Nickel-based powder high-temperature alloy structural part and preparation method thereof

Abstract

The invention discloses a nickel-based powder high-temperature alloy structural part and a preparation method thereof, and relates to the technical field of high-temperature alloys. The preparation method provided by the invention comprises the following steps: preparing a powder high-temperature alloy master alloy; powder is prepared through a PREP method, the oxygen content of the powder does not exceed 0.005%, and the particle size of the powder ranges from 50 micrometers to 100 micrometers; the powder is subjected to the procedures of vacuum degassing, sleeving, seal welding, hot isostatic pressing, heat treatment, machining and nondestructive testing, and the nickel-based powder high-temperature alloy structural part is obtained; the defect equivalent size of the nickel-based powder high-temperature alloy structural part is not larger than phi 0.4 mm. According to the preparation method of the nickel-based powder high-temperature alloy structural part, the requirements for the powder oxygen content, the powder granularity and the powder inclusions are high, the mechanical property of the powder high-temperature alloy part can be well improved, and the consistency and reliability of the structural part are improved. The high-temperature alloy powder used by the nickel-based powder high-temperature alloy structural member is high in quality, low in oxygen content and few in impurities, and has good mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature alloys, and in particular to a nickel-based powder high-temperature alloy structural part and a preparation method thereof. Background Art

[0002] As the power system of an aircraft, the aircraft engine is the "heart" of the aircraft and the "crown jewel" of the advanced manufacturing industry. The manufacturing of aircraft engines is an important symbol for measuring a country's comprehensive scientific and technological level, demonstrating the strength of a country's industrial base and comprehensive national strength. my country's aircraft engine technology is relatively backward and has not completely broken away from the imitation model. It has become a bottleneck restricting the technological progress of military and civil aviation equipment, and is also a shortcoming in the development of the entire aviation industry. From the perspective of international and domestic technological development trends and domestic practices, in order to improve the reliability and durability of the disc, the future advanced engine high-temperature alloy powder turbine disc will mainly focus on improving the comprehensive mechanical properties and purity of the disc.

[0003] The mechanical properties of the disc mainly refer to room temperature tensile strength, high temperature tensile strength, impact strength, endurance strength, creep strength and fatigue strength, etc. The purity of the disc is mainly measured by ultrasonic water immersion flaw detection.

[0004] FGH4097 is a nickel-based precipitation-strengthened powder metallurgy high-temperature alloy. The volume fraction of the γ' phase in the alloy is about 60%, and it can be used for a long time below 750℃. Compared with similar cast or forged high-temperature alloys, this alloy has uniform structure, fine grains, good tensile and endurance strength, fatigue resistance and creep resistance, as well as corrosion resistance and high-temperature oxidation resistance. It is a key material for high-performance engine turbine disks, rings and other hot end components. However, the currently prepared FGH4097 powder high-temperature alloy has low purity, which will reduce the mechanical properties of powder high-temperature alloy parts, especially the impact resistance; and the powder particle size is coarse, which easily causes the inclusion size to be too large. When the number of inclusions is large and the size exceeds 100um, the comprehensive mechanical properties and purity of the powder high-temperature alloy parts will be reduced, resulting in poor consistency and reliability of the powder high-temperature alloy parts. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the currently prepared FGH4097 powder high-temperature alloy has low purity and poor comprehensive mechanical properties.

[0006] In order to solve the above problems, the present invention proposes the following technical solutions:

[0007] The present invention provides a method for preparing a nickel-based powder high-temperature alloy structural part, comprising the following steps:

[0008] Preparation of powder high temperature alloy master alloy;

[0009] Based on the powder high temperature alloy master alloy, a plasma rotating electrode atomization method (PREP method) is used to prepare powder, wherein the oxygen content of the powder does not exceed 0.005%, and the powder particle size is 50-100 um;

[0010] The powder is subjected to vacuum degassing, casing, sealing welding, hot isostatic pressing, heat treatment, machining and non-destructive testing to obtain a nickel-based powder high-temperature alloy structural part; the defect equivalent size of the nickel-based powder high-temperature alloy structural part does not exceed

[0011] Furthermore, the vacuum degree of the vacuum degassing process is controlled at 1×10 -2 Below Pa, the temperature is controlled at 400-480℃.

