A smart roll shifting method to reduce strip wedge shape caused by uneven hot roll profile

Abstract

This invention discloses an intelligent roll shifting method for reducing strip wedge shape caused by uneven hot roll profile. The method includes: setting an initial roll shifting step length and a maximum roll shifting stroke; during the first forward roll shifting, the roll shifts according to the set initial roll shifting step length and maximum roll shifting stroke, with the roll shifting step length remaining fixed throughout the shifting process; after the first forward roll shifting is completed, the wedge shape value of each coil of strip caused by the hot roll profile is calculated during each subsequent roll shifting process. Based on the calculated wedge shape value, the roll shifting step length and maximum roll shifting stroke are intelligently optimized to reduce the average wedge shape value of the strip within a rolling unit. This intelligent roll shifting method can intelligently and dynamically adjust the roll shifting step length and stroke according to the wedge shape variation law of the strip caused by uneven hot roll profile during hot rolling, thereby effectively reducing the average wedge shape value of the strip within the entire rolling unit, and thus helping to improve the strip's same-plate difference index.

Description

Technical Field

[0001] This invention relates to the field of automated control technology in metallurgical rolling, and in particular to an intelligent roll shifting method for reducing the wedge shape of strip steel caused by uneven hot roll profile. Background Technology

[0002] Strip shape is a critical factor that requires close attention in hot-rolled strip steel production, directly affecting product quality and production stability. Wedge shape is one of the main defects in hot-rolled strip steel shape and an important indicator of the technological level and product quality of hot-rolled strip steel production. Wedge shape is a common strip shape problem in hot-rolled strip steel production. Along with wedge shape, the strip steel often also exhibits camber and single-sided wavy defects, which have a severely adverse impact on production stability and product quality. Production practice shows that asymmetric factors during the rolling process can lead to wedge shape problems.

[0003] Conventional methods for controlling roll shifting in crowning mainly include constant-stroke roll shifting and variable-stroke roll shifting. Constant-stroke roll shifting refers to a strategy where the roll shifting limit stroke, roll shifting step length, and roll shifting frequency remain constant throughout the entire rolling cycle. The roll shifting direction is changed when the roll shifting limit position is reached, and this process is repeated. The position of the constant-stroke, constant-step roll shifting is as follows: Figure 1 As shown, the strip wedge value under the equal stroke and equal step length roll shifting strategy is as follows: Figure 2 As shown. Variable stroke roll shifting refers to a roll shifting strategy that changes the roll shifting limit stroke, step length, and frequency. This type of method includes variable stroke equal step length roll shifting control method and variable stroke variable step length roll shifting control method.

[0004] Based on a large number of relevant documents, most existing roll shifting strategies focus on the uniformity of roll wear, but do not consider the uneven thermal roll shape caused by roll shifting, which leads to the problem of strip wedge shape. Summary of the Invention

[0005] This invention provides an intelligent roll shifting method to reduce strip wedge shape caused by uneven hot roll shape, thereby solving the technical problem of uneven hot roll shape caused by roll shifting, which in turn leads to strip wedge shape.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] On one hand, the present invention provides an intelligent roll shifting method for reducing strip wedge shape caused by uneven hot roll shape, the intelligent roll shifting method for reducing strip wedge shape caused by uneven hot roll shape includes:

[0008] Set the initial roll step size and maximum roll travel;

[0009] When the rolls are moved forward for the first time, the rolls are moved according to the set initial roll movement step and maximum roll movement stroke, and the roll movement step remains a fixed value during the roll movement process.

[0010] After the first forward roll shift is completed, the wedge value of each coil of strip caused by the hot roll shape is calculated in each subsequent roll shift process. After the wedge value of the strip is calculated, the roll shift step length and maximum roll shift stroke are intelligently optimized based on the wedge value of the strip to reduce the average wedge value of the strip within a rolling unit.

[0011] Furthermore, the wedge value of the strip is calculated using a roll thermal expansion model; the input of the roll thermal expansion model is the strip rolling data, and the output is the thermal roll shape distribution and the resulting strip wedge size; wherein the rolling data includes: strip thickness, strip width, strip length, stand entrance thickness, stand exit thickness, rolling force, strip temperature, rolling time, rolling gap time, and roll shifting position.

