Weld monitoring and regulation device, welding system and welding method

Abstract

This invention discloses a welding monitoring and control device, a welding system, and a welding method, relating to the field of welding technology. The welding monitoring and control device includes a tracking sensor mechanism, a controller, and a temperature regulation mechanism. The welding system includes a welding device and a welding monitoring and control device. The tracking sensor mechanism collects the molten pool morphology and surface temperature distribution in real time, and the controller receives the molten pool morphology and surface temperature distribution data collected in real time by the tracking sensor mechanism. The controller performs thermo-mechanical coupling analysis based on the thermophysical and mechanical parameters of the workpiece to be welded, as well as the molten pool morphology and surface temperature distribution data, and sends a temperature control command to the temperature regulation mechanism. The temperature regulation mechanism adjusts the temperature field of the weld according to the temperature control command, thereby adjusting the residual stress field distribution of the weld. This achieves precise control of residual stress for different welding materials and welding conditions, further reducing the welding residual stress of the workpiece.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a welding monitoring and control device, a welding system, and a welding method. Background Technology

[0002] Welding is a core process for joining materials in fields such as machinery manufacturing, construction engineering, and aerospace. It involves localized heating to melt the materials to be joined, forming a molten pool. After cooling and solidification, the molten pool completes the integrated connection of the materials. However, the welding process is inherently characterized by highly concentrated heat input, a large temperature gradient in the welding area, and a rapid cooling rate of the molten pool. This causes uneven thermal expansion and contraction of the molten pool during the cooling and solidification process. This uneven thermal deformation is constrained by the structure and cannot be released freely, thus forming residual stress inside the welded structure. Welding residual stress is a self-balancing stress that exists inside the welded structure without external load. Its presence has a significant negative impact on the performance of the welded structure, greatly reducing the fatigue life, fracture performance, and dimensional stability of the welded joint. This can lead to deformation, cracking, and other failures during long-term use, threatening the safety and reliability of the welded structure. Therefore, effective control of residual stress during welding is a key technical challenge for improving the quality of welded structures.

[0003] To address the aforementioned issues, existing technologies have proposed applying cooling or heating to the weld simultaneously during the welding process. This method regulates the temperature field distribution of the molten pool, thereby indirectly controlling the stress field and suppressing residual stress. However, existing control technologies generally employ open-loop control, with control parameters primarily determined by the operator's experience. They lack a mechanism for monitoring and feedback on the real-time state of the molten pool's temperature and stress fields during welding. This prevents real-time correction and closed-loop control based on the dynamic changes in the temperature and stress fields during welding. Consequently, existing control technologies suffer from low precision and poor adaptability, making it difficult to achieve precise control of residual stress for different welding materials and conditions, ultimately resulting in significant residual stress in the workpiece. Summary of the Invention

[0004] The purpose of this invention is to provide a welding monitoring and control device, a welding system, and a welding method to solve the problems existing in the prior art and further reduce the welding residual stress of the workpiece.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a welding monitoring and control device, comprising a tracking sensor mechanism, a controller, and a temperature adjustment mechanism. The tracking sensor mechanism is movable and configured to collect weld position, molten pool morphology, and molten pool surface temperature distribution data in real time. The controller is signal-connected to the tracking sensor mechanism to receive the real-time data on weld position, molten pool morphology, and molten pool surface temperature distribution collected by the tracking sensor mechanism. The controller is equipped with a finite element coupling simulation module, which is configured to perform thermo-mechanical coupling analysis based on the thermophysical and mechanical parameters of the workpiece to be welded, as well as the weld position, molten pool morphology, and molten pool surface temperature distribution data. The temperature adjustment mechanism is movable and signal-connected to the controller. The controller sends a temperature control command to the temperature adjustment mechanism based on the thermo-mechanical coupling analysis results. The temperature adjustment mechanism is configured to adjust the temperature field of the weld according to the temperature control command.

[0006] In some embodiments, a particle spray gun is also included, located on the side of the temperature regulating mechanism away from the welding device. The particle spray gun is signal-connected to the controller, which sends a particle spraying control command to the particle spray gun based on the results of thermo-mechanical coupling analysis. The particle spray gun is configured to spray solid particles onto the weld surface according to the particle spraying control command.

