Method, device and equipment for obtaining cold-rolled strip tension setting value

Abstract

The present application relates to the technical field of steel rolling, and discloses a cold-rolled strip tension setting value acquisition method, device and equipment. The method comprises the following steps: obtaining rolling process parameters; setting an entry tension stress condition, an exit tension stress condition and a roll gap front slip zone proportion critical value based on the rolling process parameters; calculating the roll gap front slip zone proportion under the entry tension stress condition and the exit tension stress condition; judging whether the roll gap front slip zone proportion reaches a preset roll gap front slip zone proportion critical value; and when the preset roll gap front slip zone proportion critical value is reached, calculating the entry tension and the exit tension according to the entry tension stress and the exit tension stress output by iteration update, respectively. The present application is based on the quantitative relationship between the cold-rolled strip rolling entry, exit tension stress and roll gap front slip zone proportion, and the entry and exit tension stresses are continuously iteratively optimized to adjust the roll gap front slip zone proportion to the critical value. The iterative calculation is stable and fast, and is used for entry and exit tension presetting calculation, so that the roll gap does not slip during the rolling process, and the production stability is improved.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, and in particular to a method, apparatus and equipment for obtaining the tension setting value of cold-rolled strip steel. Background Technology

[0002] As the cold rolling speed of strip steel increases, the temperature and friction conditions in the roll gap deformation zone become extremely complex, easily leading to hot slip marks and scratches on the strip surface, severely reducing product surface quality and grade. These defects are caused by roll gap slippage during rolling, where the roll linear velocity exceeds the strip exit velocity, causing relative sliding between the strip and roll. Essentially, the roll gap deformation zone is completely replaced by the backward slip zone, the forward slip zone disappears, and the neutral plane appears outside the roll gap deformation zone. Therefore, to avoid roll gap slippage during rolling, a certain proportion of forward slip zone must be maintained in the roll gap. The strip rolling inlet and outlet tensions are crucial factors affecting the formation of the forward slip zone. After determining relevant process parameters such as roll diameter, strip inlet and outlet thickness, and roll gap lubrication conditions, the influence of strip tension on roll gap slippage needs to be considered to determine the set values ​​for the strip rolling inlet and outlet tensions. Summary of the Invention

[0003] The main objective of this invention is to provide a method, apparatus, and equipment for obtaining the tension setting value of cold-rolled strip steel, aiming to solve at least one of the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention provides a method for obtaining the tension setpoint of cold-rolled strip steel, comprising:

[0005] Obtain the rolling process parameters for cold-rolled strip steel;

[0006] Based on the rolling process parameters, the inlet tension stress condition, the outlet tension stress condition, and the critical value of the roll gap forward slip zone ratio are set.

[0007] Calculate the proportion of the roll gap front slip zone under the inlet tension stress condition and the outlet tension stress condition;

[0008] Determine whether the proportion of the roll gap forward sliding zone reaches the preset critical value of the roll gap forward sliding zone proportion;

[0009] When the proportion of the roll gap forward slip zone reaches the preset critical value, the inlet tension and outlet tension are calculated based on the inlet tension and outlet tension output by iterative update.

[0010] In some embodiments, setting the inlet tensile stress condition, the outlet tensile stress condition, and the critical value of the roll gap forward slip ratio based on the rolling process parameters includes:

[0011] The inlet strip yield strength and outlet strip yield strength are obtained based on the rolling process parameters.

[0012] The initial, minimum, and maximum values ​​of the inlet tensile stress are set according to the product of different preset multiples and the yield strength of the inlet strip.

[0013] The initial, minimum, and maximum values ​​of the inlet tensile stress are used as the inlet tensile stress conditions;

[0014] The initial, minimum, and maximum values ​​of the exit tensile stress are set according to the product of different preset multiples and the yield strength of the exit strip.

[0015] The initial, minimum, and maximum values ​​of the outlet tensile stress are used as the outlet tensile stress conditions.

[0016] Set the critical value for the proportion of the roll gap front slip zone.

[0017] In some embodiments, the initial value of the inlet tensile stress is 0.1 times the yield strength of the inlet strip, the minimum value is 0.02 times the yield strength of the inlet strip, and the maximum value is 0.3 times the yield strength of the inlet strip; the initial value of the outlet tensile stress is 0.1 times the yield strength of the outlet strip, the minimum value is 0.02 times the yield strength of the outlet strip, and the maximum value is 0.3 times the yield strength of the outlet strip; the critical value of the roll gap forward slip zone ratio ranges from 0.1 to 0.5.

[0018] In some embodiments, calculating the roll gap forward slip ratio under the inlet tension stress condition and the outlet tension stress condition includes:

[0019] An initial roll profile curve is set under the inlet and outlet tension conditions, and the workpiece inlet position is determined.

[0020] Calculate the unit pressure of each section of the back slip zone from the inlet to the outlet based on the inlet position of the rolled piece;

[0021] Calculate the unit pressure of each section of the forward slip zone from the outlet to the inlet;

[0022] The distribution of unit pressure in each segment of the roll gap deformation zone is determined based on the unit pressure in each segment of the rear sliding zone and the unit pressure in each segment of the front sliding zone.

[0023] Calculate the roll gap thickness distribution based on the unit pressure distribution of each segment;

[0024] Determine whether the roll gap thickness distribution obtained from two consecutive calculations converges;

[0025] The roll gap thickness distribution is calculated upon convergence; otherwise, the next iteration is performed until the roll gap thickness distribution converges.

