EP4122622A1 - Strand guiding device and method for continuous casting of a metallic product in a continuous casting plant with such a strand guiding device - Google Patents

Abstract

The invention relates to a strand guiding device (100) for use in a continuous casting plant (110), in which a metallic product in the form of a cast strand (101) can be moved in a transport direction (T), and a method for continuously casting a metallic product in a continuous casting plant ( 110) with such a strand guide device (100) which comprises a plurality of separate supporting strand guide segments (1-9). At least one strand-guiding segment is designed to be exchangeable at a predetermined position of the strand-guiding device (100) and can therefore be exchanged for an exchangeable segment (W). Such a changeover segment (W) differs in at least one feature from the strand guide segment that was previously or originally inserted at the predetermined position of the strand guide device (100).

Description

The invention relates to a strand guiding device according to the preamble of claim 1, and to a method for continuously casting a metallic product in a continuous casting plant with such a strand guiding device according to the preamble of claim 11.

According to the state of the art, continuous casting plants for thick or thin slabs, billets or round plants are defined not only by their mold but also by the number of segments and support rollers. In order to run higher casting speeds, it is conventionally known for such continuous casting plants to lengthen the associated supporting strand guide by one or more segments. In the same way, it is known to replace defective segments with segments of the same type. The entire system configuration with all segments, roller and nozzle positions and roller diameters is stored electronically for a calculation process.

In the operation of continuous casting plants, it is state of the art to cool the cast strand after exiting the mold in the so-called secondary cooling of a supporting strand guide of such plants until the cast strand has completely solidified. This cooling process plays an important role in the resulting quality of the cast strand and the products made from it. Complete solidification of the cast strand should be achieved within the supporting strand guides that support the cast strand with the core still liquid.

The operation of the secondary cooling of a continuous casting plant is usually realized with spray or cooling water, with the amount of water on the Surfaces of the cast strand is applied, is set under specification of target temperature curves. The progression of these target temperature curves can vary depending on the material of the material to be cast and, for example, depending on certain cooling zones of the supporting strand guide and/or the casting speed. Depending on the material and the selected casting speed, a corresponding target temperature curve is then selected and the secondary cooling for applying the spray or cooling water to the surfaces of the cast strand to be cooled is thus set.

In the 16 shows a part of a conventional continuous casting installation 110 with an associated secondary cooling system 111, which is formed from nine individual strand guide segments 102. In detail, the strand guide segment arranged at position #1 comprises a total of 13 pairs of support rollers arranged opposite one another. The strand guide segments at positions #2 through #7 each include six pairs of support rolls, with the two strand guide segments at positions #8 and #9 each including seven pairs of support rolls. As a result, this secondary cooling system 111, which at the same time forms the supporting strand guide for the continuous casting installation 110, comprises a total of 63 pairs of supporting rollers

Out WO 2007/121838 A1 it is known, in relation to a strand guide stand of a continuous casting installation for casting liquid metals, in particular liquid steel materials, to determine the roller spacing of the support rollers of the strand guide stand. Here, the distances between the pairs of rollers or the roller segments in the casting direction are set to a non-stationary bulge moving at a variable casting speed, and fluctuations in the bath level in the continuous casting mold are reduced by influencing the individual frequency that arises as a result. In the course of this, such different roller distances are combined that, due to the base roller distance and the casting speed, from several or all individual frequencies of the respective support roller, an overall route profile of the Strand guide framework result, from which an optimum for maximum damping of all bulging effects is determined, based on which then optimal roller distances are divided. The advantages are stronger damping of bath level fluctuations and bulging under different casting conditions. This optimum of a low initial amplitude, continuous decay behavior, rapid damping and a high overall time constant results in a small change in volume in the mold bath level. The susceptibility to failure or the oscillation behavior of the mold bath level in the event of process-related parameter changes, such as changes in the casting speed, the steel quality, changes in thickness or width, changes in cooling, etc., cause fewer bulging effects. Nevertheless, the technology is subject to WO 2007/121838 A1 the disadvantage that in an existing system, the roller spacing in a strand guide stand cannot be changed afterwards.

Accordingly, the invention is based on the object of being able to adapt a configuration of the supporting strand guide and at least one segment thereof to different steel grades in a simple manner during the continuous casting of metal products.

This object is achieved by a strand guide device for use in a continuous casting installation having the features of claim 1, and by a method for continuously casting a metallic product having the features specified in claim 11. Advantageous developments of the invention are defined in the dependent claims.

A strand guide device according to the present invention is intended for use in a continuous casting installation in which a metal product in the form of a cast strand can be moved in a transport direction. Such a strand guide device comprises a plurality of separate supporting strand guide segments, which are arranged next to or one behind the other, viewed in the direction of transport, and each have a plurality of support rollers, preferably in the form of pairs of support rollers arranged opposite one another, with at least one strand guide segment being designed to be exchangeable at a predetermined position of the strand guide device and thus being able to be exchanged for a change segment . Such an exchangeable segment differs from the strand guide segment that was previously or originally inserted at the predetermined position of the strand guide device in at least one feature, with this feature being selected from a group of features made up of the number of rolls, roll spacing, roll diameter, and roll type , roller drive, roller spacing, type and number of nozzles for strand cooling, contact forces of the segmented cylinders, type and number of roller stirrers and/or quality of at least one frame element. In other words, the changing segment differs in at least one feature from the strand guide segment previously used or inserted at this predetermined position, as just explained.

Likewise, the present invention also provides a method of continuously casting a metallic product in a continuous caster having a strand guide assembly comprising a plurality of separate supporting strand guide segments. In this method, the metallic product in the form of a cast strand is moved in a transport direction, with the strand guide segments of the strand guide device being arranged next to or behind one another, viewed in the transport direction, and each having a plurality of support rollers, preferably in the form of pairs of support rollers arranged opposite one another . This method is characterized in that at least one strand guide segment is exchanged for a change segment at a predetermined position of the strand guide device during a batch change for the metallic product. Such a changing segment differs in comparison to the strand guide segment, which was previously or originally used at the predetermined position of the strand guide device, in at least one feature, this feature being selected from a group of features formed from the number of rolls, roll spacing, roll diameter, roll type, roll drive, roll pitch, type and number of nozzles for strand cooling, contact forces of the segment cylinders, type and number of roller stirrers and/or quality of at least one frame element.

