EP2279052A1 - Method for the continuous casting of a metal strand - Google Patents

Method for the continuous casting of a metal strand

Info

Publication number
EP2279052A1
EP2279052A1 EP09749696A EP09749696A EP2279052A1 EP 2279052 A1 EP2279052 A1 EP 2279052A1 EP 09749696 A EP09749696 A EP 09749696A EP 09749696 A EP09749696 A EP 09749696A EP 2279052 A1 EP2279052 A1 EP 2279052A1
Authority
EP
European Patent Office
Prior art keywords
strand
metal
continuous casting
taking
thickness
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.)
Granted
Application number
EP09749696A
Other languages
German (de)
French (fr)
Other versions
EP2279052B1 (en
Inventor
Kurt Dittenberger
Udo Feischl
Klemens Hauser
Wolfgang Kibler
Paul Pennerstorfer
Helmut Wahl
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.)
Primetals Technologies Austria GmbH
Original Assignee
SIEMENS VAI METALS TECHNOLOGIES GmbH
Siemens VAI Metals Technologies GmbH Austria
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 SIEMENS VAI METALS TECHNOLOGIES GmbH, Siemens VAI Metals Technologies GmbH Austria filed Critical SIEMENS VAI METALS TECHNOLOGIES GmbH
Publication of EP2279052A1 publication Critical patent/EP2279052A1/en
Application granted granted Critical
Publication of EP2279052B1 publication Critical patent/EP2279052B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands
    • 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
    • B22D11/16—Controlling or regulating processes or operations
    • B22D11/20—Controlling or regulating processes or operations for removing cast stock

Definitions

  • the present invention relates to a method for continuously casting a metal strand in a continuous casting plant.
  • the invention relates to a process for the continuous casting of a metal strand, in particular a steel strand, in a continuous casting, wherein a strand with a trapped by a strand shell, liquid core drawn from a cooled continuous casting mold, in one of
  • Continuous casting subordinate strand support means supported, cooled with coolant and optionally metallurgically reduced, wherein thermodynamic state changes of the entire strand in a mathematical simulation model, including a heat conduction equation, are also included.
  • a method for the continuous casting of a metal strand in which a strand drawn from a strand shell liquid core extracted from a cooled mold, then supported in a strand support device and cooled with coolant.
  • the state changes occurring in the course of the continuous casting process are also calculated in real time for the entire strand by means of a mathematical simulation model, including the heat conduction equation, and the cooling of the strand is set as a function of the calculated thermodynamic state changes.
  • a method for continuous casting is known from DE 10122118 A1 in which a metal strand is drawn out of a mold, supported in a strand support device, cooled with coolant and at least one pair of strand support rolls of a metallurgical reduction, specifically a reduction in thickness in the form of a liquid core reduction. is subjected.
  • the skilled person is further known that a metal strand in continuous casting in the course of its solidification of a shrinkage, ie a change of strand dimensions, is subjected.
  • the size of the strand shrinkage occurring depends on the operating parameters of the continuous casting plant, for example on physical parameters of the metal to be cast, the casting temperature, the casting speed, the strand thickness or the strand cooling.
  • the object of the invention is to provide a method of the type mentioned, with which the product quality of a metal strand, for example by reducing the porosity and / or segregations, improved surface quality and / or shape retention, can be further improved.
  • a natural shrinkage of the strand in real time taking into account the physical parameters of the metal, the temperature of the metal in the casting manifold, the constantly measured pullout speed, the strand cooling and the thickness of the Strand is also calculated and adjusable strand strand guide rollers of the strand support device can be adjusted taking into account the natural shrinkage of the metal strand.
  • the mathematical simulation model When calculating the natural shrinkage of the strand, the mathematical simulation model generates a heat equation in real time, taking into account the physical parameters of the metal, the temperature of the metal Metal in the casting manifold, the constantly measured extraction speed, the strand cooling and the thickness of the strand solved numerically.
  • the strand is discretized, ie, for example, divided into a plurality of volume elements, and the heat equation equation periodically resolved taking into account the initial and boundary conditions by means of a process computer for the plurality of discrete elements, resulting in the time-varying temperature field of the entire strand.
  • natural shrinkage is the thermal
  • Expansion behavior of the strand as a function of temperature changes After the thermodynamic state changes for each discrete element from the solution of the heat conduction equation are known, the natural shrinkage of each element can be calculated, for example, from the volume expansion or contraction. If the metal strand is not to be further metallurgically reduced, the distances of the strand guide rollers that can be attached to the strand in the strand thickness direction are adjusted such that these distances follow the natural shrinkage of the metal strand in the strand extraction direction.
  • Two further advantageous embodiments of the method according to the invention arise when a further metallurgical reduction of the metal strand in the strand support device, for example a liquid core reduction, a soft reduction (in particular a dynamic soft reduction) or a surface treatment, taking into account the natural shrinkage of
  • Metal strand is performed.
  • the person skilled in the liquid core reduction and the soft reduction are known, whereby these metallurgical reduction methods are not further explained.
  • a metallurgical surface treatment of the metal strand in the strand support device is also known from EP 1289691 Bl.
  • the method according to the invention is carried out when the thermal equation is solved numerically in the mathematical simulation model taking into account temperature-dependent density changes of the metal strand. It is known to the person skilled in the art that the change in density of metal as a function of the temperature can assume significant proportions. So m 3 at 1550 0 C (temperature of the melt in the distribution trough) increases for example in the continuous casting process, the density of steel of about 7000 kg / 7800 kg to about / m 3 at 300 0 C ( micerstarrter strand).
  • a further advantageous embodiment of the method according to the invention is that in the numerical solution of the heat equation, taking into account temperature-dependent density changes of the metal strand approximated equations are used for the enthalpy, which have the exact mass and the exact enthalpy for the entire strand.
  • the growth or the conversion between different types of microstructures can be considered advantageously in the method according to the invention if the mathematical simulation model includes a computational model describing the formation of a desired microstructure in the metal strand, in a particularly advantageous manner by the application of a continuous Avrami phase conversion model.
  • the strand cooling is adjusted taking into account the calculated thermodynamic state changes.
  • the inventive method can be used without restriction in the casting of metal strands with billet, billet, slab or thin slab cross-section of any size in order to improve the quality of the cast metal strands.
  • Strangs a setpoint as possible corresponds.
  • the controller assumes either the calculated thickness of the strand or a measured beach thickness. in the In the first case, the calculated thickness is used to determine the manipulated variable, so that the thickness of the strand or a distance between the strand guide rollers need not be detected separately.
  • the thickness of the strand is detected by means of a measuring device and fed to a controller, wherein the manipulated variable is determined taking into account the detected thickness of the strand.
  • FIG. 1 shows a continuous casting plant in a schematic side view
  • FIG. 2 shows a schematic representation of a hydraulically adjustable segment of a strand support device
  • a steel strand 1 is formed from a molten steel 2 having a specific chemical composition by casting in a cooled continuous casting mold 3.
  • the molten steel 2 is from a ladle 4 via a tundish 5 and one of the tundish 5 by means of a in the
  • Continuous mold 3 formed pouring mirror reaching pouring tube 6 poured into the continuous casting mold 3.
  • strand guide rollers 7 are provided below the continuous casting mold 3 a strand support device for supporting the steel strand 1, which still has a liquid core 8 and initially only a very thin strand shell 9.
  • the steel strand 1 emerging from the straight-through-die with a straight axis is deflected in a bending zone 10 into an arcuate path 11 and is guided by strand guide rollers 7, which are arranged in several hydraulically adjustable segments 13. supported.
  • subsequent straightening zone 12 of the steel strand 1 is again straightened and discharged via a discharge roller table or reduced directly online thickness, for example by means of an on-line roll stand.
  • the steel strand 1 For cooling the steel strand 1, it is cooled directly or indirectly via strand guide rollers 7 provided with an internal cooling, whereby a specific temperature of the steel strand 1 can be adjusted.
  • Such strand cooling taking into account the thermodynamic state changes calculated online is known from DE 4417818 Al the applicant.
  • the physical parameters of the steel 2 for example the density, the specific heat capacity and conductivity, furthermore parameters of the strand cooling, the roll pitch, the strand width, the strand thickness in the mold and measured values of the strand thickness in the segments, can still be included in an input unit of the process computer 14 13 and the continuously measured casting speed can be entered.
  • the process computer 14 are based on a mathematical simulation model, comprising a heat conduction equation and a metallurgical calculation model for the consideration of
  • Phase transformation kinetics according to Avrami which calculates the target water quantities of strand cooling.
  • the steel strand 1 is cooled in a controlled manner in each segment, wherein the cooling water quantity in individual cooling zones of the segment of one valve (in FIG. 1, for reasons of clarity, only one valve is shown in one segment) of the strand cooling is set, which in turn is provided by an output unit of the process computer 14 is controlled.
  • the steel strand 1 no further metallurgical reduction, for example, Liquid Core Reduction, soft reduction or surface treatment of the strand are subjected, where the distance of strandable strand strand guide rollers 7 of the segments 13 via one or more hydraulic cylinders 15 to the calculated strand thickness, i. considering the natural shrinkage, adjusted.
  • the changes in thickness necessary for the reduction will be calculated for the strand thicknesses - under
  • thermodynamic state changes of the steel strand 1 are preferably calculated by means of a heat conduction equation taking into account the temperature-dependent change in the density of the steel strand.
  • a two-dimensional heat equation is, for example
  • the method according to the invention is independent of the dimension of the heat conduction equation and can therefore also be used without restriction with equations of a different dimension, for example, three-dimensional equations.
  • T ref is an arbitrary but constant reference temperature (usually 25 ° C.)
  • a parallel (as shown) or conical course of the strand thickness of the steel strand 1 can be set.
  • the thickness of the steel strand 1 can be adjusted via a hydraulic adjustment of the segment 13, wherein in a displacement measuring system of a hydraulic cylinder 15, the actual position and thus the distance between opposite strand guide rollers 7 measured and passed on to the process computer.
  • the process computer 14 calculates the natural strand shrinkage via the solution of the heat conduction equation and takes it into account in further metallurgical reductions, in the specific case of an LCR reduction with a liquid core 8, and thus specifies the target thickness of the steel strand 1.
  • a manipulated variable is determined by means of a nominal-actual comparison of the strand thickness and to an electro-hydraulic valve, which the
  • Hydraulic cylinder 15 is assigned, issued.
  • the segments 13 can be used on the one hand for the adjustment of the strand guide rollers 7 to the natural strand shrinkage, on the other hand can be realized on appropriate positions of the rollers 7, of course, all metallurgical reductions in the strand support device.
  • the strand 1 is supported by the strand support rollers 7 on a lower part of a segment frame 17, on the inside of the strand, the support via strand support rollers 7 on an upper part of the segment frame 16.
  • the extension direction of the steel strand 1 is shown by an arrow. Reference sign list

