Method for correcting roll gap of pre-arrangement of finishing upstream stand based on roughing camber defect
By constructing a standard database of camber defects and using an improved DTW algorithm to identify defect types and calculate the roll gap adjustment amount of the upstream stand in the finishing mill, the strip shape problem caused by camber defects in hot rolling production was solved, automated roll gap correction was achieved, and the quality of strip steel and production efficiency were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 德龙钢铁有限公司
- Filing Date
- 2023-11-07
- Publication Date
- 2026-07-03
AI Technical Summary
In the hot rolling process, the rough rolling sickle bend defect caused by asymmetric factors affects the quality of the plate shape and is difficult to eliminate effectively through manual adjustment, resulting in equipment damage and low production efficiency.
By collecting centerline data of intermediate billets, a standard database of camber defects is constructed using the DBSCAN algorithm. Combined with the improved DTW algorithm, defect types are identified, and the roll gap adjustment amount of the upstream stand of the finishing mill is calculated to achieve automated roll gap correction.
It effectively eliminates the camber defect, improves the quality and production efficiency of strip steel, avoids equipment damage, and ensures the stability of the rolling process.
Smart Images
Figure CN117463796B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hot-rolled strip technology, and in particular to a method for correcting the pre-swing roll gap of the upstream stand in the finishing mill based on the roughing mill's sickle bend defect. Background Technology
[0002] The iron and steel metallurgical industry is a vital pillar of the national economy, providing strong raw material support for national construction and manufacturing. Among these, plate and strip steel, as high-quality, high-value-added "all-purpose steel," has made significant contributions to the sustained, stable, and healthy development of the national economy. With the rapid development and high-end transformation of my country's manufacturing industry, users have increasingly higher quality requirements for steel, and quality indicators are becoming more stringent. The level of plate quality control has become a key factor in the market competitiveness of steel enterprises. All steel companies are constantly striving to improve product quality, seeking the relationship between process parameters and product quality, and establishing more accurate and applicable quality prediction and control models.
[0003] Due to the influence of asymmetric factors, strip steel will develop shape defects during hot rolling. Among these, the roughing rolling camber defect is one of the main factors affecting the yield of high-precision strip steel. Due to the influence of rolling mill equipment and process parameters, the head of the intermediate billet at the roughing mill exit exhibits obvious lateral bending and serpentine bending. This roughing rolling camber defect not only affects the rolling stability of subsequent finishing rolling and the final exit strip shape, but in severe cases can even cause steel pile-up accidents. Furthermore, it can cause equipment shutdowns for maintenance due to impacts with the rolling equipment, seriously affecting production efficiency.
[0004] In on-site production, operators primarily rely on data from the roughing mill exit width gauge to observe the magnitude and length of the bending at the head of the intermediate slab. Based on years of experience, they adjust the roll gap difference of the finishing mill stand by pressing buttons controlling the pressure on both sides of the rolls to correct the cambered bending at the head of the intermediate slab. However, the instability and uncertainty of manual identification and adjustment make the control effect unpredictable and fail to fundamentally eliminate the camber. Therefore, a more in-depth study of the strip deviation caused by the cambered bending at the head of the intermediate slab is needed to explore its mechanism and establish a pre-control model for the head of the intermediate slab. This would allow for more timely and effective regulation, improving the finished product quality of the strip rolling process. Summary of the Invention
[0005] To address the aforementioned problems in the existing technology, the present invention aims to provide a method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the roughing mill camber defect.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0007] A method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the camber defect in the roughing mill includes the following steps:
[0008] S1. Collect centerline data and camber characteristic parameters of intermediate billets from the hot rolling roughing production line on-site to obtain a sample data set. Use the DBSCAN algorithm to perform cluster analysis on the centerline data of intermediate billets in the sample data set to qualitatively classify camber defects and construct a standard database of camber defects.
