Strip rolling load optimization method and device based on strip cold rolling strip break prediction, storage medium and computer equipment

Abstract

The application discloses a strip steel cold rolling strip breaking prediction-based rolling load optimization method and device, a storage medium and computer equipment, and the method comprises the following steps: determining whether the strip steel currently exists a strip breaking risk based on the current reduction rate ε of the strip steel, if yes, adjusting the reduction rate ε of the strip steel to not exist the strip breaking risk, and adaptively adjusting the current rolling load of the strip steel. Based on the rolling principle and mechanical analysis, a mathematical model of the rolling load, the strip steel performance and the roll diameter is derived when the strip breaking does not occur in the cold rolling process, the mathematical model is used for the pre-judgment of the strip breaking risk of the strip steel, and the current reduction rate of the strip steel is optimized through the mathematical model, so that the strip breaking risk in the cold rolling process of the strip steel is reduced, the product quality is improved, the production failure is reduced, and the production efficiency of the cold rolling machine is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cold rolling, and more particularly, relates to a rolling load optimization method and device based on strip break prediction in cold rolling, a storage medium and computer equipment. BACKGROUND

[0002] For the cold rolling process, rolling load distribution is a main factor to ensure the smooth progress of cold rolling, which is directly related to the output, production cost and product quality of the rolling mill.

[0003] At present, the rolling load of single stand reversible cold rolling mainly adopts the minimum energy consumption target method, the relative equal load rolling target, the comprehensive equal load function target, the optimal shape target method and the prevention of slipping target, and the multi-objective optimization algorithm to optimize the single stand rolling schedule, but most of these methods are based on the optimization of rolling load of cold rolling thickness, rolling force and energy parameters, and plate shape quality parameters, without considering the influence of incoming steel performance and roll size on rolling break.

[0004] When the cold rolling raw material has good elongation and low strength, the commonly used rolling load calculation method can basically ensure the smooth progress of production, and when the cold rolling raw material has high strength and poor elongation, such materials are prone to break under the current rolling load distribution method, which cannot ensure the smooth progress of production and seriously affects the product quality and production efficiency. SUMMARY

[0005] The application provides a rolling load optimization method based on strip break prediction in cold rolling, aiming to improve the above problems.

[0006] The application is implemented as follows: a rolling load optimization method based on strip break prediction in cold rolling, the method is as follows:

[0007] Determine whether the strip currently has a risk of breakage based on the current reduction rate ε of the strip, if there is, adjust the reduction rate ε of the strip to eliminate the risk of breakage, and adaptively adjust the current rolling load of the strip.

[0008] Further, when the current reduction rate ε of the strip does not satisfy the following formula (1) or formula (2), it is determined that the strip currently has a risk of breakage:

[0009]

[0010] Wherein, u is an intermediate variable, Δl is the elongation of the strip, h r is the thickness of the rolling piece at the inlet, R is the radius of the roll; F is the current rolling force, K b is the tensile stress σ b corresponding to the plane deformation resistance, B is the width of the strip;

[0011] Further, when it is determined that the strip currently has a risk of strip breakage, the current rolling reduction rate of the strip is adjusted to satisfy the above formula (1) and formula (2).

[0012] Further, the maximum reduction rate satisfying the formula (1) and formula (2) is selected as the current reduction rate of the strip.

[0013] The present application is realized in a rolling load optimization device based on strip cold rolling strip breakage prediction, the device comprises: a strip breakage risk determination unit and an optimization unit, wherein,

[0014] The strip breakage risk determination unit is used to determine whether the strip currently has a risk of strip breakage according to the current reduction rate of the strip, and if so, the reduction rate of the strip is adjusted by the optimization unit to eliminate the risk of strip breakage, and the current rolling load of the strip is adjusted adaptively.

