DE2060129A1 - Method and device for the production of blocks with increasing cast - Google Patents

Description

Patent attorney

Karl A. Brose

Dif ,! -Ing.

D-8C23 /V.rchcn - Pullach
V.'i;: ic ;;: r.:,T.?*in.79;0570,7'9317"82

DBr / Fo. Munich-Pullach, December 4, 1970

7008 & GEB.

THE BRITISH IRON AND STEEL RESEARCH ASSOCIATION, 24 Buckingham Gate, London S.W. 1, England

Method and device for manufacturing of blocks with increasing cast

When casting blocks using the top casting process, in which metal is poured into the casting mold from above, you can Splashes occur on the side walls of the mold. The metal splashes harden quickly, causing the surfaces of the block have flaws. To this and others To avoid disadvantages, it is known to use the method with increasing casting, in which individual blocks or Groups of blocks are poured by pulling the metal from the ladle through a system of channels that connects to the lower ends the casting mold or the casting molds is connected to pour. A disadvantage of the casting process with increasing cast it is that metal in the upright casting stock and the transverse channel or transverse channels that form the channel system, remains behind and has to be scrapped. When casting a single block, the resulting loss of the output can be up to 5%.

Furthermore, in the known processes, the casting increases in comparison with the processes with top casting additional watering cans through the refractory lining

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materials for the sewer system that will not be reused can be, through additional equipment and additional work required for assembly.

The invention has set itself the task of eliminating these and other disadvantages of known methods for increasing casting avoid bringing molten metal into an upright Casting stick is poured, which forms part of a pouring channel system that connects to the lower end of a block mold connected is. This object is achieved according to the invention solved in that the metal is first poured into the upright casting stock in order to get into the mold and then a pressurized medium is applied to the metal in the casting block by at least part of the meballs remaining in the pouring channel system to displace into the form. This leads to a saving in molten metal.

Another object of the invention is a device for casting with rising cast with an upright pouring stick and a base plate with a transverse channel arranged therein, the casting block and the base channel being a pouring system form, which is arranged such that, during operation, the molten metal is poured into the casting block can be in order to flow through the transverse channel into a casting mold standing on the base plate, which is particularly through Devices is characterized to seal the channel system, creating a pressurized medium when Operation can be applied to the metal located in the upright casting stock to at least one To displace part of the metal remaining in the channel system into the casting mold.

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An advantage of the invention is that the upright Casting stick, after it has been completely emptied of molten metal, can be used again and thus the Material and labor costs are reduced.

In the method according to the invention, there is initially so much Metal poured into the upright pouring stick that the mold is filled to a height that is smaller is than the desired height, and then subsequently the desired height by applying the pressurized Medium is reached. Preferably, the increased pressure of the medium is maintained for a period of time that it allows the metal to solidify enough to prevent it from being removed from the mold after depressurization flows out.

The pressure can be controlled in any convenient manner to ensure that the molten metal reaches the desired height in the mold. To this Purpose is in a process of applying pressurized gas until bubbles appear on the surface of the escape from the melt in the mold.

The upright pouring stick or pouring trumpet in known There is devices for casting with ascending casting usually made of refractory hollow components enclosed in a trumpet shaped casting or castings are. However, this arrangement is not pressure-tight and consequently the device for sealing exists of the channel system preferably from a pressure pipe of any desired cross-section, which is suitable for the upright To surround the casting stock and to be able to connect it to the base plate in a pressure-tight manner. Continue to show

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the devices for sealing the channel system preferably have a cover that is pressure-tight at the top of the Pressure pipe can be connected after the metal has been poured into the upright casting block, the lid having an inlet through which the pressurized medium is applied to the melt can be.

In known devices, the transverse channel runs horizontally and is formed by a channel in the base plate, which is lined with refractory material. The base plate is expediently formed by a base plate, in which the channel is formed, which is covered by a top plate. With such an arrangement it is difficult to displace the molten metal remaining in the transverse channel and to overcome this difficulty, In one embodiment of the invention, the transverse channel is inclined with respect to the horizontal one and extends down away from the upright pouring stick. If pressurized medium is now applied, can the molten metal in the upright pouring stock and the larger part of the transverse channel are displaced without that the medium penetrates into the mold.

In another embodiment of the invention, the transverse channel has near the end that communicates with the mold stands, an elbow, wherein the elbow is shaped such that introduced into the upright support under Pressurized medium can penetrate into the channel and displace molten metal from the part of the transverse channel between the bend and the upright casting block without the medium entering the casting mold

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penetrates. In this way, the greater part of the transverse channel be arranged horizontally whatever from the point of view is more useful in the manufacture of floor slabs.

