System and method for producing rolled metal strips

Abstract

The invention relates to a system (1) and to a method for producing rolled metal strips, preferably hot-rolled metal strips, the system (1) having: a casting machine (10) designed to produce at least one slab and to transport it in a transport line; a rolling system (50, 50b) designed to form the slab into a corresponding metal strip by rolling during transport along the transport line; a temperature adjustment system (20) that is arranged between the casting machine (10) and the rolling system (50, 50b) and designed to control the temperature of the slab in a targeted manner; a control device (100) designed to control the temperature adjustment system (20) in an open-loop and / or closed-loop manner such that the slab is brought to a desired temperature profile before entering the rolling system (50, 50b); the control device (100) being designed to access a process model for the continuous casting and rolling process (PM-GW) of the system (1) coupled to a material model (WM) for calculating precipitations in the slab in order to control the temperature adjustment system (20) in an open loop and or closed loop manner.

Description

[0001] Plant and process for the production of rolled metal strips

[0002] Technical field

[0003] The invention relates to a plant and a method for the production of rolled metal strips, preferably hot-rolled metal strips.

[0004] Background of the invention

[0005] In the production of metallic materials, a process known as "precipitation hardening" is used to selectively increase the strength and hardness of the material by forming precipitates in its microstructure. Precipitates form a separate phase or separate particles within the material's microstructure. Such precipitates arise when certain alloying elements are dissolved in a metal matrix and then precipitated by heat treatment at temperatures exceeding their solubility limits. Furthermore, precipitates impede the migration of phase and grain boundaries, for example, during grain growth and recrystallization. Precipitation formation can also be used to create a fine-grained microstructure (grain refinement), which is characterized by increased toughness and strength (fine-grain hardening).

[0006] For alloy steels to achieve the desired mechanical properties in the final product, the alloying elements must be in solution before finishing the process. This applies to alloying elements intended to influence mechanical properties through precipitation hardening (e.g., carbonitrides of the microalloying elements Nb, Ti, V, and Al) and / or to delay recrystallization (NbCN, dissolved Nb). Uncontrolled precipitation, e.g., deformation-induced precipitation, can modify the recrystallization behavior during a rolling process, which in turn affects the

[0007] Page 1 Flow stress and thus the rolling force and mass flow can be disrupted (e.g. formation of a “cobble”).

[0008] During the continuous casting process, the microalloying elements form compounds with nitrogen, carbon, etc., resulting in precipitates. These precipitates are influenced by the process control (superheating, temperature / time profiles, etc.) during continuous casting.

[0009] By reheating the cast slabs before hot rolling, also known as "solution annealing," the precipitates can be redissolved. This is achieved by precisely controlling temperature / time profiles, which may depend on factors such as the precipitate state before entering the reheating unit, the solution temperature of the precipitates, and the diffusion-controlled kinetics of precipitate dissolution.

[0010] Due to the varying temperature profiles across the strand thickness, different sizes and volume fractions of the precipitates form, resulting in different grain sizes. This, in turn, can lead to the desired mechanical properties of the rolled metal strip not being achieved, or only being insufficiently achieved, e.g., the toughness in micro-alloyed raw steels.

[0011] Description of the invention

[0012] One object of the invention is to provide an improved plant and an improved process for the production of rolled metal strips, preferably hot-rolled metal strips, and in particular to increase the quality of the rolled metal strips.

[0013] The problem is solved by a system with the features of claim 1 and a method with the features of method claim 10. Advantageous further developments follow from the dependent claims, the following description of the invention and the description of preferred embodiments.

[0014] Page 2 The plant according to the invention is used for the production of rolled, in particular hot-rolled, metal strips. The products cast and processed are made of a metal alloy, preferably steel. The plant is specifically designed for the production and further processing of thin slabs with a thickness of 40 to 160 mm.

[0015] The plant features a casting machine that is set up to produce at least one slab and transport it in a transport line.

[0016] The casting machine is preferably implemented as a vertical bending unit or as a sheet caster. However, it can also be implemented in other ways, as long as it provides a casting strand that can subsequently be cut into slabs and further processed.

[0017] The plant also features a rolling mill designed to transform the slab into a suitable metal strip by rolling it during transport along the transport line.

[0018] The rolling mill comprises one or more rolling stands in the usual manner, preferably each in a quarto configuration with two work rolls and two backup rolls, and can be operated in reverse or tandem mode. The rolling mill can include a roughing mill and / or finishing mill, or be designed as such. A hot rolling mill is particularly preferred, in which the forming of the slabs takes place at least partially from the casting heat, i.e., in this case, the slabs do not cool completely after casting on their way to the rolling mill.

