A laser-MIG hybrid welding manufacturing method for a heavy gas turbine guide bushing

Abstract

A heavy gas turbine guide bush laser-MIG composite welding manufacturing method. It solves the problems of poor consistency of manual assembly positioning, easy out-of-round deformation of thin-walled structure welding, unstable welding penetration and back forming, and easy secondary deformation in post-welding heat treatment. Method: install the guide bush body and the guide bush flange part on the positioning tool, control the assembly gap and the misalignment amount ≤0.2mm; after spot welding, seal the holes and non-welding gaps, then clean and teach the robot trajectory, open the back protective argon, seal the welding area; laser+MIG composite welding for circumferential weld; after welding, heat treat the workpiece together with the positioning tool, disassemble the tool, grind, assemble the positioning block and sandblast. The invention can improve the consistency of guide bush assembly positioning, the stability of weld penetration and the back protection effect, reduce the risk of out-of-round deformation of thin-walled structure after welding and secondary deformation, and improve the quality stability of guide bush batch manufacturing.

Description

Technical Field

[0001] This invention belongs to the field of manufacturing technology of thin-walled structural components for heavy-duty gas turbine combustion systems, specifically relating to a laser-MIG composite welding manufacturing method for a heavy-duty gas turbine guide bushing. Background Technology

[0002] The flow guide bushing is a key component in the combustion system of a heavy-duty gas turbine. Its function is to guide the high-temperature gas flow within the combustion chamber to the subsequent turbine stage, achieving a stable and uniform airflow distribution. It also serves as a heat insulation agent, erosion protectant, and thermal stress buffer. In current flow guide bushing manufacturing processes, the assembly of the bushing body and flange components relies heavily on manual alignment and experience, making it difficult to guarantee consistency in assembly gaps, misalignment, and circumferential joint positions. Because the flow guide bushing is a thin-walled cylindrical structure, it is prone to out-of-roundness, localized collapse, and post-weld deformation during welding. Conventional TIG welding involves significant heat input, and weld formation and penetration stability are significantly affected by human operation. Electron beam welding requires high standards for equipment, vacuum conditions, and clamping configuration, resulting in insufficient production flexibility. Furthermore, the inner cavity of the flow guide bushing requires high-quality flow surfaces and strong oxidation resistance. Insufficient back-side protection during welding can easily lead to oxidation of the weld back side, poor weld formation, and increased subsequent grinding. If the tooling is removed too early after welding for heat treatment, secondary deformation may occur during stress release, affecting the roundness, dimensional stability, and assembly consistency with the flame tube of the guide bushing. Therefore, it is necessary to propose a manufacturing method for the guide bushing that can take into account assembly positioning, weld penetration, back-side protection, and post-weld deformation control. Summary of the Invention

[0003] The purpose of this invention is to solve the problems of poor consistency in manual assembly and positioning, easy loss of roundness and deformation during welding of thin-walled structures, unstable weld penetration and back-side forming, and easy secondary deformation during post-weld heat treatment in the existing manufacturing process of heavy-duty gas turbine guide bushings. The invention provides a laser-MIG composite welding manufacturing method for heavy-duty gas turbine guide bushings.

[0004] A method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding, comprising the following steps:

[0005] I. Assembly Positioning:

[0006] The flow guide bushing body and the flow guide bushing flange assembly are installed on the positioning fixture. The positioning fixture's positioning groove, support ring, pressure plate, and tensioning structure constrain and position the flow guide bushing body and the flow guide bushing flange assembly, and control the assembly gap and misalignment to ≤0.2mm to complete the assembly positioning.

[0007] II. Pre-welding preparation:

[0008] After assembly and positioning, symmetrical spot fixing is performed, and holes and non-welding gaps on the guide bushing are sealed. Then, the welding area is cleaned with alcohol in one direction. The KUKA robot teaching system is used to set the laser incident angle, welding trajectory and welding start and end positions. Back protection argon gas is turned on. After the gas is filled, the welding area is sealed to ensure no leakage before proceeding to the subsequent welding stage.

