A genetic segmentation type calibration method for a strip finishing and rolling mill

Abstract

This invention relates to a genetic segmented calibration method for a strip finishing continuous rolling mill, comprising: a first work roll change calibration to find the zero-adjustment rolling force deviation during calibration; a second work roll change calibration to follow the zero-adjustment rolling force deviation found in the first work roll change; and the method for the third to nth work roll change calibrations being the same as the second work roll change calibration method. The advantages of this invention are: genetic means that the rolling force deviation is the same for the same steel grade when rolling the first piece after a new work roll change within a continuous support roll cycle; segmented adjustment means that the roll gap deviation adjustment coefficients for each stand are different, and segmented adjustment coefficients are adopted according to the rolling thickness. This eliminates accidents such as head bending, large folding, and steel jamming caused by inaccurate zero roll gap calibration due to support roll and work roll changes in the finishing continuous rolling mill, thus improving the rolling power and efficiency after roll changes and providing a favorable guarantee for smooth rolling commencement.

Description

Technical Field

[0001] This invention relates to a calibration method, and more particularly to a genetic segmented calibration method for a strip finishing mill. Background Technology

[0002] After a single support roll cycle is completed in a strip finishing continuous rolling mill, a new support roll is replaced. Due to changes in the surface precision of the support roll bearing housing and the surface condition of the stepped pad, differences in axial precision and stiffness occur on both sides of the mill. This causes a change in the zero roll gap calibration rolling force deviation during mill calibration, resulting in inaccurate zero roll gap calibration. When the first strip is rolled after the roll change, this can lead to poor strip shape, large head lateral bending, and in severe cases, accidents such as strip head bending and steel jamming. Summary of the Invention

[0003] The purpose of this invention is to provide a genetic segmented calibration method for strip finishing mills, which improves the accuracy of roll gap calibration after finishing mill roll change and reduces accidents such as strip head side bending and steel jamming caused by low roll gap calibration accuracy.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A genetic segmented calibration method for a strip finishing continuous rolling mill includes:

[0006] The first work roll change calibration is used to find the zero-adjustment rolling force deviation during calibration;

[0007] The second roll change calibration is used to follow the zero-adjustment rolling force deviation found during the first roll change;

[0008] The method for calibrating from the third work roll change to the nth work roll change is the same as the method for the second work roll change.

[0009] The first work roll change calibration includes:

[0010] S11, the gap between the work rolls is pressed against the calibrated rolling force;

[0011] S12. Adjust the rolling force deviation of each stand to within the allowable calibrated rolling force deviation range of the zero roll gap calibrated rolling mill;

[0012] S13. Based on different strip carbon content and width spacing, memorize the corresponding rolling force deviation values ​​for strip carbon content and width spacing, and extract the rolling force deviation values ​​to the rolling force deviation worksheet.

[0013] The second work roll calibration includes:

[0014] S21, The gap between the work rolls is pressed against the calibrated rolling force;

[0015] S22. Adjust the rolling force deviation of each stand to within the allowable calibrated rolling force deviation range of the zero roll gap calibration mill.

[0016] In S11, the rolling mill is turned over when the upper and lower work rolls exert rolling force. During the turn, the rolling force P... z The range is the rated rolling force P E 10% to 15%, the speed of the finishing continuous rolling mill is increased to the mill's rated speed V. b The roll gap is pressed against the rated rolling force P. b , rolling force P during calibration b The range is the rated rolling force P E The mill's rated speed is 25% to 30% of the rated speed, and the formula is as follows:

[0017] V b =V max ×50% ①

[0018] In formula ①, V b This indicates the mill's rated speed and the maximum permissible speed for each stand.

