DE102021212881A1 - Device and method for producing a rolled metal strip - Google Patents

Abstract

Device (1) and method for producing a rolled metal strip (B), preferably a hot-rolled metal strip (B), the device (1) comprising: a rolling train (10) which is set up to roll the metal strip (B) during transport plastically deforming by rolling along a conveying direction (F); a cooling device (30) with variable cooling capacity, which is arranged downstream of the rolling train (10) in the conveying direction (F) and is set up to cool the metal strip (B); a straightening machine (50) which is arranged downstream of the cooling device (30) in the conveying direction (F) and is set up to bend the metal strip (B) into a desired shape, preferably straightening it to improve flatness; a first measuring point (60), arranged between the rolling train (10) and the cooling device (30), with a flatness measuring device (61) for measuring topological properties of the metal strip (B); a second measuring point (70), arranged between the cooling device (30) and the straightening machine (50), with a further flatness measuring device (71) for measuring topological properties of the metal strip (B); and a controller (100), which is in communication with the rolling train (10), the cooling device (30), the straightening machine (50) and with the first and second measuring point (60, 70) and is set up to receive topological information from the first and second measuring point (60, 70) and the rolling train (10) and/or the cooling device (30) and/or the straightening machine (50) depending on the topological information received from the first and second measuring point (60, 70). head for.

Description

technical field

The invention relates to a device and a method for producing a rolled metal strip, preferably a hot-rolled metal strip.

Background of the Invention

A general optimization goal for rolling a metal strip in a rolling mill, especially in a hot strip mill, is to maximize the flatness of the metal strip in order to ensure trouble-free further processing and the desired product quality. For this purpose, the cooling of the rolled products following a hot rolling train can be influenced in a targeted manner, whereby for example the tendency for the metal strip to edge up and/or buckle can be influenced. If the metal strip is bent or arched too much, it may not be possible to correct this in a subsequent roller table or a straightening machine in order to ensure quality. The consequences are tape errors and an associated increased reject rate.

Conventional arrangements of hot strip mills include an in-line cooling plant and a leveler after the mill stands. If no flatness measurement is provided in this process section, the straightening process takes place outside of the process section, essentially manually by an operator.

The measurement of strip/sheet flatness is usually a separate process step in which the sheet is positioned on a special table and measured, which means that the measurement takes a lot of time. Such a flatness measurement prior to any straightening process prevents an increase in the productivity of the rolling mill.

For this reason, technologies to increase automation in the cooling and straightening process of hot-rolled metal strips are the subject of current research and development. That's how she describes it DE 10 2013 214 344 A1 a cooling section for cooling hot-rolled metal strips. In order to improve the flatness of the metal strip after leaving the cooling section, it is proposed here to install a flatness measuring device for measuring the actual flatness of the metal strip between a first and a second cooling section. A straightening system with a flatness measurement following the cooling of hot-rolled metal strips goes out of the US 10,994,316 B2 out.

Despite flatness measurement in the hot strip mill, manual interventions may still be necessary, which stand in the way of a further improvement in productivity and result in fluctuating product qualities, depending on the experience of the operator, for example.

Presentation of the invention

An object of the invention is to provide an improved device and an improved method for producing a rolled metal strip, in particular to improve the product quality and/or productivity.

The object is achieved by a device with the features of claim 1 and a method with the features of the independent method claim. Advantageous developments follow from the dependent claims, the following description of the invention and the description of preferred exemplary embodiments.

The device according to the invention is used to produce rolled, in particular hot-rolled, metal strips, with all (hot) rolled flat products, including intermediate products such as slabs, heavy plate, finished plate and the like, collectively falling under the term “metal strip”. Products made of a metal, in particular a metal alloy, preferably steel, are processed.

The device comprises a rolling train that is set up to deform the metal strip plastically by rolling during transport along a conveying direction. The device is preferably part of a hot strip mill. The rolling train preferably functions as a roughing train that is set up to roll a rolling stock, for example a slab coming from a continuous casting plant, into a heavy plate.

The rolling train can include one or more roll stands in the usual way, each of which is preferably designed as a four-roll stand (four-high roll stand), each comprising two parallel, opposite work rolls that form a roll gap, and two associated back-up rolls that are correspondingly connected to the Work rolls are in contact to support the work rolls.

The apparatus further comprises a cooling device with a variable cooling capacity, which is arranged downstream (i.e. downstream) of the rolling train and is arranged to cool the metal strip.

The cooling capacity of the cooling device is variable; the cooling capacity can preferably be regulated in sections along the cooling section defined by the cooling device. This can be achieved in that the cooling device has one or more nozzle arrangements, each with a plurality of nozzles. The nozzle arrangements define a continuous cooling section in which the metal strip is specifically cooled by applying a cooling medium, preferably water or a water mixture. The nozzles are preferably set up to spray the cooling medium onto the metal strip, in particular the two strip surfaces. For this purpose, the nozzles are suitably positioned and aligned in order to apply a variable amount of cooling medium to the metal strip. Alternatively or in addition to varying the amount of coolant that can be delivered through the nozzles, the cooling characteristics can be influenced by adjusting the height of the nozzle arrangement(s) or by other technical means for manipulating the amount of coolant and/or coolant distribution.

