EP0035958B1 - Mold for continuous casting - Google Patents

Mold for continuous casting Download PDF

Info

Publication number
EP0035958B1
EP0035958B1 EP81710011A EP81710011A EP0035958B1 EP 0035958 B1 EP0035958 B1 EP 0035958B1 EP 81710011 A EP81710011 A EP 81710011A EP 81710011 A EP81710011 A EP 81710011A EP 0035958 B1 EP0035958 B1 EP 0035958B1
Authority
EP
European Patent Office
Prior art keywords
hot
wall
continuous
compressed gas
casting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81710011A
Other languages
German (de)
French (fr)
Other versions
EP0035958A2 (en
EP0035958A3 (en
Inventor
Siegfried Prof. Dr.Ing. Engler
Herbert Dipl.-Ing. Woithe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vereinigte Aluminium Werke AG
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to AT81710011T priority Critical patent/ATE8467T1/en
Publication of EP0035958A2 publication Critical patent/EP0035958A2/en
Publication of EP0035958A3 publication Critical patent/EP0035958A3/en
Application granted granted Critical
Publication of EP0035958B1 publication Critical patent/EP0035958B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/0401—Moulds provided with a feed head
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/049—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for direct chill casting, e.g. electromagnetic casting

Definitions

  • the invention relates to a continuous casting mold, with a gas-permeable wall through which compressed gas emerges in the lateral direction in the direction of the melt, and with a hot head arranged above the gas-permeable wall, the wall of which is offset inwards relative to the gas-permeable wall and the lower region of which is a hot head overhang forms.
  • the continuous casting mold has a hot head overhang.
  • the mold wall is cooled.
  • the hot head with its overhang is movable in the direction of the mold axis and has the shape of a sleeve in order to be able to change the axial length of the mold wall which comes into contact with the liquid metal during the casting process, without the amount of the melt in the continuous casting mold being changed got to.
  • the melt therefore comes into contact with the mold wall.
  • the compressed gas which is partially introduced from above into a gap formed between the hot head overhang or the sleeve on the one hand and the positively cooled mold wall on the other hand, is used to control the melt level.
  • the continuous casting mold known from FR-A-2 090 111 also has a force-cooled mold wall without a hot head, which is known to always consist of a material of particularly low thermal conductivity, such as fireclay, asbestos or the like. Rather, the inner mold wall is provided with a coating of gas-forming plastic that is about 5 mm thick at the start of a casting process. A pressure gas cushion built up by an evaporation-like process is intended to prevent contact between the melt or the solidifying metal and the coated mold wall.
  • this embodiment has the disadvantage that with increasing wear of the Teflon layer during a casting process, the diameter of the strand becomes ever larger. Precise casting of the strand is therefore impossible. An uneven cast strand cross section is inevitably obtained.
  • the quantity of compressed gas that can be achieved in this way is also very limited, so that in practice the contact between the melt and the mold wall cannot be prevented with certainty because the pressure of the gas cushion is too low.
  • a continuous casting mold of the type mentioned at the outset is to be designed such that the hot head is connected to the gas-permeable wall and that the wall is arranged free of liquid cooling acting as primary cooling.
  • holder parts which serve to support the hot head and / or the gas-permeable wall, can intervene between the hot head and the wall, provided that they no longer come into contact with the melt during the ongoing casting operation.
  • the known radial heat flow from the inside to the outside - in particular caused by a primary cooling by means of a water-cooled mold wall and by direct contact between the melt and the mold wall - is largely prevented. This reduces the growth of the outer shells.
  • the invention also includes some constructive configurations of the continuous casting mold according to subclaims 2 to 6.
  • the invention also extends to a production method according to claim 7 which is suitable for the operation of the described casting mold.
  • the continuous casting mold shown in FIG. 1 has an outer jacket part 11 and an insert part 12. Together with a bottom part 13 and a wall part 14, these form an annular space 15 which is closed in the circumferential direction and in which the water required for cooling is contained. Between the insert part 12, on the one hand, and the base part 13 and the wall part 14, on the other hand, a ring-shaped channel 16 is formed, through which water is distributed over the circumference of a casting strand 17 to the outer peripheral surface thereof.
  • the wall part 14 ensures a uniform supply of the water fed into the annular space 15 at any point over the circumference.
  • the mold has a hot head 18 made of heat-insulating material, which among other things also serves to prevent the liquid melt introduced into the mold from cooling.
  • the hot head 18 has an inwardly projecting wall 19 in contact with the melt, which at its deepest point merges into an obliquely upward and inclined underside 20.
  • a porous wall 21 adjoins the wall 19 offset to the outside. The part of the hot head 18 protruding inwards from this represents the hot head overhang 22.
  • an annular space 23 is formed by the insert part 12, the hot head 18 and by the wall 21 itself, to which gas flows via at least one channel 24 is fed under pressure.
  • the supply can alternatively also take place wholly or partly via cavities which are formed here in the form of a network 25 in the hot head 18 and in which heat can be exchanged between the gas and the hot head 18. If necessary, the mold and in particular its area formed by the hot head 18 can be additionally heated, for example by means of an electrical heater (not shown here).
  • a solidification front designated by reference number 27 runs between the liquid melt, which is designated here by reference number 26, and the casting strand 17, which is made of solidified material.
  • the casting strand 17 is lowered in accordance with the progress of the solidification, with new melt 26 being added at the same time.
  • the gas supplied to the annular space 23 has a temperature which corresponds approximately to the liquidus temperature and is therefore only slightly lower than the temperature of the supplied melt 26.
  • the pressure and the quantity of gas supplied in the annular space 23 are such that the gas pressure in the compressed gas cushion is approximately that The sum of the atmospheric pressure and the metallostatic pressure of the melt 26 in the region of the wall 21 corresponds.
  • the pressure gas emerging from this can make contact between the wall 21 and the part of the underside 20 of the hot head 18 adjoining it, on the one hand, and the oxide skin on the outside of the casting strand 17 and in the region of the not yet solidified melt 26, on the other hand, by forming a corresponding pressure gas cushion prevent.
  • Heat dissipation in the radial direction to the outside is prevented by the temperature of the gas.
  • the solidification front 27 therefore also has a relatively flat course in the outer region, which shows that the edge-shell effect otherwise caused by primary cooling is not or at least barely present.
  • the gas can only escape downward, since the lowest point of the wall 19 is lower than the highest point of the cross-sectional part of the melt located below the hot head overhang 22.
  • the embodiment shown in FIG. 2 contains only a differently designed hot head 28 with a lateral wall 29 protruding into the melt 26.
  • a downwardly open annular recess 30 of approximately U-shaped cross section forms the underside of the hot head overhang 31.
  • the supply of the heated and pressurized gas takes place through one or more channels 32.
  • the lowest point of the wall 29 is below the highest point in the area of the recess 30 sensitive cross-sectional area of the melt 26.
  • the lower area of the hot head 28 is designed as a porous wall 37, behind which there is an annular space 38. Channels 39 open into these, through which heated compressed gas can be supplied, as can channels 32.
  • the gas supplied can only escape downwards along the outside of the casting strand 17 and cannot escape upwards along the wall 29.
  • FIG. 3 shows a further embodiment only for a hot head 33, the hot head overhang 34 of which now has an obliquely downward nose from which the wall 35 projecting into the melt 26 extends upwards.
  • a portion of the heated and pressurized gas is supplied via channels 36 on the underside of the hot head overhang 34.
  • the lower region of the hot head 33 is also designed as a porous wall 40, behind which an annular space 41 is located.
  • the hot head is stationary, because a movable arrangement of the same does not bring any advantages in terms of casting technology and would only increase the technical outlay.
  • the method proposed by the invention can be used advantageously not only for the continuous casting of aluminum and aluminum alloys, but generally for non-ferrous metals, for example for copper and magnesium, and their alloys.

