A method for online automatic control of finishing F1 rack roll gap deviation

Abstract

This invention relates to an online automatic control method for roll gap deviation on the finishing mill F1 stand. The method includes the following steps: Step 1, detection and acquisition of relevant physical quantities of the upper and lower steel blocks; Step 2, pre-adjustment of the steel block before finishing mill feeding; Step 3, dynamic control before finishing mill F7 strip threading after F1 strip threading; Step 4, automatic control from F7 strip threading until the finishing mill's steel ejection stage. This invention can achieve online automatic control of F1 roll gap deviation throughout the entire process, improving work efficiency.

Description

Technical Field

[0001] This invention relates to a control method, specifically an online automatic control method for roll gap deviation of finishing mill F1 stand, belonging to the field of hot strip steel production control technology. Background Technology

[0002] A hot strip mill finishing stand typically consists of 6-7 stands (rolling mills). The roll gap deviation adjustment of the hot strip mill stands is mainly used to ensure the stability and smoothness of the strip threading, rolling, and strip throwing processes of the finishing mill stands. Currently, conventional hot strip mills mainly rely on manual adjustment. Although some production lines have developed automatic leveling at the tail end of the hot strip mill stands, this can only serve as an auxiliary means of adjusting the roll gap deviation and cannot meet the needs of automatic control of the roll gap deviation of the finishing mill stands.

[0003] With the advancement of intelligent manufacturing, the most crucial step towards fully automated steel rolling in hot strip mills is to achieve automatic control of roll gap deviation, replacing manual operation. Patent CN202110957974.9, titled "A Novel Method for Pre-Controlling the Head of the Sickle Bending," proposes a method for pre-adjusting the roll gap deviation of the finishing mill based on the sickle bending of the roughing mill feed. However, this method does not provide an automatic control method for roll gap deviation based on the finishing mill's strip threading, rolling, and steel throwing processes. Patent CN201811554734.9, titled "A Method for Controlling the Sickle Bending of Hot-Rolled Intermediate Billets," proposes a method for controlling the sickle bending in each pass of the roughing mill. This method comprehensively considers parameters such as the stiffness difference between the two sides of the mill, the rolling force deviation between the two sides of the previous pass, and the slab center offset of the previous pass. The calculation process is complex, and this method for reciprocating rolling on a single roughing mill stand is not entirely applicable to multi-stand continuous rolling in the finishing mill.

[0004] To address the above problems, this invention proposes an online automatic control method for roll gap deviation on the finishing mill F1 stand. This invention treats the F1 mill as an integral part of the entire hot continuous rolling process. The online automatic control of the F1 mill roll gap deviation comprehensively considers factors such as the variation in the camber of the roughing mill feed head, the pressure on both sides of the guide plate at the F1 mill exit (F2 inlet side), the rolling force deviation on both sides of the tail of the upper steel F5-7 stands, and the center offset at the exit of the upper steel F7 stand. The automatic control technology of this invention can replace the original operational intervention for roll gap deviation on the finishing mill F1 stand. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by providing an online automatic control method for the roll gap deviation of the finishing mill F1 stand, thereby achieving online automatic control of the roll gap deviation of the finishing mill F1 stand and replacing the original manual operation.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: an online automatic control method for roll gap deviation of a finishing mill F1 stand, the method comprising the following steps:

[0007] Step 1: Detection and collection of relevant physical quantities of the steel block and this steel block;

[0008] Step 2: Pre-adjustment of this steel block before it is finished and rolled into steel;

[0009] Step 3: Dynamic control before finishing rolling F7 after F1 threading is completed;

[0010] Step 4: Automatic control from F7 threading until the finishing mill's steel-throwing stage.

