Process for the repair and remanufacturing of turbine blade vapor deposition coatings

Abstract

The process method for repairing and remanufacturing the turbine blade vapor deposition coating of the application comprises determining the repair area and non-repair area of the turbine blade, setting a shielding protective layer on the non-repair area, pickling the turbine blade to remove the coating, neutralizing the pickled turbine blade in lye, removing the shielding protective layer and cleaning, tempering and coloring process treatment, and recovering AlSiY coating on the blade body of the turbine blade by vacuum arc plating process after the tempering and coloring process treatment, which comprises the following steps: recovering the coating on the blade body of the turbine blade by vacuum arc plating process after tempering and coloring, if the surface reaches blue or light yellow and there is no protrusion, recovering the coating on the blade body of the turbine blade by vacuum arc plating process, and if the multiple repair areas present straw color or golden yellow, sandblasting treatment. The high efficiency of repair is realized, and the original layer is prevented from being easily damaged and the low efficiency of the traditional manual method.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallographic sample preparation methods, and particularly relates to a process method for repairing and remanufacturing a gas-phase deposition coating of a turbine blade. BACKGROUND

[0002] The high-temperature alloy turbine blade needs to withstand huge centrifugal force, thermal stress and vibration load, and is subjected to repeated erosion of high-temperature and high-speed gas flow. It has been proved that high-temperature oxidation and thermal corrosion of the gas on the blade are one of the main damage forms causing damage to the blade. The turbine blade is in a harsh environment of high temperature and high pressure, and needs to be protected by a high-temperature protective coating. The high-temperature protective coating can be prepared by various methods, such as gas deposition, thermal spraying, etc. The vacuum arc plating process is a physical vapor deposition process in the vapor deposition method, which uses the principle of field emission and cathode discharge to uniformly deposit the cathode target material on the part after vaporization and acceleration, has the advantages of easy control and adjustment of coating composition, dense organization, good coating adhesion and no environmental pollution, and is commonly used for preparing high-temperature oxidation-resistant coatings.

[0003] An AlSiY coating is prepared on the blade body of an aero-engine blade by using a vacuum arc plating process. When the engine is repaired, the coating needs to be removed and then repaired and remanufactured. The coating thickness is different in different areas of the blade. The existing process basically adopts chemical and manual polishing to completely remove the old coating, and then re-coats the coating to achieve the purpose of repairing and remanufacturing. However, there are problems such as repeated polishing, excessive removal of the substrate size, uncontrollable removal amount, and out-of-tolerance of the substrate size, which result in long repair cycle, high cost, and low repair efficiency.

[0004] Therefore, the application is proposed. SUMMARY

[0005] The application aims to provide a process method for repairing and remanufacturing a gas-phase deposition coating of a turbine blade, and solves the technical problem of low efficiency of repairing the coating of the turbine blade in the prior art. The technical solution of the application has many technical advantages, which are described below.

[0006] A process method for repairing and remanufacturing a gas-phase deposition coating of a turbine blade is provided, and the process method comprises the following steps:

[0007] Determine the to-be-repaired area and the non-repaired area of the turbine blade, the number of the to-be-repaired areas is multiple, and the coating thickness of each to-be-repaired area is different, and a shielding protective layer is arranged on the non-repaired area;

[0008] Acid wash the turbine blade to remove the coating, and neutralize the acid-washed turbine blade in alkali;

[0009] Remove the shielding protective layer and clean it;

[0010] Sandblasting treatment, Al2O3 is selected as the sand particles and the mesh size is 180 mesh, the wind pressure range of the launching device is 0.2-0.4 MPa, and the wind pressure of the launching device is adjusted to blow sand to remove surface corrosion products and residual coating on all the areas to be repaired;

[0011] The AlSiY coating of the blade body of the turbine blade is recovered by using the vacuum arc plating process after the tempering coloring process treatment, and the tempering coloring process treatment comprises the following steps:

[0012] If the surface of each of the areas to be repaired presents blue color after the tempering coloring, or more than 85% of the area presents blue color and local area presents yellow color and the yellow area has no protrusion, the AlSiY coating of the blade body of the turbine blade is recovered by using the vacuum arc plating process;

[0013] If the multiple areas to be repaired present straw color or golden yellow color, Al2O3 is selected as the sand particles for sandblasting process treatment, the wind pressure range of the launching device is 0.2-0.4 MPa, and after the golden yellow coating is removed, the AlSiY coating of the blade body of the turbine blade is recovered by using the vacuum arc plating process.

