阅读说明：本技术 用于制造金属带材或板材的方法 (Method for producing a metal strip or plate ) 是由 A·斯普罗科 C·哈塞尔 K·格里贝尔 于 2020-01-16 设计创作，主要内容包括：本发明涉及一种用于制造金属带材或板材(1)的方法,其中,所述带材或板材在多机架式的轧机(11)中被轧制并且沿输送方向(F)在轧机(11)的最后的轧机机架(14)之后被送出,其中,在多机架式的轧机(11)中和/或沿输送方向(F)观察在轧机(11)下游冷却所述带材或板材(1),其中,沿输送方向(F)观察在轧机(11)的最后的轧机机架(14)的上游测量所述带材或板材(1)的温度。然后,从该测量的温度出发,借助于轧机(11)的最后的轧机机架(14)的输出端(A)处的温度计算模型纯计算地确定带材或板材(1)的温度,利用该温度在与预先确定的参考值比较之后可控制或调节制造方法的另外的过程。(The invention relates to a method for producing a metal strip or plate (1), wherein the strip or plate is rolled in a multi-stand rolling mill (11) and is fed out in a conveying direction (F) after a last rolling stand (14) of the rolling mill (11), wherein the strip or plate (1) is cooled in the multi-stand rolling mill (11) and/or downstream of the rolling mill (11) as viewed in the conveying direction (F), wherein a temperature of the strip or plate (1) is measured upstream of the last rolling stand (14) of the rolling mill (11) as viewed in the conveying direction (F). Starting from this measured temperature, the temperature of the strip or plate (1) is then determined purely computationally by means of a temperature calculation model at the output (A) of the last roll stand (14) of the rolling mill (11), with which, after comparison with a predetermined reference value, further processes of the production method can be controlled or regulated.)

1. Method for producing a metal strip or plate (1), wherein the strip or plate is rolled in a multi-stand rolling mill (11) and is fed out in a conveying direction (F) after the last rolling stand (14) of the rolling mill (11), wherein the strip or plate (1) is cooled in the multi-stand rolling mill (11) and/or downstream of the rolling mill (11) as viewed in the conveying direction (F), wherein a temperature (T2) of the strip or plate (1) is measured upstream of the last rolling stand (14) of the rolling mill (11) as viewed in the conveying direction (F),

characterized in that the method has the following steps:

(i) calculating a Temperature (TFM) of the strip or plate (1) at the output (a) of the last rolling stand (14) of the rolling mill (11) based on the temperature (T2) of the strip or plate (1) measured upstream of the last rolling stand (14) of the rolling mill (11) by means of a temperature calculation model, wherein the calculation step is performed for a system consisting of a section of material of the strip or plate (1) between the location of the temperature (T2) measured upstream of the last rolling stand (14) and the output (a) of the last rolling stand (14);

(ii) will be directed to the rollingThe Temperature (TFM) calculated for the strip or sheet (1) at the output (A) of the last rolling stand (14) of the machine (11) is compared with a predetermined reference value (TFM)_ref) Comparing; and

(iii) taking into account the calculated Temperature (TFM) and the predetermined reference value (TFM) according to step (ii)_ref) In the case of a comparison, at least one process parameter of the strip or plate (1) is adapted (controlled, preferably regulated), wherein the strip or plate is processed, heated or cooled as a function of the process parameter.

2. Method according to claim 1, wherein the Temperature (TFM) calculated in step (i) is the surface temperature of the strip or sheet (1).

3. Method according to claim 1 or 2, characterized in that the process parameter is the temperature of an intermediate stand cooling device (22) of the rolling mill (11) arranged upstream of the last rolling stand (14) as seen in the conveying direction (F), wherein the temperature of the intermediate stand cooling device (22) is controlled, preferably adjusted, in step (iii) taking into account the comparison according to step (ii).

4. Method according to any one of claims 1 to 3, characterized in that the process parameter is the temperature of a strip pre-cooling device (24) arranged upstream of the rolling mill (11) as seen in the conveying direction (F), wherein the temperature of the strip pre-cooling device (26) is controlled, preferably adjusted, in step (iii) taking into account the comparison according to step (ii).