[0009] III. Welding process:

[0010] Laser-MIG composite welding is used to weld the circumferential weld between the flow guide bushing body and the flow guide bushing flange component. The welding parameters are followed. After the welding is completed, the surface of the weld on the front is mechanically ground and cleaned.

[0011] IV. Post-welding treatment:

[0012] The welded workpiece, along with the positioning fixture, is sent into a heat treatment furnace for heat treatment. After the heat treatment is completed, the positioning fixture is removed, the inner side of the weld is ground smooth, and then the positioning block is assembled according to the design requirements. The entire workpiece is then sandblasted, thus completing the laser-MIG composite welding manufacturing method for the heavy-duty gas turbine guide bushing.

[0013] Furthermore, the symmetrical spot welding connection described in step two: the flow guide bushing body and the flow guide bushing flange are spot welded using tungsten inert gas welding. The welding material is ER308L, the welding wire specification is Φ1.2 / Φ2.0, the welding current is 80~100A, and the gas flow rate is 8~15L / min. The spot welding layout is distributed symmetrically.

[0014] Furthermore, the sealing process described in step two involves using high-temperature resistant industrial tape.

[0015] Furthermore, in step two, the specific operation of cleaning the weld area with alcohol in one direction is as follows: Before welding, use a white silk cloth dipped in anhydrous alcohol to clean a 20mm range on both sides of the weld. Keep the cleaning direction unidirectional and do not rub back and forth to ensure complete removal of oil, water vapor, oxide scale and dust. After cleaning, let it stand for 30 seconds to wait for the alcohol to evaporate.

[0016] Furthermore, in step two, the KUKA robot teaching system is used to set the laser incident angle, welding trajectory, and welding start and end positions. Specifically, the weld path is input, the laser head posture is adjusted so that the laser beam acts on the welding interface at the set incident angle, and the positioner is rotated to ensure that the red light indicator covers the weld area throughout the entire process. During the teaching process, the focal length is calibrated every 20mm to ensure that the laser focus is consistent with the welding interface. After the teaching is completed, a no-load run is executed to check for no interference and no collision risk.

[0017] Furthermore, in step two, the flow rate of the back protective argon gas is 15-20 L / min, and the continuous inflation time is 15 min.

[0018] Furthermore, in step two, the welding area is sealed using high-temperature resistant industrial tape.

[0019] Furthermore, the welding parameters mentioned in step three include: laser power 4.7–4.9 kW, welding speed 1.2 m / min, front shielding gas flow rate 25 L / min, back argon gas flow rate 14 L / min; the welding wire used is ER308L, with a diameter of Φ1.2 mm, a dry extension of 15 mm, a wire spacing of 2.5 mm, a weld lap length of 100 mm, a weld reinforcement of 0–2 mm, and a weld width of 6–8 mm; during the welding process, segmented welding and constant wire feeding are adopted to ensure weld penetration and stable front and back surface formation.

[0020] Furthermore, the heat treatment process described in step four is as follows: heating rate ≤ 80℃ / h, heat treatment temperature 860±10℃, holding temperature for 2h, followed by air cooling to room temperature before removal from the furnace.

[0021] Furthermore, in step four, the assembly positioning block is positioned by spot welding and then segmented symmetrical welding is performed. The welding material is HGH3536, the welding wire specification is Φ1.6 / Φ2.0, the current is 80~110A, and the gas flow rate is 8~15L / min. During welding, the interpass temperature is controlled at 50~100℃ to avoid deformation. After welding, the slag and spatter are cleaned.

[0022] Advantages of this invention:

[0023] 1. This invention uses positioning fixtures to constrain and position the guide bushing body and the guide bushing flange components, controlling the assembly gap and misalignment to ≤0.2mm, stabilizing the position of the circumferential weld, reducing manual assembly alignment errors, and improving the consistency of guide bushing assembly.

