Ultra thin endless belt production

Abstract

The present invention relates to a casting and rolling plant (2) for the production of ultrathin continuous strip and a method (100) for the production of ultrathin continuous strip in a casting machine (4) for continuous strip production. The casting and rolling plant (2) comprises: i) a casting machine (4) for casting (S1) a metal strand (S), ii) a first rolling stand group (6) for continuous rolling (S2) of the cast metal strand (S) to a pre-strip (V), iii) a second rolling stand group (8) for continuous rolling (S3) of the pre-strip (V) to a hot strip (Vη), iv) a coiling arrangement (10) for selectively coiling the hot strip (Vη), v) a separating device (12) for separating the coiled hot strip (W) from subsequent hot strip (Vη and vi) a third rolling stand group (32) arranged downstream of the coiling arrangement (10) for selectively continuously rolling (S4) the hot strip (W) to a finished product (E).

Description

field of technology

[0001] The present invention relates to a casting and rolling plant for the production of ultrathin continuous strip and a method for the production of ultrathin continuous strip in a casting machine for continuous strip production. State of the art

[0002] In so-called hot-rolling mills, a strand cast by a casting machine can be hot-rolled by one or more subsequent rolling mills, i.e., one or more groups of rolling stands. Slabs, for example, can be cut from the strand and then fed through the rolling mills. With such hot-rolling mills, particularly in continuous operation where the casting machine is coupled to the rolling mills with respect to mass flow, it is possible to roll very thin metal strips, so-called hot-rolled strips. Current Arvedi ESP hot-rolling mills can thus hot-roll metal strips with a thickness down to 0.6 mm. The production of even thinner strips usually requires the use of cold-rolling technology, which, however, significantly increases energy consumption.

[0003] One factor limiting the minimum achievable strip thickness in hot rolling is the final rolling temperature at the last rolling stand. Since the strip temperature decreases with each additional rolling pass, a desired final rolling temperature may no longer be attainable when adding further rolling stands. Furthermore, in continuous rolling, the mass flow through the entire plant is constant. This results in very high strip speeds when rolling thin strips, which makes coiling more difficult. Summary of the invention

[0004] It is an object of the present invention to further improve the hot rolling of endless strips in casting and rolling plants, in particular to enable the hot rolling of ultra-thin endless strips with thicknesses of 0.6 mm or less.

[0005] This task is solved by the casting and rolling plant for the production of ultrathin continuous strip and the method for the production of ultrathin continuous strip with a casting and rolling plant for continuous strip production according to the independent claims.

[0006] Preferred embodiments of the invention are the subject of the dependent claims and the following description.

[0007] According to a first aspect of the invention, the casting and rolling plant for the production of ultrathin continuous strip comprises: i) a casting machine for casting a metal strand, ii) a first rolling stand group for continuously rolling the cast metal strand into a pre-strip, iii) a second rolling stand group for continuously rolling the pre-strip into a hot strip, iv) a reeling arrangement for selectively reeling the hot strip, v) a separating device arranged upstream of the reeling arrangement for separating the reeled hot strip from subsequent hot strip, and vi) a third rolling stand group arranged downstream of the reeling arrangement for selectively continuously rolling the hot strip into a finished product.

[0008] One aspect of the present invention is based on the approach of providing a third rolling mill in a continuous rolling mill designed for continuous operation, comprising, for example, a roughing mill (also known as a high reduction mill, HRM) and a subsequent finishing mill. The first, second, and third rolling mills preferably form a production line. During continuous production, the three rolling mills are therefore coupled; the mass flow through each of the rolling mills is constant. The third rolling mill is advantageously arranged downstream of a coiler assembly of the rolling mill in a transport direction. The hot-rolled strip, which constitutes the end product in conventional rolling mills, can thus bypass the coiler assembly and be introduced into the third rolling mill.This allows for the selective production of ultrathin metal strips, i.e., strips with thicknesses of less than 0.6 mm. The production of these ultrathin metal strips takes place in the third rolling stand at very high speeds, for example, more than 15 m / s. This enables the rolling of end products that are otherwise only achievable by cold rolling. Compared to strips produced by cold rolling, however, the end product manufactured according to the invention has a significantly better energy balance. In particular, during rolling in the third rolling stand, at least some of the heat inherent in the strip from the casting process can be utilized.

[0009] To achieve strip thicknesses of less than 0.6 mm, the third rolling stand group preferably comprises one to four rolling stands, and particularly preferably two to three rolling stands. With these additional rolling stands, the hot-rolled strip produced in the second rolling stand group, which typically has a strip thickness between 0.8 mm and 2.5 mm, can be rolled into ultra-thin hot-rolled strip.