[0026] After iterative convergence, the proportion of the front slip zone of the roll gap is obtained based on the unit pressure distribution of each segment and the boundary between the front slip zone and the back slip zone.

[0027] In some embodiments, determining whether the roll gap forward slip ratio reaches a preset roll gap forward slip ratio threshold includes:

[0028] Set the precision factor;

[0029] The judgment value is obtained by multiplying the accuracy coefficient with the preset critical value of the roll gap front slip zone ratio;

[0030] Calculate the difference between the roll gap forward slip zone ratio and the preset roll gap forward slip zone ratio critical value;

[0031] Compare the absolute value of the difference with the judgment value;

[0032] If the absolute value of the difference is less than or equal to the judgment value, then it is determined that the proportion of the roll gap front slip zone has reached the preset critical value of the roll gap front slip zone proportion.

[0033] In some embodiments, after determining whether the roll gap forward slip ratio reaches a preset roll gap forward slip ratio critical value, the method further includes:

[0034] When the proportion of the roll gap forward sliding zone does not reach the preset critical value of the roll gap forward sliding zone proportion, it is determined whether the current exit tension has reached the maximum value of the exit tension.

[0035] If the current exit tension does not reach the maximum value of the exit tension, the current exit tension is updated using the secant method, and the process returns to the step of calculating the roll gap forward slip ratio under the inlet tension condition and the exit tension condition, until the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value.

[0036] If the current exit tension reaches the maximum value of the exit tension, then the current exit tension is set to the maximum value of the exit tension, and the inlet tension is updated using the secant method. Then, the process returns to the step of calculating the roll gap forward slip ratio under the inlet tension condition and the exit tension condition, until the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value.

[0037] In some embodiments, updating the current exit tensile stress using the secant method includes:

[0038] The proportional relationship is determined based on the secant method;

[0039] Obtain the increment of the outlet tensile stress after iterative calculation;

[0040] The current exit tension is iteratively updated based on the exit tension increment and the proportional relationship to obtain the corrected exit tension.

[0041] In some embodiments, the rolling process parameters include strip inlet thickness, strip outlet thickness, strip width, inlet strip yield strength, outlet strip yield strength, work roll diameter, and roll gap friction coefficient.

[0042] Furthermore, to achieve the above objectives, the present invention also proposes a device for obtaining the tension setting value of cold-rolled strip steel, comprising:

[0043] The parameter acquisition module is used to acquire the rolling process parameters of cold-rolled strip steel.

[0044] The condition setting module is used to set the inlet tension stress condition, the outlet tension stress condition, and the critical value of the roll gap forward slip zone ratio based on the rolling process parameters.

[0045] The proportional calculation module is used to calculate the proportion of the roll gap front slip zone under the inlet tension stress condition and the outlet tension stress condition.

[0046] The critical judgment module is used to determine whether the proportion of the roll gap front sliding zone reaches the preset critical value of the roll gap front sliding zone proportion.

[0047] The tension calculation module is used to calculate the inlet tension and outlet tension respectively based on the inlet tension and outlet tension output by iterative update when the proportion of the roll gap front slip zone reaches the preset critical value of the roll gap front slip zone proportion.

[0048] Furthermore, to achieve the above objectives, the present invention also proposes an electronic device, the electronic device comprising: a memory, a processor, and a cold-rolled strip tension setting value acquisition program stored in the memory and executable on the processor, the cold-rolled strip tension setting value acquisition program being configured to implement the cold-rolled strip tension setting value acquisition method as described above.

[0049] This invention provides a method for obtaining the tension setting value of cold-rolled strip steel, comprising: obtaining the rolling process parameters of cold-rolled strip steel; setting the inlet tension stress condition, the outlet tension stress condition, and the critical value of the roll gap forward slip ratio based on the rolling process parameters; calculating the roll gap forward slip ratio under the inlet tension stress condition and the outlet tension stress condition; determining whether the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value; and when the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value, calculating the inlet tension and outlet tension respectively based on the iteratively updated inlet tension and outlet tension. Based on the established quantitative relationship between the inlet tension stress, outlet tension stress, and roll gap forward slip ratio of cold-rolled strip steel, this invention continuously iteratively optimizes the inlet tension stress and outlet tension stress, adjusting the roll gap forward slip ratio to a critical value range. The iterative calculation is stable and fast, and can be used for the preset calculation of the inlet tension and outlet tension of cold-rolled strip steel, thereby ensuring that the roll gap does not slip during the rolling process and improving production stability. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of an electronic device in the hardware operating environment involved in the embodiments of the present invention;

[0051] Figure 2 This is a flowchart illustrating an embodiment of the method for obtaining the tension setting value of cold-rolled strip steel according to the present invention;

[0052] Figure 3 This is an example flowchart of a method for obtaining the tension setting value of cold-rolled strip steel according to an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram illustrating the calculation principle of the secant method involved in the embodiments of the present invention;

[0054] Figure 5 This is a structural block diagram of an embodiment of the cold-rolled strip tension setting value acquisition device of the present invention.

[0055] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0057] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0058] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0059] Reference Figure 1, Figure 1 This is a schematic diagram of the electronic device structure of the hardware operating environment involved in the embodiments of the present invention.

[0060] like Figure 1 As shown, the electronic device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be high-speed random access memory (RAM) or stable non-volatile memory (NVM), such as a disk drive. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0061] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the electronic device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0062] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a program for acquiring the tension setting value of cold-rolled strip steel.

