EP4015104A1 - Method for continuous casting of metall - Google Patents

Abstract

Process for the continuous casting of a metal strand, in which parameter values are detected and recorded at least every 2 seconds during casting and the recorded parameter values are evaluated by means of an evaluation process. The probability of sticker events in the continuous mold is determined, and if a threshold value for the probability is exceeded, the strand withdrawal speed v_AB is reduced to a healing speed v_LOW of 100 - 130% of the permissible minimum operating speed v_MIN, with the average deceleration being between 0.7 and 5 m/min².

Description

field of technology

The invention relates to a method for the continuous casting of a metal strand by pouring liquid metal from a distributor into a continuous mold which oscillates by means of an oscillator.

State of the art

It is known to produce metal strands - for example steel strands - by means of continuous casting processes. Liquid metal is continuously fed into the continuous mold, runs through it and forms a thin strand shell as a result of cooling at the edge, which surrounds a liquid core of the metal strand. The flow of liquid metal from the outlet of a distributor is controlled or regulated using closing elements such as plugs or slides. The metal strand is withdrawn from the continuous mold at a strand withdrawal speed. After exiting the continuous mold, the metal strand is further cooled in the subsequent strand guide and guided until it has completely solidified. To prevent the strand shell from sticking to the continuous mold, the continuous mold oscillates. Despite this measure, sticking can occur; this is also known as a sticker or shell hanger. A tearing caused by this of the strand shell leads to the generation of rejects and necessitates extensive corrective measures in the operation of the continuous casting plant in order to remedy the problem.

Summary of the Invention Technical task

It is therefore an object of the present invention to provide a method for the continuous casting of a metal strand in which stickers are avoided or recognized early enough that the problem can be eliminated with little effort.

Technical solution This task is solved by a

• aktuelle Temperatur-Werte eines Überwachungssystems der Durchlaufkokille,
• aktuelle Schließorganbewegungsgeschwindigkeit,
• aktuelle Badspiegelvertikalgeschwindigkeit,
• aktuelle Strangabzugsgeschwindigkeit,

und dass eine, bevorzugt periodische, Auswertung der aufgezeichneten Parameter-Werte erfolgt mittels eines Auswerteverfahrens auf Basis der aktuellen sowie vergangener Parameter-Werte und dabei die Wahrscheinlichkeit von Sticker-Events in der Durchlaufkokille ermittelt wird, und bei Überschreitung eines Schwellenwertes für die Wahrscheinlichkeit eine Absenkung der Strangabzugsgeschwindigkeit v_AB auf eine Heilgeschwindigkeit v_LOW in Höhe von 100 - 130 % einer zulässigen Minimalbetriebsgeschwindigkeit v_MIN, bevorzugt in Höhe von 100 - 120 % der zulässigen Minimalbetriebsgeschwindigkeit v_MIN, erfolgt, wobei die gemittelte Verzögerung dabei zwischen 0,7 und 5 m/min² liegt, bevorzugt zwischen 1,0 und 2,5 m/min².Process for the continuous casting of a metal strand by pouring liquid metal from a distributor into a continuous mold,
which oscillates by means of an oscillator,
characterized,
that during casting, parameter values are recorded and recorded at least every 2 seconds,
these parameter values comprising at least

• current temperature values of a monitoring system of the continuous mold,
• current closing element movement speed,
• current bath mirror vertical speed,
• current strand take-off speed,

and that a, preferably periodic, evaluation of the recorded parameter values is carried out using an evaluation method based on the current and past parameter values and the probability of sticker events in the continuous mold is determined, and if a threshold value for the probability is exceeded, a reduction the strand withdrawal speed v _AB to a healing speed v _LOW in the amount of 100-130% of a permissible minimum operating speed v _MIN , preferably in the amount of 100-120% of the permissible minimum operating speed v _MIN , with the average deceleration being between 0.7 and 5 m /min ² is preferably between 1.0 and 2.5 m/min ² .

Averaging is done over the period from the start of the delay in lowering until the healing speed is reached.

According to one embodiment, the metal strand is a steel strand.