Landscapes

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

Abstract

The invention relates to a method for the continuous casting of a metal strand in a continuous casting plant, a strand being withdrawn from an in-line die, supported in a strand support unit, cooled by a coolant and optionally metallurgically reduced, thermodynamic changes in the entire strand being calculated in a mathematical model containing a thermal conduction equation. The aim of the invention is to provide a method which can be used to improve the product quality of a metal strand, for example by reducing the porosity and/or liquation and by improving the surface quality and form stability. Said aim is achieved by a method, according to which the natural shrinkage of the strand is calculated in real time in the mathematical simulation model, taking into consideration the physical parameters of the metal, the temperature in the casting distributor, the frequently measured withdrawal speed, the cooling of the strand and the thickness of the strand and strand guide rollers of the strand support unit, said rollers being placed against the strand, are set by taking into consideration the natural shrinkage of the metal strand.

Description

Verfahren zum Stranggießen eines Metallstrangs Method for continuous casting of a metal strand
Die vorliegende Erfindung betrifft ein Verfahren zum Stranggießen eines Metallstrangs in einer Stranggießanlage.The present invention relates to a method for continuously casting a metal strand in a continuous casting plant.
Konkret betrifft die Erfindung ein Verfahren zum Stranggießen eines Metallstrangs, insbesondere eines Stahlstrangs, in einer Stranggießanlage, wobei ein Strang mit einem, von einer Strangschale eingeschlossenen, flüssigen Kern aus einer gekühlten Durchlaufkokille ausgezogen, in einer derSpecifically, the invention relates to a process for the continuous casting of a metal strand, in particular a steel strand, in a continuous casting, wherein a strand with a trapped by a strand shell, liquid core drawn from a cooled continuous casting mold, in one of
Durchlaufkokille nachgeordneten Strangstützeinrichtung, gestützt, mit Kühlmittel gekühlt und gegebenenfalls metallurgisch reduziert wird, wobei thermodynamische Zustandsänderungen des gesamten Strangs in einem mathematischen Simulationsmodell, beinhaltend eine Wärmeleitungsgleichung, mitberechnet werden.Continuous casting subordinate strand support means, supported, cooled with coolant and optionally metallurgically reduced, wherein thermodynamic state changes of the entire strand in a mathematical simulation model, including a heat conduction equation, are also included.
Aus der DE 4417808 Al ist ein Verfahren zum Stranggießen eines Metallstrangs bekannt, bei dem ein Strang mit von einer Strangschale eingeschlossenem flüssigen Kern aus einer gekühlten Kokille ausgezogen, anschließend in einer Strangstützeinrichtung gestützt und mit Kühlmittel gekühlt wird. Die im Zuge des Stranggussprozesses passierenden Zustandsänderungen werden mittels eines mathematischen Simulationsmodells, beinhaltend die Wärmeleitungsgleichung, für den gesamten Strang in Echtzeit mitberechnet und die Kühlung des Strangs in Abhängigkeit der berechneten thermodynamischen Zustandsänderungen eingestellt.From DE 4417808 Al a method for the continuous casting of a metal strand is known, in which a strand drawn from a strand shell liquid core extracted from a cooled mold, then supported in a strand support device and cooled with coolant. The state changes occurring in the course of the continuous casting process are also calculated in real time for the entire strand by means of a mathematical simulation model, including the heat conduction equation, and the cooling of the strand is set as a function of the calculated thermodynamic state changes.
Aus der DE 10122118 Al ist ein Verfahren zum Stranggießen bekannt, bei dem ein Metallstrang aus einer Kokille ausgezogen, in einer Strangstützeinrichtung gestützt, mit Kühlmittel gekühlt und von wenigstens einem Paar von Strangstützrollen einer metallurgischen Reduktion, konkret einer Dickenreduktion in Form einer Liquid Core Reduction, unterzogen wird. Dem Fachmann ist weiters bekannt, dass ein Metallstrang beim Stranggießen im Zuge seiner Erstarrung einer Schrumpfung, d.h. einer Änderung von Strangabmessungen, unterworfen ist. Die Größe der auftretenden Strangschrumpfungen ist abhängig von Betriebsparametern der Stranggießanlage, beispielsweise von physikalischen Parametern des zu vergießenden Metalls, der Gießtemperatur, der Gießgeschwindigkeit, der Strangdicke oder der Strangkühlung.A method for continuous casting is known from DE 10122118 A1 in which a metal strand is drawn out of a mold, supported in a strand support device, cooled with coolant and at least one pair of strand support rolls of a metallurgical reduction, specifically a reduction in thickness in the form of a liquid core reduction. is subjected. The skilled person is further known that a metal strand in continuous casting in the course of its solidification of a shrinkage, ie a change of strand dimensions, is subjected. The size of the strand shrinkage occurring depends on the operating parameters of the continuous casting plant, for example on physical parameters of the metal to be cast, the casting temperature, the casting speed, the strand thickness or the strand cooling.
Die während des Stranggießprozesses auftretenden Änderungen der Betriebsparameter einer Stranggießanlage - beispielsweise Änderungen der Gießgeschwindigkeit oder der Strangkühlung - bleiben bzgl. der Abstände der Strangstützrollen der Strangstützeinrichtung unberücksichtigt und führen in weiterer Folge zu Qualitätsminderungen des Metallstrangs.The changes in the operating parameters of a continuous casting plant occurring during the continuous casting process-for example changes in the casting speed or the strand cooling-are disregarded with respect to the distances between the strand support rolls of the strand support device and subsequently lead to reductions in the quality of the metal strand.
Aufgabe der Erfindung ist es, ein Verfahren der eingangs genannten Art zu schaffen, mit welchem die Produktqualität eines Metallstrangs, beispielsweise durch eine Verringerung der Porosität und/oder von Seigerungen, einer verbesserten Oberflächenqualität und/oder Formhaltigkeit, weiter verbessert werden kann.The object of the invention is to provide a method of the type mentioned, with which the product quality of a metal strand, for example by reducing the porosity and / or segregations, improved surface quality and / or shape retention, can be further improved.
Diese Aufgabe wird durch ein Verfahren der eingangs genannten Art gelöst, bei dem im mathematischen Simulationsmodell eine natürliche Schrumpfung des Strangs in Echtzeit unter Berücksichtigung der physikalischen Parameter des Metalls, der Temperatur des Metalls im Gießverteiler, der ständig gemessenen Auszugsgeschwindigkeit, der Strangkühlung und der Dicke des Strangs mitberechnet wird und an den Strang anstellbare Strangführungsrollen der Strangstützeinrichtung unter Berücksichtigung der natürlichen Schrumpfung des Metallstrangs eingestellt werden.This object is achieved by a method of the type mentioned, in the mathematical simulation model, a natural shrinkage of the strand in real time, taking into account the physical parameters of the metal, the temperature of the metal in the casting manifold, the constantly measured pullout speed, the strand cooling and the thickness of the Strand is also calculated and adjusable strand strand guide rollers of the strand support device can be adjusted taking into account the natural shrinkage of the metal strand.
