Method for repairing blade with cooling hole

Abstract

The invention discloses a method for repairing a blade with a cooling hole, which comprises the following steps: S1, damage evaluation: comprehensively evaluating the damage condition of the blade; s2, surface treatment is conducted, specifically, ultrasonic cleaning and sand blasting are conducted, and a surface oxide layer and pollutants are removed; s3, the position of a cooling hole is selected, and the position of the cooling hole is optimized; s4, a repairing material is selected, specifically, high-temperature alloy powder is selected, the stability and corrosion resistance of the high-temperature alloy powder in the high-temperature environment are guaranteed, and it is guaranteed that cracks and defects can be filled in the repairing process by adopting a welding material with excellent fluidity; s5, a repairing process is carried out, and a high-power laser is used for melting deposition of metal powder; and S6, post-treatment is conducted, and subsequent treatment is conducted through heat treatment, surface treatment and performance detection. Through the steps, the service life of the blade can be effectively prolonged, the working performance of the blade in the high-temperature and high-pressure environment is improved, the downtime caused by blade damage is shortened, and the maintenance cost caused by blade damage is reduced.

Description

Technical Field

[0001] The invention relates to a method for repairing a blade with a cooling hole, belonging to the technical field of combustion engine blades. Background Art

[0002] Blades play a vital role in aircraft engines, gas turbines and other power machinery. They operate under extreme conditions and are often affected by high temperature, high pressure and corrosion. Therefore, cracks, wear and deformation may occur in blades during use, and traditional repair technology is difficult to effectively deal with large-area damage. The present invention aims to solve this problem and provide an efficient and reliable repair method. Summary of the invention

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for repairing a blade with cooling holes, thereby solving the above-mentioned technical problems.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a method for repairing a blade with cooling holes, comprising the following steps: Step S1: Damage assessment, using ultrasonic testing, eddy current testing or X-ray imaging non-destructive testing technology to comprehensively assess the damage of the blade and record the crack length, depth, width and damage area; Step S2: Surface treatment, using ultrasonic cleaning and sandblasting to remove the surface oxide layer and pollutants, ensuring that the surface roughness reaches Ra≤1.6μm; Step S3: Cooling hole position selection: According to fluid mechanics simulation, the cooling hole position is optimized to ensure that the airflow is evenly distributed along the blade surface; Step S4: Repair material selection: high temperature alloy powder, such as nickel-based alloy (e.g. Inconel 718) or cobalt-based alloy, is selected to ensure its stability and corrosion resistance in high temperature environment, and welding materials with excellent fluidity are used to ensure that cracks and defects can be filled during the repair process; Step S5: repair process, using a high-power laser (≥1000W) to melt and deposit metal powder; Step S6: Post-processing, including heat treatment, surface treatment and performance testing.

[0005] Furthermore, in step S1, the crack length, depth, width and damage area are recorded, wherein the crack depth is ≤5 mm, the crack length is ≤50 mm, and the total damage area is ≤100 cm².

[0006] Furthermore, in step S4, the material melting point is selected to be ≥1300°C to ensure that no deformation or damage occurs at the working temperature; the tensile strength is ≥800 MPa to ensure structural integrity under high pressure environment; and the thermal expansion coefficient is similar to that of the substrate to reduce stress concentration caused by temperature changes.

[0007] Furthermore, in step S5, a high-power laser (≥1000W) is used to melt and deposit the metal powder; laser power: adjusted according to the material and thickness, between 800W and 1200W; scanning speed: controlled at 5-10 mm / s to ensure the stability of the molten pool; powder feeding speed: 0.5-1.5 kg / h, adjusted according to actual repair needs to ensure the uniformity of the filling material; the thickness of each layer of deposition is controlled at 0.2-0.4mm to avoid deformation of the substrate due to excessive heat input.

[0008] Furthermore, in step S5, the cooling hole processing method uses laser or electric discharge machining (EDM) to open cooling holes on the repaired blade; the laser cutting power is 200W - 400W to ensure that the cooling holes are smooth and match the design requirements; the feed speed is 50-100 mm / min to avoid overheating and material damage.

[0009] Furthermore, in step S6, the heat treatment temperature is 850°C, the holding time is 2 hours, and argon protection is used to prevent oxidation; chemical or mechanical polishing methods are used to obtain a surface finish of Ra≤0.8μm to reduce aerodynamic resistance; ultrasonic and X-ray inspections are used to detect the repaired parts to ensure that there are no defects, and tensile, fatigue and hardness tests are performed on the repaired samples to ensure that their performance meets or exceeds the standards of the original blades.

[0010] The beneficial effects of the present invention are as follows: through the above steps, the large-area repair method of blades with cooling holes of the present invention can effectively extend the service life of the blades, improve their working performance under high temperature and high pressure environments, and reduce downtime and maintenance costs caused by blade damage. This method is suitable for repairing blades of aircraft engines, gas turbines and other high-performance power machinery. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail by examples below. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0012] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0013] A method for repairing a blade with cooling holes according to an embodiment of the present invention comprises the following steps: Step S1: Damage assessment, using ultrasonic testing, eddy current testing or X-ray imaging non-destructive testing technology to comprehensively assess the damage of the blade and record the crack length, depth, width and damage area; Step S2: Surface treatment, using ultrasonic cleaning and sandblasting to remove the surface oxide layer and pollutants, ensuring that the surface roughness reaches Ra≤1.6μm; Step S3: Cooling hole position selection: According to fluid mechanics simulation, the cooling hole position is optimized to ensure that the airflow is evenly distributed along the blade surface; Step S4: Repair material selection: high temperature alloy powder, such as nickel-based alloy (e.g. Inconel 718) or cobalt-based alloy, is selected to ensure its stability and corrosion resistance in high temperature environment, and welding materials with excellent fluidity are used to ensure that cracks and defects can be filled during the repair process; Step S5: repair process, using a high-power laser (≥1000W) to melt and deposit metal powder; Step S6: Post-processing, including heat treatment, surface treatment and performance testing.

