Manufacturing process of cobalt-based alloy fuel nozzle casting

Abstract

The invention relates to a manufacturing process of a cobalt-based alloy fuel nozzle casting. The manufacturing process comprises a mold manufacturing step, a shell slurry preparation step, a part wax mold preparation step, a surface layer slurry coating forming step, a back layer slurry coating forming step, a part shell dewaxing step, a part shell pre-roasting step and a part pouring step. The cobalt-based high-temperature alloy adopted in the process is Mar-M-509, and compared with a nickel-based alloy, the cobalt-based high-temperature alloy has better thermal stability, wear resistance, corrosion resistance and high-temperature oxidation resistance; the overall size phi of a casting product obtained through the process is 43 mm * 190 mm, and the minimum wall thickness is only 1.02 mm; the surface of the workpiece obtained through the process is subjected to fluorescence detection, and the qualification rate reaches 90% or above; x-Ray ray detection is carried out on the interior of the workpiece obtained through the process, and the percent of pass reaches 90% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation precision casting, and specifically discloses a manufacturing process of a cobalt-based alloy fuel nozzle casting. Background Art

[0002] The fuel nozzle is one of the important components of the engine combustion chamber. Due to its complex product structure and extremely high product quality requirements, the product is difficult to manufacture. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a manufacturing process for a cobalt-based alloy fuel nozzle casting.

[0004] According to the technical solution provided by the present invention, the manufacturing process of the cobalt-based alloy fuel nozzle casting comprises the following steps: (1) Mold manufacturing: Water-soluble wax molds and parts wax molds are manufactured according to the product structure. The water-soluble wax molds add cold wax to the thick and large middle part, and the parts wax molds use water-soluble core molding casting inner cavity structure; (2) Preparation of shell slurry: Mix quick-drying silica sol and zircon powder in a weight ratio of w1:w2 for the surface slurry, and stir evenly after mixing; The back layer slurry is made by mixing silica sol and mullite powder in a ratio of W1:W2, and stirring evenly after mixing; (3) Preparation of part wax mold: Place the water-soluble wax mold into the part wax mold, fill it with filling wax and press it into the part wax mold; (4) Forming a surface slurry coating: immerse the wax mold of the part in the surface slurry in step (2), rotate it for 3 to 5 seconds, and then take it out to obtain a uniform surface slurry coating, and evenly pour the molding sand on the surface slurry coating; (5) Repeat step (4) once; (6) Forming a back slurry coating: immerse the part wax mold obtained in step (5) into the back slurry in step (2), rotate for 3 to 5 seconds, and then take it out to obtain a uniform back slurry coating, and evenly pour the molding sand on the back slurry coating; (7) Immerse the wax model of the part obtained in step (6) in the backing slurry in step (2) and rotate for 3 to 5 seconds before taking it out to obtain a uniform backing slurry coating, and evenly pour the molding sand on the backing slurry coating; (8) Repeat step (7) once; (9) Immerse the part wax mold obtained in step (8) in the backing slurry in step (2) and rotate for 3 to 5 seconds before taking it out to obtain a uniform backing slurry coating, and evenly pour molding sand on the backing slurry coating to obtain a part shell; (10) Dewaxing of the part shell: Place the part shell into the dewaxing kettle and remove the part wax mold at temperature T1 and pressure P1; (11) Pre-baking of the part shell: Place the part shell in a baking furnace for baking to remove the residual wax and moisture in the part shell; (12) Casting of parts: Heat the part shell to the preheating temperature, keep it warm and then refine the cobalt-based alloy Mar-M-509. After refining, vacuum pour the Mar-M-509 cobalt-based alloy liquid into the part shell at temperature T2. After cooling, obtain the part with runner. Finally, cut and grind to obtain the workpiece of the required shape.

[0005] Preferably, in step (2), the viscosity of the surface layer slurry is 45-55s, the pH value is 8.5-10, the mixing ratio of the surface layer slurry w1:w2 is (2-2.5):(5-5.5), and the stirring time is more than 24h until the slurry is evenly mixed.

[0006] Preferably, in step (2), the viscosity of the backing layer slurry is 15-20s, the pH value is 8.5-10, the mixing ratio of the backing layer slurry W1:W2 is 1:(1.4-1.5), and the stirring time is more than 8h until the slurry is evenly mixed.

[0007] Preferably, in step (4), the molding sand used is 80-120 mesh.

[0008] Preferably, in step (6), the molding sand used is 60-80 mesh.

[0009] Preferably, in step (7), the molding sand used is 30-60 mesh.

[0010] Preferably, in step (9), the molding sand used is 16-30 mesh.

[0011] Preferably, in step (10), the temperature T1 is 170-190°C, and the pressure P1 is 0.8-1.0 MPa.