[0009] S2. During rolling, the centerline curve of the intermediate billet, which is collected in real time, is identified by the improved DTW algorithm to extract the camber characteristic parameters and determine the defect type of the camber in the intermediate billet.
[0010] S3. For intermediate billets with head bending defects, calculate the pre-sway roll gap value of the three upstream stands of the finishing mill and send it to the mill.
[0011] S4. Based on the on-site rolling specifications, limit the single adjustment amount of the roll gap of the three upstream stands of the finishing mill.
[0012] The method for creating the standard template library for camber defects in S1 is as follows: The DBSCAN algorithm is used to perform cluster analysis on the centerline data of the intermediate billet. Combined with practical field experience, the overall curve bending of the intermediate billet is classified into three types: head bending, body deflection, and tail bending. Simultaneously, the camber of the intermediate billet exiting the roughing mill is classified into three defect modes according to its shape: "L"-shaped camber, "C"-shaped camber, and "S"-shaped camber. The three bending modes of the intermediate billet centerline are combined with the three defect modes of the camber, and finally, eight clusters are selected as algorithm parameters to construct an eight-category standard template library for camber defects in intermediate billets.
[0013] Specifically, the eight categories of intermediate billet sickle bend defect standard template library include:
[0014] (1) Standard template library for the "L" shaped bend on the transmission side of the intermediate billet head;
[0015] (2) Standard template library for the "L" shaped bend at the tail of the intermediate billet;
[0016] (3) Standard template library for the "L" shaped bend on the operating side of the intermediate billet head;
[0017] (4) Standard template library for the "L" shaped bend at the tail of the intermediate billet;
[0018] (5) Standard template library for the C-shaped bends on the drive side of the head and tail of the intermediate billet;
[0019] (6) Standard template library for the C-shaped bends at the head and tail of the intermediate billet on the side of operation;
[0020] (7) Standard template library for "S" shaped bends on the transmission side;
[0021] (8) Standard template library for the “S” bend on the operating side.
[0022] The specific steps of S2 are as follows: After obtaining the centerline data of the intermediate billet detected by the width measuring instrument at the roughing mill exit, invalid or abnormal data with abrupt changes are first removed. Cubic cubic polynomial interpolation is used to process the centerline data to ensure the consistency of the length of the collected data. Then, Max-Min standardization is used to eliminate the influence of dimensions. Finally, the improved DTW algorithm is applied to identify the centerline curve of the intermediate billet and to determine and classify it into one of the eight types of intermediate billet sickle bend defect standard template library.
[0023] The specific steps of S3 are as follows:
[0024] S31. Calculate the theoretical roll gap adjustment ΔS of the upstream three stands of the finishing mill to eliminate the sickle bend of the incoming material using the mechanism model;
[0025] The formula for calculating ΔS is:
[0026]
[0027] In the formula,
[0028] ΔP represents the change in rolling force caused by the occurrence of camber, in kN, and the data is read from the rolling mill PLC;
[0029] L is the distance between the two hydraulic cylinders, in mm;
[0030] K represents the total stiffness of the rolling mill, measured in kN / mm. The data is read from the rolling mill PLC after each roll change.
[0031] b represents the width of the intermediate billet, in mm;
[0032] Q is the plasticity coefficient of the slab, with units of kN / mm;
[0033] The formula for calculating the plasticity coefficient Q of the slab is:
[0034]
[0035] In the formula for calculating Q, ΔP is the change in rolling force caused by the occurrence of camber, in kN; Δx is the displacement of the hydraulic cylinder, in mm; both data are read from the rolling mill PLC.
[0036] Δh represents the wedge shape change at the intermediate billet exit caused by the sickle bend, in mm;
[0037] The formula for calculating the wedge shape change Δh at the intermediate billet outlet is:
[0038]
[0039] In the formula for calculating Δh, P is the actual rolling force of the mill, in kN, and the data is read from the PLC; b is the width of the intermediate slab, in mm; ΔZ is the material deviation, in mm, measured by an industrial line-scan camera installed on the top of the finishing mill stand; L is the distance between the two hydraulic cylinders, in mm; K is the total stiffness of the mill, in kN / mm, and the data is read from the mill PLC after each roll change; Q is the slab plasticity coefficient, in kN / mm; and b is the width of the intermediate slab, in mm.
