A turbine blade wear-resistant layer surfacing method based on a vacuum argon-filled welding box

Abstract

This invention discloses a method for surfacing a wear-resistant layer on turbine blades using a vacuum argon-filled welding box, belonging to the field of surfacing technology. The method includes: placing a preheated turbine blade and welding wire into a vacuum argon-filled welding box, and then evacuating the inside of the box; within the evacuated box, performing surfacing welding on the area to be repaired on the turbine blade using sub-processes with at least three different surfacing parameters; and after surfacing welding, placing the turbine blade back into the vacuum argon-filled welding box for heat preservation and slow cooling. This invention's method for surfacing a wear-resistant layer on turbine blades using a vacuum argon-filled welding box effectively eliminates the influence of water vapor and oxygen in a vacuum environment, fundamentally preventing surfacing defects such as porosity and slag inclusions; the progressive design of the three-stage surfacing process ensures sufficient protection of the molten pool and stable and reliable weld formation quality; and the precisely controlled preheating and slow cooling processes effectively reduce thermal stress and improve the bonding strength between the wear-resistant layer and the substrate.

Description

Technical Field

[0001] This invention belongs to the field of surfacing technology, and specifically relates to a method for surfacing a wear-resistant layer on turbine blades based on a vacuum argon-filled welding box. Background Technology

[0002] As a core hot-end component of an aero-engine, the manufacturing quality of turbine blades directly affects the engine's reliability and lifespan. These components are typically made from high-performance single-crystal or equiaxed crystal cast high-temperature alloys. During operation, the blade tips of adjacent blades experience continuous impact and friction due to high-speed rotation, leading to wear. As wear intensifies, the clearance between the blade tips increases, which not only reduces the engine's aerodynamic efficiency but also significantly increases the bending moment at the blade root under the combined effects of high-temperature, high-pressure combustion gases. This greatly increases the risk of root cracks, and historically, has even resulted in serious accidents such as blade breakage.

[0003] To improve the wear resistance of blade crowns and extend their service life, the industry currently widely adopts the method of overlaying a layer of wear-resistant alloy onto the meshing surface of the blade crown. However, existing overlay welding technologies, especially those using ordinary argon arc welding, face many severe challenges in practical applications.

[0004] First, the agitation of the molten pool during argon blowing protection easily leads to defects such as porosity within the weld overlay. These defects can become crack initiation points, severely weakening the bonding strength of the wear-resistant layer and causing it to detach or flake during service. Second, because conventional argon arc welding relies on localized argon blowing protection, the protective effect is limited, and the surface of the weld overlay is prone to oxidation, affecting surface quality. Furthermore, this process is highly dependent on the welder's skill, making precise process control difficult. Welders are prone to errors, resulting in defects such as incomplete fusion and gaps in the weld, leading to large fluctuations in product quality and yield. In production practice, this manifests as long welder training periods and difficulty in overcoming technical bottlenecks.

[0005] Faced with the above dilemma, the conventional approach is to continuously optimize the technical path of ordinary welding machines, but this faces the practical obstacles of long welder training cycles and difficulty in making technological breakthroughs. Summary of the Invention

[0006] To address the above problems, this invention provides a method for welding a wear-resistant layer onto turbine blades using a vacuum argon-filled welding box, the method comprising:

[0007] The preheated turbine blades and welding wire are placed in a vacuum argon-filled welding box, and the inside of the welding box is evacuated.

[0008] Inside the welding box where the vacuuming process is completed, the area to be repaired on the turbine blade is welded using a sub-process that includes at least three different welding parameters.

[0009] After the welding is completed, the turbine blades are placed in the vacuum argon-filled welding box for heat preservation and slow cooling.

[0010] Furthermore, the preheated turbine blades and welding wire are placed in a vacuum argon-filled welding box, and the inside of the welding box is evacuated, including:

[0011] The turbine blades and the welding wire are preheated for 10-50 minutes in a temperature range of 80℃-250℃.

[0012] The preheated turbine blades and welding wire are placed in a vacuum argon-filled welding box;

[0013] The vacuum level inside the argon-filled vacuum welding box is reduced to below 3 Pa, and then inert protective gas argon is introduced into the vacuum argon-filled vacuum welding box to restore it to a positive pressure state.

[0014] Furthermore, the process of performing weld overlay on the area to be repaired of the turbine blade using sub-processes comprising at least three different weld overlay parameters includes:

[0015] The first welding sub-process involves starting an arc at the root of the area to be repaired, preheating the base material, feeding wire, and performing single-pass welding along the first direction.

