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EP0092126A1 - Method of stirring the non-solidified areas in a cast billet - Google Patents

Method of stirring the non-solidified areas in a cast billet Download PDF

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Publication number
EP0092126A1
EP0092126A1 EP83103466A EP83103466A EP0092126A1 EP 0092126 A1 EP0092126 A1 EP 0092126A1 EP 83103466 A EP83103466 A EP 83103466A EP 83103466 A EP83103466 A EP 83103466A EP 0092126 A1 EP0092126 A1 EP 0092126A1
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EP
European Patent Office
Prior art keywords
pouring
mold
melt
magnetic field
pouring stream
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.)
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Application number
EP83103466A
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German (de)
French (fr)
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EP0092126B1 (en
Inventor
Sten Dipl. Ing. Kollberg
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ABB Norden Holding AB
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ASEA AB
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    • 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
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • B22D11/114—Treating the molten metal by using agitating or vibrating means
    • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields

Definitions

  • the invention relates to a method for stirring the non-solidified areas in a casting strand according to the preamble of the claim.
  • a method for stirring the non-solidified areas in a casting strand according to the preamble of the claim is known from European patent application 81 10 3569.0.
  • the invention has for its object to modify the above-mentioned method in such a way that the last-mentioned areas of the melt are stirred at the same time.
  • the arrangement of the magnetic field according to the invention ensures that the areas in the upper part of the mold which are not stirred by the mechanical force of the pouring jet itself are stirred by the use of electromagnetic forces. In this way you get a cast (slabs, billets or blooms) with a significantly increased surface quality.
  • a voltage E is determined according to the law of induction induced, 4 being the magnetic flux and is the temporal differential quotient of the river.
  • Figures 1 and 3 show the creation of the forces and movements.
  • the voltage E induced by the magnetic field B and the direction of movement v of the penetrating melt is the vectorial product [ v x B ] proportional, whereby the vector of the induced voltage comes out of the plane of the drawing.
  • the currents i in FIG. 1 flow out of the drawing plane in the middle and into the drawing plane on the sides, as can be seen more clearly from the cross section according to FIG. 3.
  • the interaction of the currents i flowing on the sides in FIG. 3 with the magnetic field B results in forces F 2 which correspond to the vectorial product [ i x B ] are proportional and extend into the plane of the drawing in FIG.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)

Abstract

1. Method for stirring the non-solidified regions in a cast strand, the strand being formed in a mold (3), whereby a pouring stream (2) of molten metal enters the mold (3) via a pouring pipe (1) or directly, and whereby a static magnetic field (B) is generated intersecting the path of the pouring stream (2) in the melt in the mold (3) and - under the effect of the movement of the metal forming the pouring stream (2) - retarding the velocity of the pouring stream (2) in the melt and splitting the pouring stream (2), characterized in that said static magnetic field (B) is arranged, with respect to the longitudinal direction of the mold (3), so close at the pouring pipe and at the upper end of the mold (3), respectively, that the portions (6) of the melt which are located laterally of the pouring stream (2) penetrating the melt and which are therefore not stirred directly by the impact of the pouring stream (2) are stirred by the interaction between the magnetic field (B) and the currents (i) induced by said retarding of the pouring stream.

Description

Die Erfindung betrifft ein Verfahren zur Umrührung der nicht erstarrten Bereiche bei einem Gießstrang gemäß dem Oberbegriff des Patentanspruches. Ein solches Verfahren ist bekannt aus der europäischen Patentanmeldung 81 10 3569.0.The invention relates to a method for stirring the non-solidified areas in a casting strand according to the preamble of the claim. Such a method is known from European patent application 81 10 3569.0.