[0015] Further, when the strip breakage risk determination unit detects that the current reduction rate of the strip does not satisfy the following formula (1) or formula (2), it is determined that the strip currently has a risk of strip breakage:

[0016]

[0017]

[0018] Wherein, u is an intermediate variable, Δl is the elongation of the strip, h r is the thickness of the rolling piece at the inlet, R is the roll radius; F is the current rolling force, K b is the tensile stress σ b Corresponding to the plane deformation resistance, B is the width of the strip.

[0019] Further, when it is determined that the strip currently has a risk of strip breakage, the current rolling reduction rate of the strip is adjusted to satisfy the above formula (1) and formula (2).

[0020] Further, the optimization unit selects the maximum reduction rate satisfying the formula (1) and formula (2) as the current reduction rate of the strip.

[0021] The present application is realized in a storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the above-mentioned rolling load optimization method based on strip cold rolling strip breakage prediction.

[0022] The present application is realized in a storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the above-mentioned rolling load optimization method based on strip cold rolling strip breakage prediction.

[0023] The present application is based on the rolling principle and the mechanical analysis to deduce the mathematical model of the rolling load, the strip steel performance and the roll diameter when the strip steel does not break in the cold rolling process, to predict the risk of strip steel breakage based on the mathematical model, and to optimize the current reduction rate of the strip steel through the mathematical model to reduce the risk of strip steel breakage in the cold rolling process, improve the product quality, reduce the production failure and improve the production efficiency of the cold rolling mill. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The flow chart of the rolling load optimization method based on the strip steel cold rolling breakage prediction provided for the embodiment of the present application is shown in the figure;

[0025] Figure 2 The structure schematic diagram of the rolling load optimization device based on the strip steel cold rolling breakage prediction provided for the embodiment of the present application is shown in the figure;

[0026] Figure 3 The schematic diagram of the strip steel cold rolling process provided for the embodiment of the present application is shown in the figure. IMPLEMENTATION

[0027] The specific embodiments of the present application are further described below with reference to the figures and the description of the embodiments, to help the skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present application.

[0028] In the theory of material mechanics, the extension deformation hypothesis is the uniform deformation in the gauge length, so the ratio of the extension amount Δl to the gauge length l is the elongation The mechanical properties are the same everywhere in the solid material, but in the actual process, for the strip steel with poor elongation, the mechanical properties of each grain are not completely the same, and the extension amount only occurs in the local part, mainly in the fracture part of the strip steel.

[0029] The horizontal projection length of the contact arc of the rolled piece and the roll is called the roll contact arc length, as shown in the figure Figure 3 It can be seen that in the rolling process, the extension amount only occurs in the steel section corresponding to the rolling contact arc length, and the contact arc length in the rolling process has a corresponding relationship with the extension amount in the tensile test. At the same time, the internal stress σ of the rolled piece needs to be between the yield stress σ s and the tensile stress σ b , that is, σ s <σ<σ b Therefore, it can be known that:

[0030] The condition for the strip steel to have the risk of breakage is that the extension amount Δl of the strip steel is less than the extension amount λ in the rolling process, or σ>σ b .

[0031] The condition for the strip steel to have no risk of breakage is that the extension amount Δl of the strip steel is greater than the extension amount λ in the rolling process, and σ<σb .

[0032] Based on the above conditions of the risk of strip breakage, the elongation Δl of the strip, the yield stress σ s and the tensile stress σ b are inherent properties of the material, according to the rolling principle, the contact arc length of the roller during cold rolling is the cause of the elongation of the strip, and the cold rolling reduction and the contact arc length of the roller are the causes of the actual internal stress change of the strip.

