Method and device for determining deformation resistance of strip steel in cold continuous rolling, medium and electronic equipment

Abstract

The application discloses a strip steel cold continuous rolling deformation resistance determination method, device, medium and electronic equipment, wherein the method comprises the following steps: for each stand, determining the strain interval of the cold rolling strip steel in the stand based on the initial strip steel thickness and the corresponding inlet strip steel thickness and outlet strip steel thickness of the stand; for each stand included in the front stand, determining the stress value of the cold rolling strip steel in the corresponding strain interval of the stand through a first prediction model; for each stand included in the rear stand, determining the stress value of the cold rolling strip steel in the corresponding strain interval of the stand through a second prediction model based on the inlet grain diameter of the cold rolling strip steel in the stand; and constructing the deformation resistance curve of the strip steel in the cold continuous rolling mill based on the stress value of the cold rolling strip steel in the corresponding strain interval of each stand. The technical scheme provided by the application can accurately predict the deformation resistance of thin hard strip steel sheets.

Description

Technical Field

[0001] This application belongs to the field of cold strip rolling technology, and particularly relates to a method, device, medium and electronic equipment for determining the deformation resistance of cold strip rolling. Background Technology

[0002] In the cold continuous rolling production of thin and hard strip steel, the strip steel has the significant characteristics of being "thin, hard, and brittle." Traditional deformation resistance models rely on tensile tests taken from each stand to obtain stress-strain data. However, as the degree of rolling deformation increases, the strip steel in the later stands is prone to brittle fracture, making it impossible to obtain complete plastic deformation data. This leads to a decrease in the accuracy of the deformation resistance model, resulting in deviations in rolling force calculations and uneven load distribution, which seriously restricts the improvement of product shape accuracy and rolling stability.

[0003] Therefore, the inability to predict the deformation resistance of thin, rigid strip steel sheets is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] The embodiments of this application provide a method, apparatus, medium, and electronic equipment for determining the deformation resistance of cold continuous rolling of strip steel, thereby enabling accurate prediction of the deformation resistance of thin, hard strip steel sheets at least to a certain extent.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0006] According to a first aspect of the embodiments of this application, a method for determining the deformation resistance of cold-rolled strip is provided, applied to a cold rolling mill including multiple stands, wherein the multiple stands are divided into front stands and rear stands, the method comprising: Obtain the initial strip thickness of the cold-rolled strip, as well as the inlet and outlet strip thickness of the cold-rolled strip at each of the stands; For each stand, the strain range of the cold-rolled strip in the stand is determined based on the initial strip thickness and the inlet strip thickness and the outlet strip thickness corresponding to the stand; For each of the frames included in the front frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame is determined by a first prediction model, wherein the first prediction model is constructed by the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame; For each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame is determined by a second prediction model based on the inlet grain diameter of the cold-rolled strip in the frame, wherein the second prediction model is constructed by a constitutive model based on grain size based on the inlet grain diameter and the inlet strip thickness of the cold-rolled strip in each of the frames included in the front frame; Based on the stress value of the cold-rolled strip in the strain range corresponding to each stand, the deformation resistance curve of the strip in the cold continuous rolling mill is constructed.

[0007] In some embodiments of this application, based on the foregoing scheme, determining the strain range of the cold-rolled strip in the stand based on the initial strip thickness and the entry strip thickness and exit strip thickness corresponding to the stand includes: determining the starting strain point and ending strain point of the cold-rolled strip in the stand based on the initial strip thickness, the entry strip thickness and the exit strip thickness; and determining the interval formed by the starting strain point and the ending strain point as the strain range of the cold-rolled strip in the stand.

[0008] In some embodiments of this application, based on the foregoing scheme, determining the stress value of the cold-rolled strip within the strain range corresponding to the frame of each frame included in the front frame using a first prediction model includes: acquiring the actual stress data and actual strain data of the cold-rolled strip in each frame included in the front frame; determining the undetermined coefficients in the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each frame included in the front frame to obtain the first prediction model; and inputting the strain range corresponding to the frame into the first prediction model for each frame included in the front frame to obtain the stress value of the cold-rolled strip within the strain range corresponding to the frame.

[0009] In some embodiments of this application, based on the foregoing scheme, obtaining the actual stress data and actual strain data of the cold-rolled strip in each of the stands included in the front stand includes: obtaining the engineering stress data and engineering strain data of the cold-rolled strip in each stand; for the engineering stress data and engineering strain data corresponding to each stand, converting the engineering stress data into actual stress data and the engineering strain data into actual strain data.

[0010] In some embodiments of this application, based on the foregoing scheme, determining the stress value of the cold-rolled strip in the strain range corresponding to the frame of each frame included in the rear frame, based on the inlet grain diameter of the cold-rolled strip in the frame using a second prediction model, includes: obtaining the inlet grain diameter of the cold-rolled strip in each frame; for each frame included in the front frame, determining the size factor of the cold-rolled strip in the frame according to the inlet grain diameter and the inlet strip thickness; determining the undetermined coefficients in the constitutive model based on the grain size and the inlet grain diameter of each frame included in the front frame to obtain the second prediction model; for each frame included in the rear frame, inputting the inlet grain diameter of the frame into the second prediction model to obtain the stress value of the cold-rolled strip in the strain range corresponding to the frame.

[0011] In some embodiments of this application, based on the foregoing scheme, determining the size factor of the cold-rolled strip in the stand according to the inlet grain diameter and the inlet strip thickness of the stand includes: calculating the ratio of the inlet strip thickness to the inlet grain diameter corresponding to the stand as the size factor of the cold-rolled strip in the stand.

[0012] In some embodiments of this application, based on the foregoing scheme, the step of determining the undetermined coefficients in the constitutive model based on grain size to obtain the second prediction model based on the size factor and inlet grain diameter corresponding to each of the frames included in the front frame includes: obtaining a constitutive model based on grain size; substituting the size factor and inlet grain diameter corresponding to each of the frames included in the front frame into the constitutive model based on grain size, and using the least squares method to fit the true stress data and the true strain data corresponding to each frame to determine the undetermined coefficients in the constitutive model based on grain size to obtain the second prediction model.

