A submerged arc vertical welding method
By installing forming components at the vertical butt joint gap and using oscillation control with cable welding wire, the problems of collapse and temperature gradient during vertical welding were solved, enabling efficient and stable welding of thick steel plates and improving weld quality and efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU WENCHONG SHIPYARD CO LTD
- Filing Date
- 2026-04-10
- Publication Date
- 2026-06-02
AI Technical Summary
During vertical welding, the liquid metal and flux tend to collapse during traditional submerged arc welding, leading to forming defects. Furthermore, the concentrated heat source results in a large temperature gradient, affecting the welding quality and efficiency of thick steel plates.
A forming component is installed at the vertical butt joint gap to form a welding cavity. A cable welding wire is used for periodic oscillation and synchronous movement. Combined with an independent AC power supply, this achieves circumferential envelopment and constraint of the weld pool and uniform heat distribution.
The problem of collapse during vertical welding was solved, resulting in improved welding quality stability and efficiency, refined weld grains, and excellent mechanical properties.
Smart Images
Figure CN122125320A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of welding technology, and in particular to a submerged arc vertical welding method. Background Technology
[0002] In shipbuilding, bridge construction, and the assembly of large steel structures, vertical welding of thick steel plates is often involved.
[0003] While submerged arc welding (SAW) is widely used in flat and horizontal welding positions due to its high welding efficiency, stable quality, and environmental friendliness, it still faces significant technical challenges in vertical welding. Firstly, forming the molten pool in vertical welding is difficult. Traditional SAW generates a large amount of liquid metal, liquid slag, and solid flux covering it during the welding process. In vertical welding, these substances tend to flow downwards under gravity, making it difficult for the molten pool to remain stable. Liquid metal and flux can seep out from the weld seam. Collapse within the gap causes severe forming defects, making conventional submerged arc welding almost impossible to implement in vertical welding. Secondly, traditional single-wire vertical welding (such as ordinary gas-electric vertical welding) usually uses narrow gap welding, which has a limited arc coverage and a relatively concentrated heat source. When facing thick steel plates, this mode has a weak heat conduction capacity of the arc in the weld width direction, resulting in a huge temperature gradient between the center and the edge of the molten pool. The central area often suffers severe loss of alloying elements due to overheating, while the edge area is prone to defects such as incomplete fusion or slag inclusions due to insufficient heat. Summary of the Invention
[0004] The purpose of this invention is to provide a submerged arc vertical welding method. This method involves installing a forming component at the vertical butt joint gap of the workpieces to be welded to create a defined welding cavity. At least two welding wires are inserted into the welding cavity and ignited under the coverage of the welding flux to jointly establish a weld pool. By combining the periodic oscillation of the welding wires within the vertical butt joint gap with motion control of the welding wires and the forming component moving synchronously upwards along the vertical butt joint gap, the method achieves circumferential coverage and stable forming of the weld pool and welding flux, overcoming the problem of flow and collapse caused by gravity. This enables stable automated submerged arc welding at the vertical butt joint position, ensuring welding quality.
[0005] To achieve the above objectives, the present invention provides a submerged arc welding method, comprising the following steps: S1. A forming component is installed at the vertical butt joint gap of the workpiece to be welded, and the forming component and the vertical butt joint gap together form a welding cavity. S2. Insert at least two welding wires into the welding cavity and deliver welding flux into the welding cavity; S3. Control at least two of the welding wires to ignite under the coverage of the welding flux to jointly establish a weld pool; S4. Control at least two of the welding wires to swing within the vertical butt gap, and control at least two of the welding wires and at least a portion of the forming component to move synchronously upward along the vertical butt gap, so that the weld pool solidifies and the welding is completed.
[0006] Furthermore, the welding wire is a cable-type welding wire, which is formed by spirally winding multiple sub-wires.
[0007] Furthermore, in S3, at least two independent AC power supplies are used to drive the arc ignition of at least two of the welding wires in a one-to-one correspondence.
[0008] Furthermore, the welding flux is a metallic flux, and the mass content of iron in the metallic flux is 26%-34%.
[0009] Furthermore, the forming component includes a liner fixed to one side of the vertical butt gap, and a water-cooled slider located on the other side of the vertical butt gap and moving upward synchronously with the welding wire. In step S1, the gasket is placed at one side opening of the vertical butt joint gap, and the water-cooled slider is placed at the other side opening of the vertical butt joint gap, so that the gasket, the water-cooled slider, and the opposite sidewalls of the vertical butt joint gap of the workpiece to be welded together form the welding cavity.
