Vacuum box welding deformation control method

Abstract

The application discloses a kind of vacuum box welding deformation control methods, first to plate stress relief treatment, then plate is placed on tool fixture and is pre-tightened fixed, then welding is carried out, when welding, the welding sequence of the combination of symmetrical welding and sectional skip welding is used, the welding deformation of vacuum box is monitored in real time using non-contact laser measuring instrument, welding process parameters or tool fixture are adjusted in time, after welding is completed, overall stress relief annealing treatment is carried out to vacuum box, then size detection is carried out, and the small deformation existing is corrected using mechanical shaping or hydraulic shaping method.This kind of vacuum box welding deformation control method reduces the influencing factor of welding deformation from source, improves welding quality, guarantees the dimensional accuracy of vacuum box in the process of welding, the dimensional accuracy and service performance of vacuum box are significantly improved, meet the manufacturing demand of high-precision vacuum box, with good economic benefit and application prospect.

Description

Technical Field

[0001] This invention relates to vacuum chamber welding, and more particularly to a method for controlling the amount of deformation during vacuum chamber welding. Background Technology

[0002] Vacuum chambers have wide applications in numerous industrial fields, such as semiconductor manufacturing, vacuum coating, and aerospace. Welding is a critical processing technique in the manufacturing of vacuum chambers. However, uneven heat input during welding causes thermal expansion and subsequent contraction of the metal in and around the weld seam, leading to welding deformation of the vacuum chamber.

[0003] Welding deformation not only affects the dimensional accuracy of the vacuum chamber, making it difficult to meet design requirements and thus affecting the assembly accuracy with other components, but in severe cases it can also lead to changes in the internal structure of the chamber, affecting vacuum sealing performance and reducing the performance and reliability of the vacuum chamber.

[0004] To address the aforementioned issues, existing methods for controlling welding deformation primarily consist of simple rigid fixing and traditional heat input control. While simple rigid fixing can limit welding deformation to some extent, it generates significant residual stress in the welded structure, negatively impacting its strength and stability. Furthermore, traditional heat input control methods are less effective for vacuum chambers with complex shapes and diverse structures, failing to meet the manufacturing requirements of high-precision vacuum chambers.

[0005] Therefore, there is an urgent need for an efficient and reliable method to control the amount of welding deformation in vacuum chambers. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for controlling the welding deformation of vacuum chambers, which can effectively reduce the deformation of vacuum chambers during the welding process and improve the dimensional accuracy and performance of vacuum chambers.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0008] A method for controlling welding deformation of a vacuum chamber includes the following steps:

[0009] Step 1) Material pretreatment: Stress relief treatment is performed on the sheet metal used to manufacture the vacuum chamber. At the same time, the welding parts of the sheet metal are ground to remove the oxide film, oil and impurities on the surface to ensure welding quality.

[0010] Step 2) Tooling design and installation: Based on the structural characteristics and size requirements of the vacuum chamber, special welding tooling fixtures are used to place the vacuum chamber plates on the tooling fixtures according to the design requirements, and the plates are pre-tightened and fixed by the clamping device, so that the plates are in a reasonable constrained state before welding, limiting free deformation during the welding process;

[0011] Step 3) Selection of welding method: The vacuum chamber is welded using pulsed laser welding or friction stir welding.

[0012] Step 4) Welding sequence planning: A welding sequence combining symmetrical welding and segmented skip welding is adopted; first, the welds of the symmetrical parts of the vacuum chamber are welded synchronously so that the thermal stress generated during the welding process cancels each other out; then, each weld is divided into several small segments and skip welded in a certain order to avoid heat concentration and reduce local thermal deformation.