[0019] The system also features a temperature control system, which is arranged and configured between the casting machine and the rolling mill to precisely control the temperature of the slab. The temperature control system includes an induction-based heating unit, the heating unit being equipped with multiple inductive heating zones.

[0020] Page 3 The plant has a control unit configured to control and / or regulate at least the temperature setting system so that the slab is brought to a desired temperature profile before entering the rolling mill. For this purpose, the control unit is configured to access a process model for the casting and rolling process of the plant, coupled with a material model for calculating precipitates in the slab, to control and / or regulate the temperature setting system.

[0021] By coupling a process model for the casting and rolling process of the plant with a material model and applying the coupled model to calculate precipitation in the slab, alloying elements can be completely or at least selectively dissolved. In this way, the effect of the existing alloying elements on strength, toughness (depending on solid solution strengthening, fine grain hardening, precipitation strengthening, etc.) and the control of microstructure formation processes (recrystallization, grain growth, and precipitation) can be optimized, thereby improving the mechanical properties of the rolled metal strip and thus its quality.

[0022] The control unit is connected via signal technology to the components of the system to be controlled, regulated, and / or read out, specifically to the casting machine, the temperature control system, and the rolling mill. Communication between the control unit and the system components to be controlled, regulated, and / or read out can be wired or wireless, digital or analog. The control unit can receive and / or send signals (control signals, data, etc.), whereby both unidirectional and bidirectional signal transmission fall under the term "communication" in this context. The control unit does not necessarily have to be implemented by a central computer or electronic control system; rather, it can be a decentralized and / or multi-stage system, control networks, cloud systems, and the like.The control system can also be an integral part of a higher-level plant control system or communicate with one.

[0023] Page 4 It should be noted that designations of spatial relationships, for example “between”, “vertical”, “horizontal”, “above”, “below”, “upstream”, “downstream”, “in front”, “behind”, etc., are clearly defined by the structure and intended use of the plant as well as the transport direction of the casting strand or the slabs.

[0024] Preferably, the control device is configured to control and / or regulate the temperature and / or power and / or frequency of the heating device. An induction-based heating device, due to its frequency-dependent penetration depth, is particularly well-suited for precisely adjusting the temperature profile along the slab thickness.

[0025] Knowing the temperature profile of the strand or slab entering the temperature control system, as well as the precipitation profile, allows the operating parameters of the inductive heating system, particularly power and frequency, to be optimized. This enables, for example, an increase in the surface temperature to selectively dissolve precipitates. Especially in a plant where the casting and rolling process is typically coupled by a roller hearth furnace as a preheating furnace and supplemented by an induction heating system, targeted control of the temperature profile throughout the entire casting and rolling process is possible.

[0026] The determined frequencies for the induction-based heating device can be optimized to achieve the most uniform temperature profile possible across the slab thickness.

[0027] The heating device is equipped with several inductive heating zones (along the transport line), wherein the process model for the casting and rolling process of the plant is preferably configured to specify frequencies and / or powers for the heating zones over the length of the inductive heating device, in particular depending on the incoming and outgoing temperature

[0028] Page 5 and precipitation profiles. In this way, the desired forming temperature can be reliably achieved, especially with a uniform temperature profile for the slab thickness.

[0029] Preferably, the process model for the casting and rolling process is set up to theoretically determine process data, including in particular a temperature distribution of the slab, wherein the theoretical determination of the process data is preferably obtained from a simulation using the process model for the casting and rolling process.

[0030] Preferably, the process model for the casting and rolling process is divided into several sub-models, including in particular a process model of the

[0031] Casting machine and / or a process model of reheating and / or a process model of the rolling mill and / or a process model of the

[0032] Water cooling / descaling.

[0033] In this case, the control unit is configured to manage the process control and process parameters of the plant, particularly from the casting machine to the rolling mill. Relevant data, such as the slab temperature or final rolling temperature, are communicated to the control unit from the process models of the casting machine and the rolling mill.

[0034] In the reheating process model, the necessary temperature / time profile is preferably calculated using the existing precipitation state from the previous processes within the temperature control system, for example, to achieve a desired degree of precipitate resolution. The maximum possible degree of precipitate resolution is also influenced by the temperature control system.

[0035] Preferably, the process model for the casting and rolling process is coupled with the material model to provide an actual state of the precipitation profile.