Bei der Berechnung der natürlichen Schrumpfung des Strangs wird im mathematischen Simulationsmodell in Echtzeit eine Wärmeleitungsgleichung unter Berücksichtigung der physikalischen Parameter des Metalls, der Temperatur des Metalls im Gießverteiler, der ständig gemessenen Auszugsgeschwindigkeit, der Strangkühlung und der Dicke des Strangs numerisch gelöst. Hierzu wird der Strang diskretisiert , d.h. beispielsweise in eine Vielzahl von Volumenelementen zerteilt, und die Wärmeleitungsgleichung unter Berücksichtigung der Anfangs- und Randbedingungen mittels eines Prozessrechners für die Vielzahl von diskreten Elementen periodisch gelöst, wodurch sich das zeitveränderliche Temperaturfeld des gesamten Strangs ergibt. Als natürliche Schrumpfung wird das thermischeWhen calculating the natural shrinkage of the strand, the mathematical simulation model generates a heat equation in real time, taking into account the physical parameters of the metal, the temperature of the metal Metal in the casting manifold, the constantly measured extraction speed, the strand cooling and the thickness of the strand solved numerically. For this purpose, the strand is discretized, ie, for example, divided into a plurality of volume elements, and the heat equation equation periodically resolved taking into account the initial and boundary conditions by means of a process computer for the plurality of discrete elements, resulting in the time-varying temperature field of the entire strand. As natural shrinkage is the thermal
Ausdehnungsverhalten des Strangs in Abhängigkeit von Temperaturänderungen bezeichnet. Nachdem die thermodynamischen Zustandsänderungen für jedes diskrete Element aus der Lösung der Wärmeleitungsgleichung bekannt sind, kann die natürliche Schrumpfung jedes Elements beispielsweise aus der Volumenausdehnung bzw. -kontraktion berechnet werden. Soll der Metallstrang nicht weitergehend metallurgisch reduziert werden, so werden die Abstände der an den Strang anstellbaren Strangführungsrollen in Strangdickenrichtung derart eingestellt, dass diese Abstände der natürlichen Schrumpfung des Metallstrangs in Strangauszugsrichtung folgen.Expansion behavior of the strand as a function of temperature changes. After the thermodynamic state changes for each discrete element from the solution of the heat conduction equation are known, the natural shrinkage of each element can be calculated, for example, from the volume expansion or contraction. If the metal strand is not to be further metallurgically reduced, the distances of the strand guide rollers that can be attached to the strand in the strand thickness direction are adjusted such that these distances follow the natural shrinkage of the metal strand in the strand extraction direction.
Zwei weitere vorteilhafterweise Ausführungsformen des erfindungsgemäßen Verfahrens ergeben sich dann, wenn eine weitergehende metallurgische Reduktion des Metallstrangs in der Strangstützeinrichtung, beispielsweise eine Liquid Core Reduction, eine Soft Reduction (insbesondere eine dynamische Soft Reduction) oder eine Oberflächenbehandlung, unter Berücksichtigung der natürlichen Schrumpfung desTwo further advantageous embodiments of the method according to the invention arise when a further metallurgical reduction of the metal strand in the strand support device, for example a liquid core reduction, a soft reduction (in particular a dynamic soft reduction) or a surface treatment, taking into account the natural shrinkage of
Metallstrangs durchgeführt wird. Dem Fachmann sind die Liquid Core Reduction und die Soft Reduction bekannt, wodurch diese metallurgischen Reduktionsarten nicht weiter erläutert werden. Eine metallurgische Oberflächenbehandlung des Metallstrangs in der Strangstützeinrichtung ist ebenfalls aus der EP 1289691 Bl bekannt. Durch die Berücksichtigung der natürlichen Schrumpfung des Metallstrangs ist sichergestellt, dass eine weitergehende metallurgische Reduktion in allen Betriebspunkten des Stranggießprozesses - und nicht wie im Stand der Technik nur in einem Betriebspunkt - in vorteilhafter Weise durchgeführt werden kann.Metal strand is performed. The person skilled in the liquid core reduction and the soft reduction are known, whereby these metallurgical reduction methods are not further explained. A metallurgical surface treatment of the metal strand in the strand support device is also known from EP 1289691 Bl. By taking into account the natural shrinkage of the metal strand, it is ensured that a further metallurgical reduction in all Operating points of the continuous casting - and not as in the prior art only in one operating point - can be carried out in an advantageous manner.
Auf besonders genaue und daher vorteilhafte Art und Weise wird das erfindungsgemäße Verfahren ausgeführt, wenn im mathematischen Simulationsmodell die Wärmeleitungsgleichung unter Berücksichtigung temperaturabhängiger Dichteänderungen des Metallstrangs numerisch gelöst wird. Dem Fachmann ist bekannt, dass die Dichteänderung von Metall in Abhängigkeit der Temperatur signifikante Ausmaße annehmen kann. So erhöht sich beispielsweise beim Stranggussprozess die Dichte von Stahl von ca. 7000 kg/m3 bei 1550 0C (Temperatur der Schmelze im Gießverteiler) auf ca. 7800 kg/m3 bei 300 0C (durcherstarrter Strang) .In a particularly accurate and therefore advantageous manner, the method according to the invention is carried out when the thermal equation is solved numerically in the mathematical simulation model taking into account temperature-dependent density changes of the metal strand. It is known to the person skilled in the art that the change in density of metal as a function of the temperature can assume significant proportions. So m 3 at 1550 0 C (temperature of the melt in the distribution trough) increases for example in the continuous casting process, the density of steel of about 7000 kg / 7800 kg to about / m 3 at 300 0 C (durcherstarrter strand).
Eine weitere vorteilhafte Ausführungsform des erfindungsgemäßen Verfahrens besteht darin, dass bei der numerischen Lösung der Wärmeleitungsgleichung unter Berücksichtigung temperaturabhängiger Dichteänderungen des Metallstrangs approximierte Gleichungen für die Enthalpie verwendet werden, welche für den gesamten Strang die exakte Masse und die exakte Enthalpie aufweisen. Mittels dieser Ausführungsform ist sichergestellt, dass die Berechnung der natürlichen Schrumpfung des Metallstrangs sowohl richtig bzgl . der Masse als auch der Enthalpie erfolgt, wodurch eine besonders hohe Genauigkeit der Lösung, d.h. der thermodynamischen Zustandsänderungen und der natürlichen Schrumpfung, sichergestellt wird.A further advantageous embodiment of the method according to the invention is that in the numerical solution of the heat equation, taking into account temperature-dependent density changes of the metal strand approximated equations are used for the enthalpy, which have the exact mass and the exact enthalpy for the entire strand. By means of this embodiment, it is ensured that the calculation of the natural shrinkage of the metal strand is both correct with respect to. the mass as well as the enthalpy, whereby a particularly high accuracy of the solution, i. thermodynamic state changes and natural shrinkage.