5. Method according to claim 1 or 2, characterized in that the process parameter is the temperature of an induction heating device (26) arranged upstream of the rolling mill (11) as seen in the conveying direction (F), wherein the temperature of the induction heating device (26) is controlled, preferably adjusted, in step (iii) taking into account the comparison according to step (ii).

6. Method according to claim 1, 2 or 5, characterized in that the process parameter is the temperature of a furnace (28) arranged upstream of the rolling mill (11) as seen in the conveying direction (F), wherein the temperature of the furnace (28) is controlled, preferably adjusted, in step (iii) taking into account the comparison according to step (ii).

7. Method according to any one of the preceding claims, characterized in that the process parameter is the operating position of a heat shield (30) arranged upstream of the last roll stand (14) as viewed in the conveying direction (F), wherein the heat shield (30) is opened or closed in step (iii) relative to the strip or plate taking into account the comparison according to step (ii).

8. The method according to any one of claims 1 to 7, characterized in that a laminar cooling device (18) arranged downstream of the last roll stand (14) of the rolling mill (11) viewed in the conveying direction (F) is controlled, preferably regulated, in step (iii) taking into account the comparison according to step (ii).

9. The method according to any one of claims 1 to 8, characterized in that a rapid cooling device (16) arranged directly downstream of the last roll stand (14) of the rolling mill (11) viewed in the conveying direction (F) is controlled, preferably adjusted, in step (iii) taking into account the comparison according to step (ii).

10. Method according to any one of the preceding claims, characterized in that the process parameter is the temperature of an intermediate stand cooling device of the rolling mill (11) arranged upstream of the last rolling stand (14) viewed in the conveying direction (F), wherein the temperature of the intermediate stand cooling device is controlled, preferably adjusted, in step (iii) taking into account the comparison according to step (ii).

11. Method according to any of the preceding claims, characterized in that within the scope of the temperature calculation model, the total enthalpy as the free total molar enthalpy (H) of the system is found by means of the gibbs energy (G) at constant pressure (p) according to the following equation

Wherein the content of the first and second substances,

h-the molar enthalpy of the system,

g-gibbs energy of the system,

t-absolute temperature in kelvin,

p is the pressure of the system.

12. Method according to one of the preceding claims, characterized in that the temperature distribution in the system and in particular at the output (A) of the last rolling stand (14) of the rolling mill (11) is solved by means of the following Fourier thermal equation in the context of the temperature calculation model

Wherein the content of the first and second substances,

where p is the density of the resin,

c_pspecific heat capacity at constant pressure,

t-absolute temperature calculated in kelvin,

λ is the thermal conductivity of the material,

s is the position coordinate to which it belongs,

t is time, and

q ═ the energy of the system released during the phase transition from liquid to solid state before the rolling mill (11) or upstream of the rolling mill.

13. Method according to any one of the preceding claims, characterized in that, within the scope of the temperature calculation model, the Gibbs energy (G) of the entire system as a sum of the Gibbs energies of the pure phases and of the phase components of the pure phases for phase mixing is solved according to the following equation

G＝f^lG^t+f^γG^γ+f^pαG^pα+f^eαG^eα+f^ecG^ec

Wherein the content of the first and second substances,

g-gibbs energy of the system,

fⁱa Gibbs energy component for each phase or each phase component over the entire system, and

Gⁱgibbs energy of each pure phase or each phase component of the system.

14. Method according to any of the preceding claims, characterized in that the predetermined reference value (TFM) is determined by means of a tissue structure model for setting desired material properties_ref)。

15. The method of claim 14, wherein the tissue structure model is based on a predetermined reference value (TFM)_ref) Determining whether a degradation of the material is possible in the event of a deviation from the calculated Temperature (TFM), wherein the calculated Temperature (TFM) is determined as a new predetermined reference value (TFM) in the event of no possibility_ref)。

16. Method according to claim 14 or 15, characterized in that, in order to compensate for possible quality degradation, the organizational structure model is also preset with new reference values for the temperature (T3, T4) of the strip or sheet and with the associated cooling rates (CR23, CR34) at a location downstream of the last rolling stand (14) of the rolling mill (11) and/or at a location downstream of a laminar cooling device (18) arranged downstream of the last rolling stand (14) of the rolling mill (11) viewed in the conveying direction (F).

