A SLMed GH3230 lock bottom weld seam fiber laser long focal length focal point hole rotary welding method
By employing a fiber laser long focal length in-focus hole rotary welding method, the surface forming and internal defect problems of the GH3230 lock bottom weld in the existing technology have been solved, achieving high-quality welding of GH3230 components and improving manufacturing quality and reliability in the aerospace field.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING UNIV OF TECH
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-29
AI Technical Summary
The existing fiber laser welding process in a stationary state cannot meet the comprehensive quality requirements of good surface formation, no internal cracks and defects, and low porosity of 4 mm deep lock welds. This has become a bottleneck restricting the splicing manufacturing of GH3230 components manufactured by multi-segment SLM process in the aerospace field.
The fiber laser long focal length in-focus hole rotation welding method is adopted. By configuring a 330mm focusing field lens, galvanometer system, protective gas device and optimizing welding parameters, the high-speed circular rotation of the laser focus in the lock bottom joint is achieved. Combined with argon gas protection, the stability and quality of the welding process are ensured.
It effectively eliminated the humps on the weld surface, reduced porosity and microcrack defects, improved the forming quality and reliability of the weld, achieved high-quality welding of GH3230 components, and reduced manufacturing process risks and costs.
Smart Images
Figure CN122099587A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of welding technology, specifically to a method for rotating the SLMed GH3230 lock-in weld within the focal hole of a fiber laser with a long focal length. Background Technology
[0002] GH3230 is a solid solution strengthened nickel-based superalloy. Due to its excellent high-temperature strength, creep resistance and oxidation resistance, it is widely used in the manufacture of key components such as combustion chambers and air intakes in the aerospace field.
[0003] Selective Laser Melting (SLM) technology, through a layer-by-layer digital net-shape forming process, is now widely used in the additive manufacturing of hot-end components for aero-engines. The use of SLM technology for 3D printing of critical hot-end components such as the GH3230 combustion chamber and air intake in the aerospace field is becoming increasingly mature.
[0004] For large and complex components, considering factors such as the size of SLM equipment, overall manufacturing process risks, and manufacturing costs, using SLM technology for segmented printing and laser welding for overall component manufacturing remains an effective method for manufacturing large-size SLM components.
[0005] The lock-bottom joint is a typical butt joint type. Its welding process exhibits deep-penetration, non-penetrating welding characteristics. However, the high W content of GH3230, the slightly lower density of SLM-prepared components compared to traditional rolled high-temperature alloy plates, the narrow solid-liquid phase temperature range of high-temperature alloys, and poor liquid feeding capacity in the later stages of solidification lead to severe porosity and crack defects in the lock-bottom weld. Furthermore, because the butt welding depth of the lock-bottom interface is typically large, requiring high laser power, severe humps appear on the weld surface during high-power fiber laser welding, accompanied by microcracks. Due to the large penetration depth required for the lock-bottom weld, a shorter focal length laser focusing system is typically used to improve laser penetration, thereby increasing the focused spot energy density and penetration. However, the small spot size results in a high energy density at the spot center, exacerbating keyhole and molten pool fluctuations and worsening the tendency for poor weld surface formation. Poor surface formation, severe microcracks, and porosity defects have become a bottleneck restricting the reliability of the multi-stage SLM manufacturing process for GH3230 components in the aerospace field.
[0006] The existing fiber laser welding process in a stationary state cannot achieve the comprehensive quality requirements of good surface formation, no internal cracks and defects, and low porosity of 4 mm deep lock bottom welds. There is an urgent need to develop a new laser welding process to achieve the beneficial effect of high-quality welding of lock bottom joints of SLMed GH3230 components. Summary of the Invention
[0007] To address the aforementioned problems in the prior art, this invention provides a method for rotating the SLMed GH3230 lock-bottom weld within the focal hole of a long-focal-length fiber laser. This method effectively solves the problem that existing fiber laser welding processes with a stationary focal point cannot achieve good surface formation and absence of internal cracks in 4 mm deep lock-bottom welds, thus enabling high-quality welding of the lock-bottom joints of SLMed GH3230 components.
[0008] To achieve the above objectives, this invention proposes a method for rotary welding of SLMed GH3230 lock-in weld seams within a long focal length fiber laser focal hole, comprising: S1. Pre-treat the area to be welded of the SLMed GH3230 lock bottom joint; S2. Fix the pre-treated SLMed GH3230 lock bottom connector with tooling to ensure that the butt joint gap of the lock bottom connector meets the welding requirements; S3. The optical components of the fiber laser welding equipment are configured, using a focusing field lens with a focal length of 330mm, a galvanometer system, and a transmission fiber and collimation unit. S4. Set up a welding shielding gas device, using a shielding gas nozzle with a tail cover, adjust the distance between the nozzle and the workpiece surface, and introduce argon gas into the welding area to form a protective atmosphere. S5. Set the process parameters of the fiber laser welding equipment, turn on the galvanometer system to control the laser focus to make high-speed circular rotation vibration in the welding hole of the lock bottom joint, and set the rotation radius and rotation frequency of the laser focus. S6. Start the fiber laser welding equipment and weld along the butt weld trajectory of the SLMed GH3230 lock bottom joint, ensuring that the weld penetration depth is not less than 4mm, and complete the non-penetrating laser welding of the lock bottom joint.