Das Wachstum bzw. die Umwandlung zwischen unterschiedlichen Gefügearten lässt sich vorteilhaft im erfindungsgemäßen Verfahren berücksichtigen, wenn das mathematische Simulationsmodell eine die Ausbildung eines gewünschten Gefüges im Metallstrang beschreibendes Rechenmodell, in besonders vorteilhafter Weise durch die Anwendung eines kontinuierliches Phasen-Umwandlungsmodell nach Avrami, beinhaltet . In einer weiteren, besonders vorteilhaften Ausprägung des erfindungsgemäßen Verfahrens, wird die Strangkühlung unter Berücksichtigung der errechneten thermodynamischen Zustandsänderungen eingestellt. Durch diese Maßnahme wird eine äußerst hohe Produktqualität des Metallstrangs sichergestellt, da der Metallstrang unter Berücksichtigung der thermodynamischen Zustandsänderungen abgekühlt und die natürliche Strangschrumpfung bei der Einstellung der Abstände der Strangführungsrollen mitberücksichtigt wird.The growth or the conversion between different types of microstructures can be considered advantageously in the method according to the invention if the mathematical simulation model includes a computational model describing the formation of a desired microstructure in the metal strand, in a particularly advantageous manner by the application of a continuous Avrami phase conversion model. In a further, particularly advantageous embodiment of the method according to the invention, the strand cooling is adjusted taking into account the calculated thermodynamic state changes. By this measure, an extremely high product quality of the metal strand is ensured because the metal strand is cooled taking into account the thermodynamic state changes and the natural strand shrinkage is taken into account in the adjustment of the distances of the strand guide rollers.
Das erfindungsgemäße Verfahren kann uneingeschränkt beim Gießen von Metallsträngen mit Knüppel-, Vorblock-, Brammenoder Dünnbrammenquerschnitt beliebiger Abmessungen verwendet werden, um die Qualität der gegossenen Metallstränge zu verbessern .The inventive method can be used without restriction in the casting of metal strands with billet, billet, slab or thin slab cross-section of any size in order to improve the quality of the cast metal strands.
Eine weitere vorteilhafte Ausprägung des erfindungsgemäßen Verfahrens besteht darin, die an den Strang anstellbaren Strangführungsrollen so anzustellen, dass die Dicke desA further advantageous embodiment of the method according to the invention is to employ the strand guide rollers that can be attached to the strand in such a way that the thickness of the strand guide rollers can be adjusted
Strangs einem Sollwert möglichst entspricht. Mittels dieser Ausprägung des Verfahrens ist es möglich, die anstellbaren Strangführungsrollen so anzustellen, dass die Dicke bei einer bestimmten Position in Auszugsrichtung des Strangs (z.B. bei einer bestimmten Führungsrolle der Strangstützeinrichtung) einem Dicken-Sollwert, dh. einer Zieldicke des Strangs, möglichst entspricht, sodass bereits beim Stranggießen eine hohe Dickengenauigkeit des Strangs erreicht werden kann.Strangs a setpoint as possible corresponds. By means of this embodiment of the method, it is possible to adjust the engageable strand guide rollers so that the thickness at a given position in the withdrawal direction of the strand (e.g., at a particular guide roller of the strand support device) is a desired thickness value, ie. a target thickness of the strand, if possible, so that even in continuous casting a high thickness accuracy of the strand can be achieved.
Eine Ausführungsform besteht darin, dass ein Regler unterOne embodiment is that a regulator under
Zuhilfenahme eines Regelgesetzes und unter Berücksichtigung des Sollwerts und der natürlichen Schrumpfung des Strangs eine Stellgröße ermittelt, die wenigstens einer anstellbaren Strangführungsrolle zugeführt wird, sodass die Dicke des Strangs dem Sollwert möglichst entspricht. Bei dieserWith the aid of a control law and taking into account the setpoint and the natural shrinkage of the strand determines a manipulated variable, which is supplied to at least one engageable strand guide roller, so that the thickness of the strand corresponds to the desired value as possible. At this
Ausführungsform geht der Regler entweder von der berechneten Dicke des Strangs oder von einer gemessen Stranddicke aus. Im ersten Fall, wird die berechnete Dicke zur Ermittlung der Stellgröße herangezogen, sodass die Dicke des Strangs oder ein Abstand zwischen den Strangführungsrollen nicht gesondert erfasst werden muss.Embodiment, the controller assumes either the calculated thickness of the strand or a measured beach thickness. in the In the first case, the calculated thickness is used to determine the manipulated variable, so that the thickness of the strand or a distance between the strand guide rollers need not be detected separately.
Im zweiten Fall, wird die Dicke des Strangs mittels einer Messeinrichtung erfasst und einem Regler zugeführt, wobei die Stellgröße unter Berücksichtigung der erfassten Dicke des Strangs ermittelt wird. Mittels dieses Regelverfahrens ist eine hochgenaue Erreichung der Strangdicke möglich.In the second case, the thickness of the strand is detected by means of a measuring device and fed to a controller, wherein the manipulated variable is determined taking into account the detected thickness of the strand. By means of this control method, a highly accurate achievement of the strand thickness is possible.
Weitere Vorteile und Merkmale der vorliegenden Erfindung ergeben sich aus der nachfolgenden Beschreibung nicht einschränkender Ausführungsbeispiele, wobei auf die folgenden Figuren Bezug genommen wird, die Folgendes zeigen:Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, reference being made to the following figures, which show the following:
Fig. 1 eine Stranggussanlage in schematischer Seitenansicht Fig. 2 eine schematische Darstellung eines hydraulisch anstellbaren Segments einer Strangstützeinrichtung1 shows a continuous casting plant in a schematic side view, FIG. 2 shows a schematic representation of a hydraulically adjustable segment of a strand support device
Ein Stahlstrang 1 wird aus einer Stahlschmelze 2 mit einer bestimmten chemischen Zusammensetzung durch Giessen in einer gekühlten Durchlaufkokille 3 gebildet. Die Stahlschmelze 2 wird aus einer Gießpfanne 4 über ein Zwischengefäß 5 und ein vom Zwischengefäß 5 mittels eines unter den in derA steel strand 1 is formed from a molten steel 2 having a specific chemical composition by casting in a cooled continuous casting mold 3. The molten steel 2 is from a ladle 4 via a tundish 5 and one of the tundish 5 by means of a in the
