A finishing roll gap error control method and device

Abstract

The present application provides a method and device for controlling the roll gap error of a finishing rolling mill, the method comprising: obtaining the initial value of the self-learning coefficient of the roll gap error of each stand of the most recent finishing rolling mill and the new value of the self-learning coefficient of the roll gap error of each stand of the target strip steel for the finishing rolling roll change; correcting the initial value according to the new value of the self-learning coefficient of the roll gap error of each finishing rolling stand of the target strip steel to obtain the corrected value of the initial value of the self-learning coefficient of the roll gap error; calculating the preset roll gap value of each stand of the first strip steel for the next finishing rolling roll change according to the corrected value of the initial value, so as to complete the precise control of the head thickness of the first strip steel for the next roll change roll. The present application can effectively improve the preset accuracy of the finishing roll gap and the head thickness control accuracy of the first strip steel for the roll change roll.

Description

Technical Field

[0001] The invention relates to the application field of steel production and manufacturing, and in particular to a finishing roll gap error control method and device. Background Art

[0002] After the hot-rolled coil production line of the rolling mill is replaced, the mill needs to be zeroed to determine the zero position of the roll gap of the finishing mill F1-F7. The preset timing of the finishing roll gap will add the roll gap error self-learning coefficient of the corresponding frame. The existing control method will clear the F1-F7 roll gap error self-learning coefficient during the finishing zero adjustment, which often leads to the preset roll gap of the first roll gap of the roll change and the thickness of the strip head being too thick. In severe cases, the head thickness is over 500um, affecting product quality control; due to the inaccurate model calculation of the roll gap, the actual outlet thickness of each frame of the finishing mill deviates greatly from the model calculated outlet thickness, and the second flow of each frame does not match when the finishing strip head is threaded, which often leads to the high loop between the frames and the folding and stacking of the strip head, affecting the stability of the finishing rolling and the smooth production. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention proposes a finishing roll gap error control method and device, which mainly solves the problem that the pre-set accuracy of the roll gap of the first strip rolled after the finishing roll change is low, resulting in excessive thickness of the head of the first strip rolled after the roll change, affecting the rolling stability of the finishing roll change and the thickness control accuracy of the finished strip.

[0004] In order to achieve the above purpose and other purposes, the technical solution adopted by the present invention is as follows.

[0005] The present application provides a finishing roll gap error control method, comprising:

[0006] Obtain the most recent initial value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling mill and the new value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling mill for rolling the target strip;

[0007] Correcting the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of each frame to obtain a corrected value of the initial value of the roll gap error self-learning coefficient of each frame;

[0008] The preset roll gap values ​​of each stand for the next finishing rolling and roll changing for rolling the first strip are calculated according to the correction value to complete the thickness control of the head of the next finishing rolling and roll changing for rolling the first strip.

[0009] In one embodiment of the present application, obtaining the initial value of the self-learning coefficient of the roll gap error of each stand of the most recent finishing rolling mill includes:

[0010] Obtaining a historical roll gap error self-learning coefficient of each finishing mill stand for each finishing roll change and rolling of the target steel strip within a preset historical time period;

[0011] The average value of the historical roll gap error self-learning coefficient of each finishing mill stand is used as the initial value of the roll gap error self-learning coefficient.

[0012] In one embodiment of the present application, the initial value of the roll gap error self-learning coefficient is corrected according to the new value of the roll gap error self-learning coefficient of each frame, including:

[0013] The new value of the roll gap error self-learning coefficient of the corresponding frame and the corresponding initial value of the roll gap error self-learning coefficient are weighted averaged to obtain a correction value of the initial value of the roll gap error self-learning coefficient of the corresponding frame.

[0014] In one embodiment of the present application, the preset roll gap value of each stand for the next finishing rolling roll change and rolling of the first strip is calculated according to the correction value, including:

[0015] The correction value of each frame is added to the preset value of the roll gap of the corresponding frame for the next roll change and rolling of the first strip steel to obtain the preset value of the roll gap of the corresponding frame.

