Tower lug assembly of shift gas absorption tower, auxiliary welding tool of tower lug assembly and welding method of tower lug assembly

Abstract

The invention discloses a shift gas absorption tower crane lug assembly and a welding auxiliary tool and a welding method thereof, and belongs to the technical field of mechanical manufacturing welding. The problem that a low-temperature steel lifting lug is low in traditional manual welding efficiency and poor in quality stability, and consequently the production period is long is solved. The invention provides a special saddle-shaped clamping circular plate, the saddle-shaped inner curved surface of the circular plate is matched with the outer diameter of a lifting lug pipe shaft, a through hole is formed in the center of the circular plate, and the circular plate is used for being fixed on the pipe shaft to serve as a mounting base of automatic welding equipment. During welding, firstly, the clamping circular plate is installed on the pipe shaft, then the flexible bending gun automatic welding machine is installed on the clamping circular plate, and automatic welding of a pipe shaft circular seam and a base plate outer ring welding seam is completed in sequence. According to the method, the application of the automatic welding process on the large lifting lug exceeding the clamping range of existing equipment is realized through tool adaptation, the consistency of the welding efficiency and the welding seam quality is remarkably improved, and the strict detection requirements of the key welding seams of the type are met.

Description

Technical Field

[0001] This invention relates to the field of welding in mechanical manufacturing processes, specifically to a changeover gas absorption tower lifting lug assembly, its welding auxiliary tooling, and welding method. Background Technology

[0002] Shift gas absorption towers are key pieces of equipment in industrial production processes such as chemical and coal chemical industries. Their operating environment typically involves low temperatures and corrosive media; therefore, the tower body is often constructed using high-strength, high-toughness special steels, such as low-temperature steel, to ensure the equipment's safety and long-term stability under low-temperature conditions. These towers are enormous, with a total height reaching nearly 100 meters. Due to limitations in road transportation conditions and factory lifting capabilities, they are generally manufactured using a "segmented manufacturing, on-site assembly" model. After each tower segment is manufactured, it needs to be lifted, transported, and assembled on-site using lifting lugs. Therefore, the quality and efficiency of the lifting lug welding directly affect the entire tower's manufacturing cycle and structural safety.

[0003] Currently, manual arc welding is the most common method used in the industry for welding the lugs of cryogenic steel shift gas absorption towers. This is mainly because the welding process window for cryogenic steel is narrow, requiring extremely strict control of welding heat input to suppress weld joint embrittlement and ensure low-temperature impact toughness. Traditional processes specify the use of specialized cryogenic steel welding electrodes with a diameter not exceeding φ4.0mm for multi-layer, multi-pass manual welding. While this process can effectively control heat input and ensure that the mechanical properties of the weld metal meet the requirements for cryogenic use, it suffers from significant efficiency bottlenecks.

[0004] For example, a single lifting lug requires two types of critical welds: the tube shaft (approximately 740mm in diameter) and the outer ring of the backing plate (approximately 1200mm in diameter). Manual welding is labor-intensive, the working environment is harsh, and it demands high skill levels from the welder. The stability of the weld quality depends to some extent on the welder's personal experience. Furthermore, the lifting lug tube shaft 3 often has attachments welded on for positioning or reinforcement, which further increases the difficulty and time required for manual welding.

[0005] To address efficiency issues, attempts have been made to use larger diameter welding rods or increase welding current. However, this easily leads to excessive heat input, resulting in coarse grains in the weld and heat-affected zone, compromising low-temperature toughness and failing to meet quality requirements. Therefore, significantly improving the production efficiency of lifting lug welding and shortening the overall tower manufacturing cycle while ensuring the fundamental quality of low-temperature steel welding has become a pressing technical challenge in this field. Existing automated welding technologies, either lack adaptability to complex structures with attachments or fail to meet the precision process requirements of low-temperature steel welding, have not yet been effectively applied in such specific scenarios.

[0006] In summary, the existing welding process for the lifting lugs of shift gas absorption towers suffers from the problems of "large workload and long production cycle". Summary of the Invention

[0007] The purpose of this invention is to solve the problems of "large workload and long production cycle" in the welding process of existing shift gas absorption tower lifting lugs. Therefore, it provides a shift gas absorption tower lifting lug assembly, its welding auxiliary tooling, and a welding method.