[0040] S32. Based on the type of camber defect in the intermediate billet determined in S2, the roll gap adjustment amount of the upstream three stands of the finishing mill is corrected to obtain the final roll gap adjustment amount ΔS of the upstream three stands. i And distributed to the rolling mill;
[0041] ΔS i =ΔS+k*n i *ΔS R2
[0042] In the formula,
[0043] ΔS R2 This indicates the roll gap correction value, in mm.
[0044] k represents the calculation coefficient for different types of sickle bends, n i Let k represent the allocation coefficient for the i-th rack, and n represent the values of k and n. i The possible values are shown in the table below.
[0045]
[0046] The roll gap correction value ΔS R2 The calculation formula is:
[0047] ΔS R2 =β*R*L1
[0048] ΔS R2 In the calculation formula, β is a correction coefficient, with a value of 3.5 * 10. -7 R is the bending amount at the head of the intermediate billet, R = y1 - y2, in mm; L1 is the bending length at the head of the intermediate billet, L1 = x2 - x1, in mm; (x1, y1) and (x2, y2) are the coordinates of the two extreme points of the bending part at the head of the intermediate billet.
[0049] The specific limiting size of S4 is as follows:
[0050]
[0051] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:
[0052] This invention discloses a method for correcting the pre-swaying roll gap of the upstream stand in the finishing mill based on the camber defect in the roughing mill. Based on the centerline data of the intermediate billet in the hot rolling roughing mill production line and the defect morphology of the camber, a standard template library for the camber defect is constructed after data statistics and analysis. According to the specific type of the centerline of the intermediate billet, the theoretical roll gap adjustment amount of the upstream three stands in the finishing mill is effectively corrected. By effectively adjusting the roll gap of the upstream three stands in the finishing mill, the camber defect is eliminated to the maximum extent, avoiding strip deviation, which is of great significance for improving the quality of strip. Attached Figure Description
[0053] Figure 1 A flowchart of a method for correcting the pre-sway roll gap of the upstream frame based on the sickle-shaped bend line type;
[0054] Figure 2 Window constraint diagrams for different thresholds in the DTW algorithm;
[0055] Figure 3 Flowchart for the improved DTW algorithm for sickle-shaped bend classification and recognition under different threshold window constraints;
[0056] Figure 4 This is a schematic diagram showing the positions of the two extreme points at the head of the intermediate billet. Detailed Implementation
[0057] The present invention will now be described in detail with reference to the accompanying drawings.
[0058] A method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the camber defect in the roughing mill, such as... Figure 1 As shown, it includes the following steps:
[0059] S1. Collect centerline data and camber characteristic parameters of intermediate billets from the hot rolling roughing production line on-site to obtain a sample data set; perform cluster analysis on the centerline data of intermediate billets using the DBSCAN algorithm to qualitatively classify camber defects and construct a standard template library for camber defects.
[0060] The sample data acquisition period is no less than one month to ensure that the samples include all types of camber defects. The centerline data and camber characteristic parameters of the intermediate billet are obtained by measuring the width of the sample at the roughing mill exit.
[0061] The DBSCAN algorithm was used to cluster the centerline data of the intermediate billet. Combined with practical experience, the centerline curve of the intermediate billet was divided into head, middle, and tail sections to analyze its bending pattern, including head bending, body deflection, and tail bending. Simultaneously, based on the morphology of the camber defect, the intermediate billet was classified into three defect modes: "L"-shaped camber, "C"-shaped camber, and "S"-shaped camber. The three bending patterns of the intermediate billet centerline were combined with the three defect modes of the intermediate billet camber, and eight clusters were finally selected as algorithm parameters to construct an eight-category standard template library of intermediate billet camber defects, which will be used as a reference standard during subsequent finishing rolling.
