A skin pass control method for reducing plate shape defect cut loss

Abstract

The application provides a flatness control method for reducing plate shape defect cutting loss, relates to the technical field of hot-rolled strip flatness control, and comprises the following steps: intercepting plate shape defect serious steel coils according to a hot-rolled outlet plate shape curve, and recording specific information of plate shape defects of the steel coils; determining the correspondence between the operation side / transmission side of the flatness line and the operation side / transmission side of the hot-rolled main line; flatting the plate shape defect serious steel coils, reducing the flatness speed in advance according to the plate shape defect position condition, and adjusting the flatness parameters; and step four: after the flatness of the plate shape defect position is finished, the flatness parameters are returned to the normal level. Through accurate flatting of the plate shape defect serious steel coils, the application avoids plate shape defect cutting loss and improves the flatness defect flatness yield of the hot-rolled steel coils.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hot-rolled strip flattening control, in particular to a flattening control method for reducing plate shape defect cutting loss. BACKGROUND

[0002] Plate shape quality is one of the important quality indicators of hot-rolled strip products and is also the focus of hot-rolled strip production control. One of the manifestations of plate shape quality defects is wavy shape, which can directly affect the use efficiency of downstream users and must be cut off for disposal in severe cases. In order to avoid affecting customer use, hot-rolled steel coils with large wavy shape defects need to be flattened to improve the plate shape quality of the strip. At present, there is no raw material plate shape detection equipment for the flattening machine, which cannot feed forward control of the strip according to the raw material plate shape. This leads to the phenomenon of roll gap internal deviation and rolling breakage of the steel coil with too large wavy shape defects during flattening. At this time, the broken strip must be cut off, causing unnecessary flattening cutting loss, affecting the overall yield of the steel coil, and causing damage to the flattening work roll surface, resulting in waste of non-scheduled roll changing time and increasing the number of work roll grinding, which seriously affects the flattening production efficiency and the consumption of the flattening work roll.

[0003] In the prior art, the roll gap and roll shape are adjusted to correct the deviation of the strip, such as using positive and negative bending roll technology to eliminate both side waves and middle waves to ensure that the strip remains on the center line during rolling. However, frequent adjustment of the roll gap and roll shape may increase the wear and maintenance cost of the equipment and affect the production efficiency. SUMMARY

[0004] The present application is made in view of the above problems, and aims to provide a flattening control method for reducing plate shape defect cutting loss. By intercepting the steel coil with severe plate shape defects and noting the starting position, ending position and side position of the plate shape defect, the position of the defect on the strip is quickly and accurately found during the flattening process. Then, according to the plate shape defect position, the flattening speed is reduced in advance and the flattening parameters are adjusted to accurately flatten the steel coil with severe plate shape defects, avoid plate shape defect cutting loss, and improve the flattening yield of hot-rolled steel coil plate shape defects.

[0005] Specifically, the first aspect of the present application provides a flattening control method for reducing plate shape defect cutting loss, comprising the following steps:

[0006] Step 1: According to the hot-rolled outlet plate shape curve, intercept the steel coil with severe plate shape defects and note the specific information of the steel coil plate shape defect;

[0007] Step 2: Determine the corresponding situation of the operation side / transmission side of the flattening line and the operation side / transmission side of the hot-rolled main line;

[0008] Step three: flattening the steel coil with serious plate shape defects, according to the position of the plate shape defects, the flattening speed is reduced in advance, the flattening parameters are adjusted, and the flattening parameters of the defect part are set as:

[0009] The flattening speed is 0.1-0.2 times of the plate shape normal area flattening speed, the unwinding tension is 30-140 kN, and the rolling force deviation is 2-4 times of the plate shape normal area rolling force deviation;

[0010] Step four: after the flattening of the plate shape defect position is completed, the flattening parameters are adjusted to the normal level.

[0011] The adjustment of the flattening parameters is to adjust the parameters of the flattening machine. The flattening machine is particularly suitable for strip steel flattening machine and cold rolling finishing machine. After recrystallization annealing and galvanizing, the strip steel often needs to be flattened to obtain the necessary performance and surface quality to meet the requirements of the subsequent process. The flattening machine on the continuous hot galvanizing unit is essentially a small reduction rolling deformation.