The present invention is based on the essential finding that the use of an interchangeable segment in the strand guide device makes it possible to adapt to other types or grades of steel and their different material properties in the production of metallic products by means of continuous casting. For example, by using at least one interchangeable segment, it is also possible to cast special grades with a high strand quality (e.g. ultra low carbon grades, peritects, tubular or silicon steels, ferritic stainless steels). In any case, the use of such a changeable segment in the supporting strand guide of a continuous casting plant means that, thanks to the change in at least one feature of this changeable segment compared to a strand guide segment that was originally or previously used instead of the changeable segment at the predetermined position of the strand guide device, then an adaptation to another steel grade, for example in the form of the above-mentioned special grades, can be achieved in order to realize the manufacturability or castability of such a different steel grade with changed material properties. As a result, an improvement in the quality of the manufactured metallic products is achieved with certain steel grades.

Accordingly, the present invention is based on the fact that the length of the strand guide device with its respective supporting strand guide segments is not changed, but that this strand guide device is changed in relation to at least one of its associated Segments "rebuilt", namely the fact that at least one strand guide segment is replaced by a change segment. Again: This changing segment differs - as already explained above - in at least one feature from the strand guiding segment, which was originally used in the predetermined position of the strand guiding device and has now been replaced by the changing segment.. In this regard, it should also be emphasized that the positions the "neighboring segments", ie those strand guide segments that have not been replaced by a change segment, are not changed by the use of a change segment.

• Verminderung von statischem Bulging durch einen geringeren Rollenabstand;
• Verminderung von Gießspiegelschwankungen durch unterschiedliche Rollenabstände;
• Erhöhung der Produktion durch eine verstärkte Kühlung;
• Kornfeinung zur Rissvermeidung durch eine Intensivkühlung (verstärkte Kühlung);
• Verminderung der Auszugskräfte durch zusätzlich angetriebene Rollen;
• Verminderung der Segmentauffederung durch steifere Segmentrahmen;
• Möglichkeit einer dynamischen Segmentanstellung;
• Verminderung der Rollen-Durchbiegung durch mehrfach geteilte Stützrollen;
• Erhöhung der Rollenstandzeit durch den Einsatz anderer Rollenarten; und/oder
• Erstarrungsgefüge zur Verbesserung der Innenqualität durch Rollenrührer.

At this point it is pointed out separately that, according to the present invention, the following purposes are also pursued with the use of at least one interchangeable segment:

• Reduction of static bulging due to a smaller wheel spacing;
• Reduction of mold level fluctuations through different roller distances;
• increase production through increased cooling;
• Grain refinement to avoid cracks through intensive cooling (increased cooling);
• Reduction of pull-out forces through additionally driven rollers;
• Reduction of segment deflection through stiffer segment frames;
• Possibility of dynamic segment employment;
• Reduced roller deflection thanks to multi-part support rollers;
• Increase in roll life through the use of other types of rolls; and or
• Solidification structure to improve internal quality using roller stirrers.

In an advantageous further development of the strand guiding device according to the invention, it is provided that a changing segment has the same basic geometry as compared to the strand guiding segment which is originally present or used at the predetermined position of the strand guiding device. This ensures that at a predetermined position of the strand guide device, i.e. at a specific point of it, an existing strand guide segment can be selectively exchanged or replaced with a change segment. Said basic geometry can be defined by a radius of the roller guide and--seen in the transport direction--by a respective segment length. In other words, the radius of the roller guide, the segment length and the jaw width of a change segment remain the same compared to the strand guide segment that is then to be exchanged for the change segment at the predetermined position of the strand guide device.

The aforementioned replacement of at least one existing strand guide segment of the strand guide device with a respective changeable segment can take place in a curved area of the strand guide device and/or in a straight or linear area of the strand guide device, for example in its vertical or horizontal area. In the latter case, it goes without saying that such an alternating segment then also runs straight or linear and has no radius of curvature.

In an advantageous development of the invention, two segments of the strand guide device can also be exchanged or replaced by an exchangeable segment, which has the same dimensions as these two exchanged segments, but has at least one frame element with greater rigidity, for example. This means that, for example, two segments of the strand guide device can be replaced by an exchangeable segment with greater rigidity can be replaced, the change segment can have either the same or an increased number of support rollers.

In an advantageous development of the invention, the changing segment can have at least one support roller or a pair of support rollers with an additional drive. This makes it possible to generate a higher pull-out force in the transport direction for the cast strand with which such a support roller or such a support roller pair can be brought into contact. This is particularly advantageous in the case of larger strand dimensions (= wider and/or thicker cast strand).

In an advantageous development of the invention, it can be provided that an exchangeable segment is equipped with a roller stirrer. By means of such a roller stirrer, it is possible to generate an alternating magnetic field in the area of the cast strand that is still liquid. This takes place against the background that during the solidification of the liquid melt in a continuous casting plant, round grains (globulites) or oval grains (dendrites) can form, depending on the respective solidification rate. If ferritic stainless steels have too low a proportion of globulites, an undesired so-called tension cracking forms on the surface of the cold strip. But even with steel that is not frost-free, a higher proportion of globulites leads to a stronger structure and reduced central segregation. By providing the aforesaid roller stirrer in the interchangeable segment, it is possible to increase the globular structure proportion of certain grades when such an interchangeable segment is used in the strand guide device of a continuous casting plant.

In continuous casting, a target temperature curve determines the target values for the surface temperature to be achieved, which the strand achieves within the supporting strand guide, eg at the end of individual cooling zones which are part of this supporting strand guide. The amount of spray water from the secondary cooling system is regulated in such a way that these target values are achieved.

• mindestens ein weiteres Rollenpaar, und oder
• mindestens eine weitere Sekundärdüse zur Kühlung des Gießstrangs, und/oder
• mindestens eine weitere Rollenteilung, um dadurch eine verminderte Rollendurchbiegung zu erreichen, und/oder
• einen um mindestens 1 mm kleineren Rollenradius der nicht angetriebenen Rollen.

In an advantageous development of the invention, the interchangeable segment can be designed for steel grades that are susceptible to cracking. In this case, such an exchangeable segment differs from existing strand guide segments, which are designed for steel grades that are not susceptible to cracking, by the following features:

• at least one other pair of roles, and or
• at least one further secondary nozzle for cooling the cast strand, and/or
• at least one further roll division in order to thereby achieve reduced roll deflection, and/or
• a roller radius of the non-driven rollers that is at least 1 mm smaller.

• mindestens ein weiteres Rollenpaar, und oder
• mindestens eine weitere Sekundärdüse zur Kühlung des Gießstrangs, und/oder
• mindestens eine Sekundärdüse zur Kühlung des Gießstrangs, deren Regelungsbereich zu größeren Wassermengen hin verschoben ist, und/oder
• mindestens eine weitere Rollenteilung, um dadurch eine verminderte Rollendurchbiegung zu erreichen, und/oder
• einen um mindestens 1 mm kleineren Rollenradius der nicht angetriebenen Rollen.

