Marine medium plate laser hot wire-TIG composite welding device and method

Abstract

The invention discloses a laser hot wire-TIG (Tungsten Inert Gas) hybrid welding device and a laser hot wire-TIG hybrid welding method for a marine medium plate, and belongs to the technical field of welding. The method is suitable for single-face welding and double-face forming of a plate with the thickness of 6-12 mm, the laser hot wire welding process is combined with TIG welding, the preheating effect of a welding wire is achieved through the hot wire technology before the welding wire is molten, and the mode that TIG and laser share a molten pool is combined; during welding, under the condition of full preheating, a welding wire is fed into a laser-TIG molten pool, and high-quality and high-efficiency welding with high fusion depth and low porosity of the medium-thickness plate can be achieved. By means of the composite welding method, the good coupling effect of TIG and galvanometer laser is achieved, the fusion covering amount of welding wires in the welding process can be greatly increased, the large-fusion-depth and high-filling welding effect is achieved on the premise that a groove is not formed, and the quality of welding seams is improved while the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a laser hot wire-TIG composite welding device and method for medium and thick plates for ships. Background Art

[0002] At present, the main welding methods for medium and thick plates of ships are traditional arc welding, gas shielded welding and submerged arc welding, etc. Traditional welding methods require large grooves for multi-layer and multi-pass welding, and the welding process requires a large heat input, which will cause the welded structure to deform, and the welding efficiency and weld formation are also limited to a certain extent.

[0003] Laser-arc hybrid welding has attracted widespread attention and application due to its advantages such as fast welding speed, narrow heat-affected zone, small weld deformation and residual stress, and has gradually been used in the welding of medium and thick carbon steel plates in ships.

[0004] Laser welding has a large penetration depth and can adapt to single-sided welding and double-sided forming of medium and thick plates. However, due to the high precision required for plate assembly, it has been difficult to complete the welding of marine plates. The disadvantages of arc welding are slow welding speed and low energy density, but it has good gap adaptability. However, welding defects such as low wire melting efficiency, insufficient filling volume and uneven back forming are prone to occur during the composite process. In order to solve this problem, a hot wire system process solution was introduced, that is, two forms of hot wire systems (resistance hot wire and arc hot wire) were used to improve the composite welding process.

[0005] During the laser welding of medium and thick plates in ships, it is usually necessary to accurately locate the welding starting point and the assembly gap needs to be controlled within 2mm. For thicker plates, the penetration ability of laser welding is limited. Although the effect can be enhanced by increasing the laser power or using dual laser beams, the actual effect is still not as good as the traditional arc welding method. Due to the concentrated heat input of laser welding and the small heat-affected zone, it is easy to cause welding stress concentration and increase the possibility of cracks, especially when welding high-strength alloys and thick materials.

[0006] In the traditional welding process, the welding speed and deposition efficiency are often limited by the power of the heat source and the cooling speed of the molten pool. Hot wire technology heats the filler material during the welding process to preheat it or put it in a semi-molten state, thereby improving the welding speed and efficiency. This technology is suitable for scenes with thick materials or long seams, and can effectively reduce the welding cycle and working hours, and improve production efficiency. Summary of the invention

[0007] In view of the shortcomings of the prior art, in order to achieve efficient, precise welding with high adaptability to working conditions, the present invention proposes a laser hot wire-TIG composite welding method for medium and thick marine plates, providing a solution for achieving efficient and precise welding of medium and thick marine plates.

[0008] The present invention provides a laser hot wire-TIG composite welding device for medium and thick plates for ships, comprising a continuous fiber laser, a hot wire power supply, a galvanometer laser welding gun, and a TIG welding gun; the TIG welding gun is connected to the negative electrode of the TIG power supply, and the positive electrode of the TIG power supply is connected to a base material; the continuous fiber laser is connected to the galvanometer laser welding gun; the negative electrode of the hot wire power supply is connected to a wire feeding device, and the positive electrode is connected to the base material; the photoelectric center of the galvanometer laser welding gun is consistent with the arc center of the TIG welding gun; the wire feeding direction of the wire feeding device points to the laser of the galvanometer laser welding gun and the arc eutectic pool of the TIG welding gun, and the galvanometer laser welding gun, the TIG welding gun and the welding wire are located in the same plane and coincide with the welding path.