Abstract

1. Continuous-casting mould with a wall (21, 37, 40) which is permeable to gases and through which compressed gas issues laterally towards the melt (26), and with a hot top (16, 28, 33) which is located above the mould wall, the wall of this hot-top (18, 28, 33) being inwardly offset in relation to the wall (21, 37, 40) which is permeable to gases and the lower region of this hot-top (18, 28, 33) forming a hot-top overhang (22, 31, 34), characterized in that the hot-top (18, 28, 33) is connected to the wall (21, 37, 40) which is permeable to gases, and in that the wall (21, 37, 40) which is permeable to gases is arranged independently of a liquid-cooling system which provides the primary cooling.

Description

Die Erfindung betrifft eine Stranggießkokille, mit einer gasdurchlässigen Wand, durch die in seitlicher Richtung Druckgas in Richtung auf die Schmelze austritt, und mit einem oberhalb der gasdurchlässigen Wand angeordneten Heißkopf, dessen Wandung gegenüber der gasdurchlässigen Wand nach innen versetzt ist und dessen unterer Bereich einen Heißkopfüberhang bildet.The invention relates to a continuous casting mold, with a gas-permeable wall through which compressed gas emerges in the lateral direction in the direction of the melt, and with a hot head arranged above the gas-permeable wall, the wall of which is offset inwards relative to the gas-permeable wall and the lower region of which is a hot head overhang forms.

Aus der GB-A-2014487 ist eine derartige Stranggießkokille in mehreren unterschiedlichen Ausführungsformen bekannt. Bei allen Ausführungsformen hat die Stranggießkokille einen Heißkopfüberhang. Die Kokillenwandung ist zwangsgekühlt. Der Heißkopf mit seinem Überhang ist in Richtung der Kokillenachse beweglich und hat die Form einer Hülse, um die axiale Länge der in Berührung mit dem flüssigen Metall tretenden Kokillenwandung während des Gießvorganges ändern zu können, ohne daß die Menge der in der Straggießkokille befindlichen Schmelze geändert werden muß. Die Schmelze kommt also mit der Kokillenwand in Berührung. Im übrigen dient das Druckgas, das teilweise von oben her in einen zwischen dem Heißkopfüberhang bzw. der Hülse einerseits und der zwangsgekühlten Kokillenwand andererseits gebildeten Spalt eingeleitet wird, zur Steuerung der Schmelzspiegelhöhe.GB-A-2014487 discloses such a continuous casting mold in several different embodiments. In all embodiments, the continuous casting mold has a hot head overhang. The mold wall is cooled. The hot head with its overhang is movable in the direction of the mold axis and has the shape of a sleeve in order to be able to change the axial length of the mold wall which comes into contact with the liquid metal during the casting process, without the amount of the melt in the continuous casting mold being changed got to. The melt therefore comes into contact with the mold wall. In addition, the compressed gas, which is partially introduced from above into a gap formed between the hot head overhang or the sleeve on the one hand and the positively cooled mold wall on the other hand, is used to control the melt level.

Somit ergibt sich bei der bekannten Stranggießkokille ein verhältnismäßig großer Wärmeabfluß in radialer Richtung von innen nach außen. Dieser Wärmeabfluß bedingt das Auftreten des sogenannten Randschaleneffektes.Thus, in the known continuous casting mold, there is a relatively large outflow of heat in the radial direction from the inside to the outside. This heat flow causes the occurrence of the so-called edge shell effect.

Es ist ferner durch die DE-C-833394 eine Stranggießkokille beschrieben, deren Kokillenwandung in vertikaler Richtung durchgehend verläuft. Ein Heißkopfüberhang ist also nicht vorhanden. Auch wenn der obere Bereich der Stranggießkokille beheizt wird, so ist doch der unmittelbar anschließende untere Bereich zwangsgekühlt. Das Metall befindet sich sowohl in flüssigem als auch in erstrarrendem Zustand in enger Berührung mit der Kokillenwandung. Beim Eintritt in den zwangsgekühlten Bereich wird das Metall sehr plötzlich abgekühlt, was sich ebenso wie die unmittelbare Berührung von Metall und Kokillenwandung auf die Qualität des hergestellten Stranges nachteilig auswirkt.It is further described by DE-C-833394 a continuous casting mold, the mold wall of which runs continuously in the vertical direction. There is therefore no hot head overhang. Even if the upper area of the continuous casting mold is heated, the immediately adjoining lower area is forced-cooled. The metal is in close contact with the mold wall both in the liquid and in the solidifying state. When entering the forced-cooled area, the metal is cooled very suddenly, which, like the direct contact between the metal and the mold wall, has a negative effect on the quality of the strand produced.