[0012] Furthermore, based on the wedge shape of the strip, the roll shifting step length and maximum roll shifting stroke are intelligently optimized, including:

[0013] When the absolute value of the wedge value of the strip is less than the preset wedge size threshold, the roll shifting step size is corrected to 0, that is, the next roll of strip stops shifting and the roll shifting position remains unchanged;

[0014] When the absolute value of the wedge value of the strip is not less than the preset wedge size threshold or the number of strips whose roll position remains unchanged exceeds the preset strip number threshold, the roll step length is restored to the initial roll step length.

[0015] Furthermore, based on the wedge shape of the strip, the intelligent optimization of the roll shifting step length and maximum roll shifting stroke also includes:

[0016] The roll travel distance in the first forward roll shifting process is the set initial maximum roll travel distance. Subsequent forward roll shifting processes require periodic attenuation of the roll travel distance L. D The calculation formula is as follows:

[0017] L D =M·K1

[0018] Where K1 is the preset attenuation coefficient of the forward roll travel; M is the initial maximum roll travel.

[0019] Furthermore, based on the wedge shape of the strip, the intelligent optimization of the roll shifting step length and maximum roll shifting stroke also includes:

[0020] The negative roll travel is periodically reduced, and the negative roll travel L O The calculation formula is as follows:

[0021] LO =-M·K2

[0022] Where K2 is the preset attenuation coefficient of the negative roll travel; M is the initial maximum roll travel.

[0023] In another aspect, the present invention also provides an electronic device comprising a processor and a memory; wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement the above-described method.

[0024] In another aspect, the present invention also provides a computer-readable storage medium storing at least one instruction that is loaded and executed by a processor to implement the above-described method.

[0025] The beneficial effects of the technical solution provided by this invention include at least the following:

[0026] The intelligent roll shifting method of this invention sets an initial roll shifting step length and a maximum roll shifting stroke. During the first forward roll shifting, the roll shifts according to the set initial roll shifting step length and maximum roll shifting stroke, and the roll shifting step length remains fixed during the roll shifting process. After the first forward roll shifting is completed, the wedge value of each coil of strip steel caused by hot roll deformation is calculated during each subsequent roll shifting process. After calculating the wedge value of the strip steel, the roll shifting step length and maximum roll shifting stroke are intelligently optimized based on the wedge value of the strip steel to reduce the average wedge value of the strip steel within a rolling unit. Thus, based on the strip steel wedge shape change law caused by uneven hot roll deformation during hot rolling, the roll shifting step length and stroke are intelligently and dynamically adjusted, effectively reducing the average wedge value of the strip steel within the entire rolling unit. Moreover, the intelligent roll shifting method of this invention not only reduces strip steel wedge shape but also takes into account the impact of roll wear. This helps to improve the strip steel same-plate difference index. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the position of the rollers with equal stroke and equal step length;

[0029] Figure 2 This is a schematic diagram of the strip wedge shape under the condition of equal stroke and equal step length roll shifting strategy;

[0030] Figure 3 This is a schematic diagram of the intelligent roller position provided in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the wedge value under the intelligent roller shifting strategy provided in the embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram comparing the equal stroke and equal step length roller shifting strategy with the intelligent roller shifting strategy designed in this invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0034] First Embodiment

[0035] This embodiment provides an intelligent roll shifting method to reduce strip wedge shape caused by uneven hot roll shape. In this method, the roll shifting strategy of the entire rolling unit is based on a uniform roll shifting mode with a constant roll shifting step length. Based on the uniform roll shifting strategy, the size of the strip wedge shape caused by uneven hot roll shape is calculated based on the roll thermal expansion model. According to the strip wedge shape change law, the roll shifting step length and stroke are intelligently optimized.

[0036] Specifically, the execution process of this method includes the following steps:

[0037] S1, set the initial roll step size and maximum roll travel;

[0038] S2, when the roll performs the first forward roll shifting, the roll shifts according to the set initial roll shifting step length and maximum roll shifting stroke, and the roll shifting step length remains a fixed value during the roll shifting process;

[0039] S3, after the first forward roll shifting is completed, the wedge value of each coil of strip caused by the hot roll shape is calculated in each subsequent roll shifting process. After calculating the strip wedge value, the roll shifting step length and maximum roll shifting stroke are intelligently optimized based on the strip wedge value to reduce the average strip wedge value within a rolling unit.

