Acid pickling method of titanium alloy blade for gas turbine

Abstract

The invention provides a pickling method of a titanium alloy blade for a gas turbine, which comprises the following steps: outer surface cleaning, primary clamping, chemical degreasing, degreasing solution cleaning, degreasing quality inspection, drying, dismounting, isolation, degreasing, secondary clamping, primary pickling, pickling solution cleaning, defect inspection, secondary pickling, pickling solution cleaning, defect inspection and isolation removal. Cleaning the isolation solution, cooling the surface of the blade, drying and storing. Pollutants on the surface of the blade can be effectively removed, the surface quality and corrosion resistance of the blade are improved, multiple defects of the titanium alloy blade can be accurately detected, the quality and reliability of the blade are ensured, damage to the surface of the titanium alloy blade can be reduced, and the performance of the blade is protected. The pickling process is easy to control and implement; the production efficiency can be improved; the cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal surface treatment, and particularly relates to a pickling method for titanium alloy blades used in gas turbines. Background Art

[0002] In the operation of gas turbines, titanium alloy blades play a crucial role. However, during the manufacturing and use of titanium alloy blades, crack defects, overburn defects, and macrostructure defects may occur due to various factors. These defects not only reduce the strength and stability of the blades but also seriously affect the performance and service life of the blades, and may even lead to failures and damages of gas turbines. Therefore, it is very important to accurately detect these related defects before the blades are used. Only by timely discovering and repairing these defects can the quality and reliability of titanium alloy blades be ensured, thereby guaranteeing the safe and stable operation of gas turbines. This is of crucial significance for improving the efficiency and performance of gas turbines and extending their service life.

[0003] Pickling is a commonly used metal surface treatment method. For titanium alloy blades used in gas turbines, pickling can not only remove surface contaminants but also check for blade defects such as overburn defects, macrostructure defects, and crack defects, ensuring the quality and reliability of the blades. However, traditional pickling methods have some limitations when applied to titanium alloy blades used in gas turbines. For example, traditional pickling methods cannot completely remove surface contaminants of the blades, resulting in low surface quality of the blades; it is easy to cause damage to the blade surface during pickling, affecting the performance of the blades; in addition, traditional pickling methods are difficult to accurately detect all kinds of blade defects at one time, thus increasing the risk during blade use.

[0004] To overcome these limitations, it is necessary to develop a pickling method specifically for titanium alloy blades used in gas turbines, which can effectively remove surface contaminants of the blades and improve the surface quality and corrosion resistance of the blades. At the same time, this method should have the ability to accurately detect blade defects, and be able to accurately detect overburn defects, macrostructure defects, and crack defects, etc., to ensure the quality and reliability of the blades. In addition, the new pickling method should also minimize damage to the blade surface and protect the performance of the blades. During the operation process, it should be easy to control and implement to improve production efficiency and reduce costs. By adopting this new pickling method, the quality and reliability of titanium alloy blades used in gas turbines can be improved, and the safe and stable operation of gas turbines can be guaranteed. This is of great significance for improving the efficiency and performance of gas turbines and extending their service life. Summary of the Invention

[0005] The object of the present invention is to effectively remove contaminants on the surface of the blade, improve the surface quality and corrosion resistance of the blade, accurately detect various defects of the titanium alloy blade to ensure the quality and reliability of the blade, reduce damage to the surface of the titanium alloy blade to protect the performance of the blade, and be easy to control and implement, which can improve production efficiency and reduce costs, etc. A pickling method for titanium alloy blades used in gas turbines.

[0006] A pickling method for titanium alloy blades used in gas turbines, comprising the following steps:

[0007] S1, Outer surface cleaning: Wipe the surface grinding paste of the titanium alloy blade with a test paper dipped in solvent gasoline.

[0008] S2, Initial clamping: Clamp the titanium alloy blade into a special pickling basket made of polytetrafluoroethylene. During installation, ensure that the titanium alloy blade is completely immersed in the solution, and no bubbles are allowed on its surface and nearby.