[0007] In some embodiments, the tracking sensing mechanism includes an image acquisition unit and a temperature acquisition unit, wherein the image acquisition unit is configured to acquire the weld position and molten pool morphology in real time, and the temperature acquisition unit is configured to acquire the surface temperature distribution of the molten pool in real time.

[0008] In some embodiments, the temperature regulating mechanism includes a cooling section and a heat treatment section, the cooling section and the heat treatment section being arranged at intervals along the weld extension direction, the cooling section being configured to spray cooling gas toward the weld, and the heat treatment section being configured to heat the weld.

[0009] In some embodiments, the heat treatment unit includes a laser source positioned toward the workpiece to be welded and emitting a laser beam toward the weld to heat the weld.

[0010] The present invention also provides a welding system, including a welding device and a welding monitoring and control device as described in any of the above claims. The welding device is signal-connected to the controller, and the controller sends welding control commands to the welding device based on thermo-mechanical calculation results. The welding device is configured to weld the workpiece to be welded according to the welding control commands and to adjust the welding device current, voltage and welding speed.

[0011] In some embodiments, a first robotic arm and a second robotic arm are also included. The first robotic arm is connected to the welding device and the cooling unit to move the welding device and the cooling unit. The second robotic arm is connected to the tracking sensing mechanism and the heat treatment unit to move the tracking sensing mechanism and the heat treatment unit.

[0012] In some embodiments, a preheating mechanism is also included, located on the side of the welding apparatus away from the welding monitoring and control device, and the preheating mechanism is configured to preheat the workpiece to be welded.

[0013] The present invention also provides a welding method using the welding system described in any one of the above claims, comprising the following steps: Start the welding device and move the welding device to weld the workpiece to be welded; As the welding device moves, the tracking sensor mechanism collects the weld position, molten pool morphology, and molten pool surface temperature distribution in real time. The controller receives the molten pool morphology and molten pool surface temperature distribution data collected in real time by the tracking sensor mechanism. The controller performs thermo-mechanical coupling analysis based on the thermophysical parameters, mechanical parameters, molten pool morphology, and molten pool surface temperature distribution data of the workpiece to be welded, and sends temperature control commands to the temperature regulation mechanism based on the thermo-mechanical coupling analysis results. As the tracking sensor moves the temperature regulating mechanism, the temperature regulating mechanism adjusts the temperature field of the weld according to the temperature control command.

[0014] In some implementations, the finite element coupled simulation module performs thermo-mechanical coupled analysis by including the following steps: Input the thermal and mechanical properties of the workpiece to be welded; Input the target temperature field and target residual stress field that satisfy the molding quality constraints; Receives real-time data on weld position, molten pool morphology, and molten pool surface temperature distribution collected by the tracking sensor mechanism; A thermo-mechanical coupling analysis is performed to obtain the time-varying temperature field and the time-varying residual stress field, which are then compared with the target temperature field and the target residual stress field, respectively. Temperature control commands are generated based on the comparison results.

[0015] The present invention achieves the following technical effects compared to the prior art: This invention provides a welding monitoring and control device, welding system, and welding method. It uses a tracking sensor to collect real-time data on the molten pool morphology and surface temperature distribution. A controller receives this data and performs thermo-mechanical coupling analysis based on the thermophysical and mechanical parameters of the workpiece and the molten pool morphology and surface temperature distribution data. Based on the analysis results, the controller sends temperature control commands to a temperature control mechanism. The temperature control mechanism adjusts the temperature field of the weld according to the commands, thereby regulating the residual stress field distribution and suppressing residual stress. This invention achieves a real-time monitoring and feedback mechanism for the molten pool temperature and stress fields during welding. Real-time correction and closed-loop control are performed based on the dynamic changes in the temperature and stress fields during welding, enabling precise control of residual stress for different welding materials and conditions, further reducing residual stress in the workpiece. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the welding system structure in some embodiments of Example 2; Figure 2 This is a flowchart of the welding method in some embodiments of Example 3; Figure 3 This is a schematic diagram of weld temperature changes in some embodiments of Example 1; Figure 4 This is a schematic diagram of rotor modeling in some embodiments of Example 4; Figure 5 for Figure 4 A magnified view of region A; Figure 6 for Figure 5 Enlarged schematic diagram of region B; Figure 7 This is a residual stress distribution diagram on the rotor cross-section in some embodiments of Example 4; Figure 8 This is a schematic diagram comparing the residual stress on the rotor cross-section in some embodiments of Example 4 with the residual stress on the rotor cross-section in the conventional welding method.