The casting mold used can be of the bottle type with a thermally conductive stopper to form a gas-permeable one Be closure of the top of the mold. When using such a mold, the application of the pressurized medium serve to ensure the contact of the melt in the mold with the stopper. For this purpose, the form is first filled to a level below the stopper, so that only by applying the under The pressure of the medium makes contact with the stopper will be produced. Alternatively, enough metal can first be introduced into the mold to ensure that there is contact between Melt and stopper manufacture and then the pressurized medium is applied to add more metal to the To displace the casting mold in order to compensate for the shrinkage that occurs when the metal hardens. In both cases If the pressurized medium were not applied, a thin layer of solidified metal would form initially form in the point of contact with the plug. That thin skin would then be pulled away from the stopper and one Leave the air gap open and when this occurs the Effectiveness of the plug in terms of heat dissipation is largely reduced. The solidification of the metal would continue whereby the liquid metal would lose contact with the solid skin (because of the decrease in volume which the transformation accompanied by liquid in solid phase) and there would be another skin on top of the remaining melt because of the Form heat losses through radiation and conduction towards the initial skin. After that it sinks

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the level of the liquid phase continues and this process repeats until the solidification of the block is complete, resulting in a block of which only a thin one Skin encloses a primary cavity in between. The application of pressurized medium extends the Contact of the initially formed skin with the plug and further prevents the contraction of the liquid metal away from the solidifying skin over time until solidification in the channel device is complete. That The overall result is that voids of a solid skin are more essential Thickness are enclosed that persists during rolling. Using either method has the additional advantage that undesired open primary cavities in the upper part of the block are avoided can.

Using any of the techniques described, the Cross-section of the upright casting stock can be enlarged without further material losses occurring. While When filling the casting block, air pockets inevitably occur, which create turbulence during the filling process Generate casting molds that lead to imperfections in the surface of the cast block. Such inclusions are caused by Reduced enlargement of the casting trumpet diameter, with the known casting processes as a result of the scrap losses would be proportionally enlarged by the casting bones.

In the drawings, embodiments of the invention are preferably illustrated by way of example. It shows:

Fig. 1 shows a cross section through a device for pouring with increasing pouring;

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Fig. 2 shows a detail of a modification of the device of Fig.

1;

FIG. 3 shows a detail of a further modification of the device of FIG Figure 1;

Fig. 4 is a cross section through a

further device for pouring with increasing pouring.

Referring to Figure 1, there is illustrated a conventional inclined casting apparatus which has been modified in accordance with the invention. The casting mold 1 with a hot hood 2 stands on a base plate 3, which consists of a lower plate M and an upper plate 5. A pouring channel system 6 is connected to the upper end of the casting mold 1.

The pouring channel system 6 is formed by an upright pouring stock 7 and a transverse channel 8. The cross channel 8 consists of a channel formed in the lower plate 4, which is covered by the top plate 5. The cross channel 8 is lined with refractory material 9. The transverse channel 8 is lined with refractory material 9. The upright one The casting stock consists of sleeves 27 made of refractory material, but according to the invention is pressure-tight Enclosed metal tube 10, which is connected in a pressure-tight manner to the top plate 5 of the base plate 3 by means of screw bolts 11 is. The space between the casting stock 7 and the drill 10 is filled with fillers 28 such as chamotte stone, sand or filled corresponding molding material, although this is not necessary. The top plate 5 has an opening 12, which is in connection with the transverse channel 8, so that when loading

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drove the molten metal into the upright pouring rod 7 can be poured into the on the Base plate 3 standing mold to flow.

At the top of the upright pouring stick is a lid 13 arranged, which can be pressure-tightly connected to the upper end of the pressure pipe 10 after the metal was poured into the upright pouring stock 7. Of the Lid 13 is hinged at 14- and has a Closure device 15 to put it in a sealed position to hold on. The sealing of the cover 13 with respect to the pipe 10 is carried out by means of metal, rubber, asbestos and fire-proof Cement seals or other sealing parts 19 · In the cover 13 a passage 16 is formed, which at a pressurized gas line 17 is connected to under pressure direct standing gas to the top of the upright pouring rod. At the top of the cover 13 is to display the Pressure in the upright pouring stock 7 a measuring device or manometer 18 arranged.