[0014] Preferably, in step S1 of the present embodiment, the crack length, depth, width and damage area are recorded, wherein the crack depth is ≤5 mm, the crack length is ≤50 mm, and the total damage area is ≤100 cm².

[0015] Preferably, in step S4 of this embodiment, the material melting point is selected to be ≥1300°C to ensure that no deformation or damage occurs at the working temperature; the tensile strength is selected to be ≥800 MPa to ensure the structural integrity under high pressure environment; and the thermal expansion coefficient is selected to be similar to that of the substrate to reduce stress concentration caused by temperature changes.

[0016] Preferably, in step S5, a high-power laser (≥1000W) is used to melt and deposit the metal powder; laser power: adjusted according to the material and thickness, between 800W and 1200W; scanning speed: controlled at 5-10 mm / s to ensure the stability of the molten pool; powder feed speed: 0.5-1.5 kg / h, adjusted according to actual repair needs to ensure the uniformity of the filling material; the thickness of each layer of deposition is controlled at 0.2-0.4mm to avoid deformation of the substrate due to excessive heat input.

[0017] Preferably, in step S5, the cooling hole processing method uses laser or electric discharge machining (EDM) to open cooling holes on the repaired blade; laser cutting power: 200W - 400W, to ensure that the cooling holes are smooth and match the design requirements; feed speed: 50-100 mm / min, to avoid overheating and damage to the material.

[0018] Preferably, in step S6 of the present embodiment, the heat treatment temperature is 850°C, the holding time is 2 hours, and argon gas protection is used to prevent oxidation; a chemical or mechanical polishing method is used to obtain a surface finish of Ra≤0.8μm to reduce aerodynamic resistance; ultrasonic and X-ray detection are used to detect the repaired part to ensure that there are no defects, and the repaired samples are subjected to tensile, fatigue and hardness tests to ensure that their performance meets or exceeds the standards of the original blades.

[0019] Through the above steps, the large-area repair method of blades with cooling holes of the present invention can effectively extend the service life of the blades, improve their working performance under high temperature and high pressure environment, and reduce the downtime and maintenance cost caused by blade damage. This method is suitable for the repair of blades of aircraft engines, gas turbines and other high-performance power machinery.

[0020] The large-area repair method for blades with cooling holes provided by the present invention solves the shortcomings of existing repair methods by combining advanced materials and technologies, has good application prospects, and can provide important support for technological progress in related industries.

[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for repairing a blade with cooling holes, characterized in that: The following steps are involved: Step S1: Damage assessment, using ultrasonic testing, eddy current testing or X-ray imaging non-destructive testing technology to comprehensively assess the damage of the blade and record the crack length, depth, width and damage area; Step S2: Surface treatment, using ultrasonic cleaning and sandblasting to remove the surface oxide layer and pollutants, ensuring that the surface roughness reaches Ra≤1.6μm; Step S3: Cooling hole position selection: According to fluid mechanics simulation, the cooling hole position is optimized to ensure that the airflow is evenly distributed along the blade surface; Step S4: Repair material selection: high temperature alloy powder, such as nickel-based alloy (e.g. Inconel 718) or cobalt-based alloy, is selected to ensure its stability and corrosion resistance in high temperature environment, and welding materials with excellent fluidity are used to ensure that cracks and defects can be filled during the repair process; Step S5: repair process, using a high-power laser (≥1000W) to melt and deposit metal powder; Step S6: Post-processing, including heat treatment, surface treatment and performance testing.

2. A method for repairing a blade with cooling holes according to claim 1, characterized in that: In step S1, the crack length, depth, width and damage area are recorded, wherein the crack depth is ≤5 mm, the crack length is ≤50 mm, and the total damage area is ≤100 cm².

3. The method for repairing a blade with cooling holes according to claim 1, characterized in that: In step S4, the material melting point is selected to be ≥1300°C to ensure that no deformation or damage occurs at the working temperature; the tensile strength is ≥800 MPa to ensure the structural integrity under high pressure environment; and the thermal expansion coefficient is similar to that of the substrate to reduce stress concentration caused by temperature changes.

4. A method for repairing a blade with cooling holes according to claim 1, characterized in that: In the step S5, a high-power laser (≥1000W) is used to melt and deposit the metal powder; the laser power is adjusted according to the material and thickness, between 800W and 1200W; the scanning speed is controlled at 5-10 mm / s to ensure the stability of the molten pool; the powder feeding speed is 0.5-1.5 kg / h, which is adjusted according to the actual repair requirements to ensure the uniformity of the filling material; the thickness of each layer of deposition is controlled at 0.2-0.4mm to avoid deformation of the substrate due to excessive heat input.

5. The method for repairing a blade with cooling holes according to claim 1, characterized in that: In step S5, the cooling hole processing method uses laser or electric discharge machining (EDM) to open the cooling hole on the repaired blade; the laser cutting power is 200W-400W to ensure that the cooling hole is smooth and matches the design requirements; the feed speed is 50-100 mm / min to avoid overheating and material damage.

6. The method for repairing a blade with cooling holes according to claim 1, characterized in that: In step S6, the heat treatment temperature is 850°C, the holding time is 2 hours, and argon protection is used to prevent oxidation; chemical or mechanical polishing methods are used to obtain a surface finish of Ra≤0.8μm to reduce aerodynamic resistance; ultrasonic and X-ray inspection of the repaired parts are used to ensure that there are no defects, and the repaired samples are subjected to tensile, fatigue and hardness tests to ensure that their performance meets or exceeds the standards of the original blades.