[0062] The standard template library for the eight categories of intermediate billet sickle-bend defects specifically includes:
[0063] (1) Standard template library for the "L" shaped bend on the transmission side of the intermediate billet head;
[0064] (2) Standard template library for the "L" shaped bend at the tail of the intermediate billet;
[0065] (3) Standard template library for the "L" shaped bend on the operating side of the intermediate billet head;
[0066] (4) Standard template library for the "L" shaped bend at the tail of the intermediate billet;
[0067] (5) Standard template library for the C-shaped bends on the drive side of the head and tail of the intermediate billet;
[0068] (6) Standard template library for the C-shaped bends at the head and tail of the intermediate billet on the side of operation;
[0069] (7) Standard template library for "S" shaped bends on the transmission side;
[0070] (8) Standard template library for the “S” bend on the operating side.
[0071] S2. During rolling, the centerline curve of the intermediate billet, which is collected in real time, is identified by the improved DTW algorithm to extract the camber characteristic parameters and determine the defect type of the camber in the intermediate billet.
[0072] See Figure 2 , Figure 3 Combining the Sakoe-Chiba window and the Itakura parallelogram window, this paper uses window constraint methods with different thresholds to constrain the optimization path of the dynamic warping algorithm. Parallel line constraints are used as the main design idea of the window. Three parallel lines are used to divide the window area, and three different thresholds are used to constrain the window range.
[0073] After obtaining the centerline data of the intermediate billet detected by the width measuring instrument at the roughing mill exit, invalid or abnormal data with abrupt changes are first removed. Cubic cubic polynomial interpolation is used to process the centerline data to ensure the consistency of the collected data length. Then, Max-Min standardization is used to eliminate the influence of dimensions. Finally, the improved DTW algorithm is applied to identify the centerline curve of the intermediate billet and to determine and classify it into one of the eight categories of intermediate billet sickle bend defect standard template library.
[0074] For intermediate billets judged to have head bending defects, subsequent steps are used to calculate the adjustment value of the pre-swing roll gap of the upstream stand in the finishing mill, and instructions are issued to adjust the roll gap so that the intermediate billets can smoothly enter the finishing mill and maintain a certain level of alignment during the rolling process of the upstream stand to ensure the finishing effect.
[0075] For intermediate billets judged to have defects such as body deflection and tail bending, no adjustment is required for the roll gap of the upstream stand in the finishing mill. Instead, a notice is issued to the operators of the downstream stand in the finishing mill, reminding them to revise their adjustment strategies for subsequent stands.
[0076] S3. For intermediate billets with head bending defects, calculate the pre-swing roll gap value of the three upstream stands of the finishing mill and send it to the rolling mill.
[0077] When the incoming material deviation is less than -15mm or greater than 15mm, the calculation of the theoretical roll gap adjustment amount for the upstream three stands to eliminate the incoming material sickle bend is triggered. The system communicates with the PLC and the industrial line scan camera (installed on the top of the finishing mill stand) every 50ms to obtain the required data, calculate the roll gap adjustment amount, and send it to the mill.
[0078] This step specifically includes:
[0079] S31. Calculate the theoretical roll gap adjustment ΔS of the upstream three stands of the finishing mill to eliminate the sickle bend of the incoming material using the mechanism model;
[0080] Based on the relationship between the slab and the camber, the condition for ensuring the straightness of the exit slab and eliminating the incoming camber of the intermediate slab is to ensure that the cross-sectional proportions of the slab at the mill entrance and exit are equal. Based on the above principle, the theoretical roll gap adjustment ΔS of the upstream stand of the finishing mill to eliminate the incoming camber is calculated by the following formula:
[0081]
[0082] In the above formula,
[0083] ΔP is the change in rolling force caused by the occurrence of camber, in kN, and the data is read from the rolling mill PLC (Programmable Logic Controller).
