A preparation method of a high-strength γ-phase superalloy with cellular distribution ′ ​

Abstract

The present invention relates to the technical field of powder metallurgy of superalloys, and particularly relates to a preparation method of a high-strength superalloy with a cellular distribution of γ' phase, comprising: preparing superalloy powder; loading the prepared superalloy powder into a first sheath, evacuating and sealing the first sheath; performing a preheating treatment on the first sheath; dispersing the superalloy powder in the first sheath; opening the first sheath, and transferring the superalloy powder from the first sheath into a second sheath through a charging tank under vacuum conditions; performing hot isostatic pressing treatment on the second sheath after powder loading to obtain a first workpiece; cooling the first workpiece to obtain a second workpiece; removing the second sheath outside the second workpiece to obtain a blank, and performing a heat treatment on the blank to obtain a target alloy; the present invention utilizes powder metallurgy technology and adjusts the preparation process to form a γ' phase with a special distribution inside the alloy, thereby improving the tensile strength and creep strength of the alloy.

Description

Technical Field

[0001] The present invention relates to the technical field of powder metallurgy of superalloys, and particularly to a method for preparing a high-strength superalloy with a cellular distribution of γ' phase. Background Art

[0002] In many harsh application scenarios of modern industry, when traditional superalloys with established compositions cannot meet the service requirements of higher loads, in addition to alloy compositions, the microstructure is also a key factor restricting the mechanical properties of alloys. Currently, the microstructures of conventional cast and forged superalloys mostly exhibit columnar or equiaxed crystal morphologies, making the mechanical properties of superalloys approach a bottleneck. Therefore, how to break through the limitations of the microstructure and improve the tensile strength and creep strength of alloys under the realistic constraint of established compositions is a technical problem faced by this field. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention proposes a method for preparing a high-strength superalloy with a cellular distribution of γ' phase. By using powder metallurgy technology and adjusting the preparation process, a special distribution of γ' phase is formed inside the alloy, thereby improving the tensile strength and creep strength of the alloy.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention proposes a method for preparing a high-strength superalloy with a cellular distribution of γ' phase, comprising the following steps:

[0006] Step 1: Prepare superalloy powder, which is composed of fine powder and coarse powder;

[0007] Step 2: Load the prepared superalloy powder into a first jacket, evacuate the first jacket and seal it by welding;

[0008] Step 3: Perform preheating treatment on the first jacket;

[0009] Step 4: Disperse the superalloy powder in the first jacket;

[0010] Step 5: Open the first jacket, and under vacuum conditions, transfer the superalloy powder from the first jacket into a second jacket through a feed tank;

[0011] Step 6: Perform hot isostatic pressing treatment on the second jacket filled with powder to obtain a first workpiece;

[0012] Step 7: Cool the first workpiece to obtain a second workpiece;

[0013] Step 8: Remove the second jacket outside the second workpiece to obtain a blank, and perform heat treatment on the blank to obtain the target alloy.

[0014] Specifically, in step 3, the first cladding is preheated by a vacuum heat treatment furnace, an air furnace or a salt bath.

[0015] Specifically, in step 3, the temperature of the preheating treatment is 500°C to 900°C, and the time of the preheating treatment is 5h to 8h.

[0016] Specifically, in step 8, the blank is heat-treated by a salt bath.

[0017] Specifically, in step 8, the process of heat-treating the blank is as follows: first, heat the molten salt to (1140 - 1200) ± 5°C, keep the molten salt flowing at a speed of 0.9m / s to 1.5m / s, then immerse the blank in the molten salt for heat treatment, the heat treatment time is 1h to 5h, the heat treatment time starts to be counted 30min to 90min after the blank is immersed in the molten salt, after the heat treatment is completed, take out the blank and air-cool or air-blast it.

[0018] Specifically, in step 1, the fine powder is an alloy powder with a particle size ≤ 45μm, and the coarse powder is an alloy powder with a particle size in the range of 150μm to 300μm; the mass ratio of the fine powder in the superalloy powder is 55% to 85%, the peak of the laser particle size distribution of the fine powder particle size appears at 20μm to 35μm, and the peak of the laser particle size distribution of the coarse powder particle size appears at 150μm to 200μm.

[0019] Specifically, in step 6, the process of the hot isostatic pressing treatment is as follows: first, heat up at a heating rate of 10°C / min to 20°C / min to 1000°C to 1100°C, the pressure increases with the temperature to 30MPa to 50MPa, keep the temperature and pressure for 4h to 8h; then pressurize to 120MPa to 200MPa, keep the temperature and pressure for 1h to 2.5h; finally, heat up at a heating rate of 0.6°C / min to 1°C / min to 1120°C to 1170°C, keep the temperature and pressure for 10min to 30min.

