Megawatt laser welding process in-situ stress measuring device and method based on neutron source

Abstract

The invention belongs to the technical field of neutron diffraction and stress measurement, and discloses a device and method for measuring in-situ stress in a myriawatt laser welding process based on a neutron source, and the device comprises a medium and thick wall component high-power welding module, an infrared thermometer, a mobile rotating platform and a neutron diffraction module, the medium-thickness wall component high-power welding module is installed on a box body of the in-situ measuring device, the medium-thickness wall component is arranged on the movable rotating platform, and the neutron diffraction module is arranged on the periphery of the in-situ measuring device. When the device is used, the movable rotating platform is adjusted to move a given point of a to-be-detected component to a position determined by the slit and the slit which are close to mutually vertical paths, so that a neutron beam passes through the given point of the component through the slit. Diffraction characteristic signals of different positions of the component are obtained through neutrons, online coupling of a component welding device and a neutron source is achieved, the stress field evolution law in the medium-thick-wall component cooling process can be detected in situ in real time, and the purpose of detecting and regulating the residual stress of the component in situ is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of neutron diffraction technology and stress measurement technology, and in particular relates to an in-situ stress measurement device and method for a MW-class laser welding process based on a neutron source. Background Art

[0002] The 10,000-watt high-power laser welding technology is a high-efficiency, low-deformation welding technology that uses laser energy to connect medium-thick wall components. During 10,000-watt high-power laser welding, the material interacts with the laser energy, and after the liquid phase rapidly solidifies under a high temperature gradient, there are a series of complex thermal, metallurgical, and force coupling processes. In particular, residual stress affects the service performance of the weld joints of medium-thick wall components. Studying the in-situ stress evolution process can establish the correlation between "process parameters-microstructure-mechanical properties", which helps to regulate residual stress by optimizing process parameters. How to monitor and regulate the evolution of microstructure and stress during welding in real time is the difficulty and hot spot of current international cutting-edge research.

[0003] Neutron diffraction technology can be used to determine the internal stress and texture of engineering material components, as well as to perform phase analysis, obtain the statistical average experimental results of the internal microstructure information of the sample, and establish the intrinsic relationship between the microstructure and macroscopic performance. One of its unique advantages is that it can perform in-situ testing and analysis of materials during the welding process, and obtain information on the evolution of the organization and stress that is difficult to obtain under conventional conditions.

[0004] So far, there is no public report on the detection of stress and microstructure evolution during laser welding of medium-thick wall components using neutron diffraction technology.

[0005] Through the above analysis, the problems and defects of the prior art are as follows:

[0006] So far, there is no public report on the detection of stress and microstructure evolution during laser welding of medium-thick wall components using neutron diffraction technology. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides an in-situ stress measurement device for a MW-class laser welding process based on a neutron source.

[0008] The present invention is implemented as follows: a neutron source-based MW-class laser welding process in-situ stress measurement device comprises:

[0009] A high-power laser welding module for medium-thick wall components, an infrared thermometer, a mobile rotating platform and a neutron diffraction module. The high-power laser welding module for medium-thick wall components is installed on the measuring device box, the medium-thick wall components are on the mobile rotating platform, and the neutron diffraction module is arranged on the periphery of the measuring device. When in use, the mobile rotating platform is adjusted to move the given point of the component to be measured to the position determined by the slits and the slits in the nearly mutually perpendicular paths, so that the neutron beam passes through the slit and passes through the given point of the component;

[0010] The neutron diffraction module is used to emit neutron beams to measure the in-situ stress at a given point in the welding sample;

[0011] The laser welding module combines a moving guide with a laser welding head for motion control of the welding process; all welding components are electrically isolated from other motion, sensing and neutron diffraction components.

[0012] Furthermore, the mobile rotating platform is fixed by a customized aluminum stand plate, which is nearly neutron transparent to avoid shadow effects in the neutron diffraction detector; the stand pipe is actively cooled by forced compressed air; active cooling is used at the end of laser welding to reach room temperature faster for neutron diffraction measurement; the mobile rotating platform is used to translate or rotate medium and thick wall components up and down to align and fix specific positions to enter the neutron beam.