[0008] The technical solution of this invention is:

[0009] This invention provides a lifting lug assembly for a shift gas absorption tower, including a tube shaft, a baffle, a pad, and multiple stiffeners; the baffle is fixedly connected to the outer circumferential side wall of the upper part of the tube shaft; the pad is fitted onto the outer circumferential side wall of the lower part of the tube shaft, and the pad is saddle-shaped with its inner surface curvature adapted to the outer surface of the shift gas absorption tower; the multiple stiffeners are fixedly installed in a grid pattern on the inner side wall of the tube shaft; the upper end of the tube shaft is provided with auxiliary welding fixtures for installation.

[0010] Preferably, the outer diameter of the baffle is smaller than the outer diameter of the pad.

[0011] Furthermore, the plurality of stiffeners form a grid-like structure with intersecting longitudinal and transverse ribs, including at least two longitudinal ribs extending along the tube axis and at least one transverse rib that intersects the longitudinal ribs perpendicularly and is fixedly connected to them.

[0012] The present invention also provides an auxiliary tooling for welding lifting lug assemblies, including a mounting plate and a heightening cylinder; the mounting plate is installed on the upper end of the tube shaft of the lifting lug assembly; the heightening cylinder is fixedly connected to the center of the mounting plate for mounting automatic welding equipment.

[0013] The present invention also provides a method for welding lifting lugs of a shift gas absorption tower, which employs auxiliary tooling and includes the following steps: Step 1: Positioning and temporary fixing of the lifting lug assembly: Step 11: Position the tube shaft of the lifting lug assembly and spot weld it to the outer surface of the shift gas absorption tower; Step 1 and 2: Fit the pad of the lifting lug assembly onto the lower part of the tube shaft, so that its inner surface fits against the outer surface of the tower body, and spot weld the outer ring of the pad to the outer surface of the tower body, forming an outer ring seam between the pad and the tube shaft; Step 13: Fit the baffle of the lifting lug assembly onto the upper part of the tube shaft and make it fit snugly; Step 2: Installation of auxiliary tooling: Connect the mounting plate of the auxiliary tooling to the upper end of the tube shaft; Step 3: Automatic Welding Step 31: Install the automatic welding equipment on the heightening cylinder of the auxiliary tooling; Step 32: Use the automatic welding equipment to weld the circumferential joint between the pad and the tower body; Step 33: Use the automatic welding equipment to weld the outer circumferential seam between the pad plate, the pipe shaft, and the tower body.

[0014] Preferably, the automatic welding equipment in step three is a flexible bending gun automatic welding machine.

[0015] Preferably, the flexible bending gun is rotatable about its mounting axis, with a rotation range of ±90°.

[0016] Preferably, in step three, welding is performed by adjusting the angle of the flexible bending torch, and the angle between the torch and the tangent direction of the weld is controlled between 30° and 60°.

[0017] Preferably, in steps 32 and 33, the welding current is controlled between 400A and 500A; and the arc voltage is controlled between 27V and 29V.

[0018] Furthermore, it also includes:

[0019] Step 4: Quality Inspection;

[0020] Step 41: After welding is completed, non-destructive testing methods are used to inspect the weld for defects to ensure that there are no cracks, porosity, undercut, or slag inclusions.

[0021] Step 42: Perform a hardness test on the low-temperature steel weld to ensure that the weld hardness is ≤220HB, which meets the performance requirements for low-temperature steel.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The welding method provided by this invention effectively solves the quality and efficiency bottlenecks in the welding of lifting lugs for large low-temperature steel towers. Specifically, by designing and applying a saddle-shaped clamping circular plate that matches the curved surface of the lifting lug tube shaft, the automatic submerged arc welding equipment originally used for small-diameter components is adapted for circumferential welding of large-diameter (φ740mm) tube shafts. This clamping circular plate serves as an intermediate conversion tooling, ensuring reliable clamping of the automatic welding machine chuck and achieving a stable connection with the lifting lug tube shaft, enabling the high-quality, high-efficiency submerged arc automatic welding process to continue to be used in scenarios where it was previously not directly applicable.

[0024] Compared to traditional manual arc welding, this method employs an automated welding process, resulting in stable welding parameters, uniform fusion deposition, and significantly improved weld quality. This better meets the stringent quality requirements of 100% radiographic testing (RT) for this critical weld. Furthermore, the single-layer fusion deposition efficiency of automated welding is far higher than that of manual welding, reducing the overall welding time for a single lifting lug to 1 / 3 to 1 / 5 of the original time. This significantly improves production efficiency and effectively ensures the assembly schedule of large tower components manufactured in sections. Attached Figure Description

[0025] Figure 1 These are photos of the actual product at the site of this invention. Figure 2 This is a top view of the lifting lug assembly of the gas absorption tower. Figure 3 yes Figure 2 The longitudinal sectional view. Figure 4 This is a schematic diagram of the internal structure of the lifting lug assembly of the gas absorption tower.

