Device and method for producing hot-rolled metal strips

Abstract

Apparatus (1) and method for producing rolled metal strips, preferably hot-rolled metal strips, wherein the apparatus (1) comprises: a casting machine (10) configured to produce slabs (B) and transport them in a transport line of the casting machine (CLC); a rolling mill (50) configured to roll the slabs (B) into corresponding metal strips during transport along a transport line of the rolling mill (CLM); a combined transport and temperature influencing device (40) arranged between the casting machine (10) and the rolling mill (50) and configured to transport the slabs (B) at least along the transport line of the rolling mill (CLM), feed them to the rolling mill (50), and adjust the temperature of the slabs (B) to a rolling temperature;a surface device (20) arranged between the casting machine (10) and the combined transport and temperature influencing device (40) and configured to machine and / or treat and / or inspect at least one of the surfaces of the slabs (B); and a temperature influencing device (30) arranged between the casting machine (10) and the combined transport and temperature influencing device (40) and configured to modify the temperature of the slabs (B);

Description

Technical field

[0001] The invention relates to a device and a method for producing rolled metal strips, preferably hot-rolled metal strips. Background of the invention

[0002] In continuous casting, a continuous casting process for producing semi-finished products such as slabs made of iron and non-ferrous alloys, the metal is poured through a usually cooled mold and transported downwards, sideways, or in an arc with the solidified shell and the still-molten core. Subsequently, usually after cooling in a slab storage area, the slabs are fed into a rolling mill where they are formed into metal strips.

[0003] The technical design and requirements of casting / rolling plants differ depending on whether they are designed to produce so-called "thin slabs" in a thickness range of approximately 40 to 110 mm, "medium slabs" in a thickness range of approximately 110 to 200 mm, or "thick slabs" with greater thicknesses. A plant for the continuous casting and further processing of thin slabs is described, for example, in EP 0 808 672 A1.

[0004] The plants are typically designed for a single production focus and therefore have little or no flexibility for alternative products. For example, the casting thickness, i.e., the alloy-specific production of a thin or medium slab, is linked to an alloy-specific casting speed, although not all alloys are suitable for thin slab production. The target thickness and process control vary depending on the product's intended use. For example, temperature control before the start of the rolling process, between different rolling processes, and after finish rolling are key process steps for adjusting material properties. In coupled casting / rolling processes, the available modules determine the possible process steps.

[0005] To increase the product range in conventional hot strip mills, it is known to not form the rolled stock from the casting heat, but to cool it completely or partially in a slab storage area. This creates a technological separation between the casting and further processing, especially the rolling of the slabs. However, this results in mechanical, energy, and logistical disadvantages. Description of the invention

[0006] An object of the invention is to provide an improved device and an improved method for producing rolled metal strips, preferably hot-rolled metal strips, in particular to increase the processable product range without technological separation between casting and rolling.

[0007] This object is achieved by a device having the features of claim 1 and a method having the features of the subordinate method claim. Advantageous further developments follow from the subclaims, the following description of the invention, and the description of preferred embodiments.

[0008] The apparatus according to the invention is used for the production of rolled, in particular hot-rolled, metal strips. Products made of a metal, in particular a metal alloy, preferably steel, are cast and processed. The apparatus is preferably designed for the production and further processing of medium slabs with a thickness in the range of 90 to 250 mm, preferably 110 to 200 mm.

[0009] The device comprises a casting machine configured to produce slabs and transport them along a transport line of the casting machine. The casting machine is preferably implemented as a vertical bending system, also referred to as a "bend caster." However, it can also be implemented in other ways, as long as it provides a cast strand that can subsequently be cut into slabs and further processed.

[0010] The device further comprises a rolling mill which is configured to form the slabs into corresponding metal strips by rolling them during transport along a transport line of the rolling mill. The two transport lines – the transport line of the casting machine and the transport line of the rolling mill – can coincide or differ, in which case, on the way from the casting machine to the rolling mill, corresponding transverse transports of the slabs must be carried out. The rolling mill typically comprises one or more rolling stands, preferably each in a four-high design with two work rolls and two backup rolls, and can be operated reversibly or in tandem. The rolling mill can comprise a roughing mill and / or finishing mill or be designed as such. The rolling mill is particularly preferably a hot rolling mill in which the forming of the slabs takes place at least partially from the casting heat, i.e.In this case, the slabs are not completely cooled after casting on their way to the rolling mill. The device further comprises a combined transport and

[0011] A temperature control device (herein abbreviated as "KTT") is located between the casting machine and the rolling mill and is designed to transport the slabs to or along the rolling mill's transport line, feed them to the rolling mill, and adjust the temperature of the slabs to a (suitable) rolling temperature. The KTT primarily serves to logistically feed the slabs to the rolling mill at the required temperature, which generally depends on process parameters such as the alloy. The term "temperature" in this context includes not only absolute temperatures, such as the surface and core temperature, but also temperature distribution(s).

[0012] It should be noted that terms describing spatial relationships, such as "between," "vertical," "horizontal," "above," "below," "upstream," "downstream," "in front of," "behind," etc., are clearly defined by the design and intended use of the device, as well as the transport direction of the cast strand or slabs. If the KTT, as defined above, is located between the casting machine and the rolling mill, this contains, for example, the information that a slab produced by the casting machine is transported through the KTT and then through the rolling mill for forming into the desired metal strip.

[0013] The device further comprises a surface device arranged between the casting machine and the KTT and configured to machine and / or treat and / or inspect at least one of the surfaces of the slabs. Thus, the surface device can comprise a material-removing surface treatment, which is used, for example, to manufacture products with special surface requirements. Such special requirements for product surfaces are placed, for example, on use as automotive outer skins, electrical steel strip, or for optical applications. Alternatively or additionally, the surface device can be configured to correct any surface defects resulting from the casting process, so that they are removed before further process steps such as rolling take place. This means that in this case, it is a surface treatment that goes beyond mere scale removal.Alternatively or additionally, the surface device may comprise an inspection device configured to detect surface properties of the slabs by contact or contactless means.