In an advantageous development of the invention, the changing segment can be designed for high casting speeds. In this case, such a changeover segment differs from existing strand guide segments, which are designed for standard casting speeds, by the following features:

• at least one other pair of roles, and or
• at least one further secondary nozzle for cooling the cast strand, and/or
• at least one secondary nozzle for cooling the cast strand, the control range of which is shifted towards larger amounts of water, and/or
• at least one further roll division in order to thereby achieve reduced roll deflection, and/or
• a roller radius of the non-driven rollers that is at least 1 mm smaller.

Some high quality steel grades tend to bulge severely between the strand guide support rollers. This tendency can last-mentioned possible developments of the invention are countered by an increased cooling capacity, for example by a larger number of secondary nozzles for cooling the cast strand and/or by larger amounts of water, which are supplied to the secondary nozzles. In any case, an increase in the size of the strand shells of the cast strand is achieved by increased cooling, which reduces the bulging effect between the support rollers and thus also reduces the risk of internal cracks forming on the solidification front of the cast strand.

• mindestens eine Sekundärdüse weniger, um eine geringere Kühlung des Gießstrangs zu erreichen, und/oder
• mindestens eine Sekundärdüse zur Kühlung des Gießstrangs, deren Regelungsbereich zu geringeren Wassermengen hin verschoben ist, und/oder
• mindestens eine stärker gekühlte Rolle und/oder ein stärker gekühltes Rollenpaar, und/oder
• mindestens eine stärker beschichtete Rolle und/oder ein stärker beschichtetes Rollenpaar.

In an advantageous development of the invention, the changing segment can be designed for high strand temperatures. In this case, such a changeover segment differs from existing strand guide segments with stronger cooling by the following features:

• at least one secondary nozzle less in order to achieve less cooling of the cast strand, and/or
• at least one secondary nozzle for cooling the cast strand, the control range of which is shifted towards lower water quantities, and/or
• at least one more heavily cooled roller and/or a more strongly cooled pair of rollers, and/or
• at least one heavier coated roll and/or a heavier coated pair of rolls.

• dynamisch verstellbare Maulweiten, und/oder
• mindestens einen verstärkten Anstellzylinder.

In an advantageous development of the invention, the changing segment can be designed for carrying out a soft reduction for the cast strand. In this case, such a changeover segment differs from existing strand guide segments with a fixed taper by the following features:

• dynamically adjustable jaw widths, and/or
• at least one reinforced adjusting cylinder.

In an advantageous development of the invention, the interchangeable segment can have at least two adjacent ones with regard to its basic geometry strand guide segments which are arranged adjacent to one another in the original strand guide device.

The present invention also provides a continuous casting plant for producing a metallic product in the form of a cast strand. Such a continuous casting plant comprises a strand guiding device as explained above, in which the cast strand can be moved in a transport direction.

According to an advantageous further development of the method according to the invention, a changing segment of a strand guide device is used here, as explained above.

According to an advantageous development of the method according to the invention, steel grades that are sensitive to internal cracks can be processed, with static bulging being reduced through the use of the changing segment for the metallic product, while it is being moved within the supporting strand guiding device, and thus an improvement in the quality of the metallic product being achieved.

According to an advantageous development of the method according to the invention, support rollers can be used in the changing segment, the roller diameter of which is smaller and the number of which is greater than in comparison to the supporting rollers of the strand guiding segment, which was originally present or used at the predetermined position of the strand guiding device and through the changing segment has been replaced.

According to an advantageous development of the method according to the invention, steel grades can be processed with a casting speed of at least 2 m/min, with the use of the exchangeable segment reducing dynamic bulging for the cast strand and thereby improving plant safety. It may be useful that in the Exchange segment used support rollers each have a different roller spacing relative to each other.

In addition or as an alternative, it can be advantageous for the roller spacing of the support rollers used in a change segment to be different in comparison to the support rollers of the strand guide segment that was previously present at the predetermined position of the strand guide device and has now been replaced by the change segment.

According to an advantageous development of the method according to the invention, a process model can receive information regarding the arrangement of the used strand guide segments of the strand guide device and the at least one change segment used and compile the system configuration in relation to a roller and nozzle plan from a segment and nozzle catalogue. On the basis of this, the temperature of the cast strand along the supporting segments of the strand guide device is then calculated by the process model, preferably in the manner of a control.

According to an advantageous development of the method according to the invention, a process model can receive information regarding the arrangement of the used strand guide segments of the strand guide device and the at least one change segment used and compile the system configuration in relation to a roller and nozzle plan from a segment and nozzle catalogue. Based on this, a sump tip position for the cast strand along the supporting segments of the strand guide is then calculated by the process model.

This means that for a calculation method according to the present invention, the plant configuration, ie the configuration of a continuous casting plant, for example with regard to its associated support rollers and secondary nozzles for cooling the cast strand, is automatically reassembled. These are in a segment catalogue for all strand guide segments of the strand guide device, also including at least one change segment, the positions and types of support rollers and nozzles are described. Depending on the current segment selection, the roller and nozzle plans are then recompiled internally.

According to an advantageous development of the method according to the invention, steel grades or secondary steel with a copper content of ≧0.15% can be processed. Here, a grain refinement and thus an improvement in quality is achieved through the use of an exchangeable segment with increased spray water cooling for the cast strand.

According to an advantageous development of the method according to the invention, ferritic high-grade steels or silicon steels with a silicon content of at least 0.5% can also be processed. By using an exchangeable segment with at least one roller stirrer, an increased proportion of globular primary structure and thus an improvement in quality is achieved for the cast strand.

Exemplary embodiments of the invention are described in detail below using a schematically simplified drawing.