Durch die Verwendung eines statischen Magnetfeldes erzielt man eine große Eindringtiefe des Magnetfeldes. Durch das Zusammenwirken dieses Magnetfeldes mit der in Bewegung befindlichen Schmelze des in die Kokille eindringenden Gießstrahls wird eine Kraft erzeugt, die den Gießstrahl bremst und zersplittert (Prinzip der Wirbelstrombremse). Die Eindringgeschwindigkeit des Gießstrahls in die in der Kokille bereits befindliche Schmelze liegt etwa im Bereich von 1 bis 1,5 m/sec. Hierdurch wird die Eindringtiefe des Gießstrahls vermindert, und der größte Teil der Schlacke wird an der Oberfläche abgeschieden und bleibt nicht an der Innenseite der bereits erstarrten Strangschale hängen. Der in die Schmelze eindringende Strahl bewirkt durch seine Wucht mechanisch zugleich eine gewisse Umrührung in der Schmelze. Jedoch werden die Schmelzenbereiche, die im oberen Kokillenbereich seitlich des dort in die Schmelze eindringenden Gießstrahls lie- gen, von dieser Rührwirkung nicht erfaßt.By using a static magnetic field, a large penetration depth of the magnetic field is achieved. The interaction of this magnetic field with the melt in motion of the pouring jet entering the mold generates a force that brakes and splits the pouring jet (principle of the eddy current brake). The rate of penetration of the pouring jet into the melt already in the mold is approximately in the range from 1 to 1.5 m / sec. This reduces the penetration depth of the pouring jet and the majority of the slag is deposited on the surface and does not get caught on the inside of the strand shell that has already solidified. The jet penetrating into the melt mechanically causes a certain stirring in the melt. However, the melt areas in the upper mold area laterally there of penetrating into the melt pouring stream Lie g en, not covered by this stirring action.

Der Erfindung liegt die Aufgabe zugrunde, das eingangs genannte Verfahren in der Weise abzuwandeln, daß die zuletzt genannten Bereiche der Schmelze gleichzeitig umgerührt werden.The invention has for its object to modify the above-mentioned method in such a way that the last-mentioned areas of the melt are stirred at the same time.

Zur Lösung dieser Aufgabe wird ein Verfahren nach dem Oberbegriff des Anspruches vorgeschlagen, der erfindungsgemäß die im kennzeichnenden Teil des Anspruches genannten Merkmale hat.To achieve this object, a method is proposed according to the preamble of the claim, which according to the invention has the features mentioned in the characterizing part of the claim.

Durch die erfindungsgemäße Anordung des Magnetfeldes wird erreicht, daß durch die Ausnutzung elektromagnetischer Kräfte auch die Bereiche im oberen Teil der Kokille umgerührt werden, die von der mechanischen Wucht des Gießstrahls selbst nicht verrührt werden. Auf diese Weise erhält man einen Guß (slabs, billets oder blooms) mit einer wesentlich erhöhten Oberflächengüte.The arrangement of the magnetic field according to the invention ensures that the areas in the upper part of the mold which are not stirred by the mechanical force of the pouring jet itself are stirred by the use of electromagnetic forces. In this way you get a cast (slabs, billets or blooms) with a significantly increased surface quality.

Anhand der Figuren soll die Erfindung näher erläutert werden. Es zeigen

  • Fig. 1 eine Prinzipskizze zur Erläuterung der Erfindung, in der die Kokille von der Seite dargestellt ist,
  • Fig. 2 die Darstellung der Kokille gemäß Fig. 1 in einer gegenüber Fig. 1 um 90° gedrehten Seitenansicht zur Veranschaulichung der in der Schmelze auftretenden Kräfte,
  • Fig. 3 die in Fig. 1 dargestellten Verhältnisse in Draufsicht auf die Kokille.
The invention will be explained in more detail with reference to the figures. Show it
  • 1 is a schematic diagram for explaining the invention, in which the mold is shown from the side,
  • 2 shows the mold according to FIG. 1 in a side view rotated by 90 ° in relation to FIG. 1 to illustrate the forces occurring in the melt,
  • Fig. 3 shows the relationships shown in Fig. 1 in plan view of the mold.

