EP0120338B1 - Method for detecting the wear of the wall of a mould during continuous casting and for detecting the removal of the strand shell from the internal wall of the mould - Google Patents

Method for detecting the wear of the wall of a mould during continuous casting and for detecting the removal of the strand shell from the internal wall of the mould Download PDF

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Publication number
EP0120338B1
EP0120338B1 EP84102183A EP84102183A EP0120338B1 EP 0120338 B1 EP0120338 B1 EP 0120338B1 EP 84102183 A EP84102183 A EP 84102183A EP 84102183 A EP84102183 A EP 84102183A EP 0120338 B1 EP0120338 B1 EP 0120338B1
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Prior art keywords
sensor
mould wall
wear
wall
mold
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EP84102183A
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German (de)
French (fr)
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EP0120338A1 (en
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Gerhard Stadtfeld
Burkhard Dr. Christmann
Jörg Dr. Weber
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Licentia Patent Verwaltungs GmbH
Vodafone GmbH
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Licentia Patent Verwaltungs GmbH
Mannesmann AG
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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
    • B22D11/16—Controlling or regulating processes or operations

Definitions

  • the invention relates to a method according to the preamble of claim 1 and to the determination of the lifting of the strand shell from the mold inner wall.
  • the strand In the continuous casting of metals, the strand is produced by continuously pouring liquid material through a chute of the mold surrounded by the walls of the mold. As it exits the shaft, the strand consists of a solid shell and a liquid core. Further cooling outside the mold leads to complete solidification.
  • a system-specific limit e.g. 10 mm
  • the strand shell heats up again by supplying heat from the liquid strand core and expands at most until it touches the cooled mold wall again.
  • This process can be repeated several times in a strand cross-section as it passes through the mold, the position and size of the withdrawals in the shaft varying over time.
  • the gaps between the mold wall and the strand created by the lift-offs are partially filled - especially with small lift-offs (casting powder).
  • the mold shaft is designed conically for a global consideration of the shrinkage of the strand shell.
  • Taper is a critical parameter. If the taper is too low, the cooling can be reduced by lifting off, if the taper is too large, the friction between the strand and the corillem walls in the lower shaft area can become too great. For a large part of the casting programs there are empirical values that allow a satisfactory casting process.
  • the invention has for its object to provide a method with which the wear of the mold walls can be determined during the casting process, the lifting of the strand from the walls can also be determined from the result.
  • the object of determining the wear of the mold walls is achieved by the features listed in the characterizing part of patent claim 1.
  • FIG. 1 shows a mold with measuring sensors mounted in bores
  • FIG. 2 shows a mold wall with a measuring sensor in a continuous bore and a measuring sensor that measures in the area of critical wear.
  • FIG. 3 shows a mold wall with a measuring sensor in a continuous bore and a measuring sensor that measures in the area of critical wear.
  • the mold in openings 4.4 'eddy current distance sensors 3.3' are installed in openings.
  • the sensors are so far away from the strand surface 2 that it does not touch the sensors even when the mold wall is allowed to wear to the maximum extent.
  • the distance from the shaft surface sensors is given and known through the installation. This distance is denoted by L; it corresponds to zero mold wear, i. H. not worn out.
  • each distance measuring sensor determines the current distance A of the strand surface from the sensor and leads this to the elimination of the influence (temporary) lifting of the strand from the mold walls of a minimum value memory assigned to it, which respectively stores the smallest measured value supplied to it while deleting the last stored value saves.
  • the sensors can also be designed so that they only measure distance values in the area of critical wear with sufficient accuracy, cf. See Fig. 2. This enables a smaller and simpler design 5 in eddy current measuring sensors.
  • the measuring sensor opening 6 only has to be so deep that there is no more wall material (usually copper) between the measuring sensor 5 and the surface of the strand only when the wear values are critical.
  • the space between the sensor surface and the mold wall is filled with a non-magnetic, electrically non-conductive material 7, which has similar mechanical abrasion properties as the mold wall.
  • a significant improvement in the casting process is achieved by tracking the mold walls to the nominal geometry of the shaft, in which the measured wear values are fed to an adjusting device which shifts the mold walls in accordance with these values.
  • the conicity of the narrow surfaces of the mold shaft which is particularly important for the process, can be kept at the required value, particularly in the case of continuous slab casting plants.
  • a characteristic variable is determined from the measured lift-off values and is supplied to one or the conicity adjusting device mentioned above for the corresponding adjustment of the mold wall. This parameter is obtained by storing the maximum value of the lift-off values.
  • the conicity and possibly also the strand withdrawal speed should be reduced if the deformation is too great.
  • Some system states - such as the start of casting and very slow strand feed - require a different reaction from the adjusting device than an almost stationary operation. Therefore, the target values for the mold wall adjustment are determined with the aid of a computer from the measured values of the device, taking into account the relevant system parameters (strand length, take-off speed).
  • the measuring heads 8 are coupled directly to the mold wall 1.
  • the pulse-echo method is used.
  • the wear of the mold wall results from the transit time of the sound pulse reflected on the surface of the mold inner wall.
  • the reflection is influenced by the surface of the strand and the “lubricant layer” 9 between the surface of the strand and the shaft and can at times become very small.
  • a minimum value storage is therefore carried out here - analogous to the previous exemplary embodiment.
  • a determination of the strand lift is possible with sound if the space between the strand surface and the shaft is completely filled with casting powder.