[0020] Specifically, in step 7, the cooling process of the first workpiece is as follows: first, cool at a cooling rate of 4°C / min to 6°C / min to 1000°C to 1050°C, and reduce the pressure simultaneously during the cooling process. When the temperature reaches 1070°C to 1090°C, the pressure drops to 20MPa to 40MPa; finally, after 40min to 75min, reduce the temperature of the first workpiece to below 400°C.

[0021] Specifically, the first cladding is a conical cladding. After the first cladding is sealed and welded, the internal vacuum degree ≤ 2.6×10 - 3 Pa.

[0022] Specifically, the vacuum degree in the second package is not higher than that in the first package after hermetic welding.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) In step 1 of the present invention, the particle size of the superalloy powder is a powder particle size with a bimodal size distribution achieved by mixing coarse powder and fine powder. On the one hand, the loose packing density during powder filling is increased, providing more "channels" for the formation of cellular structures; on the other hand, the deformation amounts of coarse powder particles and fine powder particles during hot isostatic pressing are different. Mixing coarse powder and fine powder can obtain a larger strain at the grain boundaries of the superalloy powder and a smaller strain inside the grains of the superalloy powder, further ensuring the formation of cellular structures.

[0025] (2) In step 3 of the present invention, the superalloy powder is preheated at 500°C to 900°C, enabling interstitial atom C to fully diffuse to the surface of the superalloy powder particles. Due to the segregation of C atoms, almost no long-range diffusion of other alloy atoms occurs.

[0026] (3) In step 6 of the present invention, the hot isostatic pressing process goes through three stages. In the first stage, the temperature is raised to 1000°C~1100°C at a heating rate of 10°C / min~20°C / min, the pressure is raised to 30MPa~50MPa along with the temperature, and the temperature and pressure are maintained for 4h~8h. In this stage, the high-temperature alloy powder is allowed to reach the diffusion temperature first, and only a small stress is applied. In this case, the alloy atoms in the high-temperature alloy powder can undergo sufficient solid-state diffusion. The reason is that in step 3, the C atoms have been enriched on the particle surface of the high-temperature alloy powder. Ti, Nb, and Ta are all strong carbide-forming elements, and Ti, Nb, and Ta atoms are prone to co-segregation with C atoms. Therefore, in this stage, Ti, Nb, and Ta atoms will quickly diffuse to the surface of the high-temperature alloy powder particles, increasing the concentration of Ti, Nb, and Ta elements on the surface of the high-temperature alloy powder particles. In the second stage, the pressure is increased to 120MPa~200MPa, and the temperature and pressure are maintained for 1h~2.5h to cause solid-solid diffusion metallurgical bonding between the particles of the high-temperature alloy powder, so that the high-concentration Ti, Nb, and Ta elements are further The first step is retained at the particle boundary of the high-temperature alloy powder; the third stage is heated to 1120℃~1170℃ at a heating rate of 0.6℃ / min~1℃ / min. This stage is to further compact the alloy, dissolve the γ′ phase, effectively eliminate the original particle boundary of the high-temperature alloy powder, and prevent grain growth. When the high concentration of Ti, Nb, and Ta three γ′ phase-forming elements are concentrated at the particle boundary of the high-temperature alloy powder, a γ′ phase-forming element depletion zone is formed inside the particles of the high-temperature alloy powder, which ensures the formation of cellular structure in the subsequent heat treatment; the third step is to heat up the temperature to 1120℃~1170℃ at a heating rate of 0.6℃ / min~1℃ / min. This stage is to further compact the alloy, dissolve the γ′ phase, effectively eliminate the original particle boundary of the high-temperature alloy powder, and prevent grain growth. In step 7, the cooling process of the first part is: firstly cool to 1000°C~1050°C at a cooling rate of 4°C / min~6°C / min, and reduce the pressure during the cooling process. When the temperature reaches 1070°C~1090°C, the pressure is reduced to 20MPa~40MPa; finally, after 40min~75min, the temperature of the first part is reduced to below 400°C. Due to the difference in the concentration of γ′ phase-forming elements, large-sized γ′ phases will precipitate at the particle boundaries of the high-temperature alloy powder when slowly cooled above 1000~1050°C.

