A method for determining the first coil leveling value after finishing roll change

Abstract

The present invention relates to a method for determining the leveling value of the first roll after a finishing roll change, by recording the working rolls rolled during roll change calibration, calibration time, corresponding support rolls, deviations on both sides of the calibrated rolling force, deviations on both sides of the magnetic scale, leveling set values, leveling values ​​before finishing roll bite, leveling values ​​when strip threading is completed, standard leveling values, number of lower step pads, number of upper step pads, standard leveling values ​​before roll change, and other information, and calculating the leveling value of the first roll after the roll change based on the roll calibration data, while recording the amount of intervention of the operator on the leveling value of each frame before and after strip threading, and updating it to the roll calibration record for calculation of the leveling value after the next roll change. The present invention effectively solves the problem of unreasonable leveling values ​​given by operators in the prior art, thereby reducing the risk of head deviation and steel piling during the rolling of the first roll after the roll change, improving rolling stability, and having wide practicality and broad application prospects.

Description

Technical Field

[0001] This patent application belongs to the field of hot rolling mill automation technology in the metallurgical industry, and more specifically, it relates to a method for determining the leveling value of the first coil after finishing roll change. Background Art

[0002] During hot rolling production, the working rolls and backup rolls of the finishing mill will wear and deform after long-term use, affecting product quality and production efficiency. To ensure the surface quality and geometric dimensional control accuracy of the hot-rolled strip, the working rolls and backup rolls need to be replaced after a certain amount of strip is produced. Generally, after replacing the backup rolls, the working rolls also need to be replaced simultaneously. Under normal production rhythms, the working rolls are replaced approximately 8-12 times per day. After the roll change is completed, due to changes in factors such as roll diameter, material, roll shape, assembly, and thermal crown, it is difficult to determine the roll gap leveling value for the first roll after the roll change. In the existing technology, the leveling value is generally set manually based on experience. If the leveling value setting deviation is large, it will cause adverse conditions such as strip deviation and loss of straightness, posing a significant risk to production stability and product quality.

[0003] Patent CN103252350B discloses a leveling method for a finishing mill after roll replacement. By recording information such as the rolling force deviation and oil column deviation on both sides of the working roll during the upper roll period, the rolling force deviation on both sides is adjusted to the static deviation threshold range during the downward pressure. The downward pressure is continued and the rolling force deviation and oil column deviation after the roll gap is zeroed are recorded. The adjustment amount is calculated using the equivalent adjustment formula to make the roll gap in an equivalent parallel state.

[0004] Patent CN111922090A discloses a method and system for automatically setting the level value after replacing the working roll of a finishing mill. By obtaining the level value of the previous roll period and the level value during roll change calibration, the preset level value is calculated, avoiding the problem of manual adjustment of the working roll level value by the operator.

[0005] Patent CN111922094A discloses a method, system, equipment and medium for giving the starting rolling level value, which obtains the deviation value and level value of the rolling force of the rolling mill in the previous rolling cycle and the rolling force deviation value of the current rolling period. Based on the preset formula and the rolling characteristic coefficient, the starting rolling level value of the current cycle is obtained, thereby improving the stability and accuracy of the starting rolling after the roll change.

[0006] The above technologies all give reference values ​​or set values ​​for the first roll leveling value after roll replacement, but none of them fully consider the differences in parameters such as working rolls, support rolls, step pads, and the situation when the support rolls are replaced at the same time. To a certain extent, they cannot meet the complex on-site conditions. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for determining the leveling value of the first coil after finishing roll change, which solves the problem of unreasonable leveling value manually given by the operator in the prior art, thereby reducing the risk of head deviation and steel piling during rolling of the first coil after roll change, and improving rolling stability.