17. The method according to any one of claims 14 to 16, wherein the model of the organizational structure is formed by a data-based model based on a kriging algorithm and/or by a network of neurons.

Technical Field

The present invention relates to a method for manufacturing a metal strip or plate according to the preamble of claim 1.

Background

It is known from the prior art to set the temperature profile of a strip or sheet made of steel over the length of the plant (for example a hot-rolled strip production line or a CSP plant) in a plant for producing said strip or sheet. For example, DE 2023799 a discloses providing a rolling stand with controllable spray devices for cooling a strip in a rolling mill with a production line, wherein the spray devices are controlled by means of a temperature control system. A plurality of pyrometers are arranged along the direction of transport of the strip, and the respective temperatures of the strip are measured by means of these pyrometers. The spray image (or the amount of cooling water input) for the currently cooled strip can be changed or adapted on the basis of an adaptive feedback of the temperature measured by means of the pyrometer.

From document EP 2959984B 1, a production method for hot-rolled steel sheets is known, in which cooling water at the inside of the last stand of the rolling mill or of the end stand is sprayed into a heat-rejecting finishing mill on the process side of the lower part of the end stand, in order to thereby achieve rapid cooling of the rolled material. The surface temperature of the rolled material is measured on the entry side of the terminal stand, in order to determine the surface temperature on the entry side therefrom. Then, after this, the measured entry-side surface temperature and the predetermined entry-side target surface temperature are compared with one another, wherein, on the basis of this comparison, control commands are sent to at least one unit consisting of the coil box, the green body heating device, the descaling device and/or the intermediate roll stand cooling device, whereby the measured entry-side surface temperature is equal to the predetermined entry-side target surface temperature.

In a possible embodiment of a hot-rolled strip or finished product production line, it is known to provide a rapid cooling device directly in the connection or at the output of the last roll stand of the finished product production line, with which the strip or plate is intensively cooled as it emerges from the finished product production line in the conveying direction. For this case, there is no possibility to determine the final rolling temperature of the strip or plate after the last stand and before the first cooling at the output of the finishing line on a measurement technique.

Disclosure of Invention

The aim of the invention is to optimize the temperature regulation and/or at least one further process parameter when producing or processing a strip or plate using a multi-stand rolling stand.

This object is achieved by a method having the features of claim 1. Advantageous developments of the invention are defined in the dependent claims.

The method according to the invention is used for producing metal strips or plates which are rolled in a multi-stand rolling mill and are fed out in the conveying direction after the last rolling stand of the rolling mill. The strip or plate is cooled in the multi-stand rolling mill and/or downstream of the rolling mill, as viewed in the direction of transport, the temperature of the strip or plate being measured upstream of the last rolling stand of the rolling mill, as viewed in the direction of transport. The method comprises the following steps:

(i) calculating the temperature of the strip or plate at the output of the last rolling stand next to the rolling mill on the basis of the temperature of the strip or plate measured upstream of the last rolling stand of the rolling mill by means of a temperature calculation model, wherein the calculation step is performed on a system consisting of a section of material of the strip or plate between the location of the temperature measured upstream of the last rolling stand and the output of the last rolling stand;

(ii) comparing the temperature calculated for the strip or plate at the output of the last rolling stand of the rolling mill with a predetermined reference value; and is

(iii) (iii) adapting (controlling, preferably adjusting) at least one process parameter of the strip or sheet according to which the strip or sheet is processed, heated or cooled, taking into account the comparison of the calculated temperature with the predetermined reference value according to step (ii).