[0011] The specific steps of step one, the detection and collection of relevant physical quantities of the upper steel block and the steel block itself, are as follows:

[0012] A width measuring instrument is installed at the exit of the roughing mill R2 to detect the center offset curve of the intermediate billet along the entire length of the last pass of R2; pressure sensors are installed on the hydraulic cylinder circuits on both sides of the guide plate at the entrance of the finishing mill F2 to detect the force on the guide plates on both sides; a width measuring instrument is installed at the exit of the finishing mill F7 to detect the center offset curve of the strip at the finishing mill exit; and a pressure measuring head is installed on the F5-7 mill to detect the rolling force deviation on both sides of the F5-7 mill.

[0013] The physical quantities involved include:

[0014] 1) The maximum value of the center offset x of the head of the intermediate billet in the last pass of the R2 steel block and the previous steel block, within 10 meters. i x i-1 Positive values ​​indicate bias towards the transmission side, and negative values ​​indicate bias towards the working side. Unit: mm;

[0015] 2) After steel block F1 bites into steel and before steel block F2 bites into steel, the peak force F2SG on the side guide plates on both sides of F2 is... max Positive values ​​indicate force on the transmission side, and negative values ​​indicate force on the working side. Unit: kN;

[0016] 3) The changes in rolling force deviation on both sides of the tail section of the F5-7 rolling mill after the steel is thrown from the upstream stand (rolling force deviation on both sides = rolling force on the drive side - rolling force on the working side) are Δf5, Δf6, and Δf7, respectively, in kN;

[0017] 4) Maximum value Y of the center offset of the strip tail at the exit of the upper steel finishing mill (10 meters) i-1 Positive values ​​indicate bias towards the transmission side, and negative values ​​indicate bias towards the working side. Unit: mm.

[0018] Step two, the pre-adjustment of this steel block before finishing rolling, is as follows:

[0019] Before this steel piece is fed into the finishing mill, the roll gap deviation of the F1 mill needs to be pre-adjusted according to the shape of the incoming sheet to ensure a smooth strip threading process. The automatic pre-adjustment amount of the F1 roll gap deviation due to changes in the incoming sheet shape is defined as Δg1 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap). The target width of this steel piece is W. i ,but,

[0020]

[0021] Where Δg1 is the automatic pre-adjustment amount for the F1 roll gap deviation due to changes in the shape of the incoming material, |Δg1|≤0.3mm; x i This represents the maximum center offset of the head of the intermediate billet in the final pass of the R2 steel block, measured within 10 meters; x i-1 This represents the maximum center offset of the head of the intermediate billet in the last pass of the upper steel R2 section, measured in 10 meters; W i This is the target width of the steel block.

[0022] The dynamic control before finishing mill F7 threading after step three, F1 threading, is as follows:

[0023] After the F1 strip is rolled out, the F1 roll gap deviation needs to be dynamically controlled based on the strip head shape. The automatic adjustment amount of the F1 roll gap deviation due to the strip head shape is defined as Δg2 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap).

[0024]

[0025] Among them, Δg2 is the amount of automatic adjustment of the F1 roll gap deviation due to the strip head shape of F1 rolled strip, |Δg2|≤0.3mm; F2SG max The peak force on the side guide plates of F2 is measured after F1 bites into the steel block and before F2 bites into the steel block.

[0026] The automatic control of step four, from F7 threading to the finishing mill steel-throwing stage, is as follows:

[0027] After the F7 strip is threaded, the F1 roll gap deviation needs to be automatically controlled based on the shape of the tail section of the upper steel plate. The automatic adjustment amount of the F1 roll gap deviation due to the tail section shape of the upper steel plate is defined as Δg3 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap).