[0014] The device further comprises a temperature control device, which is arranged between the casting machine and the cathodic quenching and tempering machine and is designed to modify the temperature of the slabs. This temperature control device is used particularly in the production of crack-sensitive products, such as micro-alloyed steels. If such alloys were introduced into the cathodic quenching and tempering machine immediately after the casting process, this could lead to undesirable precipitation of microalloys in the layers near the edge, which could lead to cracking or other quality defects in subsequent steps.

[0015] Slabs do not have to pass through every station mentioned between the caster and the KTT. Rather, the stations can be integrated into or removed from the manufacturing process depending on the product or application. Slabs can pass through either the surface treatment unit or the temperature control unit, or neither. In this case, the two stations do not have to be arranged one after the other in the same line; they can be installed in parallel, with a corresponding route decision being made for the slabs, or they can be retractable into the line as needed. Alternatively, a parallel or inline arrangement can be provided, depending on requirements.

[0016] The device described above for producing metal strips, particularly hot-rolled metal strips, is highly flexible in terms of product range and simultaneously requires minimal energy consumption. The device thus eliminates conventional limitations of the product range without interrupting the manufacturing process. The device is capable of fully processing micro-alloyed steels, as well as very soft material grades or material grades intended for special surface qualities, without any technological restrictions. Depending on the plant layout, very compact arrangements and / or production modes can be realized.

[0017] The temperature control device preferably comprises a combined heating and cooling device with a heating device and a cooling device, so that the slabs can be selectively heated or cooled by the temperature control device. The heating device preferably comprises one or more inductive heating devices. The cooling device can be designed for rapid cooling of the slabs by applying a coolant, preferably cooling water. The heating device and cooling device can be installed in series or in parallel, preferably forming a common assembly.A temperature control system constructed in this way enables the surface temperature of the slabs to be treated to be quickly adjusted within a desired temperature range or removed from an adverse temperature range in a compact and flexible manner, without the need for intermediate storage and complete cooling in a slab storage facility. The core heat can be at least partially retained and used later for rolling.

[0018] Preferably, the surface device is configured to process at least one surface of the slab(s) by grinding and / or milling and / or flame-cutting. Surface processing is performed on at least one surface of the slab to be processed, preferably involving processing both the top and bottom sides of the slab as well as the longitudinal edges. The material removal per surface is, for example, in the range of 0 to 10 mm, preferably in the range of 1 to 3 mm. Surface processing preferably takes place at a slab surface temperature of more than 600°C, particularly preferably more than 900°C.

[0019] The KTT can be present in a variety of possible configurations. It preferably comprises: one or more roller tables; and / or one or more thermal insulation devices; and / or one or more inductive heating elements; and / or one or more furnaces; and / or one or more slab discharge devices for discharging slabs from the transport line of the casting machine and / or the transport line of the rolling mill; and / or one or more slab feed devices for feeding slabs into the transport line of the casting machine and / or the transport line of the rolling mill.

[0020] The design of the KTT is preferably variable with regard to the type of temperature control and logistics. In a simple variant, the KTT comprises a roller hearth furnace, which provides both temperature compensation and transports the slab. In an alternative variant, the KTT comprises a roller table as a transport element, preferably with a thermal insulation device, in combination with at least one, preferably several inductive heating elements. Alternatively or additionally, the KTT can have several walking beam furnaces arranged one behind the other, thereby achieving a very compact design. Furthermore, the KTT can function as an interface between the technologically separate casting machine and rolling mill. For this purpose, technical means (roller tables, slab ferries, walking beams, etc.) can be installed to transfer the slabs from the casting machine's transport line to the rolling mill's transport line.This flexible arrangement also makes it possible to feed slabs from other sources into the corresponding transport line or to remove them from the transport line.

[0021] According to one embodiment, the transport line of the casting machine and the transport line of the rolling mill are identical.

[0022] According to an alternative embodiment, the transport line of the casting machine and the transport line of the rolling mill differ, whereby they preferably run parallel, whereby the plant can be realized in a particularly compact manner.

[0023] In both cases, the surface device, temperature influencing device and at least parts, up to the entire KTT, can be positioned one after the other in one and the same transport line.

[0024] Preferably, multiple routes are provided which implement different process lines for the slabs, at least in sections. The surface device can be arranged in a first route and the temperature control device in a second route and configured such that the slabs pass through either the surface device or the temperature control device, but not both. A third route can also be provided which acts as a bypass, in that the slabs bypass, i.e., skip, both the surface device and the temperature control device and can be introduced into the combined transport and temperature control device immediately after casting.The route decision can be made on a batch-by-batch, product-by-product or slab-by-slab basis, depending on process parameters such as the alloy or temperature of the slabs or depending on quality requirements resulting, for example, from the intended application of the rolled products.

[0025] Preferably, the rolling mill is a hot rolling mill, which is designed to at least partially form the slabs using the casting heat of the casting machine. In this case, the device as a whole is designed so that the slabs do not cool completely after casting on their way to the rolling mill. In particular, the slabs are not removed to a slab storage area. The slab is largely "in motion" throughout. The production process is determined by the production cycles of the casting machine.