The apparatus further comprises a straightening machine which is arranged downstream (i.e. downstream) of the cooling device and is arranged to straighten the metal strip, i.e. to bend it into a desired shape, preferably to straighten it to improve flatness.

The straightening machine is preferably used to eliminate topological distortions, internal stresses or deformations in the metal strip, which can result from rolling processes, thermal and/or other loads, for example. For this purpose, the metal strip runs through the straightening machine in the conveying direction, in which the material is preferably guided through a group of upper and lower straightening rollers and is plastically deformed by adjusting the straightening rollers accordingly.

The device also includes a first measuring point, arranged between the rolling train and the cooling device, with a flatness measuring device for measuring topological properties of the metal strip. The topological properties, in particular the profile or the flatness of the metal strip, are preferably measured without contact.

The device also includes a second measuring point, arranged between the cooling device and the straightening machine, with a further flatness measuring device for measuring topological properties of the metal strip. The topological properties, in particular the profile or the flatness of the metal strip, are also measured at the second measuring point, preferably without contact.

The device also includes a controller that is in communication with the rolling train, the cooling device, the straightening machine and with the first and second measuring point and is set up to receive topological information from the first and second measuring point and the rolling train and/or the cooling device and/or to control the straightening machine depending on the topological information received from the first and second measuring point.

The term "information" here includes both analog or digital data that has already been pre-processed by the measuring points and represents a measured variable, as well as pure measurement signals, the evaluation of which is carried out completely or partially in the controller.

The controller is in communication with the corresponding components of the device to be controlled and with the measuring points, i.e. corresponding probes/sensors. Communication can be wireless or wired, digital or analog. Furthermore, a data or signal exchange in only one direction is subsumed herein under the term "communication". The control does not necessarily have to be implemented by a central computing device, but decentralized and/or multi-level and hierarchical systems, control networks, cloud systems and the like are included. The controller can also be an integral part of a higher-level system controller or communicate with one.

It should be noted that designations of spatial relations such as "before", "after", "first", "last", "upstream", "downstream", "between", "transverse" etc. generally refer to the refer to the conveying direction of the metal strip; they are clearly defined by the intended use of the device.

The device allows verification of any deviations from the desired topology of the metal strip, in particular the flatness, and automatic correction in an in-line cooling and straightening process. A manual flatness assessment by an operator can be omitted. This relieves the operating personnel and standardizes the process, which means that less expertise is required on site to use and operate the device. Furthermore, the automation of the cooling and straightening process presented here contributes to an improvement in the quality of the rolling stock, in particular with regard to flatness. The improvement in the flatness of the metal strip in the cooling process results in an improvement in the homogeneity of the material properties throughout the rolled plate Consequence. Overall, the device enables a significant increase in the degree of automation.

The controller preferably implements a control circuit for controlling the rolling train and/or the cooling device and/or the straightening machine, the control circuit using the topological information received from the first and/or second measuring point as a reference variable. Such an integral measurement and control structure allows the use of machine learning methods in the manufacturing process by processing the measured flatness values. In addition, optimal adjustment values for the leveler can be derived automatically and straightening passes can be saved, which is important for the production of steel sheets from certain materials (e.g. TRIP steels or other steels with retained austenite) in order to stimulate the hardening process as little as possible after cooling in the cooling section .

The first measuring point preferably has a temperature measuring device for measuring a surface temperature of the metal strip and/or the second measuring point has a temperature measuring device for measuring a surface temperature of the metal strip. In this case, the controller is also set up to receive temperature information from the first and/or second measuring point and to control the rolling train and/or the cooling device and/or the straightening machine depending on the temperature information received from the first and/or second measuring point, whereby the degree of automation and a self-sufficient, independent optimization of the device are further promoted.

The temperature measuring device(s) each have at least one temperature sensor. The temperature measuring device(s) are preferably set up to detect the temperature in each case in the middle of the metal strip, seen in the width direction, and/or the temperature distribution over the width of the metal strip. The temperature distribution in the direction of the width of the metal strip generally has a higher gradient than the strip profile, in particular at the strip edges before cooling or also in the central areas of the metal strip shortly after leaving the cooling section. Thus, a temperature measuring device is preferably installed both in the first and in the second measuring point.

The temperature sensors preferably work without contact, for example implemented by an infrared line scanner. If the surface temperature of the metal strip is known at one or more points in the processing line, for example through other measurements or model calculations, temperature measuring devices can be dispensed with.

The control loop of the controller, if present, preferably uses the temperature information received from the first and/or second measuring point as a reference variable.

Furthermore, a pre-leveling machine is preferably arranged between the rolling train and the first measuring device and set up to level the metal strip, i.e. to bend it into a desired shape, preferably to straighten it to improve flatness. In this case, the controller is also set up to control the device as a function of the topological information received from the first and second measuring points and, if applicable, temperature information. Furthermore, the control of the pre-leveling machine can be included in the control loop of the controller, if available. A pre-leveler integrated in this way contributes to the careful straightening of the metal strip, especially in the case of sensitive strip materials, by optimally distributing the mechanical load over the cooling process. Automatic adjustment of the process to a stable state and automatic optimization with regard to product quality and/or productivity is promoted.