[0084] L is the distance between the two hydraulic cylinders, in mm;
[0085] K represents the total stiffness of the rolling mill, measured in kN / mm. The data is read from the rolling mill PLC after each roll change.
[0086] b represents the width of the intermediate billet, in mm;
[0087] Q is the plasticity coefficient of the slab, with units of kN / mm, and its calculation formula is as follows: In the formula, Δx is the displacement of the hydraulic cylinder, in mm, and the data is read from the rolling mill PLC.
[0088] Δh represents the wedge shape change at the exit of the intermediate billet caused by the sickle bend, in mm, and its calculation formula is: In the formula, P is the actual rolling force of the mill, in kN, which is read from the PLC; ΔZ is the material deviation, in mm, which is measured by a binocular line array camera installed on the top of the finishing mill stand F1.
[0089] S32. Based on the type of camber defect in the intermediate billet determined in S2, the roll gap adjustment amount of the upstream three stands of the finishing mill is corrected to obtain the final roll gap adjustment amount of the upstream three stands and then issued to the rolling mill.
[0090] During the calculation, the correction value ΔS for eliminating the change in roll gap due to incoming material bending is first calculated based on the actual bending condition of the intermediate billet centerline. R2 Then, based on the camber defect type identified in S2, the roll gap of the upstream three stands is allocated, ultimately obtaining the final adjustment amount ΔS of the roll gap of the upstream three stands. i .
[0091] Specifically:
[0092] Based on the centerline data of the intermediate billet detected by the mill exit width measuring instrument, the two extreme points (x1, y1) and (x2, y2) of the curved section at the head of the intermediate billet are extracted. See [link to relevant documentation]. Figure 4 .
[0093] Correction value ΔS for eliminating changes in incoming material bending roll gap R2 Calculated using the following formula:
[0094] ΔS R2 =β*R*L1
[0095] In Equation IV,
[0096] β is a correction factor, with a value of 3.5 * 10. -7 ;
[0097] R is the bending amount at the head of the intermediate billet, R = y1 - y2, in mm;
[0098] L1 is the bending length of the intermediate billet head, L1 = x2 - x1, in mm.
[0099] Based on the sickle-shaped bending mode identified by S2, the calculation coefficient n is determined. i The roller gaps of the three upstream stands are allocated to obtain the final adjustment amount ΔS for each stand. i The ΔS i The calculation formula is:
[0100] ΔS i =ΔS+k*n i *ΔS R2
[0101] In the formula, k represents the calculation coefficient for different types of sickle bends, and n i Let k represent the allocation coefficient for the i-th rack, and n represent the values of k and n. i The possible values are shown in the table below.
[0102]
[0103] S4. Based on the on-site rolling specifications, limit the single adjustment amount of the roll gap of the upstream three stands.
[0104] To prevent strip edge wavy formation and over-rolling during the rolling process, the single adjustment amount of the roll gap in the upstream three stands is limited according to different rolling specifications on site. The specific limits are shown in the table below:
[0105]
[0106] The present invention will be further described in detail below through embodiments.
[0107] The standard template library for camber defects was established based on a large amount of data from the roughing mill and existing intermediate billets. Once established, the template library can be used long-term while maintaining the same intermediate billet material and rolling parameters. Subsequent use will directly begin with the defect type determination step S2.
[0108] In this embodiment,
[0109] S2. The improved DTW algorithm is used to identify the centerline curve of the intermediate billet, extract the characteristic parameters of the sickle bend, and determine the defect type of the sickle bend of the intermediate billet as: "L" shaped bend on the operating side of the head of the intermediate billet, and proceed to the calculation step of the pre-swing roll gap.
