A method for designing a rolling process of a flame tube based on welding-rolling simulation and a rolling device

Abstract

This invention discloses a design method and rolling device for flame tube rolling process based on welding-rolling simulation. The method includes the following steps: S1, establishing a material constitutive model; S2, sequential coupling of thermo-mechanical simulation of the welding process; S3, constructing a simulation model of the rolling process; S4, digital control simulation analysis of rolling process parameters; S5, establishing collaborative optimization decision rules: extracting simulation results under different combinations of rolling process parameters in step S4, selecting a circumferential path around the workpiece along the weld center, analyzing the residual stress distribution on the workpiece surface after rolling, using the reduction of welding residual stress by rolling as an evaluation index, and prioritizing the selection of rolling parameter combinations that can significantly reduce the overall residual stress level. This invention treats welding and rolling as an integrated manufacturing chain for collaborative optimization, quantitatively revealing the inherent law that rolling can significantly reduce welding residual tensile stress. The average reduction in residual stress after rolling can reach 48.6%, and the fatigue life is increased by more than 2 times.

Description

Technical Field

[0001] This invention relates to the field of aero-engine manufacturing technology, specifically to a flame tube rolling process design method and rolling device based on welding-rolling simulation. Background Technology

[0002] As a core load-bearing component of the combustion system, the flame tube of an aero-engine is subjected to long-term high-temperature combustion gas erosion and cyclic thermal loads. The flame tube is typically constructed from thin-walled GH3536 nickel-based high-temperature alloy plates joined together by argon arc welding. The welding process inevitably generates significant residual tensile stress in the weld and heat-affected zone, while the weld area exhibits significant stress concentration, which substantially accelerates the initiation and propagation of fatigue cracks. To improve the fatigue performance of the welded joint, it is necessary to remove the harmful stresses present in the weld area.

[0003] In the prior art, patent number ZL201310456578.3 discloses a method for producing the combustion chamber flame tube of an aero-gas turbine engine, but this method does not involve any stress treatment technology. Patent number ZL202110686789.0 discloses a method for processing the cylindrical section of a gas turbine flame tube, with the following main steps: the front ring is first machined by turning, then wire-cut, and finally ground; the rear ring is first wire-cut, then rolled, and welded; the front and rear rings are then welded together by argon arc welding to obtain the first, second, third, fourth, and fifth sections of the flame tube. After welding, the sections are placed in a furnace to remove stress, and then the weld seams are ground. It can be seen that this processing method removes stress in a furnace after welding, but for thin-walled structures like the flame tube, furnace heat treatment can easily lead to warping and deformation of the components, and high-temperature treatment can soften the material, reducing the mechanical properties of the weld area. Furthermore, overall furnace stress relief cannot form a beneficial compressive stress distribution on the weld surface, and its effect on improving fatigue life is also limited.

[0004] Therefore, in current engineering production, roll forming is often used to improve the fatigue performance of welded joints in aero-engine flame tubes. Roll forming can introduce residual compressive stress into the workpiece surface, partially offsetting the harmful effects of residual tensile stress from welding. However, traditional processes treat welding and roll forming as independent steps in design and optimization, lacking a quantitative understanding of their inherent interaction mechanisms, making it difficult to fully realize the potential of roll forming. In particular, the effect of roll forming process parameters such as roll forming speed and friction coefficient on residual stress control lacks a quantitative model, leading to process selection relying on experience and hindering precise control.

[0005] Therefore, designing a flame tube rolling process design method that can systematically consider the synergistic effect of welding and rolling, accurately control the rolling parameters through digital simulation models, and quantitatively optimize the residual stress in the welding area is of great significance for improving the fatigue performance of key thin-walled components such as flame tubes. Summary of the Invention

[0006] The purpose of this invention is to provide a design method and rolling device for flame tube rolling process based on welding-rolling simulation, which aims to improve the problem that the rolling process parameters of the existing rolling strengthening process lack a quantitative model for the control effect of residual stress, resulting in the process selection relying on experience and failing to achieve precise control.