[0009] The present invention further provides a laser hot wire-TIG composite welding method for medium and thick plates for ships, comprising the following steps:

[0010] Step 1: Arrange the medium and thick marine plates to be welded, and connect the above-mentioned medium and thick marine plates laser hot wire-TIG composite welding device;

[0011] Step 2: Adjust the galvanometer laser welding gun, wire feeding device, and TIG welding gun to be in the same plane and coincide with the welding path. Adjust the angles, laser defocus, and tungsten electrode extension length of the three within the set range and make sure that the axes of the three intersect at the same point to ensure the stability of the coupling of the light spot, arc, and welding wire.

[0012] Step 3: Determine the welding start position and welding stop position, turn on the hot wire power supply, galvanometer laser welding gun, TIG welding gun, and wire feeding device; adjust the welding process parameters, adjust the swing width and swing frequency of the galvanometer laser welding gun; adjust the welding speed of the TIG welding gun and the wire feeding speed of the wire feeding device according to the thickness of the medium and thick plates to be welded; adjust the current value of the hot wire power supply; observe the preheating effect of the welding wire when it turns slightly red, and then start welding;

[0013] Step 4: When welding is finished, turn off the wire feeding device first, and then turn off other devices to ensure that the welding wire is melted and separated from the base material.

[0014] Furthermore, the hot wire form of the hot wire power supply includes arc hot wire and resistance hot wire; when the arc hot wire is used, the welding wire is close to the base material but does not touch it; when the resistance hot wire is used, the welding wire contacts the base material.

[0015] Furthermore, the current of the hot wire power supply is 80-120A, and the preheating time is 1-2 minutes.

[0016] Furthermore, the laser power of the continuous fiber laser is 2700W to 3000W.

[0017] Furthermore, when the thickness of the medium and thick marine plate to be welded is less than 8 mm, the welding speed of the TIG welding gun and the galvanometer laser welding gun is the same as the wire feeding speed of the wire feeding device, and the speed is 30 to 40 mm / s; when the thickness of the medium and thick marine plate to be welded is greater than 8 mm, the welding speed of the TIG welding gun and the galvanometer laser welding gun is the same as the wire feeding speed of the wire feeding device, and the speed is 20 to 30 mm / s.

[0018] Furthermore, when the diameter of the welding wire is 0.8 and 1.2 mm, the swing width of the galvanometer laser welding gun is 2.0 mm to 3.0 mm; when the diameter of the welding wire is 1.6 mm, the swing width of the galvanometer laser welding gun is 3.0 mm to 4.0 mm; when the diameter of the welding wire is 2 mm, the swing width of the galvanometer laser welding gun is greater than 4.0 mm; the swing frequency of the galvanometer laser welding gun is greater than 200 Hz.

[0019] Furthermore, when the thickness of the medium and thick marine plate to be welded is less than 8 mm, the laser incident angle between the galvanometer laser welding gun and the parent material on the galvanometer laser welding gun side is 45° to 60°; when the thickness of the medium and thick marine plate to be welded is greater than 8 mm, the laser incident angle between the galvanometer laser welding gun and the parent material on the galvanometer laser welding gun side is 60° to 75°.

[0020] Furthermore, if the molten pool is too deep during welding, the laser incident angle is smaller to reduce the melting depth; if the molten pool is too shallow during welding, the laser incident angle is larger to increase the melting depth.

[0021] The present invention further provides an application of a laser hot wire-TIG composite welding device for medium and thick marine plates, wherein the device is applied to welding medium and thick marine plates with a thickness of 6 to 12 mm.

