface.

2. Improvement in accordance with claim 1 in which at least one of the mating surfaces is stepped to break the continuity thereof.

3. Improvement inaccordance with claim 1 in which said mold is substantially rectangular in cross-section, in which each one of one pair of opposed walls of said mold is slidably movable in its plane together with the bottom of said mold, in which the mating surfaces of said second positioning means extend throughout the range of sliding movement of said movable walls and in which the mating surfaces of said first positioning means are mounted for slidable engagement with the mating surfaces of said second positioning means in the direction and throughout the range of movement of said movable walls.

4. Improvement in accordance with claim 3 in which at least one of the mating surfaces is stepped to break the continuity thereof, said stepping being dimensioned to define a conduit between said positioning means.

5. Improvement in accordance with claim 1 in which there are additionally provided third positioning means carried by said mold and one at each end thereof and fourth positioning means carried by said jacket and one at each end thereof, and in which said third and fourth positioning means each define mating surfaces in slidable engagement with each other, said last mentioned surfaces extending substantially in the direction of the resultant defined by the lateral and longitudinal heat expansion of said mold.

6. Improvement in accordance with claim 5 in which said third and fourth positioning means substantially define at each end closures for the cooling chamber defined between the jacket and the mold, and in which mating surfaces define slidable sealing joints for each said closure.

7. Improvement in accordance with claim 1 in which said mold is substantially rectangular in cross-section, in which each one of one pair of 0pposing walls of said mold is slidably movable in its plane together with the bottom of said mold, in which themating surfaces of said second positioning means extend throughout the range of sliding movement of said movable walls, in which the mating surfaces of said first positioning means are mounted for slidable engagement with the mating surfaces of said second positioning means in the direction and throughout the range of movement of said movable walls, and in which said movable walls are removable from said mold to form an ingot cladding.

8. Improvement in accordance with claim 7 in which said removable cladding walls are provided with means for securely anchoring the same to a cast ingot.

9. Improvement in accordance with claim 8 in which at least one of the mating surfaces is stepped to break the continuity thereof, said stepping being dimensioned to define a conduit between said positioning means.

PETER OSTENDORF.

REFERENCE CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 59,189 Cornell Oct. 30, 1866 1,385,595 Ranst July 26,1921 1,472,200 Walton Oct. 30, 1923 1,692,550 Goldsmith Nov. 20, 1928 1,936,280 Williams Nov. 21, 1933 1,988,425 Sumey Jan. 15, 1935 2,107,322 Anderson Feb. 8, 1938 2,264,456 Roth -1 Dec. 2, 1941 2,310,893 Brenner Feb. 9, 1943 2,479,191 Williams Aug. 6, 1949 FOREIGN PATENTS Number Country Date 108,184 Australia Aug. 4, 1939 104,075 Sweden Jan. 22, 1942

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