[0036] Page 6 describes how to determine the slab thickness for a slab beginning, middle, and / or end. The determination of the current state is performed in real time, allowing the control unit to adjust the temperature control system so that the precipitates in the slab are set according to the target resolution level.

[0037] Preferably, the process model for the casting and rolling process of the plant is coupled with the material model in two variants: an online model, which is set up to calculate an actual state in real time, and an online pre-model, which can be executed faster than real time to predict a state, wherein the control device is set up to access the online model, the online pre-model or both models for controlling and / or regulating the temperature setting system.

[0038] The two model variants can complement each other if necessary. Alternatively or additionally, in the event of a failure of the faster model, the slower model can still be used to control and / or regulate the casting and rolling process. The real-time model constantly synchronizes with actual time, while the other, faster model requires a processing speed faster than real time.

[0039] Preferably, the control device is configured to perform one or more of the following steps: predicting a necessary temperature / time profile within the temperature control system for precipitate resolution using the process model for the casting-rolling process coupled with the material model; calculating a precipitate profile at the end of the temperature control system and before entering the rolling mill using the process model for the casting-rolling process coupled with the material model; calculating power and / or temperatures and / or frequencies for the temperature control system to achieve the desired temperature / time profile; setting a U-shaped temperature profile where the surface temperature of the slab is higher than the temperature at the center of the slab, over the

[0040] Page 7 Slab thickness; generating a homogeneous temperature profile across the slab cross-section before entering the rolling mill.

[0041] In this way, the effect of the existing alloying elements on strength, toughness (depending on solid solution strengthening, fine grain hardening, precipitation strengthening) and the control of the microstructure formation processes (recrystallization, grain growth and precipitation) can be further optimized.

[0042] Preferably, the control device is configured to access a model with offline simulation results, preferably from case studies, for the control and / or regulation of the temperature setting system, thereby further optimizing the process control of the plant, in particular compensating for any failure of the control or regulation by using online-based models.

[0043] Following the temperature control system and / or hot forming by the rolling mill, a quality assessment can be performed by determining the concentration of precipitating alloying elements in the matrix phase relative to the total content of the respective element ("Percent Precipitated"). This can be done using downstream models for calculating material properties.

[0044] The aforementioned problem is further solved by a method for producing rolled metal strips, preferably hot-rolled metal strips, wherein the method is carried out with a plant according to one of the embodiments described above. The method comprises: casting at least one slab using the casting machine; tempering the slab in the temperature control system; rolling the slab into a metal strip in the rolling mill; wherein the slab is brought to a desired temperature profile in the temperature control system before entering the rolling mill, wherein, for this purpose, a process model for the casting-rolling process of the plant is coupled with a control system for the temperature control system.

[0045] Page 8 uses a material model to calculate precipitates in the slab.

[0046] The technical effects, advantages and embodiments described in relation to the plant apply analogously to the process.

[0047] 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 individually or in combination with one or more of the features set out above, provided that the features do not contradict each other. The following description of preferred embodiments is given with reference to the accompanying drawings.

[0048] Brief description of the characters

[0049] Preferred further embodiments of the invention are explained in more detail by the following description of the figures. These show:

[0050] Figure 1 schematically shows a plant for the production of metal strips, comprising a casting machine, a temperature control system, a rolling plant and a control device with access to a process model for the casting and rolling process and a material model;

[0051] Figure 2 schematically shows the cooperation of an online model and an online pre-model for the control and / or regulation of reheating in the temperature setting system;

[0052] Figure 3 schematically illustrates a data flow between plant processes and process models for their control or regulation;

[0053] Page 9 Figure 4 schematically shows a data flow between processes of the plant and process models for their control or regulation, where a process i concerns heating in a heating plant;

[0054] Figure 5 shows a flowchart of the application of an online warming model and an online pre-warming model; and

[0055] Figure 6 schematically shows a plant for the production of metal strips, comprising a casting machine, a temperature setting system, a rolling plant and a control device with access to a process model for the casting and rolling process and a material model according to a further embodiment.

[0056] Detailed description of preferred embodiments

[0057] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the figures are designated with identical reference numerals, and repeated descriptions of these elements are sometimes omitted to avoid redundancy.

[0058] Figure 1 schematically shows a plant 1 for the production of metal strips, preferably steel strips, with a thickness of, for example, 0.8 to 3.0 mm.

