Gas-electric vertical welding joint method and gas-electric vertical welding gun structure

Abstract

The present application relates to the technical field of gas-electric vertical welding, and discloses a gas-electric vertical welding joint method and a gas-electric vertical welding gun structure. The gas-electric vertical welding joint method comprises the following steps: S1, turning on a gas protection system to supply protective gas to the top of the weld, and turning on a circulating water system to cool the water-cooled sliding block; S2, after the gas protection system and the circulating water system are turned on for a first preset time, turning on a laser emitter to preheat the top of the weld; S3, after the preheating operation is completed, turning off the laser emitter and turning on the welding gun to drive the welding gun to move upwards along the butt joint of the plate at a preset speed. The low-temperature solid weld at the interruption position in the gas-electric vertical welding process is heated to a high-temperature molten state by the laser emitter, and then the arc is restarted for welding, the hot joint method is realized, the re-arc welding area and the weld area before interruption are completely penetrated, full-penetration joint welding is realized, the quality of the weld joint is improved, and welding defects of the weld joint are prevented.

Description

Technical Field

[0001] This invention relates to the field of gas-electric vertical welding technology, and in particular to a gas-electric vertical welding joint method and a gas-electric vertical welding torch structure. Background Technology

[0002] Gas-electric vertical welding is a highly efficient automatic gas-shielded welding method applied to butt joints of steel plates in vertical welding positions. A ceramic backing is installed on the back of the welding groove, and a copper slider that forces the weld to form is located on the front of the welding groove. The copper slider provides the protective gas for the weld pool, and circulating cooling water continuously flows through the copper slider (to cool the high-temperature liquid weld pool and solid weld). This welding method can achieve single-sided single-pass welding and double-sided forming of plate butt joints, with high welding efficiency.

[0003] Welding processes are often interrupted by various unforeseen circumstances (such as sudden power outages, rain, running out of welding wire and needing replacement, accidental burn-through, and malfunctions in welding equipment and control circuits). The initial area where welding resumes after an interruption is the weld joint. Although gas-fired vertical welding is highly efficient, the resulting weld joints are of poor quality and difficult to handle.

[0004] Because gas-electric vertical welding is a single-layer, single-pass welding method, the cross-sectional area of ​​the weld joint is large. The welding arc can only be concentrated in the central area of ​​the weld bevel for heating and welding. Furthermore, the welding arc continuously feeds weld metal into the molten pool during the heating process (this is a gas metal arc welding method). However, the base temperature of the weld metal that has already solidified before the welding process is interrupted, along with the nearby base metal, is low. This leads to poor fusion defects in the transition zone of the weld joint. There are defects such as incomplete fusion and slag inclusions (from the metallurgical reaction of the flux-cored wire) between the new weld metal and the weld metal before the welding process is interrupted. These defects are particularly severe in the areas before and after the weld (from the root of the bevel to the face) and on both sides of the weld (the contact point between the weld and the weld bevel). The weld joint cannot achieve full penetration across the entire cross-section. Therefore, after the entire weld is completed, all joints of the weld need to be reworked. Rework of weld joints involves many steps, a long cycle, and high costs. The noise and harmful fumes generated during rework pose significant hazards to the environment and the health of operators.

[0005] Therefore, there is an urgent need for a gas-electric vertical welding joint method and a gas-electric vertical welding torch structure to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a gas-electric vertical welding joint method and a gas-electric vertical welding torch structure, so that the re-arc welding area and the weld area before the interruption are completely melted through, realizing full-penetration joint welding and improving the quality of the weld joint.

[0007] To achieve this objective, the present invention adopts the following technical solution: A method for gas-electric vertical welding joint includes the following steps: S1. Turn on the gas protection system to supply protective gas to the top of the weld and turn on the circulating water system to cool the water-cooled slider. S2. After the gas protection system and circulating water system have been activated for the first preset time, the laser emitter is activated to preheat the top of the weld. S3. After the preheating operation is completed, turn off the laser emitter, turn on the welding torch, and drive the welding torch to move upward along the butt joint of the plate at the preset speed.

[0008] As an improvement to the above technical solution, the preheating operation includes: determining whether the thickness of the plate to be welded is greater than a first preset thickness; if the thickness of the plate to be welded is not greater than the first preset thickness, driving the laser emitter to heat the center of the top of the weld; if the thickness of the plate to be welded is greater than the first preset thickness, controlling the laser emitter to heat the top of the weld and causing the heating area to move back and forth along a preset trajectory.

