Method for calculating edge buckling of hot rolled strip

Abstract

The present application relates to a kind of methods for calculating the edge return of hot-rolled strip steel, the method is by obtaining the thickness data of the strip steel transverse direction of detection equipment, calculate the actual width of strip steel, transverse thickness average and secondary fitting to data, using the comparison of transverse thickness average and secondary fitting value, obtain the specific position of maximum return, finally calculate the edge return amount of the driving side and working side of strip steel, realize the accurate quantification of the edge return of hot-rolled strip steel, effectively improve the determination efficiency and accuracy of strip steel edge return defect, solve the shortcomings that production efficiency and determination accuracy are not high when using manual identification and determination in prior art.

Description

Technical Field

[0001] This patent application belongs to the field of hot rolling technology in the metallurgical industry, and more specifically, it relates to a method for calculating the edge warping of hot-rolled strip steel. Background Technology

[0002] Raised edges, also known as ribs or protruding ridges, are defects in cold-rolled steel. They manifest as one or more localized raised ridges at a specific location along the width of the coil after it has been coiled. Upon uncoiling, small wavy patterns appear at the corresponding raised locations, severely impacting product usability and appearance. For appliance outer panels with high surface finish requirements, this can lead to downgrading and scrapping, significantly affecting product costs. The raised edges are typically located in the middle or sides of the strip. Edge curling in hot-rolled strip is another type of defect, characterized by an increase in thickness distribution from the center of the strip towards the edges.

[0003] The thickness distribution of hot-rolled strip steel along its width direction mainly includes indicators such as crown, straightness, wedge shape, and strip profile. Currently, most hot-rolling production lines can automatically calculate and determine the three indicators of crown, straightness, and wedge shape in their process control systems. However, for strip profile-related indicators, such as local high points, edge drop, and edge warping, there is a lack of scientific and effective calculation methods, which makes these indicators impossible to quantify. Quality inspectors often need to manually identify and determine these indicators by referring to control plans or technical notices, which often results in less than ideal production efficiency and accuracy. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for calculating the edge warping of hot-rolled strip steel, which solves the shortcomings of low production efficiency and low judgment accuracy when the edge warping of strip steel is identified and judged manually in the prior art.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for calculating edge warping of hot-rolled strip steel, comprising the following steps:

[0007] S101. Install and debug the measuring equipment at the exit of the finishing mill. When the strip passes through the measuring equipment at the exit of the finishing mill, the measuring equipment collects the thickness data of the strip in the transverse direction in real time as the transverse thickness data; the host computer matched with the finishing mill records the above transverse thickness data at a fixed frequency.

[0008] In S101, the measuring device is a multi-function instrument. The thickness of the strip in the transverse direction of the multi-function instrument includes t channels, and the channel interval length is p, with the unit being mm.

[0009] The host computer's fixed frequency is set to 1 second, which means that the host computer stores data at a frequency of once per second.

[0010] The lateral thickness data recorded by the host computer, from start to finish, is denoted as... in n represents the total number of recorded data, indicating that a total of n seconds were recorded. This is the dataset of lateral thickness recorded in the i-th second. ,in , represents the value of the j-th channel in the horizontal thickness dataset recorded in the i-th second; t represents the total number of channels, t≥j.

[0011] S102. After the strip steel has passed through the measuring equipment, the host computer processes the transverse thickness data and calculates the actual width of the strip steel, the average transverse thickness, and the correlation coefficient of the quadratic fitting curve.

[0012] In S102, the host computer processes the lateral thickness data including:

[0013] S1021. Preprocessing: According to the transverse thickness data recorded at a fixed frequency, the transverse thickness data of the head and tail s groups are removed to avoid abnormal measurement data of the head and tail of the strip affecting the calculation results.

[0014] S1022. Calculate the actual width of the strip: After removing the first s sets of data, determine the (s+1)th set of data, count the number of data greater than zero in the (s+1)th set of data, and record it as the number of valid data cnt. Then the actual width of the strip is equal to cnt*p, in mm.

[0015] S1023. Calculate the average transverse thickness of the strip. , ,in , The average value of the k-th channel in the horizontal thickness dataset along the length direction is represented by the following formula:

[0016]

[0017] In the formula, k is the sequence number of the strip in the transverse direction, recorded as 1, ..., cnt from the driving side to the operating side;

[0018] n is the number of data items;

[0019] The corresponding strip width coordinate is x. ,in

[0020]

[0021] S1024. Calculate the correlation coefficient of the quadratic fitting curve.