[0013] Further, the mobile rotating platform includes a lifting device and a rotating device, the rotating device is installed above the lifting device, the welding device is installed above the rotating device, the lifting device and the rotating device are fixed by bolts and nuts, wherein the lifting device is used to translate the welding device up and down, and the rotating device is used to change the in-situ stress measurement direction;

[0014] The temperature field distribution characteristics during the heating and cooling process of laser welding are obtained by an infrared thermometer.

[0015] Furthermore, the laser welding module includes a laser welding head and an automatic control unit, and linear welding is achieved through the laser welding head;

[0016] The laser welding rate is 10-50mm / s, the laser power is 10-20kW, the spot diameter is 0.5mm, and the defocus is -10-10mm.

[0017] Furthermore, the welding control of the medium-thick-walled components includes a medium-thick-walled component forced cooling device for cooling the medium-thick-walled components, a laser welding head for welding the medium-thick-walled components, a manipulator for welding the medium-thick-walled components, and a displacement control device for adjusting the position of the medium-thick-walled components; it also includes an incident neutron source and a neutron detector used in combination to perform neutron source residual stress detection on the medium-thick-walled components, and the incident neutron source and the neutron detector are arranged on the outside of the medium-thick-walled components; it also includes an infrared thermometer for measuring the temperature of the medium-thick-walled components.

[0018] The present invention also provides an in-situ stress measurement method for a MW laser welding process based on a neutron source, comprising the following steps:

[0019] Welding of medium-thick wall components is performed through high-power laser welding modules for medium-thick wall components;

[0020] A neutron diffraction module is used to emit neutron beams to measure stress at given points of medium-thick wall components during welding;

[0021] The position of the medium-thick wall component is adjusted by moving the rotating platform so that the given point of the component to be tested is aligned with the slit position through which the neutron beam passes;

[0022] During the welding process, the temperature field distribution characteristics of the components during heating and cooling are obtained in real time through an infrared thermometer.

[0023] Further, the method further comprises the following steps:

[0024] Customized aluminum vertical plates are used to fix medium-thick wall components to avoid shadow effects in neutron diffraction detection;

[0025] The aluminum risers are actively cooled by forced compressed air and quickly cooled to room temperature after material deposition for neutron stress measurement.

[0026] Further, the method further comprises the following steps:

[0027] The lifting device of the mobile rotating platform is used to move the medium-thick wall components up and down to adjust the welding position;

[0028] The welding direction and stress measurement direction of the components are changed by the rotating device to ensure the precise alignment of laser welding and stress measurement.

[0029] Further, the method further comprises the following steps:

[0030] Linear welding is performed through the laser welding head in the laser welding module, with a laser power of 10-20kW, a welding speed of 10-50mm / s, and a spot diameter of 0.5mm;

[0031] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0032] First, the present invention takes advantage of the fact that the transverse strain of welding is smaller than the longitudinal strain, and the fact that the longitudinal stress is in the direction of Poisson strain, and utilizes the peak shift between multiple detectors to realize the calculation of the longitudinal stress and the transverse stress.

[0033] The present invention can realize accurate acquisition of three-dimensional stress distribution characteristics by combining an infrared thermometer with a neutron diffraction test.

[0034] The present invention converts the temperature difference into an effective lattice strain to establish a quantitative error band by considering the difference between the temperature estimation values ​​of the data of multiple detectors and the infrared thermometer data, thereby achieving error estimation of the strain.

