Cold rolling control system and cold rolling control method

Abstract

To accurately calculate the temperature of electrical steel sheets and properly control the cold rolling line. [Solution] This cold rolling control system includes a steel plate temperature calculation unit 114 that calculates the steel plate temperature using a steel plate temperature calculation model, and a rolling line control unit 11 that changes the settings on the cold rolling line using the steel plate temperature calculation results. The system also includes an actual deformation resistance calculation unit 111 that calculates the actual deformation resistance from the rolling data, a deformation resistance / temperature relationship data storage unit 112 that stores deformation resistance / temperature relationship data, a rolling temperature calculation unit 113 that calculates the steel plate temperature at the rolling mill using the deformation resistance / temperature relationship data and the actual deformation resistance, and a model change unit 115 that changes the steel plate temperature calculation model using the calculated steel plate temperature at the rolling mill and the steel plate temperature measured at the rolling line.

Description

[Technical Field]

[0001] The present invention relates to a cold rolling control system and a cold rolling control method. [Background technology]

[0002] In cold rolling of electrical steel sheets with 1.5% or more silicon added, the steel sheets are heated to over 100°C before rolling to prevent cracking during rolling. However, if the temperature of the steel sheet becomes excessively high, the lubricating oil film on the sheet disappears, causing scratches on the surface of the steel sheet due to friction between the steel sheet and the rolling rolls. Therefore, in cold rolling of electrical steel sheets, it is necessary to control the temperature of the steel sheet within an appropriate range.

[0003] Furthermore, in order to reduce energy loss due to eddy currents when electrical equipment is applied, cold rolling of electrical steel sheets is sometimes performed to a thickness of 0.2 to 0.5 mm, which is thinner than that of ordinary steel sheets. For this reason, in cold rolling of electrical steel sheets, it is necessary to calculate the deformation resistance of the steel sheet used to control the thickness of the steel sheet with high precision.

[0004] Patent Document 1 describes a technique for predicting the exit temperature of rolled material by using the reduction ratio or entry / exit plate thickness and measured rolling load to determine the temperature rise ΔTp of the plate material due to processing heat during rolling and the temperature rise ΔTf of the plate material due to frictional heat. In the technique described in Patent Document 1, the temperature drop ΔTc of the rolled material due to contact is determined from the measured or predetermined entry plate temperature and the measured exit plate temperature, and adjustment parameters for predicting the exit temperature of rolled material are calculated.

[0005] Patent Document 2 describes a technique that involves providing a learning value table for each steel type, which associates plate thickness, temperature, and deformation resistance learning value with each steel type, and a learning value table for each standard, which associates plate thickness, temperature, deformation resistance learning value, and rolling date and time with each standard, and switching the calculation table according to the rolling date and time. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-290922 [Patent Document 2] Japanese Patent Publication No. 2010-247223 [Overview of the project] [Problems that the invention aims to solve]

[0007] The technology described in Patent Document 1 assumes that the entry-side plate temperature T0 has been measured or predetermined, and uses rolling performance data including rolling load to calculate the temperature rise ΔTp and ΔTf of the rolled material during rolling. It then calculates the temperature drop ΔTc of the rolled material from the difference between T0 + ΔTp + ΔTf and the measured temperature at the exit side. However, the method described in Patent Document 1 has the problem that it is not easy to accurately measure or determine the entry-side plate temperature T0.

[0008] Infrared thermometers used to measure the temperature of rolled material in cold rolling lines can malfunction or fail due to contamination by fumes generated from the evaporation of lubricating oil and coolant. Furthermore, because the temperature of the rolled material is low in cold rolling, the intensity of emitted light is weak, and the error in temperature measurements can increase depending on the surface condition of the rolled material and the surrounding environment. In other words, the technology described in Patent Document 1 is based on the premise that the temperature of the rolled material at the input and output ends is measured with sufficient accuracy. Therefore, if the accuracy of these temperature measurements is insufficient, there is a problem in that high-precision rolling cannot be performed.

[0009] The technology described in Patent Document 2 is suitable for hot rolling, as it lists continuous hot rolling equipment as an applicable rolling mill, and it is difficult to apply it directly to cold rolling. The temperature range for cold rolling is a region where a low-temperature deformation resistance region, in which deformation resistance decreases with increasing temperature, and a blue-hot brittle region, in which deformation resistance increases with increasing temperature, coexist, and the blue-hot brittle region changes depending on the strain and strain rate. For this reason, it is not easy to apply the technology described in Patent Document 2 to cold rolling. Furthermore, as explained in Patent Document 1, it is difficult to accurately predict the temperature of cold-rolled material, so it is also difficult to apply the technology of Patent Document 2 to the calculation of deformation resistance in cold rolling.