In consideration of or as a function of the calculated temperature at the output of the last rolling stand of the rolling mill and the comparison made there against, the at least one process parameter adapted (e.g. controlled or regulated) in step (iii) of the method according to the invention can be the temperature (influenced by the amount of cooling water supplied) of the intermediate stand cooling device and/or the strip pre-cooling device arranged in each case (viewed in the transport direction of the strip or plate) upstream of the last rolling stand or rolling mill. Alternatively, the at least one process parameter can also be the temperature of an induction heating device and/or a furnace, which is arranged upstream of the rolling mill, viewed in the direction of transport of the strip or plate. In addition or alternatively, the process parameter controlled or adjusted according to the invention can also be the strip speed with which the strip or plate is transported through the rolling mill. Additionally and/or alternatively, the process parameter can also be the operating position of a heat shield arranged upstream of the rolling mill, viewed in the conveying direction (F), wherein the heat shield is opened or closed in step (iii) relative to the strip or plate, taking into account the comparison according to step (ii). In any case, the above-described variants for the method according to the invention allow the temperature of the strip or plate to be set or influenced in a targeted manner during its production.

It is particularly pointed out here that, if the process parameters relate to the temperature of the cooling device, the technical implementation in the associated installation for producing or processing a strip or plate is achieved by the amount of coolant supplied and/or the number of active or switched-on cooling zones or nozzles.

In connection with the present invention it is pointed out that in connection with the manufacture of metal strip or plate not only the knowledge of the exact temperature profile but also the maintenance of this temperature profile at a predetermined nominal value is crucial for obtaining high quality products, such as thin or thick slabs as well as bars or long products of steel and iron alloys. The temperature profile of the metal strip or slab is therefore an important variable in particular for controlling the working process (for example inside and/or downstream of the finishing line), but cannot be measured directly at every point of the plant, for example by using a pyrometer.

The invention is based on the basic knowledge that, by means of the calculation according to step (i), it is possible to determine process parameters, for example in the form of the temperature of the strip or plate, directly at the output of the last rolling stand of the rolling mill, in particular also for the case in which a rapid cooling device is connected thereto. The calculated temperature may preferably be the surface temperature of the strip or plate. In contrast, if a rapid cooling device is present in the immediate vicinity of the last roll stand of the rolling mill, it is not possible according to the prior art to determine the temperature of the strip or plate exiting from the last roll stand in the transport direction at the output of the latter roll stand of the rolling mill by measurement techniques. By comparing the temperature determined by calculation according to step (ii) with a predetermined reference value, the cooling water supply can be controlled, preferably regulated, so that the temperature of the strip or plate at the outlet of the last roll stand of the rolling mill thereby reaches this predetermined reference value. In addition and/or alternatively thereto, it is possible, taking into account the comparison according to step (ii), to adapt (that is to say to control or regulate) the cooling water supply for the strip or plate also in other regions of the plant for producing metal strips or plates, for example in the case of an intermediate stand cooling device arranged upstream of the last rolling stand (viewed in the conveying direction), in the case of a laminar flow cooling device arranged downstream of the last rolling stand of the rolling mill (viewed in the conveying direction) and/or in the case of a rapid cooling device arranged directly downstream of the last rolling stand of the rolling mill (viewed in the conveying direction).

The temperature calculation model used in step (i) is a preferably dynamic temperature regulation model or program. The calculation is performed by a finite difference method. By means of this model, the temperature distribution can be determined, in particular, as a function of the process conditions in the respective section of the installation used for producing or processing the metal strip or plate. The model or program can also be used for adjustment purposes in the cooling zone of a plant for producing metal strips or sheets. As a control variable, the (surface) temperature of the strip or sheet can be used, which is determined by calculation at the output of the last rolling stand of the rolling mill on the basis of or on the basis of the temperature of the strip or sheet measured upstream of the last rolling stand of the rolling mill (viewed in the direction of transport), for example by means of a pyrometer. When this parameter is preset as a set point value, the model/program calculates the amount of water needed to reach these values/parameters in the respective cooling zones. The results are visualized directly and updated in each new loop calculation. In this sense there is online computing and online control.