Abstract

An apparatus for determining the wear of a mold wall during continuous casting of metal by using at least one distance measuring sensor disposed in the mold wall to measure the instantaneous distance from the sensor to the casting. The surface of the casting adjacent the mold wall may be irregular, so the minimum value of the distance between the sensor and casting is stored and used as the current distance between the sensor and the inner mold wall. Mold wear is determined by subtracting the current distance between the sensor and the inner mold wall from the original distance, before the abrasive casting process began. The sensor signals are also used to determine when the mold geometry should be adjusted to compensate for the wear. This is accomplished by storing the maximum distance between the sensor and casting and subtracting the current distance from this maximum, since the maximum distance increases as the casting shrinks away from the mold wall.

Description

Die Erfindung bezieht sich auf ein Verfahren gemäß dem Oberbegriff des Patentanspruchs 1 und auf die Ermittlung der Abhebung der Strangschale von der Kokilleninnenwand.The invention relates to a method according to the preamble of claim 1 and to the determination of the lifting of the strand shell from the mold inner wall.

Beim Stranggießen von Metallen wird der Strang durch kontinuierliches Gießen von flüssigem Material durch einen, von Korillenwänden umgebenen Schacht der Kokille erzeugt. Beim Austreten aus dem Schacht besteht der Strang aus einer festen Schale und einem flüssigen Kern. Weitere Kühlung außerhalb der Kokille führt zur vollständigen Erstarrung.In the continuous casting of metals, the strand is produced by continuously pouring liquid material through a chute of the mold surrounded by the walls of the mold. As it exits the shaft, the strand consists of a solid shell and a liquid core. Further cooling outside the mold leads to complete solidification.

