CN-122007174-A - Method for correcting rigidity control plate shape of rolling mill

CN122007174ACN 122007174 ACN122007174 ACN 122007174ACN-122007174-A

Abstract

The invention relates to the technical field of wide and thick plate rolling, in particular to a method for correcting the rigidity control plate shape of a rolling mill, which collects rolling force values calculated by the last first pass and the last second pass 、 And roll gap calculated value 、 And measured rolling force value 、 And the measured roll gap value 、 Calculating a pre-calculated stiffness value And the measured stiffness value Calculating the rigidity deviation judging coefficient of rolling mill If the rigidity deviation of the rolling mill is judged to be coefficient And correcting the rigidity compensation adjustment coefficient, and executing rolling force calculation based on the corrected rigidity compensation adjustment coefficient, or else executing calculation according to the set rolling force. The method has the advantages that the strip shape fluctuation caused by equipment aging or working condition change is effectively reduced through real-time monitoring and deviation compensation of the rigidity of the rolling mill, the deviation of the rolling force of the last pass is stably controlled within 60 tons, the strip shape qualification rate is improved, and the instability factors in the rolling process are reduced through the introduction of a rigidity fluctuation identification and compensation mechanism.

Inventors

NI ZHIFENG
WANG RUOGANG
PAN KAIHUA
HAN XU
HAN QIANPENG
LUO JUN
YAO ZHEN
WANG SHUAI

Assignees

鞍钢股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260316

Claims (8)

1. A method of modifying a mill stiffness control strip comprising: s1, collecting rolling force values calculated in the last first pass and the last second pass 、 And roll gap calculated value 、 And measured rolling force value 、 And the actual measured roll gap value 、 The method is used for calculating the rigidity deviation of the rolling mill; S2, calculating a pre-calculated rigidity value And the measured stiffness value The method is used for representing the theoretical rigidity and the actual rigidity of the rolling mill in the rolling process; s3, calculating a rigidity deviation judgment coefficient of the rolling mill The method is used for judging whether the rigidity of the rolling mill changes or not; S4, if the rigidity deviation of the rolling mill is judged to be the coefficient And correcting the rigidity compensation adjustment coefficient, and executing rolling force calculation based on the corrected rigidity compensation adjustment coefficient, or else executing calculation according to the set rolling force.
2. A method for modifying a mill stiffness control strip as claimed in claim 1 wherein in S2 the pre-calculated stiffness value The calculation formula of (2) is as follows: ①; Said measured stiffness value The calculation formula of (2) is as follows: ②; Wherein: Representing the pre-calculated stiffness value in KN/mm; the rolling force value calculated in the last pass is expressed in KN; representing the calculated value of the roll gap of the first pass of the reciprocal, wherein the unit is mm; representing the rolling force value calculated in the last-last pass, wherein the unit is KN; representing the calculated value of the roll gap of the last and last pass, wherein the unit is mm; Representing the measured rigidity value, wherein the unit is KN/mm; Representing the first-last-pass actual measured rolling force value in KN; representing the roll gap value measured in the last-last pass, wherein the unit is mm; representing the measured rolling force value of the next to last pass, wherein the unit is KN; the measured roll gap value of the last and last pass is expressed in mm.
3. The method for correcting a roll mill stiffness control strip of claim 1 wherein in S3 the roll mill stiffness deviation determination factor The calculation formula of (2) is as follows: ③; Wherein: The inherent stiffness of the mill is expressed in KN/mm.
4. The method for correcting a roll stand stiffness control strip of claim 1, wherein after finishing mill roll change, frame calibration and stiffness measurement are performed, and the fluctuation of stiffness before and after roll change is judged based on the measurement result, if Calculated according to the set rolling force, if And performing rigidity compensation calculation.
5. The method according to claim 1, wherein after the finishing mill changes the backup roll and the step pad size changes, the stand mill bounce test and the rigidity measurement are performed, if the measured stand rigidity is less than 8300KN/mm, the calculation is performed by the rigidity compensation adjustment coefficient 1.07 to 1.17, and if the stand rigidity is greater than or equal to 8300KN/mm, the calculation is performed by the rigidity compensation adjustment coefficient 0.9 to 1.0.
6. The method of correcting a roll stiffness control strip of claim 1, further comprising calculating a roll thickness based on a thickness equation: ④; Wherein: the idle roll gap value is expressed in mm; The idle roll gap value is represented, and the unit is m; The influence quantity of the bending force on the thickness of the outlet is expressed in mm; representing zero compensation quantity of the roll gap, wherein the unit is mm; the thickness variation of the oil film is expressed in mm; The calculation formula of the no-load roll gap value is as follows: ⑤; Wherein: the rigidity coefficient is expressed in KN/mm; The unit is KN; Representing the current rolling force calculated value, wherein the unit is KN; representing a rolling mill rigidity width correction coefficient; The length of the roll body of the roll is expressed in mm; the unit of the plate width is mm; quantity of influence of roll bending force on outlet thickness The calculation formula of (2) is as follows: ⑥; The bending force is expressed as KN; the roll bending force is shown as a factor of influence on thickness, KN/mm.
7. The method for correcting a roll mill stiffness control strip of claim 1 further comprising calculating a rolling force based on a rolling force equation The rolling force equation is: ⑦; Wherein: representing the stress coefficient; representing the average width of the rolled piece, wherein the unit is mm; the deformation resistance is expressed in kg/mm2; The contact arc length is expressed in mm; representing the rolling force function.
8. The method for correcting a roll mill stiffness control strip of claim 1 wherein in S4, the stiffness compensation adjustment factor is: ⑧。

