Method for determining leveling value of first coil after roller replacement in finish rolling

Abstract

The invention relates to a method for determining a leveling value of a first coil after roller replacement in finish rolling. The method comprises the following steps: recording information such as a rolling working roll, calibration time, a corresponding support roll, a calibration rolling force two-side deviation, a magnetoscale two-side deviation, a leveling set value, a leveling value before finish rolling steel biting, a leveling value after threading completion, a standard leveling value, a lower step pad number, an upper step pad number, a standard leveling value before roll replacement and the like during roll replacement calibration; calculating a first roll leveling value after roll replacement according to roll calibration data, recording the intervention amount of an operator on the leveling value of each rack before and after band steel threading, and updating the intervention amount to a roll calibration record for leveling value calculation after next roll replacement. The problem that in the prior art, the given leveling value is unreasonable for an operator is effectively solved, then the risks of head deviation and steel stacking during first coil rolling after roller replacement are reduced, the rolling stability is improved, the practicability is wide, and the application prospect is wide.

Description

Technical Field

[0001] This patent application belongs to the field of automation technology of hot rolling mills 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] In hot rolling production, the working rolls and support rolls of the finishing mill will wear and deform after long-term use, affecting product quality and production efficiency. In order to ensure the surface quality and geometric dimension control accuracy of hot-rolled strip, it is necessary to replace the working rolls and support rolls after producing a certain amount of strip. Generally, after replacing the support rolls, the working rolls also need to be replaced synchronously. Under normal production rhythm, the working rolls are replaced about 8-12 times a day. After the roll change is completed, due to changes in factors such as roll diameter, material, roll shape, assembly, and thermal convexity, it is difficult to determine the roll gap leveling value of the first roll after the roll change. In the prior art, the leveling value is generally given manually based on experience. When the leveling value setting deviation is large, it will cause unfavorable conditions such as strip deviation and flatness, which will bring greater risks to production stability and product quality.

[0003] Patent CN103252350B discloses a leveling method for a finishing mill after roll change. By recording the rolling force deviation, oil column deviation and other information 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 when pressing down. The rolling force deviation and oil column deviation after the roll gap is zeroed are continued to be recorded, and 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 horizontal value of rolling, which obtains the deviation value and horizontal 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, and obtains the horizontal value of the rolling in the current cycle based on a preset formula and the rolling characteristic coefficient, thereby improving the stability and accuracy of rolling after roll change.

[0006] The above technologies all give reference values ​​or set values ​​for the first roll leveling value after roll change, but they do not 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 changing, 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 changing, 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 group using a four-roller rolling mill, and the method comprises the following steps:

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

[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 rolling and the leveling value C when the strip threading is completed are recorded, the standard leveling value S is calculated, and updated to 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 magnetic scale diff , leveling setting value A, leveling value before finishing strip threading B, leveling value after finishing strip threading 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 upper 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 the 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 the calibration is completed;

[0016] Furthermore, the leveling setting value A is determined by the method of the present invention, the initial value is 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 when the first roll is produced after the roll change. The initial value is set to 0 when the calibration is completed and is updated in step S103;

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

[0019] Furthermore, the standard leveling value S is determined according to the leveling value C, the rolling force deviation F 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 changing the roll. If there is no record before changing the roll, Ts pre =0;

[0022] Further, in S102, the leveling value A calculated when the roller replacement is completed needs to be calculated according to two situations: whether the support roller is replaced;

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

[0024]

[0025] Among them, 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 for the calibration record of the most recent roll change completed within N days according to the support roll ID and the working roll ID. If there is one, then

[0037]

[0038] If not, continue to search for the calibration record of the most recent roll change. If not, 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 the roll change pre Compare, if the same, then A2 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the number of steps down the ladder Bs, this time the number of steps up the ladder Ts, the number of steps down the ladder before the roll change Bs pre , retrieve the latest roller change calibration record within M days, if there is none, 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 step pads Ts of this roll change and the number of upper step pads Ts before the roll change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the upper step pad number Ts, this time the lower step pad number Bs, the upper step pad number Ts before the roll change pre , retrieve the latest roller change calibration record within M days, if there is none, 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] Further, in S103, the leveling value B before finishing rolling is the leveling value actually used by the first coil after the roll change. Specifically, when the head of the strip enters the descaling machine before finishing rolling, the current leveling value is 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 is threaded and reaches stability. Specifically, when the head of the strip 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 head of the strip 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 actual leveling value C at this time is recorded.