[0024] 2. The present invention forms a back protective cavity by sealing holes and non-welded gaps, and continuously introduces back protective argon gas during the welding process, which can reduce the oxidation of the back side of the weld seam in the inner cavity of the guide bushing, improve the back forming quality, and reduce the difficulty of subsequent inner grinding.

[0025] 3. This invention uses robot teaching to control the welding trajectory and laser-MIG hybrid welding for circumferential weld welding, which can achieve weld penetration and stable forming with high welding efficiency, and reduce heat input fluctuations and human operation errors in traditional manual TIG welding.

[0026] 4. The present invention heat-treats the welded workpiece together with the positioning fixture as a whole, so that the flow guide bushing can complete the stress release under the positioning constraint state, which can reduce the risk of loss of roundness and secondary deformation of thin-walled structure after welding, thereby improving the welding quality of flow guide bushing, improving roundness, dimensional stability, batch manufacturing consistency and assembly position with flame tube.

[0027] 5. The present invention performs grinding of the inner side of the weld, assembly of the positioning block and sandblasting after heat treatment, which can ensure the surface quality, appearance quality and subsequent assembly requirements of the flow guide bushing inner cavity, and is conducive to improving the reliability of mass production of products.

[0028] 6. This invention provides a high-precision, high-consistency, and industrially mass-producible manufacturing process for heavy-duty gas turbine guide bushings. Through full-process positioning control, laser composite welding technology, and heat treatment stabilization, it achieves full weld penetration, suppression of welding deformation, and stable and reliable dimensions.

[0029] 7. This invention innovatively integrates "tooling positioning + laser-MIG composite welding + back argon sealing protection + heat treatment stabilization" into one, realizing full-process deformation control and microstructure stabilization of the circumferential welding of the flow guide bushing; it achieves a significant reduction in welding deformation of thin-walled heat-resistant materials and improves the repeatability of weld performance, demonstrating significant technological advancement and industrial application value.

[0030] 8. This invention achieves full penetration of the guide bushing weld, uniform weld bead, and no oxidation on either side, fully releasing welding stress and significantly reducing post-weld deformation. The maximum circumferential runout at the same position does not exceed 0.2mm. Key dimensions remain stable, the positioning block installation accuracy is excellent, and the assembly position of the guide bushing with the flame tube is highly consistent. This method significantly improves the product's welding strength, sealing performance, and fatigue life, achieving high reliability and quality consistency in the mass production of guide bushings.

[0031] This invention is applicable to the manufacture of guide bushings for heavy-duty gas turbines. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the flow guide bushing body and the flow guide bushing flange assembly installed on the positioning fixture in the embodiment. In the diagram, 1 represents the flow guide bushing flange assembly, 2 represents the pressure plate, 3 represents the tensioning structure, 4 represents the support ring, 5 represents the flow guide bushing body, and 6 represents the positioning groove. Detailed Implementation

[0033] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

[0034] Specific Implementation Method 1: This implementation method provides a laser-MIG composite welding manufacturing method for heavy-duty gas turbine guide bushings, which is achieved through the following steps:

[0035] I. Assembly Positioning:

[0036] The flow guide bushing body and the flow guide bushing flange assembly are installed on the positioning fixture. The positioning fixture's positioning groove, support ring, pressure plate, and tensioning structure constrain and position the flow guide bushing body and the flow guide bushing flange assembly, and control the assembly gap and misalignment to ≤0.2mm to complete the assembly positioning.

[0037] II. Pre-welding preparation:

[0038] After assembly and positioning, symmetrical spot fixing is performed, and holes and non-welding gaps on the guide bushing are sealed. Then, the welding area is cleaned with alcohol in one direction. The KUKA robot teaching system is used to set the laser incident angle, welding trajectory and welding start and end positions. Back protection argon gas is turned on. After the gas is filled, the welding area is sealed to ensure no leakage before proceeding to the subsequent welding stage.

