US2155283A - Ingot mold - Google Patents

Description

A ril 18, 1939. R. scHus-rEk ET AL INGOT MOLD 2 Sheets-Sheet 1 Filed Nov. 25, 1936 lnventom vV K \vnxxx Asa w 3 QMMO AW/LW/AMV Patented Apr. 18, 1939 INGOT MOLD Roman Schustek and Edmund Pakulla, Krefeld,

Germany, assignors to Deutsche Edelstahlwerke Aktiengesellschaft, Krefeld, Germany, a corporation of Germany Application November 25, 1936, Serial No. 112.642

ermany December 3, 1935 I In G 9 Claims.

Our invention relates to chill molds for simultaneously casting a plurality of ingots.

Chill or ingot molds have already been proposed comprising a hollow partition of a material of. poor'heat conductivity and intended to produce ingots free of pipes. -According to one of the methods hitherto known an ingot mold having a square cross-section is employed and is subdivided into four chambers by a starshaped insert. When using such molds the solidification of the four ingots is, however, unfavorably affected, since they are bordered on two sides by the material of poor heat conductivity. Also inother chill molds with partitions hitherto proposed the wall formed of material of poor heat conductivity which causes an accumulation of heat is very large in proportion to the walls of the chill molds proper.

It has been also proposed to insert in a chill mold four vertical dividing walls extending inward from the walls of the chill mold towards the center of the mold. In this manner four ingots are obtained which in the central portion are connected to one another.. Owing to the improper cooling the pipes, slag and segregations are not only formed in the central portion between the four ingots thus case but also at the edges of the ingots themselves. Furthermore, the ingots thus cast are diflicult to work.

The chill molds of the above-described type and especially the dividing walls arranged therein are also comparatively sensitive.

An object of our invention consists in designing a mold for casting a plurality of ingots in such a manner as to prevent the formation of pipes and segregations in the ingots proper so that the latter present a compact and homogeneous structure.

Another object of our invention consists in causing the formation of pipes and segregations in a portion of the cast body which may be easily separated from the ingot proper so as to reduce the, cutting work hitherto necessary when using multiple molds.

Another object of our invention consists in simplifying the construction of multiple molds having parts arranged therein and in rendering the parts constituting the form resistant to high stresses.

According to our invention a partition of refractory material of poor heat conductivityis arranged in a slab-shaped ingot mold, the insert dividing the mold into a plurality of chambers for the reception of the ingots. has a longitudinal hole communicating with the The insert chambers of the mold through apertures or ports. .The hollow partition is besides placed in the mold in such a manner that the smaller portion of the jacketing surface of the ingots, for instance, only'one side, abuts the insert, whereas the larger portion of the jacket surface, for 5 instance, three sides of, each ingot, contacts with the wall of the chill mold. When casting steel the fused mass contained in the hollow space of the partition remains molten longest owing to the poor heat conductivity of the refractory material. Consequently, the ingots proper may suck in still molten material from the hollow partition during the shrinkage when cooling down. The formation of pipes, therefore, takes place exclusively in that portion of the material which is contained in the hollow partition. After. the ingots have been cooled down there exists only a thin joint between the steel contained in the partition and the ingots so that the ingots may easily be separated from one another. a

Further details of our invention will be apparent from the following description of the embodiments taken in connection with the following drawings, in which a Fig. 1 is a horizontal sectional view taken :on the line I-I of Fig. 2 of an ingot mold with a partition according to our invention;

Fig. 2 is a vertical sectional view of the ingot mold taken on the line 11-11 of Fig. 1;

Fig. 3 is a vertical sectional view taken on the line IIIIII of Fig. 1; I t

Fig. 4 is a vertical sectional view of the upper part of the ingot mold shown in Fig. 2 provided with a particularly designed hood; i

Fig. 5 is a vertical sectional view of the mold shown in Fig. 2 provided with a cone-shaped partition, the partition being shown in elevation;

Fig. 6 is another view of a portion of the partition of Fig. 5, and

Figs. 7 to 9 are horizontal sectional views of other partitions differing in shape.

Referring to Fig. 1, the chill mold I is slabshaped and has three gates 2 for the bottom casting arranged in the bottom thereof. Above the central opening is disposed a partition 3 of a refractory substance having a poor heat conductivity, such as chamotte or other material used for firebrick or the like. In order to properr 1y secure the partition in the mold, recesses 4 are, as will be seen from 1, provided in the walls of the mold into which the partition, is pushed. It has, however, been found that a displacement of the partition when casting does not occur even if the recesses 4 are dispensed with.