[0016] After completing the single-pass welding process, a second multi-layer, multi-pass welding sub-process is performed by alternating between the second and first directions using a laterally oscillating welding torch; and,

[0017] The third welding sub-process involves repairing and welding defective areas after the initial welding is completed.

[0018] The first direction and the second direction are set opposite to each other.

[0019] Furthermore, the first welding sub-process is carried out under the following conditions: the initial end is held for 1-3 seconds, the welding current is 20-40A, and the welding speed is 1-2mm / s.

[0020] Furthermore, the second welding sub-process is carried out under the following conditions: welding current of 20-40A and welding speed of 2-5mm / s.

[0021] Furthermore, the third welding sub-process is carried out under the following conditions: the number of welding repairs is 1-2 times and the total time for re-arriving the arc does not exceed 3 seconds / s.

[0022] Furthermore, the method of alternating multi-layer and multi-pass welding along the second and first directions by laterally oscillating the welding torch also includes: when laterally oscillating the welding torch to the edge of the area to be repaired, controlling the welding torch to extend beyond the edge range by 2~4mm.

[0023] Furthermore, the diameter of the welding wire is 1.0-2.0 mm; the electrode of the welding gun is a tungsten electrode with a diameter of 1.2-2.0 mm.

[0024] The present invention also provides a turbine blade, wherein the turbine blade is obtained by forming a wear-resistant layer on the surface of the area to be repaired using the welding method described in the present invention.

[0025] The present invention also provides a gas turbine equipped with at least one turbine blade as described in the present invention.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The present invention relates to a method for surfacing the wear-resistant layer of turbine blades based on a vacuum argon-filled welding box. This method effectively eliminates the influence of water vapor and oxygen in a vacuum environment, fundamentally preventing welding defects such as porosity and slag inclusions. The welding process in a vacuum environment reduces oxide formation, ensuring the integrity of the metallurgical bond. The progressive design of the three-stage welding process ensures sufficient protection of the molten pool and stable and reliable weld formation quality. Precisely controlled preheating and slow cooling processes effectively reduce thermal stress and improve the bonding strength between the wear-resistant layer and the substrate. The organic combination of vacuum welding technology and multi-stage welding processes forms a unique technical solution. The systematic process design reduces operational difficulty and excessive reliance on welder skills, solving the technical problem of traditional methods struggling to balance quality and efficiency.

[0028] The beneficial effects of this invention are achieved through systematic process design and strict parameter control, ensuring welding quality while taking into account production efficiency and economic benefits, and demonstrating significant technological progress and practical value.

[0029] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the process for welding a wear-resistant layer on a turbine blade based on a vacuum argon-filled welding box, according to an embodiment of the present invention, is shown.

[0032] Figure 2A schematic diagram of the specific welding process in an embodiment of the present invention is shown;

[0033] Figure 3 A schematic diagram of the macro- and micro-structure of the wear-resistant layer obtained by the welding process in Embodiment 1 of the present invention is shown.

[0034] Figure 4 A schematic diagram of the macro- and micro-structure of the wear-resistant layer obtained by the welding process in Comparative Example 1 of the present invention is shown.

[0035] Figure 5 A schematic diagram of the microstructure of the wear-resistant layer obtained by the welding process in Comparative Example 2 of the present invention is shown.

[0036] Figure 6 This diagram shows a schematic of the wear-resistant layer obtained by the welding process in Comparative Example 3 of the present invention after grinding.

[0037] Figure 7 A schematic diagram of the macroscopic structure of the wear-resistant layer obtained by the welding process in Comparative Example 4 of the present invention is shown.

[0038] In the diagram: 1. Tungsten electrode; 2. Welding wire. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] This invention is the first to propose introducing a vacuum argon-filled welding chamber as the core solution for turbine blade cladding, fundamentally breaking free from the limitations of traditional methods. The vacuum argon-filled welding chamber can provide a protective atmosphere of high purity inert gas in the entire environment, and does not require blowing, thus eliminating the risk of air pollution and porosity in principle, creating the prerequisite for obtaining a high-purity wear-resistant layer.

[0041] Figure 1 This diagram illustrates a flow chart of a turbine blade wear-resistant layer welding method based on a vacuum argon-filled welding box, according to an embodiment of the present invention. Figure 1 The method includes: placing the preheated turbine blade and welding wire in a vacuum argon-filled welding box and evacuating the inside of the welding box; surfacing the area to be repaired on the turbine blade in the welding box after the vacuum treatment is completed, using a sub-process containing at least three different surfacing parameters; and surfacing the turbine blade in the vacuum argon-filled welding box for heat preservation and slow cooling after the surfacing is completed.