[0035] The present invention constructs a forced cooling device for medium-thick wall components to solve the problem of mismatch between welding cooling rate and neutron data acquisition speed. Other advantages, objectives and features of the present invention will be explained to some extent in the subsequent description, and to some extent, will be obvious to those skilled in the art based on the following investigation and research, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following description. According to an embodiment of the present application, further, in the measuring device, a collimator and a monochromator are sequentially arranged in the direction of the neutron beam emitted by the neutron source on one side of the periphery of the component, wherein the collimator is located in front of the neutron source, and the monochromator is located in front of the collimator; the slit is located between the monochromator and the component to be measured; the detector and the radial collimator are sequentially arranged in the direction of the neutron beam emitted by the neutron source on one side of the periphery of the component mold, and the installation path between the detector and the radial collimator is perpendicular to the installation path between the collimator and the monochromator, and the radial collimator is located in front of the detector; the slit is located between the radial collimator and the component to be measured, and the slit and the slit together play a role in sample positioning; the beam cutoff is installed on the other side of the periphery of the component, on the same line as the collimator and the slit, and is used to absorb neutrons passing through the sample.

[0036] Second, the technical solution of the present invention fills the technical gap in the industry at home and abroad: the present invention proposes a neutron source-based in-situ stress measurement device and method for a 10,000-watt laser welding process, which fills the gap in real-time stress measurement technology in high-power laser welding processes at home and abroad. By combining 10,000-watt laser welding with neutron diffraction technology, the device can monitor the stress evolution inside medium and thick-walled components in real time during the welding process, especially in the complex thermal metallurgical coupling process of high temperature and rapid solidification, and provide accurate stress data. This technology solves the problem that conventional stress measurement methods cannot obtain data in a high-temperature dynamic welding environment, and effectively makes up for the lack of real-time monitoring and control means of residual stress evolution in the existing technology during the welding process. At the same time, the innovation of the device is reflected in its ability to simultaneously obtain the microstructure and macroscopic stress change information of the weld area during the welding process, thereby providing a basis for the regulation of residual stress, and providing a new way to design the residual stress state and performance distribution inside the welded component, which helps to optimize the welding process and improve the service performance of medium and thick-walled components.

[0037] The technical solution of the present invention solves the technical problem that people have been eager to solve but have never been successful: the technical solution of the present invention effectively solves the technical problem of real-time measurement and regulation of stress in high-power laser welding, which has long been unattainable in the industry. In the process of 10,000-watt high-power laser welding, due to the complex thermomechanical coupling effect caused by high temperature gradient and rapid solidification, the influence of residual stress on weld quality and component service performance is particularly significant. Traditional stress measurement methods are difficult to obtain internal stress information in real time in a high-temperature, dynamic welding environment, which limits the effective control and optimization of residual stress. By combining neutron diffraction technology, the present invention provides an innovative device and method that can monitor stress evolution in situ and in real time during welding, breaking through this key technical bottleneck. Its unique in-situ testing capability enables the simultaneous acquisition of stress and microstructure evolution information during welding, which not only makes up for the shortcomings of traditional technology in real-time stress monitoring, but also provides an important basis for process optimization, and provides important data support for improving the welding quality and reliability of medium and thick-walled components, solving the problem that has long been unsolved in the industry.

[0038] The technical solution of the present invention overcomes technical prejudice: The technical solution of the present invention overcomes the technical prejudice in the traditional welding field, successfully combines high-power laser welding with neutron diffraction technology, and breaks the limitations of stress measurement in the past. Traditionally, people believe that the high temperature and high stress environment in the high-power laser welding process is not suitable for real-time stress measurement, especially under dynamic welding conditions, and the existing technology cannot effectively obtain stress evolution information. This technical prejudice has led to the industry's general reliance on subsequent detection methods or the use of stress measurement methods under non-in-situ conditions, and it is impossible to regulate the residual stress in the welding process in real time. By utilizing the in-situ measurement advantages of neutron diffraction technology, the present invention successfully realizes real-time monitoring of stress in a high-temperature and dynamic welding environment, breaking through the limitations of traditional concepts. Its innovation lies in that it not only realizes stress monitoring during welding, but also simultaneously obtains microstructure and macroscopic stress change information, overcoming the inherent prejudice that the welding stress of medium and thick wall components cannot be effectively controlled. The breakthrough application of this technology shows its broad prospects in precise control and optimization of welding processes.