[0007] This invention is implemented as follows:

[0008] According to one aspect of the present invention, the present invention provides a method for designing a flame tube rolling process based on welding-rolling simulation, comprising the following steps:

[0009] S1. Establish material constitutive models: Construct material constitutive models for the base material, heat-affected zone, and weld zone of the flame tube matrix material and its weld joints, respectively.

[0010] S2. Sequential coupled thermo-mechanical simulation of welding process: Input the material constitutive model established in step S1 into the finite element simulation software to simulate the movement process of the argon arc welding heat source and obtain the initial residual stress field and deformation field after welding.

[0011] S3. Construction of simulation model for rolling process: Using the post-weld workpiece configuration and residual stress field obtained in step S2 as the initial state, a rolling simulation model is established. Based on the principle of relative motion, the workpiece is set to be fixed, and the speed relationship between the active rolling head and the driven rolling head is derived.

[0012] S4. Digital control simulation analysis of rolling process parameters: In the rolling simulation model constructed in step S3, multiple sets of different combinations of rolling process parameters are set for simulation analysis to quantitatively characterize the control effect of different parameters on welding residual stress and extract the distribution characteristics of the residual stress field after rolling.

[0013] S5. Establish collaborative optimization decision rules: Extract the simulation results under different combinations of rolling process parameters in step S4, select a circumferential path around the workpiece along the center of the weld, analyze the residual stress distribution on the surface of the workpiece after rolling, take the reduction of welding residual stress by rolling as the evaluation index, and prioritize the combination of rolling parameters that can significantly reduce the overall residual stress level.

[0014] Furthermore, the flame tube matrix material in step S1 is GH3536 high-temperature alloy, and its material constitutive model includes the elastic modulus, yield strength, coefficient of thermal expansion and thermal conductivity at different temperatures.

[0015] Furthermore, in step S2, the sequential coupling thermo-mechanical simulation of the welding process specifically includes: firstly, performing heat conduction analysis to simulate the movement of the argon arc welding heat source and obtaining the temperature field distribution that changes over time; then, using the temperature field as a thermal load, performing sequential thermo-mechanical coupling analysis to obtain the initial residual stress field and deformation field after welding is completed.

[0016] Furthermore, in step S2, the Goldak double ellipsoidal heat source model is used to characterize the energy distribution of the moving electric arc, and the spatial distribution and temporal evolution law of the heat flux density are defined by the user subroutine to complete the numerical implementation of the double ellipsoidal heat source.

[0017] The Goldak dual-ellipsoidal heat source model can accurately distinguish the energy distribution characteristics of the preheating zone in front of the welding torch and the slow cooling zone behind it, which is closer to the actual heat input pattern of the GTAW arc. However, the built-in heat source model of the ABAQUS software only supports simple forms such as Gaussian surface heat sources and cannot directly realize the moving loading of the dual-ellipsoidal heat source. The spatial distribution and temporal evolution of heat flux density can be customized by writing DFLUX user subroutines in FORTRAN, thus completing the numerical implementation of the dual-ellipsoidal heat source.

[0018] Furthermore, the Goldak dual-ellipsoidal heat source model uses two semi-ellipsoidal functions to describe the volume heat flux density of the preheating zone in front of the welding torch and the slow cooling zone behind it, respectively. The heat flux density of the front ellipsoid (x≥0, corresponding to the welding direction) of the Goldak dual-ellipsoidal heat source model is:

[0019]

[0020] The heat flux density of the rear ellipsoid (x<0) in the Goldak double ellipsoidal heat source model is:

[0021]

[0022] In the formula, These are the semi-axial parameters of the front hemisphere, in mm; 1 represents the semi-axial parameter of the rear hemisphere, in mm; b represents the weld width, in mm; c represents the weld depth, in mm. , Let represent the energy distribution coefficients within the anterior and posterior hemispheres, respectively, and + =2; For thermal efficiency; Arc voltage, in volts (V). This is the welding current, measured in amperes (A).

