Construction method and leveling method of thin plate leveling process parameter model

Abstract

The invention belongs to the technical field of sheet welding deformation leveling, and discloses a construction method and a leveling method of a sheet leveling process parameter model, and the method comprises the following steps: M1, obtaining corresponding material attributes according to a sheet material needing to be leveled on site; m2, related data of the field welding process are known; m3, the initial leveling position, the heating time, the heating current and the heating frequency are obtained according to the material attributes and the welding process parameters of the thin plate; step M4, calculating the heat flux density of the Gaussian heat source model of the heating position according to the heating current, selecting the next heating position according to the heat flux density, and obtaining a heating sequence; and step M5, repeatedly executing the steps M3 to M4, and further correcting the heating time, the heating current and the heating frequency according to the actual temperature change data to obtain a final thin plate flattening process parameter model. According to the method, data of material attributes of an actual flattening heating workpiece and actual flattening working conditions are collected, and a multi-input and multi-output thin plate flattening process parameter model conforming to field working conditions is established.

Description

Technical Field

[0001] The present invention relates to the technical field of thin plate welding deformation leveling, and in particular to a method for constructing a thin plate leveling process parameter model and a leveling method. Background Art

[0002] In the field of shipbuilding, the main structures of large cruise ships, car roll-on / roll-off ships, and passenger roll-on / roll-off ships are welded from thin plates. During the welding process, problems such as uneven heating and offset heating positions are prone to occur, leading to residual stress in the weld area and, in turn, deformation of the thin plates. To address this problem of thin plate deformation, traditional water-fire leveling processes have many limitations, such as safety hazards, low efficiency, and environmental pollution. Therefore, an electromagnetic induction leveling method has been developed in recent years. This electromagnetic induction leveling method utilizes the principle of high-frequency electric heating, converting electrical energy into thermal energy through an electromagnetic field, achieving short-term, high-temperature heating. It offers high efficiency, rapid heating, and precise control, and has broad application prospects in the industrial field.

[0003] Chinese invention patent publication number CN116371969A, titled "An Electromagnetic Induction Heating Leveling System and Method," discloses an electromagnetic induction heating leveling system and method. The system utilizes an electromagnetic induction heating device within a leveling machine to adaptively adjust heating and leveling based on the varying curvatures of the surface to be leveled. The system features uniform heating temperature distribution, high heating precision, energy-saving efficiency, and high safety. The leveling machine comprises a chiller, a variable-frequency power supply, and an electromagnetic induction heating device. The electromagnetic induction heating device includes a handheld coaxial transformer and an electromagnetic induction heating coil with a curved body. The variable-frequency power supply is positioned above the chiller. The chiller is connected to the electromagnetic induction heating device via a first water pipe assembly and a second water pipe assembly. The electromagnetic induction heating device transfers water back to the chiller via a third water pipe assembly, creating a water circulation system that cools the electromagnetic induction heating device and the variable-frequency power supply. The variable-frequency power supply supplies power to the chiller and electromagnetic induction heating device via a first wire assembly and a second wire assembly.

[0004] Chinese invention patent: Publication number "CN114619161A," titled "A Model Construction and Leveling Method for Thin Plate Welding Deformation," discloses a model construction and leveling method for thin plate welding deformation. The method obtains material properties based on the thin plate material to be leveled and collects on-site welding process parameters. A mathematical model of welding deformation is established based on the corresponding data and inherent strain theory, and this model is modified through actual sampling. The type of welding deformation is determined based on the model output, and corresponding leveling heating lines are arranged. Electromagnetic induction heating is applied to level the deformed workpiece based on the position of the heating lines. After leveling, the workpiece's flatness is measured, and then, based on actual requirements, its compliance is determined. If not, further leveling is performed until the leveling meets the requirements. This invention establishes a mathematical model of welding deformation based on actual data, accurately identifies welding deformation conditions, and makes appropriate leveling heating lines. The leveling process is pollution-free, reliable, and efficient.

[0005] However, the above-mentioned existing technologies are mainly aimed at the equipment and usage methods of electromagnetic induction leveling, and lack systematic research on the construction of process parameters of electromagnetic induction leveling. Therefore, there is an urgent need for a construction method that can obtain electromagnetic induction heating process parameters such as heating position, heating sequence, and heating frequency based on raw material-related parameters such as plate model, deformation, structure, and material properties. Summary of the Invention

[0006] To address the problem in the prior art of electromagnetic induction leveling equipment and methods of use that are unable to correlate and construct electromagnetic induction heating process parameters, such as heating position, heating sequence, and heating frequency, with raw material-related parameters such as plate type, deformation, structure, and material properties, the present invention proposes a method for constructing a thin plate leveling process parameter model and a thin plate leveling method. Based on the type, deformation, structure, and material properties of the marine plate being tested, the electromagnetic induction leveling process parameters, including heating position, heating time, heating current, heating frequency, and heating sequence, are derived. This effectively improves the flatness, surface quality, and leveling efficiency of the thin plate leveling process, while reducing resource consumption.

