CONTINUOUS CASTING PLANT WITH SINGLE ROLL ADJUSTMENT

Description

Technical field

[0001] The invention relates to a continuous casting plant comprising a mold for discharging a strand and a strand guide arranged adjacent to the mold with rollers arranged in pairs. The invention further relates to a method for casting a strand using such a device. Background of the invention

[0002] The Figure 1 shows a schematic diagram of a known continuous casting plant, the design of which is referred to as a "vertical bending plant" because the cast strand is first guided vertically downwards by means of a strand guide, then deflected along a bend and transported horizontally.

[0003] The structure and functioning of the continuous casting plant of Figure 1In detail: The liquid metal to be cast is fed into a mold 1, for example from a pouring ladle (not shown). The mold 1, which can be designed as a funnel mold, brings the molten metal into the desired slab shape. The not yet fully solidified strand S emerges vertically downwards from the mold 1 and is then guided further vertically downwards along the strand guide 2 while it gradually cools down. In the present example, the strand guide 2 has two similarly constructed curved segments 21 and 22, which form a bending area of ​​the strand guide 2. The segments 21 and 22 have rollers 24 arranged in pairs to transport the strand S in a conveying direction F. The rollers 24 are not connected to a drive; rather, 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 area.During transport, the strand 1 is cooled, usually by spraying water, causing it to gradually solidify from the outside to the inside.

[0004] The straightening driver 3 can be considered part of a connection system provided between the strand guide 2 and a rolling mill 7 for rolling the cast strand S. The connection system can further comprise a separating device 4 for dividing the strand S into slabs of a specific length, a furnace 5 for homogeneously tempering the strand S 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 strand can be transported to the furnace 5 and deposited there for casting the system.

[0005] 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 melt metallurgical plant with a mold and a strand guide.

[0006] For low annual production or other reasons, such as operation in a harsh environment, cost considerations, or the production of special alloys, it may be advisable to design the system more compactly and cost-effectively in terms of both acquisition and operation. To further reduce the size of the system described above, the two segments 21 and 22 can, if necessary, be replaced by a single segment equipped with pairs of rollers to transport and bend the strand emerging from the mold before it enters the straightening driver.

[0007] One problem that prevents further downsizing of the plant is that the strand cannot be arbitrarily thin when it leaves the mold. The distance between the dip tube and the mold wall must not be too small to allow the liquid metal to circulate in the mold. The dip tube itself must have a minimum diameter to avoid clogging too quickly. Furthermore, the cold strand, which is transported from the outlet side to the mold for casting the plant, has a minimum thickness that cannot generally be less than 40 mm. The fact that the strand cannot be cast arbitrarily thin for all these reasons means that the rolling mill cannot simply be made more compact, because the rolling mill must be able to roll slabs cast with a certain minimum thickness to the desired target thickness.

[0008] US 5,853,043 A describes a continuous casting plant with adjustable rollers in the strand guide. EP 2 441 538 A1 describes a continuous casting device with dynamic strand thickness reduction. WO 02 / 090019 A1 describes a method and device for continuously casting ingots, slabs, or thin slabs. DE 196 39 302 A1 describes a method and device for producing thin slabs on a continuous casting plant. EP 0 350 431 A2 describes a continuous casting process for producing slabs with a reduced thickness compared to the as-cast state.

[0009] DE3234546A1 describes a continuous casting plant with segments with adjustable distance between the guideways in order to produce different strand cross-section formats.

[0010] Finally, US5488987A discloses a continuous casting plant with individual segments with individually adjustable rollers for thickness reduction. Description of the invention

[0011] An object of the invention is to improve a continuous casting plant of the type described above, in particular to provide a continuous casting plant (analogous process) which, while maintaining functionality, can be designed to be particularly compact and / or operated in an energy-saving manner and / or has a high level of operational reliability and / or casting quality.

[0012] The object is achieved with a continuous casting plant having the features of claim 1 and a method having the features of claim 10. Advantageous further developments follow from the subclaims, the following presentation of the invention and the description of preferred embodiments.

