A gh4099 nickel-based alloy component and a powder metallurgy forming process thereof

Abstract

The application discloses a GH4099 nickel-based alloy component and a powder metallurgy forming process thereof, and belongs to the technical field of powder metallurgy high-temperature alloys. The process is to perform hot isostatic pressing forming on GH4099 nickel-based alloy powder to obtain a powder blank, and then performing heat treatment on the powder blank to obtain a GH4099 nickel-based alloy component which meets the requirements in shape and mechanical properties. The application realizes higher precision and higher complexity of component manufacturing by hot isostatic pressing forming on GH4099 powder, and realizes rapid manufacturing and direct manufacturing of complex components. The forming quality of the powder component can be guaranteed, and the component is uniform in structure, free of defects such as pores, cracks and unfused particles. The comprehensive mechanical properties of the high-temperature alloy hot isostatic pressing forming component reach the level of forgings, so that the comprehensive mechanical properties of the high-temperature alloy component are improved, and the application range is expanded.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy high-temperature alloy technology, specifically to a GH4099 nickel-based alloy component and its powder metallurgy forming process. Background Technology

[0002] GH4099 alloy is a high-temperature alloy independently developed by my country's metallurgical and aerospace industries through extensive collaboration. It was initially designed for use in the afterburner housing of aero-gas turbine engines. Its composition is similar to the Soviet EP693 alloy. It is a typical age-hardening nickel-based high-temperature alloy with Ni and Co as the matrix, solid solution strengthening using alloying elements such as W, Mo, and Cr, and age-hardening elements such as Al and Ti. This alloy can operate at temperatures up to 1000℃ and possesses excellent comprehensive mechanical properties.

[0003] Currently, the commonly used preparation methods for GH4099 alloy are rolling and forging. However, due to the high strength and hardness of nickel-based superalloys and their poor deformation ability during plastic processing, the samples are prone to cracking, resulting in a low yield. Furthermore, the low material utilization rate of rolled and forged products keeps the cost of related products high. Powder metallurgy (PM) can prepare materials with fine microstructure, uniform composition, no macroscopic segregation, excellent mechanical properties, good stability, short manufacturing cycle, near-net-shape forming of complex parts, and high material utilization, making it one of the ideal preparation methods for superalloy components and attracting widespread attention from researchers. Summary of the Invention

[0004] The purpose of this invention is to provide a GH4099 nickel-based alloy component and its powder metallurgy forming process. This process can ensure the forming quality of the powder component, with uniform structure and no defects such as pores, cracks and unmelted particles, thereby improving the comprehensive mechanical properties of the alloy component.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A powder metallurgical forming process for GH4099 nickel-based alloy components, the powder metallurgical forming process specifically includes the following steps:

[0007] (1) Prepare GH4099 pre-alloyed powder, sieve the powder to obtain powder with a size of less than or equal to 106 micrometers, pack the sieved powder into a carbon steel or stainless steel sleeve, degas at high temperature and seal it.

[0008] (2) Hot isostatic pressing: The package containing powder obtained in step (1) is placed in a hot isostatic pressing equipment, and the predetermined temperature T1 and pressure F1 are reached by simultaneously raising the temperature and pressure. Then, heat preservation and pressure preservation treatment is carried out to ensure that the material structure is densified.

[0009] (3) Stop heating and cool the furnace to room temperature to obtain GH4099 alloy component billet;

[0010] (4) Heat treatment is performed on the alloy component blank from step (3) to obtain GH4099 nickel-based alloy components that meet the requirements in terms of shape and mechanical properties.

[0011] In step (1) above, the GH4099 pre-alloyed powder is prepared by crucibleless induction melting gas atomization (EIGA) or plasma rotating electrode process (PREP).

[0012] In step (1) above, the particle size of the sieved powder is below 106 μm, where D 10 The diameter is 15μm to 35μm, D 50 The diameter is 40μm to 70μm, D 90 The size ranges from 80μm to 100μm.

[0013] In step (2) above, the range of the hot isostatic pressing temperature T1 is (T γ‘ +120℃~(T γ‘ Between +150℃, where: T γ‘ T is the γ' dissolution temperature of GH4099 alloy. γ‘ It is 1100℃.

[0014] In step (2) above, the heat preservation time is 2h to 5h.