[0028]

[0029] Wherein, Δg3 is the automatic adjustment amount of the roll gap deviation of F1 steel due to the shape of the tail of the upper steel finishing mill, |Δg3|≤0.5mm; Δf5, Δf6, and Δf7 are the changes in the rolling force deviation on both sides of the tail of the upper steel F5-7 mill after the steel is thrown off the upstream stand (rolling force deviation on both sides = rolling force on the drive side - rolling force on the working side); W i β is the target width of this steel block; β is the thickness correction factor, given as follows:

[0030] Target thickness <1.8 mm 1.8 ≤ Target cold thickness ≤ 2.3 Target thickness > 2.3 mm Thickness correction factor β 0.8 1.0 1.2

[0031] When any of the following conditions are met

[0032] 1) When the absolute value of Δf5, Δf6, or Δf7 is less than 1000 kN;

[0033] 2)Y i-1 The absolute value is less than 100mm;

[0034] 3) Δf5, Δf6, Δf7 and Y i-1 Different symbols;

[0035] 4) The signs of Δg1, Δg2, and Δg3 are all the same;

[0036] Set Δg3 to 0.

[0037] Compared with existing technologies, this invention has the following advantages: it can achieve online automatic control of F1 roll gap deviation, replacing the original manual operation. This invention can achieve online automatic control of F1 roll gap deviation throughout the entire process, including: precise and quantitative automatic pre-adjustment based on the degree of change in the shape of the incoming finishing mill material; automatic feedback control based on the F1 rolled-out shape; and automatic control of the tail shape of the F5, F6, and F7 sections of the finishing mill stands by treating the finishing mill stands as a whole and controlling the F1 roll gap deviation to control the tail shape of the finishing mill stands. Attached Figure Description

[0038] Figure 1 Schematic diagram of the rolling process of adjacent strips. Detailed Implementation

[0039] To enhance understanding of the present invention, the embodiments will be described in detail below with reference to the accompanying drawings.

[0040] Example 1: See Figure 1 A method for online automatic control of roll gap deviation on a finishing mill F1 stand, the method comprising the following steps:

[0041] Step 1: Detection and collection of relevant physical quantities of the steel block and this steel block;

[0042] Step 2: Pre-adjustment of this steel block before it is finished and rolled into steel;

[0043] Step 3: Dynamic control before finishing rolling F7 after F1 threading is completed;

[0044] Step 4: Automatic control from F7 threading until the finishing mill's steel-throwing stage.

[0045] The specific steps of step one, the detection and collection of relevant physical quantities of the upper steel block and the steel block itself, are as follows:

[0046] A width measuring instrument is installed at the exit of the roughing mill R2 to detect the center offset curve of the intermediate billet along the entire length of the last pass of R2; pressure sensors are installed on the hydraulic cylinder circuits on both sides of the guide plate at the entrance of the finishing mill F2 to detect the force on the guide plates on both sides; a width measuring instrument is installed at the exit of the finishing mill F7 to detect the center offset curve of the strip at the finishing mill exit; and a pressure measuring head is installed on the F5-7 mill to detect the rolling force deviation on both sides of the F5-7 mill.

[0047] The physical quantities involved include:

[0048] 1) The maximum value of the center offset x of the head of the intermediate billet in the last pass of the R2 steel block and the previous steel block, within 10 meters. i x i-1 Positive values ​​indicate bias towards the transmission side, and negative values ​​indicate bias towards the working side. Unit: mm;

[0049] 2) After steel block F1 bites into steel and before steel block F2 bites into steel, the peak force F2SG on the side guide plates on both sides of F2 is... max Positive values ​​indicate force on the transmission side, and negative values ​​indicate force on the working side. Unit: kN;

[0050] 3) The changes in rolling force deviation on both sides of the tail section of the F5-7 rolling mill after the steel is thrown from the upstream stand (rolling force deviation on both sides = rolling force on the drive side - rolling force on the working side) are Δf5, Δf6, and Δf7, respectively, in kN;

[0051] 4) Maximum value Y of the center offset of the strip tail at the exit of the upper steel finishing mill (10 meters) i-1 Positive values ​​indicate bias towards the transmission side, and negative values ​​indicate bias towards the working side. Unit: mm.