[0008] In order to solve the above problems, the technical solution adopted by the present invention is:

[0009] A method for determining the first coil leveling value after finishing roll change is applied to a hot rolling finishing mill using a four-high rolling mill, the method comprising the following steps:

[0010] S101, after each roll change, recording roll calibration related information as roll change calibration into a database;

[0011] S102: When the roller change is completed, calculate the leveling setting value A;

[0012] S103. When the first coil is produced after the roll change, the leveling value B before the finishing strip threading and the leveling value C when the strip threading is completed are recorded, the standard leveling value S is calculated, and updated in the roll change calibration record.

[0013] Furthermore, in S101, the roll calibration related information is recorded according to the working roll ID as the primary key. For any working roll, the roll calibration related information includes the calibration time, the corresponding support roll ID, the calibration rolling force deviation F on both sides, and the calibration time. diff , Deviation H on both sides of the magnetic scale diff , leveling setting value A, leveling value before finishing strip threading B, leveling value when finishing strip threading is completed C, standard leveling value S, number of lower step pads Bs, number of upper step pads Ts, number of lower step pads before roll change Bs pre , Number of steps before roller change Ts pre , Standard leveling value S before roller change pre ;

[0014] Furthermore, the deviation F on both sides of the calibrated rolling force diff The rolling force on the operating side minus the rolling force on the driving side when calibration is completed;

[0015] Furthermore, the deviation H on both sides of the magnetic scale diff The magnetic scale measurement value on the operating side minus the magnetic scale measurement value on the driving side when calibration is completed;

[0016] Furthermore, the leveling setting value A is determined by the method of the present invention, has an initial value of 0, and is updated after the calculation is completed in step S102;

[0017] Furthermore, the leveling value B before finishing strip threading is the actual leveling value of each stand before the strip enters the finishing mill group during the first coil production after roll change. The initial value is set to 0 when calibration is completed and is updated in step S103.

[0018] Furthermore, the leveling value C is the leveling value when strip threading is complete and stable. Specifically, when the strip head reaches the middle position of the cold roller at the finishing exit, the current leveling value is recorded and recorded as leveling value C. When the strip head reaches the middle position of the cold roller, threading is completed. The operator completes the leveling intervention of each stand based on the actual threading situation, and the strip rolling process reaches a stable state. When calibration is completed, the initial value is set to 0 and updated in step S103.

[0019] Furthermore, the standard leveling value S is determined based on the leveling value C and the deviation F of the rolling force on both sides. diff and the theoretical stiffness S of the rolling mill t The calculation shows that the initial value is set to 0 when the calibration is completed and updated in step S103, where the theoretical stiffness of the rolling mill S t It is an important parameter that describes the rolling mill's ability to resist deformation when subjected to external loads and is a rolling mill constant.

[0020] Furthermore, the Bs pre The number of steps before roller change. If there is no record before roller change, Bs pre =0;

[0021] Furthermore, the Ts pre The number of steps before roller change. If there is no record before roller change, Ts pre =0;

[0022] Furthermore, in S102, the leveling value A calculated when the roller replacement is completed needs to be calculated based on whether the support roller is replaced or not;

[0023] If the support roll is to be replaced, the calibration record of the most recent roll change is retrieved in the database according to the work roll ID. If the record is found,

[0024]

[0025] Wherein, a is the correction coefficient, and its value range is [0.2, 0.8];

[0026] S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0027] F diff (cur) is the rolling force deviation of this roll change calibration;

[0028] S t is the theoretical stiffness of the rolling mill, a constant term.

[0029] If no record is retrieved, it means that the working roll is a new roll, then the calibration record of the most recent roll change is retrieved. If no record is retrieved, A=0, otherwise,

[0030]

[0031] Wherein, b is the correction coefficient, and its value range is [0.2, 0.8];

[0032] S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0033] F diff (cur) is the rolling force deviation of this roll change calibration;

[0034] S t is the theoretical stiffness of the roller.

[0035] If the support roller is not replaced, then A=A1+A2+A3,

[0036] Further, calculate A1, and search the calibration record of the most recent roll change completed within N days according to the support roll ID and work roll ID. If there is one, then

[0037]

[0038] If not, continue to search for the calibration record of the most recent roller change. If not, then A1=0. If yes, then

[0039]

[0040] Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0041] F diff (cur) is the rolling force deviation of this roll change calibration;

[0042] S t is the theoretical stiffness of the rolling mill, a constant term;

[0043] H diff (cur) is the magnetic scale deviation of this roller change;

[0044] H diff (old) is the magnetic scale deviation in the retrieved roller change record.