[0013] According to a second aspect of the embodiments of this application, a device for determining the deformation resistance of cold-rolled strip is provided, applied to a cold-rolling mill including multiple stands, the multiple stands being divided into front stands and rear stands, the device comprising: The acquisition unit is used to acquire the initial strip thickness of the cold-rolled strip, as well as the inlet strip thickness and outlet strip thickness of the cold-rolled strip in each of the stands. The first determining unit is used to determine, for each of the stands, the strain range of the cold-rolled strip in the stand based on the initial strip thickness and the inlet strip thickness and the outlet strip thickness corresponding to the stand; The second determining unit is used to determine the stress value of the cold-rolled strip in the strain range corresponding to the frame for each of the frames included in the front frame by using a first prediction model, wherein the first prediction model is constructed by the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame; The third determining unit is used to determine, for each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame based on the inlet grain diameter of the cold-rolled strip in the frame using a second prediction model, wherein the second prediction model is constructed based on the inlet grain diameter and the inlet strip thickness of the cold-rolled strip in each of the frames included in the front frame using a constitutive model based on grain size; A construction unit is used to construct the deformation resistance curve of the cold-rolled strip in the cold continuous rolling mill based on the stress value of the cold-rolled strip in the strain range corresponding to each stand.

[0014] According to a third aspect of the embodiments of this application, a computer-readable storage medium is provided, the computer-readable storage medium storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by a processor to perform the operation as described in any of the first aspects above.

[0015] According to a fourth aspect of the present application, an electronic device is provided, the electronic device including one or more processors and one or more memories, the one or more memories storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by the one or more processors to implement the method described in any of the embodiments of the first aspect above.

[0016] In this application, a cold rolling mill comprising multiple stands is divided into front stands and rear stands to obtain the initial strip thickness of the cold-rolled strip, as well as the entry and exit strip thicknesses of the cold-rolled strip at each stand. For each stand, the strain range of the cold-rolled strip within the stand is determined based on the initial strip thickness and the corresponding entry and exit strip thicknesses. For each stand included in the front stands, the stress value of the cold-rolled strip within the strain range corresponding to the stand is determined using a first prediction model, wherein the first prediction model is based on the strain range of the cold-rolled strip within the front stands. The true stress and strain data for each stand are constructed using the Holomon equation. For each stand included in the rear stands, the stress value of the cold-rolled strip in the strain range corresponding to the stand is determined by the second prediction model based on the grain diameter of the cold-rolled strip at the entrance of the stand. The second prediction model is constructed by a constitutive model based on grain size, based on the grain diameter and thickness of the cold-rolled strip at the entrance of each stand included in the front stands. Based on the stress value of the cold-rolled strip in the strain range corresponding to each stand, the deformation resistance curve of the strip in the cold continuous rolling mill is constructed. In other words, by dividing the machine into front and rear frames, a first prediction model is established for the front frame based on real stress-strain data using the Holomon equation to accurately calculate the deformation resistance in the low-strain zone. For the rear frame, which cannot be tested, a second prediction model is constructed based on physical mechanisms by introducing the inlet grain diameter parameter to predict the deformation resistance in the high-strain zone. Finally, the stress values ​​in the strain range of each frame are integrated to form a high-precision full-process deformation resistance curve, fundamentally solving the model distortion problem caused by the lack of data in the rear frame, thereby achieving accurate prediction of the deformation resistance of thin, hard strip steel sheets.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 A flowchart of the method for determining the cold rolling deformation resistance of strip steel in an embodiment of this application is shown; Figure 2 The document shows the strip sampling location and a physical image of the sampled strip in an embodiment of this application. Figure 3 A schematic diagram showing the sampling location and specimen size of the tensile specimen in an embodiment of this application is provided. Figure 4 The diagram shows the engineering stress-strain curves obtained after tensile testing of the steel strip specimens of each frame in the embodiments of this application. Figure 5 The deformation resistance curve of the front frame strip in an embodiment of this application is shown. Figure 6 The diagram shows the sampling location of the EBSD sample, the processing dimensions of the test surface, and the fabricated test surface diagram in the embodiments of this application. Figure 7 A schematic diagram showing the average grain diameter of the inlet strip of each rack in an embodiment of this application is shown; Figure 8 A schematic diagram showing the size factor of the inlet strip of each rack in the embodiments of this application is provided; Figure 9 The deformation resistance curve of the rear frame strip in an embodiment of this application is shown. Figure 10 The deformation resistance curve of the strip steel in the cold rolling mill in the embodiments of this application is shown; Figure 11 A block diagram of the device for determining the cold rolling deformation resistance of strip steel in an embodiment of this application is shown; Figure 12 A schematic diagram of the structure of an electronic device in an embodiment of this application is shown. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0021] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0022] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0023] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] It should also be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0025] To enable those skilled in the art to better understand this application, a brief description of the application scenarios involved in this application is provided: The thickness of a certain thin and hard strip steel is generally 0.30mm~0.50mm. It has a large deformation resistance and high brittleness. The deformation resistance can reach more than 1000MPa. Therefore, "thin, hard and brittle" are the prominent characteristics of this strip steel.

[0026] In the industrial production of strip steel, hot-rolled strip steel is used as raw material, and after multiple passes of cold rolling and annealing, finished strip steel is obtained. Among related technologies, multi-stand six-high cold continuous rolling is the mainstream production method for thin and hard strip steel. It has high production efficiency, can meet the rapidly growing market demand for thin and hard strip steel, and improve the economic benefits of enterprises. However, due to the large diameter of the work rolls in the cold continuous rolling mill (approximately 385~425mm), and the mutual influence and constraints between the stands with continuous rolling relationships, coordinating the mill load distribution caused by high rolling force and high working load is very difficult. In actual production, this increases the difficulty of controlling thickness, strip shape, etc., reduces the control performance of the mill, and ultimately affects the quality of the product and the production efficiency of the unit. Therefore, the cold continuous rolling production of thin and hard strip steel requires a more balanced load distribution.

