Laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire

Abstract

Laser-assisted fused hollow tungsten electrode argon arc coaxial filler wire welding method. The hollow tungsten electrode arc changes the welding current density distribution and arc pressure form by changing the shape of the tungsten electrode, greatly reducing the arc pressure, ensuring good weld formation, and promoting the development of tungsten inert gas shielded welding towards high productivity. However, when a hollow tungsten electrode is used, the current density, temperature, and plasma flow rate on the central axis of the TIG arc are significantly reduced, which leads to poor melting ability of the heat source welding wire and low welding efficiency during the filling welding process. The present invention comprises: a welding wire (1), an insulating layer (2), and a hollow tungsten electrode (3), wherein an insulating layer is fixed in the inner hole of the hollow tungsten electrode, the welding wire passes through the insulating layer, and the insulating layer is a ceramic tube. The present invention is used for laser-assisted fused hollow tungsten electrode argon arc coaxial filler wire welding.

Description

Technical Field

[0001] The invention relates to the technical field of hollow tungsten electrode arc welding with a filler wire, and in particular to a laser-assisted fusible hollow tungsten electrode argon arc coaxial welding method with a filler wire. Background Art

[0002] Arc welding is the earliest welding process in welding production and has been widely used in the fields of automobile, military, aerospace and high-end equipment manufacturing. Tungsten inert gas welding (TIG) has the advantages of mature welding process, simple operation, strong adaptability and low cost. However, this welding method has low heat input, low deposition rate and slow welding speed, which cannot meet the needs of improving welding production efficiency in production. Increasing welding current can greatly improve welding productivity, but the increase in welding current can easily lead to two problems: (1) TIG arc pressure increases sharply, and arc pressure has a great influence on welding quality. Under the action of arc pressure, abnormal welding defects such as melt-through and hump are easily formed. Therefore, reducing the adverse effects of welding arc pressure becomes the key to obtaining high-quality welding; (2) welding heat input increases significantly, especially for heat-sensitive materials. Increased heat input will lead to a significant deterioration of weld structure and performance, and the weld quality will be greatly reduced.

[0003] Compared with traditional tungsten inert gas welding, the hollow tungsten arc changes the welding current density distribution and arc pressure shape by changing the shape of the tungsten electrode, greatly reducing the arc pressure, ensuring good weld formation, and to a large extent promoting the development of tungsten inert gas welding towards high productivity. When the hollow tungsten arc coaxial filler wire welding method is adopted, the asymmetric shortcomings of the traditional TIG off-axis filler wire are also overcome. The welding quality is not affected by the welding direction, the stability of the welding process is improved, and the welding of two-dimensional and three-dimensional complex paths can be easily achieved. However, when a hollow tungsten electrode is used, the current density, temperature, and plasma flow rate on the central axis of the TIG arc are significantly reduced, which leads to poor melting ability of the heat source wire and low deposition efficiency during the filling wire welding process. Summary of the Invention

[0004] The purpose of the present invention is to provide a laser-assisted fused hollow tungsten electrode argon arc coaxial wire welding method to solve the problems of low wire melting speed and low welding deposition efficiency during hollow tungsten electrode arc wire welding.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A laser-assisted fused hollow tungsten electrode argon arc coaxial wire-filling welding method, the method comprising: step 1: before welding, grinding or cleaning the workpiece to be welded, and fixing the ground or cleaned workpiece to be welded; preparing welding wire, an insulating layer, and a hollow tungsten electrode, wherein the insulating layer is fixed in the inner hole of the hollow tungsten electrode, the welding wire passes through the insulating layer, and the insulating layer is a ceramic tube. The welding wire is coaxially filled from the hollow tungsten electrode into the arc, and at the same time, a laser is incident off-axis on the surface of the welding wire, so that the laser heat source and the hollow tungsten electrode arc jointly heat the welding wire;

[0007] The method specifically further includes the following steps:

[0008] Step 2: Adjust the relative position of the welding wire and the axis of the hollow tungsten electrode so that the welding wire passes through the center of the hollow tungsten electrode to form a coaxial filler wire. Adjust the laser paraxial incident angle and the position of the irradiated welding wire surface.

[0009] Step 3: Set the hollow tungsten arc parameters and laser welding parameters;

[0010] Step 4: Turn on the control switch, the hollow tungsten electrode generates an arc, the welding wire passes through the center of the hollow tungsten electrode and is fed into the arc area. At the same time, the paraxial incident laser is incident on the surface of the welding wire. The welding wire is heated and melted by the hollow tungsten electrode arc and laser and transitions to the welding pool to weld the workpiece.

[0011] In the laser-assisted fused hollow tungsten electrode argon arc coaxial wire-filling welding method, the diameter of the welding wire is no larger than the center hole of the hollow tungsten electrode. When the welding wire is fed into the center hole of the hollow tungsten electrode, the welding wire and the inner wall of the tungsten electrode are insulated by an insulating layer.

[0012] In the laser-assisted fused hollow tungsten argon arc coaxial filler wire welding method, the welding heating method of the molten pool is hollow tungsten arc heating, the laser heat source acts on the welding wire, the laser action point on the welding wire is within the hollow tungsten arc area, and the combined heating of the laser and the hollow tungsten arc increases the melting speed of the welding wire.