[0027] (4) In step 8 of the present invention, heat treatment of the blank by salt bath can precisely control the heat treatment temperature. During the heat treatment process, the molten salt is heated to (1140 - 1200) ± 5 °C, and the molten salt is maintained to flow at a speed of 0.9 m / s - 1.5 m / s. This flow rate can ensure uniform heating of the blank. The heat treatment time starts to be counted after the blank is immersed in the molten salt for 30 min - 90 min. Since it is insulated at (1140 - 1200) ± 5 °C for 1 h - 5 h, the large-sized γ' phase precipitated at the grain boundaries of the superalloy powder particles in step 7 will not be completely dissolved, but the small-sized γ' phase inside the superalloy powder particles will be completely dissolved. At the same time, this temperature range will activate the long-range diffusion of alloy atoms, causing the remaining Ti, Nb, and Ta atoms inside the superalloy powder particles to further undergo uphill diffusion under the traction of C atoms on the surface of the superalloy powder particles, forming a positive concentration gradient of Ti, Nb, and Ta elements with a relatively wide range from the surface to the inside of the superalloy powder particles; after the blank is taken out of the salt bath, air cooling or air blast with a medium cooling rate is used to precipitate γ' phase at the positions where the high-concentration Ti, Nb, and Ta elements are near the surface of the superalloy powder particles, and the precipitated γ' phase grows during the cooling process; while due to the relatively low concentration of Ti, Nb, and Ta elements inside the superalloy powder particles, small-sized γ' phase is precipitated; compared with the microstructure in step 6, after the heat treatment in step 8, the "channels" of γ' phase between the superalloy powder particles are widened, forming a special cellular structure. The large-sized γ' phase between the superalloy powder particles and the small-sized γ' phase inside the superalloy powder particles act synergistically: among them, the large-sized γ' phase distributed in a network enhances the anti-phase domain boundary shear stress, while the small-sized γ' phase distributed in a cellular form forms an extended stacking fault to hinder dislocation movement, reducing the creep rate, thereby improving the tensile strength and creep rupture strength of the alloy. Description of the Drawings

[0028] Figure 1 Microstructure photograph of the superalloy obtained in Example 1 of the present invention;

[0029] Figure 2 Microstructure photograph of the superalloy obtained in Comparative Example 1;

[0030] Figure 3 Microstructure photograph of the superalloy obtained in Comparative Example 2;

[0031] Figure 4 Microstructure photograph of the superalloy obtained in Example 3 of the present invention;

[0032] Figure 5 Microstructure photograph of the superalloy obtained in Comparative Example 3. Detailed Description of the Invention

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Example 1

[0034] This embodiment provides a preparation method of a high-strength cellular distribution γ'-phase FGH4095 superalloy, including the following steps:

[0035] Step 1: Prepare FGH4095 superalloy powder by the plasma rotating electrode method. The process of preparing FGH4095 superalloy powder is as follows: First, prepare fine powder, which is FGH4095 alloy powder with a particle size ≤ 45 μm, and then prepare coarse powder, which is FGH4095 alloy powder with a particle size in the range of 150 μm - 300 μm. Mix the fine powder and the coarse powder to form FGH4095 superalloy powder. In the FGH4095 superalloy powder, the mass ratio of the fine powder is 65%, and the mass ratio of the coarse powder is 35%. The peak of the laser particle size distribution of the FGH4095 superalloy powder particle size appears at 20 μm and 150 μm.

[0036] Step 2: Load the FGH4095 superalloy powder into the first sheath, evacuate and seal the first sheath. After sealing, the vacuum degree inside the first sheath is 2.4×10 -3 Pa. The first sheath is a conical stainless steel sheath with a powder outlet at the end.

[0037] Step 3: Place the sealed first sheath in a vacuum heat treatment furnace and perform a preheating treatment on the first sheath at 500 °C for 8 hours.

[0038] Step 4: After taking out the first sheath from the vacuum heat treatment furnace, place it on a high-frequency vibration platform to redisperse the preheated FGH4095 superalloy powder.

[0039] Step 5: Remove the first sheath from the high-frequency vibration platform, open the powder outlet of the first sheath by cutting, and transfer the FGH4095 superalloy powder into the material tank through the powder outlet under a vacuum condition of 1.5×10 -3 Pa. Subsequently, load the FGH4095 superalloy powder in the material tank into the second sheath under a vacuum condition of 1.5×10 -3 Pa. The second sheath is annular.

[0040] Step 6: Place the second package after powder filling in a hot isostatic pressing device for hot isostatic pressing treatment to obtain a first workpiece; the specific process of the hot isostatic pressing treatment is as follows: First, heat up at a heating rate of 10 °C / min to 1020 °C, and the pressure increases to 30 MPa as the temperature rises, then hold the temperature and pressure for 4 h; then quickly increase the pressure to 120 MPa, keep the temperature at 1020 °C, and hold the temperature and pressure for 1 h; finally, heat up at a heating rate of 0.8 °C / min to 1120 °C, keep the pressure at 120 MPa, and hold the temperature and pressure for 10 min;

[0041] Step 7: Cool the first workpiece along with the hot isostatic pressing device. First, cool from 1120 °C to 1000 °C at a cooling rate of 5 °C / min. When the temperature reaches 1080 °C, the pressure drops to 20 MPa; finally, after 44.6 min, cool the temperature of the first workpiece to 350 °C to obtain a second workpiece;