[0059] The plant 1 includes a casting machine 10, which is set up to produce slabs, preferably thin slabs with a thickness of 40 to 160 mm, in batch or continuous operation.

[0060] The casting machine 10 is preferably implemented as a vertical bending unit or as a sheet caster. However, the casting machine 10 can also be implemented in other ways, as long as it provides a casting strand that can subsequently be cut into slabs and further processed.

[0061] Page 10 The liquid metal to be cast is fed into a mold 11 of the casting machine 10, for example from a ladle. The mold 11 brings the molten metal into the desired slab shape, while it gradually solidifies from the outside in through 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. If the casting thickness or the casting radius requires it, the copper plates may have a funnel-shaped contour and / or be curved in a transport direction according to the casting radius of a strand guide 12.

[0062] The still-softened molten strand S emerges downwards from the mold 11, is then guided downwards along the strand guide 12 in the transport direction, and subsequently deflected into a horizontal position in a bending section while gradually cooling. It should be noted that the transport direction in the casting machine 10 generally does not denote a constant direction vector, but can depend on the strand or slab position along the system 1. After being deflected into the horizontal position, the molten strand S is conveyed along a transport line of the casting machine.

[0063] The strand guide 12 comprises rollers that transport the sintered strand S and can be angled for thickness reduction according to LCR (Liquid Core Reduction) or DSR (Dynamic Soft Reduction) such that the transport gap in which the sintered strand S is transported along the transport direction gradually narrows. The strand guide 12 can be segmented, for example, by two or more similar curved segments that form a bending section of the strand guide 12. During transport, the sintered strand S is actively or passively cooled as part of secondary cooling, for example, by spraying water, causing it to gradually solidify from the outside in.

[0064] A shaping of the casting strand S caused by the casting machine 10, in particular strand guide 12, is referred to as "primary forming"; in contrast to "forming", which refers to a shaping by a forming unit such as a rolling mill 50.

[0065] Page 11 A straightening section follows the bending section of the casting machine 10, in which the casting strand S is brought into a horizontal orientation. Here, too, rollers are provided for guiding and transporting the casting strand S. One or more of the rollers are drive rollers and propel the casting strand S in the transport direction; other rollers serve to guide and align the casting strand S. In this respect, the rollers constitute the means for driving and bending the casting strand S.

[0066] The system 1 further includes a cutting device 14, which is arranged in the transport line downstream of the straightening area of ​​the casting machine 10. The cutting device 14 serves to cut or divide the casting strand S into slabs. The cut is made along the slab thickness. "Slab thickness" is defined as the dimension of the slab that is perpendicular to both its longitudinal extent and its width. The cutting device 14 is configured to cut the casting strand S during conveying, i.e., while the casting strand S is moving along the transport line. Preferably, the cutting device 14 is a shear, in particular a pendulum shear. In this case, the shear is configured such that the transport movement of the casting strand S is tracked during the cutting process, and one or more cutting blades cut the strand in a movement perpendicular to the casting strand S.

[0067] Upstream or downstream of the separating device 14, a decoupler may be provided, for example designed as a cold strand rocker, which is set up to be able to decouple the casting strand S from the process line if necessary, for example when starting up the plant.

[0068] The system 1 can have one or more descaling devices, which, depending on the configuration, are arranged in front of and / or behind the separating device 14.

[0069] A temperature control system 20 is connected to the separating device 14 of the system 1, which in the present embodiment is a roller hearth furnace or

[0070] Page 12 comprises a preheating furnace 21 and a heating device 22. The preheating furnace 21 is configured to heat the slabs to temperatures, for example, between 1,000 and 1,150°C and / or to equalize the temperature. The heating device 22 preferably operates inductively. The heating device 22 can be positioned at several locations within the plant 1, e.g., before the cutting device 14, before or after the preheating furnace 21, or between two rolling stands of the rolling mill 50; see also the embodiment in Figure 6.

[0071] The plant 1 further comprises a rolling mill 50, which is in particular a hot rolling mill. The rolling mill 50 has one or more rolling stands 51, preferably each in a quarto configuration with two work rolls forming the roll gap and two backup rolls, and can be operated in reverse or tandem mode. The rolling mill 50 can be configured as a roughing mill and / or finishing mill. The transport path of the slabs through the rolling mill 50 is along a transport line that preferably coincides with the transport line of the casting machine.