[0015] In step (2) above, the pressure F1 during the heat preservation process should be greater than or equal to 120 MPa.

[0016] In step (4) above, the heat treatment is a solution treatment followed by aging. The solution treatment process is as follows: hold at 1150℃~1200℃ for 1h~3h, then cool in a vacuum furnace or air-cooled to room temperature. The aging treatment process is as follows: after solution treatment, hold the alloy component in a heat treatment furnace at 800℃~900℃ for 4h~6h, then cool in a vacuum furnace or air-cooled to room temperature.

[0017] The mechanical properties of the formed GH4099 nickel-based alloy components are as follows: tensile strength at room temperature not less than 1150 MPa and elongation not less than 25%; tensile strength at 550℃ not less than 1050 MPa and elongation not less than 25%; tensile strength at 900℃ not less than 390 MPa and elongation not less than 45%.

[0018] The advantages and beneficial effects of this invention are:

[0019] 1. This invention is used for hot isostatic pressing of rapidly solidified GH4099 alloy powder to eliminate macroscopic pore defects, improve the density of various parts of complex components, and thus enhance the comprehensive mechanical properties of the alloy, especially its service life.

[0020] 2. The process of this invention is simple and practical, which can improve the overall metallurgical quality and service life of powder alloys, thereby reducing their manufacturing costs.

[0021] 3. The comprehensive mechanical properties of the high-temperature alloy hot isostatic pressing components of this invention reach the level of forgings, thereby improving the comprehensive mechanical properties of high-temperature alloy components. The GH4099 nickel-based alloy hot isostatic pressing components obtained using this invention have a room temperature tensile strength of not less than 1150 MPa and an elongation of not less than 25%; a 550℃ tensile strength of not less than 1050 MPa and an elongation of not less than 25%; and a 900℃ tensile strength of not less than 390 MPa and an elongation of not less than 45%, thus expanding the application range. Attached Figure Description

[0022] Figure 1 This is a flowchart of a hot isostatic pressing process for a GH4099 nickel-based alloy component according to the present invention.

[0023] Figure 2 This is a schematic diagram of the microstructure (hot isostatic pressing) of a component prepared using the process of the present invention in Comparative Example 1.

[0024] Figure 3 This is a schematic diagram of the microstructure (hot isostatic pressing) of a component prepared using the process of the present invention in Comparative Example 2.

[0025] Figure 4 This is a schematic diagram of the microstructure (hot isostatic pressing) of the component prepared by Comparative Example 3 using the process of the present invention.

[0026] Figure 5 This is a schematic diagram of the microstructure (hot isostatic pressing) of a component prepared using the process of Example 1 of the present invention. Detailed Implementation

[0027] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0028] like Figure 1As shown, the present invention provides a hot isostatic pressing (HIP) forming process for GH4099 nickel-based alloy components: the HIP forming process specifically includes the following steps:

[0029] (1) GH4099 clean pre-alloyed powder was prepared by crucibleless induction melting gasatomization (EIGA) or plasma rotating electrode process (PREP), and powder with a size of less than or equal to 106 μm was obtained by sieving.

[0030] (2) The powder is placed in a low-carbon steel or stainless steel sheath, degassed at high temperature, and then sealed by welding. Powder with a size of less than or equal to 106 micrometers is used to reduce the amount of hollow powder; carbon steel or stainless steel sheath is used because the sheath material is completely solid and has a certain strength within the temperature range used in this invention; high-temperature degassed is to remove the gas adsorbed on the powder surface to the maximum extent, the temperature range of high-temperature degassed is 250-450℃, and the degassed time is 8 to 16 hours.

[0031] (3) Place the powder coating prepared in the first step into a hot isostatic pressing (HIP) apparatus, and begin the low-temperature pressure holding process by increasing the temperature and pressure in the furnace. The HIP temperature should be selected within (T... γ‘ +120℃~(T γ‘ The temperature should be between +150℃ and 120MPa, and the time should be between 2 hours and 5 hours. The temperature for hot isostatic pressing should be selected within (T...). γ‘ +120℃~(T γ‘ The temperature range of +150℃ is based on the following reasons: First, the hot isostatic pressing (HIP) temperature of traditional powder superalloys is 1100℃~1200℃. GH4099 has a higher degree of alloying and greater resistance to hot deformation, therefore requiring a higher HIP temperature. Second, the surface area of ​​GH4099 alloy powder electrodes increases after being powdered, making them more prone to contamination. Therefore, the HIP temperature is higher than that of traditional superalloys to break down the original particle boundaries and eliminate macroscopic porosity defects. The holding time is greater than or equal to 2 hours and less than or equal to 5 hours based on the following reasons: First, within the temperature range selected for the first step of this invention, complete compaction of the powder compact requires at least 30 minutes. Second, excessively long holding times will cause coarsening of the alloy microstructure, affecting its mechanical properties.