[0042] Step 8: After taking out the second workpiece from the hot isostatic pressing device, remove the second package to obtain a blank. Perform salt bath heat treatment on the blank. The specific process of the salt bath heat treatment is as follows: First, heat the molten salt to 1140 ± 5 °C, keep the molten salt flowing at a speed of 0.9 m / s, then immerse the blank in the molten salt for 1 h of salt bath heat treatment. The heat treatment time starts to be counted 42 min after the blank is immersed in the molten salt. After the salt bath heat treatment is completed, the blank is taken out of the salt bath and air-cooled to obtain the FGH4095 superalloy. Example 2

[0043] This example proposes a preparation method for a high-strength cellular distribution γ'-phase FGH4095 superalloy, including the following steps:

[0044] Step 1: Prepare FGH4095 superalloy powder by the plasma rotating electrode method. The process of preparing FGH4095 superalloy powder is as follows: First, prepare fine powder, which is FGH4095 alloy powder with a particle size ≤ 45 μm, and then prepare coarse powder, which is FGH4095 alloy powder with a particle size in the range of 150 μm - 300 μm. Mix the fine powder and the coarse powder to form FGH4095 superalloy powder. In the FGH4095 superalloy powder, the mass ratio of the fine powder is 68%, and the mass ratio of the coarse powder is 32%. The laser particle size distribution peak of the FGH4095 superalloy powder particle size appears at 25 μm and 170 μm;

[0045] Step 2: Load the FGH4095 superalloy powder into the first package, evacuate and seal-weld the first package. After seal-welding, the vacuum degree inside the first package is 2.0×10 -3 Pa, and the first package is a conical stainless steel package with a powder outlet at the end;

[0046] Step 3: Place the first cladding after sealing welding in a vacuum heat treatment furnace, and perform a preheating treatment on the first cladding at 600 °C for 7 hours;

[0047] Step 4: After taking out the first cladding from the vacuum heat treatment furnace, place it on a high-frequency vibration platform to redisperse the preheated FGH4095 superalloy powder;

[0048] Step 5: Remove the first cladding from the high-frequency vibration platform, open the powder inlet of the first cladding by cutting, and transfer and load the FGH4095 superalloy powder into a material tank under a vacuum condition of 1.6×10 -3 Pa. Subsequently, load the FGH4095 superalloy powder in the material tank into a second cladding under a vacuum condition of 1.6×10 -3 Pa. The second cladding is cylindrical;

[0049] Step 6: Place the second cladding after powder loading in a hot isostatic pressing device for hot isostatic pressing to obtain a first workpiece; the specific process of the hot isostatic pressing is as follows: First, heat up at a heating rate of 15 °C / min to 1050 °C, and the pressure increases to 37 MPa as the temperature rises. Keep the temperature and pressure for 6 hours; then quickly increase the pressure to 150 MPa, keep the temperature at 1050 °C, and keep the temperature and pressure for 1.5 hours; finally, heat up at a heating rate of 0.6 °C / min to 1140 °C, keep the pressure at 150 MPa, and keep the temperature and pressure for 15 minutes;

[0050] Step 7: The first workpiece cools with the hot isostatic pressing device. First, cool from 1140 °C to 1020 °C at a cooling rate of 5 °C / min. When the temperature reaches 1085 °C, the pressure drops to 25 MPa; finally, after 55 minutes, cool the temperature of the first workpiece to 380 °C to obtain a second workpiece;

[0051] Step 8: After taking out the second workpiece from the hot isostatic pressing device, remove the second cladding to obtain a blank. Perform salt bath heat treatment on the blank. The specific process of the salt bath heat treatment is as follows: First, heat the molten salt to 1160 ± 5 °C, keep the molten salt flowing at a speed of 1.0 m / s, then immerse the blank in the molten salt for 2 hours of salt bath heat treatment. The heat treatment time starts to count 50 minutes after the blank is immersed in the molten salt. After the salt bath heat treatment is completed, the blank is taken out of the salt bath and air-cooled to obtain the FGH4095 superalloy. Example 3

[0052] This example proposes a preparation method for a high-strength cellular distribution γ′-phase GH4079 superalloy, including the following steps:

[0053] Step 1: Prepare GH4079 superalloy powder by the plasma rotating electrode process. The process of preparing GH4079 superalloy powder is as follows: First, prepare fine powder, which is GH4079 alloy powder with a particle size ≤ 45μm. Then, prepare coarse powder, which is GH4079 alloy powder with a particle size in the range of 150μm - 300μm. Mix the fine powder and the coarse powder to form GH4079 superalloy powder. In the GH4079 superalloy powder, the mass ratio of the fine powder is 72%, and the mass ratio of the coarse powder is 28%. The laser particle size distribution peak of the particle size of the GH4079 superalloy powder appears at 30μm and 180μm.