[0010] Furthermore, the gasket includes a ceramic gasket and a glass fiber cloth disposed on the side of the ceramic gasket near the vertical mating gap; In S1, the liner is pressed and fixed to one side opening of the vertical docking gap using a temporary fixing bracket and wedge, so that the fiberglass cloth comes into contact with the surface of the workpiece to be welded.
[0011] Furthermore, in S2, the welding flux is supplied to the welding cavity through a flux discharge pipe, the lower end of which overlaps the top of the water-cooled slider and is located at the upper end of the welding cavity; In S4, during the welding process, the flux is replenished according to the consumption height of the flux in the welding cavity and the contact state with the flux discharge pipe opening.
[0012] Furthermore, in S4, at least two of the welding wires are controlled to periodically reciprocate within the vertical butt joint gap at a preset frequency, preset amplitude, and preset end dwell time, and at least two of the welding wires move synchronously.
[0013] Further, prior to S3, a sealing weld is welded at the bottom of the vertical butt joint gap using gas shielded welding, and the slag on the surface of the sealing weld is removed. In S3, when the arc is started, the lower end of the welding wire is controlled to contact the top surface of the bottom sealing weld, and the welding flux covers the top surface of the bottom sealing weld.
[0014] Furthermore, after S4, the welding power supply is turned off first, and then the welding wire and the water-cooled slider are controlled to move upward by 30mm-50mm.
[0015] Compared with existing technologies, the submerged arc vertical welding method of this invention has the following advantages: Firstly, by installing a forming component at the vertical butt joint gap of the workpieces to be welded and forming a welding cavity, the high-temperature weld pool, slag, and solid welding flux are circumferentially encapsulated and constrained, solving problems such as dripping, flux collapse, and forming failure caused by gravity during vertical submerged arc welding. Secondly, by controlling at least two welding wires to reciprocate within the vertical butt joint gap, the welding heat is evenly distributed within the wide weld gap of thick steel plates, and a stirring effect is generated on the weld pool, reducing the temperature gradient between the center and edge of the weld pool, mitigating regional segregation during metal crystallization, thereby refining the weld grains and ensuring excellent mechanical properties of the weld. Thirdly, by controlling at least two welding wires and at least a portion of the forming component to move synchronously upwards along the vertical butt joint gap, the automation and continuity of the vertical submerged arc welding process are achieved, improving the welding efficiency of vertical butt joints of thick steel plates. Attached Figure Description
[0016] Figure 1 This is a flowchart of the submerged arc vertical welding method according to an embodiment of the present invention; Figure 2 This is a cross-sectional structural schematic diagram of the welding process of the submerged arc vertical welding method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the welding wire structure in the submerged arc vertical welding method according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the submerged arc vertical welding method according to an embodiment of the present invention when a temporary fixed bracket is installed on the workpiece to be welded. Figure 5 This is a schematic diagram of the submerged arc vertical welding method according to an embodiment of the present invention, when installing a liner and a wedge in the clearance hole. Figure 6 This is a cross-sectional structural schematic diagram of the welding process from another angle in the submerged arc vertical welding method of this invention; Figure 7 This is a schematic diagram of the structure of the backing component in the submerged arc vertical welding method according to an embodiment of the present invention.
[0017] In the picture, 1. Workpiece to be welded; 11. Vertical butt joint gap; 12. Welding cavity; 13. Weld pool; 2. Molding components; 21. Gaskets; 211. Ceramic gaskets; 2111. Smooth grooves; 212. Fiberglass cloth; 22. Water-cooled sliders; 221. Circulating cooling water channels; 23. Temporary fixing brackets; 231. Clearance holes; 24. Wedges; 3. Welding wire; 31. Sub-wire; 4. Welding flux; 5. Swinging beam; 51. Welding torch; 511. Rotating handle; 52. Flux discharge pipe. Detailed Implementation
[0018] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.
[0019] In the description of this invention, the terms "upper," "lower," "left," "right," "front," "rear," "inner," "outer," "lateral," and "longitudinal," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.
[0020] In the description of this invention, the terms "provided with," "set up," "connected," and "placed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0021] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.
[0022] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.
