Genetic sectional type calibration method for plate and strip finish rolling continuous mill

Abstract

The invention relates to a genetic sectional type calibration method for a plate and strip finish rolling continuous mill. The first-time working roll changing calibration is used for finding out the zero-adjustment rolling force deviation during calibration; the second-time working roller replacement calibration is used for following the zero-adjustment rolling force deviation found by the first-time working roller replacement; the method from the third time of work roll changing calibration to the nth time of work roll changing calibration is the same as the second time of work roll changing calibration. The method has the advantages that the heredity means that when a first block is rolled after a new working roll is replaced within a supporting roll period, the rolling force deviations of the same steel type are the same, the roll gap deviation adjustment coefficients of all the racks are different in segmented adjustment, and the segmented adjustment coefficients are adopted according to the rolling thickness; the accidents that zero roll gap calibration of a rolling mill is not accurate due to replacement of a supporting roll and a working roll of a finish rolling and continuous rolling unit, and steel is clamped due to the fact that the head of a first block is laterally bent and folded in a large direction during roll replacement rolling are eliminated, the rolling success rate and the rolling efficiency after roll replacement of the rolling mill are improved, and a favorable guarantee is provided for smooth rolling.

Description

Technical Field

[0001] The invention relates to a calibration method, in particular to a genetic segmented calibration method for a plate and strip finishing tandem rolling mill. Background Art

[0002] After a support roll cycle is completed, a new support roll is replaced on the finishing strip tandem mill. Due to changes in the surface accuracy of the support roll bearing box and the surface state of the step pad, the axial accuracy and stiffness on both sides of the mill are different. When the mill is calibrated, the deviation value of the zero roll gap calibration rolling force changes, resulting in inaccurate zero roll gap calibration of the mill. When the roll is changed and the first piece of strip is threaded, the plate shape is poor and the head is greatly lateral. In severe cases, it may cause accidents such as folding of the strip head and steel jamming. Summary of the invention

[0003] The purpose of the present invention is to provide a genetic segmented calibration method for a strip finishing tandem mill, so as to improve the accuracy of roll gap calibration after finishing roll change and reduce the accidents of large lateral bending and folding of the strip head caused by low roll gap calibration accuracy.

[0004] To achieve the above object, the present invention is implemented through the following technical solutions:

[0005] A genetic segmented calibration method for a strip finishing tandem mill, comprising:

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

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

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

[0009] The first work roll calibration includes:

[0010] S11, the roll gap of the working roll is pressed to the calibrated rolling force;

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

[0012] S13. According to different carbon contents and width groups of the steel strip, the rolling force deviation values ​​of the corresponding carbon contents and width groups of the steel strip are memorized, and the rolling force deviation values ​​are extracted into a rolling force deviation work table.

[0013] The second work roll change calibration includes:

[0014] S21, the roll gap of the working roll is pressed to the calibrated rolling force;

[0015] S22, adjusting 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, when the upper and lower working rolls exert rolling force, the rolling force P z The range is the rated rolling force P E 10% to 15% of the speed of the finishing mill is increased to the rated speed V b , the roll gap is pressed against the calibrated rolling force P b , rolling force P during calibration b The range is the rated rolling force P E 25% to 30% of the rolling mill speed, the formula for the rolling mill speed rating is as follows:

[0017] V b =V max ×50%①

[0018] In formula ①, V b It indicates the rated speed of the rolling mill and the maximum allowable speed of each stand.

[0019] In S12, the rolling mill allows the calibrated rolling force deviation △P b The range is ±(30~80)T;

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

[0021] △P=P ws -P ds ②

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

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

[0024] △S=S ws -S ds ③

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

[0026] In S22, when the upper and lower working rolls exert rolling force, the rolling force P z The range is the rated rolling force P E 10% to 15% of the speed of the finishing mill is increased to the rated speed V b , the roll gap is pressed against the calibrated rolling force Pb , rolling force P during calibration b The range is the rated rolling force P E 25%~30% of the rolling mill’s rated speed is formula ①.

[0027] In S22, check the carbon content and width group of the first steel billet rolled in this cycle, and find the corresponding rolling force deviation memory value △P of each stand in the rolling force deviation work table. j , adjust the roller gap deviation value △S, the content is as follows:

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

[0029] 2) When |△P j |>|△P b |, according to the roll gap deviation adjustment rule in formula ③, the zero roll gap rolling force deviation △P is adjusted to the rolling force deviation △P that the rolling mill allows to calibrate through b Within the range, the roll gap adjustment amount on both sides of the rolling mill is △S t At this time, the rolling mill is calibrated to zero roll gap, and then adjusted based on zero roll gap, and the adjustment direction is the rolling force deviation memory value △P j The value direction and the roll gap deviation value formula are as follows:

[0030] △S h =|△P j -△P b |*n ④

[0031] In formula ④, △S h It indicates the correction roll gap deviation value, and n indicates the roll gap deviation adjustment coefficient; the roll gap deviation adjustment coefficient of F1 and F2 frames is n=1, the roll gap deviation adjustment coefficient of F3 and F4 frames is n=0.9, and the roll gap deviation adjustment coefficient of Fn-2, Fn-1, and Fn frames is n=0.8.

[0032] 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 calibration process of the rolling mill.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] In the genetic segmented calibration method of the plate and strip finishing tandem mill, inheritance means that when the first piece is rolled after the working roll is replaced within a support roll cycle, the rolling force deviation of the same steel grade is the same. The segmented adjustment means that the roll gap deviation adjustment coefficients of each frame are different. The segmented adjustment coefficient is adopted according to the rolling thickness. This eliminates the inaccurate calibration of the zero roll gap of the mill due to the replacement of support rolls and working rolls in the finishing tandem mill group, which causes accidents such as side bending of the head of the first piece of steel when the roll is replaced, folding and jamming. This improves the rolling success rate and efficiency of the mill after roll replacement, and provides favorable guarantee for smooth rolling. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the rolling mill pressing down. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with 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 examples are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0038] [Example 1]

[0039] The working rolls are replaced more than 100 times within 15-20 days of a backup roll cycle. Due to the change of working roll diameter, the roll gap value will change, and it is necessary to recalibrate to find the original roll gap value. Therefore, it is necessary to perform n work roll replacement calibrations. A genetic segmented calibration method for plate and strip finishing continuous rolling mill is shown in Figure 1 , the content is as follows:

[0040] 1. After the finishing rolling mill unit has replaced the new support roll, calibrate the working roll for the first time:

[0041] Step 1: The working roll gap is pressed against each other. When the rated rolling force P of the rolling mill is E When the load is 4000 tons, the rolling force coefficient of the transfer car is 15%, and the upper and lower working rolls produce a rolling force P z =600T transfer car, the nominal rolling force coefficient is 25%, the nominal rolling force P b =1000T. The finishing mill speed is increased to the rated speed V b , through the first level calibration screen on the HMI human-machine interaction screen, click the automatic calibration button AUTO CAL, and the roll gap will automatically press to the calibrated rolling force P b =1000T.

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

[0043] Rolling mill allowable calibration rolling force deviation △P b The range is -30T to +30T, adjust the roll gap deviation value △S on both sides of the rolling mill, and the roll gap value S on the working side ws Becomes smaller, the transmission side roller gap value S ds becomes larger, the rolling force deviation △P becomes larger; the working side roll gap value S ws becomes larger, the transmission side roller gap value S ds becomes smaller, and the rolling force deviation △P becomes smaller.

[0044] Step 3: After the zero roll gap calibration of the finishing rolling mill is successful, the carbon content of the hot roll material is W C %=0.03%,Width B=1150mm,See Table 1,After rolling 5 pieces, the strip head of each stand is straight and pressed against the roll gap of each stand to the calibrated 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 interactive screen, click the rolling mill force deviation memory button RECALL key to memorize the current strip carbon content W C % = 0.03% and width B = 1150mm, see Table 1. When the strip is straight, the rolling force deviation value enters the rolling mill force deviation memory table △P j3 ;

[0045] After that, another strip with carbon content W is rolled C % = 0.09% and width B = 1300mm, see Table 1. When the strip head of each stand is straight, it is pressed against the roll gap of each stand to the calibrated 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 rolling force deviation memory button RECALL again to memorize the carbon content W C % = 0.09% and width B = 1300mm, see Table 1. When the strip is straight, the rolling force deviation value enters the rolling mill force deviation memory table △P j2 ;

[0046] After that, another strip with carbon content W is rolled C %=0.15% and width B=1420mm, see Table 1. When the strip head of each stand is straight, it is pressed against the roll gap of each stand to the calibrated 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 rolling force deviation memory button RECALL again to memorize the carbon content W C % = 0.15% and width B = 1420mm, see Table 1. When the strip is straight, the rolling force deviation value enters the rolling mill force deviation memory table △P j1 ;

[0047] In this way, after changing the support roll, according to the different carbon content and width B of the rolled strip, the rolling force deviation value △P of different strip carbon content and width group spacing is memorized. j The value is automatically recorded in the rolling force deviation memory table, see Table 1 and Table 2.

[0048] Table 1: Classification table of rolling force deviation groups.

[0049]

[0050] Table 2: Rolling force deviation memory table

[0051]

[0052] 2. After the backup rolls are replaced in the finishing rolling mill, the calibration is performed when the working rolls are installed for the second time:

[0053] Step 1: The working roll gap is pressed against each other. When the upper and lower working rolls exert a rolling force P z =600T transfer car, finishing rolling mill speed increased to the rated speed V b , click the AUTO CAL button, the roll gap will automatically press to the calibrated rolling force P b =1000T.

[0054] Step 2: Adjust the roll gap deviation value and adjust the rolling force deviation △P of each stand to within the allowable rolling force deviation range △P of the zero roll gap calibration. b = within ±30T;

[0055] Check the carbon content W of the first steel rolled in this cycle C %=0.02%, width B=1180mm, see Table 1, find the rolling force deviation memory value of each stand corresponding to the carbon content and width group interval in the reference table of zero roll gap calibration rolling force deviation △P j3 , each stand rolling force deviation reference △P 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 stress 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 time, press the zero calibration button to successfully calibrate the roller gap.

[0062] [Example 2]

[0063] A genetic segmented calibration method for strip finishing tandem mill, see Figure 1 , the content is as follows:

[0064] 1. After the finishing rolling mill unit has replaced the new support roll, calibrate the working roll for the first time:

[0065] Step 1: When the rated rolling force P of the rolling mill E When the rolling force coefficient of the transfer car is 10%, the upper and lower working rolls produce a rolling force P z =500T turntable, the nominal rolling force coefficient is 30%, the nominal rolling force P b =1500T. The working roll gap is pressed against each other, and when the upper and lower working rolls press out the rolling force P z =1500T transfer car, finishing rolling mill speed increased to the calibration speed V b , click the AUTO CAL button, the roll gap will automatically press to the calibrated rolling force P b =1500T.

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

[0067] The rolling force deviation of the rolling mill is allowed to be calibrated △P b The range is -70T to +70T, adjusting the roll gap deviation value △S on both sides of the rolling mill and the roll gap value S on the working side. ws Becomes smaller, the transmission side roller gap value S ds becomes larger, the rolling force deviation △P becomes larger; the working side roll gap value Sws becomes larger, the transmission side roller gap value S ds becomes smaller, and the rolling force deviation △P becomes smaller.

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

[0069] Carbon content of hot roller material W C %=0.05% and width B=1180mm, see Table 1. After rolling 3 pieces, the strip head of each stand is straight and pressed against the roll gap of each stand to the calibrated 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 rolling mill force deviation memory button RECALL key to memorize the current strip carbon content W C % = 0.05% and width B = 1180mm, see Table 1. When the strip is straight, the rolling force deviation value enters the rolling mill force deviation memory table △P j3 ;

[0070] After that, another strip with carbon content W is rolled C % = 0.03% and width B = 1250mm, see Table 1. When the strip head of each stand is straight, it is pressed against the roll gap of each stand to the calibrated 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 rolling force deviation memory button RECALL again to memorize the carbon content W C % = 0.03% and width B = 1250mm, see Table 1. When the strip is straight, the rolling force deviation value enters the rolling mill force deviation memory table △P j2 ;

[0071] After that, another strip with carbon content W is rolled C %=0.13% and width B=1410mm, see Table 1. When the strip head of each stand is straight, it is pressed against the roll gap of each stand to the calibrated 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 rolling force deviation memory button RECALL again to memorize the carbon content W C% = 0.13% and width B = 1410mm, see Table 1. When the strip is straight, the rolling force deviation value enters the rolling mill force deviation memory table △P j1 ;

[0072] In this way, in the first working roll rolling cycle after the backup roll is replaced, the rolling force deviation values ​​△P of different strip carbon contents and width groups are memorized according to different strip carbon contents and widths B. j The value is automatically recorded in the rolling force deviation memory table.

[0073] 2. After the backup rolls are replaced in the finishing rolling mill, the calibration is performed when the working rolls are installed for the second time:

[0074] Step 1: The working roll gap is pressed against each other. When the upper and lower working rolls exert a rolling force P z =500T transfer car, finishing rolling mill speed increased to the calibration speed V b , click the AUTO CAL button, the roll gap will automatically press to the calibrated rolling force P b =1500T.

[0075] Step 2: Adjust the roll gap deviation value and adjust the rolling force deviation △P of each stand to within the allowable rolling force deviation range △P of the zero roll gap calibration. b = within ±70T;

[0076] Check the W of the first steel rolled in this cycle C % = 0.03%, width B = 1250mm, see Table 1, find the rolling force deviation memory value △P of each stand corresponding to the carbon content and width group spacing in the reference table of zero roll gap calibration rolling force deviation j2 , each stand rolling force deviation reference △P j21 , △P j22 , △P j23 , △P j2(n-1) , △P j2n At this time, the rolling force deviation memory value of F1 frame, F3 frame, Fn-1 frame, and Fn frame |△P j |≤|△P b |,|△P of F2 rack j |>|△P b |, according to the roll gap deviation adjustment rule in formula ③, adjust the roll gap deviation value so that the standard stress 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] The |△P of the F2 frame j |>|△P b |, first adjust the roller gap to △P b2 =△P f2 =△P j32 , zero roll gap calibration cleaning, according to the formula ④△S h =|△P fn -△P b2 |*n, calculate the callback roll gap value, the F2 rolling mill roll gap deviation adjustment coefficient n is 1, and substitute it into formula ④ to calculate the callback △S h value, callback direction is in accordance with △P j33 Direction adjustment, now press the zero calibration button to successfully calibrate the roller gap.

[0082] In the genetic segmented calibration method of the plate and strip finishing tandem mill of the present invention, inheritance means that when the first block is rolled after the working roll is replaced within a support roll cycle, the rolling force deviation of the same type of steel is the same, and segmented regulation means that the roll gap deviation adjustment coefficients of each frame are different. The segmented regulation coefficient is adopted according to the rolling thickness, which eliminates the inaccurate calibration of the zero roll gap of the rolling mill caused by the replacement of support rolls and working rolls of the finishing tandem mill group, resulting in accidents such as side bending of the head of the first block when the rolls are replaced and the steel is stuck, etc., thereby improving the rolling success rate and rolling efficiency of the rolling mill after the rolls are replaced, and providing a favorable guarantee for the smooth rolling.

Claims

1. A genetic segmented calibration method for a strip finishing tandem 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 is used to follow the zero adjustment rolling force deviation found in the first work roll change; The method from the third work roll change calibration to the nth work roll change calibration is the same as the second work roll change calibration method.

2. A genetic segmented calibration method for a strip finishing tandem mill according to claim 1, characterized in that: The first work roll change calibration includes: S11, the roll gap of the working roll is pressed to the calibrated rolling force; S12, adjusting the rolling force deviation of each stand to within the allowable calibrated rolling force deviation range of the zero roll gap calibration rolling mill; S13. According to different carbon contents and width groups of the steel strip, the rolling force deviation values ​​of the corresponding carbon contents and width groups of the steel strip are memorized, and the rolling force deviation values ​​are extracted into a rolling force deviation work table.

3. The genetic segmented calibration method for a strip finishing tandem mill according to claim 1, characterized in that: The second work roll change calibration includes: S21, the roll gap of the working roll is pressed to the calibrated rolling force; S22, adjusting the rolling force deviation of each stand to within the allowable calibrated rolling force deviation range of the zero roll gap calibration mill.

4. A genetic segmented calibration method for a strip finishing tandem mill according to claim 2, characterized in that: In S11, when the upper and lower working rolls exert rolling force, the rolling force P z The range is the rated rolling force P E 10% to 15% of the speed of the finishing mill is increased to the rated speed V b , the roll gap is pressed against the calibrated rolling force P b , rolling force P during calibration b The range is the rated rolling force P E 25% to 30% of the rolling mill speed, the formula for the rated speed is as follows: V b =V max ×50% ① In formula ①, V b It indicates the rated speed of the rolling mill and the maximum allowable speed of each stand.

5. The genetic segmented calibration method for a strip finishing tandem mill according to claim 2, characterized in that: In S12, the rolling mill allows the calibrated rolling force deviation △P b The range is ±(30~80)T; Adjust the roll gap deviation value on both sides of the rolling mill and the rolling force deviation on both sides of the rolling mill. The formula is as follows: △P=P ws -P ds ②In formula ②, △P represents the rolling force deviation on both sides of the rolling mill, P ws Indicates the rolling force on the working side of the rolling mill, P ds Indicates the rolling force on the transmission side of the rolling mill; The roll gap deviation value on both sides of the rolling mill is as follows: △S=S ws -S ds ③In formula ③, △S represents the roll gap deviation value on both sides of the rolling mill, S ws Indicates the roll gap on the working side of the rolling mill, S ds Indicates the roll gap on the drive side of the rolling mill.

6. A genetic segmented calibration method for a strip finishing tandem mill according to claim 3, characterized in that: In S22, when the upper and lower working rolls exert rolling force, the rolling force P z The range is the rated rolling force P E 10% to 15% of the speed of the finishing mill is increased to the rated speed V b , the roll gap is pressed against the calibrated rolling force P b , rolling force P during calibration b The range is the rated rolling force P E 25%~30% of the rolling mill’s rated speed is formula ①.

7. The genetic segmented calibration method for a strip finishing tandem mill according to claim 3 is characterized in that: In S22, check the carbon content and width group of the first steel billet rolled in this cycle, and find the corresponding rolling force deviation memory value △P of each stand in the rolling force deviation work table. j , adjust the roller gap deviation value △S, the content is as follows: 1) When |△P j |≤|△P b |, according to the roll gap deviation adjustment rule in formula ③, adjust the zero roll gap rolling force deviation △P to the memory rolling force deviation memory value △P j ; 2) When |△P j |>|△P b |, according to the roll gap deviation adjustment rule in formula ③, adjust the zero roll gap rolling force deviation △P to the rolling force deviation △P that the rolling mill allows to calibrate through b Within the range, the roll gap adjustment amount on both sides of the rolling mill is △S t At this time, the rolling mill is calibrated to zero roll gap, and then adjusted based on zero roll gap, and the adjustment direction is the rolling force deviation memory value △P j The value direction and the roll gap deviation value formula are as follows: △S h =|△P j -△P b |*n ④In formula ④, △S h It indicates the correction roll gap deviation value, and n indicates the roll gap deviation adjustment coefficient; the roll gap deviation adjustment coefficient of F1 and F2 frames is n=1, the roll gap deviation adjustment coefficient of F3 and F4 frames is n=0.9, and the roll gap deviation adjustment coefficient of Fn-2, Fn-1, and Fn frames is n=0.

8.

8. The genetic segmented calibration method for a strip finishing tandem mill according to claim 1, characterized in that: The zero adjustment rolling force deviation refers to the deviation value 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 calibration process of the rolling mill.

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