[0013] The continuous casting plant according to the invention is used to cast a strand in the molten metallurgy sector, i.e. a strand made 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 plant can also be designed as a bending plant or vertical slab plant. The continuous casting plant has a mold, which can be designed as a hopper mold. The mold is set up to discharge the strand, preferably vertically downwards in the direction of gravity. For this purpose, the molten metal to be cast is fed to the mold and formed by the mold into the desired strand or slab shape by discharging the not yet fully solidified strand from a correspondingly shaped outlet opening in the mold.Adjacent to the mold is a strand guide, which has several rollers arranged in pairs for transporting the strand in a conveying direction. The paired rollers each form a gap and, in total, a gap path through which the strand passes 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 respective rollers of the strand guide are adjustable so that, during the regular casting process, the thickness of the strand emerging from the mold is already reduced in the strand guide, preferably before it has completely solidified.

[0014] By reducing the thickness of the strand in the strand guide, any rolling mill that is connected to the strand guide or to a connecting system in the conveying direction can be designed more compactly. Typically, such a rolling mill has several, for example five, rolling stands (passes). By applying the thickness reduction in the strand guide according to the invention, at least one rolling stand can be saved. This allows the entire plant, consisting of continuous casting plant, connecting system and rolling mill, to be manufactured more compactly and possibly also more cost-effectively. Alternatively, a greater reduction in the thickness of the strand can be achieved with a conventional design of the rolling mill. It should be noted that less energy is required to compress the strand while it is still liquid in the core than would be necessary in the rolling mill if the thickness reduction in the strand guide were omitted.This technical effect leads to energy savings and further cost reductions, both in operating costs and acquisition costs. Another technical advantage of reducing the strand thickness in the strand guide is that the strand thickness at the mold end does not have to be minimized. In the "Background of the Invention" section, it was explained that the strand cannot be arbitrarily thin at the mold end for various reasons. The closer the strand thickness at the mold approaches this minimum limit, the greater the risk of breakouts or other production defects. Thickness reduction in the strand guide can thus lead to improved operational reliability if the strand thickness at the mold is chosen generously, without thereby reducing the overall thickness reduction at the mill exit.Furthermore, the internal quality of the strand can be improved because the thickness reduction in the strand guide reduces the flow of liquid melt.

[0015] According to the invention, the strand guide has one or more interchangeable segments, each with several rollers arranged in pairs. In this way, a conventional continuous casting plant can be easily retrofitted with a strand guide of the type described without any thickness reduction. By replacing one or more segments of a conventional strand guide with one or more segments with adjustable rollers, the retrofitting can be carried out in a modular manner. Thus, by subsequently purchasing segments with individual roller adjustment, lower exit thicknesses from the strand guide and thus thinner final dimensions at the exit of a rolling mill can be achieved. If thinner final dimensions are only to be produced occasionally, it is possible to work with several non-adjustable segments and only install an adjustable segment (analogous to several adjustable segments) when producing particularly thin dimensions.Alternatively, the adjustable segment (or several adjustable segments) can always be installed, whereby the adjustable rollers are only moved into a reduction position during the production of particularly thin dimensions and are otherwise in a zero position without thickness reduction.

[0016] Preferably, the rollers of the strand guide comprise first roller pairs directly adjacent to the mold and reduction roller pairs directly adjacent to the first roller pairs in the conveying direction. The rollers of the first roller pairs are not adjustable, whereby no thickness reduction of the strand takes place in this area of ​​the strand guide, i.e., an area directly adjacent to the mold. According to this preferred embodiment, the thickness reduction thus only begins "later," after the strand has passed through the first pairs of rollers. This prevents fluctuations in the casting level and prevents the strand from detaching from the mold wall, thereby further improving operational reliability. A good compromise between operational reliability, compactness, and thickness reduction is achieved when the strand guide has two or three first roller pairs and eight to fifteen reduction roller pairs.