Durchlaufkokille 3 gebildeten Gießspiegel reichenden Gießrohres 6 in die Durchlaufkokille 3 gegossen. Unterhalb der Durchlaufkokille 3 sind Strangführungsrollen 7 einer Strangstützeinrichtung zur Abstützung des Stahlstrangs 1 vorgesehen, der noch einen flüssigen Kern 8 und zunächst eine nur sehr dünne Strangschale 9 aufweist. Der aus der Durchlaufkokille mit gerader Achse austretende Stahlstrang 1 wird in einer Biegezone 10 in eine Kreisbogenbahn 11 umgelenkt und von Strangführungsrollen 7, welche in mehreren hydraulisch anstellbaren Segmenten 13 angeordnet sind, gestützt. In einer der Kreisbogenbahn 11 nachfolgenden Richtzone 12 wird der Stahlstrang 1 wiederum geradegerichtet und über einen Auslaufrollgang ausgefördert oder direkt online dickenreduziert, z.B. mittels eines online angeordneten Walzgerüstes. Zur Kühlung des Stahlstranges 1 wird dieser direkt oder indirekt - über mit einer Innenkühlung versehene Strangführungsrollen 7 - gekühlt, wodurch eine bestimmte Temperatur des Stahlstrangs 1 eingestellt werden kann. Die Versorgung des Stahlstranges 1 mit der für das gewünschte Gefüge des Stahlstranges 1 notwendigen Kühlmittelmenge erfolgt über einen geschlossenen Regelkreis mittels eines Prozessrechners 14. Eine derartige Strangkühlung unter Berücksichtigung der online berechneten thermodynamischen Zustandsänderungen ist aus der DE 4417818 Al der Anmelderin bekannt. In eine Eingabeeinheit des Prozessrechners 14 können beispielsweise noch die physikalischen Parameter des Stahls 2, beispielsweise die Dichte, die spezifische Wärmekapazität und -leitfähigkeit, weiters Parameter der Strangkühlung, die Rollenteilung, die Strangbreite, die Strangdicke in der Kokille sowie Messwerte der Strangdicke in den Segmenten 13 und die ständig gemessene Gießgeschwindigkeit eingegeben werden. In dem Prozessrechner 14 werden anhand eines mathematischen Simulationsmodells, aufweisend eine Wärmeleitungsgleichung und ein metallurgisches Rechenmodell zur Berücksichtung derContinuous mold 3 formed pouring mirror reaching pouring tube 6 poured into the continuous casting mold 3. Below the continuous casting mold 3 strand guide rollers 7 are provided a strand support device for supporting the steel strand 1, which still has a liquid core 8 and initially only a very thin strand shell 9. The steel strand 1 emerging from the straight-through-die with a straight axis is deflected in a bending zone 10 into an arcuate path 11 and is guided by strand guide rollers 7, which are arranged in several hydraulically adjustable segments 13. supported. In one of the arcuate path 11 subsequent straightening zone 12 of the steel strand 1 is again straightened and discharged via a discharge roller table or reduced directly online thickness, for example by means of an on-line roll stand. For cooling the steel strand 1, it is cooled directly or indirectly via strand guide rollers 7 provided with an internal cooling, whereby a specific temperature of the steel strand 1 can be adjusted. The supply of the steel strand 1 with the amount of coolant necessary for the desired structure of the steel strand 1 via a closed loop by means of a process computer 14. Such strand cooling taking into account the thermodynamic state changes calculated online is known from DE 4417818 Al the applicant. The physical parameters of the steel 2, for example the density, the specific heat capacity and conductivity, furthermore parameters of the strand cooling, the roll pitch, the strand width, the strand thickness in the mold and measured values of the strand thickness in the segments, can still be included in an input unit of the process computer 14 13 and the continuously measured casting speed can be entered. In the process computer 14 are based on a mathematical simulation model, comprising a heat conduction equation and a metallurgical calculation model for the consideration of
Phasenumwandlungskinetik nach Avrami, die Soll-Wassermengen der Strangkühlung errechnet. Der Stahlstrang 1 wird in jedem Segment kontrolliert abgekühlt, wobei die Kühlwassermenge in einzelnen Kühlzonen des Segments von jeweils einem Ventil (in Fig. 1 ist aus Gründen der Übersichtlichkeit nur ein Ventil bei einem Segment dargestellt) der Strangkühlung eingestellt wird, welches wiederum von einer Ausgabeeinheit des Prozessrechners 14 angesteuert wird. Aus der Lösung der Wärmeleitungsgleichung wird auch die Volumenskontraktion des Stahlstrangs 1 aufgrund der thermodynamischen Zustandsänderungen mittels der Formel dV =ß-V0-dT berechnet, wobei ß Volumenausdehnungskoeffizient V Volumen eines Elements V0 Volumen bei Referenztemperatur T Temperatur.Phase transformation kinetics according to Avrami, which calculates the target water quantities of strand cooling. The steel strand 1 is cooled in a controlled manner in each segment, wherein the cooling water quantity in individual cooling zones of the segment of one valve (in FIG. 1, for reasons of clarity, only one valve is shown in one segment) of the strand cooling is set, which in turn is provided by an output unit of the process computer 14 is controlled. From the solution of the heat conduction equation, the volume contraction of the Steel strand 1 due to the thermodynamic state changes by the formula dV = ß-V 0 -dT calculated, where ß volume expansion coefficient V volume of an element V 0 volume at reference temperature T temperature.
Soll der Stahlstrang 1 keiner weitergehenden metallurgischen Reduktion, beispielsweise Liquid Core Reduction, Soft Reduction oder eine Oberflächenbehandlung des Strangs unterzogen werden, wo wird der Abstand der an den Strang anstellbaren Strangführungsrollen 7 der Segmente 13 über einen oder mehrere Hydraulikzylinder 15 auf die errechnete Strangdicke, d.h. unter Berücksichtigung der natürlichen Schrumpfung, eingestellt. Soll jedoch eine weitergehende metallurgische Reduktion des Stahlstrangs durchgeführt werden, so werden die für die Reduktion notwendigen Dickenänderungen den errechneten Strangdicken - unterIf the steel strand 1 no further metallurgical reduction, for example, Liquid Core Reduction, soft reduction or surface treatment of the strand are subjected, where the distance of strandable strand strand guide rollers 7 of the segments 13 via one or more hydraulic cylinders 15 to the calculated strand thickness, i. considering the natural shrinkage, adjusted. However, if a further metallurgical reduction of the steel strand is to be carried out, the changes in thickness necessary for the reduction will be calculated for the strand thicknesses - under
Berücksichtigung der natürlichen Schrumpfung - überlagert.Consideration of natural shrinkage - superimposed.
Vorzugsweise werden die thermodynamischen Zustandsänderungen des Stahlstrangs 1 mittels einer Wärmeleitungsgleichung unter Berücksichtigung der temperaturabhängigen Dichteänderung des Stahlstrangs berechnet. Eine zweidimensionale Wärmeleitungsgleichung lautet beispielsweiseThe thermodynamic state changes of the steel strand 1 are preferably calculated by means of a heat conduction equation taking into account the temperature-dependent change in the density of the steel strand. A two-dimensional heat equation is, for example