[0014] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects:

[0015] The core of the present application aims to quickly repair the turbine blade by chemical reaction and sandblasting, when there are areas to be repaired, and the coating thickness of each area to be repaired is different, the chemical reaction and sandblasting can be targeted and quickly repaired, avoiding the situation that the traditional manual method is time-consuming and the original layer is easily damaged during repair. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

[0018] Following, the embodiments of the present application are illustrated by specific examples, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure of the present specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied by other different specific embodiments, and various modifications or changes can be made to the details in the present specification based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0019] As shown in the process method for repairing and remanufacturing the turbine blade vapor deposition coating, the process method comprises: Figure 1

[0020] S101: determining the repair area and non-repair area of the turbine blade, the number of repair areas is multiple, and the coating thickness of each repair area is different, and a shielding protective layer is arranged on the non-repair area, preferably,

[0021] Once sandblasting, Al2O3 sand particles with a mesh size of 60 mesh are selected, and the wind pressure of the launching device is set to 0.2-0.3 MPa; the coating surface of the repair area is sandblasted to remove surface carbon and high-temperature sintered material;

[0022] The non-repair area is coated with a shielding protective layer, and the shielding protective layer is a wax layer, which can effectively avoid corrosion by acid or alkali.

[0023] S102: pickling the turbine blade to remove the coating, and neutralizing the pickled turbine blade with alkali, the repair area is multiple and the coating thickness is different, preferably,

[0024] The acid solution is configured, including selecting nitric acid, hydrofluoric acid and chromic anhydride to prepare a mixed solution, for example, the soaking temperature is 15-30℃, the time is 50-70min, and the proportion in the mixed solution is: nitric acid 120g / l, hydrofluoric acid 11g / l, and chromic anhydride 8g / l;

[0025] The turbine blade with the shielding protective layer is soaked in the mixed solution until the coating of one repair area is crystallized or slightly crystallized, that is, when the coating of any one of the repair areas is crystallized or slightly crystallized, the turbine blade is taken out, and generally, the repair area with the thinnest coating appears crystallization first;

[0026] After soaking, remove the dust, soak the turbine blade in cold water, and use non-woven fabric or scouring pad to wipe off the surface dust, or use a high-pressure water gun to wash off the dust.​

[0027] Further, the turbine blade after the alkali solution neutralization and acid washing, specifically, after the acid washing, the turbine blade is placed in a sodium carbonate solution to neutralize the acid solution, for example, in a sodium carbonate (30g / l-50g / l) solution, at room temperature, for 3-5min, to avoid corrosion caused by the acid solution in the subsequent repair process.

[0028] S103: remove the shielding protective layer and clean, specifically:

[0029] Prepare a mixed solution of sodium carbonate and sodium phosphate;

[0030] Remove the shielding protective layer of the non-repair area in the mixed solution of sodium carbonate and sodium phosphate, and use hot water to wash twice after removing the shielding protective layer;

[0031] Use clean compressed air to dry the turbine blade.

[0032] Inspection: the surface of the first crystal appearing repair area is light gray to dark gray, if not, repeat the above steps of acid washing, neutralization, etc., until the surface of the first crystal appearing repair area is light gray to dark gray. When the crystal appears in the repair area with a relatively thin coating, it is removed.

[0033] S104: sandblasting treatment (second sandblasting treatment), select Al2O3 as sand particles and the mesh size is 180 mesh, the wind pressure range of the launching device is 0.2-0.4MPa, adjust the wind pressure of the launching device to sandblast all the repair areas to remove surface corrosion products and residual coating, and prepare for tempering treatment.

[0034] S105: tempering and coloring process treatment, and after the tempering and coloring process treatment, use vacuum arc plating process to restore AlSiY coating to the blade body of the turbine blade, preferably, the tempering temperature: 580℃±10℃, holding for 60-70min, cooling method: air cooling, including:

[0035] If all the repair areas after tempering and coloring show blue, or more than 85% of the area shows blue, less than 15% of the local area shows yellow, and there is no protrusion in the yellow area and no golden yellow on the surface, use vacuum arc plating process to restore AlSiY coating to the blade body of the turbine blade, or, when the surface reaches blue or light yellow after tempering and coloring, restore the coating when there is no protrusion, and reach blue, including: allow incomplete blue to be repaired.

[0036] If the plurality or one of the to-be-repaired areas presents straw color or golden yellow color, Al2O3 is selected as the sand particles to perform the sandblasting process treatment, the wind pressure range of the launching device is 0.2-0.4 MPa, after the golden yellow coating is removed, the AlSiY coating is restored to the blade body of the turbine blade by using the vacuum arc plating process, specifically, if the plurality or one of the to-be-repaired areas presents straw color or golden yellow color, the AlSiY coating is restored to the blade body of the turbine blade by using the vacuum arc plating process, three times of sandblasting is needed, Al2O3 is selected as the sand particles, the mesh number is 180, the wind pressure range of the launching device is 0.2-0.4 MPa, after the golden yellow coating is removed, the AlSiY coating is restored to the blade body of the turbine blade by using the vacuum arc plating process, the rapid coating repair is realized. Since the coating thicknesses of different to-be-repaired areas are different, generally 0.03 mm-0.06 mm, by adjusting the sandblasting parameters, the to-be-repaired areas with different thicknesses are subjected to the sandblasting treatment, the residual material is quickly removed and then the coating is applied, the high efficiency of repair is realized, and the repair of the aluminum-silicon-yttrium coating can be applicable.