The partition extending from the bottom of the ingot mold to the upper edge thereof subdivides the mold into two halves, as shown in Fig. 1. The partition 3 is provided with a central hollow space 5 extending over the entire height of the insert and having any cross-section, preferably a round or oval cross-section. The mold chambers formed by subdividing the ingot mold, communicate with the hollow space of the partition by longitudinal slots 6. These slots are so designed that they extend practically over the entire height of the partition, as shown in Fig. 3. Depending upon the size of the ingot mold one or more subdivisions of the longitudinal slots may be effected. Owing to the use of the partition in a slab-shaped ingot mold according to the invention only a surface of comparatively small dimensions of each part-mold abuts the partition which causes the accumulation of heat.

On the ingot mold is provided a hood I filled up with refractory substance and having arranged therein an aperture above each individual ingot for the formation of a dead head 8, 9. As will be seen from Fig. 2, the hood 1 covers the hollow space 5 of the partition.

In some cases, it may be preferable to extend the hollow space of the partition through the hood as shown in Fig. 4. To this end, an opening corresponding to the cross-section of the hollow space 5 is provided in the rammed mass of the central portion In of the hood I.

In the case of a bottom casting, the molten steel passes through the apertures 2 into each individual ingot half and into the hollow space 5 as well and rises within all spaces in a uniform manner. The mold-is filled approximately up to the upper edge of the hood I. The fused mass freezes from the side walls of the mold I towards the interior. Owing to the poor heat conductivity of the partition 3 and to the quantity of heat taken up by the partition the steel in the hollow I space 5 remains also in the molten state, even if the solidification of the part-ingots is in an advanced state without impairing the solidification of the part-ingots themselves in an undesirable manner which assists the formation of segregations. Blow holes which may sometimes be formed in the part-ingots by shrinkage are filled up by the material flowing continuously through apertures 5 and the space 5.

If the quantity of steel in the hollow space 5 is not suflicient the material will be automatically sucked in from the heads 8 and 9. In cases in which the fused mass of steel contained in the space 5 is not found sufficient the arrangement shown in Fig. 4 is preferably employed in which a greater amount of fused steel is available in view of the lengthening of the space 5..

Since the formation of pipes principally occurs in the upper part of the ingot and, therefore, the required amount of fused material capable of be ing sucked in is greatest in the upper part of the ingot the embodiment shown in Fig; 5 may be particularly employed to advantage. The round or oval cross-section of the hollow space 5 of the partition 3 flares towards the upper end thereof. On the insert is placed a hollow hood stone H projecting from the mold I, whereas the mold is covered by a cast-iron plate 12. When casting,

the mold is filled up approximately up to the upper edge of the hood stone l I.

When top casting, a container with two outlets extending into the part-ingot chambers is preferably employed, in order to ensure a uniform rising of the fused mass within both spaces. The space 5 is filled up automatically through the longitudinal apertures 6. the solidification do not differ from those when bottom casting.

In ingot molds according to the invention all kinds of steel containing a low and high percentage of carbon as well as low and high quality alloy steels may be cast to advantage and particularly also such steels which are subjected to a considerable shrinkage, such as, for instance, highly alloyed tool steels. In all cases steel ingots free of pipes and segregations having a compact. and homogeneous structure are obtained. The pipe is formed only in that portion of the material which is contained in the space 5. This core which also contains the segregations and is associated with the ingots only by the material filling up the slots 6 may be easily removed by pressing, hammering, breaking or the like, so that the part-ingots may be obtained without sawing, autogeneous fusing or similar time-absorbing operations in such a shape as to permit afurther working of the same. Only the hoods must be removed as is usually the case with the majority of ingots. -In the embodiment shown in Fig. 5 also this operation is eliminated, since the hood is only associated with the core and. is removed with the latter from the ingots.

The partitions 3 may consist of one or more pieces, preferably of two pieces, as shown in Figs. 2, 3 and 5. The design of the parts for a simple assembly thereof is shown in Fig. 6. The width of the slots 6 must be so adjusted as to always permit the passage of sufficient fused material into the part-ingot chambers. Greater widths than about one fourth of the width of the surface of the ingot side facing the partition are not necessary. On the contrary, it has been found that the results are the better, the smaller the slots 6. However, it must be observed in consideration of the freezing conditions of the material in question that a partial solidification may occurin some cases in the slots which prevents the flowing of the fused mass in the case of the slots having too small a width.