1 ist ein Gießrohr, aus dem ein Gießstrahl 2 in die Schmelze in einer Stranggießkokille 3 eindringt. Quer durch die Kokille 3 eventuell unter Einbeziehung des unteren Endes des Gießrohres wird von mehreren Polen 4 ein statisches Magnetfeld mit der Induktion B erzeugt. In dem von dem Strahl in Bewegung gesetzten Schmelzenteil wird nach dem Induktionsgesetz eine Spannung E =

Figure imgb0001
induziert, wobei 4 der magnetische Fluß und
Figure imgb0002
 der zeitliche Differentialquotient des Flusses ist.1 is a pouring tube from which a pouring jet 2 penetrates into the melt in a continuous casting mold 3. Across the mold 3, possibly including the lower end of the pouring tube, generates a static magnetic field with induction B from several poles 4. In the melt part set in motion by the beam, a voltage E = is determined according to the law of induction
Figure imgb0001
 induced, 4 being the magnetic flux and
Figure imgb0002
 is the temporal differential quotient of the river.

In der Schmelze erhält man elektrische Ströme (i), und nach dem Biot-Savart' schen Gesetz wird eine Kraft F1 (siehe Figur 2) erzeugt, die dem vektoriellen Produkt [i x B] proportional ist, wobei B der Vektor der Induktion und i der Vektor des Stromes (physikalisch exakt: der Stromdichte) ist. Die Kraft F1 ist gegen die Metallflußrichtung 5 gerichtet. Wenn die Richtung des Magnetfeldes B wechselt, so bleibt die Richtung der Kraft F1 unverändert, da ein solcher Wechsel einen Richtungswechsel der induzierten Spannung und damit des Stromes i zur Folge hat.Electrical currents (i) are obtained in the melt, and according to Biot-Savart's law a force F 1 (see FIG. 2) is generated which corresponds to the vectorial product [ i x B ] is proportional, where B is the vector of induction and i is the vector of the current (physically exact: the current density). The force F 1 is directed against the metal flow direction 5. If the direction of the magnetic field B changes, the direction of the force F 1 remains unchanged, since such a change results in a change in direction of the induced voltage and thus of the current i.

Figur 1 und 3 zeigen das Zustandekommen der Kräfte und Bewegungen. Die durch das magnetische Feld B und die Bewegungsrichtung v der eindringenden Schmelze induzierte Spannung E ist dem vektoriellen Produkt [v x B] proportional, wobei der Vektor der induzierten Spannung aus der Zeichenebene herauskommt. Entsprechend fließen die Ströme i in Fig. 1 in der Mitte aus der Zeichenebene heraus und an den Seiten in die Zeichenebene hinein, so wie es deutlicher aus dem Querschnitt gemäß Figur 3 erkennbar ist. Durch das Zusammenwirken der in Fig. 3 an den Seiten fließenden Ströme i mit dem magnetischen Feld B ergeben sich Kräfte F2, die dem vektoriellen Produkt [i x B] proportional sind und in Fig. 3 in die Zeichenebene hinein verlaufen, also entgegengerichtet zur bremsenden Kraft F1 (siehe Fig. 2). Durch eine entsprechend nahe Anordnung der Magnetpole 4 unterhalb des Schmelzenspiegels in der Kokille erhält man somit eine Umrührung durch die Kräfte F2, in den seitlich vom Gießstrahl liegenden Schmelzenbereichen 6, die durch die Wucht des auftreffenden Gießstrahls selbst nicht in Bewegung gesetzt werden würden.Figures 1 and 3 show the creation of the forces and movements. The voltage E induced by the magnetic field B and the direction of movement v of the penetrating melt is the vectorial product [ v x B ] proportional, whereby the vector of the induced voltage comes out of the plane of the drawing. Correspondingly, the currents i in FIG. 1 flow out of the drawing plane in the middle and into the drawing plane on the sides, as can be seen more clearly from the cross section according to FIG. 3. The interaction of the currents i flowing on the sides in FIG. 3 with the magnetic field B results in forces F 2 which correspond to the vectorial product [ i x B ] are proportional and extend into the plane of the drawing in FIG. 3 , that is, in the opposite direction to the braking force F 1 (see FIG. 2). A correspondingly close arrangement of the magnetic poles 4 below the melt level in the mold thus results in stirring by the forces F 2 in the melt regions 6 lying to the side of the pouring jet, which would not be set in motion by the force of the impinging pouring jet itself.