Auch die aus der FR-A-2 090 111 bekannte Stranggießkokille hat eine zwangsgekühlte Kokillenwandung ohne Heißkopf, der bekanntlich immer aus einem Material von besonders geringer Wärmeleitfähigkeit wie beispielsweise Schamotte, Asbest oder dergleichen besteht. Vielmehr ist die innere Kokillenwandung mit einer zu Beginn eines Gießvorganges etwa 5 mm starken Beschichtung aus gasbildendem Kunststoff versehen. Ein durch einen verdampfungs- ähnlichen Vorgang aufgebautes Druckgaspolster soll eine Berührung zwischen der Schmelze bzw. dem erstarrendem Metall und der beschichteten Kokillenwand verhindern. Diese Ausführungsform hat jedoch den Nachteil, daß mit zunehmendem Verschleiß der Teflonschicht während eines Gießvorganges der Durchmesser des Stranges immer größer wird. Ein maßgenaues Gießen des Stranges ist deshalb unmöglich. Man erhält zwangsläufig einen ungleichmäßigen Gußstrangquerschnitt. Auch ist die auf diese Weise erzielbare Druckgasmenge sehr begrenzt, so daß in der Praxis die Berührung zwischen Schmelze und Kokillenwandung nicht mit Sicherheit wird verhindert werden können, weil der Druck des Gaspolsters zu gering ist.The continuous casting mold known from FR-A-2 090 111 also has a force-cooled mold wall without a hot head, which is known to always consist of a material of particularly low thermal conductivity, such as fireclay, asbestos or the like. Rather, the inner mold wall is provided with a coating of gas-forming plastic that is about 5 mm thick at the start of a casting process. A pressure gas cushion built up by an evaporation-like process is intended to prevent contact between the melt or the solidifying metal and the coated mold wall. However, this embodiment has the disadvantage that with increasing wear of the Teflon layer during a casting process, the diameter of the strand becomes ever larger. Precise casting of the strand is therefore impossible. An uneven cast strand cross section is inevitably obtained. The quantity of compressed gas that can be achieved in this way is also very limited, so that in practice the contact between the melt and the mold wall cannot be prevented with certainty because the pressure of the gas cushion is too low.

Für die weiterhin aus der DE-C-869 541 bekanntgewordenen Stranggießkokille gelten annähernd die gleichen Nachteile wie für die Stranggießkokille nach der DE-C-833 394..For the continuous casting mold further known from DE-C-869 541, approximately the same disadvantages apply as for the continuous casting mold according to DE-C-833 394 ..

Allen bekannten Stranggießkokillen ist der Nachteil gemeinsam, daß immer noch in verhältnismäßig großem Maße Ungleichmäßigkeiten an der Oberfläche des Gußstranges auftreten und daß diese eine vielfach recht aufwendige Nachbearbeitung erforderlich machen.All known continuous casting molds have the disadvantage in common that irregularities on the surface of the cast strand still occur to a relatively large extent and that these require a frequently very costly post-processing.

Somit war es Aufgabe der vorliegenden Erfindung, eine Stranggießkokille zu schaffen, mit der sich eine wesentlich bessere Qualität des Gußprodukts erzielen läßt und die das Ausmaß der eventuell noch erforderlichen Nachbearbeitung weitgehend herabsetzt oder die Nachbearbeitung sogar überflüssig macht..It was therefore an object of the present invention to provide a continuous casting mold with which a substantially better quality of the cast product can be achieved and which largely reduces the extent of the post-processing that may still be required or even makes post-processing superfluous.

Zur Lösung dieser Aufgabe soll eine Strarrggießkokille der eingangs genannten Art so ausgebildet werden, daß der Heißkopf mit der.gasdurchlässigen Wand verbunden ist und daß die Wand frei von einer als Primärkühlung wirkenden Flüssigkeitskühlung angeordnet ist. Allenfalls können hierbei Halterungsteile, die der Abstützung des Heißkopfes und/oder der gasdurchlässigen Wand dienen, zwischen Heißkopf und Wand eingreifen, sofern sie während des laufenden Gießbetriebes nicht mehr mit der Schmelze in Berührung kommen.To achieve this object, a continuous casting mold of the type mentioned at the outset is to be designed such that the hot head is connected to the gas-permeable wall and that the wall is arranged free of liquid cooling acting as primary cooling. At most, holder parts, which serve to support the hot head and / or the gas-permeable wall, can intervene between the hot head and the wall, provided that they no longer come into contact with the melt during the ongoing casting operation.

Nach der Erfindung wird der bekannte radiale Wärmeabfluß von innen nach außen - insbesondere verursacht durch eine Primärkühlüng mittels einer wassergekühlten Kokillenwand so wie durch eine unmittelbare Berührung zwischen der Schmelze und der Kokillenwand - weitgehend verhindert. Hierdurch wird das Randscha= lenwachstum vermindert.According to the invention, the known radial heat flow from the inside to the outside - in particular caused by a primary cooling by means of a water-cooled mold wall and by direct contact between the melt and the mold wall - is largely prevented. This reduces the growth of the outer shells.

Zu der Erfindung gehören ferner einige konstruktive Ausgestaltungen der Stranggießkokille nach den Unteransprüchen 2 bis 6.The invention also includes some constructive configurations of the continuous casting mold according to subclaims 2 to 6.

Die Erfindung erstreckt sich ferner auch auf ein für den Betrieb der beschriebenen Strang gießkokille geeignetes Herstellungsverfahren nach Anspruch 7.The invention also extends to a production method according to claim 7 which is suitable for the operation of the described casting mold.