[0052] Step two, the pre-adjustment of this steel block before finishing rolling, is as follows:

[0053] Before this steel piece is fed into the finishing mill, the roll gap deviation of the F1 mill needs to be pre-adjusted according to the shape of the incoming sheet to ensure a smooth strip threading process. The automatic pre-adjustment amount of the F1 roll gap deviation due to changes in the incoming sheet shape is defined as Δg1 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap). The target width of this steel piece is W. i ,but,

[0054]

[0055] Where Δg1 is the automatic pre-adjustment amount for the F1 roll gap deviation due to changes in the shape of the incoming material, |Δg1|≤0.3mm; x i This represents the maximum center offset of the head of the intermediate billet in the final pass of the R2 steel block, measured within 10 meters; x i-1 This represents the maximum center offset of the head of the intermediate billet in the last pass of the upper steel R2 section, measured in 10 meters; W i This is the target width of the steel block.

[0056] The dynamic control before finishing mill F7 threading after step three, F1 threading, is as follows:

[0057] After the F1 strip is rolled out, the F1 roll gap deviation needs to be dynamically controlled based on the strip head shape. The automatic adjustment amount of the F1 roll gap deviation due to the strip head shape is defined as Δg2 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap).

[0058]

[0059] Among them, Δg2 is the amount of automatic adjustment of the F1 roll gap deviation due to the strip head shape of F1 rolled strip, |Δg2|≤0.3mm; F2SG max The peak force on the side guide plates of F2 is measured after F1 bites into the steel block and before F2 bites into the steel block.

[0060] The automatic control of step four, from F7 threading to the finishing mill steel-throwing stage, is as follows:

[0061] After the F7 strip is threaded, the F1 roll gap deviation needs to be automatically controlled based on the shape of the tail section of the upper steel plate. The automatic adjustment amount of the F1 roll gap deviation due to the tail section shape of the upper steel plate is defined as Δg3 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap).

[0062]

[0063] Wherein, Δg3 is the automatic adjustment amount of the roll gap deviation of F1 steel due to the shape of the tail of the upper steel finishing mill, |Δg3|≤0.5mm; Δf5, Δf6, and Δf7 are the changes in the rolling force deviation on both sides of the tail of the upper steel F5-7 mill after the steel is thrown off the upstream stand (rolling force deviation on both sides = rolling force on the drive side - rolling force on the working side); W i β is the target width of this steel block; β is the thickness correction factor, given as follows:

[0064] Target thickness <1.8 mm 1.8 ≤ Target cold thickness ≤ 2.3 Target thickness > 2.3 mm Thickness correction factor β 0.8 1.0 1.2

[0065] When any of the following conditions are met

[0066] 1) When the absolute value of Δf5, Δf6, or Δf7 is less than 1000 kN;

[0067] 2)Y i-1 The absolute value is less than 100mm;

[0068] 3) Δf5, Δf6, Δf7 and Y i-1 Different symbols;

[0069] 4) The signs of Δg1, Δg2, and Δg3 are all the same;

[0070] Set Δg3 to 0.

[0071] Example 2:

[0072] For the rolling of a certain steel coil with a thickness and width specification of 2.0*1100mm, the automatic control process for F1 roll gap deviation is as follows:

[0073] Step 1: Detection and collection of relevant physical quantities of the steel block and the steel block itself.

[0074] The relevant physical quantities were measured as follows:

[0075] (1) The maximum value of the center offset of the head of the intermediate billet of the last pass of the R2 steel block and the previous steel block within 10 meters x i =-20mm, x i-1 = +30mm, a positive value indicates bias towards the transmission side, and a negative value indicates bias towards the working side;

[0076] (2) After the steel block F1 bites into the steel and before F2 bites into the steel, the peak force F2SG on the side guide plates of F2. max = -50KN, a positive value indicates the force on the transmission side, and a negative value indicates the force on the working side.

[0077] (3) The changes in rolling force deviation on both sides of the tail end of the F5-7 rolling mill after the steel is thrown from the upstream stand (rolling force deviation on both sides = rolling force on the transmission side - rolling force on the working side) are Δf5 = 1050KN, Δf6 = 1100KN, and Δf7 = 1200KN, respectively.

