Galvanometer laser-indirect arc hybrid welding method and device

Abstract

The invention discloses a galvanometer laser-indirect electric arc hybrid welding method and device.According to the welding method, an electrode clamp in traditional galvanometer laser-electric arc hybrid welding is transferred to a welding wire from a workpiece, an indirect electric arc is formed between an electrode and the additionally-arranged welding wire, and most heat is concentrated on the welding wire; the heat input of the workpiece and the size of a heat affected zone are reduced, and high deposition and low heat input are achieved. The electric arc energy density is improved through the compression effect of galvanometer laser on the electric arc, the stirring effect of a molten pool is promoted, the welding process with little splashing, stable transition and good forming can be achieved, the reduction of a heat affected zone of a workpiece is facilitated, the problems of easy generation of hot cracks, grain coarsening and phase change embrittlement of a material are solved, and the number of air holes is reduced.

Description

Technical Field

[0001] This invention relates to a galvanometer laser-arc hybrid welding method and apparatus, specifically to a galvanometer laser-indirect arc hybrid welding method and apparatus. Background Technology

[0002] With the development of high-end equipment manufacturing towards larger scale and higher parameters, the application of high-performance thick plate metal materials is becoming increasingly widespread, especially in fields such as nuclear power pressure vessels, ship keels, and heavy bridges. The core challenge in thick plate welding lies in the fact that traditional arc welding requires high-current welding or low-current multi-layer, multi-pass welding, resulting in high heat input, leading to workpiece deformation and a significant increase in residual stress. Subsequent straightening costs can reach 30% of the total cost. Using a single GTAW (Gas Tungsten Arc Weld) or GMAW (Gas Metal Arc Welding) method results in low deposition rates, low efficiency when welding thick plates, and rapid cooling of the weld seam, making the heat-affected zone prone to coarse-grain embrittlement and hydrogen-induced cracking. Furthermore, traditional preheating and post-heating processes are energy-intensive and have poor precision.

[0003] To balance welding efficiency and quality, galvanometer-laser-arc hybrid welding is widely used. The addition of a galvanometer stirs the molten pool, effectively reducing the number of defects in the weld. However, it still has the following shortcomings:

[0004] In traditional galvanometer laser-arc hybrid welding, the positive electrode of the power supply is connected to the workpiece, and the energy coupling depends on the stability of the molten pool. In thick plate welding, arc drift and spatter are easily aggravated due to molten pool turbulence. Moreover, the workpiece, as the positive electrode, bears more than 70% of the arc heat, resulting in high heat input, making it difficult to achieve the synergy of "high deposition - low heat input". At the same time, the welding wire is only used as filler material, and its melting depends on arc radiation or heat conduction in the molten pool, which is inefficient. Summary of the Invention

[0005] Purpose of the invention: The first purpose of the invention is to provide a galvanometer laser-indirect arc hybrid welding method to improve the instability and spatter problems, as well as the problems of high heat input and low deposition rate in the welding process of thick plates; the second purpose of the invention is to provide a galvanometer laser-indirect arc hybrid welding device.

[0006] Technical Solution: The present invention provides a galvanometer laser-indirect arc hybrid welding method, which combines galvanometer laser welding with arc welding, wherein the arc welding adopts GTAW or GMAW; when the arc welding adopts GTAW, the electrode in the welding torch is connected to the negative terminal of the power supply, and the welding wire in the wire feeding mechanism is connected to the positive terminal of the power supply; when the arc welding adopts GMAW, the electrode in the welding torch is connected to the positive terminal of the power supply, and the welding wire in the wire feeding mechanism is connected to the negative terminal of the power supply; an indirect arc is formed between the electrode and the welding wire.

[0007] Furthermore, the galvanometer laser is either a continuous galvanometer laser or a pulsed galvanometer laser.

[0008] Furthermore, the aforementioned galvanometer laser-indirect arc hybrid welding method includes:

[0009] After beveling the thick plate and cleaning it before welding, fix it on the workbench.