[0009] Preferably, in S1, the pretreatment involves wiping and cleaning the area to be welded on the SLMed GH3230 lock bottom connector with acetone to remove oil and impurities.
[0010] Preferably, in S2, the tooling clamping and fixing method must ensure that the workpiece is not deformed during the welding process, and the butt joint gap of the bottom joint is less than 0.05mm.
[0011] Preferably, in S3, the core diameter of the transmission optical fiber is 200. The collimation unit has a focal length of 120mm, and the focusing field lens, collimation unit, and transmission optical fiber are coaxially arranged.
[0012] Preferably, in S4, the distance between the lower end of the protective gas nozzle and the workpiece surface is 1 mm, the argon gas flow rate is 10 L / min, and the argon gas continuously protects the molten pool and the high-heat zone of the weld during the welding process.
[0013] Preferably, in S4, the argon gas flows out in advance before the laser is emitted to pre-form a protective atmosphere in the welding area, and after welding is completed, argon gas is continuously supplied to the weld and molten pool area for cooling.
[0014] Preferably, in S5, the circular rotation vibration center of the laser focus coincides with the welding center of the SLMed GH3230 lock bottom connector, the rotation radius is 0.2mm, and the rotation frequency is 200Hz.
[0015] Preferably, in S5, the process parameters of the fiber laser welding equipment include laser power, defocusing amount, and welding speed. The defocusing amount is set to 0mm, and the laser power and welding speed are adjusted according to the actual welding requirements.
[0016] Preferably, the laser power is adjustable within a range of 3000W to 5000W, and the welding speed is adjustable within a range of 1.0m / min to 2.0m / min.
[0017] Preferably, in S6, the focused beam emitted by the focusing field lens is incident perpendicularly to the workpiece surface onto the welding part of the bottom joint, and welding is performed at a uniform speed along the butt weld trajectory during the welding process.
[0018] Therefore, this invention proposes a method for rotary welding of SLMed GH3230 lock-in weld seams within a long focal length fiber laser focal hole, the advantages of which are as follows: (1) Relying on the optical characteristics of the 330mm long focal length focusing field lens, the keyhole opening size is increased, the front wall angle is reduced, the keyhole and molten pool fluctuations are reduced, the welding process stability is improved, the weld surface hump is effectively eliminated, and the surface forming quality is improved.
[0019] (2) By combining the galvanometer system to achieve high-speed rotation in the laser focal hole, the keyhole and molten pool shape can be actively controlled to suppress molten pool collapse. At the same time, stirring the molten pool promotes the overflow of bubbles and significantly reduces the porosity. High-frequency rotation can also reduce the cooling rate of the molten pool and completely suppress weld microcracks. Under the premise of ensuring a weld depth of ≥4mm, the weld is crack-free and has low porosity. Moreover, the process is highly adaptable and can be extended to the welding of various alloy lock bottom joints.
[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of a method for rotary welding of SLMed GH3230 bottom-lock weld seams in a fiber laser long focal length focal hole according to the present invention; Figure 2These are the weld surface morphology diagram, weld cross-sectional diagram, and weld longitudinal section diagram obtained by using fiber laser rotational welding with and without focal holes at both short and long focal lengths in Embodiment 1 of the present invention.
[0022] Figure Labels 1. Transmission fiber; 2. Collimation unit; 3. Focusing field lens; 4. Focusing beam; 5. Left side plate of the lock bottom connector; 6. Right side plate of the lock bottom connector; 7. Keyhole; 8. Molten pool; 9. Weld seam; 10. Nozzle with tail cover protection. Detailed Implementation
[0023] To make the technical solutions, advantages, and objectives of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of this application.
[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0025] like Figures 1-2 As shown, the present invention provides a method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole, comprising: S1. Pre-treat the area to be welded of the SLMed GH3230 lock bottom joint; The pretreatment involves wiping and cleaning the areas of the SLMed GH3230 lock bottom connector to be soldered with acetone to remove oil and impurities.
[0026] S2. Fix the pre-treated SLMed GH3230 lock bottom connector with tooling to ensure that the butt joint gap of the lock bottom connector meets the welding requirements; The tooling clamping and fixing method must ensure that the workpiece is not deformed during the welding process, and the butt joint gap of the locking bottom joint is less than 0.05mm.