It is preferably an at least semi-automatic method, particularly preferably an automatic method.

With regard to the basic course of a continuous casting process for the production of a metal strand, reference is made to the explanations given at the outset regarding the prior art.

A sticker, also known as shell hanger, is a local phenomenon of the thin strand shell, when it temporarily gets stuck or sticks locally and mostly on a small scale to the oscillating mold wall, while neighboring areas with the strand cross-section are pulled further down, so that the strand shell locally tears open and hot liquid metal, such as steel, continues to flow into the torn areas. The occurrence of a bowl hanger is also called a sticker event.

The parameter values can be measured directly themselves, or they can be calculated on the basis of other measurement signals; Detection also includes such a calculation. Current parameter values are those parameter values that have been measured or calculated during the last 2 seconds.

Detection and recording of parameter values are preferably to be understood in the sense of a single action, with detection and recording thus taking place together in one action. Acquisition and recording take place at least every two seconds - i.e. a maximum of two seconds elapse between two acquisition or recording events.
Recording and evaluation preferably take place periodically. However, the period of the evaluation can also deviate from the period of the recording; it is then at most double.

During casting, parameter values are recorded and recorded at least every 2 seconds. The parameter values are measured as time-series, i.e. with a clock less than or equal to 2 seconds.

The parameter values include current temperature values of a continuous mold monitoring system; preferably all thermal data of this surveillance system. The temperature values of the continuous mold monitoring system include temperatures at several points on the mold wall at a distance of a few mm from the strand shell. The distribution temperature of the liquid steel can also be recorded and recorded independently of this.

The parameter values include the current gate movement speed. The closing member can be a plug or a slide, for example.

The parameter values include the current bath level vertical velocity, which affects bath level movement.

The parameter values include the current strand pull-off speed.

The probability of a sticker event in the continuous mold is determined by means of the evaluation process.

The threshold value for the probability of sticker events is set by the evaluation method or its evaluation model, which determines what just happens is acceptable - this is usually continuously adjusted through additional learning.

The strand take-off speed (usually in [m/min]) is the speed at which the metal strand leaves the continuous mold. In normal operation, a normal strand draw-off speed v _NORM is used. Those skilled in the art know that it can vary depending on the material being cast and other boundary conditions.

The permissible minimum operating speed (usually in [m/min]) varies depending on the chemical analysis of the metal - for example the steel - and the type of plant and, in particular, depending on the strand thickness and width; those skilled in the art know how to obtain the minimum operating speed for a given setup; he usually adheres to the specifications of the system supplier. Falling below the permissible minimum operating speed harbors potential problems, for example due to solidification too close to the mold outlet in the arch or straightening area of a continuous casting plant, for example due to the temperature of the strand surface in or behind the straightening area being too cool, for example the risk of slab quality defects such as surface cracks or internal quality increases.

In conventional methods for detecting stickers or predicting strand breakouts, the strand withdrawal speed is lowered to a creeping speed below the permissible minimum operating speed, or the metal strand is even temporarily stopped. This reduces productivity to a greater extent than with Application of the method according to the invention and harbors the problem potential mentioned, in particular it leads to devalued slabs or even scrap slabs.

The method according to the invention can be used at a strand withdrawal speed that is above the permissible minimum operating speed v _MIN when the threshold value for the probability of sticker events is exceeded.
According to the invention, there is in any case a reduction in the speed of the strand withdrawal that is currently being driven—that is, when the threshold value is exceeded. This reduction takes place with the required delay.

The amount of deceleration can be constant or change during the deceleration process.

The strand draw-off speed is preferably reduced at least semi-automatically, particularly preferably automatically.
The lowering usually takes place based on the normal strand draw-off speed v _NORM that has just been set.
The average deceleration is at least 0.7 m/min ² , preferably at least 1 m/min ² . It is up to 5 m/min ² , preferably up to 2.5 m/min ² .
Averaging is done over the period from the start of the delay in lowering until the healing speed is reached.

Usually, these are the target values to be specified in the control/regulation of the continuous casting plant, which are set within the framework of the accuracy that can be achieved according to the state of the art of the relevant plant.