[0026] In this case, the device can be implemented in a particularly compact and energy-efficient manner without compromising flexibility. For this reason, the control device described below is preferably configured to feed the slabs cast by the casting machine to the rolling mill without intermediate storage in a slab storage area. "Intermediate storage in a slab storage area" is understood here to mean any interruption in the process control of the slab(s) that leads to a substantially complete cooling of the slab(s), including the slab core, before rolling. Temperature reductions during the process control, such as during thermomechanical rolling, are not considered intermediate storage.

[0027] Preferably, the device comprises a control device which is configured to control the process control of the slabs as a function of measured and / or calculated process parameters, preferably comprising the alloy and / or temperature of the cast slabs.

[0028] The control device is connected via signal technology to the components of the device to be controlled and / or read, thus in particular to the casting machine, the surface device, the temperature control device, the KTT, and the rolling mill. Communication between the control device and the system components to be controlled and / or read can be wired or wireless, digital or analog. The control device can receive and / or transmit signals (control signals, data, etc.) accordingly, whereby both one-way and bidirectional signal transmission falls under the term "communication" in this context. The control device does not necessarily have to be implemented by a central computing device or electronic control system; decentralized and / or multi-level systems, control networks, cloud systems, and the like are also included.The control system can also be an integral part of a higher-level system control system or communicate with such a system.

[0029] The control device preferably comprises one or more process models or at least an interface to one or more process models. For example, the control device can communicate with a process model of the casting machine and a process model of the rolling mill. The control device is preferably configured to map the process control and the process parameters from the casting machine to the rolling mill. Relevant data, such as the slab temperature or final rolling temperature, are communicated from the process model of the casting machine and the process model of the rolling mill to the control device. In this way, data can be obtained that determines the production steps and influences the corresponding station settings.

[0030] Preferably, the control device is configured to heat or cool slabs (particularly of a crack-sensitive alloy) by means of the temperature control device such that the slab surface temperature before entering the combined transport and temperature control device lies outside a critical temperature range, defined by a lower threshold of preferably 600°C and an upper threshold of preferably 850°C. In such a case, the temperature control device selectively heats or cools the slab passing through it, ensuring that the slab surface temperature lies outside the critical temperature range. This preferably occurs as a function of a measured or otherwise determined slab surface temperature upstream of the temperature control device.If the control device, possibly in conjunction with a corresponding temperature sensor or calculation model, determines that the slab surface temperature at the inlet of the temperature control device is above the upper threshold or below the lower threshold, no temperature control by the temperature control device is necessary. If the slab surface temperature is within the critical temperature window, the slab is either heated or cooled by the temperature control device, depending on the direction in which the slab can be moved out of the temperature window. If both directions are possible, heating of the slab by the temperature control device is preferred.

[0031] The above-mentioned object is further achieved by a method for producing rolled metal strips, preferably hot-rolled metal strips, wherein the method is carried out using a device according to one of the embodiments set out above. The method comprises: casting a slab by means of the casting machine; transferring the slab to the KTT; hot rolling the slab in the rolling mill into a metal strip, wherein the slab does not cool completely after casting on its way to the rolling mill, and preferably the slab temperature in its core does not fall below 600°C.

[0032] The technical effects, advantages and embodiments described with regard to the device apply analogously to the method.

[0033] According to one embodiment, following step a), the slab is transported directly into the combined transport and temperature influencing device depending on one or more process parameters, or the temperature is influenced by the temperature influencing device and / or at least one surface of the slab is processed and / or treated and / or inspected by the surface device.

[0034] 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 set forth above, provided the features do not contradict each other. The following description of preferred embodiments is made with reference to the accompanying drawings. Short description of the characters

[0035] Preferred further embodiments of the invention are explained in more detail by the following description of the figures. In the figures: Figure 1 shows a schematic representation of an apparatus for producing metal strips, in particular hot-rolled metal strips; Figure 2 shows a schematic representation of a casting machine; Figure 3 shows a schematic representation of an apparatus for producing hot-rolled metal strips according to a further exemplary embodiment; Figures 4a to 4e show schematic representations of a combined transport and temperature-influencing device according to different exemplary embodiments; Figure 5 shows a schematic representation of the configurations, communication, and functioning of the control device 100 according to an exemplary embodiment. Detailed description of preferred embodiments

[0036] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements are provided with identical reference numerals in the figures, and a repeated description of these elements is partially omitted to avoid redundancy.

[0037] The Figure 1 shows schematically the basic structure of a device 1 for producing metal strips, in particular hot-rolled metal strips.

[0038] The device 1 comprises a casting machine 10, which is preferably implemented as a vertical bending system, also referred to as a "bow caster." However, the casting machine 10 can also be implemented in other ways, as long as it provides a cast strand that can subsequently be cut into slabs and further processed. Furthermore, multiple casting machines 10 can be provided for the parallel casting of multiple strands, or the casting machine 10 can be configured to cast multiple parallel strands.

[0039] The Figure 2shows a schematic of an exemplary casting machine 10. The liquid metal to be cast is fed to a mold 11 of the casting machine 10, for example from a pouring ladle. The mold 11 brings the molten metal into the desired slab shape, while the slab gradually solidifies from the outside inwards due to the cooled mold walls. The mold 11 is preferably a mold made of copper plates (or plates of a copper alloy, which may be coated), in the case of medium slabs with plane-parallel plates on the wide sides and narrow sides, which are adapted for a comparatively high casting thickness of, for example, 140 mm or more. If the casting thickness or the casting radius so require, the copper plates can have a funnel-shaped contour and / or be curved in a transport direction corresponding to the casting radius of a strand guide 12.

[0040] The not yet fully solidified cast strand S exits downward from the mold 11, is then initially guided downward in the transport direction along the strand guide 12, and is then deflected horizontally in a bending area while gradually cooling. It should be noted that the transport direction in the casting machine 10 generally does not denote a constant directional vector, but can depend on the strand or slab position along the device 100. After being deflected horizontally, the cast strand S is conveyed along a transport line of the casting machine CLC.