[0007] The present invention is achieved through the following technical solution: comprising the following steps:

[0008] Step M1. Obtain the corresponding material properties of the thin plate material to be leveled on site, including the length, width, and thickness of the thin plate, the heat transfer coefficient, the thin plate resistance, the thin plate resistivity, the thin plate magnetic permeability, and the thin plate conductivity;

[0009] Step M2. Understand the relevant data of the on-site welding process, including room temperature, maximum temperature during welding heating, maximum temperature difference during cooling, and cross-sectional area of ​​the weld;

[0010] Step M3. Obtain an initial leveling position based on the material properties of the sheet obtained in step M1 and the welding process parameters obtained in step M2, and obtain a heating time, heating current, and heating frequency based on the initial leveling position;

[0011] Step M4. Calculate the heat flux density of the Gaussian heat source model at the heating position based on the heating current obtained in step M3, and select the next heating position based on the heat flux density to obtain a specific heating order;

[0012] Step M5. Repeat steps M3 to M4, and then optimize the heating sequence according to the actual processing requirements and the heat flux density. At the same time, collect the actual temperature change data of the thin plate, and further correct the heating time, heating current, and heating frequency to obtain the final thin plate leveling process parameter model.

[0013] Furthermore, the specific steps of step M3 include:

[0014] M3.1. Based on the height of the highest point on the deformed surface and the height of the normal surface, the initial leveling position is obtained. The calculation formula is as follows:

[0015] ΔH=H1-H0(1)

[0016] Where ΔH represents the height difference of the deformed surface of the thin plate, H1 is the height of the highest point on the deformed surface, and H0 is the height of the normal surface;

[0017] M3.2. After the initial leveling position is selected, the heating time is calculated based on the sheet surface area, sheet thickness, and heating thickness. The calculation formula is as follows:

[0018] T=k·A·c·d(2)

[0019] Where T represents the heating time, k is the heat transfer coefficient, A is the surface area of ​​the sheet, c is the sheet thickness, and d is the heated thickness; the initial leveling position is where ΔH is the maximum;

[0020] M3.3. Based on the heating time T obtained in M3.2, the material properties of the thin plate obtained in M1, and the welding process parameters obtained in M2, the heating current and heating frequency are obtained as shown in the following formula:

[0021]

[0022] Where I is the heating current, P is the heating power, and R is the sheet resistance; R is the sheet resistance, ρ is the sheet resistivity, L is the sheet length, and S is the sheet cross-sectional area; P is the heating power, t1 is the maximum temperature reached during the heating process, t0 is the initial sheet temperature, k is the sheet heat transfer coefficient, T is the heating time, and A is the sheet surface area; ω is the heating current frequency, ρ is the sheet resistivity, δ is the skin depth, i.e., the required heating depth, μ is the sheet magnetic permeability, and σ is the sheet electrical conductivity.

[0023] Furthermore, the heat flux density calculation formula of the heat source model in step M4 is as follows:

[0024]

[0025] Q=η·U·I (9)

[0026] Among them, q rx is the heat flux lateral density of the heat source model, q ry is the longitudinal density of heat flux in the heat source model, q m is the maximum heat flux density at the center of the heat source, Q is the arc power during the heating process, η is the arc efficiency, I is the heating current, U is the heating voltage, r ax is the radius of the heat source's lateral action area, r by is the radius of the heat source longitudinal action area, r a r is the distance between any point in the horizontal effective range of the heat source and the center of the heat source, b It is the distance between any point within the effective longitudinal range of the heat source and the center of the heat source.

[0027] Furthermore, the temperature change calculation formula in step M5 is as follows:

[0028] Q=q m ·S·T (10)

[0029] Q=m·C·ΔT (11)

[0030]

[0031] Among them, ΔT is the actual temperature change difference of the thin plate, Q is the heat, q m is the heat flux density, S is the leveling working contact area, T is the heating time, m is the mass of the thin plate, and C is the specific heat capacity of the thin plate.

