A method for controlling the head and tail width of a hot-rolled strip

Abstract

The present application relates to the technical field of rolling steel, and particularly relates to a hot-rolled strip head and tail width control method, which comprises the following steps: constructing a double edger cooperative side pressure control model; according to the time sequence of E1 edger first rolling and E2 edger later rolling, adjusting the opening of E1 and E2 edger in real time, and adjusting the side pressure of each section of the head and tail of the strip respectively; after rolling, according to the over-wide detection result of the preset length area of the finished product head and tail, fine-tuning the simple correction coefficient of each pass of the model for the width management of the next batch of strips. The present application has the advantages that: the accuracy and stability of the input data are ensured; the preset length area of the strip head and tail is divided into several sections, which are used for calculating the edger side pressure for different sections; the section design changes the width control of the head and tail area from the traditional "overall unified control" to "sectional differentiated control", greatly improving the fine degree of control and laying a data foundation for subsequent accurate side pressure adjustment.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, and in particular to a method for controlling the width of the head and tail of hot-rolled strip steel. Background Technology

[0002] In the production of hot-rolled strip steel, width accuracy is one of the core quality indicators of the product. In particular, the width control of the head and tail of the strip steel directly affects the normal operation of subsequent processes such as shearing, pickling, and cold rolling, as well as the yield and market competitiveness of the final product.

[0003] In hot rolling production lines without a fixed width press, the roughing process is a crucial step in width control. Currently, most such production lines are equipped with a set of vertical rolls (E1 and E2) before roughing R1 and R2 for initial adjustment and correction of strip width. However, due to the inherent characteristics of strip at the beginning and end, such as uneven temperature, uneven metal flow, and stress concentration, coupled with the pre-adjustment effect of the fixed width press on the slab width, it is difficult to achieve precise width control at the beginning and end by relying solely on the traditional fixed opening control mode of the vertical rolls. In actual production, there is a common problem of severe overwidth within the preset length range of the strip beginning and end, with the overwidth usually exceeding the strip body by 20-50mm. This necessitates the removal of a large amount of the oversized portion at the beginning and end during subsequent shearing processes, which not only reduces the yield and increases production costs but also affects production efficiency.

[0004] In existing technologies, most improvements to the width control of hot-rolled strip rely on the pre-side pressure of a fixed-width press or on optimizing the overall side pressure of the vertical rolls to achieve width adjustment. However, these solutions fail to address the specific production line conditions without a fixed-width press or with two vertical rolls (before R1 and R2), and do not construct precise control models that consider the characteristics of the strip's head and tail regions. Therefore, they cannot fundamentally solve the problem of excessive width at the head and tail. For example, some solutions use fixed short-stroke control parameters without considering the influence of strip thickness, width, steel grade, and rolling speed, resulting in limited control accuracy. Other solutions, while introducing model calculations, do not align with the collaborative control logic of the two vertical rolls and lack segmented, refined design for the head and tail regions, making it difficult to achieve the target of controlling the excessive width within 0-10mm.

[0005] Therefore, developing a method that is compatible with non-fixed width presses and double vertical roll roughing production lines, and can more accurately control the width of the strip head and tail, has become an urgent technical problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a method for controlling the width of the head and tail of hot-rolled strip steel, in order to solve the problems of severe over-width (20-50mm wider than the body) strip steel head and tail, low control accuracy, and low yield in existing production lines without fixed width presses. By collecting multi-dimensional core parameters and dividing the preset head and tail areas into several segments, a dual vertical roll collaborative side pressure control model is constructed. The side pressure of each segment is adjusted according to the rolling sequence E1 first and E2 later. The correction coefficient is finely adjusted according to the over-width detection results, so as to control the over-width at the head and tail within 0-10mm, improve the width accuracy and yield, and reduce production costs.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for controlling the width of the head and tail of hot-rolled strip steel includes: S1. Parameter Acquisition and Preprocessing: Before the strip enters the roughing process, the following core parameters are collected in real time, and the core parameters are preprocessed by outlier removal and smoothing filtering. The core parameters include strip basic parameters, rolling process parameters, vertical roll basic parameters, and position detection parameters. The preset length area of ​​the strip head and tail is divided into several segments for calculating the vertical roll side pressure for different segments. S2. Construct a collaborative side pressure control model for dual vertical rollers; S3. Based on the calculated target side pressure, adjust the opening of the E1 and E2 vertical rolls in real time according to the sequence of rolling E1 first and E2 vertical roll later, and adjust the side pressure of each section of the strip head and tail respectively. S4. After rolling, based on the overwidth detection results of the pre-set length area of ​​the finished product, the simple correction coefficients of each pass of the model are fine-tuned for the width management of the next batch of strip steel.

