Method for processing thick-walled large-diameter steel pipe column

Abstract

The application discloses a thick-wall large-diameter steel pipe column processing method, which comprises the following steps: step A, cutting and rolling a steel plate for pre-forming treatment; step B, arranging a bevel one and a bevel two in a separate layer; step C, welding the bevel one and the bevel two; first, adopting gas shielded arc welding to lay a bottom in the bevel one and the bevel two to form a layer 1 and a layer 2, then using submerged arc welding to fill in the bevel one and the bevel two to form a layer 3, a layer 4, a layer 5 and a layer 6, and then using submerged arc welding to cover the bevel one and the bevel two to form a layer 7, a layer 8, a layer 9, a layer 10, a layer 11 and a layer 12. The application controls three parameters of a welding gap, a blunt edge and a bevel angle reasonably, and uses a multi-layer multi-pass welding method to weld, so that the welding quality is good, and meanwhile, the welding appearance is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel pipe welding, and particularly relates to a thick-wall large-diameter steel pipe column processing method. BACKGROUND

[0002] The steel pipe column has good compression resistance, an attractive appearance, and good anti-seismic performance, and is very widely used in engineering applications. Especially for some high-rise buildings, the cross section of the steel pipe column used is also getting larger, which brings certain difficulty to processing and manufacturing. Especially the thick-wall large-diameter welded pipe, after being coiled into a shape, the butt joint welding is difficult, and defects such as incomplete penetration of the weld, welding deformation, welding stress and cracks are easily caused.

[0003] Therefore, how to improve the butt joint welding quality of the thick-wall large-diameter steel pipe is a technical problem to be solved by the person skilled in the art. SUMMARY

[0004] The application aims to solve the above technical problems in the prior art, and provides a thick-wall large-diameter steel pipe column processing method, which controls three parameters of a welding gap, a blunt edge and a bevel angle reasonably, and uses a multi-layer multi-pass welding method for welding, so that the welding quality is good, and the appearance of the weld is ensured.

[0005] In order to solve the above technical problems, the application adopts the following technical scheme:

[0006] The thick-wall large-diameter steel pipe column processing method has the characteristics that it comprises the following steps:

[0007] Step A, cutting and coiling a steel plate to a pre-shaping treatment, the bevel form of the steel plate adopts an X-shaped bevel with a blunt edge, forming an upper bevel one and a lower bevel two, and a gap exists between the bevel one and the bevel two, the gap is 6-8mm, the blunt edge is 2mm, the angle of the bevel two is 30-40°, and the angle of the bevel one is 40-50°.

[0008] Step B, arranging the bevel one and the bevel two in a layered manner: the bevel one and the bevel two are each divided into three layers. The first layer of the bevel one adopts a one-pass mode, and is labeled as layer 1, the second layer of the bevel one adopts a two-pass mode, and is labeled as layer 5 and layer 6, and the third layer of the bevel one adopts a three-pass mode, and is labeled as layer 7, layer 8 and layer 9. The first layer of the bevel two adopts a one-pass mode, and is labeled as layer 2, the second layer of the bevel two adopts a two-pass mode, and is labeled as layer 3 and layer 4, and the third layer of the bevel two adopts a three-pass mode, and is labeled as layer 10, layer 11 and layer 12.

[0009] Step C: Welding of bevel 1 and bevel 2: First, use gas shielded arc welding to make the root pass in bevel 1 and bevel 2, forming layer 1 and layer 2. Then, use submerged arc welding to fill in bevel 1 and bevel 2, forming layer 3, layer 4, layer 5 and layer 6. Finally, use submerged arc welding to cover in bevel 1 and bevel 2, forming layer 7, layer 8, layer 9, layer 10, layer 11 and layer 12.

[0010] Furthermore, during welding, a welding wire diameter of 1.2mm is used. For the root pass and cover pass operations, the welding current is 220A. For the fill pass operation, the welding voltage is controlled between 35V and 40V.

[0011] Furthermore, the welding speed is controlled at 40 cm / min during welding.

[0012] Furthermore, during welding, the wire extension distance is 10 times the wire diameter.

[0013] Furthermore, before welding begins, the butt joint area of ​​the steel plates is preheated, with the preheating temperature controlled between 80℃ and 120℃.

[0014] Furthermore, during welding, restraint measures are set on the steel plate, specifically including the following steps:

[0015] (1) Divide the steel plates into two parts: the steel plate with a constraint structure on the inner side is designated as steel plate one, and the steel plate with a constraint structure on the outer side is designated as steel plate two.

[0016] (2) For the first layer welding position in bevel one, a constraint structure is set on the inner side of steel plate one; for the second layer welding position in bevel two, a constraint structure is set on the outer side of steel plate two.