[0023] like Figure 1 , 2 As shown, an embodiment of the submerged arc welding method of the present invention includes the following steps: S1. Install the forming component 2 at the vertical butt joint gap 11 of the workpiece 1 to be welded. The forming component 2 and the vertical butt joint gap 11 together form a welding cavity 12. S2. Insert at least two welding wires 3 into the welding cavity 12 and deliver welding flux 4 into the welding cavity 12; S3. Control at least two welding wires 3 to ignite under the coverage of welding flux 4, so as to jointly establish a weld pool 13; S4. Control at least two welding wires 3 to swing within the vertical butt joint gap 11, and control at least two welding wires 3 and at least a portion of the forming component 2 to move upward synchronously along the vertical butt joint gap 11 so that the weld pool 13 solidifies and the welding is completed.
[0024] Based on the above technical solution, a forming component 2 is installed at the vertical butt joint gap 11 of the workpiece 1 to be welded and forms a welding cavity 12. This achieves circumferential coverage and constraint of the high-temperature welding pool 13, slag, and solid welding flux 4, solving problems such as dripping, flux collapse, and forming failure caused by gravity during vertical submerged arc welding. Controlling at least two welding wires 3 to reciprocate within the vertical butt joint gap 11 achieves uniform distribution of welding heat within the wide weld gap of a thick steel plate and generates a stirring effect on the welding pool 13, reducing the temperature gradient between the center and edge of the pool, mitigating regional segregation during metal crystallization, thereby refining the weld grains and ensuring excellent mechanical properties of the weld. Controlling at least two welding wires 3 and at least a portion of the forming component 2 to move synchronously upward along the vertical butt joint gap 11 achieves automation and continuity of the vertical submerged arc welding process, improving the welding efficiency of vertical butt joints of thick steel plates.
[0025] Preferably, such as Figure 3 As shown, the welding wire 3 is a cable welding wire 3, which is made of multiple sub-wires 31 spirally wound together.
[0026] In one specific embodiment, the cable welding wire 3 is formed by spirally winding three identical and relatively thin solid welding wires 3 (e.g., solid welding wire 3 of model ER50-6) as sub-wires 31. The overall outer diameter of the wound cable welding wire 3 is controlled between 1.6mm and 2.0mm. During the welding process, the cable welding wire 3 is wound into a disc and packaged, installed on the wire feeder of the welding carriage, and moves upward with the carriage.
[0027] Under the same total outer diameter conditions, the cable-type welding wire 3, which is made of multiple thin wires 31, has less bending stiffness than a single solid core welding wire 3, making the welding wire 3 easier to bend and deform. It can be wound into a smaller disc-shaped package, which is convenient for carrying, installation and transfer at vertical welding sites such as shipbuilding. The cable-type welding wire 3 has good flexibility, and its overall outer diameter can be made larger than that of ordinary welding wire 3, thereby allowing the use of a larger welding current and significantly improving the deposition efficiency. Meanwhile, due to the gap between the sub-wires 31, the arc diameter generated during welding is larger, and the arc heating width is also increased, which increases the weld width and effectively ensures the temperature gradient balance of the vertical butt gap 11 between thick steel plates, avoiding defects of incomplete fusion. The arc of the cable welding wire 3 will generate rotational motion as the welding wire 3 is continuously fed. The rotating arc has a physical stirring effect on the weld pool 13, which can promote the internal structure and temperature distribution of the weld pool to tend to be highly uniform. The rotating arc makes the heat more dispersed, the heating range is wide, and the temperature in the central area is relatively low, which reduces the burning loss of alloying elements, makes the weld grains after crystallization finer, and improves the quality and mechanical properties of the weld.
[0028] Preferably, in S3, at least two independent AC power supplies are used to drive the arc of at least two welding wires 3 in a one-to-one correspondence.
[0029] In one specific embodiment, S3 is implemented as follows: two independent AC submerged arc welding power supplies are configured, each connected to one of the two welding wires 3. The specific process parameters are configured as follows: the welding current of one welding wire 3 (near the water-cooled slider 22) is set to 450A-500A, and the welding voltage is set to 36V-41V; the welding current of the other welding wire 3 (near the backing 21) is set to 350A-400A, and the welding voltage is set to 31V-35V. The phase or frequency of the two AC currents is coordinated by the power supply system to ensure that the two arcs remain dynamically stable within the narrow welding cavity 12 during vertical welding.