[0008] In S1: The basic parameters of the strip include the target finished width W. target Target finished product thickness h, original slab thickness H, original slab width W0, and steel grade yield strength σ; Rolling process parameters include E1 vertical roll rolling speed V E1 E2 vertical roll rolling speed V E2 The temperature T of the strip before it enters the vertical rolls of the first roughing mill stand R1 and the second roughing mill stand R2; The basic parameters of the vertical rolls include the diameter D of the vertical rolls before the first roughing mill stand R1. E1 The diameter D of the front vertical roll of the second roughing mill stand R2 E2 ; The position detection parameters include real-time acquisition of the position coordinates of the head and tail of the strip relative to the front vertical roll of the first roughing mill stand R1 and the front vertical roll of the second roughing mill stand R2.

[0009] In S1, the pre-defined length region of the strip head and tail is divided into four segments, including: S11. The strip head is divided into segments H1, H2, H3, and H4 along its length: The H1 and H2 sections are lateral pressure adjusted by the E1 vertical roller; The H3 and H4 sections are lateral pressure adjusted by the E2 vertical roller; H1 and H2, H3 and H4 are consecutive segments that are adjacent to each other along the length of the strip and do not overlap. S12, the tail of the strip is divided into segments T1, T2, T3, and T4 along its length: The T1 and T2 sections are lateral pressure adjusted by the E1 vertical roller; The T3 and T4 sections are adjusted by the side pressure of the E2 vertical roller; T1 and T2, and T3 and T4 are consecutive segments that are adjacent to each other along the length of the strip and do not overlap.

[0010] In S2, the dual vertical roller collaborative side pressure control model is constructed based on the collected preprocessed parameters. A calculation model for the side pressure of each segment within the preset length region at the head and tail is established, expressed as follows: ①; ②; In formulas ① and ②: This represents the target side pressure of the E1 vertical roller in the nth pass and the i-th segment, in mm. This represents the target side pressure of the E2 vertical roller in the nth pass and the i-th segment, in mm. This indicates the original width of the slab, in mm. Indicates the target finished product width, in mm; This indicates the initial lateral pressure of the vertical roller, in mm. This indicates the yield strength of the steel grade, expressed in MPa. This indicates the instantaneous temperature of the strip head and tail for each pass, in °C. This represents the simplified correction coefficients for each pass of the model; This indicates the rolling speed of the E1 vertical roll in the corresponding pass, in m / s. This indicates the rolling speed of the E2 vertical roll in the corresponding pass, in m / s; This indicates the diameter of the E1 vertical roller, in mm; This indicates the diameter of the E2 vertical roller, in mm. The overwidth compensation is achieved in the following way: For the preset length area at the head and tail of the strip, the E1 vertical roll performs the first stage of side pressure compensation for the H1 and H2 segments and the T1 and T2 segments, and the E2 vertical roll performs the second stage of side pressure compensation for the H3 and H4 segments and the T3 and T4 segments. The target side pressure amount is calculated for each stage based on the temperature and rolling speed parameters of their respective segments. Through the coordinated action of the two vertical rolls, the overwidth of the head and tail area is limited to the target range.

[0011] In S3, following the sequence of rolling by vertical roll E1 first and vertical roll E2 later, the opening of vertical rolls E1 and E2 is adjusted in real time to adjust the side pressure of each segment at the head and tail of the strip. Specifically, this includes: When the strip head enters the H1 section and the E1 vertical roll is in the first pass, start the first pass adjustment of the E1 vertical roll and adjust the opening of the E1 vertical roll according to the calculated target side pressure. When E1 vertical roll is switched to the second pass, the opening of E1 vertical roll continues to be adjusted according to the target side pressure of H2 segment; When the strip head enters the H3 section and the E2 vertical roll is in the first pass, start the first pass adjustment of the E2 vertical roll and adjust the opening of the E2 vertical roll according to the target side pressure of the H3 section. When the E2 vertical roll is switched to the second pass, the opening of the E2 vertical roll continues to be adjusted according to the target side pressure of the H4 segment; The adjustment logic at the tail of the strip is symmetrical to that at the head. The T1 and T2 segments are adjusted by the E1 vertical roller, and the T3 and T4 segments are adjusted by the E2 vertical roller, until the head and tail adjustment areas of the strip roughing stage have completely passed through each pass of the E1 and E2 vertical rollers, and then the strip body width is switched to the conventional control mode.

