Aluminizing preparation process for turbine moving blade of gas turbine

Abstract

The invention relates to the technical field of turbine moving blade machining, in particular to a gas turbine moving blade aluminizing preparation process. The method comprises the steps of ultrasonic cleaning of the turbine moving blade, filling of aluminizing powder, coating of an anti-seepage layer, charging aluminizing, cleaning of the anti-seepage layer and the aluminizing powder and cleaning and drying of the turbine moving blade. According to the method, the aluminizing thickness of the inner cavity of the turbine moving blade and the aluminum content of the aluminizing layer can be controlled, it is guaranteed that the aluminizing layer of the turbine moving blade has excellent high-temperature oxidation resistance and hot corrosion resistance, and the product quality consistency is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of turbine moving blade processing, in particular to an aluminum infiltration preparation process for a gas turbine turbine moving blade. Background Art

[0002] In the field of surface protection of engine turbine components, it is necessary to perform aluminizing treatment on the blades to improve the blades' resistance to high-temperature oxidation and thermal corrosion. The aluminizing layer of gas turbine turbine moving blades is a common coating that resists high-temperature oxidation and thermal corrosion. In the prior art, by filling aluminizing powder into the inner cavity of the part, the aluminum element is infiltrated into the surface of the part by atomic diffusion at high temperature to form an aluminizing layer, so that the coating thickness and chemical element composition meet the requirements.

[0003] The existing aluminizing process cannot form a sufficient aluminizing layer in the complex inner cavity of the parts, and cannot achieve controllable aluminizing thickness of the complex inner cavity and aluminum content of the aluminizing layer, resulting in inconsistent aluminizing effects of different parts and poor product quality consistency. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned existing production technology, the present application provides a gas turbine turbine blade aluminizing preparation process, which can achieve controllable aluminizing thickness in the inner cavity of the turbine blade and aluminum content in the aluminizing layer, thereby ensuring that the aluminizing layer of the turbine blade has excellent resistance to high-temperature oxidation and thermal corrosion.

[0005] The technical solution adopted by the present invention is as follows: A gas turbine turbine rotor blade aluminizing preparation process, comprising the following steps: (1) Ultrasonic cleaning of turbine blades: first add the alloy degreasing agent into the ultrasonic cleaning machine, immerse the entire turbine blade in the alloy degreasing agent, start the ultrasonic cleaning machine for ultrasonic degreasing, and after the degreasing is completed, add water into the ultrasonic cleaning machine, immerse the entire turbine blade in the water, and start the ultrasonic cleaning machine for ultrasonic dust removal; (2) Filling with aluminized powder: Use tape to seal the holes in the blade crown of the turbine rotor blade, and pour aluminized powder into the inner hole at the bottom of the tenon of the turbine rotor blade. During the process of pouring aluminized powder, use a hammer to continuously hit the tenon to ensure that the aluminized powder is filled. After the inner hole at the bottom of the tenon of the turbine rotor blade is filled with aluminized powder, use tape to seal the opening of the inner hole at the bottom of the tenon. Tear off the tape used to seal the holes in the blade crown of the turbine rotor blade, and then pour aluminized powder into the holes in the blade crown of the turbine rotor blade. During the process of pouring aluminized powder, use a hammer to continuously hit the blade body to ensure that the aluminized powder is filled. Finally, use tape to seal the opening of the hole in the blade crown of the turbine rotor blade. (3). Apply the anti-seepage layer: After the aluminized powder is filled, first use a brush to evenly apply the anti-seepage agent on the blade profile and edge plate surface of the turbine blade, and then apply it on the tenon and Schengen surface to form the first bottom anti-seepage layer of the turbine blade. After the brushing is completed, the turbine blade is naturally dried. After the first bottom anti-seepage layer is completely dried, the second bottom anti-seepage layer is applied. According to this step, a total of three bottom anti-seepage layers are applied; After the bottom anti-seepage layer is finally processed, use a brush to evenly apply the anti-seepage agent on the surface of the bottom anti-seepage layer to form the first layer of the turbine blade. After the brushing is completed, the turbine blade is naturally dried. After the first layer of the anti-seepage layer is completely dried, the second layer of the anti-seepage layer is applied. According to this step, a total of three layers of the anti-seepage layer are applied; (4). Furnace loading and aluminizing: First, spread a layer of alumina powder on the bottom of the infiltration box, load the turbine blades that have been coated with an anti-seepage layer and dried completely into the infiltration box, then fill the infiltration box with alumina powder, and then use a leather hammer to knock on the outer wall of the infiltration box to make the alumina powder fill the infiltration box. Next, place the infiltration box with turbine blades on the rack, and lift the rack with the infiltration box into the infiltration metal furnace for aluminizing. Perform vapor phase infiltration at 850-950℃ for 7-12 hours, and take out the furnace after the temperature drops to room temperature. (5) Cleaning of the anti-seepage layer and aluminized powder: Place the turbine blades that have been aluminized on the work surface for surface cleaning. First, use a rubber hammer to break the anti-seepage layer on the surface of the turbine blades. Use compressed air to blow away the fragments of the anti-seepage layer. Then use a rubber hammer to tap the blade surface to clean out the aluminized powder in the inner cavity of the turbine blades. Then use a water flow detection device to clean the inner cavity of the turbine blades. Pass water through any hole at the bottom of the turbine blade tenon, and block the remaining holes with your hands to let water flow out from the tip hole of the turbine blade. After passing water for 3 to 5 minutes, use compressed air to blow out the inner cavity to blow out the residual powder. Repeat the above operation several times until water flows out of all holes at the blade tip. Then pass water for another 3 to 5 minutes to finally clean the inner cavity and surface. (6) Cleaning and drying of turbine blades: After the anti-seepage layer and aluminized powder are cleaned, the turbine blades are placed in an ultrasonic cleaner for cleaning. Alcohol is used as the cleaning medium. After ultrasonic cleaning, the turbine blades are placed in a drying box for drying.