During operation, with the lid 13i open, first of all melted material Metal poured into the upright casting stock 7 in order to get into the casting mold 1 up to this the level of the melt is reached, which is indicated by the dash-dotted line Lines A-A in Figure 1 is indicated. When using warm hoods, the usual mixtures of substances can be applied normally the upper end of the block and also preferably the upper end of the upright casting stick 7 be fed to maintain a surface of liquid metal.

Then the cover 13 is closed and sealed with respect to the pipe 10 and it is via the gas line

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17 on the metal in the upright pouring stock 7 below Pressurized gas applied to at least part of the metal remaining in the runner system into the To displace the casting mold 1 in order to mix there with the metal located in the casting mold 1. The pressure will amplified until the liquid level of the melt in the upright pouring stock the level B-B (Fig. 1) and the Liquid level in the mold reaches the desired height C-C. The gas pressure is indicated by the pressure gauge 18 and must be sufficient to push the melt level down to level B-B, but not past B-B, if Gas should not penetrate into the transverse channel 8 and the cast block. E.g. is if the difference between A-A and B-B is 53 inches in height, a gas pressure of one Atmospheric overpressure necessary to push the metal level down from A-A to B-B. This pressure will be sufficient Maintained size for a period of time that allows the metal located in the transverse channel 8 completely stiffens. E.g. four to five minutes may be necessary for a sewer system with a clear width of two inches be.

The DruckrohriO and the cover 13 must with respect to the base plate or the pressure pipe 10 must be locked sufficiently to withstand the pressures that occur.

When using the method just described, only the metal remaining in the transverse channel 8 must be scrapped.

FIG. 2 illustrates a modification of that illustrated in FIG Device in which the transverse channel 19 against

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the horizontal is inclined and raised from the bottom of the upright Casting stock 7 extends downward away. In the device modified in this way, the melt level be lowered in the channel system to the level D-D after application of the pressurized gas, without the pressurized gas } enters the block. In this way only a small amount of metal remains in the which must be scrapped Transverse channel 19

In Figure 3, an alternative modification of the device illustrated in Figure 1 is illustrated, the opposite the device illustrated in Figure 2 has the advantage that the transverse channel over most of its Length runs horizontally. The sub-plate 4- and the Top plate 5 are when using a horizontal channel Easier to manufacture than when using the illustrated in Figure 2 obliquely downward transverse. channel. The lower plate 4 and the upper plate 5 have a Recess 21 which receives a block 22 of refractory material, in which a bore 23, which is part of the Forms transverse channel, is arranged. The bore 23 has a bend which is shaped such that, if pressurized medium into the upright pouring stick is initiated, the level of the melt can be lowered to the level E-E without gas entering the block entry. In this way, the molten metal from the part of the transverse channel 20 between the manifold and the upright casting stock 7 are displaced.

Instead of using the pressure gauge 18, an alternative method of controlling the pressure of the upright pouring stock 7 of each of those illustrated in Figures 1-3 is an alternative method Device supplied gas, sufficient pressure

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add until gas bubbles on the surface of the liquid Metal can be perceived exiting in the casting mold 1. This then indicates that the sewer system has been emptied and the pressure is then simply maintained at this value until a skin has solidified at the bottom of the mold, which is sufficient to seal the channel system against the casting mold

In FIG. 4, one is generally that illustrated in FIG Device-like device, however, using a quasi-closed casting mold 24 of the bottle type beveled shoulders 25 illustrated. The casting mold 24 has a thermally conductive plug 29, for example made of cast iron, the one gas-permeable closure with the opening 26 in the Forms the head of the mold 24.

The casting mold 24 is filled as previously described, until the liquid level of the melt in the casting mold 24 and in the upright casting stock 7 at the level F-F (FIG. 4) a little below the opening 26 in the head of the casting mold 24. The height F-F is determined in such a way that the remaining, unfilled volume of the casting mold is slightly smaller than the volume that is then made from the metal displaced in the sewer system is ingested.

Then the stopper 29 is inserted into the opening 26 and the cover 13 is attached to the top of the pressure pipe 10. Afterward gas pressure is applied so that the channel system is emptied and the liquid metal is displaced into the casting mold 24 until the metal comes into contact with the plug 29 and shoulders 25 of the mold. The plug 29 acts as a The cooling element and the metal in contact with the plug solidify. Since by means of the gas pressure the fluid

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sige metal in contact with that of the plug 29 and the beveled shoulders 25 of the mold solidifying Metal is maintained, a thick solidified zone then extends from the plug 29. The benefit This method is that the open or closed primary cavities, which are normally in a Block would form without a hot hood, enclosed as secondary cavities in a solidified skin of sufficient thickness will.