[0023] Furthermore, in step S3, the speed relationship between the active rolling head and the driven rolling head is determined by the following formula:

[0024]

[0025] In the formula, R is the radius of the flame tube. The radius of the rolling head is... The rotational angular velocity of the active rolling head, The rotational angular velocity of the driven rolling head, The revolution angular velocity of the driven rolling head.

[0026] Furthermore, the rolling process parameters in step S4 include the rolling head rotation speed ω and the friction coefficient μ, and the rolling time is controlled by the total analysis time t.

[0027] Furthermore, the decision rule in step S5 is as follows: taking the improvement effect of the overall residual stress field after rolling as the evaluation index, the rolling parameter combination that can reduce the overall residual stress level by more than 30% compared with the post-weld state is given priority.

[0028] According to a second aspect of the present invention, the present invention provides a rolling device for performing rolling processing on a flame tube welded workpiece according to the rolling parameters optimized by the above-mentioned flame tube rolling process design method based on welding-rolling simulation; the rolling device includes:

[0029] The machine body, which is equipped with a power source and a pressure pump,

[0030] An active rolling head is connected to a power source to provide rotational driving force.

[0031] The driven rolling head is connected to a pressure pump and cooperates with the active rolling head to clamp the workpiece and apply rolling force.

[0032] The control module, electrically connected to the power source and pressure pump, is used to input the preferred rolling parameters to the power source and pressure pump.

[0033] Furthermore, a drive shaft is horizontally rotatably mounted on the machine body, one end of which is connected to a power source, and the other end is detachably mounted with a drive rolling head; a hydraulic cylinder is vertically mounted on the machine body, which is connected to a pressure pump, and a driven rolling head is detachably and rotatably mounted on the lower end of the piston rod of the hydraulic cylinder, with the driven rolling head and the drive rolling head arranged vertically opposite to each other.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. This invention treats welding and rolling as an integrated manufacturing chain for synergistic optimization, and quantitatively reveals the inherent law that rolling can significantly reduce residual tensile stress in welding. The average reduction in residual stress after rolling can reach 48.6%.

[0036] 2. This invention establishes a digital control model for rolling process parameters. By changing parameters such as friction coefficient and rolling head speed, the control effect of different parameters on residual stress can be quantitatively evaluated, realizing a leap from experience-based trial and error to digital precision control.

[0037] 3. The quantitative decision-making rule proposed in this invention, with "the effect of improving the overall residual stress field after rolling" as the core, provides a clear basis for the optimization of rolling process parameters. The optimized combined process can reduce the residual stress in the weld area by 48.6% and increase the fatigue life by more than 2 times.

[0038] 4. The rolling device provided by the present invention has a simple structure and is easy to adjust. It can be matched with the flame tube rolling process design method to achieve accurate conversion of simulation parameters into actual process. Attached Figure Description

[0039] Figure 1 A flowchart illustrating the flame tube rolling process design method based on welding-rolling simulation provided by this invention;

[0040] Figure 2 This is a cloud diagram showing the equivalent stress distribution of the workpiece before and after rolling after welding.

[0041] Figure 3 The graph shows the variation of radial residual stress under different friction coefficients.

[0042] Figure 4 The graph shows the variation of radial residual stress under different rolling head rotation speeds.

[0043] Figure 5 This is a comparison diagram of the residual stress distribution along the weld path before and after rolling.

[0044] Figure 6 This is a schematic diagram of the rolling device.

[0045] In the diagram: 1. Machine body; 2. Power source; 3. Pressure pump; 4. Active rolling head; 5. Driven rolling head; 6. Control module; 7. Active drive shaft; 8. Hydraulic cylinder. Detailed Implementation

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details:

[0048] Example 1

[0049] This embodiment provides a design method for flame tube rolling process based on welding-rolling simulation, such as... Figure 1 As shown, the specific steps include the following:

[0050] S1. Establish a constitutive model of the material.