A third measuring point is preferably arranged downstream of the straightening machine, with the third measuring point having a further flatness measuring device for measuring topological properties of the metal strip and also being able to include a further temperature measuring device. In this case, the controller is also in communication with the third measuring point and is set up to receive topological information and, if applicable, temperature information from the third measuring point and the rolling train and/or the cooling device and/or the straightening machine and/or the pre-straightening machine, if present , depending on the information received from the third measuring point. Furthermore, the topological information and, if applicable, temperature information from the third measuring point can be included as a reference variable in the control loop of the controller, if available, whereby the result after the final straightening by the straightening machine is included in the control/regulation and thus improves the entire control or regulation loop becomes.

Preferably, the flatness measuring device of the first measuring point and/or the flatness measuring device of the second measuring point and/or the flatness measuring device of the third measuring point, if present, each have a plurality of lasers based distance sensors, which are mounted across a width direction of the metal strip, whereby the corresponding flatness measuring device provides the controller with distance values at several measuring points as topological information. The use of laser-based distance sensors allows a particularly precise and flexible measurement. The surveying grid can be adapted to different circumstances, for example changed materials or dimensions of the metal strip, without a great deal of mechanical engineering effort. A number of tasks/optimizations can be performed on the software side without having to redesign the measuring point.

The distance sensors and, if applicable, temperature sensors of the measuring points are preferably mounted such that they can be adjusted spatially, for example, they can be slid on a rail and/or rotated, tilted, and the like. Particularly preferably, the distance sensors and optionally the temperature sensors can be manually or automatically adjusted or relocated at least in the width direction of the metal strip.

The controller is preferably set up to convert the received distance values of the several measuring points into relative height differences of the measuring points, to synchronize them with positions of the measuring points in a local coordinate system of the rolled strip to determine measuring tracks and to use the measuring tracks with a predefined function to determine a topological image of the metal strip to interpolate. The basic idea of such processing of the topological data is based on the assumption that the shape of the metal strip can be described by a continuous and smooth function, preferably a polynomial function or spline function. In this way, the measuring points of the distance sensors can be further processed to produce a topological image of the metal strip that can be visualized and used in other ways.

The controller is preferably also set up to evaluate the topological image of the metal strip using self-learning algorithms and/or neural networks, which means that in addition to quantitative measurement results, qualitative statements can be made fully automatically and used for automated optimization of the overall process.

For the same reason, the controller is preferably set up to detect and correct topological defects, preferably flatness defects, from the topological information of the first and/or second and/or third measuring point, in particular using self-learning algorithms and/or neural networks.

The above object is also achieved by a method for producing a rolled metal strip, preferably a hot-rolled metal strip, the method comprising: deforming the metal strip by rolling in a rolling train while the metal strip is being transported along a conveying direction; detecting topological properties of the metal strip formed by the rolling train by means of a flatness measuring device at a first measuring point; then cooling the metal strip by means of a cooling device with variable cooling capacity; detecting topological properties of the metal strip cooled by the cooling device by means of a flatness measuring device at a second measuring point; then straightening the metal strip, preferably improving the flatness of the metal strip, by means of a straightening machine; receiving topological information from the first and second measurement site by a controller; and controlling the rolling train and/or the cooling device and/or the straightening machine as a function of the topological information received from the first and second measuring point.

The features, technical effects, advantages and exemplary embodiments that have been described in relation to the device apply analogously to the method.

For the above-mentioned reasons, the controller preferably implements a control circuit, with the control controlling the rolling train and/or the cooling device and/or the leveler and/or pre-leveler, if present, with the data from the first and/or second measuring point and/or or third measuring point, if available, includes received topological information as a reference variable.

Preferably, the first measuring point includes a temperature measuring device that detects a surface temperature of the metal strip before cooling by the cooling device, and/or the second measuring point includes a temperature measuring device that detects a surface temperature of the metal strip after cooling by the cooling device, with the controller in this case Receives temperature information from the first and/or second measuring point and controls the rolling train and/or the cooling device and/or the leveler and/or the pre-leveler, if present, depending on the temperature information received from the first and/or second measuring point. Analogously, the measurements of a possible third measuring point behind the straightening machine can be included. Furthermore, the temperature information from one or more of the measuring points can act as a reference variable in a control loop of the controller.

Preferably, the flatness measuring device of the first measuring point and/or the flatness measuring device of the second measuring point each comprise a plurality of laser-based distance sensors that are mounted across a width direction of the metal strip, as a result of which the corresponding flatness measuring device provides the controller with distance values at a number of measuring points as topological information. In this case, for the reasons mentioned above, the controller preferably carries out the following data processing: converting the received distance values of the plurality of measurement points into relative height differences of the measurement points; synchronizing the measurement with positions of the measurement points in a local coordinate system of the rolled strip to determine measurement tracks; and interpolating the measurement tracks with a predefined function to determine a topological image of the metal strip.

The controller preferably also evaluates the topological image using self-learning algorithms and/or neural networks.