[0027] Rolling force calculation is the core issue of load distribution in cold continuous rolling. If the rolling force model is inaccurate, it will lead to an unreasonable load distribution strategy, affecting rolling efficiency. The accuracy of the rolling force calculation model depends heavily on the accuracy of the strip deformation resistance model. Generally, samples of the strip rolled on each stand are taken and tensile tests are conducted. After obtaining the stress-strain data of the material through the tests, the undetermined parameters in the deformation resistance model are determined by fitting.

[0028] However, as the degree of cold rolling deformation increases, thin, hard strip steel becomes thinner, harder, and more brittle. This makes the specimens more prone to fracture in tensile tests, making it difficult to obtain a complete stress-strain curve. Brittle fracture may even occur before reaching the yield strength, making it impossible to obtain stress-strain data during the plastic deformation stage. Due to the difficulty in obtaining material test data, the accuracy of strip deformation resistance model calculations is greatly reduced, leading to inaccurate rolling force calculations and uneven rolling load distribution.

[0029] To address the aforementioned issues, the method in this application involves temporarily halting multiple stands at the production site to sample thin, hard strip steel produced throughout the cold continuous rolling process. Tensile specimens are then prepared for each stand's strip steel, and stress-strain data for n stands's strip steel material are obtained using room-temperature tensile tests. Based on this data, the deformation resistance of the strip steel is analyzed and calculated. Using the test data from each stand's rolled specimens, a deformation resistance model for the entire cold continuous rolling process of the strip steel is constructed within the strain range corresponding to each stand. The model employs n segmented curves, each calculated based on the stress-strain data of the plastic segment obtained from the tensile tests. For the strip steel of the rear frame, which is thin, hard and brittle, the tensile specimens fractured during the elastic deformation stage or when the plastic strain was very small after crossing the yield point. It was difficult to obtain stress-strain data during the plastic deformation stage. Therefore, the deformation resistance of the thin plate of the rear frame was predicted based on the grain size. The prediction was based on the stress-strain data of the plastic section of the strip steel of the front frame, the strip thickness and the average grain diameter. The average grain diameter was obtained by characterization through EBSD test.

[0030] Figure 1 A flowchart illustrating a method for determining the cold rolling deformation resistance of strip steel according to an embodiment of this application is shown. This method for determining the cold rolling deformation resistance of strip steel can be executed by a device with computational processing capabilities. (Refer to...) Figure 1 As shown, the method for determining the deformation resistance of the cold-rolled strip includes: Step 101: Obtain the initial strip thickness of the cold-rolled strip, as well as the inlet strip thickness and outlet strip thickness of the cold-rolled strip at each stand; Step 102: For each stand, determine the strain range of the cold-rolled strip in the stand based on the initial strip thickness and the inlet strip thickness and outlet strip thickness corresponding to the stand; Step 103: For each of the frames included in the front frame, determine the stress value of the cold-rolled strip in the strain range corresponding to the frame using a first prediction model, wherein the first prediction model is constructed based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame using the Holomon equation; Step 104: For each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame is determined by the second prediction model based on the inlet grain diameter of the cold-rolled strip in the frame, wherein the second prediction model is constructed by a constitutive model based on grain size based on the inlet grain diameter and the inlet strip thickness of the cold-rolled strip in each of the frames included in the front frame; Step 105: Based on the stress value of the cold-rolled strip in the strain range corresponding to each stand, construct the deformation resistance curve of the strip in the cold continuous rolling mill.

[0031] Through the above steps, by dividing the machine into front and rear frames, a first prediction model is established for the front frame based on real stress-strain data using the Holomon equation to accurately calculate the deformation resistance in the low-strain zone. For the rear frame, which cannot be tested, a second prediction model is constructed based on physical mechanisms by introducing the inlet grain diameter parameter to predict the deformation resistance in the high-strain zone. Finally, the stress values ​​in the strain range of each frame are integrated to form a high-precision full-process deformation resistance curve, fundamentally solving the model distortion problem caused by the lack of rear frame data, thereby achieving accurate prediction of the deformation resistance of thin, hard strip steel sheets.

[0032] The method for determining the deformation resistance of cold-rolled strip proposed in this application is applicable to cold-rolling mills comprising multiple stands, such as multi-stand six-high mills. These multiple stands can be divided into front stands and rear stands based on, but is not limited to, the degree of deformation and material brittleness of the strip passing through the stands. Specifically, stands corresponding to strips with high deformation degrees and extremely brittle material (i.e., strips for which data cannot be obtained through tensile testing) can be classified as rear stands.

[0033] In the embodiment provided in step 101, the initial strip thickness is the original thickness of the strip before it enters the first stand of the entire cold rolling mill. For example, if the hot rolling mill delivers a 2.5mm thick steel coil, then the initial strip thickness H0 = 2.5mm.

[0034] Optionally, in this embodiment, the aforementioned inlet strip thickness is the thickness of the strip when it enters the i-th stand. The aforementioned inlet strip thickness is a variable, and its value differs for different stands i. For example, for the first stand, its inlet strip thickness equals the initial strip thickness (since its inlet is the inlet of the entire rolling line); because the strip continuously enters from one stand to the next, for the second stand and subsequent stands, its inlet strip thickness equals the outlet strip thickness of the previous stand.

[0035] Optionally, in this embodiment, the aforementioned exit strip thickness refers to the thickness of the strip when it leaves the i-th stand. The exit strip thickness is the target and result of the rolling process on each stand. The cold continuous rolling mill controls the final exit strip thickness by adjusting process parameters such as rolling force and speed to ensure that the finished product thickness meets the standard. In other words, the exit strip thickness of the last stand is the thickness of the finished strip.

[0036] Optionally, in this embodiment, the inlet and outlet strip thicknesses of the cold-rolled strip at each stand can be obtained, but are not limited to, by means of the following: By temporarily shutting down multiple stands at the production site, samples were taken from a coil of thin, hard strip steel rolled throughout the entire cold continuous rolling process. This resulted in inlet and outlet sample strip steel samples for each stand. Specifically, the process involved: first, shutting down the emulsion spray between each stand and reducing the strip rolling speed; then, simultaneously shutting down all stands. At the entrance of each stand, strip steel of a certain length and width (the actual production width) was cut along the rolling direction. Due to obstruction from external equipment, the sampling location was between stands and as close as possible to the mill entrance. The strip steel at the entrance of each stand was thus obtained as the inlet sample strip steel. Similarly, the strip steel at the exit of each stand was obtained as the outlet sample strip steel. The thickness of the cold-rolled strip at the entrance and exit of each stand was measured using a digital micrometer to obtain the thickness of the cold-rolled strip at the entrance and exit of each stand.

