A method for controlling the first pass of a roughing mill sickle bend

Abstract

This invention provides a method for controlling the first pass of roughing mill camber, comprising the following steps: collecting relevant process parameters of roughing mill camber and performing data preprocessing; based on the total number of rolling passes and the bending amount of each pass, taking the influence weight of the odd-numbered passes, denoted as matrix A; calculating the camber adjustment amount of the first pass of the current steel block based on the camber amount of the i-th pass of the previous steel block; calculating the camber leveling value of the first pass of the current steel block; and sending the camber leveling value of the first pass of the current steel block to the automatic control system of the rolling mill base to achieve automatic control of the first pass of camber. This invention achieves the purpose of automatic control of the first pass of roughing mill camber, reducing camber problems and subsequent accidents.

Description

Technical Field

[0001] This invention relates to the field of slab camber control technology in the roughing stage of hot rolling of strip and plate, and particularly to a method for controlling the first pass of roughing camber. Background Technology

[0002] Sickle bending is a common shape defect in hot-rolled strip rolling. It significantly hinders the control and stability of subsequent finishing and final rolling accuracy, severely impacting strip steel production. Many factors influence slab sickle bending. During on-site rolling, asymmetric factors inevitably cause changes in the set process parameters, primarily including incoming material factors, equipment factors, and operating conditions. These factors all lead to asymmetry in the rolling state along the roll axis, resulting in differences in the reduction rate along the mill width, thus generating and affecting sickle bending.

[0003] As a mainstream research direction in modern strip rolling, slab camber control has always received much attention. Hot rolling roughing is a continuous and reversible rolling process. Under normal circumstances, on-site operators do not make much adjustment to the camber leveling value of the first pass of slab rolling. The camber leveling value is inherited from the first pass of the previous steel block. After the first pass is completed, targeted adjustments are made in subsequent passes based on the rolling effect. However, due to many complex factors on-site, the first pass of slab rolling can result in a large camber, which can easily cause the risk of impacting the side guide plate. Furthermore, in the hot rolling roughing process, if the manual control intervention of the slab camber in the first pass is not timely, it can easily lead to a large camber impacting the side guide plate, or even steel piling accidents. Summary of the Invention

[0004] This invention addresses the aforementioned problems and aims to provide a method for controlling the first pass of roughing mill camber. First, relevant process parameters for roughing mill camber are collected and preprocessed. Second, the influence weight of the bending amount of each pass of the upper steel block on the bending amount of the first pass of the current steel block is calculated. Then, the adjustment amount and leveling value of the first pass camber for this steel block are calculated. Finally, the leveling value of the first pass camber for this steel block is sent to the automated control system of the rolling mill, achieving automatic control of the first pass of roughing mill camber and reducing camber problems and subsequent accidents.

[0005] Specifically, the first aspect of the present invention provides a method for controlling the first pass of roughing mill camber, comprising the following steps:

[0006] Step 1: Collect relevant process parameters for the rough rolling camber bend and perform data preprocessing;

[0007] Step 2: Based on the total number of rolling passes N′ of the upper steel block and the bending amount of each pass, obtain the influence weight of the bending amount of the i-th pass of the upper steel block on the bending amount of the first pass of the current steel block, denoted as a.i Let i be the number of channels, and take the influence weight of the odd number of channels, denoted as matrix A;

[0008] Based on a large amount of historical rolling data, when the bending amount of the upper block steel in the i-th pass exceeds the normal range, different adjustment amounts are given according to the degree of bending. The effect of the bending amount on the first pass of the lower block steel is observed and statistically analyzed to obtain the influence weight of the bending amount of the upper block steel in the i-th pass on the bending amount of the current block steel in the first pass.