[0022] S103. Based on the comparison between the average transverse thickness and the quadratic fitting value in the quadratic fitting curve, the specific location of the maximum warping is obtained, specifically referring to...

[0023] S1031. Calculate the average lateral thickness at each position within the width range of both the drive side and the working side. ;

[0024] S1032. Based on the expression of the quadratic fitting curve Calculate the corresponding The second-order fitting value of the position ;

[0025] S1033. Calculate the average lateral thickness at various locations within the width range of the drive side and the working side. With the second-order fitted values Deviation;

[0026] S1034. Obtain the maximum deviation on the drive side and record the corresponding position number as d, which is the position of the maximum value of the drive side edge warping. The corresponding average transverse thickness is Obtain the maximum deviation on the working side and record the corresponding position number as 'o', which is the location of the maximum backlash on the operating side. The corresponding average lateral thickness is ;

[0027] S1035. Calculate the intermediate position number m and intermediate position of the strip in the transverse direction. When the number of valid data points cnt is even, m = cnt / 2. = *m, otherwise m=(cnt+1) / 2, = *m.

[0028] S104. Calculate the amount of edge warping of the strip steel based on the specific location. This step specifically includes:

[0029] S1041. Calculate the back warping amount on the drive side. First, in the lateral position... to Between these points, the average lateral thickness of the drive side is obtained from the corresponding position number between d and m. The minimum value is denoted as ymin. DS The amount of back warping on the driving side is -ymin DS ;

[0030] S1042. Calculate the warping amount on the working side edge. First, at the horizontal coordinate position... to Between m and o, the average lateral thickness of the working side is obtained from the corresponding position number. The minimum value is denoted as ymin. OS The amount of warping on the working side is -ymin OS

[0031] In addition, there are many other details, which can be found in the detailed implementation section.

[0032] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are:

[0033] This invention provides a method for calculating edge warping of hot-rolled strip steel. By acquiring thickness data of the strip steel in the transverse direction from a detection device, the actual width of the strip steel, the average transverse thickness, and performing a second-order fitting on the data, the specific location of the maximum warping is obtained by comparing the average transverse thickness with the second-order fitted value. Finally, the edge warping amount on the driving side and working side of the strip steel is calculated, realizing accurate quantification of edge warping of hot-rolled strip steel and effectively improving the efficiency and accuracy of judging edge warping defects of strip steel.

[0034] The calculation method of this invention is fast, intuitive and efficient. By quantifying the indicators, it avoids identification and judgment, thereby improving production efficiency and obtaining high or ideal judgment accuracy. Attached Figure Description

[0035] Figure 1 This is a flowchart of the method of the present invention.

[0036] Figure 2 This is a curve showing the average transverse thickness of the strip and its quadratic fitting in Embodiment 1 of the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments.

[0038] The present invention will now be clearly and completely described with reference to the accompanying drawings, so that those skilled in the art can fully implement the present invention without the need for creative effort.

[0039] This invention provides a method for calculating edge warping of hot-rolled strip steel, which solves the shortcomings of low production efficiency and low judgment accuracy when the edge warping of strip steel is identified and judged manually in the prior art.

[0040] See Figure 1 This invention provides a method for calculating edge warping of hot-rolled strip steel, comprising the following steps:

[0041] Step 101: Install and debug the measuring equipment at the exit of the finishing mill. When the strip passes through the measuring equipment at the exit of the finishing mill, the measuring equipment collects the thickness data of the strip in the transverse direction in real time as the transverse thickness data; the host computer matched with the finishing mill records the transverse thickness data at a fixed frequency.

[0042] Furthermore, the measuring device is a multi-function instrument. The multi-function instrument collects the thickness of the strip in the transverse direction through t channels, with a channel spacing length of p, in mm. Therefore, the maximum measurable strip width is t*p (mm).

[0043] Furthermore, the host computer is set to a fixed frequency of 1 second, meaning that the host computer stores data at a frequency of recording once per second.

[0044] Furthermore, the lateral thickness data recorded by the host computer, from beginning to end, is denoted as... ,in n represents the total number of data records, i.e., a total of n seconds were recorded. This is the dataset of lateral thickness recorded in the i-th second. ,in , represents the value of the j-th channel in the horizontal thickness dataset recorded in the i-th second; t represents the total number of channels, t≥j.

[0045] Step 102: After the strip steel has passed through the measuring equipment, the host computer processes the transverse thickness data, calculates the actual width of the strip steel, calculates the average transverse thickness, and calculates the correlation coefficient of the quadratic fitting curve.

[0046] The host computer processes the lateral thickness data in the following steps.