Durch die Zuführung von entsprechend er wärmtem Druckgas wird die Abgabe von Wärme aus der Schmelze im Bereich der gasdurchlässigen Wand verringert. Je höher die Temperatur des Druckgases ist, desto geringer wird auch der radiale Wärmefluß von innen nach außen und desto stärker läßt sich das Randschalenwachs tum unterdrücken, so daß die Erstarrungsfront im äußeren Strangbereich einen wesentlich flacheren Verlauf aufweist. Eine obere Grenze für die zu wählende Gastemperatur wird im allgemeinen durch die Liquidustemperatur oder eine allenfalls nur wenige Grade über dieser liegende Temperatur gegeben sein. Im übrigen enthalten die Unteransprüche 8-10 weitere vorteilhafte Verfahrensschritte.By supplying compressed gas that is heated accordingly, the emission of heat from the melt in the region of the gas-permeable wall is reduced. The higher the temperature of the compressed gas, the lower the radial heat flow from the inside to the outside and the stronger the edge shell wax can be suppress tum so that the solidification front in the outer strand area has a much flatter course. An upper limit for the gas temperature to be selected will generally be given by the liquidus temperature or, at most, only a few degrees above this temperature. Otherwise subclaims 8-10 contain further advantageous method steps.

Nachfolgend werden einige Ausgestaltungen der Erfindung anhand einer Zeichnung näher beschrieben. Im einzelnen zeigt

  • Fig. 1 einen Teilschnitt durch eine Kokille;
  • Fig. 2 in einer der Darstellung nach Fig. 1 entsprechenden Darstellung einen Teilschnitt durch eine andere Ausführungsform der Kokille;
  • Fig. 3 einen Teilbereich aus einem solchen Teilschnitt, der eine andere Form des Heißkopfüberhanges darstellt.
Some embodiments of the invention are described in more detail below with reference to a drawing. In detail shows
  • 1 shows a partial section through a mold.
  • FIG. 2 shows a partial section through another embodiment of the mold in a representation corresponding to FIG. 1;
  • Fig. 3 shows a partial area from such a partial section, which represents a different shape of the hot head overhang.

Für alle Ausführungsformen gilt gemeinsam, daß jeweils der links einer Mittelachse 10 befindliche Teil einer Kokille dargestellt ist, wobei diese einen kreisförmigen Querschnitt hat. Selbstverständlich ist die Erfindung auch für Kokillen . anwendbar, die eine andere Querschnittsform haben.It is common to all embodiments that the part of a mold located to the left of a central axis 10 is shown, whereby this has a circular cross section. Of course, the invention is also for molds. applicable that have a different cross-sectional shape.

Die in Fig. 1 dargestellte Stranggießkokille hat einen äußeren Mantelteil 11 und einen Einsatzteil 12. Diese bilden zusammen mit einem Bodenteil 13 und einem Wandteil 14 einen in Umfangsrichtung geschlossenen Ringraum 15, in dem das für die Kühlung benötigte Wasser enthalten ist. Zwischen dem Einsatzteil 12 einerseits und dem Bodenteil 13 und dem Wandteil 14 andererseits ist ein ringspattförmiger Kanal 16 gebildet, durch den über den Umfang eines Gießstranges 17 verteilt Wasser an die äußere Umfangsfläche desselben herangeführt wird. Der Wandteil 14 gewährleistet über den Umfang hin eine gleichmäßige Zuführung des an beliebiger Stelle in den Ringraum 15 eingespeisten Wassers.The continuous casting mold shown in FIG. 1 has an outer jacket part 11 and an insert part 12. Together with a bottom part 13 and a wall part 14, these form an annular space 15 which is closed in the circumferential direction and in which the water required for cooling is contained. Between the insert part 12, on the one hand, and the base part 13 and the wall part 14, on the other hand, a ring-shaped channel 16 is formed, through which water is distributed over the circumference of a casting strand 17 to the outer peripheral surface thereof. The wall part 14 ensures a uniform supply of the water fed into the annular space 15 at any point over the circumference.

Die Kokille hat einen Heißkopf 18 aus wärmeisolierendem Material, der unter anderem auch dazu dient, eine Abkühlung der in die Kokille eingebrachten flüssigen Schmelze zu verhindern. Der Heißkopf 18 hat eine nach innen ragende und mit der Schmelze in Berührung stehende Wandung 19, die an ihrem tiefsten Punkt in eine schräg nach oben und geneigt verlaufende Unterseite 20 übergeht. Gegenüber der Wandung 19 nach außen versetzt schließt eine poröse Wand 21 an. Der von dieser aus nach innen hervorstehende Teil des Heißkopfes 18 stellt den Heißkopfüberhang 22 dar. An der Rückseite der Wand 21 ist durch den Einsatzteil 12, den Heißkopf 18 und durch die Wand 21 selbst ein Ringraum 23 gebildet, dem über mindestens einen Kanal 24 Gas unter Druck zugeführt wird. Die Zuführung kann alternativ ganz oder teilweise auch über Hohlräume erfolgen, die hier in Form eines Netzwerkes 25 im Heißkopf 18 ausgebildet sind und in denen Wärme zwischen dem Gas und dem Heißkopf 18 getauscht werden kann. Gegebenenfalls können die Kokille und insbesondere ihr durch den Heißkopf 18 gebildeter Bereich zusätzlich beheizt werden, zum Beispiel mittels einer hier nicht dargestellten elektrischen Heizung.The mold has a hot head 18 made of heat-insulating material, which among other things also serves to prevent the liquid melt introduced into the mold from cooling. The hot head 18 has an inwardly projecting wall 19 in contact with the melt, which at its deepest point merges into an obliquely upward and inclined underside 20. A porous wall 21 adjoins the wall 19 offset to the outside. The part of the hot head 18 protruding inwards from this represents the hot head overhang 22. On the rear side of the wall 21, an annular space 23 is formed by the insert part 12, the hot head 18 and by the wall 21 itself, to which gas flows via at least one channel 24 is fed under pressure. The supply can alternatively also take place wholly or partly via cavities which are formed here in the form of a network 25 in the hot head 18 and in which heat can be exchanged between the gas and the hot head 18. If necessary, the mold and in particular its area formed by the hot head 18 can be additionally heated, for example by means of an electrical heater (not shown here).