[0010] Adjust the placement and tilt angle of the GTAW or GMAW welding torch; adjust the arc welding parameters of the GTAW or GMAW, including current type, welding current, arc voltage, welding speed, shielding gas flow rate, and electrode extension length; adjust the galvanometer laser parameters, including laser power, scanning path, scanning frequency, and scanning amplitude; adjust the wire feeding rate and welding wire angle of the wire feeding mechanism; adjust the galvanometer to be horizontal with the worktable, and adjust the distance between the galvanometer and the thick plate, the GTAW or GMAW welding torch, and the welding wire;

[0011] A high-speed camera is used to capture images of the weld pool and display them in the control system. Welding parameters are then manually adjusted based on the condition of the weld pool.

[0012] Furthermore, the tilt angle between the welding torch and the laser is 20° to 90°, the welding wire is placed at an angle greater than 60° with the vertical direction, the distance between the tip of the welding torch and the thick plate is 1 to 5 mm, the distance between each pair of the laser beam, the tip of the welding torch and the welding wire is 1 to 5 mm, the laser beam, the welding torch and the welding wire are on the same plane, and the welding wire and the welding torch are located on both sides of the laser beam or on the same side of the laser beam.

[0013] Furthermore, when the arc welding is GTAW, the scanning path of the galvanometer is transverse scanning, longitudinal scanning, or circular scanning, the scanning amplitude is 0.5–4 mm, the duty cycle is 20%–60%, and the scanning frequency is 50–300 Hz; the dry extension of the non-consumable electrode ranges from 6 to 20 mm.

[0014] Furthermore, when the arc welding is GMAW, the scanning path of the galvanometer is transverse scanning, longitudinal scanning, or circular scanning, the scanning amplitude is 0.5–4 mm, the duty cycle is 20%–60%, and the scanning frequency is 50–300 Hz; the wire feed speed in the welding torch of the consumable electrode ranges from 1 to 12 m / min, and the wire extension ranges from 6 to 20 mm.

[0015] This invention discloses a galvanometer laser-indirect arc hybrid welding device, comprising a galvanometer, a welding torch, a power supply, a wire feeding mechanism, a programmer, a robotic arm, a laser, a mechanical control device, and an arc welding machine. The galvanometer is mounted at the end of the robotic arm, and the laser is connected to the robotic arm. Simultaneously, the laser, galvanometer, and robotic arm are each connected to the programmer. The programmer can control the robotic arm to adjust the position and orientation of the galvanometer, and to adjust the parameters of the laser and galvanometer. The welding torch is mounted on the mechanical control device, and the mechanical control device and the arc welding machine are each connected to a welding machine controller. The welding machine controller can control the mechanical control device to adjust the tilt angle and height of the welding torch, and to adjust the arc welding parameters. The external wire feeding mechanism is controlled separately by an independent wire feeding controller. The electrode in the welding torch is connected to the negative terminal of the power supply, and the welding wire in the external wire feeding mechanism is connected to the positive terminal of the power supply; alternatively, the electrode in the welding torch is connected to the positive terminal of the power supply, and the welding wire in the external wire feeding mechanism is connected to the negative terminal of the power supply.

[0016] Furthermore, the aforementioned galvanometer laser-indirect arc hybrid welding system also includes a xenon lamp, a high-speed camera, and a control system. The xenon lamp, in conjunction with the high-speed camera, captures real-time images of the weld pool and displays them on the control system, providing a basis for manually adjusting welding parameters.

[0017] Furthermore, the arc welding machine is connected to a gas cylinder. When galvanometer laser and GTAW are combined, if MIG is used, an inert gas is used as the shielding gas. If MAG is used, a certain amount of active gas is added to the inert gas, and the mixed gas is used as the shielding gas. When galvanometer laser and GMAW are combined, an inert gas or a mixed gas is used as the shielding gas.