[0037] It should be noted that, in the embodiments proposed in this application, the parameter values ​​of the sampled strip obtained based on the above sampling process can be equivalent to the parameter values ​​of the cold-rolled strip in the corresponding stand. Alternatively, the entry and exit strip thicknesses of the cold-rolled strip in the corresponding stand can be accurately measured by other means.

[0038] In the embodiment provided in step 102, the strain range is used to indicate the starting and ending strain points of each stand in the cold continuous rolling process. The starting strain point represents the total cumulative deformation of the cold-rolled strip from its original state until it enters the i-th stand. The ending strain point represents the total cumulative deformation of the cold-rolled strip from its original state until it leaves the i-th stand.

[0039] In one embodiment of this application, the strain range of the cold-rolled strip in the stand can be determined, but is not limited to, by the following method based on the initial strip thickness and the entry strip thickness and exit strip thickness corresponding to the stand: determining the starting strain point and the ending strain point of the cold-rolled strip in the stand based on the initial strip thickness, the entry strip thickness and the exit strip thickness; and determining the interval formed by the starting strain point and the ending strain point as the strain range of the cold-rolled strip in the stand.

[0040] Optionally, in this embodiment, it can be, but is not limited to, using a formula. The initial strain point of the cold-rolled strip in each stand is determined based on the initial strip thickness, the inlet strip thickness, and the outlet strip thickness. The initial strain point, This represents the initial strip thickness. Let be the thickness of the inlet strip of the i-th rack; The thickness of the strip at the outlet of the i-th frame; can be determined by, but is not limited to, the formula. The final strain point of the cold-rolled strip in each stand is determined based on the initial strip thickness, the inlet strip thickness, and the outlet strip thickness. To end the strain point, This represents the initial strip thickness. Let be the thickness of the inlet strip of the i-th rack; Let be the exit strip thickness of the i-th stand; the strain range corresponding to each stand is obtained by measuring the initial and final strain points of the cold-rolled strip at each stand. , ].

[0041] In the embodiment provided in step 103, the stress value of each stand in the aforementioned front stand within the corresponding strain range is the true stress value. It represents the force per unit area of ​​the strip steel in the stand at an instantaneous cross-section, reflecting the internal resistance of the strip steel when plastic deformation (reduction of cross-section) occurs. During strip steel rolling, the stress value indicates its deformation resistance, representing the strip steel's ability to resist compression deformation by the rolls during rolling. The higher the stress value, the more difficult the strip steel is to roll (requiring greater rolling force).

[0042] Optionally, in this embodiment, the first prediction model is a mathematical model used to calculate the stress value of cold-rolled strip in the strain range corresponding to each stand included in the front stand, and its core is the Hollomon equation.

[0043] In one embodiment of this application, for each frame included in the front frame, the stress value of the cold-rolled strip within the strain range corresponding to the frame can be determined by a first prediction model in the following manner, but not limited to: obtaining the actual stress data and the actual strain data of the cold-rolled strip in each frame included in the front frame; determining the undetermined coefficients in the Holomon equation based on the actual stress data and the actual strain data of the cold-rolled strip in each frame included in the front frame to obtain the first prediction model; and inputting the strain range corresponding to the frame into the first prediction model for each frame included in the front frame to obtain the stress value of the cold-rolled strip within the strain range corresponding to the frame.

[0044] Optionally, in this embodiment, for each frame included in the front frame, the Hollomon equation is used to fit the true stress data and true strain data of the plastic deformation section of each frame specimen, and the undetermined coefficients in the equation are determined to obtain the first prediction model; then the stress value of each frame in each strain range is calculated through the first prediction model.

[0045] Specifically, this includes: calculation formulas based on the Hollomon equation. The actual stress data of each rack and real strain data Substitute into the Hollomon equation to determine its undetermined yield strength. Strengthening coefficient The first prediction model is obtained by taking the hardening index n and the first prediction model; the stress value of each frame in each strain range is calculated by the first prediction model.

[0046] In one embodiment of this application, the actual stress data and actual strain data of the cold-rolled strip in each of the stands included in the front stand can be obtained by, but is not limited to, the following methods: obtaining the engineering stress data and engineering strain data of the cold-rolled strip in each stand; for the engineering stress data and engineering strain data corresponding to each stand, converting the engineering stress data into actual stress data and the engineering strain data into actual strain data.

[0047] Optionally, in this embodiment, it can be, but is not limited to, using a formula Convert engineering stress data into real stress data, where... For engineering stress data, For engineering strain data, For actual stress data; it can be obtained, but is not limited to, through formulas. Converting engineering strain data into real strain data, where... For engineering strain data, This is real-world strain data.

[0048] Optionally, in this embodiment, the engineering stress data and engineering strain data of the cold-rolled strip in each stand can be obtained by means of, but not limited to, the following: preparing tensile specimens for the cold-rolled strip of each stand, with the sampling position of the specimen being the central region of the strip and the long axis direction of the tensile specimen corresponding to the rolling direction of the strip; performing room temperature tensile tests on the strip specimens of each stand to obtain the engineering stress data and engineering stress-strain data of the strip specimens of each stand.

[0049] In the embodiment provided in step 104, the aforementioned inlet grain diameter is the average size of the internal metal grains of the strip when it enters a specific rack.

[0050] Optionally, in this embodiment, the second prediction model is a prediction tool based on microscopic physical mechanisms proposed in this application to solve the core problem of the inability to conduct experiments on the rear rack. Essentially, it is a constitutive model based on grain size.