[0016] In one embodiment of the present application, the calculation method of the preset roll gap value includes:

[0017] Gap[std]=H[std]-T[std]-F[std]+O[std]-R[std]-M[std]-C[std]+L[std]+InitG[std]

[0018] In the formula: std: finishing mill stand number; Gap[std]: calculated value of finishing roll gap; H[std]: calculated value of outlet thickness of each finishing mill stand; T[std]: calculated value of bounce roll gap; F[std]: calculated value of roll system deformation; O[std]: calculated value of oil film thickness; R[std]: calculated value of thermal expansion roll gap; M[std]: calculated value of wear roll gap; C[std]: calculated value of shifting roll gap; L[std]: zero adjustment position; InitG[std]: correction value of the initial value of roll gap error self-learning coefficient.

[0019] In one embodiment of the present application, before obtaining the most recent initial value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling mill and the new value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling roll change and rolling of the target strip, the method further includes:

[0020] Providing a process parameter table, wherein the process parameter table includes a roll gap error self-learning coefficient of each frame;

[0021] According to the new value of the roll gap error self-learning coefficient of each stand for each finishing roll change and rolling of the target strip, the roll gap error self-learning coefficient in the process parameter table is assigned after the finishing rolling of each strip is completed.

[0022] In one embodiment of the present application, before the initial value of the roll gap error self-learning coefficient is corrected according to the new value of the roll gap error self-learning coefficient of each frame, the method further includes:

[0023] Obtain the steel type of the first strip steel for roll changing and rolling;

[0024] If the steel type is a patterned plate, the initial value of the self-learning coefficient of the roll gap error of the finishing rolling mill stand is set to zero.

[0025] The present application also provides a finishing roll gap error control device, comprising:

[0026] A roll gap error self-learning coefficient acquisition module is used to obtain the initial value of the roll gap error self-learning coefficient of each stand of the finishing rolling and the new value of the roll gap error self-learning coefficient of each stand of the finishing rolling roll change and rolling target strip;

[0027] A correction module, used for correcting the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of each frame, so as to obtain a correction value of the initial value of the roll gap error self-learning coefficient of each frame;

[0028] The roll gap presetting module is used to calculate the roll gap presetting value of each frame for the next finishing rolling roll change and rolling of the first strip according to the correction value, so as to complete the head thickness control of the first strip for the next roll change and rolling.

[0029] As described above, the method and device for controlling the error of the finishing roll gap of the present invention have the following beneficial effects.

[0030] The present application amends the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of the target strip steel for roll change rolling, so as to compensate for the roll gap error self-learning coefficient of the first strip steel for roll change rolling. The initial value of the roll gap error self-learning coefficient after compensation adjustment is used for the roll gap pre-setting calculation of the first strip steel for the next roll change rolling, which can effectively improve the roll gap pre-setting accuracy of the first strip steel for roll change rolling, and improve the thickness control accuracy of the head of the first strip steel for roll change rolling; solves the problem of folding and piling of steel at the head of the strip steel due to the mismatch of the second flow rate between the frames when threading the strip for the first strip steel for roll change rolling, which can effectively improve the finishing rolling stability of the first strip steel for roll change rolling, and ensure stable and smooth production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the process of the finishing roll gap error control method in one embodiment of the present application.

[0032] Figure 2 This is a module diagram of a finishing roll gap error control device in one embodiment of the present application. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0035] See also Figure 1 The present invention provides a finishing roll gap error control method, the method comprising the following steps:

[0036] Step S100, obtaining the initial value of the self-learning coefficient of the roll gap error of each stand in the most recent finishing rolling and the new value of the self-learning coefficient of the roll gap error of each stand in the finishing rolling roll change and rolling of the target strip;

[0037] Step S110, correcting the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of each frame to obtain a corrected value of the initial value of the roll gap error self-learning coefficient of each frame;

[0038] Step S120, calculating the preset roll gap value of each stand for the next finishing rolling and roll changing for the first strip according to the correction value, so as to complete the head thickness control of the next finishing rolling and roll changing for the first strip.

[0039] In one embodiment, the existing control technology lacks the function of compensating the roll gap error self-learning coefficient when the first strip is rolled after the roll change, which leads to frequent over-thickness of the head thickness of the first strip, seriously affecting the quality control of the head and full-length thickness of the strip. Therefore, the initial variables of the roll gap error self-learning coefficients of each finishing mill stand can be added to record the stability of the thickness control after each roll change. The values ​​of the roll gap error self-learning coefficients corresponding to the initial variables of each finishing mill stand are called each time the first strip is rolled after the roll change, and the roll gap pre-setting calculation of the corresponding stand is performed, thereby improving the roll gap pre-setting accuracy of the first strip when the roll change is rolled.

