Method of repairing wear in a guider inner ring

Abstract

The repair method of the inner ring wear of the guider of the application comprises determining the repair area of the inner ring of the guider, cutting the actual defects of the inner ring to form an opening as the repair area, fixing the guider through a clamp, installing the clamp on the mounting platform of a laser deposition device and repairing the repair area, wherein the laser deposition device is placed with first repair powder, the material of the first repair powder is different from that of the guider, the repaired repair area is subjected to nondestructive testing, and the guider is placed on the machining platform of a machine tool for polishing and size recovery process treatment. The method solves the difficult weldability of the base material and the problem of easy deformation of the end face of the part, and reduces the overhaul cost of the aero-engine.

Description

Technical Field

[0001] This invention relates to the technical field of repairing aerospace parts, and more particularly to a method for repairing wear on the inner ring of a guide. Background Technology

[0002] The IV, V, and VI level inner rings are sub-components of the IV, V, and VI level turbine guide vanes, respectively. The journals of the same level guide vanes (IV, V, or VI level) are inserted into the radial holes on the outer cylindrical surface of the inner ring. The rear end face of the front baffle of the inner edge plate of the vane mates with the front end face of the inner ring, and the front end face of the rear baffle of the inner edge plate mates with the rear end face of the inner ring, forming the inner ring of the guide vane. An air baffle mounting edge, which provides inter-stage sealing, is installed on the inner mounting edge of the inner ring. The function of this inner ring is to limit movement, dampen the vibration of the guide vanes, and provide a mounting location for the air baffle mounting edge, which provides inter-stage sealing. The main failure of the guide vane inner ring is due to wear on the mating surfaces with the guide vanes caused by vane vibration during engine operation (wear on the front and rear end faces of the inner ring and friction between the radial holes), resulting in an inability to meet assembly requirements and leading to component failure and scrapping.

[0003] The inner ring of the guide is made of GH4033, which has a high total amount of aluminum and titanium in its chemical composition and is in an aged state. Its weldability is generally poor. Traditional repair processes such as argon arc welding and plasma welding have excessive heat input during the welding process, which can easily cause deformation of the parts and make it difficult to repair the inner ring of the guide. Summary of the Invention

[0004] In view of this, the repair method for wear of the inner ring of the guide provided by the present invention solves the problems of difficult welding of the guide base material and easy deformation of the end face of the component, reduces the overhaul cost of aero-engines, shortens the repair cycle, and achieves high-quality repair of components.

[0005] A method for repairing wear on the inner ring of a guide, the method comprising:

[0006] Determining the repairable area of ​​the inner ring of the guide includes cutting the actual defect of the inner ring to form a notch, the notch serving as the repairable area;

[0007] The guide is fixed by a clamp;

[0008] The fixture is installed on the mounting platform of the laser deposition equipment and the area to be repaired is repaired. The laser deposition equipment contains a first repair powder, the material of which is different from that of the guide.

[0009] The repaired area to be repaired undergoes non-destructive testing.

[0010] The guide is placed on the machining platform of the machine tool for grinding and dimensional restoration processes.

[0011] Beneficial effects

[0012] The method of this invention can achieve the repair of large repair surfaces and thin-walled structures; it can greatly reduce the problems of concentrated heat influence and excessive heat influence on the repaired edge, reduce thermal stress, avoid deformation and cracking, and achieve high-quality and high-performance repair; using the special repair tooling designed in this invention can effectively solve problems such as collapse and deformation during the repair process, and can realize low-power small-spot laser forming repair of thin-walled structures. Furthermore, it minimizes the thermal influence and deformation on the entire part, reduces the cost of aero-engine overhaul, and shortens the repair cycle. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0015] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0016] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0017] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0018] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that these aspects can be practiced without these specific details.