[0010] Up to the coiling arrangement, the casting and rolling mill preferably corresponds to a known casting and rolling mill designed for continuous operation. In this respect, the casting and rolling mill according to the invention may advantageously additionally comprise: a heating device between the first and second rolling stands for heating the strip to a temperature suitable for rolling in the second rolling stand; a cooling section after the second rolling stand for cooling the hot strip to a coiling temperature suitable for coiling by means of the coiling arrangement; one or more descaling devices, for example upstream of the first and / or the second rolling stand for descaling the cast metal strand or the strip; and / or a strip separating device for separating the strip between the first and second rolling stands, for example in the case of a high-rise mill (i.e., a high-rise mill).The formation of a so-called cobble) before the second rolling stand group or another production disruption in the area of ​​the second rolling stand group or downstream of it. In this respect, the third rolling stand group can be used as an extension of a conventional casting and rolling mill, i.e., such a conventional casting and rolling mill can be retrofitted with the third rolling stand group.

[0011] The arrangement of the third rolling stand group downstream of the coiler allows for the selective commencement of ultrathin continuous strip production in this group. In short, the casting rolling mill can be started up as usual, and the hot strip produced can be coiled by the coiler until a suitable strip thickness for tapping into the third rolling stand group is reached. At this point, the coiled hot strip can be separated from the subsequent hot strip by the separating device, and the subsequent hot strip can be fed past the coiler into the third rolling stand group. This process is described in more detail below in connection with the method for producing ultrathin continuous strip.

[0012] In particular, a control device may be provided to carry out this process, coordinating the rolling processes in the first, second, and third rolling stands. The control device is also advantageously configured to selectively feed the hot strip to the first coiler assembly, i.e., to initiate the coiling of the hot strip rolled in the second rolling stand assembly, or to feed it to the third rolling stand assembly, i.e., to initiate the rolling of the hot strip into the final product in the third rolling stand assembly. The control device may, for example, be configured to control a corresponding strip diverter or to position guide rollers of the coiler assembly so that a head end of the hot strip is selectively fed to a coiler of the coiler assembly, or—at a predetermined time—the hot strip is cut, and the resulting head end is fed to the third rolling stand assembly.

[0013] Since the hot strip can cool down as it passes through the coiling assembly, i.e., until it reaches the third rolling stand, it is advantageous to install a reheating device upstream of the third rolling stand to warm the hot strip. The reheating device is preferably particularly short, for example, as an induction heating device. In principle, induction coil arrangements are suitable for generating both a longitudinal and a transverse magnetic flux in the hot strip being reheated.

[0014] To enable the transport of the finished rolled product, it is also preferred to provide a further reel assembly for coiling the product and a further separating device arranged upstream of this further reel assembly for separating the coiled product from the subsequent product. To enable coiling at a predetermined coil temperature, a final cooling section is advantageously provided downstream of the third rolling stand group for cooling the product rolled in the third rolling stand group. The further reel assembly and the further separating device are advantageously arranged downstream of the final cooling section.

[0015] The third rolling stand group is preferably part of a finishing arrangement. This finishing arrangement expediently also includes the reheating device, the final cooling section, the additional coiling arrangement, and / or the additional cutting device. The finishing arrangement, also known as a Thin Gauge Outlet (TGO), can be connected to a known continuous-operation casting and rolling mill, for example, by means of a roller table. The finishing arrangement can therefore be designed as an extension or module for retrofitting an existing continuous-operation casting and rolling mill. The reheating device, the final cooling section, the additional coiling arrangement, and the additional cutting device allow for a high degree of control over the manufacturing process in the finishing arrangement.

[0016] The aforementioned additional reel arrangement is preferably designed to reel tapes with thicknesses down to 0.4 mm and / or at speeds of 20 m / s and above. To significantly reduce the risk of so-called "cobbles" (the formation of "cobbles") with such thin and / or fast-moving tapes, the additional reel arrangement is preferably designed as a carousel winder. With a carousel winder, the head end of the finished product can be threaded into a reel of the carousel winder in a straight line; thus, no deflection of the very thin and fast-moving tape head is necessary.

[0017] For stable rolling in the third rolling stand group, i.e., for producing a flat end product with the desired thickness profile in the transverse direction and for reducing the risk of rollover, it is advantageous for the hot-rolled strip to enter the first rolling stand of the third rolling stand group centered. Therefore, a strip alignment device is preferably arranged between the second and third rolling stands, which is configured to regulate the strip alignment in a transverse direction. The strip alignment device is thus configured to align the centerline of the hot-rolled strip with respect to the transverse direction. In this context, a transverse direction is preferably a direction transverse to the transport direction in the strip plane, i.e., in a direction transverse to the surface normal on the upper or lower surface of the strip.The strip alignment device can therefore regulate the "lateral" alignment of the hot strip upstream of the third rolling stand group.

[0018] Such a strip alignment device can, for example, comprise a pair of drive rollers, also known as pinch rolls, wherein at least one of these drive rollers is pivotable and / or displaceable along the roller axis. The two drive rollers are advantageously offset from each other in such a way that the hot-rolled strip is guided around the two drive rollers in an S-shape.

[0019] Alternatively, three consecutive rollers can be provided, with the middle roller offset relative to the plane of the belt so that the belt runs in a loop around the middle roller. The two outer rollers are preferably designed as driver rollers; the middle roller serves as a deflection roller. Here, too, it is advantageous for at least one of the rollers to be pivotable and / or displaceable along its axis to influence the alignment of the belt centerline.