[0039] Third, the present invention solves several key technical problems faced by the prior art in industrial applications and has achieved significant technical progress, which is specifically reflected in the following aspects:

[0040] 1. The problem of accurate stress monitoring: In the existing 10,000-watt laser welding process, it is difficult to monitor the internal stress changes in the weld area in real time and accurately. Traditional stress measurement methods often need to be performed after welding is completed, and cannot dynamically adjust the stress state during the welding process. The present invention introduces a neutron diffraction module and an infrared thermometer to achieve in-situ three-dimensional stress real-time monitoring of the weld and surrounding areas during the welding process, effectively solving this problem.

[0041] 2. Synchronous control and electrical isolation of multiple components: In the prior art, when multiple components such as the laser welding head, mobile platform, and sensor work simultaneously, electromagnetic interference often causes unstable system operation and affects welding accuracy. The present invention ensures the stability of the system and accurate signal transmission by electrically isolating the welding component from the sensor and diffraction components, thereby improving the reliability of the welding process.

[0042] 3. Optimization of signal reception: In the process of high-power laser welding, improving the efficiency of signal reception is a major challenge in the prior art. The present invention achieves coverage of a larger area of ​​the welding area and improves the range of signal reception by optimizing the position of the welding head and the neutron source and the adjustment mechanism of the mobile rotating platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural block diagram of an in-situ stress measurement device for a MW-class laser welding process based on a neutron source provided in an embodiment of the present invention.

[0044] Figure 2 is a welding temperature field distribution diagram provided by an embodiment of the present invention;

[0045] Figure 3 is a schematic diagram of stress changes in neutron testing provided by an embodiment of the present invention;

[0046] Figure 4 : Distribution diagram of longitudinal residual stress after welding;

[0047] Figure 5 : Distribution diagram of transverse residual stress after welding.

[0048] Figure 1 In: 1. High-power laser welding module; 2. Infrared thermometer; 3. Medium-thick wall components; 4. Incident neutron source; 5. Neutron detector 1; 6. Neutron detector 2; 7. Neutron detector 3; 8. Rotating device; 9. Waste gas collection device; 10. Forced cooling device for medium-thick wall components. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] An in-situ stress measurement device for a MW-class laser welding process based on a neutron source provided by an embodiment of the present invention comprises:

[0051] A medium-thick wall component high-power welding module, a mobile rotating platform and a neutron diffraction module, wherein the medium-thick wall component high-power welding module is fixedly mounted on the rotating mobile rotating platform, the medium-thick wall component is on the high-power welding module, and the neutron diffraction module is arranged at the periphery of the medium-thick wall component high-power welding module. When in use, the mobile rotating platform is adjusted to move a given point of the component to be tested to a position determined by slits and slits in mutually perpendicular paths, so that the neutron beam passes through the slit and passes through the given point of the component;

[0052] The neutron diffraction module is used to emit neutron beams to measure the in-situ stress at a given point in the welding sample;

[0053] The laser welding module will be used with the moving guide rail and laser welding head 1 for motion control of the welding process; all welding components are electrically isolated from other motion, sensing and neutron diffraction components.

[0054] The mobile rotating platform provided in an embodiment of the present invention is fixed by a customized aluminum riser, which is nearly neutron transparent to avoid shadow effects in neutron diffraction detectors; the riser is actively cooled by forced compressed air; active cooling is used at the end of deposition of each portion of material to reach room temperature more quickly for neutron measurement; the mobile rotating platform is used to translate or rotate thick-walled components up and down to align and fix specific positions to enter the neutron beam.