[0017] Preferably, the rollers of the strand guide further comprise final roller pairs which adjoin the reduction roller pairs in the conveying direction, are preferably adjustable, but do not lead to any further reduction in the thickness of the strand. According to this embodiment, no further reduction in the strand thickness takes place in the last section of the strand guide, for example before the strand is gripped by the rollers of a straightening driver. Preferably, the system is controlled such that the sump tip of the strand lies in the region of the last roller pairs during regular casting. The sump tip is the position of the strand in the conveying direction at which the just-liquid core transitions into the fully solidified region. Since the strand first solidifies on the surface and the temperature increases from the outside inwards, the liquid core has approximately the shape of a cone in the conveying direction, with the tip of the cone being referred to as the sump tip.

[0018] If a straightening driver is connected to the strand guide in the conveying direction, which has several driven rollers and is designed to actively pull the strand out of the strand guide, the strand is preferably completely solidified when it reaches the straightening driver.

[0019] The strand guide preferably has a bending area in which the strand is bent. If the continuous casting plant is designed as a vertical bending plant, the strand exits the mold vertically downwards, is guided downwards by the strand guide, and then deflected along an arc. In this case, the strand does not have to be bent completely to the horizontal within the strand guide. The remaining bending to the horizontal takes place in the straightening driver. The strand can then be transported horizontally to pass through further stations, such as a straightening driver, a cutting device for cutting the strand into slabs of a specific length, a furnace, and a rolling mill.

[0020] The adjustable rollers are preferably hydraulically, magnetically, or electromotively actuated. According to a particularly preferred embodiment, the strand guide has one or more hydraulic cylinders, in each of which a piston can be hydraulically displaced to adjust an adjustable roller attached to it. By hydraulic control, for example by means of oil, the piston can be moved back and forth between the zero position and the reduction position. Both rollers of a pair of rollers, or just one roller of the pair, can be adjustable. Furthermore, in certain design variants, it can be useful for adjustable rollers to be able to be brought into more than two positions, in particular to be continuously adjustable. Thus, according to a variable embodiment, the strand thickness can be reduced to different exit thicknesses.Alternatively or additionally, a frame part of the above-mentioned segment (analogously several segments) of the strand guide can be designed to be adjustable, whereby several rollers can be adjusted in groups to reduce the strand thickness.

[0021] The method according to the invention relates to the casting of a strand using a device of the type described above, wherein one or more rollers of the strand guide are adjusted such that the thickness of the strand in the strand guide is reduced during the regular casting process. The technical effects, preferred embodiments, and contributions to the prior art described with reference to the device apply analogously to the method.

[0022] The roller pitch profile can be suitably adjusted depending on the degree of reduction, reduction distance, strand material, etc. For example, the decreasing positions of the rollers can be distributed linearly or parabolically, so that the thickness reduction occurs linearly or parabolically along the strand guide.

[0023] According to a particularly preferred embodiment, the thickness reduction of the strand takes place when the core is not completely solidified, which enables energy-saving operation of the plant and also contributes to an improvement in the casting quality.

[0024] Preferably, the adjustable rollers are adjusted taking into account process parameters and using a temperature calculation model that can be used to determine temperature properties of the strand, such as the position of the sump tip and / or the strand shell thickness.

[0025] Further advantages and features of the present invention will become apparent from the following description of preferred embodiments. The features described therein can be implemented alone or in combination with one or more of the features presented above, provided the features do not contradict one another. The following description of the preferred embodiments is made with reference to the accompanying drawings. Short description of the characters

[0026] The Figure 1 shows a schematic view of a continuous casting plant, designed as a "vertical bending plant", with two strand guide segments and a straightening driver for transporting the cast strand. The Figure 2 shows a schematic of a continuous casting plant with adjustable rollers. Figures 3a and 3b show a hydraulic control of adjustable rollers. Detailed description of preferred embodiments

[0027] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements are provided with identical reference numerals, and a repetitive description of these elements is partially omitted to avoid redundancies.