[0054] Step 2: Load the GH4079 superalloy powder into the first sheath, evacuate and seal-weld the first sheath. After seal-welding, the vacuum degree inside the first sheath is 1.8×10 -3 Pa. The first sheath is a conical stainless steel sheath with a powder discharging port at the end.

[0055] Step 3: Place the seal-welded first sheath in a vacuum heat treatment furnace and perform a preheating treatment on the first sheath at 800°C for 6 hours.

[0056] Step 4: After taking out the first sheath from the vacuum heat treatment furnace, place it on a high-frequency vibration platform to redisperse the preheated GH4079 superalloy powder.

[0057] Step 5: Remove the first sheath from the high-frequency vibration platform, open the powder discharging port of the first sheath by cutting. Under the vacuum condition of 1.3×10 -3 Pa, transfer and load the GH4079 superalloy powder into a material tank through the powder discharging port. Then, under the vacuum condition of 1.3×10 -3 Pa, load the GH4079 superalloy powder in the material tank into the second sheath. The second sheath is cylindrical.

[0058] Step 6: Place the powder-loaded second sheath in a hot isostatic pressing device for hot isostatic pressing treatment to obtain the first workpiece. The specific process of the hot isostatic pressing treatment is as follows: First, heat up at a heating rate of 18°C / min to 1080°C, and the pressure increases with the temperature to 45MPa, then hold the temperature and pressure for 7 hours. Then, quickly pressurize to 180MPa, keep the temperature at 1080°C, and hold the temperature and pressure for 2 hours. Finally, heat up at a heating rate of 0.9°C / min to 1150°C, keep the pressure at 180MPa, and hold the temperature and pressure for 25 minutes.

[0059] Step 7: The first workpiece is cooled with the hot isostatic pressing device. First, it is cooled from 1150 °C to 1030 °C at a cooling rate of 5 °C / min. When the temperature reaches 1070 °C, the pressure is reduced to 35 MPa. Finally, after 65 minutes, the temperature of the first workpiece is reduced to 300 °C to obtain the second workpiece;

[0060] Step 8: After taking out the second workpiece from the hot isostatic pressing device, the second cladding is removed to obtain a blank. The blank is subjected to salt bath heat treatment. The specific process of the salt bath heat treatment is as follows: First, the molten salt is heated to 1180 ± 5 °C, and the molten salt is maintained to flow at a speed of 1.2 m / s. Then the blank is immersed in the molten salt for 3 hours of salt bath heat treatment. The heat treatment time starts to be counted 70 minutes after the blank is immersed in the molten salt. After the salt bath heat treatment is completed, the blank is taken out of the salt bath and air-cooled to obtain the GH4079 superalloy. Example 4

[0061] This example presents a preparation method for a high-strength cellular distribution γ'-phase GH4079 superalloy, including the following steps:

[0062] Step 1: The GH4079 superalloy powder is prepared by the plasma rotating electrode method. The process of preparing the GH4079 superalloy powder is as follows: First, fine powder is prepared. The fine powder is GH4079 alloy powder with a particle size ≤ 45 μm. Then coarse powder is prepared. The coarse powder is GH4079 alloy powder with a particle size in the range of 150 μm to 300 μm. The fine powder and the coarse powder are mixed to form the GH4079 superalloy powder. In the GH4079 superalloy powder, the mass ratio of the fine powder is 75%, and the mass ratio of the coarse powder is 25%. The laser particle size distribution peak of the particle size of the GH4079 superalloy powder appears at 35 μm and 200 μm;

[0063] Step 2: The GH4079 superalloy powder is loaded into the first cladding, and the first cladding is evacuated and sealed. After sealing, the vacuum degree inside the first cladding is 1.3×10 -3 Pa. The first cladding is a conical stainless steel cladding with a powder inlet at the end;

[0064] Step 3: The sealed first cladding is placed in a vacuum heat treatment furnace and preheated at 900 °C for 5 hours;

[0065] Step 4: After taking out the first cladding from the vacuum heat treatment furnace, it is placed on a high-frequency vibration platform to redisperse the preheated GH4079 superalloy powder;

[0066] Step 5: The first cladding is taken off the high-frequency vibration platform, and the powder inlet of the first cladding is opened by cutting. At 1.0×10 -3Under a vacuum condition of Pa, transfer and load the GH4079 superalloy powder into the feed tank through the powder feeding port, and then under a vacuum condition of 1.0×10 -3 Pa, load the GH4079 superalloy powder in the feed tank into the second sheath, and the second sheath is annular;