[0040] In this embodiment, the size of the strip wedge caused by the hot roll shape is calculated using a roll thermal expansion model. The rolling data of the strip, including strip thickness, strip width, strip length, stand entrance thickness, stand exit thickness, rolling force, strip temperature, rolling time, rolling gap time, and roll shifting position, are input into the roll thermal expansion model. This yields the distribution of the hot roll shape and the resulting size of the strip wedge.

[0041] Furthermore, according to the wedge value of the strip steel, the principle of intelligently optimizing the roll shifting step length and the maximum roll shifting stroke is as follows: judge whether the wedge value of the strip steel caused by the hot roll profile is close to zero. When the wedge value of the strip steel caused by the hot roll profile is close to zero, adjust the roll shifting step length to zero, that is, the roll shifting position remains unchanged. And considering the influence on roll wear, the number of roll shifting holding blocks does not exceed the given block number range, that is, after keeping the roll shifting position of several coils of strip steel unchanged, it is necessary to re-enter the uniform roll shifting strategy mode and restore the original roll shifting step length until the next judgment condition is triggered, and so on; at the same time, the roll shifting stroke is periodically attenuated to reduce the wedge size of the strip steel at the roll shifting limit position, and further reduce the average wedge value of the strip steel within one rolling unit.

[0042] Specifically, in this embodiment, the strategy of intelligently optimizing the roll shifting step length and the maximum roll shifting stroke is as follows:

[0043] Within one rolling unit, the upper work roll first starts to shift from the roll shifting zero position towards the drive side DS of the stand at a fixed step length. Set this direction as the forward roll shifting, the roll shifting step length is S, and the forward maximum roll shifting stroke is L D . During the process of the roll first shifting from the zero position to the forward maximum stroke, the roll shifting step length remains a fixed value, that is, the roll shifting step length is not corrected. After the roll first reaches the forward maximum stroke position, it then shifts towards the operator side OS, and judges the wedge value H of the strip steel caused by the hot roll profile during the roll shifting process. Set the wedge size threshold h = 3.5 μm. When |H| < h, correct the roll shifting step length S to 0, that is, the roll shifting of the next coil of strip steel stops and the roll shifting position remains unchanged. When |H| > h, the roll shifting step length S restores the original roll shifting step length. Moreover, considering the influence on roll wear, the number of roll shifting holding blocks does not exceed the maximum value n, where n = 5, that is, when the number of roll shifting holding blocks exceeds 5, the roll shifting holding ends. During the subsequent roll shifting process, the wedge of the strip steel caused by the hot roll profile is judged. If the judgment condition is met, the roll shifting step length is corrected.

[0044] Furthermore, to reduce the wedge value of the strip steel at the roll shifting limit position and further reduce the average wedge value of the strip steel within the entire rolling unit, the roll shifting stroke is periodically attenuated. Specifically, the first forward roll shifting stroke is the maximum roll shifting stroke allowed by the equipment. The subsequent forward roll shifting strokes need to be corrected, and the calculation formula is as follows:

[0045] L D = M·K1

[0046] where K1 is the attenuation coefficient of the forward roll shifting stroke, with a value of 0.7; M is the maximum roll shifting stroke allowed by the equipment set in advance, in units of mm.

[0047] The negative roll shifting stroke also needs to be corrected, and the calculation formula is as follows:

[0048] LO = -M·K2

[0049] where L O is the negative roll shifting stroke, K2 is the attenuation coefficient of the negative roll shifting stroke, with a value of 0.7; M is the maximum allowable roll shifting stroke preset for the equipment, in mm.

[0050] Thus, the intelligent roll shifting strategy for reducing the strip wedge caused by uneven hot roll shape is completed.

[0051] Next, to verify the effectiveness of the method of the present invention, a practical application example is used for verification.

[0052] For example, in a hot rolled coil production line of a certain factory, the strip width is 2040 mm, the finished strip length is 391.48 mm, the thickness at the entrance of the stand is 5.61 mm, the thickness at the exit of the stand is 4.97 mm, the finished thickness is 4.97 mm, the rolling force is 1665.6 t, the strip temperature is 971 °C, the rolling time is 50 s, the rolling gap time is 30 s. The above data is input into the roll thermal expansion model to calculate the strip wedge size caused by uneven hot roll shape.

[0053] The upper work roll first starts to shift from the zero roll shifting position towards the drive side DS of the stand at a fixed step size. This direction is set as the positive roll shifting direction, the roll shifting step size is S = 10 mm, and the positive maximum roll shifting stroke is L D = M = 100 mm. During the process of the roll shifting from the zero position to the positive maximum stroke for the first time, the roll shifting step size remains a fixed value, that is, the roll shifting step size is not corrected.

