Ultrahigh-strength strip steel low-heat-magnetic-vibration coupling aging residual stress regulation and control method

Abstract

The invention relates to the technical field of strip steel production, and discloses an ultrahigh-strength strip steel low-heat-magnetic-vibration coupling aging residual stress regulation and control method which comprises the following steps: S1, performing residual stress aging treatment on hot-rolled ultrahigh-strength strip steel under the low-heat-magnetic-vibration coupling action. And S2, before low heat-magnetic-vibration coupling aging residual stress regulation and control are carried out, the step S1 is repeated, and a hot-rolled ultra-high-strength steel residual stress regulation and control prediction model based on the Kriging algorithm is established. And S3, a second-generation non-dominated sorting genetic algorithm is used for seeking an optimal hot-rolled ultra-high-strength strip steel low-heat-magnetic-vibration coupling aging residual stress regulation and control scheme combination. The method has the advantages that the residual stress reduction effect is good, the efficiency is high, the low-heat-magnetism-vibration coupling residual stress reduction process is carried out through the waste heat of the hot-rolled ultrahigh-strength strip steel, secondary heating is not needed, and therefore the method has the advantages of being environmentally friendly, low in carbon, low in cost and the like. On the basis, a low thermal-magnetic-vibration coupling aging process parameter optimization method is provided, and the calculation method has great advantages in the aspects of calculation speed, convergence and robustness.

Description

Technical Field

[0001] The invention relates to the technical field of strip steel production, and more specifically discloses a method for regulating and controlling low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel. Background Art

[0002] Plate and strip are the main products of the steel industry and important raw materials for various sectors of the national economy. According to the mechanical strength of the finished product, it can be divided into ordinary strength strip steel, high strength strip steel and ultra-high strength strip steel. Among them, ultra-high strength strip steel has a very high cost performance and is expected to replace extremely expensive aluminum alloys and titanium alloys. It is used in aerospace, military equipment, civil railways, automobiles and deep-sea submersibles. At the same time, it has strength and durability far exceeding that of traditional metal materials, which can effectively reduce the accident rate of the equipment and extend the service life of the equipment.

[0003] Plate shape is one of the main quality indicators of strip steel products. However, in the production process of ultra-high-strength strip steel, the plate shape problem is presented in a new form due to the large internal amplitude of non-uniform residual stress. The plate shape problem of ordinary strength steel plates, especially thin gauge steel plates, is mainly manifested as visible plate shape buckling or warping defects. However, the plate shape problem of ultra-high-strength steel plates is mainly manifested as "latent" plate shape defects, also known as "dark" plate shape, that is, the steel plate is obviously "flat" and "straight" when visually inspected, but if it is cut, stripped, or cut into blocks, it will immediately warp. This is mainly due to the high residual stress inside the ultra-high-strength steel plate. Therefore, traditional plate shape control technology that relies on mechanical work such as rolling mills, levelers, or straighteners can no longer be used for plate shape control of high-strength steel plates. The plate shape control of high-strength steel plates focuses on the control of internal residual stress.

[0004] Thermal aging is a traditional residual stress / plate shape stress control method, which achieves residual stress control under the action of a specific temperature field by applying heating, insulation and cooling treatment to ultra-high strength strip steel for a specific time. This method is difficult to implement on the production line because it needs to be heated to a higher temperature. At the same time, this method also has problems such as low residual stress reduction efficiency and high energy consumption. In order to solve the above problems, it is necessary to explore a low-carbon and fast online control method for residual stress of ultra-high strength strip steel, so as to realize dynamic real-time, green and efficient control of internal stress of strip steel.