[0041] The strand guide 12 comprises rollers 13 that transport the cast strand S and can be adjusted for thickness reduction according to LCR ("Liquid Core Reduction") or DSR ("Dynamic Soft Reduction") such that the transport gap in which the cast strand is transported along the transport direction gradually narrows. The strand guide 12 can be constructed in a segmented manner, for example, by two or more similarly curved segments that form a bending area of ​​the strand guide 12. During transport, the cast strand S is actively or passively cooled as part of a secondary cooling process, for example by spraying water, whereby it gradually solidifies from the outside inward.

[0042] A shaping of the cast strand S caused by the casting machine 10, in particular strand guide 12, is referred to as "primary shaping"; in contrast to "forming", which refers to shaping by a forming unit such as a rolling mill.

[0043] Adjacent to the bending area of ​​the casting machine 10 is a straightening area in which the cast strand S is brought into a horizontal alignment. Here, too, rollers 13 are provided for guiding and transporting the cast strand S. One or more of the rollers 13 are drive rollers and drive the cast strand S in the transport direction; other rollers 13 serve to guide and align the cast strand S. In this respect, the rollers 13 form means for driving and bending the cast strand S. Further devices can be arranged downstream of the casting machine.

[0044] The device 1 further comprises a cutting device 14, which is arranged in the transport line CLC behind the straightening area of ​​the casting machine 10. The cutting device 14 serves to cut or divide the cast strand S into slabs B. The cut is made along the slab thickness. The "slab thickness" refers to the dimension of the slab B that is perpendicular to the longitudinal extent and perpendicular to the width (in the Figure 2perpendicular to the plane of the paper) of the slab B. In this case, the cutting device 14 is set up to cut the cast strand S during conveyance, i.e. during the movement of the cast strand S along the transport line CLC. Preferably, the cutting device 14 is a shear, in particular a pendulum shear. In this case, the shear is set up such that the transport movement of the cast strand S is tracked during the cutting process and one or more cutting blades cut the strand in a movement vertical to the cast strand S. In contrast to a flame cutter, a shear has the advantage that the cutting time is less than 5 minutes, preferably less than one minute, and no deburring of the slab head / foot is required.

[0045] The slabs B to be cast are preferably medium slabs, i.e., slabs B with a thickness in the range of approximately 90 to 250 mm, preferably 110 to 200 mm. The casting speed is preferably in the range of 0.5 to 7 m / min, particularly preferably in the range of 1 to 4.8 m / min.

[0046] Upstream or downstream of the separating device 14, a decoupler 15 can be provided, for example in the form of a cold strand rocker, which is designed to be able to decouple the cast strand S from the process line when required, for example when starting up the plant.

[0047] The device 1 may have one or more descaling devices 16, which are arranged in front of and / or behind the separating device 14, depending on the configuration.

[0048] One or more heating devices 17, preferably inductive, with gas burners, or electrically operated, can be installed at different positions in the process line. They can perform the function of the heating device 31 individually or in combination. Preferably, one or more heating devices 17 are located substantially directly upstream of the separating device 14 or the decoupler 15, if present, and / or downstream of the separating device 14. Heating devices 17 of this type can, on the one hand, contribute to shortening the cooling section, and, on the other hand, they simplify slab logistics.

[0049] In close proximity, downstream of the casting machine 10, an inspection system 18 for checking the slab quality, for example the surfaces of the slabs B, can also be installed.

[0050] Coming back to the Figure 1The device 1 further comprises a rolling mill 50, which is preferably a hot rolling mill. The rolling mill 50 has one or more rolling stands, preferably each in a four-high design with two work rolls forming the roll gap and two backup rolls, and can be operated in reversing mode or in tandem. The rolling mill 50 can be designed as a roughing mill and / or a finishing mill. The transport path of the slabs B through the rolling mill 50 takes place along a transport line CLM, which can coincide with the transport line of the casting machine CLC (see. Figures 3, 4a, 4b, 4c ) or may differ from it (cf. Figures 4d and 4e ).

[0051] In terms of process technology, between the casting machine 10 and the rolling mill 50 there is a combination of assemblies, comprising according to the embodiment of the Figure 1a surface device 20, a temperature control device 30, and a combined transport and temperature control device 40 (also abbreviated herein as "KTT"). The nature and spatial arrangement of the assemblies can vary, as shown in the following exemplary embodiments. The combination of the assemblies 20, 30, 40 is selected such that the device 1 enables the processing of various products, in particular both surface-sensitive products and temperature-sensitive products, along individual process steps, wherein the products are fed to the rolling process directly after the casting process, i.e., in particular, without intermediate storage of the products in a slab storage facility.

[0052] In addition to the surface device 20, the temperature control device 30, and the KTT 40, further assemblies can be arranged between the casting machine 10 and the rolling mill 50, for example, additional separating devices, emergency roller tables, additional heating / cooling elements, thermal insulation hoods, general transport roller tables, and the like. Such assemblies / devices are preferably arranged between the casting machine 10 and the KTT 40.

[0053] In the embodiment of the Figure 1 the surface device 20 and the temperature influencing device 30 are arranged in parallel and thus form alternative routes for the slabs B. Furthermore, a third route is provided which functions as a bypass in that the slabs B bypass both the surface device 20 and the temperature influencing device 30, ie skip them, and can be introduced into the KTT 40 immediately after casting.