[0018] In the diagram: 1-Conveyor belt; 2-Workpiece to be welded; 3-Second robotic arm; 4-Particle spray gun; 6-Heat treatment unit; 7-Image acquisition unit; 8-Temperature acquisition unit; 9-Cooling unit; 10-Welding device; 11-First robotic arm; 12-Controller. Detailed Implementation

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

[0020] The purpose of this invention is to provide a welding monitoring and control device, a welding system, and a welding method to solve the problems existing in the prior art and further reduce the welding residual stress of the workpiece.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1 This embodiment provides a welding monitoring and control device, such as... Figure 1As shown, the system includes a tracking sensor mechanism, a controller 12, and a temperature regulation mechanism. The tracking sensor mechanism is movable and configured to acquire the weld position, molten pool morphology, and molten pool surface temperature distribution in real time. The controller 12 is signal-connected to the tracking sensor mechanism to receive the weld position, molten pool morphology, and molten pool surface temperature distribution data acquired in real time by the tracking sensor mechanism. The controller 12 is equipped with a finite element coupling simulation module, which is configured to perform thermo-mechanical coupling analysis based on the thermophysical and mechanical parameters of the workpiece 2 to be welded, as well as the weld position, molten pool morphology, and molten pool surface temperature distribution data. The temperature regulation mechanism is movable and signal-connected to the controller 12. The controller 12 sends temperature control commands to the temperature regulation mechanism based on the thermo-mechanical coupling analysis results. The temperature regulation mechanism is configured to adjust the temperature field of the weld according to the temperature control commands. The tracking sensor collects the weld position, molten pool morphology, and molten pool surface temperature distribution in real time. The controller 12 receives the data collected in real time by the tracking sensor. The controller 12 performs thermo-mechanical coupling analysis based on the thermophysical and mechanical parameters of the workpiece 2 to be welded, as well as the data on the weld position, molten pool morphology, and molten pool surface temperature distribution. Based on the results of the thermo-mechanical coupling analysis, the controller sends a temperature control command to the temperature regulation mechanism. The temperature regulation mechanism adjusts the temperature field of the weld according to the temperature control command, thereby adjusting the distribution of the residual stress field of the weld to suppress residual stress. This realizes a real-time monitoring and feedback mechanism for the temperature and stress fields of the molten pool during the welding process. Based on the dynamic changes of the temperature and stress fields during the welding process, real-time correction and closed-loop control are performed, thereby achieving precise control of residual stress for different welding materials and welding conditions, and further reducing the welding residual stress of the workpiece.

[0023] In some embodiments, the welding monitoring and control device further includes a particle spray gun 4, which is located on the side of the temperature regulation mechanism away from the welding device 10. The particle spray gun 4 is signal-connected to the controller 12, and the controller 12 sends a particle spraying control command to the particle spray gun 4 according to the thermo-mechanical coupling analysis results. The particle spray gun 4 is configured to spray solid particles onto the weld surface according to the particle spraying control command. In some embodiments, the solid particles are selected as high-hardness, low-brittle solid particles, such as metal particles, ceramic particles, flux particles or composite particles, with a particle size of 10-300 μm, a particle mass flow rate of 0.1-20 g / min, and a spraying distance of 5-30 mm. The weld and heat-affected zone metal undergo a "melting-rapid cooling" process. During cooling and contraction, it is rigidly constrained by the surrounding unmelted matrix, thereby forming a residual tensile stress field on the surface and inside of the weld. The particle impact causes the surface metal (usually tens to hundreds of micrometers deep) to undergo plastic elongation deformation. After the particle impact load is removed, the surface metal cannot recover synchronously with the elastically deformed matrix. Therefore, the elastic recovery force of the matrix forces the surface metal to generate continuous compressive stress, ultimately forming a stable residual compressive stress field on the surface of the weld and heat-affected zone to offset the residual tensile stress field and reduce the residual stress of the weld.