[0005] Magnetic vibration composite residual stress reduction is a new technology that induces microscopic plastic deformation in local areas of the strip through alternating stress fields and pulsed magnetic fields, thereby achieving relaxation, reduction and elimination of residual stress in aging parts. This technology has the advantages of high reduction efficiency, low carbon and environmental protection. The patent "A magnetic vibration composite residual stress reduction device" (application / patent number: CN202111617448.4) and the patent "A magnetic vibration composite aging residual stress reduction device" (application / patent number: CN201510406517.5) respectively designed two magnetic vibration composite residual stress reduction devices with different structures. The principle is that the aging parts produce local microscopic plastic deformation under the superposition of the dynamic stress transmitted by the lower excitation head and the magnetic field applied by the upper electromagnetic aging device, thereby achieving the purpose of relaxation, reduction and elimination of residual stress.

[0006] Since thermal aging reduces residual stress by inducing microscopic plastic yield in the local area of ​​the aging part, and the yield strength of ultra-high strength strip steel is high, plastic deformation is relatively difficult, resulting in poor residual stress reduction effect. If thermal aging and magnetic vibration composite aging are applied to ultra-high strength strip steel together, the advantages of the two are complementary and mutually beneficial. The inherent characteristics of magnetic vibration composite aging can be fully utilized, and the same or even better stress elimination effect can be achieved more efficiently under the condition of lowering the heating temperature, thereby reducing energy consumption and pollution. Based on this, a low thermal-magnetic-vibration coupling aging method suitable for ultra-high strength steel strip is proposed. However, the current application of this method in the online regulation of residual stress in strip steel has the following problems: (1) Online regulation has not yet been achieved. In order to achieve online regulation of residual stress during low thermal-magnetic-vibration coupling aging, the first consideration is online heating. The high temperature of hot-rolled ultra-high strength strip can be utilized, which not only helps to achieve online regulation of residual stress during low thermal-magnetic-vibration coupling aging, but also helps to save energy and reduce emissions because no secondary heating is required, further reducing energy consumption and pollution, and helping to achieve the "dual carbon" goal; (2) The formulation of residual stress reduction process parameters for ultra-high strength strip depends on the operator's experience, lacks scientific basis, and often results in unsatisfactory stress reduction effects; at the same time, for the new low thermal-magnetic-vibration coupling aging process, there are many adjustable parameters involved, which are difficult to achieve simply relying on the operator's experience.

[0007] In summary, how to regulate the residual stress of ultra-high-strength strip steel in an efficient and environmentally friendly manner is one of the main problems currently faced. In addition, the volume of the strip steel is large, and if the residual stress reduction work is carried out after it is offline, it will undoubtedly increase the difficulty of the work, so online stress reduction is of great significance. Therefore, it is urgent to develop a new online regulation method for the residual stress of ultra-high-strength strip steel, and on this basis, propose a scientific, efficient and accurate process formulation method to solve the problems of unsatisfactory residual stress reduction effect of ultra-high-strength strip steel, high reduction efficiency, and high blindness of reduction process parameters, so as to quickly and effectively determine the best online regulation process plan for ultra-high-strength strip steel, so as to achieve the purpose of reducing and homogenizing the internal residual stress of ultra-high-strength strip steel and improving the service life. Summary of the invention

[0008] The present invention mainly provides a method for regulating residual stress of ultra-high strength strip steel with low thermal-magnetic-vibration coupling aging, which can solve the problems of unsatisfactory residual stress reduction effect of ultra-high strength strip steel, high reduction efficiency, and high blindness of reduction process parameters.

[0009] To solve the above technical problems, according to one aspect of the present invention, more specifically, a method for regulating residual stress of ultra-high strength strip steel by low thermal-magnetic-vibration coupling aging, comprising the following steps:

[0010] S1. Perform residual stress aging treatment on the hot-rolled ultra-high strength strip under low heat-magnetic-vibration action: for the hot-rolled ultra-high strength strip, after cooling to a lower temperature through laminar water cooling, it enters the residual stress online non-destructive testing equipment at a speed v1 through the transmission equipment, obtains the residual stress mean value σ0 of the hot-rolled ultra-high strength strip every distance l0, and transmits σ0 to the magnetic aging equipment and the vibration aging equipment. The magnetic aging equipment and the vibration aging equipment select the optimal residual stress control parameters according to σ0. After the ultra-strong strip exits the residual stress online non-destructive testing equipment, it enters the magnetic-vibration composite aging area for aging; the magnetic aging time of the hot-rolled ultra-high strength strip is T m ; The vibration aging time of hot-rolled ultra-high strength strip steel is T v , in the above process, the transmission speed of the strip steel remains unchanged, and the residual stress of the hot-rolled ultra-high strength strip steel is regulated by low thermal-magnetic-vibration coupling aging;