[0072] During the rolling process in the rolling mill 50, the temperatures of the slabs decrease through radiation and cooling. The rolled material then enters a cooling section or cooling unit 60, the cooling parameters of which are set so that the rolled material is rapidly cooled to temperatures within a range of, for example, 400 to 650°C, preferably below 450°C. The cooling unit 60 can include cooling beams 61 with water cooling, although other cooling concepts are also possible.

[0073] The rolled and heat-treated strip is then wound onto a reel unit 70.

[0074] Due to the different temperature profiles across the strand thickness, precipitates of varying sizes and volume fractions form along the strand thickness. Knowing the temperature profile of strand S or the slabs entering the temperature control system 20, and the precipitate profile...

[0075] On page 13, the operating parameters, in particular those of the heating device 22, i.e., in the inductive case, especially the power and frequency, can be optimized so that the surface temperature is increased in particular to selectively dissolve precipitates. In a system 1, in which the casting and rolling process is typically coupled by a roller hearth furnace as a preheating furnace 21 and supplemented by an induction heater as a heating device 22, targeted control of the temperature profile over the entire casting and rolling process is possible.

[0076] To achieve this, process models for the PM-GW casting and rolling process (continuous casting, transport, cooling, hot forming, reheating, etc.) are coupled with a WM material model for calculating the precipitates.

[0077] For this purpose, a control unit 100 is provided, which communicates with the various assemblies 10, 20, 50, 60, 70, actuators, sensors and the like, and is set up to control and / or regulate the process depending on process parameters.

[0078] The control unit 100 is connected via signal technology to the components of plant 1 to be controlled, regulated, and / or read out, specifically to the casting machine 10, the temperature control system 20, the rolling mill 50, the cooling unit 60, and the reeling unit 70. Communication between the control unit 100 and the plant components to be controlled, regulated, and / or read out can be wired or wireless, digital or analog. The control unit 100 can accordingly receive and / or send signals (control signals, data, etc.), whereby both unidirectional and bidirectional signal transmission fall under the term "communication" in this context. The control unit 100 does not necessarily have to be implemented by a central computer or electronic control system; rather, it can be a decentralized and / or multi-stage system, control networks, cloud systems, and the like.The control unit can also be an integral part of a higher-level plant control system or communicate with one.

[0079] Page 14 100 can also communicate with lower-level plant controls, i.e., controls assigned to the corresponding facilities.

[0080] The control unit 100 comprises 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 necessary calculations are performed in a process model connected to the control unit 100 and the calculations are communicated to the control unit 100, or whether the control unit 100 itself comprises the process model.

[0081] In the embodiment shown in Figure 1, the control unit 100 communicates with a process model for the casting and rolling process PM-GW and a material model WM coupled to it.

[0082] The process model for the casting and rolling process PM-GW can be divided into several sub-models or communicate with such, including, for example, a process model of the casting machine PM-G, a process model of the reheating PM-E ​​and a process model of the rolling mill PM-W.

[0083] The control unit 100 is configured to manage the process control and process parameters of plant 1, in particular from the casting machine 10 to the rolling mill 50. Relevant data, such as the slab temperature or final rolling temperature, are communicated to the control unit 100 from the process model of the casting machine PM-G and the process model of the rolling mill PM-W.

[0084] Data exchange with a production planning system or process control system can facilitate the work of the control unit 100 and automate process control, the necessary calculations and the transmission of control signals.

[0085] Page 15 In the embodiment shown in Figure 1, the control unit 100 retrieves 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 unit 100 that defines the manufacturing steps and influences the corresponding settings of the units 10, 20, 50, 60, and 70.

[0086] The settings of the casting machine 10, the temperature control system 20, 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, slab surface, and / or microstructure is available at the output of the casting machine 10. This 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 unit 100.

[0087] Taking into account the information provided by the casting machine 10, the control unit 100 now determines the parameters necessary for further process control and sets them on the relevant components.

[0088] In the PM-W reheating process model, the necessary temperature / time profile for achieving the maximum possible precipitate resolution is calculated using the existing precipitation state from the previous processes within temperature control system 20. The maximum possible precipitate resolution is also influenced by temperature control system 20.

[0089] The control of the reheating in the temperature setting system 20 is particularly important under non-stationary conditions (e.g., reduction of the casting rate, buffering of slabs in a holding oven during

[0090] Page 16 (roller changes, etc.), which can lead to changes in the precipitation behavior, are of interest.

[0091] In addition, the material model WM can transmit quality information to downstream processes, for example, the precipitation state to the process model of the rolling mill PM-W. Quality assessment is based, for instance, on the concentration of precipitation-forming alloying elements in the matrix phase (e.g., austenite) or on parameters calculated from this ("Percent Precipitated").

