Laser melt-brazing method for seam welding wheel

Abstract

The invention relates to a laser welding-brazing method for a seam welding wheel, and belongs to the technical field of welding. According to the technical scheme, in the welding direction, a laser beam (1) and a stainless steel welding wire (2) are arranged in a groove (603) in the connecting position of a seam welding wheel gland (602) and a seam welding wheel body (601); during welding, a water cooling plate (7) is arranged below a seam welding wheel, and under the protection of argon, spots of a laser beam (1) swing in a groove according to a specific laser beam spot track (5), so that a stainless steel welding wire is completely molten, copper on the side wall of the groove is not molten or slightly molten, and a laser molten pool (3) is formed; and the laser molten pool (3) is finally cooled and solidified to form a welding seam (4). The method has the beneficial effects that the stainless steel welding wire is adopted as a filling material, the energy distribution of laser on the welding seam is changed through swinging of the laser beam in the groove, accurate control over heat input is achieved, the effects that the stainless steel welding wire is melted, and a copper material is not melted or slightly melted are achieved, and it is guaranteed that the welding seam is formed well and stably.

Description

Technical Field

[0001] The invention relates to a laser melting brazing method for a seam welding wheel, belonging to the technical field of welding. Background Art

[0002] Seam welding wheels refer to the upper and lower wheel-shaped electrodes of the seam welding machine. During seam welding, the upper and lower seam welding wheels clamp the workpiece to be welded, and positive and negative currents are continuously or intermittently applied between the two electrodes, so that the workpieces to be welded come into contact and generate heat, and a linear weld is formed by continuous or intermittent rolling. Seam welding wheels are usually composed of a main body and a gland. Commonly used materials are chromium-zirconium copper and beryllium copper. A cooling water channel is provided between the two components to ensure the heat dissipation effect of the welding wheel during operation.

[0003] The special structure and usage scenarios of the seam welding wheel make it more demanding on the welding joints. At present, most seam welding wheels at home and abroad are welded by brazing or argon arc welding. Due to the high thermal conductivity of copper (almost 5 times that of pure iron and 1.7 times that of pure aluminum), traditional arc welding and brazing methods cannot achieve the ideal welding effect. Specifically, the seam welding wheel produced by the brazing method has poor heat resistance. During use, it is easy to cause local deformation of the parts due to temperature changes, thereby stretching the weld and cracking the weld. In addition, brazing requires heating the entire seam welding wheel, which affects the performance of the overall material, especially the hardness will be reduced. The argon arc welding method has high requirements on welding parameters, it is not easy to control the weld formation, and the weld processing of the seam welding wheel argon arc welding is relatively complicated, which consumes manpower, raw materials, and time, and the parts are seriously deformed after welding.

[0004] The laser beam has the characteristics of small focus, high energy density, high energy transfer efficiency, etc., which makes it fast, efficient and with low heat input when welding. Compared with traditional arc welding or brazing, it has advantages. However, when conventional laser welding is directly used for seam welding, there are the following problems: First, copper has a high reflectivity to lasers (the reflectivity to lasers with a wavelength of 1μm is over 95% at room temperature), and conventional wavelength (about 1070μm) fiber lasers are almost impossible to weld. Even if shorter wavelength lasers are used for welding, the energy conversion efficiency during welding is greatly reduced, the welding efficiency is extremely low, and the production cost is high. Secondly, copper has a high thermal conductivity, which means a large amount of energy is lost, which requires the use of higher power lasers to achieve effective welding. Finally, in terms of wire selection, the soft nature of copper wire makes wire feeding very unstable, which in turn affects welding stability and quality. Summary of the invention

[0005] The purpose of the present invention is to provide a laser brazing method for a seam welding wheel, which adopts stainless steel welding wire as a filling material, changes the energy distribution of the laser on the weld by swinging the laser beam in the groove, realizes precise control of heat input, achieves the effect of melting the stainless steel welding wire while the copper material does not melt or slightly melts, has high welding efficiency, and the weld quality is stable and reliable during long-term welding operations, thereby solving the problems existing in the background technology.