[0013] Step 5) Welding parameter control: Strictly control the welding current, voltage, and welding speed parameters; determine the optimal combination of welding parameters through experiments based on the material and thickness of the plate; during the welding process, use a real-time welding parameter monitoring system to monitor and adjust the welding current and voltage parameters in real time to ensure the stability of the welding parameters, thereby controlling the uniformity of welding heat input and reducing welding deformation;

[0014] Step 6) Deformation monitoring: During the welding process, a non-contact laser measuring instrument is used to monitor the welding deformation of the vacuum chamber in real time;

[0015] Step 7) Deformation control: Based on the deformation monitoring data, when the deformation exceeds the allowable range, adjust the welding process parameters or tooling fixtures in a timely manner;

[0016] Step 8) Stress relief treatment: After welding, the vacuum chamber is subjected to overall stress relief annealing to further reduce welding deformation;

[0017] Step 9) Shaping process: After stress relief treatment, the vacuum chamber is inspected for size. For any remaining minor deformations, mechanical or hydraulic shaping methods are used to correct them so that the dimensional accuracy meets the design requirements and the processing is completed.

[0018] Furthermore, in step 1), the stress relief treatment adopts a stress-relief annealing process, in which the plate is first heated to 550-650°C, held for 2-4 hours, and then cooled to room temperature in the furnace.

[0019] Furthermore, in step 2), the pre-tightening force of the clamping device for pre-tightening and fixing the plate is adjusted according to the material, thickness and welding process parameters of the plate, and is generally controlled between 5 and 15 N / mm².

[0020] Further, in step 2), the welding fixture includes a rigid fixing platform. The rigid fixing platform has a rectangular array of several vertically connected fixing holes. Support feet are provided at its bottom corners, and a clamping device for clamping and fixing the vacuum chamber is provided at the top. The clamping device includes a fixture for clamping and fixing the side of the vacuum chamber. The fixture is fixedly connected to the rigid fixing platform by locking screws. A pressing device for clamping the top of the vacuum chamber is provided on the fixture.

[0021] Furthermore, a transition cavity is provided at the center of the back side of the tooling fixture, and a fixing hole with vertical connection is provided at the bottom of the transition cavity. The locking screw passes through the fixing hole and the corresponding fixing connection hole and fixes the tooling fixture on the rigid fixing platform through the nut that cooperates with it. The front side and left and right sides of the tooling fixture have a number of insertion holes that communicate with the inside and outside of the transition cavity. The clamping device is inserted into the insertion hole.

[0022] Furthermore, the clamping device consists of a guide limiting part, a plug-in part, and a threaded pressure rod; the plug-in part is fixedly welded to one side of the guide limiting part, and the included angle between the plug-in part and the guide limiting part is 90°, and the plug-in part is plugged into the plug-in hole; the guide limiting part has a threaded hole that is connected vertically at the center of its end, and the threaded pressure rod is screwed into the threaded hole, with its upper and lower ends extending outside the upper and lower ends of the guide limiting part, respectively; the top of the threaded pressure rod has a knob that is fixedly connected to it, and the bottom has a pressure head.

[0023] Furthermore, in step 4), the length of each weld segment is 50 to 150 mm.

[0024] Furthermore, the deformation monitoring method in step 6) is as follows: a laser measuring instrument is arranged around the vacuum chamber to measure the deformation of key parts, and the measurement data is recorded every 1 to 2 minutes to draw a deformation curve so as to understand the trend of welding deformation in a timely manner.

[0025] Furthermore, the deformation control method in step 7) is as follows: when the deformation is large, the welding speed is appropriately reduced to reduce heat input; or the clamping force of the tooling fixture is adjusted to apply reverse constraint to the deformed part in order to correct the deformation. At the same time, local heating or cooling methods can also be used to adjust the stress of the deformed part and reduce the deformation.

[0026] Furthermore, in step 8), during the annealing process, the vacuum chamber is first placed in a heating furnace and heated to 500-600°C at a heating rate of 10-20°C / h, held at that temperature for 3-5 hours, and then cooled to room temperature at a cooling rate of 5-10°C / h to eliminate residual welding stress.