[0017] (3) Set up a clamping structure for steel plate 1 and steel plate 2, and then place steel plate 2 on the I-beam. At this time, the constraint structure of steel plate 2 is supported on the I-beam. Then, install a rotating structure on the clamping structure of steel plate 2, and then set up a support structure on steel plate 2. Then, place steel plate 1 on the support structure and fix the clamping structure and rotating structure of steel plate 1 at the same time. At this time, the bevel 2 of steel plate 2 and the bevel 1 of steel plate 1 are set upward, so that steel plate 1 and steel plate 2 are connected into an integral structure.

[0018] (4) Install fixed frames on the left and right sides of the rotating structure, and then install support frames on the rotating structure. The support frames are supported on the ground so that the rotating structure can rotate on the support frames. Then, insert a limiting rod horizontally into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. Then, make a bottom in the bevel one of the steel plate one to form a layer 1, and at the same time, make a bottom in the bevel two of the steel plate two to form a layer 2.

[0019] (5) Take out the limiting rod from the limiting hole one of the support frame and the limiting hole two of the fixed frame, rotate the rotating structure on the support frame, flip the whole structure 180°, and then horizontally insert the limiting rod into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. At this time, the bevel one of steel plate two and the bevel two of steel plate one are set upward. Then remove the constraint structure on steel plate one and steel plate two, and then make a bottom in the bevel two of steel plate one to form 2 layers. At the same time, make a bottom in the bevel one of steel plate two to form 1 layer. Then fill in the bevel one of steel plate two to form 5 and 6 layers. At the same time, fill in the bevel two of steel plate one to form 3 and 4 layers.

[0020] (6) Take out the limiting rod from the limiting hole one of the support frame and the limiting hole two of the fixed frame, rotate the rotating structure on the support frame, flip the whole structure 180°, and then horizontally insert the limiting rod into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. At this time, the bevel two of steel plate two and the bevel one of steel plate one are set upwards. Then fill the bevel one of steel plate one to form 5 layers and 6 layers. At the same time, fill the bevel two of steel plate two to form 3 layers and 4 layers. Then cover the bevel one of steel plate one to form 7 layers, 8 layers and 9 layers. At the same time, cover the bevel two of steel plate two to form 10 layers, 11 layers and 12 layers.

[0021] (7) Take out the limiting rod from the limiting hole one of the support frame and the limiting hole two of the fixed frame, rotate the rotating structure on the support frame, flip the whole structure 180°, and then horizontally insert the limiting rod into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. At this time, the bevel one of the steel plate two and the bevel two of the steel plate one are set upwards, and then cover the bevel two of the steel plate one to form 10 layers, 11 layers and 12 layers. At the same time, cover the bevel one of the steel plate two to form 7 layers, 8 layers and 9 layers.

[0022] (8) After welding, the overall structure is placed for a set time, then the limit rod, support frame and fixing frame are removed, and then the rotating structure, support structure and clamping structure are removed to obtain the required steel pipe.

[0023] Furthermore, a single constraint structure includes two fixed supports and a T-shaped steel, with a butt joint set between the two fixed supports; when installing the constraint structure, the fixed supports and the steel plate are welded together, and the T-shaped steel is fixedly connected to the fixed supports by bolts; when dismantling the constraint structure, the fixed supports are directly cut from the steel plate.

[0024] Furthermore, the clamping structure includes a clamping plate and a connecting component. The inner side of the clamping plate is an arc surface. The connecting component includes a connecting shaft and a connecting plate. The connecting plate is circumferentially welded to the outer side of the connecting shaft. The clamping plate is equipped with a screw, and the connecting plate is equipped with a slot. When installing the clamping structure, the connecting shaft is inserted into the tube hole of the steel plate, and then the screw of the clamping plate is slid into the slot. The arc surface of the clamping plate is then attached to the outer side of the steel plate. A nut is then screwed into the screw and tightened. Next, a central rod is moved into the tube hole of the steel plate and inserted into the shaft hole of the connecting shaft. The central rod is equipped with a fixing plate, and two symmetrical limiting plates are fixed to the fixing plate with screws. Simultaneously, the steel plate is inserted into the slot of the limiting plate.

[0025] Furthermore, the rotating structure includes a rotating plate one and a rotating plate two, both of which are equipped with a rotating shaft. When installing the rotating structure, rotating plate one is fixed to the threaded hole of the connecting shaft with bolts, and then a clamping plate is installed on the screw two of the central rod. The two clamping plates are used to clamp rotating plate two. Then, nut two is screwed into screw two and tightened. The rotating shaft of rotating plate two and the rotating shaft of rotating plate one are at the same height. When the clamping structure of steel plate one and the rotating structure are fixed, screw two is slid into the opening of the clamping plate, and then nut two is screwed into screw two and tightened. When installing the support frame, the rotating shaft is rotated through the rotating hole of the support frame.