[0078] (4) Maximum value of Y, the center offset of the strip tail 10 meters from the outlet of the upper steel finishing mill i-1 =110mm, a positive value indicates bias towards the transmission side, and a negative value indicates bias towards the working side.

[0079] Step 2: Pre-adjustment of this steel block before it is finished and rolled into steel;

[0080] Before this steel piece is fed into the finishing mill, the roll gap deviation of the F1 mill needs to be pre-adjusted according to the shape of the incoming sheet to ensure a smooth strip threading process. The automatic pre-adjustment amount of the F1 roll gap deviation due to changes in the incoming sheet shape is defined as Δg1 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap). Given that the target width of this steel piece is 1100mm, then...

[0081]

[0082] The automatic pre-adjustment amount for the F1 roll gap deviation due to changes in the shape of the incoming material is 0.18mm.

[0083] Step 3: Dynamic control before finishing rolling F7 after F1 threading is completed;

[0084] After the F1 strip is rolled out, the F1 roll gap deviation needs to be dynamically controlled based on the strip head shape. The automatic adjustment amount for the F1 roll gap deviation due to the strip head shape is Δg2 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap), calculated as follows:

[0085]

[0086] That is, the automatic control adjustment of the F1 roll gap deviation is 0.17mm based on the strip head shape of the F1 rolled strip.

[0087] Step 4: Automatic control from F7 threading until the finishing mill's steel ejection stage;

[0088] After the F7 strip is threaded onto the upper steel block, the F1 roll gap deviation needs to be automatically controlled based on the shape of the upper steel block at the tail of the finishing mill. Since the automatic adjustment amount for the F1 roll gap deviation based on the shape of the upper steel block at the tail of the finishing mill is Δg3 (a positive value indicates increasing the drive-side roll gap, and a negative value indicates decreasing the drive-side roll gap), then...

[0089]

[0090] Where |Δg3|≤0.5mm; β is the thickness correction factor, and β is taken as 1.0 according to the table below.

[0091] Target thickness <1.8 mm 1.8 ≤ Target cold thickness ≤ 2.3 Target thickness > 2.3 mm Thickness correction factor β 0.8 1.0 1.1

[0092] Because the following condition (4) is satisfied:

[0093] Condition (1) The absolute value of Δf5, Δf6, or Δf7 is less than 1000 kN, which is not satisfied;

[0094] Condition(2)Y i-1 The absolute value is less than 100mm, which does not meet the requirement;

[0095] Condition (3) Δf5, Δf6, Δf7 and Y i-1 Different symbols, therefore not satisfied.

[0096] Condition (4) Δg1, Δg2, and Δg3 all have the same sign, which is satisfied.

[0097] Then Δg3 needs to be set to 0, that is, the automatic control adjustment amount of F1 roll gap deviation based on the tail shape of the upper steel is 0. This is mainly because Δg1 and Δg2 have both implemented the same direction adjustment of F1 roll gap deviation. At this time, Δg3 does not need to be superimposed and can also meet the automatic control of the tail shape of this steel.

[0098] Example 3:

[0099] For the rolling of a certain steel coil with a thickness and width specification of 3.0*1200mm, the automatic control process for F1 roll gap deviation is as follows:

[0100] Step 1: Detection and collection of relevant physical quantities of the steel block and this steel block.

[0101] The relevant physical quantities were measured as follows:

[0102] (1) The maximum value of the center offset of the head of the intermediate billet of the last pass of the R2 steel block and the previous steel block within 10 meters x i =+40mm, x i-1 = -20mm, a positive value indicates bias towards the transmission side, and a negative value indicates bias towards the working side;

[0103] (2) After the steel block F1 bites into the steel and before F2 bites into the steel, the peak force F2SG on the side guide plates of F2. max = -70KN, a positive value indicates the force on the transmission side, and a negative value indicates the force on the working side.