[0030] The side near the water-cooled slider 22 uses a high current (450A-500A) and high voltage (36V-41V) for high heat input, while the side near the liner 21 uses a relatively lower current (350A-400A) and relatively lower voltage (31V-35V). This ensures the stable formation of the weld pool 13 while reducing the thermal shock to the liner 21 and preventing the risk of burning through the liner 21. A high-energy electric arc is positioned near the water-cooled slider 22, which has a forced cooling function. The water-cooled slider 22 absorbs the high heat from the front while rapidly cooling the contact surface metal, forming a robust solidified shell structure, thereby... In the vertical direction, it provides stable mechanical support for the upper welding pool 13, further avoiding the collapse and loss of the molten pool due to excessive volume and gravity in vertical submerged arc welding. In the narrow space of vertical butt welding, if DC power is used, the strong current between the two welding wires 3 will generate severe magnetic blow, causing the arc to swing randomly. In this embodiment, the one-to-one drive of independent AC power supply, supplemented by the system coordination of phase and frequency, makes the magnetic field directions of the two arcs cancel each other out with the AC cycle, ensuring that even inside the space-constrained welding cavity 12, the arc can still maintain directional stability, avoiding incomplete fusion or slag inclusion caused by arc deflection.
[0031] Preferably, the welding flux 4 is a metallic flux, and the mass content of iron in the metallic flux is 26%-34%.
[0032] In one specific embodiment, the iron content in the metal mold flux is preferably 30% by mass, and the composition and mass percentage ratio of the metal mold flux are as follows: Because the internal space of the welding cavity 12 is limited, it cannot accommodate the large amount of welding slag generated by conventional welding. The high proportion of metallic iron powder in the welding flux 4 melts directly into the molten pool under the action of electric arc heat, becoming part of the weld metal. The metal deposition efficiency of the submerged arc vertical welding method is improved compared with the conventional process. Since part of the filler metal is provided by the welding flux 4, the welding speed can be appropriately increased while ensuring that the weld is filled, thereby reducing the heat input per unit length of weld, preventing coarse grains in the heat-affected zone of thick steel plates, and reducing welding deformation. The welding flux 4 not only contains a high proportion of Fe, but also precisely proportions alloying elements such as Ni, Ti, V, and Mo. During the submerged arc welding reaction, the alloying elements enter the weld pool 13 through the alloying effect, which plays a role in refining grains and improving regional segregation. Alloying elements such as Ti and V can act as non-spontaneous nuclei to promote the formation of acicular ferrite, thereby improving the comprehensive mechanical properties of the weld metal.
[0033] Preferably, such as Figure 1 , 6As shown, the forming component 2 includes a pad 21 fixed to one side of the vertical docking gap 11, and a water-cooled slider 22 located on the other side of the vertical docking gap 11 and moving upward synchronously with the welding wire 3. In step S1, the liner 21 is placed at one side opening of the vertical butt joint gap 11, and the water-cooled slider 22 is placed at the other side opening of the vertical butt joint gap 11, so that the liner 21, the water-cooled slider 22 and the opposite side walls of the vertical butt joint gap 11 of the workpiece 1 to be welded together form a welding cavity 12.
[0034] In one specific embodiment, the water-cooled slider 22 is made of copper material with high thermal conductivity, has a circulating cooling water channel 221 inside, and is installed on the lifting mechanism of the welding carriage. Before arc ignition, the water-cooled slider 22 is pressed against the opening on one side of the vertical docking gap 11 by a mechanical pressurizing device, and moves in coordination with the welding torch 51 inside.
[0035] More preferably, such as Figure 6 , 7 As shown, the padding component 21 includes a ceramic pad 211 and a glass fiber cloth 212 disposed on the side of the ceramic pad 211 near the vertical mating gap 11. In S1, the temporary fixing bracket 23 and wedge 24 are used to press and fix the pad 21 to one side opening of the vertical docking gap 11, so that the fiberglass cloth 212 comes into contact with the surface of the workpiece 1 to be welded.
[0036] In one specific embodiment, the ceramic gasket 211 has a cross-section of a smooth groove 2111 for assisting in the formation of one side of the weld. The ceramic gasket 211 is covered with glass fiber cloth 212 with high temperature resistance and good deformation ability on the side near the vertical butt joint gap 11 and at both the upper and lower ends of the ceramic gasket 211.
[0037] The installation process of the pad 21 is as follows: First, at the opening on one side of the vertical butt joint gap 11 of the workpiece 1 to be welded, a number of temporary "door" shaped clips are spot welded to connect the two thick steel plates to be welded. Each temporary clip has a clearance hole 231 in the middle for the pad 21 to pass through. Second, a number of ceramic pads 211 covered with fiberglass cloth 212 are passed through the clearance holes 231 of each temporary clip in sequence, with the side with the smooth groove 2111 facing the vertical butt joint gap 11. The ends of the multiple pads 21 are tightly abutted by the fiberglass cloth 212 in sequence. Finally, a wedge 24 is driven between the temporary clip and the pad 21. The mechanical extrusion force generated by the wedge 24 is transmitted to the fiberglass cloth 212 through the ceramic pad 211, causing it to compress and deform and tightly fill the tiny gap between the pad 21 and the uneven steel plate surface.