Die Erfindung kann im Rahmen des offenbarten allgemeinen Erfindungsgedankens in vielfacher Weise variiert werden.The invention can be varied in many ways within the scope of the general inventive idea disclosed.

Claims (1)

Verfahren zur Umrührung der nicht erstarrten Bereiche in einem Gießstrang, wobei der Strang in einer Kokille geformt wird und ein Gießstrahl über ein Gießrohr oder direkt in die Kokille gelangt und wobei ein statisches Magnetfeld (B) erzeugt wird, welches den Weg des Gießstrahls in der in der Kokille befindlichen Schmelze schneidet und unter Ausnutzung der Bewegung des den Gießstrahl bildenden Metalls die Geschwindigkeit des Gießstrahls in der Schmelze bremst und den Gießstrahl zersplittert, dadurch gekennzeichnet, daß das Magnetfeld, in Längsrichtung der Kokille gesehen, so nahe am Gießrohr bzw. am oberen Ende der Kokille angeordnet wird, daß die Schmelzenbereiche (6), die sich seitlich des in die Schmelze eindringenden Gießstrahls (2) befinden und somit nicht direkt von der Wucht des Gießstrahls durchrührt werden, von den durch das Zusammenwirken des Magnetfeldes (B) und der beim Bremsen des Gießstrahls induzierten Ströme (i) umgerührt werden.Process for stirring the non-solidified areas in a casting strand, wherein the strand is formed in a mold and a pouring jet reaches a casting tube or directly into the mold and a static magnetic field (B) is generated, which the path of the pouring jet in the the melt located in the mold cuts and using the movement of the metal forming the pouring jet slows down the speed of the pouring jet in the melt and splits the pouring jet, characterized in that the magnetic field, viewed in the longitudinal direction of the die, is so close to the pouring tube or at the upper end the mold is arranged so that the melt areas (6), which are located on the side of the pouring jet (2) penetrating into the melt and are therefore not directly affected by the force of the pouring jet, by the interaction of the magnetic field (B) and the Braking the pouring stream induced currents (i) are stirred.
EP83103466A 1982-04-19 1983-04-09 Method of stirring the non-solidified areas in a cast billet Expired EP0092126B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8202431 1982-04-19
SE8202431A SE8202431L (en) 1982-04-19 1982-04-19 MOVING STRING

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EP0092126A1 true EP0092126A1 (en) 1983-10-26
EP0092126B1 EP0092126B1 (en) 1986-03-26

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EP (1) EP0092126B1 (en)
JP (1) JPS58188555A (en)
BR (1) BR8301965A (en)
DE (1) DE3362650D1 (en)
ES (1) ES521581A0 (en)
SE (1) SE8202431L (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0467360A1 (en) * 1990-07-20 1992-01-22 Gec Alsthom Sa Method for producing a high performance joint between a metal and a superconducting ceramic article
EP0543290A3 (en) * 1991-11-13 1993-06-09 Aluminum Company Of America A process for ingot casting employing a magnetic field for reducing macrosegregation and associated apparatus and ingot
WO1998012008A1 (en) * 1996-09-19 1998-03-26 Hoogovens Staal B.V. Continuous casting machine
CN1046874C (en) * 1993-01-19 1999-12-01 瑞典通用电器勃朗勃威力公司 Device in continuous casting in a mould
WO2015162039A1 (en) * 2014-04-25 2015-10-29 Thyssenkrupp Steel Europe Ag Method and device for thin-slab strand casting