[0010] The object of the present invention is to provide a cold rolling control system and a cold rolling control method that can accurately calculate the temperature of electrical steel sheets and appropriately control the cold rolling line. [Means for solving the problem]

[0011] To solve the above problems, for example, the configuration described in the claims is adopted. This application includes several means for solving the above problems, but to give one example, the cold rolling control system of the present invention is: A steel plate temperature calculation unit that calculates the steel plate temperature using a steel plate temperature calculation model, A cold rolling control system comprising: a rolling line control unit that changes settings on the cold rolling line using the steel plate temperature calculation results from a steel plate temperature calculation unit, A unit that calculates actual deformation resistance from rolling data, A deformation resistance-temperature relationship data storage unit stores deformation resistance-temperature relationship data showing the relationship between deformation resistance and steel plate temperature, A rolling temperature calculation unit calculates the steel sheet temperature in the rolling mill using deformation resistance-temperature relationship data and actual deformation resistance, The system includes a model modification unit that modifies the steel plate temperature calculation model using the steel plate temperature at the rolling mill calculated by the rolling temperature calculation unit and the steel plate temperature measured at the rolling line. [Effects of the Invention]

[0012] According to the present invention, since the temperature of the steel sheet in the rolling mill can be calculated based on the rolling data, even if the thermometer installed on the line malfunctions or fails, the temperature of the electrical steel sheet can be calculated accurately and the cold rolling line can be controlled. Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0013] [Figure 1] This is a block diagram showing an example configuration of a cold rolling control system according to a first embodiment of the present invention. [Figure 2] This figure shows an example of the temperature dependence of the deformation resistance of an electrical steel sheet and another steel sheet according to a first embodiment of the present invention. [Figure 3] This figure shows an example of deformation resistance-temperature relationship data according to a first embodiment of the present invention. [Figure 4] This figure shows an example of an approximation between deformation resistance and steel plate temperature according to a first embodiment of the present invention. [Figure 5] This flowchart shows an example of cold rolling control processing (Example 1) according to a first embodiment of the present invention. [Figure 6] This flowchart shows an example of cold rolling control processing (Example 2) according to the first embodiment of the present invention. [Figure 7] This is a block diagram showing an example configuration of a cold rolling control system according to a second embodiment of the present invention. [Figure 8] This flowchart shows an example of cold rolling control processing (Example 1) according to a second embodiment of the present invention. [Figure 9] This flowchart shows an example of cold rolling control processing according to a second embodiment of the present invention (Example 2). [Modes for carrying out the invention]

[0014] <Example of the first embodiment> The cold rolling control system and cold rolling control method of the first embodiment of the present invention will be described below with reference to Figures 1 to 6.

[0015] [Explanation of the temperature dependence of the deformation resistance of electrical steel sheets] First, referring to Figure 2, the change in deformation characteristics of electrical steel sheets with respect to temperature is shown in comparison to other steel sheets. In Figure 2, the vertical axis represents deformation resistance, and the horizontal axis represents steel sheet temperature. The inventors of this invention meticulously analyzed the properties of electrical steel sheets and data obtained from cold rolling of electrical steel sheets, and found that electrical steel sheets do not exhibit blue-hot brittleness, where deformation resistance increases with increasing temperature.

[0016] Figure 2 compares the deformation characteristics of electrical steel sheets with those of other steel sheets (shown by dashed lines) as a function of temperature. In other commonly known steel sheets, due to their blue-hot brittleness, the temperature dependence of deformation resistance is low within the cold-rolling temperature range. On the other hand, since electrical steel sheets do not exhibit blue-hot brittleness, their deformation resistance decreases monotonically with increasing temperature, and their temperature dependence of deformation resistance is also greater compared to other steel sheets. One of the features of this embodiment is to utilize this temperature dependence of the deformation resistance of electrical steel sheets within the cold rolling temperature range.

[0017] [Configuration of the cold rolling control system] Figure 1 shows the configuration of the cold rolling control system 1 in this embodiment. The cold rolling control system 1 comprises a rolling line control unit 11, a steel sheet temperature calculation unit 10, and a control transmission / reception unit 12. The steel sheet temperature calculation unit 10 receives rolling data input from the cold rolling line 3 received by the control transmission / reception unit 12.

[0018] The rolling data input to the steel plate temperature calculation unit 10 via the control transmission / reception unit 12 includes the following data: • Reduction force P in cold rolling mills 310, 320, ..., 370 • The radius R of the work roll that contacts the steel plate among the multiple rolls of each rolling mill. • Width b of steel plate 4 ·Thickness th of the steel sheet on the inlet side of the rolling mill in ·Thickness th of the steel sheet on the outlet side of the rolling mill out ·Moving speed v of the steel sheet 4 ·Friction coefficient μ ·Coolant ejection amount of steel sheet cooling nozzles 312, 313, 322, 323, …, 372, 373 ·Coolant ejection amount of work roll cooling nozzles 314, 324, …, 374 ·Lubricant ejection amount of lubricant nozzles 315, 325, …, 375 ·Temperature T of the steel sheet measured by thermometers 301, 311, … 371 meas In the following description, the work roll is simply referred to as a roll.