[0009] Step 3: Based on the bending amount C of the sickle in the i-th pass of the upper steel block. i The formula for calculating the initial camber adjustment amount of this steel block is as follows:

[0010] ΔT1=AB T ;

[0011] B = [b1 b3 b5 b7] T ;

[0012]

[0013] Where: ΔT1 is the adjustment amount of the first sickle bend of this steel block;

[0014] A is the weighting matrix of the influence of the odd-numbered bending amount of the upper steel block on the first bending amount of the current steel block;

[0015] B T This is the transpose of the matrix representing the bending values ​​of the upper steel head.

[0016] B is the matrix of values ​​for the bending of the upper steel head;

[0017] C i The bending amount of the sickle in the i-th pass of the upper steel block;

[0018] b i The value for the head bending of the i-th pass of the upper steel block is taken;

[0019] C′ i The threshold value for the bending amount of the sickle in the i-th pass is set.

[0020] i represents the number of passes;

[0021] Step 4: Calculate the first-pass camber leveling value for this steel block, using the following formula:

[0022] T = T1′ + ΔT1;

[0023] Where: T is the leveling value of the first sickle bend of this steel block;

[0024] ΔT1 is the adjustment amount for the first camber bend of this steel block;

[0025] T1′ is the actual leveling value of the first sickle bend of the upper steel block;

[0026] Step 5: Send the first pass camber leveling value of this steel block to the rolling foundation automation control system to realize automatic control of the first pass camber.

[0027] The impact of odd-numbered and even-numbered passes on camber in roughing steel production differs significantly. During odd-numbered passes, the workpiece may deviate due to the instantaneous inconsistency in speed before and after the rollers caused by the switching of speed direction, especially in reversible rolling processes. Since both the front and rear guide plates of R2 are electrically driven, their straightening capability for the slab is insufficient, and coupled with the odd number of rolling passes, camber may occur.

[0028] In contrast, during even-numbered rolling passes, the acceleration and deceleration sequence of the mill is the same as during odd-numbered passes, except that the direction of the speed setting is exactly opposite. Finishing mills typically roll the workpiece in 5-7 passes. Even-numbered passes usually involve straightening later to reduce camber. Therefore, this invention studies the influence of odd-numbered passes on the amount of camber in order to reduce its occurrence.

[0029] Furthermore, the relevant process parameters for the rough rolling sickle bend specifically include: the total number of rolling passes for the upper block steel, the total number of rolling passes for the current block steel, the rolling pass number, the head bending amount of each pass for the upper block steel, and the actual leveling value of the sickle bend in the first pass for the upper block steel.

[0030] Furthermore, the data preprocessing involves using the Raida criterion to remove outliers from the collected data.

[0031] Furthermore, the matrix A in step two is represented as follows:

[0032] When the total number of rolling passes N′ for the upper steel block is 7:

[0033] A = [a1 a3 a5 a7];

[0034] When the total number of rolling passes N′ for the upper steel block is 5:

[0035] A = [a1 a3 a5 0];

[0036] Where: a i Let i be the weight of the influence of the i-th bending amount of the upper block steel on the first bending amount of the current block steel, where i is 1, 3, 5, or 7.

[0037] Furthermore, the size range of the data in matrix A is:

[0038] 0.02≤a1<a3<a5<a7≤0.09;

[0039] Where: a iLet i be the weight of the influence of the i-th bending amount of the upper block steel on the first bending amount of the current block steel, where i is 1, 3, 5, or 7.

[0040] Secondly, the present invention also provides a computing device that has the function of implementing the method described in the first aspect. The beneficial effects are described in the first aspect and will not be repeated here. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function. In one possible design, the device structure includes an acquisition module and a training module; optionally, it may also include a construction module. These modules can implement the function of training nodes in the method examples of the first aspect, as detailed in the method examples, and will not be repeated here.

[0041] Thirdly, the present invention also provides a computing device for implementing the functions of the method described in the first aspect above. The beneficial effects are described in the first aspect and will not be repeated here. The computing device includes a processor and a memory, the memory being used to store instructions and / or data. The memory is coupled to the processor, and when the processor executes the program instructions stored in the memory, it can implement the function of the training node in the example of the first aspect above. The computing device also includes a communication interface for communicating with other devices.