Further advantages and features of the present invention are evident from the following description of preferred exemplary embodiments. The features described therein can be implemented on their own or in combination with one or more of the features set out above, provided the features do not contradict one another. The following description of preferred exemplary embodiments is made with reference to the accompanying drawings.

character list

• 1 eine schematische Darstellung einer Vorrichtung zur Herstellung eines gewalzten Metallbandes; und
• 2 eine schematische Ansicht einer Messstelle mit Planheits- und Tem peraturmesseinrichtung.

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

• 1 a schematic representation of a device for producing a rolled metal strip; and
• 2 a schematic view of a measuring point with a flatness and temperature measuring device.

Detailed description of preferred embodiments

Preferred exemplary embodiments are described below with reference to the figures. Elements that are the same, similar or have the same effect are provided with identical reference symbols in the figures, and a repeated description of these elements is sometimes dispensed with in order to avoid redundancy.

The 1 1 shows a device 1 for producing a rolled metal strip B. The device 1 has a rolling train 10 with one or more roll stands 11 and a cooling/straightening device 20 for cooling and straightening the metal strip B, which is connected to the rolling train 10. The device 1 is preferably part of a hot strip mill.

During processing, the metal strip B is transported along a conveying direction F through the rolling train 10 and the cooling/straightening device 20 . Designations of spatial relations such as "before", "behind", "first", "last", "upstream", "downstream", "between", "transverse" etc. refer to the conveying direction F. The metal strip B is on usual way over a roller table 90 (cf. 2 ) transported and guided along the conveying direction F.

The metal strip B is used here as the rolling stock, with all intermediate products such as slabs, heavy plate, finished plate and the like collectively falling under the term “metal strip”. The term "metal strip" also includes all metals and alloys in sheet form that are suitable for rolling, in particular steel and non-ferrous metals such as aluminum or nickel alloys.

The device 1 is particularly preferably used for steel sheet production, i.e. it can primarily be used on all steel sheets whose material properties are adjusted in an in-line continuous cooling process after the rolling process. However, the device 1 is also applicable to metal strips B which are not subject to an in-line continuous cooling process; in this case, it serves to improve profile and flatness regulation in the rolling process.

The roll stands 11 are preferably each designed as a four-high stand (four-high roll stand), comprising two parallel, opposite work rolls 11a, which form a roll gap, and two associated back-up rolls 11b, which are correspondingly in contact with the work rolls 11a in order to support the work rolls 11a to support.

The rolling train 10 preferably functions as a roughing train that is set up to roll a rolling stock, for example a slab coming from a continuous casting plant, into a heavy plate. The heavy plate then passes through the cooling/levelling device 20, in which it is cooled and leveled to produce the desired flatness, and can then be finish-rolled to a desired final thickness in a finishing train (not shown).

The cooling/straightening device 20 comprises a cooling device 30 which has one or more nozzle arrangements 31 each with a plurality of nozzles 31a. The nozzle assemblies 31 define a continuous cooling section in which the metal strip B is cooled in a targeted manner and, apart from any measuring points/sensors, is preferably located directly behind the rolling train 10 or behind a pre-leveling machine 40, as in the exemplary embodiment of FIG 1 shown, begins. However, it should be pointed out that other units, such as a descaler, a thermal insulation hood, shears and the like, can certainly also be installed.

The nozzle assemblies 31 comprise a fluid system with pump(s), distribution line(s), valve(s) and the like in which 1 not shown in detail, to supply the nozzles 31a with a fluid cooling medium, preferably water or a water mixture. The nozzles 31a are set up to spray the cooling medium onto the metal strip B, in particular the two strip surfaces. For this purpose, the nozzles 31a are suitably positioned and aligned in order to apply a variable amount of cooling medium to the metal strip B, preferably controllable in sections along the cooling section and/or over the width of the cooling section. Alternatively or in addition to varying the amount of coolant that can be delivered through the nozzles 31a, the cooling characteristics can be influenced by adjusting the height of the nozzle arrangement(s) 31 or by other technical means for manipulating the amount of coolant and/or coolant distribution.

The cooling capacity can preferably be regulated by width masking and/or divided cooling units with adjustable water flows for inner and outer zones along the cooling section and/or across the width of the cooling section. In this way, it is possible to react extremely flexibly to any unevenness measured in the cooling section.

A straightening machine 50 is arranged behind the cooling device 30 and is set up to straighten the metal strip B, in particular its profile in the width direction b (cf. 2 ), ie transversely to the conveying direction F, to bend into a desired shape, in particular to straighten to optimize the flatness. This applies equally to the optional pre-leveling machine 40. The leveling machine 50 and any pre-leveling machine 40 eliminate, for example, distortions, internal stresses or deformations on the metal strip B, which can result from rolling processes, thermal and/or other loads. For this purpose, the metal strip B runs through the straightening machine(s) 40, 50, in which the material is guided through a group of upper and lower straightening rollers 41, 51 and is thereby plastically deformed by a corresponding adjustment of the straightening rollers 41, 51.

