WO2019086192A1 - Continuous casting line having individual roller engagement - Google Patents

Abstract

The invention relates to a continuous casting line, which has a mold (1) for the output of a strand (S) and a strand guide (2) connecting to the mold (1) having a plurality of rollers (24) arranged in pairs for transporting the strand (S) in a conveying direction (F), wherein one or more of the rollers (24) can be engaged such that a thickness reduction of the strand (S) occurs in the strand guide.

Description

 Continuous casting plant with single roll adjustment

Technical area

The invention relates to a continuous casting plant, which has a mold for discharging a strand and a strand guide adjoining the mold with rolls arranged in pairs. The invention further relates to a method for casting a strand by means of such a device.

Background of the invention

1 shows schematically a known continuous casting plant, the structure of which is referred to as "vertical bending plant", as the cast strand by means of a strand guide initially guided vertically downwards, then deflected along an arc and transported horizontally.

The structure and operation of the continuous casting of Figure 1 in detail: The liquid metal to be cast is fed to a mold 1, such as a ladle, not shown. The mold 1, which can be designed as a funnel mold, brings the molten metal in the desired slab shape. The not yet solidified strand S emerges vertically downwards from the mold 1 and is then further guided vertically along the strand guide 2, while it gradually cools. The strand guide 2 has in the present example, two building-like curved segments 21 and 22, which form a bending region of the strand guide 2. The segments 21 and 22 have pairs of rollers 24 to transport the strand S in a conveying direction F. The rollers 24 are not connected to a drive, but the strand S is pulled out of the strand guide 2 by a straightening driver 3, which is located at the end of the bending region. While of transport, the strand 1 is cooled, usually by splashing, whereby it gradually solidifies from outside to inside.

The straightening driver 3 may be considered as part of a joint system provided between the strand guide 2 and a rolling mill 7 for rolling the cast strand S. The connection system may further comprise a separating device 4 for dividing the strand S into slabs of a certain length, a furnace 5 for tempering the strand S homogeneously and bringing it to a temperature suitable for rolling, and a cold strand rocker 6. If a cold strand rocker 6 is provided, a cold leg for casting the plant can be transported to the oven 5 and stored there.

A continuous casting plant of the type described above is described in DE 10 2015 210 865 A1. DE 10 2015 215 187 A1 also describes a comparable molten metallurgical plant with a mold and a strand guide.

For a low annual production or for other reasons, such as when used in a difficult environment or for cost reasons or in the production of special alloys, it may be useful to construct the system more compact and cheaper to purchase and operate. In order to further reduce the plant of the type described above, the two segments 21, 22 may be replaced by a single segment, which is equipped with pairs of rollers to transport the emerging from the mold strand and bend before entering the Richttreiber occurs.

A problem that precludes a further reduction of the plant, is that the strand must not be arbitrarily thin when leaving the mold. The distance between the dip tube and the mold wall must not be too low, so that the liquid metal can circulate in the mold. The dip tube itself must have a minimum diameter so as not to clog too quickly. Furthermore, the cold strand, which is used for casting the system of the Outlet side is transported to the mold, a minimum thickness, which can not fall below 40 mm in the rule. The fact that the strand for all these reasons can not be poured arbitrarily thin, now leads to the fact that the rolling mill can not be designed easily compact, because the mill must be able to the cast with a certain minimum thickness slabs to the desired target thickness roll.

Presentation of the invention

An object of the invention is to improve a continuous casting of the type described above, in particular to provide a continuous casting (analogous method), which can be designed compactly and / or energy-saving while maintaining the functionality and / or high reliability and / or casting quality having.

The object is achieved with a continuous casting plant having the features of claim 1 and a method having the features of claim 11. Advantageous developments follow from the subclaims, the following description of the invention and the description of preferred embodiments.