[0042] Fourthly, the present invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the methods described in the first aspect and various possible designs of the first aspect.

[0043] Fifthly, the present invention also provides a computer program product containing instructions that, when run on a computer, cause the computer to perform the methods described in the first aspect and various possible designs of the first aspect.

[0044] In a sixth aspect, the present invention also provides a computing chip connected to a memory, the chip being used to read and execute a software program stored in the memory, and to execute the methods described in the first aspect and various possible implementations of the first aspect. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this drawing. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0046] Figure 1This is a flowchart of the steps of the present invention.

[0047] The purpose, features, and advantages of this accompanying drawing will be further explained in conjunction with the embodiments and with reference to the accompanying drawing. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0049] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0050] To better understand the solutions of the embodiments of the present invention, some related terms and concepts that may be involved in the embodiments of the present invention will be introduced below.

[0051] (1) Rough rolling is a metal processing technology, mainly used to pre-deform steel billets or slabs through a rolling mill to achieve the required basic size and shape. The main task of rough rolling is to widen the slab or flat ingot to the required width and perform large compression and elongation, thereby providing suitable intermediate billets for the subsequent finishing rolling process.

[0052] (2) Roughing sickle bend refers to the phenomenon of bending in the length direction of hot-rolled strip due to various factors during the roughing stage. This bending typically manifests as both sides of the strip bending to the same side, resembling a sickle, hence the name. The causes of sickle bend are complex and varied, including roll crossing, incoming material wedge shape, differences in stiffness on both sides of the mill, uneven temperature, and uneven roll wear. Sickle bend not only affects the quality of the strip but also the subsequent finishing rolling process and the processing performance of the product. For example, sickle bend can cause problems such as strip deviation and scraping during cold rolling, seriously affecting product quality. Therefore, controlling and eliminating sickle bend is crucial in actual production.

[0053] (3) The Raida criterion, also known as the three Sigma criterion, is a statistical method used to identify and eliminate gross errors. Based on the assumption of a normal distribution, this criterion determines an interval by calculating the standard deviation. Errors exceeding this interval are considered gross errors, not random errors, and should be eliminated. Specifically, the Raida criterion assumes that a set of test data contains only random errors and calculates the standard deviation. Then, based on the characteristics of a normal distribution, an interval is determined, typically the mean plus or minus three standard deviations. Data outside this interval are considered outliers or bad values ​​and should be eliminated.

[0054] (4) The camber control amount refers to the adjustment amount made during the hot rolling process to control the camber phenomenon of the slab. Specifically, the calculation and adjustment of the camber control amount involves multiple factors, including the wedge shape of the incoming material, the roll cross angle, the roll gap ratio, the reduction amount, and the slab thickness.

[0055] In this embodiment, as Figure 1 As shown, a method for controlling the first pass of the roughing mill sickle bend includes the following steps:

[0056] Step 1: Collect relevant process parameters for the rough rolling camber bend and perform data preprocessing;

[0057] Step 2: Based on the total number of rolling passes N′ of the upper steel block and the bending amount of each pass, obtain the influence weight of the bending amount of the i-th pass of the upper steel block on the bending amount of the first pass of the current steel block, denoted as a. i Let i be the number of channels, and take the influence weight of the odd number of channels, denoted as matrix A;

[0058] Based on a large amount of historical rolling data, when the bending amount of the upper block steel in the i-th pass exceeds the normal range, different adjustment amounts are given according to the degree of bending. The effect of the bending amount on the first pass of the lower block steel is observed and statistically analyzed to obtain the influence weight of the bending amount of the upper block steel in the i-th pass on the bending amount of the current block steel in the first pass.

[0059] Step 3: Based on the bending amount C of the sickle in the i-th pass of the upper steel block. i The formula for calculating the initial camber adjustment amount of this steel block is as follows:

[0060] ΔT1=AB T ;

[0061] B = [b1 b3 b5 b] 7 ];

[0062]

[0063] Where: ΔT1 is the adjustment amount of the first sickle bend of this steel block;

[0064] A is the weighting matrix of the influence of the odd-numbered bending amount of the upper steel block on the first bending amount of the current steel block;

[0065] B T This is the transpose of the matrix representing the bending values ​​of the upper steel head.