[0033] According to the elongation Δl of the strip > the elongation λ during rolling, the condition that the reduction rate satisfies is derived:

[0034] According to the principle of invariable volume, the elongation rate δ during cold rolling satisfies the equation: Wherein, h r is the thickness of the rolled piece at the inlet, and h c is the thickness of the rolled piece at the outlet;

[0035] The contact arc length l of the roller is: Wherein, R is the radius of the roller, and Δh is the thickness difference between the inlet and the outlet of the rolled piece, Δh = h r -h c ;

[0036] The elongation λ during rolling: λ = lδ;

[0037] From the elongation Δl of the strip > the elongation λ during rolling, the following formula is obtained:

[0038]

[0039] The rolling reduction rate is brought into formula (1) to obtain:

[0040]

[0041] Let the intermediate parameter and u > 0, formula (2) is simplified as the following formula:

[0042] ε 3 -u(1-ε 2 )<0 (3)

[0043] ε 3 -uε 2 +2uε-u<0 (4)

[0044] For a monomial cubic equation: ax 3 +bx 2 +cx+d = 0, when the Cardan formula discriminant At this time, there is only one solution:

[0045]

[0046] wherein,

[0047] According to the rolling theory, the rolling reduction rate is 0 < ε < 1, u > 0 in this interval is a monotonic increasing function, it can be known that the discriminant of the Kadan formula has one solution. The formula (4) is brought into the Kadan formula (5) to obtain:

[0048]

[0049] wherein, u is an intermediate variable, Δl is the elongation of the strip, h r is the thickness of the rolling piece at the inlet, and R is the radius of the roll.

[0050] (2) According to the plastic deformation of the rolling piece, no fracture occurs, at this time, the internal stress of the rolling piece needs to meet σ < σ b ; according to the rolling theory, the plane deformation resistance during rolling is the internal stress K of the rolling piece during rolling, K = 1.15σ q ; the rolling force wherein, B is the width of the strip, and thus it can be known that, in the actual cold rolling process, the rolling load is determined by the actual rolling force, the roll diameter, and the internal stress of the material, and the internal stress of the rolling piece needs to meet σ < σ b , and thus it can be known that:

[0051]

[0052] wherein, F is the current rolling force, K b is the tensile stress σ b corresponding to the plane deformation resistance, and B is the width of the strip.

[0053] Figure 1 A flowchart of the rolling load optimization method based on the strip cold rolling strip breakage prediction provided by the embodiment of the present application is shown in the figure, and the method is specifically as follows:

[0054] Whether the strip currently exists the strip breakage risk is determined based on the current reduction rate ε of the strip, if yes, the reduction rate ε of the strip is adjusted to not exist the strip breakage risk, and the current rolling load of the strip is self-adaptively adjusted. Specifically, when the reduction rate ε of the strip meets the above formula (6) and formula (7), the strip does not exist the strip breakage risk, of course, when the reduction rate ε of the strip does not meet the above formula (6) or formula (7), the strip currently exists the strip breakage risk.

[0055] Therefore, the present application judges the strip breaking risk of the current strip steel based on the above formula (6) and formula (7), when it is judged that the strip steel currently does not have the strip breaking risk, the rolling reduction of the strip steel does not need to be adjusted, and when it is judged that the strip steel currently has the strip breaking risk, the current rolling reduction of the strip steel is adjusted to satisfy the above formula (6) and formula (7), and the maximum rolling reduction satisfying the formula (6) and formula (7) is selected as the current rolling reduction, and then the current rolling load is adaptively adjusted.

[0056] Figure 2 The structure schematic diagram of the rolling load optimization device based on the strip steel cold rolling strip breaking prediction provided by the embodiment of the present application is shown, only the parts related to the embodiment of the present application are shown for the convenience of description, the device comprises a strip breaking risk judging unit and an optimization unit, wherein,

[0057] The strip breaking risk judging unit is used for judging whether the strip steel currently has the strip breaking risk according to the current rolling reduction of the strip steel, if yes, the rolling reduction of the strip steel is adjusted to not have the strip breaking risk by the optimization unit, and the current rolling load of the strip steel is adaptively adjusted.