The extent of the delay primarily has an influence on transient flow phenomena in the mold - both for the liquid steel and for the casting powder, the casting slag and the meniscus line - but also on interactions with, for example, the oscillating mold or with the closing elements.

• Machine Learning,
• Deep Learning.

According to a preferred embodiment, the probability of sticker events is determined in the evaluation process using deviation analysis.
The evaluation method then uses deviation rules for the deviation analysis. The deviation rules of the evaluation method are preferably created on the basis of past data using at least one member of the group consisting of

• machine learning,
• deep learning

Machine learning means the artificial generation of model knowledge from experience and data: the artificial system learns from examples - training data - and can generalize them. To do this, machine learning algorithms build a data model based on training data. The machine learning methods used are, for example, random forest, boosted tree, support vector machine, etc.

Deep learning is understood to mean even more in-depth methods of machine learning that use artificial neural networks ANN with numerous intermediate layers between the input layer and output layer, thereby forming an extensive inner structure. The deep learning that may be used here has at least 4 layers. In which The applied deep learning is, for example, Long-Short-Term-Memory LSTM.

In an evaluation method using deviation analysis based on past data - for example evaluation using machine learning and/or deep learning - data model-based deviation rules are created, which are used to determine the probability of sticker events using deviation analysis. This happens, for example, in such a way that so-called features and key features are modeled, which in (suitable) combination as models can predict the future over 5 - 30 seconds, for example. If these features or key features deviate significantly from the feature or key feature values determined on the basis of the acquisition and evaluation of the parameter values, which takes place at least every 2 seconds, and are in a supercritical range, a sticker alarm is triggered and the strand withdrawal speed is reduced, preferably as quickly as possible. initiated; this is preferably done at least semi-automatically, particularly preferably automatically.

Advantageous Effects of the Invention

Compared to conventional breakout detection, the procedure according to the invention initiates a reduction in the strand draw-off speed much earlier; 5 - 30 seconds earlier are achievable. Because the sticker has not yet formed or is not yet very pronounced at such an early stage, it is enough to avoid it or healing, to perform a smaller delay compared to conventional breakout detection.

The threshold value for a deviation into a supercritical range is set by the evaluation model of the evaluation method, if necessary with the operator's adjustment options. The threshold may depend on the type of anomaly being considered. A threshold value is preferably set in such a way that it is already exceeded when a sticker is predicted for a position in the strand or a strand cross-section at which, at this point in time, the thickness of the strand shell is only 1-15 mm, preferably between 2 and 8 mm. present. As a result, the healing process can be carried out with less drastic means than with stickers, which are only predicted or recognized when the strand shells are thicker. Since the base nucleus for shell hangers often already arises at the meniscus line, it can be possible in extreme cases that the method according to the invention even issues an anomaly alarm or sticker alarm at a point in time and suggests a delay in the strand withdrawal speed or, if necessary, initiates it - for example semi-automatically or automatically , where not even the basic germ has emerged. The delay and throughput reduction leads to a very early calming down and problem avoidance.

There are several positive effects on the quality of the strand:
First, no sticker will be created if it has not yet physically appeared when the threshold is exceeded; the strand shell will therefore not exhibit any quality-reducing hanger faults.

On the other hand, a strand of the desired quality is still produced even when the strand draw-off speed is reduced, since the lowering takes place gently and since the minimum operating speed relevant for this quality is not undershot.
In addition, especially when the threshold value is exceeded when a sticker forms or nucleates on the meniscus line, the strand shell and a surface defect due to the sticker is so thin that it is removed during further processing of the slabs obtained from the steel strand - for example by descaling - so that the sticker for the slabs does not cause any loss of quality in the further processing product.

Preferably, after the healing speed v _LOW has been reached, the strand withdrawal speed is maintained at the healing speed v _LOW for a period of at least 50%, preferably at least 65%, and up to 120%, preferably up to 100%, of a continuous mold run with v _Low , and then with a average acceleration of at least 0.2 m/min ² , preferably at least 0.5 m/min ² , and up to 5 m/min ² , preferably up to 2 m/min ² .
Averaging is done over the period from the start of acceleration to the end of acceleration.