[0019] The steel sheet temperature calculation unit 10 includes an actual deformation resistance calculation unit 111, a rolling temperature calculation unit 113, a temperature calculation unit 114, and a model changing unit 115. The cold rolling control system 1 also includes a deformation resistance-temperature relationship data storage unit 112 outside the steel sheet temperature calculation unit 10. Although in Fig. 1, the deformation resistance-temperature relationship data storage unit 112 is not included in the steel sheet temperature calculation unit 10, the deformation resistance-temperature relationship data storage unit 112 may be included in the steel sheet temperature calculation unit 10. The actual deformation resistance calculation unit 111 uses the rolling data input from the control transmitting / receiving unit 12 to calculate the actual deformation resistance K by the following [Equation 1] act . [Equation 1] K act = [P / (L cont ×b)] / Q p Here, L cont is the length of the contact portion between the steel sheet and the rolls of the rolling mill, and can be calculated, for example, using the following formula. [Equation 2] L cont =[R'×(th in -th out )] 1 / 2 R' is the radius of the roll flattened by the rolling reduction force, and can be calculated, for example, using the following formula. [Formula 3] R' = R×[1 + P×C H / (th in -th out )] In [Equation 3], C H This constant is determined from the Poisson's ratio ν0 and Young's modulus E0 of the roll material using the following formula, and is determined separately for the roll from the rolling data. [Formula 4] C H = 16 × (1 - ν) 2 ) / (π×E0)

[0020] Also, in [Equation 1], Q p This is called the pressure function and can be calculated using, for example, the following formula. [Formula 5] Qp = 1.08 + 1.79 × r 3 / 2 ×μ / φ in -1.02 × r Here, r is the reduction ratio, φ in This is called the entry contact angle and is calculated using the following formula. [Formula 6] r = 1-th out / th in [Formula 7] φ in = arccos(1-th in / R')

[0021] The actual deformation resistance calculation unit 111 calculates the P, R, b, and th values ​​from the rolling data input from the control transmission / reception unit 12. in , th out By substituting the above equations, we can obtain the actual deformation resistance K. act It is possible to calculate this. The series of formulas described above are just examples of formulas that can be implemented in the actual deformation resistance calculation unit 111, and it is of course possible to implement other formulas as well. When implementing other formulas, the input data for the corresponding formulas will include rolling data input from the control transmission / reception unit 12, such as the advance rate and tension.

[0022] The deformation resistance-temperature relationship data storage unit 112 stores data on the relationship between deformation resistance and steel sheet temperature. Electrical steel sheets come in multiple types depending on the content of alloying elements including silicon, the thickness of the steel sheet, the width of the steel sheet, and the magnetic properties. For each of these steel types, the deformation resistance-temperature relationship data storage unit 112 stores data describing the deformation resistance during rolling and data representing the temperature dependence of the deformation resistance of each steel type. The deformation resistance-temperature relationship data stored by the deformation resistance-temperature relationship data storage unit 112 is, for example, the data shown in Figure 3.

[0023] The deformation resistance-temperature relationship data shown in Figure 3 is as follows: In other words, the deformation resistance-temperature relationship data includes a temperature-independent portion K within the deformation resistance. r The parameters k0, ε0, and n are included when expressed in [Equation 8]. In addition, the deformation resistance-temperature relationship data includes the slope s when linearly approximating the change in steel sheet temperature T with respect to the change in deformation resistance K in the general temperature range of electrical steel sheets in cold rolling, and when K is K r This includes a temperature T0 that is approximately equal to [the given value]. [Formula 8] K r (ε) = k0 × (ε - ε0) n In [Equation 8], ε is the rolling strain, and ln(th) is calculated from the steel plate thickness before and after rolling. in / th out It is calculated using the formula ).

[0024] Figure 4 shows the gradient s when the change in steel plate temperature T and deformation resistance K is linearly approximated. Here, as shown in Figure 4, the relationship between the steel sheet temperature T and the deformation resistance K in the general temperature range ta of electrical steel sheets in cold rolling is approximated by the following equation. [Formula 9] T = T0+s×[KK r ]

[0025] Figures 3 and 4 show an example where s = ΔT / ΔK is preserved, but s' = ΔK / ΔT may also be preserved. In other words, the deformation resistance-temperature relationship data may be either the coefficient obtained when approximating the change in steel plate temperature with respect to deformation resistance using a mathematical function, or the coefficient obtained when approximating the change in deformation resistance with respect to steel plate temperature using a mathematical function. Thus, according to this embodiment, it becomes possible to handle both cases: one where the coefficients are preserved when approximating the change in steel plate temperature with respect to deformation resistance using a mathematical function, and another where the coefficients are preserved when approximating the change in deformation resistance with respect to steel plate temperature using a mathematical function. Alternatively, for deformation resistance-temperature relationship data, the temperature or deformation resistance may be divided into multiple intervals, and s or s' may be saved for each interval. Furthermore, while Figure 4 shows an example of linear approximation, linear approximation is just one example; the coefficients can also be preserved when approximating using other functions such as step functions, polynomial functions, exponential functions, or power functions.