[0054] The Figure 3shows an alternative embodiment in which the surface device 20, the temperature influencing device 30, and the KTT 40 are arranged in one and the same transport line. Furthermore, an additional heating device 60, preferably in the form of an inductive heating element, is provided, for example, immediately after the outlet of the casting machine 10. This provides an additional flexibility advantage for temperature control, especially for slowly cast slabs B. Furthermore, the above-mentioned separating device 14 can be installed as an assembly of the casting machine 10 or separately in the process line. A further separating device 70 can be installed for emergencies / accidents in order to further divide and discharge a cast strand S emerging from the casting machine.

[0055] A control device 100 is provided which is in communication with the various assemblies 10, 20, 30, 40, 50, actuators, sensors and the like and is configured to control the process control depending on process parameters, for example the alloy and the temperature of the cast product.

[0056] A method for producing hot-rolled metal strip directly after the casting process, i.e., without intermediate storage of the slabs B in a slab storage facility, can comprise the following steps: a) Producing a slab B with a specified alloy and dimensions using the casting machine 10; b) Transferring the slab B to the KTT 40; c) Hot rolling the slab B into a strip in the rolling mill 50. The forming in the rolling mill 50 takes place at least partially from the casting heat, i.e., the slab B does not cool completely after casting on its way to the rolling mill 50. The above formulation "directly after the casting process" thus means that there is no logistical transfer of the slab B to a slab storage facility, and the slab temperature in its core preferably does not fall below 600°C. The slab is largely "in motion" throughout. The production sequence is determined by the production cycles of the casting machine.

[0057] Between steps a) and b), further processing steps can be initiated in accordance with a signal from the control device 100. In other words, following the casting process, a route decision can be made to transport the slab(s) B through the surface device 20, the temperature influencing device 30, or bypassing both, directly into the KTT 40. The route decision can be made manually or automatically, for product batches or individually for each slab, for example, depending on at least one measured or calculated process parameter. In the exemplary embodiment of the Figure 1 the route decision implies at least partially different transport routes, while in the case of Figure 3the route decision relates solely to the selective processing of slabs B or not by the corresponding assemblies 20, 30, 40, etc. Alternatively or additionally, one or more of the assemblies 20, 30, 40 can be moved into or out of the process line as required.

[0058] The surface device 20 is a device for machining and / or treating and / or inspecting one or more surfaces of the slabs B.

[0059] Thus, the surface device 20 can comprise a material-removing surface treatment, which is used, for example, to process products with special surface requirements. Such special requirements for the product surfaces are placed, for example, on use as automotive outer skins, electrical steel strip, or for optical applications. Alternatively or additionally, the surface device 20 can be configured to correct any surface defects resulting from the casting process, so that they are removed before further process steps such as rolling take place. This means that in this case, it is a surface treatment that goes beyond mere scale removal.

[0060] The surface treatment is carried out on at least one surface of the slab B to be treated, with both the top and bottom sides of the slab B and also the longitudinal edges preferably being treated. The material removal per surface is preferably in the range of 0 to 10 mm, particularly preferably 1 to 3 mm. The feed rate of the slab B can be in the range of 5 to 50 m / min. The surface treatment preferably takes place at a slab surface temperature of more than 600°C, particularly preferably more than 900°C, so that no storage and cooling of the slabs B in a slab storage facility is required for the surface treatment.

[0061] The surface device 20 is preferably a scarfing device configured to process the relevant surfaces of the slabs B by removing material. According to an alternative embodiment, the surface device 20 may comprise a grinding device or milling device for machining one or more slab surfaces. Alternatively or additionally, the surface device 20 may comprise an inspection device configured to detect surface properties of the slabs B by contact or contactless means. The surface information thus determined can be used by the control device 100 for further process control.

[0062] The surface device 20 is implemented in a process-technical manner without intermediate storage. With regard to the layout of the device 1, this may mean that the surface device 20 is arranged in the transport line of the casting machine CLC. If necessary, the surface device 20 can be configured to be removable from the process line when not in use. Alternatively, the surface device 20 can be arranged outside, but close to, the process line, so that the slab B is removed from the process line for processing and then returned. In this case, the slabs B are preferably returned at a slab surface temperature of more than 600°C.

[0063] The temperature influencing device 30 preferably comprises a combined heating and cooling device with a heating device 31 and a cooling device 32.

[0064] The temperature control device 30 is used in particular in the manufacture of crack-sensitive products, for example micro-alloyed steels. If such alloys are fed into the KTT 40 immediately after the casting process, i.e., within a specific temperature range, this can lead to undesirable precipitation of micro-alloys in the layers close to the edge, which can lead to crack formation or other quality defects in subsequent steps. This critical temperature range refers to the surface temperature of the slab B and is designated T critical with a lower threshold value T u and an upper threshold value T o . For the majority of crack-sensitive alloys, T u is approximately 600°C and T o is approximately 850°C.

[0065] In such a case of crack-sensitive products, the temperature influencing device 30 selectively heats or cools the slabs B passing through it, thus ensuring that the slab surface temperature lies outside the critical temperature range T critical . For this purpose, the control device 100 controls either the heating device 31 or the cooling device 32 accordingly so that the surface temperature of the slab B does not fall within the aforementioned temperature window. This is preferably done as a function of a measured or otherwise determined slab surface temperature. If the control device 100 determines, optionally in conjunction with a corresponding sensor, that the slab surface temperature at the inlet of the temperature influencing device 30 is above T o or below T u , no temperature influence by the temperature influencing device 30 is necessary.If the slab surface temperature is within T critical , the slab B is either heated or cooled by the temperature control device 30, depending on the direction in which the slab B can be expediently moved out of the temperature window T critical . If both directions are possible, heating of the slab B by the temperature control device 30 is preferred.

[0066] The heating device 31 is preferably an inductive heating device, which allows for quick and individual adjustment of the heating power with a compact design. Alternatively or additionally, a gas- or electric-powered continuous furnace can also be used.