• wobei v_AB größer v_MIN ist,
• und wobei v_AB größer v_Low ist,
• und wobei v_Low der - aus dem Verfahren definierte - Sollwert für die Heilgeschwindigkeit ist,

• ergeben,
• wobei bei einem Ergebnis der Formel unter 50 die Untergrenze des Zeitintervalls bei 50 % der Dauer des
• Durchlaufkokillendurchlaufs gesetzt wird.

The duration of holding at the healing speed v _Low as a percentage of the duration of a continuous mold cycle with the healing speed v _Low is preferred
within the percentage time interval,
whose limit values are derived from the formula $$\left[\left(\mathrm{50}+\mathrm{20}*\left({\mathrm{v}}_{\mathrm{AWAY}}-{\mathrm{v}}_{\mathrm{Low}}\right)/{\mathrm{v}}_{\mathrm{Low}}\right)+/-\mathrm{15}\right],$$

• where v _AB is greater than v _MIN ,
• and where v _AB is greater than v _Low ,
• and where v _Low is the target value for the healing speed defined from the method,

• result,
• where if the result of the formula is less than 50, the lower limit of the time interval is 50% of the duration of the
• Continuous mold run is set.

For a possibly desired semi-automatic or automatic operation, the actual value to be selected for the duration of the hold - i.e. a target value for the duration of the hold - is specified, for example, by the plant operator or the system supplier within the percentage time interval resulting from the formula. For the sake of simplicity, the plant operator could, for example, aim for the middle of the time interval.

If, for example, the formula results in the limit values 60 and 90, the duration of the hold is selected from the interval 60% - 90% of the duration of a continuous mold run with healing speed v _Low .
If, for example, the formula results in the limit values 40 and 70, the duration of the hold is selected from the interval 50% - 70% of the duration of a continuous mold run with healing speed v _Low .

While maintaining the healing speed, oscillations of up to +/- 15% around the target value for the healing speed v _LOW are permissible - whereby the minimum operating speed must not be undershot.
It is preferable to keep the healing speed essentially constant.
The strength of the acceleration can be constant or change during the acceleration process.

According to a variant of the method, after the healing speed v _LOW has been reached, the speed of the strand withdrawal is reduced for a period of at least 50%, preferably at least 65%, up to 120%, preferably up to 100%
continuous mold passage with v _Low at a healing speed v _LOW in the amount of 100-130% of the permissible minimum operating speed v _MIN , preferably in the amount of 100-120% of the permissible minimum operating speed v _MIN ,
and thereafter increased with an average acceleration of at least 0.2 m/min ² , preferably at least 0.5 m/min ² , and up to 5 m/min ² , preferably up to 2 m/min ² .
Averaging is done over the period from the start of acceleration to the end of acceleration.

In this variant, a strand withdrawal speed of 100-130% of the permissible minimum operating speed v _MIN , preferably 100-120% of the permissible minimum operating speed v _MIN , is present throughout the entire duration, but it changes suddenly at least once, or it changes steadily - at least once - during at least part of that period. It can also change throughout the duration. Before, during and after Change is the strand withdrawal speed in the range 100-130% of the allowable minimum operating speed v _MIN , preferably in the amount of 100-120% of the allowable minimum operating speed v _MIN .

The strength of the acceleration can be constant or change during the acceleration process.

In the method according to the invention, the duration of the passage through the continuous mold results from the total length L [m] of the relevant continuous mold and the healing speed v _LOW from the relationship (L−0.1 m)/v _LOW .

Compared to conventional breakout detection, the procedure according to the invention initiates a reduction in the strand draw-off speed much earlier; 5 - 30 seconds earlier are achievable. Because the sticker has not yet developed or is not yet very pronounced at such an early point in time, it is sufficient to avoid or heal it by delaying the healing speed to a high level compared to conventional breakout detection, and comparatively briefly to this healing speed remain. Since the difference between the healing speed and the strand pull-off speed that is usually aimed for before the lowering is small, a low acceleration compared to conventional breakout detection is sufficient afterwards.
In the interests of higher production rates, a normal strand withdrawal speed should nevertheless be reached quickly, but with increasing acceleration the risk of stickers occurring increases again.