[0067] Step 6: Place the second sheath after powder loading in a hot isostatic pressing device for hot isostatic pressing treatment to obtain a first workpiece; the specific process of the hot isostatic pressing treatment is as follows: First, heat up at a heating rate of 20°C / min to 1100°C, and the pressure increases to 50 MPa as the temperature rises, hold the temperature and pressure for 8 h; then quickly pressurize to 200 MPa, keep the temperature at 1100°C, hold the temperature and pressure for 2.5 h; finally, heat up at a heating rate of 1°C / min to 1170°C, keep the pressure at 200 MPa, hold the temperature and pressure for 30 min;

[0068] Step 7: Cool the first workpiece with the hot isostatic pressing device. First, cool from 1170°C to 1050°C at a cooling rate of 5°C / min. When the temperature reaches 1090°C, the pressure drops to 40 MPa; finally, after 75 min, cool the temperature of the first workpiece to 200°C to obtain a second workpiece;

[0069] Step 8: After taking out the second workpiece from the hot isostatic pressing device, remove the second sheath to obtain a blank, and perform salt bath heat treatment on the blank. The specific process of the salt bath heat treatment is as follows: First, heat the molten salt to 1200±5°C, keep the molten salt flowing at a speed of 1.5 m / s, then immerse the blank in the molten salt for 5 h of salt bath heat treatment. The heat treatment time starts to be counted 90 min after the blank is immersed in the molten salt. After the salt bath heat treatment is completed, the blank is taken out of the salt bath and air-cooled to obtain the GH4079 superalloy.

[0070] In the above examples, the powder feeding port diameter of the first sheath is 50 - 100 mm, the height is 100 - 200 mm, and the shape of the second sheath matches the shape of the workpiece.

[0071] Comparative Example 1

[0072] This comparative example is a conventional preparation method for FGH4095 superalloy, including the following steps:

[0073] Step 1: Prepare FGH4095 superalloy powder with a particle size in the range of 53 - 150 μm by the plasma rotating electrode method;

[0074] Step 2: Under a vacuum condition of 1.5×10 -3 Pa, transfer and load the FGH4095 superalloy powder into the feed tank, and then under a vacuum condition of 1.5×10 -3 Pa, load the FGH4095 superalloy powder in the feed tank into the second sheath, and the second sheath is annular;

[0075] Step 3: Place the second cladding after powder filling into a hot isostatic pressing device for hot isostatic pressing treatment to obtain a first workpiece; the specific process of the hot isostatic pressing treatment is as follows: Heat up at a heating rate of 3 °C / min to 1120 °C, and the pressure rises to 120 MPa as the temperature increases, then hold the temperature and pressure for 4 h;

[0076] Step 4: Cool the first workpiece with the hot isostatic pressing device. After 1.5 h, the furnace temperature drops to 350 °C to obtain a second workpiece;

[0077] Step 5: After taking out the second workpiece from the hot isostatic pressing equipment, remove the second cladding to obtain a blank. Heat-treat the blank in an air furnace. The heat treatment temperature is 1155 ± 10 °C, and the heat treatment time is 1 h. After the heat treatment is completed, take out the blank and cool it in a salt bath at 583 °C to obtain the FGH4095 superalloy.

[0078] Comparative Example 2

[0079] This comparative example presents a preparation method of the FGH4095 superalloy, including the following steps:

[0080] Step 1: Prepare FGH4095 superalloy powder by the plasma rotating electrode process. In the FGH4095 superalloy powder, the mass ratio of fine powder with a particle size ≤ 45 μm is 95%;

[0081] Step 2: Under a vacuum condition of 1.5×10 -3 Pa, transfer and load the FGH4095 superalloy powder into a charging tank. Subsequently, under a vacuum condition of 1.5×10 -3 Pa, load the FGH4095 superalloy powder in the charging tank into a second cladding, and the second cladding is annular;

[0082] Step 3: Place the second cladding after powder filling into a hot isostatic pressing device for hot isostatic pressing treatment to obtain a first workpiece. The specific process of the hot isostatic pressing treatment is as follows: First, heat up at a heating rate of 10 °C / min to 1020 °C, and the pressure rises to 120 MPa as the temperature increases, then hold the temperature and pressure for 4 h; then heat up at a heating rate of 0.8 °C / min to 1120 °C, keep the pressure at 120 MPa, and hold the temperature and pressure for 10 min;

[0083] Step 4: Cool the first workpiece with the hot isostatic pressing device. After 1.5 h, the temperature drops to 350 °C to obtain a second workpiece;

[0084] Step 5: After taking out the second workpiece from the hot isostatic pressing equipment, remove the second jacket to obtain a blank. Then, perform salt bath heat treatment on the blank. The specific process of the salt bath heat treatment is as follows: Heat the molten salt to 1140 ± 5 °C, keep the molten salt flowing at a speed of 0.9 m / s, then immerse the blank into the molten salt for 1 h of salt bath heat treatment. The heat treatment time starts to be counted 42 min after the blank is immersed in the molten salt. After the salt bath heat treatment is completed, the blank is taken out of the salt bath and air-cooled to obtain the FGH4095 superalloy.