[0009] S3, Chemical degreasing: Perform chemical degreasing treatment in a degreasing tank with a solution composition of 30 - 50 grams per liter of trisodium phosphate and 1 - 3 grams per liter of OP emulsifier. The degreasing temperature is 60 - 80 degrees Celsius, and the time is 14 - 16 minutes.

[0010] S4, Cleaning the degreasing solution: Immerse the titanium alloy blade in a flowing hot water tank at 60 - 80 degrees Celsius and wash it 4 - 5 times.

[0011] S5, Degreasing quality inspection: Immerse the titanium alloy blade in a flowing cold water tank and wash it 1 - 2 times. The surface of the blade with complete degreasing should be completely wetted by water, and the water should flow evenly from the surface of the blade; on the surface of the blade with poor degreasing effect, aggregated water droplets remain after cleaning.

[0012] S6, Drying, disassembling, isolating and degreasing: Blow dry the moisture on the surface of the titanium alloy blade with clean compressed air, take out the titanium alloy blade from the above-mentioned special cleaning basket, and the surface that does not need to be pickled should be treated with an isolation glue with a composition and mass fraction of 20% - 30% white wax, 40% - 50% paraffin wax and 20% - 40% turpentine in an isolation tank for isolation treatment, and wipe the surface of the titanium alloy blade that has not been coated with isolation glue with Vienna gypsum clay slurry.

[0013] S7, Clamping again;

[0014] S8, Initial pickling: Perform pickling in a pickling tank with a solution composition of 415 - 700 grams per liter of nitric acid and 65 - 104 grams per liter of hydrofluoric acid. The pickling temperature is 18 - 25 degrees Celsius, and the time is 0.5 - 1 minute.

[0015] S9, Cleaning the pickling solution: Immerse the titanium alloy blade in a flowing cold water tank and wash it 3 - 4 times.

[0016] S10, Defect inspection: Inspect the overburning defects of the titanium alloy blades;

[0017] S11, Re - pickling: Conduct pickling in a pickling tank with a solution composition of 415 - 700 grams per liter of nitric acid and 65 - 104 grams per liter of hydrofluoric acid. The pickling temperature is 18 - 25 degrees Celsius and the time is 2 - 8 minutes;

[0018] S12, Clean the pickling solution;

[0019] S13, Defect inspection: Inspect the macroscopic structure defects and crack defects of the titanium alloy blades;

[0020] S14, De - isolation: Conduct de - isolation treatment in a de - isolation tank with a solution composition of 30 - 50 grams per liter of sodium carbonate. The de - isolation temperature is 80 - 10 degrees Celsius until the isolation glue is completely removed;

[0021] S15, Clean the isolation solution: Immerse the titanium alloy blades in a flowing hot water tank at 60 - 80 degrees Celsius and wash 6 - 8 times;

[0022] S16, Blade surface cooling: Immerse the titanium alloy blades in a flowing cold water tank and wash 2 - 3 times. Cold water washing the blades can quickly and evenly cool the blades, and at the same time provide a clean blade surface for the drying and storage steps;

[0023] S17, Drying and storage: Use clean compressed air to blow dry the moisture on the surface of the titanium alloy blades, and use a special fixture to take out the titanium alloy blades from the special pickling basket and store them in a dry, clean and well - ventilated environment.

[0024] Further, the degreasing tank in S3 and the de - isolation tank in S14 are made of carbon steel, and have a steam coil with a pressure - resistant grade of 0.3 MPa and a side discharge port.

[0025] Further, in S6, the compressed air blows the mirror or filter paper at least once every half month, and there is no moisture and grease residue on the mirror or filter paper to determine whether the compressed air is clean.

[0026] Further, the isolation tank in S6 is made of carbon steel and has a steam coil with a pressure - resistant grade of 0.3 MPa and an electric heater.

[0027] Further, the pickling tank in S8 is made of carbon steel and has a lining of polyvinyl chloride board and a side discharge port.