[0032] The present invention will be further described in detail below with reference to the accompanying drawings, comparative examples and embodiments.

[0033] The composition of the alloys in the following comparative examples and embodiments is shown in Table 1:

[0034] Table 1. Composition of GH4099 alloy (wt.%)

[0035]

[0036] T γ‘ T is the γ' dissolution temperature of GH4099 alloy. γ‘ It is 1100℃;

[0037] Comparative Example 1

[0038] Comparative Example 1: The alloy powder was prepared using a plasma rotating electrode atomization method. Powder with a size of less than 106 micrometers was packed into a stainless steel sheath, degassed under vacuum, and then subjected to hot isostatic pressing. The following process regime (A) was selected for this alloy:

[0039] The furnace is heated and pressurized to reach hot isostatic pressure conditions: (T) γ‘ +65℃ / 140MPa / 4 hours, then cool with the furnace after completion.

[0040] Comparative Example 2

[0041] The difference from Comparative Example 1 is that the hot isostatic pressing temperature was increased from (Tγ'+65)℃ to (T γ‘ +100)℃.

[0042] Comparative Example 2: The alloy powder was prepared using a plasma rotating electrode atomization method. Powder with a size of less than 106 micrometers was packed into a stainless steel sleeve, degassed under vacuum, and then subjected to hot isostatic pressing. The following process regime (B) was selected for this alloy:

[0043] The furnace is heated and pressurized to reach hot isostatic pressure conditions: (T) γ‘ +100)℃ / 140MPa / 4 hours, then cool with the furnace after completion.

[0044] The microstructure of the alloy components prepared in Comparative Examples 1-2 is as follows: Figure 2-3 As shown, it can be seen that: Figure 2 No defects such as pores or inclusions were observed in the microstructure, indicating that the material has been fully densified and has an equiaxed structure similar to that of forged alloys, with discontinuous carbides distributed at the grain boundaries. Figure 3 The carbides are continuously distributed, with a small number of original particle boundaries.

[0045] The mechanical properties of the alloy components prepared in Comparative Examples 1-2 are shown in Table 1.

[0046] Table 1. Mechanical properties of powder metallurgy GH4099 alloys prepared by process A and process B

[0047]

[0048] Comparative Example 3

[0049] The difference from Comparative Example 2 is that the hot isostatic pressing temperature was increased from (Tγ'+100)℃ to (Tγ'+130)℃.

[0050] Example 1 describes the preparation of the alloy powder using a plasma rotating electrode atomization method. Powder with a size less than 106 micrometers was packed into a stainless steel sheath, degassed under vacuum, and then subjected to hot isostatic pressing. The following process regime (C) was selected for this alloy:

[0051] The furnace is heated and pressurized to reach hot isostatic pressure conditions: (T) γ‘ +130℃ / 140MPa / 4 hours, then cool with the furnace after completion.

[0052] Example 1

[0053] The difference from Comparative Example 3 is that solution treatment and aging heat treatment were performed after process regime (C).

[0054] In this embodiment, the alloy powder is prepared by plasma rotating electrode atomization. Powder with a size of less than 106 micrometers is packed into a stainless steel sheath, degassed under vacuum, and then subjected to hot isostatic pressing. The following process regime (D) was selected for this alloy:

[0055] The furnace is heated and pressurized to reach hot isostatic pressure conditions: (T) γ‘ +130℃ / 140MPa / 4 hours, then cool with the furnace after completion.

[0056] Solution treatment method: hold at 1175℃ for 1 hour, then cool to room temperature in a vacuum furnace;

[0057] Aging treatment method: After solution treatment, the alloy component is kept at 850°C in a heat treatment furnace for 5 hours and then cooled to room temperature in a vacuum furnace.