[0009] As an improvement to the above technical solution, the preheating operation further includes: determining the expected preheating time based on the thickness of the plate to be welded, and controlling the laser emitter to continuously heat the top of the weld for the expected preheating time.

[0010] As an improvement to the above technical solution, the expected preheating time increases with the increase of the thickness of the plate to be welded.

[0011] A gas-electric vertical welding torch structure for use in any of the gas-electric vertical welding joint methods described above includes a welding torch and a laser emitter, wherein the laser emitter is connected to the welding torch and is movable with the welding torch.

[0012] As an improvement to the above technical solution, the gas-electric vertical welding torch structure also includes a fixed base, which is connected to the welding torch, and the laser emitter is connected to the fixed base.

[0013] As an improvement to the above technical solution, the gas-electric vertical welding torch structure further includes a cover plate and a rotary drive component. The rotary drive component is disposed on the fixed base, and the cover plate is connected to the rotary drive component. The rotary drive component can drive the cover plate to swing, so that the cover plate can swing between a first working position and a second working position. When the cover plate is in the first working position, the cover plate blocks the emission port of the laser emitter. When the cover plate is in the second position, the emission port of the laser emitter is exposed on the cover plate.

[0014] As an improvement to the above technical solution, the gas-electric vertical welding torch structure further includes a rotating shaft and a support base. The support base is fixedly installed on the side wall of the laser emitter. The rotating shaft is rotatably connected to the support base, and one end of the rotating shaft is connected to the rotating drive component, while the other end is connected to the cover plate.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The gas-electric vertical welding joint method of the present invention involves heating the low-temperature solid weld metal at the interrupted welding position to a high-temperature molten state using a laser emitter under the protection of shielding gas and a cooling slider, before restarting the arc welding. This process only involves heating; no welding wire is fed. Then, the laser system is electrically shut down, and the gas-electric vertical welding system is simultaneously restarted for arc welding. By heating the low-temperature solid weld at the interrupted position to a high-temperature molten state using a laser emitter before restarting the arc welding, a hot joint method is achieved. This ensures complete fusion between the restarted arc welding area and the weld area before the interruption, resulting in a full-penetration joint weld. This improves the quality of the weld joint, prevents welding defects, avoids complex subsequent rework, increases construction efficiency, and saves construction costs. Attached Figure Description

[0016] Figure 1 This is a top view of a portion of the structure during gas-electric vertical welding provided in an embodiment of the present invention; Figure 2 This is a schematic diagram (partial cross-section) of the laser emitter starting to heat the top of the weld in the gas-electric vertical welding joint method provided in the embodiment of the present invention. Figure 3 This is a schematic diagram (partial cross-section) of the laser emitter heating the top of the weld for a period of time in the gas-electric vertical welding joint method provided in the embodiment of the present invention. Figure 4 This is a schematic diagram (partial cross-section) of the welding torch starting when the laser emitter heats the top of the weld after the welding torch has finished heating the weld seam in the gas-electric vertical welding joint method provided in the embodiment of the present invention. Figure 5 This is a schematic diagram (partial cross-section) of the weld seam after the laser emitter heats the top of the weld seam and the welding torch has been used for a period of time in the gas-electric vertical welding joint method provided in the embodiment of the present invention. Figure 6 The weld joint is formed by the gas-electric vertical welding method provided in the embodiments of the present invention.

[0017] In the picture: 1. Welding torch; 2. Laser emitter; 3. Mounting base; 4. Cover plate; 5. Rotary drive component; 6. Rotary shaft; 7. Support base; 10. Welding wire; 20. Water-cooled slider; 30. Carbon dioxide gas chamber; 40. Ceramic gasket; 100, First steel plate; 200, Second steel plate; 300, First solid weld; 400, Joint transition weld; 500, Second solid weld. 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, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0022] Gas-electric vertical welding is a highly efficient automatic gas-shielded welding method applied to butt joints of steel plates in vertical welding positions. A ceramic backing 40 is installed on the back of the welding groove, and a copper slider that forces the weld to form is on the front of the welding groove. The copper slider provides the protective gas for the weld pool, and circulating cooling water continuously flows through the inside of the copper slider (to cool the high-temperature liquid weld pool and solid weld). This welding method can achieve single-sided single-pass welding and double-sided forming of plate butt joints, with high welding efficiency.