[0027] Compared with existing technologies, the advantages of this invention are as follows: This method for controlling welding deformation of vacuum chambers reduces the influencing factors of welding deformation from the source by performing stress relief treatment on the material before welding and designing and installing reasonable tooling, laying the foundation for controlling welding deformation; the use of low heat input welding methods, optimized welding sequence, and precisely controlled welding parameters effectively reduces heat input during the welding process, reduces deformation caused by thermal expansion and contraction, and improves welding quality; real-time deformation monitoring and control during the welding process can promptly detect and correct welding deformation, ensuring the dimensional accuracy of the vacuum chamber during the welding process; post-weld stress relief and shaping treatment further eliminates residual welding stress and corrects minor deformations, significantly improving the dimensional accuracy and performance of the vacuum chamber, meeting the manufacturing requirements of high-precision vacuum chambers, and possessing good economic benefits and application prospects. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a three-dimensional structural diagram of the tooling fixture in the vacuum box welding deformation control method of the present invention;

[0030] Figure 2 This is a schematic diagram of the front axial side structure of the tooling fixture in the tooling jig of the present invention;

[0031] Figure 3 This is a schematic diagram of the back axial structure of the tooling fixture in the tooling jig of the present invention;

[0032] Figure 4 This is a three-dimensional structural diagram of the clamping device in the tooling fixture of the present invention;

[0033] Figure 5 This is a top view schematic diagram of the clamping device in the tooling fixture of the present invention;

[0034] Figure 6 yes Figure 5 Structural cross-sectional view of AA;

[0035] Figure 7 This is a schematic diagram of the assembly structure of the vacuum chamber and tooling fixture in Embodiment 1 of the present invention;

[0036] Figure 8 This is a schematic diagram of the vacuum chamber structure in Embodiment 1 of the present invention.

[0037] In the diagram: 1. Rigid fixed platform; 11. Fixed connection hole; 12. Support leg; 2. Tooling fixture; 21. Insertion hole; 22. Transition cavity; 23. Locking screw; 3. Clamping device; 31. Guide limiting part; 311. Threaded hole; 32. Insertion part; 33. Threaded pressure rod; 331. Knob; 332. Pressure head; 4. Vacuum chamber. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the embodiments of the invention, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" indicate orientation or positional relationships based on the orientation or positional relationships shown in the drawings, or the orientation or positional relationships commonly used when the product is in use, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] Furthermore, the use of terms such as "horizontal" or "vertical" does not imply that the component must be absolutely horizontal or vertical, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure or component must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, "multiple" means at least two.

[0042] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0043] A method for controlling welding deformation of a vacuum chamber includes the following steps:

[0044] Step 1) Material Pretreatment: The sheet metal used to manufacture the vacuum chamber undergoes stress relief treatment using a stress-relief annealing process. The sheet metal is first heated to 550–650°C and held for 2–4 hours, then cooled to room temperature in the furnace to eliminate residual stress generated during processing and prevent it from accumulating with welding stress, which could lead to greater deformation. At the same time, the welding areas of the sheet metal are ground to remove oxide films, oil stains, and other impurities from the surface, ensuring welding quality.

[0045] Step 2) Tooling Design and Installation: Based on the structural characteristics and dimensional requirements of the vacuum chamber, special welding tooling fixtures are used. The plates of the vacuum chamber are placed on the tooling fixtures according to the design requirements, and the plates are pre-tightened and fixed by the clamping device. The pre-tightening force of the clamping device on the plates is adjusted according to the material, thickness and welding process parameters of the plates, and is generally controlled at 5 to 15 N / mm², so that the plates are in a reasonable constrained state before welding and the free deformation during the welding process is limited.

[0046] Step 3) Selection of Welding Method: Low-heat-input welding methods such as pulsed laser welding or friction stir welding are used to weld the vacuum chamber. Pulsed laser welding has advantages such as high energy density, small heat-affected zone, and fast welding speed. By reasonably setting parameters such as pulse frequency, pulse width, and peak power, the welding heat input can be precisely controlled. Friction stir welding is a solid-state welding method in which the material does not melt during the welding process, which can effectively reduce welding deformation. For different parts of the vacuum chamber, the appropriate welding method is selected according to its structure and welding requirements. For example, pulsed laser welding is preferred for thin-walled structures, while friction stir welding can be used for thick-plate structures.