[0024] In some embodiments, the tracking sensing mechanism includes an image acquisition unit 7 and a temperature acquisition unit 8. The image acquisition unit 7 is configured to acquire the weld position and molten pool morphology in real time, and the temperature acquisition unit 8 is configured to acquire the molten pool surface temperature distribution in real time, so as to obtain weld position, molten pool morphology, and molten pool surface temperature distribution data and transmit them to the controller 12. In some embodiments, the image acquisition unit 7 includes an industrial camera, specifically a CMOS camera, equipped with an 808nm narrow-bandpass filter to suppress arc light, to acquire the weld position and molten pool morphology parameters, such as the width and length of the molten pool; the temperature acquisition unit 8 includes a thermal imaging camera based on the principle of infrared radiation thermometry to acquire molten pool surface temperature distribution data.

[0025] In some embodiments, the temperature regulating mechanism includes a cooling section 9 and a heat treatment section 6, which are arranged at intervals along the weld extension direction. The cooling section 9 is configured to spray cooling gas toward the weld, and the heat treatment section 6 is configured to heat the weld. In some embodiments, the cooling section 9 includes a nozzle and a gas storage tank. A flow regulating valve and a proportional valve are provided on the connecting pipe between the gas storage tank and the nozzle. The cooling medium is an inert gas or a mixed gas, and the cooling flow rate can be continuously adjusted within the range of 0 to 60 L / min. In some embodiments, the heat treatment section 6 includes a laser source. The laser source is positioned toward the workpiece 2 to be welded and emits a laser beam toward the weld to heat the weld. The heating temperature range is 100 to 900°C. Induction coil heating or infrared heating can also be used. In some embodiments, the cooling section 9 is located between the heat treatment section 6 and the welding device 10. The temperature change process after the end of welding stage I in conventional welding is divided into a rapid cooling stage II and a high-temperature creep stage III, such as... Figure 3 As shown, during the rapid cooling stage, the weld zone rapidly decreases from the peak temperature to room temperature or the martensitic transformation temperature. The weld zone shrinks under the rigid constraint of the cold base material, resulting in tensile residual stress. The faster the cooling rate and the greater the temperature gradient, the higher the peak value of the residual stress. At this time, the weld zone is cooled by the cooling section 9 to accelerate the cooling rate of the weld zone, increase the temperature gradient, and thus reduce the peak value of the residual stress. During the high-temperature creep stage, due to the low yield strength of the weld zone, it undergoes slight creep deformation under the action of thermal stress. This deformation will offset some of the stress generated by thermal expansion, thereby reducing the residual stress in the subsequent cooling stage. At this time, the weld zone is heated by the heat treatment section 6 to prolong the residence time of the weld zone in the high-temperature creep stage, fully generate creep deformation, and fully release stress, thereby reducing the residual stress in the subsequent cooling stage.

[0026] Example 2 This embodiment provides a welding system, such as Figure 1As shown, the system includes a welding apparatus 10 and the welding monitoring and control device in Embodiment 1. The welding apparatus 10 is signal-connected to a controller 12. The controller 12 sends welding control commands to the welding apparatus 10 based on thermo-mechanical calculations. The welding apparatus 10 is configured to weld the workpiece 2 according to the welding control commands, and adjusts the current, voltage, and welding speed of the welding apparatus 10. A tracking sensor mechanism collects the weld position, molten pool morphology, and molten pool surface temperature distribution in real time. The controller 12 receives the weld position, molten pool morphology, and molten pool surface temperature distribution data collected in real time by the tracking sensor mechanism. The controller 12 then analyzes the thermophysical parameters, mechanical parameters, molten pool morphology, and molten pool surface temperature distribution data based on these parameters. The data is subjected to thermo-mechanical coupling analysis, and welding control commands are sent to the welding device 10 based on the results of the thermo-mechanical coupling analysis. The welding device 10 welds the workpiece 2 according to the welding control commands, and adjusts the current, voltage and welding speed of the welding device 10 to control the heat input during welding, thereby controlling the temperature gradient of the molten pool and the surrounding area to suppress residual stress. This realizes a real-time monitoring and feedback mechanism for the temperature field and stress field of the molten pool during welding. Real-time correction and closed-loop control are performed based on the dynamic changes of the temperature field and stress field during welding, thereby realizing precise control of residual stress for different welding materials and welding conditions, and further reducing the welding residual stress of the workpiece.