The continuous casting plant according to the invention is used for casting a strand in the area of fusion metallurgy, ie a strand of a metal, in particular a metal alloy, preferably steel. The plant is preferably designed as a vertical bending plant, but it can also have a different design. For example, the system can also be designed as a sheet or vertical slab system. The continuous casting plant has a mold, which can be designed as a funnel mold. The mold is adapted to deploy the strand, preferably viewed vertically downwards in the direction of gravity. For this purpose, the mold is to be cast Supplied molten metal and brought from the mold in the desired strand or slab mold by the not yet solidified strand is discharged from a correspondingly shaped outlet opening of the mold. The mold is followed by a strand guide, which has a plurality of rollers arranged in pairs for transporting the strand in a conveying direction. The paired rollers each form a gap and a total of a gap, through which the strand occurs in the conveying direction. According to the invention, one or more of the rollers of the strand guide can be adjusted so that a reduction in the thickness of the strand takes place in the strand guide. In other words, the relevant roles of the strand guide are adjustable so that during the regular casting process, the thickness of the emerging from the mold strand is already reduced in the strand guide, preferably before it is completely solidified. By reducing the thickness of the strand in the strand guide, a possible rolling mill, which adjoins the strand guide or a connection system in the conveying direction, can be made more compact. Typically, such a rolling mill has several, for example five, rolling stands (stitches). By using the thickness reduction according to the invention in the strand guide, at least one rolling stand can be saved. As a result, the entire system, consisting of continuous casting, connection system and rolling mill, overall more compact and possibly also cost-effective manufacture. Alternatively, with a conventional design of the rolling mill, a greater reduction in the thickness of the strand can be achieved. It should be noted that for the compression of the core still liquid strand less energy is needed than would be required in the rolling mill, would be dispensed with the thickness reduction in the strand guide. This technical effect leads to an energy saving and to a further cost reduction, both in the operating costs and in the acquisition costs. Another technical advantage of the reduction in the thickness of the strand in the strand guide is that the strand thickness at the mold end does not have to be minimized. In the section "Background of the invention" has been stated that the strand at the Kokillenende for various reasons can not be arbitrarily thin. The further the strand thickness at the mold approaches this minimum limit, the greater the risk of breakthroughs or other production errors. The reduction in thickness in the strand guide can thus lead to an improvement in the reliability when the strand thickness is chosen generously on the mold, without thereby reducing the total thickness reduction at the outlet of the mill. Furthermore, the inner quality of the strand can be improved since the reduction in thickness in the strand guide reduces the flow of liquid melt.

Preferably, the rollers of the strand guide comprise first pairs of rollers immediately adjacent to the mold, and reduction pairs of rollers immediately adjacent to the first pairs of rollers in the direction of conveyance, the rollers of the first pair of rollers not being adjustable, thereby reducing in this area the strand guide, i. an area that adjoins directly to the mold, no reduction in thickness of the strand takes place. The thickness reduction thus according to this preferred embodiment, only "later" after the strand has passed through the first pair of rollers. As a result, fluctuations in the mold level can be prevented, and it is prevented that the strand detaches from the mold wall, whereby the reliability is further improved. A good compromise between reliability, compactness and thickness reduction is achieved when the strand guide has two or three first pairs of rolls and eight to fifteen pairs of reduction rolls.

Preferably, the rollers of the strand guide further include last pairs of rollers which connect in the conveying direction of the Reduzierungsrollenpaare, preferably be adjusted, but do not lead to any further reduction in the thickness of the strand. According to this embodiment, in the last section of the strand guide, for example, before the strand is caught by the rollers of a straightening driver, there is no further reduction of the strand thickness. Preferably, the Plant controlled so that the sump tip of the strand during normal casting is in the range of the last pair of rolls. The sump tip here is the position of the strand in the conveying direction, at which the liquid core, which is still liquid, passes into the solidified area. Since the strand first solidifies on the surface and the temperature increases from the outside inwards, the liquid core in the conveying direction has approximately the shape of a cone, wherein the tip of the cone is referred to as a sump tip.