[0047] Step 4) Welding sequence planning: A welding sequence combining symmetrical welding and segmented skip welding is adopted; first, the welds of the symmetrical parts of the vacuum chamber are welded synchronously so that the thermal stress generated during the welding process cancels each other out; then, each weld is divided into several small segments, the length of which is determined according to the plate thickness and welding method, generally 50-150mm, and then skip welding is performed in a certain order to avoid heat concentration and reduce local thermal deformation; for example, for the four frame welds of a rectangular vacuum chamber, the first segment of the two opposite welds is welded simultaneously, then the first segment of the other two opposite welds is welded, and so on, until all welds are completed;

[0048] Step 5) Welding Parameter Control: Strictly control relevant parameters such as welding current, voltage, and welding speed; determine the optimal combination of welding parameters through experiments based on the material and thickness of the plate; during the welding process, use a real-time welding parameter monitoring system to monitor and adjust parameters such as welding current and voltage in real time to ensure the stability of welding parameters, thereby controlling the uniformity of welding heat input and reducing welding deformation; for example, for stainless steel plates with a thickness of 3mm, when using pulsed laser welding, the welding current is controlled at 80-120A, the pulse frequency is 20-50Hz, the pulse width is 2-5ms, and the welding speed is 0.5-1.5m / min;

[0049] Step 6) Deformation monitoring: During the welding process, a non-contact laser measuring instrument is used to monitor the welding deformation of the vacuum chamber in real time. During monitoring, the laser measuring instrument is placed around the vacuum chamber to measure the deformation of key parts. The measurement data is recorded every 1 to 2 minutes, and the deformation curve is plotted to understand the trend of welding deformation in a timely manner.

[0050] Step 7) Deformation control: Based on the deformation monitoring data, when the deformation exceeds the allowable range, adjust the welding process parameters or tooling fixtures in a timely manner. Specifically, when the deformation is large, appropriately reduce the welding speed to reduce heat input; or adjust the clamping force of the tooling fixtures to apply reverse constraint to the deformed parts to correct the deformation. At the same time, local heating or cooling methods can also be used to adjust the stress of the deformed parts and reduce the deformation.

[0051] Step 8) Stress relief treatment: After welding, the vacuum chamber is subjected to overall stress relief annealing. During annealing, the vacuum chamber is first placed in a heating furnace and heated to 500-600℃ at a heating rate of 10-20℃ / h, held for 3-5 hours, and then cooled to room temperature at a cooling rate of 5-10℃ / h to eliminate residual welding stress and further reduce welding deformation.

[0052] Step 9) Shaping treatment: After stress relief treatment, the vacuum chamber is inspected for size. For any remaining minor deformations, mechanical or hydraulic shaping methods are used for correction. According to the location and degree of deformation, appropriate shaping molds and shaping pressures are selected to shape the vacuum chamber so that its dimensional accuracy meets the design requirements, thus completing the processing.