[0012] In S4, the simplified correction coefficients for each stage of the model are fine-tuned, specifically including: After each batch of strip steel is rolled, the simplified correction coefficients for each pass of the model are adjusted based on the overwidth detection results of the pre-set length regions at the ends of the finished product. Make fine adjustments, with each adjustment not exceeding 0.2. If the excess width of the finished product is generally greater than 10mm, then increase the correction factor of the corresponding vertical roller. If the excess width of the finished product is less than 0 mm, then reduce the correction factor of the corresponding vertical roller.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. In S1, the strip base parameters, rolling process parameters, vertical roll base parameters, and position detection parameters are collected in real time, and outlier removal and smoothing filtering preprocessing are performed to ensure the accuracy and stability of the input data. At the same time, the preset length area of ​​the strip head and tail is divided into several segments for calculating the vertical roll side pressure for different segments. This segmented design changes the width control of the head and tail areas from the traditional "overall unified control" to "segmented differentiated control", which greatly improves the precision of the control and lays a data foundation for subsequent precise side pressure adjustment. 2. Construct a dual vertical roll collaborative side pressure control model. This model integrates multiple parameters such as the difference between the original width of the slab and the target finished width, the yield strength of the steel grade, the head and tail temperatures of each pass, the rolling speed, and the diameter of the vertical rolls. Compared with the existing technology that relies on fixed opening or single vertical roll control, this invention can dynamically adapt to the width control requirements of different specifications and working conditions, realize the phased and collaborative work of E1 and E2 vertical rolls, avoid the limitations of single vertical roll control, and significantly improve the control accuracy of the head and tail width. 3. Strictly follow the timing sequence of rolling with E1 vertical roll first and E2 vertical roll later, and adjust the opening of E1 and E2 vertical rolls in real time to adjust the side pressure of each segment at the head and tail of the strip. This timing control logic is precisely matched with the segment division (H1~H4, T1~T4) to ensure that each segment in the head and tail area receives accurate side pressure compensation in the corresponding vertical roll pass. Through the verification of the embodiments, after adopting the present invention, the overwidth of each segment in the preset length area of ​​the head and tail of the strip can be controlled within the range of 0-10mm, which is a significant improvement over the 20-50mm overwidth in the prior art, thus improving the width accuracy. 4. Based on the overwidth detection results of the pre-set length area of ​​the finished product, the simple correction coefficients of each pass of the model are fine-tuned for the width management of the next batch of strip steel. This fine-tuning mechanism does not require complex deviation calculations or model reconstruction. It only needs to be based on the overwidth detection results (increase the correction coefficient if it is too large, decrease the correction coefficient if it is too small, and the fine-tuning range does not exceed 0.2 each time) to achieve rapid adaptive optimization of the model, adapt to the fluctuation of production line conditions, and ensure stable and reliable control accuracy of strip steel of different batches and specifications. 5. Based on the existing vertical rollers and testing equipment on the production line, more precise control of the head and tail width can be achieved simply by optimizing the control methods (S1~S4). There is no need to add large equipment such as a width-fixing press. The transformation cost is low and the implementation cycle is short. At the same time, after the head and tail overwidth is controlled within 0-10mm, the subsequent shearing process does not need to remove a large amount of the oversized head and tail, which improves the yield, reduces the rework and scrap of products with unqualified width, and significantly reduces production costs and energy consumption. Detailed Implementation

[0014] The present invention will now be described in detail, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0015] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0016] Example 1:

[0017] A method for controlling the width of the head and tail of hot-rolled strip steel includes: S1. Parameter Acquisition and Preprocessing: Before the strip enters the roughing process, the following core parameters are collected in real time, and the core parameters are preprocessed by outlier removal and smoothing filtering. The core parameters include strip basic parameters, rolling process parameters, vertical roll basic parameters, and position detection parameters. The preset length area of ​​the strip head and tail is divided into several segments for calculating the vertical roll side pressure for different segments.

[0018] For example, the product specifications are: thickness 3.8mm, width 1000mm, and the specific parameters collected are as follows: Basic parameters of strip steel: original slab thickness H=230mm, original slab width Target finished product width The target finished product thickness h=3.8mm, and the yield strength of the steel grade is... .