When a straightening driver adjoins the strand guide in the conveying direction, which has a plurality of driven rollers and is set up to actively pull the strand out of the strand guide, the strand is preferably solidified upon reaching the straightening driver.

Preferably, the strand guide has a bending region in which the strand is bent. When the continuous casting plant is constructed as a vertical bending plant, the strand emerges vertically downward from the mold, is guided by the strand guide down and then deflected along an arc. In this case, the strand does not have to be bent completely within the strand guide to the horizontal. The remaining bend to the horizontal takes place in the straightening driver. Thereafter, the strand may be transported horizontally to pass through other stations, such as a straightening device, a separator for dividing the strand into slabs of a particular length, an oven and a rolling mill. Preferably, the strand guide has one or more exchangeable segments, each having a plurality of rollers arranged in pairs. In this way, a conventional continuous casting without thickness reduction can be retrofitted in a simple manner with a strand guide of the type described. By replacing one or more segments of a conventional strand guide with one or more segments with engageable roles retrofitting can be modular. So can subsequently by the acquisition of Segments with single roller adjustment lower outlet thicknesses from the strand guide and thereby thinner final dimensions are obtained at the outlet of any rolling mill. If only occasionally thinner final dimensions are to be produced, it is possible to work with several unachievable segments and to install only an adjustable segment (analogous to several adjustable segments) only in the production of the particularly thin dimensions. Alternatively, the engagable segment (analogous to several engagable segments) can always be installed, wherein the engageable roles are driven only in the production of particularly thin dimensions in a reduction position and are otherwise in a zero position without thickness reduction.

Preferably, the engageable rollers are hydraulically, magnetically or by electric motor actuated. According to a particularly preferred embodiment, the strand guide on one or more hydraulic cylinders, in each of which a piston for adjusting an adjoining engageable roller is hydraulically displaceable. By hydraulic control, such as by means of oil, the piston between the zero position and the reduction position can be reciprocated. It can be provided adjustable both roles of a pair of rollers or only one role of the pair. In addition, it may be useful in certain embodiments that engageable roles can be brought in more than two positions, in particular infinitely adjustable. Thus, according to a variable embodiment, the strand thickness can be reduced to different outlet thicknesses. Alternatively or additionally, a frame part of the above-mentioned segment (analogous to a plurality of segments) of the strand guide can be set to be adjustable, whereby a plurality of rollers can be adjusted in groups in order to reduce the strand thickness.

The inventive method relates to the casting of a strand by means of a device of the type described above, wherein one or more rollers of the strand guide are employed so that during the regular casting process the thickness of the strand in the strand guide is reduced. The technical effects, preferred embodiments, and contributions to the prior art described with respect to the apparatus apply analogously to the method.

The pitch profile of the rollers can be suitably determined depending on the degree of reduction, reduction distance, material of the strand, etc. Thus, the decreasing positions of the rollers may be distributed approximately linearly or parabolically, so that the thickness reduction along the strand guide linear or parabolic takes place.

According to a particularly preferred embodiment, the thickness reduction of the strand takes place with not solidified core, which allows energy-saving operation of the system and also contributes to an improvement in the casting quality.

Preferably, the engageable roles are made taking into account process parameters and a temperature calculation model with which temperature properties of the strand, such as the position of the sump tip and / or the strand shell thickness, can be determined.

Further advantages and features of the present invention will be apparent from the following description of preferred embodiments. The features described therein may be implemented alone or in combination with one or more of the features set forth above insofar as the features do not conflict. The following description of the preferred embodiments will be made with reference to the accompanying drawings. Brief description of the figures

1 shows schematically a continuous casting plant, designed as a "vertical bending plant", with two strand guide segments and a straightening device for transporting the cast strand.

FIG. 2 shows schematically a continuous casting plant with adjustable rollers.

FIGS. 3a and 3b show a hydraulic control of adjustable rollers.