[0032] The present invention also provides a thin plate leveling method using a leveling process parameter model, comprising the following steps:

[0033] Step 1: Construct a thin plate leveling process parameter model to understand the relevant properties of the leveling workpiece material and the relevant parameters of the on-site welding process. Based on the obtained data and relevant formulas, the initial heating position, heating time, heating current, heating frequency, and heating sequence are calculated. Based on multiple on-site sampling experiments, the actual temperature changes of the thin plate are obtained, and the heating time, heating current, and heating frequency are further modified to obtain the final thin plate leveling process parameter model;

[0034] Step 2: Plan the five major process parameters required for processing the thin plate according to the final thin plate leveling process parameter model obtained in step 1;

[0035] Step 3: Utilize the magnetic conductivity of the metal itself to generate eddy current effect through induced current to rapidly heat the steel plate and achieve electromagnetic induction heating and leveling;

[0036] Step 4: Check the flatness and surface quality of the leveled sheet to determine whether further correction is needed.

[0037] Furthermore, the specific steps of step 1 include:

[0038] Step 1.1: Obtain the corresponding material properties of the thin plate material to be leveled on site, including the length, width, and thickness of the thin plate, heat transfer coefficient, thin plate resistance, thin plate resistivity, thin plate magnetic permeability, and thin plate conductivity;

[0039] Step 1.2: Understand the relevant data of the on-site welding process, including room temperature, maximum temperature during welding heating, maximum temperature difference during cooling, and cross-sectional area of ​​the weld;

[0040] Step 1.3: Obtain an initial leveling position based on the material properties of the thin plate obtained in step 1.1 and the welding process parameters obtained in step 1.2. Obtain a heating time, heating current, and heating frequency based on the initial leveling position.

[0041] Step 1.4. Calculate the heat flux density of the Gaussian heat source model at the heating position based on the heating current obtained in step 1.3. Select the next heating position based on the heat flux density to obtain the specific heating order.

[0042] Step 1.5. Repeat steps 1.3 to 1.4, and then optimize the heating sequence according to the actual processing requirements and heat flux density. At the same time, collect the actual temperature change data of the thin plate, and further modify the heating time, heating current, and heating frequency to obtain the final thin plate leveling process parameter model.

[0043] Furthermore, the specific steps of step 1.3 include:

[0044] 1.3.1. Based on the height of the highest point on the deformed surface and the normal surface height, the initial leveling position is obtained. The calculation formula is as follows:

[0045] αH=H1-H0

[0046] 1.3.2. After the initial leveling position is selected, the heating time is calculated based on the sheet surface area, sheet thickness, and heating thickness. The calculation formula is as follows:

[0047] T=k·A·c·d

[0048] 1.3.3. Based on the heating time T obtained in step 1.3.2, the material properties of the thin plate obtained in step 1.1, and the welding process parameters obtained in step 1.2, the heating current and heating frequency are obtained as shown in the following formula:

[0049]

[0050] The heat flux calculation formula of the heat source model in step 1.4 is as follows:

[0051]

[0052] Q = η·U·I.

[0053] Furthermore, the steps for planning the five process parameters required for processing the thin plate in step 2 are as follows:

[0054] Step 2.1: Determine the sheet metal leveling heating position and related process parameters

[0055] Calculate the surface deformation of the flattened heated sheet, select the position with the maximum deformation as the initial flattening position, and calculate the heating time, heating current, and heating frequency required for that position based on the relevant data of the heating position;

[0056] Step 2.2: Plan the heating sequence for sheet metal leveling

[0057] Calculate the heat flux density at different locations of the position after the thin plate is leveled and heated. According to actual processing requirements, the area with a larger heat flux density can more effectively change the shape of the thin plate, so it is used as the next leveling heating point.

[0058] Furthermore, the step of judging whether the thin plate needs further correction in step 4 includes: testing the flatness and surface quality of the thin plate after leveling, and if the final leveling result does not meet the actual processing requirements, further using electromagnetic induction heating leveling correction; if the requirements are met, the leveling is completed.

[0059] Furthermore, the surface area A of the thin plate in step M3.2 is obtained by laser scanning the model, and the thickness c of the thin plate is obtained by actual measurement.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] 1. The present invention collects relevant data on the material properties of the actual leveling and heating workpiece and the data on the actual leveling working conditions, and incorporates the actual leveling material data into the formulas for heating position, heating time, heating current, heating frequency, and heating sequence to establish a multi-input and multi-output mathematical model of thin plate leveling process parameters that meets on-site working conditions.

[0062] 2. Use the multi-input and multi-output thin plate leveling process parameter model constructed by the present invention to perform leveling and heating of the workpiece, collect relevant data of the workpiece after leveling and heating, correct the error of the theoretical model, and make the leveling parameters output by the required model more accurate.

[0063] 3. The present invention determines the heating time, heating current and heating frequency required for the heating position according to the heating position. After the heating is completed, the next heating position is quickly located according to the distribution of heat flux density at the heating position. This process is repeated to achieve the best leveling effect and improve the leveling efficiency.