[0053] See the attached instruction manual. Figure 1 As shown, in step 2), the welding fixture includes a rigid fixing platform 1. The top surface of the rigid fixing platform 1 is horizontal. In this embodiment, the rigid fixing platform 1 has a rectangular structure. The surface of the rigid fixing platform 1 has a rectangular array of several vertically connected fixing connection holes 11. Support legs 12 are provided at its bottom corners. In this embodiment, a support leg 12 is provided at each of the four bottom corners of the rigid fixing platform 1. A clamping device for clamping and fixing the vacuum chamber is provided on the top of the rigid fixing platform 1. The clamping device is arranged according to the structural requirements of the vacuum chamber. The clamping device includes a fixture 2 for clamping and fixing the side of the vacuum chamber. The fixture 2 is fixedly connected to the rigid fixing platform 1 by locking screws 23, and the front is used to clamp the vacuum chamber. See the attached manual. Figure 2 and 3 As shown, in this embodiment, the tooling fixture 2 has a right-angled triangle or right-angled trapezoidal structure on its sides. The front and both sides are vertical planes perpendicular to the rigid fixing platform 1. A transition cavity 22 is provided at the center of the back of the tooling fixture 2. The bottom of the transition cavity 22 has vertically connected fixing holes. There are at least two fixing holes, and their spacing is the same as the spacing of the fixing connection holes 11. After the tooling fixture 2 is arranged on the rigid fixing platform 1 according to the clamping requirements of the vacuum chamber, the locking screw 23 passes through the fixing holes and the corresponding fixing connection holes 11 on the tooling fixture 2. The tooling fixture 2 is then fixed to the rigid fixing platform 1 from the bottom using a nut that mates with the locking screw 23. The tooling fixture 2 has several insertion holes 21 arranged on its front and left and right sides, communicating with the inside and outside of the transition cavity 22. The tooling fixture 2 is provided with a clamping device 3 for clamping the top of the vacuum chamber, and the clamping device 3 is inserted into the insertion holes 21. (See attached instruction manual.) Figures 4 to 6As shown, the clamping device 3 consists of a guide limiting part 31, a plug-in part 32, and a threaded pressure rod 33. The plug-in part 32 is fixedly welded to one side of the guide limiting part 31. The plug-in part 32 and the guide limiting part 31 form a "├" shape, and the included angle between them is 90°. The plug-in part 32 is plugged into the plug-in hole 21. The guide limiting part 31 has a threaded hole 311 at the center of its end, which is connected vertically. The threaded pressure rod 33 is screwed into the threaded hole 311, and its upper and lower ends extend outside the upper and lower ends of the guide limiting part 31, respectively. The top of the threaded pressure rod 33 is provided with a knob 331 fixedly connected to it, and the bottom is provided with a pressure head 332. Rotating the knob 331 can drive the threaded pressure rod 33 to move up and down relative to the guide limiting part 31, and drive the pressure head 332 to move up and down synchronously, so that the pressure head 332 can press against the top surface of the vacuum chamber or the part that needs to be pressed. Example 1

[0054] Instruction manual attached Figure 8 The image shows a rectangular stainless steel vacuum chamber with dimensions of 1000mm × 800mm × 600mm and a sheet metal thickness of 3mm. The specific welding method is as follows:

[0055] First, the stainless steel sheet is placed in a heating furnace and heated to 600℃ at a heating rate of 15℃ / h. It is then held at that temperature for 3 hours and cooled to room temperature in the furnace for stress-relieving annealing. After that, the welded parts of the sheet are ground to remove surface impurities.

[0056] According to the instruction manual Figure 7 As shown, the plates of vacuum chamber 4 are assembled according to requirements and placed on the tooling fixture, and fixed by applying a pre-tightening force of 10N / mm² through the clamping device;

[0057] Next, pulsed laser welding is used, such as... Figure 8 As shown, first weld the first segment of the two opposite long side welds simultaneously, with a weld length of 100mm. Then weld the first segment of the other two opposite long side welds. Next, weld the short side welds, i.e., the second segment shown in the figure, in the same way. Weld the segments in sequence according to the first to tenth segments shown in the figure until all welds are completed. During welding, the welding current is controlled at 100A, the pulse frequency is 30Hz, the pulse width is 3ms, and the welding speed is 1m / min.

[0058] During welding, a non-contact laser measuring instrument is used to monitor the four corners and the midpoints of the four sides of the vacuum chamber 4 in real time, and the deformation data is recorded every minute. During the welding process, when the deformation of a certain side is found to exceed 0.5mm, the welding speed is reduced to 0.8m / min, and the clamping force of the tooling fixture on that side is appropriately increased to effectively control the deformation.

[0059] After welding, the welded vacuum chamber 4 is placed in a heating furnace and heated to 550°C at a heating rate of 12°C / h, held at that temperature for 4 hours, and then cooled to room temperature at a cooling rate of 8°C / h for stress-relieving annealing.