Description

Method for correcting rigidity control plate shape of rolling mill Technical Field The invention relates to the technical field of wide and thick plate rolling, in particular to a method for correcting the rigidity control plate shape of a rolling mill. Background In the production of a thermo-mechanical control process (TMCP) steel plate, rolling parameters are reasonably set, so that the optimal distribution of rolling load (including rolling force, rolling reduction and the like) of a finishing mill is realized, the uneven deformation in the rolling process is reduced, and the method is a key technical measure for controlling the shape of the steel plate and ensuring the quality of the shape. The calculation of the roll gap load distribution model to the dynamic adjustment of the rolling process are all dependent on the accurate calculation and control of parameters such as rolling force, roll gap, rolling reduction and the like. Once the calculation accuracy is insufficient, the plate shape control will lose stability. In recent years, with the increase of service life of equipment, the precision of key parts of a rolling mill gradually decreases, a series of production and equipment problems are continuously displayed, and the plate shape of a steel plate and the stability of the rolling process are seriously affected. The specific expression is various plate-shaped defects, such as: common wave shape defects such as single-side waves, double-side waves, middle waves, buckling and the like; composite waves, especially composite deformations that are difficult to meet laminar cooling process requirements. In the actual plate shape regulation test, the apparent fluctuation of the rigidity of the rolling mill exists in the last two rolling passes. The rigidity of the rolling mill is an important index for measuring the precision of the rolling mill, and the fluctuation of the rigidity can directly influence the accuracy of model calculation of rolling force and roll gap, so that the distribution of residual stress in the steel plate is changed, the unstable rolling process is caused, and the quality of a product is reduced or even scrapped. The traditional plate shape control model generally calculates a rolling force set value according to factors such as the thickness of incoming materials, the steel grade, the thermal convexity of a roller, the abrasion of the roller, actual plate shape feedback and the like, regards the rigidity of a rolling mill as a fixed constant, and performs fine adjustment on subsequent billets only through a self-adaptive function. Such curing process has failed to accommodate current equipment conditions and production conditions. Once the rigidity is changed, the rolling force setting is misaligned, so that the actual input effect of the bending force and the tandem roller amount is affected, and the plate shape control is deteriorated, the rolling risk is increased, the efficiency is reduced, and the reject rate are increased. Part of the plate shape control methods have been disclosed in the prior art, such as: Publication number CN102284507a, patent name "a rolling mill plate shape control method for high strength thin gauge steel plate", which improves plate shape by controlling steel plate convexity, but does not involve control strategy when rolling mill rigidity is changed; Publication number is CN103302106A, the patent name is a method for improving flatness of a thick steel plate in the rolling process and a control mode thereof, and parameters such as biting speed, rolling speed, acceleration, final pass rolling force and the like are limited, so that the method is suitable for the steel plate with the thickness of more than or equal to 40mm, and the influence of fluctuation of rigidity of a rolling mill is not considered; the publication number is CN104942018A, the patent name is a rolling mill plate type control method for thick high-grade marine steel, and the rolling mill plate type control method is suitable for steel plates with the thickness of 50-60 mm by restraining the parameters such as final rolling reduction, maximum torque, roll bending force and the like, and the rigidity change of the rolling mill is not compensated. Therefore, a method capable of effectively identifying and compensating the rigidity change of the rolling mill and improving the plate shape control precision and rolling stability is lacking in the prior art, and particularly, the method aims at the requirements of ageing equipment with frequent rigidity fluctuation or high-precision plate shape control. Disclosure of Invention The invention aims to provide a method for correcting the rigidity control plate shape of a rolling mill, which aims to solve the problems of model setting misalignment and plate shape quality reduction caused by the rigidity fluctuation of the rolling mill in the existing plate shape control technology; based on the judging result, a rigidity compensation mecha