Thin-walled tube base welding process
By adopting laser welding technology, the joints and bases of thin-walled pipe bases are assembled through interference and matching, and appropriate joint parameters are set, which solves the problems of insufficient weld melting depth and pipe wall collapse and breakdown in traditional argon arc welding methods, achieving high-quality welding results.
Patent Information
- Application Number
- CN202411846189.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-02-28
AI Technical Summary
The existing thin-walled pipe base adopts traditional argon arc welding method, which is prone to the problem of insufficient weld melting depth. If the welding current is increased, the pipe wall collapse and breakdown are prone to occur.
Using laser welding technology, through interference matching joints and bases, the laser head is 90° vertically downward, and the distance between the welding gun and the workpiece surface is 8 to 10mm, to find the best focus point, and set appropriate welding parameters, such as the welding gun operation speed, welding power, overcut angle, welding frequency and duty cycle, to perform laser welding and laser repair.
The stability and welding speed of the welding process are improved, and the welding quality is ensured. The weld melting depth reaches 1.8mm, the weld strength meets the blasting pressure of more than 45Mpa, the weld is free of debris, no overburning, no oxidation and discoloration, no false welding, and the weld leakage rate is less than 1x10-9atm.cc/sec.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of mechanical processing, in particular to a welding process for a thin-walled pipe base. Background Art
[0002] Laser welding technology is currently widely used in the semiconductor field. With the increasing demand for different welding technologies, there are also many challenges in overcoming welding technology.
[0003] The existing thin-walled pipe base adopts the traditional argon arc welding method, which is prone to the problem of insufficient weld penetration after welding. If the welding current is increased, the pipe wall is prone to collapse and breakdown. Summary of the invention
[0004] Aiming at the technical problem that the conventional argon arc welding method for thin-walled pipe base in the above-mentioned prior art has insufficient welding penetration, the present invention provides a thin-walled pipe base welding process.
[0005] A thin-walled tube base welding process of the present invention comprises a joint and a base, and the welding process comprises the following steps: S1. Assemble the joint and the base together by interference fit; S2. Clamp the assembled workpiece on the welding fixture; S3. Laser welding: The laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 8 to 10 mm, the best focus point is found, the welding gun runs at a speed of 1000 to 1100 mm / min, the welding power is 90% to 100% of the normal power, the overcut angle is 40° to 50°, the welding frequency shall not be less than 4000 Hz, and the duty cycle is set to 100%; S4. Laser repair: Adjust the welding parameters so that the welding gun runs at a speed of 750 to 850 mm / min, the welding power is 40% to 50% of the normal power, and the overcut angle is 145° to 155°.
[0006] Preferably, in step S1, an assembly jig is used for assembly, and the assembly jig includes a jig body, a first assembly hole and a second assembly hole are provided in the middle of the jig body from top to bottom, the first assembly hole and the second assembly hole are connected, the first assembly hole and the second assembly hole pass through the jig body, the inner diameter of the second assembly hole is larger than the inner diameter of the first assembly hole, the first assembly hole cooperates with the joint, and the second assembly hole cooperates with the base, a connecting hole is provided in the middle of the base, the base is placed in the second assembly hole, the lower end of the joint is inserted into the first assembly hole, and the lower end of the joint is inserted downward into the connecting hole in the middle of the base by external force.
[0007] Preferably, in step S3, the operating speed of the welding gun is 1100 mm / min, the welding power is 100% of the normal power, and the overcut angle is 50°.
[0008] Preferably, in step S4, the operating speed of the welding gun is 800 mm / min, the welding power is 45% of the normal power, and the overcut angle is 150°.
[0009] Preferably, in step S3, laser welding is performed under a protective atmosphere; in step S4, laser repair is performed under a protective atmosphere. Further, the protective atmosphere is at least one of CO2, Ar, He, and N2.
[0010] Preferably, step S2 further includes performing surface treatment on the parts to be welded of the assembled workpieces. Further, the surface treatment includes degreasing, cleaning and drying.
[0011] Preferably, the welding process further comprises the following steps: S5. Grinding treatment: Grind the welding surface to make the surface roughness Ra ≤ 0.1μm.
[0012] Compared with the prior art, the thin-walled pipe base welding process of the present invention improves the process stability and welding speed by improving the welding process and related parameters in the welding process, thereby ensuring the welding quality and the weld leakage rate is less than 1x10 -9 atm.cc / sec, the weld has no debris, no overburning, no oxidation discoloration, no false welds, the weld penetration reaches 1.8mm, and the weld strength meets the blasting pressure requirement of more than 45Mpa. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0014] Figure 1 It is a structural schematic diagram of an assembly fixture according to an embodiment of the present invention.
[0015] Figure 2 for Figure 1 Cross-sectional view along the AA direction.
[0016] Figure 3 This is a schematic diagram of an assembly jig in use according to an embodiment of the present invention. DETAILED DESCRIPTION
[0017] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.
[0018] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.