[0026] The rolling temperature calculation unit 113 calculates the actual deformation resistance K calculated by the actual deformation resistance calculation unit 111. act Then, using the data corresponding to the steel type for which the temperature is to be calculated, stored in the deformation resistance / temperature relationship data storage unit 112, the actual deformation resistance K act Steel sheet temperature T in the rolling mill corresponding to calc The rolling temperature calculation unit 113 uses, for example, [Equation 10] for its calculations, and the calculation results are output to the model modification unit 115. [Formula 10] T calc (K act , ε) = T0+s×[K act -K r (ε)]

[0027] The temperature calculation unit 114 uses a steel sheet temperature prediction model stored internally to calculate the temperature of the steel sheet moving along the cold rolling line. The steel sheet temperature prediction model is a computer-processable version of the heat conduction equation for steel sheets, obtained by discretizing it using the finite element method, finite volume method, finite difference method, or other methods.

[0028] For example, a model obtained by using the heat conduction equation [Equation 11] that considers only the thickness direction of the steel plate, discretizing the space using the finite difference method, and discretizing the time evolution using the Crank-Nicolson method is given by [Equation 12], [Equation 13], and [Equation 14]. [Formula 11] dT / dt =α×d 2 T / dy 2 + q / (ρ×C) [Formula 12] -a×T n+1,i+1 +(1+2×a)×T n+1,i -a×T n+1,i-1 = a × T n,i+1 +(1-2×a)×T n,i +a×T n,i-1 +q / (ρ×C) [Formula 13] α = λ / (ρ × C) [Formula 14] a =α × Δt / (2 × Δy 2 )

[0029] Here, λ is the thermal conductivity of the steel plate, ρ is the density of the steel plate, C is the specific heat of the steel plate, q is the amount of heat generated per unit volume per unit time, and T n,i is time t=t n The temperature at point i on the steel plate, Δt is t n+1 and t n Δy represents the time interval between points i and i+1, respectively. q is a factor representing the processing heat and frictional heat generated when the steel plate and roll come into contact. For example, the formula described on pages 148-149 of "Theory and Practice of Plate Rolling (Revised Edition)" (2010, Iron and Steel Institute of Japan), edited by the Rolling Theory Subcommittee of the Joint Research Committee of the Iron and Steel Institute of Japan, can be used.

[0030] As an example, the amount of heat generated by processing, q w This can be calculated from the rolling data using the following [Equation 15]. [Formula 15] q w = A × [P / (L cont ×b)]×ln(th in / thout ) / t cont Here, A is the heat equivalent of work, representing the ratio of plastic deformation work converted into heat, and is a parameter that is adjusted by the type of steel, rolling conditions, etc. P, b, th in , th out , L cont This value is obtained from rolling data.

[0031] Among the rolling data, t cont This is the time the steel plate and the roll are in contact, and it can be calculated from the rolling data using the following formula. [Formula 16] t cont = L cont × (th in +2 × th out ) / (3×v out ×th out ) Here, v out This is the speed at which the steel plate moves on the roll exit side.

[0032] Cooling by contact with air, coolant, or rolls has a heat transfer coefficient h at a point N on the surface of the steel plate when the ambient temperature is T e The boundary conditions for heat exchange can be expressed, for example, by the following equation. [Formula 17] -λ×(T n+1,N -T n+1,N-1 ) / Δy = h×(T n+1,N -T e ) Here the ambient temperature T e θ represents the temperature of the air, coolant, or roll. The heat transfer coefficient h with the fluid, air or coolant, is known to change in accordance with the flow characteristics, and for example, the formula described on pp. 146-148 of "Theory and Practice of Plate Rolling (Revised Edition)" (2010, Iron and Steel Institute of Japan), edited by the Rolling Theory Subcommittee of the Joint Research Committee of the Iron and Steel Institute of Japan, can be used.

[0033] As an example, the heat transfer coefficient in emulsion cooling is expressed by the following formula. [Formula 18] h emul = w c1×T c2 ×exp[c3×(1-C / 100)+c3×C / 100] Here, w is the flow density of the emulsion, T is the temperature of the steel plate, C is the concentration of the emulsion, and c1, c2, c3, c4 are parameters. The parameters c1, c2, c3, and c4 can be obtained by empirical formulas, but since they depend on the detailed state of the emulsion, the surface state of the steel plate, and the state of the injection nozzles, appropriate adjustments are required.

[0034] The temperature calculation unit 114 calculates the temperature of the steel plate moving on the cold rolling line by using a steel plate temperature prediction model including a plurality of parameters that require appropriate adjustment. The model changing unit 115 obtains the calculated value T of the steel plate temperature in the cold rolling mills 310, 320, ..., 370 calculated by the rolling temperature calculation unit 113 calc and the steel plate temperature T measured by thermometers 301, 311, 321, ..., 371 meas is used as training data to change one or more parameters stored in the temperature calculation unit 114.