The cooling/straightening device 20 has at least two measuring points 60, 70 in order to be able to specifically control or regulate the cooling capacity in the cooling section and the straightening machine(s) 40, 50, as explained in detail below. A first measuring point 60 is arranged in front of the cooling device 30 , preferably between the pre-leveling machine 40 and the cooling device 30 , and a second measuring point 70 is arranged behind the cooling device 30 . The measuring points 60, 70 each include at least one flatness measuring device 61, 71, which further below with respect to the 2 be explained. Preferably, the measuring points 60, 70 also each have at least one temperature measuring device 62, 72 (cf. 2 ) on, whereby the temperature measurement can also be carried out by separate devices. However, the combination of several sensors for detecting different variables, here in particular flatness and temperature, at corresponding measuring points 60, 70 is preferred for mechanical engineering reasons, for example for the modularization of the system. According to a further exemplary embodiment, a third measuring point 80 with an analog structure can be installed behind the straightening machine 50 .

The device 1 also has a controller 100 which is set up to control and/or regulate the processing of the metal strip B, in particular the rolling, cooling and straightening process.

For this purpose, the controller 100 is in communication with the components of the device 1 to be controlled and/or regulated, as well as with the measuring points 60, 70, 80 and any other probes/sensors. Communication can be wireless or wired, digital or analog. Furthermore, a data or signal exchange in only one direction is subsumed herein under the term "communication". The controller 100 does not necessarily have to be implemented by a central computing device, but rather includes decentralized and/or multi-level and hierarchical systems, control networks, cloud systems and the like. The control 100 can also be an integral part of a higher-level system control or communicate with such.

For the process engineering integration of flatness measurements in the in-line cooling and straightening process, as well as retrospectively optionally in the profile and flatness regulation of the rolling train 10, a flatness measurement of the metal strip B takes place at least before and after the cooling section, defined by the cooling device 30, by means of the first and second Measuring point 60, 70 instead. A third measuring point 80 can be installed behind the straightening machine 50 .

An embodiment of a measuring point 60, 70, 80 is in 2 shown. The first and second measuring point 60, 70 and the optional third measuring point 80 are in this case constructed essentially identically, so that for the description of 2 the distinction between the first, second and third measuring point 60, 70, 80 is dispensed with. However, the measuring points 60, 70, 80 can also differ structurally depending on requirements.

The measuring point 60, 70, 80 has a flatness measuring device 61, 71, 81, which is set up to measure the profile of the metal strip B in the width direction b. The flatness measuring device 61, 71, 81 preferably works without contact, in particular using laser-based distance sensors 61a, 71a, 81a. In the embodiment of 2 seven distance sensors 61a, 71a, 81a are installed above the metal strip B. More or fewer distance sensors 61a, 71a, 81a can be installed as required.

The distance sensors 61a, 71a, 81a are mounted across the width of the roller table 90, preferably symmetrically to the middle of the roller table. The statistical distribution of the rolled product widths can be used for the optimal positioning of the distance sensors 61a, 71a, 81a, in which the largest possible number of metal strips B is detected with a number of measuring tracks.

The distance sensors 61a, 71a, 81a have an absolute accuracy of about 1 mm at a maximum measuring frequency of 200 Hz, for example. The distance to the surface of the metal strip B is determined by evaluating the phase shift of the reflected laser beam.

The measuring point 60, 70, 80 also has a temperature measuring device 62, 72, 82, each with at least one temperature sensor 62a, 72a, 82a. The temperature measuring device 62, 72, 82 is preferably set up to detect the temperature in the middle of the metal strip B, viewed in width direction b, and/or the temperature distribution over the width of the metal strip B. For this purpose, the temperature sensor 62a, 72a, 82a is preferably installed centrally with respect to the roller table 90.

The temperature distribution in the width direction b of the metal strip B generally has a higher gradient than the strip profile, in particular at the strip edges before cooling or also in central areas of the metal strip B shortly after leaving the cooling section. Thus, a temperature measuring device 62, 72, 82 is preferably installed in all measuring points 60, 70, 80.

The temperature sensor 62a, 72a, 82a preferably works in a non-contact manner, for example implemented by an infrared line scanner, and is generally designed in such a way that it essentially determines the surface temperature of the metal strip B. The temperature range of the temperature sensor 62a, 72a, 82a is, for example, in the range of 200° C. to 1500° C., and it measures, for example, at a frequency of up to 150 Hz for 1000 points over the scanned area. If the surface temperature of the metal strip B is known at one or more points in the processing line, for example through other measurements or model calculations, temperature measuring devices 62, 72, 82 in the measuring points 60, 70, 80 may be dispensed with.

The distance sensors 61a, 71a, 81a and temperature sensors 62a, 72a, 82a are preferably spatially adjustable, for example mounted on a rail 63, 73, 83 so that they can be moved. The installation allows the distance sensors 61a, 71a, 81a and temperature sensors 62a, 72a, 82a to be manually or automatically displaced at least in the width direction of the roller table 90.

The distance sensors 61a, 71a, 81a and temperature sensors 62a, 72a, 82a are mounted (possibly via the rail 63, 73, 83) on a frame 64, 74, 84, which extends over the roller table 90 like a bridge. The frame 64, 74, 84 is installed at a certain distance from the cooling path, defined by the cooling device 30, in order to avoid errors in the measurement due to coolant that may escape. The frame 64, 74, 84 has, for example, a width of about 9 meters and a height of about 6 meters above the roller table level.