[0040] In one embodiment, before obtaining the most recent initial value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling mill, the following steps are also included:

[0041] Step S101, providing a process parameter table, wherein the process parameter table includes an initial value of a roll gap error self-learning coefficient of each frame, a roll gap error self-learning coefficient, and the like.

[0042] Specifically, it is assumed that the hot rolling production line includes 7 finishing mills, denoted as F1-F7, and a variable for recording the initial value of the roll gap error self-learning coefficient and the roll gap error self-learning coefficient is provided for each finishing mill, and the variables corresponding to the finishing mills F1-F7 are recorded in the process parameter table.

[0043] Step S102, assigning the roll gap error self-learning coefficient in the process parameter table after finishing rolling of each strip of steel is completed according to the new value of the roll gap error self-learning coefficient of each stand for rolling the target strip of steel each time the rolls are changed.

[0044] Specifically, the historical roll gap error self-learning coefficients of each finishing stand after each finishing roll change within a preset time period can be collected, and the variables corresponding to the roll gap error self-learning coefficients in the process parameter table can be assigned initial values ​​according to the historical roll gap error self-learning coefficients of the time period. The preset time period can be selected from the most recent year or the most recent month, or other specified historical time periods. The selection of the specific preset time period can be adjusted according to actual application requirements, and is not limited here. Since the head thickness of the third strip steel after roll change and rolling is basically controlled normally, the roll gap error self-learning coefficients of the finishing F1-F7 stands are in a relatively normal state at this time. Therefore, the third strip steel can be used as the target strip steel, and the roll gap error self-learning coefficients of each stand when the roll is changed and the third strip steel is rolled can be selected as the reference basis for the historical roll gap error self-learning coefficients. The roll gap error self-learning coefficients of each stand when the roll is changed and the third strip steel is rolled in the past year are counted. The average value of the roll gap error self-learning coefficients of the finishing F1-F7 stands is taken as the initial value of the corresponding roll gap error self-learning coefficient after roll change. The initial value of the roll gap error self-learning coefficient is assigned to the corresponding variable in the process parameter table. The corresponding initial value of the roll gap error self-learning coefficient can be obtained from the process parameter table as needed.

[0045] In step S100, the current time node is used as the starting node for the preset roll gap time, and the initial value of the roll gap error self-learning coefficient of each finishing mill stand in the process parameter table can be obtained as the initial value of the roll gap error self-learning coefficient of the first strip steel rolled in the most recent finishing rolling roll change. The control system will adjust the value of the roll gap error self-learning coefficient when the subsequent strip steel is rolled according to the initial value of the roll gap error self-learning coefficient of the first strip steel rolled in the roll change. Still taking the third strip steel as the target strip steel as an example, the new value of the roll gap error self-learning coefficient of each finishing mill stand when the third strip steel was rolled in the most recent finishing rolling roll change can be further obtained.

[0046] In step S110, after obtaining the initial value of the self-learning coefficient of the roll gap error of each finishing stand that rolled the first piece of steel strip in the most recent finishing roll change and the new value of the self-learning coefficient of the roll gap error of each finishing stand that rolled the third piece of steel strip, the new value of the self-learning coefficient of the roll gap error of the corresponding finishing stand and the initial value of the self-learning coefficient of the roll gap error can be weighted averaged, and the specific weight ratios of different values ​​can be set and adjusted according to actual production needs, and there is no restriction here. The value obtained by weighted average is used as the correction value of the initial value of the self-learning coefficient of the roll gap error of the corresponding finishing stand. Then, according to the correction value, the initial value of the self-learning coefficient of the roll gap error of the corresponding stand in the process parameter table is reassigned to complete the adaptive adjustment of the self-learning coefficient of the roll gap error of the finishing roll, so as to be used for the preset calculation of the roll gap of the corresponding stand for the next finishing roll change. The adaptive adjustment calculation method of the self-learning coefficient of the roll gap error of each finishing stand can be expressed as follows:

[0047] NewInitGapErr[std]=InitGapErr[std]+K[std]*(ReGapErr[std]-InitGapErr[std])

[0048] Among them, std: finishing mill stand number 1-7; NewInitGapErr[std]: correction value of the initial value of the roll gap error self-learning coefficient; InitGapErr[std]: initial value of the roll gap error self-learning coefficient of the finishing mill stands F1-F7; K[std]: gain coefficient, which can be set for each stand according to the F1-F7 stands; ReGapErr[std]: new value of the roll gap error self-learning coefficient for changing rolls and rolling the third strip.