[0019] Rolling process parameters: E1 vertical roll rolling speed , ; E2 vertical roll rolling speed , .

[0020] Temperatures of each pass in E1 and E2: Head first segment temperature (E1 vertical roller first pass head temperature). Tail section temperature (Temperature at the tail end of the first pass of E1 vertical roller); Head Second Segment Temperature (E1 vertical roller second pass head temperature); Tail section temperature (Temperature at the tail end of the second pass of E1 vertical roller); Head third segment temperature (E2 vertical roller head temperature in the first pass); Tail third segment temperature (Temperature at the tail end of the first pass of E2 vertical roller); Head fourth segment temperature (E2 vertical roller second pass head temperature); Tail fourth segment temperature (Temperature at the tail end of the second pass of the E2 vertical roller).

[0021] Vertical roller foundation parameters: Diameter of the front vertical roll of the first roughing mill stand R1 ; The diameter of the front vertical roll of the second roughing mill stand R2 is... .

[0022] Position detection parameters: The position coordinates of the strip head and tail relative to the front vertical rolls of the first roughing mill stand R1 and the second roughing mill stand R2 are collected in real time. For example, laser position detectors are installed 1.5m before the entrance of vertical roll E1 and 1.5m before the entrance of vertical roll E2, with a detection accuracy of ±5mm, to determine whether the strip head and tail have entered the starting position of each segment. When the strip head is detected to have reached the starting position of segment H1, the first pass side pressure adjustment of vertical roll E1 is triggered; when the strip head is detected to have reached the starting position of segment H3, the first pass side pressure adjustment of vertical roll E2 is triggered.

[0023] The pre-set length area (pre-set length 5m) of the strip head and tail is divided into four segments, including: S11. The strip head is divided into H1, H2, H3 and H4 segments along the length direction, each segment being 1.25m long. The H1 and H2 segments are controlled by the side pressure of the E1 vertical roller; the H3 and H4 segments are controlled by the side pressure of the E2 vertical roller. H1 and H2, and H3 and H4 are consecutive segments that are adjacent to each other along the length direction of the strip and do not overlap.

[0024] S12. The tail of the strip is divided into segments T1, T2, T3 and T4 along the length direction, and each segment is 1.25m long. The T1 and T2 segments are controlled by the side pressure of the E1 vertical roller; the T3 and T4 segments are controlled by the side pressure of the E2 vertical roller; T1 and T2, T3 and T4 are consecutive segments that are adjacent to each other along the length direction of the strip and do not overlap.

[0025] S2. Construct a collaborative side pressure control model for dual vertical rollers; The dual vertical roller collaborative side pressure control model is constructed based on the collected preprocessed parameters. A calculation model for the side pressure of each segment within the preset length region at the beginning and end is established, expressed as follows: ①; ②; In formulas ① and ②: This represents the target side pressure of the E1 vertical roller in the nth pass and the i-th segment, in mm. This represents the target side pressure of the E2 vertical roller in the nth pass and the i-th segment, in mm. This indicates the original width of the slab, in mm. Indicates the target finished product width, in mm; This indicates the initial lateral pressure of the vertical roller, in mm. This indicates the yield strength of the steel grade, expressed in MPa. This indicates the instantaneous temperature of the strip head and tail for each pass, in °C. This represents the simplified correction coefficients for each pass of the model; This indicates the rolling speed of the E1 vertical roll in the corresponding pass, in m / s. This indicates the rolling speed of the E2 vertical roll in the corresponding pass, in m / s; This indicates the diameter of the E1 vertical roller, in mm; This indicates the diameter of the E2 vertical roller, in mm. For example, Initial side pressure of vertical roller .

[0026] The initial simplified correction coefficients for each pass of the model are set as follows: , , , .

[0027] Calculate the target lateral pressure for each vertical roller in each pass and each section: E1 vertical roller first pass (corresponding to H1 segment): mm.

[0028] E1 vertical roller, second pass (corresponding to H2 segment): mm.

[0029] The side pressure of the T1 and T2 sections at the tail of the E1 vertical roller is calculated using the same method, with a range of 30.25-30.26 mm.

[0030] E2 vertical roller first pass (corresponding to H3 segment): mm.

[0031] E2 vertical roller, second pass (corresponding to H4 segment): mm.

[0032] The side pressure of the T3 and T4 sections at the tail of the E2 vertical roller is calculated using the same method, with a range of 30.45-30.46 mm.