[0051] In one embodiment of this application, for each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame can be determined by a second prediction model based on the inlet grain diameter of the cold-rolled strip in the frame, but not limited to the following methods: obtaining the inlet grain diameter of the cold-rolled strip in each frame; for each of the frames included in the front frame, determining the size factor of the cold-rolled strip in the frame based on the inlet grain diameter and the inlet strip thickness; determining the undetermined coefficients in the constitutive model based on the grain size based on the size factor and the inlet grain diameter of each of the frames included in the front frame to obtain the second prediction model; for each of the frames included in the rear frame, inputting the inlet grain diameter of the frame into the second prediction model to obtain the stress value of the cold-rolled strip in the strain range corresponding to the frame.

[0052] Optionally, in this embodiment, the entry grain diameter of the cold-rolled strip at each stand can be obtained, but is not limited to, by means of the following: the grain size of the entry strip at each stand is characterized by using the EBSD test, and the average grain diameter of the entry strip at each stand is obtained as the above-mentioned entry grain diameter.

[0053] It should be noted that the EBSD samples for the strip entering each stand were obtained by sampling a coil of thin, hard strip rolled throughout the entire cold continuous rolling process through temporary shutdowns of multiple stands on the production site. Alternatively, EBSD samples can be prepared separately for the strip entering each stand.

[0054] In one embodiment of this application, the size factor of the cold-rolled strip in the stand can be determined, but is not limited to, by the following method based on the inlet grain diameter and the inlet strip thickness corresponding to the stand: calculating the ratio of the inlet strip thickness to the inlet grain diameter corresponding to the stand as the size factor of the cold-rolled strip in the stand.

[0055] Optionally, in this embodiment, it can be, but is not limited to, using a formula The size factor is calculated based on the inlet strip thickness h and inlet grain diameter d of each frame. .

[0056] In one embodiment of this application, the second prediction model can be obtained by determining the undetermined coefficients in the constitutive model based on grain size, based on the size factor and inlet grain diameter corresponding to each of the frames included in the front frame, in the following manner: obtaining the constitutive model based on grain size; substituting the size factor and inlet grain diameter corresponding to each of the frames included in the front frame into the constitutive model based on grain size, and using the least squares method to fit the true stress data and the true strain data corresponding to each frame, thereby determining the undetermined coefficients in the constitutive model based on grain size to obtain the second prediction model.

[0057] Optionally, in this embodiment, obtaining a constitutive model based on grain size includes... ,in, The critical shear stress of a single crystal. , This refers to the grain boundary resistance formed when stress is transmitted across grain boundaries in a polycrystalline material. m is the orientation factor of a single crystal, which is usually taken as 2, and M is the orientation factor of a polycrystalline slip system, which is usually taken as 3.06.

[0058] Substitute the size factor and inlet grain diameter of each frame included in the front frame into the above constitutive model based on grain size to determine the results of k0, n0, k1 and n1 in the constitutive model of grain size for each frame.

[0059] Furthermore, the functions of k0, n0, k1, and n1 with respect to the size factor are expressed as follows: , , , Where a0, a1, a2, a3, b0, b1, b2, b3, c1, c2, and c3 are undetermined coefficients, and the least squares method is used to fit the functions to determine each function.

[0060] The entry size factor of the rear rack Substitute the inlet grain diameter d into the constitutive model of the grain size determined above, and calculate the stress value in the corresponding strain range.

[0061] In the embodiment provided in step 105, based on the stress value of the cold-rolled strip in the strain range corresponding to each stand, a deformation resistance curve of the strip in the cold continuous rolling mill is constructed. The deformation resistance curve is used to depict the change of the cold-rolled strip's ability to resist deformation (deformation resistance) with the cumulative deformation (total true strain) throughout the entire cold continuous rolling process.

[0062] To enable those skilled in the art to better understand the method for determining the deformation resistance of cold-rolled strip steel proposed in this application, a five-stand cold-rolling production line (i.e., a cold-rolling mill including stands 1 to 5) applied to the production of thin, hard strip steel will be used as an example below. Figures 2 to 10 The process of constructing the deformation resistance curve of strip steel in a cold rolling mill is explained.

[0063] By temporarily shutting down multiple stands at the production site, a sample of a thin, hard strip steel coil rolled throughout the entire cold continuous rolling process was taken: first, the emulsion spray between each stand was shut down and the rolling speed of the strip steel was reduced, and then each stand mill was shut down simultaneously. Figure 2 The sampling location of the steel strip and a physical image of the sampled steel strip are shown in the embodiments of this application, as follows: Figure 2 As shown, strips of a certain length and width, equal to the actual production width, were cut at each stand entrance along the rolling direction. Due to obstruction from external equipment, the sampling locations were situated between stands and as close as possible to the mill entrance. A total of five strips of different thicknesses were obtained from the entrances of the 1st, 2nd, 3rd, 4th, and 5th stands. The thicknesses of the strips at each stand entrance and the finished strip were measured using a digital micrometer. The thicknesses of the strips at the 1st, 2nd, 3rd, 4th, and 5th stand entrances and the finished strip were 2.523 mm, 1.481 mm, 0.933 mm, 0.649 mm, 0.480 mm, and 0.400 mm, respectively.

[0064] Tensile specimens were prepared for each stand of strip. The specimens were taken from the central region of the strip, and the major axis of the tensile specimens corresponded to the rolling direction of the strip. Figure 3 A schematic diagram showing the sampling location and specimen size of the tensile specimen in an embodiment of this application is provided, as follows: Figure 3As shown, the total length of the sample is 192 mm, the length of the parallel section is 50 mm, the radius of the transition arc is 25 mm, and the two ends of the sample are machined with pin holes with a diameter of 25 mm.

[0065] Figure 4 The following diagram illustrates the engineering stress-strain curves obtained after tensile testing of the steel strip specimens of each frame in the embodiments of this application, as shown below. Figure 4 As shown, room temperature tensile tests were conducted on strip steel specimens from each frame to obtain engineering stress-strain data (i.e., engineering stress data and engineering strain data) for five frame strip steel specimens. The results are named according to the "frame number". Considering the different maximum strain values ​​obtained for each specimen, in order to more clearly display the test results, the engineering stress-strain curve of the first frame is placed in a separate graph, with the horizontal axis strain range of 0~0.250; the engineering stress-strain curves of the second and third frames are placed together in a graph, with the horizontal axis strain range of 0~0.040; the engineering stress-strain curves of the fourth and fifth frames are also placed together in a graph, with the horizontal axis strain range of 0~0.010.

