CN102126088A - Double-sided laser arc composite welding method for thick plate T-joint - Google Patents

Abstract

The invention relates to a double-sided laser arc composite welding method for a thick plate T-joint, belonging to the field of laser arc composite welding. The invention solves the problem of low welding efficiency existing in the traditional welding method for the thick plate T-joint. Two welding guns and two laser beam mirror images are arranged at both sides of a vertical plate of the thick plate T-joint, and synchronized laser arc composite welding is performed. In the process of laser arc composite welding, arc welding is performed by arranging the welding guns close to the part to be welded of the thick plate T-joint so that the optical axes of the laser beams and the central axes of the welding guns are arranged on the same plane and all form an included angel alpha of 10-50 DEG with the face plate of the thick plate T-joint, the optical axes of the laser beams and the central axes of the welding guns form an included angle of 25-45 DEG, and the distance D from the incidence point of the laser beam on the part to be welded to the tail end of a welding wire of each welding gun is 2-6 mm. The double-sided laser arc composite welding method for the thick plate T-joint is a laser arc composite welding method.

Description

Double-sided Laser Arc Hybrid Welding Method for Thick Plate T-joints

technical field

The invention relates to a double-sided laser arc composite welding method for thick plate T-shaped joints, belonging to the field of laser arc composite welding.

Background technique

With the development of industries such as ships, aerospace and vehicles to the direction of large tonnage and large carrying capacity, the welding technology of thick plate structures, especially the welding deformation control, welded joint performance and welding efficiency of thick plate T-joints are more and more demanding. come higher.

For the welding of thick plate T-shaped joints, the following methods are generally adopted at present: 1. Manual arc welding: it uses _CO2 gas shielded welding and submerged arc welding to weld sequentially from both sides of the joint. The defects of this method are: welding The seam groove is relatively large, the cladding metal of the weld seam is large, and the welding workload is large. When welding, pre-weld preheating, carbon arc gouging, root cleaning, grooving, grinding, post-weld heat treatment, and post-weld correction are required. There are many processes, resulting in high labor intensity for workers, large welding deformation and stress, low welding efficiency, and affected welding quality; 2. Double-sided double-arc welding method: such as the Chinese patent "Double-sided double-arc welding welding method", the publication number is CN1603045, the publication date is 2005.04.06. Compared with manual arc welding, the disclosed welding method simplifies the welding process, but the problems of larger weld bevel and more cladding metal in the weld have not been solved. At the same time, it There are also the problems of small arc penetration, slow welding speed and multi-layer multi-pass welding when welding thick plates. There are still problems of large welding workload, difficult control of stress and deformation, and low welding efficiency.

The above-mentioned two arc welding methods are difficult to meet the requirements of modern industry for welding quality and welding efficiency due to the above-mentioned defects in the welding of thick plate T-joints. Due to the advantages of high energy density, low heat input, high welding speed, large aspect ratio, narrow heat-affected zone and small welding deformation, laser welding is more and more used in the welding of thick plate T-joints.

The existing laser welding methods for T-joints are: 1. Use a single laser beam to perform penetration welding from the panel of the T-joint or use a single laser beam and two arcs to weld simultaneously from both sides of the panel and the joint, such as China The patent "Laser-double-arc double-sided composite welding method for T-shaped joints", the publication number is CN101306492, and the publication date is 2008.11.19. The welding method disclosed by it is feasible for T-shaped joints of thin plates. This method is used for T-shaped joints of thick plates. When the joint is welded, penetration welding cannot be formed; 2. Using single laser beam or double laser beam filling wire or powder filling welding technology, welding is performed sequentially from both sides of the T-shaped joint. This method has low welding efficiency and is harmful to wire feeding or welding. The directivity of powder feeding and welding process requirements are strict, and the welding process is unstable; and the welding heat source is asymmetrical, and the stress and deformation are not easy to control; 3. Dual-beam lasers are used to weld simultaneously from both sides of the T-joint, such as the Chinese patent "T-joint Double-beam laser synchronous welding method and device", the publication number is CN1586787, and the publication date is 2005.03.02, the disclosed content; or the simultaneous welding of both sides of the laser-arc, such as the Chinese patent "Used for T-shaped joint laser-arc on both sides Synchronous Welding Device", the publication number is CN201380364, and the publication date is 2010.01.13. Although the disclosed welding device solves the problem of asymmetrical welding heat source, the powder feeding process requires strict requirements, the molten pool formed by the laser is small, and the cladding The amount of metal is less. In short, the existing laser welding method has unique advantages in the welding of T-joints of thin plates, but in the welding of thick plates, it cannot form penetration welding to varying degrees, the requirements for wire feeding or powder feeding are extremely strict, and the welding efficiency is low. And other issues.