[0012] The flattening speed usually refers to the speed of the flattening machine when flattening the plate, the unwinding tension is the tension between the uncoiler and the flattening work roll, and the main purpose is to prevent the strip from loosening or interlayer sliding during unwinding, thereby avoiding scratches or other defects on the surface of the strip; the rolling force deviation refers to the difference between the rolling force applied to the operation side and the transmission side of the flattening machine during flattening. The more serious the plate shape defect, the greater the required rolling force deviation.

[0013] Further, the hot rolling outlet plate shape curve is a curve representing the edge wave or middle wave of the hot rolled strip steel measured by a multifunctional instrument or a flatness instrument at the hot rolling outlet.

[0014] Multifunctional instrument: The multifunctional instrument is usually installed at the outlet of the finishing mill and can measure center line thickness, cross-sectional thickness, temperature, crown, width, edge drop and plate shape, etc. in real time and continuously. These measurement data help operators optimize operations, improve production efficiency and product quality.

[0015] Flatness instrument: The flatness instrument is mainly used to measure the flatness of the strip steel to ensure that the shape of the strip steel meets the requirements during production. The flatness instrument usually adopts non-contact measurement technology, such as laser triangulation or optical measurement technology, which can detect and feedback flatness data in real time on the high-speed production line.

[0016] In the present application, the multifunctional instrument and the flatness instrument are used to measure the plate shape of the steel coil, that is, the flatness of the steel coil, which can detect the change of the wave value of the strip steel with the length of the strip steel. The wave value is the unevenness of the strip steel, which is convenient for marking the defect serious area.

[0017] Further, the serious plate shape defect refers to a plate shape curve value exceeding a set threshold.

[0018] The threshold of the serious plate shape defect of the plate shape unevenness is determined according to the actual situation of the production, and is determined based on the statistical analysis of the historical production data and the actual measurement data in the rolling process.

[0019] Further, the specific information of the plate shape defect of the steel coil includes the start position, the end position, and whether the defect is close to or far from the operation side of the steel coil.

[0020] Further, the step two specifically includes: determining whether the corresponding relationship between the operation side position of the hot rolling main line and the defect position of the steel coil is consistent with the operation side of the tempering line or consistent with the driving side of the tempering line.

[0021] The corresponding relationship between the operation side of the hot rolling main line and the operation side of the tempering line is determined to quickly locate the position of the wave shape defect of the plate shape, and the rolling force of one side needs to be increased or decreased to adjust the wave shape defect of the single side. Only when it is known which side the wave shape is, it is known whether the rolling force needs to be increased or decreased, and which side needs to be operated.

[0022] The specific adjustment condition is: the defect curve is negative, and the defect is on the operation side, so more pressure is applied to the driving side, that is, the rolling force of the driving side is increased; the defect curve is negative, and the defect is on the driving side, so more pressure is applied to the operation side, that is, the rolling force of the operation side is increased; the defect curve is positive, and the defect is on the operation side, so less pressure is applied to the operation side, that is, the rolling force of the operation side is decreased; the defect curve is positive, and the defect is on the driving side, so less pressure is applied to the driving side, that is, the rolling force of the driving side is decreased.

[0023] Further, the advance reduction of the tempering speed is specifically at least 20 m in advance.

[0024] In the second aspect, the application further provides a computing device having the function of implementing the method described in the first aspect. The beneficial effects can be referred to the description of the first aspect, and will not be described here. The function can be realized by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In one possible design, the structure of the device includes an acquisition module and a training module, and optionally, a construction module. These modules can realize the function of training the nodes in the method examples of the first aspect, and the specific description can be referred to the detailed description in the method examples, and will not be described here.

[0025] In a third aspect, the present application provides a computing device for implementing the method of the first aspect, and the beneficial effects can be referred to the description of the first aspect. The computing device comprises a processor and a memory. The memory is configured to store instructions and / or data. The memory is coupled to the processor. The processor implements the functions of the node in the first aspect when executing the program instructions stored in the memory. The computing device further comprises a communication interface for communicating with other devices.

[0026] In a fourth aspect, the present application provides a computer readable storage medium storing instructions, which when executed on a computer, cause the computer to perform the method of the first aspect and the possible designs of the first aspect.