[0020] Particularly efficient use of the strip alignment device can be achieved if it is also configured to detect and / or regulate the relative mass flow between the second and third rolling stands. For example, the strip alignment device can include a sensor that detects the force exerted by the guided hot strip on the roll(s). If the detected force deviates from a target value, this can indicate an excessively high or low mass flow in the third rolling stand. Alternatively or additionally, the strip alignment device can contribute to regulating the mass flow by increasing or decreasing the transport distance between the second and third rolling stands through pivoting and / or shifting at least one of the rolls.For example, by shifting the middle deflection pulley relative to the two outer deflection pulleys, the size of the loop formed by the hot strip as it passes over the middle deflection pulley can be determined. Depending on the design of the strip alignment device, a dedicated mass flow control device, such as a loop lifter, may be unnecessary, or such a dedicated mass flow control device can be made smaller.

[0021] Such a (dedicated) mass flow control device is expediently arranged between the second and third rolling stands and is designed to regulate the mass flow in the area of ​​the third rolling stand. The mass flow control device can thus regulate the amount of mass flow into the third rolling stand. Such a dedicated mass flow control device can create, if necessary, additional capacity to detect an undesirable deviation in the mass flow, i.e., the rolling speed, in the third rolling stand (relative to the mass flow from the second rolling stand) and to react to it promptly.

[0022] Such a mass flow control device is preferably designed as a loop lifter. These loop lifters are typically arranged within a rolling stand assembly for mass flow control. Similar to the previously described strip alignment device with three deflection rollers, the strip is guided in a loop by means of a loop lifter, the size of which can be varied as required. To increase the mass flow downstream of the loop lifter, at least temporarily, the size of the loop can be reduced; conversely, to temporarily decrease the mass flow, the size of the loop can be increased.

[0023] To prevent the hot strip from unintentionally advancing to the third rolling stand, for example, when the hot strip is actually intended to be wound onto the coiler, a strip catcher can be provided to block the transport path to the third rolling stand. This strip catcher can block the transport path, in particular, whenever the first and second rolling stands are in operation, but the third rolling stand is not. This also increases operational reliability.

[0024] Preferably, the control device is configured to introduce the strip catcher into the transport path or to initiate such an introduction depending on an operating state of the third rolling stand group, for example when the third rolling stand group is not in operation.

[0025] The rolling stands of the third group can be designed as quarto stands, in which the work rolls are supported and driven by a backup roll. Such quarto stands can be equipped with small-diameter work rolls, which are particularly well suited for rolling thin strip, for example, hot-rolled strip produced by the second group of rolling stands.

[0026] Even thinner work rolls can be used with six-to roll stands, in which backup rolls support intermediate rolls, which in turn support the work rolls. Therefore, it is particularly advantageous if the third group of roll stands comprises several stands designed as six-to roll stands. This allows the work rolls that contact the hot-rolled strip to be designed with a particularly small diameter. Such six-to roll stands are uncommon in hot rolling. Conventionally, such six-to roll stands are used exclusively in cold rolling.

[0027] According to a second aspect of the invention, the method for producing ultrathin continuous strip in a casting and rolling mill for continuous strip production, in particular a casting and rolling mill according to the first aspect of the invention, comprises the steps: i) casting a metal strand by means of a casting machine, ii) continuous rolling of the cast metal strand to roughing in a first rolling stand group, iii) continuous rolling of the roughing to hot strip in a second rolling stand group, and iv) continuous rolling of the hot strip to a finished product in a third rolling stand group.

[0028] Advantageously, the hot-rolled strip is guided past the cutting device and the coiling assembly. In the inventive method, the casting machine, the first rolling stand group, the second rolling stand group, and the third rolling stand group are advantageously coupled to one another; that is, rolling takes place in all three rolling stand groups with essentially the same mass flow. The hot-rolled strip can therefore enter the third rolling stand group directly without being rewound or otherwise removed from the system in the interim. In other words, an endless strip is advantageously fed to the third rolling stand group.

[0029] This process enables the production of particularly thin metal strips at correspondingly high speeds, for example, strip thicknesses of less than 0.6 mm at speeds exceeding 15 m / s. Therefore, the process can be used to manufacture end products that would otherwise only be achievable by cold rolling. Compared to cold rolling, however, the process according to the invention offers significant energy savings. In particular, entire cold rolling mills and annealing plants can potentially be eliminated.

[0030] If the casting and rolling mill for continuous strip production has a cooling section between the second rolling stand group and the first coiling arrangement, this cooling section is expediently taken out of service when rolling the hot strip using the third rolling stand group.