Reibung zwischen Strang und Kokillenwänden führt zu einem Abrieb an den Wänden (beim Stahlbrammen-Stranggießen etwa 0,5 mm in 10 Betriebsstunden). Überschreitet die dadurch bedingte Abnahme der Stärke der Kokillenwände einen anlagenspezifischen Grenzwert (z. B. 10 mm), so muß die Kokille ausgetauscht werden. Derzeit wird die Abnahme der Wandstärke während der Gießpausen ermittelt. Wegen der starken Zunahme der maximalen Gießzeiten in den letzten Jahren ist eine Feststellung der Abnutzung während der Gießprozesse von großer Bedeutung. Eine solche Festellung wird durch das zeitlich und örtlich variierende « Abheben des Stranges von den Kokillenwänden sehr erschwert. Das Abheben wird durch Schrumpfen des Strangquerschnittes bei der Abkühlung der Strangschale durch Kontakt mit den gekühlten Kokillenwänden verursacht. Nach dem Abheben erwärmt sich die Strangschale durch Wärmezufuhr aus dem flüssigen Strangkern wieder und dehnt sich maximal so weit aus, bis sie wieder die gekühlte Kokillenwand berührt. Dieser Vorgang kann sich in einem Strangquerschnitt beim Durchgang durch die Kokille mehrfach wiederholen, wobei Lage und Größe der Abhebungen im Schacht zeitlich variieren. Die durch die Abhebungen entstehenden Spalte zwischen Kokillenwand und Strang sind teilweise - insbesondere bei kleinen Abhebungen - gefüllt (Gießpulver).Friction between the strand and the mold walls leads to abrasion on the walls (in steel slab continuous casting, about 0.5 mm in 10 operating hours). If the resulting decrease in the thickness of the mold walls exceeds a system-specific limit (e.g. 10 mm), the mold must be replaced. The decrease in wall thickness is currently being determined during the casting breaks. Because of the sharp increase in maximum casting times in recent years, it is very important to determine wear during the casting processes. Such a determination is made very difficult by the time and location of the strand being lifted off the mold walls. Lifting is caused by the shrinkage of the strand cross-section when the strand shell cools down due to contact with the cooled mold walls. After lifting off, the strand shell heats up again by supplying heat from the liquid strand core and expands at most until it touches the cooled mold wall again. This process can be repeated several times in a strand cross-section as it passes through the mold, the position and size of the withdrawals in the shaft varying over time. The gaps between the mold wall and the strand created by the lift-offs are partially filled - especially with small lift-offs (casting powder).

Die Verringerung der Strangkühlung durch Abheben schwächt das Schalenwachstum in der Kokille und kann Störungen des Gießprozesses hervorrufen, in besonders krassen Fällen sogar Strangdµrchbrüche. Daher ist für eine globale Berücksichtigung der Schrumpfung der Strangschale der Kokillen-Schacht konisch ausgeführt. Die Konizität ist ein kritischer Parameter. Bei zu geringer Konizität kann die Minderung der Kühlung durch Abhebung, bei zu großer Konizität die Reibung zwischen Strang und Korillemwänden im unteren Schachtbereich zu groß werden. Für einen großen Teil der Gießprogramme liegen Erfahrungswerte vor, die einen befriedigenden Gießablauf erlauben.The reduction of the strand cooling by lifting weakens the shell growth in the mold and can cause disturbances in the casting process, in particularly severe cases even strand breaks. Therefore, the mold shaft is designed conically for a global consideration of the shrinkage of the strand shell. Taper is a critical parameter. If the taper is too low, the cooling can be reduced by lifting off, if the taper is too large, the friction between the strand and the corillem walls in the lower shaft area can become too great. For a large part of the casting programs there are empirical values that allow a satisfactory casting process.

In diesen Fällen ist die kontinuierliche Überprüfung der Abnutzung der Kokillenwände und gegebenenfalls eine die Abnutzung kompensierende Nachstellung der Wände von großer Bedeutung. Für besonders kritische Gießaufgaben sind jedoch Messungen von Abhebungen in der Kokille und Einstellung der Konizität nach diesen Werten erforderlich. Das gilt insbesondere bei stark variierenden Gießgeschwindigkeiten. Eine Messung der Abhebung war bisher nicht möglich.In these cases it is very important to continuously check the wear of the mold walls and, if necessary, readjust the walls to compensate for the wear. For particularly critical casting tasks, however, measurements of withdrawals in the mold and adjustment of the taper according to these values are required. This is especially true when casting speeds vary widely. Up until now it was not possible to measure the withdrawal.