Contents of the invention

The purpose of the present invention is to solve the problem of low welding efficiency in the welding method of T-joints of thick plates, and provide a double-sided laser arc hybrid welding method of T-joints of thick plates.

In the method of the present invention, two welding torches and two laser beams are mirrored on both sides of the vertical plate of the T-shaped joint of the thick plate, and synchronous laser arc hybrid welding is carried out. During the laser arc hybrid welding process:

Place the welding torch close to the part to be welded of the thick plate T-joint for arc welding, so that the optical axis of the laser beam and the central axis of the welding torch are in the same plane, and both form 10° to 50° with the panel of the thick plate T-joint The included angle α, the optical axis of the laser beam and the central axis of the welding torch forms an included angle β of 25° to 45°, and the incident point of the laser beam on the part to be welded is between the welding wire end of the welding torch The spacing D is 2 mm to 6 mm.

The advantages of the present invention are: the present invention is aimed at the thick plate T-joints widely used in industries such as ships, aerospace and vehicles, and adopts double-sided laser-arc hybrid welding technology, which solves the problems existing in the current welding methods of thick plate T-joints. There are many welding procedures, heavy welding workload, difficult control of stress and deformation, poor welding quality and low welding efficiency.

In the method of the present invention, the composite heat sources on both sides of the vertical plate of the thick plate T-shaped joint act together on a molten pool, so that the molten pool flows more fully, reduces welding defects, makes the weld seam uniform in composition, increases the fusion area, and improves the welded joint. performance. Welding is symmetrically performed on both sides of the vertical plate of the thick plate T-shaped joint, and the weld seam is cooled and shrinks at the same time, which is beneficial to the control of stress and deformation, and improves the welding quality. The method of the invention reduces the processes of carbon arc gouging, root cleaning, groove grooving, grinding and the like, shortens the working cycle and improves the welding efficiency. The speed of traditional arc welding is generally 0.12m/min～0.25m/min, the speed of composite welding of the method of the present invention is generally between 1.0m/min～2.0cm/min, and the welding speed has been increased by more than 4 times. Under the condition of linear energy, the penetration depth of one welding can reach about 15mm, which greatly improves the welding efficiency.

Description of drawings

Fig. 1 is in the welding method of the present invention, the schematic diagram of the positional relationship between the T-joint of the thick plate to be welded, the welding torch and the laser beam, and the mark 4 in the figure shows the weld seam;

Fig. 2 is a structural schematic diagram of a K-shaped groove of a T-shaped joint of a thick plate;

Fig. 3 is a schematic diagram of the weld seam appearance of the T-shaped joint of the thick plate after bottom welding described in Embodiment 6;

Fig. 4 is a schematic diagram of the weld seam appearance of the T-shaped joint of the thick plate after backing welding and filling welding described in Embodiment 6;

Figure 5 is a schematic diagram of the weld seam appearance of a thick plate T-joint welded by the traditional arc multi-layer multi-pass welding method;

Fig. 6 is a schematic diagram of the weld seam appearance of a thick plate T-joint welded by a single laser beam;

Figure 7 is a schematic diagram of the weld seam appearance of the thick plate T-joint welded by the laser-double TIG arc double-sided composite welding method;

Figure 8 is a schematic diagram of the weld seam appearance of a thick plate T-joint welded by a single laser beam sequential welding method;

Fig. 9 is a schematic diagram of the weld seam appearance of a thick plate T-joint welded by the laser-arc simultaneous welding method on both sides;

Fig. 10 is a schematic diagram of the weld seam appearance of a thick plate T-joint welded by the welding method of the present invention.