Controller 100 is responsible for evaluating and further processing the measurement signals from distance sensors 61a, 71a, 81a and temperature sensors 62a, 72a, 82a.

Coming back to the 1 the first measuring point 60 is installed in front of the cooling device 30, preferably behind the pre-leveling machine 40, if present. For structural integration, the flatness measuring device 61 and/or the temperature measuring device 62 can be mounted on the pre-leveling machine 40 on the side of the cooling section via a carrier.

The first and second measuring point 60, 70 as well as the optional third measuring point 80 and a correspondingly designed controller 100 allow a flatness measurement to be integrated into the process in the in-line cooling and straightening process, as well as retrospectively in the profile and flatness control of the device 1 possible. Any flatness defects are automatically detectable, including a classification of flatness defects, and correctable, preferably using machine learning or AI algorithms. The optional third measuring point 80 allows an additional flatness measurement after the final straightening in order to check the straightening result and to improve the entire control or regulation loop.

To evaluate the measurement data, the measured temperature and profile traces are stored, for example, in a database with a metal strip number, a time stamp, conveying speed and any other process parameters.

• Flacherzeugnisse werden nicht nur nach Qualitätsparametern wie mechanischen Eigenschaften, Oberflächendefekte und Geometrie des Querschnittes sondern auch nach der Planheit bewertet und qualifiziert. Die Rand- und Mittelwellen sind dabei die am häufigsten registrierten Fehler. Als Ursache kommen zu hohe Resteigenspannungen im Querschnitt in Betracht, die durch eine ungleichmäßige Ausdehnung, während der Umformschritte und auch aufgrund einer ungleichmäßigen Abkühlung entstehen können.

In contrast to temperature measurement, the flatness measurement requires more extensive data pre-processing, which is described in more detail below:

• Flat products are not only evaluated and qualified according to quality parameters such as mechanical properties, surface defects and cross-section geometry, but also according to flatness. The edge and medium waves are the most frequently registered errors. The cause may be excessive residual stresses in the cross section, which can be caused by uneven expansion during the forming steps and also due to uneven cooling.

During the process, the flatness of the metal strip B can be influenced by changing the internal stress distribution. For example, straightening after the cooling process can eliminate any flatness errors; however, this can lead to a deterioration in the mechanical properties due to the hardening of the material. The avoidance or reduction of internal stresses during cooling also poses an enormous challenge for cooling technology. The in-line measurement of the topology of metal strip B presented here opens up the possibility of controlling and optimizing the forming processes in rolling train 10, cooling in the cooling device 30, the straightening in the straightening machines 40, 50 and any heat treatment with regard to the quality of the flatness.

For this purpose, a method to determine the topology of the metal strip B between the process steps is required. As explained above, a measuring point 60, 70, 80 comprises a plurality of distance sensors 61a, 71a, 81a, which are preferably mounted symmetrically to the center of the roller table 90 in accordance with the statistical distribution of the product widths over the roller table 90. The statistical distribution serves for the optimal positioning of the distance sensors 61a, 71a, 81a, in which the largest possible number of different metal strips B can be detected with as many measuring tracks as possible over the strip width b. The measurement preferably runs continuously, with the metal strip B to be measured moving under the flatness measuring device 61 , 71 , 81 .

The basic idea of such a structure is based on the assumption that the shape of the metal strip B can be described by a continuous and smooth function. The strength and thickness of the rolled products mean that the curvature function over the strip width b usually appears as a polynomial function or spline function of a smaller order.

1. a) Messen von Abständen zur Oberfläche des Metallbandes B an diskreten Positionen über die Bandbreite b durch die Abstandssensoren 61a, 71a, 81a;
2. b) Umrechnen der Abstände in relative Höhenunterschiede der Messpunkte;
3. c) Synchronisieren der Messung mit Positionen der Messpunkte in einem lokalen Koordinatensystem des Walzbandes B über die Position des Walzbandes B relativ zur Position der Planheitsmesseinrichtung 61, 71, 81 zur Ermittlung von Messspuren;
4. d) Interpolieren der Messspuren mit einer vordefinierten Funktion zur Ermittlung eines topologischen Abbilds oder eines anderen Maßes für die Planheit und gegebenenfalls Visualisierung des Abbilds bzw. der Planheit;
5. e) Optional Ablegen des topologischen Abbilds in Form eines Bildes zur Klassifikation mit Hilfe selbstlernender Algorithmen, vorzugsweise unter Verwendung neuronaler Netze mit mehreren Zwischenlagen („Deep Learning“ Algorithmen), um zusätzlich zu quantitativen Messergebnissen qualitative Aussagen vollautomatisch treffen zu können

A preferred method for measuring the flatness or topology of the metal strip B and processing the measurement data by the controller 100 comprises the following steps:

1. a) measuring distances to the surface of the metal strip B at discrete positions over the strip width b by the distance sensors 61a, 71a, 81a;
2. b) converting the distances into relative height differences of the measuring points;
3. c) synchronizing the measurement with positions of the measuring points in a local coordinate system of the rolled strip B via the position of the rolled strip B relative to the position of the flatness measuring device 61, 71, 81 for determining measuring tracks;
4. d) interpolating the measurement traces with a predefined function to determine a topological image or another measure of the flatness and optionally visualizing the image or the flatness;
5. e) Optional storage of the topological image in the form of an image for classification using self-learning algorithms, preferably using neural networks with several intermediate layers (“deep learning” algorithms) in order to be able to make fully automatic qualitative statements in addition to quantitative measurement results

The data processing of the measured distances can be carried out fully automatically and optimized by using statistical methods, for example the so-called “Gaussian Mixture Model” (GMM method). The statistical processing of the measurement data can be used to assess the quality of the measurements, e.g wise, taking into account the variance of the distribution, and thus used synergistically as an indicator for the state of the measuring point(s) 60, 70, 80, which, for example, indicates the need to clean and/or repair the distance sensors 61a, 71, 81a and temperature sensors 62a, 72a, 82a.