[0028] The Figure 2 shows schematically a continuous casting plant, the basic structure of which is the Figure 1 The strand guide 2 is connected to the mold 1. At the exit of the strand guide 2, the straightening driver 3 is provided for pulling the strand S out of the strand guide 2.

[0029] In contrast to the investment of Figure 1 The strand guide 2 of the embodiment of the Figure 2only a single segment 23, even though several segments can be provided according to other embodiments. A continuous casting plant with only one segment 23 has greater rigidity and can absorb the bending forces generated by the straightening driver 3 better than a continuous casting plant of the same length with several segments. In a continuous casting plant with two or more segments, all segments may have to be replaced one after the other after a malfunction, such as a breakout. These changeover times are generally much shorter in a continuous casting plant whose strand guide 2 has only a single segment 23, since the entire strand guide 2 can be replaced without segments having to be connected to one another. When segments are connected to one another, there is a risk that two adjacent segments will not be connected precisely.Contamination, wear, and / or incorrect alignment of the segments can lead to stresses in the strand S, which increases the 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 system.

[0030] Segment 23 has a plurality of rollers 24a, 24b, 24c (collectively referred to as rollers 24) arranged in pairs, whereby they form a gap (two rollers 24 always facing each other) through which the strand S emerging downwards from the mold 1 passes and is guided along a curved path. The not yet fully solidified strand is therefore first guided vertically downwards, then deflected along a curve by the strand guide 2 and then transported horizontally. During transport, the strand S cools, which can be actively supported and / or controlled by applying a cooling fluid if necessary.

[0031] The straightening driver 3 is arranged as part of a connecting system in the conveying direction F behind the segment 23 in order to pull the strand S out of the strand guide 2 and bend it completely into the horizontal position. For this purpose, the straightening driver 3 has several rollers 31 arranged in pairs, which are driven rollers, for example, driven by one or more electric motors (not shown).

[0032] Even if in the Figure 2 For the sake of clarity, the representation of further components has been omitted, the continuous casting plant of the present embodiment can be operated as shown in the Figure 1 a separating device, a furnace, a cold strand rocker, a rolling mill and / or other components.

[0033] In contrast to the continuous casting plant of the Figure 1According to the present embodiment, one or more rollers 24 of the strand guide 23 are adjustable, which can include, in particular, adjustability during the casting process. The adjustability or adjustability is provided such that one or more pairs of rollers can be moved together, whereby the transport gap can be varied, in particular reduced, along the conveying direction F.

[0034] To distinguish between different roller groups of the strand guide 2, one or more roller pairs directly below the mold 1 are referred to as the first roller pairs 24a. Roller pairs that follow them in the conveying direction F are referred to as the middle roller pairs or reduction roller pairs 24b. The remaining roller pairs of the strand guide 2, which are located directly in front of the straightening driver 3, are referred to as the last roller pair 24c. Since the rollers 24 of the strand guide 2 are generally arranged in pairs, the reference numerals 24a, 24b, 24c are also used to designate the rollers themselves of the respective pair.

[0035] According to a particularly preferred embodiment, the first rollers 24a are not adjustable, with this first roller group preferably comprising two or three roller pairs 24a. By making the first roller pairs 24a non-adjustable, i.e., fixedly mounted, fluctuations in the casting level can be suppressed, and the strand S is prevented from detaching from the mold wall.

[0036] The middle roller pairs 24b, for example, 8 to 15 roller pairs, preferably 11 roller pairs, can be adjusted individually or in groups. In particular, they can be moved together, thereby reducing the thickness of the strand S, which has not yet solidified in the core, in the strand guide 2. Starting, for example, from a thickness of 52 to 45 mm at the mold exit, the thickness is reduced to approximately 32 to 35 mm, preferably down to 20 mm, at the exit of the strand guide 2.