[0042] In this embodiment of the invention, the technical terms mentioned in the method of surfacing wear-resistant layer of turbine blade based on vacuum argon-filled welding box are explained. Surfacing is a surface treatment process that improves the wear resistance, heat resistance and corrosion resistance of a workpiece by depositing materials with specific properties onto the surface of the workpiece. Slow cooling is a process measure in the metallurgical and heat treatment fields to improve the material properties by controlling the cooling rate. It is mainly used to prevent metal cracking, eliminate internal stress and optimize the microstructure. Arc ignition is the process of igniting an electric arc during surfacing.

[0043] In this embodiment of the invention, to clearly demonstrate the implementation process of the technical solution, the blade crown meshing area of ​​a turbine blade is selected as a typical application scenario for specific description. This area is subjected to high-frequency mechanical meshing and impact during operation, and is a high-risk area for wear. Therefore, it has strong demonstrative significance as a representative area for wear-resistant layer weld repair.

[0044] This positioning is merely a preferred embodiment for illustrating the technical solution of the present invention, and is intended to concretize the technical means, not to limit the scope of protection of the present invention. In actual operation and application, the technical solution of the present invention is not limited to this specific embodiment.

[0045] Regarding the base material: the welding method of the present invention is not limited to the specific turbine blades mentioned in the embodiments, but is also applicable to other structures or types of blades such as stationary blades, moving blades, crowned or uncrowned blades, and even other gas turbine components such as nozzles and combustion chamber components that need to be surface strengthened or repaired. The specific structure of the base material is not a limitation of the present invention.

[0046] Regarding the location of the area to be repaired: The core of the method described in this invention is to provide a universal high-quality overlay welding process. Its application is not targeted at or limited to the blade crown meshing area. The method can be equally applied to any area on the turbine blade that needs to be enhanced in terms of wear resistance, corrosion resistance, or dimensional restoration, such as, but not limited to: the inlet or outlet edge of the blade, the blade back or blade base area, the tenon or tenon tooth part of the blade, and any local surface that needs to be repaired due to wear, corrosion, or machining errors.

[0047] Optionally, in this embodiment of the invention, to achieve the best protection effect and process stability, the inert gas filled into the vacuum argon-filled welding box after vacuuming is preferably high-purity argon, with a purity of not less than 99.999%. This choice is based on the following technical considerations: Argon, as a monatomic inert gas, has extremely stable chemical properties and can effectively isolate reactive gases such as oxygen and nitrogen during high-temperature welding, preventing oxidation and nitriding of molten metal, thereby ensuring the metallurgical quality of the weld; high-purity argon can provide stable arc characteristics, which is particularly suitable for the tungsten inert gas shielded welding process used in this invention, and is conducive to obtaining a well-formed weld layer without internal defects; compared with other high-purity inert gases such as helium, argon is easier to obtain industrially, has higher cost-effectiveness, and is suitable for large-scale production applications.

[0048] However, it must be emphasized that the choice of argon gas is merely illustrative, intended to demonstrate the feasible implementation of the invention, and is by no means a limitation on the type of protective gas used in this technical solution. In practical applications of this invention, those skilled in the art can select other suitable high-purity inert gases or mixed gases as the protective medium based on specific process requirements, equipment conditions, and cost considerations. As long as the selected gas meets the two core requirements of "high purity" and "inertness," and ensures that the welding process is carried out in an environment that effectively prevents metal oxidation, thereby achieving the goal of a high-quality weld layer, it constitutes a reasonable modification and equivalent substitution of the technical solution of this invention and should fall within the scope of protection sought by this invention.

[0049] Specifically, the preheated turbine blade and welding wire 2 are placed in a vacuum argon-filled welding box. The vacuum treatment inside the welding box includes: preheating the turbine blade and welding wire 2 at a temperature range of 80℃-250℃ for 10-50 minutes; placing the preheated turbine blade and welding wire 2 in a vacuum argon-filled welding box; evacuating the vacuum degree inside the vacuum argon-filled welding box to below 3Pa, and then filling the vacuum argon-filled welding box with inert protective gas argon to restore the vacuum argon-filled welding box to a positive pressure state.

[0050] It should be noted that, in this embodiment of the invention, to meet the service requirements of turbine blades under high temperature and high wear conditions, the welding wire 2 used in the welding process is specially selected. Specifically, cobalt-based alloy welding wires are used in this embodiment, mainly including two types: Co-Cr-Mo and Co-Cr-W. The specific examples of Co-Cr-Mo and Co-Cr-W welding wires are merely illustrative and intended to demonstrate the preferred direction for high-performance wear-resistant materials in this invention, and are by no means a limitation on the material of welding wire 2.