[0019] In S12, the mill is allowed to calibrate the rolling force deviation ΔP. b The range is ±(30~80)T;

[0020] The formula for adjusting the roll gap deviation on both sides of the rolling mill and the rolling force deviation on both sides of the rolling mill is as follows:

[0021] △P=P ws -P ds ②

[0022] In formula ②, △P represents the deviation of rolling force on both sides of the rolling mill, P ws P represents the rolling force on the working side of the rolling mill. ds Indicates the rolling force on the drive side of the rolling mill;

[0023] The formula for the deviation value of the roll gap on both sides of the rolling mill is as follows:

[0024] △S=S ws -S ds ③

[0025] In formula ③, △S represents the deviation value of the roll gap on both sides of the rolling mill, S ws S represents the working side roll gap of the rolling mill. ds This indicates the roll gap on the drive side of the rolling mill.

[0026] In S22, the rolling mill is turned over when the upper and lower work rolls exert rolling force. During the turn, the rolling force P... z The range is the rated rolling force P E 10% to 15%, the speed of the finishing continuous rolling mill is increased to the mill's rated speed V. b The roll gap is pressed against the rated rolling force P.b , rolling force P during calibration b The range is the rated rolling force P E 25% to 30%, the mill's rated speed is given by formula ①.

[0027] In S22, check the carbon content and width group distance of the first billet rolled in this cycle, and find the corresponding rolling force deviation memory value △P for each stand in the rolling force deviation worksheet. j The roll gap deviation value △S is adjusted and is as follows:

[0028] 1) When |△P j |≤|△P b At that time, according to the roll gap deviation adjustment rule in formula ③, the zero roll gap rolling force deviation △P is adjusted to the memory rolling force deviation value △P. j ;

[0029] 2) When |△P j |>|△P b At that time, according to the roll gap deviation adjustment rule in formula ③, the zero roll gap rolling force deviation △P is adjusted to the mill's allowable calibrated passing rolling force deviation △P. b Within the range, the adjustment amount of the roll gap on both sides of the rolling mill is △S t At this point, the mill is calibrated to zero roll gap, and then adjusted back based on the zero roll gap, with the adjustment direction being the rolling force deviation memory value △P. j The formula for the roll gap deviation value in the direction of value correction is as follows:

[0030] △S h =|△P j -△P b |*n ④

[0031] In formula ④, △S h The value represents the roll gap deviation, and n represents the roll gap deviation adjustment coefficient. The roll gap deviation adjustment coefficient n = 1 for frames F1 and F2, n = 0.9 for frames F3 and F4, and n = 0.8 for frames Fn-2, Fn-1, and Fn.

[0032] Zero-adjustment rolling force deviation refers to the deviation between the rolling force on the working side and the rolling force on the transmission side when the roll gaps on both sides of the rolling mill are horizontal during the mill calibration process.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] In the genetic segmented calibration method of the strip finishing continuous rolling mill, genetics refers to the fact that when rolling the first piece of the same steel grade after replacing the work roll within one support roll cycle, the rolling force deviation is the same. Segmented adjustment means that the roll gap deviation adjustment coefficient of each stand is different. The segmented adjustment coefficient is adopted according to the rolling thickness. This eliminates the accidents such as head side bending, large straight breakage and steel jamming caused by inaccurate zero roll gap calibration of the mill due to the replacement of support rolls and work rolls in the finishing continuous rolling mill. It improves the rolling power and rolling efficiency after the mill roll change and provides a favorable guarantee for smooth rolling. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the rolling mill pressing down. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0037] 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.

[0038]

Example 1

[0039] A single support roll cycle involves changing the work roll over a hundred times every 15-20 days. Due to variations in the work roll diameter, the roll gap value changes, requiring recalibration to find the original roll gap value. Therefore, n work roll change calibrations are necessary. A genetic segmented calibration method for strip finishing continuous rolling mills is described below. Figure 1 The content is as follows:

[0040] I. Calibration during the first installation of work rolls after replacing the new support rolls in the finishing continuous rolling mill:

[0041] Step 1: Press the work roll gap together, when the mill's rated rolling force P... E When the load is 4000 tons, the rolling force coefficient of the turntable is taken as 15%, and the rolling force P exerted by the upper and lower work rolls is... z =600T rotary rolling mill, rated rolling force coefficient is 25%, rated rolling force P b =1000T. The speed of the finishing continuous rolling mill is increased to the rated speed V. b By clicking the AUTO CAL button on the primary calibration screen of the HMI (Human-Machine Interface), the roll gap will automatically press against the calibrated rolling force P. b =1000T.