[0066] The engineering stress-strain data of five strip steel specimens under tension were converted into true stress-strain data. The calculation method is as follows: , ,in, For engineering stress data; For engineering strain data; This is based on actual stress data; This is real-world strain data.

[0067] Using the stress-strain data of the rolled samples from each stand, a deformation resistance model (i.e., deformation resistance curve) for the entire cold continuous rolling process of strip steel is constructed within the strain range corresponding to each stand. This model contains 5 segmented curves: Based on the entry and exit strip thicknesses of each stand, calculate the corresponding initial strain point of each stand's sample during cold continuous rolling. and the end strain point The calculation method is as follows: , ,in, The initial strip thickness, The thickness of the inlet strip for each rack. Let i be the thickness of the strip steel at the exit of each frame, i = 1, ..., 5.

[0068] Calculations show that the initial and final strain points for the first frame are 0 and 0.481, respectively; for the second frame, 0.481 and 0.987, respectively; for the third frame, 0.987 and 1.403, respectively; for the fourth frame, 1.403 and 1.771, respectively; and for the fifth frame, 1.771 and 2.021, respectively. The strain intervals for each segmented curve are thus [0, 0.481], (0.481, 0.987], (0.987, 1.403], (1.403, 1.771], and (1.771, 2.021).

[0069] In the first, second, and third stands, the Hollomon equation was used to fit the stress-strain data of the plastic deformation segment of the specimens in each stand. Then, the undetermined coefficients in the equation were determined, and the stress values ​​within each strain interval were calculated based on the determined equation. Specifically, the calculation formula for the Hollomon equation is as follows: ,in, This represents the actual stress data for the plastic segment; For true plastic strain data, For yield strength, is the strengthening coefficient, and n is the hardening exponent.

[0070] After calculation, the Hollomon equations for rack 1, rack 2, and rack 3 are shown in equations (1) to (3), respectively: (1) (2) (3) Figure 5 The deformation resistance curve of the front frame strip in an embodiment of this application is shown, as follows: Figure 5 As shown, the stress values ​​of the strip in their respective strain ranges [0, 0.481], (0.481, 0.987], and (0.987, 1.403] are calculated using formulas (1) to (3).

[0071] EBSD specimens were prepared for the strip at the entrance of each frame. The sampling location of the specimen was the central area of ​​the strip, and the test surface of EBSD was selected as the cross section in the width-thickness direction. Figure 6 The following diagram illustrates the sampling location, processing dimensions of the test surface, and fabricated test surface diagram of the EBSD sample in the embodiments of this application. Figure 6 As shown, the sample has a dimension of 5 mm in the rolling direction, a dimension of 12 mm in the width direction, and a dimension in the thickness direction equal to the thickness of the strip itself.

[0072] The grain size of the inlet strip of each rack was characterized by EBSD test, and the average grain diameter (i.e., inlet grain diameter) of the inlet strip of each rack was obtained. Figure 7 A schematic diagram showing the average grain diameter of the strip at the inlet of each rack in an embodiment of this application is shown, as follows: Figure 7 As shown, the average grain diameters of the strip steel at the five rack inlets are 158.28µm, 117.29µm, 84.42µm, 71.71µm and 48.73µm, respectively.

[0073] The size factor is calculated based on the thickness of the strip at the entrance of each rack and the average grain diameter. The calculation formula is: Where h is the thickness of the strip at the entrance of each stand; d is the average grain diameter of the strip at the entrance of each stand; after calculation, Figure 8 A schematic diagram showing the size factor of the inlet strip of each rack in the embodiments of this application is shown, such as... Figure 8 As shown, the size factors of the strips for the five frames are 14.11, 11.77, 9.87, 7.66 and 7.80, respectively.

[0074] A constitutive model based on grain size was adopted. First, the size factor and average grain diameter of the strip steel at the entrances of stands 1, 2, and 3 were substituted into the constitutive model. Then, the least squares method was used to fit the stress-strain data of the plastic deformation segment of the strip steel samples from these three stands to determine the undetermined coefficients k0, n0, k1, and n1 in the grain size constitutive model for these three stands. The calculation formula for the grain size-based constitutive model is as follows: ,in, The critical shear stress of a single crystal is given by the following formula: ; The grain boundary resistance formed when stress is transmitted across grain boundaries in a polycrystalline material is calculated using the following formula: m is the orientation factor for a single crystal, typically taken as 2; M is the orientation factor for a polycrystalline slip system, typically taken as 3.06.

[0075] The calculation results for k0, n0, k1, and n1 in the constitutive models of grain size for racks 1, 2, and 3 are shown in Table 1. Table 1

[0076] Express k0, n0, k1, and n1 as functions of the size factor, as shown in formulas (4) to (7), respectively: (4) (5) (6) (7) In formulas (4) to (7), a0, a1, a2, a3, b0, b1, b2, b3, c1, c2, and c3 are undetermined coefficients. The least squares method is used for fitting to determine these undetermined coefficients. After calculation, k0, n0, k1, and n1 are related to the size factor. The functions are shown in formulas (8) to (11): (8) (9) (10) (11) Substitute the size factor and average grain diameter of the inlet strip of the 4th and 5th frames into the above-determined grain size constitutive model, and calculate the stress values ​​in the corresponding strain range.

[0077] Figure 9 The deformation resistance curve of the rear frame strip in an embodiment of this application is shown, as follows. Figure 9 As shown, the stress values ​​of frame S4 ​​in the strain range (1.403, 1.771) and frame S5 in the strain range (1.771, 2.021) are calculated.

[0078] Figure 10 The following diagram illustrates the deformation resistance curve of the strip steel in the cold rolling mill according to an embodiment of this application: Figure 10 As shown, the final deformation resistance curve for the entire cold continuous rolling process of strip steel is formed based on the five segmented curves.

[0079] In the above process, by integrating online sampling of multiple stands, grain size characterization and physical mechanism modeling, the industry problem of not being able to obtain deformation resistance data through tensile tests for thin and hard strip steel due to brittle fracture in the rear stand was effectively solved. A high-precision full-process deformation resistance curve was successfully constructed, which significantly improved the prediction accuracy of the rolling force model, thereby realizing the optimized distribution of load of the continuous rolling mill and greatly improving the product thickness, strip shape quality and production stability.