[0051] Before welding, prepare welding wire 2 according to the product process specifications. Use an oven or heat treatment furnace to preheat the blade and welding wire 2 at 80~250℃ for 10-50 minutes. Then immediately put them into a vacuum argon-filled welding box and evacuate to a vacuum degree below 3Pa. Then fill the welding box with 99.999% pure argon gas to positive pressure to eliminate the influence of water vapor.

[0052] After welding, the blades are kept in a vacuum argon-filled welding chamber for 20-30 minutes to allow them to cool slowly, preventing rapid cooling and thermal cracking. They are then removed from the chamber to avoid impact. Specifically, in this embodiment of the invention, the vacuum environment is maintained until the blade temperature uniformly drops to a safe range. The 20-30 minute slow cooling time described in this invention is an optimized parameter for a typical turbine blade structure. In practical applications, those skilled in the art can make adaptive adjustments within the range of 15-40 minutes based on specific factors such as blade thickness and weld overlay area. These adjustments are all equivalent implementations of this invention.

[0053] In this embodiment, during the surfacing welding process, the welding operator holds the welding gun in one hand and the welding wire 2 in the other hand using a clamp while wearing a vacuum glove, and performs the surfacing welding operation in a vacuum argon-filled welding box protected by argon gas.

[0054] In this embodiment of the invention, the preferred diameter of the welding wire 2 is 1.0-2.0 mm, and the electrode of the welding torch is a tungsten electrode 1, with a preferred diameter of 1.2-2.0 mm. Extensive process testing has verified that this parameter combination achieves the following technical indicators: arc length fluctuation controlled within ±0.3 mm; weld width variation coefficient ≤8%; porosity <0.5%; and slag inclusion defects <0.3%. It should be noted that the parameter range described in this invention is a preferred implementation scheme for turbine blade repair. In practical applications, those skilled in the art can make adaptive adjustments according to specific working conditions: the lower limit parameter can be used for the special structure of thin-walled regions; the upper limit parameter can be approached for heavy wear conditions; and the optimal parameter combination for specific applications can be determined through conventional experiments.

[0055] The above parameter ranges have been experimentally verified to have an optimal process window, but should not be construed as limiting the scope of protection of this invention. Any adaptive adjustments to the parameters based on the core technical concept of this invention are considered equivalent implementations of this invention.

[0056] However, simply using a vacuum argon-filled welding box is insufficient; without precisely matched welding process parameters and control methods, it remains impossible to stably form a high-quality wear-resistant layer. To overcome the shortcomings of existing processes and reduce defects in the welded wear-resistant blocks for turbine blades, this invention provides a complete turbine blade wear-resistant block welded process based on a vacuum argon-filled welding box, along with related process parameters.

[0057] Not only was a vacuum argon-filled welding box creatively selected as the technical platform for solving this problem, but a complete set of detailed and reliable welding processes were also provided, thus systematically solving the problem of stable preparation of high-quality wear-resistant layers.

[0058] Specifically, the process of performing weld overlay on the area to be repaired of the turbine blade using sub-processes comprising at least three different weld overlay parameters includes:

[0059] The first welding sub-process involves starting an arc at the root of the area to be repaired, preheating the base material, feeding wire, and performing single-pass welding along the first direction.

[0060] After completing the single-pass welding process, a second multi-layer, multi-pass welding sub-process is performed by alternating between the second and first directions using a laterally oscillating welding torch; and,

[0061] The third welding sub-process involves repairing and welding defective areas after the initial welding is completed.

[0062] The first direction and the second direction are set opposite to each other.

[0063] Specifically, a detailed explanation of the sub-processes with three different welding parameters in the embodiments of the present invention will be provided:

[0064] The first welding sub-process is carried out under the following conditions: 1-3 seconds at the starting end, welding current of 20-40A, and welding speed of 1-2mm / s.

[0065] The second welding sub-process is carried out under the following conditions: welding current of 20-40A and welding speed of 2-5mm / s.

[0066] The third welding process is carried out under the following conditions: the number of welding repairs is 1-2 times and the total time for re-arriving the arc does not exceed 3 seconds / s.

[0067] Optionally, in this embodiment of the invention, the method of alternating multi-layer and multi-pass welding along the second direction and the first direction by laterally oscillating the welding gun further includes: when laterally oscillating the welding gun to the edge of the area to be repaired, controlling the welding gun to extend beyond the edge range by 2-4mm.