Fig. 1

eine schematisch vereinfachte Seitenansicht einer Stranggießanlage mit einer zugehörigen Strangführungseinrichtung gemäß der vorliegenden Erfindung,

Fig. 2, 7, 8

jeweils schematisch vereinfachte Seitenansichten der Stützrollen eines Wechselsegments, welches Teil einer Strangführungseinrichtung gemäß der vorliegenden Erfindung ist,

Fig. 3

eine schematisch vereinfachte Seitenansicht der Stützrollen eines Strangführungssegments, welches Teil einer Strangführungseinrichtung gemäß der vorliegenden Erfindung ist,

Fig. 4

eine schematisch vereinfachte Seitenansicht eines Wechselsegments, welches Teil einer Strangführungseinrichtung gemäß der vorliegenden Erfindung ist,

Fig. 5, 6

jeweils schematisch vereinfachte Seitenansichten einer Stranggießanlage mit weiteren Ausführungsformen einer zugehörigen Strangführungseinrichtung gemäß der vorliegenden Erfindung,

Fig. 9

eine schematisch vereinfachte Ansicht von Stützrollen eines Strangführungssegments, welches Teil einer Strangführungseinrichtung gemäß der vorliegenden Erfindung ist,

Fig. 10

eine schematisch vereinfachte Ansicht von Stützrollen eines Wechselsegments, welches Teil einer Strangführungseinrichtung gemäß der vorliegenden Erfindung ist,

Fig. 11

eine schematisch vereinfachte Seitenansicht eines Wechselsegments, welches zwischen zwei anderen Strangführungssegmenten einer erfindungsgemäßen Strangführungseinrichtung angeordnet ist,

Fig. 12-14

jeweils schematisch vereinfachte Draufsichten auf ein Wechselsegment, welches Teil einer Strangführungseinrichtung gemäß der vorliegenden Erfindung ist, und

Fig. 15

eine schematisch vereinfachte Seitenansicht eines Wechselsegments, das neben einem anderen Strangführungssegment einer erfindungsgemäßen Strangführungseinrichtung angeordnet ist.

Show it:

1

a schematically simplified side view of a continuous casting installation with an associated strand guiding device according to the present invention,

Figures 2, 7, 8

each schematically simplified side views of the support rollers of a changing segment, which is part of a strand guiding device according to the present invention,

3

a schematically simplified side view of the support rollers of a strand guide segment, which is part of a strand guide device according to the present invention,

4

a schematically simplified side view of a changing segment, which is part of a strand guiding device according to the present invention,

Figures 5, 6

each schematically simplified side views of a continuous casting plant with further embodiments of an associated strand guiding device according to the present invention,

9

a schematically simplified view of support rollers of a strand guide segment, which is part of a strand guide device according to the present invention,

10

a schematically simplified view of support rollers of a changing segment, which is part of a strand guiding device according to the present invention,

11

a schematically simplified side view of a changing segment, which is arranged between two other strand guiding segments of a strand guiding device according to the invention,

12-14

each schematically simplified plan view of a changing segment, which is part of a strand guide device according to the present invention, and

15

a schematically simplified side view of a changing segment, which is arranged next to another strand guiding segment of a strand guiding device according to the invention.

Below are with reference to the Figures 1 to 15 preferred embodiments for a supporting strand guide device 100, an associated continuous caster 110 and a method for continuously casting a metallic product in such a continuous caster 110 according to the present invention, with which a cast strand 101 of metal is produced by means of continuous casting. Same features are in the drawing each provided with the same reference numerals. At this point it is pointed out separately that the drawing is merely simplified and in particular is not shown to scale.

1 shows a basically simplified side view of the strand guide device 100 and an associated continuous casting plant 110 according to a first embodiment of the present invention.

At this point it is pointed out separately that for the following description the terms metallic product, metal strand or cast strand are optionally used as synonyms.

The continuous caster 110 after 1 comprises a mold 112 having a lower opening 113 and thereby a vertical outlet downwards. Liquid metal is poured into the mold 112 up to a casting level or bath level 114, e.g. As steel or a steel alloy.

In the area of a secondary cooling system 111, the continuous casting plant 110 comprises the supporting strand guiding device 100, which is connected to the lower opening 113 of the mold. Thus, the supporting strand guide device 100 of the mold 112 is arranged immediately downstream or downstream thereof. During operation of the continuous casting plant 110 and when a corresponding method according to the invention is carried out, a cast or metal strand 101 emerges downwards from the lower opening 113 of the mold 112 and is then moved or transported along the strand guide device 100 in a transport direction T.

The secondary cooling system 111 comprises individual cooling segments (not specified) along the strand guide device 100, which ensure that a cooling medium, in particular in the form of water, is applied to both sides of the metal strand 101, e.g targeted cooling. These cooling segments are each fed with cooling liquid via lines (not shown) and are each equipped with spray or secondary nozzles (to be explained below). Accordingly, it is possible to apply cooling liquid to the surfaces of the metal strand 101 through the spray nozzles of the individual cooling segments, namely on its upper side and/or lower side.

The continuous casting plant 110 comprises a control or regulation unit 132 which is connected to the cooling segments of the supporting strand guide device 100 via a signal path 134 for signaling purposes, among other things. This signal path 134 can be wired or wireless, e.g. by a radio link or the like.

The control or regulation unit 132 includes a process computer 133 on which suitable software is installed.

The control or regulation unit 132 is connected to a data memory 136 in which the required process data for the continuous casting plant 110 are stored. Furthermore, current process data from the continuous casting plant 110 can also be collected or stored in the data memory. To this extent, this data memory 136 forms a database. It is possible to input or read individual process data PD into the data memory 136 via an interface (not shown). This input option is in the 1 symbolized by an arrow with "PD".

The continuous casting plant 110 is equipped with at least one (unspecified) temperature sensor, or a plurality of such sensors, which is/are arranged adjacent to the supporting strand guide device 100 . By means of such a sensor or a plurality of such sensors, the temperature of the metal strand 101 can be determined in order, for example, to compare the previously calculated temperature of the metal strand 101 with the to adjust the measurement. The temperature data from the sensor or sensors are first fed to a data acquisition unit 138 and sent from there to the open-loop or closed-loop control unit 132 via the signal path 134 .

Variables or parameters are stored in the data memory 136, on the basis of which setpoint temperatures can be set or specified for the individual cooling segments along the supporting strand guide device 100. A specific setpoint temperature and a predetermined distance from the bath or meniscus 114 can belong to these variables. These variables depend on a specific material or a specific group of materials from which the metal strand 101 is produced, and in any case independently of a specific continuous casting plant.

On the basis of the parameters mentioned above, which are stored in data memory 136, control and regulation unit 132 can be used for the individual cooling segments along supporting strand guide device 100 in the area of secondary cooling 111 of a specific continuous casting plant, e.g. continuous casting plant 110 from 1 , Target temperatures can be set or specified.

The strand guiding device 100 comprises a plurality of supporting strand guiding segments, which in the embodiment of FIG 1 are each denoted by the numbers 1-9. These strand guide segments 1-9 are arranged next to or one behind the other as seen in the transport direction T and each have a plurality of support rollers 118 .

In the embodiment of 1 For example, the strand guide segment at position #1 of the strand guide device 100 comprises a total of 13 pairs of support rollers 118, with the two strand guide segments at positions #8 and #9 each being equipped with seven pairs of support rollers 118. Furthermore, the strand guide segments are at positions #2 through #7, at least in one original plant configuration of the continuous casting plant 110, each equipped with six pairs of support rollers 118.