[0080] The method proposed in this application predicts the deformation resistance of thin, hard strip steel sheets based on grain size. The method is simple and clear, conforms to the objective laws of metal plastic deformation, and effectively solves the problem of difficulty in accurately obtaining the deformation resistance of thin, hard strip steel in the rear stand of cold continuous rolling mill. It improves the calculation accuracy of the mill deformation resistance model and the calculation accuracy of the mill rolling force model, enabling the mill computer to perform reasonable load distribution and avoiding the problem of uneven load distribution in actual rolling.

[0081] The following describes an embodiment of the apparatus described in this application, which can be used to execute the method for determining the deformation resistance of cold-rolled strip steel in the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method for determining the deformation resistance of cold-rolled strip steel described above in this application.

[0082] See Figure 11 The diagram shows a block diagram of the device for determining the cold rolling deformation resistance of strip steel in an embodiment of this application.

[0083] like Figure 11 As shown, the strip cold rolling deformation resistance determination device (1100) according to an embodiment of this application is applied to a cold rolling mill including multiple stands, the multiple stands being divided into front stands and rear stands, including: The system includes an acquisition unit 1101, a first determination unit 1102, a second determination unit 1103, a third determination unit 1104, and a construction unit 1105.

[0084] The acquisition unit is used to acquire the initial strip thickness of the cold-rolled strip, as well as the inlet strip thickness and outlet strip thickness of the cold-rolled strip in each of the stands. The first determining unit is used to determine, for each of the stands, the strain range of the cold-rolled strip in the stand based on the initial strip thickness and the inlet strip thickness and the outlet strip thickness corresponding to the stand; The second determining unit is used to determine the stress value of the cold-rolled strip in the strain range corresponding to the frame for each of the frames included in the front frame by using a first prediction model, wherein the first prediction model is constructed by the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame; The third determining unit is used to determine, for each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame based on the inlet grain diameter of the cold-rolled strip in the frame using a second prediction model, wherein the second prediction model is constructed based on the inlet grain diameter and the inlet strip thickness of the cold-rolled strip in each of the frames included in the front frame using a constitutive model based on grain size; A construction unit is used to construct the deformation resistance curve of the cold-rolled strip in the cold continuous rolling mill based on the stress value of the cold-rolled strip in the strain range corresponding to each stand.

[0085] In some embodiments of this application, based on the foregoing scheme, the first determining unit is used to: determine the starting strain point and the ending strain point of the cold-rolled strip on the stand based on the initial strip thickness, the inlet strip thickness and the outlet strip thickness; and determine the interval formed by the starting strain point and the ending strain point as the strain interval of the cold-rolled strip on the stand.

[0086] In some embodiments of this application, based on the foregoing scheme, the second determining unit is configured to: acquire the actual stress data and actual strain data of the cold-rolled strip in each of the stands included in the front stand; determine the undetermined coefficients in the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each of the stands included in the front stand to obtain the first prediction model; and for each of the stands included in the front stand, input the strain interval corresponding to the stand into the first prediction model to obtain the stress value of the cold-rolled strip in the strain interval corresponding to the stand.

[0087] In some embodiments of this application, based on the foregoing scheme, the second determining unit is used to: acquire the engineering stress data and engineering strain data of the cold-rolled strip in each of the stands; for the engineering stress data and engineering strain data corresponding to each stand, convert the engineering stress data into real stress data and the engineering strain data into real strain data.

[0088] In some embodiments of this application, based on the foregoing scheme, the third determining unit is used to: obtain the inlet grain diameter of the cold-rolled strip in each of the stands; for each stand included in the front stand, determine the size factor of the cold-rolled strip in the stand according to the inlet grain diameter and the inlet strip thickness corresponding to the stand; determine the undetermined coefficients in the constitutive model based on the grain size based on the size factor and the inlet grain diameter corresponding to each stand included in the front stand to obtain the second prediction model; for each stand included in the rear stand, input the inlet grain diameter corresponding to the stand into the second prediction model to obtain the stress value of the cold-rolled strip in the strain range corresponding to the stand.

[0089] In some embodiments of this application, based on the foregoing scheme, the third determining unit is used to: calculate the ratio of the thickness of the inlet strip to the diameter of the inlet grain corresponding to the stand as the size factor of the cold-rolled strip in the stand.

[0090] In some embodiments of this application, based on the foregoing scheme, the third determining unit is used to: obtain a constitutive model based on grain size; substitute the size factor and inlet grain diameter corresponding to each of the frames included in the front frame into the constitutive model based on grain size; use the least squares method to fit the true stress data and the true strain data corresponding to each frame; and determine the undetermined coefficients in the constitutive model based on grain size to obtain the second prediction model.

[0091] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing at least one computer program instruction, which is loaded and executed by a processor to perform the operations described above.

[0092] Based on the same inventive concept, this application also provides an electronic device, see reference. Figure 12 The diagram shows a schematic of the structure of an electronic device according to an embodiment of this application. The electronic device includes one or more memories 1204, one or more processors 1202, and at least one computer program (computer program instruction) stored in the memory 1204 and executable on the processor 1202. When the processor 1202 executes the computer program, it implements the method described above.

[0093] Among them, Figure 12 In this document, a bus architecture (represented by bus 1200) is used. Bus 1200 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 1202 and memory represented by memory 1204. Bus 1200 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 1205 provides an interface between bus 1200 and receiver 1201 and transmitter 1203. Receiver 1201 and transmitter 1203 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 1202 is responsible for managing bus 1200 and general processing, while memory 1204 may be used to store data used by processor 1202 during operation.