[0018] Furthermore, there are multiple external wire feeding mechanisms, which are connected by optical fibers and controlled by the same wire feeding controller. Different parameters can be set for different external wire feeding mechanisms during adjustment.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0020] (1) This invention transfers the electrode clamp from the workpiece to the welding wire in traditional galvanometer laser-arc hybrid welding, forming an indirect arc between the electrode and the welding wire. The workpiece no longer directly bears the arc heat, reducing the welding heat input. The welding wire is no longer just a filler material; it acts as the core heat-generating body, directly subjected to the arc heat, achieving active melting of the welding wire and improving the welding wire melting efficiency. This invention can significantly improve deposition efficiency. After converting the arc energy from the workpiece to the welding wire, the heat input is reconstructed (most of the heat is concentrated on the welding wire, reducing the heat input to the workpiece and the size of the heat-affected zone), fundamentally reducing the heat impact on the base material and achieving the effect of "high deposition, low heat input".

[0021] (2) The laser-induced arc is induced by the galvanometer. The plasma and high-temperature metal vapor generated by the laser provide a low-resistance conductive channel for the arc, which can attract, guide and compress the arc, promote the increase of arc energy density, and under the action of the galvanometer, it can also play the role of dynamically stirring the molten pool, so that the arc is stable and does not drift during the welding process, stabilizes the welding process, improves the problems of spatter and smoke, reduces defects in the post-weld structure, and makes the weld structure more excellent.

[0022] (3) Galvanometer lasers have high energy density and a concentrated action area, which is beneficial for deep penetration welding; indirect arc lasers have relatively low energy density and a wider action area, which allows for more extensive heat input and effectively reduces the problems of grain coarsening and phase transformation strengthening caused by excessively fast cooling rates in deep penetration welding. The synergistic effect of the two can produce continuous or periodic stable coupling, making energy transmission more efficient and the behavior of the molten pool more stable. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a galvanometer laser-indirect arc hybrid welding device provided in an embodiment of the present invention. Detailed Implementation

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] 1. Galvanometer; 2. Welding wire; 3. Welding torch; 4. Xenon lamp; 5. Gas cylinder; 6. Power supply; 7. Wire feeding mechanism; 8. Programmer; 9. Robotic arm; 10. Control system; 11. High-speed camera.

[0026] Example 1

[0027] like Figure 1 As shown, Embodiment 1 provides a galvanometer laser-indirect arc hybrid welding device, including a galvanometer 1, a welding torch 3, a xenon lamp 4, a gas cylinder 5, a power supply 6, a wire feeding mechanism 7, a programmer 8, a robotic arm 9, a control system 10, a high-speed camera 11, a laser, a mechanical control device, and an arc welding machine, wherein the laser, the mechanical control device, and the arc welding machine are not shown in the figure.

[0028] A galvanometer 1 is mounted at the end of a robotic arm 9. The laser is connected to the robotic arm 9 via an optical fiber. The laser, galvanometer 1, and robotic arm 9 are all connected to a programmer 8. The programmer 8 can control the robotic arm 9 to adjust the position and orientation of the galvanometer 1, as well as the parameters of the laser and galvanometer 1.

[0029] The welding torch 3 is mounted on a mechanical control device, which, along with the arc welding machine, is connected to the welding machine controller. The welding machine controller can control the mechanical control device to adjust the tilt angle and height of the welding torch 3 (the distance between it and the thick plate), as well as adjust the arc welding parameters (such as the type of current, the magnitude of the current and voltage).

[0030] The additional wire feeding mechanism 7 is controlled separately by an independent wire feeding controller.

[0031] When the galvanometer laser and GTAW are combined, the electrode in the welding torch 3 is connected to the negative terminal of the power supply 6, and the welding wire 2 in the external wire feeding mechanism 7 is connected to the positive terminal of the power supply 6 through the wire feeding tube-conductive clamp-conductive rod. There can be more than one external wire feeding mechanism 7. The external wire feeding mechanisms 7 are connected by optical fibers and controlled by the same wire feeding controller. Different parameters can be set for different external wire feeding mechanisms 7 during adjustment.

[0032] When the galvanometer laser is combined with GMAW, the electrode in the welding torch 3 is connected to the positive terminal of the power supply 6, and the welding wire 2 in the external wire feeding mechanism 7 is connected to the negative terminal of the power supply 6 through the wire feeding tube-conductive clamp-conductive rod (for GMAW welding, the welding torch 3 already contains welding wire, which is connected to the positive terminal, so the external welding wire 2 is connected to the negative terminal). Similarly, there can be more than one external wire feeding mechanism 7.