Es ist durch die DE-OS 31 10 012 eine Anordnung bekanntgeworden, bei der durch einen Fühler unterhalb und damit außerhalb der Kokille die Änderung des Abstandes zur Strangoberfläche festgestellt wird. In Abhängigkeit von dieser Änderung wird die Konizität der Kokille während des Gießprozesses nachgestellt. Durch diese Anordnung wird aber die Abnutzung der Kokillenwand nicht erfaßt. Daher ist auch eine optimale Nachstellung der Konizität nicht möglich. Außerdem sind Probleme durch Ausdehnung des Stranges nach Verlassen der Kokille zu erwarten, so daß nicht sicher unterschieden werden kann, ob eine Änderung des Abstandes Strangoberfläche - Sensor durch Änderung der Strangabhebung in der Kokille oder der Ausbauchung des Stranges außerhalb der Kokille hervorgerufen wird.An arrangement has become known from DE-OS 31 10 012, in which the change in the distance to the strand surface is determined by a sensor below and thus outside the mold. Depending on this change, the taper of the mold is adjusted during the casting process. With this arrangement, however, the wear of the mold wall is not recorded. Therefore, an optimal adjustment of the taper is not possible. In addition, problems due to expansion of the strand after leaving the mold are to be expected, so that it cannot be reliably distinguished whether a change in the distance between the surface of the strand and the sensor is caused by changing the strand lift in the mold or the bulging of the strand outside the mold.

Aus den, den oberbegriff des Anspruchs 1 , bildenden Patents Abstracts of Japan, Band 6, Nr. 224 (M-170) (1102), 9. November 1982 ; & JP-A-57127559 (Nippon Kokan K.K.) 07.08.1982 ist es bekannt, den Erstarrungszustand des Strahles in einer Stranggießkokille festzustellen. Dazu wird ein Ultraschallsender/-empfänger in die Kokillenwand eingebaut; aus den Echos - bei Nichtvorliegen von Abhebungen - wird die momentane Dicke der bereits erstarrten Schmelze an der Meßstelle bestimmt.From the patent abstracts of Japan forming the preamble of claim 1, volume 6, no. 224 (M-170) (1102), November 9, 1982; & JP-A-57127559 (Nippon Kokan K.K.) 07.08.1982 it is known to determine the state of solidification of the jet in a continuous casting mold. For this purpose, an ultrasonic transmitter / receiver is installed in the mold wall; the instantaneous thickness of the already solidified melt at the measuring point is determined from the echoes - in the absence of withdrawals.

Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren anzugeben, mit dem während des Gießprozesses die Abnutzung der Kokillenwände ermittelt werden kann, wobei aus dem Ergebnis auch die Abhebung des Stranges von den Wänden festgestellt werden kann.The invention has for its object to provide a method with which the wear of the mold walls can be determined during the casting process, the lifting of the strand from the walls can also be determined from the result.

Gemäß der Erfindung wird die Aufgabe der Festellung der Abnutzung der Kokillenwände durch die im Kennzeichen des Patentanspruchs 1 aufgeführten Merkmale gelöst.According to the invention, the object of determining the wear of the mold walls is achieved by the features listed in the characterizing part of patent claim 1.

Die Ermittlung der Abhebung der Strangschale von der Kokilleninnenwand wird durch die Merkmale des Kennzeichens des Patentanspruchs 2 angegeben. Das Verfahren gemäß der Erfindung und ihre Verwendung wird in den nachstehend beschriebenen Ausführungsbeispielen anhand der Zeichnung näher erläutert.The determination of the lifting of the strand shell from the mold inner wall is indicated by the features of the characterizing part of patent claim 2. The method according to the invention and its use is explained in more detail in the exemplary embodiments described below with reference to the drawing.

Ein Ausführungsbeispiel mit Wirbelstrom-Abstandssensoren wird anhand der Figuren 1 und 2 beschrieben. Figur 1 zeigt eine Kokille mit in Bohrungen angebrachten Meßsensoren, die Figur 2 eine Kokillenwand mit einem Meßsensor in einer durchgehenden Bohrung und einem Meßsensor, der im Bereich der kritischen Abnutzung mißt. Ein weiteres Ausführungsbeispiel mit Ultraschall-Meßsensoren wird an Hand der Figur 3 beschrieben.An embodiment with eddy current distance sensors is described with reference to Figures 1 and 2. FIG. 1 shows a mold with measuring sensors mounted in bores, FIG. 2 shows a mold wall with a measuring sensor in a continuous bore and a measuring sensor that measures in the area of critical wear. Another embodiment with ultrasonic measuring sensors is described with reference to FIG. 3.