[0027] In a fifth aspect, the present application provides a computer program product comprising instructions, which when executed on a computer, cause the computer to perform the method of the first aspect and the possible designs of the first aspect.

[0028] In a sixth aspect, the present application provides a computing chip, which is connected to a memory. The chip is configured to read and execute the software program stored in the memory, and perform the method of the first aspect and the possible designs of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the drawings, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 The step flow chart of the present application;

[0031] Figure 2 The finishing outlet plate shape curve diagram of the embodiment of the present application;

[0032] Figure 3 The schematic diagram of the relative position of the operation platform and the production line of the hot rolling production line and the skin pass line of the embodiment of the present application;

[0033] Figure 4 The real-time adjustment diagram of the skin pass parameter in the embodiment of the present application.

[0034] The implementation, functional features and advantages of the drawings will be further described with reference to the drawings. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described and illustrated in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein merely serve to explain the present application and should not be used to limit the present application. Based on the embodiments provided herein, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0036] Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application, and for those of ordinary skill in the art, the present application can also be applied to other similar scenarios without creative effort based on these drawings. In addition, it should be understood that although the efforts made in this development process can be complex and lengthy, for those of ordinary skill in the art related to the content disclosed herein, some design, manufacture or production changes based on the technology disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the present application.

[0037] If not specifically stated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0038] If not specifically stated, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0039] If not specifically stated, all steps of the present application can be performed in sequence or randomly, and the preferred sequence is sequential. For example, the method comprises steps (a) and (b), which means that the method can comprise sequentially performed steps (a) and (b), or sequentially performed steps (b) and (a). For example, the method can further comprise step (c), which means that step (c) can be added to the method in any order. For example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0040] If not specifically stated, the "includes" and "contains" mentioned in the present application are open-ended and can also be closed. For example, the "includes" and "contains" can mean that other components not listed can also be included or contained, or only the listed components can be included or contained.

[0041] If not specifically stated, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following satisfy the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0042] In order to better understand the scheme of the embodiments of the present application, some related terms and concepts that may be involved in the embodiments of the present application will be introduced first.

[0043] (1) Hot rolling is a metal processing technology mainly used in the production of steel materials. In the hot rolling process, the billet is heated to a high temperature (usually more than 926℃), and then compressed into the required shape and size through a series of rollers. This process can improve the mechanical properties of steel, such as refining grains, eliminating casting defects, etc., but also has some disadvantages, such as rough surface, poor toughness and flatness.

[0044] (2) The flattening machine is particularly suitable for strip steel flattening machine and cold rolling finishing machine. After recrystallization annealing and galvanizing, the strip steel often needs to be flattened to obtain the necessary performance and surface quality to meet the requirements of the subsequent process. The flattening machine on the continuous hot galvanizing line is essentially a small reduction rolling deformation.

[0045] In this embodiment, as shown in Figure 1 A flattening control method for reducing plate shape defect cutting loss includes the following steps:

[0046] Step one: According to the hot rolling outlet plate shape curve, intercept the plate shape defect serious steel coil, and note the specific information of the plate shape defect of the steel coil;

[0047] Step two: Determine the corresponding situation of the operation side / drive side of the flattening line and the operation side / drive side of the hot rolling main line;

[0048] Step three: Flatten the plate shape defect serious steel coil, according to the plate shape defect position, reduce the flattening speed in advance, adjust the flattening parameters, and the flattening parameters of the defect part are set as:

[0049] The flattening speed is 0.1 times the flattening speed of the plate shape normal area, the unwinding tension is 50kN-100kN, and the rolling force deviation is 3 times the rolling force deviation of the plate shape normal area;

[0050] Step four: After the plate shape defect position flattening is finished, the flattening parameters are returned to the normal level.

[0051] The adjustment of the flattening parameters is specifically adjusting the parameters of the flattening machine. The flattening machine is particularly suitable for strip steel flattening machine and cold rolling finishing machine. After recrystallization annealing and galvanizing, the strip steel often needs to be flattened to make the strip steel obtain the necessary performance and surface quality to meet the requirements of the subsequent process. The flattening on the continuous hot galvanizing unit is essentially a kind of rolling deformation with small reduction.