[0026] In the diagram: 1. Baffle, 2. Pipe shaft, 3. Pad, 4. Rib plate, 5. Mounting round plate, 6. Heightening cylinder, 7. Automatic welding equipment, A. Outer ring circumferential seam. Detailed Implementation

[0027] Specific implementation method one: Combining Figures 1 to 4 This embodiment describes a shift gas absorption tower lifting lug assembly, comprising a tube shaft 2, a baffle 1, a pad 3, and multiple stiffening plates 4. The baffle 1 is fixedly connected to the outer circumferential side wall of the upper part of the tube shaft 2. The pad 3 is fitted onto the outer circumferential side wall of the lower part of the tube shaft 2, and the pad 3 is saddle-shaped with its inner surface curvature adapted to the outer surface of the shift gas absorption tower. The multiple stiffening plates 4 are fixedly installed in a grid pattern on the inner side wall of the tube shaft 2. The upper end of the tube shaft 2 is provided with auxiliary welding fixtures for installation.

[0028] The lifting lug assembly of this embodiment provides a reliable connection structure for the hoisting of large tower structures, and also lays the foundation for efficient welding processes. Its standardized installation interface, specifically designed for the upper end of the tube shaft, facilitates rapid positioning and clamping of welding auxiliary tooling, ensuring stable alignment of the automatic welding machine during welding—a prerequisite for subsequent high-quality automatic welding. The assembly has a compact structure and a clear force transmission path, meeting the strength requirements of low-temperature steel materials under heavy-load hoisting conditions.

[0029] Specific Implementation Method Two: Combining Figures 1 to 4 In this embodiment, the outer diameter of the baffle 1 is smaller than the outer diameter of the pad 3.

[0030] In this embodiment, the outer diameter of the baffle is smaller than that of the backing plate, ensuring that the weld area around the outer ring of the backing plate is fully exposed. This provides the automatic welding torch with an interference-free operating space, ensuring that the torch can continuously weld the entire weld ring according to the set angle and trajectory. Simultaneously, this design facilitates non-destructive testing of critical welds after welding, ensuring that the weld quality meets the stringent requirements of 100% radiographic inspection.

[0031] Specific implementation method three: Combining Figures 1 to 4This embodiment describes a plurality of stiffening plates 4 forming a grid-like structure with intersecting longitudinal and transverse lines, including at least two longitudinal stiffeners extending axially along the tube axis 2 and at least one transverse stiffener perpendicularly intersecting and fixedly connected to the longitudinal stiffeners.

[0032] This crisscrossing grid-like stiffening structure primarily enhances the local rigidity and overall stability of the lifting lug's tube shaft. During lifting operations, the connection between the tube shaft root and the tower body bears complex bending moments and shear forces. The internal longitudinal stiffeners effectively transfer axial loads, while the transverse stiffeners restrain tube wall deformation and prevent local instability. This structure allows the tube shaft to maintain its shape under heavy loads, disperses stress concentration, and provides stable support for accessories such as the upper baffle and pads, thereby ensuring the structural safety of the lifting lug during long-term use.

[0033] Specific implementation method four: Combination Figures 1 to 4 This embodiment describes an auxiliary tooling system including a mounting plate 5 and a heightening cylinder 6. The mounting plate 5 is mounted on the upper end of the tube shaft 2 of the lifting lug assembly. The heightening cylinder 6 is fixedly connected to the center of the mounting plate 5 and is used to install an automatic welding device 7.

[0034] This auxiliary fixture provides a stable and reliable mounting base for the automatic welding equipment. The mounting plate quickly aligns and locks with the lifting lug shaft via its central structure, ensuring concentric positioning of the fixture and the workpiece. When the height of the shaft itself is insufficient, limiting the welding torch's working space, the added extension tube can raise the welding torch to a suitable height, ensuring that the welding torch can reach the welding position in a preset posture. The entire fixture enables rapid and precise mounting of the automatic welding machine and the large lifting lug assembly, creating the necessary conditions for subsequent continuous and stable automatic welding operations.