[0031] There are essentially two ways to commission the third rolling stand group and thus start the production of ultrathin continuous strip. For example, to commence operation of the third rolling stand group, the stands can be preset so that hot-rolled strip with a predetermined initial entry thickness can be rolled into a finished product with a predetermined initial thickness. In particular, the roll gaps of the third rolling stand group can be adjusted accordingly. Advantageously, hot-rolled strip with the predetermined initial entry thickness is then rolled. The rolled hot-rolled strip can then be pierced, i.e., threaded, into the preset rolling stands of the third rolling stand group. The hot-rolled strip can then be rolled to the predetermined initial thickness.If necessary, a thickness reduction during operation is required to roll the final product to the desired target strip thickness. This thickness reduction during operation can thus be carried out more easily exclusively in the third rolling stand (although including the first and / or second rolling stand in this thickness reduction during operation is not excluded). This approach minimizes scrap. If the desired target strip thickness, i.e., the strip thickness of a final product to be manufactured in the current production sequence, is not too small, the hot strip can even be fed into the third rolling stand and rolled directly to the desired target strip thickness. In some cases, production of the desired final product can therefore begin immediately upon commissioning the third rolling stand.

[0032] The first predetermined entry thickness at which the third rolling stand is punctured is advantageously greater than or equal to a minimum thickness at which reliable punctuation of the hot strip in the third rolling stand can be guaranteed. This minimum thickness is, for example, 1.5 mm. The first predetermined entry thickness can therefore be, for example, between 1.5 mm and 2.0 mm. It is thus not necessary to produce the thinnest possible hot strip before commissioning the third rolling stand.

[0033] Alternatively, to initiate operation of the third rolling stand group, the hot strip can be rolled to a second predetermined entry thickness. This second predetermined entry thickness is advantageously smaller than the first predetermined entry thickness. Preferably, the hot strip rolled in this way is guided through open rolling stands of the third rolling stand group. Subsequently, the rolling stands of the third rolling stand group can be closed, preferably sequentially, and adjusted so that the hot strip with the second predetermined entry thickness is rolled to a final product with the target strip thickness. This allows particularly thin strips to be fed into the third rolling stand group. Consequently, the thickness in the third rolling stand group does not need to be reduced as much to achieve the desired target strip thickness. This can result in fewer thickness adjustments being necessary during operation.

[0034] The second predetermined entry thickness is advantageously smaller than the minimum thickness, for example, smaller than 1.5 mm. In particular, the second predetermined entry thickness can be the minimum thickness to which continuous rolling can be achieved using the first and second rolling stands. The second predetermined entry thickness can therefore be, for example, 0.8 mm or even 0.6 mm.

[0035] In both cases, therefore, preferably before commissioning the third rolling stand group, hot strip is first conventionally rolled and coiled. Advantageously, the thickness of the rolled hot strip is reduced until the first or second predetermined entry thickness is reached. Then the transport path between the coiling arrangement can be opened, the hot strip coiled up to that point can be separated from the following hot strip, and the following hot strip can be fed to the third rolling stand group, where it is either directly pierced or first passed through open rolling stands and threaded into the further coiling arrangement.

[0036] To optimize rolling stability, it is particularly advantageous to reduce the roll gaps of the rolling stands, especially those of the third rolling stand group, after they have engaged with the hot strip being rolled, during operation until the hot strip is rolled to the target thickness. Preferably, at least one (or more) flying gauge changes are performed in the third rolling stand group to achieve the target thickness. For example, if the strip thickness of the final product needs to be reduced by a total of 1 mm to reach the target thickness, the thickness of the hot strip can be reduced by a total of 0.1 mm in the second rolling stand group and by a further 0.8 mm in the third rolling stand group. Thus, more than 90% of the strip thickness change can be carried out in the third rolling stand group. In this case, the other rolling stand groups contribute only minimally to the thickness change.For example, it is conceivable that the thickness of the pre-strip (between the first and second scaffold group) is adjusted very slowly, via one or more virtual bundles to be produced from the strip.

[0037] Alternatively, the reduction of the strip thickness can of course also be carried out sequentially via the first, second and third rolling stand group if a change is to be made from one target strip thickness to another.

[0038] If further rolling in the third rolling stand is no longer necessary, it may be required to first increase the final product thickness during operation, for example, to the minimum thickness mentioned above. Once this minimum thickness is reached or exceeded, the hot-rolled strip can be separated upstream of the coiler assembly using the separating device, and the subsequent hot-rolled strip can be wound onto a coiler of this assembly. The third rolling stand can then be taken out of service.

[0039] Since starting up the third rolling stand group requires some lead time—namely, adjusting the first and second rolling stands so that hot strip with the first or second predetermined entry thickness is rolled—strategies that enable the third rolling stand group to operate as continuously as possible are advantageous. To enable an inline roll change in a rolling stand of the third rolling stand group, the roll gap in at least one other rolling stand of the third rolling stand group is therefore expediently reduced so that the thickness of the rolled end product does not change when the rolling stand is opened with the roll being replaced. The roll change can thus take place during ongoing production. Alternatively, an end product from the current production sequence with a greater target strip thickness can also be rolled during the roll change.

[0040] Since the strip is sensitive during rolling in the third rolling stand due to its thinness, it is preferred that the hot strip be heated in a protective gas atmosphere, for example by means of a reheating device, before entering the third rolling stand and / or rolled into the final product in a protective gas atmosphere. This minimizes scale formation.

[0041] Nitrogen (N2) can be used as a protective gas, for example.