[0047] Step 1021, Preprocessing: Based on the transverse thickness data recorded at a fixed frequency, the transverse thickness data from the beginning and end (s groups) are removed to avoid abnormal measurement data from the beginning and end of the strip affecting the calculation results. To avoid abnormal measurement data from the beginning and end of the strip affecting the calculation results, the beginning and end (s groups) datasets are removed; preferably, the beginning and end (3 groups) datasets are removed.

[0048] Step 1022: Calculate the actual width of the strip, remove the first s sets of data, and use the (s+1)th set of data. Calculate the (s+1)th set of data The number of valid data points cnt, y （s+1）j >0 is considered valid data. The actual width of the strip is equal to cnt*p, in mm.

[0049] Step 1023: Calculate the average transverse thickness of the strip. , ,in , The average value of the k-th channel in the horizontal thickness dataset along the length direction is represented by the following formula:

[0050]

[0051] In the formula, k is the sequence number of the strip in the transverse direction, recorded as 1, ..., cnt from the driving side to the operating side;

[0052] n is the number of data items;

[0053] The corresponding strip width coordinate is x. ,in

[0054]

[0055] Step S1024, the correlation coefficient of the quadratic fitting curve is calculated, including a, and The least squares method is used for calculation, that is, for the sequence {x, Linear fitting is performed using the least squares method, i.e., estimation. ,in

[0056]

[0057]

[0058]

[0059] Step 103: Based on the comparison between the average horizontal thickness and the quadratic fitting value in the quadratic fitting curve, obtain the specific location of the maximum warping.

[0060] S1031. Calculate the average lateral thickness at each position within the width range of both the drive side and the working side. ;

[0061] S1032. Based on the expression of the quadratic fitting curve Calculate the corresponding The second-order fitting value of the position ;

[0062] S1033. Calculate the average lateral thickness at various locations within the width range of the drive side and the working side. With the second-order fitted values Deviation;

[0063] S1034. Obtain the maximum deviation on the drive side and record the corresponding position number as d, which is the position of the maximum value of the drive side edge warping. The corresponding average transverse thickness is Obtain the maximum deviation on the working side and record the corresponding position number as 'o', which is the location of the maximum backlash on the operating side. The corresponding average lateral thickness is ;

[0064] S1035. Calculate the intermediate position number m and intermediate position of the strip in the transverse direction. When the number of valid data points cnt is even, m = cnt / 2. = *m, otherwise m=(cnt+1) / 2, = *m. This refers to the position on the drive side. to Strip width range, working side is the position to Strip width range.

[0065] Step 104: Calculate the amount of edge warping of the strip steel according to the specific location.

[0066] Furthermore, the strip edge warping includes drive side warping and working side warping;

[0067] Furthermore, to calculate the edge warping of the strip, first calculate the lateral position of the maximum edge warping value, including the lateral position of the maximum edge warping value on the drive side. The lateral position of the maximum value of the back warping on the working side. Calculate the midpoint x of the strip in the transverse direction. m When the number of valid data points cnt is even, m = cnt / 2; otherwise, m = (cnt + 1) / 2, and 1 ≤ d ≤ m ≤ o ≤ cnt. = *m;

[0068] Furthermore, on the driving side, i.e., within the range of position number 1 ≤ k ≤ m, the average transverse thickness of the strip at each position is calculated. With the second-order fitted value The deviation is calculated, and the position number corresponding to the maximum deviation is obtained and recorded as d, which is the position where the maximum backlash of the drive side is located. The corresponding average lateral thickness is ;

[0069] Furthermore, on the working side, i.e., within the range of position number m ≤ k ≤ cnt, the average transverse thickness of the strip at each position is calculated. With the second-order fitted value The deviation is calculated, and the position number corresponding to the maximum deviation is obtained and recorded as 'o', which is the position where the maximum back warping value of the working side edge is located. The corresponding average lateral thickness is ;

[0070] Furthermore, the calculation of the back warping of the driving side is first performed on the lateral coordinate. to The minimum lateral thickness on the drive side is obtained between k=d and k=m, denoted as ymin. DS The amount of back warping on the driving side is -ymin DS ;

[0071] Furthermore, to calculate the warping of the working side, first on the horizontal coordinate... to The minimum lateral thickness ymin on the working side is obtained between k=m and k=o. OS The amount of back warping on the driving side is -ymin OS .