[0094] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0095] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0096] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0097] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing computer program instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0098] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for determining the deformation resistance of a strip steel in cold continuous rolling, characterized in that, Applied to a cold continuous rolling mill comprising multiple stands, the multiple stands being divided into front stands and rear stands, the method includes: Obtain the initial strip thickness of the cold-rolled strip, as well as the inlet and outlet strip thickness of the cold-rolled strip at each of the stands; For each stand, the strain range of the cold-rolled strip in the stand is determined based on the initial strip thickness and the inlet strip thickness and the outlet strip thickness corresponding to the stand; For each of the frames included in the front frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame is determined by a first prediction model, wherein the first prediction model is constructed by the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame; For each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame is determined by a second prediction model based on the inlet grain diameter of the cold-rolled strip in the frame, wherein the second prediction model is constructed by a constitutive model based on grain size based on the inlet grain diameter and the inlet strip thickness of the cold-rolled strip in each of the frames included in the front frame; Based on the stress value of the cold-rolled strip in the strain range corresponding to each stand, the deformation resistance curve of the strip in the cold continuous rolling mill is constructed. The constitutive model of the grain size includes wherein, is the critical shear stress of single crystal, , is the grain boundary resistance formed when the stress in the polycrystal transmits across the grain boundary, m is the orientation factor of single crystal, M is the orientation factor of slip system of polycrystal, h is the thickness of the strip steel at the inlet of each stand, and d is the average grain diameter of the strip steel at the inlet of each stand.

2. The method of claim 1, wherein, The determination of the strain range of the cold-rolled strip in the stand based on the initial strip thickness and the inlet and outlet strip thicknesses corresponding to the stand includes: The initial strain point and the final strain point of the cold-rolled strip on the stand are determined based on the initial strip thickness, the inlet strip thickness, and the outlet strip thickness. The interval formed by the starting strain point and the ending strain point is defined as the strain interval of the cold-rolled strip corresponding to the stand.

3. The method of claim 1, wherein, For each of the frames included in the front frame, determining the stress value of the cold-rolled strip within the strain range corresponding to that frame using a first prediction model includes: Obtain the actual stress data and the actual strain data of the cold-rolled strip in each of the stands included in the front stand; Based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame, the undetermined coefficients in the Holomon equation are determined to obtain the first prediction model. For each frame included in the front frame, the strain range corresponding to the frame is input into the first prediction model to obtain the stress value of the cold-rolled strip in the strain range corresponding to the frame.

4. The method of claim 3, wherein, The acquisition of the actual stress data and actual strain data of the cold-rolled strip in each of the stands included in the front stand includes: Obtain the engineering stress data and engineering strain data of the cold-rolled strip in each of the stands; For each of the aforementioned frames, the engineering stress data and engineering strain data are converted into actual stress data and the engineering strain data are converted into actual strain data.

5. The method of claim 1, wherein, For each of the rear stands, the stress value of the cold-rolled strip within the strain range corresponding to the stand is determined using a second prediction model based on the grain diameter of the cold-rolled strip at the entrance of the stand, including: Obtain the grain diameter at the entrance of the cold-rolled strip in each of the stands; For each of the frames included in the front frame, the size factor of the cold-rolled strip in the frame is determined according to the inlet grain diameter and the inlet strip thickness corresponding to the frame; The second prediction model is obtained by determining the undetermined coefficients in the constitutive model based on the grain size based on the size factor and inlet grain diameter of each of the frames included in the front frame; For each of the frames included in the rear frame, the inlet grain diameter corresponding to the frame is input into the second prediction model to obtain the stress value of the cold-rolled strip in the strain range corresponding to the frame.

6. The method of claim 5, wherein, The step of determining the size factor of the cold-rolled strip at the stand based on the inlet grain diameter and the inlet strip thickness includes: The ratio of the thickness of the inlet strip to the diameter of the inlet grain corresponding to the stand is calculated as the size factor of the cold-rolled strip in the stand.

7. The method of claim 3, wherein, The process of determining the undetermined coefficients in the constitutive model based on grain size, based on the size factor and inlet grain diameter of each frame included in the front frame, to obtain the second prediction model includes: Obtain a constitutive model based on grain size; Substitute the size factor and inlet grain diameter of each frame included in the front frame into the constitutive model based on grain size, and use the least squares method to fit the actual stress data and actual strain data corresponding to each frame to determine the undetermined coefficients in the constitutive model based on grain size to obtain the second prediction model.

8. A device for determining the deformation resistance of cold-rolled strip steel, characterized in that, An apparatus applicable to a cold continuous rolling mill comprising multiple stands, the stands being divided into front stands and rear stands, the apparatus comprising: The acquisition unit is used to acquire the initial strip thickness of the cold-rolled strip, as well as the inlet strip thickness and outlet strip thickness of the cold-rolled strip in each of the stands. The first determining unit is used to determine, for each of the stands, the strain range of the cold-rolled strip in the stand based on the initial strip thickness and the inlet strip thickness and the outlet strip thickness corresponding to the stand; The second determining unit is used to determine the stress value of the cold-rolled strip in the strain range corresponding to the frame for each of the frames included in the front frame by using a first prediction model, wherein the first prediction model is constructed by the Holomon equation based on the actual stress data and actual strain data of the cold-rolled strip in each of the frames included in the front frame; The third determining unit is used to determine, for each of the frames included in the rear frame, the stress value of the cold-rolled strip in the strain range corresponding to the frame based on the inlet grain diameter of the cold-rolled strip in the frame using a second prediction model, wherein the second prediction model is constructed based on the inlet grain diameter and the inlet strip thickness of the cold-rolled strip in each of the frames included in the front frame using a constitutive model based on grain size; A construction unit is used to construct the deformation resistance curve of the cold-rolled strip in the cold rolling mill based on the stress value of the cold-rolled strip in the strain range corresponding to each stand. The constitutive model of the grain size includes ,in, The critical shear stress of a single crystal. , This refers to the grain boundary resistance formed when stress is transmitted across grain boundaries in a polycrystalline material. m is the orientation factor of the single crystal, M is the orientation factor of the polycrystalline slip system, h is the thickness of the inlet strip of each stand, and d is the average grain diameter of the inlet strip of each stand.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions that are loaded and executed by a processor to perform the operations described in any one of claims 1 to 7.

10. An electronic device comprising a processor and a memory, characterized in that, The memory stores computer program instructions that can be executed by the processor, and when the processor executes the computer program instructions, it implements the instructions of the method as described in any one of claims 1 to 7.

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