[0033] The overwidth compensation is achieved as follows: For a preset 5m length area at the beginning and end of the strip, the E1 vertical roll performs the first stage of lateral pressure compensation for segments H1 and H2, and segments T1 and T2, with target lateral pressure amounts of 30.25mm and 30.29mm, respectively; the E2 vertical roll performs the second stage of lateral pressure compensation for segments H3 and H4, and segments T3 and T4, with target lateral pressure amounts of 30.45mm and 30.50mm, respectively. The target lateral pressure amounts are calculated for each stage based on the temperature and rolling speed parameters of their respective segments. Through the coordinated action of the two vertical rolls, the overwidth in the beginning and end areas is reduced from the original 20-50mm to the target range of 0-10mm.

[0034] S3. Perform segmented side pressure control according to the timing sequence: Based on the calculated target side pressure, the opening of the E1 and E2 vertical rolls is adjusted in real time according to the sequence of rolling first with the E1 vertical roll and then with the E2 vertical roll. The side pressure is adjusted for each segment at the head and tail of the strip, with an adjustment frequency of 10Hz.

[0035] Specifically, it includes: When the strip head enters the H1 section and the E1 vertical roll is in the first pass, start the first pass control of the E1 vertical roll and adjust the opening of the E1 vertical roll according to the target side pressure of 30.25mm.

[0036] When the E1 vertical roll is switched to the second pass, the opening of the E1 vertical roll continues to be adjusted according to the target side pressure of 30.29mm for the H2 segment.

[0037] When the strip head enters the H3 section and the E2 vertical roll is in the first pass, start the first pass control of the E2 vertical roll and adjust the opening of the E2 vertical roll according to the target side pressure of 30.45mm for the H3 section.

[0038] When the E2 vertical roll is switched to the second pass, the opening of the E2 vertical roll continues to be adjusted according to the target side pressure of 30.50mm for the H4 segment.

[0039] The control logic for the tail end of the strip is symmetrical to that for the head end. Sections T1 and T2 are controlled sequentially by vertical roller E1 (side pressure of approximately 30.25mm and 30.26mm respectively), while sections T3 and T4 are controlled by vertical roller E2 (side pressure of approximately 30.45mm and 30.46mm respectively). This continues until the head and tail control areas of the strip in the roughing stage have completely passed through each pass of vertical rollers E1 and E2, at which point the system switches to the conventional strip width control mode. The conventional control mode means that the intermediate body portion of the strip outside the preset head and tail areas is controlled with a fixed target width or a constant side pressure based on a conventional model, without requiring segmented fine-tuning.

[0040] S4. Fine-tuning of correction coefficients: After rolling, based on the overwidth detection results of the pre-set length region at the beginning and end of the finished product, the simplified correction coefficients of each pass of the model are fine-tuned for the control of the next batch of strip steel. For example, after rolling, the width of each segment in the pre-set length region at the beginning and end is detected. The results show that the overwidth of each segment is in the range of 1.2~8.7mm, all controlled within the target range of 0~10mm, and no coefficient fine-tuning is required.

[0041] If the overwidth result exceeds the target range, fine-tuning will be performed according to the following rules: After each batch of strip steel is rolled, the simplified correction coefficients for each pass of the model will be adjusted based on the overwidth detection results of the preset length regions at the beginning and end of the finished product. Make fine adjustments, with each adjustment not exceeding 0.2 mm. If the finished product's overwidth is generally greater than 10 mm, increase the correction coefficient of the corresponding vertical roller. If the finished product's overwidth is less than 0 mm, decrease the correction coefficient of the corresponding vertical roller.

[0042] Example 2:

[0043] In this embodiment, the method for controlling the width of the head and tail of hot-rolled strip is the same as in Embodiment 1, but with the addition of an adaptive correction process for thin-gauge strip, as detailed below: I. Control of thin-gauge strip (thickness 2.5mm, width 1300mm); Using the same control steps as in Example 1, the following parameters were collected: The original thickness of the slab is H=230mm, and the original width of the slab is... Target finished product width The target finished product thickness h = 2.5 mm, and the yield strength of the steel grade is... ; E1 vertical roll first pass rolling speed E1 vertical roll second pass rolling speed ; E2 vertical roll first pass rolling speed E2 vertical roll second pass rolling speed ; Temperatures of each pass in E1 and E2: Head first segment temperature (E1 vertical roller first pass head temperature). Tail section temperature (Temperature at the tail end of the first pass of E1 vertical roller); Head Second Segment Temperature (E1 vertical roller second pass head temperature); Tail section temperature (Temperature at the tail end of the second pass of E1 vertical roller); Head third segment temperature (E2 vertical roller head temperature in the first pass); Tail third segment temperature (Temperature at the tail end of the first pass of E2 vertical roller); Head fourth segment temperature (E2 vertical roller second pass head temperature); Tail fourth segment temperature (Temperature at the tail end of the second pass of the E2 vertical roller).