[0051] Taking the flame tube of a certain type of aero-engine as an example, its matrix material is GH3536 high-temperature alloy. The elastic modulus, yield strength, coefficient of thermal expansion, and thermal conductivity of each region at different temperatures are obtained through high-temperature tensile tests, establishing an isotropic hardening model. The yield criterion adopts the Von Mises criterion. Alternatively, the coefficient of thermal expansion and thermal conductivity of each region at different temperatures can be obtained through thermophysical property testing.

[0052] S2. Sequential coupling thermo-mechanical simulation of the welding process.

[0053] A welding simulation model of the thin-walled structure of the flame tube was established using finite element software. The Goldak double ellipsoidal heat source model was used to simulate the heat input of argon arc welding. The spatial distribution and temporal evolution of heat flux density were realized by writing the DFLUX user subroutine in FORTRAN.

[0054] The Goldak dual-ellipsoidal heat source model uses two semi-ellipsoidal functions to describe the volumetric heat flux density in the preheating zone in front of the welding torch and the slow cooling zone behind it, respectively. The heat flux density of the front ellipsoid (x≥0, corresponding to the welding direction) of the Goldak dual-ellipsoidal heat source model is:

[0055]

[0056] The heat flux density of the rear ellipsoid (x<0) in the Goldak double ellipsoidal heat source model is:

[0057]

[0058] In the formula, These are the semi-axial parameters of the front hemisphere, in mm; 1 represents the semi-axial parameter of the rear hemisphere, in mm; b represents the weld width, in mm; c represents the weld depth, in mm. , Let represent the energy distribution coefficients within the anterior and posterior hemispheres, respectively, and + =2; For thermal efficiency; Arc voltage, in volts (V). This is the welding current, measured in amperes (A).

[0059] A fully thermo-mechanical coupling method was adopted, and two transient analysis steps were set up for the welding stage and the cooling stage to obtain the geometric deformation of the workpiece and the initial residual stress field after welding.

[0060] like Figure 2 As shown on the left, after welding, there is obvious residual tensile stress concentration in the weld area, with an equivalent stress peak of about 859.5 MPa and an average residual stress of about 678.6 MPa. The central area of ​​the weld shows obvious tensile stress.

[0061] S3. Construction of simulation model for rolling process.

[0062] The welded workpiece calculated in S2 is imported into the rolling simulation model as the initial state. The workpiece is a conical cylinder with a wall thickness of 0.8mm, and the rolling head is a cylinder with a radius of 40mm and a thickness of 10mm. Based on the principle of relative motion, the workpiece is fixed, and the rotational speed ω1 of the lower rolling head (active rolling head) is set. The rotational speed ω2 and revolution speed ω3 of the upper rolling head (driven rolling head) are derived as follows:

[0063]

[0064] The contact between the rolling head and the workpiece is determined using the penalty function method, and the friction model is the Coulomb friction model, with the reference friction coefficient set to 0.3.

[0065] S4. Digital control simulation analysis of rolling process parameters.

[0066] To achieve precise digital control of welding residual stress, multiple sets of friction coefficients (0.05, 0.1, 0.3, 0.5) and rolling head speeds (6.28 rad / s, 9.42 rad / s, 12.57 rad / s, 15.71 rad / s) were set for simulation analysis to quantitatively evaluate the control effect of each parameter on residual stress.

[0067] like Figure 3As shown, different friction coefficients have a significant regulating effect on radial residual stress (S33). When the friction coefficient is 0.05, the radial residual compressive stress is small, and the regulating effect is limited; when the friction coefficient increases to 0.3, the radial residual compressive stress reaches its maximum value, and the regulating effect is optimal; when the friction coefficient continues to increase to 0.5, the radial residual compressive stress decreases instead. Simulation results show that, through digital control, the optimal compressive stress regulating effect is obtained when the friction coefficient is 0.3.

[0068] like Figure 4 As shown, different rolling head rotation speeds have a significant controlling effect on radial residual stress (S33). The radial residual compressive stress is highest and the controlling effect is strongest when the rolling head rotational angular velocity is 6.28 rad / s. As the rotational speed increases to 15.71 rad / s, the radial residual compressive stress gradually decreases, and the controlling effect weakens. Simulation results indicate that, through digital control, determining a lower rolling speed is beneficial for obtaining a deeper compressive stress layer, and a rolling head rotation speed of 12.57 rad / s can achieve a good controlling effect while ensuring efficiency.