Preferably, the strand draw-off speed is essentially increased to the strand draw-off speed prevailing before the lowering. In this context, essentially means a deviation of maximum +/- 15%.

• Parameter-Werte Verteiler,
• nicht-thermische Parameter-Werte an der Durchlaufkokille,
• Parameter-Werte am Oszillator,
• Parameter-Werte der Bewegung des Metallstranges
• Parameter-Werte des Metallstranges;
• Parameter-Werte des Gießprozesses.

According to an advantageous embodiment, the parameter values also include at least one, preferably at least two, particularly preferably at least three, further current parameter values of at least one type of parameter values from the group consisting of

• parameter values distributor,
• non-thermal parameter values at the continuous mold,
• parameter values on the oscillator,
• Parameter values of the movement of the metal strand
• parameter values of the metal strand;
• Parameter values of the casting process.

This means that stickers can be predicted or avoided even more precisely. The conventional rule is: the more parameter values are used, the better, because this improves the model formation and thus the prediction quality.

The type of parameter value "parameter values distributor" can be, for example, parameter values such as content / volume / mass of the liquid metal in the distributor, current distributor temperature and current distributor level height, current closing element position, current distributor height position, current distributor height movement speed.

The type of parameter value “non-thermal parameter values on the continuous mold” can, for example, be parameter values such as bath level height position—indicating the fill level of the continuous mold; also called meniscus height position -, waviness of the meniscus, amount of casting powder added based, for example, on a unit of time or on the strand withdrawal speed, casting powder thickness on the bath level, casting powder thickness distribution over the surface of the bath level. The thickness of the casting powder on the bath level is to be understood as meaning the average layer height of the casting powder on the surface of the bath level, consisting of a liquid portion near the bath level and solid portions that lie above it.

The type of parameter value "parameter values on the oscillator" can be, for example, values of oscillation parameters such as frequency, stroke, sinusoidality, or parameter values such as hydraulic pressure, oscillation force, inclination of the oscillator.

The type of parameter value "parameter values of the movement of the metal strand" can be, for example, pull-out forces on strand guide segments.
It is generally known that, for the continuous casting of a metal strand, a strand guide with strand guide segments is used as the current state of the art in terms of plant engineering. Individual rollers of such strand guide segments can be driven and exert driving forces, so-called pull-out forces, on the metal strand, which can be measured.

The type of parameter value "parameter values of the metal strand" can be, for example, strand frictional force, strand frictional energy, strand frictional power, for example per strand, per perimeter length unit, per strand guiding surface unit in the strand guiding mold.

The type of parameter value "parameter values of the casting process" is, for example, the immersion tube immersion depth below the bath level, or a characteristic value of the dynamic strand bulging - also called dynamic bulging.
It can also be parameter values for the negative strip time or for the negative strip. They describe the time or the distance covered by the continuous mold during this time, during which the continuous mold overtakes the metal strand within an oscillation cycle.

The embodiments of the method according to the invention described above are preferably carried out at least semi-automatically, particularly preferably automatically; preferably at least the method steps in the characterizing part of claim 1 are carried out semi-automatically, particularly preferably automatically.

The methods according to the invention are preferably computer-implemented methods, for example implemented in the plant control or plant regulation of a continuous casting plant.

A further subject matter of the present application is a computer for executing a computer-implemented method according to the invention.

A further object of the present application is a plant control and/or regulation of a continuous casting plant with a computer for carrying out a computer-implemented method according to the invention.

A further subject matter of the present application is a computer program product, comprising instructions which, when the computer program is executed by a computer, cause the latter to carry out the steps of the method according to the invention.

A further subject matter of the present application is a computer-readable data carrier on which such a computer program product is stored. A computer program product is to be understood as a computer program stored on a carrier.