[0058] The microstructures of Comparative Example 3 and Example 1 after hot isostatic pressing are as follows: Figure 4-5 As shown, it can be seen that: Figure 4 The powder particles break at their boundaries, and the carbides partially dissolve, losing their pinning effect on the grain boundaries. Figure 5 The powder particles have completely broken boundaries, and the microstructure is a completely equiaxed structure with uniform structure and no defects such as pores, cracks and unmelted particles.

[0059] The mechanical properties of the alloy components prepared in Comparative Example 3 and Example 1 are shown in Table 2.

[0060] Table 2. Mechanical properties of powder metallurgy GH4099 alloys prepared by process C and process D

[0061]

[0062] In summary, the GH4099 nickel-based alloy complex components prepared by the hot isostatic pressing method of this invention exhibit a room temperature tensile strength of not less than 1150 MPa and an elongation of not less than 25%; a 550°C tensile strength of not less than 1050 MPa and an elongation of not less than 25%; and a 900°C tensile strength of not less than 390 MPa and an elongation of not less than 45%, thereby expanding their application range. They can meet the strength and plasticity requirements of aerospace products for GH4099 nickel-based alloy components. Specific embodiments of this invention have been described above. It should be understood that this invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this invention.

Claims

1. A powder metallurgical forming process of a GH4099 nickel-based alloy component, characterized in that: The powder metallurgy forming process specifically comprises the following steps: (1) preparing GH4099 pre-alloy powder, screening the powder to obtain powder with a size of less than or equal to 106 microns, loading the screened powder into a carbon steel or stainless steel can, high-temperature degassing and sealing welding; the temperature range of high-temperature degassing is 250-450℃, and the degassing time is 8-16h; (2) Hot isostatic pressing treatment: the canning containing the powder obtained in step (1) is put into a hot isostatic pressing device, and a predetermined temperature T1 and pressure F1 are reached in a simultaneous temperature and pressure increasing manner, and then a temperature and pressure maintaining treatment is carried out, so as to ensure the densification of the material organization; the value of the predetermined temperature T1 is in the range of (T γ ' + 120℃)~(T γ ' + 150℃), wherein: T γ ' is the γ' solvus temperature of the GH4099 alloy, T γ ' is 1100℃; (3) stopping heating and cooling in the furnace to room temperature to obtain a GH4099 alloy component blank; (4) performing heat treatment on the alloy component blank of step (3), the heat treatment being a solid solution + aging treatment, the solid solution treatment process being: heat preservation at 1150-1200℃ for 1-3h, vacuum furnace cooling to room temperature; the aging treatment process: after the solid solution treatment, heat preservation of the alloy component blank in a heat treatment furnace at 800-900℃ for 4-6h, vacuum furnace cooling to room temperature; obtaining a GH4099 nickel-based alloy component with both shape and mechanical properties meeting the requirements.

2. The powder metallurgical forming process of a GH4099 nickel-base alloy component according to claim 1, characterized in that: In step (1), the GH4099 pre-alloy powder is prepared by electrode induction melting gas atomization (EIGA) or plasma rotating electrode process (PREP).

3. The powder metallurgy forming process of a GH4099 nickel-base alloy component of claim 1, characterized in that: In step (1), the particle size of the sieved powder is 106 μm or less, wherein D 10 is 25 μm to 35 μm, D 50 is 40 μm to 60 μm, and D 90 is 80 μm to 100 μm.

4. The powder metallurgy forming process of a GH4099 nickel-base alloy component of claim 1, characterized in that: In step (2), the heat preservation time is 2-5h.

5. The powder metallurgy forming process of a GH4099 nickel-base alloy component of claim 1, characterized by: In step (2), the pressure F1 during the heat preservation process should be greater than or equal to 120MPa.

6. A GH4099 nickel-based alloy component formed by the process of any one of claims 1-5.

7. The GH4099 nickel-base alloy component of claim 6, wherein: The mechanical property requirements of the nickel-based alloy component are: the tensile strength at room temperature is not less than 1150MPa, and the elongation is not less than 25%; the tensile strength at 550℃ is not less than 1050MPa, and the elongation is not less than 25%; the tensile strength at 900℃ is not less than 390MPa, and the elongation is not less than 45%.

Images