Detailed description of preferred embodiments

In the following, preferred embodiments will be described with reference to the figures. In this case, identical, similar or equivalent elements are provided with identical reference numerals, and a repetitive description of these elements is partially omitted in order to avoid redundancies.

FIG. 2 schematically shows a continuous casting plant whose basic structure is similar to that of FIG. At the mold 1, the strand guide 2 connects. At the output of the strand guide 2, the straightening driver 3 is provided for pulling out the strand S from the strand guide 2.

In contrast to the system of FIG. 1, the strand guide 2 of the exemplary embodiment of FIG. 2 has only a single segment 23, even if a plurality of segments may be provided according to other exemplary embodiments. A continuous casting machine with only one segment 23 has a greater rigidity and can better absorb the bending forces generated by the straightening driver 3 than an equally long continuous casting machine with several segments. In a continuous casting plant with two or more segments, if necessary, all segments must be replaced one after the other in the event of an accident, such as a breakthrough. These change times are in a continuous casting, whose Strand guide 2 has only a single segment 23, usually much shorter, because the entire strand guide 2 can be changed without segments must be connected to each other. When connecting segments to each other there is a risk that two adjacent segments are not connected to each other exactly. Impurities, wear and / or incorrect alignment of the segments can lead to stresses in the strand S, which leads to an increased risk of cracking. These sources of error can be reduced with a strand guide 2 with a single segment 23, which is why this embodiment is preferred, particularly with regard to a compact and cost-effective plant.

The segment 23 has a plurality of rollers 24a, 24b, 24c (collectively referred to as rollers 24) which are arranged in pairs, whereby they (always two rollers 24 are facing each other) form a gap through which the emerging from the mold 1 down Strand S occurs along a curved path and is guided. The not yet solidified strand is therefore first led vertically downwards, then deflected by the strand guide 2 along a bend and then transported horizontally. During transport, a cooling of the strand S takes place, which may optionally be actively supported and / or controlled by applying a cooling fluid.

The straightening device 3 is arranged as part of a connection system in the conveying direction F behind the segment 23 in order to pull the strand S out of the strand guide 2 and to completely bend it into the horizontal. For this purpose, the straightening driver 3 comprises a plurality of pairs of rollers 31, which are driven rollers, such as driven by one or more electric motors (not shown).

Although the representation of further components has been omitted in FIG. 2 for the sake of clarity, the continuous casting plant of the present invention can be used Embodiment as in Figure 1, a separator, an oven, a cold strip rocker, a rolling mill and / or other components.

In contrast to the continuous casting installation of FIG. 1, according to the present exemplary embodiment, one or more rollers 24 of the strand guide 23 can be adjusted, wherein in particular an adjustability during the casting process can be encompassed. The adjustability or adjustability is provided in such a way that one or more pairs of rollers can be moved together, as a result of which the transport gap can vary, in particular reduce, along the conveying direction F.

In order to distinguish different roller groups of the strand guide 2, one or more roller pairs immediately below the mold 1 are referred to as the first roller pairs 24a. Roller pairs that follow in the conveying direction F are referred to as middle roller pairs or reduction roller pairs 24b. The remaining pairs of rollers of the strand guide 2, which lie directly in front of the straightening device 3, are referred to as the last pair of rollers 24 c. Since the rollers 24 of the strand guide 2 are usually arranged in pairs, the reference numerals 24a, 24b, 24c are also used to designate the rollers themselves of the respective pair.

According to a particularly preferred embodiment, the first rollers 24a can not be adjusted, this first roller group preferably having two or three roller pairs 24a. By not turning the first pair of rollers 24a, i. are firmly mounted, fluctuations in the mold level can be prevented, and it is prevented that the strand S detaches from the mold wall.

The middle pairs of rollers 24b, for example, 8 to 15 pairs of rollers, preferably 1 1 pairs of rollers are individually or in groups employable. In particular, they can be moved together, whereby the thickness of the core not yet solidified strand S in the strand guide 2 is reduced. Starting, for example, from a thickness of 52 to 45 mm at Kokillenaustritt the Thickness reduced to about 32 to 35 mm, preferably up to 20 mm, at the exit of the strand guide 2.