[0042] Step 2: Adjust the rolling force deviation △P of each stand to the zero roll gap calibration allowable rolling force deviation range.

[0043] The allowable deviation of the calibrated rolling force ΔP of the rolling mill b The range is -30T to +30T. Adjust the roll gap deviation value △S on both sides of the mill and the roll gap value S on the working side. ws The value of the roller gap on the drive side decreases. ds As the rolling force deviation ΔP increases, the working side roll gap value S also increases. ws Increase, drive side roller gap value S ds As the rolling force deviation ΔP decreases, the rolling force deviation also decreases.

[0044] Step 3: After successful zero roll gap calibration of the finishing continuous rolling mill, roll steel and heat-press the roll material with carbon content W. C % = 0.03%, width B = 1150mm, see Table 1. After rolling 5 strips, the strip head of each stand is straight and pressed against the roll gap of each stand to the rated rolling force of 1000T. At this time, the rolling force deviation values ​​of each stand are: △P j31 , △P j32 , △P j33 , △P j3(n-1) , △P j3n Through the HMI (Human-Machine Interface) screen, clicking the RECALL button (for remembering mill force deviation) will remember the current carbon content (W) of the strip steel. C With % = 0.03% and width B = 1150mm, see Table 1. When the strip is straight, the rolling force deviation value is entered into the mill force deviation memory table △P. j3 ;

[0045] Then roll another strip of steel with a carbon content of W C % = 0.09% and width B = 1300mm, see Table 1. When the strip head of each stand is straight and flat, press against the roll gap of each stand to the rated rolling force of 1000T. At this time, the rolling force deviation values ​​of each stand are: △P j21 , △P j22 , △P j23 , △P j2(n-1) , △P j2n Click the RECALL button again to remember the carbon content W. C % = 0.09% and width B = 1300mm, see Table 1. When the strip is straight, the rolling force deviation value is entered into the mill force deviation memory table △P. j2 ;

[0046] Then roll another strip of steel with a carbon content of W C % = 0.15% and width B = 1420mm, see Table 1. When the strip head of each stand is straight and flat, press against the roll gap of each stand to the rated rolling force of 1000T. At this time, the rolling force deviation values ​​of each stand are: △P j11 , △P j12 , △P j13 , △P j1(n-1), △P j1n Click the RECALL button again to remember the carbon content W. C With % = 0.15% and width B = 1420mm, see Table 1. When the strip is straight, the rolling force deviation value is entered into the mill force deviation memory table △P. j1 ;

[0047] Using this method, after changing the support rolls, the rolling force deviation value △P for different strip carbon content and width B is memorized. j The value is automatically recorded in the rolling force deviation memory table, as shown in Table 1 and Table 2.

[0048] Table 1: Classification of Rolling Force Deviation Groups.

[0049]

[0050] Table 2: Rolling Force Deviation Memory Table

[0051]

[0052] II. Calibration during the second installation of work rolls after replacing the support rolls in the finishing continuous rolling mill:

[0053] Step 1: The work roll gaps are pressed together, and the upper and lower work rolls exert rolling force P. z =600T turntable, finishing continuous rolling mill speed increased to the rated speed V b Click the AUTO CAL button, and the roll gap will automatically press against the calibrated rolling force P. b =1000T.