[0110] S3. For intermediate billets with head bending defects, calculate the pre-swing roll gap value of the three upstream stands of the finishing mill and send it to the rolling mill.
[0111] S31. Calculate the theoretical roll gap adjustment ΔS of the upstream three stands of the finishing mill:
[0112]
[0113] In the formula,
[0114] When the F1 frame bites the steel, the PLC reads ΔP as 282.559kN;
[0115] L is 2740mm;
[0116] After changing the roller, the PLC reads K as 5635 kN / mm.
[0117] The width b was measured to be 1000 mm using a width measuring instrument at the mill exit.
[0118] The rolling mill PLC reads data Δx as -2.319mm, so Q is calculated to be -121.845kN / mm;
[0119] The rolling mill PLC reads P as 20000kN, and the width measuring instrument at the rolling mill exit measures ΔZ as 19.487mm. Therefore, Δh = 0.037 is calculated.
[0120] Substituting the above data into the ΔS calculation formula, we get ΔS = 0.078 mm.
[0121] S32. Calculate the correction value to obtain the final adjustment amount of the roll gap of the upstream three frames.
[0122] Calculate the correction value ΔS for the change in roll gap R2
[0123] ΔS R2 =β*R*L1=3.5*10 -7 *(y1-y2)*(x2-x1)=3.5*10 -7 *58*3313.118
[0124] =0.068mm
[0125] Based on the identified sickle-bend mode, the roll gap of the upstream frame is allocated to obtain the roll gap inclination adjustment value ΔS for each frame. i .
[0126] ΔS i =ΔS+k*n i *ΔS i_R2
[0127] K, n i The possible values are shown in the table below.
[0128]
[0129] The calculated roll gap adjustment amount after correction for the three upstream machine stands is as follows:
[0130] ΔS1=0.079mm
[0131] ΔS2=0.079mm
[0132] ΔS3=0.078mm
[0133] S4. Based on the rolling specifications on site, limit the single and total adjustment amounts of the roll gap for the three upstream stands. Using the roughing mill data, the target thickness of this strip is 3.5mm, and the limit for a single roll gap adjustment is 0.04mm. Therefore, 0.04mm is sent to the stands.
[0134] After the finishing mill F1, F2, and F3 are all adjusted by 0.04mm, the system still maintains communication with the PLC and industrial line scan camera every 50ms to update the required data in a timely manner, calculate the real-time roll gap adjustment amount, and send it to the mill.
[0135] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention, without departing from the technical scope of the present invention, shall be covered by the present invention.
Claims
1. A method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the camber defect in the roughing mill, characterized in that... Includes the following steps: S1. Collect centerline data and camber characteristic parameters of intermediate billets from the hot rolling roughing production line on-site to obtain a sample data set. Use the DBSCAN algorithm to perform cluster analysis on the centerline data of intermediate billets in the sample data set to qualitatively classify camber defects and construct a standard template library for camber defects. The method for constructing the standard template library of sickle bend defects in S1 is as follows: Cluster analysis of the intermediate billet centerline data is performed using the DBSCAN algorithm. Combined with practical field experience, the overall curve bending mode of the intermediate billet is divided into three types: head bending, body deflection, and tail bending. Simultaneously, the sickle bend of the intermediate billet exiting the roughing mill is classified into three defect modes according to its shape: "L"-shaped sickle bend, "C"-shaped sickle bend, and "S"-shaped sickle bend. The three bending modes of the intermediate billet centerline are combined with the three defect modes of the sickle bend, and finally, eight clusters are selected as algorithm parameters to construct an eight-category standard template library of intermediate billet sickle bend defects. The standard template library for the eight types of intermediate billet sickle-bend defects includes: (1) Standard template library for the "L" shaped bend on the transmission side of the intermediate billet head; (2) Standard template library for the "L" shaped bend at the tail of the intermediate billet; (3) Standard template library for the "L" shaped bend on the operating side of the intermediate billet head; (4) Standard template library for the "L" shaped bend at the tail of the intermediate billet; (5) Standard template library for the "C" shaped bends on the drive side of the head and tail of the intermediate billet; (6) Standard template library for the C-shaped bends of the head and