[0033] The control system 10 uses a computer, a xenon lamp 4, and a high-speed camera 11 to capture the welding pool in real time and display it on the control system 10, providing a basis for manually adjusting the arc welding parameters.

[0034] Gas cylinder 5 is connected to the arc welding machine, and the shielding gas is delivered to the welding area. The specific shielding gas used depends on the situation. When galvanometer laser and GTAW are combined, if MIG is used, an inert gas (pure argon) is used as the shielding gas. If MAG is used, a certain amount of active gas is added to the inert gas, and the mixed gas is used as the shielding gas. When galvanometer laser and GMAW are combined, the shielding gas can be either an active gas or an inert gas, so the shielding gas can be either pure argon or a mixed gas.

[0035] In some embodiments, the galvanometer 1 and the laser can be operated manually instead of by the robotic arm 9, i.e., by using a handheld laser for welding. During welding, the welding speed, the tilt angle of the welding wire, and the distance from the thick plate are manually controlled. The angle between the welding galvanometer laser and the tungsten electrode can be kept fixed, the distance between the tungsten electrode and the welding wire is maintained at 1-5 mm, and the welding wire should maintain an angle greater than 60° with the vertical direction.

[0036] Example 2

[0037] Example 2 provides a galvanometer laser-indirect arc hybrid welding method, which combines galvanometer laser with arc welding. The arc welding uses GTAW or GMAW, and the galvanometer laser uses continuous galvanometer laser or pulsed galvanometer laser.

[0038] When GTAW is used for arc welding, the electrode in the welding torch 3 is connected to the negative terminal of the power supply 6, and the welding wire 2 in the wire feeding mechanism 7 is connected to the positive terminal of the power supply 6; when GMAW is used for arc welding, the electrode in the welding torch 3 is connected to the positive terminal of the power supply 6, and the welding wire 2 in the wire feeding mechanism 7 is connected to the negative terminal of the power supply 6; an indirect arc is formed between the electrode and the welding wire 2.

[0039] The operational steps of the galvanometer laser-indirect arc hybrid welding method include:

[0040] S1. After beveling the thick plate and cleaning it before welding, fix it on the workbench; the cleaning process includes grinding to remove rust and wiping with alcohol.

[0041] S2. Adjust the placement and tilt angle of the GTAW or GMAW welding torch; adjust the arc welding parameters of the GTAW or GMAW, including current type, welding current, arc voltage, welding speed, shielding gas flow rate, and electrode extension length; adjust the galvanometer laser parameters, including laser power, scanning path, scanning frequency, and scanning amplitude; adjust the wire feeding rate of the wire feeding mechanism and the angle of the welding wire; adjust the galvanometer to be horizontal with the worktable, and adjust the distance between the galvanometer and the thick plate, the GTAW or GMAW welding torch, and the welding wire;

[0042] Specifically, the protective gas flow rate is configured to be 10–30 L / min.

[0043] The angle between the welding torch and the laser is 20° to 90°. The angle between the welding wire and the vertical direction is greater than 60°. The distance between the tip of the welding torch and the thick plate is 1 to 5 mm. The distance between each pair of the laser beam, the tip of the welding torch, and the welding wire is 1 to 5 mm. The laser beam, the welding torch, and the welding wire are all on the same plane. The welding wire and the welding torch are located on both sides of the laser beam or on the same side of the laser beam.

[0044] When the arc welding is GTAW, the scanning path of the galvanometer is transverse scanning, longitudinal scanning or circular scanning, the scanning amplitude is 0.5 to 4 mm, the duty cycle is 20% to 60%, and the scanning frequency is 50 to 300 Hz; the laser can be a continuous laser or a pulsed laser, and the dry extension of the non-consumable electrode is 6 to 20 mm.

[0045] When the arc welding is GMAW, the scanning path of the galvanometer is transverse scanning, longitudinal scanning or circular scanning, the scanning amplitude is 0.5 to 4 mm, the duty cycle is 20% to 60%, and the scanning frequency is 50 to 300 Hz; the laser can be a continuous laser or a pulsed laser, the wire feed speed in the welding torch of the consumable electrode is 1 to 12 m / min, and the wire extension is 6 to 20 mm.