[0011] S2. Before performing low thermal-magnetic-vibration coupling aging residual stress regulation, repeat step S1. Based on the equipment, process parameter constraint range and residual stress size, Latin hypercube experimental design is used to design a process scheme to improve low thermal-magnetic-vibration coupling aging reduction or reduce the residual stress of hot-rolled ultra-high strength strip steel. The input parameters are the transmission speed v1 of hot-rolled ultra-high strength strip steel, the residual stress value distance l0, the IU value z of hot-rolled ultra-high strength strip steel, and the average residual stress σ along a certain direction i. i0. Temperature T0 of high-strength strip steel when it enters magnetic aging area and vibration aging area, number of excitation coils N, current intensity A of excitation equipment, alternating magnetic field frequency f m , magnetic aging time T m , vibration aging time T v , vibration frequency f v , amplitude A v , the output parameter is the reduction rate of residual stress of the entire hot-rolled ultra-high strength strip along a certain direction Δσ i , the rate of change of IU value Δz; screen and correct the data, and perform normalization or standardization at the same time, divide the data in a ratio of 8:1:1 to generate a training set, a validation set, and a test set for establishing a Kriging proxy model, select appropriate kernel functions and parameters, and then find the optimal functional relationship between input and output through sample training and sample testing steps, and finally establish a hot-rolled ultra-high strength steel residual stress control prediction model based on the Kriging algorithm;

[0012] S3. Use the second-generation non-dominated sorting genetic algorithm to find the best combination of low thermal-magnetic-vibration coupled aging residual stress control solutions for hot-rolled ultra-high strength strip steel to reduce the residual stress of hot-rolled ultra-high strength strip steel. Use the fast non-dominated sorting method to rank each group of solutions to evaluate the quality of the variables corresponding to the solution. The higher the rank, the better the variable corresponding to the solution. The steps of the fast non-dominated sorting method are as follows:

[0013] S31. Calculate the dominance relationship of individuals (solutions), and calculate the number n of each individual (solution) dominated by other individuals (solutions) i And the number S of other individuals (solutions) dominated by each individual (solution) i ;

[0014] S32, obtain each satisfying condition n i = 0 are assigned to the first non-dominated layer and stored in the set W i , and assign the layer to level i rank =1;

[0015] S33, set W i The solution dominated by the solution in i -1, and the new n i = 0 are assigned to the second non-dominated layer and stored in the new set E i , and assign the layer to level i rank =2; repeat the above steps to obtain all non-dominated layers;

[0016] The individual (solution) in the above is the residual stress reduction rate Δσ obtained by the hot-rolled ultra-high strength steel residual stress control prediction model in step S2 iand the rate of change of IU value Δz;

[0017] S4. For a certain solution, find two solutions close to the solution on the non-dominated layer where the solution is located and calculate the function difference between the two solutions. This value is the congestion degree i of this solution. d , and through the non-dominated level i of the solution rank and congestion degree i d , get the crowding comparison operator, the crowding comparison operator indicates that when two solutions are compared and selected, if the non-dominated level i rank If the non-dominated level i is different, the solution corresponding to the smaller value is selected; rank If they are the same, select congestion degree i d The solution with large value;

[0018] S5, initialization, randomly generating an initial population m0 of N in the region determined by the process parameter constraints in step S2, and performing fast non-dominated sorting on the initial population;