[0039] III. Welding process:

[0040] Laser-MIG composite welding is used to weld the circumferential weld between the flow guide bushing body and the flow guide bushing flange component. The welding parameters are followed. After the welding is completed, the surface of the weld on the front is mechanically ground and cleaned.

[0041] IV. Post-welding treatment:

[0042] The welded workpiece, along with the positioning fixture, is sent into a heat treatment furnace for heat treatment. After the heat treatment is completed, the positioning fixture is removed, the inner side of the weld is ground smooth, and then the positioning block is assembled according to the design requirements. The entire workpiece is then sandblasted, thus completing the laser-MIG composite welding manufacturing method for the heavy-duty gas turbine guide bushing.

[0043] The purpose of the constraint positioning in step one of this embodiment is to stabilize the circumferential position of the weld seam and avoid the product from sticking to the tooling due to the heat effect of the weld seam.

[0044] In step one of this embodiment, controlling the assembly gap and misalignment to be ≤0.2mm is achieved by using measuring tools to detect and calibrate the positioning during assembly, with the aim of ensuring the consistency of the shrinkage space reserved for welding.

[0045] After completing the assembly and positioning in step one of this implementation method, the workpiece needs to be shaped to ensure structural stability and minimize subsequent welding deformation.

[0046] In step two of this embodiment, the spot welding layout is distributed symmetrically to prevent stress concentration and local deformation.

[0047] The purpose of sealing in step two of this embodiment is to form a back protective cavity in the inner cavity of the guide bushing, to ensure the sealing of the back cavity during welding, and to ensure the sealing continuity of the subsequent back protective argon gas.

[0048] In step two of this embodiment, the purpose of activating the back protective argon gas is to fully expel the air from the cavity and form an inert protective environment. After the gas filling is completed in step two, the welding area is sealed and no leakage is ensured to form a closed protective cavity. The way to ensure no leakage in step two is to check the gas filling pressure and the air circuit sealing.

[0049] In step three of this embodiment, the purpose of mechanical grinding and cleaning is to ensure a smooth transition of the weld. For areas with slight undercut or insufficient fusion, manual argon arc welding is used for fine repair welding. The welding parameters are the same as those for spot welding. After welding, the weld is ground and repaired again to make the weld uniform and smooth, laying the foundation for heat treatment and subsequent inspection.

[0050] In step four of this embodiment, the welded workpiece, together with the positioning fixture, is sent into a heat treatment furnace for heat treatment. The purpose is to allow the workpiece to release stress under the constraint of the positioning fixture.

[0051] The purpose of grinding the inside of the weld in step four of this embodiment is to make the weld flush with the base material and restore the flow surface quality of the bushing cavity.

[0052] The purpose of sandblasting the entire workpiece in step four of this embodiment is to remove the surface oxide layer, contaminants and particles, and to ensure that the appearance and surface quality of the bushing meet the installation and service requirements.

[0053] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the symmetrical spot welding connection in step two involves using tungsten inert gas (TIG) welding to spot weld the flow guide bushing body and the flow guide bushing flange assembly. The welding material is ER308L, the welding wire specification is Φ1.2 / Φ2.0, the welding current is 80–100A, and the gas flow rate is 8–15L / min. The spot welding layout is symmetrically distributed. Other steps and parameters are the same as in Specific Implementation Method One.

[0054] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that the sealing step in step two uses high-temperature resistant industrial tape. Other steps and parameters are the same as in Specific Implementation Method One.

[0055] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the specific operation of unidirectional alcohol cleaning of the weld area in step two is as follows: Before welding, use a white silk cloth soaked in anhydrous alcohol to clean a 20mm area on both sides of the weld. The cleaning direction should be unidirectional, without back-and-forth rubbing, to ensure complete removal of oil, moisture, oxide scale, and dust. After cleaning, let it stand for 30 seconds to allow the alcohol to evaporate. Other steps and parameters are the same as in Specific Implementation Method One.