[0023] Although gas-fired vertical welding has high welding efficiency, the weld joints produced during the welding process are of poor quality and difficult to handle. During the welding process, there are often a variety of uncontrollable reasons (such as sudden power outages, rain, the need to replace the welding wire when it runs out, accidental burn-through, welding equipment and control circuit failures, etc.) that cause the welding process to be interrupted. The area where the welding process is interrupted and then restarted is the area (i.e., the weld joint). When gas-electric vertical welding is interrupted, the crater area at the extinguished arc position loses the continuous heating of the welding arc. Under the combined cooling conditions of the steel plate and the cooling copper slider, it will rapidly cool down to near atmospheric temperature. When the conditions for re-ignition of the arc are met, the diameter of the welding arc is small, and it can only heat a local area of ​​the weld joint (concentrated in the central area) and cannot reach the edge area between the weld and the base material. However, the cross-sectional area of ​​the weld joint is large, and the molten liquid metal pool will flow to the periphery of the welding arc under the action of gravity. At this time, the temperature of the area far away from the welding arc is still relatively low, and the newly molten liquid metal pool cannot completely melt into the edge area of ​​the original welding crater (as the welding process continues, this area forms an incomplete penetration defect).

[0024] Because gas-electric vertical welding is a single-layer, single-pass welding method, the cross-sectional area of ​​the weld joint is large. The welding arc can only be concentrated in the middle area of ​​the welding groove for heating and welding. The welding arc continuously feeds weld metal to the weld pool during the heating process (this is the gas metal arc welding method). However, the base temperature of the weld metal that has solidified before the welding process is interrupted and the nearby base metal is low, which leads to poor fusion defects in the transition area of ​​the weld joint. There are defects of incomplete fusion and slag inclusions (from the welding metallurgical reaction of flux-cored wire 10) between the new weld metal and the weld metal before the welding process is interrupted. The defects are particularly serious in the areas before and after the weld (from the root of the groove to the face) and on both sides of the weld (the contact position between the weld and the welding groove). The weld joint cannot achieve full penetration of the entire cross-section. After the entire weld is completed, all joints of the weld need to be reworked. First, carbon arc gouging is used to completely gouge one side (root or face) of each joint area to 2 / 3 of the steel plate thickness, thoroughly removing any existing welding defects. Then, a grinder is used to thoroughly grind the gouged area to a metallic luster. Next, manual shielded metal arc welding or manual CO2 gas semi-automatic welding is used to repair the gouged and ground area using multi-layer, multi-pass welding. After repair, a grinder is used to grind the weld surface of the repaired area until it matches the shape of the adjacent unrepaired weld surface. After the first side is repaired, a similar method is used to goug, grind, weld, and grind the other side of the weld joint (the second side). The gouging depth of the second side is ≥1 / 3 of the steel plate thickness, and all welding defects in the gouged area are thoroughly removed. The entire rework process is multi-step, time-consuming, and costly. Furthermore, the noise and harmful fumes generated during the rework process pose significant hazards to the environment and the health of operators.

[0025] In response to the above problems, such as Figure 1-6 As shown, this embodiment provides a method for gas-electric vertical welding joint, including the following steps: S1. Turn on the gas protection system to supply protective gas to the top of the weld and turn on the circulating water system to cool the water-cooled slider 20. S2. After the gas protection system and circulating water system are activated for the first preset time, the laser emitter 2 is activated to preheat the top of the weld. S3. After the preheating operation is completed, turn off the laser emitter 2 and turn on the welding torch 1. Control the welding torch 1 to move upward along the butt joint of the plate at a preset speed.

[0026] The gas-electric vertical welding joint method provided in this embodiment involves heating the low-temperature solid weld metal at the interrupted welding position to a high-temperature molten state using a laser emitter 2 under the protection of shielding gas and a cooling slider before the welding torch 1 restarts the arc. This process only involves heating; no welding wire 10 is fed. Then, the laser system is electrically shut down, and the gas-electric vertical welding system is simultaneously restarted for arc initiation. By heating the low-temperature solid weld at the interrupted position to a high-temperature molten state using the laser emitter 2 before restarting the arc, a hot joint method is achieved. This ensures complete penetration between the restarted arc welding area and the weld area before the interruption, resulting in a full-penetration joint. This improves the quality of the weld joint, prevents welding defects, avoids complex subsequent rework, increases construction efficiency, and saves construction costs.