In an advantageous development of the invention, the temperature distribution in the system (i.e. in the section of the strip or plate between the location where the temperature is measured upstream of the last rolling stand of the rolling mill and the output of the last rolling stand) can be determined by means of a fourier thermal equation in the context of or when applying the temperature calculation model, said thermal equation being shown below:

wherein:

where p is the density of the resin,

c_pspecific heat capacity at constant pressure,

t-the calculated absolute temperature in kelvin,

λ is the thermal conductivity of the material,

s is the position coordinate to which it belongs,

t is time, and

q-the energy of the system released during the phase transition from liquid to solid before or upstream of the rolling mill.

In an advantageous development of the invention, the temperature distribution in the system (i.e. in the section of the strip or plate between the location where the temperature is measured upstream of the last rolling stand of the rolling mill and the output of the last rolling stand), the total enthalpy as a free total molar enthalpy (H) of the system, can be determined within the scope of the temperature calculation model or when applying the temperature calculation model, at a constant pressure (p) by means of gibbs energy (G) according to the following equation:

wherein:

h-the molar enthalpy of the system,

g-gibbs energy of the system,

t is the absolute temperature in Kelvin, and

p is the pressure of the system.

In an advantageous development of the invention, in the context of or when applying the temperature calculation model, in the system (that is to say in a section of the strip or plate between the location at which the temperature is measured upstream of the last rolling stand of the rolling mill and the output of the last rolling stand), the gibbs energy (G) of the entire system for phase mixing is determined as the sum of the gibbs energies of the pure phases and of their phase components according to the following equation:

G＝f^lG^l+f^γG^γ+f^pαG^pα+f^eαG^eα+f^ecG^ec

wherein:

G-Gibbs energy of the system, fⁱA Gibbs energy component for each phase or each phase component over the entire system, and

Gⁱgibbs energy of each pure phase or each phase component of the system.

As explained, the invention makes it possible to specifically control or regulate selected cooling zones of a plant for producing or processing metal strips or sheets with respect to the quantity of coolant supplied. In other words, the method according to the invention is characterized in that at least one cooling zone of such a plant is controlled or regulated by means of a temperature calculation model configured as a metallurgical process model.

Since gibbs energy can be provided for almost all materials manufactured worldwide today, the temperature profile in the mentioned system of the strip or plate (that is to say in a section of the strip or plate which is located between the location at which the temperature is measured upstream of the last rolling stand of the rolling mill and the output of the last rolling stand) can be determined in a material-dependent manner, with the aim of determining the temperature of the strip or plate at the output of the last rolling stand of the rolling mill from this precisely by calculation. The invention therefore also provides for the temperature profile to be determined and set in the material piece or material section in a material-dependent manner by means of a temperature calculation model.

Since with the method according to the invention the temperature of the strip or plate at the output of the last roll stand of the rolling mill can be calculated very quickly and in real time, the use of the method or the calculation method is particularly suitable for carrying out this use online and for controlling the production process of the strip or plate. In one embodiment, the use is further characterized in that the aforementioned temperature calculation model is used not only for the online determination of the temperature of the strip or plate at the output of the last roll stand of the rolling mill, but also for controlling at least one cooling zone of a plant for producing such a strip or plate.

By means of the invention and the associated method, an improved quality of the product can be achieved and at the same time a lower amount of waste material is achieved.

Drawings

The invention is explained in more detail below, wherein the various figures are attached for ease of understanding. These figures show:

FIG. 1 shows a view of Gibbs energy for pure iron;

FIG. 2 shows a phase diagram using Gibbs energy (as constructed);

FIG. 3 shows the variation of the total enthalpy according to Gibbs for low carbon steel;

fig. 4 shows a schematic simplified side view of a device with which a metal strip or plate is produced according to the method according to the invention;

FIG. 5 shows a temperature profile for the strip or plate over the length of the apparatus shown in FIG. 4; and

fig. 6 and 7 each show a schematic simplified side view of a device according to an embodiment that is complementary to fig. 4, with which a metal strip or plate is produced according to the method according to the invention.