[0064] 4. The present invention uses electromagnetic induction heating to level the thin plate. The induction heating heat source has high heating efficiency, is easy to control, and will not have any collateral effects. It is highly controllable, has high thermal efficiency, is energy-saving and clean, and has a significant thin plate leveling effect.

[0065] 5. The present invention detects the flatness and surface quality of the thin plate after leveling and heating, and compares the test results with the required flatness and surface quality, further ensuring the final leveling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is an overall flow chart of the method for constructing a thin plate leveling process parameter model of the present invention.

[0067] Figure 2 This is an overall flow chart of the flattening method of the thin plate flattening process parameter model of the present invention. DETAILED DESCRIPTION

[0068] The advantages and features of the present invention are illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings.

[0069] The present invention provides a method for constructing a thin plate leveling process parameter model and a leveling method. The method obtains corresponding material properties based on the material of the thin plate to be leveled, collects process parameters such as the leveling method, heating time, heating current, and heating frequency of on-site leveling heating, obtains a multi-input and multi-output thin plate leveling process parameter model based on the corresponding data using a physical model modeling method, and modifies the model through actual sampling. The thin plate leveling process parameters and the leveling sequence output by the evidence model are used to level the deformed thin plate. After leveling, the flatness and surface quality of the thin plate are measured, and whether the leveling meets the standards is determined based on actual requirements. If it does not meet the standards, further leveling is performed. If it meets the standards, the leveling work is terminated. The present invention establishes a multi-input and multi-output thin plate leveling process parameter model based on actual data, which can accurately output the relevant process parameters and heating sequence required for leveling, and uses electromagnetic induction heating technology for leveling, thereby achieving a pollution-free and efficient leveling effect.

[0070] like Figure 1 As shown, the present invention provides a method for constructing a thin plate leveling process parameter model, which uses a physical model modeling method to obtain a multi-input and multi-output thin plate leveling process parameter model, including the following steps:

[0071] Step M1. Obtain the corresponding material properties of the thin plate material to be leveled on site, including the length, width, and thickness of the thin plate, the heat transfer coefficient, the thin plate resistance, the thin plate resistivity, the thin plate magnetic permeability, and the thin plate conductivity;

[0072] Step M2. Understand the relevant data of the on-site welding process, including room temperature, maximum temperature during welding heating, maximum temperature difference during cooling, and cross-sectional area of ​​the weld;

[0073] Step M3. Obtain an initial leveling position based on the material properties of the sheet obtained in step M1 and the welding process parameters obtained in step M2, and obtain a heating time, heating current, and heating frequency based on the initial leveling position;

[0074] The steps for determining the initial leveling position and processing parameters such as heating time, heating current, and heating frequency based on the material properties of the thin plate obtained in step M1 and the welding process parameters obtained in step M2 include: first, determining the initial leveling position; then determining the heating time and heating frequency based on the thickness of the initial leveling position; and finally, determining the heating current based on the heating time and the relevant properties of the material at the initial leveling position. The specific steps are as follows:

[0075] M3.1. Based on the height of the highest point on the deformed surface and the height of the normal surface, the initial leveling position is obtained. The calculation formula is as follows:

[0076] ΔH=H1-H0(1)

[0077] Among them, ΔH represents the height difference at the deformed surface of the thin plate, which is used to determine the deformation position and the initial leveling point. H1 is the height of the highest point on the deformed surface, and H0 is the normal surface height. The initial leveling position is the area with the largest height difference at the deformed surface of the thin plate (that is, the position where ΔH is the largest).

[0078] M3.2. After the initial leveling position is selected, the heating time is calculated based on the sheet surface area, sheet thickness, and heating thickness. The calculation formula is as follows:

[0079] T=k·A·c·d(2)

[0080] Where T represents the heating time, k is the heat transfer coefficient, A is the sheet surface area, which can be determined from a laser scanning model or sheet CAD drawing, c is the sheet thickness, which can be directly obtained from the sheet model design parameters or actual measurement, and d is the heating thickness, which can be determined from empirical standard values ​​related to the existing material thickness and the target leveling effect (for example, for a total sheet thickness of 1-3 mm, the recommended heating thickness is 0.8-1.2 mm, for a total sheet thickness of 4-6 mm, the recommended heating thickness is 1.2-2.5 mm, etc.).