[0049] In one embodiment, before the initial value of the roll gap error self-learning coefficient is corrected according to the new value of the roll gap error self-learning coefficient of each frame, the method further includes:

[0050] Obtain the steel type of the first strip steel for roll changing and rolling;

[0051] If the steel type is a patterned plate, the initial value of the self-learning coefficient of the roll gap error of the finishing rolling mill stand is set to zero.

[0052] Specifically, it can be determined whether the first steel strip rolled after the roll change is a patterned plate. If the first steel strip rolled after the roll change is a patterned plate, the initial value of the self-learning coefficient of the roll gap error of the finishing rolling stand F7 will be cleared to ensure that the texture height of the first patterned plate rolled after the roll change is controlled; the initial value of the self-learning coefficient of the roll gap error of the finishing rolling stand F1-F6 can still be corrected and adjusted according to the above steps.

[0053] In step S120, the preset roll gap value of each frame for the next finishing rolling and roll changing and rolling of the first strip is calculated according to the correction value, including: adding the correction value of each frame to the preset roll gap value of the corresponding frame for the next finishing rolling and roll changing and rolling of the first strip, to obtain the preset roll gap value of the corresponding frame.

[0054] Specifically, after determining the correction value of the initial value of the roll gap error self-learning coefficient of each finishing mill stand according to the above steps, the roll gap presetting calculation method for the first strip steel in the next roll change can be expressed as follows:

[0055] Gap[std]=H[std]-T[std]-F[std]+O[std]-R[std]-M[std]-C[std]+L[std]+InitG[std]

[0056] In the formula: std: finishing mill stand number; Gap[std]: calculated value of finishing roll gap; H[std]: calculated value of outlet thickness of each finishing mill stand; T[std]: calculated value of bounce roll gap; F[std]: calculated value of roll system deformation; O[std]: calculated value of oil film thickness; R[std]: calculated value of thermal expansion roll gap; M[std]: calculated value of wear roll gap; C[std]: calculated value of shifting roll gap; L[std]: zero adjustment position; InitG[std]: correction value of the initial value of roll gap error self-learning coefficient.

[0057] Further, the roll gap pre-setting adjustment is performed to complete the precise control of the thickness of the head of the first piece of strip steel when the roll is changed and rolled next time. Based on the technical solution of the above embodiment of the present application, the problem of excessive thickness of the head or the entire length of the first piece of strip steel when the roll is changed and rolled in the existing control technology can be effectively solved. The thickness deviation of the head of the first piece of strip steel when the roll is changed and rolled can be controlled within ±50μm, which effectively improves the control accuracy of the head and the entire length of the first piece of strip steel when the roll is changed and rolled, and improves the product quality control accuracy; it effectively solves the problem of low roll gap pre-setting accuracy when the roll is changed and rolled for the first piece of strip steel, resulting in mismatched second flow rates between the finishing mill frames, and the problem of folding and piling steel at the head during the strip threading process, improves the stability of finishing rolling, and provides support for the smooth production of the production line.

[0058] See also Figure 2 This embodiment also provides a finishing roll gap error control device, which is used to execute the finishing roll gap error control method described in the above method embodiment. Since the technical principle of the device embodiment is similar to the technical principle of the above method embodiment, the same technical details will not be repeated.

[0059] In one embodiment, a finishing roll gap error control device includes: a roll gap error self-learning coefficient acquisition module 10, which is used to obtain the initial value of the roll gap error self-learning coefficient of each frame of the most recent finishing rolling and the new value of the roll gap error self-learning coefficient of each frame for the finishing rolling roll change and rolling of the target strip; a correction module 11, which is used to correct the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of each frame, and obtain the correction value of the initial value of the roll gap error self-learning coefficient of each frame; a roll gap pre-setting module 12, which is used to calculate the roll gap pre-setting value of each frame for the next finishing rolling roll change and rolling of the first strip according to the correction value, so as to complete the head thickness control of the first strip in the next roll change and rolling.