tail of the intermediate billet on the side of operation; (7) Standard template library for "S" shaped bends on the transmission side; (8) Standard template library for "S" shaped bends on the operating side; S2. During rolling, the centerline curve of the intermediate billet, which is collected in real time, is identified by the improved DTW algorithm to extract the camber characteristic parameters and determine the defect type of the camber in the intermediate billet. S3. For intermediate billets with head bending defects, calculate the pre-sway roll gap value of the three upstream stands of the finishing mill and send it to the mill. S4. Based on the rolling specifications on site, limit the single adjustment amount of the roll gap of the three upstream stands of the finishing mill; The specific steps of S2 are as follows: After obtaining the centerline data of the intermediate billet detected by the width measuring instrument at the roughing mill exit, invalid or abnormal data with abrupt changes are first removed. Cubic cubic polynomial interpolation is used to process the centerline data to ensure the consistency of the length of the collected data. Then, Max-Min standardization is used to eliminate the influence of dimensions. Finally, the improved DTW algorithm is applied to identify the centerline curve of the intermediate billet and to determine and classify it into one of the eight categories of intermediate billet sickle bend defect standard template library.
2. The method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the roughing mill camber defect as described in claim 1, characterized in that: The specific steps of S3 include: S31. Calculate the theoretical roll gap adjustment ΔS of the upstream three stands of the finishing mill to eliminate the sickle bend of the incoming material using the mechanism model; The formula for calculating ΔS is: In the formula, The change in rolling force caused by the occurrence of camber is expressed in kN, and the data is read from the rolling mill PLC. L is the distance between the two hydraulic cylinders, in mm; K represents the total stiffness of the rolling mill, measured in kN / mm. The data is read from the rolling mill PLC after each roll change. b represents the width of the intermediate billet, in mm; Q is the plasticity coefficient of the slab, with units of kN / mm; The wedge shape change at the exit of the intermediate billet caused by the sickle bend is expressed in mm. S32. Based on the type of camber defect in the intermediate billet determined in S2, the roll gap adjustment amount of the upstream three stands of the finishing mill is corrected to obtain the final roll gap adjustment amount Δ of the upstream three stands. S i And distributed to the rolling mill; In the formula, ΔS R2 This indicates the roll gap correction value, in mm. k represents the calculation coefficient for different types of sickle bends. n i Indicates the first i The rack allocation coefficient, k, and n i The possible values are shown in the table below. 。 3. The method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the roughing mill camber defect, as described in claim 2, is characterized in that: The formula for calculating the plasticity coefficient Q of the slab is: In the formula, The change in rolling force caused by the camber is expressed in kN. The displacement of the hydraulic cylinder is in mm; both data are read from the rolling mill PLC. The formula for calculating the wedge shape change Δh at the intermediate billet outlet is: In the formula, P is the actual rolling force of the rolling mill, in kN, and the data is read from the PLC; The measurement is the material deviation, expressed in mm, and is obtained using an industrial line scan camera mounted on the top of the finishing mill stand.
4. The method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the roughing mill camber defect, as described in claim 2, is characterized in that: The roll gap correction value ΔS R2 The calculation formula is: In the formula, β is a correction coefficient, with a value of 3.5 * 10. -7 ; R is the bending amount at the head of the intermediate billet, R=y1-y2, in mm; L1 is the bending length of the intermediate billet head, L1=x2-x1, in mm; (x1, y1) and (x2, y2) are the coordinates of the two extreme points of the curved part at the head of the intermediate billet.
5. The method for correcting the pre-sway roll gap of the upstream stand in the finishing mill based on the roughing mill camber defect, as described in claim 1, is characterized in that... The specific limiting size of S4 is as follows: 。