[0026] Furthermore, the support structure includes support plates, which are T-shaped; during the installation of the support structure, the webs of the two support plates are fixed with bolts.

[0027] The present invention, by adopting the above-described technical solution, has the following beneficial effects:

[0028] (1) The present invention adopts an X-shaped bevel with a blunt edge to form a bevel one and a bevel two distributed vertically. There is a gap between bevel one and bevel two. The three parameters of welding gap, blunt edge and bevel angle are controlled to achieve the effect of controlling welding quality.

[0029] The blunt edge is the un-beveled end face along the thickness direction of the weldment when beveling. The blunt edge prevents root burn-through, but its size must ensure the first weld pass through. A larger blunt edge makes penetration more difficult, while a smaller or non-existent blunt edge makes the root pass easier to penetrate. The gap is the space left between the joint roots before welding. Its purpose is to ensure root penetration during the root pass. Therefore, a proper setting of the blunt edge and gap, with a gap of 6-8 mm and a blunt edge of 2 mm, ensures weld penetration while avoiding defects such as burn-through and weld beads.

[0030] When the current and voltage are constant, the shape of the electric arc remains unchanged, but it will move up and down depending on the size of the bevel angle, without any left or right change. Clearly, with a constant arc voltage, the distance from the arc's melting point to the base material is the same. The smaller the bevel angle, the more the arc moves upward to maintain its original shape, resulting in a larger distance at the root of the bevel below the arc; conversely, the larger the bevel angle, the more the arc moves downward to maintain its original shape, resulting in a smaller distance. Therefore, a larger bevel angle requires more filler wire, inevitably wasting material and significantly increasing the construction period. To ensure full weld penetration while saving welding costs, the angle of bevel two is 30°–40°, and the angle of bevel one is 40°–50°.

[0031] (2) Because the steel plate of the circular tube column is relatively thick, in order to reduce the heat input during welding, reduce the internal force of welding and welding deformation, a multi-layer, multi-pass welding method is used for welding. During welding, gas shielded arc welding is first used for the root pass (such as 1 or 2 layers). Gas shielded arc welding is an arc fusion welding method that uses external gas as the arc medium and protects the arc and welding area. It directly relies on the gas flow selected from the nozzle to create a local gas protective layer around the arc, so that the electrode end, molten droplet and molten pool are mechanically isolated from the air, ensuring the stability of the welding process and preventing angular deformation and burn-through during automatic welding. Then, submerged arc welding is used for the fill pass (such as 3 to 6 layers). Submerged arc welding can use a larger welding current, and the current density can be greatly increased, resulting in high production efficiency. The flux provides reliable protection for the arc space, the welding process is stable, and it is not easy to produce incomplete penetration defects, resulting in good weld quality. Finally, submerged arc welding is used for the cap pass (such as 7 to 12 layers) to ensure the aesthetics of the weld. Attached Figure Description

[0032] The present invention will be further described below with reference to the accompanying drawings:

[0033] Figure 1 This is a schematic diagram of the steel plate bevel structure in this invention;

[0034] Figure 2 This is a schematic diagram of the structure of the present invention when a constraint structure is provided on the inner side of the steel plate;

[0035] Figure 3 This is a schematic diagram of the structure of the present invention when a constraint structure is set on the outside of the second steel plate;

[0036] Figure 4 This is an exploded view of the constraint structure in this invention;

[0037] Figure 5 This is a schematic diagram of the connector structure in this invention;

[0038] Figure 6 This is a schematic diagram of the clamping plate in this invention;

[0039] Figure 7 This is a schematic diagram of the structure of the central rod in this invention;

[0040] Figure 8 This is a structural diagram of the present invention with a clamping structure and a limiting plate.

[0041] Figure 9 This is a schematic diagram of the structure of the present invention, in which the second steel plate is placed on the I-beam;

[0042] Figure 10 This is a schematic diagram of the structure of the rotating plate one in this invention;

[0043] Figure 11 This is a schematic diagram of the clamping plate in this invention;

[0044] Figure 12 This is a schematic diagram of the structure of the rotating plate two in this invention;

[0045] Figure 13 This is a schematic diagram of the structure of the present invention when the rotating structure is installed;

[0046] Figure 14 This is a schematic diagram of the fixing frame in this invention;

[0047] Figure 15 This is a schematic diagram of the limiting rod in this invention;

[0048] Figure 16 This is a schematic diagram of the structure when steel plate one and steel plate two are connected into an integral structure according to the present invention;

[0049] Figure 17 This is a schematic diagram of the support frame in this invention;

[0050] Figure 18 This is a schematic diagram of the structure of the present invention when the bottom is formed in the bevel 2 of steel plate 1 and the bevel 1 of steel plate 2.