[0045] Further, calculate A2, based on the number of lower step pads Bs of this roll change and the number of lower step pads Bs before roll change pre Compare, if the same, then A2 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Bs, this step pad number Ts, the step pad number Bs before the roll change pre , search for the latest roller change calibration record within M days, if there is no record, then A2=0, otherwise

[0046] A2=S(old)-Spre (old)

[0047] Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0048] S pre (old) is the standard leveling value before roller change in the retrieved roller change calibration record.

[0049] Further, calculate A3, based on the number of upper steps Ts of the roller change and the number of upper steps Ts before the roller change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Ts, this step pad number Bs, the step pad number Ts before the roll change pre , search for the latest roller change calibration record within M days, if there is no record, then A3=0, otherwise

[0050] A3=S(old)-S pre (old)

[0051] Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0052] S pre (old) is the standard leveling value before roller change in the retrieved roller change calibration record.

[0053] The value range of M is [1,10], preferably, M=5.

[0054] Output the leveling set value A to the rolling mill for execution.

[0055] Furthermore, in S103, the leveling value B before finishing strip threading is the leveling value actually used by the first coil after the roll change. Specifically, when the strip head enters the descaling machine before finishing rolling, the current leveling value is recorded and recorded as the leveling value B.

[0056] B=A+m1

[0057] Among them, m1 is the manual intervention of the operation before finishing rolling and threading.

[0058] Furthermore, the leveling value C is the leveling value when the strip threading is completed and reaches stability. Specifically, when the strip head reaches the middle position of the cold roller at the finishing exit layer, the current leveling value is recorded and recorded as the leveling value C.

[0059] C=B+m2

[0060] Among them, m2 is the leveling intervention amount given by the operator according to the actual situation during the strip threading process. When the strip head reaches the middle position of the layer cold roller, the strip threading is completed. The operator completes the leveling intervention of each frame according to the actual threading situation. The strip rolling process reaches a stable state and the rolling mill leveling is completed. Therefore, the actual leveling value C at this time is recorded.

[0061] Furthermore, the standard leveling value S is calculated, and the deviation F of the rolling force on both sides is calculated based on the leveling value C. diff and the theoretical stiffness S of the rolling mill t Calculated, specifically

[0062]

[0063] Furthermore, the leveling value B before finishing strip threading, the leveling value C when the strip threading is completed and reaches stability, and the calculated standard leveling value S are updated to the roll change calibration record.

[0064] Due to the adoption of the above technical solution, the beneficial effects achieved by the present invention are:

[0065] The present invention relates to a method for determining the leveling value of the first coil after a finishing roll change. The method records information such as the ID of the working roll rolled during roll change calibration, the calibration time, the ID of the corresponding support roll, the deviation on both sides of the calibrated rolling force, the deviation on both sides of the magnetic scale, the leveling setting value, the leveling value before finishing roll biting, the leveling value when strip threading is completed, the standard leveling value, the number of lower step pads, the number of upper step pads, and the standard leveling value before roll change. The method calculates the leveling value of the first coil after the roll change based on the roll calibration data, and simultaneously records the amount of intervention of the operator on the leveling value of each frame before and after strip threading is completed, and updates the amount of intervention to the roll calibration record for use in the calculation of the leveling value after the next roll change.

[0066] The method for determining the first coil leveling value after a roll change, provided by the present invention, fully considers the matching relationship between the work rolls, backup rolls, and step pads, the rolling force deviation on both sides during calibration, magnetic scale deviation, mill stiffness, and the operator's intervention in mill leveling. It calculates the leveling value suitable for stable rolling after a roll change for each stand, effectively resolving the problem of unreasonable operator-defined leveling values ​​in the prior art. This method reduces the risk of head deviation and steel accumulation during the first coil rolling after a roll change, thereby improving rolling stability. The present invention has broad practicality and promising application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 A flow chart of a method for determining the first coil leveling value after finishing roll change provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0068] The present invention is further described in detail below with reference to the embodiments.