[0013] The laser-assisted fused hollow tungsten argon arc coaxial wire-filling welding method adopts a laser power of 10 to 6000 W, a CO2 gas laser, a YAG solid-state laser, a semiconductor laser or a fiber laser, and the laser output is a continuous laser or a pulsed laser.

[0014] In the laser-assisted fused hollow tungsten argon arc coaxial wire-filling welding method, the laser spot diameter of the laser is no larger than the welding wire diameter, and the welding wire diameter is 0.8 mm-2.4 mm.

[0015] The laser-assisted fused hollow tungsten argon arc coaxial wire-filling welding method uses a dual-beam laser, the laser power ratio of the dual-beam laser is continuously adjustable, and the beam arrangement is continuously adjustable 360 ​​degrees.

[0016] The laser-assisted fused hollow tungsten electrode argon arc coaxial wire filling welding method is a scanning laser, and the laser scanning path includes "I" shape, "8" shape, circle, polygon, sawtooth shape and sine waveform, etc. Each scanning path has two different beam movement directions: clockwise and counterclockwise.

[0017] Beneficial effects of the present invention:

[0018] 1. Compared with the solid tungsten arc, the hollow tungsten arc used in the present invention has a platform-like pressure and reduced arc pressure, resulting in shallow weld penetration and low dilution rate. Good weld formation can still be achieved under high current conditions.

[0019] 2. The laser energy used in this invention is concentrated, heating a small area, and acting on the surface of the welding wire. This results in high laser energy utilization, effectively increasing the melting rate of the welding wire and enhancing the deposition efficiency of the welding process. The laser energy is primarily used to melt the welding wire, not directly into the molten pool. This does not increase the heat input to the base material, resulting in low heat input to the base material during welding. When the laser melts the welding wire, the generated laser plasma has a certain stabilizing effect on the hollow tungsten arc.

[0020] 3. Compared with conventional tungsten arc welding with filler wire, the welding method adopted by the present invention effectively improves the welding speed and welding deposition efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attachment Figure 1 It is a schematic diagram of the working principle structure of the present invention;

[0022] In the figure: 1. Welding wire; 2. Insulation layer; 3. Hollow tungsten electrode; 4. Arc; 5. Laser. DETAILED DESCRIPTION

[0023] Example 1:

[0024] A laser-assisted fused hollow tungsten electrode argon arc coaxial filler wire welding method is disclosed. The method includes: preparing a welding wire 1, an insulating layer 2, and a hollow tungsten electrode 3. Step 1: Before welding, the workpiece to be welded is polished or cleaned and then secured. Low-alloy steel is used as the cladding base material, with dimensions of 30 mm × 150 mm × 300 mm. A nickel-based alloy ERNiCrFe-7 is used as the filler wire, with a diameter of 1.2 mm. The hollow tungsten electrode has an outer diameter of 6 mm and an inner diameter of 3 mm. A ceramic tube is secured to the inner hole of the tungsten electrode as an insulating layer between the welding wire and the inner wall of the hollow tungsten electrode. The ceramic tube has an outer diameter of 3 mm and an inner diameter of 1.5 mm. Before welding, the low-alloy steel base material is polished or cleaned and then secured.

[0025] An insulating layer is fixed in the inner hole of the hollow tungsten electrode, and the welding wire passes through the insulating layer, which is a ceramic tube. The welding wire is coaxially filled from the hollow tungsten electrode to the arc, and at the same time, the laser is incident on the surface of the welding wire by the side axis, so that the laser heat source and the hollow tungsten electrode arc jointly heat the welding wire;

[0026] The method specifically further includes the following steps:

[0027] Step 2: Adjust the relative position of the welding wire and the axis of the hollow tungsten electrode so that the welding wire passes through the center of the hollow tungsten electrode to form a coaxial filler wire. Adjust the laser paraxial incident angle and the position of the irradiated welding wire surface. Adjust the hollow tungsten electrode to be perpendicular to the workpiece surface. The tungsten electrode height is 5 mm. Adjust the welding wire and the hollow tungsten electrode to be coaxial. The welding wire passes through the hollow tungsten electrode. Adjust the laser incident angle so that the laser irradiates the welding wire surface. The distance between the laser spot on the welding wire surface and the tungsten electrode is 2 mm.

[0028] Step 3: Set the hollow tungsten arc 4 parameters and laser 5 welding parameters, set the hollow tungsten arc current to 350A, set the laser power to 300W, set the welding speed to 300mm / min, and set the wire feed speed to 5m / min;

[0029] Step 4: Turn on the control switch, the hollow tungsten electrode generates an arc, the welding wire passes through the center of the hollow tungsten electrode and is fed into the arc area. At the same time, the paraxial incident laser is incident on the surface of the welding wire. The welding wire is heated and melted by the hollow tungsten electrode arc and laser and transitions to the welding pool to weld the workpiece.