(8E1nJxJ) dEtrans{x,t)Λ_d2u(x,t) d2u(x,t) y d Tt" + Vcast \t) d Zz J ~ O äx~~2 o Hy~~2 wobei t Zeit in [s] x die Koordinate in Strangdickenrichtung y die Koordinate in Strangauszugsrichtung(8E 1n JxJ) dE trans {x, t) Λ_d 2 u (x, t) d 2 u (x, t) yd Tt "+ V cast \ t ) d Zz J ~ O ax ~~ 2 o Hy ~~ 2 where t is time in [s] x the coordinate in the strand thickness direction y the coordinate in the strand extension direction
— partielle Ableitung nach der Zeit t dt d dPartial derivation after the time t dt dd
—,— partielle Ableitungen nach dem Ort x, y dx dy x Ortsvektor in einem rechtwinkeligen Koordinatensystem Emass\x,t) Massenbezogene Enthalpie an der Stelle x zur Zeit t ξ Dimensionslose Laufvariable -, - partial derivatives according to the location x, y dx dy x position vector in a rectangular coordinate system E mass \ x, t) mass-related enthalpy at the point x at time t ξ dimensionless running variable
T[x,t) Temperatur an der Stelle x zur Zeit tT [x, t) temperature at point x at time t
Etrans{x,t) Transformierte massenbezogene Enthalpie an derE trans {x, t) Transformed mass enthalpy at the
Stelle x zur Zeit tPlace x at time t
Das erfindungsgemäße Verfahren ist unabhängig von der Dimension der Wärmeleitungsgleichung und kann daher uneingeschränkt auch mit Gleichungen anderer Dimension, z.B, dreidimensionalen Gleichungen, verwendet werden.The method according to the invention is independent of the dimension of the heat conduction equation and can therefore also be used without restriction with equations of a different dimension, for example, three-dimensional equations.
Vorteilhafterweise werden zwei Ansätze für eine, bzgl. der Masse und der Enthalpie global richtige, transformierte Enthalpie Etrans{x,t) verwendet. Oberhalb des Durcherstarrungspunkts lautet der AnsatzAdvantageously, two approaches are used for one, with respect to the mass and the enthalpy globally correct, transformed enthalpy E trans {x, t). Above the solidification point is the approach
Etans (x, t) = \ \p(ξ) ■ Emass (ξ) - ) - Emass (ξ))\ dξ . Hingegen verwendet man unterhalb des Durcherstarrungspunkts den Ansatz E tans (x, t) = \\ p (ξ) ■ E mass (ξ) -) - E mass (ξ)) \ dξ. On the other hand, the approach is used below the solidification point
Hierin bedeutenHerein mean
Tref eine beliebige, aber konstante Referenztemperatur (üblicherweise 25 0C)T ref is an arbitrary but constant reference temperature (usually 25 ° C.)
Ttund Temperatur des Metalls im Gießspiegel in [° K]T t and temperature of the metal in the pouring mirror in [° K]
Emassχx,t) Zeitliche Ableitung der massenbezogenen Enthalpie Einfacherweise wird die Wärmeleitungsgleichung auf Lagrange' sehe Koordinaten xLag transformiert, d.h. von einem mit der Strangauszugsbewegung mitbewegten Beobachter betrachtet. Die Wärmeleitungsgleichung in Lagrange' sehen Koordinaten kann mit Standardverfahren der numerischenE mass χx, t) Time derivative of the mass enthalpy The heat equation is simply transformed to Lagrange's coordinates x Lag , ie viewed by an observer moving along with the string extraction movement. The heat equation in Lagrange 'can see coordinates using standard methods of numerical
Mathematik, beispielsweise dem Verfahren der Finiten Volumen, gelöst werden.Mathematics, for example, the method of finite volume, be solved.
In Fig. 2 ist ein einstellbares Segment 13 der Strangstützeinrichtung näher gezeigt. Pro Segment 13 kann ein paralleler (wie dargestellt) oder konischer Verlauf der Strangdicke des Stahlstrangs 1 eingestellt werden. Hierbei kann die Dicke des Stahlstrangs 1 über eine hydraulische Anstellung des Segments 13 verstellt werden, wobei in einem Wegmessystem eines Hydraulikzylinders 15 die Ist-Position und somit auch den Abstand zwischen gegenüberliegenden Strangführungsrollen 7 gemessen und an den Prozessrechner weitergeben wird. Der Prozessrechner 14 errechnet über die Lösung der Wärmeleitungsgleichung die natürliche Strangschrumpfung und berücksichtigt diese bei weiteren metallurgischen Reduktionen, im konkreten Fall einer LCR Reduktion mit einem flüssigen Kern 8, und gibt somit die Soll-Dicke des Stahlstrangs 1 vor. Von einem nicht dargestellten Positionsregler wird mittels eines Soll-Ist- Vergleichs der Strangdicke eine Stellgröße ermittelt und an ein elektro-hydraulisches Ventil, welches demIn Fig. 2, an adjustable segment 13 of the strand support device is shown in more detail. For each segment 13, a parallel (as shown) or conical course of the strand thickness of the steel strand 1 can be set. Here, the thickness of the steel strand 1 can be adjusted via a hydraulic adjustment of the segment 13, wherein in a displacement measuring system of a hydraulic cylinder 15, the actual position and thus the distance between opposite strand guide rollers 7 measured and passed on to the process computer. The process computer 14 calculates the natural strand shrinkage via the solution of the heat conduction equation and takes it into account in further metallurgical reductions, in the specific case of an LCR reduction with a liquid core 8, and thus specifies the target thickness of the steel strand 1. By a position controller, not shown, a manipulated variable is determined by means of a nominal-actual comparison of the strand thickness and to an electro-hydraulic valve, which the
Hydraulikzylinder 15 zugeordnet ist, ausgegeben. Prinzipiell können die Segmente 13 einerseits für die Nachstellung der Strangführungsrollen 7 an die natürliche Strangschrumpfung verwendet werden, andererseits lassen sich über entsprechende Stellungen der Rollen 7 natürlich sämtliche metallurgischen Reduktionen in der Strangstützeinrichtung realisieren. Auf der Außenseite stützt sich der Strang 1 über die Strangstützrollen 7 an einem Unterteil eines Segmentrahmens 17 ab, an der Innenseite des Strangs erfolgt die Abstützung über Strangstützrollen 7 an einem Oberteil des Segmentrahmens 16. Die Auszugsrichtung des Stahlstrangs 1 ist durch einen Pfeil dargestellt. Bezugs zeichenlisteHydraulic cylinder 15 is assigned, issued. In principle, the segments 13 can be used on the one hand for the adjustment of the strand guide rollers 7 to the natural strand shrinkage, on the other hand can be realized on appropriate positions of the rollers 7, of course, all metallurgical reductions in the strand support device. On the outside, the strand 1 is supported by the strand support rollers 7 on a lower part of a segment frame 17, on the inside of the strand, the support via strand support rollers 7 on an upper part of the segment frame 16. The extension direction of the steel strand 1 is shown by an arrow. Reference sign list
1 Stahlstrang1 steel strand
2 Stahlschmelze2 molten steel
3 Durchlaufkokille3 continuous casting mold
4 Gießpfanne4 ladle
5 Zwischengefäß5 intermediate vessel
6 Gießrohr6 pouring tube
7 Strangführungsrolle7 strand guide roller
8 Flüssiger Kern8 Liquid core
9 Strangschale9 strand shell
10 Biegezone10 bending zone
11 Kreisbogenbahn11 circular arc
12 Richtzone12 straightening zone
13 Segment der Strangstützeinrichtung13 segment of the strand support device
14 Prozessrechner14 process computers
15 Hydraulikzylinder15 hydraulic cylinders
16 Segmentrahmen Oberteil16 segment frame upper part
17 Segmentrahmen Unterteil 17 Segment frame lower part