[0037] The last roller pairs 24c, preferably approximately four roller pairs, are also preferably adjustable. However, this adjustment only serves to follow the previously adjusted strand thickness. In this case, no further thickness reduction of the strand S takes place in the section of the last roller pairs 24c.

[0038] By varying the casting speed and / or cooling capacity, such as the amount of spray water, the position of the solidification (sump tip) in the roller conveyor is regulated, in particular, positioned so that complete solidification is not located within the region of the middle roller pairs 24b. A thickness reduction of the solidified strand would require significantly higher setting forces, which would increase the risk of cracking.

[0039] The angle profile of the middle rollers 24b can be suitably determined depending on the degree of reduction, reduction distance, material of the strand S, etc. Thus, the decreasing positions of the rollers 24b can be distributed approximately linearly or parabolically. For example, if a strand with a thickness of 50 mm at the mold exit is to be reduced to 34 mm in a linear manner, with 11 reduction rollers 24b, then the reduction at each of the reduction rollers 24b is 16 mm / 11 = 1.4545 mm. At the first rollers of the middle rollers 24b, the reductions can also be somewhat greater and decrease parabolically or in another way, so that at the last reduction roller 24b, the strand thickness decreases by only approximately 1 mm.

[0040] According to a structurally simple, cost-effective embodiment, shown in the Figures 3a and 3b, the middle rollers 24b (and possibly also the last rollers 24c) can be moved into exactly two positions by hydraulic cylinders. In this case, in one position, the zero position ( Figure 3a ), no thickness reduction takes place, while the thickness of the strand S on the corresponding roller pair 24b in the second position, the reduction position ( Figure 3b ), is reduced.

[0041] In the embodiment of the Figures 3a and 3bA piston 25, to which a roller 24b or 24c is attached, is provided so as to be displaceable in a cylinder 26. By hydraulic control, for example by means of oil, the piston 25 can be moved back and forth between the zero position and the reduction position. Both rollers of a roller pair 24b or just one roller 24b of the pair can be adjustable. Preferably, only the rollers 24b, 24c on the loose side are adjustable. Furthermore, the adjustment of the rollers 24b, 24c can also be technically realized in other ways, for example magnetically or electromotively. Furthermore, in certain design variants, it can be useful for one, several or all of the middle rollers 24b and / or last rollers 24c to be able to be brought into more than two positions, in particular to be continuously adjustable. In this way, according to a variable embodiment, the strand thickness can be reduced to different outlet thicknesses.Alternatively or additionally, a portion of the segment frame, preferably the upper frame, can be adjustable, whereby several rollers 24b, 24c can be adjusted in groups to reduce the strand thickness. Here, too, no thickness reduction preferably takes place at the first rollers 24a and last rollers 24c. According to a further embodiment, two rollers or pairs of rollers 24a, 24b, 24c can be combined in a cassette; these rollers can then be adjusted individually or together, if necessary.

[0042] The thickness reduction in the strand guide 2 described above allows the rolling mill 7 to be designed more compactly. Typically, the rolling mill has several, for example five, rolling stands (passes). In this case, it is possible to eliminate at least one rolling stand. This allows the entire plant to be manufactured more compactly and, if necessary, also more cost-effectively. Alternatively, a greater thickness reduction of the strand S can be achieved with a conventional design of the rolling mill 7. It should be noted that less energy is required to compress the strand S, which is still liquid in the core, than would be necessary in the rolling mill if the thickness reduction in the strand guide 2 were omitted. This technical effect leads to energy savings and a further cost reduction, both in terms of operating costs and acquisition costs.A further technical advantage of reducing the thickness of the strand S in the strand guide 2 is that the strand thickness at the end of the mold does not have to be minimized. It has already been explained that the strand at the end of the mold cannot be arbitrarily thin for various reasons. Typically, this limit is around 45 mm, depending on the material and the process parameters. The closer the strand thickness at the mold approaches this limit, the greater the risk of breakouts. The thickness reduction in the strand guide 2 can therefore lead to improved production reliability if the strand thickness at the mold is selected to be larger, without thereby reducing the overall thickness reduction at the outlet of the rolling mill 7. Furthermore, the internal quality of the strand can be improved, since the thickness reduction in the strand guide 2 reduces the flow of liquid melt, thereby reducing undesirable segregation.