[0069] S5. Establish collaborative optimization decision-making rules.

[0070] Stress analysis was performed along a circumferential path around the workpiece at the weld center. Radial stress components were extracted to evaluate the overall effect of rolling on reducing residual welding stress. Figure 5 As shown, the residual stress distribution along the weld path changes significantly before and after rolling. Before rolling, the peak residual stress in the weld area is approximately 680-720 MPa, with uneven stress distribution and obvious stress concentration; after rolling, the residual stress is significantly reduced to approximately 230-360 MPa, with a more uniform stress distribution and a substantial reduction in the overall residual stress level.

[0071] like Figure 2 As shown on the right, after rolling, the maximum equivalent stress of the workpiece decreased to 601.0 MPa, and the average equivalent stress decreased from 678.6 MPa to 348.8 MPa, a reduction of 48.6%, with the overall residual stress level decreasing by more than 30%. This indicates that, through the digital control model established in this invention, the rolling process can effectively convert welding residual tensile stress into compressive stress or significantly reduce its amplitude, forming an ideal stress distribution state.

[0072] Analysis of the improvement effect of different combinations of rolling parameters on the overall residual stress field:

[0073] When the friction coefficient μ=0.3 and the rolling head speed ω=12.57rad / s, the average value of the overall residual stress drops to 348.8MPa, a reduction of 48.6%, which is the optimal control effect;

[0074] When the friction coefficient μ=0.5, the average value of the overall residual stress drops to 412.5MPa, a decrease of only 39.2%, indicating insufficient control effect;

[0075] When the rolling head speed ω=15.71rad / s, the average value of the overall residual stress drops to 425.6MPa, a decrease of only 37.3%, indicating that excessively high rolling speed is not conducive to the full control of residual stress.

[0076] Optimization effect verification:

[0077] Based on the above digital control analysis, and taking the improvement effect of the overall residual stress field after rolling as the decision-making basis, the optimal combination of process parameters was determined to be: welding parameters (voltage 10V, current 17A, welding speed 10mm / s); rolling parameters (friction coefficient 0.3, rolling head speed 12.57rad / s). Under this parameter combination, the overall residual stress level was reduced by 48.6%, achieving precise digital control of the stress in the welding area.

[0078] A comparative experiment was conducted using this optimized scheme and a traditional scheme (the company's current welding parameters: voltage 12V, current 20A, welding speed 5mm / s; no rolling). The test results show that, using the optimized welding-rolling combination process of this invention, rolling reduced the average residual stress of the weld from 678.6MPa to 348.8MPa, a reduction of 48.6%, and increased the fatigue life of the weld area by approximately 2.3 times. This fully verifies the effectiveness and reliability of this invention in optimizing the stress in the weld area through a digital control model.

[0079] In summary, this invention treats welding and rolling as an integrated manufacturing chain for synergistic optimization, quantitatively revealing the inherent law that rolling can significantly reduce residual tensile stress in welding, with an average reduction of up to 48.6% in residual stress after rolling. This invention establishes a digital control model for rolling process parameters. By changing parameters such as the friction coefficient and rolling head speed, the effect of different parameters on residual stress control can be quantitatively evaluated, achieving a leap from empirical trial and error to precise digital control. The quantitative decision-making rule proposed in this invention, centered on the "improvement effect of the overall residual stress field after rolling," provides a clear basis for the optimal selection of rolling process parameters. The optimized combined process can reduce residual stress in the weld area by 48.6% and increase fatigue life by more than 2 times.

[0080] Example 2

[0081] This embodiment provides a rolling device that performs rolling processing on the flame tube welded workpiece according to the rolling parameters selected by the flame tube rolling process design method based on welding-rolling simulation provided in Embodiment 1.