Zwischen der flüssigen Schmelze, die hier mit der Bezugsziffer 26 bezeichnet ist, und dem aus bereits erstarrtem Material bestehenden Gießstrang 17 verläuft eine mit der Bezugsziffer 27 bezeichnete Erstarrungsfront.A solidification front designated by reference number 27 runs between the liquid melt, which is designated here by reference number 26, and the casting strand 17, which is made of solidified material.

Während des Gießens wird der Gießstrang 17 entsprechend dem Fortschritt der Erstarrung abgesenkt, wobei gleichzeitig neue Schmelze 26 hinzugegeben wird. Das dem Ringraum 23 zugeführte Gas hat eine Temperatur, die etwa der Liquidustemperatur entspricht und somit nurwenig niedriger ist als die Temperatur der zugeführten Schmelze 26. Der Druck sowie die zugeführte Menge des Gases im Ringraum 23 sind so bemessen, daß der Gasdruck im Druckgaspolster etwa der Summe aus dem Atmosphärendruck und dem metallostatischen Druck der Schmelze 26 im Bereich der Wand 21 entspricht. Somit kann das aus dieser austretende Druckgas eine Berührung zwischen der Wand 21 und dem an diese angrenzenden Teil der Unterseite 20 des Heißkopfes 18 einerseits und der Oxydhaut an der Außenseite des Gießstranges 17 und im Bereich der noch nicht erstarrten Schmelze 26 andererseits durch Bildung eines entsprechenden Druckgaspolsters verhindern. Durch die Temperatur des Gases wird eine Wärmeabfuhr in radialer Richtung nach außen unterbunden. Die Erstarrungsfront 27 hat deshalb auch im äußeren Bereich einen verhältnismäßig flachen Verlauf, der erkennen läßt, daß der sonst durch Primärkühlung bewirkte Randschaleneffekt nicht oder zumindest kaum mehr vorhanden ist. Wie Fig. 1 ferner erkennen läßt, kann das Gas nur nach unten entweichen, da der tiefste Punkt der Wandung 19 tiefer liegt, als der höchste Punkt des unterhalb des Heißkopfüberhanges 22 befindlichen Querschnittsteiles der Schmelze.During the casting, the casting strand 17 is lowered in accordance with the progress of the solidification, with new melt 26 being added at the same time. The gas supplied to the annular space 23 has a temperature which corresponds approximately to the liquidus temperature and is therefore only slightly lower than the temperature of the supplied melt 26. The pressure and the quantity of gas supplied in the annular space 23 are such that the gas pressure in the compressed gas cushion is approximately that The sum of the atmospheric pressure and the metallostatic pressure of the melt 26 in the region of the wall 21 corresponds. Thus, the pressure gas emerging from this can make contact between the wall 21 and the part of the underside 20 of the hot head 18 adjoining it, on the one hand, and the oxide skin on the outside of the casting strand 17 and in the region of the not yet solidified melt 26, on the other hand, by forming a corresponding pressure gas cushion prevent. Heat dissipation in the radial direction to the outside is prevented by the temperature of the gas. The solidification front 27 therefore also has a relatively flat course in the outer region, which shows that the edge-shell effect otherwise caused by primary cooling is not or at least barely present. As can also be seen in FIG. 1, the gas can only escape downward, since the lowest point of the wall 19 is lower than the highest point of the cross-sectional part of the melt located below the hot head overhang 22.

Erst unterhalb der porösen Wand 21 und damit unterhalb der Erstarrungsfront 27 erfolgt eine Kühlung durch das aus dem ringspaltförmigen Kanal 16 austretende Wasser. Unmittelbar im Austrittsbereich des Kanals 16 wird die Kühlwirkung an der Außenfläche des Gießstranges 17 zunächst noch dadurch etwas herabgesetzt, daß das Druckgas dort mit einer verhältnismäßig hohen Temperatur austritt. Für Aluminium-Strangguß zum Beispiel gilt eine Temperatur in der Größenordnung von 700° C.Only below the porous wall 21 and thus below the solidification front 27 is there cooling by the water emerging from the annular gap-shaped channel 16. Immediately in the exit region of the channel 16, the cooling effect on the outer surface of the casting strand 17 is initially somewhat reduced by the fact that the compressed gas exits there at a relatively high temperature. For example, for aluminum continuous casting, a temperature in the order of 700 ° C applies.

Gegenüber der Ausführungsform nach Fig. 1 enthält die in Fig. 2 dargestellte Ausführungsform nur einen unterschiedlich ausgebildeten Heißkopf 28 mit einer in die Schmelze 26 hineinragenden seitlichen Wandung 29. Eine nach unten offene ringförmige Aussparung 30 von etwa U-förmigem Querschnitt bildet die Unterseite des Heißkopfüberhanges 31. Die Zuführung des erwärmten und unter Druck stehenden Gases erfolgt durch ein oder mehrere Kanäle 32. Wie Fig. erkennen läßt, liegt auch hier der tiefste Punkt der Wandung 29 unterhalb des höchsten Punktes des im Bereich der Aussparung 30 befindlichen Querschnittsbereiches der Schmelze 26. Der untere Bereich des Heißkopfes 28 ist als poröse Wand 37 ausgebildet, hinter der sich ein Ringraum 38 befindet. In diesen münden Kanäle 39, durch die ebenso wie durch die Kanäle 32 erhitztes Druckgas zugeführt werden kann. Wie Fig. erkennen läßt, kann das zugeführte Gas nur an der Außenseite des Gießstranges 17 entlang nach unten entweichen und nicht entlang der Wandung 29 nach oben austreten.Compared to the embodiment according to FIG. 1, the embodiment shown in FIG. 2 contains only a differently designed hot head 28 with a lateral wall 29 protruding into the melt 26. A downwardly open annular recess 30 of approximately U-shaped cross section forms the underside of the hot head overhang 31. The supply of the heated and pressurized gas takes place through one or more channels 32. As can be seen in FIG. 1, the lowest point of the wall 29 is below the highest point in the area of the recess 30 sensitive cross-sectional area of the melt 26. The lower area of the hot head 28 is designed as a porous wall 37, behind which there is an annular space 38. Channels 39 open into these, through which heated compressed gas can be supplied, as can channels 32. As can be seen in FIG. 1, the gas supplied can only escape downwards along the outside of the casting strand 17 and cannot escape upwards along the wall 29.

