A method for recycling powder superalloy coarse powder return

Abstract

The application provides a powder superalloy coarse powder return material recycling method. The powder superalloy coarse powder return material recycling method comprises the following steps: S1, collecting and classifying: collecting powder superalloy coarse powder return material, and classifying according to alloy types, components and the like; S2, impurity removal: adopting a physical screening method, screening the coarse powder return material by using a screen with a suitable mesh number, and removing large-particle impurities and caked materials in the coarse powder return material. The powder superalloy coarse powder return material recycling method provided by the application ensures the consistency of the return material in alloy components by strict collecting and classifying processes, avoids the mixing of impurities, makes the powder superalloy products manufactured in subsequent processes have few differences in chemical components from the products produced by using brand-new raw materials, and thus guarantees the stability of key indexes such as high-temperature mechanical properties and oxidation resistance of the products.

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloy technology, and in particular to a method for reusing recycled high-temperature alloy coarse powder. Background Technology

[0002] With the rapid development of the aerospace industry, the demand for powder metallurgy superalloys, as a key material for manufacturing core components of powder turbine disks, continues to rise. Currently, when preparing superalloy powders using argon atomization, the yield of powder with a particle size smaller than 60μm is less than 70%, and over 30% of the coarse powder cannot be used directly due to increased oxygen, nitrogen, and other gas content and non-metallic inclusions, resulting in serious resource waste and keeping the cost of powder turbine disks high. Furthermore, due to the large quantity and long storage time of the coarse powder remelted material, its internal content of gaseous elements such as O and N is high, especially N, which is difficult to remove during smelting, severely limiting the recycling of coarse powder remelted material. Developing an effective coarse powder remelting and reuse technology would greatly reduce the cost of powder metallurgy superalloys, enhance the competitiveness of my country's powder metallurgy superalloy turbine disks, and improve the effective utilization rate of resources.

[0003] However, directly remelting recycled coarse powder of high-temperature alloys presents numerous problems. For example, the powder is non-conductive, making inductive melting difficult; it easily flies during melting, affecting valves and vacuum systems in the melting equipment; it can also easily enter crucible cracks, affecting crucible lifespan and introducing non-metallic inclusions. Furthermore, the billets obtained by traditional pressing have low strength and weak interparticle adhesion, making them extremely prone to breakage and secondary pulverization during operation, leading to powder absorption in a vacuum. Simultaneously, existing technologies for reusing recycled coarse powder are limited. Existing waste recycling technologies from casting and machining also face technical challenges when processing recycled coarse powder, including difficulties in powder forming before melting, severe vacuum powder absorption, poor thermal conductivity and transfer, and difficulty in removing oxide inclusions and achieving deep removal of O and N.

[0004] Therefore, it is necessary to provide a method for reusing recycled powdered high-temperature alloy coarse powder to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a method for reusing recycled high-temperature alloy coarse powder, which solves the problems in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for reusing recycled powder high-temperature alloy coarse powder, which includes the following steps:

[0007] S1. Collection and Classification: Collect the recycled powder of high-temperature alloy coarse powder and classify it according to alloy type, composition, etc.

[0008] S2. Impurity Removal: Physical screening is used to sieve the coarse powder return material with a suitable mesh size to remove large particles and agglomerates.

[0009] S3. Airflow milling: The coarse powder returned after S2 pretreatment is fed into the airflow mill. High-pressure airflow causes the powder particles to collide and rub against each other and the mill wall, thereby refining the powder.

[0010] S4. Grading process: The refined powder is graded by an air classifier to separate out coarse powder particles that do not meet the particle size requirements. These coarse particles are then returned to the air mill for further refining to ensure the uniformity of the final powder particle size.

[0011] S5. Vacuum degassing: The refined and graded powder is placed in a vacuum furnace for degassing.

[0012] S6. Hot isostatic pressing densification: The degassed powder is packed into a sleeve, sealed, and then placed in a hot isostatic press.

[0013] S7. Post-processing: The densified billet is forged and rolled to obtain powder high-temperature alloy products of the required shape and size.

[0014] Preferably, the mesh size of the sieve in S2 is in the range of 220-300 mesh.

[0015] Preferably, magnetic separation can also be used in step S2 to remove ferromagnetic impurities present in the coarse powder.

[0016] Preferably, in step S3, the operating parameters of the air jet mill are adjusted to refine the coarse powder to a particle size of less than 100 μm.

[0017] Preferably, in step S3, during the powder refining process of the air jet mill, a gas dryer is provided at the air inlet of the air jet mill to reduce the humidity of the incoming gas to 5%-10%.