[0069] The present invention is described clearly and completely below in conjunction with the accompanying drawings so that those skilled in the art can fully implement the present invention without making any creative work.

[0070] See also Figure 1 The embodiment of the present invention provides a method for determining the first coil leveling value after finishing roll change, comprising the following steps:

[0071] S101. After each roll change, the roll calibration related information is recorded in the database as roll change calibration.

[0072] Among them, the roll calibration related information is recorded according to the working roll ID as the main key. For any working roll, the roll calibration related information includes the calibration time, the corresponding support roll ID, the deviation F on both sides of the calibration rolling force, and the calibration time. diff , Deviation H on both sides of the magnetic scale diff , leveling setting value A, leveling value before finishing strip threading B, leveling value when finishing strip threading is completed C, standard leveling value S, number of lower step pads Bs, number of upper step pads Ts, number of lower step pads before roll change Bs pre , Number of steps before roller change Ts pre , Standard leveling value S before roller change pre ;

[0073] Furthermore, the deviation F on both sides of the calibrated rolling force diff The rolling force on the operating side minus the rolling force on the driving side when calibration is completed;

[0074] Furthermore, the deviation H on both sides of the magnetic scale diff The magnetic scale measurement value on the operating side minus the magnetic scale measurement value on the driving side when calibration is completed;

[0075] Furthermore, the leveling setting value A is determined by the method of the present invention, has an initial value of 0, and is updated after the calculation in step S102 is completed;

[0076] Furthermore, the leveling value B before finishing strip threading is the actual leveling value of each stand before the strip enters the finishing mill group during the first coil production after roll change. The initial value is set to 0 when calibration is completed and is updated in step S103.

[0077] Furthermore, the leveling value C at the completion of strip threading is the leveling value when strip threading is complete and reaches stability. Specifically, when the strip head reaches the middle position of the cold roller at the finishing exit layer, the current leveling value is recorded and recorded as leveling value C. When the strip head reaches the middle position of the cold roller, the strip threading is completed. The operator completes the leveling intervention of each stand based on the actual strip threading situation, and the strip rolling process reaches a stable state. When calibration is completed, the initial value is set to 0 and updated in step S103.

[0078] Furthermore, the standard leveling value S is determined based on the leveling value C and the deviation F on both sides of the calibrated rolling force. diff and the theoretical stiffness S of the rolling mill t The calculation shows that the initial value is set to 0 when the calibration is completed and updated in step S103, where the theoretical stiffness of the rolling mill S t It is an important parameter that describes the rolling mill's ability to resist deformation when subjected to external loads and is a rolling mill constant.

[0079] Furthermore, the Bs pre The number of steps before roller change. If there is no record before roller change, Bs pre =0;

[0080] Furthermore, the Ts pre The number of steps before roller change. If there is no record before roller change, Ts pre =0;

[0081] S102: When the roller change is completed, the leveling setting value A is calculated.

[0082] The leveling setting value A calculated when the roller replacement is completed needs to be calculated based on whether the support roller is replaced or not;

[0083] If the support roll is to be replaced, the calibration record of the most recent roll change is retrieved in the database according to the work roll ID. If the record is found,

[0084]

[0085] Wherein, a is the correction coefficient, and its value range is [0.2, 0.8];

[0086] S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0087] F diff (cur) is the rolling force deviation of this roll change calibration;

[0088] S t is the theoretical stiffness of the rolling mill, a constant term.

[0089] If no record is retrieved, it means that the working roll is a new roll, then the calibration record of the most recent roll change is retrieved. If no record is retrieved, A=0, otherwise,

[0090]

[0091] Wherein, b is the correction coefficient, and its value range is [0.2, 0.8];

[0092] S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0093] F diff (cur) is the rolling force deviation of this roll change calibration;

[0094] S t is the theoretical stiffness of the rolling mill, a constant term.