In der Fig. 1 sind in einer Kokillenwand 1 der Kokille in Offnungen 4,4' Wirbelstrom-Abstandsmeßsensoren 3,3' eingebaut. Die Sensoren sind dabei so weit von der Strangoberfläche 2 entfernt, daß diese auch bei maximal erlaubter Abnutzung der Kokillenwand die Sensoren nicht berührt. Bei einer noch nicht benutzten Kokille ist der Abstand Schachtoberfläche-Sensoren durch den Einbau gegeben und bekannt. Dieser Abstand sei mit L bezeichnet; er entspricht einer Kokillenabnutzung von Null, d. h. nicht abgenutzt. Während des Gießens ermittelt jeder Abstandsmeßsensor den jeweils aktuellen Abstand A der Strangoberfläche zum Sensor und führt diesen zur Eliminierung des Einflusses (zeitweiser) Abhebungen des Stranges von den Kokillenwänden einem ihm zugeordneten Minimalwertspeicher zu, der jeweils den kleinsten ihm zugeführten Meßwert unter Löschung des zuletzt gespeicherten Wertes speichert. Der momentane Wert der Abnutzung der Kokillenwand ergibt sich aus dem gespeicherten Abstandswert A' zu ΔL = L - A'. Aus den AL-Werten der eingesetzten Sensoren folgt, wann die Kokille ausgetauscht und gegebenenfalls das Gießen abgebrochen werden muß.In Fig. 1, the mold in openings 4.4 'eddy current distance sensors 3.3' are installed in openings. The sensors are so far away from the strand surface 2 that it does not touch the sensors even when the mold wall is allowed to wear to the maximum extent. In the case of a mold that has not yet been used, the distance from the shaft surface sensors is given and known through the installation. This distance is denoted by L; it corresponds to zero mold wear, i. H. not worn out. During the casting process, each distance measuring sensor determines the current distance A of the strand surface from the sensor and leads this to the elimination of the influence (temporary) lifting of the strand from the mold walls of a minimum value memory assigned to it, which respectively stores the smallest measured value supplied to it while deleting the last stored value saves. The current value of the wear of the mold wall results from the stored distance value A 'to ΔL = L - A'. From the AL values of the sensors used, it follows when the mold has to be replaced and, if necessary, the casting has to be stopped.

Die Sensoren können auch so ausgeführt werden, daß sie nur Abstandswerte im Bereich der kritischen Abnutzung ausreichend genau messen, vgl. dazu Fig. 2. Das ermöglicht bei Wirbelstrom-Meßsensoren eine kleinere und einfachere Bauform 5. Zudem muß die Meßsensoröffnung 6 nur so tief sein, daß sich erst bei kritischen Werten der Abnutzung kein Wandmaterial (üblicherweise Kupfer) mehr zwischen Meßsensor 5 und Strangoberfläche befindet.The sensors can also be designed so that they only measure distance values in the area of critical wear with sufficient accuracy, cf. See Fig. 2. This enables a smaller and simpler design 5 in eddy current measuring sensors. In addition, the measuring sensor opening 6 only has to be so deep that there is no more wall material (usually copper) between the measuring sensor 5 and the surface of the strand only when the wear values are critical.

Damit der Strang nicht durch die für den Sensor notwendige Öffnung 4 in der Kokillenwand mechanisch belastet wird, wird der Raum zwischen Sensorfläche und Kokillenwand mit einem unmagnetischen, elektrisch nicht leitenden Material 7 ausgefüllt, welches ähnliche mechanische Abriebeigenschaften wie die Kokillenwand hat.So that the strand is not mechanically stressed by the opening 4 required for the sensor in the mold wall, the space between the sensor surface and the mold wall is filled with a non-magnetic, electrically non-conductive material 7, which has similar mechanical abrasion properties as the mold wall.