[0028] Further, when the pickling solution in S8 is a newly configured solution, the temperature does not exceed 23 degrees Celsius.

[0029] Further, the re - clamping in S7 is the same as the S2 step.

[0030] Further, the cleaning of the pickling solution in step S12 is the same as that in step S9.

[0031] The beneficial effects of the present invention are as follows:

[0032] The present invention can effectively remove the contaminants on the surface of the blade, thereby improving the surface quality and corrosion resistance of the blade. It can accurately detect various defects of the titanium alloy blade, thereby ensuring the quality and reliability of the blade. It can reduce the damage to the surface of the titanium alloy blade, thereby protecting the performance of the blade. The pickling process is easy to control and implement, which can improve production efficiency and reduce costs. Description of the Drawings

[0033] Figure 1 is a flowchart of the present invention. Detailed Embodiments

[0034] The present invention will be further described below with reference to the accompanying drawings.

[0035] As Figure 1 shown, a pickling method for a titanium alloy blade used in a gas turbine includes the following steps:

[0036] S1, Outer surface cleaning: Wipe the surface grinding paste of the titanium alloy blade with a test paper dipped in solvent gasoline.

[0037] S2, Initial clamping: Clamp the titanium alloy blade into a special pickling basket made of polytetrafluoroethylene. During installation, ensure that the titanium alloy blade is completely immersed in the solution, and no bubbles are allowed to exist on its surface and nearby.

[0038] S3, Chemical degreasing: Perform chemical degreasing treatment in a degreasing tank with a solution composition of 30 - 50 grams per liter of trisodium phosphate and 1 - 3 grams per liter of OP emulsifier. The degreasing temperature is 60 - 80 degrees Celsius, and the time is 14 - 16 minutes.

[0039] The degreasing tank is made of carbon steel and has a steam coil with a pressure rating of 0.3 MPa and a side discharge port.

[0040] S4, Cleaning the degreasing solution: Immerse the titanium alloy blade in a flowing hot water tank at 60 - 80 degrees Celsius and wash it 4 - 5 times.

[0041] S5, Degreasing quality inspection: Immerse the titanium alloy blade in a flowing cold water tank and wash it 1 - 2 times. The surface of the blade with complete degreasing should be completely wetted by water, and the water should flow evenly from the surface of the blade; the surface of the blade with poor degreasing effect will have aggregated water droplets after washing.

[0042] S6, Drying, Disassembly, Isolation and Degreasing: Blow dry the moisture on the surface of the titanium alloy blade with clean compressed air, take out the titanium alloy blade from the special cleaning basket, and apply an isolation glue with a composition of 20% - 30% white wax, 40% - 50% paraffin wax and 20% - 40% turpentine on the surface that does not require pickling in the isolation tank for isolation treatment, and wipe the surface of the titanium alloy blade without the applied isolation glue with Vienna gypsum clay slurry;

[0043] Blow the mirror surface or filter paper with compressed air at least once every half month. There is no residual moisture and grease on the mirror surface or filter paper to determine whether the compressed air is clean; The isolation tank is made of carbon steel and has a steam coil and an electric heater with a pressure resistance level of 0.3 MPa

[0044] S7, Re-clamping: Clamp the titanium alloy blade into a special pickling basket made of polytetrafluoroethylene. During installation, ensure that the titanium alloy blade is completely immersed in the solution, and no bubbles are allowed on its surface and nearby;

[0045] S8, Initial Pickling: Conduct pickling in a pickling tank with a solution composition of 415 - 700 grams per liter of nitric acid and 65 - 104 grams per liter of hydrofluoric acid. The pickling temperature is 18 - 25 degrees Celsius and the time is 0.5 - 1 minute;

[0046] The pickling tank is made of carbon steel and has a lining of polyvinyl chloride board and a side discharge port; When the pickling solution is newly prepared, the temperature does not exceed 23 degrees Celsius;

[0047] S9, Cleaning the Pickling Solution: Immerse the titanium alloy blade in a flowing cold water tank and clean it 3 - 4 times;