[0095] If the support roller is not replaced, then A=A1+A2+A3,

[0096] Further, calculate A1, and search the calibration record of the most recent roll change completed within N days according to the support roll ID and work roll ID. If there is one, then

[0097]

[0098] H diff (cur) is the magnetic scale deviation of this roller change;

[0099] H diff (old) is the magnetic scale deviation in the retrieved roller change record.

[0100] If not, continue to search for the calibration record of the most recent roller change. If not, then A1=0. If yes, then

[0101]

[0102] Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0103] F diff (cur) is the rolling force deviation of this roll change calibration;

[0104] S t is the theoretical stiffness of the rolling mill, a constant term;

[0105] H diff (cur) is the magnetic scale deviation of this roller change;

[0106] H diff (old) is the magnetic scale deviation in the retrieved roller change record.

[0107] Further, calculate A2, based on the number of lower step pads Bs of this roll change and the number of lower step pads Bs before roll change pre Compare, if the same, then A2 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Bs, this step pad number Ts, the step pad number Bs before the roll change pre , search for the latest roller change calibration record within M days, if there is no record, then A2=0, otherwise

[0108] A2=S(old)-S pre (old)

[0109] Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0110] S pre (old) is the standard leveling value before roller change in the retrieved roller change calibration record.

[0111] Further, calculate A3, based on the number of upper steps Ts of the roller change and the number of upper steps Ts before the roller change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Ts, this step pad number Bs, the step pad number Ts before the roll change pre , search for the latest roller change calibration record within M days, if there is no record, then A3=0, otherwise

[0112] A3=S(old)-S pre (old)

[0113] Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record;

[0114] S pre (old) is the standard leveling value before roller change in the retrieved roller change calibration record.

[0115] The value range of M is [1,10], preferably, M=5.

[0116] Output the leveling set value A to the rolling mill for execution.

[0117] Furthermore, in S103, the leveling value B before finishing strip threading is the leveling value actually used by the first coil after the roll change. Specifically, when the strip head enters the descaling machine before finishing rolling, the current leveling value is recorded and recorded as the leveling value B before finishing strip threading.

[0118] B=A+m1

[0119] Among them, m1 is the manual intervention of the operation before finishing rolling and threading.

[0120] Furthermore, the leveling value C when the strip threading is completed is the leveling value when the strip threading is completed and reaches stability. Specifically, when the strip head reaches the middle position of the cold roller table at the finishing rolling exit layer, the current leveling value is recorded and recorded as the leveling value C when the strip threading is completed.

[0121] C=B+m2

[0122] Among them, m2 is the leveling intervention amount given by the operator according to the actual situation during the strip threading process. When the strip head reaches the middle position of the layer cold roller, the threading is completed. The operator completes the leveling intervention of each frame according to the actual threading situation. The strip rolling process reaches a stable state and the rolling mill leveling is completed. Therefore, the leveling value C when the finishing rolling threading is completed under the actual situation at this time is recorded.

[0123] Furthermore, the standard leveling value S is calculated based on the leveling value C when the finishing strip is completed and the deviation F on both sides of the calibrated rolling force. diff and the theoretical stiffness S of the rolling mill t Calculated, specifically

[0124]

[0125] Furthermore, the leveling value B before finishing strip threading, the leveling value C when the strip threading is completed and reaches stability, and the calculated standard leveling value S are updated to the roll change calibration record.

[0126] The present invention relates to a method for determining the leveling value of the first coil after a finishing roll change. The method records information such as the ID of the working roll rolled during roll change calibration, the calibration time, the ID of the corresponding support roll, the deviation on both sides of the calibrated rolling force, the deviation on both sides of the magnetic scale, the leveling setting value, the leveling value before finishing strip threading, the leveling value when finishing strip threading is completed, the standard leveling value, the number of lower step pads, the number of upper step pads, and the standard leveling value before roll change. The method calculates the leveling value of the first coil after the roll change based on the roll calibration data, and simultaneously records the intervention amount of the operator on the leveling value of each frame before and after the strip threading is completed, and updates the information to the roll calibration record for use in calculating the leveling value after the next roll change.