[0012] Preferably, the temperature of the calcining furnace in step (11) is 900-1000° C., and the calcining time is 1.0-1.5 h.

[0013] Preferably, the preheating temperature of step (12) is 1140-1160°C, the holding time is 1.5h-2h, and the temperature T2 is 1500-1520°C.

[0014] The cobalt-based high-temperature alloy used in the process of the present invention is Mar-M-509, which has better thermal stability, wear resistance, corrosion resistance and high-temperature oxidation resistance than nickel-based alloys; the overall size of the casting product obtained by the process of the present invention is φ43mm×190mm, and the minimum wall thickness is only 1.02mm; the surface of the workpiece obtained by the process of the present invention is subjected to fluorescence detection, and the qualified rate reaches more than 90%; the inside of the workpiece obtained by the process of the present invention is subjected to X-Ray ray detection, and the qualified rate reaches more than 90%. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0016] Example 1 A manufacturing process of a cobalt-based alloy fuel nozzle casting (used in an aero-derivative engine BOEING 777), the manufacturing process comprising the following steps: (1) Mold manufacturing: Water-soluble wax molds and parts wax molds are manufactured according to the product structure. The water-soluble wax molds add cold wax to the thick and large middle part, and the parts wax molds use water-soluble core molding casting inner cavity structure; (2) Preparation of shell slurry: The surface slurry is prepared by mixing quick-drying silica sol and zircon powder in a weight ratio of w1:w2 of 1:2. The viscosity of the surface slurry is 45s and the pH value is 8.5. After mixing, stir for more than 24 hours until the surface slurry is evenly mixed. The back layer slurry is made by mixing silica sol and mullite powder in a ratio of W1:W2 of 1:1.4. The viscosity of the back layer slurry is 15s and the pH value is 8.5. After mixing, stir for more than 8 hours until the back layer slurry is evenly mixed. (3) Preparation of part wax mold: Place the water-soluble wax mold into the part wax mold, fill it with filling wax and press it into the part wax mold; (4) Forming a surface slurry coating: immerse the wax mold of the part in the surface slurry in step (2), rotate for 3 seconds, and then take it out to obtain a uniform surface slurry coating, and evenly pour 80-mesh molding sand on the surface slurry coating; (5) Repeat step (4) once; (6) Forming a back slurry coating: immerse the part wax mold obtained in step (5) into the back slurry in step (2), rotate for 3 seconds, and then take it out to obtain a uniform back slurry coating, and evenly pour 60-mesh molding sand on the back slurry coating; (7) Immerse the wax model of the part obtained in step (6) in the backing slurry in step (2), rotate for 3 seconds, and then take it out to obtain a uniform backing slurry coating, and evenly pour 30-mesh molding sand on the backing slurry coating; (8) Repeat step (7) once; (9) Immerse the part wax mold obtained in step (8) in the backing slurry in step (2) and rotate for 3 seconds before taking it out to obtain a uniform backing slurry coating. Evenly pour 16-mesh molding sand on the backing slurry coating to obtain a part shell; (10) Dewaxing of the part shell: Place the part shell into the dewaxing kettle and remove the part wax mold at temperature T1 and pressure P1, where the temperature T1 is 170°C and the pressure P1 is 0.8Mpa; (11) Pre-baking of the part shell: Place the part shell in a baking furnace and bake it at a temperature of 900°C for 1.0 h to remove the residual wax and moisture in the part shell; (12) Casting of parts: Heat the part shell to the preheating temperature of 1140℃ and keep it at this temperature for 2h. After keeping it at this temperature, refine the cobalt-based alloy Mar-M-509. After refining, vacuum pour the Mar-M-509 cobalt-based alloy liquid into the part shell at temperature T2 of 1500℃. After cooling, obtain the part with runner. Finally, cut and grind it to obtain the workpiece of the required shape. The overall size of the workpiece is φ43mm×190mm, and the minimum wall thickness is only 1.02mm.

[0017] The surface of the workpiece obtained by the process of Example 1 was subjected to fluorescence detection, and the qualified rate was more than 90%; the inside of the workpiece obtained by the process of Example 1 was subjected to X-Ray detection, and the qualified rate was more than 90%.