[0052] The flattening speed generally refers to the speed of the flattening machine when flattening the plate, the unwinding tension is the tension between the uncoiler and the flattening work roll, and the main purpose is to prevent the strip from loosening or interlayer sliding during unwinding, thereby avoiding scratches or other defects on the surface of the strip; the rolling force deviation refers to the difference between the rolling forces applied to the operating side and the driving side of the flattening machine during flattening. The more serious the plate shape defect on one side, the greater the required rolling force deviation.

[0053] Further, the hot rolling outlet plate shape curve is a curve measured by a multifunctional instrument or a flatness instrument at the outlet of the hot continuous rolling, which represents the edge wave or the middle wave of the hot rolled strip. In the embodiment, the plate shape curve diagram measured by the flatness instrument at the outlet of the finishing mill is shown in Figure 2 .

[0054] Multifunctional instrument: The multifunctional instrument is usually installed at the outlet of the finishing mill and can measure the center line thickness, cross-sectional thickness, temperature, crown, width, edge drop and plate shape, etc. in real time and continuously. These measurement data help operators optimize operation, improve production efficiency and product quality.

[0055] Flatness instrument: The flatness instrument is mainly used to measure the flatness of the strip steel to ensure that the shape of the strip steel meets the requirements during production. The flatness instrument usually adopts non-contact measurement technology, such as laser triangulation or optical measurement technology, which can detect and feedback flatness data in real time on the high-speed production line.

[0056] In the present application, the multifunctional instrument and the flatness instrument are used to measure the plate shape of the steel coil, that is, the flatness of the steel coil, which can detect the change of the wave value of the strip steel with the length of the strip steel. The wave value is the unevenness of the strip steel, which is convenient for marking the serious defect area.

[0057] Further, the serious plate shape defect refers to the plate shape curve value exceeding the set threshold value.

[0058] The set threshold value of the serious plate shape defect of the plate shape unevenness is determined according to the specific production conditions, and the present application is determined based on the statistical analysis of the historical production data and the actual measurement data in the rolling process.

[0059] Further, the specific information of the plate shape defect of the steel coil includes the starting position, the ending position, whether the defect is close to the operating side or away from the operating side.

[0060] Further, the step two specifically comprises: determining whether the corresponding relationship between the operation side position of the hot rolling main line and the defect position of the steel coil is consistent with the operation side of the tempering line or consistent with the transmission side of the tempering line. In the embodiment, the relative position of the operation side of the hot rolling main line and the production line and the relative position of the operation side of the tempering line and the production line are shown in the schematic view as Figure 3

[0061] The corresponding relationship between the operation side of the hot rolling main line and the operation side of the tempering line is determined to quickly locate the position of the wave defect of the plate shape. The wave defect on one side needs to be adjusted by increasing or decreasing the rolling force on one end. Only when the wave is on which side, it is known that the rolling force needs to be increased or decreased, and which side needs to be operated.

[0062] The specific adjustment condition is: the defect curve is negative, and the defect is on the operation side, so more pressure is applied to the transmission side, that is, the rolling force of the transmission side is increased; the defect curve is negative, and the defect is on the transmission side, so more pressure is applied to the operation side, that is, the rolling force of the operation side is increased; the defect curve is positive, and the defect is on the operation side, so less pressure is applied to the operation side, that is, the rolling force of the operation side is decreased; the defect curve is positive, and the defect is on the transmission side, so less pressure is applied to the transmission side, that is, the rolling force of the transmission side is decreased.

[0063] Further, the tempering speed is reduced in advance, specifically, the tempering speed needs to be reduced by at least 20 m in advance.

[0064] In the embodiment, the set threshold of the plate shape curve is 200 IU, and IU is the uneven value unit. Figure 2 As can be seen, the peak value of the plate shape of the steel coil is less than -450 IU, which exceeds the interception standard, and the system determines that the plate shape defect needs to be intercepted. The plate shape defect region of the steel coil is 0-100 m, and the detailed repair information is as follows: "the operation side single wave of the hot rolling head 0-100 m region is eliminated by tempering, and attention should be paid to adjusting the tempering parameters".