[0056] In step two of this embodiment, the purpose of letting the alcohol stand for 30 seconds to evaporate is to ensure that the welding interface is stable and free of residual solvent, thus avoiding becoming a potential source of porosity.

[0057] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that step two uses the KUKA robot teaching system to set the laser incident angle, welding trajectory, and welding start and end positions. Specifically: input the weld path, adjust the laser head posture so that the laser beam acts on the welding interface at the set incident angle, and use a positioner to rotate to ensure that the red light indicator covers the weld area throughout the entire process; during the teaching process, focus calibration is performed every 20mm to ensure that the laser focus is consistent with the welding interface; after the teaching is completed, a no-load run program is executed to check for interference and collision risks. Other steps and parameters are the same as in Specific Implementation Method One.

[0058] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that the flow rate of the back protective argon gas in step two is 15-20 L / min, and the continuous inflation time is 15 min. Other steps and parameters are the same as in Specific Implementation Method One.

[0059] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that, in step two, the welding area is sealed using high-temperature resistant industrial tape. All other steps and parameters are the same as in Specific Implementation Method One.

[0060] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the welding parameters in step three include: laser power 4.7–4.9 kW, welding speed 1.2 m / min, front shielding gas flow rate 25 L / min, back argon gas flow rate 14 L / min; the welding wire used is ER308L, diameter Φ1.2 mm, extension length 15 mm, wire spacing 2.5 mm, weld overlap length 100 mm, weld reinforcement 0–2 mm, and weld width 6–8 mm; during the welding process, segmented welding and constant wire feeding are used to ensure weld penetration and stable formation on both sides. Other steps and parameters are the same as in Specific Implementation Method One.

[0061] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that the heat treatment process in step four is as follows: heating rate ≤ 80℃ / h, heat treatment temperature 860±10℃, holding at that temperature for 2 hours, followed by air cooling to room temperature before removal from the furnace. Other steps and parameters are the same as in Specific Implementation Method One.

[0062] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that, in step four, the assembly and positioning block is positioned by spot welding and then subjected to segmented symmetrical welding. The welding material is HGH3536, the welding wire specifications are Φ1.6 / Φ2.0, the current is 80–110A, and the gas flow rate is 8–15L / min. During welding, the interpass temperature is controlled at 50–100℃ to avoid deformation. After welding, the slag and spatter are cleaned. Other steps and parameters are the same as in Specific Implementation Method One.

[0063] The beneficial effects of the present invention are verified through the following embodiments:

[0064] The following description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0065] Example:

[0066] A method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding, comprising the following steps:

[0067] I. Assembly Positioning:

[0068] The flow guide bushing body and the flow guide bushing flange assembly are installed on the positioning fixture. The positioning fixture's positioning groove, support ring, pressure plate, and tensioning structure constrain and position the flow guide bushing body and the flow guide bushing flange assembly, and control the assembly gap and misalignment to ≤0.2mm to complete the assembly positioning.

[0069] II. Pre-welding preparation:

[0070] After assembly and positioning, symmetrical spot fixing is performed, and holes and non-welding gaps on the guide bushing are sealed. Then, the welding area is cleaned with alcohol in one direction. The KUKA robot teaching system is used to set the laser incident angle, welding trajectory and welding start and end positions. Back protection argon gas is turned on. After the gas is filled, the welding area is sealed to ensure no leakage before proceeding to the subsequent welding stage.

[0071] III. Welding process:

[0072] Laser-MIG composite welding is used to weld the circumferential weld between the flow guide bushing body and the flow guide bushing flange component. The welding parameters are followed. After the welding is completed, the surface of the weld on the front is mechanically ground and cleaned.

[0073] IV. Post-welding treatment:

[0074] The welded workpiece, along with the positioning fixture, is sent into a heat treatment furnace for heat treatment. After the heat treatment is completed, the positioning fixture is removed, the inner side of the weld is ground smooth, and then the positioning block is assembled according to the design requirements. The entire workpiece is then sandblasted, thus completing the laser-MIG composite welding manufacturing method for the heavy-duty gas turbine guide bushing.