[0043] A conventional continuous casting plant without thickness reduction in the strand guide 2 can be retrofitted with adjustable rollers 24b, 24c. By replacing one or more segments of a conventional strand guide with a segment 23 containing the adjustable rollers 24b, 24c, the retrofitting can be carried out in a modular manner. Thus, by subsequently purchasing segments with individual roller adjustment, lower exit thicknesses from the strand guide 2 and thus thinner final dimensions can be achieved at the exit of the hot rolling mill 7. If thinner final dimensions are only to be produced occasionally, it is possible to work with several non-adjustable segments 21, 22 and only install the adjustable segment 23 (analogously to several adjustable segments) when producing particularly thin dimensions.Alternatively, the adjustable segment 23 (analogously several adjustable segments) can always be installed, whereby the adjustable rollers 24b, 24c are only moved into the reduction position during the production of the particularly thin dimensions and are otherwise in the zero position.

[0044] The following describes a method for reducing the strand thickness in the strand guide 2 according to an exemplary embodiment: The continuous casting plant is started up in a conventional manner with the aid of a dummy bar. As soon as the dummy bar has been uncoupled and, if necessary, stowed away using the dummy bar rocker 6, the strand thickness can be reduced. If the strand head (for example 52 to 45 mm) is too thick for the rolling mill 7, the unreduced strand head (for example 4 m long, which corresponds to the length of the casting machine, i.e. the path between the mold 1 and the outlet of the strand guide 2) can be reduced to scrap in the separating device 4. The adjustable reduction rollers 24b of the strand guide 2 then reduce the strand S, which has not yet solidified in the core. If necessary, the position of the sump tip and the strand shell thickness at all roller positions can be calculated using a temperature calculation model.The position of the strand S in the transport direction at which the still liquid core transitions into the fully solidified region is referred to as the sump tip. Since the strand S solidifies first on the surface and the temperature increases from the outside inwards, the liquid core in the transport direction has approximately the shape of a cone, with the tip of the cone being referred to as the sump tip. The casting speed and cooling capacity, preferably the amount of spray water, are now regulated so that the sump tip moves forward into the area of ​​the last pairs of rollers 24c. There the strand thickness is not reduced any further. If the already solidified strand S were compressed, the required adjusting forces would increase significantly and the risk of internal cracks would arise. The average temperature at the inlet of the furnace 5 is higher the closer the sump tip moves to the end of the casting machine, i.e. to the outlet of the strand guide 2.When reaching the straightening driver 3, the strand S is preferably completely solidified.

[0045] By controlling the continuous casting plant so that the sump tip is located in the area of ​​the last rollers 24c, an optimal thickness reduction in the strand guide 2 can be achieved, since all reduction rollers 24b exert their effect, which would not be the case if the strand S were started too early.

[0046] By variably controlling the reduction rollers 24b, different strand thicknesses can be cast, and the reduction distribution can be adapted to the current process values. This is useful because the reduction distribution is preferably selected such that higher reductions occur in the region with a still completely liquid core (liquid core reduction "LCR") than in the region with initial dendrite growth in the core (soft reduction). This reduces the risk of internal cracks. Since the positions of the liquid boundary and the sump tip change dynamically with the process values ​​(casting speed, analysis, superheating, mold level, water quantities, water temperature, etc.), a dynamic temperature calculation model is preferably used to calculate them. During reduction in the strand guide 2, the last reduction is preferably not so far away from the mold 1 that no more melt can flow.