[0035] For changing the parameters of the steel plate temperature prediction model, methods well known as black-box optimization in the field of numerical optimization can be used. Examples of such methods include, for example, the following: · Bayesian Optimization · Evolutionary Algorithm · Simulated Annealing · Surrogate-Assisted Evolutionary Algorithm · Sequential Model-Based Global Optimization

[0036] The model modification unit 115 modifies the parameters of the steel plate temperature calculation model using the example optimization method or other methods so that the error between the steel plate temperature calculated by the temperature calculation unit 114 and the training data described above is minimized. To this end, the model modification unit 115 sends the parameters to the temperature calculation unit 114 and receives the steel plate temperature calculation results from the temperature calculation unit 114. Once the parameter modification is complete, the model modification unit 115 sends a completion signal to the temperature calculation unit 114.

[0037] The temperature calculation unit 114 transmits the steel plate temperature calculation result to the model change unit 115 when a model change is in progress, and transmits the calculation result to the rolling line control unit 11 when a model change is not in progress. The rolling line control unit 11 controls the heating temperature in the heating furnace 300 installed in the cold rolling line 3, the amount of coolant ejected from the steel sheet cooling nozzles 312, 313, 322, 323, ..., 372, 373, or the moving speed of the steel sheet 4, based on the calculated value of the received steel sheet temperature. Any one of these controls may be used, or a combination of each control may be used. As a result, according to this embodiment, more precise rolling control becomes possible by controlling the heating temperature in the heating furnace 300, the amount of coolant ejected from the steel sheet cooling nozzles 312, 313, 322, 323, ..., 372, 373, and the moving speed of the steel sheet 4.

[0038] The steel plate temperature calculation unit 10 and the rolling line control unit 11 can be configured as, for example, a computer. For example, as shown in Figure 1, the steel plate temperature calculation unit 10 has a hardware configuration in which a CPU (Central Processing Unit) 10a, memory 10b, storage 10c, interface (I / F) 10d, etc., are connected to each other via a bus line so that they can communicate with one another.

[0039] The CPU 10a then executes a program prepared in memory 10b or storage 10c to configure a processing unit that performs calculations within memory 10b, and transmits the results calculated by that processing unit to the rolling line control unit 11 via interface 10c. Storage 10c stores data and models necessary for calculations such as deformation resistance and temperature-related data. However, configuring the steel plate temperature calculation unit 10 and the rolling line control unit 11 as computers equipped with a CPU and memory is just one example. For instance, some or all of the functions performed by the steel plate temperature calculation unit 10 and the rolling line control unit 11 may be implemented by hardware such as FPGAs (Field Programmable Gate Arrays) or ASICs (Application Specific Integrated Circuits).

[0040] [Cold rolling control process (Example 1)] Next, we will describe the cold rolling control process as a cold rolling control method executed by the cold rolling control system 1 of this embodiment. Figure 5 is a flowchart showing an example of the cold rolling control process (Example 1) in this embodiment. First, when processing in the cold rolling control system 1 begins, the control transmission / reception unit 12 performs rolling data reception processing and receives rolling data from the cold rolling line 3 (step S1). The received rolling data is sent to the steel sheet temperature calculation unit 10.

[0041] When the steel plate temperature calculation unit 10 receives rolling data, the actual deformation resistance calculation unit 111 performs an actual deformation resistance calculation process to calculate the actual deformation resistance from the rolling data (step S2). Then, the rolling temperature calculation unit 113 performs a deformation resistance / temperature relationship data acquisition process to obtain deformation resistance / temperature relationship data corresponding to the steel type of the steel plate from the deformation resistance / temperature relationship data storage unit 112 (step S3). Note that the deformation resistance / temperature relationship data storage unit 112 must perform a deformation resistance / temperature relationship data storage process in advance. Then, the rolling temperature calculation unit 113 uses the actual deformation resistance obtained in step S2 and the deformation resistance-temperature relationship data obtained in step S3 to perform a rolling temperature calculation process to calculate the steel sheet temperature in the rolling mill (step S4). Furthermore, the temperature calculation unit 114 performs a steel sheet temperature calculation process (step S5) to calculate the temperature of the steel sheet moving along the cold rolling line using the rolling data received in step S1.

[0042] Subsequently, the model modification unit 115 determines whether or not a change to the steel plate temperature calculation model is necessary (step S6). In this step S6 process, for example, the model modification unit 115 calculates and determines the error between the steel plate temperature calculated in step S5 and the steel plate temperature measured in the rolling mill and the steel plate temperature measurement received in step S1. If the error is smaller than a threshold set in advance by the user, the model modification unit 115 determines that no change is necessary (Yes in step S6).