Particularly, as far as the removal of the core is concerned shapes of the slots have proved advantageous which have not throughout the same internal width as shown in Fig. 7 but are tapered in the direction towards the part-ingots as'shown in Fig- 1.

Besides split ingot molds according to Figs. 1 to 5 others consisting of a plurality of pieces, for instance, three or four pieces may also be employed according to the invention. Inserts for molds of three or four pieces are shown in Fig. 8 and 9 respectively. The mold is so designed that 'the part-ingots are substantially slab-shaped and lie with their axis in the direction of the slots 6. In the central portion of the star thus formed is arranged the hollow partition.

We claim as our invention:

1. In combination with a chill mold of rectangular cross-section for casting solid, slabshaped ingots, a partition of refractory material of poor heat conductivity, said partition being inserted in said mold so as to divide it into two individual chambers and having an internal hollow space provided with a-gate and with openings forming a communication between said hollow space and each of said chambers, said mold and said partition being so shaped that the portion 71' The processes during of the wall surface of each of said chambers which is. formed by said partition is smaller than the surface portion formed by the mold itself.

2. A mold for casting solid; slab-shaped ingots,

comprising a metallic container having at least two vertically extending ingot chambers, and a hollow partition of refractory materialof poor heat conductivity disposed between said chambers so as toform only onev of the four longii0 tudinal walls of each chamber, the other three walls of each chamber being formed by said metallicv container, said partition having lateral openings connecting the interior space of the partition with said chambers for the passage of s the molten metal. I A

3. A mold for casting 88 formed by said metallic container,- said partition having longitudinal slots forming a communica-' tion between the interior space of said partition and each of said chambers, said slots having a width of at most 3 of the width of said wall so formed by said partition.

4. In combination with a mold for casting ingots, a partition consisting of a non-metallic material of poor heat conductivity vertically 1 dividing the mold into a plurality of individual 35 chambers each designed for producing one ingot of substantially r ngular cross'section, said partition forming only one of the four longitudinal wall surfaces of each of said chambers and having a central hollow space and lateral slots 0 connecting said hollow space with each of said chambers, said slots being tapered from said hollow space of said partition to said chambers.

5. In combination with a mold for casting ingots, a hollow partition of refractory material of poor heat conductivity vertically dividing the mold into a plurality of individual chambers each for one ingot, the portionof the wall surface of each chamber formed of said partition .being smaller than the portion of the wall surface a formed of the mold itself, the'hollow space'of' chambers said partition communicating with the solid, slab-shaped ingots, comprising a metallic container having a\piuother, a hollow partition disposed longitudinally between said chambersand forming a longitudin'al wall portion of each chamber, the greater w part of the longitudinal wall being formed by said container,'said partition having slots forming a communication between the interior of the partition and each of said chambers, and guiding means forming an integral part of said container for securing said partition in its position.

7. A mold for casting solid ingots, comprising an iron container 'ofsubstantimly rectangular cross section having longitudinal recesses in two opposite inner walls near the center portion of go said walls, and ahollow partition of non-metallic material of poor heat conductivity longitudinally.

dividing said container into two individual chambers, said partition being detachably mounted in said recesses and having lateral openings connecting its hollowwith said two chambers.

8. A mold for casting solid ingots, comprising an iron container having a plurality of vertically extending ingot chambers of substantially rectangular cross section, and a hollow non-metallic go partition of poor heat conductivity forming, the feeder of the mold and being arranged between said chambers so as to form at most one of the four longitudinal walls of each chamber, said partition having lateral outlets into said cham bers, and a hood for the formation of dead heads arranged so as to cover said container and said partition.

9. A mold for casting a plurality of ingots, comprising an iron container having a plurality 4g of vertical chambers of substantially rectangular cross section, and a non-metallic partition of poor heat conductivity detachably moimted in said container between said chambers so as to form at most Y of the longitudinal wall surface of each chamber, said partition having a funnelshaped hollow tapering in. the downward direction and slots forming communications between said hollow and said chambers.

EDMUND PAKUILA.

Images