[0060] Finally, the dimensions of the vacuum chamber 4 were inspected. If a slight deformation of 0.3mm was found in one corner, a hydraulic shaping method was used. Appropriate pressure was applied using a suitable shaping mold to shape the corner so that its dimensional accuracy met the design requirements. After inspection, the welding deformation of the vacuum chamber 4 was controlled within the allowable range, and the dimensional accuracy and sealing performance were good, thus completing the processing. Example 2

[0061] A cylindrical aluminum alloy vacuum chamber, with a diameter of 800mm, a height of 1200mm, and a plate thickness of 4mm, is welded as follows:

[0062] First, the aluminum alloy sheet is subjected to stress-relief annealing by heating to 350℃ and holding for 2.5 hours. Then, it is cooled in the furnace for stress-relief annealing treatment. After that, the welded parts of the aluminum alloy sheet are polished to remove surface impurities.

[0063] according to Figure 1 The tooling fixture shown clamps and fixes the aluminum alloy sheet onto the rigid fixing platform 1 using a clamping device, and applies a preload of 8 N / mm² to fix it.

[0064] Friction stir welding was employed, starting from the bottom of the vacuum chamber and using a segmented spiral welding sequence, with each weld segment being 120mm long, gradually moving upwards. During welding, the stirring head rotated at 800 rpm, and the welding speed was 0.8 m / min. Simultaneously, a laser measuring instrument was used to monitor the circumferential and axial deformation of the cylinder in real time, recording data every 2 minutes. When the circumferential deformation was detected to be large, the downward pressure and rotation speed of the stirring head were adjusted, and the welded parts were locally cooled to control the deformation.

[0065] After welding, the vacuum chamber is heated to 300°C and held at that temperature for 3.5 hours, then slowly cooled to eliminate residual welding stress.

[0066] After the residual welding stress is eliminated, the deformed parts are lightly tapped and corrected using mechanical shaping tools to ensure that the dimensions of the vacuum chamber meet the design standards. After inspection, the welding deformation of the vacuum chamber is effectively controlled, meets the usage requirements, and the processing is completed.

[0067] This method for controlling welding deformation in vacuum chambers reduces the influencing factors of welding deformation at the source by performing stress relief treatment on the material before welding and designing and installing reasonable tooling, laying the foundation for controlling welding deformation. Employing a low-heat-input welding method, optimized welding sequence, and precisely controlled welding parameters effectively reduces heat input during the welding process, minimizing deformation caused by thermal expansion and contraction, and improving welding quality. Real-time deformation monitoring and control during welding can promptly detect and correct welding deformation, ensuring the dimensional accuracy of the vacuum chamber during welding. Post-weld stress relief and shaping further eliminate residual welding stress and correct minor deformations, significantly improving the dimensional accuracy and performance of the vacuum chamber, meeting the manufacturing requirements of high-precision vacuum chambers, and demonstrating good economic benefits and application prospects.