[0067] The cooling device 32 is preferably configured to realize rapid cooling of the slabs B by applying a coolant, preferably cooling water. The applied cooling water quantity is preferably more than 500 m 3 / h / m 2 , particularly preferably more than 650 m 3 / h / m 2 , applied over a cooling section length of preferably 3 to 10 m, particularly preferably 4 to 6 m, so that at different slab speeds, a near-surface temperature reduction to a temperature below T u occurs. "Near-surface" in this context means a penetration depth of up to 15 mm from the slab surface. The exposure time of the cooling water is preferably less than 3 minutes. Alternatively or in addition to rapid cooling, laminar cooling or other cooling equipment can be installed.

[0068] One advantage of near-surface cooling is that the core temperature of slab B is not affected or only slightly affected, while the surface temperature drops to a temperature where cracking due to microprecipitations is avoided. The constant or only slightly reduced core temperature facilitates the subsequent reheating of slab B to the desired hot rolling temperature, whereby the required heating power and heating time can be minimized compared to heating a completely cooled slab B from a slab storage facility. This leads to significant energy savings.

[0069] The heating device 31 of the temperature control device 30 is also advantageous for the production of Si steel, as the overall temperature can be maintained at a desired level and the temperature setting before hot rolling, which must be adjusted to ensure a final rolling temperature, is subject to fewer fluctuations. The aluminum nitrides precipitated on the surface during solidification of the slab B are redissolved and held there in order to be selectively precipitated again during hot rolling. The time required to dissolve the aluminum nitrides can thus be distributed among various units, namely the temperature control device 30 and the KTT 40 described below, allowing for more flexible process control, a shorter plant layout, and shorter residence times in the KTT 40.

[0070] The combined transport and temperature control system 40 serves for the logistical supply of slabs B to the rolling mill 50 with the alloy-dependent, process-related, or desired temperature and temperature distribution. The temperature control of slabs B and the logistical transport take place simultaneously.

[0071] Depending on whether the slab B is conveyed directly from the casting machine 10 into the KTT 40 or whether intermediate process steps such as surface treatment and / or temperature control have taken place, an individual inlet temperature into the KTT 40 results. Thus, the heating power and / or residence time of the slab B in the KTT 40 can preferably be adjusted in order to maintain a temperature at the outlet of the KTT 40 which ensures the suitable rolling temperature at the inlet of the rolling mill 50.

[0072] The KTT 40 is controlled by the control device 100, which takes into account any process steps that may have been carried out beforehand.

[0073] The design of the KTT 40 is preferably variable with regard to the type of temperature control and logistics. This is demonstrated below using exemplary embodiments.

[0074] In a first, simple variant, the KTT 40 comprises a roller-hearth furnace, which provides both temperature equalization and transport of the slab B. The use of a roller-hearth furnace can cause surface defects and / or track marks in the product due to accumulated scale on the furnace rollers. Therefore, it may be advisable to consider alternative designs for the KTT 40, particularly with regard to crack-sensitive and / or surface-sensitive products.

[0075] The Figure 4ashows such an alternative variant, in which the KTT 40 comprises a roller conveyor 41 as a transport element, preferably with a thermal insulation device, in combination with at least one, preferably several, inductive heating elements 45. The heating elements 45 can be integrated into the entire roller conveyor section. By arranging a plurality of inductive heating elements 45, individual temperature adjustment can be carried out particularly easily.

[0076] The mechanically simple variant according to Figure 4a enables a compact design, which is particularly suitable for a plant configuration in which the transport line of the casting machine CLC and the transport line of the rolling mill CLM are identical. If the transport lines CLC and CLM of the casting machine 10 and the rolling mill 50 are identical, individual slabs B or a continuous rolled product can be conveyed into the rolling mill 50.

[0077] The Figure 4bshows a further variant in which the KTT 40 comprises one or more walking beam furnaces 42 arranged one behind the other. Such a sequence of walking beam furnaces 42 enables a very compact design, preferably for plant configurations in which the transport lines CLC, CLM of the casting machine 10 and the rolling mill 50 are identical. If the transport lines CLC, CLM are identical, individual slabs B or a continuous rolled product can be conveyed into the rolling mill 50.

[0078] The Figure 4c shows another variant, in which, based on the design of the Figure 4aone or more slab discharge device(s) and / or slab insertion device(s) are installed transversely to the transport line CLC, CLM. This increases the plant flexibility in that not only slabs B can be fed to the rolling mill 50 directly after the casting process, but also slabs B can be discharged to another station, for example, the slab storage area, or inserted from another station, for example, the slab storage area, into the transport line CLC, CLM. Furthermore, an emergency discharge can be carried out in this way, for example in the event of a breakdown of the casting machine 10 or the rolling mill 50. The slab transport transversely to the conveying direction can be carried out, for example, via a slab ferry 43 and / or a corresponding roller table element 44. Such a possibility of inserting and / or removing slabs B transversely to the transport line CLC, CLM is not only based on the basic structure of the Figure 4apossible, but can generally be implemented for any design of the KTT 40, for example starting from the design of the Figure 4b .

[0079] According to a further variant of the KTT 40, the transport lines CLC, CLM of the casting machine 10 and the rolling mill 50 are not identical, but are arranged at a distance and in parallel, as in the embodiments of the Figures 4d and 4e This allows for a particularly compact design.

[0080] According to the embodiment of the Figure 4dThe slabs B are transported in the respective transport lines CLC and CLM via several roller tables 41, if necessary with thermal insulation equipment. Transport transverse to the transport lines CLC and CLM can be carried out via one or more walking beam furnaces 46. The walking beam furnaces 46 can be electrically and / or gas-fired. A walking beam furnace 46 can transport and influence the temperature simultaneously. When several walking beam furnaces 46 are used, the furnaces can vary in the working ranges of their temperature levels and / or cycle times. This allows the residence time of the slabs B in the walking beam furnaces 46 to be individually controlled.