The controller 100 preferably implements a control loop that uses the temperature and profile data obtained in this way as reference variable(s) for automated straightening and/or cooling.

The device 1 presented here and the method for producing a rolled metal strip B allow verification of any deviations from the flatness of the metal strip B that occur during the in-line cooling and straightening process. This enables optimization of the cooling strategies to reduce flatness deviations in the metal strip B on the basis of statistical analysis and correlations of process settings and flatness values determined. The flatness measurements carried out in this way can be fed into the system automation of the cooling device 30, straightening machine(s) 40, 50, rolling train 10 and any profile and flatness control of a finishing rolling stand.

The integral measurement and control structure allows the use of machine learning methods in the manufacturing process by processing the measured flatness values. Furthermore, for example, setting values for the leveling machine(s) 40, 50 can be derived automatically and leveling passes can be saved, which is important for the production of steel sheets from certain materials (e.g. TRIP steels or other steels with retained austenite) in order to start the hardening process after cooling to stimulate as little as possible in the cooling section. This also applies, for example, to pipe steels with specific yield point/tensile strength ratios.

A manual flatness assessment by an operator can be omitted. This relieves the operating personnel and standardizes the process, which means that less expertise is required to use and operate the device 1 . Furthermore, the automation of the cooling and straightening process presented here contributes to an improvement in the quality of the rolling stock, in particular with regard to flatness. The improvement in the flatness of the metal strip B in the cooling process results in an improvement in the homogeneity of the material properties throughout the rolled plate.

The automation of the cooling and straightening process, in particular using the control circuit, also contributes to improving the reliability and durability of the device 1, for example by reducing the risk of damage to the straightening rollers 41, 51 through correct adjustment of the front rollers 41, 51 of the Leveler(s) 40, 50 based on information about the shape of the metal strip head.

As far as applicable, all of the individual features that are presented in the exemplary embodiments can be combined with one another and/or exchanged without departing from the scope of the invention.

Reference List

1

Device for producing a rolled metal strip

10

rolling mill

11

mill stand

11 a

stripper

11b

backup roll

20

cooling/straightening device

30

cooling device

31

nozzle arrangement

31a

jet

40

pre-leveler

41

straightening roll

50

leveler

51

straightening roll

60

First measuring point

61

flatness measuring device

61a

distance sensor

62

temperature measuring device

62a

temperature sensor

63

rail

64

Frame

70

Second measuring point

71

flatness measuring device

71a

distance sensor

72

temperature measuring device

72a

temperature sensor

73

rail

74

Frame

80

Third measuring point

81

flatness measuring device

81a

distance sensor

82

temperature measuring device

82a

temperature sensor

83

rail

84

Frame

90

roller table

100

steering

B

metal strap

b

width direction of the metal strip

f

conveying direction

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102013214344 A1 [0005]
• US 10994316 B2 [0005]

Claims (14)