[0027] Furthermore, the preheating operation includes: determining whether the thickness of the plate to be welded is greater than a first preset thickness; if the thickness is not greater than the first preset thickness, then driving the laser emitter 2 to heat the center of the weld top; if the thickness is greater than the first preset thickness, then controlling the laser emitter 2 to heat the top of the weld and causing the heating area to move back and forth along a preset trajectory. The heating area here is the laser irradiation area, and moving the heating area back and forth along the preset trajectory is equivalent to moving the laser irradiation area back and forth, ensuring that all areas of the weld top are heated uniformly. The center of the weld top is the middle part of the weld top in both the thickness and width directions. When the thickness of the plate to be welded is small, melting the weld top can be achieved by heating the center area of ​​the weld top with the laser. However, when the thickness of the plate to be welded is large, it is necessary to move the laser heating area back and forth along the preset trajectory to ensure uniform heating of the weld top and improve the melting effect of the weld top. Those skilled in the art will understand that, for gas-electric vertical welding, the welding relies on the continuous feeding of welding wire and the plate to be welded to generate a welding arc that heats the welding wire and the plate to be welded, causing them to melt and then re-solidify to achieve welding. This welding principle determines that only by continuously feeding the welding wire can a stable welding arc be maintained between the welding wire and the plate to be welded; otherwise, the welding arc will be interrupted. Therefore, it is impossible to improve the melting effect of the top of the weld by heating the top of the weld with the welding arc alone without feeding the welding wire.

[0028] Furthermore, the preheating operation also includes: determining the expected preheating time based on the thickness of the plate to be welded, and controlling the laser emitter 2 to continuously heat the top of the weld for the expected preheating time. Determining the expected heating time based on the thickness of the plate to be welded can further improve the melting effect of the preheating operation on the top of the weld. Specifically, in this embodiment, the expected preheating time increases with the increase of the thickness of the plate to be welded.

[0029] like Figure 2As shown, this embodiment also provides a gas-electric vertical welding torch structure for the above-mentioned gas-electric vertical welding joint method, including a welding torch 1 and a laser emitter 2. The laser emitter 2 is connected to the welding torch 1 and can move with the welding torch 1.

[0030] Furthermore, such as Figures 2-5 As shown, the gas-electric vertical welding torch structure also includes a fixed base 3, which is connected to the welding torch 1, and the laser emitter 2 is connected to the fixed base 3. The fixed base 3 connects the laser emitter 2 to the welding torch 1, allowing the laser emitter 2 to move with the welding torch 1.

[0031] Furthermore, such as Figures 2-5 As shown, the gas-electric vertical welding torch structure also includes a cover plate 4 and a rotary drive component 5. The rotary drive component 5 is mounted on the fixed base 3, and the cover plate 4 is connected to the rotary drive component 5. The rotary drive component 5 can drive the cover plate 4 to swing, allowing the cover plate 4 to swing between a first working position and a second working position. When the cover plate 4 is in the first working position, the cover plate 4 blocks the emission port of the laser emitter 2. When the cover plate 4 is in the second position, the emission port of the laser emitter 2 is exposed on the cover plate 4. By setting the cover plate 4 and the rotary drive component 5, when the laser emitter 2 is not needed, the emission port of the laser emitter 2 can be blocked by the cover plate 4, which protects the laser emitter 2 and prevents damage to the laser emitter 2 during normal welding of the welding torch 1. In this embodiment, the cover plate 4 is a metal cover plate, and the rotary drive component 5 is an electrically controlled rotary motor.

[0032] Specifically, such as Figures 2-5 As shown, the gas-electric vertical welding torch structure also includes a rotating shaft 6 and a support base 7. The support base 7 is fixedly mounted on the side wall of the laser emitter 2. The rotating shaft 6 is rotatably connected to the support base 7, and one end of the rotating shaft 6 is connected to the rotating drive component 5, while the other end is connected to the cover plate 4. The rotating shaft 6 is supported by the support base 7 to improve the stability of the movement of the cover plate 4.