A method according to the invention can be used alone, or it can be used in addition to conventional methods for detecting stickers or predicting strand breakouts. It is easy to retrofit and results in increased productivity. If it is used in addition to conventional methods for detecting stickers or predicting strand breakthroughs, there is the advantage that the number of conventional sticker alarms is reduced, since the circumstances leading to them are prevented to a high percentage by the method according to the invention as a precaution.

A further subject matter of the present application is a signal processing device with a machine-readable program code which has regulation commands and/or control commands for carrying out a method according to the invention. The signal processing device is, for example, a control and/or regulating device, for example a plant control and/or plant regulation of a continuous casting plant.

A further subject matter of the present application is a continuous casting plant comprising such a signal processing device.
A further object of the present application is a machine-readable program code for such a signal processing device, the program code having control commands and/or regulation commands which cause the signal processing device to carry out a method according to the invention.
A further object of the present application is a storage medium with such a machine-readable program code stored thereon.

Automatic means that in a method according to the invention, the individual steps such as acquisition, recording, evaluation, data model creation, data model evaluation, deviation analysis, target/actual comparison, risk assessment/calculation, risk value comparison with threshold value, determination of the delay value, initiation of the Delay by triggering, setting the healing speed, healing time at low speed, re-acceleration, setting the new speed setpoint, et cetera without any intervention carried out by humans, with the exception that a human developed, programmed, imported and commissioned the entire computer, control and regulation program.
Semi-automatic means that in a method according to the invention, the human being intervenes at one point or another in the overall process, for example when initiating the delay using the trigger, or when determining the healing time, or when determining which new target speed after the sticker -Healing to be discontinued. In other words: an operator of the continuous casting plant is involved in the overall process of the method according to the invention and he or she confirms or rejects the decisions suggested by the method according to the invention and its computer program for individual steps in the sequence of the individual step chain.

Brief description of the drawings

Fig. 1

eine schematische Darstellung eines erfindungsgemäßen Verlaufes der Strangabzugsgeschwindigkeit gegen die Zeit.

Fig. 2

ein grobes Schema einer Stranggußanlage.

The invention will now be explained in more detail using exemplary embodiments. The drawings are exemplary and are intended to explain the idea of the invention, but in no way restrict or even conclusively reproduce it. It shows:

1

a schematic representation of a course according to the invention of the strand draw-off speed versus time.

2

a rough scheme of a continuous casting plant.

Description of the embodiments examples

figure 1 shows a continuous schematic representation of a course according to the invention of the strand pull-off speed versus time in comparison to the broken line course when using a conventional method for detecting stickers or predicting strand breakthroughs. It shows how the reduction of the previously prevailing normal strand take-off speed v _NORM 1.2 m/min begins automatically and immediately according to the invention when the threshold value is exceeded. The lowering takes place with an average deceleration of 1.5 m/min ² to a healing speed v _LOW 0.8 m/min. The healing speed v _LOW is 100% of the minimum operating speed v _MIN . The healing speed v _LOW is maintained for 45 seconds, which is 75% of the duration of a run mold run at that speed. Then, with an average acceleration of 0.8 m/min ² , the normal strand take-off speed v _NORM is accelerated and production is continued.
The progression when using a conventional method is shown as a solid line. Lowering of the strand withdrawal speed occurs later, the deceleration to a lower strand withdrawal speed serving for healing, in this case a creeping speed below the minimum operating speed v _MIN , is much greater. Crawl speed is maintained for 60 seconds. The subsequent acceleration is lower than in the case of the curve according to the invention, and the normal strand withdrawal speed v _NORM is only reached later. As a result, with the invention Process produces more strand, which means that the plant productivity is improved with it.

figure 2 shows a rough diagram of a continuous casting plant 1 with which a metal strand 2 - for example a steel strand - is produced by means of a continuous casting process. Liquid metal 3 is fed continuously into the continuous mold 5 via a distributor 4 . It runs through them and forms a thin strand shell as a result of cooling at the edge, which shell surrounds a liquid core of the metal strand 2 . The flow of the liquid metal 3 from the outlet 6 - here a dip tube - of the distributor 4 is controlled or regulated via closing elements such as plugs or slides. The metal billet 2 is drawn off at a billet draw-off speed from the continuous mold 5, which oscillates by means of an oscillator (not explicitly shown). After exiting the continuous mold 5, the metal strand 2 is further cooled in the subsequent strand guide 7 and guided until it has completely solidified.