[0046] S3. Use a high-speed camera to photograph the weld pool and display it in the control system. Manually adjust the welding parameters according to the weld pool condition.

[0047] Here is a specific example.

[0048] This example combines galvanometer pulsed laser welding with TIG welding, controlled by a robotic arm. The material is a 4mm thick 2205 duplex stainless steel plate. A 1.2mm diameter ER2209 solid welding wire is connected to the positive terminal of the power supply, while the tungsten electrode is connected to the negative terminal.

[0049] S1. Make a Y-shaped bevel on the stainless steel plate with a blunt edge height of 1mm, a bevel depth of 3mm, and a bevel angle of 20°. Wipe the stainless steel plate with alcohol to clean the surface after beveling. Fix a 4mm thick 2205 duplex stainless steel plate on the workbench, and then connect the positive terminal of the power supply to the welding wire and the negative terminal of the power supply to the tungsten electrode.

[0050] S2. Adjust the tungsten electrode to form a 45° angle with the worktable;

[0051] The TIG welding current is set to 200A, the voltage to 10V, the welding speed to 8mm / s, and the shielding gas flow rate to 15L / min.

[0052] The galvanometer is set to circular scanning with a scanning amplitude of 2mm, a scanning frequency of 200Hz, a duty cycle of 40%, and a laser power of 2500W.

[0053] The welding wire is set to be at a 25° angle with the worktable by the wire feeding mechanism, and the wire feeding speed is 15 mm / s.

[0054] Adjust the galvanometer laser light source to be perpendicular to the worktable, ensuring that the distance between the welding wire and the tungsten electrode is 2-3 mm, and the distance between the welding wire, the tungsten electrode and the workpiece is 2-3 mm.

[0055] S3. A high-speed camera captures images of the weld pool, which are then displayed on a computer, allowing for real-time adjustment of welding parameters.

[0056] This invention improves upon traditional galvanometer laser-arc hybrid welding by introducing a wire feeding mechanism to fill the weld wire and connecting the power supply directly to the welding wire. The galvanometer laser's compression of the arc increases its energy density and promotes molten pool stirring, resulting in less spatter, a smoother transition, and better weld formation, thus reducing hot cracking, porosity, and coarse grains in the weld. When the positive terminal of the power supply is connected to the welding wire, the wire acts as both filler material and a conductive electrode, with the arc burning directly between the wire and the tungsten electrode. The workpiece does not act as an electrode; its heat primarily comes from the heat carried by molten metal dripping from the wire tip, the radiative and convective heat of the arc, and the direct effect of the laser. By forming an indirect arc between the wire and the tungsten electrode, most of the energy is concentrated on melting the wire, significantly improving deposition efficiency while substantially reducing the heat directly applied to the workpiece, achieving "high deposition, low heat input." Based on this, the stability of the welding process can be improved, the fixed arc between the tungsten electrode and the welding wire is more stable, and with the control of the molten pool by the galvanometer laser, a welding process with less spatter and a stable transition can be achieved, resulting in a weld with excellent shape.

Claims

1. A galvanometer laser-indirect arc hybrid welding method, characterized in that, The galvanometer laser is combined with arc welding, wherein the arc welding adopts GTAW or GMAW; when the arc welding adopts GTAW, the electrode in the welding gun is connected to the negative terminal of the power supply, and the welding wire in the wire feeding mechanism is connected to the positive terminal of the power supply; when the arc welding adopts GMAW, the electrode in the welding gun is connected to the positive terminal of the power supply, and the welding wire in the wire feeding mechanism is connected to the negative terminal of the power supply; an indirect arc is formed between the electrode and the welding wire.

2. The galvanometer laser-indirect arc hybrid welding method according to claim 1, characterized in that, The galvanometer laser is either a continuous galvanometer laser or a pulsed galvanometer laser.