[0006] The technical solution of the present invention is: A laser melting brazing method for a seam welding wheel comprises the following steps: arranging a laser beam and a stainless steel welding wire in a groove where a seam welding wheel gland and a seam welding wheel body are connected along a welding direction; during welding, placing a water cooling plate below the seam welding wheel, and under the protection of argon gas, swinging a laser beam spot in the groove according to a specific laser beam spot trajectory, so that the stainless steel welding wire is fully melted, and the copper material on the side wall of the groove is not melted or slightly melted, thereby forming a laser molten pool; and the laser molten pool is finally cooled and solidified to form a weld.

[0007] Preferably, the track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 1.5 mm to 14.3 mm, the track width D2 of the laser beam spot on the weld surface along the welding direction is 0.1 mm to 10 mm, and the laser oscillation frequency is 5 Hz to 200 Hz.

[0008] Preferably, the angle α between the laser beam and the vertical direction is 0°~30°, the angle β between the stainless steel welding wire and the horizontal direction is 15°~60°, and the angle between the laser beam and the center line of the stainless steel welding wire is γ=α+(90°-β).

[0009] Preferably, the laser beam power is 1kW~4kW, the spot diameter of the laser beam on the weld surface is 0.2mm~1mm; the diameter of the stainless steel welding wire is 0.8mm~1.6mm, the wire feeding speed is 500mm / min~2000mm / min, the shielding gas flow rate is 10L / min~50L / min; the welding speed is 100mm / min~1000mm / min.

[0010] Preferably, the groove depth W of the welding wheel to be welded is 1mm~6mm, a butt groove with a single-sided groove angle θ of 20°~50° is set, and the cooling water temperature T of the water cooling plate below the seam welding wheel is 0~60°C.

[0011] Preferably, the laser beam spot trajectory is in any shape, such as an ellipse, a straight line, a C-shape, a square, or the like.

[0012] The beneficial effects of the present invention are: stainless steel welding wire is used as the filling material, and the energy distribution of the laser on the weld is changed by swinging the laser beam in the groove, so as to achieve precise control of the heat input, so as to achieve the effect that the stainless steel welding wire is melted, while the copper material is not melted or slightly melted, thereby ensuring good and stable weld formation. The water cooling plate can quickly transfer the excess welding heat, effectively avoiding the influence on the parent material, greatly improving the welding efficiency and significantly improving the service life of the seam welding wheel. Stainless steel welding wire is low in price and high in stability, and can greatly reduce the production cost while ensuring the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the seam welding wheel of the present invention; Figure 2 for Figure 1 AA section diagram of ; Figure 3 It is a cross-sectional schematic diagram of the seam welding wheel gland of the present invention; Figure 4 It is a schematic cross-sectional view of the main body of the seam welding wheel of the present invention; Figure 5 It is a schematic cross-sectional view of a water cooling plate of the present invention; Figure 6 It is a schematic diagram of assembling the water cooling plate and the seam welding wheel of the present invention; Figure 7 This is a front view of the principle of the present invention; Figure 8 It is a top view of the principle of the present invention; Fig. 9 It is a side view of the principle of the present invention; Fig.10 This is a macroscopic photograph of a cross section of a weld in Example 1 of the present invention; Fig.11 This is a macroscopic photograph of the cross section of the weld in Example 2 of the present invention; Fig.12 This is a macroscopic photograph of the cross section of the weld in Example 3 of the present invention; Fig.13 This is a macroscopic photograph of the cross section of the weld in Example 4 of the present invention; Fig.14 This is a macroscopic photograph of the cross section of the weld in Example 5 of the present invention; In the figure: laser beam 1, stainless steel welding wire 2, laser molten pool 3, welding seam 4, laser beam spot track 5, seam welding wheel body 601, seam welding wheel pressure cover 602, groove 603, water cooling plate 7, cooling water joint 8. DETAILED DESCRIPTION

[0014] The present invention will be further described below by way of examples in conjunction with the accompanying drawings.

[0015] See attached Figure 1-9A laser brazing method for a seam welding wheel, wherein a water cooling plate 7 is placed under the seam welding wheel; a laser beam 1 and a stainless steel welding wire 2 are arranged in a butt groove at a connection between a seam welding wheel gland 602 and a seam welding wheel body 601 along a welding direction; during welding, under argon protection, a spot of the laser beam 1 swings inside the groove according to a specific laser beam spot trajectory 5, irradiating the stainless steel welding wire and part of the groove, so that the stainless steel welding wire is fully melted, and the copper material on the side wall of the groove is not melted or slightly melted, forming a laser molten pool 3; the laser molten pool 3 is finally cooled and solidified to form a weld 4.