[0060] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A finishing roll gap error control method, characterized in that: include: Obtain the most recent initial value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling mill and the new value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling mill for rolling the target strip; Obtaining the initial value of the self-learning coefficient of the roll gap error of each finishing stand in the most recent finishing rolling, including: obtaining the historical self-learning coefficient of the roll gap error of each finishing stand for each finishing rolling roll change and rolling of the target strip within a preset historical time period; taking the average of the historical self-learning coefficients of the roll gap error of each finishing stand as the initial value of the self-learning coefficient of the roll gap error; The initial value of the roll gap error self-learning coefficient is corrected according to the new value of the roll gap error self-learning coefficient of each frame to obtain the corrected value of the initial value of the roll gap error self-learning coefficient of each frame; the initial value of the roll gap error self-learning coefficient is corrected according to the new value of the roll gap error self-learning coefficient of each frame, including: taking a weighted average of the new value of the roll gap error self-learning coefficient of the corresponding frame and the corresponding initial value of the roll gap error self-learning coefficient to obtain the corrected value of the initial value of the roll gap error self-learning coefficient of the corresponding frame; The preset roll gap value of each frame for the next finishing rolling and roll changing and rolling of the first strip is calculated according to the correction value to complete the head thickness control of the first strip for the next rolling and roll changing; the preset roll gap value of each frame for the next finishing rolling and roll changing and rolling of the first strip is calculated according to the correction value, including: adding the correction value of each frame to the preset roll gap value of the corresponding frame for the next rolling and roll changing and rolling of the first strip, to obtain the preset roll gap value of the corresponding frame; the calculation method of the preset roll gap value includes: Gap[std]=H[std]-T[std]-F[std]+O[std]-R[std]-M[std]-C[std]+L[std]+InitG[std] In the formula: std: finishing mill stand number; Gap[std]: calculated value of finishing roll gap; H[std]: calculated value of outlet thickness of each finishing mill stand; T[std]: calculated value of bounce roll gap; F[std]: calculated value of roll system deformation; O[std]: calculated value of oil film thickness; R[std]: calculated value of thermal expansion roll gap; M[std]: calculated value of wear roll gap; C[std]: calculated value of shifting roll gap; L[std]: zero adjustment position; InitG[std]: correction value of the initial value of roll gap error self-learning coefficient.

2. The finishing roll gap error control method according to claim 1, characterized in that: Before obtaining the most recent initial value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling and the new value of the self-learning coefficient of the roll gap error of each stand of the finishing rolling roll change and rolling target strip, it also includes: Providing a process parameter table, wherein the process parameter table includes a roll gap error self-learning coefficient of each frame; According to the new value of the roll gap error self-learning coefficient of each stand for each finishing roll change and rolling of the target strip, the roll gap error self-learning coefficient in the process parameter table is assigned after the finishing rolling of each strip is completed.

3. The finishing roll gap error control method according to claim 1, characterized in that: Before correcting the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of each frame, the method further includes: Obtain the steel type of the first strip steel for roll changing and rolling; If the steel type is a patterned plate, the initial value of the self-learning coefficient of the roll gap error of the finishing rolling mill stand is set to zero.

4. A finishing roll gap error control device for executing the finishing roll gap error control method according to any one of claims 1 to 3, characterized in that: include: A roll gap error self-learning coefficient acquisition module is used to obtain the initial value of the roll gap error self-learning coefficient of each stand of the finishing rolling and the new value of the roll gap error self-learning coefficient of each stand of the finishing rolling roll change and rolling target strip; A correction module, used for correcting the initial value of the roll gap error self-learning coefficient according to the new value of the roll gap error self-learning coefficient of each frame, so as to obtain a correction value of the initial value of the roll gap error self-learning coefficient of each frame; The roll gap presetting module is used to calculate the roll gap presetting value of each frame for the next finishing rolling roll change and rolling of the first strip according to the correction value, so as to complete the head thickness control of the first strip for the next roll change and rolling.

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