[0051] Figure 19 This is a schematic diagram of the structure after welding of bevel one and bevel two according to the present invention. Detailed Implementation

[0052] like Figures 1 to 19 The diagram illustrates the processing method for thick-walled, large-diameter steel pipe columns according to the present invention. Specifically, the welding method for the steel pipe columns is designed, including the following steps:

[0053] Step A: Cut and roll the steel plate a into pre-forming material. The steel plate a forms a pipe hole 16. The bevel of the steel plate a adopts an X-shaped bevel with a blunt edge 15, forming bevel one 13 and bevel two 14 distributed vertically, with a gap between them. Controlling the welding gap, the blunt edge 15, and the bevel angle are three parameters to control the welding quality.

[0054] The blunt edge 15 is the un-beveled end face along the thickness direction of the weldment when beveling. The blunt edge 15 prevents root burn-through, but its size must also ensure the first weld pass through. A larger blunt edge 15 makes penetration more difficult, while a smaller or non-existent blunt edge 15 makes root pass easier. The gap is the pre-reserved space between the joint roots before welding. Its purpose is to ensure root pass through when welding the root pass. Therefore, a proper setting of the blunt edge 15 and gap (6-8mm for the gap and 2mm for the blunt edge) ensures weld penetration while avoiding defects such as burn-through and weld beads.

[0055] When the current and voltage are constant, the shape of the electric arc remains unchanged, but it will move up and down depending on the size of the bevel angle, without any left or right change. Clearly, with a constant arc voltage, the distance from the arc melting point to the base material is the same. The smaller the bevel angle, the more the arc moves upward to maintain its original shape, resulting in a larger distance at the root of the bevel below the arc; conversely, the larger the bevel angle, the more the arc moves downward to maintain its original shape, resulting in a smaller distance. Therefore, a larger bevel angle requires more filler wire, which inevitably wastes material and significantly increases the construction period. To ensure full weld penetration while saving welding costs, the angle of bevel 2-14 is 30°–40°, and the angle of bevel 1-13 is 40°–50°.

[0056] Step B: Arrange bevels 13 and 24 in separate layers: Both bevels 13 and 24 are divided into three layers. The first layer of bevel 13 uses a single-path method, labeled as layer 1; the second layer uses two-path methods, labeled as layers 5 and 6; and the third layer uses three-path methods, labeled as layers 7, 8, and 9. The first layer of bevel 24 uses a single-path method, labeled as layer 2; the second layer uses two-path methods, labeled as layers 3 and 4; and the third layer uses three-path methods, labeled as layers 10, 11, and 12 (e.g., ...). Figure 19 (As shown).

[0057] Step C: Welding of Groove 13 and Groove 24: Because the circular tube column steel plate a is relatively thick, a multi-layer, multi-pass welding method is used to reduce heat input, welding internal force, and welding deformation during welding. During welding, gas-shielded arc welding is first used to create the root pass in Groove 13 and Groove 24, forming layers 1 and 2. Gas-shielded arc welding is an arc fusion welding method that uses an external gas as the arc medium to protect the arc and the welding area. It directly relies on the gas flow selected from the nozzle to create a local gas protective layer around the arc, mechanically isolating the electrode tip, molten droplets, and molten pool from the air, ensuring the stability of the welding process and preventing angular deformation and burn-through during automatic welding. Submerged arc welding is then used to fill the grooves in Groove 13 and Groove 24, forming layers 3, 4, 5, and 6. Submerged arc welding can use a larger welding current, greatly increasing the current density and improving production efficiency. The flux provides reliable protection for the arc space, ensuring a stable welding process, minimizing the risk of incomplete penetration, and resulting in high-quality welds. Submerged arc welding is then used to cover the welds at bevel 13 and bevel 24, forming 7, 8, 9, 10, 11, and 12 layers to guarantee the aesthetic appearance of the weld.

[0058] This invention allows for the selection of welding current, welding voltage, welding speed, and welding wire length, as detailed below:

[0059] 1. The current flowing through the welding circuit during welding is called the welding current. The magnitude of the welding current has a significant impact on the melting rate of the electrode, the penetration depth of the base metal, the internal quality of the weld, the performance of the weld joint, and production efficiency. If the welding current is too high, undercut or even burn-through can easily occur on both sides of the base metal. If the welding current is too low, the base metal will not be sufficiently heated, easily leading to defects such as slag inclusions and incomplete penetration. A large welding current results in a large penetration depth, while a small welding current results in a small penetration depth. Furthermore, in the welding of thick plates, excessive current can cause significant deformation of the welded component. Therefore, the appropriate selection of current parameters has a significant effect on quality control. The arc voltage, also known as the welding voltage, is the main factor determining the weld width. When the welding voltage is too high, the amount of flux melted increases, the arc becomes unstable, and in severe cases, undercut and porosity defects can occur. When the welding voltage is too low, arc ignition is difficult, and the welding process is unstable. Only when the arc voltage and welding current are well matched can a good welding process be obtained, with minimal spatter and good weld formation. Therefore, when welding, the welding wire diameter should be 1.2mm, the welding current for the root pass and cover pass should be around 220A, and the welding voltage for the middle fill pass should be between 35 and 40V.