Detailed ways

Specific Embodiment 1: This embodiment is described in conjunction with FIG. 1. In this embodiment, two welding torches 2 and two laser beams 1 are mirrored on both sides of the vertical plate 32 of the thick plate T-shaped joint, and synchronous laser arc hybrid welding is performed. In the process of laser arc hybrid welding:

Carry out arc welding with the welding torch 2 close to the part to be welded of the thick plate T-joint, so that the optical axis of the laser beam 1 and the central axis of the welding torch 2 are in the same plane, and both form 10 with the panel 31 of the thick plate T-joint. °～50° angle α, the optical axis of the laser beam 1 and the central axis of the welding torch 2 form an angle β of 25°～45°, and the incident point of the laser beam 1 on the part to be welded and The distance D between the welding wire ends of the welding torch 2 is 2mm˜6mm.

The laser beam 1 is perpendicular to the normal direction of the transverse surface of the panel 31 of the thick plate T-joint, and performs welding, and the welding is carried out along the normal direction of the transverse surface of the panel 31 of the thick plate T-joint.

The welding method described in this embodiment involves two laser beams and two welding torches 2, wherein one laser beam and one welding torch 2 realize laser-arc hybrid welding on one side of the T-shaped joint of the thick plate. On the other side of the T-shaped joint, another laser beam and another welding torch 2 are used to simultaneously realize laser-arc hybrid welding, thereby realizing synchronous welding on both sides of the thick plate T-shaped joint. The T-shaped upper panel of the thick plate T-shaped joint is used as the panel 31 , and the other panel of the thick plate T-shaped joint is used as the vertical plate 32 .

Specific embodiment 2: This embodiment is described in conjunction with FIG. 1. This embodiment is a further description of Embodiment 1. The included angle α is 45°; the included angle β is 30°, and the distance D is 3 mm to 4mm. Others are the same as the first embodiment.

In welding technology, the plate with a thickness less than 4mm is generally called a thin plate, the plate with a thickness between 4mm and 12mm is called a medium plate, and the plate with a thickness greater than 12mm is called a thick plate. This embodiment is particularly suitable for the welding of T-joints whose thicknesses of the vertical plate 32 and the panel 31 are both between 12 mm and 15 mm. Before the welding of the T-shaped joints of thick plates meeting this thickness requirement, there is no need to open a bevel on the vertical plate 32 . The surface on the panel 31 that is in contact with the vertical plate 32 is taken as the xy plane, and the direction perpendicular to the panel 31 on the vertical plate 32 is taken as the z-axis direction, then the central axis of the laser beam 1 and the central axis of the welding torch 2 are 45° to the xy plane angle. The laser beam 1 is perpendicular to the normal direction of the transverse surface of the panel 31 of the thick plate T-joint, that is, the laser beam 1 is perpendicular to the x-axis.

Specific embodiment three: This embodiment is described in conjunction with Fig. 1 and Fig. 2. This embodiment is a further description of Embodiment one. mouth processing. Others are the same as the first embodiment.

Embodiment 4: This embodiment is described in conjunction with FIG. 2. This embodiment is a further description of Embodiment 3. The groove processing is to process K-shaped grooves on both sides of the vertical plate 32 of the thick plate T-shaped joint. K The blunt edge d of the type groove is 12mm~15mm, and the angle θ of the K type groove is 10°~30°. Others are the same as the third embodiment.