[0035] Specific Implementation Method Five: Combining Figures 1 to 4 This embodiment describes a method for welding lifting lugs of a shift gas absorption tower, which uses the aforementioned auxiliary tooling and includes the following steps: Step 1: Positioning and temporary fixing of the lifting lug assembly: Step 11: Position the tube shaft 2 of the lifting lug assembly and spot weld it to the outer surface of the shift gas absorption tower; Step 1 and 2: Fit the pad 3 of the lifting lug assembly onto the lower part of the tube shaft 2, so that its inner surface is in contact with the outer surface of the tower body, and spot weld the outer ring of the pad 3 to the outer surface of the tower body, forming an outer ring circumferential seam A between the pad 3 and the tube shaft 2; Step 13: Fit the baffle 1 of the lifting lug assembly onto the upper part of the tube shaft 2 and make it fit snugly; Step 2: Installation of auxiliary tooling: The mounting plate 5 of the auxiliary tooling is connected to the upper end of the tube shaft 2; Step 3: Automatic Welding Step 31: Install the automatic welding equipment 7 onto the heightening cylinder 6 of the auxiliary tooling; Step 32: Use the automatic welding equipment 7 to weld the circumferential joint between the pad 3 and the tower body; Step 33: Use the automatic welding equipment 7 to weld the outer circumferential seam A between the pad 3, the tube shaft 2, and the tower body.

[0036] This method achieves efficient and reliable automated welding of large lifting lugs by combining step-by-step positioning with specialized tooling. First, spot welding is used to precisely position the main components of the lifting lug, forming a stable temporary assembly that provides accurate weld interfaces for subsequent automated welding. The specialized auxiliary tooling then provides a stable and centered working platform for the automated welding machine.

[0037] During the automated welding phase, the platform is used to first weld the main load-bearing circumferential seam between the pipe shaft and the tower body, forming a core connection. Then, the equipment is adjusted to complete the welding of the outer sealing circumferential seam between the pad plate and the pipe shaft. This sequence ensures that critical welds are prioritized, and all welds are completed under stable parameters of the automated welding machine. This significantly improves overall operational efficiency while ensuring welding quality meets inspection requirements, achieving a balance between quality and efficiency.

[0038] Specific Implementation Method Six: Combination Figures 1 to 4 This embodiment describes an automatic welding device 7 in step three, which is a flexible bending gun automatic welding machine.

[0039] The flexible bending torch automatic welding machine of this embodiment solves the welding accessibility problem caused by the complex geometry of the lifting lug. Since there are usually other accessories or structures around the lifting lug tube shaft, straight torch welding machines have difficulty avoiding obstacles and reaching all welding positions. The flexible bending torch's nozzle can flexibly deflect within a certain angle, thereby bypassing obstacles and achieving continuous, dead-angle-free welding of the circumferential seam. This feature ensures that high-quality, all-position automatic welding can be completed without temporary disassembly of surrounding structures, guaranteeing weld integrity and avoiding the additional time and risks associated with disassembling and assembling accessories.

[0040] Specific implementation method seven: Combination Figures 1 to 4 This embodiment describes a flexible bending gun that can rotate around its mounting axis within a range of ±90°.

[0041] This rotation function allows the welding torch to flexibly adapt to changes in the spatial orientation of the weld. When welding large-diameter circumferential seams, the weld position continuously changes relative to the welding torch's mounting center. The ±90° rotation range allows the welding torch, while fixed to the mounting plate, to adjust its working position in real time through its own rotation, ensuring that the welding wire tip is always precisely aligned with the center of the weld bevel. This guarantees that the weld pool remains uniform and stable throughout the entire circumference of the weld, avoiding defects such as undercut, lack of fusion, or weld discontinuity caused by positional deviations, thus ensuring consistent welding quality across the entire circumference of the circumference.

[0042] Specific implementation method eight: Combination Figures 1 to 4 In this embodiment, in step three, welding is performed by adjusting the angle of the flexible bending torch, and the angle between the torch and the tangent of the weld is controlled between 30° and 60°.

[0043] The aforementioned angle control is primarily used to optimize the weld formation quality of the outer circumferential seam of the backing plate. Maintaining an angle of 30° to 60° between the welding torch and the weld tangent ensures proper guidance of the arc force and molten pool flow direction. A suitable angle helps the deposited metal fill the groove evenly, promoting good slag separation and coverage, thereby forming a smooth surface and dense internal weld bead. This parameter range has been verified in practice to effectively prevent insufficient penetration due to an excessively small angle or arc force dispersion due to an excessively large angle. It is a key process guarantee for achieving one-time formation of the outer circumferential seam in all positions and meeting subsequent non-destructive testing requirements.