In the 3 1 shows a strand guide segment which can be originally arranged at position #4 of the strand guide device 100 and - as explained - is equipped with six pairs of support rollers 118 . If, as explained, the strand guide device 110 is equipped with the above-mentioned strand guide segments 1-9 at its positions #1 to #9, the total number of support roller pairs for the strand guide device 110, taking these nine strand guide segments 1-9 into account, is 63, in the same way as in the representation of 16 .

According to the invention, a standard strand-guiding segment can be exchanged or replaced by an interchangeable segment W in the strand-guiding device 100 at a predetermined position thereof. Details on this are explained below:
A comparison of 2 with 3 clarifies that a segment length L of a change segment W ( 2 ) with that of strand guiding segment #4 ( 3 ) matches. The same applies to a radius around which the changing segment W and the strand guide segment #4 are each curved. The match in terms of segment length L and radius of curvature, with which a basic geometry of the respective segments of the strand guide device is defined, makes it possible in the present case for strand guide segment #4 to be replaced by interchangeable segment W, as explained. For this example, it is understood that the predetermined position of the strand guide device 100 at which a previously existing strand guide segment is exchanged for the changing segment W corresponds to position #4.

The embodiment of 1 is now characterized in that the strand guide segment at position #4 can be exchanged for an interchangeable segment W, which differs from the previously used strand guide segment at position #4 in at least one feature. In the example shown here, this distinguishing feature is formed, inter alia, by a larger number of pairs of support rollers 118 - namely, the changing segment W is equipped here with a total of seven pairs of support rollers 118, as can be seen from the simplified view of FIG 2 is illustrated. Taking into account this larger number of support roller pairs 118 of the changing segment W, if this according to the representation of 1 is inserted into the strand guide device 110 at position # 4, there is then a total of 64 pairs of support rollers 118.

Another comparison of 2 with 3 makes it clear that in the alternating segment W (cf. 2 ) the diameter of the support rollers 118 is smaller than that of the support rollers 118 of strand guide segment #4 (cf. 3 ). This makes it possible for the changing segment W to have an additional pair of rollers with the same segment length L, namely a total of seven pairs of support rollers 118. This results in an additional roller gap, which means that the quantity of cooling water applied to the cast strand 101 is increased with the secondary nozzles otherwise being the same. The following numerical example may make this clearer: if the number of pairs of support rollers is increased from six to seven, the amount of cooling water increases by 1/6, and thus by 16.66%.

In the representation of 1 is symbolized by the arrow "W" that at position #4 in the strand guide device 110 the changing segment W with its total of seven pairs of support rollers 118 has already been inserted. The remaining eight strand guide segments at positions 1-3 and 5-9 are standard strand guide segments that were also previously present in the strand guide device 100. Considering of the change segment W used, the strand guide device 110 now contains a total of 64 pairs of support rollers 118, as already explained.

Referring to the 4 , which shows a simplified side view of an interchangeable segment W, further details and features of such an interchangeable segment W are explained below:
The changing segment W comprises an upper frame element 116 and a lower frame element 117. Support rollers 118 are rotatably mounted on these frame elements 116, 117 in each case. In the assembled state of the interchangeable segment W, as evidenced by the representation of 4 , these supporting rollers 118, which are respectively attached to the upper frame member 116 and the lower frame member 117, are arranged opposite to each other, thereby forming respective pairs of supporting rollers.

• Mit der Strecke "a" ist ein Rollenabstand bezeichnet, d.h. ein Abstand, um den zwei zueinander benachbarte Stützrollen 118 voneinander beanstandet sind.
• Mit "D" ist exemplarisch für eine Stützrolle 118 deren Rollendurchmesser gezeigt.
• Mit "120" ist ein Anstellzylinder angezogen, mit dem das obere Rahmenelement 116 und das untere Rahmenelement 117 relativ zueinander verstellt werden können, um dadurch beispielsweise eine Maulweite zwischen der oberen und der unteren Reihe von Stützrollen 118 zu verändern. Hierdurch lassen sich unterschiedlich große Dicken von Gießsträngen 101 erzeugen.
• Mit "122" ist ein zusätzlicher Antrieb bezeichnet, mit dem eine Stützrolle 118 ausgerüstet sein kann. In der Darstellung von Fig. 4 sind die Stützrollen 118, die mit einem Antrieb ausgerüstet sind, symbolisch vereinfacht durch ein "X" ausgefüllt, vorliegend - und rein beispielhaft zu verstehen - zwei Stützrollen 118 in der oberen Reihe. Jedenfalls kann es sich bei dem mit "122" bezeichneten Antrieb um einen solchen handeln, der lediglich für das Wechselsegment W vorgesehen ist, wobei ein Standard-Strangführungssegment nicht über einen solch zusätzlichen Antrieb verfügt. Entsprechend ist es mittels eines solchen Wechselsegments W bei dessen Einsatz in der Strangführungseinrichtung 100 möglich, auf den Gießstrang 101 dann größere Auszugskräfte auszuüben.
• Mit "124" und jeweils schraffierten Bereichen angedeutet sind Rollenrührer, mit denen eine entsprechende Stützrolle 118 ausgerüstet sein kann. Die Bedeutung eines solchen Rollenrührers 124 und dessen Funktionsweise sind vorstehend bereits an anderer Stelle erläutert worden, so dass zur Vermeidung von Wiederholungen hierauf verwiesen werden darf.

For further features of a change segment W according to 4 the following explanations:

• The distance "a" designates a roller distance, ie a distance by which two support rollers 118 that are adjacent to one another are spaced apart from one another.
• "D" is an example of a support roller 118 whose roller diameter is shown.
• An adjusting cylinder is tightened with "120" with which the upper frame element 116 and the lower frame element 117 can be adjusted relative to one another in order to thereby change, for example, an opening width between the upper and the lower row of support rollers 118. In this way, cast strands 101 of different thicknesses can be produced.
• "122" denotes an additional drive with which a support roller 118 can be equipped. In the representation of 4 are the support rollers 118, which are equipped with a drive, filled out symbolically simplified by an "X", present - and to be understood purely as an example - two support rollers 118 in the upper row. In any case, the drive labeled "122" can be one that is only provided for the changing segment W, with a standard strand guide segment not having such an additional drive. Accordingly, it is possible by means of such a changeable segment W when it is used in the strand guide device 100 to then exert greater pull-out forces on the cast strand 101 .
• Roller agitators, with which a corresponding support roller 118 can be equipped, are indicated with "124" and in each case hatched areas. The importance of such a roller stirrer 124 and the way it works have already been explained elsewhere, so that reference may be made to this in order to avoid repetition.