The last pair of rollers 24c, preferably about four pairs of rollers, are preferably also adjustable. However, this employment only serves to follow the previously set strand thickness. In this case, no further thickness reduction of the strand S takes place in the section of the last pairs of rollers 24c.

By varying the casting speed and / or cooling power, such as spray amount, the position of the solidification (sump tip) is regulated in the roller conveyor, in particular so placed that the complete Durcherstarrung is not within the region of the middle roller pairs 24b. Reducing the thickness of the solidified strand would require much higher setting forces, which would increase the risk of cracking.

The employment profile of the middle rollers 24b can be suitably determined depending on the degree of reduction, reduction distance, material of the strand S and so on. Thus, the decreasing positions of the rollers 24b may be distributed approximately linearly or parabolically. For example, if a strand having a thickness of 50 mm at the die exit is to be reduced to 34 mm in a linear manner, with 1 1 reduction rolls 24b, then the decrease at each of the reduction rolls 24b is 16 mm / 1 1 = 1.4545 mm. At the first rollers of the middle rollers 24b, the decreases may also be somewhat stronger and may fall off parabolically or in some other way so that only a decrease in the strand thickness of about 1 mm takes place at the last reduction roller 24b.

According to a structurally simple, inexpensive embodiment, shown in Figures 3a and 3b, the middle rollers 24b (possibly also the last rollers 24c) by hydraulic cylinders in exactly two positions can be moved. In this case, in a position, the zero position (Figure 3a), no Thickness reduction takes place while the thickness of the strand S at the respective pair of rollers 24b in the second position, the reduction position (Figure 3b) is reduced. In the embodiment of Figures 3a and 3b, a piston 25, on which a roller 24b or 24c is mounted, provided in a cylinder 26 slidably. By hydraulic control, such as by means of oil, the piston 25 between the zero position and the reduction position can be reciprocated. Both rollers of a pair of rollers 24b or just one roller 24b of the pair can be adjustably arranged. Preferably, only the rollers 24b, 24c on the lot side can be adjusted. Furthermore, the adjustment of the rollers 24b, 24c can be technically realized in other ways, such as magnetic or electric motor. In addition, it may be useful in certain embodiments that one, several or all of the middle rollers 24b and / or last rollers 24c can be brought into more than two positions, in particular steplessly adjustable. Thus, according to a variable embodiment, the strand thickness can be reduced to different outlet thicknesses. Alternatively or additionally, a part of the segment frame, preferably the upper frame, be set adjustable, whereby a plurality of rollers 24b, 24c are groupwise adjustable to reduce the strand thickness. Again, it is true that preferably no reduction in thickness takes place at the first rollers 24a and last rollers 24c. According to a further embodiment, two rolls or pairs of rolls 24a, 24b, 24c can also be combined in one cassette; These roles can then be made individually or together if necessary.

By the above-described thickness reduction in the strand guide 2, the rolling mill 7 can be made more compact. Typically, the mill has several, for example five, rolling stands (stitches). In this case, it is possible to save at least one rolling stand. As a result, the overall system can be made more compact and, if necessary, less expensive. Alternatively, in conventional design of the rolling mill 7 a stronger Thickness reduction of the strand S can be achieved. It should be noted that for the compression of the core still liquid strand S less energy is needed than would be required in the rolling mill, if the thickness reduction in the strand guide 2 would be omitted. This technical effect leads to an energy saving and to a further cost reduction, both in the operating costs and in the acquisition costs. Another technical advantage of the thickness reduction of the strand S in the strand guide 2 is that the strand thickness at the mold end does not have to be minimized. It has already been stated that the strand may not be arbitrarily thin at the end of the mold for various reasons. Typically, this limit, depending on the material and the process parameters, is about 45 mm. The further the strand thickness at the mold approximates this limit, the greater the risk of breakthroughs. The reduction in thickness in the strand guide 2 can thus lead to an improvement in production safety, if the strand thickness is chosen to be greater on the mold, without thereby reducing the total thickness reduction at the outlet of the rolling mill 7. Furthermore, the inner quality of the strand can be improved because the reduction in thickness in the strand guide 2 reduces the flow of liquid melt, which reduces unwanted segregation.