[0044] Specific Implementation Method Nine: Combining Figures 1 to 4 In this embodiment, in steps 3.2 and 3.3, the welding current is controlled between 400A and 500A, and the arc voltage is controlled between 27V and 29V.

[0045] The current and voltage parameters in this embodiment are set to meet the specific process requirements of low-temperature steel welding. A current of 400A to 500A provides sufficient and stable heat input, ensuring good penetration and sidewall fusion even with large wall thicknesses. An arc voltage of 27V to 29V works synergistically with the current to maintain a stable arc length and concentrated energy, resulting in a uniformly formed weld bead. This optimized parameter combination ensures welding efficiency while strictly controlling the welding heat input, avoiding adverse effects on the heat-affected zone of the low-temperature steel base material due to overheating, and ultimately ensuring that the mechanical properties and low-temperature toughness of the weld meet the equipment operation requirements.

[0046] Specific Implementation Method Ten: Combining Figures 1 to 4 This embodiment describes the following:

[0047] Step 4: Quality Inspection;

[0048] Step 41: After welding is completed, non-destructive testing methods are used to inspect the weld for defects to ensure that there are no cracks, porosity, undercut, or slag inclusions.

[0049] Step 42: Perform a hardness test on the low-temperature steel weld to ensure that the weld hardness is ≤220HB, which meets the performance requirements for low-temperature steel.

[0050] After the automated welding process is completed, the weld seam is fully scanned using non-destructive testing methods such as magnetic particle and ultrasonic testing. This aims to proactively identify and eliminate any internal or surface defects, ensuring the integrity and reliability of the weld seam. Based on this, hardness testing of the weld area is performed and controlled below 220 HB. This directly verifies the effectiveness of the welding heat input and process parameters, ensuring that the welding process does not damage the mechanical properties of the low-temperature steel base material and the heat-affected zone, especially its low-temperature toughness. This confirms from an intrinsic quality perspective that the welding results meet the technical conditions for the long-term safe operation of the equipment.

[0051] Combination Figures 1 to 4 Description of embodiments of the present invention:

[0052] Tooling preparation and equipment selection

[0053] First, the core tooling—a saddle-shaped mounting plate—was prepared. Q345R structural steel, compatible with low-temperature steel, was selected as the raw material. The saddle-shaped inner curved surface was machined according to the outer diameter of the lifting lug shaft (740mm in diameter) to ensure a fit of at least 95% with the outer surface of the shaft during assembly. A 300mm diameter through hole was CNC machined at the center of the plate, and the hole wall was precision machined to control its surface roughness to within Ra1.6μm to prevent scratching the shaft surface during installation.

[0054] The welding equipment selected is a KRⅡ-500 flexible bending torch automatic welding machine. The bending torch head of this equipment can rotate ±90°, adapting to the arc welding trajectory of 740mm pipe shaft circumferential seams and 1200mm outer circumferential seams of backing plates. The angle of the welding torch is adjusted via a graduated automatic positioning bracket to precisely control the welding posture.

[0055] II. Welding Operation Procedures The actual operation shall be carried out according to the following steps:

[0056] Tooling installation: The prepared saddle-shaped mounting plate is fitted onto the predetermined position on the lifting lug tube shaft and tightened with the positioning bolts on the edge of the plate to ensure that the coaxiality error between the plate and the tube shaft is no more than 2mm, thereby providing a stable installation reference for the automatic welding machine.

[0057] Pipe shaft circumferential weld: Start the automatic welding equipment. Use H06Mn35DR welding wire with SJ208DR flux for welding. Set the welding current to 400-500A and the arc voltage to 27-29V. The equipment drives the flexible bending torch to move uniformly along the pipe shaft circumferential weld at a speed of 8-10cm / min. Multiple layers of welding are usually required, with each layer using the above parameters to ensure the weld thickness meets design requirements.

[0058] Welding of the outer ring of the backing plate: The angle between the welding torch and the tangent of the outer ring weld of the backing plate is adjusted to 45° (ideally within the range of 30°-60°) through equipment program settings. Welding current and voltage parameters remain the same. The equipment moves along the circumference of the 1200mm diameter weld and automatically performs arc movements according to changes in weld height to maintain the stability of the welding torch posture. During welding, after completing approximately 500mm of weld bead, the weld formation must be checked, and the welding torch angle must be finely adjusted as necessary to prevent defects such as weld bead discontinuity.