[0038] Fiberglass cloth 212 has certain chemical stability at high temperatures. It can not only assist in forming, but also make it easier for the liner 21 to separate from the weld after the weld cools and solidifies. Since the ceramic debris of the fiberglass cloth 212 is not easily stuck to the weld surface, it reduces the amount of cleaning and grinding work after welding and avoids mechanical damage that may be caused by direct pressing on the surface of the workpiece 1 to be welded or the liner 21.
[0039] More preferably, such as Figure 2 As shown, in S2, welding flux 4 is supplied to the welding cavity 12 through the flux discharge pipe 52. The lower end of the flux discharge pipe 52 overlaps the top of the water-cooled slider 22 and is located at the upper end of the welding cavity 12. In S4, during the welding process, the flux is replenished according to the consumption height of the flux 4 in the welding cavity 12 and the contact state with the nozzle of the flux discharge pipe 52.
[0040] Preferably, such as Figure 6 As shown, in S4, at least two welding wires 3 are controlled to periodically reciprocate within the vertical butt joint gap 11 at a preset frequency, preset amplitude, and preset end dwell time, and at least two welding wires 3 move synchronously.
[0041] In one specific embodiment, two welding torches 51 are respectively mounted on the same swing beam 5 via two rotating handles 511. To prevent short-circuit interference between the two independent AC power supplies, insulating gaskets are provided at the connection points between the two welding torches 51 and the swing beam 5, thereby achieving electrical insulation between the welding torches 51 and the beam. By releasing the rotating handles 511, the welding torches 51 can slide along the swing beam 5 to adjust the distance between the two welding torches 51. According to the welding process requirements, the distance between the two torches can be adjusted to be closer to the water-cooled slider 22. The angle between the welding torch 51 and the swing beam 5 is set to 5° to 15° to enhance the penetration force of the arc on the front bevel; the welding torch 51 near the ceramic backing 211 is set to a vertical state, that is, at a 0° angle with the swing beam 5, to stabilize the forming; inside the welding cavity 12, the minimum gap between the welding wire 3 near the ceramic backing 211 and the ceramic backing 211 is maintained at 20mm to 30mm; the minimum gap between the welding wire 3 near the water-cooled slider 22 and the water-cooled slider 22 is maintained at 15mm to 25mm.
[0042] A flux discharge pipe 52 is also fixedly installed on the swing beam 5. The discharge pipe swings synchronously with the beam, and its lower end overlaps the opening at the top of the water-cooled slider 22 to ensure that the flux is accurately replenished into the welding cavity 12. During the welding process in step S4, the swing beam 5, which integrates two welding guns 51 and flux discharge pipe 52, swings periodically back and forth under the drive mechanism and moves upward at a constant speed with the welding carriage.
[0043] Preferably, before S3, a gas-shielded welding is used to weld a bottom sealing weld at the bottom of the vertical butt joint gap 11, and the welding slag on the surface of the bottom sealing weld is removed. In S3, when the arc is started, the lower end of the welding wire 3 is controlled to contact the top surface of the bottom sealing weld, and the welding flux 4 covers the top surface of the bottom sealing weld.
[0044] Preferably, after S4, the welding power supply is turned off first, and then the welding wire 3 and the water-cooled slider 22 are controlled to move upward by 30mm-50mm.
[0045] In vertical submerged arc welding, the weld pool 13 is large and has concentrated heat. If the filler wire remains stationary after the power is turned off, the weld pool 13 cools and solidifies rapidly, and the end of the welding wire 3 is easily stuck inside the solidified weld. By moving it upwards by 30mm-50mm, it can be ensured that the end of the welding wire 3 is removed from the weld pool 13 area in time before the liquid metal completely loses its fluidity, thus preventing equipment damage and subsequent cleaning problems caused by the welding wire 3 sticking to the weld.