[0018] Preferably, the vacuum degree of the vacuum furnace in S5 is 10. -3 Pa-10 -4 Pa, temperature of 500-600℃, holding time of 2-4h, to allow gaseous impurities in the powder to fully escape, thereby improving the purity of the powder.

[0019] Preferably, during vacuum degassing in step S5, the heating rate inside the furnace is controlled at 80-100℃ / min, and the cooling rate is controlled at 60-80℃ / min.

[0020] Preferably, the process conditions for the S6 hot isostatic pressing are a pressure of 100-200 MPa and a holding time of 8-16 min.

[0021] Preferably, the material of the sheath in S6 is low-carbon steel or stainless steel.

[0022] Preferably, the material of the sleeve used in S6 is stainless steel, specifically 304 stainless steel or 316 stainless steel, with a thickness of 4-8mm.

[0023] Compared with related technologies, the method for reusing recycled powder high-temperature alloy coarse powder provided by the present invention has the following beneficial effects:

[0024] This invention provides a method for reusing recycled coarse powder of high-temperature alloys. Through a strict collection and classification process, the consistency of the alloy composition of the recycled material is ensured, and impurities are avoided. This ensures that the chemical composition of the powder high-temperature alloy products produced after subsequent processing is almost identical to that produced using virgin raw materials. This guarantees the stability of key indicators such as high-temperature mechanical properties and oxidation resistance. After fine processing such as air jet milling, vacuum degassing, and hot isostatic pressing densification, the powder particles are uniform in size and tightly packed, with a significant reduction in internal porosity. The final product has a more uniform and fine microstructure, effectively improving the comprehensive performance of the material, such as fatigue strength and creep resistance, thus meeting the stringent requirements of high-end equipment for high-performance materials. Attached Figure Description

[0025] Figure 1 This is a schematic flowchart of a preferred embodiment of the method for reusing coarse powder of high-temperature alloy provided by the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Please refer to the following: Figure 1 ,in, Figure 1 This is a schematic flowchart of a preferred embodiment of the method for reusing coarse powder of high-temperature alloy provided by the present invention.

[0028] Example 1

[0029] The method for reusing recycled coarse powder of powder superalloys includes the following steps:

[0030] S1. Collection and Classification: Collect the recycled powder of high-temperature alloy coarse powder and classify it according to alloy type, composition, etc.

[0031] S2. Impurity Removal: Physical screening is used to sieve the coarse powder return material using a sieve with an appropriate mesh size, ranging from 220 mesh, to remove large particles and agglomerates. Magnetic separation can also be used to remove ferromagnetic impurities present in the coarse powder.

[0032] S3. Airflow milling: The coarse powder returned after S2 pretreatment is fed into the airflow mill. High-pressure airflow causes collisions and friction between powder particles and between particles and the mill wall, thereby refining the powder. The working parameters of the airflow mill are adjusted to refine the coarse powder to a particle size of less than 100μm. During the powder refining process of the airflow mill, a gas dryer is installed at the air inlet of the airflow mill to reduce the humidity of the incoming gas to 10%.

[0033] S4. Grading process: The refined powder is graded by an air classifier to separate out coarse powder particles that do not meet the particle size requirements. These coarse particles are then returned to the air mill for further refining to ensure the uniformity of the final powder particle size.

[0034] S5. Vacuum Degassing: The refined and graded powder is placed in a vacuum furnace for degassing treatment at a vacuum degree of 10. -3 Pa, temperature is 500℃, holding time is 2h, so that gaseous impurities in the powder can be fully released, and the purity of the powder can be improved. During vacuum degassing, the heating rate in the furnace is controlled at 80℃ / min and the cooling rate is controlled at 60℃ / min.

[0035] S6. Hot isostatic pressing densification: The degassed powder is packed into a 304 stainless steel sleeve with a thickness of 4mm, sealed, and placed in a hot isostatic press. Under a pressure of 100MPa, the pressure holding time is 8min.

[0036] S7. Post-processing: The densified billet is forged and rolled to obtain powder high-temperature alloy products of the required shape and size.

[0037] Example 2

[0038] The method for reusing recycled coarse powder of powder superalloys includes the following steps:

[0039] S1. Collection and Classification: Collect the recycled powder of high-temperature alloy coarse powder and classify it according to alloy type, composition, etc.

[0040] S2. Impurity Removal: Physical screening is used to sieve the coarse powder return material using a sieve with an appropriate mesh size, ranging from 240 mesh, to remove large particles and agglomerates. Magnetic separation can also be used to remove ferromagnetic impurities present in the coarse powder.

[0041] S3. Airflow milling: The coarse powder returned after S2 pretreatment is fed into the airflow mill. High-pressure airflow causes collisions and friction between powder particles and between particles and the mill wall, thereby refining the powder. The working parameters of the airflow mill are adjusted to refine the coarse powder to a particle size of less than 100μm. During the powder refining process of the airflow mill, a gas dryer is installed at the air inlet of the airflow mill to reduce the humidity of the incoming gas to 8%.