Embodiment 5: This embodiment is a further description of Embodiment 4. The welding method is repeated n times, and n is a natural number. Others are the same as Embodiment 4.

Specific Embodiment 6: This embodiment is described in conjunction with Fig. 1 to Fig. 10. This embodiment is a further description of Embodiment 3, 4 or 5. The included angle α is 20°; the included angle β is 30°. The distance D is 3mm˜4mm. Others are the same as Embodiment 3, 4 or 5.

This embodiment is particularly suitable for the welding of T-joints whose thicknesses of both the vertical plate 32 and the panel 31 are greater than 15 mm. According to the thickness characteristics of the thick-plate T-joint, it is necessary to process K-shaped slopes on both sides of the vertical plate 32 of the thick-plate T-joint. In the mouth, the welding method described in Embodiment 4 is used for backing welding, and the steps 1 and 2 are repeated as required, and filling welding is performed once or more times, so that the T-shaped joint of the thick plate can achieve the best welding effect . Before welding, the thick plate T-joint can be fixed on the fixture to be welded.

As shown in Figure 5, the seam groove of the T-joint of the thick plate is a K-shaped groove, without blunt edges, and the groove angle θ is 50°. One-way welding, the welding workload is heavy, the welding process is many, the stress deformation is not easy to control, and the welding efficiency is low; as shown in Figure 6, it uses a single laser beam to perform penetration welding from the panel 31 of the thick plate T-joint. , it is impossible to form penetration welding; as shown in Figure 7, a single laser beam and two arcs are used to weld synchronously from both sides of the panel and the joint respectively, because the plate is thick, and penetration welding cannot be formed; as shown in Figure 8, a single laser beam is used Beam or double-beam wire-filling or powder-filling welding technology welds sequentially from both sides of the joint, and laser welding sequentially. It can be seen from the diagram that this method is difficult to maintain the symmetry of the welds on both sides of the welded joint, making it difficult to control the stress and deformation ; At the same time, it is difficult to ensure that the two molten pools are fused together, which is prone to produce pores and incomplete penetration, which affects the quality of the welded joint; as shown in Figure 9, the laser-arc is used for simultaneous welding on both sides. The asymmetry of the welds on both sides makes it more difficult to control the welding stress and deformation. Fig. 10 is a weld forming diagram of double-sided laser-arc compound synchronous welding from both sides of the vertical plate 32 of the thick-plate T-joint by adopting the method of the present invention. During the double-sided laser-arc compound welding process, The laser and the arc form a composite heat source. The guiding effect of the laser on the arc and the preheating effect of the arc on the workpiece make the welding process more stable and greatly improve the energy utilization rate. Compared with traditional arc welding, the method of the present invention reduces the size of the weld groove, and the angle of the weld groove can be reduced from 50° to 30°. The traditional arc welding weld groove has no blunt edge, while the inventive method The blunt edge of the weld bevel is 12mm to 15mm, which reduces the amount of weld metal cladding and saves welding materials, thereby reducing the cost.

Embodiment 7: This embodiment is a further description of Embodiments 1, 2, 3, 4, 5 or 6. The two laser beams 1 are divided into two laser beams by a laser using splitting technology, and transmitted by optical fiber Formed; Or emit a beam of laser beam 1 respectively by two lasers; Said laser beam 1 is YAG solid-state laser, semiconductor laser or fiber laser; Shielded welding arc (MAG). Others are the same as Embodiment 1, 2, 3, 4, 5 or 6.

Embodiment 8: This embodiment is a further description of Embodiments 1, 2, 3, 4, 5 or 6. The power of the laser is 3kW-20kW; the current of the arc generated by the welding torch 2 is 100A-400A. Others are the same as Embodiment 1, 2, 3, 4, 5 or 6.

In this embodiment, the power of the laser and the current of the arc generated by the welding torch 2 are selected according to the thickness of the T-shaped joint of the thick plate.