[0066] B is the matrix of values ​​for the bending amount of the upper steel head;

[0067] C i The bending amount of the sickle in the i-th pass of the upper steel block;

[0068] b i The value for the head bending of the i-th pass of the upper steel block is taken;

[0069] C′ i The threshold value for the bending amount of the sickle in the i-th pass is set.

[0070] i represents the number of passes;

[0071] Step 4: Calculate the first-pass camber leveling value for this steel block, using the following formula:

[0072] T = T′1 + ΔT1;

[0073] Where: T is the leveling value of the first sickle bend of this steel block;

[0074] ΔT1 is the adjustment amount for the first camber bend of this steel block;

[0075] T′1 is the actual leveling value of the first sickle bend of the upper steel block;

[0076] Step 5: Send the first pass camber leveling value of this steel block to the rolling foundation automation control system to realize automatic control of the first pass camber.

[0077] The impact of odd-numbered and even-numbered passes on camber in roughing steel production differs significantly. During odd-numbered passes, the workpiece may deviate due to the instantaneous inconsistency in speed before and after the rollers caused by the switching of speed direction, especially in reversible rolling processes. Since both the front and rear guide plates of R2 are electrically driven, their straightening capability for the slab is insufficient, and coupled with the odd number of rolling passes, camber may occur.

[0078] In contrast, during even-numbered rolling passes, the acceleration and deceleration sequence of the mill is the same as during odd-numbered passes, except that the direction of the speed setting is exactly opposite. Finishing mills typically roll the workpiece in 5-7 passes. Even-numbered passes usually involve straightening later to reduce camber. Therefore, this invention studies the influence of odd-numbered passes on the amount of camber in order to reduce its occurrence.

[0079] Furthermore, the relevant process parameters for the roughing rolling sickle bend include: the total number of rolling passes for the upper block steel, the total number of rolling passes for the current block steel, the rolling pass number, the head bending amount of each pass for the upper block steel, and the actual leveling value of the sickle bend in the first pass for the upper block steel.

[0080] Furthermore, data preprocessing involves using the Raida criterion to remove outliers from the collected data.

[0081] The Raida criterion, also known as the three sigma criterion, is a statistical method used to identify and eliminate gross errors. Based on the assumption of a normal distribution, this criterion calculates the standard deviation to determine an interval; errors exceeding this interval are considered gross errors rather than random errors and should be eliminated.

[0082] Specifically, the Raida criterion assumes that a set of test data contains only random errors and calculates the standard deviation. Then, based on the characteristics of the normal distribution, an interval is determined, usually the mean plus or minus three standard deviations. Data outside this interval are considered outliers or bad values ​​and should be removed.

[0083] Furthermore, the representation of matrix A in step two is as follows:

[0084] When the total number of rolling passes N′ for the upper steel block is 7:

[0085] A = [a1 a3 a5 a7];

[0086] When the total number of rolling passes N′ for the upper steel block is 5:

[0087] A = [a1 a3 a5 0];

[0088] Where: a i Let i be the weight of the influence of the i-th bending amount of the upper block steel on the first bending amount of the current block steel, where i is 1, 3, 5, or 7.

[0089] Furthermore, the size range of the data in matrix A is:

[0090] 0.02≤a1<a3<a5<a7≤0.09;

[0091] Where: a i Let i be the weight of the influence of the i-th bending amount of the upper block steel on the first bending amount of the current block steel, where i is 1, 3, 5, or 7.