Fig. 3 schließlich zeigt eine weitere Ausführungsform nur für einen Heißkopf 33, dessen Heißkopf-Überhang 34 jetzt eine schräg nach unten gerichtete Nase hat, von der aus sich die in die Schmelze 26 hineinragende Wandung 35 nach oben erstreckt. Ein Teil des erwärmten und unter entsprechendem Druck stehenden Gases wird über Kanäle 36 an der Unterseite des Heißkopf-Überhanges 34 zugeführt. Im übrigen ist auch hier der untere Bereich des Heißkopfes 33 als poröse Wand 40 ausgebildet, hinter der sich ein Ringraum 41 befindet.Finally, FIG. 3 shows a further embodiment only for a hot head 33, the hot head overhang 34 of which now has an obliquely downward nose from which the wall 35 projecting into the melt 26 extends upwards. A portion of the heated and pressurized gas is supplied via channels 36 on the underside of the hot head overhang 34. Otherwise, the lower region of the hot head 33 is also designed as a porous wall 40, behind which an annular space 41 is located.

Im übrigen gilt, soweit es hier nicht ausdrücklich unter Bezug auf die Fig. 1 und/oder 2 anders beschrieben ist, das im Zusammenhang mit der Ausführungsform nach Fig. 1 Gesagte.Otherwise, unless otherwise expressly described with reference to FIGS. 1 and / or 2, what has been said in connection with the embodiment according to FIG. 1 applies.

Bei allen Ausführungsformen ist also der Heißkopf stationär, denn eine bewegliche Anordnung desselben bringt keine gußtechnischen Vorteile und würde nur den technischen Aufwand erhöhen.In all embodiments, the hot head is stationary, because a movable arrangement of the same does not bring any advantages in terms of casting technology and would only increase the technical outlay.

Da gemäß der von der Erfindung vorgeschlagenen technischen Lehre im Bereich der Stranggießkokille ein Wärmeabfluß nach außen möglichst weitgehend herabgesetzt werden soll, sind zur Bildung des Druckgaspolsters Kohlendioxyd, Stickstoff, Argon, Luft oder Mischungen aus diesen Gasen besonders geeignet, da diese Gase eine verhältnismäßig geringe Wärmeleitfähigkeit haben. Im übrigen wird im Rahmen der Erfindung ganz bewußt auf eine herkömmliche Primärkühlung der Schmelze mittels einer wassergekühlten Kokillenwand verzichtet.Since, according to the technical teaching proposed by the invention in the area of the continuous casting mold, heat outflow to the outside is to be reduced as much as possible, carbon dioxide, nitrogen, argon, air or mixtures of these gases are particularly suitable for forming the compressed gas cushion, since these gases have a relatively low thermal conductivity to have. Otherwise, conventional primary cooling of the melt by means of a water-cooled mold wall is deliberately avoided in the context of the invention.

Das von der Erfindung vorgeschlagene Verfahren ist nicht nur zum Stranggießen von Aluminium und Aluminium-Legierungen mit Vorteil anwendbar, sondern allgemein für NichteisenMetalle, zum Beispiel für Kupfer und Magnesium, sowie deren Legierungen.The method proposed by the invention can be used advantageously not only for the continuous casting of aluminum and aluminum alloys, but generally for non-ferrous metals, for example for copper and magnesium, and their alloys.

Durch die Unterbringung von Kühlwasser in dem Ringraum 15 und durch die Ableitung desselben über den ringspaltförmigen Kanal 16 wird in keinem Fall eine indirekte Kühlung der Schmelze auf dem Weg über die Kokillenwand bewirkt. Ein Wärmefluß bestimmter Größe durch den Heißkopf insbesondere in Richtung auf das Kühlwasser ist unvermeidbar, im übrigen aber für das Verfahren ohne Bedeutung. Es ist aber vorteilhaft, das Kühlsystem so auszubilden und mit Hilfe des ringspaltförmigen Kanals 16 die Kühlung in einer genau definierten und scharf begrenzten Zone des Gußstranges zur Wirkung zu bringen, um eine möglichst gleichmäßige Schrumpfung des Gußstranges über dem Umfang zu erzielen.By accommodating cooling water in the annular space 15 and by draining it via the annular-shaped channel 16, indirect cooling of the melt on the way over the mold wall is never brought about. A heat flow of a certain size through the hot head, in particular in the direction of the cooling water, is unavoidable, but is otherwise of no importance for the method. It is advantageous, however, to design the cooling system and, with the aid of the annular gap-shaped channel 16, to bring the cooling into effect in a precisely defined and sharply delimited zone of the cast strand in order to achieve the most uniform possible shrinkage of the cast strand over the circumference.