A conventional continuous casting without reduction in thickness in the strand guide 2 can be retrofitted with engageable rollers 24b, 24c. By replacing the one or more segments of a conventional strand guide with a segment 23 containing the engageable rollers 24b, 24c, the retrofitting can be modular. Thus, subsequent purchase of segments with single roller adjustment lower outlet thicknesses of the strand guide 2 and thereby thinner final dimensions at the outlet of the hot rolling mill 7 can be obtained. If only occasionally thinner final dimensions are to be produced, it is possible to work with a plurality of non-engageable segments 21, 22 and only in the production of particularly thin dimensions the engageable segment 23 (analogous to several adjustable segments). Alternatively, the engageable segment 23 (analogous to several engagable segments) can always be installed, wherein the engageable rollers 24b, 24c are driven only in the production of the particularly thin dimensions in the reduction position and are otherwise in the zero position.

In the following, a method for strand thickness reduction in the strand guide 2 according to one embodiment is described: The continuous casting plant is started up in the conventional manner with the aid of a cold strand. As soon as the cold strand is decoupled and if necessary stowed away by means of the cold strand rocker 6, the strand thickness can be reduced. If the strand head (for example with 52 to 45 mm) is too thick for the rolling mill 7, the non-reduced strand head (for example of 4 m length, that of the length of the casting machine, ie the path between the mold 1 and the outlet of the strand guide 2 , corresponds) in the separator 4 are crushed to scrap. The engagable reduction rollers 24b of the strand guide 2 then reduce the not yet solidified in the core strand S. If necessary, can be calculated by a temperature calculation model, the position of the sump tip and the strand shell thickness at all roll positions. In this case, the sump tip is the position of the strand S in the transport direction, at which the liquid core, which is still liquid, merges into the solidified area. Since the strand S first solidifies on the surface and the temperature increases from outside to inside, the liquid core in the transporting direction has approximately the shape of a cone, the tip of the cone being called the sump tip. The casting speed and cooling capacity, preferably amount of spray water, are now controlled so that the sump tip shifts forward into the area of the last pair of rollers 24c. There, the strand thickness is not further reduced. When squeezing the already solidified strand S, the required Anstellkräfte would increase sharply and the risk of internal cracks occur. The average temperature at the inlet of the furnace 5 is the greater, the closer the sump tip to the end of the casting machine, that is, to the outlet of the strand guide 2, zoom. Upon reaching the straightening driver 3, the strand S is preferably completely solidified.

By controlling the continuous caster so that the sump tip is in the area of the last rollers 24c, an optimum thickness reduction can be achieved in the strand guide 2, since all the reduction rollers 24b have their effect, which would not be the case with a strand S that starts too early ,

By a variable control of the reduction rollers 24b different strand thicknesses can be cast, and the acceptance distribution can be adapted to the current process values. This is useful because the decrease distribution is preferably chosen to produce higher decreases in the area of the still-liquid core (LCR) than in the area of first dendrite growth in the core (soft reduction) Since the positions of the liquid boundary and the sump tip change dynamically with the process values (casting speed, analysis, superheating, casting level, water quantities, water temperature, etc.), preferably a dynamic temperature calculation model is used for their calculation the last decrease is preferably not so far away from the mold 1 that no more melt can flow in. Where applicable, all the individual features illustrated in the exemplary embodiments can be combined and / or exchanged without departing from the scope of the invention leave. LIST OF REFERENCE NUMBERS