[0104] (3) The changes in rolling force deviation on both sides of the tail end of the F5-7 rolling mill after the steel is thrown on the upstream stand (rolling force deviation on both sides = rolling force on the transmission side - rolling force on the working side) are Δf5 = 1200KN, Δf6 = 1300KN, and Δf7 = 1250KN, respectively.

[0105] (4) Maximum value of Y, the center offset of the strip tail 10 meters from the outlet of the upper steel finishing mill i-1 =80mm, a positive value indicates bias towards the transmission side, and a negative value indicates bias towards the working side.

[0106] Step 2: Pre-adjustment of this steel block before it is finished and rolled.

[0107] Before this steel piece is fed into the finishing mill, the roll gap deviation of the F1 mill needs to be pre-adjusted according to the shape of the incoming sheet to ensure a smooth strip threading process. The automatic pre-adjustment amount of the F1 roll gap deviation due to changes in the incoming sheet shape is defined as Δg1 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap). Given that the target width of this steel piece is 1200mm, then...

[0108]

[0109] The automatic pre-adjustment amount for the F1 roll gap deviation due to changes in the shape of the incoming material is -0.25mm.

[0110] Step 3: Dynamic control before finishing mill F7 threading after F1 threading is completed.

[0111] After the F1 strip is rolled out, the F1 roll gap deviation needs to be dynamically controlled based on the strip head shape. The automatic adjustment amount for the F1 roll gap deviation due to the strip head shape is Δg2 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap), calculated as follows:

[0112]

[0113] That is, the automatic control adjustment of the F1 roll gap deviation is 0.20mm based on the strip head shape of the F1 rolled strip.

[0114] Step four, automatic control from F7 threading until the finishing mill's steel discarding stage.

[0115] After the F7 strip is threaded onto the upper steel block, the F1 roll gap deviation needs to be automatically controlled based on the shape of the upper steel block at the tail of the finishing mill. Since the automatic adjustment amount for the F1 roll gap deviation based on the shape of the upper steel block at the tail of the finishing mill is Δg3 (a positive value indicates increasing the drive-side roll gap, and a negative value indicates decreasing the drive-side roll gap), then...

[0116]

[0117] Where |Δg3|≤0.5mm; β is the thickness correction factor, and β is taken as 1.0 according to the table below.

[0118] Target thickness <1.8 mm 1.8 ≤ Target cold thickness ≤ 2.3 Target thickness > 2.3 mm Thickness correction factor β 0.8 1.0 1.1

[0119] Because the following condition (2) is satisfied:

[0120] Condition (1) The absolute value of Δf5, Δf6, or Δf7 is less than 1000 kN, which is not satisfied;

[0121] Condition(2)Y i-1 The absolute value is less than 100mm, which satisfies the condition;

[0122] Condition (3) Δf5, Δf6, Δf7 and Y i-1 Different symbols, therefore not satisfied.

[0123] Condition (4) Δg1, Δg2, and Δg3 all have the same sign, which is satisfied.

[0124] Then Δg3 needs to be set to 0, that is, the automatic control adjustment of the F1 roll gap deviation is 0 based on the shape of the upper strip tail of the finishing mill. This is mainly because the tail of the upper strip is only 80mm off at the center of the finishing mill exit, which does not completely match the degree of pressure difference change at the tail of F5-7. To avoid incorrect adjustment, Δg3 does not need to be adjusted at this time.

[0125] Example 4:

[0126] For the rolling of a certain steel coil with a thickness * width specification of 2.5 * 1000 mm, the automatic control process for F1 roll gap deviation is as follows:

[0127] Step 1: Detection and collection of relevant physical quantities of the steel block and this steel block.

[0128] The relevant physical quantities were measured as follows:

[0129] (1) The maximum value of the center offset of the head of the intermediate billet of the last pass of the R2 steel block and the previous steel block within 10 meters x i =-40mm, x i-1 = +20mm, a positive value indicates bias towards the transmission side, and a negative value indicates bias towards the working side;

[0130] (2) After the steel block F1 bites into the steel and before F2 bites into the steel, the peak force F2SG on the side guide plates of F2. max = -30KN, a positive value indicates the force on the transmission side, and a negative value indicates the force on the working side.