Eine wesentliche Verbesserung des Gießprozesses wird durch Nachführen der Kokillenwände auf die Sollgeometrie des Schachtes erreicht, in dem die gemessenen Abnutzungswerte einer Verstelleinrichtung zugeführt werden, die die Kokillenwände entsprechend diesen Werten verschiebt. Mit Hilfe geeignet angeordneter Meßsensoren 3 und 3' in Fig. 1 kann so insbesondere bei Brammen-Stranggießanlagen die für den Prozeßverlauf besonders wichtige Konizität der Schmalflächen des Kokillenschachtes auf dem geforderten Wert gehalten werden. Die Vorrichtung zur Ermittlung der Kokillenwandabnutzung gemäß der Erfindung wird dazu verwendet, die Abhebung der Strangschale von der Kokilleninnenwand zu ermitteln. Dies geschieht dadurch, daß aus der Differenz zwischen dem aktuell gemessenen Abstand A zwischen Meßsensor und Strangoberfläche und dem gespeicherten kleinsten Abstandswert A' die Abhebung AA = A - A' der Strangoberfläche von der Kokilleninnenwand ermittelt wird. Aus den gemessenen Abhebewerten wird eine Kenngröße ermittelt, die einer oder der oben genannten Konizitäts-Verstelleinrichtung zur entsprechenden Verstellung der Kokillenwand zugeleitet wird. Diese Kenngröße wird durch Maximalwertspeicherung der Abhebewerte gewonnen.A significant improvement in the casting process is achieved by tracking the mold walls to the nominal geometry of the shaft, in which the measured wear values are fed to an adjusting device which shifts the mold walls in accordance with these values. With the aid of suitably arranged measuring sensors 3 and 3 'in FIG. 1, the conicity of the narrow surfaces of the mold shaft, which is particularly important for the process, can be kept at the required value, particularly in the case of continuous slab casting plants. The device for determining the mold wall wear according to the invention is used to determine the lifting of the strand shell from the mold inner wall. This is done in that the difference AA = A - A 'of the strand surface from the inner mold wall is determined from the difference between the currently measured distance A between the measuring sensor and the strand surface and the stored smallest distance value A'. A characteristic variable is determined from the measured lift-off values and is supplied to one or the conicity adjusting device mentioned above for the corresponding adjustment of the mold wall. This parameter is obtained by storing the maximum value of the lift-off values.

Mit einem Meßsensor 3" kurz unterhalb der Kokille wird die Verformung der Strangschale nach Austritt aus der Kokille beobachtet. Sie hängt vorwiegend von der Strangabzugsgeschwindigkeit und dem Kontakt zwischen Strang und Kokilleninnenwänden und damit von der Konizität ab.With a measuring sensor 3 "just below the mold, the deformation of the strand shell after it emerges from the mold is observed. It mainly depends on the strand withdrawal speed and the contact between the strand and the mold inner walls and thus on the taper.

Da mit der Verformung die Gefahr des Entstehens von Materialfehlern in der Strangschale oder gar des Aufreißens wächst, soll bei zu großer Verformung die Konizität und gegebenenfalls auch die Strangabzugsgeschwindigkeit verringert werden. Einige Anlagenzustände - wie zum Beispiel Gießbeginn und sehr langsamer Strangvorschub - erfordern eine andere Reaktion der Verstelleinrichtung als ein annähernd stationärer Betrieb. Daher werden die Sollgrößen für die Kokillenwandverstellung unter Berücksichtigung der in dieser Hinsicht relevanten Anlagenparameter (Stranglänge, Abzugsgeschwindigkeit) mit Hilfe eines Rechners aus den Meßwerten der Vorrichtung bestimmt.Since the risk of material defects in the strand shell or even tearing increases with the deformation, the conicity and possibly also the strand withdrawal speed should be reduced if the deformation is too great. Some system states - such as the start of casting and very slow strand feed - require a different reaction from the adjusting device than an almost stationary operation. Therefore, the target values for the mold wall adjustment are determined with the aid of a computer from the measured values of the device, taking into account the relevant system parameters (strand length, take-off speed).