[0018] Example 2 A manufacturing process of a cobalt-based alloy fuel nozzle casting (used in an aero-derivative engine BOEING 777), the manufacturing process comprising the following steps: (1) Mold manufacturing: Water-soluble wax molds and parts wax molds are manufactured according to the product structure. The water-soluble wax molds add cold wax to the thick and large middle part, and the parts wax molds use water-soluble core molding casting inner cavity structure; (2) Preparation of shell slurry: The surface slurry is prepared by mixing quick-drying silica sol and zircon powder in a weight ratio of w1:w2 of 2:5.5. The viscosity of the surface slurry is 55s and the pH value is 10. After mixing, stir for more than 24 hours until the surface slurry is evenly mixed. The back layer slurry is made by mixing silica sol and mullite powder in a ratio of W1:W2 of 1:1.5. The viscosity of the back layer slurry is 20s and the pH value is 10. After mixing, stir for more than 8 hours until the back layer slurry is evenly mixed. (3) Preparation of part wax mold: Place the water-soluble wax mold into the part wax mold, fill it with filling wax and press it into the part wax mold; (4) Forming a surface slurry coating: immerse the wax mold of the part in the surface slurry in step (2), rotate it for 5 seconds, and then take it out to obtain a uniform surface slurry coating, and evenly pour 120 mesh molding sand on the surface slurry coating; (5) Repeat step (4) once; (6) Forming a back slurry coating: immerse the part wax mold obtained in step (5) into the back slurry in step (2), rotate for 5 seconds, and then take it out to obtain a uniform back slurry coating, and evenly pour 80-mesh molding sand on the back slurry coating; (7) Immerse the wax model of the part obtained in step (6) in the backing slurry in step (2), rotate for 5 seconds, and then take it out to obtain a uniform backing slurry coating. Evenly pour 60-mesh molding sand on the backing slurry coating; (8) Repeat step (7) once; (9) Immerse the part wax mold obtained in step (8) in the backing slurry in step (2), rotate for 5 seconds, and then take it out to obtain a uniform backing slurry coating. Evenly pour 30-mesh molding sand on the backing slurry coating to obtain a part shell; (10) Dewaxing of the part shell: Place the part shell into the dewaxing kettle and remove the part wax mold at temperature T1 and pressure P1, where the temperature T1 is 190°C and the pressure P1 is 1.0 MPa; (11) Pre-baking of the part shell: Place the part shell in a baking furnace and bake it at a temperature of 1000°C for 1.5 hours to remove the residual wax and moisture in the part shell; (12) Casting of parts: Heat the part shell to the preheating temperature of 1160℃ and keep it at this temperature for 1.5h. After keeping it at this temperature, refine the cobalt-based alloy Mar-M-509. After refining, vacuum pour the Mar-M-509 cobalt-based alloy liquid into the part shell at temperature T2 of 1520℃. After cooling, obtain the part with runner. Finally, cut and grind it to obtain the workpiece of the required shape. The overall size of the workpiece is φ43mm×190mm, and the minimum wall thickness is only 1.02mm.

[0019] The surface of the workpiece obtained by the process of Example 2 was subjected to fluorescence detection, and the qualified rate was more than 90%; the inside of the workpiece obtained by the process of Example 2 was subjected to X-Ray detection, and the qualified rate was more than 90%.

[0020] Example 3 A manufacturing process of a cobalt-based alloy fuel nozzle casting (used in an aero-derivative engine BOEING 777), the manufacturing process comprising the following steps: (1) Mold manufacturing: Water-soluble wax molds and parts wax molds are manufactured according to the product structure. The water-soluble wax molds add cold wax to the thick and large middle part, and the parts wax molds use water-soluble core molding casting inner cavity structure; (2) Preparation of shell slurry: The surface slurry is prepared by mixing quick-drying silica sol and zircon powder in a weight ratio of w1:w2 of 2.2:5.3. The viscosity of the surface slurry is 50s and the pH value is 9. After mixing, stir for more than 24 hours until the surface slurry is evenly mixed. The back layer slurry is made by mixing silica sol and mullite powder in a ratio of W1:W2 of 1:1.45. The viscosity of the back layer slurry is 17s and the pH value is 9. After mixing, stir for more than 8 hours until the back layer slurry is evenly mixed. (3) Preparation of part wax mold: Place the water-soluble wax mold into the part wax mold, fill it with filling wax and press it into the part wax mold; (4) Forming a surface slurry coating: immerse the wax mold of the part in the surface slurry in step (2), rotate for 4 seconds, and then take it out to obtain a uniform surface slurry coating, and evenly pour 100-mesh molding sand on the surface slurry coating; (5) Repeat step (4) once; (6) Forming a back slurry coating: immerse the part wax mold obtained in step (5) into the back slurry in step (2), rotate for 4 seconds, and then take it out to obtain a uniform back slurry coating, and evenly pour 70 mesh molding sand on the back slurry coating; (7) Immerse the wax model of the part obtained in step (6) in the backing slurry in step (2), rotate for 4 seconds, and then take it out to obtain a uniform backing slurry coating, and evenly pour 50-mesh molding sand on the backing slurry coating; (8) Repeat step (7) once; (9) Immerse the part wax mold obtained in step (8) in the backing slurry in step (2), rotate for 4 seconds, and then take it out to obtain a uniform backing slurry coating. Evenly pour 20-mesh molding sand on the backing slurry coating to obtain a part shell; (10) Dewaxing of the part shell: Place the part shell into the dewaxing kettle and remove the part wax mold at temperature T1 and pressure P1, where the temperature T1 is 180°C and the pressure P1 is 0.9 MPa; (11) Pre-baking of the part shell: Place the part shell in a baking furnace and bake it at a temperature of 950°C for 1.25 hours to remove the residual wax and moisture in the part shell; (12) Casting of parts: Heat the part shell to the preheating temperature of 1150℃ and keep it at this temperature for 1.8h. After keeping it at this temperature, refine the cobalt-based alloy Mar-M-509. After refining, vacuum pour the Mar-M-509 cobalt-based alloy liquid into the part shell at temperature T2 of 1510℃. After cooling, obtain the part with runner. Finally, cut and grind it to obtain the workpiece of the required shape. The overall size of the workpiece is φ43mm×190mm, and the minimum wall thickness is only 1.02mm.