Claims

Patentansprüche / Patent Claims Claims / Patent Claims
1. Verfahren zum Stranggießen eines Metallstrangs, insbesondere eines Stahlstrangs, in einer Stranggießanlage, wobei ein Strang mit einem, von einer Strangschale eingeschlossenen, flüssigen Kern aus einer gekühlten Durchlaufkokille ausgezogen, in einer der Durchlaufkokille nachgeordneten Strangstützeinrichtung, gestützt, mit Kühlmittel gekühlt und gegebenenfalls metallurgisch reduziert wird, wobei thermodynamische Zustandsänderungen des gesamten Strangs in einem mathematischen Simulationsmodell, beinhaltend eine Wärmeleitungsgleichung, mitberechnet werden, dadurch gekennzeichnet, dass im mathematischen Simulationsmodell eine natürliche Schrumpfung des Strangs in Echtzeit unter Berücksichtigung der physikalischen Parameter des Metalls, der Temperatur des Metalls im Gießverteiler, der ständig gemessenen Auszugsgeschwindigkeit, der Strangkühlung und der Dicke des Strangs mitberechnet wird und an den Strang anstellbare Strangführungsrollen der Strangstützeinrichtung unter Berücksichtigung der natürlichen Schrumpfung des Metallstrangs eingestellt werden.1. A process for the continuous casting of a metal strand, in particular a steel strand, in a continuous casting, wherein a strand with a trapped by a strand shell, liquid core drawn from a cooled continuous casting mold, in a continuous casting mold downstream strand support, supported, cooled with coolant and optionally metallurgical characterized in that in the mathematical simulation model a natural shrinkage of the strand in real time taking into account the physical parameters of the metal, the temperature of the metal in the casting manifold, the constantly measured pullout speed, the strand cooling and the thickness of the strand is also calculated and strand strand rollers of the strand support device which can be attached to the strand Considering the natural shrinkage of the metal strand can be adjusted.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass eine metallurgische Reduktion des Metallstrangs in der Strangstützeinrichtung unter Berücksichtigung der natürlichen Schrumpfung des Metallstrangs durchgeführt wird.2. The method according to claim 1, characterized in that a metallurgical reduction of the metal strand in the strand support device is carried out taking into account the natural shrinkage of the metal strand.
3. Verfahren nach Anspruch 2, dadurch gekennzeichnet, dass als metallurgische Reduktion entweder eine Liquid Core Reduction, eine Soft Reduction oder eine3. The method according to claim 2, characterized in that as metallurgical reduction either a liquid core reduction, a soft reduction or a
Oberflächenbehandlung des Metallstrangs durchgeführt wird.Surface treatment of the metal strand is performed.
4. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass im mathematischen Simulationsmodell die Wärmeleitungsgleichung unter4. The method according to any one of the preceding claims, characterized in that in the mathematical simulation model, the heat equation under
Berücksichtigung temperaturabhängiger Dichteänderungen des Metallstrangs numerisch gelöst wird. Consideration of temperature-dependent density changes of the metal strand is solved numerically.
5. Verfahren nach Anspruch 4, dadurch gekennzeichnet, dass bei der numerischen Lösung der Wärmeleitungsgleichung unter Berücksichtigung temperaturabhängiger Dichteänderungen des Metallstrangs approximierte Gleichungen für die Enthalpie verwendet werden, welche für den gesamten Strang die exakte Masse und die exakte Enthalpie aufweisen.5. The method according to claim 4, characterized in that in the numerical solution of the heat equation, taking into account temperature-dependent density changes of the metal strand approximated equations are used for the enthalpy, which have the exact mass and the exact enthalpy for the entire strand.
6. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das mathematische Simulationsmodell eine die Ausbildung eines gewünschten Gefüges im Metallstrang beschreibendes Rechenmodell beinhaltet .6. The method according to any one of the preceding claims, characterized in that the mathematical simulation model includes a the formation of a desired structure in the metal strand descriptive computing model.
7. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass im mathematischen7. The method according to any one of the preceding claims, characterized in that in the mathematical
Simulationsmodell ein Phasen-Umwandlungsmodell des Metalls integriert ist, insbesondere ein kontinuierliches Phasen- Umwandlungsmodell nach Avrami .Simulation model is a phase transformation model of the metal is integrated, in particular a continuous phase conversion model according to Avrami.
8. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Strangkühlung unter Berücksichtigung der errechneten thermodynamischen Zustandsänderungen eingestellt wird.8. The method according to any one of the preceding claims, characterized in that the strand cooling is adjusted taking into account the calculated thermodynamic state changes.
9. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die an den Strang anstellbaren Strangführungsrollen so angestellt werden, dass die Dicke des Strangs einem Sollwert möglichst entspricht.9. The method according to any one of the preceding claims, characterized in that the engageable with the strand strand guide rollers are employed so that the thickness of the strand corresponds to a desired value as possible.
10. Verfahren nach Anspruch 9, dadurch gekennzeichnet, dass ein Regler unter Zuhilfenahme eines Regelgesetzes und unter Berücksichtigung des Sollwerts und der natürlichen Schrumpfung des Strangs eine Stellgröße ermittelt, die wenigstens einer anstellbaren Strangführungsrolle zugeführt wird, sodass die Dicke des Strangs dem Sollwert möglichst entspricht . 10. The method according to claim 9, characterized in that a controller with the aid of a control law and taking into account the setpoint and the natural shrinkage of the strand determines a manipulated variable which is supplied to at least one engageable strand guide roller, so that the thickness of the strand corresponds to the desired value as possible.
11. Verfahren nach Anspruch 10, dadurch gekennzeichnet, dass die Dicke des Strangs mittels einer Messeinrichtung erfasst und einem Regler zugeführt wird, wobei die Stellgröße unter Berücksichtigung der erfassten Dicke des Strangs ermittelt wird. 11. The method according to claim 10, characterized in that the thickness of the strand is detected by means of a measuring device and fed to a controller, wherein the manipulated variable is determined taking into account the detected thickness of the strand.
EP09749696.2A 2008-05-21 2009-04-22 Method for the continuous casting of a metal strand Active EP2279052B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ATA816/2008A AT506976B1 (en) 2008-05-21 2008-05-21 METHOD FOR CONTINUOUSLY GASING A METAL STRUCTURE
PCT/EP2009/054786 WO2009141206A1 (en) 2008-05-21 2009-04-22 Method for the continuous casting of a metal strand

Publications (2)

Publication Number Publication Date
EP2279052A1 true EP2279052A1 (en) 2011-02-02
EP2279052B1 EP2279052B1 (en) 2016-11-09

Family

ID=40897529

Family Applications (1)

Application Number Title Priority Date Filing Date
EP09749696.2A Active EP2279052B1 (en) 2008-05-21 2009-04-22 Method for the continuous casting of a metal strand