[0068] In this embodiment of the invention, the specific process of welding overlay is also described in detail. Figure 2 A schematic diagram of the specific welding process in an embodiment of the present invention is shown. Figure 2 In the diagram, the left side of the turbine blade's repair area is welding wire 2, and the right side is welding clamp / tweezers and the tungsten electrode 1. Steps ①, ②, and ③ represent three sub-steps with different welding parameters. It should be noted that, to more specifically illustrate the welding method of this semi-inventive, Figure 2The document also explains the direction of the weld overlay, using horizontal and vertical directions to indicate the direction of the weld overlay. The first direction and the second direction represent the opposite directions of the horizontal direction.

[0069] ① First welding process:

[0070] Use appropriate tooling to clamp and fix the turbine blade. The maximum welding current is 20-40A. The diameter of welding wire 2 is Ф1.0-2.0mm. The diameter of tungsten electrode 1 is Ф1.2~2.0mm. The turbine blade is connected to DC positive polarity. Start the arc on the right side of the root of the meshing surface and hold for 1~3 seconds / s. After the base metal melts, add welding wire 2. The arc is close to the root and moves to the left at 1~2mm / s to the edge of the meshing surface.

[0071] In the first stacking welding process of this invention embodiment, by sticking close to the root and moving slowly, defects of incomplete fusion are avoided at the root due to the relatively cold meshing surface at the beginning of the arc.

[0072] ② Second welding process

[0073] Arc edge Figure 2 The trajectory moves longitudinally and oscillates laterally, and the welding wire 2 follows the arc to complete the wire feeding. The arc moving speed is 2~5mm / s. One oscillation is counted as one oscillation from the start of the arc. When the longitudinal surfacing is completed, the number of oscillations should be 3~6. When the oscillation reaches the left and right edges, the tungsten electrode 1 should be controlled to extend 2~4mm beyond the two edges so that the molten droplets can better cover the left and right edges.

[0074] In the second welding process of this invention embodiment, when the tungsten electrode 1 is swung laterally to the left and right edges, it is controlled to extend 2-4 mm beyond the two edges so that the molten droplets can better cover the left and right edges and prevent missing material after grinding.

[0075] ③ The third welding process

[0076] When longitudinally surfacing to the end, if there is a lack of material at the edge or the wear-resistant layer height is less than 2mm, the arc can be restarted and the wire fed again and the arc extinguished 1 to 2 times. The total time for restarting the arc should not exceed 3 seconds / s.

[0077] In the third welding process of this invention embodiment, in order to prevent the end penetration from being too deep and affecting the service performance of the turbine blade, the total time for re-arcing the arc does not exceed 3 seconds / s.

[0078] In this embodiment of the invention, the beneficial effects of the turbine blade wear-resistant layer surfacing method based on a vacuum argon-filled welding box were scientifically verified through a systematic comparative experimental design. The technical advantages of the present invention are explained in detail below through comparative data from specific embodiments and comparative examples.

[0079] Example 1

[0080] According to product specifications, Co-Cr-Mo welding wire was used to surfacing turbine blades of a certain type of aero-engine. The diameter of welding wire 2 was 1.6mm, the diameter of tungsten electrode 1 was 1.6mm, and the maximum welding current was 32A. The blade and welding wire 2 were preheated at 200℃ for 30min. The arc was initiated on the right side of the root of the meshing surface and held for 2 seconds / s. After the base metal melted, welding wire 2 was added. The arc was moved to the left side at 1 mm / s, close to the root, until the edge of the meshing surface. The subsequent arc movement speed was 3 mm / s. After the longitudinal surfacing was completed, the lateral oscillation was performed 4 times. When the lateral oscillation reached the left and right edges, the tungsten electrode 1 was controlled to extend 3mm beyond the two edges. When the longitudinal surfacing reached the end, the arc was initiated again, the wire was fed, and the arc was extinguished once. The total time for re-initiating the arc should not exceed 2 seconds / s.

[0081] Figure 3 This diagram illustrates the macro- and micro-structure of the wear-resistant layer obtained using the welding process described in Embodiment 1 of the present invention. Figure 3 The weld overlay exhibits a uniform metallic luster, free from surface defects such as oxidation discoloration and pits. Measurements using a 3D topology analyzer show that the surface roughness Ra value is controlled within 3.2 μm, fully meeting the aerodynamic performance requirements of turbine blades. The weld beads are neatly arranged, without macroscopic defects such as undercut or lack of fusion. A high-precision micro-nano CT system was used to perform a full-area scanning analysis of the weld overlay, revealing a porosity defect rate of <0.1%, with pore sizes all less than 10 μm. No cracks, slag inclusions, or other dangerous defects were observed, and no lack of fusion was observed in the interlayer bonding area.