[0082] Specifically, such as Figure 6As shown, the rolling device has a body 1, on which a power source 2 and a pressure pump 3 are mounted. The power source 2 includes a drive motor and a reducer connected to the drive motor, providing adjustable rotary driving force. A drive shaft 7 is horizontally rotatably mounted on the body 1 along the power transmission path. One end of the drive shaft 7 is connected to the reducer of the power source 2, and the other end is detachably mounted with a drive rolling head 4. Thus, the torque output from the power source 2 is transmitted to the drive rolling head 4 through the drive shaft 7, enabling it to rotate at a set speed, providing active rotary driving force for the rolling process.

[0083] A hydraulic cylinder 8 is vertically mounted on the machine body 1 along the clamping and force application path. The oil circuit of the hydraulic cylinder 8 is connected to the pressure pump 3, which drives its piston rod to extend and retract. A driven rolling head 5 is detachably and rotatably mounted on the lower end of the piston rod of the hydraulic cylinder 8. The driven rolling head 5 and the driving rolling head 4 are arranged vertically opposite each other. During operation, the pressure pump 3 drives the piston rod of the hydraulic cylinder 8 to extend downward, causing the driven rolling head 5 to press against the flame tube workpiece placed on the driving rolling head 4, thereby applying controllable rolling pressure. The driving rolling head 4 and the driven rolling head 5 can be selected in different sizes according to the diameter of the flame tube. The driving rolling head 4 and the driven rolling head 5 of the same size can also have different surface roughness or knurled tooth profiles to provide different friction coefficients, thereby meeting the requirements for adjusting the rolling friction coefficient under different welding process parameters. In addition, the machine body 1 is provided with a storage structure for storing driving rolling heads 4 and driven rolling heads 5 of various specifications.

[0084] To achieve automated and precise control of the processing, the rolling device also includes a control module 6. Control module 6 comprises an electrical control box, which houses a programmable logic controller (PLC), a frequency converter connected to the PLC output, and an analog-to-digital converter (ADC). The frequency converter is electrically connected to the power source 2 and is used to adjust the rotational speed of the active rolling head 4. The ADC is electrically connected to the pressure pump 3 and is used to control the rolling pressure of the driven rolling head 5. Control module 6 receives the rolling parameters optimized by the aforementioned flame tube rolling process design method based on welding-rolling simulation, and precisely controls the rotational speed of the active rolling head 4 output from the power source 2, as well as the hydraulic oil pressure output from the pressure pump 3 to the hydraulic cylinder 8, thereby adjusting the rolling load applied to the workpiece by the driven rolling head 5, ultimately achieving automated and digital rolling processing of the flame tube welded workpiece.

[0085] In summary, the rolling device provided by this invention has a simple structure and is easy to adjust. It can be matched with the flame tube rolling process design method, and realize the accurate conversion of simulation parameters into actual process.

[0086] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A design method for flame tube rolling process based on welding-rolling simulation, characterized in that, Includes the following steps: S1. Establish material constitutive models: Construct material constitutive models for the base material, heat-affected zone, and weld zone of the flame tube matrix material and its weld joints, respectively. S2. Sequential coupled thermo-mechanical simulation of welding process: Input the material constitutive model established in step S1 into the finite element simulation software to simulate the movement process of the argon arc welding heat source and obtain the initial residual stress field and deformation field after welding. S3. Construction of simulation model for rolling process: Using the post-weld workpiece configuration and residual stress field obtained in step S2 as the initial state, a rolling simulation model is established. Based on the principle of relative motion, the workpiece is set to be fixed, and the speed relationship between the active rolling head and the driven rolling head is derived. S4. Digital control simulation analysis of rolling process parameters: In the rolling simulation model constructed in step S3, multiple sets of different combinations of rolling process parameters are set for simulation analysis to quantitatively characterize the control effect of different parameters on welding residual stress and extract the distribution characteristics of the residual stress field after rolling. S5. Establish collaborative optimization decision rules: Extract the simulation results under different combinations of rolling process parameters in step S4, select a circumferential path around the workpiece along the center of the weld, analyze the residual stress distribution on the surface of the workpiece after rolling, take the reduction of welding residual stress by rolling as the evaluation index, and prioritize the combination of rolling parameters that can significantly reduce the overall residual stress level.