[0006] Furthermore, in step (1), the ultrasonic cleaner has an oil removal working time of 20 to 30 minutes and an oil removal working temperature of 35 to 45°C, and an ultrasonic cleaner has an dust removal working time of 20 to 30 minutes and a dust removal working temperature of 35 to 45°C.

[0007] Furthermore, after the turbine blades are degreased and dusted, the surface of the turbine blades is blown with water-free and oil-free compressed air to remove the degreaser remaining on the surface of the turbine blades, and then the turbine blades are placed in a drying box for drying at a temperature of 55 to 65°C and a drying time of 25 to 35 minutes.

[0008] Furthermore, in step (2), the aluminized powder is formed by mixing metal aluminum powder, aluminum oxide powder and aluminum fluoride powder, the metal aluminum powder accounts for 3% to 5% of the total mass of the aluminized powder, the particle size of the metal aluminum powder is 200 to 325 mesh, the aluminum oxide powder accounts for 90% to 95% of the total mass of the aluminized powder, and the aluminum fluoride powder accounts for 0.5% to 1% of the total mass of the aluminized powder.

[0009] Furthermore, in step (3), the natural drying time of each anti-seepage layer is 0.5 to 1.5 hours, the total thickness of the bottom anti-seepage layer is 1 to 2 mm, and the total thickness of the surface anti-seepage layer is 1 to 2 mm.

[0010] Furthermore, in step (5), after the surface of the turbine moving blade is cleaned, the tenon tooth portion is protected with a thermal spray tape and loaded into a wet sandblasting tool for wet sandblasting. The sandblasting pressure is 0.4-0.45 MPa. The purpose of wet sandblasting is to clean the blade surface and improve the appearance.

[0011] Furthermore, in step (6), the ultrasonic cleaner operates for 20 to 30 minutes, the drying temperature is 70 to 90° C., and the drying time is greater than 2 hours.

[0012] The beneficial effects of the present invention are as follows: The present invention can realize the controllable aluminizing thickness of the inner cavity of the turbine rotor blade and the aluminum content of the aluminizing layer, thereby ensuring that the aluminizing layer of the turbine rotor blade has excellent high-temperature oxidation resistance and thermal corrosion resistance, and ensuring product quality consistency. DETAILED DESCRIPTION

[0013] The specific embodiments of the present invention are described below.

[0014] A gas turbine turbine rotor blade aluminizing preparation process comprises the following steps: (1) Ultrasonic cleaning of turbine blades: first add the alloy degreasing agent into the ultrasonic cleaning machine, place the entire turbine blade in the ultrasonic cleaning machine and immerse it in the alloy degreasing agent, start the ultrasonic cleaning machine to perform ultrasonic degreasing on the turbine blades, the ultrasonic cleaning machine works for 20 to 30 minutes, and the degreasing working temperature is 35 to 45°C; after the degreasing is completed, add water into the ultrasonic cleaning machine, place the entire turbine blade in the ultrasonic cleaning machine and immerse it in water, start the ultrasonic cleaning machine to perform ultrasonic dust removal on the turbine blades, the ultrasonic cleaning machine works for 20 to 30 minutes, and the dust removal working temperature is 35 to 45°C; After the turbine blades are degreased and dusted, use water-free and oil-free compressed air to blow the surface of the turbine blades to remove the residual degreaser on the surface of the turbine blades, and then place the turbine blades in a drying box for drying at a temperature of 55~65℃ and a drying time of 25~35 minutes.