[0054] Step 2: Adjust the roll gap deviation value to bring the rolling force deviation ΔP of each stand to within the allowable rolling force deviation range specified by the roll gap calibration. b =Within ±30T;

[0055] Check the carbon content W of the first piece of steel rolled in this cycle. C % = 0.02%, width B = 1180mm, see Table 1. Find the rolling force deviation memory value △P for each stand corresponding to the carbon content and width group spacing in the zero roll gap calibration rolling force deviation reference table. j3 Reference △P for rolling force deviation of each stand j31 , △P j32 , △P j33 , △P j3(n-1) , △P j3n , and |△P j3 |≤|△P b Adjust the roll gap deviation value so that the standard force deviation of the zero roll of each stand is:

[0056] △Pb1 =△P f2 =△P j31

[0057] △P b2 =△P f2 =△P j32

[0058] △P b3 =△P f3 =△P j33

[0059] △P bn-1 =△P fn-1 =△P j3(n-1)

[0060] △P bn =△P fn =△P j3n ;

[0061] At this point, pressing the zero calibration button will successfully calibrate the roll gap.

[0062]

Example 2

[0063] A genetic segmented calibration method for a strip finishing continuous rolling mill, see [link to documentation]. Figure 1 The content is as follows:

[0064] I. Calibration during the first installation of work rolls after replacing the new support rolls in the finishing continuous rolling mill:

[0065] Step 1: When the rated rolling force P of the rolling mill E When the load is 5000 tons, the rolling force coefficient of the turntable is taken as 10%, and the rolling force P exerted by the upper and lower work rolls is... z =500T rotary locomotive, rated rolling force coefficient is 30%, rated rolling force P b =1500T. The work roll gap is pressed together, and when the upper and lower work rolls exert rolling force P... z =1500T turntable, finishing continuous rolling mill speed increased to the rated speed V b Click the AUTO CAL button, and the roll gap will automatically press against the calibrated rolling force P. b =1500T.

[0066] Step 2: Adjust the rolling force deviation △P of each stand to the zero roll gap calibration allowable rolling force deviation range.

[0067] The allowable deviation of the calibrated rolling force ΔP of the rolling mill b The range is -70T to +70T. Adjust the roll gap deviation value △S on both sides of the mill, and the roll gap value S on the working side. ws The value of the roller gap on the drive side decreases. ds As the rolling force deviation ΔP increases, the working side roll gap value S also increases.ws Increase, drive side roller gap value S ds As the rolling force deviation ΔP decreases, the rolling force deviation also decreases.

[0068] Step 3: After successful zero roll gap calibration of the finishing continuous rolling mill, steel is rolled.

[0069] Carbon content W of the ironing roller material C % = 0.05% and width B = 1180mm, see Table 1. After rolling 3 strips, the strip head of each stand is straight and pressed against the roll gap of each stand to the rated rolling force of 1300T. At this time, the rolling force deviation values ​​of each stand are: △P j31 , △P j32 , △P j33 , △P j3(n-1) , △P j3n Click the "RECALL" button to remember the current carbon content (W) of the strip steel. C % = 0.05% and width B = 1180mm, see Table 1. When the strip is straight, the rolling force deviation value is entered into the mill force deviation memory table △P. j3 ;

[0070] Then roll another strip of steel with a carbon content of W C % = 0.03% and width B = 1250mm, see Table 1. When the strip head of each stand is straight and flat, press against the roll gap of each stand to the rated rolling force of 1300T. At this time, the rolling force deviation values ​​of each stand are: △P j21 , △P j22 , △P j23 , △P j2(n-1) , △P j2n Click the RECALL button again to remember the carbon content W. C With % = 0.03% and width B = 1250mm, see Table 1. When the strip is straight, the rolling force deviation value is entered into the mill force deviation memory table △P. j2 ;

[0071] Then roll another strip of steel with a carbon content of W C % = 0.13% and width B = 1410mm, see Table 1. When the strip head of each stand is straight and flat, press against the roll gap of each stand to the rated rolling force of 1500T. At this time, the rolling force deviation values ​​of each stand are: △P j11 , △P j12 , △P j13 , △P j1(n-1) , △P j1n Click the RECALL button again to remember the carbon content W. CWith % = 0.13% and width B = 1410mm, see Table 1. When the strip is straight, the rolling force deviation value is entered into the mill force deviation memory table △P. j1 ;

[0072] Using this method, during the first work roll rolling cycle after changing the support rolls, the rolling force deviation value △P for different strip carbon content and width B is recorded based on the different strip spacing. j The value is automatically recorded in the rolling force deviation memory table.