[0019] S6. After sorting, the solutions in the population obtain their corresponding non-dominated levels i rank , let the current iteration number be k=0, use the tournament selection algorithm to process the initial population, and use the comparison operator to copy and mutate the initial population to generate the child population q0, combine it with the initial population m0 to generate the parent-child population 2N, and re-perform the fast non-dominated sorting and crowding calculation on it;

[0020] S7, for the parent-child population in step S6, use the elite strategy and the crowding comparison operator to select the parent-child population, so as to obtain a new parent population. When the number of individuals in the new parent population reaches N, the selection ends;

[0021] S8, select, cross, and mutate the new parent population to regenerate a new child population, enter the next iteration, and increase the number of iterations k to the maximum number of iterations k max As the optimization termination condition;

[0022] S9, determine whether the algorithm's iteration condition k is met <k max If it is satisfied, set k=k+1 and go to step S6 to continue the algorithm iteration. Otherwise, go directly to step S10.

[0023] S10, output the optimal individual, and the iteration is terminated, that is, the algorithm ends after finding the global optimal solution, and finally determines the optimal low thermal-magnetic-vibration coupled aging process parameter combination for reducing the residual stress of hot-rolled ultra-high strength steel.

[0024] Furthermore, in step S1, the heat in the low thermal-magnetic-vibration coupled aging comes from the waste heat of the upstream rolling process of the hot-rolled ultra-high strength strip, and the magnetic aging and vibration aging of the hot-rolled ultra-high strength strip start at the same time, but the end time is not necessarily the same.

[0025] Furthermore, in step S2, the magnetic aging time T m and vibration aging time T v The change is achieved by changing the width b of the magnetic aging region. m and the width b of the vibration aging area v To change, the relationship is:

[0026]

[0027] Furthermore, in step S2, the process parameter constraint range refers to the maximum and minimum values ​​of the following parameters: hot-rolled ultra-high strength strip transmission speed v1, residual stress value distance l0, IU value z of hot-rolled ultra-high strength strip, and residual stress average value σ along a certain direction i. i 0. Temperature T0 of high-strength steel strip when it enters the magnetic field, number of excitation coils N, current intensity A of the excitation equipment, frequency f of the alternating magnetic field m , magnetic aging time T m , vibration aging time T v , vibration frequency f v , amplitude A v .

[0028] Furthermore, in step S6 and step S8, the mutation methods mainly include bit mutation, gene mutation, insertion mutation, uniform mutation, non-uniform mutation and Laplace mutation.

[0029] Furthermore, in step S8, the crossover methods mainly include single-point crossover, multi-point crossover, uniform crossover, sequential crossover, arithmetic crossover, partial matching crossover and skew crossover.

[0030] Furthermore, in step S5, the population size N ranges from 50 to 500.

[0031] Furthermore, in step S8, the maximum number of iterations k max The value range is 200 to 1000.

[0032] The beneficial effects of the method for regulating residual stress of ultra-high strength strip steel by low heat-magnetic-vibration coupling aging of the present invention are as follows: the method has good residual stress reduction effect, high efficiency, and the low heat-magnetic-vibration coupling residual stress reduction process utilizes the waste heat of hot-rolled ultra-high strength strip steel, and does not require secondary heating, so it also has the advantages of being green, low carbon, and low cost. On this basis, a method for optimizing process parameters of low heat-magnetic-vibration coupling aging is proposed. This calculation method has great advantages in calculation speed, convergence, and robustness, and is suitable for online regulation of residual stress of hot-rolled ultra-high strength strip steel, thereby realizing the optimized setting of process parameters of low heat-magnetic-vibration coupling aging of hot-rolled ultra-high strength strip steel, and improving the residual stress reduction effect and reduction efficiency while ensuring the straightness of ultra-high strength strip steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] Figure 1 A schematic diagram of the method flow chart.

[0035] Figure 2 It is a schematic diagram of the structure of the low thermal-magnetic-vibration residual stress control device.

[0036] Figure 3 It is a schematic diagram of the top view of the low thermal-magnetic-vibration residual stress control device.