[0030] Example 2:

[0031] According to the laser-assisted fused hollow tungsten electrode argon arc coaxial wire filling welding method described in Example 1, the diameter of the welding wire is not larger than the center hole of the hollow tungsten electrode. When the welding wire is fed into the center hole of the hollow tungsten electrode, the welding wire and the inner wall of the tungsten electrode are insulated by an insulating layer.

[0032] Example 3:

[0033] According to the laser-assisted fused hollow tungsten electrode argon arc coaxial filler wire welding method described in Example 1, the welding heating method of the molten pool is hollow tungsten electrode arc heating, the laser heat source acts on the welding wire, and the laser action point on the welding wire is within the hollow tungsten electrode arc area. The combined heating of the laser and the hollow tungsten electrode arc increases the melting rate of the welding wire.

[0034] Example 4:

[0035] According to the laser-assisted fused hollow tungsten inert argon arc coaxial wire welding method described in Example 1, the laser power used is 10 to 6000 W, the laser used is a CO2 gas laser, a YAG solid laser, a semiconductor laser or a fiber laser, and the laser output is a continuous laser or a pulsed laser.

[0036] Example 5:

[0037] According to the laser-assisted fused hollow tungsten argon arc coaxial wire-filling welding method described in Example 1, the laser spot diameter of the laser is no larger than the welding wire diameter, and the welding wire diameter is 0.8 mm-2.4 mm.

[0038] Example 6:

[0039] According to the laser-assisted fused hollow tungsten argon arc coaxial wire-filling welding method described in Example 1, the laser is a dual-beam laser, the laser power ratio of the dual-beam laser is continuously adjustable, and the beam arrangement is continuously adjustable 360 ​​degrees.

[0040] Example 7:

[0041] According to the laser-assisted fused hollow tungsten electrode argon arc coaxial wire filling welding method described in Example 1, the laser is a scanning laser, and the laser scanning path includes "I" shape, "8" shape, circle, polygon, sawtooth shape and sine waveform, etc. Each scanning path has two different beam movement directions: clockwise and counterclockwise.

Claims

1. A laser-assisted fused hollow tungsten argon arc coaxial filler wire welding method, the method comprising: Step 1: Before welding, grind or clean the workpiece to be welded, and fix the grinded or cleaned workpiece to be welded; Preparation, welding wire, insulating layer and hollow tungsten electrode, characterized in that: the insulating layer is fixed in the inner hole of the hollow tungsten electrode, the welding wire passes through the insulating layer, the insulating layer is a ceramic tube, the welding wire is coaxially filled from the hollow tungsten electrode to the arc, and at the same time, the laser is incident on the surface of the welding wire by the side axis, so that the laser heat source and the hollow tungsten electrode arc jointly heat the welding wire; The method specifically further includes the following steps: Step 2: Adjust the relative position of the welding wire and the axis of the hollow tungsten electrode so that the welding wire passes through the center of the hollow tungsten electrode to form a coaxial filler wire, and adjust the off-axis incident angle of the laser and the position of the irradiated welding wire surface; the laser spot diameter of the laser is not larger than the diameter of the welding wire to avoid the laser energy acting on the inside of the molten pool or increasing the heat input of the parent material; when the laser melts the welding wire, laser plasma is generated to improve the stability of the hollow tungsten electrode arc; Step 3: Set the hollow tungsten arc parameters and laser welding parameters; Step 4: Turn on the control switch, the hollow tungsten electrode generates an arc, the welding wire passes through the center of the hollow tungsten electrode and is fed into the arc area. At the same time, the paraxial incident laser is incident on the surface of the welding wire. The welding wire is heated and melted by the hollow tungsten electrode arc and laser and transitions to the welding pool to weld the workpiece.

2. The laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire according to claim 1, characterized in that: The diameter of the welding wire is not larger than the center hole of the hollow tungsten electrode. When the welding wire is fed into the center hole of the hollow tungsten electrode, the welding wire and the inner wall of the tungsten electrode are insulated by the insulating layer.

3. The laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire according to claim 1 or 2, characterized in that: The welding heating method of the molten pool is hollow tungsten arc heating, the laser heat source acts on the welding wire, the laser action point on the welding wire is within the hollow tungsten arc area, and the combined heating of the laser and the hollow tungsten arc increases the melting speed of the welding wire.

4. The laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire according to claim 1 or 2, characterized in that: The laser power used is 10-6000W, the laser used is CO2 gas laser, YAG solid laser, semiconductor laser or fiber laser, and the laser output is continuous laser or pulsed laser.

5. The laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire according to claim 1 or 2, characterized in that: The diameter of the welding wire is 0.8mm-2.4mm.

6. The laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire according to claim 1 or 2, characterized in that: The laser is a dual-beam laser, the laser power ratio of the dual-beam laser is continuously adjustable, and the beam arrangement is continuously adjustable 360 ​​degrees.

7. The laser-assisted fused hollow tungsten argon arc coaxial welding method with filler wire according to claim 1 or 2, characterized in that: The laser is a scanning laser, and the laser scanning paths include "I" shape, "8" shape, circle, polygon, sawtooth shape and sine waveform. Each scanning path has two different beam movement directions: clockwise and counterclockwise.

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