[0044] II. Calculation process: Initial side pressure of vertical roller .

[0045] The initial simplified correction coefficients for each stage of the model are set as follows: , , , (For thin strip steel, the correction factor should be appropriately reduced to avoid overpressure).

[0046] Calculate the target lateral pressure for each vertical roller in each pass and each section: E1 vertical roller first pass (corresponding to H1 segment): mm.

[0047] E1 vertical roller, second pass (corresponding to H2 segment): mm.

[0048] E2 vertical roller first pass (corresponding to H3 segment): mm.

[0049] E2 vertical roller, second pass (corresponding to H4 segment): mm.

[0050] The tail section T1~T4 is calculated using the same method, and the lateral pressure range is consistent with the corresponding head section.

[0051] III. Control Effect: Using the control method of this invention, the overwidth range of each segment in the 5m area at the beginning and end is 0.8-7.9mm, all meeting the target requirement of 0-10mm; compared with the original production mode, the overwidth at the beginning and end (20-50mm) is greatly reduced, verifying the applicability of this invention to thin strip steel.

[0052] Example 3:

[0053] In this embodiment, the method for controlling the width of the head and tail of hot-rolled strip is the same as in Embodiment 1, except that an adjustment process for the correction coefficient of thicker strip is added based on Embodiment 1 and / or Embodiment 2, as detailed below: I. Thick strip steel control (thickness 5.8mm, width 1500mm); Using the same control steps as in Example 1, the following parameters were collected: The original thickness of the slab is H=230mm, and the original width of the slab is... Target finished product width The target finished product thickness h=5.8mm, and the yield strength of the steel grade is... ; E1 vertical roll first pass rolling speed E1 vertical roll second pass rolling speed ; E2 vertical roll first pass rolling speed E2 vertical roll second pass rolling speed ; Temperatures of each pass in E1 and E2: Head first segment temperature (E1 vertical roller first pass head temperature). Tail section temperature (Temperature at the tail end of the first pass of E1 vertical roller); Head Second Segment Temperature (E1 vertical roller second pass head temperature); Tail section temperature (Temperature at the tail end of the second pass of E1 vertical roller); Head third segment temperature (E2 vertical roller head temperature in the first pass); Tail third segment temperature (Temperature at the tail end of the first pass of E2 vertical roller); Head fourth segment temperature (E2 vertical roller second pass head temperature); Tail fourth segment temperature (Temperature at the tail end of the second pass of the E2 vertical roller).

[0054] II. Calculation process: Initial side pressure of vertical roller .

[0055] The initial simplified correction coefficients for each stage of the model are set as follows: , , , (For thicker strip steel, the correction factor should be appropriately increased to compensate for greater metal flow inhomogeneity).

[0056] Calculate the target lateral pressure for each vertical roller in each pass and each section: E1 vertical roller first pass (corresponding to H1 segment): mm.

[0057] E1 vertical roller, second pass (corresponding to H2 segment): mm.

[0058] E2 vertical roller first pass (corresponding to H3 segment): mm.

[0059] E2 vertical roller, second pass (corresponding to H4 segment): mm.

[0060] The tail section T1~T4 is calculated using the same method, and the lateral pressure range is consistent with the corresponding head section.

[0061] III. Control Effect: Using the control method of this invention, the overwidth range of each segment in the 5m area at the beginning and end is 0.5-6.8mm, which fully meets the target requirement of 0-10mm. Compared with the original production mode, the overwidth at the beginning and end is greatly reduced, further verifying the versatility and control accuracy of this invention on thick strip steel.