[0037] Figure 4 This is a front view structural schematic diagram of the low thermal-magnetic-vibration residual stress control device.

[0038] In the figure: 1. Hot-rolled ultra-high strength strip steel; 2. Vibration head; 3. Excitation device; 4. Conveying device; 5. Excitation device hanging bracket; 6. Vibration platform. DETAILED DESCRIPTION

[0039] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0040] According to one aspect of the present invention, a method for regulating residual stress of ultra-high strength steel strip with low thermal-magnetic-vibration coupling aging is provided. The method is based on Figure 2-4The low thermal-magnetic-vibration residual stress control device shown in the figure is implemented, the hot-rolled ultra-high strength strip steel 1 is cooled to a lower temperature from the upstream production line through laminar water cooling and then transferred to the low thermal-magnetic-vibration residual stress control device. At this time, the hot-rolled ultra-high strength strip steel 1 itself carries heat, and the hot-rolled ultra-high strength strip steel 1 is transferred forward through the conveying device 4. The excitation platform 6 generates vibration under the hot-rolled ultra-high strength strip steel 1, and the vibration is transmitted to the strip steel through the excitation head 2. At the same time, the excitation device 3 on the excitation device hanging bracket 5 emits an alternating magnetic field, which combines the heat of the hot-rolled ultra-high strength strip steel 1 itself to form a low thermal-magnetic-vibration coupled aging residual stress control, which specifically includes the following steps, such as Figure 1 As shown:

[0041] (a) The hot-rolled ultra-high strength strip is subjected to residual stress aging treatment under low heat-magnetic-vibration action. The main contents include: for the hot-rolled ultra-high strength strip, after being cooled to a lower temperature by laminar water cooling, it enters the residual stress online non-destructive testing equipment at a speed v1 through the transmission equipment, and obtains the residual stress mean value σ0 of the hot-rolled ultra-high strength strip every distance l0, and σ0 is transmitted to the magnetic aging equipment and the vibration aging equipment. The magnetic aging equipment and the vibration aging equipment select the optimal residual stress control parameters according to σ0. After the ultra-high strength strip exits the residual stress online non-destructive testing equipment, it enters the magnetic-vibration composite aging area for aging; the magnetic aging time of the hot-rolled ultra-high strength strip is T m ; The vibration aging time of hot-rolled ultra-high strength strip steel is T v In the above process, the transmission speed of the strip steel remains unchanged, and the residual stress of the hot-rolled ultra-high strength strip steel is regulated by low thermal-magnetic-vibration coupling aging. Among them, the heat in the low thermal-magnetic-vibration coupling aging comes from the waste heat of the upstream rolling process of the hot-rolled ultra-high strength strip steel. The magnetic aging and vibration aging of the hot-rolled ultra-high strength strip steel start at the same time, but the end time is not necessarily the same.

[0042] (b) Before the low thermal-magnetic-vibration coupling aging residual stress regulation is performed, step (a) is repeated. Based on the equipment, process parameter constraint range and residual stress size, a Latin hypercube experimental design is used to design a process scheme for improving the low thermal-magnetic-vibration coupling aging reduction or reducing the residual stress of the hot-rolled ultra-high strength strip. The input parameters are the transmission speed v1 of the hot-rolled ultra-high strength strip, the residual stress value distance l0, the IU value z of the hot-rolled ultra-high strength strip, and the average residual stress σ along a certain direction i. i 0. Temperature T0 of high-strength strip steel when it enters magnetic aging area and vibration aging area, number of excitation coils N, current intensity A of excitation equipment, alternating magnetic field frequency f m , magnetic aging time T m , vibration aging time T v , vibration frequency f v , amplitude A v, the output parameter is the reduction rate of residual stress of the entire hot-rolled ultra-high strength strip along a certain direction Δσ i , the rate of change of IU value Δz; screen and correct the data, and perform normalization or standardization at the same time, divide the data in a ratio of 8:1:1 to generate training set, validation set and test set for establishing Kriging proxy model, select appropriate kernel function and parameters, and then find the optimal functional relationship between input and output through sample training and sample inspection, and finally establish the residual stress control prediction model of hot-rolled ultra-high strength steel based on Kriging algorithm. The magnetic aging time T m and vibration aging time T v The change is achieved by changing the width b of the magnetic aging region. m and the width b of the vibration aging area v To change, the relationship is:

[0043]

[0044] The process parameter constraint range refers to the transmission speed v1 of the hot-rolled ultra-high strength strip, the residual stress value distance l0, the IU value z of the hot-rolled ultra-high strength strip, and the average residual stress σ along a certain direction i. i 0. Temperature T0 of high-strength steel strip when it enters the magnetic field, number of excitation coils N, current intensity A of the excitation equipment, frequency f of the alternating magnetic field m , magnetic aging time T m , vibration aging time T v , vibration frequency f v , amplitude A v The maximum and minimum values ​​of .

[0045] (c) The second generation non-dominated sorting genetic algorithm is used to find the best combination of low thermal-magnetic-vibration coupled aging residual stress control schemes for hot-rolled ultra-high strength strip steel, so as to reduce the residual stress of hot-rolled ultra-high strength strip steel. The fast non-dominated sorting method is used to rank the solutions to evaluate the quality of the variables corresponding to the solutions. The higher the rank, the better the variables corresponding to the solutions. The steps of the fast non-dominated sorting method are as follows:

[0046] (1) Calculate the dominance relationship of individuals (solutions) and the number n of each individual (solution) dominated by other individuals (solutions) i And the number S of other individuals (solutions) dominated by each individual (solution) i ;

[0047] (2) Get all n that meet the conditions i = 0 are assigned to the first non-dominated layer and stored in the set W i , and assign the layer to level i rank =1;

[0048] (3) Set W i The solution dominated by the solution in i -1, and the new n i = 0 are assigned to the second non-dominated layer and stored in the new set E i , and assign the layer to level i rank =2; repeat the above steps to obtain all non-dominated layers;

[0049] The individual (solution) in the above is the residual stress reduction rate Δσ obtained by the hot-rolled ultra-high strength steel residual stress control prediction model in step S2 i And the rate of change of IU value Δz.

[0050] (d) For a certain solution, find two solutions close to the solution on the non-dominated layer where the solution is located and calculate the function difference between the two solutions. This value is the congestion degree i of this solution. d , and through the non-dominated level i of the solution rank and congestion degree i d , get the crowding comparison operator, the crowding comparison operator indicates that when two solutions are compared and selected, if the non-dominated level i rank If the non-dominated level i is different, the solution corresponding to the smaller value is selected; rank If they are the same, select congestion degree i d Large value solution.

[0051] (e) Initialization: In the region determined by the process parameter constraints in step 2, randomly generate an initial population m0 of N in number, and perform fast non-dominated sorting on the initial population. The value range of N is 50-500.

[0052] (f) After sorting, the solutions in the population obtain their corresponding non-dominated levels i rank , let the current iteration number be k=0, use the tournament selection algorithm to process the initial population, and use the comparison operator to copy and mutate the initial population and generate the child population q0, which is combined with the initial population m0 to generate the parent-child population 2N, and re-execute the fast non-dominated sorting and crowding calculation on it. The mutation methods mainly include bit mutation, gene mutation, insertion mutation, uniform mutation, non-uniform mutation and Laplace mutation.

[0053] (g) For the parent-child population in step 6, use the elite strategy and crowding comparison operator to select the parent-child population to obtain a new parent population. When the number of individuals in the new parent population reaches N, the selection ends.

[0054] (h) Select, crossover, and mutate the new parent population to regenerate a new child population and enter the next iteration, increasing the number of iterations k to the maximum number of iterations kmax As the optimization termination condition. Among them, the crossover methods mainly include single-point crossover, multi-point crossover, uniform crossover, sequential crossover, arithmetic crossover, partial matching crossover and skew crossover. The mutation methods mainly include bit mutation, gene mutation, insertion mutation, uniform mutation, non-uniform mutation and Laplace mutation. The maximum number of iterations k max The value range is 200 to 1000.