With regard to all of the above-mentioned features of a changer segment W, it is understood that this changer segment W can differ in at least one of these features from a standard strand guide segment of a strand guide device 100, for which the changer segment W is used at the predetermined position of the strand guide device 100.

figure 5 shows a basically simplified side view of the strand guide device 100 and an associated continuous casting plant 110 according to a second embodiment of the present invention. Here, in contrast to the first embodiment of 1 provided that a change segment W can be used at positions #2 and #4 in the strand guide device 100 in order to replace a standard strand guide segment there, as explained. This is in the figure 5 each with "W" and symbolized by corresponding arrows.

According to the representation of figure 5 the two changing segments W are each equipped with a total of seven pairs of support rollers 118, in accordance with the representation of FIG 2 or 4 . If the other standard strand guide segments those of 1 correspond, arise for the example of the strand guide device 100 according to figure 5 then a total of 65 pairs of support rollers.

Regarding the embodiment of figure 5 At this point, it should be pointed out separately that the predetermined position of the strand guide device 100, at which a previously existing strand guide segment is replaced by a replacement segment W, in the present case corresponds to positions #2 and #4.

6 shows a basically simplified side view of the strand guide device 100 and an associated continuous casting plant 110 according to a third embodiment of the present invention. Here, in contrast to the first embodiment of 1 provided that a change segment W can be used at positions #2, #3 and #4 in the strand guide device 100 in order to replace a standard strand guide segment there, as explained. This is in the 6 each with "W" and symbolized by corresponding arrows.

According to the representation of 6 the three changing segments W are each equipped with a total of seven pairs of support rollers 118, in accordance with the representation of FIG 2 or 4 . If the other standard strand guide segments of the strand guide device 100 those of 1 correspond, arise for the example of the strand guide device 100 according to 6 then a total of 66 pairs of support rollers.

Regarding the embodiment of 6 may be separately pointed out at this point that the predetermined position of the strand guide device 100, at which a previously existing strand guide segment respectively is replaced by a change segment W, here corresponds to positions #2, #3 and #4.

In the embodiments according to figure 5 and 6 it is therefore possible, as explained, for changing segments W to replace the strand guiding segments that were originally used there at a plurality of predetermined positions of the strand guiding device 100 and to differ from these original strand guiding segments in at least one feature.

If, according to the invention, a plurality of interchangeable segments W are used at predetermined positions of the strand guide device 100, it is also possible here for these interchangeable segments W to differ from one another by at least one feature.

Regarding the embodiment of figure 5 and 6 it is understood that such a continuous casting plant 100 is also equipped with a control and regulation unit 132, as is the case for the embodiment of FIG 1 shown and explained. In any case, for all of these embodiments of a continuous casting plant 110 with a strand guide device 100 according to the present invention, it is possible for a calculation method to be carried out using the control and regulation unit 132 and the associated process computer 133 if, as explained, at least one changeable segment W is inserted into the strand guide device 100 is used in order to then reassemble the roller and nozzle plan for the continuous casting plant 110.

In the Figures 7 and 8 are again possible embodiments of a changing segment W and its arrangement of pairs of support rollers 118 shown in simplified form, each with seven pairs of support rollers 118 along the segment length L.

In the embodiment of 7 one of the pairs of support rollers 118 is provided with an additional drive, referred to here simply as "122". Here can be provided that the roll diameter D of the support rollers 118, which are equipped with the additional drive 122, is selected to be larger in comparison to the adjacent support rollers without a drive. For the rest, to avoid repetition, refer to the explanations on how such an additional drive 122 works 4 to get expelled.

9 shows a schematically simplified arrangement of support rollers 118 of a strand guide segment of the strand guide device 100, either a standard strand guide segment or a change segment W. In any case, these support rollers 118 in the change segment W are undivided along their longitudinal extent.

During continuous casting, the hydrostatic pressure of the still liquid melt in the core of the cast strand exerts pressure on the strand guide segments of the strand guide device, which causes them to spring open and the supporting rollers involved to bend slightly outwards between the associated supporting roller bearings. In the case of crack-sensitive grades in the metallic product produced, this can lead to internal defects or defects on the surface. To address this problem, for a change segment W according to the embodiment of 10 be provided that the associated support rollers 118 are each formed twice or divided several times along their longitudinal extent. In other words, the respective support rollers 118 according to 10 formed in their total length of three parts, with several bearing points are then provided accordingly. By dividing the support rollers 118 in this way, it is possible to reduce the above-mentioned disadvantageous effect of roller deflection, as a result of which the quality of the cast strand 101 and the metallic products produced therefrom is increased.

At this point, with respect to the embodiment of 10 In addition, it should be noted that for the support rollers 118 of a change segment Alternatively, a different division can also be provided in each case, for example a two-part or four-part division.

The aforementioned effect of a possible spring-back of the segment also depends, among other things, on the strand width. If a greater strand width is now to be cast, the spring-back can increase and the strand thickness produced in the middle of the strand may be outside a tolerance range. In the case of larger strand thicknesses, according to the invention, an interchangeable segment W can be used in the strand guide device 100, which segment reduces this spring-back through a reinforced segment frame. In the 11 (In the middle) such a change segment W is shown, which compared to standard strand guide segments 102 in the 11 disposed and shown adjacent thereto has reinforced frame members 116 and 117 of greater rigidity.

In the 11 the deflections of the support rollers 118, which occur as a result of the hydrostatic pressure of the cast strand 101, are each shown by dashed lines with the designation "C _Traverse ". It can be seen here that the deflection of the support rollers 118 for a changing segment W is less than for the adjacent standard strand guide segments 102, namely thanks to its reinforced upper and lower frame elements 116, 117.

Below are with reference to the Figures 12-14 further embodiments for a changeable segment W are shown and explained, with which the cooling capacity for cooling a cast strand 101 can be changed and in particular increased.

The embodiment of 12 shows an exchangeable segment W, in which a total of seven rows of secondary nozzles 126 for cooling the cast strand 101 are provided along the segment length L. Compared to an embodiment of 13 , in which only six rows of secondary nozzles 126 are provided, results accordingly for the embodiment according to FIG 12 through the one additional Row of secondary nozzles 126 a correspondingly larger amount of cooling water that can be applied to the cast strand 101.