[0043] Furthermore, in step S6, if it is determined that a change to the steel plate temperature calculation model is not unnecessary (i.e., a change is necessary) (No. in step S6), the model change unit 115 executes a model change process that modifies the parameters of the steel plate temperature prediction model using a numerical optimization method to minimize the aforementioned error (step S7). In step S7, once the model change process is executed, the process returns to step S5, and the temperature calculation unit 114 executes the steel plate temperature calculation process. Furthermore, if the number of times the model change process (step S7) for a single steel plate is executed reaches a certain upper limit, the model change unit 115 may determine in step S6 that no change is necessary.

[0044] Then, after the model modification unit 115 determines that no changes are needed (Yes in step S6), the rolling line control unit 11 executes the rolling line control process (step S8), and after controlling the operation of the cold rolling line 3 based on the steel sheet temperature calculated in step S5, the cold rolling control process shown in Figure 5 is completed.

[0045] [Cold rolling control process (Example 2)] Figure 6 is a flowchart showing an example of the cold rolling control process (Example 2) in this embodiment. In Figure 6, the same step numbers are assigned to processes identical to the cold rolling control process described in Figure 5, and redundant explanations are omitted. In the cold rolling control process example shown in Figure 6, after receiving rolling data in step S1, the steel plate temperature calculation unit 10 performs a change implementation determination process to determine whether or not it is necessary to change the steel plate temperature calculation model (step S9).

[0046] If it is determined in step S9 that a change to the steel plate temperature calculation model is necessary (Yes in step S9), the process moves to step S2, and the model change process in step S7 is executed as necessary, following the same flow as the cold rolling control process explained in Figure 5. On the other hand, if it is determined in step S9 that no change to the steel plate temperature calculation model is necessary (No. in step S9), the temperature calculation unit 114 executes the steel plate temperature calculation process (step S5'). This steel plate temperature calculation process in step S5' is the same as the steel plate temperature calculation process in step S5, and after the steel plate temperature calculation process in step S5' is performed, the process moves to the rolling line control process in step S8.

[0047] In step S9, for example, if rolling continues with either the steel type or rolling conditions, or both, being substantially the same, or if the processes in steps S5 and S7 are repeated multiple times and the cumulative execution time is long, it is determined that it is not necessary to change the steel sheet temperature calculation model.

[0048] As described above, in the cold rolling control system 1 of this embodiment, the temperature dependence of the deformation resistance of the electrical steel sheet in the cold rolling temperature range is used to calculate the actual deformation resistance K from the rolling data. act Steel sheet temperature T in the rolling mill corresponding to calc This data is used as training data for the steel sheet temperature prediction model. This makes it possible to adjust the parameters of the steel sheet temperature prediction model even if the thermometer installed on the rolling line malfunctions or fails. Therefore, the cold rolling control system 1 in this embodiment can accurately calculate and control the temperature of the electrical steel sheet.

[0049] <Second Embodiment> Next, a cold rolling control system and a cold rolling control method according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 9. In FIGS. 7 to 9 for describing the second embodiment, parts that have the same configuration or perform the same processing as in FIGS. 1 to 6 described for the first embodiment are denoted by the same reference numerals, and repeated description is omitted.

[0050] FIG. 7 shows the configuration of a cold rolling control system 1' according to the present embodiment. The cold rolling control system 1' shown in FIG. 7 differs from the cold rolling control system 1 shown in FIG. 1 in that it includes a temperature-corrected deformation resistance calculation unit 13. Furthermore, in the cold rolling control system 1' shown in FIG. 7, the data stored in the deformation resistance-temperature relationship data storage unit 112 is supplied not only to the steel plate temperature calculation unit 10 but also to the temperature-corrected deformation resistance calculation unit 13.

[0051] The temperature-corrected deformation resistance calculation unit 13 calculates a deformation resistance value used for sheet thickness control using the data output from the deformation resistance-temperature relationship data storage unit 112 and the temperature calculated by the temperature calculation unit 114. For example, in the case of the example of deformation resistance-temperature relationship data shown in FIG. 3, the temperature-corrected deformation resistance calculation unit 13 calculates a temperature-corrected deformation resistance K with temperature dependence corrected using the following formula T . [Formula 19] K T (ε, T calc ) = K r (ε) + (T calc -T0) / s The second term on the right-hand side of [Formula 19] corresponds to a correction term for the temperature dependence of deformation resistance.

[0052] By correcting the temperature dependence of the deformation resistance of electrical steel sheets as described above, the cold rolling control system 1' of the present embodiment can calculate the deformation resistance in cold rolling of electrical steel sheets with higher accuracy. The temperature-corrected deformation resistance K calculated by the temperature-corrected deformation resistance calculation unit 13 T is sent to a rolling line control unit 10, and the rolling line control unit 11 uses the temperature-corrected deformation resistance K TBased on this, the line settings related to plate thickness control, such as the gap between the upper and lower rolls, are controlled.