Detailed Description

A preferred embodiment of the method according to the invention for producing a metal strip or plate 1 is explained below with reference to fig. 1 to 7. It is specifically noted here that the illustrations in fig. 4, 6 and 7 are shown merely simplified and not to scale.

In the method according to the invention, a temperature calculation model is used, with which the temperature of the produced metal strip or sheet 1 at the output of the last roll stand of the rolling mill can be calculated in a targeted manner.

First, to further illustrate the temperature calculation model and its application in an apparatus for manufacturing or processing a strip or sheet, a general rule is shown for the temperature calculation of a metal strip or sheet:

the temperature calculation is based on Fourier thermal equation (1), where c_PDenotes the specific heat capacity of the system, λ denotes the thermal conductivity, ρ denotes the density and s denotes the position coordinate. T represents the calculated temperature. The term Q on the right considers the energy released during the phase transition (equation 2). This term characterizes the heat of fusion when transitioning from a liquid to a solid, f_sIndicating the degree of phase change.

As essential input variables for the equation, the heat transfer and the total enthalpy are particularly important, since these variables influence the temperature result decisively. Thermal conductivity is a function of temperature, chemical composition, and phase components, and can be accurately found by experimentation.

The total enthalpy H or molar enthalpy of a material region or material section can be calculated by the gibbs energy as follows (3):

wherein the molar Gibbs energy of the system is G. For phase mixing, the Gibbs energy of the entire system can be calculated from the Gibbs energies of the pure phases and their phase components:

G＝f^lG^l+f^γG^γ+f^pαG^pα+f^eαG^eα+f^ecG^ec (4)

wherein the phase component of phase phi is f^φAnd the molar Gibbs energy of this phase is G^φ. For the austenite, ferrite and liquid phases, the gibbs energy is:

^magnG^φ＝RTln(1+β)f(τ) (7)

in equation (4), the terms correspond to the individual element energies, the contribution to ideal mixing, and the contribution to non-ideal mixing and magnetic energy, respectively (equation 7). With the known gibbs energy of the system, the molar specific heat capacity can be calculated from this:

the parameters of the terms of equations (5) - (7) are listed in the Thermocalc and Matcalc databases and can be used to find the Gibbs energy of the steel composition. The total enthalpy of this steel composition is derived from the mathematical derivatives.

Figure 1 shows a view of gibbs energy for pure iron. It can thus be seen that for a particular characterized temperature range, the individual phases, i.e. ferrite, austenite and liquid phase, are at a minimum, within which temperature range these phases are stable.

The phase boundaries of the Fe — C alloy with 0.02% Si, 0.310% Mn, 0.018% P, 0.007% S, 0.02% Cr, 0.02% Ni, 0.027% a1 and variable C content are shown in fig. 2. With the representation of gibbs energy, it is possible to construct such a phase diagram with arbitrary chemical composition and show stable phase components.

Fig. 3 shows the profile of the total enthalpy of low carbon steel (low carbon) as a function of temperature according to gibbs. Further, the solidus temperature and the liquidus temperature are shown in the image.

The illustration in fig. 4 shows, in principle, a simplified side view of a device 10 for applying the method according to the invention, with which the strip or plate 1 is produced or processed in the conveying direction F.

The plant 10 comprises a multi-stand rolling mill 11, which in the example shown here has a first roll stand 12, an intermediate roll stand 13 and a final roll stand 14. A rapid cooling device 16 is arranged next to the last roll stand 14 or its outlet end a, to which further cooling in the form of a laminar cooling device 18 is connected. At the end of the manufacturing line a capstan 20 is provided, with which the manufactured strip 1 can be wound.

An intermediate stand cooling device, not shown in detail, for the rolling mill 11 is arranged between the first rolling stand 12 and the intermediate rolling stand 13.

In the illustration of fig. 4, the direction of transport (from left to right in the region of the drawing) in which the strip or plate 1 is moved in the installation 10 or passes through the rolling mill 11 with the rolling stands 12 to 14 is indicated by an arrow "F".