[0060] 2. If the welding speed is too fast and the molten pool temperature is insufficient, defects such as incomplete penetration, lack of fusion, and poor weld formation are likely to occur. If the welding speed is too slow, the high-temperature dwell time will increase, the heat-affected zone will widen, the grains of the weld joint will coarsen, the mechanical properties will decrease, and the deformation will increase. Therefore, a suitable welding speed can avoid the occurrence of weld defects. The welding speed can be controlled at around 40 cm / min.

[0061] 3. The wire extension length has a significant impact on the actual output current of the welding machine. During the welding process, when the wire extension length is large, the resistance of the welding wire increases, and the actual current decreases. Therefore, even with a constant wire feed speed, the weld penetration may become shallower, or even fail to penetrate the root. Due to the increased resistance, the welding wire may overheat and melt in sections, resulting in severe metal spatter and an increased likelihood of air intrusion into the weld, leading to porosity defects. When the wire extension length is small, the resistance of the welding wire decreases, and the actual current increases. The distance between the nozzle and the workpiece is shortened, resulting in an excessively high weld, poor weld formation, and overheating of the contact tip, potentially burning it out and causing the welding wire to become clogged. Furthermore, spatter can stick to or block the nozzle, affecting gas flow and resulting in porosity in the weld. Generally, the wire extension length should be 10 times the welding wire diameter.

[0062] Preheating temperature and interlayer temperature control in this invention:

[0063] Cold cracks are prone to occur in the heat-affected zone (HAZ) of welded steel. Therefore, the weld zone of the thick steel plate a should be preheated before the formal welding work begins. Preheating can alleviate the rapid heating and cooling process in the weld zone, reduce shrinkage stress during welding, and remove moisture and humidity from the weld zone. For this round tube, preheating can be done using electric heating or flame heating, with the preheating temperature controlled between 80℃ and 120℃. Interpass temperature is the instantaneous highest temperature of the multi-pass weld and base material before the next weld pass. Excessively high interpass temperatures can cause coarse grains in the HAZ, reducing weld strength and low-temperature impact toughness. If the interpass temperature is lower than the preheating temperature, cracks may occur during welding. For this round tube, the interpass temperature should be controlled between 120℃ and 250℃ during welding. Temperature monitoring is done using an infrared laser thermometer; the laser point should be 100mm on both sides of the weld.

[0064] Using rigid fixation on both sides of the weld can effectively reduce welding deformation. During automatic welding, to maintain welding continuity, existing techniques involve welding a retaining plate to the back of the weld for fixation, which is then removed after welding is complete. When welding thick-walled steel pipes, multi-layer, multi-pass symmetrical welding is employed. If conventional fixation methods are used, repeated welding and cutting of the retaining plate on both the inner and outer sides is required to exchange the fixation surfaces. This method is cumbersome and easily damages the original component. To address this technical problem, the present invention sets constraint measures on steel plate a during the welding process, specifically including the following steps:

[0065] (1) Divide the steel plate into two parts: the steel plate with the constraint structure 17 on the inner side is designated as steel plate a1, and the steel plate with the constraint structure 17 on the outer side is designated as steel plate a2.

[0066] (2) For the welding position at the first layer of the bevel, a constraint structure 17 is set on the inner side of the steel plate a1 (e.g. Figure 2 As shown), for the second layer welding position in bevel two, a constraint structure 17 is set on the outside of steel plate two a2 (as shown). Figure 3(As shown).

[0067] A single constraint structure 17 includes two fixed supports 18 and a T-shaped steel 19, with a butt joint set between the two fixed supports 18. When the constraint structure 17 is installed, the fixed supports 18 and the steel plate are welded and fixed, and the T-shaped steel 19 is fixedly connected to the fixed supports 18 by bolts. The T-shaped steel 19 can be recycled later to reduce welding costs.