[0022] The beneficial effects of the present invention are:

[0023] 1. Aiming at the technical difficulties of single-sided welding and double-sided forming of medium and thick marine plates, the present invention innovatively proposes a hybrid welding device based on low-power laser arc to achieve high-efficiency and high-penetration welding effect under the premise of low cost and low heat input. By introducing galvanometer laser and TIG hybrid welding, the disadvantage of poor adaptability of single laser working conditions is solved, and the welding reliability of assembly gaps within 2 mm is improved. At the same time, the welding efficiency of the traditional TIG welding process is increased by more than 9 times, and single-sided welding and double-sided forming of 6-12 mm thick plates are achieved through the laser and arc eutectic pool.

[0024] 2. In order to achieve a good coupling effect between TIG and galvanometer laser, the present invention designs the relative posture and related parameters, and provides a suitable process window in combination with different plate thicknesses to ensure that the welding wire melts evenly during the welding process and the molten pool is stable and free of spatter.

[0025] 3. The present invention innovatively introduces a hot wire system, which improves the melting efficiency of the welding wire while achieving high-efficiency and high-penetration welding effects, fills more deposited metal per unit time to reduce the welding process, and further improves welding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a diagram of the laser hot wire-TIG composite welding device for medium and thick plates for ships of the present invention;

[0027] Figure 2 This is a schematic diagram of laser oscillation for laser hot wire-TIG composite welding of medium and thick plates for ships of the present invention;

[0028] Figure 3 This is the macroscopic morphology of the laser TIG hot wire weld; among them, (a) overall macroscopic morphology; (b) weld area 200 times; (c) weld area 500 times; (d) fusion line 200 times; (e) fusion line 500 times.

[0029] Among them, 1. TIG power supply; 2. TIG power supply positive electrode; 3. TIG power supply negative electrode; 4. Continuous fiber laser; 5. Laser start and emergency stop buttons; 6. Laser parameter adjustment panel; 7. Hot wire power supply; 8. Hot wire power supply positive electrode; 9. Hot wire power supply negative electrode; 10. Galvanometer laser welding gun; 11. TIG welding gun; 12. TIG welding gun ceramic nozzle; 13. Tungsten electrode; 14. Wire feeder; 15. Welding wire; 16. Wire guide wheel; 17. Laser TIG welding molten pool; 18. Base material. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings.

[0031] like Figure 1As shown, the present invention discloses a laser hot wire-TIG composite welding device for medium and thick plates for ships, comprising a continuous fiber laser 4, a galvanometer laser welding gun 10, a hot wire power supply 7, a TIG power supply 1, a TIG welding gun 11, and a wire feeding device; the positive electrode 2 of the TIG power supply is connected to a base material 18, and the negative electrode 3 of the power supply is connected to the TIG welding gun (tungsten electrode) 11; the continuous fiber laser 4 is connected to the galvanometer laser welding gun 10; the positive electrode 8 of the hot wire power supply is connected to the base material 18, and the negative electrode 9 is connected to the wire feeding device; the wire feeding device is used to load the welding wire and pass through the hot wire The power supply is connected, and the welding wire 15 is preheated by electric arc / resistance heating according to the different forms of the hot wire; the photoelectric center of the galvanometer laser welding gun 10 is guaranteed to be consistent with the arc center of the TIG power supply 1, and the welding wire 15 points to the eutectic pool of the laser and TIG. The galvanometer laser welding gun 10, the TIG welding gun 11 and the welding wire 15 are located in the same plane and coincide with the welding path. When the arc heating wire is used, the welding wire 15 is close to the base material 18 but does not touch it, and when the resistance heating wire is used, the welding wire 15 contacts the base material 18, ensuring that the axes of the galvanometer laser welding gun 10, the TIG welding gun 11 and the welding wire 15 intersect at one point.