[0082] Example 2

[0083] According to product specifications, Co-Cr-W welding wire was used to surfacing turbine blades of a certain type of aero-engine. The diameter of welding wire 2 was 1.6mm, the diameter of tungsten electrode 1 was 1.5mm, and the maximum welding current was 30A. The blade and welding wire 2 were preheated at 200℃ for 30min. The arc was initiated on the right side of the root of the meshing surface and held for 2 seconds / s. After the base metal melted, welding wire 2 was added. The arc was moved to the left side at 1 mm / s, close to the root, until the edge of the meshing surface. The subsequent arc movement speed was 3 mm / s. After the longitudinal surfacing was completed, the lateral oscillation was performed 4 times. When the lateral oscillation reached the left and right edges, the tungsten electrode 1 was controlled to extend 2mm beyond the two edges. When the longitudinal surfacing reached the end, the arc was initiated again, the wire was fed, and the arc was extinguished twice. The total time for re-initiating the arc should not exceed 2 seconds / s.

[0084] After the welding was completed, the surface of the weld overlay exhibited a uniform metallic luster, free from surface defects such as oxidation color and pits. The weld beads were neatly arranged, without macroscopic defects such as undercut or lack of fusion. A high-precision micro-nano CT system was used to perform a full-area scanning analysis of the weld overlay, revealing a porosity defect rate of <0.1%, with pore sizes all less than 10μm. No dangerous defects such as cracks or slag inclusions were observed, and there was no lack of fusion in the interlayer bonding area.

[0085] In this embodiment of the invention, Comparative Example 1 is compared with Example 1. The beneficial effects of this invention, which uses a vacuum argon-filled welding box for surfacing, are explained: it effectively eliminates the influence of water vapor and oxygen, fundamentally preventing the generation of surfacing defects such as porosity and slag inclusions. The surfacing process in a vacuum environment reduces the generation of oxides and ensures the integrity of the metallurgical bond.

[0086] Comparative Example 1

[0087] In Comparative Example 1, the method of vacuum argon-filled welding box described in this invention was not used; instead, a conventional argon arc welding machine was used to deposit the wear-resistant layer of the turbine blade.

[0088] According to product specifications, use Co-Cr-Mo welding wire, wire 2 with a diameter of 1.6mm, tungsten electrode 1 with a diameter of 1.6mm, and a maximum welding current of 32A. Preheat the blades and wire 2 at 200℃ for 30 minutes. Initiate the arc on the right side of the root of the meshing surface and hold for 2 seconds / s. After the base metal melts, add more wire 2. Move the arc close to the root to the left at 1 mm / s to the edge of the meshing surface. The subsequent arc movement speed is 3 mm / s. After completing the longitudinal surfacing, perform 4 transverse oscillations. When the transverse oscillation reaches the left and right edges, control the tungsten electrode 1 to extend appropriately beyond the two edges by 3mm. When the longitudinal surfacing reaches the end, initiate the arc again, feed the wire, and extinguish the arc once. The total time for re-initiating the arc should not exceed 2 seconds / s.

[0089] Figure 4 This diagram illustrates the macro- and micro-structure of the wear-resistant layer obtained using the welding process described in Comparative Example 1 of this invention. Figure 4 In the case where the wear-resistant layer obtained by welding without using the vacuum argon-filled welding box described in this invention has an oxide layer on its surface, and micro-nano CT analysis shows that the wear-resistant layer contains... Figure 4 The pore at the location of the elliptical coil.

[0090] In this embodiment of the invention, Comparative Example 2 is used to compare with Example 1 to illustrate the beneficial effects of adhering closely to the root and moving slowly in the first stack welding process.

[0091] Comparative Example 2

[0092] In Comparative Example 2, the electric arc is moved to the left at a speed of 4 mm / s along the root to the edge of the meshing surface.

[0093] According to product specifications, a Co-Cr-Mo welding wire was used to surfacing a turbine blade of a certain type of aero-engine. The diameter of welding wire 2 was 1.6 mm, the diameter of tungsten electrode 1 was 1.6 mm, and the maximum welding current was 32 A. The blade and welding wire 2 were preheated at 200℃ for 30 min. The arc was initiated on the right side of the root of the meshing surface and held for 2 seconds / s. After the base metal melted, welding wire 2 was added. The arc was moved to the left side at 4 mm / s, close to the root, until the edge of the meshing surface. The subsequent arc movement speed was 3 mm / s. After the longitudinal surfacing was completed, the lateral oscillation was performed 4 times. When the lateral oscillation reached the left and right edges, the tungsten electrode 1 was controlled to extend 3 mm beyond the two edges. When the longitudinal surfacing reached the end, the arc was initiated again, the wire was fed, and the arc was extinguished once. The total time for re-initiating the arc should not exceed 2 seconds / s.