[0061] Furthermore, the standard leveling value S is calculated, and the leveling value C and the rolling force deviation F on both sides are calculated. 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 invention relates to a method for determining the leveling value of the first roll after roller changing in finishing rolling. The method records the working roll ID, calibration time, corresponding support roll ID, deviation on both sides of the calibrated rolling force, deviation on both sides of the magnetic scale, leveling setting value, leveling value before steel biting in finishing rolling, leveling value when strip threading is completed, standard leveling value, number of lower step pads, number of upper step pads, standard leveling value before roller changing and other information during roller changing calibration. The leveling value of the first roll after roller changing is calculated according to roller calibration data. At the same time, the intervention amount of the operator on the leveling value of each frame before and after strip threading is completed is recorded and updated to the roller calibration record for calculating the leveling value after the next roller change.

[0066] The method for determining the leveling value of the first roll after roll change provided by the present invention fully considers the matching relationship between the working roll and the support roll, the step pad, the rolling force deviation on both sides during calibration, the magnetic scale deviation, the rolling mill stiffness, and the intervention of the operator on the rolling mill leveling, and calculates the leveling value suitable for stable rolling after the roll change of each frame, effectively solving the problem of unreasonable leveling value given by the operator in the prior art, thereby reducing the risk of head deviation and steel piling during the rolling of the first roll after roll change, and improving the rolling stability. The present invention has wide practicability and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 A flow chart of a method for determining the leveling value of the first coil after roller change in finishing rolling 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 having to make 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 magnetic scale diff , leveling setting value A, leveling value before finishing strip threading B, leveling value after finishing strip threading 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 upper 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 the 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 the calibration is completed;

[0075] Furthermore, the leveling setting value A is determined by the method of the present invention, the initial value is 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 when the first roll is produced after the roll change. The initial value is set to 0 when the calibration is completed and is updated in step S103;

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

[0078] Furthermore, the standard leveling value S is determined according to the leveling value C, 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 changing the roll. If there is no record before changing the roll, 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 from the database according to the work roll ID. If the record is found,

[0084]

[0085] Among them, 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 for the calibration record of the most recent roll change completed within N days according to the support roll ID and the working 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 roll change. If not, 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 the roll change pre Compare, if the same, then A2 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the number of steps down the ladder Bs, this time the number of steps up the ladder Ts, the number of steps down the ladder before the roll change Bs pre , retrieve the latest roller change calibration record within M days, if there is none, 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 step pads Ts of this roll change and the number of upper step pads Ts before the roll change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the upper step pad number Ts, this time the lower step pad number Bs, the upper step pad number Ts before the roll change pre , retrieve the latest roller change calibration record within M days, if there is none, 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] Further, in S103, the leveling value B before finishing rolling is the leveling value actually used by the first coil after the roll change. Specifically, when the head of the strip enters the descaling machine before finishing rolling, the current leveling value is recorded and recorded as the leveling value B before finishing rolling.

[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 finishing strip threading is completed is the leveling value when the strip threading is completed and reaches stability. Specifically, when the head of the strip reaches the middle position of the cold roller table 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.

[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 head of the strip 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 leveling of the rolling mill is completed. Therefore, the leveling value C when the finishing rolling is completed under the actual situation at this time is recorded.

[0123] Furthermore, the standard leveling value S is calculated according to 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 invention relates to a method for determining the leveling value of the first roll after roller replacement in finishing rolling. The method records the working roll ID, calibration time, corresponding support roll ID, deviation on both sides of the calibrated rolling force, deviation on both sides of the magnetic scale, leveling setting value, leveling value before finishing rolling strip threading, leveling value when finishing rolling strip threading is completed, standard leveling value, number of lower step pads, number of upper step pads, standard leveling value before roller replacement and other information during roller replacement calibration. The leveling value of the first roll after roller replacement is calculated according to roller calibration data. At the same time, the intervention amount of the operator on the leveling value of each frame before and after the strip threading is completed is recorded and updated to the roller calibration record for calculating the leveling value after the next roller replacement.