[0042] To ensure that the permissible rolling forces are maintained and wear is minimized during rolling to the target strip thickness in the third rolling stand group, a thickness reduction of between 30% and 60%, preferably between 40% and 50%, preferably takes place in the third rolling stand group. For example, hot-rolled strip with a thickness of 1.2 mm can be rolled to a final product with a thickness of 0.7 mm. Brief description of the drawings

[0043] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of an exemplary embodiment, which is explained in more detail in conjunction with the drawings. These drawings show: FIG 1 an example of a casting rolling mill, FIG 2 an example of a strip alignment device, FIG 3 a first example of commissioning the third rolling stand group made of FIG 1 and FIG 4 a second example of commissioning the third rolling stand group from FIG 1 .

[0044] Where appropriate, the same reference numerals are used in the figures for the same or corresponding elements of the invention. Description of the embodiments

[0045] FIG 1 Figure 1 shows an example of a casting and rolling plant 2 with a casting machine 4 for casting a metal strand S, a first rolling stand group 6 with one to four rolling stands (three in this example) for continuously rolling the metal strand S into a roughing strip V, a second rolling stand group 8 with three to seven rolling stands (five in this example) for continuously rolling the roughing strip V into a hot strip W, a reeling arrangement 10 for coiling the hot strip W, a cutting device 12 for cutting the hot strip W, and a finishing arrangement 30. The finishing arrangement 30 comprises at least a third rolling stand group 32 with one to four rolling stands (two in this example) for continuously rolling the hot strip W into a finished product E, as well as a further cutting device 36 and a further reeling arrangement 34 for coiling the finished product E.The further reel assembly 34 is advantageously designed, as indicated, as a carousel winder. Thus, the further reel assembly 34 has at least two reels 34a, 34b, which can be moved into a reeling position on a carousel. In this reeling position, the finished product E, rolled by means of the third rolling stand group 32, can advantageously be threaded directly, i.e., without being deflected, into the respective reel 34a, 34b that is currently in the reeling position.

[0046] In the present example, the finishing arrangement 30 also includes a reheating device 38 and a final cooling section 42. The finishing arrangement 30 is advantageously located downstream, i.e., in a transport direction of the hot strip W, behind the coiling arrangement 10. The third rolling stand group 32, like the first rolling stand group and / or the second rolling stand group, advantageously has loopers, also referred to as loopers, between the individual rolling stands. Induction heating elements can also be provided between the individual rolling stands.

[0047] In the example shown here, the casting and rolling mill 2 also has a descaling device 14 upstream of both the first rolling stand group 6 and the second rolling stand group 8, as well as a heating device 16 between the first rolling stand group 6 and the second rolling stand group 8. Additionally, in this example, a cooling section 18 is provided downstream of the second rolling stand group 8 to bring the hot strip W to a coiling temperature suitable for winding by means of the coiling arrangement 10. To enable the first rolling stand group 6 to be disconnected from the second rolling stand group 8 in the event of an operational malfunction in or downstream of the second rolling stand group 8, a pre-strip separating device 20 is provided, which is expediently arranged directly downstream of the first rolling stand group 6.To avoid interrupting the casting process with the casting machine 4 in the event of such a malfunction, the strip V can also be cut by means of a further strip cutting device 22, and the resulting strip section can be removed from the production line formed by the casting rolling mill 2 by means of a strip exiting device 24 arranged between the strip cutting device 20 and the further strip cutting device 22. The strip cutting device 20 and / or the further strip cutting device 22 can also be used to operate the casting rolling mill 2 in a semi-continuous mode, in which strip sections are cut from the strip V, which is continuously rolled in the first rolling stand group 6, and these sections are then wound onto coils by means of the reeling arrangement 10 to form one or more bundles.

[0048] The casting and rolling mill 2, up to the coiling assembly 10, can thus be an existing continuous casting and rolling mill, to which the finishing assembly 30 is connected, for example by means of a roller table 26. Consequently, conventional hot-rolled strip W with a thickness down to 0.8 mm, and optionally even down to 0.6 mm, can also be produced with the casting and rolling mill 2. This hot-rolled strip W is expediently coiled into a bundle by means of a coiler 10a of the coiling assembly 10 in a known manner. As soon as the bundle has reached a predetermined size or weight, the hot-rolled strip W can be cut by means of the cutting device 12, and the subsequent hot-rolled strip W can be coiled by another coiler 10b of the coiling assembly 10.

[0049] Furthermore, the casting and rolling mill can also be used to produce ultrathin continuous strip, i.e., an end product E with a thickness of 0.6 mm or less. For this purpose, the casting and rolling mill 2 expediently has a control device 50, which can control a process 100 for the production of an ultrathin continuous strip. In particular, the control device 50 can cause the continuous metal strand S to be cast in a first process step S1, the pre-strip V to be rolled from this metal strand S in a further process step S2, a hot-rolled strip W to be produced from this pre-strip V in a further process step S3, and the end product E, i.e., an ultrathin continuous strip with a thickness of 0.6 mm or less, to be rolled from this hot-rolled strip W in a further process step S4.