[0072] This invention provides a method for calculating edge warping of hot-rolled strip steel. By acquiring thickness data of the strip steel in the transverse direction from a detection device, the actual width of the strip steel, the average transverse thickness, and performing a second-order fitting on the data, the specific location of the maximum warping is obtained by comparing the average transverse thickness with the second-order fitted value. Finally, the edge warping amount on the driving side and working side of the strip steel is calculated, realizing accurate quantification of edge warping of hot-rolled strip steel and effectively improving the efficiency and accuracy of judging edge warping defects of strip steel.

[0073] The following typical application example will further illustrate the technical solution of this embodiment:

[0074] Example 1

[0075] A hot rolling production line has installed a multi-function instrument (such as the Thermo Scientific™ SIPRO instantaneous multi-function instrument) at the finishing mill exit as a testing device to detect the thickness data of the strip in the transverse direction. A total of 550 testing channels are set up, and the length of each channel is 4mm, that is, t=550, p=4, and the maximum width of the strip that can be detected is 550*4=2200mm.

[0076] When the hot rolling production line produces SPHC strip with a target thickness of 3.50mm and a target width of 1272mm, the host computer records the thickness detection data of 550 transverse channels of the strip at a frequency of once per second when the multi-function instrument starts detection.

[0077] After the strip steel has passed through the multifunction analyzer, the host computer processes the transverse thickness data. A total of 61 sets of valid data are recorded from start to finish, i.e., n=61, and each set includes 550 thickness measurements in the transverse direction of the strip steel. To avoid the measurement data at the beginning and end of the strip affecting the calculation results, sets 2 to 5 of the beginning and end datasets are discarded. Preferably, sets 3 of the beginning and end datasets are discarded, i.e., s=3. Sets 4 to 58 are used to calculate the edge warping of the strip steel, and the number of valid data points (cnt) is calculated using set 4. Since 319 data points in set 4 are greater than zero, the number of valid data points (cnt) is 319. Furthermore, the actual width of the strip steel is calculated as p*319=4*319=1276mm.

[0078] Furthermore, the average transverse thickness of the strip is calculated. The corresponding strip width coordinates ,in ;

[0079] Furthermore, for the sequence {x, Linear fitting is performed using the least squares method, i.e., estimation. The parameters of the quadratic fitting curve, calculated using the least squares method, are c=3479.090576, b=0.173556, and a=-0.000134. That is, the relationship between the fitted thickness value in the transverse direction of the strip and the strip width coordinate x can be expressed as a quadratic function:

[0080]

[0081] Furthermore, the average transverse thickness of the strip on the drive side and the working side were calculated separately. Corresponding Location thickness fitting value The deviation is calculated, and the position number corresponding to the maximum deviation on the drive side is obtained as d=16, which is the position of the maximum deviation on the drive side. Obtain the position number o=301 corresponding to the maximum deviation on the operating side, which is the position of the maximum deviation on the working side. The middle position of the strip in the transverse direction .

[0082] Furthermore, the calculation of the back warping of the driving side is first performed on the lateral coordinate. to The lateral thickness of the drive side is obtained between k=16 and 160. The minimum value ymin DS =3502.866μm, then the drive side part warps back. -ymin DS =3505.178-3502.866=0.31μm (rounded to 2 decimal places).

[0083] Furthermore, to calculate the warping of the working side, first on the horizontal coordinate... to The working side lateral thickness is obtained between k=160 and 319. The minimum value ymin OS =3504.084μm, then the warping of the working side edge is -ymin OS =3508.795-3504.084=4.71μm (rounded to 2 decimal places).

[0084] This invention provides a method for calculating edge warping of hot-rolled strip steel. By acquiring thickness data of the strip steel in the transverse direction from a detection device, the actual width of the strip steel, the average transverse thickness, and performing a second-order fitting on the data, the specific location of the maximum warping is obtained by comparing the average transverse thickness with the second-order fitted value. Finally, the edge warping amount on the driving side and working side of the strip steel is calculated, realizing accurate quantification of edge warping of hot-rolled strip steel and effectively improving the efficiency and accuracy of judging edge warping defects of strip steel.

[0085] The method for calculating edge warping of hot-rolled strip provided by this invention can effectively solve the shortcomings of low production efficiency and low judgment accuracy when the edge warping of strip is identified and judged manually in the prior art.