[0055] like Figure 1 As shown, the working principle of the in-situ stress measurement device for the 10,000-watt laser welding process based on a neutron source involves the coordinated work between multiple modules. First, the high-power welding module 1 for medium-thick wall components is fixedly mounted on a rotating mobile platform 8, so that the medium-thick wall components 3 can be accurately positioned and adjusted at any time during the welding process. The rotating platform can move flexibly to align the welding area with the irradiation area of ​​the neutron source 4. The neutron diffraction module is used to emit a neutron beam, which passes through the slit in the welding area, so that the neutron beam can accurately penetrate the component and measure the stress changes during welding. This device ensures that during the welding process, the given point of the sample can be consistent with the neutron beam path.

[0056] Secondly, the function of the neutron diffraction module is to measure the stress state generated during the welding process of medium and thick wall components in real time. In the device, multiple neutron detectors 5, 6, and 7 are arranged at different angles to capture the neutron beam information after penetrating the components. Through the feedback of these detectors, the system can calculate the changes in stress during the welding process. Since neutron diffraction can penetrate thicker materials, this measurement method is particularly suitable for accurate detection of stress during the welding process of medium and thick wall components. In this way, the stress can be monitored and adjusted at any time during the welding process to ensure the welding quality.

[0057] At the same time, the laser welding module is connected to the laser welding head through the moving guide rail for motion control during the welding process to ensure the stability and accuracy of the welding process. The high-power laser welding head performs the welding operation according to the set path, and cooperates with other motion control devices to ensure that the weld is carried out in the appropriate position. At the same time, the heat released during the welding process will also be taken away by the forced cooling device 10 in time to avoid the accumulation of welding heat and the excessive thermal stress on the components.

[0058] Finally, the electrical isolation design of each component of the entire system avoids electrical interference, ensuring that each module can work efficiently and accurately. The neutron detection module, welding module, and sensor module are physically and electrically isolated to ensure the independence and stability of their respective operations. The exhaust gas collection device 9 is responsible for the collection and treatment of harmful gases generated during the welding process to ensure the safety and cleanliness of the entire operation process. The design of the overall system realizes real-time monitoring of the stress of medium-thick wall components during high-power laser welding, providing important technical support for precision welding.

[0059] The mobile rotating platform provided in the embodiment of the present invention comprises a lifting device and a rotating device 8, wherein the rotating device 8 is installed above the lifting device, and the welding device is installed above the rotating device 8, and the lifting device and the rotating device 8 are fixed by bolts and nuts, wherein the lifting device is used to translate the welding device up and down, and the rotating device 8 is used to change the in-situ stress measurement direction;

[0060] The temperature field distribution characteristics during welding heating and cooling are obtained by infrared thermometer.

[0061] The in-situ stress measurement device for the MW-class laser welding process based on a neutron source of the present invention combines high-power laser welding, neutron diffraction measurement and motion control technology, and can measure the in-situ stress of the weld and its surrounding area in real time during the welding process.

[0062] High-power welding module 1 for medium-thick wall components: This module is responsible for high-power laser welding. It generates a 10,000-watt laser beam through the laser welding head and acts on the surface of the medium-thick wall component 3 to achieve laser welding of the material. The robotic arm connected to the laser welding head is fixed on the moving guide rail at the top of the in-situ measurement device box. The position of the laser welding head is adjusted through the motion control system to ensure that the welding process is carried out on a precise path. During the entire laser welding process, the welding head is linked with the moving guide rail to control the movement of the welding head and the accuracy of the welding process.

[0063] Mobile rotating platform 8 and welding motion control: The mobile rotating platform 8 is used to fix and adjust the position of the welding head and the medium-thick wall component 3 to be welded. During the welding process, the medium-thick wall component 3 is accurately positioned through the rotation and translation of the platform, so that different points of the welding can be moved to the designated area of ​​neutron diffraction measurement in sequence, ensuring that the stress at different positions of the weld is measured during the welding process. In addition, the platform motion system ensures the synchronization of the welding process to avoid interference of the welding movement on the stress measurement.