List of References

1

continuous casting plant

2

metal strand

3

liquid metal

4

distributor

5

continuous mold

6

outlet

7

strand guide

Claims (15)

Process for the continuous casting of a metal strand by pouring liquid metal from a distributor into a continuous mold,
which oscillates by means of an oscillator,
characterized,
that during casting, parameter values are recorded and recorded at least every 2 seconds,
these parameter values comprising at least - current temperature values of a monitoring system of the continuous mold, - current shutter movement speed, - current bath level vertical speed, - current strand take-off speed, and that a, preferably periodic, evaluation of the recorded parameter values is carried out using an evaluation method based on the current and past parameter values and the probability of sticker events in the continuous mold is determined, and if a threshold value for the probability is exceeded, a reduction the strand withdrawal speed v _AB to a healing speed v _LOW in the amount of 100-130% of a permissible minimum operating speed v _MIN , preferably in the amount of 100-120% of the permissible minimum operating speed v _MIN , with the average deceleration being between 0.7 and 5 m/min ² , preferably between 1.0 and 2.5 m/min ² . Method according to Claim 1, characterized in that the probability of sticker events is determined in the evaluation process using deviation analysis. Method according to Claim 1 or 2, characterized in that after the healing speed v _LOW has been reached, the strand withdrawal speed for a period of at least 50%, preferably at least 65%, and up to 120%, preferably up to 100%, of a continuous mold run with v _Low healing speed v _LOW is maintained, and then with an average acceleration of at least 0.2 m/min ² , preferably at least 0.5 m/min ² , and up to 5 m/min ² , preferably up to 2 m/min ² , is increased. The method according to any one of claims 1 to 3, characterized in that
the duration of holding at the healing speed v _Low as a percentage of the duration of a continuous mold cycle with the healing speed v _Low
is within the percentage time interval
whose limit values are derived from the formula $$\left[\left(\mathrm{50}+\mathrm{20}*\left({\mathrm{v}}_{\mathrm{AWAY}}-{\mathrm{v}}_{\mathrm{Low}}\right)/{\mathrm{v}}_{\mathrm{Low}}\right)+/-\mathrm{15}\right],$$

where v _AB is greater than v _MIN , and where v _AB is greater than v _Low , result, where, if the result of the formula is less than 50, the lower limit of the time interval is set at 50% of the duration of the continuous mold run. Method according to one of Claims 1 to 4, characterized in that the strand draw-off speed is essentially increased to the strand draw-off speed prevailing before the lowering. Method according to one of claims 2 to 5, characterized in that deviation rules of the evaluation method are created using at least one member of the group consisting of - machine learning, - Deep Learning. Method according to one of Claims 1 to 6, characterized in that the parameter values also include at least one, preferably at least two, particularly preferably at least three, further current parameter values of at least one type of parameter values from the group consisting of - parameter values distributor, - non-thermal parameter values at the continuous mold, - parameter values on the oscillator, - parameter values of movement of the metal strand, - parameter values of the metal strand, - parameter values of the casting process, include. Method according to one of Claims 1 to 7, characterized in that it is a computer-implemented method. Signal processing device with a machine-readable program code, characterized in that it has control commands and/or regulation commands for carrying out a method according to one of Claims 1 to 8. Machine-readable program code for a signal processing device according to Claim 9, characterized in that the program code has control commands and/or regulation commands which cause the signal processing device to carry out a method according to one of Claims 1 to 8. Storage medium with machine-readable program code according to claim 10 stored thereon. Computer for executing a computer-implemented method according to claim 8. Plant control and/or regulation of a continuous casting plant with a computer for executing a computer-implemented method according to claim 8. Computer program product, comprising instructions which, when the computer program is executed by a computer, cause it to carry out the steps of a method according to any one of claims 1 to 8. A computer-readable data carrier on which a computer program product according to claim 14 is stored.

Images