[0075] The symmetrical spot welding connection described in step two of this embodiment is as follows: the flow guide bushing body and the flow guide bushing flange are spot welded using tungsten inert gas welding. The welding material is ER308L, the welding wire specification is Φ1.2, the welding current is 90A, and the gas flow rate is 10L / min. The spot welding layout is distributed symmetrically.

[0076] The sealing step in this embodiment uses high-temperature resistant industrial tape.

[0077] In step two of this embodiment, the specific operation of cleaning the weld area with alcohol in one direction is as follows: Before welding, use a white silk cloth dipped in anhydrous alcohol to clean a 20mm range on both sides of the weld. Keep the cleaning direction unidirectional and do not rub back and forth to ensure complete removal of oil, water vapor, oxide scale and dust. After cleaning, let it stand for 30 seconds to wait for the alcohol to evaporate.

[0078] In step two of this embodiment, the KUKA robot teaching system is used to set the laser incident angle, welding trajectory, and welding start and end positions. Specifically, the weld path is input, the laser head posture is adjusted so that the laser beam acts on the welding interface at the set incident angle, and the positioner is rotated to ensure that the red light indicator covers the weld area throughout the entire process. During the teaching process, the focal length is calibrated every 20mm to ensure that the laser focus is consistent with the welding interface. After the teaching is completed, a no-load run program is executed to check for no interference and no collision risk.

[0079] In step two of this embodiment, the flow rate of the back protective argon gas is 20 L / min, and the continuous inflation time is 15 min.

[0080] In step two of this embodiment, the welding area is sealed using high-temperature resistant industrial tape.

[0081] The welding parameters described in step three of this embodiment include: laser power 4.8kW, welding speed 1.2m / min, front shielding gas flow rate 25L / min, back argon gas flow rate 14L / min; the welding wire used is ER308L, with a diameter of Φ1.2mm, a dry extension of 15mm, a wire spacing of 2.5mm, a weld overlap length of 100mm, a weld reinforcement of 0-2mm, and a weld width of 6-8mm; during the welding process, segmented welding and constant wire feeding are adopted to ensure weld penetration and stable front and back surface formation.

[0082] The heat treatment process described in step four of this embodiment is as follows: heating rate 80℃ / h, heat treatment temperature 860℃, holding temperature for 2h, followed by air cooling to room temperature before removal from the furnace.

[0083] The assembly positioning block described in step four of this embodiment is as follows: after spot welding for positioning, segmented symmetrical welding is performed. The welding material is HGH3536, the welding wire specification is Φ1.6, the current is 90A, and the gas flow rate is 10L / min. During welding, the interpass temperature is controlled at 50~100℃ to avoid deformation. After welding, the slag and spatter are cleaned.

[0084] In this embodiment, the raw material for the guide bushing body and the guide bushing flange component is 022Cr19Ni10 plate; the raw material for the positioning block is GH3536.

[0085] This embodiment presents a schematic diagram of the flow guide bushing body and the flow guide bushing flange assembly installed on the positioning fixture, as shown below. Figure 1 As shown.

[0086] The heavy-duty gas turbine guide bushing manufactured using the method described in this embodiment achieves full penetration welds, uniform weld bead distribution, and no oxidation on either side. Welding stress is fully released, post-weld deformation is significantly reduced, and the appearance and surface quality meet installation and service requirements. Key dimensions remain stable, the positioning block installation accuracy is excellent, and the alignment with the flame tube is highly consistent. This method significantly improves the product's welding strength, sealing performance, and fatigue life, achieving high reliability and consistent quality in the mass production of guide bushings.