[0021] The surface of the workpiece obtained by the process of Example 3 was subjected to fluorescence detection, and the qualified rate was more than 90%; the inside of the workpiece obtained by the process of Example 3 was subjected to X-Ray detection, and the qualified rate was more than 90%.

[0022] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A manufacturing process for a cobalt-based alloy fuel nozzle casting, characterized in that The manufacturing process includes the following steps: (1) Mold manufacturing: Water-soluble wax molds and parts wax molds are manufactured according to the product structure. The water-soluble wax molds add cold wax to the thick and large middle part, and the parts wax molds use water-soluble core molding casting inner cavity structure; (2) Preparation of shell slurry: Mix quick-drying silica sol and zircon powder in a weight ratio of w1:w2 for the surface slurry, and stir evenly after mixing; The back layer slurry is made by mixing silica sol and mullite powder in a ratio of W1:W2, and stirring evenly after mixing; (3) Preparation of part wax mold: Place the water-soluble wax mold into the part wax mold, fill it with filling wax and press it into the part wax mold; (4) Forming a surface slurry coating: immerse the wax mold of the part in the surface slurry in step (2), rotate it for 3 to 5 seconds, and then take it out to obtain a uniform surface slurry coating, and evenly pour the molding sand on the surface slurry coating; (5) Repeat step (4) once; (6) Forming a back slurry coating: immerse the part wax mold obtained in step (5) into the back slurry in step (2), rotate for 3 to 5 seconds, and then take it out to obtain a uniform back slurry coating, and evenly pour the molding sand on the back slurry coating; (7) Immerse the wax model of the part obtained in step (6) in the backing slurry in step (2) and rotate for 3 to 5 seconds before taking it out to obtain a uniform backing slurry coating, and evenly pour the molding sand on the backing slurry coating; (8) Repeat step (7) once; (9) Immerse the part wax mold obtained in step (8) in the backing slurry in step (2) and rotate for 3 to 5 seconds before taking it out to obtain a uniform backing slurry coating, and evenly pour molding sand on the backing slurry coating to obtain a part shell; (10) Dewaxing of the part shell: Place the part shell into the dewaxing kettle and remove the part wax mold at temperature T1 and pressure P1; (11) Pre-baking of the part shell: Place the part shell in a baking furnace for baking to remove the residual wax and moisture in the part shell; (12) Casting of parts: Heat the part shell to the preheating temperature, keep it warm and then refine the cobalt-based alloy Mar-M-509. After refining, vacuum pour the Mar-M-509 cobalt-based alloy liquid into the part shell at temperature T2. After cooling, obtain the part with runner. Finally, cut and grind to obtain the workpiece of the required shape.

2. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (2), the viscosity of the surface layer slurry is 45-55s, the pH value is 8.5-10, the mixing ratio of the surface layer slurry w1:w2 is: (2-2.5): (5-5.5), and the stirring time is more than 24h until the slurry is evenly mixed.

3. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (2), the viscosity of the backing layer slurry is 15-20s, the pH value is 8.5-10, the mixing ratio of the backing layer slurry W1:W2 is: 1:(1.4-1.5), and the stirring time is more than 8h until the slurry is evenly mixed.

4. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (4), the molding sand used is 80-120 mesh.

5. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (6), the molding sand used is 60-80 mesh.

6. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (7), the molding sand used is 30-60 mesh.

7. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (9), the molding sand used is 16-30 mesh.

8. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (10), the temperature T1 is 170-190°C, and the pressure P1 is 0.8-1.0 MPa.

9. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: In step (11), the temperature of the calcining furnace is 900-1000° C., and the calcining time is 1.0-1.5 h.

10. The manufacturing process of the cobalt-based alloy fuel nozzle casting according to claim 1, characterized in that: The preheating temperature of step (12) is 1140-1160°C, the holding time is 1.5h-2h, and the temperature T2 is 1500-1520°C.