[0020] See Figure 1 The method for repairing wear on the inner ring of the guide shown includes:

[0021] S101: Determine the repair area of ​​the inner ring of the guide, including cutting the actual defect of the inner ring to form a notch, the notch serving as the repair area; preferably, the notch is a U-shaped curved surface. Specifically:

[0022] Based on the actual defects of the inner ring of the guide, the shape and size of the area to be repaired are customized, for example, a U-shaped curved surface. Machining is then performed according to the designed shape and size to remove the defective portion of the inner ring of the guide. The area formed after removing the defective portion of the inner ring of the guide is the area to be repaired.

[0023] S102: The guide is fixed by a clamp, specifically:

[0024] First, the area to be repaired is sanded to remove the oxide scale, burrs, and stains, and then cleaned.

[0025] Then, a fixture is made, which includes a symmetrical split half ring. The inner ring surface of the split half ring is provided with a groove that matches the size of the guide. The grooves of the two split half rings can hold the guide, and both ends of the split half ring are provided with lugs with central openings.

[0026] After placing the guide in the grooves of the two split semi-rings, bolts are used to pass through the two corresponding lugs to fix the guide. The part (guide) is clamped using a clamping method, with the inner circle surface conforming to the shape of the outer circle of the part. The outer circle mounting edge of the part is clamped by the inner circle stop of the tooling to prevent the repair area of ​​the part mounting edge from warping downward. Pressure plates are used at both ends of the reserved repair area to press the welding area, further preventing the part mounting edge from warping upward during the laser direct deposition additive repair process. The circumferentially distributed square pressure plates are in close contact with the surface of the part, which facilitates the transfer of heat generated by laser repair to the tooling and facilitates heat dissipation.

[0027] Furthermore, the fixture also includes L-shaped pressure blocks, preferably with an arc-shaped transition. Pressure blocks are symmetrically placed on the sides of each split half-ring. One end of each pressure block contacts the non-repair area of ​​the inner ring, and the other end is bolted to the side of the split half-ring to increase the clamping force of the guide within the split half-ring. Generally, 16-20 pressure blocks are used. Preferably, pressure blocks are placed at intervals on one side of each split half-ring. The purpose of the pressure blocks is to increase pressure, thereby increasing the pressure between the part and the tooling fixture to achieve better processing results. They also increase friction, improving the stability of the part during clamping, preventing slippage and displacement, thus ensuring processing accuracy and quality. Additionally, the pressure blocks prevent damage to the part during clamping and uncontrollable deformation due to localized high temperatures during repair, ensuring the integrity of the part and controllable deformation.

[0028] S103: Install the fixture on the mounting platform of the laser deposition equipment and repair the area to be repaired. The laser deposition equipment contains first repair powder, the material of which differs from that of the guide. Specifically:

[0029] The first repair powder is GH3625 metal powder. Before use, the GH3625 powder to be repaired is dried and preheated to ensure stable quality in the laser direct deposition additive manufacturing repair process. The guide inner ring is made of GH4033 metal. Using powders of different materials for repair represents a breakthrough from traditional single-material powder repair. The use of this first repair powder solves problems such as collapse and deformation during the repair process, enabling high-quality, high-performance laser direct deposition additive manufacturing repair of the guide inner ring. GH3625 metal powder is a solid solution-strengthened nickel-based superalloy with molybdenum and niobium as the main strengthening elements. It exhibits good performance from low temperatures to 980℃, meeting the service environment requirements of the guide inner ring end face. Furthermore, the aluminum and titanium content in GH3625 powder is less than 0.8%, resulting in good weldability. In contrast, GH4033 contains approximately 4% aluminum and titanium, leading to generally lower weldability.

[0030] Obtain the dimensional parameters of all areas to be repaired and input them into the CNC program of the laser deposition equipment. The operating parameters of the laser deposition equipment are set as follows: laser spot diameter of 2mm, laser power of 650W, scanning speed of 0.010m / min, first repair powder feeding speed of 0.5rpm and gas flow rate of 5L / min, protective argon gas flow rate of 15L / min, defocusing amount of +4.5mm, and nozzle-to-workpiece distance of 8mm.

