A method for controlling edge wave defects in a cold-continuous-rolling steel coil

Abstract

The application discloses a method for controlling edge wave defects of a cold continuous rolling steel coil, and collects a finishing temperature setting value T of the steel coil in a hot rolling process z , and performs the following steps: first, the strip steel of the steel coil is divided into n sections according to a length direction of the steel coil with unit length as a position interval, and temperature data of the n sections of the strip steel in the hot rolling process are respectively output to form a steel coil hot rolling temperature data set T; then, a total work roll bending force correction setting value in a cold continuous rolling process is calculated according to the steel coil hot rolling temperature data set T, and the total work roll bending force correction setting value is distributed to work rolls and intermediate rolls; according to a difference between an actual rolling temperature of the steel coil in the hot rolling process and the set finishing temperature, the bending force setting value in the cold rolling process is corrected, so that the bending force in the cold continuous rolling process is matched with the rolling force required by the steel coil, and the problem of the edge wave defects of the hot rolling steel coil in the existing cold continuous rolling process is greatly relieved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of cold continuous rolling steel coil shear edge wave defect control method, belong to cold rolling rolling control technical field. BACKGROUND

[0002] Before hot-rolled steel coil is carried out in cold continuous rolling mill, operating personnel will calculate the preset cold rolling rolling force according to the average deformation resistance of hot-rolled steel coil, and the bending roll force in the cold rolling process is set according to the preset cold rolling rolling force, after setting is completed, hot-rolled steel coil is carried out in cold continuous rolling mill and is rolled, it is found that when the tail of hot-rolled steel coil strip enters the fifth rack of cold continuous rolling mill and is sheared, edge wave defect will appear. Because there is loss of tension in the cold rolling shearing process, the plate shape detection is distorted, so that the edge wave defect generated after shearing cannot be improved by plate shape feedback control, causing the tail of the coil to appear unrepaired shear edge wave defect. The skilled person finds that the reason why the tail of hot-rolled steel coil strip appears shear edge wave defect when cold rolling is that the deformation resistance of the tail of hot-rolled steel coil strip is greater than the average deformation resistance, so that the bending roll force set when the cold continuous rolling mill rolls the tail of hot-rolled steel coil strip is smaller than the actual rolling force required, so that edge wave defect occurs when shearing. The skilled person also finds that the reason why the deformation resistance of the tail of hot-rolled steel coil strip is large is that the finish rolling temperature of a small section of strip at the tail of hot-rolled steel coil during the tail rolling process is significantly lower than the finish rolling temperature set in hot rolling. The lower finish rolling temperature of the tail directly leads to the coarse grain structure of the head, and the deformation resistance of the material at the corresponding position is higher than the average deformation resistance of the material of the whole coil. Therefore, the methods for solving the shear edge wave defect of the steel coil in the cold rolling process in the prior art mainly include the following two kinds: one is to add a heat preservation device in the hot rolling process to maintain the finish rolling temperature of the tail of hot-rolled steel coil, so that the deformation resistance of the tail of hot-rolled steel coil is not higher than the average deformation resistance. Two, manually adjust the bending roll force according to experience in the cold continuous rolling process, so that the bending roll force for shearing the tail of hot-rolled steel coil matches the rolling force required, to avoid shear edge wave defect. The existing technology one has the problem of high cost due to the need to add new equipment in the hot rolling process. The existing technology two has the problem that manual bending roll force compensation is only suitable for small-scale rolling at slow speed, and it is difficult for large-scale cold continuous rolling to manually compensate the bending roll force. SUMMARY

[0003] The technical problem to be solved by the present application is how to adjust the bending roll force preset value in the rolling process to match the bending roll force with the actual rolling force, and to solve the shear edge wave defect of the steel coil in the cold continuous rolling process.