[0081] According to the variant of the Figure 4eThe transport and heating of the slabs B in the CLC and / or CLM transport lines takes place via roller conveyors 41 with integrated heating elements 45, which are preferably inductive heating elements. The transport of the slabs B transversely to the CLC and CLM transport lines takes place using one or more slab ferries 43.

[0082] The combination options of transport elements and heating elements in the KTT can be further combined as desired.

[0083] Based on the designs of the Figures 4d and 4eIt is possible to install one or more slab discharge device(s) and / or slab insertion device(s) along the transport lines CLC, CLM. This increases the plant flexibility in that not only can slabs B be fed to the hot rolling mill 50 directly after the casting process, but slabs B can also be discharged to another station, for example, the slab storage area, or inserted from another station, for example, the slab storage area, into the corresponding transport line CLC, CLM. Furthermore, an emergency discharge can be carried out in this way, for example in the event of a breakdown of the casting machine 10 or the rolling mill 50. The slab transport transversely to the conveying direction can be carried out, for example, via a slab ferry 43 and / or a corresponding roller table element 44.

[0084] In the following, an exemplary configuration of the control device 100 is described with reference to the Figure 5 described.

[0085] The control device 100 is signal-connected to the components of the device 1 to be controlled and / or read, thus in particular to the casting machine 10, the surface device 20, the temperature control device 30, the KTT 40, and the rolling mill 50. Communication between the control device 100 and the system components to be controlled and / or read can be wired or wireless, digital or analog. The control device 100 can receive and / or transmit signals (control signals, data, etc.) accordingly, whereby both signal transport in one direction and in both directions falls under the term "communication" in this context. The control device 100 does not necessarily have to be implemented by a central computing device or electronic control system; rather, decentralized and / or multi-level systems, control networks, cloud systems, and the like are included.The control system can also be an integral part of a higher-level system control system or communicate with such a system.

[0086] The control device 100 preferably comprises one or more process models or at least an interface to one or more process models. For communication with the devices to be controlled or read, it is irrelevant whether the required calculations are performed in a process model connected to the control device 100 and the calculations are communicated to the control device 100, or whether the control device 100 comprises the process model itself.

[0087] In the embodiment of the Figure 5The control device 100 communicates with a process model of the casting machine PMC and a process model of the rolling mill PMM. The process models PMC and PMM can comprise overlapping submodels that preferably cover the area between the casting machine 10 and the rolling mill 50 that is relevant for the control device 100. Alternatively, only one of the mentioned areas can cover the relevant area, or a separate submodel can be implemented.

[0088] The control device 100 can communicate with lower-level system controls, ie controls assigned to the corresponding devices.

[0089] The control device 100 is configured to map the process control and the process parameters from the casting machine 10 to the rolling mill 50. Relevant data, such as the slab temperature or final rolling temperature, are communicated from the process model of the casting machine PMC and the process model of the rolling mill PMM to the control device 100.

[0090] Data exchange with a production planning system or a process control planning system can facilitate the work of the control device 100 and automate the process control, the necessary calculations and the transmission of the control signals.

[0091] In the embodiment of the Figure 5The control device 100 obtains a data set of a product to be manufactured from a process control plan, for example, a so-called "Level 3 system," and thus receives information about the planned production steps and the final specifications of the finished product. Data is now available in the control device 100 that defines the manufacturing steps and influences the corresponding settings of the devices 10, 20, 30, 40, and 50.

[0092] The settings of the casting machine 10 and the rolling mill 50 can be based on extensive technological-physical model calculations, so that information about, for example, the slab alloy, slab geometry, slab temperature, slab speed, and / or slab surface is available at the output of the casting machine 10. The information can be determined by calculation and / or measurement (e.g., temperature measurement, surface inspection, etc.). The corresponding values / information are provided in the control device 100.

[0093] The control device 100 now determines the parameters necessary for further process control, in particular the slab speed after the casting machine 10, taking into account the information provided by the casting machine 10, and adjusts these parameters on the relevant components.

[0094] The control device 100 determines whether the slab B is to be subjected to processing and / or inspection in the surface device 20 and initiates this process if necessary.

[0095] The control device 100 calculates from the transmitted slab temperature whether temperature control in the temperature control device 30 is necessary for the alloy in question. If such temperature control is necessary, the control device 100 calculates the setting of a corresponding cooling or heating power of the temperature control device 30 from the required heat flow.

[0096] The control device 100 calculates the slab temperature to be maintained at the end of the KTT 40 and related parameters such as slab speed, minimum residence time in the KTT 40, if applicable the heating power to be set based on the geometric dimensions, in particular thickness and length of the slab B, and the like.

[0097] If required, it may be necessary to feed further data from intermediate steps into the control device 100 as a basis for calculation, as indicated by arrows in the Figure 5 is illustrated.

[0098] The apparatus 1 presented herein for producing metal strips, in particular hot-rolled metal strips, is highly flexible in terms of product range and simultaneously requires minimal energy consumption. Depending on the plant layout, very compact arrangements and / or production modes can be realized.