[0064] In-situ stress measurement of neutron diffraction module 4: Neutron diffraction module 4 is installed on the periphery of medium-thick wall component high-power welding module 1. The module emits neutron beams through incident neutron source 4, and uses the penetrability of neutron beams to pass through medium-thick wall components 3 and their surrounding areas in real time during welding. Neutron diffraction module 4 sets a slit to limit the path of the neutron beam, so that the neutron beam only passes through a specified point in the welding area, and measures the internal stress changes at the point. In-situ stress measurement can be calculated based on the change in neutron scattering angle and Bragg's law and generalized Hooke's law.

[0065] Signal sensing and system isolation: All welding components, including laser welding heads, motion control components, neutron detectors, etc., are electrically isolated from other sensors and the neutron diffraction module 4. This isolation design can effectively prevent electromagnetic interference during the welding process from affecting the accuracy of stress measurement. In addition, the infrared thermometer 2 is used to monitor the temperature changes during the welding process in real time, verify the accuracy of the neutron diffraction data, and provide information for analyzing phase changes and lattice strain behavior. The exhaust gas collection device 9 is responsible for timely discharging the exhaust gas generated during the welding process to ensure the safety of the equipment and operating environment.

[0066] Through the above working principle, the device realizes real-time monitoring of stress in zone 3 of medium-thick wall components during 10,000-watt laser welding, and provides real-time data support for welding process optimization.

[0067] The laser welding module 1 provided in the embodiment of the present invention comprises a laser welding head and an automatic control unit, and linear welding is achieved through the laser welding head;

[0068] The laser welding rate is 10-50mm / s, the laser power is 10-20kW, the spot diameter is 0.5mm, and the defocus is -10-10mm.

[0069] The welding control of medium and thick-walled components provided in an embodiment of the present invention includes a medium and thick-walled component forced cooling device 10 for cooling the medium and thick-walled components, a laser welding head for heating the medium and thick-walled components, a manipulator for welding the medium and thick-walled components, and a displacement control device for adjusting the position of the medium and thick-walled components; it also includes an incident neutron source 4 and a neutron detector 5, a neutron detector 6, and a neutron detector 7 used in combination to perform neutron source residual stress detection on the medium and thick-walled components, the incident neutron source 4 and the neutron detector 5 are arranged on both sides of the medium and thick-walled components; they are arranged on the same side of the medium and thick-walled components 3 as the neutron detector 6 and the neutron detector 7, and also include an infrared thermometer 2 for measuring the temperature of the medium and thick-walled components 3.

[0070] The specific experimental steps of the present invention are as follows:

[0071] (1) In this experiment, low-alloy high-strength steel with a size of 200 mm × 20 mm × 10 mm was first laser welded with a power of 10 kW and a welding rate of 20 mm / s.

[0072] During welding, an infrared thermometer is used to measure the temperature changes in the welding area in real time, so that the temperature field distribution characteristics during welding heating and cooling can be accurately obtained.

[0073] (2) Active cooling of the riser on the welding work platform base uses forced compressed air to solve the mismatch between the welding cooling rate and the neutron data acquisition speed. When using active cooling, the peak welding temperature reaches a temperature close to room temperature in about 30 minutes, while it takes more than an hour without active cooling. Figure 1 The device of the present invention provides a displacement control device for adjusting the position of the platform. In this embodiment, the above devices are all located inside the box, and an exhaust gas collection device 9 is provided on the box.

[0074] (3) During the sample welding process, a laser welding head is used to weld the welding area at a rate of 10-20 mm / s, a laser power of 10-20 kW, a spot diameter of 0.5 mm, and a defocus amount of 0. At the same time, a forced cooling device 10 mainly composed of a vertical plate and a circulating compression control unit is used to cool the substrate area, and the air flow rate is 5-10 mm / s. Establish the relationship between the temperature, structure and stress in the welding heat affected zone and time Figure 2 .

[0075] (4) Figure 3 The temperature change of the heat affected zone of welding under 10kW laser power and the microstructure change of the heat affected zone of the sample.