[0032] The present invention further discloses a laser hot wire-TIG composite welding method for medium and thick plates for ships, comprising the following steps:

[0033] Step 1: Arrange the medium and thick marine plates to be welded, the continuous fiber laser 4, the galvanometer laser welding gun 10, the hot wire power supply 7, the TIG power supply 1, the TIG welding gun 11, and the wire feeding device; the positive electrode 2 of the TIG power supply is connected to the base material 18, and the negative electrode 3 of the power supply is connected to the TIG welding gun (tungsten electrode) 11; the continuous fiber laser 4 is connected to the galvanometer laser welding gun 10; the positive electrode 8 of the hot wire power supply is connected to the base material 18, and the negative electrode 9 is connected to the wire feeder 14; for plates with a thickness of 6 to 8 mm, no assembly gap needs to be reserved, and for plates with a thickness of 8 to 12 mm, an assembly gap of 0 to 2 mm needs to be reserved. The reserved gap is to better achieve the penetration effect of the composite welding to obtain a double-sided weld with better forming. The gap should not be too large to prevent the welding wire from fully melting and extending into the gap to affect the welding effect.

[0034] Step 2: Adjust the galvanometer laser welding gun 10, the wire feeder 14, and the TIG welding gun 11 to be in the same plane and coincide with the welding path, with the welding wire perpendicular to the welding direction, and adjust the angles, laser defocus amount, and tungsten electrode extension length of the three within the set range and the axes of the three intersect at the same point to ensure that the coupling of the light spot-arc-welding wire is stable;

[0035] Step 3: Determine the welding start position and the welding stop position, turn on the continuous fiber laser 4, the hot wire power supply 7, the TIG power supply 1, and the wire feeding device; first set the laser power between 2700W and 3000W. Within this power range, the non-fusible single-sided welding and double-sided forming of 12mm thick steel plates can be achieved. The introduction of the TIG power supply can assist in achieving the effect of fuse and gap adaptation; according to the thickness of the material to be welded, set the welding speed between 20mm / s and 40mm / s, the 6-8mm plate is set to 30-40mm / s, and the 8-12mm plate is set to 20m m / s~30mm / s, the energy density of the composite heat source per unit time is increased by changing the welding speed, and the melting depth of the composite heat source is increased; then the swing width and swing frequency are set according to the different diameters of the welding wire 15. When the diameter of the welding wire 15 is selected between 0.8 and 1.2mm, the swing width is set between 2.0mm~3.0mm, when the diameter of the welding wire 15 is selected between 1.6mm, the swing width is set between 3.0mm~4.0mm, when the diameter of the welding wire 15 is selected between 2.0mm, the swing width is set above 4.0mm, and the frequency is set above 200Hz for better forming. The hot wire current is divided into resistance heating and arc heating according to different hot wire methods. The resistance heating needs to set the current value between 80~120A and preheat for about 1min. When starting welding, observe the preheating effect of the welding wire and start welding when it turns slightly red.

[0036] Step 4: Adjust the laser incident angle through the laser-TIG composite molten pool. When the thickness of the medium and thick marine plate to be welded is less than 8mm, the laser incident angle between the galvanometer laser welding gun 10 and the parent material 18 on the side of the galvanometer laser welding gun 10 is 45° to 60°; when the thickness of the medium and thick marine plate to be welded is greater than 8mm, the laser incident angle between the galvanometer laser welding gun 10 and the parent material 18 on the side of the galvanometer laser welding gun 10 is 60° to 75°. If the molten pool is deep, the laser incident angle can be appropriately reduced, and the laser incident angle is too small to reduce the depth of penetration; if the molten pool is shallow, the laser incident angle is appropriately increased, and the laser incident angle is too large to increase the depth of penetration. The laser forms a deep melting effect on the basis of the molten pool formed by TIG, and the laser power below 3000W is used to achieve the effect of double-sided forming of medium and thick plates on one side. The welding wire is preheated by the hot wire power supply to achieve efficient cladding and cover the weld position. During T-type welding, the hot wire current and wire feeding speed can be appropriately increased according to welding requirements to achieve efficient welding of the welding wire to meet welding standards.

[0037] Step 5: When welding starts, make sure the arc is in front and the laser is behind. Start the TIG arc first by controlling the switch to ensure that the laser is irradiated in the TIG molten pool to meet the adaptability of the welding process to the gap.

[0038] Step 6: When welding is finished, first turn off the wire feeder switch, then turn off the laser-TIG-hot wire welding power supply to ensure that the welding wire is melted and separated from the base material.