[0062] This invention acquires strip base parameters, rolling process parameters, vertical roll base parameters, and position detection parameters in real time in S1, and performs outlier removal and smoothing filtering preprocessing to ensure the accuracy and stability of the input data. Simultaneously, the preset length region at the head and tail of the strip is divided into several segments for calculating the vertical roll side pressure for different segments. This segmented design transforms the width control of the head and tail regions from traditional "overall unified control" to "segmented differentiated control," significantly improving the precision of control and laying a data foundation for subsequent precise side pressure adjustment. A dual-vertical-roll collaborative side pressure control model is constructed, which integrates the original slab width and the target... By considering multiple parameters such as the difference in finished product width, steel yield strength, head and tail temperatures of each pass, rolling speed, and vertical roll diameter, this invention dynamically adapts to the width control requirements of different specifications and working conditions compared to existing technologies that rely on fixed opening or single vertical roll control. It achieves phased and coordinated operation of E1 and E2 vertical rolls, avoiding the limitations of single vertical roll control and significantly improving the control accuracy of head and tail width. Strictly adhering to the sequence of rolling with E1 vertical roll first and E2 vertical roll later, the opening of E1 and E2 vertical rolls is adjusted in real time, and lateral pressure is adjusted for each segment at the head and tail of the strip. This timing control logic is consistent with the segment division (H... Precise matching of sections 1~H4 and T1~T4 ensures accurate lateral pressure compensation for each segment in the head and tail regions at the corresponding vertical roller passes. Verification through examples shows that, using this invention, the overwidth of each segment in the preset length region of the strip can be controlled within the range of 0-10mm, a significant improvement over the 20-50mm overwidth of existing technologies, thus enhancing width accuracy. Based on the overwidth detection results of the preset length region of the finished product, the simplified correction coefficients of each pass in the model are fine-tuned for width management of the next batch of strip. This fine-tuning mechanism does not require complex deviation calculations or model reconstruction; it only needs to adjust the correction coefficient based on the overwidth detection results (increasing the correction coefficient if it is too large, decreasing it if it is too small). By reducing the correction coefficient (with each fine-tuning increment not exceeding 0.2), the model can achieve rapid adaptive optimization, adapting to fluctuations in production line conditions and ensuring stable and reliable control accuracy for different batches and specifications of strip steel. Based on the existing vertical rollers and testing equipment on the production line, more precise control of the head and tail width can be achieved simply by optimizing the control methods (S1~S4), without the need for adding large equipment such as a width-fixing press. The transformation cost is low and the implementation cycle is short. At the same time, after controlling the head and tail overwidth to 0-10mm, the subsequent shearing process does not need to remove a large amount of the overwidth portion, improving the yield, reducing rework and scrap of products with unqualified width, and significantly reducing production costs and energy consumption.

Claims

1. A method for controlling the width of the head and tail of hot-rolled strip steel, characterized in that, include: S1. Parameter Acquisition and Preprocessing: Before the strip enters the roughing process, the following core parameters are collected in real time, and the core parameters are preprocessed by outlier removal and smoothing filtering. The core parameters include strip basic parameters, rolling process parameters, vertical roll basic parameters, and position detection parameters. The preset length area of ​​the strip head and tail is divided into several segments for calculating the vertical roll side pressure for different segments. S2. Construct a collaborative side pressure control model for dual vertical rollers; S3. Based on the calculated target side pressure, adjust the opening of vertical rolls E1 and E2 in real time according to the sequence of rolling E1 first and rolling E2 later, and adjust the side pressure of each section of the strip head and tail respectively. S4. After rolling, based on the overwidth detection results of the pre-set length area of ​​the finished product, the simple correction coefficients of each pass of the model are fine-tuned for the width management of the next batch of strip steel.

2. The method for controlling the width of the head and tail of hot-rolled strip steel according to claim 1, characterized in that, In S1: The basic parameters of the strip steel include the target finished product width W. target Target finished product thickness h, original slab thickness H, original slab width W0, and steel grade yield strength σ; The rolling process parameters include the E1 vertical roll rolling speed V. E1 E2 vertical roll rolling speed V E2 The temperature T of the strip before it enters the vertical rolls of the first roughing mill stand R1 and the second roughing mill stand R2; The basic parameters of the vertical rolls include the diameter D of the vertical rolls before the first roughing mill stand R1. E1 The diameter D of the front vertical roll of the second roughing mill stand R2 E2 ; The position detection parameters include real-time acquisition of the position coordinates of the head and tail of the strip relative to the front vertical roll of the first roughing mill stand R1 and the front vertical roll of the second roughing mill stand R2.