[0099] Where applicable, all individual features shown in the embodiments may be combined and / or exchanged with one another without departing from the scope of the invention. List of reference symbols

[0100] 1Device for producing metal strips 10Casting machine 11Mold 12Strand guide 13Roller 14Cutting device 16Descaling device 17Heating device 18Inspection system 20Surface device 30Temperature control device 31Heating device 32Cooling device 40Combined transport and temperature control device 41Roller table 42Walking beam furnace 43Slab ferry 44Roller table segment 45Heating element 46Walking beam furnace 50Rolling mill 60Additional heating device 70Additional cutting device 100Control device SCasting strand BSlab PMCProcess model of the casting machine PMMProcess model of the rolling mill CLCTransport line of the casting machine CLMTransport line of the rolling mill

Claims

1. Apparatus (1) for producing rolled metal strips, preferably hot-rolled metal strips, the apparatus (1) comprising: a casting machine (10) configured to produce slabs (B) and transport them in a transport line of the casting machine (CLC); a rolling mill (50) configured to roll the slabs (B) into corresponding metal strips during transport along a transport line of the rolling mill (CLM); a combined transport and temperature control device (40) arranged between the casting machine (10) and the rolling mill (50) and configured to transport the slabs (B) to or along the transport line of the rolling mill (CLM), feed them to the rolling mill (50), and adjust the temperature of the slabs (B) to a rolling temperature;a surface device (20) arranged between the casting machine (10) and the combined transport and temperature influencing device (40) and configured to machine and / or treat and / or inspect at least one of the surfaces of the slabs (B); and a temperature influencing device (30) arranged between the casting machine (10) and the combined transport and temperature influencing device (40) and configured to modify the temperature of the slabs (B); characterized in that a plurality of routes are provided which implement at least sectionally different process lines for the slabs (B), wherein the surface device (20) is arranged in a first route and the temperature influencing device (30) is arranged in a second route and are arranged such that the slabs (B) pass through either the surface device (20) or the temperature influencing device (30).

2. Device (1) according to claim 1, characterized in that the temperature influencing device (30) comprises a combined heating and cooling device with a heating device (31) and a cooling device (32), so that the slabs (B) can be selectively heated or cooled by the temperature influencing device (30), wherein the heating device (31) preferably comprises an inductive heating device and / or the cooling device (32) is preferably designed to realize rapid cooling of the slabs (B) by applying a coolant.

3. Device (1) according to claim 1 or 2, characterized in that the surface device (20) is arranged to process at least one surface of the slabs (B) by grinding and / or milling and / or flame cutting.

4. Device (1) according to one of the preceding claims, characterized in thatthe combined transport and temperature control device (40) comprises: one or more roller tables (41); and / or one or more thermal insulation devices; and / or one or more inductive heating elements (45); and / or one or more furnaces (42, 46); and / or one or more slab discharge devices for discharging slabs (B) from the transport line of the casting machine (CLC) and / or the transport line of the rolling mill (CLM); and / or one or more slab insertion devices for inserting slabs (B) into the transport line of the casting machine (CLC) and / or the transport line of the rolling mill (CLM).

5. Device (1) according to one of the preceding claims, characterized in thatthe transport line of the casting machine (CLC) and the transport line of the rolling mill (CLM) coincide, wherein the surface device (20), the temperature influencing device (30) and the combined transport and temperature influencing device (40) are preferably arranged one behind the other in one and the same transport line.

6. Device (1) according to one of claims 1 to 4, characterized in that the transport line of the casting machine (CLC) and the transport line of the rolling mill (CLM) differ, preferably running parallel, wherein the combined transport and temperature influencing device (40) is preferably further configured to transport the slabs (B) from the transport line of the casting machine (CLC) into the transport line of the rolling mill (CLM).

7. Device (1) according to one of the preceding claims, characterized in thata third route is provided along which the slabs (B) leave both the surface device (20) and the temperature influencing device (30) and can thus be introduced directly into the combined transport and temperature influencing device (40).

8. Device (1) according to one of the preceding claims, characterized in that the rolling mill (50) is a hot rolling mill and is designed to at least partially form the slabs (B) from the casting heat of the casting machine (10).

9. Device (1) according to one of the preceding claims, characterized in that this has a control device (100) which is designed to control the process control of the slabs (B) as a function of measured and / or calculated process parameters, preferably comprising an alloy and / or temperature of the cast slabs (B).

10. Device (1) according to claim 9, characterized in thatthe control device (100) is designed to heat or cool slabs (B), preferably of a crack-sensitive alloy, by means of the temperature influencing device (30) such that the slab surface temperature before entering the combined transport and temperature influencing device (40) is outside a critical temperature range (T kritisch ), defined by a lower threshold (T u ) of preferably 600°C and an upper threshold value (T o ) of preferably 850°C.

11. Device (1) according to claim 9 or 10, characterized in that the control device (100) is arranged to feed the slabs (B) cast by the casting machine (10) to the rolling mill (50) without intermediate storage in a slab storage facility.

12. Device (1) according to one of the preceding claims, characterized in thatthe casting machine (10) is designed to cast medium slabs with a thickness in the range of 90 to 250 mm, preferably 110 to 200 mm.

13. A method for producing rolled metal strips, preferably hot-rolled metal strips, by means of a device (1) according to one of the preceding claims, the method comprising: a) casting a slab (B) by means of the casting machine (10); b) transferring the slab (B) into the combined transport and temperature influencing device (40); and c) hot-rolling the slab (B) in the rolling mill (50) to form a metal strip, wherein no complete cooling of the slab (B) takes place after casting on the way to the rolling mill (50), preferably the slab temperature in its core does not fall below 600°C.

14. Method according to claim 13, characterized in thatFollowing step a), depending on one or more process parameters, the slab (B) is transported directly into the combined transport and temperature influencing device (40), a temperature influence is carried out by the temperature influencing device (40) and / or a processing and / or treatment and / or inspection of at least one surface of the slab (B) is carried out by the surface device (20).

15. Method according to claim 13 or 14, characterized in that the slab is a medium slab with a thickness in the range of 90 to 250 mm, preferably 110 to 200 mm.

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