The same effect is in the embodiment of a change segment W according to 14 achieved, after which the secondary nozzles 126 used here are each reinforced and hereby - viewed in the transport direction T - a greater width for the ejection of cooling water onto a surface of the cast strand 101 is possible.

Regarding the embodiment of 14 it should be pointed out that such a wider discharge of cooling water by means of the reinforced secondary nozzles 126 is also possible in the same way in the event that a different number of rows is provided for the secondary nozzles 126, for example seven rows of nozzles, as is the case, for example, in 12 is shown.

Alternatively or additionally, other nozzles with, for example, a larger spray angle in the casting or transport direction T (depth angle) can also be installed for certain grades in a change segment. By increasing the number of nozzles in a roll gap while simultaneously reducing the spray angle over the strand width, the water exposure for the cast strand 101 can also be increased.

• Alternativ oder zusätzlich können für bestimmte Güten in einem Wechselsegment W auch andere Sekunderdüsen 126 mit zum Beispiel einem größeren Spritzwinkel in Gießrichtung (Tiefenwinkel) eingebaut werden. Durch eine Erhöhung der Düsenanzahl in einem Rollenspalt bei gleichzeitiger Verminderung des Spritzwinkels über der Strangbreite kann ebenfalls die Wasserbeaufschlagung für den Gießstrang 101 erhöht werden.
• Für jede Düse existiert ein minimaler und ein maximaler Wasserdurchfluss (Regelbereich), bei dem die Düse die Wassermenge mit einem genügend hohen Impact auf die Strangoberfläche befördern kann. Wenn nun bei einer bestimmten Stahl-Güte immer eine höhere Wasserbeaufschlagung gewünscht ist, können in einem Wechselsegment W auch andere Düsen mit einem zu höheren Wassermengen hin verschobenen Regelbereich bei gleicher Düsenanzahl und gleichen Spritzwinkeln benutzt werden.

According to further advantageous embodiments for an interchangeable segment W, the following aspects can also be provided:

• As an alternative or in addition, other secondary nozzles 126 with, for example, a larger spray angle in the casting direction (depth angle) can also be installed for certain grades in an alternating segment W. By increasing the number of nozzles in a roll gap while simultaneously reducing the spray angle over the strand width, the water exposure for the cast strand 101 can also be increased.
• For each nozzle there is a minimum and a maximum water flow rate (control range) in which the nozzle can transport the amount of water onto the strand surface with a sufficiently high impact. If a higher water application is always desired for a certain steel grade, other nozzles with a control range shifted towards higher water quantities can also be used in a changing segment W with the same number of nozzles and the same spray angles.

In the 15 another embodiment for a changeable segment W (shown on the right) is shown. Compared to a standard 102 (in 15 shown on the left) the adjusting cylinders 120 are reinforced in this interchangeable segment W. Correspondingly, when using such an exchangeable segment W, it is possible to set a stronger taper within the supporting strand guiding device 100 when casting a different steel grade with a different shrinkage behavior.

The use of reinforced hydraulic or adjusting cylinders 120 can also be helpful in connection with carrying out a so-called "soft reduction". Here, depending on the position of the bottom tip of the cast strand 101, selected segments of the strand guide device 100 are turned on, ie closed. Special soft reduction segments are required for this. If, for example, high-quality grades are to be processed during operation of the continuous casting plant 100, in this case at least one standard strand guide segment 102, or also a plurality of selected standard strand guide segments 102, can be replaced by a respective interchangeable segment W according to the embodiment of 15 be used, which thanks to its reinforced adjusting cylinder 120 is suitable for dynamic adjustment or soft reduction.

At this point it is again specifically pointed out that with the help of the present invention it is possible in a continuous casting plant 110, as shown in figure 1 , figure 5 or. 6 has been shown and explained above to also shed high-quality grades by using at least one interchangeable segment W in the strand guide device 100 at selected positions to replace a standard strand guide segment 102 . As explained, these interchangeable segments W have the same basic geometry, i.e., for example, the same segment length L and possibly the same radius of curvature, as the "old" standard strand guide segments 102 that were replaced the total number of support rollers 118 within the continuous casting plant 100 and thus the design of such a plant can be changed or adapted to a specific steel grade.

Finally, with respect to the embodiments according to FIG 1 , 5 and 6 pointed out that an interchangeable segment W can be used in an arched, ie curved area of the strand guide device 100 at different predetermined positions, for example and as explained at positions #2, #3 and/or #4. In addition or as an alternative, it is also possible to use a changing segment W in a horizontal part of the strand guide device 100 that has no curvature. If such interchangeable segments W have a smaller roller pitch, regardless of their exact position for use in the strand guide device 100, it is hereby possible to both achieve and maintain high casting speeds in the continuous casting process.

Reference List

1-9

Support roller segments (of the supporting strand guide device 100)

1-66

Support roller pairs (support roller segments 1-9)

100

supporting strand guiding device

101

metallic product/cast strand

102

Standard strand guide segment

110

continuous caster

111

secondary cooling

112

mold

113

lower opening (of mold 112)

114

Bathroom mirror / pouring mirror

116

upper frame element

117

lower frame element

118

Support rollers / pairs of rollers

120

Segment or adjustment cylinder

122

additional drive

124

roller stirrer

126

Secondary nozzle(s) (for cooling the cast strand 101)

132

control or regulation unit

133

process computer

134

signal path or signal connection

136

Database or data storage

138

data collection

a

roller spacing

D

roll diameter

L

segment length

T

Transport direction (for the cast strand 101)

W

change segment

Claims (21)