[0127] The method for determining the first coil leveling value after a roll change, provided by the present invention, fully considers the matching relationship between the work rolls, backup rolls, and step pads, the rolling force deviation on both sides during calibration, magnetic scale deviation, mill stiffness, and the operator's intervention in mill leveling. It calculates the leveling value suitable for stable rolling after a roll change for each stand, effectively resolving the problem of unreasonable operator-defined leveling values ​​in the prior art. This method reduces the risk of head deviation and steel accumulation during the first coil rolling after a roll change, thereby improving rolling stability. The present invention has broad practicality and promising application prospects.

[0128] The technical solution of this embodiment is further illustrated below by a typical application example: a hot rolling production line includes seven four-high finishing mills, denoted as F1-F7. Each finishing mill includes a backup roll and a work roll. The theoretical stiffness of F1-F7 is:

[0129]

[0130] During a roll change, the work roll of F7 was replaced. After the calibration was completed, the roll calibration related information was recorded in the database as roll change calibration record 1, including:

[0131]

[0132]

[0133] Next, calculate the leveling setpoint A;

[0134] First, determine whether to replace the support roller. The number of rolling blocks of the current support roller YZFB016 = 689 > 0. Therefore, the support roller is not replaced. At this time, A = A1 + A2 + A3.

[0135] Further, calculation A1 is performed, and the most recent roll change calibration completion record within N days is retrieved according to the support roll ID YZFB016 and the work roll ID XTFG044. Preferably, N=2. The retrieved roll change calibration record 2 is:

[0136] Roll calibration information value Work roll ID XTFG044 Calibration time 2024-03-14 16:21:10 Support roller ID YZFB016 <![CDATA[Calibrate the deviation of rolling force on both sides F diff > 143.1KN <![CDATA[Magnetic scale bilateral deviation H diff > 0.79mm Leveling setting value A 0.115mm Leveling value B before finishing strip threading 0.115mm Leveling value C when finishing strip threading is completed 0.121mm Standard leveling value S 0.107mm Number of lower step pads Bs for this roller change 3 The number of upper steps for this roller change Ts 5 <![CDATA[Number of lower stepped pads Bs before roll change pre > 3 <![CDATA[Number of upper stepped pads Ts before roll change pre > 4 <![CDATA[Standard leveling value S before roll change pre > 0.151mm

[0137] therefore,

[0138]

[0139] Further, calculate A2, based on the number of lower step pads Bs of this roll change and the number of lower step pads Bs before roll change pre Compare, if the same, then A2 = 0, otherwise based on the support roll ID, work roll ID, this step pad number Bs, this step pad number Ts, the step pad number Bs before the roll change pre , retrieve the latest roller change calibration record within M days, preferably M=5, if not, then A2=0, otherwise

[0140] A2=S(old)-S pre (old)

[0141] Since the number of lower steps for this roll change is Bs=3, the number of lower steps before the roll change is Bs pre =3, so A2=0;

[0142] Further, calculate A3, based on the number of upper steps Ts of the roller change and the number of upper steps Ts before the roller change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Ts, this step pad number Bs, the step pad number Ts before the roll change pre , retrieve the latest roller change calibration record within M days, preferably M=5, if not, then A3=0, otherwise

[0143] A3=S(old)-S pre (old)

[0144] Since the number of upper steps for this roll change is Ts=5, the number of upper steps before the roll change is Ts pre =4, so based on the support roll ID, work roll ID, the number of steps Ts this time, the number of steps Bs this time, the number of steps Ts before changing the roll pre , search for the latest roller change calibration record within 5 days, and retrieve roller change calibration record 3:

[0145]

[0146]

[0147] therefore,

[0148] A3=S(old)-S pre (old)=0.107-0.151=-0.044mm

[0149] Therefore, A = A1 + A2 + A3 = 0.1244 + 0 + (-0.044) = 0.12 mm

[0150] Update A=0.12mm to the roll change calibration record 1 and use it as the leveling value of the F7 stand when the first coil is rolled after the roll change.