[0086] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. The preferred embodiments of the present invention have been described above. It should be noted that the present invention is not limited to the specific embodiments described above. Devices and structures not described in detail should be understood as being implemented in a common manner in the art. Any simple modifications, equivalent changes and modifications made by those skilled in the art to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for calculating edge warping of hot-rolled strip steel, characterized in that... Includes the following steps: S101. Install and debug the measuring equipment at the exit of the finishing mill. When the strip passes through the measuring equipment at the exit of the finishing mill, the measuring equipment collects the thickness data of the strip in the transverse direction in real time as the transverse thickness data; the host computer matched with the finishing mill records the above transverse thickness data at a fixed frequency. S102. After the strip steel has passed through the measuring equipment, the host computer processes the transverse thickness data and calculates the actual width of the strip steel, the average transverse thickness, and the correlation coefficient of the quadratic fitting curve. S103. Based on the comparison between the average transverse thickness and the quadratic fitting value in the quadratic fitting curve, obtain the specific location of the maximum warping. S104. Calculate the amount of edge warping of the strip steel according to the specific location; In S101, the measuring device is a multi-function instrument. The thickness of the strip in the transverse direction of the multi-function instrument includes t channels, and the channel interval length is p, with the unit being mm. In S103, "obtaining the specific location of maximum warping by comparing the average transverse thickness with the quadratic fitting value in the quadratic fitting curve" refers to... S1031. Calculate the average lateral thickness at each position within the width range of both the drive side and the working side. , This represents the average thickness of the k-th channel in the horizontal thickness dataset along the length direction. S1032. Based on the expression of the quadratic fitting curve Calculate the corresponding The second-order fitting value of the position ; S1033. Calculate the average lateral thickness at various locations within the width range of the drive side and the working side. With the second-order fitted values Deviation; S1034. Obtain the maximum deviation on the drive side and record the corresponding position number as d, which is the position of the maximum value of the drive side edge warping. The corresponding average lateral thickness is Obtain the maximum deviation on the working side and record the corresponding position number as 'o', which is the location of the maximum backlash on the operating side. The corresponding average lateral thickness is ; S1035. Calculate the intermediate position number m and intermediate position of the strip in the transverse direction. When the number of valid data points cnt is even, m = cnt / 2. Otherwise, m = (cnt + 1) / 2. The driving side is the position. to Strip width range, working side is the position to Strip width range; In S104, "calculate the edge warping amount of the strip steel according to the specific location" refers to calculating the edge warping amount of the strip steel on the drive side and the working side, including the following steps: S1041. Calculate the back warping amount on the drive side. First, in the lateral position... to Between these points, the average lateral thickness of the drive side is obtained from the corresponding position number between d and m. The minimum value is denoted as ymin. DS The amount of back warping on the driving side is ; S1042. Calculate the warping amount on the working side edge. First, at the horizontal coordinate position... to Between m and o, the average lateral thickness of the working side is obtained from the corresponding position number. The minimum value is denoted as ymin. OS The amount of warping on the working side is .

2. The method for calculating edge warping of hot-rolled strip steel according to claim 1, characterized in that: In S101, the fixed frequency of the host computer is set to 1 second, which means that the host computer stores data at a frequency of once per second. The lateral thickness data recorded by the host computer, from start to finish, is denoted as... in n represents the total number of recorded data, indicating that a total of n seconds were recorded. This is the dataset of lateral thickness recorded in the i-th second. ,in , represents the value of the j-th channel in the horizontal thickness dataset recorded in the i-th second; t represents the total number of channels, t≥j.

3. The method for calculating edge warping of hot-rolled strip steel according to claim 2, characterized in that: In S102, the host computer processes the lateral thickness data, including... S1021. Preprocessing: According to the transverse thickness data recorded at a fixed frequency, the transverse thickness data of the head and tail s groups are removed to avoid abnormal measurement data of the head and tail of the strip affecting the calculation results. S1022. Calculate the actual width of the strip: After removing the first s sets of data, determine the (s+1)th set of data, count the number of data points greater than zero in the (s+1)th set, and record this as the number of valid data points cnt. Then the actual width of the strip is equal to... The unit is mm; S1023. Calculate the average transverse thickness of the strip. , ,in The calculation formula is: In the formula, k is the sequence number of the strip in the transverse direction, recorded as 1, ..., cnt from the driving side to the operating side; n is the number of data items; The corresponding strip width coordinate is x. ,in ; S1024. Calculate the correlation coefficient of the quadratic fitting curve.

4. The method for calculating edge warping of hot-rolled strip steel according to claim 3, characterized in that: The correlation coefficients of the quadratic fitting curves, including a, b, and c, are calculated using the least squares method, representing the correlation coefficients for the sequence. Linear fitting is performed using the least squares method to estimate... ,in .

5. The method for calculating edge warping of hot-rolled strip steel according to claim 3, characterized in that: In S1021, the value of s ranges from 2 to 5.

6. The method for calculating edge warping of hot-rolled strip steel according to claim 5, characterized in that: The value of s is 3.

Images