[0050] For this purpose, the control device 50 is also expediently configured to orchestrate a changeover between conventional operation, i.e., the production of hot-rolled strip W with a strip thickness down to 0.8 mm or even 0.6 mm and the coiling of this hot-rolled strip W using the coiling arrangement 10, and the method 100. For example, the control device 50 can be configured to control the commissioning of the third rolling stand group 32, particularly from conventional operation. For this purpose, the control device 50 can preferably execute the steps described below in connection with FIG 3 und 4 Initiate the described steps.

[0051] To ensure precise rolling in the third rolling stand 32, it is advantageous to closely monitor and, if necessary, influence the properties and transport of the hot-rolled strip W. Therefore, a number of sensors are preferably provided both upstream and downstream of the third rolling stand 32 to detect strip temperature, strip tension, surface quality, strip thickness, strip flatness, strip position, and / or the like. Furthermore, it is advantageous to also provide a strip alignment device for aligning the hot-rolled strip W before it enters the reheating unit 38 and / or a mass flow control device for compensating for mass flow fluctuations between the second and third rolling stands 8, 32. Such a mass flow control device can, for example, be arranged in the form of a loop lifter directly upstream of the third rolling stand 32.A belt alignment device is discussed below in connection with . FIG 2 described: FIG 2 Figure 1 shows an example of a belt alignment device 60. In the present example, the belt alignment device 60 comprises three deflection rollers 62a, 62b, 62c. A middle deflection roller 62c is positioned relative to the two outer deflection rollers 62a, 62b out of the plane of the belt, in the FIG 2 In the example shown, the hot strip W is offset downwards. The hot strip W runs around the deflection rollers 62a, 62b, 62c in such a way that a loop Wa is formed. By pivoting at least the middle deflection roller 62c relative to the transport direction T of the hot strip W and / or by longitudinally displacing this deflection roller 62c along the roller axis, the orientation of the hot strip W behind the strip alignment device 60, i.e., as it unwinds on the rear deflection roller 62b, can be influenced. The hot strip W can thus be adjusted in a transverse direction in the strip plane that runs perpendicular to the transport direction T, i.e., "laterally" in FIG 2 They can be moved into or out of the figure plane.

[0052] The strip alignment device 60 can also be used to detect a mass flow difference between a second rolling stand group upstream of the strip alignment device 60 and a third rolling stand group downstream of the strip alignment device 60 (see FIG 1 ) are used. In this case, the strip alignment device 60 expediently has a sensor 64 for detecting a force F exerted by the guided hot strip W on at least one of the deflection rollers 62a, 62b, 62c. In the FIG 2 In the example shown, sensor 64 measures the force F acting on the middle deflection roller 62c. If the mass flow downstream of the strip alignment device 60 is higher than upstream, the tension in the hot strip W increases. This increases the force F acting on the deflection rollers 62a, 62b, 62c. Conversely, the strip tension decreases if the mass flow downstream is lower than upstream of the strip alignment device 60. Accordingly, the force F acting on the deflection rollers 62a, 62b, 62c also decreases.

[0053] If necessary, the strip alignment device 60 can also be used to regulate the mass flow downstream of the strip alignment device 60, for example in the third rolling stand group. For this purpose, the middle deflection roller 62c is advantageously displaceable parallel to its roller axis and essentially transversely to the transport direction T. In this way, the size of the loop Wa can be increased or decreased, and thus the hot strip W can be supplied faster or slower, at least temporarily, downstream of the strip alignment device 60.

[0054] FIG 3 shows a first example of the commissioning of the third rolling mill group 32 from FIG 1 . Here, the following are consistently included: FIG 1 The steps S1, S2, and S3 shown are carried out. The hot-rolled strip W produced is first coiled using the coiling arrangement 10. During coiling, the third rolling stand group 32 is adjusted in process step S5 so that hot-rolled strip W with a predetermined initial entry thickness is rolled into an end product E with a predetermined initial end product thickness, or optionally even directly to a desired target strip thickness. Advantageously, the roll gaps of the rolling stands of the third rolling stand group 32 are adjusted accordingly for this purpose.

[0055] In a further process step S6a, the hot-rolled strip W is produced with the first predetermined entry thickness. If necessary, it may be required to gradually reduce the thickness of the hot-rolled strip W rolled in the second rolling stand group 8 during operation until the first predetermined entry thickness is reached. Such a procedure may be necessary, in particular, if the first predetermined entry thickness is so small that a corresponding thickness reduction via the rolling stands of the first rolling stand group 6 and the second rolling stand group 8 cannot be achieved directly at the first entry point, or if the loads acting on the work rolls of the rolling stands of the first and second rolling stand groups 6 and 8 would be too high.