[0053] [Cold rolling control process (Example 1)] Figure 8 is a flowchart showing an example of the cold rolling control process (Example 1) in this embodiment. In Figure 8, the same step numbers are assigned to processes identical to the cold rolling control processes described in Figures 5 and 6, and redundant explanations are omitted. In the cold rolling control process example shown in Figure 8, the difference from the flowchart in Figure 5 is that after determining that a model change is unnecessary in the model change determination process in step S6 (Yes in step S6), the temperature-corrected deformation resistance calculation unit 13 performs the temperature-corrected deformation resistance calculation process (step S10).

[0054] In step S10, the temperature-compensated deformation resistance calculation process uses the results of the deformation resistance-temperature relationship data acquisition process obtained in step S3 and the results of the steel plate temperature calculation process in step S5 to calculate the temperature-compensated deformation resistance K T To do. Then, the temperature-compensated deformation resistance calculation unit 13 calculates the temperature-compensated deformation resistance K T This is then passed to the rolling line control processing in the rolling line control unit 11 in step S8. The processes other than step S10 are the same as in the flowchart in Figure 5.

[0055] [Cold rolling control process (Example 2)] Figure 9 is a flowchart showing an example of the cold rolling control process (Example 2) in this embodiment. The process shown in Figure 9 is the cold rolling control process of Example 2 described in the first embodiment, as shown in the flowchart of Figure 6, with the addition of the temperature-corrected deformation resistance calculation in the temperature-corrected deformation resistance calculation unit 13 in this embodiment. In Figure 9, the same step numbers are assigned to processes identical to the cold rolling control process described in Figure 6, and redundant explanations are omitted.

[0056] In the process shown in Figure 9, similar to the example in Figure 8, the difference from the flowchart in Figure 6 is that, after determining that no model change is necessary in the model change determination process in step S6 (Yes in step S6), the temperature-corrected deformation resistance calculation unit 13 performs the temperature-corrected deformation resistance calculation process (step S10).

[0057] Furthermore, in the process shown in Figure 9, similar to the process in Figure 6, after receiving rolling data in step S1, the steel plate temperature calculation unit 10 performs a change implementation determination process to determine whether or not it is necessary to implement a change to the steel plate temperature calculation model (step S9). If it is determined in step S9 that it is not necessary to implement a change to the calculation model (No. in step S9), the rolling temperature calculation unit 113 performs deformation resistance / temperature-related data acquisition processing in step S3', and then the temperature calculation unit 114 performs steel plate temperature calculation processing in step S5'.

[0058] After the deformation resistance / temperature relationship data acquisition process in step S3' and the steel plate temperature calculation process in step S5' are performed, the process moves to step S10, where the temperature-corrected deformation resistance calculation unit 13 executes the temperature-corrected deformation resistance calculation process. If the processes in steps S3' and S5' have been performed, the temperature-corrected deformation resistance calculation unit 13 calculates the temperature-corrected deformation resistance in step S10 using the deformation resistance / temperature relationship data acquired in step S3' and the steel plate temperature calculation process calculated in step S5'.

[0059] In the case of the process shown in Figure 9, similar to the example in Figure 6, the temperature-corrected deformation resistance can be calculated appropriately without unnecessarily increasing the processing load. In the case of the process in Figure 9, the reason for deciding that no change is necessary in step S9 is similar to the example in Figure 6, for example, when rolling continues with either the steel type or rolling conditions, or both, being substantially the same, or when the processes in steps S5, S6, and S7 are repeated multiple times, resulting in a long cumulative execution time.

[0060] As described above, the cold rolling control system 1' of this embodiment can accurately calculate and control the temperature of the electrical steel sheet, similar to the first embodiment. Furthermore, in the second embodiment, in order to compensate for the temperature dependence of the deformation resistance of the electrical steel sheet, it becomes possible to calculate the deformation resistance of the electrical steel sheet during cold rolling with even greater accuracy.

[0061] [Differentiation] Furthermore, the cold rolling control system and cold rolling control method of the present invention are not limited to the configurations and processes described in the above-described embodiments, and various modifications can be implemented without departing from the gist of the invention as described in the claims. In addition, the above-described embodiments are described in detail for the purpose of clearly explaining the present invention, and are not necessarily limited to those having all the configurations described. For example, the above-described embodiment involved cold rolling of electrical steel sheets, but this is just one example of how the present invention can be applied to the rolling of other types of steel sheets.