[0063] exist Figure 1 In the electronic device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the electronic device of the present invention can be set in the electronic device, and the electronic device calls the cold-rolled strip tension setting value acquisition program stored in the memory 1005 through the processor 1001, and executes the cold-rolled strip tension setting value acquisition method provided in the embodiment of the present invention.

[0064] This invention proposes a method, apparatus, and equipment for obtaining the tension setting value of cold-rolled strip steel.

[0065] This invention provides a method for obtaining the tension setting value of cold-rolled strip steel, referring to... Figure 2 , Figure 2This is a flowchart illustrating an embodiment of the method for obtaining the tension setting value of cold-rolled strip steel according to the present invention.

[0066] like Figure 2 As shown, the method for obtaining the tension setting value of cold-rolled strip includes:

[0067] Step S100: Obtain the rolling process parameters for cold-rolled strip steel;

[0068] Step S200: Based on the rolling process parameters, set the inlet tension stress condition, the outlet tension stress condition, and the critical value of the roll gap forward slip zone ratio;

[0069] Step S300: Calculate the proportion of the roll gap forward slip zone under the inlet tension stress condition and the outlet tension stress condition;

[0070] Step S400: Determine whether the ratio of the roll gap forward sliding zone has reached the preset critical value of the roll gap forward sliding zone ratio;

[0071] Step S500: When the proportion of the roll gap forward slip zone reaches the preset critical value of the roll gap forward slip zone proportion, calculate the inlet tension and outlet tension respectively based on the inlet tension and outlet tension output by the iterative update.

[0072] It should be noted that the execution subject in this embodiment can be an electronic device, which can be a computer device with data processing function, or other devices that can achieve the same or similar functions. This embodiment does not limit this. In this embodiment, a computer device is used as an example for explanation.

[0073] In one embodiment, rolling process parameters for cold-rolled strip are obtained. These rolling process parameters include, but are not limited to, strip inlet thickness, strip outlet thickness, strip width, inlet strip yield strength, outlet strip yield strength, work roll diameter, and roll gap friction coefficient.

[0074] Specifically, the rolling process parameters for cold-rolled strip steel are obtained, including but not limited to the strip entry thickness h0, exit thickness h1, strip width B, and entry strip yield strength σ. s0 Yield strength σ of exported strip steel s1 The working roll diameter D and the roll gap friction coefficient μ.

[0075] In one embodiment, setting the inlet tensile stress condition, the outlet tensile stress condition, and the critical value of the roll gap forward slip ratio based on the rolling process parameters includes: obtaining the inlet strip yield strength and the outlet strip yield strength according to the rolling process parameters; setting the initial, minimum, and maximum values ​​of the inlet tensile stress according to different preset multiples and the product of the inlet strip yield strength; using the initial, minimum, and maximum values ​​of the inlet tensile stress as the inlet tensile stress condition; setting the initial, minimum, and maximum values ​​of the outlet tensile stress according to different preset multiples and the product of the outlet strip yield strength; using the initial, minimum, and maximum values ​​of the outlet tensile stress as the outlet tensile stress condition; and setting the critical value of the roll gap forward slip ratio.

[0076] In one embodiment, the initial value of the inlet tensile stress is 0.1 times the yield strength of the inlet strip, the minimum value is 0.02 times the yield strength of the inlet strip, and the maximum value is 0.3 times the yield strength of the inlet strip; the initial value of the outlet tensile stress is 0.1 times the yield strength of the outlet strip, the minimum value is 0.02 times the yield strength of the outlet strip, and the maximum value is 0.3 times the yield strength of the outlet strip; the critical value of the roll gap forward slip zone ratio ranges from 0.1 to 0.5.

[0077] Specifically, the initial value of the inlet tensile stress is set. Minimum value t 0min and the maximum value t 0max The initial value of the outlet tensile stress Minimum value t 1min and the maximum value t 1max And the critical value η0 of the proportion of the roll gap front slip zone.

[0078] For example, an initial value is set for the inlet tensile stress. 0.1σ s0 Minimum value t 0min 0.02σ s0 Maximum value t 0max 0.3σ s0 Setting the outlet tensile stress The initial value is 0.1σ s1 Minimum value t 1min 0.02σ s1 Maximum value t 1max 0.3σ s1 The critical value η0 for the proportion of the roll gap forward slip zone ranges from 0.1 to 0.5. This embodiment uses a critical value η0 of 0.15 as an example for illustration.

[0079] In one embodiment, calculating the roll gap forward slip ratio under the inlet and outlet tension stress conditions includes: setting an initial roll profile curve and determining the workpiece inlet position under the inlet and outlet tension stress conditions; calculating the unit pressure of each segment of the backward slip zone from the inlet to the outlet based on the workpiece inlet position; calculating the unit pressure of each segment of the forward slip zone from the outlet to the inlet; determining the unit pressure distribution of each segment of the roll gap deformation zone based on the unit pressure of each segment of the backward slip zone and the unit pressure of each segment of the forward slip zone; calculating the roll gap thickness distribution based on the unit pressure distribution of each segment; determining whether the roll gap thickness distribution obtained from two adjacent calculations converges; calculating the roll gap thickness distribution when converged, otherwise proceeding to the next iteration calculation until the roll gap thickness distribution converges; and obtaining the roll gap forward slip ratio based on the unit pressure distribution of each segment and the boundary segment between the forward and backward slip zones after iteration convergence.