[0056] Once the predetermined initial entry thickness is reached, in a further process step S7 the hot strip W, wound up by the coiling arrangement 10, can be separated by the separating device 12 and the subsequent hot strip W can be guided past the coiling arrangement 10 to the third rolling stand group 32 preset in step S5. A [missing information] can also be [missing information] FIG 1 The strip catcher (not shown) at the entrance of the finishing device 30 is removed from the transport path between the second and third rolling stands 8, 32. In a further process step S8a, the hot strip W with the first predetermined entry thickness is then pierced in the preset third rolling stand 32 and rolled to the predetermined first end product thickness. Side guides can be used here to bring the hot strip into a predetermined orientation relative to the third rolling stand 32 and / or reliably guide it into the third rolling stand 32. The end product E rolled in this way can be threaded into the further coiling arrangement 34 and wound onto the coiler in a further process step S9. Here, too, side guides can be used to bring the end product E into a predetermined orientation relative to the further coiling arrangement 34 and / or reliably guide it into the further coiling arrangement 34.Once sufficient tensile stress has been achieved in the final product E by coiling, a thickness change can be carried out in a further process step S10a during operation – provided the predetermined initial final product thickness does not already correspond to the desired target strip thickness – until the final product E is rolled to the desired target strip thickness. This thickness change during operation can be carried out via the first, second, and / or third rolling stand group 6, 8, 32. However, due to increased rolling stability, it is preferred that this thickness change during operation is carried out exclusively or at least predominantly via the third rolling stand group 32.

[0057] This means the in FIG 1 The state shown is reached in which the process step S4 shown there is carried out.

[0058] FIG 4 shows a second example of the commissioning of the third rolling mill group 32 from FIG 1 . Here too, it is assumed that the process steps S1, S2 and S3 are carried out continuously. FIG 1 and the resulting hot-rolled strip W is wound up using the winding arrangement 10. In process step S6b, the hot-rolled strip W is then rolled to a second predetermined inlet thickness. Advantageously, for this purpose - as in connection with FIG 3 As already described, a reduction in belt thickness was carried out during operation.

[0059] In process step S7, the following is done analogously to the one in FIG 3 In the example shown, the coiled hot strip W is separated from the following hot strip W by means of the separating device 12, and the following hot strip W is guided to the third rolling stand group 32. Here, too, a strip catcher is expediently removed from the transport path between the second and third rolling stands 8, 32. The rolling stands of the third rolling stand group 32 are, in contrast to the one in FIG 3 In the example shown, however, it is more expedient to open or have been opened beforehand. In a further process step S8b, the hot strip W can thus be guided through the open rolling stands of the third rolling stand group 32. In this case, the hot strip W therefore initially passes through the third rolling stand group 32 without being rolled.

[0060] In process step S9, the hot strip W is then, again analogously to the one in FIG 3 The example shown is expediently threaded into the further reel arrangement 34 and reeled on.

[0061] After the coiling of the hot strip W, which has been guided through the open rolling stands of the third rolling stand group 32, has begun, the rolling stands of the third rolling stand group 32 can finally be closed in a further process step S10b and adjusted so that the hot strip W with the second predetermined entry thickness is rolled into the final product E with the target strip thickness. For this purpose, the roll gaps of the rolling stands of the third rolling stand group 32 are expediently reduced sequentially or, if necessary, simultaneously during operation. If necessary, the first and second rolling stand groups 6, 8 can also contribute to the thickness reduction during operation.

[0062] Here too, the in FIG 1 The state shown is reached in which the process step S4 shown there is carried out.

[0063] Both during the commissioning of the third rolling stand group 32 according to the example from FIG 3 as well as according to the example from FIG 4The cooling section 18 can be in operation as long as the hot strip W is being coiled by the reeling arrangement 10, i.e., as long as no hot strip W with the first or second predetermined entry thickness is being rolled by the first and second rolling stands 6, 8. Advantageously, the cooling section 18 is taken out of operation in process steps S7 or S8b, since the subsequently produced hot strip W is no longer to be coiled at a reeling temperature, but is to be rolled further in the third rolling stand 32. Conversely, it may therefore be necessary to reheat the hot strip W by means of the reheating device 38 before it enters the third rolling stand 32. This may be particularly necessary if austenitic rolling is to be carried out in the third rolling stand 32. Alternatively, it is also conceivable to roll only ferritic in the third rolling stand 32.The temperature requirement for the hot strip W upon entering the third rolling stand group 32 is then significantly lower. Therefore, the reheating device 38 does not necessarily need to be operated, or at least only with reduced heating power.

[0064] Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by the person skilled in the art without leaving the scope of protection of the invention. Reference symbol list

[0065] 2 Casting and rolling mill 4 Casting machine 6 First rolling stand group 8 Second rolling stand group 10 Reel assembly 10a, 10b Reel 12 Cutting device 14 Descaling device 16 Heating device 18 Cooling section 20 Pre-strip cutting device 22 Further pre-strip cutting device 24 Pre-strip exit device 26 Roll table 30 Finishing arrangement 32 Third rolling stand group 34 Further reel arrangement 34a, 34b Reel 36 Further cutting device 38 Reheating device 42 Final cooling section 50 Control device 60 Belt alignment device 62a, 62b, 62c Deflection roller 64 Sensor 100 procedures S1 Casting S2 Endless rolling in first rolling stand group S3 Endless rolling in second rolling stand group S4 Endless rolling in third rolling stand group S5 Presetting the first predetermined entry thickness S6a, S6b Producing hot strip S7 Cutting the hot strip S8a Piercing the hot strip in the third rolling stand group S8b Guiding the hot strip through the third rolling stand group S9 Threading and reeling the finished product S10a, S10b Achieving the target strip thickness TTransport direction SMetal strand VPre-band WWstrip Wa loop EEnd product FForce