[0055] (i) Determine whether the algorithm's iteration condition k is met <k max If it is satisfied, set k=k+1 and go to step 6 to continue the algorithm iteration; otherwise, go directly to step 10.

[0056] (j) Output the optimal individual and the iteration is terminated, that is, the algorithm ends after finding the global optimal solution, and finally determines the optimal combination of low thermal-magnetic-vibration coupled aging process parameters for reducing the residual stress of hot-rolled ultra-high strength steel.

[0057] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A method for regulating residual stress of ultra-high strength strip steel by low thermal-magnetic-vibration coupling aging, characterized in that: The following steps are involved: S1. Perform residual stress aging treatment on the hot-rolled ultra-high strength strip under low heat-magnetic-vibration action: for the hot-rolled ultra-high strength strip, after cooling to a lower temperature through laminar water cooling, it enters the residual stress online non-destructive testing equipment at a speed v1 through the transmission equipment, obtains the residual stress mean value σ0 of the hot-rolled ultra-high strength strip every distance l0, and transmits σ0 to the magnetic aging equipment and the vibration aging equipment. The magnetic aging equipment and the vibration aging equipment select the optimal residual stress control parameters according to σ0. After the ultra-strong strip exits the residual stress online non-destructive testing equipment, it enters the magnetic-vibration composite aging area for aging; the magnetic aging time of the hot-rolled ultra-high strength strip is T m ; The vibration aging time of hot-rolled ultra-high strength strip steel is T v , in the above process, the transmission speed of the strip steel remains unchanged, and the residual stress of the hot-rolled ultra-high strength strip steel is regulated by low thermal-magnetic-vibration coupling aging; S2. Before performing low thermal-magnetic-vibration coupling aging residual stress regulation, repeat step S1. Based on the equipment, process parameter constraint range and residual stress size, Latin hypercube experimental design is used to design a process scheme to improve low thermal-magnetic-vibration coupling aging reduction or reduce the residual stress of hot-rolled ultra-high strength strip steel. The input parameters are the transmission speed v1 of hot-rolled ultra-high strength strip steel, the residual stress value distance l0, the IU value z of hot-rolled ultra-high strength strip steel, and the average residual stress σ along a certain direction i. i 0. Temperature T0 of high-strength strip steel when it enters magnetic aging area and vibration aging area, number of excitation coils N, current intensity A of excitation equipment, alternating magnetic field frequency f m , magnetic aging time T m , vibration aging time T v , vibration frequency f v , amplitude A v , the output parameter is the reduction rate of residual stress of the entire hot-rolled ultra-high strength strip along a certain direction Δσ i , the rate of change of IU value Δz; screen and correct the data, and perform normalization or standardization at the same time, divide the data in a ratio of 8:1:1 to generate a training set, a validation set, and a test set for establishing a Kriging proxy model, select appropriate kernel functions and parameters, and then find the optimal functional relationship between input and output through sample training and sample testing steps, and finally establish a hot-rolled ultra-high strength steel residual stress control prediction model based on the Kriging algorithm; S3. Use the second-generation non-dominated sorting genetic algorithm to find the best combination of low thermal-magnetic-vibration coupled aging residual stress control solutions for hot-rolled ultra-high strength strip steel to reduce the residual stress of hot-rolled ultra-high strength strip steel. Use the fast non-dominated sorting method to rank each group of solutions to evaluate the quality of the variables corresponding to the solution. The higher the rank, the better the variable corresponding to the solution. The steps of the fast non-dominated sorting method are as follows: S31. Calculate the dominance relationship of individuals (solutions), and calculate the number n of each individual (solution) dominated by other individuals (solutions) i And the number S of other individuals (solutions) dominated by each individual (solution) i ; S32, obtain each satisfying condition n i = 0 are assigned to the first non-dominated layer and stored in the set W i , and assign the layer to level i rank =1; S33, set W i The solution dominated by the solution in i -1, and the new n i = 0 are assigned to the second non-dominated layer and stored in the new set E i , and assign the layer to level i rank =2; repeat the above steps to obtain all non-dominated layers; The individual (solution) in the above is the residual stress reduction rate Δσ obtained by the hot-rolled ultra-high strength steel residual stress control prediction model in step S2 i and the rate of change of IU value Δz; S4. For a certain solution, find two solutions close to the solution on the non-dominated layer where the solution is located and calculate the function difference between the two solutions. This value is the congestion degree i of this solution. d , and through the non-dominated level i of the solution rank and congestion degree i d , get the crowding comparison operator, the crowding comparison operator indicates that when two solutions are compared and selected, if the non-dominated level i rank If the non-dominated level i is different, the solution corresponding to the smaller value is selected; rank If they are the same, select congestion degree i d The solution with large value; S5, initialization, randomly generating an initial population m0 of N in the region determined by the process parameter constraints in step S2, and performing fast non-dominated sorting on the initial population; S6. After sorting, the solutions in the population obtain their corresponding non-dominated levels i rank , let the current iteration number be k=0, use the tournament selection algorithm to process the initial population, and use the comparison operator to copy and mutate the initial population to generate the child population q0, combine it with the initial population m0 to generate the parent-child population 2N, and re-perform the fast non-dominated sorting and crowding calculation on it; S7, for the parent-child population in step S6, use the elite strategy and the crowding comparison operator to select the parent-child population, so as to obtain a new parent population. When the number of individuals in the new parent population reaches N, the selection ends; S8, select, cross, and mutate the new parent population to regenerate a new child population, enter the next iteration, and increase the number of iterations k to the maximum number of iterations k max As the optimization termination condition; S9, determine whether the algorithm's iteration condition k is met <k max If it is satisfied, set k=k+1 and go to step S6 to continue the algorithm iteration. Otherwise, go directly to step S10. S10, output the optimal individual, and the iteration is terminated, that is, the algorithm ends after finding the global optimal solution, and finally determines the optimal low thermal-magnetic-vibration coupled aging process parameter combination for reducing the residual stress of hot-rolled ultra-high strength steel.