Device (1) for producing a rolled metal strip (B), preferably a hot-rolled metal strip (B), the device (1) having: a rolling train (10) which is set up to deform the metal strip (B) plastically during transport along a conveying direction (F) by rolling; a cooling device (30) with variable cooling capacity, which is arranged downstream of the rolling train (10) in the conveying direction (F) and is set up to cool the metal strip (B); a straightening machine (50) which is arranged downstream of the cooling device (30) in the conveying direction (F) and is set up to bend the metal strip (B) into a desired shape, preferably straightening it to improve flatness; a first measuring point (60), arranged between the rolling train (10) and the cooling device (30), with a flatness measuring device (61) for measuring topological properties of the metal strip (B); a second measuring point (70), arranged between the cooling device (30) and the straightening machine (50), with a further flatness measuring device (71) for measuring topological properties of the metal strip (B); and a controller (100), which is in communication with the rolling train (10), the cooling device (30), the straightening machine (50) and with the first and second measuring point (60, 70) and is set up to receive topological information from the first and second measuring point (60, 70) and to control the rolling train (10) and/or the cooling device (30) and/or the straightening machine (50) depending on the topological information received from the first and second measuring point (60, 70). . Device (1) after claim 1 , characterized in that the controller (100) implements a control circuit for controlling the rolling train (10) and/or the cooling device (30) and/or the straightening machine (50), the control circuit from the first and/or second measuring point ( 60, 70) uses received topological information as reference variable. Device (1) after claim 1 or 2 , characterized in that the first measuring point (60) has a temperature measuring device (62) for measuring a surface temperature of the metal strip (B) and/or the second measuring point (70) has a temperature measuring device (72) for measuring a surface temperature of the metal strip (B), wherein the controller (100) is set up to receive temperature information from the first and/or second measuring point (60, 70) and the rolling train (10) and/or the cooling device (30) and/or the straightening machine (50) as a function of the temperature information received from the first and/or second measuring point (60, 70). Device (1) after claim 2 and 3 , characterized in that the control loop of the controller (100) uses the temperature information received from the first and/or second measuring point (60, 70) as a reference variable. Device (1) according to one of the preceding claims, characterized in that a pre-leveling machine (40) is also arranged between the rolling train (10) and the first measuring device (60) and set up to bend the metal strip (B) into a desired shape To straighten, preferably to improve the flatness, the controller (100) being set up to control the device (40) depending on the topological information received from the first and second measuring points (60, 70). Device (1) according to one of the preceding claims, characterized in that a third measuring point (80) is arranged behind the straightening machine (50), the third measuring point (80) having a further flatness measuring device (81) for measuring topological properties of the metal strip (B ) and the controller (100) is in communication with the third measuring point (80) and is set up to receive topological information from the third measuring point (80) and the rolling train (10) and/or the cooling device (30) and /or to control the straightening machine (50) depending on the topological information received from the third measuring point (80). Device (1) according to one of the preceding claims, characterized in that the flatness measuring device (61) of the first measuring point (60) and/or the flatness measuring device (71) of the second measuring point (70) each have a plurality of laser-based distance sensors (61a, 71a), which are mounted across a width direction (b) of the metal strip (B), whereby the corresponding flatness measuring device (61, 71) provides the controller (100) with distance values at a number of measuring points as topological information. Device (1) after claim 7 , characterized in that the controller (100) is set up to convert the received distance values of the several measuring points into relative height differences of the measuring points, to synchronize them with positions of the measuring points in a local coordinate system of the rolled strip (B) for determining measuring tracks and the measuring tracks with a predefined function for determining a topological image of the metal strip (B) to interpolate, the controller (100) preferably also being set up to evaluate the topological image using self-learning algorithms and/or neural networks. Device (1) according to one of the preceding claims, characterized in that the controller (100) is set up to detect and correct topological defects, preferably flatness defects, from the topological information of the first and/or second measuring point (60, 70). , preferably using self-learning algorithms and/or neural networks. Process for the production of a rolled metal strip (B), preferably a hot-rolled metal strip (B), the process comprising: Reshaping of the metal strip (B) by rolling in a rolling train (10) while the metal strip (B) is being transported along a conveying direction (F); detecting topological properties of the metal strip (B) formed by the rolling train (10) by means of a flatness measuring device (61) at a first measuring point (60); then cooling the metal strip (B) by means of a cooling device (30) with variable cooling capacity; detecting topological properties of the metal strip (B) cooled by the cooling device (30) by means of a flatness measuring device (71) at a second measuring point (70); then straightening the metal strip (B), preferably improving the flatness of the metal strip (B), by means of a straightening machine (50); Receiving topological information from the first and second measuring point (60, 70) by a controller (100); and Controlling the rolling train (10) and/or the cooling device (30) and/or the straightening machine (50) as a function of the topological information received from the first and second measuring points (60, 70). procedure after claim 10 , characterized in that the controller (100) implements a control loop and the control a regulation of the rolling train (10) and / or the cooling device (30) and / or the straightening machine (50) with the from the first and / or second measuring point ( 60, 70) includes received topological information as a reference variable. procedure after claim 10 or 11 , characterized in that the first measuring point (60) comprises a temperature measuring device (62) and detects a surface temperature of the metal strip (B) before cooling by the cooling device (30) and/or the second measuring point (70) comprises a temperature measuring device (72). and detects a surface temperature of the metal strip (B) after cooling by the cooling device (30), the controller (100) receiving temperature information from the first and/or second measuring point (60, 70) and the rolling train (10) and/or the Cooling device (30) and/or the straightening machine (50) depending on the temperature information received from the first and/or second measuring point (60, 70), the controller (100) preferably implementing a control circuit and the control controlling the rolling train ( 10) and/or the cooling device (30) and/or the straightening machine (50) with the temperature information received from the first and/or second measuring point (60, 70) as a reference variable. Method according to one of the preceding claims, characterized in that the flatness measuring device (61) of the first measuring point (60) and/or the flatness measuring device (71) of the second measuring point (70) each have a plurality of laser-based distance sensors (61a, 71a) which have a Width direction (b) of the metal strip (B) are mounted, whereby the corresponding flatness measuring device (61, 71) of the controller (100) provides distance values at several measuring points as topological information, and the controller (100) converts the received distance values of the several measuring points into relative height differences of the measuring points are converted, synchronized with positions of the measuring points in a local coordinate system of the rolled strip (B) to determine measuring tracks and interpolate the measuring tracks with a predefined function to determine a topological image of the metal strip (B), wherein the controller (100) preferably also evaluates the topological image using self-learning algorithms and/or neural networks. Procedure according to one of Claims 10 until 13 , characterized in that this with a device according to one of Claims 1 until 9 is carried out.

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