Claims

1. Casting and rolling plant (2) for the production of ultra-thin continuous strip, comprising: - a casting machine (4) for casting (S1) a metal strand (S), - a first rolling stand group (6) for continuous rolling (S2) of the cast metal strand (S) to a roughing strip (V), - a second rolling stand group (8) for continuous rolling (S3) of the roughing strip (V) to a hot strip (W), - a coiling arrangement (10) for selectively coiling the hot strip (W), - a separating device (12) arranged upstream of the coiling arrangement (10) for separating the coiled hot strip (W) from subsequent hot strip (W), and - a third rolling stand group (32) arranged downstream of the coiling arrangement (10) for selectively continuously rolling (S4) the hot strip (W) to a finished product (E).

2. Casting and rolling plant (2) according to claim 1, wherein the third rolling stand group (32) is part of a finishing arrangement (30) which has a reheating device (38) upstream of the third rolling stand group (32) for heating the hot strip (W), a final cooling section (42) arranged downstream of the third rolling stand group (32) for cooling the end product (E) rolled in the third rolling stand group (32), a further reeling arrangement (34) arranged downstream of the final cooling section (42) for reeling the end product (E) and a further separating device (36) arranged upstream of the further reeling arrangement (34) for separating the reeled end product (E) from the subsequent end product (E).

3. Casting rolling plant (2) according to claim 2, wherein the further reel arrangement (34) is designed as a carousel winder.

4. Casting and rolling plant (2) according to one of the preceding claims, with a strip alignment device (60) arranged between the second rolling stand group (8) and the third rolling stand group (32), which is designed to regulate the strip alignment in a transverse direction.

5. Casting and rolling plant according to claim 4, wherein the strip alignment device (60) is configured to detect the relative mass flow between the second rolling stand group (8) and the third rolling stand group (32) and / or to regulate this mass flow.

6. Casting and rolling plant (2) according to one of the preceding claims, with a strip catcher for blocking the transport path to the third rolling stand group (32) when the first rolling stand group (6) and the second rolling stand group (8) are in operation, but the third rolling stand group (32) is not.

7. Casting and rolling plant (2) according to one of the preceding claims, with a mass flow control device arranged between the second rolling stand group (8) and the third rolling stand group (32), which is designed to control the mass flow in the area of ​​the third rolling stand group (32).

8. Casting and rolling plant (2) according to one of the preceding claims, wherein the third rolling stand group (32) comprises several rolling stands designed as sexto rolling stands.

9. Method (100) for producing ultrathin continuous strip in a casting machine (2) for continuous strip production, in particular according to claim 1, comprising the steps of: - casting (S1) a metal strand (S) using a casting machine (4); - continuous rolling (S2) of the cast metal strand (S) to pre-strip (V) in a first rolling stand group (6); - continuous rolling (S3) of the pre-strip (V) to hot strip (W) in a second rolling stand group (8); - continuous rolling (S4) of the hot strip (W) to a finished product (E) in a third rolling stand group (32).

10. Method (100) according to claim 9, wherein, to commence operation of the third rolling stand group (32), - rolling stands of the third rolling stand group (32) are preset such that a hot strip (W) with a first predetermined entry thickness can be rolled to an end product (E) with a first predetermined end product thickness (S5), - hot strip (W) with the first predetermined entry thickness is rolled (S6a) and - the rolled hot strip (W) is punctured in the preset rolling stands of the third rolling stand group (32) (S8a).

11. Method (100) according to claim 9, wherein, to commence operation of the third rolling stand group (32), - hot strip (W) is rolled with a second predetermined entry thickness (S6b), - the rolled hot strip (W) is guided through open rolling stands of the third rolling stand group (32) (S8b), - the rolling stands of the third rolling stand group (32) are closed and adjusted so that the hot strip (W) with the second predetermined entry thickness is rolled to a final product (E) with a target strip thickness (S10b).

12. Method (100) according to one of claims 10 or 11, wherein the roll gaps of the rolling stands of at least the third rolling stand group (32), after they have been brought into engagement with the hot strip (W) to be rolled, are reduced during operation (S10a, S10b) until the hot strip (W) is rolled to a final product (E) with a target strip thickness.

13. Method (100) according to any one of claims 9 to 12, wherein an inline roll change is carried out in a rolling stand of the third rolling stand group (32) by reducing the roll gap in at least one other rolling stand of the third rolling stand group (32) such that the thickness of the rolled end product (E) does not change when the rolling stand is opened with the roll to be replaced.

14. Method (100) according to any one of claims 9 to 13, wherein the hot strip (W) is heated in a protective gas atmosphere and / or rolled to the final product (E) in a protective gas atmosphere before entering the third rolling stand group (32).

15. Method (100) according to one of claims 9 to 14, wherein in the third rolling stand group (32) a thickness reduction of between 30% and 60%, preferably between 40% and 50%, takes place.

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