[0033] In this embodiment, the protective gas is carbon dioxide. The protective gas is supplied to the carbon dioxide gas chamber 30 through a carbon dioxide supply pipe, and then supplied to the top of the weld seam through the carbon dioxide gas chamber 30. In this embodiment, the plates to be welded are a first steel plate 100 and a second steel plate 200. The butt joint of the plates is formed by the interval between the ends of the first steel plate 100 and the second steel plate 200; the butt joint is also the gap between the first steel plate 100 and the second steel plate 200. During the welding process of the first steel plate 100 and the second steel plate 200, the rear of the welding area of ​​the butt joint is shielded by a ceramic gasket 40, and the front is shielded by a water-cooled slider 20.

[0034] like Figure 5 and Figure 6As shown, the weld joint formed by the gas-electric vertical welding method includes a first solid weld 300, a joint transition weld 400, and a second solid weld 500, which are connected sequentially from bottom to top. The joint transition weld 400 is relatively thin, has a uniform thickness, and low slag content, thus requiring no further rework.

[0035] 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 method for gas-electric vertical welding joint, characterized in that, Includes the following steps: S1. Turn on the gas protection system to supply protective gas to the top of the weld and turn on the circulating water system to cool the water-cooled slider (20); S2. After the gas protection system and circulating water system are turned on for the first preset time, the laser emitter (2) is turned on to preheat the top of the weld. S3. After the preheating operation is completed, turn off the laser emitter (2) and turn on the welding gun (1). Control the welding gun (1) to move upward along the butt joint of the plate at a preset speed. The preheating operation includes: determining whether the thickness of the plate to be welded is greater than the first preset thickness; if the thickness of the plate to be welded is not greater than the first preset thickness, driving the laser emitter (2) to heat the center of the top of the weld; if the thickness of the plate to be welded is greater than the first preset thickness, controlling the laser emitter (2) to heat the top of the weld and causing the heating area to move back and forth along a preset trajectory. The preheating operation also includes: determining the expected preheating time based on the thickness of the plate to be welded, and controlling the laser emitter (2) to continuously heat the top of the weld for the expected preheating time; When the gas-electric vertical welding process is interrupted, before the welding torch (1) restarts the arc welding, under the protection of the shielding gas and the cooling slider, the laser emitter (2) heats the low-temperature solid weld metal at the arc-extinguishing position to a high-temperature melting state. This heating process only heats the metal and does not feed the welding wire (10). Then, the laser system is shut down by electric control, and the gas-electric vertical welding system is started to start the arc welding. The low-temperature solid weld at the interrupted position of the gas-electric vertical welding process is heated to a high-temperature melting state by the laser emitter (2) and then the arc welding is started again to realize the hot joint method, so that the area where the arc is restarted is completely melted into the weld area before the interruption, and the full penetration joint welding is realized.

2. The gas-electric vertical welding joint method according to claim 1, characterized in that, The expected preheating time increases with the increase of the thickness of the plate to be welded.

3. A gas-electric vertical welding torch structure, characterized in that, The gas-electric vertical welding joint method according to any one of claims 1-2 includes a welding torch (1) and a laser emitter (2), wherein the laser emitter (2) is connected to the welding torch (1) and is movable with the welding torch (1).

4. The gas-electric vertical welding torch structure according to claim 3, characterized in that, The gas-electric vertical welding torch structure also includes a fixed base (3), which is connected to the welding torch (1), and the laser emitter (2) is connected to the fixed base (3).

5. The gas-electric vertical welding torch structure according to claim 4, characterized in that, The gas-electric vertical welding torch structure also includes a cover plate (4) and a rotary drive (5). The rotary drive (5) is disposed on the fixed base (3). The cover plate (4) is connected to the rotary drive (5). The rotary drive (5) can drive the cover plate (4) to swing so that the cover plate (4) can swing between a first working position and a second working position. When the cover plate (4) is in the first working position, the cover plate (4) blocks the emission port of the laser emitter (2). When the cover plate (4) is in the second position, the emission port of the laser emitter (2) is exposed on the cover plate (4).

6. The gas-electric vertical welding torch structure according to claim 5, characterized in that, The gas-electric vertical welding torch structure also includes a rotating shaft (6) and a support base (7). The support base (7) is fixedly installed on the side wall of the laser emitter (2). The rotating shaft (6) is rotatably connected to the support base (7), and one end of the rotating shaft (6) is connected to the rotating drive component (5) for transmission, and the other end is connected to the cover plate (4).

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