[0027] In some embodiments, the welding system further includes a first robotic arm 11 and a second robotic arm 3. The first robotic arm 11 is connected to the welding device 10 and the cooling unit 9 to move the welding device 10 and the cooling unit 9 to weld the workpiece 2. The second robotic arm 3 is connected to the tracking sensing mechanism and the heat treatment unit 6 to move the tracking sensing mechanism and the heat treatment unit 6 to collect the weld position, molten pool morphology, and molten pool surface temperature distribution in real time, and adjust the temperature field of the weld, thereby adjusting the residual stress field distribution of the weld. In some embodiments, during the welding process, the second robotic arm 3 drives the tracking sensing mechanism and the temperature adjustment mechanism to move synchronously with the welding device 10. After the welding device 10 welds the workpiece 2, the tracking sensing mechanism collects the weld position, molten pool morphology, and molten pool surface temperature distribution in real time, and the temperature adjustment mechanism adjusts the temperature field of the weld.

[0028] In some embodiments, the welding system further includes a preheating mechanism located on the side of the welding apparatus 10 away from the welding monitoring and control device. The preheating mechanism is configured to preheat the workpiece 2 to be welded in order to increase the initial temperature of the area to be welded, reduce the temperature difference between the weld and the base material, smooth the temperature gradient, and thereby reduce the peak value of residual stress.

[0029] In some embodiments, the welding system further includes a conveyor belt 1, on which the workpieces 2 to be welded are placed sequentially along the length of the conveyor belt 1. The conveyor belt 1 transports the workpieces 2 to the welding station and then stops moving. After welding is completed and the workpieces have cooled, the conveyor belt 1 is started to transport the next workpiece 2 to the welding station for welding.

[0030] Example 3 This embodiment provides a welding method using the welding system described in Embodiment 2, such as... Figure 2 As shown, it includes the following steps: Place the workpiece 2 to be welded in the welding station; Before welding begins, the preheating mechanism is activated to preheat the workpiece 2 to be welded, thereby increasing the initial temperature of the area to be welded. Start the welding device 10 and move the welding device 10 to weld the workpiece 2; As the welding device 10 moves to track the sensing mechanism, the welding position, molten pool morphology, and molten pool surface temperature distribution are collected in real time through the tracking sensing mechanism. Specifically, the image acquisition unit 7 collects the welding position and molten pool morphology in real time, and the temperature acquisition unit 8 collects the molten pool surface temperature distribution in real time. The controller 12 receives the welding position, molten pool morphology, and molten pool surface temperature distribution data collected in real time by the tracking sensing mechanism. The controller 12 performs thermo-mechanical coupling analysis based on the thermophysical parameters, mechanical parameters, welding position, molten pool morphology, and molten pool surface temperature distribution data of the workpiece 2 to be welded, and sends temperature control commands to the temperature regulation mechanism based on the thermo-mechanical coupling analysis results. As the tracking sensor moves the temperature regulation mechanism, the temperature regulation mechanism adjusts the temperature field of the weld according to the temperature control command. Specifically, the cooling unit 9 first sprays cooling gas toward the weld so that areas with large melting depth or poor heat conduction in the molten pool can also be cooled quickly. Then, the heat treatment unit 6 heats the weld to increase the temperature of the weld in the high-temperature creep stage and reduce the cooling rate of the molten pool. Solid particles are sprayed onto the weld surface by the particle spray gun 4 according to the particle spraying control command, which further offsets the residual tensile stress field and reduces the residual stress of the weld.

[0031] In some implementations, the finite element coupled simulation module includes the following steps when performing thermo-mechanical coupling analysis: Input the thermal and mechanical properties of the workpiece 2 to be welded; Input the target temperature field and target residual stress field that satisfy the forming quality constraints (weld width, penetration depth, and molten pool temperature corresponding to meeting the quality requirements); Receives real-time data on weld position, molten pool morphology, and molten pool surface temperature distribution collected by the tracking sensor mechanism; A thermo-mechanical coupling analysis is performed to obtain the time-varying temperature field and the time-varying residual stress field, which are then compared with the target temperature field and the target residual stress field, respectively. Temperature control commands are generated based on the comparison results.