Bei dem in Figur 3 gezeigten Ausführungsbeispiel mit Schallsensoren werden die Meßköpfe 8 direkt an die Kokillenwand 1 angekoppelt. Gearbeitet wird nach dem Puls-Echo-Verfahren. Die Abnutzung der Kokillenwand ergibt sich aus der Laufzeit des an der Oberfläche der Kokilleninnenwand reflektierten Schallimpulses. Die Reflektion wird durch die Strangoberfläche und die « Schmiermittelschicht » 9 zwischen Strang-und Schachtoberfiäche beeinflußt und kann zeitweise sehr klein werden. Daher wird hier - analog zum vorigen Ausführungsbeispiel - eine Minimalwertspeicherung durchgeführt. Eine Bestimmung der Strangabhebung ist mit Schall dann möglich, wenn der Raum zwischen Strangoberfläche und Schacht vollständig mit Gießpulver ausgefüllt ist.In the exemplary embodiment shown in FIG. 3 with sound sensors, the measuring heads 8 are coupled directly to the mold wall 1. The pulse-echo method is used. The wear of the mold wall results from the transit time of the sound pulse reflected on the surface of the mold inner wall. The reflection is influenced by the surface of the strand and the “lubricant layer” 9 between the surface of the strand and the shaft and can at times become very small. A minimum value storage is therefore carried out here - analogous to the previous exemplary embodiment. A determination of the strand lift is possible with sound if the space between the strand surface and the shaft is completely filled with casting powder.

Claims (9)

1. Method for the determination of the mould wall wear during the casting process, wherein one or more spacing measurement sensors (3, 3', 8) are installed in the mould walls (1), characterised thereby, that the smallest resulting spacing signal for the spacing between a spacing measurement sensor (3, 3', 8) and the cast strand surface (2) or the surface of the inside mould wall is conducted to a minimum value store whilst deleting the last stored value and the difference is formed from the initial value L of the spacing between measurement sensor and inside mould wall surface and the respectively stored smallest spacing value A' of measurement sensor from cast strand surface or of measurement sensor from mould wall surface.
2. Method according to claim 1, characterised thereby, that for the determination of the lifting of the cast strand shell away from the inside mould wall, the lifting-off AA = A - A' of the cast strand surface from the inside mould wall is determined from the difference between the actually measured spacing A between measurement sensor and cast strand surface and the stored smallest spacing value A'.
3. Method according to claim 1 or 1 and 2, characterised thereby, that the measurement sensor is an eddy current sensor.
4. Method according to claim 3, characterised thereby, that the mould wall (1) possesses an opening (4, 6), which contains the sensor (3, 5) and is so structured that only material permeable by high-frequency is disposed between the end face of the sensor and the cast strand surface (2).
5. Method according to claim 4, characterised thereby, that the opening (4) in the mould wall is so closed off by a material (7), which is nonmagnetic, electrically non-conductive and has similar wear properties as the mould wall, that the inside mould walls always form a planar surface.
6. Method according to claim 1 or 1 and 2, characterised thereby, that the measurement sensor is an ultrasonic sensor.
7. Method according to claim 1, characterised thereby, that in the case of adjustable moulds, the determined wear of a mould wall is conducted to an adjusting equipment which displaces the mould wall according to the wear.
8. Method according to claim 2 or 2 and 7, characterised thereby, that a characteristic magnitude, which is conducted to a or the conicity- adjusting equipment for the appropriate adjustment of the mould wall, is determined from the measured lift-off values.
9. Method according to claim 8, characterised thereby, that this characteristic magnitude is obtained through maximum value storage of the lift-off values.
EP84102183A 1983-03-16 1984-03-01 Method for detecting the wear of the wall of a mould during continuous casting and for detecting the removal of the strand shell from the internal wall of the mould Expired EP0120338B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84102183T ATE25016T1 (en) 1983-03-16 1984-03-01 PROCEDURE FOR DETERMINING MOLD WEAR WEAR DURING THE CASTING PROCESS AND DETERMINING THE LIFTING OF THE STRIP SHELL FROM THE INNER WALL OF THE MOLD.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19833309885 DE3309885A1 (en) 1983-03-16 1983-03-16 DEVICE FOR DETECTING THE CHILLER WALL WEAR DURING THE MOLDING PROCESS AND USING THE SAME FOR DETERMINING THE LIFTING OF THE STRAND SHELL FROM THE CHILLER INNER WALL
DE3309885 1983-03-16