The device 10 is equipped with a plurality of temperature measuring devices in order to determine the temperature of the strip or plate at different locations by means of measuring techniques. These temperature measuring devices include: a first pyrometer P1, which is arranged upstream of the first roll stand 12, viewed in the conveying direction F; a second pyrometer P2, which is arranged between the second roll stand 13 and the last roll stand 14 (and is therefore arranged upstream of the last roll stand 14, viewed in the conveying direction F); a third pyrometer P3, which is arranged, as viewed in the conveying direction F, between the rolling mill 11 and the laminar-flow cooling device 18; and a fourth pyrometer P4 disposed between the laminar cooling device 18 and the capstan 20.

With regard to the second pyrometer P2, which is arranged upstream of the last roll stand 14, viewed in the conveying direction F, it is separately emphasized that the temperature T2 which the strip or plate 1 has before it enters the last roll stand 14 is thereby measured. In the same way, the temperature measured with the pyrometers P1, P3 or T4 is denoted below by T1, T3 or T4.

The use of the rapid cooling device 16 results in the strip or plate 1 being cooled between the second pyrometer P2(═ T2) and the third pyrometer P3(═ T3) at a cooling rate CR 23. The same applies to the region between the third pyrometer P3(═ T3) and the fourth pyrometer P4(═ T4), in which region the laminar cooling device 18 is used for cooling at a cooling rate CR 34.

The device 10 also comprises calculation and control means, hereinafter simply referred to as control means, indicated with "100" in fig. 4 and in simplified form in the form of a rectangle. The control device 100 is equipped with a temperature calculation model. The temperature calculation model may have or be based on DTR or DSC (dynamic temperature regulation/dynamic freeze control) regulation means. The calculation is performed by a finite difference method.

The vertical arrows shown between the apparatus 10 and the rectangle for the control device 100 in the illustration of fig. 4 represent the interaction between the various components of the apparatus 10 and the control device 100. The arrows pointing upwards respectively show in detail that the temperatures measured by means of the pyrometers P1-P4 respectively are input into the control device 100 and processed therein by signal technology. The respective downwardly pointing arrows indicate that the associated components of the system 10 can be controlled or regulated by the control device 10, which relate to the intermediate stand cooling device (between the first rolling stand 12 and the intermediate rolling stand 13), the last rolling stand 14, the rapid cooling device 16 and/or the laminar flow cooling device 18, for example, in connection with the supply of coolant to these components.

With the aid of the previously described temperature calculation model, the temperature TFM is then determined by calculation, based on or as a function of the temperature T2 measured upstream of the last rolling stand 14 by means of the second pyrometer P2 and input into the control device 100 as explained, which temperature is then directly present at the output a of the last rolling stand 14 for the strip or sheet 1. This calculation is performed according to the finite difference method for a system of strips or sheets 1 constituted by the section of material of the strip or sheet 1 between the position where the second pyrometer P2 is arranged and the output a of the last rolling stand 14. As already explained above, in order to calculate the temperature profile or temperature TFM, the fourier thermal equation is solved. In this case, the boundary conditions in the rolling mill 11 (for example, the delivery temperature to the air and also to the rolls of the last roll stand 14 by radiation and convection) and the boundary conditions in the cooling line (delivery temperature to the water cooling, air and roller tables) are taken into account. The heat generation occurring by the phase change is likewise taken into account, which can occur in the rolling mill 11 or also in the cooling section.

The different temperatures T1-T4 set along the length of the apparatus 10 for the strip or plate 1 thus produced are shown in the diagram of fig. 5 with corresponding curve variations. The temperatures TFM determined by calculation (at the output a of the last roll stand 14) and the cooling rates CR23 and CR34 already described above are also recognizable here.

After the temperature TFM has been determined by calculation, it is compared by the control device 100 with a predetermined reference value TFM_refA comparison is made. Taking this comparison into account, the control device 100 can then be used to adapt, i.e. control or regulate, the cooling water supply for the strip or plate 1 as appropriate. This control (or regulation) of the cooling water input can be carried out in such a way that the temperature of the strip or plate 1 at the output a of the last rolling stand 14 is practically identical to the predetermined temperatureReference value TFM of_refThe further temperature T3 (in the case of the pyrometer P3) and/or T4 (in the case of the pyrometer P4) are adapted in a consistent and/or, in particular, suitable manner.