[0019] A thin-walled tube base welding process of the present invention, the thin-walled tube base includes a joint 11 and a base 12, and the welding process includes the following steps: S1. Assemble the connector 11 and the base 12 together by interference fit; S2. Clamp the assembled workpiece on the welding fixture; S3. Laser welding: The laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 8 to 10 mm, the best focus point is found, the welding gun runs at a speed of 1000 to 1100 mm / min, the welding power is 90% to 100% of the normal power, the overcut angle is 40° to 50°, the welding frequency shall not be less than 4000 Hz, and the duty cycle is set to 100%; S4. Laser repair: If the weld collapses and becomes rough after laser welding, adjust the welding parameters so that the welding gun runs at a speed of 750 to 850 mm / min, the welding power is 40% to 50% of the normal power, the overcut angle is 145° to 155°, the welding frequency is still not less than 4000 Hz, and the duty cycle is still 100%.
[0020] The distance between the welding gun and the workpiece surface is 8 to 10 mm, which is convenient for quickly finding the best focusing point of the laser; too small welding frequency and duty cycle will reduce the weld penetration and may result in incomplete welds; this is for a welding speed of 750-850mm / min. If the welding frequency and duty cycle are reduced, the welding speed will also decrease accordingly.
[0021] In step S1, in order to ensure the assembly effect, use assembly fixture 2 for assembly, see Figures 1 to 3The assembly jig 2 includes a jig body 20, and the middle part of the jig body 20 is provided with a first assembly hole 21 and a second assembly hole 22 from top to bottom. The first assembly hole 21 and the second assembly hole 22 are connected, and the first assembly hole 21 and the second assembly hole 22 pass through the jig body 20. The inner diameter of the second assembly hole 22 is larger than the inner diameter of the first assembly hole 21. The first assembly hole 21 matches with the joint 11, and the second assembly hole 22 matches with the base 12. A connecting hole is provided in the middle part of the base 12, and the base 12 is placed in the second assembly hole 22. The lower end of the joint 11 is inserted into the first assembly hole 21, and the lower end of the joint 11 is inserted downward into the connecting hole in the middle part of the base 12 by external force. The welding surface is the end face of the base 12 away from the joint 11, and the welding part is the position where the base 12 contacts the joint 11 on the welding surface. This assembly method can effectively reduce assembly deformation, reduce assembly errors, and ensure the welding quality of the thin-walled tube base.
[0022] In step S3, the welding gun operates at a speed of 1100 mm / min, the welding power is 100% of the normal power, and the overcut angle is 50°.
[0023] In step S4, the welding gun operates at a speed of 800 mm / min, the welding power is 45% of the normal power, and the overcut angle is 150°.
[0024] In order to avoid oxidation reaction and ensure welding quality, in step S3, laser welding is performed under a protective atmosphere; in step S4, laser repair is performed under a protective atmosphere. The protective atmosphere is at least one of CO2, Ar, He, and N2.
[0025] In order to ensure the welding quality, step S2 also includes performing surface treatment on the parts to be welded of the assembled workpieces, and the surface treatment includes degreasing, cleaning and drying.
[0026] In order to ensure the surface flatness of the thin-walled tube base, thereby ensuring the sealing performance when applied to the semiconductor industry, the welding process also includes the following steps: S5. Grinding treatment: Grind the welding surface to make the surface roughness Ra ≤ 0.1μm.
[0027] Embodiment 1: The thin-walled tube base includes a joint and a base, a connecting hole is provided in the middle of the base, and the thin-walled tube base is welded in the following manner: S1. Assemble the connector and the base together by interference fit using an assembly jig; S2. Surface treatment is performed on the parts of the assembled workpiece to be welded, and the assembled workpiece is clamped on the welding fixture; S3. Laser welding: The laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 8mm, the best focus point is found, the welding gun runs at a speed of 1000mm / min, the welding power is 90% of the normal power, the overcut angle is 40°, the welding frequency is 4000Hz, and the duty cycle is 100%; S4. Laser repair: The welding gun runs at a speed of 750 mm / min, the welding power is 40% of the normal power, the overcut angle is 145°, the welding frequency is 4000 Hz, and the duty cycle is 100%; Laser welding and laser modification are performed under argon atmosphere.
[0028] Embodiment 2: The thin-walled tube base includes a joint and a base, a connecting hole is provided in the middle of the base, and the thin-walled tube base is welded in the following manner: S1. Assemble the connector and the base together by interference fit using an assembly jig; S2. Surface treatment is performed on the parts of the assembled workpiece to be welded, and the assembled workpiece is clamped on the welding fixture; S3. Laser welding: The laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 9mm, the best focus point is found, the welding gun runs at a speed of 1050mm / min, the welding power is 95% of the normal power, the overcut angle is 45°, the welding frequency is 4000Hz, and the duty cycle is 100%; S4. Laser repair: The welding gun running speed is 800mm / min, the welding power is 45% of the normal power, the overcut angle is 145°, the welding frequency is 4000Hz, and the duty cycle is 100%; Laser welding and laser modification are performed in a nitrogen environment.