[0080] Specifically, the proportion η of the roll gap front slip zone is calculated under the set inlet and outlet tension conditions.

[0081] It should be noted that the roll gap leading slip ratio refers to the proportion of the area where metal undergoes plastic deformation before entering the roll gap during the metal rolling process, relative to the entire roll gap length. This ratio is crucial for controlling the rolling process and product quality. There are several methods for calculating the roll gap leading slip ratio; the following is an example calculation method.

[0082] In one example, step S300 includes:

[0083] S301. Set the initial roll profile curve and determine the entry position of the workpiece.

[0084] Assuming the roll is undeformed and arc-shaped, δ(x) = 0. Discretizing the deformation zone: Dividing the deformation zone into n segments (e.g., n = 1000), the roll gap thickness model equation under the arc-shaped roll profile is: Where x(i) is the x-coordinate of the i-th segment, h(i) is the thickness of the i-th segment of the rolled piece, x(n) = 0, h(n) = h1, therefore Discrete segment length R is the radius of the work roll, and R is half the diameter D of the work roll.

[0085] S302, calculate the unit pressure of each section of the back slide from the inlet to the outlet. Specifically:

[0086] Using the backslip formula, the unit pressure in the inlet section (segment 1) under sliding friction conditions is calculated from the inlet to the outlet. The Aitken iterative method is used to solve for p(1). bWhere t0 is the inlet tensile stress (the inlet tensile stress updated in the current iteration), in MPa; K is the deformation resistance, in MPa; and μ is the roll gap friction coefficient.

[0087] The unit pressure of the back-slip region under sliding friction conditions is calculated sequentially for the second, third, and nth segments using the stress differential equation. Specifically, the stress differential equation of the back-slip region under sliding friction conditions is written in finite difference form:

[0088]

[0089] Summarized as follows:

[0090]

[0091] The frictional stress in the backward slip zone under sliding friction conditions is: t(i) b _sli=μp(i) b _sli.

[0092] S303. Calculate the unit pressure of each segment of the forward sliding zone from the outlet to the inlet. Similar to the calculation method for the backward sliding zone described above, specifically: using the forward sliding zone formula, calculate the unit rolling pressure of the outlet segment (segment n) under sliding friction conditions from the outlet to the inlet. The solution is obtained using the Aitken iterative method; where t1 is the exit tensile stress (the exit tensile stress updated in the current iteration), in MPa; K is the deformation resistance, in MPa; and μ is the roll gap friction coefficient.

[0093] The unit pressure of the forward sliding zone under sliding friction conditions is calculated sequentially using the stress differential equation of the (n-1)th segment, the (n-2)th segment, and then up to the first segment. Specifically, the stress differential equation of the forward sliding zone under sliding friction conditions is written in finite difference form:

[0094]

[0095] Summarized as follows:

[0096]

[0097] The Aitken iterative method is used to solve for p(i). f _sli.

[0098] The frictional stress in the forward sliding zone under sliding friction conditions is: t(i) f _sli=-μp(i) f _sli, the negative sign indicates that the frictional stress direction in the forward slip zone is towards the inlet side (opposite to the rolling direction).

[0099] S304. Determine the unit pressure of each section in the roll gap deformation zone.

[0100] Compare the two sets of unit pressure p(1) calculated using the forward slip zone formula and the backward slip zone formula. f p(2) f ...p(n) f and p(1) b p(2) b ...p(n) b Find the segment with the smallest difference (let's assume it's the r-th segment). This segment is the boundary between the forward and backward slip regions (i.e., the neutral surface), and x(r) = x(1) + (r-1)ΔX. Keep p(1). f p(2) f ... p(r-1) f p(r) f Or p(r) b p(r+1) b ...p(n) b The unit pressure distribution under the specified roll profile has now been calculated, i.e., p(1) = p(1). f p(2) = p(2) f ... p(r-1) = p(r-1) f p(r) = p(r) f Or p(r) = p(r) b p(r+1)=p(r+1) b ...p(n)=p(n) b .

[0101] S305. Calculate the roll gap thickness distribution based on the unit pressure distribution.

[0102] The roll gap thickness h(i) is calculated using the unit pressure distribution. However, to ensure convergence, a smoothing coefficient (relaxation factor) e is introduced to make the unit pressure in each segment calculated in the two iterations change gradually.

[0103] That is, p m+1 (i)=ep(i)+(1-e)p m (i), 0 < e < 1

[0104] Where p(i) is the calculated unit pressure distribution under a specified roll profile; p m (i) represents the unit pressure distribution used in the m-th iteration; p m+1 (i) represents the unit pressure distribution used in the (m+1)th iteration.

[0105] Using the relaxed unit pressure distribution p m+1 (i) Calculate the elastic flattening deformation δ(x(j)) of the roll, and calculate the elastic flattening of the roll at the x(j) position by the cumulative summation method. j = 1, 2, 3…n, si unit pressure p m +1 (i) The x-coordinate corresponding to the x-coordinate.

[0106] The distribution of the deformed roll profile curve is then determined as follows:

[0107]

[0108] The roll gap thickness distribution is as follows:

[0109] In the formula, y(x(j)) min This represents the ordinate of the lowest point of the deformed roll profile curve, in mm.

[0110] S306. Determine whether the roll gap thickness distribution obtained from the two calculations converges.

[0111] S307. When convergence is achieved, the roll gap thickness distribution is calculated; otherwise, proceed to the next iteration until the roll gap thickness distribution converges.