[0037] Technical effects:

[0038] 1. The old coating does not need to be completely removed, the substrate removal amount is reduced, and the substrate size out-of-tolerance is avoided.

[0039] 2. The old coating is removed by using the chemical + sandblasting combined mode, manual polishing is not needed, and the efficiency is high.

[0040] 3. The coating removal amount can be accurately controlled by the sandblasting parameters, and the quality is more controllable.

[0041] The product provided by the application is described in detail. The principle and implementation mode of the application are described by applying specific examples in the present paper, and the above examples are only used to help understand the core idea of the application. It should be pointed out that, for ordinary skilled persons in the technical field, without departing from the principle of the application, the application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the application claims.

Claims

1. A process for the repair remanufacturing of a turbovane gas phase deposition coating characterized in that, The process comprises: determining the repair area and non-repair area of the turbine blade, the number of repair areas is multiple and the coating thickness of each repair area is different, and the non-repair area is provided with a shielding protective layer; pickling the turbine blade to remove the coating, and neutralizing the pickled turbine blade in lye, wherein the acid solution is configured by selecting nitric acid, hydrofluoric acid and chromic anhydride for proportioning to make a mixed solution, immersing the turbine blade provided with the shielding protective layer in the mixed solution until the coating of the first repair area is crystallized, and then taking out the turbine blade; removing the shielding protective layer and cleaning; sandblasting treatment, selecting Al2O3 as the sand particles and the sand particle mesh number is 180 mesh, the wind pressure range of the launching device is 0.2-0.4 MPa, adjusting the wind pressure of the launching device to sandblast all the repair areas to remove the surface corrosion products and the remaining coating; tempering coloring process treatment, and restoring the AlSiY coating of the blade body of the turbine blade by vacuum arc plating process after the tempering coloring process treatment, comprising: if the surface of each repair area presents blue color after the tempering coloring, or more than 85% of the area presents blue color and local area presents yellow color and the yellow area has no protrusion, restoring the AlSiY coating of the blade body of the turbine blade by vacuum arc plating process; if the multiple repair areas present golden yellow color, selecting Al2O3 as the sand particles for sandblasting process treatment, and the wind pressure range of the launching device is 0.2-0.4 MPa, after removing the golden yellow coating, restoring the AlSiY coating of the blade body of the turbine blade by vacuum arc plating process; determining the repair area and non-repair area of the turbine blade, and providing the non-repair area with a shielding protective layer, comprising: once sandblasting, selecting Al2O3 sand particles and the sand particle mesh number is 60 mesh, and setting the wind pressure of the launching device to 0.2-0.3 MPa, sandblasting the coating surface of the repair area to remove the surface carbon and high-temperature sintered material; the non-repair area is coated with a shielding protective layer, and the shielding protective layer is a wax layer.

2. The process of claim 1, wherein, The immersion temperature is 15°C-30°C, the time is 50min-70min, and the proportioning in the mixed solution is: nitric acid 120g / L, hydrofluoric acid 11g / L and chromic anhydride 8g / L; after immersion, remove the dust, immerse the turbine blade in cold water, wipe off the surface dust with non-woven fabric or scour off the dust with a high-pressure water gun.

3. The process of claim 2, wherein, neutralizing the pickled turbine blade in lye, comprising: after pickling, placing the turbine blade in a sodium carbonate solution to neutralize the residual acid solution on the turbine blade.

4. The process of claim 1, wherein, removing the shielding protective layer and cleaning, comprising: preparing a mixed solution of sodium carbonate and sodium phosphate; removing the shielding protective layer of the non-repair area in the mixed solution of sodium carbonate and sodium phosphate, and cleaning with hot water after removing the shielding protective layer; blowing dry the turbine blade with clean compressed air.

5. The process of claim 1, wherein, restoring the coating after the tempering coloring process treatment, and restoring the AlSiY coating of the blade body of the turbine blade by vacuum arc plating process, comprising: tempering temperature: 580℃±10℃, holding for 60-70min, cooling mode: air cooling, and the Al2O3 mesh number for sandblasting treatment after the tempering coloring process treatment is 180 mesh.

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