[0068] It should be emphasized that 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 method for controlling the welding deformation of a vacuum chamber, characterized in that, Includes the following steps: Step 1) Material pretreatment: Stress relief treatment is performed on the sheet metal used to manufacture the vacuum chamber. At the same time, the welding parts of the sheet metal are ground to remove the oxide film, oil and impurities on the surface to ensure welding quality. Step 2) Tooling Design and Installation: Based on the structural characteristics and dimensional requirements of the vacuum chamber, a special welding fixture is used to place the vacuum chamber plate on the fixture according to the design requirements. The plate is then pre-tightened and fixed by a clamping device to ensure that the plate is under reasonable constraint before welding, thus limiting free deformation during the welding process. The welding fixture includes a rigid fixing platform (1), which has a rectangular array of several vertically connected fixing connection holes (11) and support feet (12) at its bottom corners. 2) A clamping device for clamping and fixing the vacuum chamber is provided at the top. The clamping device includes a tooling fixture (2) for clamping and fixing the side of the vacuum chamber. The tooling fixture (2) is fixedly connected to the rigid fixing platform (1) by locking screws (23). A pressing device (3) for clamping the top of the vacuum chamber is provided on the tooling fixture (2). A transition cavity (22) is provided at the center of the back of the tooling fixture (2). A fixing hole with vertical connection is provided at the bottom of the transition cavity (22). The locking screws (23) The tooling fixture (2) is fixed on the rigid fixed platform (1) by passing through the fixing hole and the corresponding fixing connection hole (11) and by the nut that mates with it. The tooling fixture (2) has several insertion holes (21) arranged on the front and left and right sides that communicate with the inside and outside of the transition cavity (22). The clamping device (3) is inserted into the insertion hole (21). The clamping device (3) consists of a guide limiting part (31), an insertion part (32) and a threaded pressure rod (33). The insertion part (32) is welded to the guide limiting part (31). On one side of the guide limiting part (31), the included angle between it and the guide limiting part (31) is 90°, and the plug-in part (32) is plugged into the plug-in hole (21); the guide limiting part (31) has a threaded hole (311) that is connected to the upper and lower ends at the center of its end, and the threaded pressure rod (33) is screwed into the threaded hole (311), with its upper and lower ends extending outside the upper and lower ends of the guide limiting part (31) respectively. The threaded pressure rod (33) has a knob (331) fixedly connected to it at the top and a pressure head (332) at the bottom. Step 3) Selection of welding method: The vacuum chamber is welded using pulsed laser welding or friction stir welding. Step 4) Welding sequence planning: A welding sequence combining symmetrical welding and segmented skip welding is adopted; first, the welds of the symmetrical parts of the vacuum chamber are welded synchronously so that the thermal stress generated during the welding process cancels each other out; then, each weld is divided into several small segments, each segment of which is 50-150mm in length, and skip welding is performed in sequence to avoid heat concentration and reduce local thermal deformation. Step 5) Welding parameter control: Strictly control the welding current, voltage, and welding speed parameters; determine the optimal combination of welding parameters through experiments based on the material and thickness of the plate; during the welding process, use a real-time welding parameter monitoring system to monitor and adjust the welding current and voltage parameters in real time to ensure the stability of the welding parameters, thereby controlling the uniformity of welding heat input and reducing welding deformation; Step 6) Deformation monitoring: During the welding process, a non-contact laser measuring instrument is used to monitor the welding deformation of the vacuum chamber in real time. The deformation monitoring method is as follows: the laser measuring instrument is placed around the vacuum chamber to measure the deformation of key parts. The measurement data is recorded every 1 to 2 minutes, and the deformation curve is plotted to understand the trend of welding deformation in a timely manner. Step 7) Deformation control: Based on the deformation monitoring data, when the deformation exceeds the allowable range, adjust the welding process parameters or tooling fixtures in a timely manner; The deformation control methods are as follows: when the deformation is large, reduce the welding speed and reduce the heat input; or adjust the clamping force of the tooling fixture to constrain the deformed part in the opposite direction to correct the deformation. At the same time, use local heating or cooling methods to adjust the stress of the deformed part and reduce the deformation. Step 8) Stress relief treatment: After welding, the vacuum chamber is subjected to overall stress relief annealing to further reduce welding deformation; Step 9) Shaping process: After stress relief treatment, the vacuum chamber is inspected for dimensions. For any remaining deformation, mechanical or hydraulic shaping methods are used to correct it so that the dimensional accuracy meets the design requirements and the processing is completed.

2. The method for controlling welding deformation of a vacuum chamber according to claim 1, characterized in that, In step 1), the stress relief treatment adopts a stress-relief annealing process, in which the plate is first heated to 550-650°C and held for 2-4 hours, and then cooled to room temperature in the furnace.

3. The method for controlling welding deformation of a vacuum chamber according to claim 1, characterized in that, In step 2), the pre-tightening force of the clamping device for pre-tightening and fixing the plate is adjusted according to the material, thickness and welding process parameters of the plate, and controlled within 5 to 15 N / mm².

4. The method for controlling welding deformation of a vacuum chamber according to claim 1, characterized in that, In step 8), the vacuum chamber is first placed in a heating furnace and heated to 500-600°C at a heating rate of 10-20°C / h. It is then held at that temperature for 3-5 hours and cooled to room temperature at a cooling rate of 5-10°C / h to eliminate residual welding stress.

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