[0085] Comparative Example 3

[0086] This comparative example presents a preparation method for the GH4079 superalloy, which includes the following steps:

[0087] Step 1: Prepare GH4079 superalloy powder by the plasma rotating electrode process. The process of preparing GH4079 superalloy powder is as follows: First, prepare fine powder with a particle size ≤ 45 μm, then prepare coarse powder with a particle size in the range of 150 - 300 μm, and mix the fine powder and the coarse powder to form GH4079 superalloy powder; in the GH4079 superalloy powder, the mass fraction of the fine powder is 72%, and the mass fraction of the coarse powder is 28%. The peak of the laser particle size distribution of the GH4079 superalloy powder particle size appears at 30 μm and 180 μm.

[0088] Step 2: Under a vacuum condition of 1.3×10 -3 Pa, transfer and load the GH4079 superalloy powder into the powder can. Subsequently, under a vacuum condition of 1.3×10 -3 Pa, load the GH4079 superalloy powder in the powder can into the second jacket, and the second jacket is cylindrical.

[0089] Step 3: Place the second jacket filled with powder in a hot isostatic pressing device for hot isostatic pressing treatment to obtain the first workpiece; the specific process of the hot isostatic pressing treatment is as follows: Heat up to 1150 °C at a heating rate of 3 °C / min, and the pressure rises to 160 MPa as the temperature rises, and keep the temperature and pressure for 4 h.

[0090] Step 7: Cool the first workpiece with the hot isostatic pressing device. First, cool from 1150 °C to 1030 °C at a cooling rate of 5 °C / min. When the temperature reaches 1070 °C, the pressure is reduced to 35 MPa; finally, after 65 min, the temperature of the first workpiece is reduced to 300 °C to obtain the second workpiece.

[0091] Step 8: After taking out the second workpiece from the hot isostatic pressing device, remove the second jacket to obtain a blank. Perform salt bath heat treatment on the blank. The specific process of the salt bath heat treatment is as follows: First, heat the molten salt to 1180 ± 5 °C, keep the molten salt flowing at a speed of 1.2 m / s, then immerse the blank in the molten salt for 3 h of salt bath heat treatment. The heat treatment time starts to be counted 70 min after the blank is immersed in the molten salt. After the salt bath heat treatment is completed, the blank is taken out of the salt bath and air-cooled to obtain the GH4079 superalloy.

[0092] Dissect the superalloys prepared in Example 1 and Comparative Examples 1 - 2. Take samples from the rim (1#), spoke (2#), first sampling location of the hub (3#), and second sampling location of the hub (4#) of the superalloys respectively. Test the tensile properties of the samples with reference to GB / T 4338, and test the creep properties of the samples with reference to GB / T 2039. Table 1 and Table 2 are respectively the test results of the tensile properties and creep properties of the superalloy obtained in Example 1. Table 3 and Table 4 are respectively the test results of the tensile properties and creep properties of the superalloy obtained in Comparative Example 1. Table 5 and Table 6 are respectively the test results of the tensile properties and creep properties of the superalloy obtained in Comparative Example 2:

[0093] Table 1 Tensile properties of the superalloy obtained in Example 1 at 650 °C

[0094]

[0095] Table 2 Creep properties of the superalloy obtained in Example 1

[0096]

[0097] Table 3 Tensile properties of the superalloy obtained in Comparative Example 1 at 650 °C

[0098]

[0099] Table 4 Creep properties of the superalloy obtained in Comparative Example 1

[0100]

[0101] Table 5 Tensile properties of the superalloy obtained in Comparative Example 2 at 650 °C

[0102]

[0103] Table 6 Creep properties of the superalloy obtained in Comparative Example 2

[0104]

[0105] As can be seen from Tables 1 - 6, the tensile properties and creep properties of the superalloy obtained in Example 1 are better than those of the superalloys obtained in Comparative Examples 1 - 2. From Figures 1 to 3It can be seen that cellular γ'-phase structures are formed inside the superalloy obtained in Example 1, while no cellular γ'-phase structures are formed inside the superalloys obtained in Comparative Examples 1-2.