[0112] Corresponding to the unit pressure distribution, the roll gap thickness is "relaxed," i.e., h m+1 (j)=eh(j)+(1-e)h m (j)

[0113] Where h(j) is the calculated thickness of each roll gap; h m (j) represents the roll gap thickness used in the m-th iteration; h m+1 (j) represents the thickness of each roll gap used in the (m+1)th iteration.

[0114] Then, the new roll gap thickness distribution (h) is utilized. m+1 (j) Recalculate the unit pressure distribution and frictional stress distribution under the roll profile using the same method described above, and repeat this iterative process until convergence. The convergence condition is: the difference between the corresponding roll gap thicknesses calculated in the two consecutive calculations is less than the accuracy value, i.e., h(j) - h m (j)≤ε×h(j), where ε is the convergence precision, for example, take ε=0.001.

[0115] S308. After the iteration converges, the unit pressure distributions p(1), p(2), p(3), ... p(n) that satisfy the conditions have been calculated, as well as the boundary segment between the forward and backward slip regions (the r-th segment, i.e., the neutral surface), x(r) = x(1) + (r-1)ΔX. Then the proportion of the forward slip region is...

[0116] Understandably, in another example, the general steps for calculating the front slip zone ratio of the roll gap include: defining relevant parameters such as the total length of the roll gap, the plastic deformation length of the metal in the roll gap (i.e., the distance the metal travels after entering the roll gap and undergoes plastic deformation), and the length of the front slip zone of the metal in the roll gap; calculating the front slip zone length: the front slip zone length can usually be obtained by measurement or calculation based on the plastic deformation characteristics of the material, for example, it can be assumed that the front slip zone length is related to factors such as the plasticity of the material, the roll gap pressure, and the roll speed; and calculating the front slip zone ratio based on the total length of the roll gap, the length of the front slip zone, and the plastic deformation length of the metal in the roll gap.

[0117] In practical applications, the calculation method for the roll gap forward slip ratio involves the physical phenomena and mechanical principles of the metal rolling process. The calculation methods for the roll gap forward slip ratio include, but are not limited to: calculations based on rolling force models: by establishing a mathematical model of rolling force, factors such as material elasticity, plastic deformation, and friction can be considered to calculate the forward slip ratio. Calculations based on material flow laws: according to material flow laws, such as the Coulomb friction model, the flow of metal in the roll gap can be calculated. This method, for example, includes the following steps: calculating the equivalent plastic strain of the metal during rolling; determining the length of the forward slip zone using its relationship with the roll gap length; and calculating the forward slip ratio. Empirical formula methods: based on a large amount of experimental data, some empirical formulas can be summarized to estimate the forward slip ratio, such as calculating the roll gap forward slip ratio based on the thickness difference before and after rolling, the material thickness before rolling, and empirical coefficients. Numerical simulation method: Numerical simulation of the rolling process using finite element analysis (FEA) or finite volume method (FVM) can obtain the flow of metal in the roll gap, thereby calculating the forward slip ratio. For example, simulating the rolling process using finite element software can obtain the stress-strain field of the metal, and further calculate the length of the forward slip. Artificial intelligence method: Using machine learning or deep learning algorithms, a model is trained based on a large amount of rolling data and corresponding detection results to predict the forward slip ratio. In practical applications, it may be necessary to combine multiple methods, or to improve and adjust specific methods to adapt to actual conditions. This embodiment does not impose any limitations on this.

[0118] For example, the Aitken iteration method (Aitken acceleration method) is used to accelerate the convergence of linear sequences, especially to improve the speed of iterative convergence when solving equations in numerical analysis. This method optimizes the iterative process. To use the Aitken iteration method to solve physical problems involving pressure, the mathematical model of the problem needs to be transformed into a form that can be solved using iterative methods, thus applying the Aitken acceleration method for iterative calculations.

[0119] In one embodiment, determining whether the roll gap forward slip ratio reaches a preset roll gap forward slip ratio critical value includes: setting an accuracy coefficient; obtaining a judgment value based on the product of the accuracy coefficient and the preset roll gap forward slip ratio critical value; calculating the difference between the roll gap forward slip ratio and the preset roll gap forward slip ratio critical value; comparing the absolute value of the difference with the judgment value; if the absolute value of the difference is less than or equal to the judgment value, then determining that the roll gap forward slip ratio has reached the preset roll gap forward slip ratio critical value.

[0120] In one embodiment, after determining whether the roll gap forward slip ratio has reached a preset roll gap forward slip ratio critical value, the method further includes: when the roll gap forward slip ratio has not reached the preset roll gap forward slip ratio critical value, determining whether the current exit tension has reached the maximum exit tension; if the current exit tension has not reached the maximum exit tension, updating the current exit tension using the secant method, and returning to the step of calculating the roll gap forward slip ratio under the inlet tension condition and the exit tension condition, until the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value; if the current exit tension has reached the maximum exit tension, setting the current exit tension to the maximum exit tension, updating the inlet tension using the secant method, and returning to the step of calculating the roll gap forward slip ratio under the inlet tension condition and the exit tension condition, until the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value.

[0121] Specifically, such as Figure 3 As shown, it is determined whether the calculated roll gap forward slip ratio η satisfies the set critical value η0. If it does, the calculation ends; if it does not, it is determined whether the exit tension has reached its maximum value. If the exit tension has not reached its maximum value, the exit tension is increased, and then the process returns to step S300 to recalculate until the above conditions are met. If the exit tension has reached its maximum value, the exit tension is set to the maximum value t. 1max And reduce the inlet tensile stress, then proceed to step S300 to recalculate until the above conditions are met.