[0054] After that, it shifts towards the operating side OS, and during the roll shifting process, the strip wedge value H caused by the hot roll shape is judged. For each coil of strip, the wedge value H is judged, and the wedge size judgment value h = 3.5 μm. When the roll shifting position S 14 = 70 mm, H = 1.488 μm. At this time, |H| < h, so the roll shifting step size S is corrected to 0, that is, the next coil of strip stops roll shifting, and the roll shifting position S 15 remains unchanged; when the roll shifting position S 15 = 70 mm, H = 0.008 μm. At this time, |H| < h, and the roll shifting position S 16 remains unchanged; when the roll shifting position S 16 = 70 mm, H = -0.72 μm. At this time, |H| < h, and the roll shifting position S 17 remains unchanged; when the roll shifting position S 17 = 70 mm, H = -1.1 μm. At this time, |H| < h, and the roll shifting position S 18 remains unchanged; when the roll shifting position S 18When it is 70mm, H = -1.32μm. At this time, |H| < h. To prevent excessive uneven wear of the work roll caused by stopping the roll shift, the maximum number of roll shift retaining blocks n does not exceed 5. The roll shift position S 18 After that, the roll shift step S resumes the original roll shift step. When the roll shift step S is improved, the strip wedge value at the extreme roll shift position is too large, and an attenuation correction needs to be performed on the roll shift stroke: L O = -M·K2 = -100×0.7mm = -70mm. When L O = S 32 it starts to move forward.

[0055] After that, when the roll shift position S 38 = -10mm, H = -3.39μm. At this time, |H| < h, the roll shift position S 39 remains stationary; when the roll shift position S 39 = -10mm, H = -0.75μm. At this time, |H| < h, the roll shift position S 40 remains stationary; when the roll shift position S 40 = 70mm, H = 0.814μm. At this time, |H| < h, the roll shift position S 41 remains stationary; when the roll shift position S 41 = 70mm, H = 1.852μm. At this time, |H| < h, the roll shift position S 42 remains stationary; when the roll shift position S 42 = 70mm, H = 2.51μm. At this time, |H| < h, the maximum number of roll shift retaining blocks n does not exceed 5. The roll shift position S 42 After that, the roll shift step S resumes the original roll shift step until the zero position.

[0056] After that, the upper work roll starts to move forward, and an attenuation correction needs to be performed on L D : L D = M·K1 = 100×0.7mm = 70mm. After the upper work roll reaches point L D , it moves backward and reaches the roll shift position S 54 = 30mm, H = 0.101μm. At this time, |H| < h, the roll shift position S 55 remains stationary; when the roll shift position S[[ID=I45]] 55 = 30mm, H = -1.72μm. At this time, |H| < h, the roll shift position S 56 remains stationary; when the roll shift position S 56 = 30mm, H = -2.64μm. At this time, |H| < h, the roll shift position S 57 remains stationary; when the roll shift position S 57 = 30mm, H = -3.14μm. At this time, |H| < h, the roll shift position S 58Stay stationary; when the roll shifting position S 58 = 30 mm, H = -3.41 μm. At this time, |H| < h, and the maximum number of roll shifting retaining blocks n does not exceed 5. The roll shifting position S 58 After that, the roll shifting step size S returns to the original roll shifting step size until the roll shifting ends.

[0057] So far, the design of the intelligent roll shifting strategy with variable stroke and variable step size is completed (as Figure 3 shown). Under the conditions of this intelligent roll shifting strategy, the wedge values are as Figure 4 shown. The comparison between the equal-stroke and equal-step roll shifting strategy and this intelligent roll shifting strategy is as Figure 5 shown. The comparison between the equal-stroke and equal-step roll shifting strategy, the intelligent roll shifting strategy designed in this invention, and their wedge values is shown in Table 1 below.

[0058] Table 1 Comparison between the equal-stroke and equal-step roll shifting strategy, the intelligent roll shifting strategy of this invention, and their wedge values

[0059]

[0060]

[0061]

[0062] By calculation, the average wedge value of the equal-stroke and equal-step roll shifting strategy is 25.54 μm, and the average wedge value of the intelligent roll shifting strategy designed in this invention is 17.45 μm, with a reduction rate of about 31.68%. It can be seen that the intelligent roll shifting strategy designed in this invention effectively reduces the average strip wedge value in the entire rolling unit by intelligently and dynamically adjusting the roll shifting step size and stroke. Moreover, the intelligent roll shifting strategy designed in this invention can not only reduce the strip wedge, but also take into account the influence of roll wear. Thus, it helps to improve the same-plate difference index of the strip.