It is not necessary that the initially poured metal only reach height F-F. Likewise, initially the metal can be poured until it contacts the plug 29, and then the pressurized can subsequently Medium can only be applied to the upright casting stick to add more metal to the casting mold displace to compensate for the shrinkage that occurs when the metal hardens in the casting mold.

In any of the described embodiments of the invention the emptied upright casting stock can be removed by unscrewing the bolts 11 and reused several times will.

The device illustrated in FIG. 4 has several Cross channels 8 so that several blocks can be cast at the same time and it is obvious that the in the device illustrated in FIGS. 1 to J in the same way can be designed to cast multiple blocks at the same time.

All technical details recognizable in the description and shown in the drawings are for the Invention of importance.

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Claims (12)

PATENT CLAIMS 1. A method of rising casting, in which molten metal is poured into an upright pouring stick, the forms part of a sprue system with the lower end a block casting mold is connected, characterized in that the metal is first to be in the mold (1, 24) is poured into the upright casting stock (7), and then a pressurized medium is applied to the metal located in the casting block (7) in order to reduce at least part of the metal in the casting channel system (6) to displace remaining metal in the form (1, 24). 2. The method according to claim 1, characterized in that first so much metal is poured into the upright casting stock (7) that the mold (1, 24) up to a height is filled, which is smaller than the desired height and then the desired height by applying the under Pressure standing medium is achieved. 3. The method according to claim 1 and 2, characterized in that the increased pressure of the medium is maintained for a period of time which enables the metal to solidify enough to prevent it from being removed from the mold (1, 24) after the pressure has been relieved. flows out. 4. The method according to one or more of the preceding claims, characterized in that the otehende under pressure medium is a gas solder, and is applied until bubbles on the surface of the ¹ occur in the mold (1, 24) melt located. 10 9 8 2 5/1368 2 O 6 U 1 2 υ 5. The method according to one or more of claims 1 to 3, characterized in that the mold (24) of the bottle type with a thermally conductive stopper (29) for training a non-gas-tight closure of the upper end of the casting mold (24), and the pressurized medium is such is applied that the melt in the mold (24) comes into contact with the plug (29). 6. The method according to one or more of claims 1 to 3, characterized in that the casting mold (24) is of the bottle type with a thermally conductive plug (29) for forming a non-gas-tight seal of the upper end of the Casting mold (24) is, and first enough metal is introduced into the mold (24) to ensure contact between the melt and stopper (29), and then the pressurized medium is applied to reduce the shrinkage that occurs during Hardening of the metal occurs to compensate. 7. Device for performing the method according to one or more of claims 1 to 6 with an upright Casting stock and a base plate with a transverse channel arranged therein, the casting stock and the bottom channel being a Form the pouring system which is arranged such that the molten metal is poured into the pouring block during operation can be to flow into the mold standing on the bottom plate, characterized in that a sealed The pouring channel system (6) is provided, by means of which the unpressurized medium is transferred to that in the upright Cast iron (7) located metal can be applied to at least part of the remaining in the channel system (6) To displace metal in the mold. ORIGINAL INSPECTED 109825/1368 -W (IIIBI "IfP (FW Wf ·· um II-BIPHIIHI in ι,. ,, 8. Apparatus according to claim 7i, characterized in that the sealed duct system comprises a pressure pipe (10) of any desired cross-section suitable for the upright pouring stick (7) to surround, with the pipe (10) can be connected to the base plate (5) in a pressure-tight manner. 9 «Device according to claim 8, characterized in that the sealed channel system includes a lid (13) which is designed to be pressure-tight at the top the pressure pipe (10) is arranged after pouring the metal into the upright casting block (7), and the one inlet (16) has, through which the pressurized medium is applied to the melt. 10. Device according to one or more of claims 7 to 9, characterized in that a transverse channel (19) to the horizontal is inclined and extends downward from the bottom of the upright pouring rod (7). 11. The device according to one or more of claims 7 to 9, characterized in that the transverse channel (20) according to his with the mold (1) connected end has a bend (23) which is formed such that the in the upright casting stock (7) introduced pressurized medium metal / from the between the casting stock (7) and the Elbow (23) lying part of the transverse channel (20) is displaced without penetrating into the mold (1). 12. The device according to one or more of claims 7 to 11 ,, characterized in that a mold (24) of the bottle type on a thermally conductive plug (29) for producing a non-gas-tight seal at the top of the Casting mold (24) is used. 109825/136 8 Le e rs et te