[0062] Furthermore, in the configuration diagrams shown in Figures 1 and 7, only control lines and information lines deemed necessary for explanation are shown, and not all control lines and information lines are necessarily shown in the actual product. In reality, it can be assumed that almost all components are interconnected. Furthermore, the flowcharts shown in Figures 5, 6, 8, and 9 are just examples; if the processing results are the same, some processing orders may be changed, or multiple processes may be executed simultaneously. [Explanation of symbols]

[0063] 1,1′…Cold rolling control system, 3…Cold rolling line, 4…Steel plate, 10…Steel plate temperature calculation unit, 11…Rolling line control unit, 12…Control transmission / reception unit, 13…Temperature-corrected deformation resistance calculation unit, 111…Actual deformation resistance calculation unit, 112…Deformation resistance / temperature-related data storage unit, 113…Rolling temperature calculation unit, 114…Temperature calculation unit, 115…Model change unit, 300…Heating furnace, 301…Heating furnace exit thermometer, 310…First rolling mill, 311…First rolling mill exit thermometer, 312…Steel plate cooling nozzle at the top of the exit of the first rolling mill, 313…Steel plate cooling nozzle at the bottom of the exit of the first rolling mill, 314…First rolling mill work roll cooling nozzle, 315…First rolling mill lubricating liquid nozzle, 320…Second rolling mill, 370...Rolling mill No. 7, 380...Winding machine

Claims

1. A steel plate temperature calculation unit that calculates the steel plate temperature using a steel plate temperature calculation model, A cold rolling control system comprising: a rolling line control unit that changes settings on the cold rolling line using the steel plate temperature calculation results from the steel plate temperature calculation unit, A unit that calculates actual deformation resistance from rolling data, A deformation resistance / temperature relationship data storage unit stores deformation resistance / temperature relationship data showing the relationship between deformation resistance and steel plate temperature, A rolling temperature calculation unit calculates the steel sheet temperature in the rolling mill using the deformation resistance-temperature relationship data and the actual deformation resistance. The system includes a model modification unit that modifies the steel sheet temperature calculation model using the steel sheet temperature at the rolling mill calculated by the rolling temperature calculation unit and the steel sheet temperature measured at the rolling line. Cold rolling control system.

2. The settings on the cold rolling line that the rolling line control unit changes based on the steel sheet temperature calculation results include one or more of the following: heating temperature of the heating furnace, amount of coolant ejected from the steel sheet cooling nozzle, and moving speed of the steel sheet. The cold rolling control system according to claim 1.

3. The system includes a temperature-corrected deformation resistance calculation unit that calculates temperature-corrected deformation resistance using the deformation resistance and temperature-related data stored in the deformation resistance and temperature-related data storage unit and the calculation results of the steel sheet temperature in the rolling temperature calculation unit. The cold rolling control system according to claim 1.

4. The settings on the cold rolling line that the aforementioned rolling line control unit changes based on the steel sheet temperature calculation results include the gap between the upper and lower rolls of the rolling mill. The cold rolling control system according to claim 3.

5. The data stored in the aforementioned deformation resistance / temperature relationship data storage unit includes coefficients obtained when approximating the change in steel plate temperature with respect to deformation resistance using a mathematical function. The cold rolling control system according to claim 1.

6. The data stored in the aforementioned deformation resistance / temperature relationship data storage unit includes coefficients obtained by approximating the change in deformation resistance with respect to steel plate temperature using a mathematical function. The cold rolling control system according to claim 1.

7. A steel plate temperature calculation process that uses a steel plate temperature calculation model to calculate the steel plate temperature from the rolling data received in the rolling data reception process, A cold rolling control method that performs rolling line control processing to change settings on a cold rolling line using the steel plate temperature calculation results obtained from the steel plate temperature calculation processing, A process for calculating actual deformation resistance using rolling data, A deformation resistance-temperature relationship data storage process that stores deformation resistance-temperature relationship data showing the relationship between deformation resistance and steel plate temperature, A rolling temperature calculation process is performed to calculate the steel sheet temperature in the rolling mill using the aforementioned deformation resistance-temperature relationship data and the aforementioned actual deformation resistance. The process includes a model modification process that modifies the steel sheet temperature calculation model using the steel sheet temperature at the rolling mill calculated by the aforementioned rolling temperature calculation process and the steel sheet temperature measured at the rolling line. Cold rolling control method.

8. The settings on the cold rolling line that are changed in the aforementioned rolling line control process based on the calculation results of the steel sheet temperature are: Includes one or more of the following: heating temperature of the heating furnace, amount of coolant ejected from the steel plate cooling nozzle, and moving speed of the steel plate. The cold rolling control method according to claim 7.

9. This process includes a temperature-corrected deformation resistance calculation process that uses the deformation resistance and temperature relationship data saved in the aforementioned deformation resistance and temperature relationship data saving process and the calculation result of the steel plate temperature in the aforementioned rolling temperature calculation process to calculate the temperature-corrected deformation resistance. The cold rolling control method according to claim 7.

10. The aforementioned rolling line control process includes settings on the cold rolling line that are changed based on the steel sheet temperature calculation results, including the gap between the upper and lower rolls of the rolling mill. The cold rolling control method according to claim 9.

11. The data saved by the aforementioned deformation resistance-temperature relationship data saving process includes coefficients obtained when approximating the change in steel plate temperature with respect to deformation resistance using a mathematical function. The cold rolling control method according to claim 7.

12. The data saved by the aforementioned deformation resistance-temperature relationship data saving process includes coefficients obtained when approximating the change in deformation resistance with respect to steel plate temperature using a mathematical function. The cold rolling control method according to claim 7.

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