[0016] Preferably, the track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 1.5 mm to 14.3 mm, the track width D2 of the laser beam spot on the weld surface along the welding direction is 0.1 mm to 10 mm, and the laser oscillation frequency is 5 Hz to 200 Hz.

[0017] Preferably, the angle α between the laser beam and the vertical direction is 0°~30°, the angle β between the stainless steel welding wire and the horizontal direction is 15°~60°, and the angle between the laser beam and the center line of the stainless steel welding wire is γ=α+(90°-β).

[0018] Preferably, the laser beam power is 1kW~4kW, the spot diameter of the laser beam on the weld surface is 0.2mm~1mm; the diameter of the stainless steel welding wire is 0.8mm~1.6mm, the wire feeding speed is 500mm / min~2000mm / min, the shielding gas flow rate is 10L / min~50L / min; the welding speed is 100mm / min~1000mm / min.

[0019] Preferably, the groove depth W of the welding wheel to be welded is 1mm~6mm, a butt groove with a single-sided groove angle θ of 20°~50° is set, and the cooling water temperature T of the water cooling plate below the seam welding wheel is 0~60°C.

[0020] Preferably, the laser beam spot trajectory is in any shape, such as an ellipse, a straight line, a C-shape, a square, or the like. Embodiment 1

[0021] The thickness of the weld wheel workpiece to be welded is 9 mm, the groove depth W is 2.5 mm, the single-sided groove angle θ is 30°, and the cooling water temperature T of the lower water cooling plate is 15°C; The laser beam 1 spot oscillates along an elliptical trajectory inside the groove. During welding, the track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 3.1 mm, and the track width D2 of the laser beam spot on the weld surface along the welding direction is 0.6 mm. The laser oscillation frequency is 30 Hz. The angle α between the laser beam and the vertical direction is 0°, the angle β between the stainless steel welding wire and the horizontal direction is 30°, and the angle between the laser beam and the center line of the stainless steel welding wire is γ=60°; The laser beam power is 2.5kW, and the spot diameter of the laser beam on the weld surface is 0.4mm; the diameter of the stainless steel welding wire is 1.2mm, the wire feeding speed is 1300mm / min, the shielding gas flow rate is 35L / min; the welding speed is 240mm / min.

[0022] Welding effect Fig.10 shown. Embodiment 2

[0023] The thickness of the weld wheel workpiece to be welded is 11 mm, the groove depth W is 3 mm, the single-sided groove angle θ is 26°, and the cooling water temperature T of the lower water cooling plate is 10°C; The laser beam 1 spot swings along a straight trajectory inside the groove. During welding, the track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 3.2 mm. Other parameters are consistent with those in the first embodiment.

[0024] Welding effect Fig.11 shown. Embodiment 3

[0025] The thickness of the weld wheel workpiece to be welded is 12 mm, the groove depth W is 2.2 mm, the single-sided groove angle θ is 35°, and the cooling water temperature T of the lower water cooling plate is 10°C; The laser beam 1 spot swings along a C-shaped trajectory inside the groove. During welding, the track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 3.5 mm, and the track width D2 of the laser beam spot on the weld surface along the welding direction is 1 mm. The laser swing frequency is 20 Hz. The angle α between the laser beam and the vertical direction is 0°, the angle β between the stainless steel welding wire and the horizontal direction is 35°, and the angle between the laser beam and the center line of the stainless steel welding wire is γ=55°; The laser beam power is 2.6kW, and the spot diameter of the laser beam on the weld surface is 0.4mm; the diameter of the stainless steel welding wire is 1.2mm, the wire feeding speed is 1100mm / min, the shielding gas flow rate is 25L / min; the welding speed is 240mm / min.

[0026] Welding effect Fig.12 shown. Embodiment 4

[0027] The thickness of the weld wheel workpiece to be welded is 10 mm, the groove depth W is 1.25 mm, the single-sided groove angle θ is 45°, and the cooling water temperature T of the lower water cooling plate is 15°C; The laser beam 1 spot swings along an elliptical trajectory inside the groove. During welding, the track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 3 mm, and the track width D2 of the laser beam spot on the weld surface along the welding direction is 0.5 mm. The laser swing frequency is 20 Hz. The angle α between the laser beam and the vertical direction is 5°, the angle β between the stainless steel welding wire and the horizontal direction is 35°, the angle between the laser beam and the center line of the stainless steel welding wire is γ=60°, and the other parameters are the same as those in Example 3.