3. The galvanometer laser-indirect arc hybrid welding method according to claim 1 or 2, characterized in that, include: After beveling the thick plate and cleaning it before welding, fix it on the workbench. Adjust the placement and tilt angle of the GTAW or GMAW welding torch; adjust the arc welding parameters of the GTAW or GMAW, including current type, welding current, arc voltage, welding speed, shielding gas flow rate, and electrode extension length; adjust the galvanometer laser parameters, including laser power, scanning path, scanning frequency, and scanning amplitude; adjust the wire feeding rate and welding wire angle of the wire feeding mechanism; adjust the galvanometer to be horizontal with the worktable, and adjust the distance between the galvanometer and the thick plate, the GTAW or GMAW welding torch, and the welding wire; A high-speed camera is used to capture images of the weld pool and display them in the control system. Welding parameters are then manually adjusted based on the condition of the weld pool.

4. The galvanometer laser-indirect arc hybrid welding method according to claim 3, characterized in that, The angle between the welding torch and the laser is 20° to 90°. The angle between the welding wire and the vertical direction is greater than 60°. The distance between the tip of the welding torch and the thick plate is 1 to 5 mm. The distance between each pair of the laser beam, the tip of the welding torch, and the welding wire is 1 to 5 mm. The laser beam, the welding torch, and the welding wire are all on the same plane. The welding wire and the welding torch are located on both sides of the laser beam or on the same side of the laser beam.

5. The galvanometer laser-indirect arc hybrid welding method according to claim 3, characterized in that, When the arc welding is GTAW, the scanning path of the galvanometer is transverse scanning, longitudinal scanning or circular scanning, the scanning amplitude is 0.5 to 4 mm, the duty cycle is 20% to 60%, and the scanning frequency is 50 to 300 Hz; the dry extension of the non-consumable electrode is 6 to 20 mm.

6. The galvanometer laser-indirect arc hybrid welding method according to claim 3, characterized in that, When the arc welding is GMAW, the scanning path of the galvanometer is transverse scanning, longitudinal scanning or circular scanning, the scanning amplitude is 0.5 to 4 mm, the duty cycle is 20% to 60%, and the scanning frequency is 50 to 300 Hz; the wire feed speed in the welding torch of the consumable electrode is 1 to 12 m / min, and the wire extension is 6 to 20 mm.

7. A galvanometer laser-indirect arc hybrid welding device, characterized in that, The system includes a galvanometer, welding torch, power supply, wire feeding mechanism, programmer, robotic arm, laser, mechanical control device, and arc welding machine. The galvanometer is mounted at the end of the robotic arm, and the laser is connected to the robotic arm. The laser, galvanometer, and robotic arm are all connected to the programmer. The programmer controls the robotic arm to adjust the position and orientation of the galvanometer, as well as the parameters of the laser and galvanometer. The welding torch is mounted on the mechanical control device, which is connected to the welding machine controller. The welding machine controller controls the mechanical control device to adjust the tilt angle and height of the welding torch, as well as the arc welding parameters. The external wire feeding mechanism is controlled independently by a separate wire feeding controller. The electrode in the welding torch is connected to the negative terminal of the power supply, and the welding wire in the external wire feeding mechanism is connected to the positive terminal of the power supply; alternatively, the electrode in the welding torch is connected to the positive terminal of the power supply, and the welding wire in the external wire feeding mechanism is connected to the negative terminal of the power supply.

8. The galvanometer laser-indirect arc hybrid welding system according to claim 7, characterized in that, It also includes a xenon lamp, a high-speed camera, and a control system. The xenon lamp, together with the high-speed camera, captures the weld pool in real time and displays it on the control system, providing a basis for manually adjusting welding parameters.

9. The galvanometer laser-indirect arc hybrid welding system according to claim 7, characterized in that, The arc welding machine is connected to a gas cylinder. When galvanometer laser and GTAW are combined, if MIG is used, an inert gas is used as the shielding gas. If MAG is used, a certain amount of active gas is added to the inert gas, and the mixed gas is used as the shielding gas. When galvanometer laser and GMAW are combined, an inert gas or a mixed gas is used as the shielding gas.

10. The galvanometer laser-indirect arc hybrid welding system according to claim 7, characterized in that, There are multiple external wire feeding mechanisms, which are connected by optical fibers and controlled by the same wire feeding controller. Different parameters can be set for different external wire feeding mechanisms during adjustment.

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