2. The method for regulating low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S1, the heat in the low thermal-magnetic-vibration coupled aging comes from the waste heat of the upstream rolling process of the hot-rolled ultra-high strength strip. The magnetic aging and vibration aging of the hot-rolled ultra-high strength strip start at the same time, but the end time is not necessarily the same.

3. The method for controlling low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S2, the magnetic aging time T m and vibration aging time T v The change is achieved by changing the width b of the magnetic aging region. m and the width b of the vibration aging area v To change, the relationship is:

4. The method for regulating low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S2, the process parameter constraint range refers to the maximum and minimum values ​​of the following parameters: hot-rolled ultra-high strength strip transmission speed v1, residual stress value distance l0, IU value z of hot-rolled ultra-high strength strip, and residual stress average value σ along a certain direction i. i 0. Temperature T0 of high-strength steel strip when it enters the magnetic field, number of excitation coils N, current intensity A of the excitation equipment, frequency f of the alternating magnetic field m , magnetic aging time T m , vibration aging time T v , vibration frequency f v , amplitude A v .

5. The method for regulating low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S6 and step S8, the mutation methods mainly include bit mutation, gene mutation, insertion mutation, uniform mutation, non-uniform mutation and Laplace mutation.

6. The method for regulating low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S8, the crossover methods mainly include single-point crossover, multi-point crossover, uniform crossover, sequential crossover, arithmetic crossover, partial matching crossover and skew crossover.

7. The method for regulating low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S5, the population size N ranges from 50 to 500.

8. The method for regulating low thermal-magnetic-vibration coupled aging residual stress of ultra-high strength strip steel according to claim 1, characterized in that: In step S8, the maximum number of iterations k max The value range is 200 to 1000.

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