Claims (10)

1. Continuous-casting mould with a wall (21, 37, 40) which is permeable to gases and through which compressed gas issues laterally towards the melt (26), and with a hot-top (16, 28, 33) which is located above the mould wall, the wall of this hot-top (18, 28, 33) being inwardly offset in relation to the wall (21, 37, 40) which is permeable to gases and the lower region of this hot-top (18, 28, 33) forming a hot-top overhang (22, 31, 34), characterized in that the hot-top (18, 28, 33) is connected to the wall (21, 37, 40) which is permeable to gases, and in that the wall (21, 37, 40) which is permeable to gases is arranged independently of a liquid-cooling system which provides the primary cooling.
2. Continuous-casting mould according to claim 1, characterized in that the lowest point of the hot-top overhang (22, 31, 34) is located at a lower level than the highest point of the wall (21, 37, 40) which is permeable to gases.
3. Continuous-casting mould according to claim 1 or 2, characterized in that the underside of the hot-top overhang (31, 34) possesses outlet openings (32, 36), through which an additional, downward-directed flow of compressed gas issues.
4. Continuous-casting mould according to one of the preceding claims, characterized in that portions of the hot-top (18) possess cavities (25) through which gas flows and in which heat is exchanged between the gas and the hot-top (18).
5. Continuous-casting mould according to one of the preceding claims, characterized in that the hot-top (18, 28, 33) can be heated by means of the compressed gas, and/or electrically.
6. Continuous-casting mould according to one of the preceding claims, characterized in that the hot-top overhang (22, 31, 34) is installed in a manner such that it does not move.
7. Process for the manufacture of semi-finished products by continuous-casting, employing a continuous-casting mould which is designed in accordance with one or more of claims 1 to 6, characterized in that, while the casting unit is in operation, the melt (26) is supported, facing those portions of the mould which are situated beneath the hot-top overhang (22, 31, 34) but without contact, this being effected by means of the cushion of compressed gas, in that the compressed gas is directed against the melt after having been heated to at least 100°C above room temperature, and in that the pressure of the cushion of compressed gas is sufficiently high to ensure that, while casting is underway, the melt (26) does not come into contact with those portions (21, 37, 40) of the mould which lie below the hot-top (18,28,33).
8. Process according to claim 7, characterized in that the continuous-casting mould is heated before the casting operation begins.
9. Process according to claim 7 or 8, characterized in that the compressed gas is supplied at a temperature which is sufficiently high to prevent heat-transport from the melt (26) from taking place in the radially outward direction, in the region of the cushion of compressed gas, and hence to prevent the growth of a surface shell, to a substantial degree.
10. Process according to one of claims.7 to 9, characterized in that carbon dioxide, nitrogen, argon or air, or mixtures of these gases, are employed for the purpose of forming the cushion of compressed gas.
EP81710011A 1980-03-07 1981-03-04 Mold for continuous casting Expired EP0035958B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81710011T ATE8467T1 (en) 1980-03-07 1981-03-04 CONTINUOUS CASTING MOLD.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3008781 1980-03-07
DE3008781A DE3008781C2 (en) 1980-03-07 1980-03-07 Process for the continuous casting of metals

Publications (3)

Publication Number Publication Date
EP0035958A2 EP0035958A2 (en) 1981-09-16
EP0035958A3 EP0035958A3 (en) 1981-11-25
EP0035958B1 true EP0035958B1 (en) 1984-07-18

Family

ID=6096546

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81710011A Expired EP0035958B1 (en) 1980-03-07 1981-03-04 Mold for continuous casting

Country Status (3)

Country Link
EP (1) EP0035958B1 (en)
AT (1) ATE8467T1 (en)
DE (2) DE3008781C2 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2534832A1 (en) * 1982-10-20 1984-04-27 Wagstaff Engineering Inc APPARATUS AND TECHNIQUE FOR DIRECT CASTING OF METAL SHELLS
GB2129345A (en) * 1982-10-15 1984-05-16 Alcan Int Ltd Continuous casting of aluminium alloy
US4598763A (en) * 1982-10-20 1986-07-08 Wagstaff Engineering, Inc. Direct chill metal casting apparatus and technique
FR2585597A1 (en) * 1985-07-30 1987-02-06 Pechiney Aluminium Method and device for batch casting metals
EP0213049A1 (en) * 1985-07-30 1987-03-04 Aluminium Pechiney Method and apparatus for casting metals
WO1991006386A1 (en) * 1989-11-01 1991-05-16 Alcan International Limited Method of controlling the rate of heat extraction in mould casting
US5873405A (en) * 1997-06-05 1999-02-23 Alcan International Limited Process and apparatus for direct chill casting
US6260605B1 (en) 1996-04-05 2001-07-17 Ugine-Savoie Imphy Facility and method for the continuous casting of metals
CN110842048A (en) * 2019-11-27 2020-02-28 杭州富通电线电缆有限公司 Method for producing copper rod and copper rod wire drawing device

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3207777C2 (en) * 1982-03-04 1984-09-06 Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt e.V., 5000 Köln Method and device for continuous pipe casting of metals, inbes. Nickel and cobalt alloys
BE1015358A3 (en) * 2003-02-12 2005-02-01 Ct Rech Metallurgiques Asbl Continuous pouring procedure for molten metal uses feeder of refractory material and double meniscus
US7077186B2 (en) * 2003-12-11 2006-07-18 Novelis Inc. Horizontal continuous casting of metals
US7322397B2 (en) * 2004-11-16 2008-01-29 Rmi Titanium Company Continuous casting of reactionary metals using a glass covering
CN105108080B (en) * 2015-08-05 2017-03-29 东北大学 Suppress the Semi-continuous casting crystallizer and its using method of magnesium alloy ingot blank cracking
CN110340329A (en) * 2019-08-28 2019-10-18 江苏亚太航空科技有限公司 A kind of aluminium and aluminium alloy low pressure Semi-continuous casting crystallizer cooling system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE833394C (en) * 1942-01-14 1952-03-06 Wieland Werke Ag Casting mold for continuous casting of metals
DE869541C (en) * 1943-10-23 1953-03-05 Wieland Werke Ag Heated casting mold for continuous casting of metals
SU339099A1 (en) * 1970-05-18 1977-12-05 Livanov V A Water-jacketed mould for continuous casting of ingots
DE2518903A1 (en) * 1974-07-12 1976-01-22 Atsumi Ohno Continuous casting billets free from surface defects - using gas-curtain in mould to prevent melt touching the mould wall
GR65264B (en) * 1978-02-18 1980-07-31 British Aluminium Co Ltd Metal casting
GB2014487B (en) * 1978-02-18 1982-06-16 British Aluminium Co Ltd Varying metal-mould contact in continous casting