[0068] (3) A clamping structure is provided for steel plate a1 and steel plate a2. The clamping structure includes a clamping plate 23 and a connecting piece. The inner side of the clamping plate 23 is an arc surface 24. The connecting piece includes a connecting shaft 20 and a connecting plate 21. The connecting plate 21 is circumferentially welded to the outer side of the connecting shaft 20. The clamping plate 23 is provided with a screw 25, and the connecting plate 21 is provided with a slot 22. When installing the clamping structure, the connecting shaft 20 is inserted into the tube hole 16 of the steel plate, and then the screw 25 of the clamping plate 23 is slid into the slot 22. The arc surface 24 of the clamping plate 23 is attached to the outer side of the steel plate. Then, a nut is screwed into the screw 25 and tightened. Next, the central rod 26 is moved into the tube hole 16 of the steel plate and inserted into the shaft hole 28 of the connecting shaft 20. The central rod 26 is equipped with a fixing plate 37, and then two symmetrical limiting plates 38 are fixed on the fixing plate 37 with screws. At the same time, the steel plate is inserted into the slot of the limiting plate 38. The clamping structure clamps and constrains the rolled and formed steel plate a, preventing the steel plate a from springing back and deforming, effectively reducing welding deformation. At this time, each steel plate a only needs to be set with 2 to 3 sets of constraint structures 17, which can reduce the number of subsequent cutting and fixing supports 18 and avoid damage to the original components. Moreover, the force on the steel plate a can be transmitted to the central rod 26 through the limiting plate 38, making the overall structure of the connection between steel plate a1 and steel plate a2 less likely to tip over when rotating.

[0069] Steel plate 2a2 is placed on I-beam 29. At this time, the constraint structure 17 of steel plate 2a2 is supported on I-beam 29. Then, a rotating structure is installed on the clamping structure of steel plate 2a2. The rotating structure includes rotating plate 1 30 and rotating plate 2 32, both of which are equipped with rotating shafts 33. When installing the rotating structure, rotating plate 1 30 is fixed to the threaded hole of connecting shaft 20 by bolts. Then, clamping plate 31 is installed on screw 27 of center rod 26. The two clamping plates 31 are used to clamp rotating plate 2 32. Then, nut 2 is screwed into screw 27 and tightened. The rotating shaft 33 of rotating plate 2 32 and the rotating shaft 33 of rotating plate 1 30 are at the same height. By setting a rotating structure, the overall structure connecting steel plate a1 and steel plate a2 can be rotated 180° and limited, which facilitates the conversion of the positions of steel plate a1 and steel plate a2. Moreover, by adopting the above-mentioned rotating structure, the rotating shaft 33 of rotating plate 30 and rotating plate 32 can be at the same height, so that the overall structure connecting steel plate a1 and steel plate a2 can rotate smoothly.

[0070] A support structure is then installed on steel plate a2, including a support plate 36, which is T-shaped. During installation, the webs of the two support plates 36 are fixed with bolts. Steel plate a1 is then placed on the support structure, and its clamping and rotating structures are fixed. Specifically, screw 27 is slid into the opening 36 of clamping plate 31, and nut 2 is screwed into screw 27 and tightened. At this point, the bevel 14 of steel plate a2 and the bevel 13 of steel plate a1 face upwards, connecting steel plate a1 and steel plate a2 into a single structure. This invention employs a clamping structure, a lifting structure, and a support structure, enabling simultaneous welding of two steel plates a, thus improving the welding speed of the butt joint.

[0071] (4) Install fixing brackets 34 on the left and right sides of the rotating structure. Fixing brackets 34 are fixed to screws 3 on clamping plate 31 and rotating plate 30. Then screw nuts 3 into screws 3 and tighten nuts 3. Then install support brackets 39 on the rotating structure. Rotate the shaft 33 through the rotating hole 40 of support bracket 39. Support bracket 39 is supported on the ground, so that the rotating structure rotates on support bracket 39. Then, horizontally insert limiting rods 35 into limiting holes 41 of support bracket 39 and limiting holes 42 of fixing bracket 34, so that the rotating structure is limited on support bracket 39. Then, make a base in bevel 13 of steel plate a1 to form 1 layer. At the same time, make a base in bevel 14 of steel plate a2 to form 2 layers.

[0072] (5) Take out the limiting rod 35 from the limiting hole 41 of the support frame 39 and the limiting hole 42 of the fixed frame 34, rotate the rotating structure on the support frame 39, flip the whole structure 180°, and then horizontally insert the limiting rod 35 into the limiting hole 41 of the support frame 39 and the limiting hole 42 of the fixed frame 34 so that the rotating structure is limited on the support frame 39. At this time, the bevel 13 of the steel plate 2a2 and the bevel 14 of the steel plate 1a1 are set upward. Then remove the constraint structure 17 on the steel plate 1a1 and the steel plate 2a2. When the constraint structure 17 is removed, cut the fixed support 18 directly from the steel plate. Then, a base layer is formed in bevel 14 of steel plate a1, forming 2 layers. At the same time, a base layer is formed in bevel 13 of steel plate a2, forming 1 layer. Then, the bevel 13 of steel plate a2 is filled to form 5 and 6 layers. At the same time, the bevel 14 of steel plate a1 is filled to form 3 and 4 layers.