[0131] (3) The changes in rolling force deviation on both sides of the tail end of the F5-7 rolling mill after the steel is thrown out of the upstream stand (rolling force deviation on both sides = rolling force on the transmission side - rolling force on the working side) are Δf5 = -700KN, Δf6 = -800KN, and Δf7 = -600KN, respectively.

[0132] (4) Maximum value of Y, the center offset of the strip tail 10 meters from the outlet of the upper steel finishing mill i-1 = -60mm, a positive value indicates bias towards the transmission side, and a negative value indicates bias towards the working side.

[0133] Step 2: Pre-adjustment of this steel block before it is finished and rolled.

[0134] Before this steel piece is fed into the finishing mill, the roll gap deviation of the F1 mill needs to be pre-adjusted according to the shape of the incoming sheet to ensure a smooth strip threading process. The automatic pre-adjustment amount of the F1 roll gap deviation due to changes in the incoming sheet shape is defined as Δg1 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap). Given that the target width of this steel piece is 1100mm, then...

[0135]

[0136] The automatic pre-adjustment amount for the F1 roll gap deviation due to changes in the shape of the incoming material is 0.24mm.

[0137] Step 3: Dynamic control before finishing mill F7 threading after F1 threading is completed.

[0138] After the F1 strip is rolled out, the F1 roll gap deviation needs to be dynamically controlled based on the strip head shape. The automatic adjustment amount for the F1 roll gap deviation due to the strip head shape is Δg2 (a positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap), calculated as follows:

[0139]

[0140] That is, the automatic control adjustment of the F1 roll gap deviation is 0.13mm based on the strip head shape of the F1 rolled strip.

[0141] Step four, automatic control from F7 threading until the finishing mill's steel discarding stage.

[0142] After the F7 strip is threaded onto the upper steel block, the F1 roll gap deviation needs to be automatically controlled based on the shape of the upper steel block at the tail of the finishing mill. Since the automatic adjustment amount for the F1 roll gap deviation based on the shape of the upper steel block at the tail of the finishing mill is Δg3 (a positive value indicates increasing the drive-side roll gap, and a negative value indicates decreasing the drive-side roll gap), then...

[0143]

[0144] Where |Δg3|≤0.5mm; β is the thickness correction factor, and β is taken as 1.0 according to the table below.

[0145] Target thickness <1.8 mm 1.8 ≤ Target cold thickness ≤ 2.3 Target thickness > 2.3 mm Thickness correction factor β 0.8 1.0 1.1

[0146] Because the following conditions (1) and (2) are satisfied:

[0147] Condition (1) The absolute value of Δf5, Δf6, or Δf7 is less than 1000 kN, which is satisfied;

[0148] Condition(2)Y i-1 The absolute value is less than 100mm, which satisfies the condition;

[0149] Condition (3) Δf5, Δf6, Δf7 and Y i-1 Different symbols, therefore not satisfied.

[0150] Condition (4) Δg1, Δg2, and Δg3 all have the same sign, which is not satisfied.

[0151] Then Δg3 needs to be set to 0, that is, the automatic control adjustment of the F1 roll gap deviation is 0 based on the shape of the tail of the upper strip. This is mainly because the tail pressure difference of F5-7 is small, and the tail of the upper strip is only offset by -60mm at the center of the finishing mill exit. At this time, Δg3 does not need to be adjusted, and the automatic control of the tail shape of this strip can be met.