[0151] Furthermore, when the first roll of strip steel is produced after the roll change is completed, the current leveling value of F7 is recorded when the strip head enters the descaling machine before finishing rolling, and is recorded as the leveling value B before finishing rolling and threading. B=0.12mm, B=A+m1. Since A=0.12mm, m1=0, indicating that no manual intervention was performed in the operation before finishing rolling and threading.

[0152] Furthermore, when the strip head reaches the middle position of the cold roller at the finishing exit layer, the current leveling value is recorded and recorded as the leveling value C when the finishing strip threading is completed, C = 0.235mm, C = B + m2, since B = 0.12mm, therefore m2 = 0.235-0.12 = 0.115mm, indicating that during the strip threading process, the operator performed a leveling intervention of 0.115mm according to the actual situation.

[0153] Furthermore, the standard leveling value S is calculated based on the leveling value C when the finishing strip is completed and the deviation F on both sides of the calibrated rolling force. diff and the theoretical stiffness S of the rolling mill t [Same as above] Calculated, specifically

[0154]

[0155] Finally, the leveling value B=0.12mm before finishing strip threading, the leveling value C=0.235mm when the strip threading is completed when stability is reached, and the calculated standard leveling value S=0.1876mm are updated to the roll change calibration record 1.

[0156] The present invention relates to a method for determining the leveling value of the first coil after a finishing roll change. The method records information such as the ID of the working roll rolled during roll change calibration, the calibration time, the ID of the corresponding support roll, the deviation on both sides of the calibrated rolling force, the deviation on both sides of the magnetic scale, the leveling setting value, the leveling value before finishing roll biting, the leveling value when strip threading is completed, the standard leveling value, the number of lower step pads, the number of upper step pads, and the standard leveling value before roll change. The method calculates the leveling value of the first coil after the roll change based on the roll calibration data, and simultaneously records the amount of intervention of the operator on the leveling value of each frame before and after strip threading is completed, and updates the amount of intervention to the roll calibration record for use in the calculation of the leveling value after the next roll change.

[0157] The method for determining the first coil leveling value after a roll change, provided by the present invention, fully considers the matching relationship between the work rolls, backup rolls, and step pads, the rolling force deviation on both sides during calibration, magnetic scale deviation, mill stiffness, and the operator's intervention in mill leveling. It calculates the leveling value suitable for stable rolling after a roll change for each stand, effectively resolving the problem of unreasonable operator-defined leveling values ​​in the prior art. This method reduces the risk of head deviation and steel accumulation during the first coil rolling after a roll change, thereby improving rolling stability. The present invention has broad practicality and promising application prospects.