[0039] like Figure 2 As shown, when double welding wires are used for welding, different welding wires enter the molten pool through different conductive nozzles, and the galvanometer laser welding gun 10 swings on the surface of the double welding wires to cover the double welding wires, effectively ensuring the welding effect.

[0040] Example 1

[0041] A laser hot wire-TIG composite welding method for medium and thick marine plates comprises the following steps:

[0042] Step 1: Use an angle grinder to clean the groove of the EH3612mm thick marine medium and thick plate, remove surface oil and rust, and fasten it to the welding platform through a fixture; connect the laser hot wire-TIG composite welding device.

[0043] Step 2: Adjust the galvanometer laser welding gun 10, wire feeding device, and TIG welding gun 11 to be in the same plane and coincide with the welding path, with the welding wire perpendicular to the welding direction. Adjust the angles, laser defocus amount, and tungsten electrode extension length of the three within the set range and make sure that the axes of the three intersect at the same point to ensure the stability of the coupling of the light spot, arc, and welding wire. The included angle of the laser incident angle between the galvanometer laser welding gun 10 and the base material 18 on the galvanometer laser welding gun 10 side is 60° to 75°.

[0044] Step 3: When the laser power is 3000W and the diameter of the welding wire 15 is 1.2mm, the swing width of the galvanometer laser welding gun 10 is 3.0mm and the swing frequency is 200Hz. The welding speed of the galvanometer laser welding gun 10 and the TIG welding gun 11 is 30mm / s, and the wire feeding speed of the wire feeding device is 30mm / s; the energy density of the composite heat source per unit time is increased by changing the welding speed, and the penetration depth of the composite heat source is increased; the welding wire contacts the base material, and the resistance heating wire current is 100A;

[0045] Step 4: Set the parameters of TIG power supply 1, TIG current to 120A, shielding gas flow rate to 5-10L / min, start the TIG power supply before welding and determine the relative position of the laser according to the spot welding position to ensure that the laser spot is consistent with the spot welding center.

[0046] Step 5: When welding starts, make sure the arc is in front and the laser is behind. Start the TIG arc first by controlling the switch to ensure that the laser is irradiated in the TIG molten pool to meet the adaptability of the welding process to the gap.

[0047] Step 6: After welding, turn off the wire feeding device first, then turn off other devices, and get the welded marine medium and thick plate. Figure 3 shown.

[0048] The laser hot wire-TIG composite welding method for medium and thick plates for ships of the present invention utilizes an external hot wire power supply to preheat the welding wire before welding, and designs a laser hot wire-TIG composite welding system to ensure the stability and continuity of the composite welding process. Aiming at the shortcomings of low efficiency and unstable forming of traditional welding processes for medium and thick plates for ships, the laser hot wire TIG method can not only realize efficient cladding of the welding wire, but also realize the welding of EH36 ship steel plates of 12 mm and below. For T-profile welding, the welding leg height required by welding can be met by increasing the hot wire current and the wire feeding speed. At the same time, the galvanometer laser method is used to achieve the effect of double-wire cover welding. The swing width of 2 to 8 mm can better adapt to metal welding wires with a diameter of 0.8 to 2.0 mm, ensuring that the welding wire is fully melted and the composite quality requirements of the cladding amount are met.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A laser hot wire-TIG composite welding device for medium and thick plates for ships, characterized in that: The invention comprises a continuous fiber laser (4), a hot wire power supply (7), a galvanometer laser welding gun (10), and a TIG welding gun (11); the TIG welding gun (11) is connected to the negative electrode of the TIG power supply (1), and the positive electrode of the TIG power supply (1) is connected to a base material (18); the continuous fiber laser (4) is connected to the galvanometer laser welding gun (10); the negative electrode of the hot wire power supply (7) is connected to a wire feeding device, and the positive electrode is connected to the base material (18); the photoelectric center of the galvanometer laser welding gun (10) is consistent with the arc center of the TIG welding gun (11); the wire feeding direction of the welding wire (15) of the wire feeding device points to the laser of the galvanometer laser welding gun (10) and the arc eutectic pool of the TIG welding gun (11); the galvanometer laser welding gun (10), the TIG welding gun (11) and the welding wire (15) are located in the same plane and overlap with the welding path.