[0015] (2) Filling with aluminized powder: Use tape to seal the holes in the crown of the turbine blade, and pour aluminized powder into the inner hole at the bottom of the tenon of the turbine blade. During the process of pouring aluminized powder, use a hammer to continuously hit the tenon to ensure that the aluminized powder is filled. After the inner hole at the bottom of the tenon of the turbine blade is filled with aluminized powder, use tape to seal the opening of the inner hole at the bottom of the tenon. Tear off the tape used to seal the holes in the crown of the turbine blade, and then pour aluminized powder into the holes in the crown of the turbine blade. During the process of pouring aluminized powder, use a hammer to continuously hit the blade body to ensure that the aluminized powder is filled. Finally, use tape to seal the opening of the hole in the crown of the turbine blade.

[0016] The aluminizing powder is loaded from both ends of the inner cavity hole of the turbine rotor blade respectively, so that the inner cavity hole of the turbine rotor blade can be filled with the aluminizing powder.

[0017] The aluminized powder is formed by mixing metal aluminum powder, aluminum oxide powder and aluminum fluoride powder, wherein the metal aluminum powder accounts for 3% to 5% of the total mass of the aluminized powder, the particle size of the metal aluminum powder is 200 to 325 meshes, the aluminum oxide powder accounts for 90% to 95% of the total mass of the aluminized powder, and the aluminum fluoride powder accounts for 0.5% to 1% of the total mass of the aluminized powder.

[0018] Before filling the aluminizing powder, the turbine blades are weighed. After filling the aluminizing powder, the turbine blades are weighed again. The difference obtained by subtracting the previous and subsequent weighing data is the weight of the filled aluminizing powder. The weight of the filled aluminizing powder should be equal to or greater than the theoretical filling value. The theoretical filling value is determined by the experimental process. If it does not meet the theoretical filling value, continue to knock on the blade body of the turbine blade and continue to fill the aluminizing powder until the weight of the filled aluminizing powder is equal to or greater than the theoretical filling value.

[0019] (3) Apply the anti-seepage layer: After the aluminized powder is filled, first use a brush to evenly apply the anti-seepage agent on the blade profile and edge plate surface of the turbine blade, and then apply it on the tenon and Schengen surface to form the first bottom anti-seepage layer of the turbine blade. After the brushing is completed, the turbine blade is naturally dried for 0.5~1.5 hours. After the first bottom anti-seepage layer is completely dry, the second bottom anti-seepage layer is applied. According to this step, a total of three bottom anti-seepage layers are applied to ensure that the total thickness of the final bottom anti-seepage layer is 1~2mm; After the bottom anti-seepage layer is finally processed, use a brush to evenly apply the anti-seepage agent on the surface of the bottom anti-seepage layer to form the first anti-seepage layer of the turbine blades. After brushing, let the turbine blades dry naturally for 0.5~1.5 hours. After the first anti-seepage layer is completely dry, apply the second anti-seepage layer. According to this step, a total of three anti-seepage layers are brushed to ensure that the total thickness of the final surface anti-seepage layer is 1~2mm.

[0020] During the application process of the bottom anti-seepage layer and the surface anti-seepage layer, it is required to be applied evenly without accumulation of the anti-seepage agent. Visual inspection should be carried out to ensure that no anti-seepage agent is missed and there is no metallic color in the anti-seepage parts.

[0021] During the natural drying process of the turbine blades, touch the anti-seepage layer with a gloved hand. If there is no obvious deformation of the anti-seepage layer, it can be determined that the anti-seepage layer is in a completely dry state.

[0022] For the newly opened anti-seepage agent, use a stirrer to stir the anti-seepage agent at a speed of 2000rpm for 25 to 35 minutes. If the anti-seepage agent slurry cannot be dispersed during the stirring process, add alcohol to dilute it. The alcohol addition ratio is as follows: add 2 to 3 grams of alcohol per 100 grams of anti-seepage agent slurry. After adding alcohol, it can prevent the anti-seepage agent slurry from accumulating and agglomerating during the anti-seepage agent application process.