[0046] In summary, this invention provides a submerged arc vertical welding method. A forming component 2 is installed at the vertical butt joint gap 11 of the workpiece 1 to be welded, forming a welding cavity 12. This achieves circumferential coverage and constraint of the high-temperature weld pool 13, slag, and solid welding flux 4, solving problems such as dripping, flux collapse, and forming failure caused by gravity during vertical submerged arc welding. Controlling at least two welding wires 3 to reciprocate within the vertical butt joint gap 11 achieves uniform distribution of welding heat within the wide weld gap of a thick steel plate, and also stirs the weld pool 13, reducing the temperature gradient between the center and edge of the pool, mitigating regional segregation during metal crystallization, thereby refining the weld grains and ensuring excellent mechanical properties of the weld. Controlling at least two welding wires 3 and at least a portion of the forming component 2 to move synchronously upwards along the vertical butt joint gap 11 achieves automation and continuity of the vertical submerged arc welding process, improving the welding efficiency of vertical butt joints of thick steel plates.
[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.
Claims
1. A submerged arc vertical welding method, characterized in that, Includes the following steps: S1. A forming component (2) is installed at the vertical butt gap (11) of the workpiece (1) to be welded, and the forming component (2) and the vertical butt gap (11) together form a welding cavity (12). S2. Insert at least two welding wires (3) into the welding cavity (12) and deliver welding flux (4) into the welding cavity (12). S3. Control at least two of the welding wires (3) to ignite under the coverage of the welding flux (4) to jointly establish a weld pool (13). S4. Control at least two of the welding wires (3) to swing within the vertical butt gap (11), and control at least two of the welding wires (3) and at least a portion of the forming component (2) to move upward synchronously along the vertical butt gap (11) so that the weld pool (13) solidifies and the welding is completed.
2. The submerged arc vertical welding method according to claim 1, characterized in that, The welding wire (3) is a cable welding wire (3), which is made of multiple sub-wires (31) spirally wound together.
3. The submerged arc vertical welding method according to claim 1, characterized in that, In S3, at least two independent AC power supplies are used to drive the arc of at least two of the welding wires (3) to start.
4. The submerged arc vertical welding method according to claim 1, characterized in that, The welding flux (4) is a metallic flux, and the mass content of iron in the metallic flux is 26%-34%.
5. The submerged arc vertical welding method according to claim 1, characterized in that, The forming component (2) includes a pad (21) fixed to one side of the vertical docking gap (11) and a water-cooled slider (22) located on the other side of the vertical docking gap (11) and moving upward synchronously with the welding wire (3). In step S1, the liner (21) is placed at one side opening of the vertical butt gap (11), and the water-cooled slider (22) is placed at the other side opening of the vertical butt gap (11), so that the liner (21), the water-cooled slider (22), and the opposite sidewalls of the vertical butt gap (11) of the workpiece to be welded (1) together form the welding cavity (12).
6. The submerged arc vertical welding method according to claim 5, characterized in that, The padding component (21) includes a ceramic pad (211) and a glass fiber cloth (212) disposed on the side of the ceramic pad (211) near the vertical mating gap (11). In S1, the pad (21) is pressed and fixed to one side opening of the vertical docking gap (11) by using a temporary fixing bracket (23) and a wedge (24), so that the glass fiber cloth (212) comes into contact with the surface of the workpiece (1) to be welded.
7. The submerged arc vertical welding method according to claim 6, characterized in that, In S2, the welding flux (4) is supplied to the welding cavity (12) through the flux discharge pipe (52), the lower end of the flux discharge pipe (52) overlaps the top of the water-cooled slider (22) and is located at the upper end of the welding cavity (12); In S4, during the welding process, the flux is replenished according to the consumption height of the flux (4) in the welding cavity (12) and the contact state with the opening of the flux discharge pipe (52).
8. The submerged arc vertical welding method according to claim 1, characterized in that, In S4, at least two of the welding wires (3) are controlled to periodically reciprocate within the vertical butt joint gap (11) at a preset frequency, preset amplitude and preset end dwell time, and at least two of the welding wires (3) move synchronously.
9. The submerged arc vertical welding method according to claim 1, characterized in that, Before S3, a sealing weld is welded at the bottom of the vertical butt joint gap (11) using gas shielded welding, and the slag on the surface of the sealing weld is removed. In S3, when the arc is started, the lower end of the welding wire (3) is controlled to contact the top surface of the bottom sealing weld, and the welding flux (4) covers the top surface of the bottom sealing weld.
10. The submerged arc vertical welding method according to any one of claims 1-8, characterized in that, After S4, first turn off the welding power supply, and then control the welding wire (3) and the water-cooled slider (22) to move upward by 30mm-50mm.