Country Status (5)

Country Link
EP (1) EP2279052B1 (en)
KR (1) KR101781805B1 (en)
CN (1) CN102149492B (en)
AT (1) AT506976B1 (en)
WO (1) WO2009141206A1 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011082158A1 (en) 2011-09-06 2013-03-07 Sms Siemag Ag Casting, in particular continuous casting
EP2633929A1 (en) * 2012-03-01 2013-09-04 Siemens Aktiengesellschaft Modelling of a casting-rolling assembly
RU2678112C2 (en) 2014-12-24 2019-01-23 ДжФЕ СТИЛ КОРПОРЕЙШН Continuous steel casting method
TWI580496B (en) * 2014-12-25 2017-05-01 Jfe Steel Corp Continuous Casting of Steel
CN106141127A (en) * 2015-04-17 2016-11-23 宝钢工程技术集团有限公司 Continuous casting producing method under weight
DE102015215328A1 (en) 2015-08-11 2017-02-16 Sms Group Gmbh A method of continuously casting a metal strand and determining the shrinkage of a continuously cast metal strand
CN107282904B (en) * 2017-05-09 2019-03-05 江阴兴澄特种钢铁有限公司 A kind of setting of Continuous Casting Soft Reduction thickness measuring roller and control method
CN107552750B (en) * 2017-08-07 2023-05-23 中冶连铸技术工程有限责任公司 Multi-stream continuous casting machine capable of producing extra-large section special-shaped blank or plate blank and production method
DE102017219289A1 (en) * 2017-10-27 2019-05-02 Sms Group Gmbh Method for separating a cast strand or intermediate strip by means of a pair of scissors
CN109848383B (en) * 2017-11-30 2020-12-22 宝山钢铁股份有限公司 Flexible reduction method for improving internal quality of casting blank
EP3831511A1 (en) 2019-12-05 2021-06-09 Primetals Technologies Austria GmbH Method and computer system for predicting a shrinkage of a cast metal product

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT408197B (en) * 1993-05-24 2001-09-25 Voest Alpine Ind Anlagen METHOD FOR CONTINUOUSLY casting a METAL STRAND
DE10007706A1 (en) * 2000-02-19 2001-08-23 Sms Demag Ag Process and plant for casting primary products in a continuous caster
DE10025452A1 (en) * 2000-05-23 2001-11-29 Sms Demag Ag Method and device for placing one or more roller segments in a continuous casting installation for metals, in particular for steel materials
AT409352B (en) * 2000-06-02 2002-07-25 Voest Alpine Ind Anlagen METHOD FOR CONTINUOUSLY casting a METAL STRAND
AT411026B (en) * 2001-11-30 2003-09-25 Voest Alpine Ind Anlagen METHOD FOR CONTINUOUS CASTING
TWI253360B (en) * 2001-12-18 2006-04-21 Sms Demag Ag Feed opening adjustment of segments for continuous casting systems
DE10251716B3 (en) * 2002-11-06 2004-08-26 Siemens Ag Modeling process for a metal
DE102004002783A1 (en) * 2004-01-20 2005-08-04 Sms Demag Ag Method and device for determining the position of the sump tip in the casting strand in the continuous casting of liquid metals, in particular of liquid steel materials
DE102005028711A1 (en) * 2005-06-20 2006-12-28 Siemens Ag Process to regulate by algorithm the operation of an adjustable roller segment receiving extruded metal and determine output dimensions

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2009141206A1 *

Also Published As

Publication number Publication date
WO2009141206A1 (en) 2009-11-26
CN102149492A (en) 2011-08-10
AT506976A1 (en) 2010-01-15
KR20110020854A (en) 2011-03-03
KR101781805B1 (en) 2017-10-23
AT506976B1 (en) 2012-10-15
EP2279052B1 (en) 2016-11-09
CN102149492B (en) 2014-06-11

Similar Documents

Publication Publication Date Title
EP2279052B1 (en) Method for the continuous casting of a metal strand
EP3184202B1 (en) Method for continuously casting a metal strand
AT408197B (en) METHOD FOR CONTINUOUSLY casting a METAL STRAND
DE19612420C2 (en) Method and device for controlling the cooling of a strand in a continuous caster
EP2753439B1 (en) Casting method, more particularly continuous casting method
EP1200216B1 (en) Method and device for making a metal strand
EP1289691B1 (en) Method for continuously casting a metal strand
DE10033307C2 (en) Method and device for casting a metallic endless strand
EP2346631B1 (en) Method and device for controlling the solidification of a cast strand in a continuous casting plant at startup of the casting process
EP2762251B1 (en) Method and device for casting a strand
WO2009141205A1 (en) Method for the continuous casting of a metal strand
AT502525B1 (en) METHOD FOR CONTINUOUSLY GRAZING A METAL MELT
EP2673099B1 (en) Method for regulating a temperature of a strand by positioning a movable cooling nozzle in a strand guide of a strand casting system
EP3173166B1 (en) Method and device for setting the width of a continuously cast metal strand
EP1385656B1 (en) Method for continuously casting ingots, slabs or thin slabs
DE102009048567B4 (en) Method and arrangement for cooling a cast strand in a continuous casting plant
EP2804708B1 (en) Modelling of a cast rolling device
AT508790B1 (en) METHOD AND DEVICE FOR FORGING METALLIC MELTING FOR CURRENT CAST PRODUCTS IN A CONTINUOUS CASTING MACHINE
EP2295170A2 (en) Method and strand casting device for remoulding a hot cast line of metal, in particular steel or steel materials
EP1743721A2 (en) Method and device for the continuous casting and direct shaping of a metal strand, in particular a steel cast strand
DE69000282T2 (en) METHOD AND DEVICE FOR THE PRODUCTION OF THICK METAL PRODUCTS BY MEANS OF CONTINUOUS CASTING.
EP4091737A1 (en) Conversion of measured temperature values of a continuous casting mould
EP1013362A1 (en) Process and plant for continuous casting slabs
WO2002083340A2 (en) Increase in format thickness for thin slab continuous casting systems

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

17P Request for examination filed

Effective date: 20101103

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA RS

DAX Request for extension of the european patent (deleted)
RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: PRIMETALS TECHNOLOGIES AUSTRIA GMBH

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20160727

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 843414

Country of ref document: AT

Kind code of ref document: T

Effective date: 20161115

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502009013353

Country of ref document: DE

REG Reference to a national code

Ref country code: NL

Ref legal event code: FP

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

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 9

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

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170209

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170210

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

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

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170309

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170309

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

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

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

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

Ref country code: FR

Payment date: 20170419

Year of fee payment: 9

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502009013353

Country of ref document: DE

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

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170209

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

Ref country code: FI

Payment date: 20170412

Year of fee payment: 9

Ref country code: SE

Payment date: 20170419

Year of fee payment: 9

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

Effective date: 20170810

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

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Effective date: 20170422

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

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

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

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

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170430

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170422

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170430

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170422

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20170430

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

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170422

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

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170430

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

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

REG Reference to a national code

Ref country code: SE

Ref legal event code: EUG

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

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180423

Ref country code: FI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180422

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

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180430

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

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20090422

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

Ref country code: CY

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20161109

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

Ref country code: AT

Payment date: 20190423

Year of fee payment: 11

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

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

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

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20161109

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 843414

Country of ref document: AT

Kind code of ref document: T

Effective date: 20200422

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

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200422

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

Ref country code: IT

Payment date: 20230426

Year of fee payment: 15

Ref country code: DE

Payment date: 20230420

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: 20240418

Year of fee payment: 16