[0027] S3. The optical components of the fiber laser welding equipment are configured, including a focusing field lens 3 with a focal length of 330mm, a galvanometer system, and a transmission fiber 1 and a collimation unit 2. The core diameter of transmission fiber 1 is 200. The focal length of the collimation unit 2 is 120mm, and the focusing field lens 3, the collimation unit 2 and the transmission fiber 1 are coaxially arranged.
[0028] S4. Set up a welding shielding gas device, using a shielding gas nozzle 10 with a tail cover, adjust the distance between the nozzle and the workpiece surface, and introduce argon gas into the welding area to form a protective atmosphere. The distance between the lower end of the protective gas nozzle 10 with tail cover and the workpiece surface is 1mm, and the argon gas flow rate is 10L / min. The argon gas continuously protects the molten pool 8 and the high-heat zone of the weld 9 during the welding process.
[0029] Argon gas is released in advance before laser emission to pre-form a protective atmosphere in the welding area. After welding is completed, argon gas is continuously supplied to the weld 9 and the molten pool 8 area for cooling.
[0030] S5. Set the process parameters of the fiber laser welding equipment, turn on the galvanometer system to control the laser focus to make high-speed circular rotation vibration in the welding hole of the lock bottom joint, and set the rotation radius and rotation frequency of the laser focus. The circular rotation vibration center of the laser focus coincides with the welding center of the SLMed GH3230 lock bottom connector, with a rotation radius of 0.2mm and a rotation frequency of 200Hz.
[0031] The process parameters of fiber laser welding equipment include laser power, defocusing amount, and welding speed. The defocusing amount is set to 0mm, and the laser power and welding speed are adjusted according to the actual welding requirements.
[0032] The laser power can be adjusted from 3000W to 5000W, and the welding speed can be adjusted from 1.0m / min to 2.0m / min.
[0033] S6. Start the fiber laser welding equipment and weld along the butt weld line 9 of the SLMed GH3230 lock bottom joint, ensuring that the weld penetration depth is not less than 4mm, and complete the non-penetrating laser welding of the lock bottom joint.
[0034] The focused beam 4 emitted by the focusing field lens 3 is perpendicular to the workpiece surface and is incident on the welding part of the lock bottom joint. During the welding process, the welding is carried out at a uniform speed along the trajectory of the butt weld 9.
[0035] This invention takes the 4mm deep non-penetrating laser welding of the SLMed GH3230 lock-bottom connector as an example to verify the practical application effect of the rotational welding method within the focal hole of a long focal length fiber laser. The specific implementation process is as follows: Pre-treatment of the parts to be welded: Wipe the parts to be welded on the left side plate 5 and right side plate 6 of the SLMed GH3230 lock bottom connector with acetone to remove oil and impurities. After the pre-treatment is completed, the parts are clamped and fixed with tooling to ensure that the butt gap is less than 0.05mm and that the workpiece is not deformed during the welding process. Equipment component configuration: Assemble the fiber laser welding equipment, using a core diameter of 200 mm. The transmission fiber 1, the collimation unit 2 with a focal length of 120mm and the focusing field lens 3 with a focal length of 330mm are coaxially arranged. The focusing field lens 3 is equipped with a galvanometer system to ensure that the focused beam 4 is perpendicularly incident on the bottom joint to be welded. Debugging of protective gas device: Install the protective nozzle 10 with tail cover, adjust the distance between its lower end and the workpiece surface to 1mm, set the argon gas protection flow rate to 10L / min, and turn on the argon gas in advance to pre-form a protective atmosphere in the welding area. Welding parameter settings: The laser power is set to 4800W, the defocusing amount is 0mm, and the welding speed is 1.5m / min. The laser focus is controlled by the galvanometer system to make high-speed circular rotation vibration in the welding hole, with a rotation radius of 0.2mm and a rotation frequency of 200Hz. The vibration center coincides with the welding center of the lock bottom joint. The welding process parameters and field lens focal length are shown in Table 1.
[0036] Table 1
[0037] Laser welding implementation: Start the fiber laser welding equipment and weld at a constant speed along the trajectory of the butt weld 9 of the lock bottom joint. During the welding process, argon gas continuously protects the molten pool 8 and the high-heat zone of weld 9 to ensure that the welding penetration is not less than 4mm. After welding, wire cutting is used to cut along the center of the weld to obtain the longitudinal section of the weld, and cutting perpendicular to the center of the weld to obtain the cross section of the weld.
[0038] Post-weld protection: After welding, continue to supply argon gas to the molten pool 8 and weld 9 area to cool to room temperature, then turn off the argon gas to complete the fiber laser long focal length focal hole rotary welding operation of the entire SLMed GH3230 lock bottom joint.