[0004] The technical solution proposed by the present application is: a kind of cold continuous rolling steel coil shear edge wave defect control method, collect the finish rolling temperature setting value T z of the steel coil in the hot rolling process And execute the following steps:

[0005] Step 1: dividing the strip of the steel coil into n segments according to the length direction of the steel coil with unit length as the position interval, n is a natural number greater than 2; outputting the temperature data of the n segments of the strip in the hot rolling process to form a steel coil hot rolling temperature data set T, as shown in the following formula (1),

[0006] T = {T1, T2,..., Tn} (1), n

[0007] In formula (1), T1 is the temperature data of the first segment of the strip of the steel coil in the hot rolling process; T2 is the temperature data of the second segment of the strip of the steel coil in the hot rolling process; Tn is the temperature data of the last segment of the strip of the steel coil in the hot rolling process; n

[0008] Selecting the last A segments of the strip in the length direction of the steel coil as the tail segment of the strip of the steel coil, A is a natural number greater than 0 and less than n;

[0009] The hot rolling tail average temperature output value T of the tail segment of the strip is calculated by the following formula (2), w

[0010] T = (T1 + T2 + T3 +... + Tn) / A (2); w n n-1 n-2 n-A

[0011] Step 2: setting the base work roll bending force ΔWRB5 in the cold rolling process, B T

[0012]

[0013] In formula (3), k is a temperature difference proportion coefficient;

[0014] The total work roll bending force correction set value ΔWRB5' in the cold rolling process is calculated by the following formula (4),

[0015] ΔWRB5' = ΔWRB5 + ΔWRB5 (4), B T

[0016] The total work roll bending force correction set value ΔWRB5' is distributed to the work roll and the intermediate roll in the cold rolling process in turn by the following formulas (5) and (6) to obtain the work roll bending force set value ΔWRB5 of the work roll and the intermediate roll bending force set value ΔIRB5 of the intermediate roll, ​​​​​​​​​​​​

[0017]

[0018] In formula (5), a is the proportion of the work roll in the distribution of the total work roll bending roll force correction set value ΔWRB5', and b is the proportion of the intermediate roll in the distribution of the total work roll bending roll force correction set value ΔWRB5';

[0019]

[0020] In formula (6), c is the conversion ratio between the work roll bending roll force and the intermediate roll bending roll force;

[0021] According to the work roll bending roll force set value ΔWRB5 of the work roll and the intermediate roll bending roll force set value ΔIRB5 of the intermediate roll, corresponding bending roll forces are respectively output for rolling.

[0022] The present application has the following beneficial effects: According to the difference between the actual rolling temperature of the steel coil in the hot rolling process and the set finishing temperature, the bending roll force set value in the cold rolling process is corrected, so that the bending roll force in the cold continuous rolling process matches the rolling force required by the steel coil, and the problem of shear edge wave defects of the hot rolled steel coil in the existing cold continuous rolling process is greatly alleviated. DETAILED DESCRIPTION

[0023] The present application is further described below in combination with a specific embodiment of a method for controlling shear edge wave defects of a cold continuous rolled steel coil

[0024] The present application is further described below in combination with a specific embodiment of a method for controlling shear edge wave defects of a cold continuous rolled steel coil z The following steps are then performed:

[0025] Step 1: The strip steel of the steel coil is divided into n segments in the length direction of the steel coil with unit length as the position interval, n is a natural number greater than 2; the temperature data of the n segments of strip steel in the hot rolling process are output to form a steel coil hot rolling temperature data set T, as shown in the following formula (1),

[0026] T={T1, T2,..., T n}(1),

[0027] In formula (1), T1 is the temperature data of the first segment of strip steel of the steel coil in the hot rolling process; T2 is the temperature data of the second segment of strip steel of the steel coil in the hot rolling process; Tn is the temperature data of the last segment of strip steel of the steel coil in the hot rolling process; n

[0028] The last A segments of strip steel in the length direction of the steel coil are selected as the tail segment of the strip steel, and A is a natural number greater than 0 and less than n.​