[0092] In this embodiment, the total number of rolling passes for the upper steel block is 7, i.e., N′=7, and matrix A is represented as follows:

[0093] A = [a1 a3 a5 a7];

[0094] The actual matrix A obtained is:

[0095] A = [0.09 0.05 0.03 0.02];

[0096] The bending value of the upper steel sickle is:

[0097] C1=45, C3=32, C5=23, C7=10;

[0098] The threshold value for the bending amount of the sickle set for the i-th pass is:

[0099] C′1=40, C′3=30, C′5=C′7=25;

[0100] The resulting matrix B, representing the bending values ​​at the head of the upper steel piece, is:

[0101] B = [1 1 0 0];

[0102] The adjustment amount ΔT1 for the first camber bend of this steel block is calculated according to the formula as follows:

[0103] ΔT1 = 0.14;

[0104] The total number of rolling passes for this steel block is 5, i.e., N=5. The actual leveling value T′1 of the first pass of the previous steel block is the reference value of the first pass of this steel block, which is taken as 0.1. Then, the leveling value T of the first pass of this steel block is calculated according to the formula:

[0105] T = T′1 + ΔT1;

[0106] With T=0.24 obtained, the first pass camber leveling value of this steel block is sent to the automatic control system of the rolling base to complete the automatic control of the first pass camber of the slab, reducing the camber situation of the first pass of roughing rolling by more than 85%.

[0107] It should be noted that the present invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments that have the same structure and perform the same effects as the technical concept within the scope of the present invention are included within the scope of the present invention. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of the present invention, are also included within the scope of the present invention.

Claims

1. A method for controlling the first pass of a roughing mill sickle bend, characterized in that, Includes the following steps: Step 1: Collect relevant process parameters for the rough rolling camber bend and perform data preprocessing; Step 2: Based on the total number of rolling passes of the upper steel block The influence weight of the bending amount of the upper steel block in the first bending step on the bending amount of the current steel block in the first bending step is obtained by considering the bending amount of each bending step. This weight is denoted as... Let i be the number of channels, and take the influence weight of the odd number of channels, denoted as matrix A; Step 3: Based on the bending amount of the sickle in the i-th pass of the upper steel block. The formula for calculating the initial camber adjustment amount of this steel block is as follows: ； ； ； in: The amount of the first sickle bend adjustment for this steel block; This is the weighting matrix for the influence of odd-numbered bending passes of the upper steel block on the first bending pass of the current steel block. This is the transpose of the matrix representing the bending values ​​of the upper steel head. This is a matrix representing the bending values ​​of the upper steel head. The bending amount of the sickle in the i-th pass of the upper steel block; The value for the head bending of the i-th pass of the upper steel block is taken; The threshold value for the bending amount of the sickle in the i-th pass is set. The number of times for the Tao; Step 4: Calculate the first-pass camber leveling value for this steel block, using the following formula: ； in: This is the leveling value for the first sickle bend of this steel block; The amount of the first sickle bend adjustment for this steel block; This is the actual leveling value for the first sickle bend of the upper steel block; Step 5: Send the first pass camber leveling value of this steel block to the automatic control system of the rolling base to realize automatic control of the first pass camber. The relevant process parameters for the rough rolling sickle bend include: total rolling passes of the upper block steel, total rolling passes of the current block steel, rolling pass number, head bending amount of each pass of the upper block steel, and actual leveling value of the sickle bend of the first pass of the upper block steel. The data preprocessing involves using the Raida criterion to remove outliers from the collected data.

2. The method for controlling the first pass of the roughing mill sickle bend according to claim 1, characterized in that, In step two, matrix A is represented as follows: Total number of rolling passes for the steel block It is 7 o'clock: ； Total number of rolling passes for the steel block When it is 5: ； in: Let i be the weight of the influence of the i-th bending amount of the upper block steel on the first bending amount of the current block steel, where i is 1, 3, 5, or 7.

3. The method for controlling the first pass of the roughing mill sickle bend according to claim 2, characterized in that, The size range of the data in matrix A is: ； in: Let i be the weight of the influence of the i-th bending amount of the upper block steel on the first bending amount of the current block steel, where i is 1, 3, 5, or 7.

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