[0076] The technical solution of the present invention has a wide range of applications in the field of high-power laser welding, and is particularly suitable for the welding and stress control of medium-thick wall components. Typical application fields include the manufacture of high-demand structural parts such as bridges, marine engineering, aerospace, and large ships. Since the components in these fields usually face complex service conditions and high strength requirements, the generation of residual stress during welding has a significant impact on the service life and reliability of the components. The present invention provides an effective means for optimizing process parameters and regulating residual stress by real-time monitoring of stress evolution during laser welding, which can significantly improve the quality of welds and thus enhance the service performance of medium-thick wall components.

[0077] In addition, the in-situ stress measurement technology of the present invention can also be applied to related fields such as welding process research, material science research and welding quality control. Specific product applications include laser welding robots, intelligent welding equipment, industrial online detection systems, etc. By integrating neutron source stress monitoring devices, these products are provided with real-time stress feedback functions, which significantly improves the accuracy and control capabilities of the welding process, further expanding the technical value and market potential of the present invention. These specific applications not only verify the innovativeness of the present invention, but also provide important support for the improvement of welding technology and industrial development.

[0078] Relevant evidence of the technical effects achieved by the embodiments of the present invention.

[0079] Experimental device and test piece: A medium-thick wall steel plate was selected as the experimental test piece, and a 10,000-watt laser welding process was used for welding. At the same time, the neutron source in-situ stress measurement device of the present invention was installed. During the welding process, the stress distribution of the weld area and its heat-affected zone was measured in real time.

[0080] Acquisition of stress evolution data: Through neutron diffraction technology, the stress change curves of the weld and heat-affected zone at different time points during the welding process were obtained. Experimental data show that in a high-temperature dynamic environment, neutron diffraction can accurately capture the stress evolution during the welding process, especially the residual stress area formed in the rapid cooling stage, providing accurate stress values.

[0081] Figure 3 : The stress versus time curve shows the real-time evolution trend of the longitudinal stress during welding. The curve shows that the stress fluctuates significantly with the change of temperature gradient and tends to stabilize after the cooling process.

[0082] Figure 4 Figure 3: Distribution of longitudinal residual stress after welding. By measuring the stress at different locations on the weld cross section, the high and low distribution areas of the longitudinal residual stress are shown, verifying that the distribution of stress after welding is consistent with the experimental prediction model.

[0083] Figure 5Figure 3: Distribution of transverse residual stress after welding. By measuring the stress at different locations on the weld cross section, the high and low distribution areas of transverse residual stress are shown, verifying that the distribution of stress after welding is consistent with the experimental prediction model.

[0084] Technical effect analysis: Experimental data show that the device of the present invention can monitor stress evolution in real time and accurately during welding, especially in the rapid cooling stage, and can capture stress data that cannot be obtained by conventional detection methods. Compared with traditional post-welding stress measurement technology, in-situ stress monitoring can provide real-time feedback on stress changes during welding, providing support for optimizing process parameters and effectively regulating residual stress to improve weld quality.

[0085] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A neutron source-based in-situ stress measurement device for a 10,000-watt laser welding process, characterized in that: include: A medium-thick wall component high-power welding module, a mobile rotating platform and a neutron diffraction module, wherein the medium-thick wall component high-power welding module is fixedly mounted on the mobile rotating platform, the medium-thick wall component is located on the high-power welding module, and the neutron diffraction module is arranged at the periphery of the medium-thick wall component high-power welding module; the medium-thick wall component high-power welding module is used for high-power laser welding of the medium-thick wall component, and the mobile rotating platform is used for adjusting the position of the medium-thick wall component so that the neutron beam emitted by the neutron diffraction module passes through the welding area; The neutron diffraction module includes at least one neutron source and a plurality of neutron detectors, which are arranged at different angles to capture the neutron beam information penetrating the medium-thick wall component, and to monitor the stress changes inside the component in real time during the welding process in combination with the measurement results of the neutron diffraction; The device also includes a waste gas collection device and a forced cooling device for medium and thick wall components. The heat released during welding is cooled by the forced cooling device, and harmful gases are collected and processed by the waste gas collection device; all welding components are electrically isolated from the motion, sensing and neutron diffraction components to ensure the stability and accuracy of each component during operation.