[0158] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0159] The above describes the preferred embodiments of the present invention. It should be pointed out that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures not described in detail should be understood to be implemented in a common manner in the art; any simple modifications, equivalent changes and modifications made to the above embodiments by any technician familiar with the art based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A method for determining the first coil leveling value after finishing roll change, characterized in that The following steps are involved: S101, after each roll change, recording roll calibration related information as roll change calibration into a database; The roll calibration related information is recorded according to the working roll ID as the primary key. For any working roll, the roll calibration related information includes the calibration time, the corresponding support roll ID, the deviation F on both sides of the calibration rolling force, and the calibration time. diff , Deviation H on both sides of the magnetic scale diff , leveling setting value A, leveling value before finishing strip threading B, leveling value when finishing strip threading is completed C, standard leveling value S, number of lower step pads Bs, number of upper step pads Ts, number of lower step pads before roll change Bs pre , Number of steps before roller change Ts pre , Standard leveling value S before roller change pre ; S102: When the roller change is completed, calculate the leveling setting value A; The leveling setting value A calculated when the roller replacement is completed needs to be calculated based on whether the support roller is replaced or not; If the support roll is to be replaced, the calibration record of the most recent roll change is retrieved in the database according to the work roll ID. If the record is found, Wherein, a is the correction coefficient, and its value range is [0.2, 0.8]; S(old) is the standard adjustment value in the retrieved roller change calibration record; F diff (cur) is the rolling force deviation of this roll change calibration; S t is the theoretical stiffness of the rolling mill, a constant term; If no record is retrieved, it means that the working roll is a new roll, then the calibration record of the most recent roll change is retrieved. If no record is retrieved, A=0, otherwise, Wherein, b is the correction coefficient, and its value range is [0.2, 0.8]; S(old) is the standard adjustment value in the retrieved roller change calibration record; F diff (cur) is the rolling force deviation of this roll change calibration; S t is the theoretical stiffness of the rolling mill, a constant term; S103, when the first coil is produced after the roll change, the leveling value B before the finishing strip threading and the leveling value C after the strip threading are completed are recorded, the standard leveling value S is calculated, and updated in the roll change calibration record; The standard leveling value S is based on the leveling value C when the finishing strip is completed and the deviation F on both sides of the calibrated rolling force. diff and the theoretical stiffness S of the rolling mill t Calculated, specifically Finally, the leveling value B before finishing strip threading, the leveling value C when the strip threading is completed and reaches stability, and the calculated standard leveling value S are updated to the roll change calibration record.

2. The method for determining the first coil leveling value after finishing roll change according to claim 1, characterized in that: If the support roller is not replaced, then A=A1+A2+A3; The method for determining A1 is: according to the ID of the support roll and the ID of the working roll, the calibration record of the most recent roll change completed within N days is retrieved. If there is one, then H diff (cur) is the magnetic scale deviation of this roller change; H diff (old) is the magnetic scale deviation in the retrieved roller change record; If not, continue to search for the calibration record of the most recent roller change. If not, then A1=0. If yes, then Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record; F diff (cur) is the rolling force deviation of this roll change calibration; S t is the theoretical stiffness of the rolling mill, a constant term; H diff (cur) is the magnetic scale deviation of this roller change; H diff (old) is the magnetic scale deviation in the retrieved roller change record; The method for determining A2 is as follows: the number of lower step pads Bs of the current roll change and the number of lower step pads Bs before the roll change pre Compare, if the same, then A2 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Bs, this step pad number Ts, the step pad number Bs before the roll change pre , search for the latest roller change calibration record within M days, if there is no record, then A2=0, otherwise A2=S(old)-S pre (old) Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record; S pre (old) is the standard leveling value before roller change in the retrieved roller change calibration record; The method for determining A3 is as follows: the number of upper steps Ts of the roller change and the number of upper steps Ts before the roller change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, work roll ID, this step pad number Ts, this step pad number Bs, the step pad number Ts before the roll change pre , search for the latest roller change calibration record within M days, if there is no record, then A3=0, otherwise A3=S(old)-S pre (old) Wherein, S(old) is the standard adjustment value in the retrieved roller change calibration record; S pre (old) is the standard leveling value before roller change in the retrieved roller change calibration record; The value range of M is [1,10].

3. The method for determining the first coil leveling value after finishing roll change according to claim 2, characterized in that: The leveling value B before finishing strip threading is the leveling value actually used for the first coil after the roll change. Specifically, when the strip head enters the descaling machine before finishing rolling, the current leveling value is recorded and recorded as the leveling value B before finishing strip threading. B=A+m1 Among them, m1 is the manual intervention of the operation before finishing rolling and threading.

4. The method for determining the first coil leveling value after finishing roll change according to claim 3, characterized in that: The leveling value C when the strip threading is completed is the leveling value when the strip threading is completed and reaches stability. Specifically, when the strip head reaches the middle position of the cold roller at the finishing exit layer, the current leveling value is recorded and recorded as the leveling value C when the strip threading is completed. C=B+m2 Where m2 is the leveling intervention amount given by the operator according to the actual situation during the strip threading process.

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