[0152] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for online automatic control of roll gap deviation on a finishing mill F1 stand, characterized in that, The method includes the following steps: Step 1: Detection and collection of relevant physical quantities of the steel block and this steel block; Step 2: Pre-adjustment of this steel block before it is finished and rolled into steel; Step 3: Dynamic control before finishing rolling F7 after F1 threading is completed; Step 4: Automatic control from F7 threading until the finishing mill's steel ejection stage; The specific steps of step one, the detection and collection of relevant physical quantities of the upper steel block and the steel block itself, are as follows: 1) Maximum center offset of the head of the intermediate billet in the last pass of the R2 steel block (both the original and the previous blocks) within 10 meters. , Positive values ​​indicate bias towards the transmission side, and negative values ​​indicate bias towards the working side. Unit: mm; 2) After steel block F1 bites into steel and before steel block F2 bites into steel, the peak force F2SG on the side guide plates on both sides of F2 is... max Positive values ​​indicate force on the transmission side, and negative values ​​indicate force on the working side. Unit: kN; 3) The changes in rolling force deviation on both sides of the tail section after the F5-7 rolling mill throws the steel from the upstream stand are Δf5, Δf6, and Δf7, respectively, in kN; the rolling force deviation on both sides = rolling force on the drive side - rolling force on the working side. 4) Maximum center offset of the strip tail at the exit of the upper steel finishing mill (10 meters) Positive values ​​indicate bias towards the transmission side, and negative values ​​indicate bias towards the working side. Unit: mm; Step 2: Pre-adjustment of this steel block before finishing rolling, as follows: Before this steel piece is fed into the finishing mill, the roll gap deviation of the F1 mill needs to be pre-adjusted according to the shape of the incoming sheet to ensure a smooth strip threading process. The automatic pre-adjustment amount of the F1 roll gap deviation due to changes in the incoming sheet shape is defined as Δg1. A positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap. The target width of this steel piece is W. i ,but, Wherein, Δg1 is the automatic pre-adjustment amount of the F1 roll gap deviation due to the change in the shape of the incoming material, |Δg1|≤0.3mm; This represents the maximum center offset of the head of the intermediate billet in the last pass of the R2 steel block, within 10 meters. This represents the maximum center offset of the head of the intermediate billet in the last pass of the upper steel R2 section, measured in 10 meters; W i This is the target width of the steel block; Step 3: After F1 threading is completed, the dynamic control before finishing mill F7 threading is as follows: After the F1 strip is rolled out, the F1 roll gap deviation needs to be dynamically controlled based on the strip head shape. The automatic adjustment amount of the F1 roll gap deviation due to the strip head shape is defined as Δg2. A positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap. Among them, Δg2 is the amount of automatic adjustment of the F1 roll gap deviation due to the strip head shape of F1 rolled strip, |Δg2|≤0.3mm; F2SG max This represents the peak force on the side guide plates of F2 after F1 bites into the steel block and before F2 bites into the steel block. Step 4, the automatic control from F7 threading until the finishing mill's steel ejection stage, is as follows: After the F7 strip is threaded, the F1 roll gap deviation needs to be automatically controlled based on the tail shape of the upper steel strip. The automatic adjustment amount of the F1 roll gap deviation due to the tail shape of the upper steel strip is defined as Δg3. A positive value indicates an increase in the drive-side roll gap, and a negative value indicates a decrease in the drive-side roll gap. Wherein, Δg3 is the automatic adjustment amount of the roll gap deviation of F1 of this steel due to the shape of the tail of the upper steel finishing mill, |Δg3|≤0.5mm; Δf5, Δf6, and Δf7 are the changes in rolling force deviation on both sides of the tail of the upper steel F5-7 mill after the steel is thrown out of the upstream stand, and the rolling force deviation on both sides = rolling force on the drive side - rolling force on the working side; W i β represents the target width of this steel block; β is the thickness correction factor, given as follows: When any of the following conditions are met 1) When the absolute value of Δf5, Δf6, or Δf7 is less than 1000 kN; 2) The absolute value is less than 100mm; 3) Δf5, Δf6, Δf7 and Different symbols; 4) The signs of Δg1, Δg2, and Δg3 are all the same; Set Δg3 to 0.

Images