[0073] (6) Take out the limiting rod 35 from the limiting hole 41 of the support frame 39 and the limiting hole 42 of the fixed frame 34, rotate the rotating structure on the support frame 39, flip the whole structure 180°, and then horizontally insert the limiting rod 35 into the limiting hole 41 of the support frame 39 and the limiting hole 42 of the fixed frame 34 so that the rotating structure is limited on the support frame 39. At this time, the bevel 14 of the steel plate 2a2 and the bevel 13 of the steel plate 1a1 are set upwards. Then fill the bevel 13 of the steel plate 1a1 to form 5 layers and 6 layers. At the same time, fill the bevel 14 of the steel plate 2a2 to form 3 layers and 4 layers. Then cover the bevel 13 of the steel plate 1a1 to form 7 layers, 8 layers and 9 layers. At the same time, cover the bevel 14 of the steel plate 2a2 to form 10 layers, 11 layers and 12 layers.

[0074] (7) Take out the limiting rod 35 from the limiting hole 41 of the support frame 39 and the limiting hole 42 of the fixing frame 34, rotate the rotating structure on the support frame 39, flip the whole structure 180°, and then horizontally insert the limiting rod 35 into the limiting hole 41 of the support frame 39 and the limiting hole 42 of the fixing frame 34 so that the rotating structure is limited on the support frame 39. At this time, the bevel 13 of the steel plate 2a2 and the bevel 14 of the steel plate 1a1 are set upwards, and then cover the bevel 14 of the steel plate 1a1 to form 10, 11 and 12 layers. At the same time, cover the bevel 13 of the steel plate 2a2 to form 7, 8 and 9 layers.

[0075] (8) After welding, the overall structure is placed for a set time, then the limit rod 35, support frame 39 and fixing frame 34 are removed, and then the rotating structure, support structure and clamping structure are removed to obtain the required steel pipe.

[0076] This invention enables simultaneous layered welding of two steel plates a using bevel 13 and bevel 24. During the welding process, the root pass, fill pass, and cover pass are always performed with the butt joint facing upwards, allowing the solder to sink within the bevel and cool fully, resulting in a uniform and full weld and improved welding quality. In the root pass, fill pass, and cover pass operations, a clamping structure tightly binds and constrains the rolled-up steel plate a, allowing for a 180° rotation of the two plates a.

[0077] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for processing thick-walled, large-diameter steel pipe columns, characterized in that, Includes the following steps: Step A: Cut and roll the steel plate into pre-forming treatment. The steel plate adopts an X-shaped bevel with a blunt edge to form bevel one and bevel two distributed vertically. There is a gap between bevel one and bevel two, which is 6-8mm. The blunt edge is 2mm. The angle of bevel two is 30°-40° and the angle of bevel one is 40°-50°. Step B: Arrange the ramps in two layers for ramp one and ramp two: Both bevel one and bevel two are divided into three layers; The first layer of bevel 1 uses a single method and is labeled as layer 1; the second layer of bevel 1 uses a two-step method and is labeled as layer 5 and layer 6; the third layer of bevel 1 uses a three-step method and is labeled as layer 7, layer 8 and layer 9. The first layer of the second bevel uses a single-pass method and is numbered 2. The second layer of the second bevel uses a two-pass method and is numbered 3 and 4. The third layer of the second bevel uses a three-pass method and is numbered 10, 11 and 12. Step C: Welding of bevel one and bevel two: First, gas shielded arc welding is used to make the root pass in groove one and groove two to form layer 1 and layer 2. Then, submerged arc welding is used to fill the groove one and groove two to form layer 3, layer 4, layer 5 and layer 6. Finally, submerged arc welding is used to cover the groove one and groove two to form layer 7, layer 8, layer 9, layer 10, layer 11 and layer 12. During welding, constraint measures are set on the steel plate, specifically including the following steps: (1) Divide the steel plates into two parts: the steel plate with a constraint structure on the inner side is designated as steel plate one, and the steel plate with a constraint structure on the outer side is designated as steel plate two. (2) For the first layer welding position in bevel one, a constraint structure is set on the inner side of steel plate one; for the second layer welding position in bevel two, a constraint structure is set on the outer side of steel plate two. (3) Set up a clamping structure for steel plate 1 and steel plate 2, and then place steel plate 2 on the I-beam. At this time, the constraint structure of steel plate 2 is supported on the I-beam. Then install a rotating structure on the clamping structure of steel plate 2, and then set up a support structure on steel plate 2. Then place steel plate 1 on the support structure, and fix the clamping structure and rotating structure of steel plate 1 at the same time. At this time, the bevel 2 of steel plate 2 and the bevel 1 of steel plate 1 are set upward, so that steel plate 1 and steel plate 2 are connected into an integral structure. (4) Install fixed frames on the left and right sides of the rotating structure, and then install support frames on the rotating structure. The support frames are supported on the ground so that the rotating structure can rotate on the support frames. Then, insert a limiting rod horizontally into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. Then, make a bottom in the bevel one of the steel plate one to form 1 layer, and at the same time make a bottom in the bevel two of the steel plate two to form 2 layers. (5) Take out the limiting rod from the limiting hole one of the support frame and the limiting hole two of the fixed frame, rotate the rotating structure on the support frame, flip the overall structure 180°, and then horizontally insert the limiting rod into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. At this time, the bevel one of the steel plate two and the bevel two of the steel plate one are set upward. Then remove the constraint structure on the steel plate one and the steel plate two. Then make a bottom in the bevel two of the steel plate one to form 2 layers. At the same time, make a bottom in the bevel one of the steel plate two to form 1 layer. Then fill the bevel one of the steel plate two to form 5 and 6 layers. At the same time, fill the bevel two of the steel plate one to form 3 and 4 layers. (6) Take out the limiting rod from the limiting hole one of the support frame and the limiting hole two of the fixed frame, rotate the rotating structure on the support frame, flip the whole structure 180°, and then horizontally insert the limiting rod into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. At this time, the bevel two of steel plate two and the bevel one of steel plate one are set upwards. Then fill the bevel one of steel plate one to form 5 layers and 6 layers. At the same time, fill the bevel two of steel plate two to form 3 layers and 4 layers. Then cover the bevel one of steel plate one to form 7 layers, 8 layers and 9 layers. At the same time, cover the bevel two of steel plate two to form 10 layers, 11 layers and 12 layers. (7) Take out the limiting rod from the limiting hole one of the support frame and the limiting hole two of the fixed frame, rotate the rotating structure on the support frame, flip the whole structure 180°, and then horizontally insert the limiting rod into the limiting hole one of the support frame and the limiting hole two of the fixed frame so that the rotating structure is limited on the support frame. At this time, the bevel one of the steel plate two and the bevel two of the steel plate one are set upwards, and then cover the surface in the bevel two of the steel plate one to form 10 layers, 11 layers and 12 layers. At the same time, cover the surface in the bevel one of the steel plate two to form 7 layers, 8 layers and 9 layers. (8) After welding, the overall structure is placed for a set time, then the limit rod, support frame and fixing frame are removed, and then the rotating structure, support structure and clamping structure are removed to obtain the required steel pipe.

2. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: During welding, a welding wire diameter of 1.2mm is used. For the root pass and cover pass operations, the welding current is 220A. For the fill pass operation, the welding voltage is controlled between 35V and 40V.

3. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: During welding, the welding speed is controlled at 40cm / min.

4. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: During welding, the wire extension distance is 10 times the wire diameter.

5. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: Before welding begins, the butt joint area of ​​the steel plates is preheated, with the preheating temperature controlled between 80℃ and 120℃.

6. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: Each constraint structure includes two fixed supports and a T-shaped steel section, with a butt joint located between the two fixed supports. When installing the constraint structure, the fixed supports and the steel plate are welded together, and the T-shaped steel section is fixedly connected to the fixed supports by bolts. When dismantling the constraint structure, the fixed supports are simply cut from the steel plate.

7. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: The clamping structure includes a clamping plate and a connecting member. The inner side of the clamping plate is an arc surface. The connecting member includes a connecting shaft and a connecting plate. The connecting plate is circumferentially welded to the outer side of the connecting shaft. The clamping plate is provided with a screw, and the connecting plate is provided with a slot. When installing the clamping structure, the connecting shaft is inserted into the tube hole of the steel plate, and then the screw of the clamping plate is slid into the slot. The arc surface of the clamping plate is then attached to the outer side of the steel plate. Then, a nut is screwed into the screw and tightened. Next, a central rod is moved into the tube hole of the steel plate and inserted into the shaft hole of the connecting shaft. The central rod is provided with a fixing plate. Then, two symmetrical limiting plates are fixed on the fixing plate with screws, and the steel plate is inserted into the slot of the limiting plate.

8. The method for processing thick-walled, large-diameter steel pipe columns according to claim 7, characterized in that: The rotating structure includes a first rotating plate and a second rotating plate, both of which are equipped with a rotating shaft. During installation, the first rotating plate is bolted into the threaded hole of the connecting shaft. A clamping plate is then inserted into the second screw of the central rod, and the two clamping plates clamp the second rotating plate. A second nut is then screwed into the second screw and tightened. The rotating shafts of the second rotating plate and the first rotating plate are at the same height. When the clamping structure of the first steel plate and the rotating structure are fixed, the second screw is slid into the opening of the clamping plate, and then the second nut is screwed into the second screw and tightened. When installing the support frame, the rotating shaft is rotated through the rotating hole of the support frame.

9. The method for processing thick-walled, large-diameter steel pipe columns according to claim 1, characterized in that: The support structure includes a support plate, which is T-shaped; when installing the support structure, the webs of the two support plates are fixed together with bolts.

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