[0042] S4. Grading process: The refined powder is graded by an air classifier to separate out coarse powder particles that do not meet the particle size requirements. These coarse particles are then returned to the air mill for further refining to ensure the uniformity of the final powder particle size.

[0043] S5. Vacuum Degassing: The refined and graded powder is placed in a vacuum furnace for degassing treatment at a vacuum degree of 10. -3 PaPa, temperature is 550℃, holding time is 3h, to allow gaseous impurities in the powder to escape fully and improve the purity of the powder. During vacuum degassing, the heating rate in the furnace is controlled at 90℃ / min and the cooling rate is controlled at 70℃ / min.

[0044] S6. Hot isostatic pressing densification: The degassed powder is packed into a 316 stainless steel sleeve with a thickness of 4mm, sealed, and placed in a hot isostatic press. Under a pressure of 150MPa, the pressure holding time is 14min.

[0045] S7. Post-processing: The densified billet is forged and rolled to obtain powder high-temperature alloy products of the required shape and size.

[0046] Example 3

[0047] The method for reusing recycled coarse powder of powder superalloys includes the following steps:

[0048] S1. Collection and Classification: Collect the recycled powder of high-temperature alloy coarse powder and classify it according to alloy type, composition, etc.

[0049] S2. Impurity Removal: Physical screening is used to sieve the coarse powder return material using a sieve with an appropriate mesh size, ranging from 270 mesh, to remove large particles and agglomerates. Magnetic separation can also be used to remove ferromagnetic impurities present in the coarse powder.

[0050] S3. Airflow milling: The coarse powder returned after S2 pretreatment is fed into the airflow mill. High-pressure airflow causes collisions and friction between powder particles and between particles and the mill wall, thereby refining the powder. The working parameters of the airflow mill are adjusted to refine the coarse powder to a particle size of less than 100μm. During the powder refining process of the airflow mill, a gas dryer is installed at the air inlet of the airflow mill to reduce the humidity of the incoming gas to 7%.

[0051] S4. Grading process: The refined powder is graded by an air classifier to separate out coarse powder particles that do not meet the particle size requirements. These coarse particles are then returned to the air mill for further refining to ensure the uniformity of the final powder particle size.

[0052] S5. Vacuum Degassing: The refined and graded powder is placed in a vacuum furnace for degassing treatment at a vacuum degree of 10.-4 Pa, temperature is 500℃, holding time is 2h, so that gaseous impurities in the powder can be fully released, and the purity of the powder can be improved. During vacuum degassing, the heating rate in the furnace is controlled at 80℃ / min and the cooling rate is controlled at 60℃ / min.

[0053] S6. Hot isostatic pressing densification: The degassed powder is packed into a 304 stainless steel sleeve with a thickness of 6mm, sealed, and placed in a hot isostatic press. Under a pressure of 100MPa, the pressure holding time is 8min.

[0054] S7. Post-processing: The densified billet is forged and rolled to obtain powder high-temperature alloy products of the required shape and size.

[0055] Example 4

[0056] The method for reusing recycled coarse powder of powder superalloys includes the following steps:

[0057] S1. Collection and Classification: Collect the recycled powder of high-temperature alloy coarse powder and classify it according to alloy type, composition, etc.

[0058] S2. Impurity Removal: Physical screening is used to sieve the coarse powder return material using a sieve with an appropriate mesh size, ranging from 300 mesh, to remove large particles and agglomerates. Magnetic separation can also be used to remove ferromagnetic impurities present in the coarse powder.

[0059] S3. Airflow milling: The coarse powder returned after S2 pretreatment is fed into the airflow mill. High-pressure airflow causes collisions and friction between powder particles and between particles and the mill wall, thereby refining the powder. The working parameters of the airflow mill are adjusted to refine the coarse powder to a particle size of less than 100μm. During the powder refining process of the airflow mill, a gas dryer is installed at the air inlet of the airflow mill to reduce the humidity of the incoming gas to 5%.

[0060] S4. Grading process: The refined powder is graded by an air classifier to separate out coarse powder particles that do not meet the particle size requirements. These coarse particles are then returned to the air mill for further refining to ensure the uniformity of the final powder particle size.

[0061] S5. Vacuum Degassing: The refined and graded powder is placed in a vacuum furnace for degassing treatment at a vacuum degree of 10. -4 Pa, temperature is 600℃, holding time is 4h, so that gaseous impurities in the powder can be fully released, and the purity of the powder can be improved. During vacuum degassing, the heating rate in the furnace is controlled at 100℃ / min and the cooling rate is controlled at 80℃ / min.