[0059] Post-welding quality inspection

[0060] After welding, the weld must undergo rigorous quality inspection. First, non-destructive testing methods such as magnetic particle testing (MT), ultrasonic testing (UT), and penetrant testing (PT) are used to comprehensively inspect the weld area, confirming the absence of defects such as cracks, porosity, undercut, and slag inclusions. Subsequently, hardness testing is performed on the low-temperature steel weld to ensure its hardness value does not exceed 220 HB, meeting the performance requirements for use in low-temperature environments. Practice shows that the quality of automated welds obtained using this method is significantly superior to that of traditional manual welding.

[0061] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make other changes within the spirit of the invention and apply it to fields not mentioned in the invention. Of course, all such changes made in accordance with the spirit of the invention should be included within the scope of protection claimed by the invention.

Claims

1. A shift gas absorption tower lifting lug assembly, characterized in that, It includes a tube shaft (2), a baffle (1), a pad (3) and multiple stiffening plates (4); The baffle (1) is fixedly connected to the outer circumferential side wall of the upper part of the tube shaft (2); the pad (3) is fitted onto the outer circumferential side wall of the lower part of the tube shaft (2), the pad (3) is saddle-shaped, and its inner surface curvature is adapted to the outer side surface of the gas absorption tower; the multiple stiffeners (4) are fixedly installed on the inner side wall of the tube shaft (2) in a grid pattern; the upper end of the tube shaft (2) is provided with auxiliary welding fixtures for installation.

2. The lifting lug assembly according to claim 1, characterized in that, The outer diameter of the baffle (1) is smaller than the outer diameter of the pad (3).

3. The lifting lug assembly according to claim 1, characterized in that, The plurality of stiffeners (4) form a grid-like structure with cross-sections, including at least two longitudinal stiffeners extending axially along the tube axis (2) and at least one transverse stiffener that intersects the longitudinal stiffeners perpendicularly and is fixedly connected to them.

4. An auxiliary tooling for welding the lifting lug assembly according to any one of claims 1 to 3, characterized in that, Includes mounting plate (5) and height-increasing cylinder (6); The mounting plate (5) is installed on the upper end of the tube shaft (2) of the lifting lug assembly; the heightening cylinder (6) is fixedly connected to the center of the mounting plate (5) for installing the automatic welding equipment (7).

5. A method for welding lifting lugs of a shift gas absorption tower, characterized in that, The auxiliary tooling described in claim 4 is used, and the following steps are included: Step 1: Positioning and temporary fixing of the lifting lug assembly: Step 11: Position the tube shaft (2) of the lifting lug assembly and spot weld it to the outer side of the conversion gas absorption tower; Step 1 and 2: Fit the pad (3) of the lifting lug assembly onto the lower part of the tube shaft (2), so that its inner surface is in contact with the outer surface of the tower body, and spot weld the outer ring of the pad (3) to the outer surface of the tower body, forming an outer ring seam (A) between the pad (3) and the tube shaft (2). Step 13: Fit the baffle (1) of the lifting lug assembly onto the upper part of the tube shaft (2) and make it fit; Step 2: Auxiliary tooling installation: Connect the mounting plate (5) of the auxiliary tooling to the upper end of the tube shaft (2); Step 3: Automatic welding: Step 3 1: Install the automatic welding equipment (7) on the heightening cylinder (6) of the auxiliary tooling; Step 32: Use the automatic welding equipment (7) to weld the circumferential joint between the pad (3) and the tower body; Step 33: Use the automatic welding equipment (7) to weld the outer ring seam (A) between the pad (3), the tube shaft (2), and the tower body.

6. The method according to claim 5, characterized in that, The automatic welding equipment (7) in step three is a flexible bending gun automatic welding machine.

7. The method according to claim 6, characterized in that, The flexible bending gun can rotate around its mounting axis, with a rotation range of ±90°.

8. The method according to claim 7, characterized in that, In step three, welding is performed by adjusting the angle of the flexible bending torch, and the angle between the torch and the tangent of the weld is controlled between 30° and 60°.

9. The method according to claim 8, characterized in that, In steps 3.2 and 3.3, the welding current is controlled between 400A and 500A; the arc voltage is controlled between 27V and 29V.

10. The method according to claim 5 or 9, characterized in that, Also includes: Step 4: Quality Inspection; Step 41: After welding is completed, non-destructive testing methods are used to inspect the weld for defects to ensure that there are no cracks, porosity, undercut, or slag inclusions. Step 42: Perform a hardness test on the low-temperature steel weld to ensure that the weld hardness is ≤220HB, which meets the performance requirements for low-temperature steel.

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