2. The in-situ stress measurement device for a 10,000-watt laser welding process based on a neutron source as claimed in claim 1, characterized in that: The mobile rotating platform is fixed by a customized aluminum riser, which is nearly neutron transparent to avoid shadow effects in neutron diffraction detectors; the riser is actively cooled by forced compressed air; active cooling is used at the end of deposition of each part of the material to reach room temperature faster for neutron measurement; the mobile rotating platform is used to translate or rotate medium-thick wall components up and down to align and fix specific positions to enter the neutron beam.

3. The in-situ stress measurement device for a 10,000-watt laser welding process based on a neutron source as claimed in claim 1, characterized in that: The mobile rotating platform includes a lifting device and a rotating device, the rotating device is installed above the lifting device, the welding device is installed above the rotating device, the lifting device and the rotating device are fixed by bolts and nuts, wherein the lifting device is used to translate the welding device up and down, and the rotating device is used to change the in-situ stress measurement direction; The temperature field distribution characteristics during welding heating and cooling are obtained by infrared thermometer.

4. The in-situ stress measurement device for a 10,000-watt laser welding process based on a neutron source as claimed in claim 1, characterized in that: The laser welding module includes a laser welding head and an automatic control unit, and linear welding is achieved through the laser welding head; The laser welding rate is 10-50mm / s, the laser power is 10-20kW, the spot diameter is 0.5mm, and the defocus is -10-10mm.

5. The in-situ stress measurement device for a 10,000-watt laser welding process based on a neutron source as claimed in claim 1, characterized in that: The welding control of the medium-thick wall components includes a medium-thick wall component forced cooling device for cooling the medium-thick wall components, a laser welding head for heating the medium-thick wall components, a manipulator for welding the medium-thick wall components, and a displacement control device for adjusting the position of the medium-thick wall components; it also includes an incident neutron source and a neutron detector used in combination to perform neutron source residual stress detection on the medium-thick wall components, and the incident neutron source and the neutron detector are arranged on both sides of the medium-thick wall components; it also includes an infrared thermometer for measuring the weld temperature.

6. A method for measuring in-situ stress in a 10,000-watt laser welding process based on a neutron source, characterized in that: The following steps are involved: Welding of medium-thick wall components is performed through high-power welding modules for medium-thick wall components; A neutron diffraction module is used to emit neutron beams to measure stress at given points of medium-thick wall components during welding; The position of the medium-thick wall component is adjusted by moving the rotating platform so that the given point of the component to be tested is aligned with the slit position through which the neutron beam passes; During the welding process, the temperature field distribution characteristics of the components during heating and cooling are obtained in real time through an infrared thermometer.

7. The in-situ stress measurement method for a MW-class laser welding process based on a neutron source as claimed in claim 6, characterized in that: The following steps are also included: Customized aluminum risers are used to fix thick-walled components to avoid shadowing effects in neutron diffraction detection; The aluminum riser is actively cooled by forced compressed air and quickly cooled to room temperature after material deposition for neutron stress measurements.

8. The in-situ stress measurement method for a MW-class laser welding process based on a neutron source as claimed in claim 7, characterized in that: The following steps are also included: The lifting device of the mobile rotating platform is used to move the medium-thick wall components up and down to adjust the welding position; The welding direction and stress measurement direction of the components are changed by the rotating device to ensure the precise alignment of laser welding and stress measurement.

9. The in-situ stress measurement method for a MW-class laser welding process based on a neutron source as claimed in claim 7, characterized in that: The following steps are also included: Linear welding is performed by the laser welding head in the laser welding module, with a laser power of 10-20kW, a welding speed of 10-50mm / s, and a spot diameter of 0.5mm.

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