[0039] Welding result analysis: Without rotation, a 330mm field lens produces fewer pores in the longitudinal section of the weld compared to a 170mm focal length field lens, but both parameters result in numerous crack defects in the weld. Under the same focal length, compared to straight-line welding, rotating the laser focus in the hole with a 170mm field lens can transform the continuous pores of straight-line welding into dispersed pores, with the pores being essentially circular. However, crack defects are present in the lower part of the weld.
[0040] Under the same rotation parameters, the 330mm field lens has a slightly larger weld cross-sectional size than the 170mm focal length field lens, resulting in better suppression of porosity and cracks. There are sporadic pores and no crack defects in the transverse and longitudinal interfaces of the weld.
[0041] Compared with linear welding and short focal length laser focus rotation welding, the fiber laser long focal length focus hole rotation welding process for SLMed GH3230 lock-bottom connectors involved in this invention can completely suppress crack defects in the weld and significantly reduce the number of pores.
[0042] Therefore, this invention provides a method for rotating the SLMed GH3230 lock-bottom weld seam in a fiber laser long focal length focal hole, which effectively controls the surface formation, surface microcracks, porosity, and internal weld cracks, improves the welding manufacturing quality and reliability of SLMed GH3230 high-temperature alloy components, realizes high-quality laser welding manufacturing of SLMed GH3230 components, reduces the process risks and costs of laser selective melting manufacturing of large-size GH3230 components, and improves manufacturing quality.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole, characterized in that, include: S1. Pre-treat the area to be welded of the SLMed GH3230 lock bottom joint; S2. Fix the pre-treated SLMed GH3230 lock bottom connector with tooling to ensure that the butt joint gap of the lock bottom connector meets the welding requirements; S3. The optical components of the fiber laser welding equipment are configured, using a focusing field lens with a focal length of 330mm, a galvanometer system, and a transmission fiber and collimation unit. S4. Set up a welding shielding gas device, using a shielding gas nozzle with a tail cover, adjust the distance between the nozzle and the workpiece surface, and introduce argon gas into the welding area to form a protective atmosphere. S5. Set the process parameters of the fiber laser welding equipment, turn on the galvanometer system to control the laser focus to make high-speed circular rotation vibration in the welding hole of the lock bottom joint, and set the rotation radius and rotation frequency of the laser focus. S6. Start the fiber laser welding equipment and weld along the butt weld trajectory of the SLMed GH3230 lock bottom joint, ensuring that the weld penetration depth is not less than 4mm, and complete the non-penetrating laser welding of the lock bottom joint.
2. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 1, characterized in that, In S1, the pretreatment involves wiping and cleaning the area to be welded on the SLMed GH3230 lock bottom connector with acetone to remove oil and impurities.
3. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 1, characterized in that, In S2, the tooling clamping and fixing method must ensure that the workpiece is not deformed during the welding process, and the butt joint gap of the locking bottom joint is less than 0.05mm.
4. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 1, characterized in that, In S3, the core diameter of the transmission optical fiber is 200. The collimation unit has a focal length of 120mm, and the focusing field lens, collimation unit, and transmission optical fiber are coaxially arranged.
5. The method for rotary welding of SLMed GH3230 lock-in weld seams in a fiber laser long focal length focal hole according to claim 1, characterized in that, In S4, the distance between the lower end of the protective gas nozzle and the workpiece surface is 1 mm, the argon gas flow rate is 10 L / min, and the argon gas continuously protects the molten pool and the high-heat zone of the weld during the welding process.
6. The method for rotary welding of SLMed GH3230 lock-in weld seams in a fiber laser long focal length focal hole according to claim 1, characterized in that, In S4, the argon gas flows out in advance before the laser is emitted to pre-form a protective gas atmosphere in the welding area. After welding is completed, argon gas is continuously supplied to the weld and molten pool area for cooling.
7. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 1, characterized in that, In S5, the circular rotation vibration center of the laser focus coincides with the welding center of the SLMed GH3230 lock bottom connector, with a rotation radius of 0.2mm and a rotation frequency of 200Hz.
8. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 1, characterized in that, In S5, the process parameters of the fiber laser welding equipment include laser power, defocusing amount, and welding speed. The defocusing amount is set to 0mm, and the laser power and welding speed are adjusted according to the actual welding requirements.
9. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 8, characterized in that, The laser power is adjustable from 3000W to 5000W, and the welding speed is adjustable from 1.0m / min to 2.0m / min.
10. The method for rotary welding of SLMed GH3230 lock-in weld seams within a fiber laser long focal length focal hole according to claim 1, characterized in that, In S6, the focused beam emitted by the focusing field lens is perpendicular to the workpiece surface and incident on the welding part of the bottom joint, and the welding is performed at a constant speed along the butt weld trajectory during the welding process.