[0127] The method for determining the leveling value of the first roll after roll change provided by the present invention fully considers the matching relationship between the working roll and the support roll, the step pad, the rolling force deviation on both sides during calibration, the magnetic scale deviation, the rolling mill stiffness, and the intervention of the operator on the rolling mill leveling, and calculates the leveling value suitable for stable rolling after the roll change of each frame, effectively solving the problem of unreasonable leveling value given by the operator in the prior art, thereby reducing the risk of head deviation and steel piling during the rolling of the first roll after roll change, and improving the rolling stability. The present invention has wide practicability and broad application prospects.

[0128] The technical solution of this embodiment is further described below through a typical application example: a hot rolling production line includes 7 four-roller finishing mills, which are respectively denoted as F1-F7. Each finishing mill includes a support roll and a working roll. The theoretical stiffness of F1-F7 is:

[0129]

[0130] During a roll change, the working 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, A1 is calculated, and the most recent roll change calibration completion record within N days is retrieved according to the support roll ID YZFB016 and the working roll ID XTFG044, preferably N=2, and the retrieved roll change calibration record 2 is:

[0136] Roller 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 rolling 0.115mm Leveling value C when finishing strip threading is completed 0.121mm Standard leveling value S 0.107mm The number of lower step pads for this roll change Bs 3 The number of upper steps for this roll change Ts 5 <![CDATA[Number of lower step 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]

[0140] 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 the roll change pre Compare, if the same, then A2 = 0, otherwise based on the support roll ID, work roll ID, this time the number of steps down the ladder pad Bs, this time the number of steps up the ladder pad Ts, the number of steps down the ladder pad Bs before the roll change pre ,, Retrieve the latest roll change calibration record within M days, preferably M = 5, if not, then A2 = 0, otherwise

[0141] A2=S(old)-S pre (old)

[0142] Since the number of lower step pads Bs for this roll change is 3, the number of lower step pads Bs before roll change pre =3, so A2=0;

[0143] Further, calculate A3, based on the number of upper step pads Ts of this roll change and the number of upper step pads Ts before the roll change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the upper step pad number Ts, this time the lower step pad number Bs, the upper step pad number Ts before the roll change pre , retrieve the latest roll change calibration record within M days, preferably M = 5, if not, then A3 = 0, otherwise

[0144] A3=S(old)-S pre (old)

[0145] 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, therefore based on the support roll ID, working roll ID, the number of steps Ts this time, the number of steps Bs this time, the number of steps Ts before changing rolls pre , search for the latest roller change calibration record within 5 days, and retrieve roller change calibration record 3:

[0146]

[0147]

[0148] therefore,

[0149] A3=S(old)-S pre (old)=0.107-0.151=-0.044mm

[0150] Therefore, A = A1 + A2 + A3 = 0.1244 + 0 + (-0.044) = 0.12 mm

[0151] 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 roll is rolled after the roll change.

[0152] 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 head of the strip steel 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, and since A=0.12mm, m1=0, indicating that no manual intervention was performed before finishing rolling and threading.

[0153] 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, and since B=0.12mm, m2=0.235-0.12=0.115mm, indicating that the operator performed a leveling intervention of 0.115mm according to the actual situation during the strip threading process.

[0154] Furthermore, the standard leveling value S is calculated according to 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

[0155]

[0156] 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.

[0157] The invention relates to a method for determining the leveling value of the first roll after roller changing in finishing rolling. The method records the working roll ID, calibration time, corresponding support roll ID, deviation on both sides of the calibrated rolling force, deviation on both sides of the magnetic scale, leveling setting value, leveling value before steel biting in finishing rolling, leveling value when strip threading is completed, standard leveling value, number of lower step pads, number of upper step pads, standard leveling value before roller changing and other information during roller changing calibration. The leveling value of the first roll after roller changing is calculated according to roller calibration data. At the same time, the intervention amount of the operator on the leveling value of each frame before and after strip threading is completed is recorded and updated to the roller calibration record for calculating the leveling value after the next roller change.