Publications (2)

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EP0120338A1 EP0120338A1 (en) 1984-10-03
EP0120338B1 true EP0120338B1 (en) 1987-01-21

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EP84102183A Expired EP0120338B1 (en) 1983-03-16 1984-03-01 Method for detecting the wear of the wall of a mould during continuous casting and for detecting the removal of the strand shell from the internal wall of the mould

Country Status (5)

Country Link
US (1) US4545420A (en)
EP (1) EP0120338B1 (en)
JP (1) JPS59169658A (en)
AT (1) ATE25016T1 (en)
DE (1) DE3309885A1 (en)

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DE102008011277A1 (en) * 2008-02-27 2009-09-10 Siemens Aktiengesellschaft Mold for casting liquid metal, comprises volumes limited by a mold boundary for receiving a liquid metal, and a device intended for detecting liquid metal in a detection zone using ultrasonic waves and having a transmitter and a receiver

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US4774751A (en) * 1981-06-15 1988-10-04 Diffracto, Ltd. Electro-optical and robotic casting quality assurance
DE3908328A1 (en) * 1989-03-10 1990-09-13 Mannesmann Ag CONICITY CONTROL DEVICE
DE4117073A1 (en) * 1991-05-22 1992-11-26 Mannesmann Ag TEMPERATURE MEASUREMENT SLAM CHOCOLATE
US5477618A (en) * 1994-05-03 1995-12-26 Gibson; Stephen P. Sand core dimension checking apparatus
DE102007039882A1 (en) * 2007-04-26 2008-11-06 Sms Demag Ag continuous casting
EP3135402B1 (en) * 2015-08-27 2018-07-25 Primetals Technologies Austria GmbH Mould and method for monitoring a mould
DE102017205886A1 (en) * 2017-04-06 2018-10-11 Sms Group Gmbh Device with wearing part and measuring device for wear

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US3204460A (en) * 1962-08-13 1965-09-07 United States Steel Corp System for indicating the liquid level in a continuous-casting mold or the like
US3745828A (en) * 1972-02-09 1973-07-17 United States Steel Corp Temperature sensing device for continuouscasting molds
US4027233A (en) * 1973-07-23 1977-05-31 Eduard Ivanovich Shmakov Contactless inductance pickup for detecting the interface of two media
DE2447580A1 (en) * 1974-10-05 1976-04-08 Betr Forsch Inst Angew Forsch METHOD AND DEVICE FOR MONITORING THE SOLIDIFICATION OF STEEL IN A CONTINUOUS CASTING GOLD
SU914173A1 (en) * 1980-04-04 1982-03-23 Nii Tyazhelogo Mash Apparatus for measuring conicity and wear of mould walls
JPS57127559A (en) * 1981-01-29 1982-08-07 Nippon Kokan Kk <Nkk> Detection of solidification state of ingot in mold for continuous casting machine
DE3110012C1 (en) * 1981-03-11 1982-11-04 Mannesmann AG, 4000 Düsseldorf Arrangement for monitoring and adjusting the inclination of the narrow side of a continuous casting mold
JPS57171554A (en) * 1981-04-14 1982-10-22 Kawasaki Steel Corp Automatic controller for short side of mold
JPS58163561A (en) * 1982-03-24 1983-09-28 Nippon Steel Corp Method for testing immersion nozzle for continuous casting

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008011277A1 (en) * 2008-02-27 2009-09-10 Siemens Aktiengesellschaft Mold for casting liquid metal, comprises volumes limited by a mold boundary for receiving a liquid metal, and a device intended for detecting liquid metal in a detection zone using ultrasonic waves and having a transmitter and a receiver

Also Published As

Publication number Publication date
DE3309885C2 (en) 1987-06-25
DE3309885A1 (en) 1984-09-20
ATE25016T1 (en) 1987-02-15
US4545420A (en) 1985-10-08
JPS59169658A (en) 1984-09-25
EP0120338A1 (en) 1984-10-03

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