[0023] (4). Furnace loading and aluminizing: First, spread a layer of alumina powder on the bottom of the infiltration box, load the turbine blades coated with an anti-seepage layer and dried completely into the infiltration box, then fill the infiltration box with alumina powder, and then use a leather hammer to knock on the outer wall of the infiltration box to fill the infiltration box with alumina powder. If the height of the alumina powder drops during the knocking process, it is necessary to replenish the alumina powder; then, place the infiltration box with the turbine blades on the rack. After the infiltration box is placed, use nickel-chromium wire to fix the infiltration box and the rack to ensure stable support. The rack with the infiltration box is hoisted into the infiltration metal furnace for aluminizing, and vapor phase infiltrated at 850~950℃ for 7~12h, and then removed from the furnace after the temperature drops to room temperature.

[0024] (5) Cleaning of the anti-seepage layer and aluminized powder: Place the turbine blades that have been aluminized on the work surface for surface cleaning. First, use a rubber hammer to break the anti-seepage layer on the surface of the turbine blades. Use compressed air to blow away the fragments of the anti-seepage layer. Then use a rubber hammer to tap the blade surface to clean out the aluminized powder in the inner cavity of the turbine blades. Use a stainless steel wire that is no larger than the inner cavity diameter to clean out the outermost aluminized powder. During the cleaning process, do not damage the surface of the turbine blades and the aluminized layer in the inner cavity of the turbine blades. Then use a water flow detection device to clean the inner cavity of the turbine blades. Let water flow through any hole at the bottom of the blade tenon, and block the remaining holes by hand to let water flow out from the tip hole of the turbine moving blade. After letting water flow for 3 to 5 minutes, use compressed air to blow out the inner cavity to blow out the residual powder. Repeat the above operation several times until water flows out of all holes at the blade tip, and then let water flow for another 3 to 5 minutes to finally clean the inner cavity and surface. After the surface of the turbine moving blade is cleaned, use hot spray tape to protect the tenon part, install it in the wet sand blowing tooling for wet sand blowing, and the sand blowing pressure is 0.4 to 0.45Mpa, in order to clean the blade surface and improve the appearance. Finally, weigh the turbine blades. The weight of the turbine blades should be basically the same as the weight before aluminizing. If the weight of the turbine blades is too heavy, it proves that the powder has not been cleaned up. Continue cleaning until the weight of the turbine blades is basically the same as the weight before aluminizing.

[0025] (6) Cleaning and drying of turbine blades: After the anti-seepage layer and aluminized powder are cleaned, the turbine blades are placed in an ultrasonic cleaner for cleaning. Alcohol is used as the cleaning medium. The ultrasonic cleaner works for 20 to 30 minutes. After ultrasonic cleaning, the turbine blades are placed in a drying oven for drying. The drying temperature is 70 to 90°C and the drying time is more than 2 hours.