[0122] For example, it is determined whether the calculated roll gap forward slip ratio η satisfies the set critical value η0 for the roll gap forward slip ratio. Specifically, it is considered to satisfy the condition when η - η0| ≤ γ × η0, where γ is the accuracy coefficient, which can be taken as γ = 0.001. Figure 3As shown, if the conditions are met, the calculation ends; if not, it is determined whether the outlet tension has reached its maximum value. If the outlet tension has not reached its maximum value, the outlet tension is increased. Specifically, the new outlet tension value is calculated using the secant method, and then the process returns to step S300 to recalculate until the above conditions are met. If the outlet tension has reached its maximum value, the outlet tension is set to the maximum value, and the inlet tension is reduced. Specifically, the new inlet tension is calculated using the secant method, and then the process returns to step S300 to recalculate until the above conditions are met.

[0123] In one embodiment, updating the current exit tension stress using the secant method includes: setting a proportional relationship based on the secant method; obtaining the increment of the exit tension stress after iterative calculation; and iteratively updating the current exit tension stress according to the increment of the exit tension stress and the proportional relationship to obtain the corrected exit tension stress.

[0124] It should be noted that the calculation of the exit tensile stress, which is updated iteratively, is used as an example for explanation. The calculation principle of the secant method is as follows: Figure 4 As shown, the proportional relationship indicates that:

[0125]

[0126] Assume that the increment (correction) of the exit tensile stress after the first iteration of this iterative calculation cycle is Δt1. (1) For example, Δt1 can be taken. (1) =5, and from the above derivation, we can see that:

[0127] When m=1, t1 (2) =t1 (1) +Δt1 (1) When m≥2,

[0128] Wherein, η0 is the set critical value for the proportion of the roll gap forward slip zone; η (m) η is the proportion of the roll gap leading slip zone calculated in the m-th iteration; (m-1) Δt1 is the proportion of the roll gap leading slip zone calculated in the (m-1)th iteration. (m-1) The output tensile stress increment (correction) is obtained after the (m-1)th iteration; Δt1 (m) This is the increment (correction) of the outlet tensile stress obtained after the m-th iteration calculation;

[0129] The corrected exit tension is then:

[0130] t1=t1 (m+1) =t1 (m) +Δt1 (m)

[0131] It should be noted that the principle of the secant method used to calculate the updated inlet tensile stress is the same as the steps described above, and will not be repeated here.

[0132] In one embodiment, the inlet tension and outlet tension are calculated based on the inlet tension and outlet tension output by the iterative update.

[0133] Specifically, during continuous rolling or stretching processes, materials typically experience tensile stress. Tensile stress refers to the force per unit area of ​​a material under tension. Tension is the total force acting across the entire cross-section of the material. Based on the tensile stress at the inlet and outlet, the corresponding tension can be calculated.

[0134] T = σ·A

[0135] Where T is tension; σ is tensile stress; and A is the cross-sectional area of ​​the material.

[0136] For example, based on the inlet tensile stress σ in and outlet tensile stress σ out and the cross-sectional area A of the material in and A out (The cross-sectional areas at the inlet and outlet may differ due to material tension), and the inlet tension T can be calculated separately. in and export tension T out .

[0137] It should be noted that the feasibility of the method described in this embodiment is further illustrated by two examples below. For example, the working roll diameter in both examples is 70 mm, the strip width is 1200 mm, and the strip inlet thickness, outlet thickness, roll gap friction coefficient, inlet strip yield strength, and outlet strip yield strength are shown in columns 2 to 6 of Table 1, respectively.

[0138] Table 1 shows the calculation parameters and iterative calculation results for the two examples.

[0139]

[0140] For the first example, the initial inlet tension was 54.6 MPa, and the initial outlet tension was 82.6 MPa. The calculated forward slip ratio was 0.0348, which is less than the set critical value of 0.15. In subsequent iterative calculations, the outlet tension was increased first. When the outlet tension calculated using the secant method was 139 MPa (less than the maximum outlet tension of 247.8 MPa), the calculated forward slip ratio was 0.1502, which met the calculation requirements. Thus, the inlet tension of this example can be further calculated from the inlet tension as 151 kN, and the outlet tension can be further calculated from the outlet tension as 250 kN.

[0141] For the second example, the initial inlet tension was 82.6 MPa, and the initial outlet tension was 101.2 MPa. The calculated forward slip ratio was 0.0659, which was less than the set critical value of 0.15. In subsequent iterative calculations, the outlet tension was increased. When the outlet tension calculated using the secant method reached its maximum value of 303.6 MPa, the calculated forward slip ratio was 0.136, still less than the set critical value of 0.15. Therefore, the outlet tension was set to its maximum value of 303.6 MPa, and the inlet tension was decreased. When the inlet tension calculated using the secant method reached 49.6 MPa (greater than the minimum inlet tension of 16.5 MPa), the calculated forward slip ratio was 0.1512, meeting the calculation requirements. Thus, the inlet tension of this example could be further calculated as 89 kN from the inlet tension, and the outlet tension as 357 kN from the outlet tension.