[0081] M3.3. Based on the heating time T obtained in M3.2, the material properties of the thin plate obtained in M1, and the welding process parameters obtained in M2, the heating current and heating frequency are obtained as shown in the following formula:

[0082]

[0083] Where I is the heating current, P is the heating power, and R is the sheet resistance; R is the sheet resistance, ρ is the sheet resistivity, L is the sheet length, and S is the sheet cross-sectional area; P is the heating power, t1 is the highest temperature reached during the heating process, t0 is the initial sheet temperature, k is the sheet heat transfer coefficient, T is the heating time, and A is the sheet surface area; ω is the heating current frequency, ρ is the sheet resistivity, δ is the skin depth, i.e., the required heating depth, μ is the sheet magnetic permeability, and σ is the sheet electrical conductivity.

[0084] Step M4. Calculate the heat flux density of the Gaussian heat source model at the heating position based on the heating current obtained in step M3, and select the next heating position based on the heat flux density to obtain a specific heating order;

[0085] Since the heat source energy is highly concentrated during the flattening process of thin plates, the heat in the central area is the highest and diffuses to the surrounding areas, so the Gaussian heat source model is used to approximate the energy distribution inside the flattening area. The heat flux density of the heat source model is shown as follows:

[0086]

[0087]

[0088] Q=η·U·I (9)

[0089] Among them, q rx is the heat flux lateral density of the heat source model, q ry is the longitudinal density of heat flux in the heat source model, q m is the maximum heat flux density at the center of the heat source, Q is the arc power during the heating process, η is the arc efficiency, I is the heating current, U is the heating voltage, r ax is the radius of the heat source's lateral action area, r by is the radius of the heat source longitudinal action area, r a r is the distance between any point in the horizontal effective range of the heat source and the center of the heat source, b The distance between any point within the effective longitudinal range of the heat source and the center of the heat source;

[0090] Step M5. Repeat M3 to M4, and then optimize the heating sequence according to the actual processing requirements and heat flux density. At the same time, collect the actual temperature change data of the thin plate, and further correct the heating time, heating current, and heating frequency to obtain the final thin plate leveling process parameter model.

[0091] In step M5, the inputs such as the sheet model, sheet deformation, sheet structure, and sheet material properties are combined with the five outputs of the marine electromagnetic induction heating leveler to form a multi-input and multi-output sheet leveling process parameter model. The sheet material properties include sheet length, width, and thickness, heat transfer coefficient, sheet resistance, sheet resistivity, sheet magnetic permeability, and sheet conductivity. The five outputs are heating position, heating time, heating current, heating frequency, and heating sequence, which can be calculated using formulas 1 to 9. Finally, through multiple on-site sampling experiments, the actual temperature change of the sheet is obtained, and the heating time, heating current, and heating frequency are further corrected. The specific temperature change calculation is shown in the following formula:

[0092] Q=q m ·S·T (10)

[0093] Q=m·C·ΔT (11)

[0094]

[0095] Among them, ΔT is the actual temperature change difference of the thin plate, Q is the heat, q m is the heat flux density, S is the leveling working contact area, T is the heating time, m is the mass of the thin plate, and C is the specific heat capacity of the thin plate.

[0096] like Figure 2 As shown, the present invention also provides a thin plate leveling method using a leveling process parameter model, comprising the following steps:

[0097] Step 1: Construct a thin plate leveling process parameter model to understand the relevant properties of the leveling workpiece material and the relevant parameters of the on-site welding process. Based on the obtained data and relevant formulas, the initial heating position, heating time, heating current, heating frequency, and heating sequence are calculated. Based on multiple on-site sampling experiments, the actual temperature changes of the thin plate are obtained, and the heating time, heating current, and heating frequency are further modified to obtain the final thin plate leveling process parameter model;

[0098] Step 1.1: Obtain the corresponding material properties of the thin plate material to be leveled on site, including the length, width, and thickness of the thin plate, heat transfer coefficient, thin plate resistance, thin plate resistivity, thin plate magnetic permeability, and thin plate conductivity;

[0099] Step 1.2: Understand the relevant data of the on-site welding process, including room temperature, maximum temperature during welding heating, maximum temperature difference during cooling, and cross-sectional area of ​​the weld;

[0100] Step 1.3: Obtain an initial leveling position based on the material properties of the thin plate obtained in step 1.1 and the welding process parameters obtained in step 1.2. Obtain a heating time, heating current, and heating frequency based on the initial leveling position.