[0048] S10, Defect Inspection: Check for overburn defects of the titanium alloy blade;

[0049] S11, Re-pickling: Conduct pickling in a pickling tank with a solution composition of 415 - 700 grams per liter of nitric acid and 65 - 104 grams per liter of hydrofluoric acid. The pickling temperature is 18 - 25 degrees Celsius and the time is 2 - 8 minutes;

[0050] S12, Cleaning the Pickling Solution: Immerse the titanium alloy blade in a flowing cold water tank and clean it 3 - 4 times;

[0051] S13, Defect Inspection: Check for macroscopic structure defects and crack defects of the titanium alloy blade;

[0052] S14, Removing Isolation: Conduct removing isolation treatment in a removing isolation tank with a solution composition of 30 - 50 grams per liter of sodium carbonate. The removing isolation temperature is 80 - 10 degrees Celsius until the isolation glue is completely removed;

[0053] The removing isolation tank is made of carbon steel and has a steam coil with a pressure resistance level of 0.3 MPa and a side discharge port;

[0054] S15, Cleaning the isolation solution: Immerse the titanium alloy blade in a flowing hot water bath at 60 - 80 °C and clean it 6 - 8 times.

[0055] S16, Cooling the blade surface: Immerse the titanium alloy blade in a flowing cold water bath and clean it 2 - 3 times. Cleaning the blade with cold water can quickly and evenly cool the blade, and at the same time provide a clean blade surface for the drying and storage steps.

[0056] S17, Drying and storage: Blow dry the moisture on the surface of the titanium alloy blade with clean compressed air, take out the titanium alloy blade from the special pickling basket using a special fixture, and store it in a dry, clean, and well-ventilated environment.

[0057] Among them, the degreasing tank of S3 and the de-isolation tank of S14 are made of carbon steel, and have a steam coil with a pressure resistance level of 0.3 MPa and a side discharge port.

[0058] The present invention can efficiently remove pollutants: Compared with traditional pickling methods, the present invention adopts steps of chemical degreasing and multiple cleanings, and can more effectively remove pollutants such as grinding paste and oil stains on the blade surface, improving the surface quality and corrosion resistance of the blade.

[0059] Precisely detect defects: By primary pickling and secondary pickling, and checking for defects at different pickling stages, various defects such as overburn defects, macrostructure defects, and crack defects of the titanium alloy blade can be more precisely detected, ensuring the quality and reliability of the blade.

[0060] Reduce blade damage: During the pickling process, parameters such as solution composition, temperature, and time are strictly controlled, reducing the damage to the blade surface and protecting the performance of the blade.

[0061] Easy to control and implement: The pickling method of the present invention has clear steps, simple operation, is easy to control and implement, can improve production efficiency, and reduce production costs.

[0062] Improve the pickling steps: Steps such as chemical degreasing, isolation, and de-isolation are added, making the pickling process more perfect and better meeting the pickling requirements of titanium alloy blades for gas turbines.

[0063] Optimize the solution formula: The compositions of the pickling solution and the degreasing solution are optimized, improving the pickling and degreasing effects.