2. The flame tube rolling process design method based on welding-rolling simulation according to claim 1, characterized in that, The flame tube matrix material in step S1 is GH3536 high-temperature alloy, and its material constitutive model includes the elastic modulus, yield strength, coefficient of thermal expansion and thermal conductivity at different temperatures.

3. The flame tube rolling process design method based on welding-rolling simulation according to claim 1, characterized in that, In step S2, the sequential coupling thermo-mechanical simulation of the welding process specifically includes: first, performing heat conduction analysis to simulate the movement of the argon arc welding heat source and obtain the temperature field distribution that changes over time; then, using the temperature field as a thermal load, performing sequential thermo-mechanical coupling analysis to obtain the initial residual stress field and deformation field after welding is completed.

4. The flame tube rolling process design method based on welding-rolling simulation according to claim 1, characterized in that, In step S2, the Goldak double ellipsoidal heat source model is used to characterize the energy distribution of the moving electric arc. The spatial distribution and temporal evolution of the heat flux density are defined using a user subroutine to complete the numerical implementation of the double ellipsoidal heat source.

5. The flame tube rolling process design method based on welding-rolling simulation according to claim 4, characterized in that, The heat flux density of the front ellipsoid of the Goldak double ellipsoidal heat source model is: The heat flux density of the rear ellipsoid in the Goldak double ellipsoidal heat source model is: In the formula, These are the semi-axial parameters of the front hemisphere, in mm; 1 represents the semi-axial parameter of the rear hemisphere, in mm; b represents the weld width, in mm; c represents the weld depth, in mm. , Let represent the energy distribution coefficients within the anterior and posterior hemispheres, respectively, and + =2; For thermal efficiency; Arc voltage, in volts (V). This is the welding current, measured in amperes (A).

6. The flame tube rolling process design method based on welding-rolling simulation according to claim 1, characterized in that, In step S3, the speed relationship between the active rolling head and the driven rolling head is determined by the following formula: In the formula, R is the radius of the flame tube. The radius of the rolling head is... The rotational angular velocity of the active rolling head, The rotational angular velocity of the driven rolling head, The revolution angular velocity of the driven rolling head.

7. The flame tube rolling process design method based on welding-rolling simulation according to claim 6, characterized in that, The rolling process parameters in step S4 include the rolling head rotation speed ω and the friction coefficient μ, and the rolling time is controlled by the total analysis time t.

8. The flame tube rolling process design method based on welding-rolling simulation according to claim 1, characterized in that, The decision rule in step S5 is as follows: taking the improvement effect of the overall residual stress field after rolling as the evaluation index, the rolling parameter combination that can reduce the overall residual stress level by more than 30% compared with the post-weld state is given priority.

9. A rolling device, characterized in that, The preferred rolling parameters of the flame tube rolling process design method based on welding-rolling simulation according to any one of claims 1 to 8 are used to perform rolling processing on the flame tube welded workpiece; the rolling device includes: The machine body, which is equipped with a power source and a pressure pump, An active rolling head is connected to a power source to provide rotational driving force. The driven rolling head is connected to a pressure pump and cooperates with the active rolling head to clamp the workpiece and apply rolling force. The control module, electrically connected to the power source and pressure pump, is used to input the preferred rolling parameters to the power source and pressure pump.

10. The rolling device according to claim 9, characterized in that, A drive shaft is horizontally rotatably mounted on the machine body. One end of the drive shaft is connected to a power source, and the other end is detachably mounted with a drive rolling head. A hydraulic cylinder is vertically mounted on the machine body. The hydraulic cylinder is connected to a pressure pump. The lower end of the piston rod of the hydraulic cylinder is detachably and rotatably mounted with a driven rolling head. The driven rolling head and the drive rolling head are arranged opposite each other.

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