[0058] In the embodiment of the present application, when the strip breaking risk judging unit detects that the current rolling reduction of the strip steel does not satisfy the following formula (6) or formula (7), it is judged that the strip steel currently has the strip breaking risk:

[0059] When the strip breaking risk judging unit judges that the strip steel currently has the strip breaking risk, the optimization unit adjusts the current rolling reduction of the strip steel to satisfy the above formula (6) and formula (7), in order to further improve the work efficiency, in the case of not having the strip breaking risk, the optimization unit selects the maximum rolling reduction satisfying the formula (6) and formula (7) as the current rolling reduction of the strip steel.

[0060] The embodiment of the present application further provides a storage medium which stores a computer program, and the computer program is executed by a processor to realize the steps of the above rolling load optimization method based on the strip steel cold rolling strip breaking prediction.

[0061] The embodiment of the present application provides a computer device which comprises a processor and a storage medium storing program code, and the program code is executed by the processor to realize the steps of the above rolling load optimization method based on the strip steel cold rolling strip breaking prediction.

[0062] The present application is described exemplarily, and it is obvious that the specific implementation of the present application is not limited by the above method, as long as various non-essential improvements are adopted, or the concept and technical scheme of the present application are directly applied to other occasions without improvement, all of which are within the protection scope of the present application.

Claims

1. A method for optimizing rolling load based on strip cold rolling strip break prediction, characterized in that, The method is specifically as follows: based on the current reduction ratio of the strip determining whether the strip currently has a risk of breakage, and if so, adjusting the reduction ratio of the strip to the absence of the risk of breakage and the current rolling load of the strip is adjusted adaptively; at the current reduction ratio of the strip The strip is determined to be at risk of breaking if the following equation (1) or equation (2) is not satisfied: （1） （2） wherein is an intermediate variable, , is the elongation of the strip, is the entry thickness of the rolled piece, is the roll radius; is the current rolling force, is the tensile stress is the corresponding plane deformation resistance, is the strip width.

2. The method for strip rolling load optimization based on strip cold rolling strip break prediction according to claim 1, characterized in that, adjusting the current reduction ratio of the strip steel when it is determined that the strip steel currently has a risk of strip breakage to satisfy the above formula (1) and formula (2).

3. The method for strip rolling load optimization based on strip cold rolling strip break prediction according to claim 2, characterized in that, The maximum reduction rate satisfying the formula (1) and the formula (2) is selected as the current reduction rate of the strip.

4. A rolling load optimization device based on strip cold rolling strip break prediction, characterized by, The device comprises a strip breakage risk judging unit and an optimization unit, wherein, a strip break risk determination unit configured to determine whether the strip currently has a strip break risk according to a current reduction ratio of the strip determine whether the strip currently has a strip break risk, and if so, adjust the reduction ratio of the strip through the optimization unit to a situation where the strip does not have a strip break risk, and the rolling load of the strip is adaptively adjusted The strip breakage risk determination unit detects the current reduction ratio of the strip steel When the following equation (1) or equation (2) is not satisfied, it is determined that the strip steel currently has a strip breakage risk: （1） （2） wherein is an intermediate variable, , is the elongation of the strip, is the entry thickness of the rolled piece, is the roll radius; is the current rolling force, is the tensile stress is the corresponding plane deformation resistance, is the strip width.

5. The strip rolling load optimization device based on strip cold rolling strip break prediction according to claim 4, characterized in that, When it is determined that the strip currently has a risk of breakage, the optimization unit adjusts the current reduction ratio of the strip to satisfy the above formula (1) and formula (2).

6. The strip rolling load optimization device based on strip cold rolling strip break prediction according to claim 5, wherein, The optimization unit selects the maximum reduction rate satisfying formula (1) and formula (2) as the current reduction rate of the strip.

7. A storage medium storing a computer program, characterized by The computer program, when executed by a processor, implements the steps of the rolling load optimization method based on strip breakage prediction in cold rolling of strip steel according to any one of claims 1 to 3.

8. A computer device comprising a processor and a storage medium having stored program code, characterized in that, The program code, when executed by a processor, implements the steps of the rolling load optimization method based on strip breakage prediction in cold rolling of strip steel according to any one of claims 1 to 3.

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