[0065] In the production process, the steel coil is taken in the form of up-coiling on the hot rolling production line and in the form of open-coiling on the tempering line. Therefore, as shown in the figure, Figure 3 when the steel coil produced by the hot rolling production line 1 is lifted to the tempering line, the north-south direction of the steel coil must be reversed to achieve the state of open-coiling. Since the operation side of the hot rolling production line 1 and the operation side of the tempering line are opposite to the relative position of the production line, when the steel coil of the hot rolling production line 1 is opened on the tempering line, the operation side and the transmission side are not reversed, that is, the operation side of the hot rolling production line 1 is the operation side of the tempering line. Similarly, when the steel coil produced by the hot rolling production line 2 is lifted to the tempering line, the north-south direction of the steel coil is reversed, and since the operation side of the hot rolling production line 2 and the operation side of the tempering line are the same relative position of the production line, the operation side of the hot rolling production line 2 is the transmission side of the tempering line.

[0066] ​The steel coil in the embodiment is produced by the hot rolling production line 2, and the operation side corresponds to the transmission side of the flattening line. The position of the plate shape defect on the flattening line can be accurately positioned by combining the length position of the plate shape defect at the hot rolling outlet, that is, on the flattening line, and the single-sided wave exists in the 0-100m of the transmission side of the inner circle of the incoming steel coil.

[0067] In the embodiment, the operator reduces the speed by 20m in advance on the basis of the length information of the plate shape defect in the remarks. In the embodiment, the flattening reduction is very small, so the flattening speed is consistent with the unwinding machine speed, the flattening speed of the plate shape normal area is 300m / min, the flattening speed of the plate shape defect area is 30m / min, the unwinding tension is the tension between the unwinding machine and the flattening work roll, the unwinding tension of the plate shape normal area is 0kN, the unwinding tension of the plate shape defect area is 50-100kN, which is adjusted according to the uneven value of the current steel coil flattening position; the rolling force deviation is the difference between the operation side rolling force value and the transmission side rolling force value, the rolling force deviation of the plate shape normal area is 20kN, and the rolling force deviation of the plate shape defect area is 60kN. The real-time adjustment chart of the flattening parameters in the embodiment of the application is shown in Figure 4 .

[0068] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and playing the same role and effect within the scope of the technical solutions of the present application are all included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications of the embodiments that can be thought of by those skilled in the art, and other ways constructed by combining part of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method of reducing the flatness defect cutback of a temper mill control, characterized by, The method comprises the following steps: Step 1: intercepting the steel coil with serious plate shape defects according to the plate shape curve at the hot rolling outlet, and recording specific information of the plate shape defects of the steel coil; Step 2: determining the correspondence between the operation side / drive side of the temper mill and the operation side / drive side of the hot rolling main line; Step 3: tempering the steel coil with serious plate shape defects, reducing the tempering speed in advance according to the position of the plate shape defects, and adjusting the tempering parameters, wherein the tempering parameters of the defect part are set as follows: the tempering speed is 0.1-0.2 times the tempering speed of the normal plate shape area, the unwinding tension is 30-140 kN, and the rolling force deviation is 2-4 times the rolling force deviation of the normal plate shape area; Step 4: after the tempering of the plate shape defect position is completed, the tempering parameters are returned to the normal level; the serious plate shape defects refer to the plate shape curve value exceeding the set threshold value; the specific information of the plate shape defects of the steel coil includes the starting position, the ending position, and whether the defect is close to or far from the operation side of the steel coil; Step 2 specifically comprises: determining whether the correspondence between the operation side position of the hot rolling main line and the defect position of the steel coil is consistent with the operation side of the temper mill or consistent with the drive side of the temper mill; the reduction of the tempering speed in advance specifically refers to reducing the tempering speed by at least 20 m in advance; the defect curve is negative, and more pressure is applied to the drive side when the defect is on the operation side, i.e., the rolling force of the drive side is increased; the defect curve is negative, and more pressure is applied to the operation side when the defect is on the drive side, i.e., the rolling force of the operation side is increased; the defect curve is positive, and less pressure is applied to the operation side when the defect is on the operation side, i.e., the rolling force of the operation side is reduced; the defect curve is positive, and less pressure is applied to the drive side when the defect is on the drive side, i.e., the rolling force of the drive side is reduced.

2. A temper rolling control method for reducing the occurrence of plate shape defects according to claim 1, characterized in that, the plate shape curve at the hot rolling outlet is a curve representing the edge wave or the center wave of the hot rolled strip measured by a multifunction instrument or a flatness instrument at the hot continuous rolling outlet.

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