[0028] Welding effect Fig.13 shown. Embodiment 5

[0029] The thickness of the weld wheel workpiece to be welded is 12 mm, the groove depth W is 2.1 mm, the single-sided groove angle θ is 30°, and the cooling water temperature T of the lower water cooling plate is 10°C; The laser beam 1 spot oscillates along a square track inside the groove. During welding, the track width of the laser beam spot on the weld surface perpendicular to the welding direction is D1, and the track width of the laser beam spot on the weld surface along the welding direction is D2, both of which are 3 mm. The laser oscillation frequency is 20 Hz. The angle α between the laser beam and the vertical direction is 0°, the angle β between the stainless steel welding wire and the horizontal direction is 25°, and the angle between the laser beam and the center line of the stainless steel welding wire is γ=65°; The laser beam power is 2.6kW, and the spot diameter of the laser beam on the weld surface is 0.5mm; the diameter of the stainless steel welding wire is 1.2mm, the wire feeding speed is 1100mm / min, the shielding gas flow rate is 25L / min; the welding speed is 240mm / min.

[0030] Welding effect Fig.14 shown.

[0031] The present invention places a water cooling plate under the workpiece to be welded, and cooling water joints are respectively provided on both sides of the water cooling plate; during the welding process, a swinging laser beam is used to irradiate the stainless steel welding wire and part of the groove under the protection of argon gas to form a laser molten pool, thereby realizing precise control of heat input within a certain range, achieving the effect that the stainless steel welding wire is fully melted while the copper material is not melted or slightly dissolved, realizing the welding of the seam welding wheel, and ensuring good and stable weld formation. Applying a water cooling plate under the seam welding wheel can quickly transfer excess welding heat, effectively avoid the influence of the parent material, solve the problems of reflection of the copper welding wire and unstable wire feeding, and significantly improve the welding efficiency while significantly improving the service life of the seam welding wheel. In addition, stainless steel welding wire is low in price and high in stability, which can greatly reduce production costs while ensuring welding quality.

Claims

1. A laser brazing method for a seam welding wheel, characterized in that: Along the welding direction, a laser beam (1) and a stainless steel welding wire (2) are arranged in a groove (603) at the connection between a seam welding wheel pressure cover (602) and a seam welding wheel body (601); during welding, a water cooling plate (7) is placed below the seam welding wheel, and under the protection of argon gas, a spot of the laser beam (1) swings inside the groove according to a specific laser beam spot trajectory (5), so that the stainless steel welding wire is fully melted and the copper material on the side wall of the groove is not melted or slightly melted, thereby forming a laser molten pool (3); the laser molten pool (3) is finally cooled and solidified to form a weld (4).

2. The laser brazing method of a seam welding wheel according to claim 1, characterized in that: The track width D1 of the laser beam spot on the weld surface perpendicular to the welding direction is 1.5mm~14.3mm, the track width D2 of the laser beam spot on the weld surface along the welding direction is 0.1mm~10mm, and the laser oscillation frequency is 5Hz~200Hz.

3. The laser brazing method of a seam welding wheel according to claim 1 or 2, characterized in that: The angle α between the laser beam and the vertical direction is 0°~30°, the angle β between the stainless steel welding wire and the horizontal direction is 15°~60°, and the angle between the laser beam and the center line of the stainless steel welding wire is γ=α+(90°-β).

4. The laser brazing method of a seam welding wheel according to claim 3, characterized in that: The laser beam power is 1kW~4kW, the spot diameter of the laser beam on the weld surface is 0.2mm~1mm; the diameter of the stainless steel welding wire is 0.8mm~1.6mm, the wire feeding speed is 500mm / min~2000mm / min, the shielding gas flow rate is 10L / min~50L / min; the welding speed is 100mm / min~1000mm / min.

5. The laser brazing method of a seam welding wheel according to claim 4, characterized in that: The groove depth W of the welding wheel to be welded is 1mm~6mm, and the butt groove with a single-sided groove angle θ of 20°~50° is set, and the cooling water temperature T of the water cooling plate below the seam welding wheel is 0~60°C.

6. The laser brazing method of a seam welding wheel according to claim 1 or 2, characterized in that: The laser beam spot trajectory (5) is elliptical, linear, C-shaped or square.

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