1 mold

 2 strand guide

 3 guide drivers

 4 separating device

 5 oven

6 cold-rod rocker

 7 rolling mill

21, 22, 23 segments of the strand guide

 24 rolls of strand guide

24a First rolls / pairs of rolls

24b reduction rollers / reduction roller pairs

24c Last rolls / pairs of rolls

 25 pistons

 26 hydraulic cylinders

 31 rolls of the guidebook

S strand / slab

 F conveying direction

Claims

claims Continuous casting plant comprising a mold (1) for discharging a strand (S) and a strand guide (2) adjoining the mold (1) with a plurality of rollers (24) arranged in pairs for transporting the strand (S) in a conveying direction (F). having,  one or more of the rollers (24) are adjustable so that a reduction in thickness of the strand (S) takes place in the strand guide. Continuous casting plant according to claim 1, characterized in that the rollers (24) connect first pairs of rollers (24a) directly adjoining the mold (1) and reduction roller pairs (24b), which in the conveying direction (F) directly adjoin the first pairs of rollers (24). 24a), wherein the rollers of the first pair of rollers (24a) are not adjustable, whereby no reduction in the thickness of the strand (S) takes place in this area of the strand guide (2), while one or more, preferably all, of the rollers of the reduction roller pairs ( 24b) can be adjusted, so that in this region of the strand guide (2) takes place a reduction in thickness of the strand (S). Continuous casting plant according to claim 2, characterized in that the strand guide (2) has two or three first roller pairs (24a) and preferably eight to fifteen reduction roller pairs (24b). Continuous casting plant according to claim 2 or 3, characterized in that the rollers (24) further include last pair of rollers (24c), which in the conveying direction (F) to the Reduzierungsrollenpaare (24b) connect, preferably be adjusted, but no further reduction in the thickness of the strand (S) lead. Continuous casting plant according to claim 4, characterized in that it is arranged so that the sump tip of the strand (S) during the regular casting process in the region of the last pair of rollers (24c). Continuous casting plant according to one of the preceding claims, characterized in that the strand guide (2) has a bending region in which the strand (S) is bent, preferably the continuous casting plant is constructed as a vertical bending plant, wherein the strand (S) vertically downwards emerges from the mold (1), guided by the strand guide (2) down and then completely or partially deflected along an arc in the direction of the horizontal and further transported. Continuous casting plant according to one of the preceding claims, characterized in that the strand guide has one or more exchangeable segments (23) each having a plurality of rollers (24) arranged in pairs. Continuous casting plant according to one of the preceding claims, characterized in that in the conveying direction (F) to the strand guide (2) adjoining a directional driver (3) having a plurality of driven rollers (31) and is adapted to the strand (S) from the Pull out the strand guide (2) and completely bend it to the horizontal. Continuous casting plant according to one of the preceding claims, characterized in that the engageable rollers (24) are hydraulically, magnetically or electromotively operable, preferably, the strand guide (2) one or more hydraulic cylinders (26), in which piston (25) for adjusting the adjustable rollers (24) are hydraulically displaceable. Continuous casting plant according to one of the preceding claims, characterized in that the engageable rollers (24) can each assume exactly two positions, a zero position in which no thickness reduction of the strand (S) takes place at the relevant position in the strand guide (2), and a reduction position in which a thickness reduction of the strand (S) takes place at the respective position in the strand guide (2); or  That the engageable rollers (24) during the casting operation between the zero position and the reduction position Method for casting a strand (S) by means of a device according to one of the preceding claims, one or more of the rollers (24) of the strand guide (2) being adjusted so that the thickness of the strand (S) during the casting process in the strand guide ( 2) is reduced. A method according to claim 1 1, characterized in that the reduction in thickness of the strand (S) in the strand guide (2) takes place at not durcherstarrtem core of the strand (S). The method of claim 1 1 or 12, characterized in that the engageable rollers (24) taking into account process parameters and based on a temperature calculation model, with the temperature characteristics of the strand (S), preferably the position of the sump tip and / or the strand shell thickness can be determined , be employed.