Strand guide device (100) for use in a continuous casting plant (110), in which a metallic product in the form of a cast strand (101) can be moved in a transport direction (T), comprising a plurality of separate supporting strand guide segments (1-9) which are arranged next to or behind one another as viewed in the transport direction (T) and each have a plurality of support rollers, preferably in the form of pairs of support rollers arranged opposite one another, with at least one strand guide segment on a predetermined position of the strand guide device (100) and can therefore be exchanged for an exchangeable segment (W), characterized, that the changing segment (W) differs in at least one feature from the strand guide segment that was previously or originally used at the predetermined position of the strand guide device (100), this feature being selected from a group of features formed from the number of rolls , roller distance (a), roller diameter (D), roller type, roller drive (122), roller pitch, type and number of nozzles (126) for strand cooling, contact forces of the segmented cylinder (120), type and number of roller stirrers (124) and/or properties of at least one frame element (126, 127). Strand guide device (100) according to Claim 1, characterized in that a changing segment (W) has the same basic geometry as compared to the strand guide segment which was previously used at the predetermined position of the strand guide device (100) of the strand guide device (100), preferably that the basic geometry is defined by a radius of the roller guide and--seen in the transport direction (T)--by a respective segment length (L). Strand guide device (100) according to Claim 1 or 2, characterized in that the changing segment (W) has at least one support roller (118) or a pair of support rollers with an additional drive (122), so that for the cast strand (101) with which such a Support roller (118) or such a pair of support rollers can be brought into contact, a higher pull-out force in the direction of the transport direction (T) can be generated. Strand guide device (100) according to one of the preceding claims, characterized in that a changing magnetic field can be generated in the still liquid region of the cast strand (101) by means of a roller stirrer of the changing segment (W). Strand guide device (100) according to one of the preceding claims, characterized in that the changing segment (W) is designed for crack-sensitive steel grades and in comparison to existing strand guide segments (1-9), which are designed for crack-resistant steel grades, differs in that: - at least one further pair of rollers (118), and or - at least one further secondary nozzle (126) for cooling the cast strand (101), and/or - at least one further roll division, in order to thereby achieve reduced roll deflection, and/or - a roller radius of the non-driven rollers that is at least 1 mm smaller. Strand guide device (100) according to one of the preceding claims, characterized in that the changing segment (W) is designed for high casting speeds and in comparison to existing strand guide segments (1-9), which are designed for standard casting speeds, differs by: - at least one further pair of rollers (118), and or - at least one further secondary nozzle (126) for cooling the cast strand (101), and/or - at least one secondary nozzle (126) for cooling the cast strand (101), the control range of which is shifted towards larger water quantities, and/or - at least one further roll division, in order to thereby achieve reduced roll deflection, and/or - a roller radius of the non-driven rollers that is at least 1 mm smaller. Strand guide device (100) according to one of the preceding claims, characterized in that the changing segment (W) is designed for high strand temperatures and compared to existing strand guide segments (1-9) with stronger cooling differs by - at least one secondary nozzle (126) less in order to achieve less cooling of the cast strand (101), and/or - at least one secondary nozzle (126) for cooling the cast strand (101), the control range of which is shifted towards lower water quantities, and/or - at least one more heavily cooled roller (118) and/or a more strongly cooled roller pair (118), and/or - At least one roller (118) with a stronger coating and/or a pair of rollers (118) with a stronger coating. Strand guide device (100) according to one of the preceding claims, characterized in that the changing segment (W) is designed for carrying out a soft reduction for the cast strand (101) and Compared to existing strand guide segments (1-9) with a fixed taper differs by: - dynamically adjustable jaw widths, and/or - At least one reinforced adjusting cylinder (120). Strand guide device (100) according to one of the preceding claims, characterized in that the changing segment (W) in terms of its basic geometry corresponds to at least two adjacent strand guide segments (1-9) which are arranged adjacent to one another in the original strand guide device (100). Continuous casting plant (110) for producing a metallic product in the form of a cast strand (101), comprising a strand guide device (100) with at least one changeable segment (W) according to one of Claims 1 to 9, in which the cast strand (101) moves in a transport direction (T ) is movable. Method for continuously casting a metallic product in a continuous casting plant (110) with a strand guide device (100) comprising a plurality of separate supporting strand guide segments (1-9), the metallic product in the form of a cast strand (101) in a transport direction (T) is moved and for this purpose the strand guide segments (1-9) of the strand guide device (100) are arranged next to or one behind the other as seen in the transport direction (T) and each have a plurality of support rollers, preferably in the form of pairs of support rollers arranged opposite one another, characterized ,
that during a batch change for the metallic product at least one strand guide segment is replaced by a change segment (W) at a predetermined position of the strand guide device (100), the change segment (W) being different in comparison to the strand guide segment, which was previously or originally used at the predetermined position of the strand guide device (100), differs in at least one feature, this feature being selected from a group of features formed from the number of rolls, roll spacing (a), roll diameter (D), roll type, Roller drive (122), roller spacing, type and number of nozzles (126) for strand cooling, contact forces of the segmented cylinders (120), type and number of roller stirrers (124) and/or the nature of at least one frame element (126, 127). Method according to Claim 11, characterized in that a changing segment (W) of a strand guide device (100) according to one of Claims 1 to 9 is used here. Method according to Claim 11 or 12, characterized in that steel grades that are sensitive to internal cracks are processed, with the use of the changing segment (W) for the metallic product, while it is being moved within the supporting strand guide device (100), reducing static bulging and thus a Quality improvement for the metallic product is achieved. Method according to Claim 13, characterized in that support rollers are used in the changing segment (W), the roller diameter (D) of which is smaller and the number of which is greater than in comparison to the support rollers of the strand guide segment which was originally at the predetermined position of the strand guide device (100). was present or used and has been replaced by the change segment (W). Method according to one of Claims 11 to 14, characterized in that steel grades are processed with a casting speed of at least 2 m/min, with the use of the changeable segment (W) a reduction in dynamic bulging for the cast strand (101) is achieved, thereby improving plant safety. Method according to Claim 15, characterized in that the support rollers (118) used in the changing segment (W) each have a different roller spacing (a) relative to one another. Method according to Claim 15 or 16, characterized in that a roller spacing (a) of the support rollers (118) used in the changeover segment (W) compared to the support rollers of the strand guide segment which, at the predetermined position of the strand guide device (100) through the changeover segment ( W) has been replaced, each is designed differently. Method according to one of Claims 11 to 17, characterized in that a process model receives information regarding the arrangement of the strand guide segments (1-9) used of the strand guide device (100) and the at least one change segment (W) used and from a segment and nozzle catalog the Plant configuration in relation to a roller and nozzle plan, the process model based on which calculates and regulates the temperature of the cast strand (101) along the supporting segments (1-9) of the strand guide device (100). Method according to one of Claims 11 to 14, characterized in that a process model receives information regarding the arrangement of the strand guide segments (1-9) used of the strand guide device (100) and the at least one change segment (W) used and from a segment and nozzle catalog the Assembles plant configuration in terms of roll and nozzle plan, based on which the process model establishes a sump tip position for the cast strand (101) calculated along the supporting segments (1-9) of the strand guide device (100). Method according to one of Claims 11 to 19, characterized in that steel grades or secondary steel with a copper content of ≥ 0.15% are processed, with the use of an exchangeable segment (W) with increased spray water cooling for the cast strand (101) a grain refinement and thus an improvement in quality is achieved. Method according to one of Claims 11 to 19, characterized in that ferritic stainless steels or silicon steels with a silicon content of at least 0.5% are processed, with the use of an exchangeable segment (W) with at least one roller stirrer for the cast strand (101). increased proportion of globular primary structure and thus an improvement in quality is achieved.

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