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2129345A (en) * 1982-10-15 1984-05-16 Alcan Int Ltd Continuous casting of aluminium alloy
AU567872B2 (en) * 1982-10-20 1987-12-10 Wagstaff Engineering, Inc. Direct chill casting
GB2129344A (en) * 1982-10-20 1984-05-16 Wagstaff Engineering Inc Direct chill casting
JPS5992147A (en) * 1982-10-20 1984-05-28 ワグスタツフ・エンジニアリング・インコ−ポレイテツド Direct chill casting method and its device
US4598763A (en) * 1982-10-20 1986-07-08 Wagstaff Engineering, Inc. Direct chill metal casting apparatus and technique
JPS6147622B2 (en) * 1982-10-20 1986-10-20 Wagusutatsufu Eng Inc
FR2534832A1 (en) * 1982-10-20 1984-04-27 Wagstaff Engineering Inc APPARATUS AND TECHNIQUE FOR DIRECT CASTING OF METAL SHELLS
FR2585597A1 (en) * 1985-07-30 1987-02-06 Pechiney Aluminium Method and device for batch casting metals
EP0213049A1 (en) * 1985-07-30 1987-03-04 Aluminium Pechiney Method and apparatus for casting metals
FR2599650A2 (en) * 1985-07-30 1987-12-11 Pechiney Aluminium Device for batch casting of metals
WO1991006386A1 (en) * 1989-11-01 1991-05-16 Alcan International Limited Method of controlling the rate of heat extraction in mould casting
US6260605B1 (en) 1996-04-05 2001-07-17 Ugine-Savoie Imphy Facility and method for the continuous casting of metals
US5873405A (en) * 1997-06-05 1999-02-23 Alcan International Limited Process and apparatus for direct chill casting
CN110842048A (en) * 2019-11-27 2020-02-28 杭州富通电线电缆有限公司 Method for producing copper rod and copper rod wire drawing device
CN110842048B (en) * 2019-11-27 2021-05-28 杭州富通电线电缆有限公司 Method for producing copper rod and copper rod wire drawing device

Also Published As

Publication number Publication date
EP0035958A2 (en) 1981-09-16
DE3008781C2 (en) 1982-08-26
DE3164805D1 (en) 1984-08-23
DE3008781A1 (en) 1981-09-17
ATE8467T1 (en) 1984-08-15
EP0035958A3 (en) 1981-11-25

Similar Documents

Publication Publication Date Title
EP0035958B1 (en) Mold for continuous casting
DE3205480C2 (en)
DE2909990A1 (en) METHOD OF CASTING BLOCKS
DE2952150A1 (en) METHOD AND DEVICE FOR PRODUCING BARS FROM METAL COMPOSITIONS BY DIRECTIONALIZING
DE3526689A1 (en) METHOD AND DEVICE FOR HORIZONTAL CONTINUOUS CASTING OF METAL
DD141276A5 (en) METHOD AND APPARATUS FOR THE CONTINUOUS CASTING OF ROUGHFUL PRODUCTS
EP0301170B1 (en) Process for the production of thin band
DE3832306C2 (en) Method and device for continuous casting of hollow metal blocks
DE60205168T2 (en) Method and device for vertical casting of rough blocks and ingot produced in this way
DE1252375B (en) Process for casting steel alloys using the low-pressure casting process and further processing of the cast parts
DE3502532C2 (en) Device for the continuous casting of a hollow metallic strand
DE2406252C3 (en) Method and device for continuous casting and further processing of the cast strand
DE19710887C2 (en) Use of a mold for the production of bars from light metal or a light metal alloy, in particular from magnesium or a magnesium alloy
DE3241405A1 (en) CHILLET OR INDUCTION CONTINUOUS METHOD
DE19814988A1 (en) Method for producing a thin metal strip requiring no separate smoothing operations
DE1104124B (en) Process for feeding the lubricant into a mold with a horizontal axis for the continuous casting of metals
EP0229589B1 (en) Device and process for continuous casting of metals
DE102018130698A1 (en) Roll ingot mold for the continuous casting of aluminum and aluminum alloys
DE102017115087B4 (en) Device for producing a cast component
CH362800A (en) Permanent mold for continuous casting of molten metal and process for its operation
DE2143445C3 (en) Method and device for the production of metallic blocks
DE2240795C3 (en) Method and device for the continuous casting of strips made of copper, copper alloys or zinc-aluminum alloys
AT209009B (en) Liquid-cooled continuous mold for the continuous casting of metals
DE2248922C3 (en) Method for guiding and cooling a steel strand emerging from an essentially rectangular continuous casting mold
DE10115999A1 (en) hot head mold

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT NL SE

17P Request for examination filed

Effective date: 19811027

ITF It: translation for a ep patent filed

Owner name: DR. ING. A. RACHELI & C.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 8467

Country of ref document: AT

Date of ref document: 19840815

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3164805

Country of ref document: DE

Date of ref document: 19840823

ET Fr: translation filed
BECH Be: change of holder

Free format text: 840718 *VERREINIGTE ALUMINIUM-WERKE A.G.

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: CH

Ref legal event code: PUE

Owner name: VEREINIGTE ALUMINIUMWERKE AKTIENGESELLSCHAFT, BERL

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

ITPR It: changes in ownership of a european patent

Owner name: CESSIONE;VEREINIGTE ALUMINIUM - WERKE AG

NLS Nl: assignments of ep-patents

Owner name: VEREINIGTE ALUMINIUM-WERKE AKTIENGESELLSCHAFT TE B

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732

ITTA It: last paid annual fee
EAL Se: european patent in force in sweden

Ref document number: 81710011.8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950210

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19950317

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19950324

Year of fee payment: 15

Ref country code: AT

Payment date: 19950324

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19950331

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19950406

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19950418

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950523

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960304

Ref country code: AT

Effective date: 19960304

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19960305

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19960331

Ref country code: CH

Effective date: 19960331

Ref country code: BE

Effective date: 19960331

BERE Be: lapsed

Owner name: VERREINIGTE ALUMINIUM-WERKE A.G.

Effective date: 19960331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19961001

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960304

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19961129

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19961001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19961203

EUG Se: european patent has lapsed

Ref document number: 81710011.8

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST