A roll gap optimization control method based on rigidity correction on both sides of a rolling mill

Abstract

The application discloses a kind of based on the roll gap optimization control method of mill two side stiffness correction, based on the historical data of having rolled pass after each roll change, respectively correction to two side stiffness is established;Accordingly, the working side roll gap and the drive side roll gap of the next to be rolled pass are respectively set to be corrected, to form the plate shape optimization control based on roll gap optimization.The application discloses a kind of based on the roll gap optimization control method of mill two side stiffness correction, based on the relatively accurate two side mill stiffness difference obtained by big data, reduce the difference of the rolled piece two sides by optimization control, so as to improve sickle bend, and obtain excellent thickness precision.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hot rolling mill control, and particularly relates to a roll gap optimization control method based on rigidity correction of both sides of a rolling mill. BACKGROUND

[0002] Rolling mill rigidity is the ability of the rolling mill to resist elastic deformation caused by rolling pressure, also known as rolling mill modulus or rolling mill modulus. During rolling, the rolling piece produces plastic deformation, while the rolling mill rolls, rolling mill bearings, bearing seats, pads, pressure cylinders and housings and a series of parts corresponding to the elastic deformation. Most of the existing technologies of plate and strip hot rolling mills consider that the rolling mill rigidity is a constant regular value, and the rigidity of both sides of the rolling mill is the same. However, in fact, such elastic deformation will have certain differences on both sides of the rolling mill, that is, under the condition of the same set roll gap, the roll gap caused by springback is different, thereby causing the thickness of the rolled piece to be different on both sides, which will cause the thickness to be uneven on both sides, and even cause rolling accidents.

[0003] When dealing with the problem of rigidity difference on both sides of the rolling mill, there are several common solutions: the first type is to adjust the mechanical structure, such as replacing the rolling mill support roll, adjusting the gap between the bearing seat and the housing, adjusting the pressure plate, adjusting the oil cylinder gasket, etc. This method can only be carried out during downtime, and it takes a long downtime. The second type is to balance the rigidity difference by adjusting the rolling force and the roll gap difference on both sides. This method belongs to the adjustment through the rolling force difference and change, and each rolling pass is different, which is unstable.

[0004] The invention application with the application number CN201210006219.3 discloses a "hot continuous rolling mill zero adjustment after two-side deviation control method". The control method involves a certain corresponding relationship between the rolling force deviation and the roll gap deviation after zero adjustment, combines the rigidity characteristics of different stands, adopts the rolling force deviation conversion control method to modify and control the deviation, and simultaneously adopts the actual rolling state comparison method in the corresponding opening deviation opening process, thereby meeting the requirements of zero adjustment opening stability.

[0005] The application number is: CN201310372086.6, the invention application discloses "a kind of finishing roll gap horizontal automatic adjusting method", first, the corresponding relationship of the force detected by pressure detection device in the process of pressing and the length variation of AGC hydraulic cylinder is used to calculate the stiffness difference of the frame on both sides;Second, the pre-adjusted roll gap value and the roll gap adjustment value in the rolling process are calculated;Third, before rolling, the roll gap deviation is calculated according to the difference between the set rolling force and the pressing force combined with the stiffness of rolling mill, and the roll gap deviation is preset according to the calculation, and the abnormality is manually corrected after pre-setting;Fourth, during rolling, the roll gap is automatically adjusted according to the rolling force deviation and the deviation direction of strip steel.

[0006] The application number is: CN201310741694.X, the invention application discloses "an automatic control method for improving camber in rough rolling intermediate blank", the control method is divided into two parts: setting the roll gap inclination adjustment value of this pass and correcting the roll gap inclination adjustment value of the camber at the outlet of last pass.The former can be calculated by analytical model according to the set rolling force, the set outlet thickness, the roll gap set value on both sides, the zero-adjusted rolling force and the stiffness value of rolling mill on both sides;The latter is calculated by the slab plastic deformation coefficient of this pass and the measured rolling force and slab plastic deformation coefficient on both sides of last pass.

[0007] The application number is: CN202111003543.5, the invention application discloses "a comprehensive optimization method of bending roll force for dynamic roll gap control of cold continuous rolling mill", including the following steps: collecting equipment parameters of 1 to 5 racks in the rolling process of cold continuous rolling mill, mainly including: working roll diameter, intermediate roll diameter, support roll diameter, working roll profile distribution, intermediate roll profile distribution, support roll profile distribution, working roll body length, intermediate roll body length, support roll body length, intermediate distance of screwdown, intermediate roll screwdown intermediate distance, support roll screwdown intermediate distance;It fully considers that the hot crown increases with rolling time in the rolling process of cold continuous rolling mill, which leads to low outlet plate shape quality, by studying the influence of working roll bending force and intermediate roll bending force on dynamic change of loaded roll gap, the corresponding bending force optimization model is established. SUMMARY

[0008] To provide a thickness control with good precision suitable for thick plate rolling mill and hot rolling rough rolling mill, the present application provides a roll gap optimization control method based on stiffness correction on both sides of rolling mill, and the technical scheme is as follows:

[0009] A roll gap optimization control method based on stiffness correction on both sides of rolling mill, characterized in that:

[0010] Based on the historical data of the rolled passes after each roll change, the respective correction of the stiffness of both sides is established; according to which the working side roll gap and the driving side roll gap of the next to be rolled pass are respectively corrected and set, so as to form the plate shape optimization control based on the roll gap optimization.

[0011] According to the roll gap optimization control method based on the stiffness correction of both sides of the rolling mill of the application, characterized in that:

[0012] The historical data is counted from the first steel block after the roll change,

[0013] The establishment of the respective correction of the stiffness of both sides is started from the Nth steel block after the roll change.

[0014] According to the roll gap optimization control method based on the stiffness correction of both sides of the rolling mill of the application, characterized in that:

[0015] The historical data includes the rolling force of the working side of the steel block, the rolling force of the driving side, the actual roll gap of the working side, the actual roll gap of the driving side, the set rolling force of the pass, the initial roll gap, the inlet thickness of the rolled piece, the target outlet thickness, the working side thickness and the driving side thickness of each steel block after rolling;

[0016] Firstly, according to the historical data, the judgment of whether the thickness deviation and the stiffness deviation trend conform to the rule is established,

[0017] The first stiffness optimization gradient which does not conform to the rule and the second stiffness optimization gradient which conforms to the rule are formed;

[0018] Then, the judgment based on whether the thickness deviation of both sides is greater than the set threshold is established for the second stiffness optimization gradient,

[0019] The first sub-gradient in which the thickness deviation of both sides is less than the set threshold and the second sub-gradient in which the thickness deviation of both sides is greater than the set threshold are formed in the second stiffness optimization gradient;

[0020] According to the first stiffness optimization gradient and the first and second sub-gradients in the second stiffness optimization gradient:

[0021] The first-level stiffness optimization rule which does not conform to the rule is established;

[0022] The second-level stiffness optimization rule which conforms to the rule but the thickness deviation of both sides is less than the set threshold is established;

[0023] The third-level stiffness optimization rule which conforms to the rule but the thickness deviation of both sides is greater than the set threshold is established;

[0024] According to the actual corresponding stiffness optimization rule level, the working side roll gap and the driving side roll gap of the corresponding to be rolled pass are respectively corrected.

[0025] The roll gap optimization control method based on the rigidity correction of the two sides of a rolling mill according to the application is characterized in that:

[0026] The judgment of whether the trend of the thickness deviation and the rigidity deviation of the two sides conforms to the rule is established based on the following formula:

[0027] Jc = ΔT x (Kgo - Kgd),

[0028] When the calculation result is a positive number, it is judged that it does not conform to the rule; when the calculation result is a negative number, it is judged that it conforms to the rule;

[0029] In the formula,

[0030] Jc: judgment factor;

[0031] ΔT: thickness difference of the two sides, unit: mm;

[0032] Kgo: rigidity of the working side, unit, N / mm;

[0033] Kgd: rigidity of the driving side, unit: N / mm.

[0034] The roll gap optimization control method based on the rigidity correction of the two sides of a rolling mill according to the application is characterized in that:

[0035] The thickness deviation of the two sides is determined by subtracting the outlet thickness of the driving side from the outlet thickness of the working side;

[0036] The threshold value is determined according to the target outlet thickness.

[0037] The roll gap optimization control method based on the rigidity correction of the two sides of a rolling mill according to the application is characterized in that:

[0038] The first-level rigidity optimization rule is set according to the system default rigidity;

[0039] The second-level rigidity optimization rule is based on the rigidity setting represented by the bounce equation;

[0040] The third-level rigidity optimization rule is based on the rigidity setting represented by the bounce equation with a correction factor.

[0041] The roll gap optimization control method based on the rigidity correction of the two sides of a rolling mill according to the application is characterized in that:

[0042] The rigidity setting based on the bounce equation is specifically:

[0043] ,

[0044] ,

[0045] In the formula,

[0046] : working side stiffness, unit: N / mm;

[0047] : transmission side stiffness, unit: N / mm;

[0048] : rolling force on working side, unit: N;

[0049] : rolling force on transmission side, unit: N;

[0050] : roll gap on working side, unit: mm;

[0051] : roll gap on transmission side, unit: mm;

[0052] : set rolling force of the rolling pass, unit: N;

[0053] : initial roll gap, unit: mm.

[0054] A roll gap optimization control method based on mill two-side stiffness correction according to the present application is characterized in that:

[0055] The stiffness setting based on the elastic rebound equation provided with a correction factor is specifically:

[0056] ,

[0057] ,

[0058] In the formula,

[0059] : working side stiffness, unit: N / mm;

[0060] : transmission side stiffness, unit: N / mm;

[0061] : rolling force on working side, unit: N;

[0062] : rolling force on transmission side, unit: N;

[0063] : roll gap on working side, unit: mm;

[0064] : roll gap on transmission side, unit: mm;

[0065] : the set rolling force of the rolling pass, unit: N;

[0066] : initial roll gap, unit: mm;

[0067] , : correction factor;

[0068] wherein,

[0069] Delta T: thickness difference on both sides, unit: mm;

[0070] H: entry piece thickness, unit: mm;

[0071] h: target exit thickness, unit: mm;

[0072] P: adjustment coefficient.

[0073] The roll gap optimization control method based on mill two-side stiffness correction according to the application is characterized in that:

[0074] The working side roll gap and the driving side roll gap of the corresponding rolling pass to be rolled are respectively corrected according to the actual corresponding stiffness optimization rule level, specifically:

[0075] A two-side stiffness reference table is established according to the roll change mark, the division of rolling width range, the division of rolling force range and the stiffness corresponding to the stiffness optimization rule level of each piece of steel determined by calculation, and the determination of the two-side stiffness corresponding to the rolling width and the rolling force is completed;

[0076] The next rolling pass to be rolled reads the corresponding two-side stiffness in the reference table according to its own roll change mark, its own rolling width range and rolling force range, and completes the respective correction according to the read stiffness.

[0077] The roll gap optimization control method based on mill two-side stiffness correction according to the application is characterized in that:

[0078] The division of the rolling width range is limited to causing the sudden change of the mill stiffness;

[0079] The division of the rolling force range is limited to the linear distribution of the stiffness in the rolling force range.

[0080] The roll gap optimization control method based on mill two-side stiffness correction according to the application is characterized in that:

[0081] The "establishing a two-side stiffness reference table according to the roll change mark, the division of rolling width range, the division of rolling force range and the stiffness corresponding to the stiffness optimization rule level of each piece of steel determined by calculation, and completing the determination of the two-side stiffness corresponding to the rolling width and the rolling force", specifically:

[0082] The rolled steel blocks in the rolling width range and the rolling force range are counted, and the stiffness of each steel block is calculated according to the stiffness optimization rule level thereof, the stiffness of all the steel blocks is calculated by mean value or median, and the determination of the two-side stiffness corresponding to the rolling width and the rolling force is completed.

[0083] According to the roll gap optimization control method based on mill two-side stiffness correction provided by the application, the features are as follows:

[0084] The two-side stiffness reference table is self-iteratively updated according to the continuous accumulation of data.

[0085] According to the roll gap optimization control method based on mill two-side stiffness correction provided by the application, the features are as follows:

[0086] The data acquisition is based on L1,

[0087] The data storage and the operation based on the data are performed at L2.

[0088] According to the roll gap optimization control method based on mill two-side stiffness correction provided by the application, the features are as follows:

[0089] The adjustment coefficient ρ is determined according to the roll diameter, the roll body length, the rolling material and the number of rolls.

[0090] The roll gap optimization control method based on mill two-side stiffness correction provided by the application can obtain relatively accurate two-side mill stiffness difference based on big data, reduce the difference between the two sides of the rolled piece through optimization control, thereby improving the camber and obtaining excellent thickness precision. The method is mainly suitable for thick plate mills and hot rolling roughing mills. The optimization is performed for the roll gap correction based on stiffness optimization, the stiffness optimization is performed for the separate optimization of the working side and the driving side stiffness, so as to form the separate optimization of the working side roll gap and the driving side roll gap, and finally the optimization is performed according to the division of the rolling width range and the rolling force range, the final stiffness optimization setting is formed by processing all the historical data in the corresponding range, and the roll gap correction is completed. BRIEF DESCRIPTION OF DRAWINGS

[0091] Figure 1 It is a schematic diagram of the bounce equation in the working principle of the application;

[0092] Figure 2 It is a schematic diagram of the step sequence in the working principle of the application. DETAILED DESCRIPTION

[0093] Hereinafter, the roll gap optimization control method based on mill two-side stiffness correction provided by the application will be further specifically described according to the drawings and the specific embodiments.

[0094] A roll gap optimization control method based on mill two-side stiffness correction, based on the historical data of the rolled pass after each roll change, the respective correction of the two-side stiffness is established; according to the correction, the working side roll gap and the driving side roll gap of the next to-be-rolled pass are respectively corrected and set to form the plate shape optimization control based on the roll gap optimization.

[0095] wherein,

[0096] The historical data is counted from the first steel block after the roll change,

[0097] The establishment of the respective correction of the two-side stiffness is performed from the Nth steel block after the roll change.

[0098] wherein,

[0099] The historical data includes the rolling force of the working side of the steel block, the rolling force of the driving side, the actual roll gap of the working side, the actual roll gap of the driving side, the set rolling force of the pass, the initial roll gap, the inlet rolled piece thickness, the target outlet thickness, the working side thickness and the driving side thickness of each steel block after rolling;

[0100] First, according to the historical data, the determination of whether the thickness deviation and the stiffness deviation trend conform to the rule is established,

[0101] The first stiffness optimization gradient that does not conform to the rule and the second stiffness optimization gradient that conforms to the rule are formed;

[0102] Then, the determination of whether the two-side thickness deviation is greater than the set threshold value is established for the second stiffness optimization gradient,

[0103] The first sub-gradient of the two-side thickness deviation less than the set threshold value and the second sub-gradient of the two-side thickness deviation greater than the set threshold value in the second stiffness optimization gradient are formed;

[0104] According to the first stiffness optimization gradient and the first and second sub-gradients in the second stiffness optimization gradient,

[0105] The first-level stiffness optimization rule that does not conform to the rule;

[0106] The second-level stiffness optimization rule that conforms to the rule but the two-side thickness deviation is less than the set threshold value;

[0107] The third-level stiffness optimization rule that conforms to the rule but the two-side thickness deviation is greater than the set threshold value;

[0108] According to the actual corresponding stiffness optimization rule level, the working side roll gap and the driving side roll gap of the corresponding to-be-rolled pass are respectively corrected.

[0109] wherein,

[0110] The determination of whether the trend of the thickness deviation of two sides and the stiffness deviation conforms to the rule is based on the following formula:

[0111] Jc = ΔT × (Kgo- Kgd),

[0112] When the calculation result is a positive number, it is determined that it does not conform to the rule; when the calculation result is a negative number, it is determined that it conforms to the rule;

[0113] In the formula,

[0114] Jc: determination factor;

[0115] ΔT: thickness difference of two sides, unit: mm;

[0116] Kgo: stiffness of the working side, unit, N / mm;

[0117] Kgd: stiffness of the transmission side, unit: N / mm.

[0118] Wherein,

[0119] The thickness deviation of the two sides is determined by subtracting the outlet thickness of the transmission side from the outlet thickness of the working side;

[0120] The set threshold value is determined according to the target outlet thickness.

[0121] Wherein,

[0122] The first-level stiffness optimization rule is set according to the system default stiffness;

[0123] The second-level stiffness optimization rule is based on the stiffness setting represented by the bounce equation;

[0124] The third-level stiffness optimization rule is based on the stiffness setting represented by the bounce equation with a correction factor.

[0125] Wherein,

[0126] The stiffness setting represented by the bounce equation is specifically:

[0127] ,

[0128] ,

[0129] In the formula,

[0130] Kgo: stiffness of the working side, unit: N / mm;

[0131] Kgd: stiffness of the transmission side, unit: N / mm;

[0132] F: rolling force of the working side, unit: N;

[0133] : rolling force on the drive side, unit: N;

[0134] : roll gap on the working side, unit: mm;

[0135] : roll gap on the drive side, unit: mm;

[0136] : set rolling force of the rolling pass, unit: N;

[0137] : initial roll gap, unit: mm.

[0138] wherein,

[0139] The rigidity setting based on the elastic rebound equation with the correction factor is specifically:

[0140] ,

[0141] ,

[0142] In the formula,

[0143] : rigidity on the working side, unit: N / mm;

[0144] : rigidity on the drive side, unit: N / mm;

[0145] : rolling force on the working side, unit: N;

[0146] : rolling force on the drive side, unit: N;

[0147] : roll gap on the working side, unit: mm;

[0148] : roll gap on the drive side, unit: mm;

[0149] : set rolling force of the rolling pass, unit: N;

[0150] : initial roll gap, unit: mm;

[0151] , : correction factor;

[0152] wherein,

[0153] ΔT: thickness difference between two sides, unit: mm;

[0154] H: entry piece thickness, unit: mm;

[0155] h: target exit thickness, unit: mm;

[0156] ρ: adjustment coefficient.

[0157] wherein,

[0158] According to the actual corresponding stiffness optimization rule level, the working side roll gap and the driving side roll gap of the corresponding to-be-rolled pass are respectively corrected, specifically as follows:

[0159] According to the roll change mark, the division of the rolling width range, the division of the rolling force range, and the stiffness corresponding to the stiffness optimization rule level of each steel determined by calculation, a two-side stiffness reference table is established to determine the two-side stiffness corresponding to the rolling width and the rolling force;

[0160] The next to-be-rolled pass reads the corresponding two-side stiffness in the reference table according to its own roll change mark, rolling width range and rolling force range, and completes the respective correction according to the read stiffness.

[0161] wherein,

[0162] The division of the rolling width range is limited to causing a sudden change in the stiffness of the rolling mill;

[0163] The division of the rolling force range is limited to the stiffness being linearly distributed within the rolling force range.

[0164] wherein,

[0165] The "establishing a two-side stiffness reference table according to the roll change mark, the division of the rolling width range, the division of the rolling force range, and the stiffness corresponding to the stiffness optimization rule level of each steel determined by calculation, and determining the two-side stiffness corresponding to the rolling width and the rolling force", specifically as follows:

[0166] The rolled steel blocks within the rolling width range and the rolling force range are counted, and the stiffness of each steel block calculated according to its stiffness optimization rule level is read. The stiffness of all steel blocks is calculated by mean value or median value to determine the two-side stiffness corresponding to the rolling width and the rolling force.

[0167] wherein,

[0168] The two-side stiffness reference table is updated by itself through iteration according to the continuous accumulation of data.

[0169] wherein,

[0170] The data acquisition is based on L1.

[0171] The storage of data and the operation based on the data are performed at L2.

[0172] wherein,

[0173] The adjustment coefficient p is determined according to four factors of the roll diameter, the roll body length, the rolling material and the number of rolls.

[0174] Working process and principle

[0175] The technical idea is as follows: relying on the rolling force deviation data recorded in the database of the secondary control system and the feedback data of the rolling thickness gauge, the stiffness of the two sides of the rolling mill is obtained by calculation. The stiffness of the two sides is used as the basic data to calculate the roll gap setting, that is, the total roll gap is calculated from the total stiffness of the rolling mill, and the roll gaps of the two sides are calculated from the stiffness of the two sides. Specifically as follows:

[0176] 1. Stiffness calculation of the two sides of the rolling mill

[0177] The rolling force Fr of the horizontal rolling mill is measured by two pressure measuring devices distributed on the two sides of the rolling mill (working side Fro and driving side Frd, Fr=Fro+Frd). This data is normally fed back to the secondary control system and exists in the database. The database also records the set rolling force Fs, the initial roll gap Gs and the actual roll gap Ga data of the two sides corresponding to the rolling force Fr of this rolling pass, and the stiffness Kg data of the two sides (Kgo and Kgd are the stiffness coefficients of the working side and the driving side of the rolling mill respectively, Kgo=(|2*Fro-Fs|) / (|Gao-Gs|), Kgd=(|2*Frd-Fs|) / (|Gad-Gs|)) can be calculated by the bounce equation. In addition, the thickness measurement data is also stored in the database, and the stiffness data is optimized again through the thickness deviation of the two sides. First, the logic is whether the thickness deviation AT (working side-transmission side) and the stiffness deviation trend are consistent with the rules (the stiffness is large, the outlet thickness h is small, the stiffness is small, the outlet thickness h is large, here Jc=AT*(Kgo-Kgd) is negative), if not (Jc>0), Kgo and Kgd are optimized to the system default stiffness; if the trend is consistent (Jc<0) and AT is less than a certain threshold Lt (this coefficient is related to the parameters of the rolling mill, which is an empirical value), the calculated stiffness is maintained; if AT is greater than a certain threshold Lt, the increasing coefficient p (the absolute value of p is a number less than 1, the specific value is related to the properties of the rolling mill, here the working side thickness is large, the stiffness is small, p takes a positive value; otherwise, it takes a negative value), the stiffness calculation formula is as follows:

[0178]

[0179]

[0180] 2. Establishing the reference table of the mill rigidity on both sides

[0181] The reference table of the mill rigidity on both sides is established according to the backup roll information, the rolling width and the rolling force range. When the backup roll is replaced, the data of the mill rigidity on both sides need to be recalculated, and the number of blocks is at least BN blocks. Because the rolling width has a certain influence on the calculation of the mill rigidity on both sides, the rolling width is taken as one of the grades, and the width grade does not need to be too many, and 2 to 3 grades are enough. The grade is based on the difference data of the mill rigidity. The rolling force is set according to the size of the mill and the size of the rolling force. According to the law of the mill rigidity, the rigidity presents a linear law after a certain rolling force, that is, the rigidity value is relatively fixed within a certain rolling force range. Therefore, the rigidity values calculated are divided into calculation ranges according to the rolling force intervals, and the median or average of the rigidity data in each rolling force range is taken to determine the mill rigidity coefficient of each rolling force range. The reference table format is shown in Table 1.

[0182] Table 1 Reference table style of mill rigidity coefficient on both sides

[0183]

[0184] 3. Optimization of two-level control algorithm

[0185] The original two-level system (L2) calculates a total mill roll gap according to the rigidity of the whole mill. Now the roll gaps on both sides of the mill are calculated respectively by using the rigidity on both sides, and are set to the one-level system. The calculation method is based on the bounce equation, such as Figure 1 where P is the rolling pressure, Fs is the set total rolling force, H is the inlet workpiece thickness, h is the target outlet thickness, Kgd and Kgo are the rigidity of the drive side and the working side respectively, and S0d and S0o are the initial roll gaps of the drive side and the working side respectively.

[0186] 4. Logic of the new calculation method of the two-level system

[0187] After the work roll is replaced, the mill rigidity or the difference with the reference table is large due to the gap. The initial WN blocks are calculated according to the original logic, and the subsequent roll gap is calculated by using the new logic.

[0188] 5. Separate setting of the roll gap of the one-level system

[0189] The original control mode is often a total roll gap, and the two-level system (L2) originally sends a total roll gap value Gs to the one-level system (L1). Now it is improved that the two-level system sends two values of the working side roll gap Gso (target value) and the drive side roll gap Gsd (target value) to the one-level system. When the two-level system calculates the roll gap according to the original logic, Gso and Gsd are both Gs.

[0190] EMBODIMENT

[0191] Plate finishing mill, support roll diameter 2600mm; work roll diameter 1150mm, roll body length 5000mm; BN value 100, WN value 20 blocks. After the mill, thickness gauge, after the normal pass, the thickness can be measured; Lt value 0.5mm at the outlet thickness 20-100mm; 0.3mm at 15-20mm, 0.2mm at 6-15mm; stiffness calculation adjustment coefficient p=0.6; width is divided into three grades, 1300-2500mm, 2500-3500mm, 3500-4800mm; according to the total rolling force 25000kN, divided into 4 grades, 25000-40000kN, 40000-55000kN, 55000-70000kN, 70000-84000kN (no such grade when the width specification is narrow).

[0192] The rolling information of a pass is as follows, the inlet thickness H=63.5mm, the width 2700mm, the outlet thickness 51.4, the set total rolling force of a certain point 48000kN, the roll gap 49.057mm, the actual rolling force Fro=25200kN, the actual rolling force Frd=268000, the roll gap Gao=48.838mm, Gad=48.524

[0193] Initial calculation of mill stiffness on both sides:

[0194] Kgo=(|2*Fro-Fs|) / (|Gao-Gs|)=(|50400-48000|) / (|48.8-49.1|)=9160kN / mm

[0195] Kgd=(|2*Frd-Fs|) / (|Gad-Gs|)=(|53600-48000|) / (|48.6-49.1|)=9722kN / mm

[0196] The thickness after rolling this pass, To=51.5mm, Td=51.3mm, consistent with the stiffness trend, but ΔT=0.2mm

[0197]

[0198] After the work roll rolling block number reaches 20 blocks, the calculation of the roll gap of a certain steel plate is as follows

[0199] The inlet steel plate information of a D-class ship plate steel plate in the nth pass: thickness*width: 19.4mm*2897mm

[0200] Target size information of the nth pass: 17.4mm*2897mm

[0201] The total rolling force calculated is 58000kN

[0202] The total roll gap is 16.49mm according to the calculation logic of the system stiffness 10000kN / mm

[0203] The working side roll gap is 16.41mm and the driving side roll gap is 16.54mm according to the calculation of the two side stiffness reference table

[0204] The working side roll gap is 16.41mm and the driving side roll gap is 16.54mm according to the calculation of the two side stiffness reference table

[0205] The camber is very small during the rolling process, and the thickness difference after rolling is small.

[0206] The roll gap optimization control method based on the stiffness correction of the two sides of the rolling mill is based on the relatively accurate difference of the two sides of the rolling mill obtained by big data, and the difference of the two sides of the rolled piece is reduced through optimization control, so as to improve the camber and obtain good thickness precision. It is mainly suitable for thick plate rolling mill and hot rolling rough rolling mill. The optimization is for the roll gap correction based on stiffness optimization, and the stiffness optimization is for the optimization of the working side and the driving side stiffness respectively, so as to form the optimization of the working side roll gap and the driving side roll gap. On this basis, the final optimization is carried out according to the division of the rolling width range and the rolling force range, and the final stiffness optimization setting is formed by processing all the historical data in the corresponding range, so as to complete the correction of the roll gap.

Claims

1. A method for roll gap optimization control based on the correction of the stiffness of both sides of a rolling mill, characterized in that: based on historical data of the rolled passes after each roll change, the correction of the stiffness of both sides of the rolling mill is established; and according to the correction, the working side roll gap and the driving side roll gap of the next to be rolled pass are respectively corrected and set to form the plate shape optimization control based on the roll gap optimization; the historical data includes the rolling force of the working side of the steel block, the rolling force of the driving side, the actual roll gap of the working side, the actual roll gap of the driving side, the set rolling force of the pass, the initial roll gap, the inlet thickness of the rolled piece, the target outlet thickness, the working side thickness and the driving side thickness of each steel block after rolling; first, the judgment of whether the trend of the thickness deviation and the stiffness deviation of both sides of the rolling mill conforms to the rule is established according to the historical data, the first stiffness optimization gradient that does not conform to the rule and the second stiffness optimization gradient that conforms to the rule are formed; then, the judgment of whether the thickness deviation of both sides of the rolling mill is greater than the set threshold value is established for the second stiffness optimization gradient, the first sub-gradient that the thickness deviation of both sides of the rolling mill is less than the set threshold value and the second sub-gradient that the thickness deviation of both sides of the rolling mill is greater than the set threshold value are formed in the second stiffness optimization gradient; the following rules are established according to the first stiffness optimization gradient and the first sub-gradient and the second sub-gradient in the second stiffness optimization gradient: the first level stiffness optimization rule that does not conform to the rule; the second level stiffness optimization rule that conforms to the rule but the thickness deviation of both sides of the rolling mill is less than the set threshold value; and the third level stiffness optimization rule that conforms to the rule but the thickness deviation of both sides of the rolling mill is greater than the set threshold value; the working side roll gap and the driving side roll gap of the corresponding to be rolled pass are respectively corrected according to the actual corresponding stiffness optimization rule level; the judgment of whether the trend of the thickness deviation and the stiffness deviation of both sides of the rolling mill conforms to the rule is established based on the following formula: Jc = ΔT × (Kgo - Kgd), when the calculation result is positive, it is judged that it does not conform to the rule; and when the calculation result is negative, it is judged that it conforms to the rule; in the formula, Jc is the judgment factor, ΔT is the thickness difference of both sides of the rolling mill, unit: mm, Kgo is the working side stiffness, unit: N / mm, and Kgd is the driving side stiffness, unit: N / mm; the first level stiffness optimization rule is based on the system default stiffness setting; the second level stiffness optimization rule is based on the stiffness setting represented by the springback equation; and the third level stiffness optimization rule is based on the stiffness setting represented by the springback equation with a correction factor. 2.The method for roll gap optimization control based on the correction of the stiffness of both sides of a rolling mill according to claim 1, characterized in that: the historical data are counted from the first steel block after the roll change; and the correction of the stiffness of both sides of the rolling mill is established from the Nth steel block after the roll change. 3.The method for roll gap optimization control based on the correction of the stiffness of both sides of a rolling mill according to claim 1, characterized in that: the thickness deviation of both sides of the rolling mill is determined by subtracting the outlet thickness of the driving side from the outlet thickness of the working side; and the set threshold value is determined according to the target outlet thickness. 4.The method for roll gap optimization control based on the correction of the stiffness of both sides of a rolling mill according to claim 1, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The rigidity setting based on the springback equation is specifically: Kgo =（|2× Fro-Fs |） / (| Gao-Gs |)， ， In the formula, : working side stiffness, in N / mm; : transmission side stiffness, unit: N / mm; : rolling force at the working side, in N; : rolling force on the drive side, in N; : working side roll gap, in mm; : Drive side roll gap, in mm; : the set rolling force of the rolling pass, unit: N; Gs : initial roll gap, in mm.

5. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 1, characterized in that: The rigidity setting based on the springback equation provided with the correction factor is specifically: ， ， In the formula, : working side stiffness, in N / mm; Kgd : transmission side stiffness, unit: N / mm; Fro : rolling force at the working side, in N; : rolling force on the drive side, in N; : working side roll gap, in mm; : roll gap at drive side, unit: mm; : the set rolling force of the rolling pass, unit: N; : initial roll gap, in mm; , : correction factor; Wherein, ΔT: the thickness difference of both sides of the rolling mill, unit: mm; H: the thickness of the inlet rolled piece, unit: mm; h: the target outlet thickness, unit: mm; ρ: the adjustment coefficient.

6. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 1, characterized in that: According to the actual corresponding rigidity optimization rule level, the working side roll gap and the driving side roll gap of the corresponding to-be-rolled pass are respectively corrected, which is specifically: According to the roll change mark, the division of the rolling width range, the division of the rolling force range, and the rigidity corresponding to the rigidity optimization rule level of each steel determined by calculation, a rolling mill rigidity reference table is established to determine the rigidity of both sides of the rolling mill corresponding to the rolling width and the rolling force; The next to-be-rolled pass reads the corresponding rigidity of both sides of the rolling mill in the reference table according to its own roll change mark, its own rolling width range and rolling force range, and completes the respective correction according to the read rigidity.

7. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 6, characterized in that: The division of the rolling width range is limited to causing the mutation of the rigidity of the rolling mill; The division of the rolling force range is limited to the linear distribution of the rigidity in the rolling force range.

8. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 6, characterized in that: The "establishment of the rolling mill rigidity reference table according to the roll change mark, the division of the rolling width range, the division of the rolling force range, and the rigidity corresponding to the rigidity optimization rule level of each steel determined by calculation, and the determination of the rigidity of both sides of the rolling mill corresponding to the rolling width and the rolling force" is specifically: The rolled steels in the rolling width range and the rolling force range are counted, and the rigidity of each steel calculated according to its rigidity optimization rule level is read, the rigidity of all steels is calculated by mean or median, and the rigidity of both sides of the rolling mill corresponding to the rolling width and the rolling force is determined accordingly.

9. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 6, characterized in that: The rolling mill rigidity reference table is updated by itself through self-iteration according to the continuous accumulation of data.

10. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 1, characterized in that: The data acquisition is based on the primary system L1, The data storage and the operation based on the data are performed on the secondary system L2.

11. The roll gap optimization control method based on the rigidity correction of both sides of the rolling mill according to claim 5, characterized in that: The adjustment coefficient ρ is determined according to the roll diameter, the roll body length, the rolling material, and the number of rolls.

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