[0094] Figure 5 This diagram shows a schematic of the microstructure of the wear-resistant layer obtained using the welding process described in Comparative Example 2 of the present invention. Figure 5 During the welding process, the weld overlay layer exhibits a uniform metallic luster, free from surface defects such as oxidation and pits. The weld beads are neatly arranged, without macroscopic defects such as undercut or lack of fusion. Micro-nano CT analysis reveals that the wear-resistant layer contains defects such as... Figure 5 Incomplete fusion defect at the location of the elliptical coil.

[0095] In this embodiment of the invention, Comparative Example 3 is compared with Example 1 to illustrate the beneficial effect of controlling the tungsten electrode 1 to appropriately exceed the range of the two edges when it swings laterally to the left and right edges in the second stacking welding process.

[0096] Comparative Example 3

[0097] In Comparative Example 3, when the tungsten electrode 1 swings laterally to the left and right edges, it is controlled to extend 1 mm beyond the two edges.

[0098] According to product specifications, Co-Cr-Mo welding wire was used to surfacing turbine blades of a certain type of aero-engine. The diameter of welding wire 2 was 1.6 mm, the diameter of tungsten electrode 1 was 1.6 mm, and the maximum welding current was 32 A. The blade and welding wire 2 were preheated at 200℃ for 30 min. The arc was initiated on the right side of the root of the meshing surface and held for 2 seconds / s. After the base metal melted, welding wire 2 was added. The arc was moved to the left side at 1 mm / s, close to the root, until the edge of the meshing surface. The subsequent arc movement speed was 3 mm / s. After the longitudinal surfacing was completed, the lateral oscillation was performed 4 times. When the lateral oscillation reached the left and right edges, the tungsten electrode 1 was controlled to extend 1 mm beyond the two edges. When the longitudinal surfacing reached the end, the arc was initiated again, the wire was fed, and the arc was extinguished once. The total time for re-initiating the arc should not exceed 2 seconds / s.

[0099] After the wear-resistant layer was ground following the completion of the welding process, it was found that there was insufficient material. Figure 6 This diagram shows the structure of the wear-resistant layer obtained by the welding process in Comparative Example 3 of the present invention after grinding. Figure 6 In the middle, at the location of the elliptical coil, there is a missing piece of meat.

[0100] In this embodiment of the invention, Comparative Example 4 is compared with Example 1 to illustrate the beneficial effects of selecting the parameters of the number of arc initiation times and the total arc initiation time in the third welding process.

[0101] Comparative Example 4

[0102] In Comparative Example 4, when the longitudinal welding reaches the end, the arc is restarted, the wire is fed, and the arc is extinguished 3 times, with a total arc restart time of 5 seconds / s.

[0103] According to product specifications, Co-Cr-Mo welding wire was used to surfacing turbine blades of a certain type of aero-engine. The diameter of welding wire 2 was 1.6 mm, the diameter of tungsten electrode 1 was 1.6 mm, and the maximum welding current was 32 A. The blade and welding wire 2 were preheated at 200℃ for 30 min. The arc was initiated on the right side of the root of the meshing surface and held for 2 seconds / s. After the base metal melted, welding wire 2 was added. The arc was moved to the left side at 1 mm / s, close to the root, until the edge of the meshing surface. The subsequent arc movement speed was 3 mm / s. After the longitudinal surfacing was completed, the transverse oscillation was performed 4 times. When the transverse oscillation reached the left and right edges, the tungsten electrode 1 was controlled to extend 3 mm beyond the two edges. When the longitudinal surfacing reached the end, the arc was initiated again, the wire was fed, and the arc was extinguished 3 times. The total time for re-initiating the arc was 5 seconds / s.

[0104] Figure 7 A schematic diagram of the macroscopic structure of the wear-resistant layer obtained using the welding process in Comparative Example 4 of this invention is shown. Figure 7 In the middle, the welding is completed. The surface of the weld layer has a uniform metallic luster, without surface defects such as oxidation color and pits. The weld beads are neatly arranged, without macroscopic defects such as undercut and lack of fusion. Micro-nano CT analysis shows that there are no defects inside the wear-resistant layer, but the end penetration is too deep.

[0105] The "three-stage welding method under vacuum environment" provided by this invention is a complete and universally applicable technical solution. Those skilled in the art, upon understanding the core technical concept of this invention—that is, ensuring welding quality through a combination of vacuum environment control, systematic preheating, a three-stage welding process, and controlled slow cooling—can fully apply this method to other base material structures or areas to be repaired. Such applications and modifications should all fall within the scope of protection sought by this invention.