[0142] It is understood that the purpose of this embodiment is to provide a method for obtaining the tension setpoint of cold-rolled strip steel, used for the pre-setting calculation of the inlet and outlet tensions of cold-rolled strip steel rolling, in order to solve the problem of production instability caused by roll slippage during the rolling process. The method described in this embodiment is based on an established quantitative relationship between the inlet and outlet tensions of cold-rolled strip steel rolling and the proportion of the roll slippage zone. By continuously iteratively optimizing the inlet and outlet tensions, the proportion of the roll slippage zone is adjusted to a critical range, thereby ensuring that the rolls do not slip during the rolling process and improving production stability. The method described in this embodiment has a clear and explicit principle, stable and rapid iterative calculations, and can be used for the pre-setting calculation of the inlet and outlet tensions of cold-rolled strip steel rolling.

[0143] This embodiment provides a method for obtaining the tension setting value of cold-rolled strip steel, including: obtaining the rolling process parameters of cold-rolled strip steel; setting the inlet tension stress condition, the outlet tension stress condition, and the critical value of the roll gap forward slip ratio based on the rolling process parameters; calculating the roll gap forward slip ratio under the inlet tension stress condition and the outlet tension stress condition; determining whether the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value; when the roll gap forward slip ratio reaches the preset roll gap forward slip ratio critical value, calculating the inlet tension and outlet tension respectively based on the iteratively updated inlet tension and outlet tension. This embodiment, based on the established quantitative relationship between the inlet tension, outlet tension, and roll gap forward slip ratio of cold-rolled strip steel rolling, continuously iteratively optimizes the inlet tension and outlet tension to adjust the roll gap forward slip ratio to the critical value range. The iterative calculation is stable and fast, and can be used for the preset calculation of the inlet tension and outlet tension of cold-rolled strip steel rolling, thereby ensuring that the roll gap does not slip during the rolling process and improving production stability.

[0144] Furthermore, this embodiment of the invention also proposes a storage medium storing a cold-rolled strip tension setting value acquisition program, which, when executed by a processor, implements the steps of the cold-rolled strip tension setting value acquisition method described above.

[0145] Reference Figure 5 , Figure 5 This is a structural block diagram of an embodiment of the cold-rolled strip tension setting value acquisition device of the present invention.

[0146] like Figure 5 As shown, the cold-rolled strip tension setting value acquisition device includes:

[0147] The parameter acquisition module 10 is used to acquire the rolling process parameters of cold-rolled strip steel.

[0148] Condition setting module 20 is used to set the inlet tension stress condition, the outlet tension stress condition, and the critical value of the roll gap forward slip zone ratio based on the rolling process parameters.

[0149] The proportional calculation module 30 is used to calculate the proportion of the roll gap front slip zone under the inlet tension stress condition and the outlet tension stress condition;

[0150] Critical judgment module 40 is used to determine whether the proportion of the roll gap front slip zone reaches the preset critical value of the roll gap front slip zone proportion.

[0151] The tension calculation module 50 is used to calculate the inlet tension and outlet tension respectively based on the inlet tension and outlet tension output by iterative update when the proportion of the roll gap front slip zone reaches the preset critical value of the roll gap front slip zone proportion.

[0152] This embodiment provides a device for obtaining the tension setting value of cold-rolled strip. Based on the established quantitative relationship between the inlet tension, outlet tension and the ratio of the roll gap forward slip zone of cold-rolled strip, the device continuously iteratively optimizes the inlet tension and outlet tension to adjust the ratio of the roll gap forward slip zone to a critical range. The iterative calculation is stable and fast, and can be used for the pre-setting calculation of the inlet tension and outlet tension of cold-rolled strip, thereby ensuring that the roll gap does not slip during the rolling process and improving production stability.

[0153] It should be noted that technical details not described in detail in this embodiment of the cold-rolled strip tension setting value acquisition device can be found in any embodiment of the present invention applied to the cold-rolled strip tension setting value acquisition method as described above, and will not be repeated here.

[0154] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0155] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0156] Furthermore, it should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0157] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0158] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory (ROM) / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0159] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method of acquiring a tension setting value of a cold-rolled steel strip, characterized by, The method comprises the following steps: obtaining rolling process parameters of a cold-rolled strip steel; setting an entry tensile stress condition, an exit tensile stress condition and a roll gap front slip zone proportion critical value based on the rolling process parameters; calculating a roll gap front slip zone proportion under the entry tensile stress condition and the exit tensile stress condition; judging whether the roll gap front slip zone proportion reaches a preset roll gap front slip zone proportion critical value; when the roll gap front slip zone proportion reaches the preset roll gap front slip zone proportion critical value, calculating an entry tension and an exit tension according to the entry tensile stress and the exit tensile stress output by iteration update respectively; setting the entry tensile stress condition, the exit tensile stress condition and the roll gap front slip zone proportion critical value based on the rolling process parameters comprises the following steps: obtaining an entry strip steel yield strength and an exit strip steel yield strength according to the rolling process parameters; setting an initial value, a minimum value and a maximum value of the entry tensile stress according to a product of different preset multiples and the entry strip steel yield strength; taking the initial value, the minimum value and the maximum value of the entry tensile stress as the entry tensile stress condition; setting an initial value, a minimum value and a maximum value of the exit tensile stress according to a product of different preset multiples and the exit strip steel yield strength; taking the initial value, the minimum value and the maximum value of the exit tensile stress as the exit tensile stress condition; setting a roll gap front slip zone proportion critical value.