3. The method for controlling the width of the head and tail of hot-rolled strip steel according to claim 1, characterized in that, In S1, the pre-defined length region of the strip head and tail is divided into four segments, including: S11. The strip head is divided into segments H1, H2, H3, and H4 along its length: The H1 and H2 sections are lateral pressure adjusted by the E1 vertical roller; The H3 and H4 sections are lateral pressure adjusted by the E2 vertical roller; H1 and H2, H3 and H4 are consecutive segments that are adjacent to each other along the length of the strip and do not overlap. S12, the tail of the strip is divided into segments T1, T2, T3, and T4 along its length: The T1 and T2 sections are lateral pressure adjusted by the E1 vertical roller; The T3 and T4 sections are adjusted by the side pressure of the E2 vertical roller; T1 and T2, and T3 and T4 are consecutive segments that are adjacent to each other along the length of the strip and do not overlap.

4. The method for controlling the width of the head and tail of hot-rolled strip steel according to claim 1, characterized in that, In S2, the construction of the dual vertical roller collaborative side pressure control model is based on the collected preprocessed parameters, and a calculation model for the side pressure of each segment in the preset length region at the head and tail is constructed. The expression is: ①； ②； In formulas ① and ②: This represents the target side pressure of the E1 vertical roller in the nth pass and the i-th segment, in mm. This represents the target side pressure of the E2 vertical roller in the nth pass and the i-th segment, in mm. This indicates the original width of the slab, in mm. Indicates the target finished product width, in mm; This indicates the initial lateral pressure of the vertical roller, in mm. This indicates the yield strength of the steel grade, expressed in MPa. This indicates the instantaneous temperature of the strip head and tail for each pass, in °C. This represents the simplified correction coefficients for each pass of the model; This indicates the rolling speed of the E1 vertical roll in the corresponding pass, in m / s. This indicates the rolling speed of the E2 vertical roll in the corresponding pass, in m / s; This indicates the diameter of the E1 vertical roller, in mm; This indicates the diameter of the E2 vertical roller, in mm. The overwidth compensation is achieved in the following way: For the preset length area at the head and tail of the strip, the E1 vertical roll performs the first stage of side pressure compensation for the H1 and H2 segments and the T1 and T2 segments, and the E2 vertical roll performs the second stage of side pressure compensation for the H3 and H4 segments and the T3 and T4 segments. The target side pressure amount is calculated for each stage based on the temperature and rolling speed parameters of their respective segments. Through the coordinated action of the two vertical rolls, the overwidth of the head and tail area is limited to the target range.

5. The method for controlling the width of the head and tail of hot-rolled strip steel according to claim 1, characterized in that, In S3, the timing of rolling with the E1 vertical roll first and the E2 vertical roll later, and the real-time adjustment of the opening of the E1 and E2 vertical rolls, to adjust the side pressure of each segment at the head and tail of the strip, specifically includes: When the strip head enters the H1 section and the E1 vertical roll is in the first pass, start the first pass adjustment of the E1 vertical roll and adjust the opening of the E1 vertical roll according to the calculated target side pressure. When E1 vertical roll is switched to the second pass, the opening of E1 vertical roll continues to be adjusted according to the target side pressure of H2 segment; When the strip head enters the H3 section and the E2 vertical roll is in the first pass, start the first pass adjustment of the E2 vertical roll and adjust the opening of the E2 vertical roll according to the target side pressure of the H3 section. When the E2 vertical roll is switched to the second pass, the opening of the E2 vertical roll continues to be adjusted according to the target side pressure of the H4 segment; The adjustment logic at the tail of the strip is symmetrical to that at the head. The T1 and T2 segments are adjusted by the E1 vertical roller, and the T3 and T4 segments are adjusted by the E2 vertical roller, until the head and tail adjustment areas of the strip roughing stage have completely passed through each pass of the E1 and E2 vertical rollers, and then the strip body width is switched to the conventional control mode.

6. The method for controlling the width of the head and tail of hot-rolled strip steel according to claim 1, characterized in that, In S4, the fine-tuning of the simplified correction coefficients for each stage of the model specifically includes: After each batch of strip steel is rolled, the simplified correction coefficients for each pass of the model are adjusted based on the overwidth detection results of the pre-set length regions at the ends of the finished product. Make fine adjustments, with each adjustment not exceeding 0.

2. If the excess width of the finished product is generally greater than 10mm, then increase the correction factor of the corresponding vertical roller. If the excess width of the finished product is less than 0 mm, then reduce the correction factor of the corresponding vertical roller.

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