[0029] Embodiment 3: The thin-walled tube base includes a joint and a base, a connecting hole is provided in the middle of the base, and the thin-walled tube base is welded in the following manner: S1. Assemble the connector and the base together by interference fit using an assembly jig; S2. Surface treatment is performed on the parts of the assembled workpiece to be welded, and the assembled workpiece is clamped on the welding fixture; S3. Laser welding: the laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 10mm, the best focus point is found, the welding gun runs at a speed of 1100mm / min, the welding power is 100% of the normal power, the overcut angle is 50°, the welding frequency is 4000Hz, and the duty cycle is 100%; S4. Laser repair: The welding gun running speed is 800mm / min, the welding power is 45% of the normal power, the overcut angle is 150°, the welding frequency is 4000Hz, and the duty cycle is 100%; Laser welding and laser modification are performed in a helium environment.
[0030] Embodiment 4: The thin-walled tube base includes a joint and a base, a connecting hole is provided in the middle of the base, and the thin-walled tube base is welded in the following manner: S1. Assemble the connector and the base together by interference fit using an assembly jig; S2. Surface treatment is performed on the parts of the assembled workpiece to be welded, and the assembled workpiece is clamped on the welding fixture; S3. Laser welding: the laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 9mm, the best focus point is found, the welding gun runs at a speed of 1100mm / min, the welding power is 100% of the normal power, the overcut angle is 50°, the welding frequency is 4000Hz, and the duty cycle is 100%; S4. Laser repair: The welding gun runs at a speed of 850 mm / min, the welding power is 50% of the normal power, the overcut angle is 155°, the welding frequency is 4000 Hz, and the duty cycle is 100%; Laser welding and laser modification are performed in a nitrogen environment.
[0031] The outer diameter of the joint of the thin-walled tube base in Examples 1 to 4 is 6.38 mm, and the hole diameter is 4.4 mm.
[0032] After testing, the weld leakage rate of the thin-walled pipe base welded in Examples 1 to 4 is less than 1x10 -9 atm.cc / sec, the weld has no debris, no overburning, no oxidation discoloration, no false welds, the weld penetration reaches 1.8mm, and the weld strength meets the blasting pressure requirement of more than 45Mpa.
[0033] The thin-walled pipe base welding process of the present invention improves the welding process and related parameters in the welding process, thereby improving the process stability and welding speed, ensuring the welding quality, and the weld leakage rate is less than 1x10 -9 atm.cc / sec, the weld has no debris, no overburning, no oxidation discoloration, no false welds, the weld penetration reaches 1.8mm, and the weld strength meets the blasting pressure requirement of more than 45Mpa.
[0034] The present invention has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present invention. In addition, the technical features involved in the different embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.
Claims
1. A thin-walled tube base welding process, characterized in that: The thin-walled tube base comprises a joint and a base, and the welding process comprises the following steps: S1. Assemble the joint and the base together by interference fit; S2. Clamp the assembled workpiece on the welding fixture; S3. Laser welding: The laser head is 90° vertically downward, the distance between the welding gun and the workpiece surface is 8 to 10 mm, the best focus point is found, the welding gun runs at a speed of 1000 to 1100 mm / min, the welding power is 90% to 100% of the normal power, the overcut angle is 40° to 50°, the welding frequency shall not be less than 4000 Hz, and the duty cycle is set to 100%; S4. Laser repair: Adjust the welding parameters so that the welding gun runs at a speed of 750 to 850 mm / min, the welding power is 40% to 50% of the normal power, and the overcut angle is 145° to 155°.
2. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: In step S1, assembly is performed using an assembly jig, the assembly jig comprising a jig body, a first assembly hole and a second assembly hole being sequentially provided in the middle of the jig body from top to bottom, the first assembly hole being connected to the second assembly hole, the first assembly hole and the second assembly hole passing through the jig body, the inner diameter of the second assembly hole being larger than the inner diameter of the first assembly hole, the first assembly hole being matched with the joint, the second assembly hole being matched with the base, a connecting hole being provided in the middle of the base, the base being placed in the second assembly hole, the lower end of the joint being inserted into the first assembly hole, and the lower end of the joint being inserted downward into the connecting hole in the middle of the base by external force.
3. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: In step S3, the welding gun operates at a speed of 1100 mm / min, the welding power is 100% of the normal power, and the overcut angle is 50°.
4. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: In step S4, the welding gun operates at a speed of 800 mm / min, the welding power is 45% of the normal power, and the overcut angle is 150°.
5. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: In step S3, laser welding is performed under a protective atmosphere.
6. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: In step S4, laser repair is performed under a protective atmosphere.
7. A thin-walled pipe base welding process as claimed in claim 5 or 6, characterized in that: The protective atmosphere is at least one of CO2, Ar, He, and N2.
8. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: Step S2 also includes performing surface treatment on the parts to be welded of the assembled workpieces.
9. A thin-walled pipe base welding process as claimed in claim 8, characterized in that: The surface treatment includes degreasing, cleaning and drying.
10. A thin-walled pipe base welding process as claimed in claim 1, characterized in that: The welding process also includes the following steps: S5. Grinding treatment: Grind the welding surface to make the surface roughness Ra ≤ 0.1μm.