Claims

1. A method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding, characterized in that, It is implemented in the following steps: I. Assembly Positioning: The flow guide bushing body and the flow guide bushing flange assembly are installed on the positioning fixture. The positioning fixture's positioning groove, support ring, pressure plate, and tensioning structure constrain and position the flow guide bushing body and the flow guide bushing flange assembly, and control the assembly gap and misalignment to ≤0.2mm to complete the assembly positioning. II. Pre-welding preparation: After assembly and positioning, symmetrical spot fixing is performed, and holes and non-welding gaps on the guide bushing are sealed. Then, the welding area is cleaned with alcohol in one direction. The KUKA robot teaching system is used to set the laser incident angle, welding trajectory and welding start and end positions. Back protection argon gas is turned on. After the gas is filled, the welding area is sealed to ensure no leakage before proceeding to the subsequent welding stage. III. Welding process: Laser-MIG composite welding is used to weld the circumferential weld between the flow guide bushing body and the flow guide bushing flange component. The welding parameters are followed. After the welding is completed, the surface of the weld on the front is mechanically ground and cleaned. IV. Post-welding treatment: The welded workpiece, along with the positioning fixture, is sent into a heat treatment furnace for heat treatment. After the heat treatment is completed, the positioning fixture is removed, the inner side of the weld is ground smooth, and then the positioning block is assembled according to the design requirements. The entire workpiece is then sandblasted, thus completing the laser-MIG composite welding manufacturing method for the heavy-duty gas turbine guide bushing.

2. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, The symmetrical spot welding connection described in step two: The flow guide bushing body and the flow guide bushing flange are spot welded using tungsten inert gas welding. The welding material is ER308L, the welding wire specification is Φ1.2 / Φ2.0, the welding current is 80~100A, and the gas flow rate is 8~15L / min. The spot welding layout is distributed symmetrically.

3. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, The sealing process described in step two involves using high-temperature resistant industrial tape.

4. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, The specific steps for cleaning the weld area with alcohol in step two are as follows: Before welding, use a white silk cloth dipped in anhydrous alcohol to clean a 20mm area on both sides of the weld. Keep the cleaning direction unidirectional and do not rub back and forth to ensure complete removal of oil, water vapor, oxide scale and dust. After cleaning, let it stand for 30 seconds to allow the alcohol to evaporate.

5. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, In step two, the KUKA robot teaching system is used to set the laser incident angle, welding trajectory, and welding start and end positions. Specifically, the weld path is input, the laser head posture is adjusted so that the laser beam acts on the welding interface at the set incident angle, and the positioner is rotated to ensure that the red light indicator covers the weld area throughout the entire process. During the teaching process, the focal length is calibrated every 20mm to ensure that the laser focus is consistent with the welding interface. After the demonstration is completed, execute the empty run procedure to check for interference and collision risks.

6. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, In step two, the flow rate of the back protective argon gas is 15-20 L / min, and the continuous inflation time is 15 min.

7. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, In step two, the welding area is sealed using high-temperature resistant industrial tape.

8. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, The welding parameters mentioned in step three include: laser power 4.7-4.9kW, welding speed 1.2m / min, front shielding gas flow rate 25L / min, back argon gas flow rate 14L / min; the welding wire used is ER308L, with a diameter of Φ1.2mm, a dry extension of 15mm, a wire spacing of 2.5mm, a weld overlap length of 100mm, a weld reinforcement of 0-2mm, and a weld width of 6-8mm; during the welding process, segmented welding and constant wire feeding are adopted to ensure weld penetration and stable formation on both sides.

9. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, The heat treatment process described in step four is as follows: heating rate ≤ 80℃ / h, heat treatment temperature 860±10℃, holding temperature for 2h, followed by air cooling to room temperature before removal from the furnace.

10. The method for manufacturing a heavy-duty gas turbine guide bushing using laser-MIG hybrid welding according to claim 1, characterized in that, The assembly positioning block described in step four: After spot welding for positioning, segmented symmetrical welding is performed. The welding material is HGH3536, the welding wire specification is Φ1.6 / Φ2.0, the current is 80~110A, and the gas flow rate is 8~15L / min. During welding, the interpass temperature is controlled at 50~100℃ to avoid deformation. After welding, the slag and spatter are cleaned.

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