[0073] II. Calibration during the second installation of work rolls after replacing the support rolls in the finishing continuous rolling mill:

[0074] Step 1: The work roll gaps are pressed together, and the upper and lower work rolls exert rolling force P. z =500T turntable, finishing continuous rolling mill speed increased to the rated speed V b Click the AUTO CAL button, and the roll gap will automatically press against the calibrated rolling force P. b =1500T.

[0075] Step 2: Adjust the roll gap deviation value to bring the rolling force deviation ΔP of each stand to within the allowable rolling force deviation range specified by the roll gap calibration. b =Within ±70T;

[0076] Check the W of the first piece of steel rolled in this cycle. C % = 0.03%, width B = 1250mm, see Table 1. Find the rolling force deviation memory value △P corresponding to the carbon content and width group spacing for each stand in the zero roll gap calibration rolling force deviation reference table. j2 Reference △P for rolling force deviation of each stand j21 , △P j22 , △P j23 , △P j2(n-1) , △P j2n At this time, the rolling force deviation memory values ​​for stands F1, F3, Fn-1, and Fn are |△P j |≤|△P b |, F2 rack |△P j |>|△P b According to the roll gap deviation adjustment rule in formula ③, adjust the roll gap deviation value so that the standard force deviation of the zero roll of each stand is:

[0077] △P b1 =△P f2 =△P j31

[0078] △P b3 =△P f3 =△P j33

[0079] △P bn-1 =△P fn-1 =△P j3(n-1)

[0080] △P bn =△P fn =△P j3n ;

[0081] And the F2 frame's |△P j |>|△P b First, adjust the roller gap to △P. b2 =△P f2 =△P j32 Zero roll gap calibration and cleaning requires following formula ④△S h =|△P fn -△P b2 In formula ④, the pullback roll gap value is calculated. The roll gap deviation adjustment coefficient n for the F2 mill is set to 1. The pullback ΔS is then calculated by substituting this value into formula ④. h Value, callback direction according to △P j33 After adjusting the direction, press the zero calibration button to successfully calibrate the roll gap.

[0082] In the genetic segmented calibration method for strip finishing mills of this invention, genetics refers to the fact that when rolling the first piece of the same steel grade after replacing the work roll within one support roll cycle, the rolling force deviation is the same. Segmented adjustment means that the roll gap deviation adjustment coefficients of each stand are different. The segmented adjustment coefficients are adopted according to the rolling thickness. This eliminates the accidents such as head side bending, large straight breakage and steel jamming caused by inaccurate zero roll gap calibration of the mill due to the replacement of support rolls and work rolls in the finishing mill. It improves the rolling power and rolling efficiency after the mill rolls are replaced, and provides a favorable guarantee for smooth start of rolling.