[0047] Where applicable, all individual features presented in the embodiments may be combined and / or interchanged with one another within the scope of the applicable claims. List of reference symbols

[0048] 1Mold 2Strand guide 3Straightening driver 4Separator 5Furnace 6Cold strand rocker 7Rolling mill 21, 22, 23Segments of the strand guide 24Strand guide rollers 24aFirst rollers / pairs of rollers 24bReduction rollers / pairs of reduction rollers 24cLast rollers / pairs of rollers 25Piston 26Hydraulic cylinder 31Rolls of the straightening driver SStray / slab FConveyor direction

Claims

1. Continuous casting plant comprising a mould (1) for delivering a strip (S) and a strip guide (2), which connects with the mould (1), with a plurality of rollers (24), which are arranged in pairs, for transporting the strip (S) in a conveying direction (F), wherein one or more of the rollers (24) is or are so adjustable that a thickness reduction of the strip (S) in the strip guide takes place, characterised in that the strip guide (2) comprises one or more exchangeable segments (23) with a respective plurality of adjustable rollers (24) arranged in pairs.

2. Continuous casting plant according to claim 1, characterised in that the rollers (24) comprise first roller pairs (24a), which directly connect with the mould (1), and reducing roller pairs (24b), which directly connect with the first roller pair (24a) in conveying direction (F), wherein the rollers of the first roller pair (24a) are not adjustable so that in this region of the strip guide (2) no thickness reduction of the strip (S) takes place, whereas one or more, preferably all, of the rollers of the reducing roller pairs (24b) are adjustable so that in this region of the strip guide (2) a thickness reduction of the strip (S) takes place.

3. Continuous casting plant according to claim 2, characterised in that the strip guide (2) comprises two or three first roller pairs (24a) and preferably eight to fifteen reducing roller pairs (24b).

4. Continuous casting plant according to claim 2 or 3, characterised in that the rollers (24) further comprise last roller pairs (24c) which connect with the reducing roller pairs (24b) in conveying direction (F) and are preferably adjustable, but do not lead to a further thickness reduction of the strip (S).

5. Continuous casting plant according to claim 4, characterised in that this is so arranged that the end of the liquid phase of the strip (S) during the regular casting process lies in the region of the last roller pair (24c).

6. Continuous casting plant according to any one of the preceding claims, characterised in that the strip guide (2) has a bending region in which the strip (S) is bent, the continuous casting plant preferably being constructed as a perpendicular / bending-away plant in which the strip (S) issues vertically downwardly from the mould (1) and is guided downwardly by the strip guide (2) and subsequently deflected wholly or partly along a curve in the direction of the horizontal and transported onward.

7. Continuous casting plant according to any one of the preceding claims, characterised in that a straightening driver (3), which comprises a plurality of driven rollers (31) and is arranged to withdraw the strip (S) from the strip guide (2) and bend it over completely into the horizontal, connects with the strip guide (2) in conveying direction (F).

8. Continuous casting plant according to any one of the preceding claims, characterised in that the adjustable rollers (24) are actuable hydraulically, magnetically or by electric motor, the strip guide (2) preferably comprising one or more hydraulic cylinders (26) in which pistons (25) for adjusting the adjustable rollers (24) are hydraulically displaceable.

9. Continuous casting plant according to any one of the preceding claims, characterised in that in that the adjustable rollers (24) can each adopt exactly two settings, namely a zero setting in which no thickness reduction of the strip (S) takes place at the respective position in the strip guide (2) and a reduction setting in which a thickness reduction of the strip (S) takes place at the respective position in the strip guide (2).

10. Method of casting a strip (S) by means of a device according to any one of the preceding claims, wherein one or more of the rollers (24) of the strip guide (2) are so adjusted that the thickness of the strip (S) during the casting process is reduced in the strip guide (2).

11. Method according to claim 10, characterised in that the thickness reduction of the strip (S) takes place in the strip guide (2) when the core of the strip (S) is not hardened through.

12. Method according to claim 10 or 11, characterised in that the adjustable rollers (24) are adjusted with consideration of process parameters and on the basis of a temperature computation model by which temperature characteristics of the strip (S), preferably the position of the end of the liquid phase and / or the strip thickness, can be determined.