[0031] S104: Perform non-destructive testing on the repaired area, specifically:

[0032] After the area to be repaired is repaired, stress-relieving heat treatment is performed. For example, stress-relieving heat treatment of the repaired part after repair can remove the stress in the repaired area and surrounding areas. Heat treatment regime: holding temperature is 650±10℃, holding time is 150min-180min;

[0033] All repaired areas are colored and inspected sequentially by X-ray. Two adjacent X-ray beams are used for inspection, with a 50% overlap rate between the beams. The scanning path is cross-shaped. Metallographic inspection is performed on all repaired areas sequentially, and the metallographic inspection results are judged to meet the standards. If they do, room temperature tensile and high temperature tensile tests are performed. If they do not meet the standards, the laser parameters are optimized and the repair is repeated before metallographic inspection is performed again. Good laser direct deposition (LDD) repair quality was achieved. The overlap rate of two adjacent laser beams was 50%, and the laser beams of two adjacent deposition layers were perpendicular to each other. The scanning path was cross-shaped. Metallographic examination of the repaired area showed no obvious defects such as cracks or lack of fusion in the LDD area. The substrate and the LDD additive manufacturing area had good metallurgical bonding. At the bonding surface, the equiaxed grains of the substrate did not show obvious growth under the first laser scan, and the heat-affected zone was not obvious. The microstructure of the LDD area showed a dendritic distribution. Due to the rapid laser scanning and high molten pool cooling rate, the dendrites were small and distributed at different angles, roughly parallel to the additive deposition direction. The dendrite growth direction of the upper layer was similar to that of the adjacent layer.

[0034] S105: The guide is placed on the machining platform of the machine tool for grinding and dimensional restoration processes. Specifically:

[0035] After repair, all areas to be repaired are machined and polished according to the standard dimensions of the guide inner ring to restore the guide inner ring to the standard dimensions. In particular, the repair areas are machined and polished until the repair areas have the same shape and size as the areas to be repaired, so that the guide inner ring is restored to its original shape and size.

[0036] After grinding and dimensional restoration, each repaired area is coated with KF-307C material to form a protective layer. The purpose of spraying KF-307C is that the inner ring of the turbine guide vane, used to fix the turbine guide vane blade rim, is part of the inner wall of the turbine gas passage. During engine operation, fretting wear occurs between the blade rim and the inner ring end face. The KF-307C material sprayed on the guide vane end face has a certain degree of wear resistance, and its hardness is lower than that of the blade rim. When the engine is running, fretting occurs between the blade rim and the inner ring end face; the wear is limited to the surface KF-307C coating, protecting the blade rim from wear.

[0037] Ensure that the interface contamination between the protective layer and the laser-deposited layer is less than 20%, and that the pores are uniformly distributed with a porosity of less than 6%.

[0038] Furthermore, a tensile test with a tensile strength ≥45 MPa is performed to meet the standard requirements. If the tensile test fails to meet the standard, the laser parameters are optimized and the problem is repaired again before the tensile test is performed again.

[0039] The part is clamped using a clamping method, with the inner circular surface conforming to the shape of the outer circular surface of the part. The outer circular mounting edge of the part is clamped by the inner circular stop of the tooling to prevent the repair area of ​​the mounting edge from warping downwards. Pressure plates are used at both ends of the reserved repair area to press the welding area, further preventing the mounting edge of the part from warping upwards during the laser direct deposition additive manufacturing repair process. The circumferentially distributed square pressure plates are in close contact with the part surface, facilitating the transfer of heat generated during laser repair to the tooling and promoting heat dissipation. Compared with existing technologies, the laser direct deposition additive manufacturing repair method for wear damage to the inner ring of an aero-engine guide vane provided by this invention has the following advantages:

[0040] This laser direct deposition additive manufacturing repair tooling, featuring a split-ring clamping method and circumferentially distributed pressure blocks, achieves the fixation of the large repair surface and thin-walled end face of the guide inner ring, as well as the protection treatment of the area to be repaired. It enables high-quality, high-performance laser direct deposition forming of damaged dimensional repair parts with large repair surfaces and thin-walled end faces. Laser direct deposition of dissimilar materials and spraying on non-repair surfaces meet the surface wear resistance requirements of the guide inner ring end face, until the final size of the part is achieved.