[0101] The steps for calculating the initial leveling position and the values ​​of the processing parameters such as heating time, heating current, and heating frequency based on the material properties of the thin plate obtained in step 1.1 and the welding process parameters obtained in step 1.2 include: first, determining the initial leveling position; then determining the heating time and heating frequency based on the thickness of the initial leveling position; and finally calculating the heating current based on the heating time and the relevant properties of the material at the initial leveling position. The specific steps are as follows:

[0102] 1.3.1. Based on the height of the highest point on the deformed surface and the normal surface height, the initial leveling position is obtained. The calculation formula is as follows:

[0103] ΔH=H1-H0(13)

[0104] Where ΔH represents the height difference of the deformed surface of the thin plate, H1 is the height of the highest point on the deformed surface, and H0 is the height of the normal surface;

[0105] 1.3.2. After the initial leveling position is selected, the heating time is calculated based on the sheet surface area, sheet thickness, and heating thickness. The calculation formula is as follows:

[0106] T=k·A·c·d(14)

[0107] Where T represents the heating time, k is the heat transfer coefficient, A is the surface area of ​​the sheet, c is the thickness of the sheet, and d is the heated thickness;

[0108] 1.3.3. Based on the heating time T obtained in step 1.3.2, the material properties of the thin plate obtained in step 1.1, and the welding process parameters obtained in step 1.2, the heating current and heating frequency are obtained as shown in the following formula:

[0109]

[0110]

[0111] Where I is the heating current, P is the heating power, and R is the sheet resistance; R is the sheet resistance, ρ is the sheet resistivity, L is the sheet length, and S is the sheet cross-sectional area; P is the heating power, t1 is the highest temperature reached during the heating process, t0 is the initial sheet temperature, k is the sheet heat transfer coefficient, T is the heating time, and A is the sheet surface area; ω is the heating current frequency, ρ is the sheet resistivity, δ is the skin depth, i.e., the required heating depth, μ is the sheet magnetic permeability, and σ is the sheet electrical conductivity.

[0112] Step 1.4. Calculate the heat flux density of the Gaussian heat source model at the heating position based on the heating current obtained in step 1.3. Select the next heating position based on the heat flux density to obtain the specific heating order.

[0113] Since the heat source energy is highly concentrated during the flattening process of thin plates, the heat in the central area is the highest and diffuses to the surrounding areas, so the Gaussian heat source model is used to approximate the energy distribution inside the flattening area. The heat flux density of the heat source model is shown as follows:

[0114]

[0115] Q=η·U·I (21)

[0116] Among them, q rx is the heat flux lateral density of the heat source model, q ry is the longitudinal density of heat flux in the heat source model, q m is the maximum heat flux density at the center of the heat source, Q is the arc power during the heating process, η is the arc efficiency, I is the heating current, U is the heating voltage, r ax is the radius of the heat source's lateral action area, r by is the radius of the heat source longitudinal action area, r a r is the distance between any point in the horizontal effective range of the heat source and the center of the heat source, b The distance between any point within the effective longitudinal range of the heat source and the center of the heat source;

[0117] Step 1.5. Repeat steps 1.3 to 1.4, and then optimize the heating sequence according to the actual processing requirements and heat flux density. At the same time, collect the actual temperature change data of the thin plate, and further modify the heating time, heating current, and heating frequency to obtain the final thin plate leveling process parameter model.

[0118] Under the premise of ignoring the local effect, the actual temperature change difference of the thin plate is calculated. The calculation formula is as follows:

[0119] Q=q m ·S·T (22)

[0120] Q=m·C·ΔT (23)

[0121]

[0122] Among them, ΔT is the actual temperature change difference of the thin plate, Q is the heat, q m is the heat flux density, S is the leveling working contact area, T is the heating time, m is the mass of the thin plate, and C is the specific heat capacity of the thin plate.

[0123] Step 2: Based on the final thin plate leveling process parameter model obtained in step 1, the five major process parameters required for processing the thin plate are planned: initial heating position, heating time, heating current, heating frequency, and heating sequence;

[0124] The leveling heating input parameters are obtained based on the multi-input and multi-output thin plate leveling process parameter model. The process includes:

[0125] Based on the constructed multi-input and multi-output thin plate leveling process parameter model, the first heating position is determined. The required heating time, heating current, and heating frequency are then determined based on the heating position. After heating is completed, the next heating position is quickly located based on the distribution of heat flux density at the heating position. In actual production, the process of reasonable thin plate leveling heating using the multi-input and multi-output thin plate leveling process parameter model is as follows:

[0126] Step 2.1: Determine the sheet metal leveling heating position and related process parameters

[0127] Calculate the surface deformation of the flattened heated sheet, select the position with the maximum deformation as the initial flattening position, and calculate the heating time, heating current, and heating frequency required for that position based on the relevant data of the heating position.

[0128] Step 2.2: Plan the heating sequence for sheet metal leveling

[0129] Calculate the heat flux density at different locations of the position after the thin plate is leveled and heated. According to actual processing requirements, the area with a larger heat flux density can more effectively change the shape of the thin plate, so it is used as the next leveling heating point.