[0158] The method for determining the leveling value of the first roll after roll change provided by the present invention fully considers the matching relationship between the working roll and the support roll, the step pad, the rolling force deviation on both sides during calibration, the magnetic scale deviation, the rolling mill stiffness, and the intervention of the operator on the rolling mill leveling, and calculates the leveling value suitable for stable rolling after the roll change of each frame, effectively solving the problem of unreasonable leveling value given by the operator in the prior art, thereby reducing the risk of head deviation and steel piling during the rolling of the first roll after roll change, and improving the rolling stability. The present invention has wide practicability and broad application prospects.

[0159] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0160] The preferred embodiments of the present invention are described above. 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, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for determining the leveling value of the first coil after finishing roll change, characterized in that The following steps are involved: S101, after each roll change, recording roll calibration related information into a database as roll change calibration; S102, when the roller change is completed, calculate the leveling setting value A; S103. When the first coil is produced after the roll change, the leveling value B before the finishing rolling and the leveling value C when the strip threading is completed are recorded, the standard leveling value S is calculated, and updated to the roll change calibration record.

2. The method for determining the first coil leveling value after roller change in finishing rolling according to claim 1 is characterized in that: 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 magnetic scale diff , leveling setting value A, leveling value before finishing strip threading B, leveling value after finishing strip threading 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 upper steps before roller change Ts pre , Standard leveling value S before roller change pre .

3. According to the method for determining the leveling value of the first coil after the finishing roll change according to claim 2, the hot rolling is that: the leveling setting value A calculated when the roll change is completed needs to be calculated according to whether the support roll is replaced or not; If the support roll is to be replaced, the calibration record of the most recent roll change is retrieved from the database according to the work roll ID. If the record is found, in, 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; If the support roller is not replaced, then A=A1+A2+A3.

4. A method for determining the leveling value of the first coil after the finishing roll change according to claim 3, wherein the hot rolling comprises: the method for determining A1 is: searching the calibration record of the most recent roll change completed within N days according to the backup roll ID and the work roll ID, and if there is one, then H idff (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 roll change. If not, A1 = 0. If yes, then in, 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.

5. According to the method for determining the leveling value of the first coil after the finishing roll change according to claim 3, the hot rolling is: the method for determining A2 is: according to the lower step pad number Bs of the current roll change and the lower step pad number Bs before the roll change pre Compare, if the same, then A2 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the number of steps down the ladder Bs, this time the number of steps up the ladder Ts, the number of steps down the ladder before the roll change Bs pre , retrieve the latest roller change calibration record within M days, if there is none, then A2=0, otherwise A2=S(old)-S pre (old) in, 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.

6. According to the method for determining the leveling value of the first coil after the finishing roll change according to claim 3, the hot rolling is: the A3 determination method is: according to the upper step pad number Ts of the current roll change and the upper step pad number Ts before the roll change pre Compare, if the same, then A3 = 0, otherwise based on the corresponding support roll ID, working roll ID, this time the upper step pad number Ts, this time the lower step pad number Bs, the upper step pad number Ts before the roll change pre , retrieve the latest roller change calibration record within M days, if there is none, then A3=0, otherwise A3=S(old)-S pre (old) in, S(old) is the standard adjustment value in the retrieved roller change calibration record; S pre (old) is the standard leveling value before roller changing in the retrieved roller changing calibration record; The value range of M is [1,10].

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

8. The method for determining the first coil leveling value after roller change in finishing rolling according to claim 7 is characterized in that: The leveling value C when the finishing strip threading is completed is the leveling value when the strip threading is completed and reaches stability. Specifically, when the head of the strip reaches the middle position of the cold roller table 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=B+m2 Where m2 is the leveling intervention amount given by the operator during the strip threading process based on actual conditions.

9. The method for determining the first coil leveling value after finishing roll change according to claim 8, characterized in that: 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.

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