[0041] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for repairing wear on the inner ring of a guide, characterized in that, Determining the repairable area of ​​the inner ring of the guide includes cutting the actual defect of the inner ring to form a notch, the notch serving as the repairable area; The guide is fixed by a clamp; The fixture is installed on the mounting platform of the laser deposition equipment and the area to be repaired is repaired. The laser deposition equipment contains a first repair powder. The material of the first repair powder is different from that of the guide. The first repair powder is made of GH3625 metal powder, and the inner ring of the guide is made of GH4033 metal. The repaired area to be repaired undergoes non-destructive testing. The guide is placed on the machining platform of the machine tool for grinding and dimensional restoration processes.

2. The repair method according to claim 1, characterized in that, The notch is U-shaped.

3. The repair method according to claim 1, characterized in that, The guide is fixed by a clamp, including: The area to be repaired is polished to remove the oxide scale, burrs and stains, and then cleaned. The clamp includes a symmetrical split half-ring, wherein the inner ring surface of the split half-ring is provided with a groove adapted to the size of the guide, the groove can hold the guide, and both ends of the split half-ring are provided with lugs with central openings. After placing the guide in the groove of the two split semi-rings, bolts are used to pass through the two lugs corresponding to the positions to fix the guide.

4. The repair method according to claim 3, characterized in that, The clamp also includes an L-shaped pressure block, which is symmetrically placed on the side of each of the split half rings. One end of the pressure block contacts the non-repair area of ​​the inner ring, and the other end is bolted to the side of the split half ring to increase the tightening force of the guide within the split half ring.

5. The repair method according to claim 3, characterized in that, The pressure block is placed at intervals on one side of each of the split semi-rings.

6. The repair method according to claim 3, characterized in that, Mounting the fixture on the mounting platform of the laser deposition equipment and repairing the area to be repaired includes: The dimensional parameters of all areas to be repaired are obtained and input into the CNC program of the laser deposition equipment. The operating parameters of the laser deposition equipment are set as follows: laser spot diameter of 2 mm, laser power of 650 W, scanning speed of 0.010 m / min, powder feeding speed of the first repair powder of 0.5 rpm and gas flow rate of 5 L / min, protective argon flow rate of 15 L / min, defocusing amount of +4.5 mm, and distance from nozzle to workpiece of 8 mm.

7. The repair method according to claim 1, characterized in that, Non-destructive testing of the repaired area includes: The area to be repaired is then subjected to stress-relieving heat treatment. All repaired areas are colored and sequentially inspected by X-ray. Two adjacent X-ray beams are used for inspection, with a beam overlap rate of 50% between the two beams. The scanning path is cross-shaped. Metallographic inspection is performed on all repaired areas sequentially, and it is determined whether the metallographic inspection results meet the standards. If yes, room temperature tensile and high temperature tensile tests are performed. If no, the laser parameters are optimized and the repair is repeated, and metallographic inspection is performed again until the standards are met.

8. The repair method according to claim 1, characterized in that, The guide is placed on the machining platform of the machine tool for grinding and dimensional restoration processes, including: After repair, all the areas to be repaired are machined and polished according to the standard dimensions of the guide inner ring, so that the guide inner ring is restored to the standard dimensions; After grinding and dimensional restoration processes, each repaired area is sprayed with KF-307C material to form a protective layer. Ensure that the interface contamination between the protective layer and the laser-deposited layer is <20%, and that the pores are uniformly distributed with a porosity of <6%; Tensile testing with a tensile strength ≥45 MPa is performed to meet the standard requirements. If the tensile test fails to meet the standard, the laser parameters are optimized and the test is repeated.

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