[0130] Step 3: Utilizing the magnetic conductivity of the metal itself, the eddy current effect is generated by the induction current to rapidly heat the steel plate, generating a large temperature gradient in the thickness direction of the steel plate, which then contracts after rapid cooling to eliminate the original deformation and achieve the effect of electromagnetic induction heating leveling;

[0131] The induction heating leveling process includes:

[0132] By utilizing the inherent magnetic conductivity of metal, induction current, and the eddy current effect of electromagnetic induction, a "skin effect" is created on the heated surface of the steel plate, rapidly heating the heated surface to the metal's Curie temperature. This in turn creates a large temperature gradient across the thickness of the steel plate, causing rapid cooling and contraction to eliminate the original deformation and achieve the electromagnetic induction heating leveling effect. Induction heating leveling offers advantages such as high controllability, high thermal efficiency, energy conservation and cleanliness, and significant thin plate leveling results.

[0133] Step 4: Check the flatness and surface quality of the leveled sheet to determine whether further correction is needed.

[0134] The process of determining whether correction is needed based on the leveling effect includes:

[0135] The flatness and surface quality of the thin plate after leveling are tested. If the final leveling result does not meet the actual processing requirements, electromagnetic induction heating leveling correction is further used; if the requirements are met, the leveling is completed.

[0136] In addition to the above embodiments, the present invention may also have other implementation methods. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A method for constructing a thin plate leveling process parameter model, characterized by: The steps include: Step M1. Obtain the corresponding material properties of the thin plate material to be leveled on site, including the length, width, and thickness of the thin plate, the heat transfer coefficient, the thin plate resistance, the thin plate resistivity, the thin plate magnetic permeability, and the thin plate conductivity; Step M2. Understand the relevant data of the on-site welding process, including room temperature, maximum temperature during welding heating, maximum temperature difference during cooling, and cross-sectional area of ​​the weld; Step M3. Obtain an initial leveling position based on the material properties of the sheet obtained in step M1 and the welding process parameters obtained in step M2, and obtain a heating time, heating current, and heating frequency based on the initial leveling position; Step M4. Calculate the heat flux density of the Gaussian heat source model at the heating position based on the heating current obtained in step M3, and select the next heating position based on the heat flux density to obtain a specific heating order; Step M5. Repeat steps M3 to M4, and then optimize the heating sequence according to the actual processing requirements and the heat flux density. At the same time, collect the actual temperature change data of the thin plate, and further correct the heating time, heating current, and heating frequency to obtain the final thin plate leveling process parameter model.

2. The method for constructing a thin plate leveling process parameter model according to claim 1, characterized in that: The specific steps of step M3 include: M3.

1. Based on the height of the highest point on the deformed surface and the height of the normal surface, the initial leveling position is obtained. The calculation formula is as follows: ΔH=H1-H0(1)where ΔH represents the height difference of the deformed surface of the sheet, H1 is the height of the highest point of the deformed surface, and H0 is the height of the normal surface; the initial leveling position is the point where ΔH is the largest; M3.

2. After the initial leveling position is selected, the heating time is calculated based on the sheet surface area, sheet thickness, and heating thickness. The calculation formula is as follows: T = k·A·c·d (2) where T represents the heating time, k is the heat transfer coefficient, A is the surface area of ​​the sheet, c is the thickness of the sheet, and d is the heated thickness; M3.

3. Based on the heating time T obtained in M3.2, the material properties of the thin plate obtained in M1, and the welding process parameters obtained in M2, the heating current and heating frequency are obtained as shown in the following formula: Where I is the heating current, P is the heating power, and R is the sheet resistance; R is the sheet resistance, ρ is the sheet resistivity, L is the sheet length, and S is the sheet cross-sectional area; P is the heating power, t1 is the maximum temperature reached during the heating process, t0 is the initial sheet temperature, k is the sheet heat transfer coefficient, T is the heating time, and A is the sheet surface area; ω is the heating current frequency, ρ is the sheet resistivity, δ is the skin depth, i.e., the required heating depth, μ is the sheet magnetic permeability, and σ is the sheet electrical conductivity.

3. The method for constructing a thin plate leveling process parameter model according to claim 2, characterized in that: The heat flux calculation formula of the heat source model in step M4 is as follows: Q=η·U·I (9) Among them, q rx is the heat flux lateral density of the heat source model, q ry is the longitudinal density of heat flux in the heat source model, q m is the maximum heat flux density at the center of the heat source, Q is the arc power during the heating process, η is the arc efficiency, i is the heating current, U is the heating voltage, r ax is the radius of the heat source's lateral action area, r by is the radius of the heat source longitudinal action area, r a r is the distance between any point in the horizontal effective range of the heat source and the center of the heat source, b It is the distance between any point within the effective longitudinal range of the heat source and the center of the heat source.