[0026] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A gas turbine turbine blade aluminizing preparation process, characterized in that: The steps include: (1) Ultrasonic cleaning of turbine blades: first add the alloy degreasing agent into the ultrasonic cleaning machine, immerse the entire turbine blade in the alloy degreasing agent, start the ultrasonic cleaning machine for ultrasonic degreasing, and after the degreasing is completed, add water into the ultrasonic cleaning machine, immerse the entire turbine blade in the water, and start the ultrasonic cleaning machine for ultrasonic dust removal; (2) Filling with aluminized powder: Use tape to seal the holes in the blade crown of the turbine rotor blade, and pour aluminized powder into the inner hole at the bottom of the tenon of the turbine rotor blade. During the process of pouring aluminized powder, use a hammer to continuously hit the tenon to ensure that the aluminized powder is filled. After the inner hole at the bottom of the tenon of the turbine rotor blade is filled with aluminized powder, use tape to seal the opening of the inner hole at the bottom of the tenon. Tear off the tape used to seal the holes in the blade crown of the turbine rotor blade, and then pour aluminized powder into the holes in the blade crown of the turbine rotor blade. During the process of pouring aluminized powder, use a hammer to continuously hit the blade body to ensure that the aluminized powder is filled. Finally, use tape to seal the opening of the hole in the blade crown of the turbine rotor blade. (3). Apply the anti-seepage layer: After the aluminized powder is filled, first use a brush to evenly apply the anti-seepage agent on the blade profile and edge plate surface of the turbine blade, and then apply it on the tenon and Schengen surface to form the first bottom anti-seepage layer of the turbine blade. After the brushing is completed, the turbine blade is naturally dried. After the first bottom anti-seepage layer is completely dried, the second bottom anti-seepage layer is applied. According to this step, a total of three bottom anti-seepage layers are applied; After the bottom anti-seepage layer is finally processed, use a brush to evenly apply the anti-seepage agent on the surface of the bottom anti-seepage layer to form the first layer of the turbine blade. After the brushing is completed, the turbine blade is naturally dried. After the first layer of the anti-seepage layer is completely dried, the second layer of the anti-seepage layer is applied. According to this step, a total of three layers of the anti-seepage layer are applied; (4). Furnace loading and aluminizing: First, spread a layer of alumina powder on the bottom of the infiltration box, load the turbine blades that have been coated with an anti-seepage layer and dried completely into the infiltration box, then fill the infiltration box with alumina powder, and then use a leather hammer to knock on the outer wall of the infiltration box to make the alumina powder fill the infiltration box. Next, place the infiltration box with turbine blades on the rack, and lift the rack with the infiltration box into the infiltration metal furnace for aluminizing. Perform vapor phase infiltration at 850-950℃ for 7-12 hours, and take out the furnace after the temperature drops to room temperature. (5) Cleaning of the anti-seepage layer and aluminized powder: Place the turbine blades that have been aluminized on the work surface for surface cleaning. First, use a rubber hammer to break the anti-seepage layer on the surface of the turbine blades. Use compressed air to blow away the fragments of the anti-seepage layer. Then use a rubber hammer to tap the blade surface to clean out the aluminized powder in the inner cavity of the turbine blades. Then use a water flow detection device to clean the inner cavity of the turbine blades. Pass water through any hole at the bottom of the turbine blade tenon, and block the remaining holes with your hands to let water flow out from the tip hole of the turbine blade. After passing water for 3 to 5 minutes, use compressed air to blow out the inner cavity to blow out the residual powder. Repeat the above operation several times until water flows out of all holes at the blade tip. Then pass water for another 3 to 5 minutes to finally clean the inner cavity and surface. (6) Cleaning and drying of turbine blades: After the anti-seepage layer and aluminized powder are cleaned, the turbine blades are placed in an ultrasonic cleaner for cleaning. Alcohol is used as the cleaning medium. After ultrasonic cleaning, the turbine blades are placed in a drying box for drying.

2. A gas turbine turbine rotor blade aluminizing preparation process according to claim 1, characterized in that: In the step (1), the ultrasonic cleaning machine has an oil removal working time of 20 to 30 minutes and an oil removal working temperature of 35 to 45°C, and an ultrasonic cleaning machine has an dust removal working time of 20 to 30 minutes and a dust removal working temperature of 35 to 45°C.

3. A gas turbine turbine rotor blade aluminizing preparation process according to claim 2, characterized in that: After the turbine blades are degreased and dusted, the surface of the turbine blades is blown with water-free and oil-free compressed air to remove the degreaser remaining on the surface of the turbine blades, and then the turbine blades are placed in a drying box for drying at a temperature of 55-65° C. for 25-35 minutes.

4. A gas turbine turbine rotor blade aluminizing preparation process according to claim 1, characterized in that: In the step (2), the aluminized powder is formed by mixing metal aluminum powder, aluminum oxide powder and aluminum fluoride powder, the metal aluminum powder accounts for 3% to 5% of the total mass of the aluminized powder, the particle size of the metal aluminum powder is 200 to 325 meshes, the aluminum oxide powder accounts for 90% to 95% of the total mass of the aluminized powder, and the aluminum fluoride powder accounts for 0.5% to 1% of the total mass of the aluminized powder.

5. A gas turbine turbine rotor blade aluminizing preparation process according to claim 1, characterized in that: In the step (3), the natural drying time of each anti-seepage layer is 0.5 to 1.5 hours, the total thickness of the bottom anti-seepage layer is 1 to 2 mm, and the total thickness of the surface anti-seepage layer is 1 to 2 mm.

6. A gas turbine turbine rotor blade aluminizing preparation process according to claim 1, characterized in that: In the step (5), after the surface of the turbine moving blade is cleaned, the tenon part is protected with a thermal spray tape and loaded into a wet sandblasting tool for wet sandblasting. The sandblasting pressure is 0.4-0.45 MPa. The purpose of wet sandblasting is to clean the blade surface and improve the appearance.

7. A gas turbine turbine rotor blade aluminizing preparation process according to claim 1, characterized in that: In the step (6), the ultrasonic cleaner works for 20 to 30 minutes, the drying temperature is 70 to 90° C., and the drying time is greater than 2 hours.