2. The method of claim 1, wherein, The initial value of the entry tensile stress is 0.1 times the entry strip steel yield strength, the minimum value is 0.02 times the entry strip steel yield strength, and the maximum value is 0.3 times the entry strip steel yield strength; the initial value of the exit tensile stress is 0.1 times the exit strip steel yield strength, the minimum value is 0.02 times the exit strip steel yield strength, and the maximum value is 0.3 times the exit strip steel yield strength; the roll gap front slip zone proportion critical value ranges from 0.1 to 0.

5.

3. The method of claim 1, wherein, The calculation of the roll gap front slip zone proportion under the entry tensile stress condition and the exit tensile stress condition comprises the following steps: setting an initial roll contour curve under the entry tensile stress condition and the exit tensile stress condition, and determining a roll piece entry position; calculating unit pressures of each segment of a back slip zone from the entry to the exit based on the roll piece entry position; calculating unit pressures of each segment of a front slip zone from the exit to the entry; determining a unit pressure distribution of each segment of a roll gap deformation zone according to the unit pressures of each segment of the back slip zone and the unit pressures of each segment of the front slip zone; calculating a roll gap thickness distribution according to the unit pressure distribution of each segment; judging whether the roll gap thickness distributions obtained by two adjacent times of calculation converge; when the roll gap thickness distributions converge, obtaining a roll gap thickness distribution, otherwise, entering a next round of iteration calculation until the roll gap thickness distributions converge; after the iteration converges, obtaining a roll gap front slip zone proportion according to the unit pressure distribution of each segment and a junction segment of the front slip zone and the back slip zone.

4. The method of claim 1, wherein, The judgment of whether the roll gap front slip zone proportion reaches the preset roll gap front slip zone proportion critical value comprises the following steps: setting a precision coefficient; obtaining a judgment value according to a product of the precision coefficient and the preset roll gap front slip zone proportion critical value; calculating a difference value between the roll gap front slip zone proportion and the preset roll gap front slip zone proportion critical value; comparing an absolute value of the difference value with the judgment value; If the absolute value of the difference is less than or equal to the judgment value, it is determined that the front roll gap slip zone ratio reaches a preset front roll gap slip zone ratio threshold value.

5. The method of claim 1, wherein, After judging whether the front roll gap slip zone ratio reaches the preset front roll gap slip zone ratio threshold value, the method further comprises: When the front roll gap slip zone ratio does not reach the preset front roll gap slip zone ratio threshold value, it is judged whether the current exit tensile stress reaches the maximum exit tensile stress; If the current exit tensile stress does not reach the maximum exit tensile stress, the secant method is used to update the current exit tensile stress, and the step of calculating the front roll gap slip zone ratio under the conditions of the entry tensile stress and the exit tensile stress is returned until the front roll gap slip zone ratio reaches the preset front roll gap slip zone ratio threshold value; If the current exit tensile stress reaches the maximum exit tensile stress, the current exit tensile stress is set as the maximum exit tensile stress, the secant method is used to update the entry tensile stress, and the step of calculating the front roll gap slip zone ratio under the conditions of the entry tensile stress and the exit tensile stress is returned until the front roll gap slip zone ratio reaches the preset front roll gap slip zone ratio threshold value.

6. The method of claim 5, wherein, The step of updating the current exit tensile stress by using the secant method comprises: Setting a proportional relationship based on the secant method; Obtaining an exit tensile stress increment after iterative calculation; Iteratively updating the current exit tensile stress according to the exit tensile stress increment and the proportional relationship to obtain a corrected exit tensile stress.

7. The method of any one of claims 1 to 6, wherein, The rolling process parameters include the strip steel entry thickness, the strip steel exit thickness, the strip steel width, the entry strip steel yield strength, the exit strip steel yield strength, the work roll diameter and the roll gap friction coefficient.

8. A device for obtaining the tension setting value of cold-rolled strip steel, characterized in that, It comprises: A parameter acquisition module is configured to acquire rolling process parameters of a cold-rolled strip steel. A condition setting module is configured to set entry tensile stress conditions, exit tensile stress conditions and a front roll gap slip zone ratio threshold value based on the rolling process parameters. A ratio calculation module is configured to calculate a front roll gap slip zone ratio under the conditions of the entry tensile stress and the exit tensile stress. A threshold judgment module is configured to judge whether the front roll gap slip zone ratio reaches a preset front roll gap slip zone ratio threshold value. A tension calculation module is configured to calculate entry tension and exit tension according to the entry tensile stress and the exit tensile stress output by iterative updating when the front roll gap slip zone ratio reaches the preset front roll gap slip zone ratio threshold value. Setting the entry tensile stress conditions, the exit tensile stress conditions and the front roll gap slip zone ratio threshold value based on the rolling process parameters comprises: acquiring the entry strip steel yield strength and the exit strip steel yield strength according to the rolling process parameters; setting initial values, minimum values and maximum values of the entry tensile stress according to the products of different preset multiples and the entry strip steel yield strength; taking the initial values, the minimum values and the maximum values of the entry tensile stress as the entry tensile stress conditions; setting initial values, minimum values and maximum values of the exit tensile stress according to the products of different preset multiples and the exit strip steel yield strength; taking the initial values, the minimum values and the maximum values of the exit tensile stress as the exit tensile stress conditions; and setting the front roll gap slip zone ratio threshold value.

9. An electronic device, comprising: The electronic device comprises a memory, a processor, and a cold-rolled strip tension setting value acquisition program stored on the memory and executable on the processor, and the cold-rolled strip tension setting value acquisition program is configured to implement the cold-rolled strip tension setting value acquisition method according to any one of claims 1 to 7.

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