2. A laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 1, characterized in that: The following steps are involved: Step 1: Arrange the medium and thick marine plates to be welded, and connect the above-mentioned medium and thick marine plates laser hot wire-TIG composite welding device; Step 2: Adjust the galvanometer laser welding gun (10), the wire feeding device, and the TIG welding gun (11) to be located in the same plane and coincide with the welding path, adjust the angles, laser defocus amount, and tungsten electrode extension length of the three within the set range, and make the axes of the three intersect at the same point to ensure that the coupling of the light spot-arc-welding wire is stable; Step 3: Determine the welding start position and the welding stop position, turn on the hot wire power supply (7), the galvanometer laser welding gun (10), the TIG welding gun (11), and the wire feeding device; adjust the welding process parameters, adjust the swing width and swing frequency of the galvanometer laser welding gun (10); adjust the welding speed of the TIG welding gun (11) and the wire feeding speed of the wire feeding device according to the thickness of the medium and thick plate to be welded; adjust the current value of the hot wire power supply (7); observe the preheating effect of the welding wire when starting welding, and start welding when it turns slightly red; Step 4: When welding is finished, turn off the wire feeding device first, and then turn off other devices to ensure that the welding wire is melted and separated from the base material.

3. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 2 is characterized in that: The hot wire of the hot wire power source (7) includes arc hot wire and resistance hot wire; when the arc hot wire is used, the welding wire (15) is close to the base material (18) but does not touch it; when the resistance hot wire is used, the welding wire (15) touches the base material (18).

4. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 3 is characterized in that: The current of the hot wire power supply (7) is 80-120A, and the preheating time is 1-2 minutes.

5. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 2, characterized in that: The laser power of the continuous fiber laser (4) is 2700W-3000W.

6. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 2, characterized in that: When the thickness of the medium and thick marine plate to be welded is less than 8 mm, the welding speed of the TIG welding gun (11) and the galvanometer laser welding gun (10) is the same as the wire feeding speed of the wire feeding device, and the speed is 30 to 40 mm / s; when the thickness of the medium and thick marine plate to be welded is greater than 8 mm, the welding speed of the TIG welding gun (11) and the galvanometer laser welding gun (10) is the same as the wire feeding speed of the wire feeding device, and the speed is 20 to 30 mm / s.

7. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 2, characterized in that: When the diameter of the welding wire (15) is 0.8 and 1.2 mm, the swing width of the galvanometer laser welding gun (10) is 2.0 mm to 3.0 mm; when the diameter of the welding wire (15) is 1.6 mm, the swing width of the galvanometer laser welding gun (10) is 3.0 mm to 4.0 mm; when the diameter of the welding wire (15) is 2 mm, the swing width of the galvanometer laser welding gun (10) is greater than 4.0 mm; and the swing frequency of the galvanometer laser welding gun (10) is greater than 200 Hz.

8. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 2, characterized in that: When the thickness of the medium and thick shipboard plate to be welded is less than 8 mm, the included angle of the laser incident angle between the galvanometer laser welding gun (10) and the parent material (18) on the side of the galvanometer laser welding gun (10) is 45° to 60°; when the thickness of the medium and thick shipboard plate to be welded is greater than 8 mm, the included angle of the laser incident angle between the galvanometer laser welding gun (10) and the parent material (18) on the side of the galvanometer laser welding gun (10) is 60° to 75°.

9. The laser hot wire-TIG composite welding method for medium and thick marine plates according to claim 8, characterized in that: If the molten pool is too deep during welding, the laser incident angle is smaller to reduce the melting depth; if the molten pool is too shallow during welding, the laser incident angle is larger to increase the melting depth.

10. An application of the laser hot wire-TIG composite welding device for medium and thick marine plates according to claim 1, characterized in that: The device is used for welding medium and thick plates for ships with a thickness of 6 to 12 mm.

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