[0032] Specifically, the finite element coupled simulation module adopts a two-layer architecture, namely an offline high-fidelity finite element model and an online reduced-order real-time model. The thermophysical and mechanical parameters of the workpiece 2 to be welded are input into the offline high-fidelity finite element model. Based on the received weld position, molten pool morphology and molten pool surface temperature distribution data, the online reduced-order real-time model performs thermo-mechanical coupling analysis, which can complete the sequential calculation within 1 to 5 seconds to obtain the temperature field and the residual stress field that change with time. Then, it is compared with the target temperature field and the target residual stress field, respectively, and a temperature control command is generated based on the comparison results.

[0033] Example 4 The rotor is a key component of the steam turbine, and its safety and lifespan are greatly affected by the superposition of welding residual stress and working load stress. In this embodiment, the rotor is welded using the welding monitoring and control device, welding system and welding method described in Embodiments 1 to 3, and the technical effect of the welding monitoring and control device, welding system and welding method described in Embodiments 1 to 3 in reducing the welding residual stress of the workpiece is verified.

[0034] The welding device uses an IPG YLS-2000 fiber laser with a maximum power of 2KW and a maximum focal length of 60mm. In this embodiment, the laser power is set to P=1200 W and the welding speed is set to v=120 mm / min. The power of the fiber laser is dynamically adjusted by the controller, and the adjustment response time is <10ms.

[0035] The high-temperature section of the rotor uses CrMoV steel, and the low-temperature section uses 30Cr2Ni4MoV steel. A two-dimensional finite element model is used in ABAQUS software to simulate the entire welding process. Figures 4-6As shown, a refined mesh is used in the weld seam and its vicinity, with a minimum element size of 0.5mm × 0.5mm. The multi-pass welding process is achieved through the "element birth and death" technique. Material thermophysical parameters (such as density, specific heat, thermal conductivity, and coefficient of thermal expansion) and mechanical parameters (yield strength, elastoplastic constitutive properties, and creep parameters) are input into the ABAQUS software. A heat source model is established and a heat source subroutine DFLUX is written. In this case, a double ellipsoidal heat source is selected. Boundary conditions and loads are then set. Boundary heat transfer includes convection and radiation. Next, the birth and death of elements and mesh generation are performed. By calling the heat source subroutine, a thermo-mechanical coupling analysis is conducted to obtain the temperature field and the residual stress field that vary with time. In the thermo-mechanical coupling analysis, temperature-related thermophysical and mechanical properties are considered. The Von Mises yield criterion and kinematic hardening law are adopted. Solid-state phase transitions are not considered in the simulation. Mechanical boundary conditions are only used to constrain the rigid body displacement of the rotor.

[0036] The heat source is controlled using the heat conduction control equation: ; in ρ Material density (kg / m³) 3 ), c p is the temperature-dependent specific heat capacity (J / kg·K), and k is the temperature-dependent thermal conductivity (W / m·K). Q laser As the laser heat source input, a double ellipsoidal heat source model is used for description. Q loss For heat loss, T It's temperature, ▽ T yes T The Laplace operator represents the diffusion intensity of the temperature field.

[0037] Stress field calculations are based on an elastoplastic model: ; in For elastic strain rate, The strain rate is plastic and obeys the Von Mises yield criterion and the isotropic hardening law.

[0038] The local creep process simulation involved rapid cooling from the welding temperature to 600°C, holding at that temperature for 20 hours, and then cooling to room temperature at a rate of 100°C / h. The creep stress redistribution during the holding period followed Norton's power law: ; in, σ is the creep strain rate, σ is the stress, and T is the absolute temperature. C 1 ,C 2 , C 3 It is a material constant (in this example) C 1 =4.40×10-28, C 2 =4.312, C 3 =27912).

[0039] After welding is completed, as follows Figures 7-8 As shown, the circumferential stress in the weld area is tensile stress, and the circumferential stress near the outer surface is higher than that near the inner surface. There are two circumferential compressive stress zones in the base material region adjacent to the weld, which tend to be on the inner surface. The axial stress is tensile stress in the outer surface region and compressive stress in the inner surface region to balance the larger axial tensile stress. Compared with the traditional welding method, the rotor residual stress is significantly reduced to below 150 MPa. This proves the effectiveness of the welding monitoring and control device, welding system and welding method in Examples 1 to 3 in reducing the residual stress of the workpiece welding.