[0062] S6. Hot isostatic pressing densification: The degassed powder is packed into a 316 stainless steel sleeve with a thickness of 6mm, sealed, and placed in a hot isostatic press. Under a pressure of 200MPa, the pressure holding time is 16min.

[0063] S7. Post-processing: The densified billet is forged and rolled to obtain powder high-temperature alloy products of the required shape and size.

[0064] The working principle of the recycling method for coarse powder of high-temperature alloy provided by the present invention is as follows:

[0065] The coarse powder of high-temperature alloys is collected and classified according to alloy type and composition. A physical screening method is used, employing a sieve with an appropriate mesh size to remove large particles and agglomerates. The pre-treated coarse powder is then fed into an air jet mill, where high-pressure airflow causes collisions and friction between powder particles and between particles and the mill wall, thus refining the powder. The refined powder is then classified using an air classifier to separate out coarse particles that do not meet the particle size requirements. These coarse particles are returned to the air jet mill for further refinement to ensure the uniformity of the final powder particle size. The refined and classified powder is then placed in a vacuum furnace for degassing. The degassed powder is then packed into a sealed container and placed in a hot isostatic press. Finally, the densified billet is forged and rolled to obtain powder high-temperature alloy products of the desired shape and size.

[0066] Compared with related technologies, the method for reusing recycled powder high-temperature alloy coarse powder provided by the present invention has the following beneficial effects:

[0067] Through a rigorous collection and classification process, the consistency of alloy composition in the returned materials is ensured, and impurities are avoided. This ensures that the powder superalloy products produced after subsequent processing are virtually indistinguishable from those produced using virgin raw materials in terms of chemical composition. This guarantees the stability of key indicators such as high-temperature mechanical properties and oxidation resistance. After fine processing such as air jet milling, vacuum degassing, and hot isostatic pressing densification, the powder particles are uniform in size and tightly packed, with a significant reduction in internal porosity. The final product has a more uniform and fine microstructure, effectively improving the comprehensive performance of the material, such as fatigue strength and creep resistance, thus meeting the stringent requirements of high-end equipment for high-performance materials.

[0068] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for reusing recycled powder superalloy coarse powder, characterized in that, Includes the following steps: S1. Collection and Classification: Collect the recycled powder of high-temperature alloy coarse powder and classify it according to alloy type and composition; S2. Impurity Removal: Physical screening is used to sieve the coarse powder return material with a suitable mesh size to remove large particles and agglomerates. S3. Airflow milling: The coarse powder returned after S2 pretreatment is fed into the airflow mill. High-pressure airflow causes the powder particles to collide and rub against each other and the mill wall, thereby refining the powder. S4. Grading process: The refined powder is graded by an air classifier to separate out coarse powder particles that do not meet the particle size requirements. These coarse particles are then returned to the air mill for further refining to ensure the uniformity of the final powder particle size. S5. Vacuum degassing: The refined and graded powder is placed in a vacuum furnace for degassing. S6. Hot isostatic pressing densification: The degassed powder is packed into a sleeve, sealed, and then placed in a hot isostatic press. S7. Post-processing: The densified billet is forged and rolled to obtain powder high-temperature alloy products of the required shape and size.

2. The method for reusing recycled powdered high-temperature alloy coarse powder according to claim 1, characterized in that, The mesh size of the sieve in S2 ranges from 220 to 300 mesh.

3. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, Magnetic separation can also be used in S2 to remove ferromagnetic impurities present in the coarse powder.

4. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, In step S3, the operating parameters of the air jet mill are adjusted to refine the coarse powder to a particle size of less than 100 μm.

5. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, In step S3, during the powder refining process of the air jet mill, a gas dryer is installed at the air inlet of the air jet mill to reduce the humidity of the incoming gas to 5%-10%.

6. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, The vacuum degree of the vacuum furnace in S5 is 10. -3 Pa -10 -4 Pa, temperature of 500-600℃, holding time of 2-4h, to allow gaseous impurities in the powder to fully escape and improve the purity of the powder.

7. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, During the S5 vacuum degassing process, the heating rate inside the furnace is controlled at 80-100℃ / min, and the cooling rate is controlled at 60-80℃ / min.

8. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, The process conditions for S6 hot isostatic pressing are a pressure of 100-200 MPa and a holding time of 8-16 min.

9. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 1, characterized in that, The material of the sheath in S6 is low-carbon steel or stainless steel.

10. The method for reusing recycled powder high-temperature alloy coarse powder according to claim 9, characterized in that, The sleeve used in S6 is made of stainless steel, specifically 304 stainless steel or 316 stainless steel, with a thickness of 4-8mm.

Images