[0092] The coupled calculations can be time-consuming, making real-time control impossible or impractical. Alternatively, two process chains can be simulated: one in real time and the second faster than real time. This allows for the early determination of the temperature / time profile for precipitation resolution based on the predicted precipitation state. This profile can then be fed into the real-time reheating process model PM-E ​​for control. Simplified models using offline simulation results from case studies can also be used for reheating control in temperature setting system 20.

[0093] In this context, the control unit 100 is specifically designed to control and / or regulate the heating or reheating of the slabs in the temperature control system 20. The temperature control system 20, in particular the heating unit 22, is controlled and / or regulated based on the process model for the casting-rolling process PM-GW and the coupled material model WM. The material model WM preferably provides a simulation of the precipitated alloying elements. The simulation can be performed online, or the control unit 100 can alternatively access stored simulation results from one or more offline models. The online models preferably run in real time or even faster in order to calculate actual states and / or make predictions.

[0094] Page 17 In this context, simulations of the actual state of the precipitation profiles across the strip thickness are particularly preferred for a slab beginning, a slab middle and a slab end.

[0095] Depending on the model results thus determined, the control unit 100 controls and / or regulates the temperature setting system 20, in particular with regard to the necessary temperature(s), holding time(s), power(s) and / or frequency(ies) in the case of inductive heating media, in order to dissolve the precipitated alloy components completely or partially by reheating.

[0096] A procedure for reheating the slabs in the temperature control system 20 may include the following steps:

[0097] ■ Prediction of the necessary temperature / time profile within the temperature setting system 20 for the resolution of the precipitation using the process model for the casting rolling process PM-GW coupled with the material model WM for the casting strand S or its slabs.

[0098] ■ Calculation of the precipitation profiles at the end of the temperature setting system 20 and before entering the hot forming process, i.e. before entering the rolling mill 50, using the process model for the casting rolling process PM-GW coupled with the material model WM.

[0099] ■ Calculation of heating outputs for temperature control systems, which may consist of several modules.

[0100] ■ Calculation of the heating power of the heating device 22 (in the case of an inductive heating device comprising frequencies, with preferably several inductors connected in series) to achieve the desired temperature / time profile.

[0101] ■ Establishing a U-shaped temperature profile, i.e., the surface temperature of the slab is higher than the temperature in the center of the slab, across the slab thickness, since precipitates occur more frequently in the area near the edge of the slab. The temperature profile across the slab thickness is particularly influenced by the frequency.

[0102] Page 18 ■ Generation of a homogeneous temperature profile across the slab cross-section before entering hot forming, i.e. before entering the rolling mill 50.

[0103] In this way, the effect of the existing alloying elements on strength, toughness (depending on solid solution strengthening, fine grain hardening, precipitation strengthening), and the control of microstructure formation processes (recrystallization, grain growth, and precipitation) can be optimized. This can be achieved by dissolving the alloying elements completely or at least selectively, as there are also applications where precipitates are intentionally required to prevent grain growth, for example, in thermomechanical rolling.

[0104] The prediction of temperature / time profiles and the calculation of precipitation profiles are preferably performed at least in real time. In particular, models that calculate the current state preferably run in real time, while models for prediction / forecast run faster than real time.

[0105] Preferably, the models, in particular the process model for the casting-rolling process PM-GW and / or the material model WM, are presented in two variants: as real-time model(s) and online pre-model(s). This allows for continued control and / or regulation of the casting-rolling process in the event of a failure of the faster model by using the slower model. The real-time model constantly synchronizes with real time, while the other, faster model requires a computation speed faster than real time.

[0106] Figure 2 illustrates the cooperation of an online model (real-time) and an online pre-model (faster than real-time for forecasting) for controlling and / or regulating reheating in the temperature setting system 20, comprising several heating zones 1 to n.

[0107] Page 19 Figure 3 illustrates the data flow between processes of plant 1 and the associated process models.

[0108] A data flow between processes and process models, where process i involves heating in a heating system, is shown in Figure 4.

[0109] In the embodiment shown in Figure 4, a technological assistant is included that receives information from the process, for example, about the material or its chemical composition, the transport speed through the heating system, and / or the geometry of the casting strand or slab. The technological assistant sends basic settings for the heating system to the process and the models, such as target temperatures for the individual heating zones depending on the input data, heating power and frequency for the individual heating zones depending on the input data, minimum and maximum values ​​for the heating power and frequency for each heating zone, and / or target volume fractions of the precipitates after dissolution for the material.