Claims

1. A genetic segmented calibration method for a strip finishing continuous rolling mill, characterized in that, include; The first work roll change calibration is used to find the zero-adjustment rolling force deviation during calibration; The second work roll change calibration follows the zero-adjustment rolling force deviation found during the first work roll change; The method for calibrating from the third work roll change to the nth work roll change is the same as the method for calibrating from the second work roll change. The first work roll change calibration includes: S11, the gap between the work rolls is pressed against the calibrated rolling force; S12. Adjust the rolling force deviation of each stand to within the allowable calibrated rolling force deviation range of the zero roll gap calibrated rolling mill; S13. Based on different strip carbon content and width spacing, memorize the corresponding rolling force deviation values ​​for strip carbon content and width spacing, and extract the rolling force deviation values ​​to the rolling force deviation worksheet. The second work roll calibration includes: S21, The gap between the work rolls is pressed against the calibrated rolling force; S22. Adjust the rolling force deviation of each stand to within the allowable calibrated rolling force deviation range of the zero roll gap calibrated rolling mill; Check the carbon content and width group spacing of the first steel billet rolled in this cycle, and find the corresponding rolling force deviation memory value for each stand in the rolling force deviation worksheet. Adjustment roll gap deviation value The content is as follows: 1) When | |≤| At that time, according to the roll gap deviation adjustment rule in formula ③, the zero roll gap rolling force deviation is adjusted. Adjust to the memory value of rolling force deviation ; 2) When | |>| At that time, according to the roll gap deviation adjustment rule in formula ③, the zero roll gap rolling force deviation is adjusted. Adjust to the mill's allowable calibration through rolling force deviation Within the range, the adjustment amount of the roll gap on both sides of the rolling mill is At this point, the mill is calibrated to zero roll gap, and then adjusted back based on the zero roll gap, with the adjustment direction being the rolling force deviation memory value. The formula for the roll gap deviation value in the direction of value correction is as follows: △ =| - *n ④ In formula ④, △ This indicates the roll gap deviation value during the pullback. This indicates the roll gap deviation adjustment coefficient; for frames F1 and F2, the roll gap deviation adjustment coefficient n=1; for frames F3 and F4, the roll gap deviation adjustment coefficient n=0.9; for frames Fn-2, Fn-1, and Fn, the roll gap deviation adjustment coefficient n=0.

8. Formula ③ is as follows: = - ③ In formula ③, This indicates the deviation value of the roll gap on both sides of the rolling mill. Indicates the roll gap on the working side of the rolling mill. This indicates the roll gap on the drive side of the rolling mill.

2. The genetic segmented calibration method for a strip finishing continuous rolling mill according to claim 1, characterized in that, In S11, the rolling mill is turned over when the upper and lower work rolls exert rolling force. During the turn, the rolling force... The range is the rated rolling force 10%~15%, the speed of the finishing continuous rolling mill is increased to the mill's rated speed. The roll gap is pressed against the specified rolling force. calibrated rolling force The range is the rated rolling force The mill's rated speed is 25%~30% of the rated speed, and the formula is as follows: = ×50% ① In formula ①, Indicates the mill's rated speed. This indicates the maximum permissible speed for each rack.

3. The genetic segmented calibration method for a strip finishing continuous rolling mill according to claim 1, characterized in that, In S12, the mill is allowed to calibrate the rolling force deviation. The range is ±(30) 80)T; The formula for adjusting the roll gap deviation on both sides of the rolling mill and the rolling force deviation on both sides of the rolling mill is as follows: = - ② In formula ②, This indicates the deviation of rolling force on both sides of the rolling mill. Indicates the rolling force on the working side of the rolling mill. Indicates the rolling force on the drive side of the rolling mill; The formula for the deviation value of the roll gap on both sides of the rolling mill is as follows: = - ③ In formula ③, This indicates the deviation value of the roll gap on both sides of the rolling mill. Indicates the roll gap on the working side of the rolling mill. This indicates the roll gap on the drive side of the rolling mill.

4. The genetic segmented calibration method for a strip finishing continuous rolling mill according to claim 2, characterized in that, In S22, the rolling mill is turned over when the upper and lower work rolls exert rolling force. During the turn, the rolling force... The range is the rated rolling force 10%~15%, the speed of the finishing continuous rolling mill is increased to the mill's rated speed. The roll gap is pressed against the specified rolling force. , rolling force at calibration The range is the rated rolling force 25%~30%, the mill's calibrated speed is given by formula ①.

5. The genetic segmented calibration method for a strip finishing continuous rolling mill according to claim 1, characterized in that, The zero-adjustment rolling force deviation refers to the deviation between the rolling force on the working side and the rolling force on the transmission side when the roll gaps on both sides of the rolling mill are horizontal during the mill calibration process.

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