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2413153A1 (en) * 1978-01-02 1979-07-27 Siderurgie Fse Inst Rech MAGNETOROTATIVE CONTINUOUS CASTING PROCESS WITH SUBMERSIBLE NOZZLE AND COVERING MILK
DE2903234A1 (en) * 1978-02-10 1979-08-16 Asea Ab PROCEDURE AND CONDUCTING ARRANGEMENT FOR STIRRING A METALLIC MELT
DE2945018A1 (en) * 1978-11-09 1980-05-22 Asea Ab METHOD FOR STIRRING THE UNDERGROUND AREAS OF A CASTING STRAND
EP0040383A1 (en) * 1980-05-19 1981-11-25 Asea Ab Method and apparatus for stirring the molten metal in a continuous-casting strand

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2437900A1 (en) * 1978-10-05 1980-04-30 Siderurgie Fse Inst Rech CONTINUOUS CASTING PROCESS FOR METALS WITH BREWING IN THE SECONDARY COOLING AREA
DE2944760A1 (en) * 1979-11-06 1981-05-07 Siemens AG, 1000 Berlin und 8000 München DEVICE FOR STIRRING METAL MELT IN CONTINUOUS CASTING MILLS

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2413153A1 (en) * 1978-01-02 1979-07-27 Siderurgie Fse Inst Rech MAGNETOROTATIVE CONTINUOUS CASTING PROCESS WITH SUBMERSIBLE NOZZLE AND COVERING MILK
DE2903234A1 (en) * 1978-02-10 1979-08-16 Asea Ab PROCEDURE AND CONDUCTING ARRANGEMENT FOR STIRRING A METALLIC MELT
DE2945018A1 (en) * 1978-11-09 1980-05-22 Asea Ab METHOD FOR STIRRING THE UNDERGROUND AREAS OF A CASTING STRAND
EP0040383A1 (en) * 1980-05-19 1981-11-25 Asea Ab Method and apparatus for stirring the molten metal in a continuous-casting strand

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0467360A1 (en) * 1990-07-20 1992-01-22 Gec Alsthom Sa Method for producing a high performance joint between a metal and a superconducting ceramic article
EP0543290A3 (en) * 1991-11-13 1993-06-09 Aluminum Company Of America A process for ingot casting employing a magnetic field for reducing macrosegregation and associated apparatus and ingot
CN1046874C (en) * 1993-01-19 1999-12-01 瑞典通用电器勃朗勃威力公司 Device in continuous casting in a mould
WO1998012008A1 (en) * 1996-09-19 1998-03-26 Hoogovens Staal B.V. Continuous casting machine
EP0832704A1 (en) 1996-09-19 1998-04-01 Hoogovens Staal B.V. Continuous casting machine
US6460606B2 (en) 1996-09-19 2002-10-08 Corus Staal Bv Continuous casting machine
WO2015162039A1 (en) * 2014-04-25 2015-10-29 Thyssenkrupp Steel Europe Ag Method and device for thin-slab strand casting
EP3134220B1 (en) 2014-04-25 2019-09-04 ThyssenKrupp Steel Europe AG Method and device for thin-slab strand casting
US10486228B2 (en) 2014-04-25 2019-11-26 Thyssenkrupp Steel Europe Ag Method and device for thin-slab strand casting

Also Published As

Publication number Publication date
EP0092126B1 (en) 1986-03-26
JPH0338018B2 (en) 1991-06-07
BR8301965A (en) 1983-12-20
SE8202431L (en) 1983-10-20
JPS58188555A (en) 1983-11-04
ES8503263A1 (en) 1985-02-16
DE3362650D1 (en) 1986-04-30
ES521581A0 (en) 1985-02-16

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