4. The method for constructing a thin plate leveling process parameter model according to claim 3, characterized in that: The temperature change calculation formula in step M5 is as follows: Q=q m ·S·T (10) Q=m·C·ΔT (11) Among them, ΔT is the actual temperature change difference of the thin plate, Q is the heat, q m is the heat flux density, S is the leveling working contact area, T is the heating time, m is the mass of the thin plate, and C is the specific heat capacity of the thin plate.

5. A thin plate leveling method using a leveling process parameter model, characterized in that: The steps include: Step 1: Construct a thin plate leveling process parameter model to understand the relevant properties of the leveling workpiece material and the relevant parameters of the on-site welding process. Based on the obtained data and relevant formulas, the initial heating position, heating time, heating current, heating frequency, and heating sequence are calculated. Based on multiple on-site sampling experiments, the actual temperature changes of the thin plate are obtained, and the heating time, heating current, and heating frequency are further modified to obtain the final thin plate leveling process parameter model; Step 2: Plan the five major process parameters required for processing the thin plate according to the final thin plate leveling process parameter model obtained in step 1; Step 3: Utilize the magnetic conductivity of the metal itself to generate eddy current effect through induced current to rapidly heat the steel plate and achieve electromagnetic induction heating and leveling; Step 4: Check the flatness and surface quality of the leveled sheet to determine whether further correction is needed.

6. The thin plate leveling method according to claim 5, characterized in that: The specific steps of step 1 include: Step 1.1: Obtain the corresponding material properties of the thin plate material to be leveled on site, including the length, width, and thickness of the thin plate, heat transfer coefficient, thin plate resistance, thin plate resistivity, thin plate magnetic permeability, and thin plate conductivity; Step 1.2: Understand the relevant data of the on-site welding process, including room temperature, maximum temperature during welding heating, maximum temperature difference during cooling, and cross-sectional area of ​​the weld; Step 1.3: Obtain an initial leveling position based on the material properties of the thin plate obtained in step 1.1 and the welding process parameters obtained in step 1.

2. Obtain a heating time, heating current, and heating frequency based on the initial leveling position. Step 1.

4. Calculate the heat flux density of the Gaussian heat source model at the heating position based on the heating current obtained in step 1.

3. Select the next heating position based on the heat flux density to obtain the specific heating order. Step 1.

5. Repeat steps 1.3 to 1.4, and then optimize the heating sequence according to the actual processing requirements and heat flux density. At the same time, collect the actual temperature change data of the thin plate, and further modify the heating time, heating current, and heating frequency to obtain the final thin plate leveling process parameter model.

7. The thin plate leveling method according to claim 6, characterized in that: The specific steps of step 1.3 include: 1.3.

1. Based on the height of the highest point on the deformed surface and the normal surface height, the initial leveling position is obtained. The calculation formula is as follows: ΔH=H1-H0 1.3.

2. After the initial leveling position is selected, the heating time is calculated based on the sheet surface area, sheet thickness, and heating thickness. The calculation formula is as follows: T=k·A·c·d 1.3.

3. Based on the heating time T obtained in step 1.3.2, the material properties of the thin plate obtained in step 1.1, and the welding process parameters obtained in step 1.2, the heating current and heating frequency are obtained as shown in the following formula: The heat flux calculation formula of the heat source model in step 1.4 is as follows: Q = η·U·I.

8. The thin plate leveling method according to claim 7, characterized in that: The steps for planning the five process parameters required for processing the thin plate in step 2 are as follows: Step 2.1: Determine the sheet metal leveling heating position and related process parameters Calculate the surface deformation of the flattened heated sheet, select the position with the maximum deformation as the initial flattening position, and calculate the heating time, heating current, and heating frequency required for that position based on the relevant data of the heating position; Step 2.2: Plan the heating sequence for sheet metal leveling Calculate the heat flux density at different locations of the position after the thin plate is leveled and heated. According to actual processing requirements, the area with a larger heat flux density can more effectively change the shape of the thin plate, so it is used as the next leveling heating point.

9. The thin plate leveling method according to claim 8, characterized in that: The step of judging whether the thin plate needs further correction in step 4 includes: testing the flatness and surface quality of the thin plate after leveling; if the final leveling result does not meet the actual processing requirements, further using electromagnetic induction heating leveling correction; if the requirements are met, the leveling is terminated.

10. The method for constructing a thin plate leveling process parameter model according to claim 2, characterized in that: The surface area A of the thin plate in step M3.2 is obtained by laser scanning the model, and the thickness c of the thin plate is obtained by actual measurement.

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