[0110] The heating process receives information from process i-1, for example, about the material or chemical composition, transport speed through the heating system, geometry of the casting strand or slab, and / or (measured) temperatures. The heating process receives information from the online model for the current process data, for example, about target temperatures of the individual heating zones, the heating power and frequency of the individual heating zones, and / or volume fractions of the precipitates from the material model of the online model.

[0111] The online heating model receives the basic settings of the heating system from the heating technology assistant, the current process data from the heating process, the parameters for setting the heating system and the microstructure requirements from the heating technology assistant, and the temperatures and microstructure data from the previous process model.

[0112] Page 20 The online heating model sends the settings of the heating system to the process, such as target temperatures of the individual heating zones depending on the input data, heating power and frequency of the individual heating zones depending on the input data and transport speed.

[0113] The online heating model can communicate with an online material model of heating. This model uses the temperature-time profile for the current process data to calculate the microstructure fractions. These calculated microstructure fractions can include: phase fractions of matrix and precipitate phases, distribution function of precipitates, chemical composition of the matrix and precipitates, dislocation density, grain size, and / or subgrain size.

[0114] The online pre-model of heating receives all the data of the online model of heating and additionally the results of a microstructure simulation from the online pre-model of process i-1.

[0115] Faster than real-time, the online pre-model calculates whether the microstructure requirements are met using the current data from process i-1 and the basic data from the technological assistant. If the requirements are not met, the heating system's settings are optimized, taking into account the information on the min-max values ​​from the technological assistant.

[0116] The online pre-heating model can communicate with an online pre-material model of the heating process. This model calculates the microstructure fractions using the temperature-time profile for the optimized process data.

[0117] If a better setting (heating power, frequency or transport speed) is found, it is forwarded to the online heating model and from there to the process.

[0118] Page 21 Figure 5 shows a flowchart of the application of the online heating model and the online pre-heating model according to an exemplary embodiment.

[0119] In addition to controlling and / or regulating the temperature setting system 20 using real-time model(s) and / or online pre-model(s), the temperature setting system 20 can also be controlled and / or regulated by using case studies with offline models. In other words, the reheating parameters in this case are based on predefined model results that do not change. These results are generated through simulation of the material and depend on the temperature profile of the slabs.

[0120] It is possible that the temperature and / or precipitation profiles will change along the length of the slab if process parameters are not consistently constant. The calculated temperature and precipitation profiles may depend on previous processes.

[0121] The determined frequencies for the heating device 22, if induction-based, can be optimized to achieve the most uniform temperature profile possible across the slab thickness.

[0122] If the temperature setting system 20 includes a holding furnace, the temperature of the holding furnace is preferably set above the precipitation temperatures if significant precipitation occurs during the holding time until hot forming.

[0123] Following the temperature control system 20 and / or the hot forming process in the rolling mill 50, a quality assessment can be carried out by determining the concentration of the precipitate-forming alloying elements in the matrix phase in relation to the total content of the respective element. This can be achieved using downstream models for calculating material properties.

[0124] Page 22 Figure 6 schematically shows a plant 1 for producing metal strips according to a further embodiment. Plant 1 differs from the embodiment of Figure 1, among other things, in that the rolling mill comprises a roughing mill 50a and a finishing mill 50b. The temperature control system 20 is arranged between the casting machine 10 and the finishing mill 50b of the rolling mill. Furthermore, several roller hearth furnaces or preheating furnaces 21 and heating devices 22, in particular induction-based, are installed as components of the temperature control system 20.

[0125] Temperature control system 20 extends with its components to the left and right of the main road 50a.

[0126] Where applicable, all individual features shown in the exemplary embodiments can be combined and / or exchanged without leaving the scope of the invention.