[0029] The hot rolling tail average temperature output value T of the tail strip section is calculated by the following formula (2) w ,

[0030] T w = (T n +T n-1 +T n-2 +...+T n-A ) / A (2);

[0031] Step 2: Set the base work roll bending force ΔWRB5 in the cold continuous rolling process B The total work roll bending force set value ΔWRB5 in the cold continuous rolling process is calculated by the following formula (3) T ,

[0032]

[0033] In formula (3), k is the temperature difference proportionality coefficient;

[0034] The total work roll bending force correction set value ΔWRB5' in the cold continuous rolling process is calculated by the following formula (4)

[0035] ΔWRB5' = ΔWRB5 B + ΔWRB5 T (4),

[0036] The total work roll bending force correction set value ΔWRB5' is distributed to the work roll and the intermediate roll in the cold continuous rolling process in turn by the following formulas (5) and (6) to obtain the work roll bending force set value ΔWRB5 of the work roll and the intermediate roll bending force set value ΔIRB5 of the intermediate roll,

[0037]

[0038] In formula (5), a is the proportion of the work roll when the total work roll bending force correction set value ΔWRB5' is distributed, and b is the proportion of the intermediate roll when the total work roll bending force correction set value ΔWRB5' is distributed;

[0039]

[0040] In formula (6), c is the conversion proportion between the work roll bending force and the intermediate roll bending force;

[0041] The corresponding bending forces are output according to the work roll bending force set value ΔWRB5 of the work roll and the intermediate roll bending force set value ΔIRB5 of the intermediate roll respectively for rolling.

Claims

1. A method of controlling edge wave defects in a cold-rolled steel coil, characterized by: collecting a finish rolling temperature setting value T of the steel coil in a hot rolling process z and performing the following steps: Step 1: dividing the strip of the steel coil into n sections according to the length direction of the steel coil with unit length as the position interval, n is a natural number greater than 2; outputting the temperature data of the n sections of the strip during the hot rolling process to form a steel coil hot rolling temperature data set T, as shown in the following formula (1), T = {T1, T2,..., T n}(1), In formula (1), T1 is the temperature data of the first section of the strip of the steel coil during the hot rolling process; T1 is the temperature data of the second section of the strip of the steel coil during the hot rolling process; T n is the temperature data of the last piece of strip steel in the hot rolling process of the steel coil; selecting the last A section of the strip in the length direction of the steel coil as the tail section of the strip of the steel coil, A is a natural number greater than 0 and less than n; The hot rolling tail average temperature output value T of the tail strip section is calculated by the following formula (2) w , T w = (T n +T n-1 +T n-2 +...+T n-A ) / A (2); Step 2: Set the bending force of the work roll in the cold continuous rolling process ΔWRB5 B The total bending force setting value of the work roll in the cold continuous rolling process ΔWRB5 is calculated by the following formula (3) T , In formula (3), k is a temperature difference proportion coefficient; The total work roll bending force correction setting value ΔWRB5' in the cold continuous rolling process is calculated by the following equation (4), ΔWRB5' = ΔWRB5 B + ΔWRB5 T (4), The total work roll bending force correction set value ΔWRB5' is distributed to the work roll and the intermediate roll in the cold continuous rolling process in turn through the following formulas (5) and (6) to obtain the work roll bending force set value ΔWRB5 of the work roll and the intermediate roll bending force set value ΔIRB5 of the intermediate roll, In formula (5), a is the proportion of the work roll when the total work roll bending force correction set value ΔWRB5' is distributed, and b is the proportion of the intermediate roll when the total work roll bending force correction set value ΔWRB5' is distributed; In formula (6), c is the conversion proportion between the work roll bending force and the intermediate roll bending force; According to the work roll bending force set value ΔWRB5 of the work roll and the intermediate roll bending force set value ΔIRB5 of the intermediate roll, the corresponding bending force is outputted for rolling.

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