Specific Embodiment 9: This embodiment is a further description of Embodiments 1, 2, 3, 4, 5 or 6. The gas flow rate of the shielding gas of the welding torch 2 is between 15L/min and 30L/min; In the welding method, the flow rate of shielding gas for laser welding is between 15L/min and 30L/min. Others are the same as Embodiment 1, 2, 3, 4, 5 or 6.

The selection of the parameters in this embodiment needs to be selected according to the thickness of the T-joint of the thick plate.

Specific Embodiment Ten: This embodiment is a further description of Embodiments 1, 2, 3, 4, 5 or 6. The diameter of the welding wire used in the welding method is between 1.0 mm and 1.6 mm; the dry elongation of the welding wire Between 15mm and 25mm. Others are the same as Embodiment 1, 2, 3, 4, 5 or 6.

The selection of the parameters in this embodiment needs to be selected according to the thickness of the T-joint of the thick plate.

The present invention is not limited to the above-mentioned embodiments, and may also be a reasonable combination of the technical features described in the above-mentioned embodiments.

Claims (10)

1. A double-sided laser arc hybrid welding method for a thick plate T-joint, characterized in that: it mirrors two torches (2) and two laser beams (1) and is arranged on the vertical plate (32) of the thick plate T-joint ) both sides, carry out synchronous laser arc hybrid welding, in the process of said laser arc hybrid welding: Place the welding torch (2) close to the part to be welded of the T-shaped joint of the thick plate for arc welding, so that the optical axis of the laser beam (1) and the central axis of the welding torch (2) are in the same plane, and both are in line with the T-shaped joint of the thick plate. The panel (31) of the joint forms an included angle α of 10° to 50°, an included angle β of 25° to 45° is formed between the optical axis of the laser beam (1) and the central axis of the welding torch (2), and the The distance D between the incident point of the laser beam (1) on the part to be welded and the end of the welding wire of the welding torch (2) is 2 mm to 6 mm. 2. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 1, characterized in that: the included angle α is 45°; the included angle β is 30°, and the distance D is 3mm ~4mm. 3. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 1, characterized in that: before the laser arc hybrid welding is performed, groove processing is performed on the part to be welded of the thick plate T-joint . 4. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 3, characterized in that: the groove processing is to process K-shaped slopes on both sides of the vertical plate (32) of the thick plate T-joint The blunt edge d of the K-shaped groove is 12mm to 15mm, and the angle θ of the K-shaped groove is 10° to 30°. 5. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 4, characterized in that: the welding method is repeated n times, and n is a natural number. 6. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 5, characterized in that: the included angle α is 20°; the included angle β is 30°, and the distance D is 3mm ~4mm. 7. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 1, 2, 3, 4, 5 or 6, characterized in that: the two laser beams (1) are formed by a laser Two laser beams are divided into two laser beams by splitting technology, and formed by optical fiber transmission; or a laser beam (1) is emitted by two lasers respectively; the laser beam (1) is a YAG solid-state laser, a semiconductor laser or a fiber laser; the arc is MIG arc or MIG arc. 8. The double-sided laser arc hybrid welding method for thick plate T-joints according to claim 1, 2, 3, 4, 5 or 6, characterized in that: the power of the laser is 3kW～20kW; the welding torch ( 2) The current for arc generation is 100A~400A. 9. According to claim 1, 2, 3, 4, 5 or 6, the double-sided laser arc hybrid welding method for thick plate T-joints is characterized in that: the gas flow rate of the shielding gas of the welding torch (2) is 15L /min～30L/min; the flow rate of shielding gas for laser welding in the welding method is between 15L/min～30L/min. 10. According to claim 1, 2, 3, 4, 5 or 6, the thick-plate T-joint double-sided laser arc hybrid welding method is characterized in that: the welding wire used in the welding method has a diameter of 1.0 mm to 1.6 mm; the dry elongation of the wire is between 15mm and 25mm.

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