[0127] Page 23 Reference List

[0128] I Plant for the production of metal strips

[0129] 10 Casting machine

[0130] II mold

[0131] 12 strand guide

[0132] 14 Separating device

[0133] 20 Temperature setting system

[0134] 21 Preheating oven

[0135] 22 Heating system

[0136] 50 rolling mill

[0137] 50a Vorstraße

[0138] 50b Finishing Road

[0139] 51 Rolling mill

[0140] 60 Cooling unit

[0141] 61 cooling beams

[0142] 70 reel unit

[0143] S casting strand

[0144] PM-GW process models for the casting and rolling process

[0145] WM Material Model

[0146] PM-G process model of the casting machine

[0147] PM-E process model of neither heating

[0148] PM-W process model of the rolling mill

[0149] Page 24

Claims

Patent claims 1. Plant (1) for the production of rolled metal strips, preferably hot-rolled metal strips, wherein the plant (1) comprises: a casting machine (10) configured to produce at least one slab and transport it in a transport line; a rolling mill (50, 50b) configured to transform the slab into a corresponding metal strip by rolling during transport along the transport line; a temperature control system (20) arranged between the casting machine (10) and the rolling mill (50, 50b) and configured to selectively temperature-control the slab, wherein the temperature control system (20) comprises an induction-based heating device (22) and the heating device (22) is equipped with several induction heating zones;a control device (100) configured to control and / or regulate the temperature setting system (20) such that the slab is brought to a desired temperature profile before entering the rolling mill (50, 50b); wherein the control device (100) is configured to access a process model for the casting rolling process (PM-GW) of the plant (1) coupled with a material model (WM) for calculating precipitates in the slab for the control and / or regulation of the temperature setting system (20).

2. System (1) according to claim 1 , characterized in that the control device (100) is configured to control and / or regulate the temperature and / or power and / or frequency of the heating device (22). Page 25 3. Plant (1) according to claim 2, characterized in that the process model for the casting rolling process (PM-GW) of the plant (1) is coupled with the material model (WM) to specify frequencies and / or powers for the heating zones over the length of the inductive heating device (22), preferably depending on the incoming and outgoing temperature and precipitation profiles of the slab.

4. Plant (1) according to one of the preceding claims, characterized in that the process model for the casting rolling process (PM-GW) is set up to theoretically determine process data, preferably comprising a temperature distribution of the slab, wherein the theoretical determination of the process data is preferably obtained from a simulation using the process model for the casting rolling process (PM-GW).

5. Plant (1) according to claim 4, characterized in that the process model for the casting rolling process (PM-GW) is subdivided into several sub-models, preferably comprising a process model of the casting machine (PM-G) and / or a process model of reheating (PM-E) and / or a process model of the rolling mill (PM-W) and / or a process model of water cooling / descaling.

6. Plant (1) according to one of the preceding claims, characterized in that the process model for the casting rolling process (PM-GW) is coupled with the material model (WM) to determine an actual state of the precipitation profile over the slab thickness for a slab start and / or a slab middle and / or a slab end.

7. Plant (1) according to one of the preceding claims, characterized in that the process model for the casting rolling process (PM-GW) of plant (1) coupled with the material model (WM) is available in two variants, namely as an online model which is set up to calculate an actual state in real time, and as an online pre-model which is set up to predict a state faster than in Page 26 is executable in real time, wherein the control device (100) is configured to access the online model, the online pre-model or both models for the control and / or regulation of the temperature setting system (20).

8. Annex (1) according to one of the preceding claims, characterized in that the control device (100) is configured to perform one or more of the following steps: - Predictions of a necessary temperature / time profile within the temperature setting system (20) for dissolving the precipitates using the process model for the casting rolling process (PM-GW) coupled with the material model (WM); - Calculating a precipitation profile of the slab at the end of the temperature setting system (20) and before entering the rolling mill (50, 50b) using the process model for the casting rolling process (PM-GW) coupled with the material model (WM); - Calculating power and / or temperatures and / or frequencies for the temperature control system (20) to achieve the desired temperature / time profile; - Setting a U-shaped temperature profile where the surface temperature of the slab is higher than the temperature in the center of the slab, across the slab thickness; - Generating a homogeneous temperature profile across the slab cross-section before entering the rolling mill (50, 50b).

9. System (1) according to one of the preceding claims, characterized in that the control device (100) is configured to access a model with offline simulation results, preferably from case studies, for the control and / or regulation of the temperature setting system (20).

10. Method for producing rolled metal strips, preferably hot-rolled metal strips, using a system (1) according to one of the preceding claims, wherein the method comprises: Page 27 Pouring at least one slab using the casting machine (10); Tempering the slab in the temperature control system (20); Rolling the slab in the rolling mill (50, 50b) to a metal strip; wherein the slab is brought to a desired temperature profile in the temperature control system (20) before entering the rolling mill (50, 50b), wherein for this purpose a process model for the casting rolling process (PM-GW) of the plant (1) coupled with a material model (WM) for calculating precipitates in the slab is used to control and / or regulate the temperature control system (20). Page 28

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