In fig. 6, a further embodiment of the device 10 is shown, wherein, in contrast to the embodiment of fig. 4, additionally components are provided, namely an induction heating device 26, a furnace 28 and/or a heat shield 30. As can be seen, these assemblies 26, 28, 30 (viewed in the direction of transport F of the strip or sheet) are each arranged upstream of the rolling mill 11, wherein the strip or sheet 1 can be guided through these assemblies. The arrows pointing from the control device 100 to these components 26, 28 or 30 indicate that the induction heating device 26, the furnace 28 and/or the heat shield 30 can be controlled or regulated by means of the control device 100, i.e. as described above, as a function of the calculated temperature TFM, which is compared with a predetermined reference value TFM_refThe comparison thus established is performed. The temperature of the strip or plate 1 is thereby influenced or increased in a targeted manner.

In particular, it should be noted with regard to the manner of operation of the heat shield 30 that it is a device for insulating the strip or sheet 1. The degree of thermal insulation for the strip or plate 1 at the roller table can be influenced by the opening or closing of the heat shield 30. By means of the actuation by means of the control device 100, the heat shield 30 is opened or closed accordingly, or is also moved into an intermediate position, wherein the temperature of the strip or sheet 1 is influenced depending on the respective position of the heat shield 30.

In the embodiment of fig. 7, upstream of the rolling mill 11, a strip pre-cooling device 24 is provided for the installation 10 (viewed in the direction of transport F of the strip or sheet 1), which can also be controlled or regulated by means of the control device 100, as indicated by the reference arrows. Based on the calculated temperature TFM and a predetermined reference value TFM_refThen the amount of cooling agent for the strip pre-cooling device 24 is controlled or regulated in order to influence or reduce the temperature of the strip or plate 1 in a targeted manner.

In the views of fig. 4, 6 and 7, the intermediate frame cooling device is designated by "22", which can likewise be controlled or regulated by means of the control device 100, i.e. by adapting the amount of coolant supplied and/or by the number of nozzles used.

In a further development of the method according to the invention, it can be provided that the respective reference values T1ref, T2ref, T3ref, T4ref are preset in the control device 100 or for the temperature calculation models stored therein also for the temperatures T1, T2, T3 and T4 as a function of the tissue structure model, in order to be able to achieve optimum behavior. Alternatively, the reference value must be determined based on empirical values or measurement and production data. These may be models based on, for example, neuronal networks, Kriging algorithms (Kriging Algorithmus), and the like.

In the case of deviations from T2, which can also be determined by means of the texture model, the quality of the strip 1 to be produced is not reduced. For this case, the measured value of the temperature T2 of the strip is then changed to a new target value, wherein the new target value is calculated for T3 and T4, respectively. Additionally, the cooling rates CR23 and/or CR34 may be varied to achieve the same characteristics with varied temperature profiles. The same applies to deviations from T3 to T3ref or T4 to T4 ref.

It is also possible to make this determination by means of empirical models based on data, based on existing measurement data and production data. These may be models based on, for example, neural networks, kriging algorithms, and the like.

The temperature calculation may be performed by gibbs energy and enthalpy. In this respect, reference may be made to the explanations above with respect to equations (1) - (8).

List of reference numerals

1 strip or plate

10 device

11 rolling mill

12 (of rolling mill 11) first roll stand

13 (of rolling mill 11) central roll stand

14 (of rolling mill 11) last rolling stand

16 quick cooling device

18 laminar cooling device

20 capstan

22 inter-frame cooling device

24 strip pre-cooling device

26 induction heating device

28 furnace

30 Heat shield

100 computing and control device

A (of the last roll stand 14) output

F (of the strip or sheet 1) direction of conveyance

P1 first pyrometer

P2 second pyrometer

P3 third pyrometer

P4 fourth pyrometer

Temperature of the strip or plate 1 at the measuring position of the pyrometer P1-P4T 1-T4