[0106] The superalloys prepared in Example 3 and Comparative Example 3 were dissected, and samples were taken from the first sampling location (A) at the edge of the superalloy, the second sampling location (B) at the edge of the superalloy, the first sampling location (C) in the core of the superalloy, and the second sampling location (D) in the core of the superalloy respectively. The mechanical properties of the samples were tested. The tensile properties of the samples were tested with reference to GB / T 228.1, and the creep properties of the samples were tested with reference to GB / T 4338. Table 7 shows the test results of the mechanical properties of the superalloy obtained in Example 3, and Table 8 shows the test results of the mechanical properties of the superalloy obtained in Comparative Example 3:

[0107] Table 7 Mechanical Properties of the Superalloy Obtained in Example 3

[0108]

[0109] Table 8 Mechanical Properties of the Superalloy Obtained in Comparative Example 3

[0110]

[0111] As can be seen from Tables 7-8, the mechanical properties of the superalloy obtained in Example 3 are superior to those of the superalloy obtained in Comparative Example 3. From Figures 4 to 5 It can be seen that cellular γ'-phase structures are formed inside the superalloy obtained in Example 3, while no cellular γ'-phase structures are formed inside the superalloy obtained in Comparative Example 3.

[0112] The specific implementation manners of the present invention enable those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0113] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A preparation method of a high-strength cellular distribution γ'-phase superalloy, the superalloy being FGH4095 superalloy or GH4079 superalloy, characterized in that, It includes the following steps: Step 1: Prepare superalloy powder, which is composed of fine powder and coarse powder. The fine powder is alloy powder with a particle size ≤ 45μm, and the coarse powder is alloy powder with a particle size in the range of 150μm - 300μm; the mass proportion of the fine powder in the superalloy powder is 55% - 85%, the peak of the laser particle size distribution of the fine powder particle size appears at 20μm - 35μm, and the peak of the laser particle size distribution of the coarse powder particle size appears at 150μm - 200μm; Step 2: Load the prepared superalloy powder into the first jacket, evacuate the first jacket and seal it by welding; Step 3: Conduct preheating treatment on the first jacket; Step 4: Disperse the superalloy powder in the first jacket; Step 5: Open the first jacket, and under vacuum conditions, transfer the superalloy powder from the first jacket into the second jacket through a feed tank; Step 6: Conduct hot isostatic pressing treatment on the second jacket after powder loading to obtain the first workpiece; The process of the hot isostatic pressing treatment is as follows: First, heat at a heating rate of 10℃ / min - 20℃ / min to 1000℃ - 1100℃, the pressure increases with the temperature to 30MPa - 50MPa, keep the temperature and pressure for 4h - 8h; then increase the pressure to 120MPa - 200MPa, keep the temperature and pressure for 1h - 2.5h; finally, heat at a heating rate of 0.6℃ / min - 1℃ / min to 1120℃ - 1170℃, keep the temperature and pressure for 10min - 30min; Step 7: Cool the first workpiece to obtain the second workpiece; Step 8: Remove the second jacket outside the second workpiece to obtain a blank, and conduct heat treatment on the blank to obtain the target alloy; The process of conducting heat treatment on the blank is as follows: First, heat the molten salt to 1140℃ - 1200℃, keep the molten salt flowing at a speed of 0.9m / s - 1.5m / s, then immerse the blank in the molten salt for heat treatment, the heat treatment time is 1h - 5h, the heat treatment time starts to be counted 30min - 90min after the blank is immersed in the molten salt, after the heat treatment is completed, take out the blank and air-cool it or air-cool it with forced air.

2. The preparation method of a high-strength cellular distribution γ'-phase superalloy according to claim 1, characterized in that, In Step 3, preheat the first jacket through a vacuum heat treatment furnace, an air furnace or a salt bath.

3. The preparation method of a high-strength cellular distribution γ'-phase superalloy according to claim 1, characterized in that, In Step 3, the temperature of the preheating treatment is 500℃ - 900℃, and the time of the preheating treatment is 5h - 8h.

4. The preparation method of a high-strength cellular distributed γ'-phase superalloy according to claim 1, characterized in that In Step 7, the cooling process of the first workpiece is as follows: First, cool at a cooling rate of 4℃ / min - 6℃ / min to 1000℃ - 1050℃, and reduce the pressure simultaneously during the cooling process. When the temperature reaches 1070℃ - 1090℃, the pressure is reduced to 20MPa - 40MPa; finally, after 40min - 75min, reduce the temperature of the first workpiece to below 400℃.

5. The preparation method of a high-strength cellular distribution γ'-phase superalloy according to claim 1, characterized in that, The first sheath is a conical sheath. After the first sheath is sealed by welding, the internal vacuum degree ≤ 2.6×10 -3 Pa.

6. The preparation method of a high-strength cellular distribution γ'-phase superalloy according to claim 1, characterized in that, The vacuum degree inside the second jacket is not higher than the vacuum degree inside the first jacket after sealing by welding.

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