[0040] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A welding monitoring and control device, characterized in that: The system includes a tracking sensor, a controller, and a temperature control mechanism. The tracking sensor is movable and configured to acquire real-time data on weld position, molten pool morphology, and molten pool surface temperature distribution. The controller is signal-connected to the tracking sensor to receive the real-time data on weld position, molten pool morphology, and molten pool surface temperature distribution acquired by the tracking sensor. The controller includes a finite element coupled simulation module configured to perform thermo-mechanical coupling analysis based on the thermophysical and mechanical parameters of the workpiece to be welded, as well as the data on weld position, molten pool morphology, and molten pool surface temperature distribution. The temperature control mechanism is movable and signal-connected to the controller. The controller sends temperature control commands to the temperature control mechanism based on the thermo-mechanical coupling analysis results. The temperature control mechanism is configured to adjust the temperature field of the weld according to the temperature control commands.

2. The welding monitoring and control device according to claim 1, characterized in that: It also includes a particle spray gun, which is located on the side of the temperature regulating mechanism away from the welding device. The particle spray gun is signal-connected to the controller, which sends a particle spraying control command to the particle spray gun based on the thermo-mechanical coupling analysis results. The particle spray gun is configured to spray solid particles onto the weld surface according to the particle spraying control command.

3. The welding monitoring and control device according to claim 1, characterized in that: The tracking sensing mechanism includes an image acquisition unit and a temperature acquisition unit. The image acquisition unit is configured to acquire the weld position and molten pool morphology in real time, and the temperature acquisition unit is configured to acquire the surface temperature distribution of the molten pool in real time.

4. The welding monitoring and control device according to claim 1, characterized in that: The temperature regulating mechanism includes a cooling section and a heat treatment section, which are arranged at intervals along the weld extension direction. The cooling section is configured to spray cooling gas toward the weld, and the heat treatment section is configured to heat the weld.

5. The welding monitoring and control device according to claim 4, characterized in that: The heat treatment section includes a laser source, which is positioned toward the workpiece to be welded and emits a laser beam toward the weld to heat the weld.

6. A welding system, characterized in that: The invention includes a welding apparatus and a welding monitoring and control device according to any one of claims 1 to 5, wherein the welding apparatus is signal-connected to the controller, the controller sends welding control commands to the welding apparatus according to thermo-mechanical calculation results, and the welding apparatus is configured to weld the workpiece to be welded according to the welding control commands, and to adjust the welding apparatus current, voltage and welding speed.

7. The welding system according to claim 6, characterized in that: It also includes a first robotic arm and a second robotic arm. The first robotic arm is connected to the welding device and the cooling unit to drive the welding device and the cooling unit to move. The second robotic arm is connected to the tracking sensing mechanism and the heat treatment unit to drive the tracking sensing mechanism and the heat treatment unit to move.

8. The welding system according to claim 6, characterized in that: It also includes a preheating mechanism located on the side of the welding device away from the welding monitoring and control device, the preheating mechanism being configured to preheat the workpiece to be welded.

9. A welding method using the welding system according to any one of claims 6 to 8, characterized in that: Includes the following steps: Start the welding device and move the welding device to weld the workpiece to be welded; As the welding device moves, the tracking sensor mechanism collects the molten pool morphology and surface temperature distribution in real time. The controller receives the molten pool morphology and surface temperature distribution data collected in real time by the tracking sensor mechanism. The controller performs thermo-mechanical coupling analysis based on the thermophysical parameters and mechanical parameters of the workpiece to be welded, as well as the weld position, molten pool morphology and surface temperature distribution data. Based on the thermo-mechanical coupling analysis results, the controller sends a temperature control command to the temperature regulation mechanism. As the tracking sensor moves the temperature regulating mechanism, the temperature regulating mechanism adjusts the temperature field of the weld according to the temperature control command.

10. The welding method according to claim 9, characterized in that: When the finite element coupled simulation module performs thermo-mechanical coupled analysis, it includes the following steps: Input the thermal and mechanical properties of the workpiece to be welded; Input the target temperature field and target residual stress field that satisfy the molding quality constraints; Receive the molten pool morphology and molten pool surface temperature distribution data collected in real time by the tracking sensing mechanism; A thermo-mechanical coupling analysis is performed to obtain the time-varying temperature field and the time-varying residual stress field, which are then compared with the target temperature field and the target residual stress field, respectively. Temperature control commands are generated based on the comparison results.

Images