[0064] Strictly control parameters: Parameters such as temperature and time in each step are strictly controlled, ensuring the stability and reliability of the pickling process.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for pickling titanium alloy blades for gas turbines, characterized in that: The following steps are involved: S1, external surface cleaning: use a test paper soaked in solvent gasoline to wipe the abrasive paste on the surface of the titanium alloy blade; S2, initial clamping: Clamp the titanium alloy blade into a special pickling basket made of polytetrafluoroethylene. During installation, ensure that the titanium alloy blade is completely immersed in the solution, and no bubbles are allowed on its surface or nearby. S3, chemical degreasing: chemical degreasing treatment is carried out in a degreasing tank with a solution composition of 30-50 g / L trisodium phosphate and 1-3 g / L OP emulsifier, the degreasing temperature is 60-80 degrees Celsius, and the time is 14-16 minutes; S4, cleaning degreasing solution: immersing the titanium alloy blade in a flowing hot water tank at 60 to 80 degrees Celsius for 4 to 5 times; S5, degreasing quality inspection: immerse the titanium alloy blade in a flowing cold water tank for 1 to 2 times. The surface of the blade that has been completely degreased should be completely soaked in water, and the water should flow evenly down the surface of the blade; the surface of the blade with poor degreasing effect will have accumulated water droplets after cleaning; S6, drying, disassembly, isolation and degreasing: Use clean compressed air to blow dry the moisture on the surface of the titanium alloy blade, take the titanium alloy blade out of the special cleaning basket, and apply isolation glue with a composition and mass fraction of 20% to 30% white ceresin, 40% to 50% paraffin and 20% to 40% turpentine in the isolation tank for isolation treatment on the surface that does not need to be pickled. Use Vienna gypsum clay slurry to wipe the surface of the titanium alloy blade that is not coated with isolation glue; S7, clamp again; S8, initial pickling: pickling in a pickling tank containing 415-700 g / L nitric acid and 65-104 g / L hydrofluoric acid, at a pickling temperature of 18-25 degrees Celsius for 0.5-1 minute; S9, cleaning the pickling solution: immersing the titanium alloy blade in a flowing cold water tank for 3 to 4 times; S10, defect inspection: inspect the overburning defects of titanium alloy blades; S11, pickling again: pickling in a pickling tank containing 415 to 700 g / L nitric acid and 65 to 104 g / L hydrofluoric acid, at a pickling temperature of 18 to 25 degrees Celsius, for 2 to 8 minutes; S12, cleaning the pickling solution; S13, defect inspection: inspect the macroscopic structural defects and crack defects of the titanium alloy blades; S14, de-isolation: de-isolation treatment is performed in a de-isolation tank with a solution composition of 30 to 50 grams per liter of sodium carbonate, and the de-isolation temperature is 80 to 10 degrees Celsius until the isolation glue is completely removed; S15, cleaning the isolation solution: immersing the titanium alloy blade in a flowing hot water tank at 60 to 80 degrees Celsius for 6 to 8 times; S16, cooling the blade surface: immersing the titanium alloy blade in a flowing cold water tank for 2 to 3 times. Cleaning the blade with cold water can quickly and evenly cool the blade and provide a clean blade surface for the drying and storage steps. S17, Drying and storage: Use clean compressed air to dry the moisture on the surface of the titanium alloy blades and use special clamps to remove the titanium alloy blades from the special pickling basket and store them in a dry, clean and well-ventilated environment.

2. The pickling method for titanium alloy blades for gas turbine according to claim 1, characterized in that: The degreasing tank of S3 and the de-isolating tank of S14 are made of carbon steel and have a steam coil with a pressure resistance level of 0.3 MPa and a side discharge port.

3. The pickling method for titanium alloy blades for gas turbine according to claim 1, characterized in that: In the S6, the compressed air is blown on the mirror surface or filter paper at least once every half a month, and there is no moisture and grease residue on the mirror surface or filter paper to determine whether the compressed air is clean.

4. The pickling method for titanium alloy blades for gas turbine according to claim 1, characterized in that: The isolation tank in S6 is made of carbon steel and has a steam coil and an electric heater with a pressure resistance level of 0.3 MPa.

5. The pickling method for titanium alloy blades for gas turbine according to claim 1, characterized in that: The pickling tank in S8 is made of carbon steel, lined with polyvinyl chloride plates and has a side discharge port.

6. A method for pickling a titanium alloy blade for a gas turbine according to claim 1, characterized in that: When the pickling solution in S8 is a newly prepared solution, the temperature does not exceed 23 degrees Celsius.

7. The pickling method for titanium alloy blades for gas turbine according to claim 1, characterized in that: The re-clamping in S7 is the same as step S2.

8. The pickling method for titanium alloy blades for gas turbine according to claim 1, characterized in that: Cleaning the pickling solution in S12 is the same as step S9.

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