[0063] Second Embodiment

[0064] This embodiment provides an electronic device, which includes a processor and a memory; wherein, at least one instruction is stored in the memory, and the instruction is loaded and executed by the processor to implement the method of the first embodiment.

[0065] This electronic device may have relatively large differences due to different configurations or performances, and may include one or more processors (central processing units, CPUs) and one or more memories. Among them, at least one instruction is stored in the memory, and the instruction is loaded and executed by the processor to perform the above method.

[0066] Third Embodiment

[0067] This embodiment provides a computer-readable storage medium storing at least one instruction, which is loaded and executed by a processor to implement the method of the first embodiment described above. The computer-readable storage medium may be a ROM, random access memory, CD-ROM, magnetic tape, floppy disk, or optical data storage device, etc. The instruction stored therein can be loaded and executed by a processor in a terminal.

[0068] Furthermore, it should be noted that the present invention can be provided as a method, apparatus, or computer program product. Therefore, embodiments of the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0069] Embodiments of the present invention are described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0070] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing terminal equipment to cause a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0071] It should also be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0072] Finally, it should be noted that the above description represents a preferred embodiment of the present invention. It should be pointed out that although preferred embodiments have been described, those skilled in the art, once they understand the basic inventive concept of the present invention, can make various improvements and modifications without departing from the principles described herein. These improvements and modifications should also be considered within the scope of protection of the present invention. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A smart roll shifting method for reducing strip wedge shape caused by uneven hot roll profile, characterized in that, include: Set the initial roll step size and maximum roll travel; When the rolls are moved forward for the first time, the rolls are moved according to the set initial roll movement step and maximum roll movement stroke, and the roll movement step remains a fixed value during the roll movement process. After the first forward roll shift is completed, the wedge value of each coil of strip caused by the hot roll shape is calculated in each subsequent roll shift process. After the wedge value of the strip is calculated, the roll shift step length and maximum roll shift stroke are intelligently optimized based on the wedge value of the strip to reduce the average wedge value of the strip within a rolling unit. The intelligent optimization of the roll shifting step length and maximum roll shifting stroke based on the wedge value of the strip includes: When the absolute value of the wedge value of the strip is less than the preset wedge size threshold, the roll shifting step size is corrected to 0, that is, the next roll of strip stops shifting and the roll shifting position remains unchanged; When the absolute value of the wedge value of the strip is not less than the preset wedge size threshold or the number of strips whose roll position remains unchanged exceeds the preset strip number threshold, the roll step length is restored to the initial roll step length.

2. The intelligent roll shifting method for reducing strip wedge shape caused by uneven hot roll profile as described in claim 1, characterized in that, The wedge value of the strip is calculated using a roll thermal expansion model; wherein the input of the roll thermal expansion model is the strip rolling data, and the output is the thermal roll shape distribution and the resulting strip wedge size; wherein the rolling data includes: strip thickness, strip width, strip length, stand entrance thickness, stand exit thickness, rolling force, strip temperature, rolling time, rolling gap time, and roll shifting position.

3. The intelligent roll shifting method for reducing strip wedge shape caused by uneven hot roll profile as described in claim 1, characterized in that, The method of intelligently optimizing the roll shifting step length and maximum roll shifting stroke based on the wedge value of the strip also includes: The roll travel distance in the first forward roll shifting process is the set initial maximum roll travel distance. Subsequent forward roll shifting processes require periodic attenuation of the roll travel distance L. D The calculation formula is as follows: L D = M·K1 Where K1 is the preset attenuation coefficient of the forward roll travel; M is the initial maximum roll travel.

4. The intelligent roll shifting method for reducing strip wedge shape caused by uneven hot roll profile as described in claim 3, characterized in that, The method of intelligently optimizing the roll shifting step length and maximum roll shifting stroke based on the wedge value of the strip also includes: The negative roll travel is periodically reduced, and the negative roll travel L O The calculation formula is as follows: L O = -M·K2 Where K2 is the preset attenuation coefficient of the negative roll travel; M is the initial maximum roll travel.

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