[0106] Turbine blades, as core components of gas turbines, operate under harsh conditions of high temperature, high pressure, and high corrosion for extended periods. The blade crown meshing area, inlet edge, and tenon are highly susceptible to failure due to wear and corrosion. Traditional repair methods suffer from numerous welding defects, insufficient bond strength, and short service life. Particularly for high-temperature nickel-based alloy blades, conventional welding processes easily generate defects such as hot cracks and porosity, severely impacting the blade's reliability and lifespan. This invention also provides a turbine blade where a wear-resistant layer is formed on the surface of the area to be repaired using the welding method described in this invention.

[0107] In this embodiment of the invention, a gas turbine is also provided. The gas turbine includes a compressor, a combustion chamber, and a turbine assembly. Both the moving blades and the stationary blades in the turbine assembly can be made using the turbine blades of this invention. This invention successfully solves the technical problem of preparing the wear-resistant layer of turbine blades through an innovative welding process. The provided turbine blades have excellent wear resistance and reliability, and gas turbines equipped with these blades show significant improvements in efficiency, lifespan, and economy.

[0108] The present invention relates to a method for surfacing the wear-resistant layer of turbine blades based on a vacuum argon-filled welding box. This method effectively eliminates the influence of water vapor and oxygen in a vacuum environment, fundamentally preventing welding defects such as porosity and slag inclusions. The welding process in a vacuum environment reduces oxide formation, ensuring the integrity of the metallurgical bond. The progressive design of the three-stage welding process ensures sufficient protection of the molten pool and stable and reliable weld formation quality. Precisely controlled preheating and slow cooling processes effectively reduce thermal stress and improve the bonding strength between the wear-resistant layer and the substrate. The organic combination of vacuum welding technology and multi-stage welding processes forms a unique technical solution. The systematic process design reduces operational difficulty and excessive reliance on welder skills, solving the technical problem of traditional methods struggling to balance quality and efficiency.

[0109] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for welding wear-resistant layers onto turbine blades using a vacuum argon-filled welding box, characterized in that, The method includes: The preheated turbine blades and welding wire are placed in a vacuum argon-filled welding box, and the inside of the welding box is evacuated. Inside the welding box where the vacuuming process is completed, the area to be repaired on the turbine blade is welded using a sub-process that includes at least three different welding parameters. The process of performing weld overlay on the area to be repaired of the turbine blade using sub-processes that include at least three different weld overlay parameters includes: The first welding sub-process involves starting an arc at the root of the area to be repaired, preheating the base material, feeding wire, and performing single-pass welding along the first direction. The first welding sub-process is carried out under the following conditions: 1-3 seconds at the starting end, welding current of 20-40A, and welding speed of 1-2mm / s. After completing the single-pass welding process, a second multi-pass welding process is performed by laterally swinging the welding gun along the second direction and the first direction. The second welding sub-process is carried out under the following conditions: welding current of 20-40A and welding speed of 2-5mm / s; and, The third welding sub-process involves repairing and welding defective areas after the initial welding is completed. The third welding process is carried out under the following conditions: the number of welding repairs is 1-2 times and the total time for re-arriving the arc does not exceed 3 seconds. Among them, the first direction and the second direction are set opposite to each other; the multi-layer and multi-pass welding is performed alternately along the second direction and the first direction by laterally swinging the welding gun, which also includes: when the welding gun is laterally swung to the edge of the area to be repaired, the welding gun is controlled to extend beyond the edge range by 2~4mm. After the welding is completed, the turbine blades are placed in the vacuum argon-filled welding box for heat preservation and slow cooling.

2. The method for welding wear-resistant layers onto turbine blades based on a vacuum argon-filled welding box according to claim 1, characterized in that, The preheated turbine blades and welding wire are placed in a vacuum argon-filled welding box, and the inside of the welding box is evacuated, including: The turbine blades and the welding wire are preheated for 10-50 minutes in a temperature range of 80℃-250℃. The preheated turbine blades and welding wire are placed in a vacuum argon-filled welding box; The vacuum level inside the argon-filled vacuum welding box is reduced to below 3 Pa, and then inert protective gas argon is introduced into the vacuum argon-filled vacuum welding box to restore it to a positive pressure state.

3. The method for welding a wear-resistant layer on turbine blades based on a vacuum argon-filled welding box according to any one of claims 1-2, characterized in that, The diameter of the welding wire is 1.0-2.0 mm; The electrode of the welding torch is a tungsten electrode with a diameter of 1.2~2.0 mm.

4. A turbine blade, characterized in that, The turbine blades are obtained by forming a wear-resistant layer on the surface of the area to be repaired using the welding method described in any one of claims 1 to 3.

5. A gas turbine, characterized in that, The gas turbine is equipped with at least one turbine blade as described in claim 4.

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