[0012] Furthermore, the temperature of the hot isostatic pressing process is (1200±5)°C, the pressure is ≥130MPa, the insulation time is 4-5h, and then the furnace is cooled.

[0013] Furthermore, the heat treatment process is as follows: (1200±10)℃ insulation for 4h, air cooling; (910±10)℃ insulation for 3h, air cooling; (750±10)℃ insulation for 8h, air cooling; (700±10)℃ insulation for 17h, air cooling.

[0014] Furthermore, the nondestructive testing process is to use ultrasonic water immersion testing, and the diameter of the flat bottom hole is

[0015] Furthermore, the powder prepared by the plasma rotating electrode atomization method has an upper limit of particle size of 150 mesh or 180 mesh and a lower limit of particle size of 270 mesh.

[0016] Furthermore, the number of inclusions in every 1 kg of the powder does not exceed 10.

[0017] Furthermore, the powder high-temperature alloy master alloy is prepared by a single process of vacuum induction melting, or by a triple process consisting of vacuum induction melting, electroslag remelting, and vacuum consumable melting.

[0018] Furthermore, the powder high temperature alloy master alloy is FGH4097 master alloy.

[0019] The present invention also provides a nickel-based powder high-temperature alloy structural part, which is prepared by the above-mentioned preparation method. The defect equivalent size of the nickel-based powder high-temperature alloy structural part provided by the present invention does not exceed

[0020] Compared with the prior art, the technical effects achieved by the present invention include:

[0021] The method for preparing a nickel-based powder high-temperature alloy structural part provided by the present invention has high requirements on powder oxygen content, powder particle size and powder inclusions, and can well improve the mechanical properties of the powder high-temperature alloy parts and improve the consistency and reliability of the structural parts.

[0022] The high-temperature alloy powder used for the nickel-based powder high-temperature alloy structural part provided by the present invention has high quality, low oxygen content, few impurities, good mechanical properties and excellent reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0024] Figure 1 A process roadmap for the method for preparing a nickel-based powder high-temperature alloy structural part provided by the present invention;

[0025] Figure 2 The metallographic structure photographs of the FGH4097 powder high temperature alloy discs prepared in Examples 1 and 2 of the present invention in an uncorroded state; Figure 3 The metallographic structure photographs of the corrosion state of the FGH4097 powder high-temperature alloy disks prepared in Example 1 and Example 2 of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Similar component numbers in the drawings represent similar components. Obviously, the embodiments described below are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0028] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0029] Example 1

[0030] The embodiment of the present invention provides a nickel-based powder high-temperature alloy structural part and a preparation method thereof. Figure 1 , which is the main process route diagram of the method for preparing nickel-based powder high-temperature alloy structural parts provided by the present invention. The specific steps are described as follows:

[0031] S1. FGH4097 master alloy rods are prepared by vacuum induction melting. After the head and tail of the rods are cut off and the surface oxide scale and defects are machined by turning, the surface of the rods is machined by external cylindrical grinding.

[0032] S2. The FGH4097 master alloy rod is atomized by a plasma rotating electrode to form a powder, and then sieved through 150 mesh and 270 mesh screens to obtain the desired finished powder. The oxygen content of the powder is 0.0035%; the powder particle size is 50-100um; the number of inclusions in each 1kg of finished powder is 5, and the maximum size is 74um.

[0033] Specifically, an advanced plasma rotating electrode atomization device is used, with a rotation speed of 10000-20000 r / min, preferably 15000-18000 r / min. Under this speed range, the yield of 50-100 um powder can be guaranteed. The rotation speed of this embodiment is 18000 r / min. At the same time, an argon + helium protective atmosphere is used in the preparation process to control the oxygen content of the powder.

[0034] In terms of inclusion control, clean equipment is used, and the newly prepared powder is used to wash the furnace. In addition, powder transfer and screening are both carried out in a Class 10,000 clean room to ensure that no foreign inclusions are introduced, thereby ensuring that the number of inclusions in every 1kg of finished powder is 5, with a maximum size of 74um.

[0035] S3, vacuum dynamic degassing the finished powder, packing the package and sealing the package. The vacuum degree of vacuum dynamic degassing is controlled at 1×10 -2 Below Pa, the temperature is 450℃.

[0036] S4. The above-mentioned package is subjected to hot isostatic pressing treatment at a temperature of (1200±5)°C, a pressure of 150MPa, a heat preservation time of 5h, and is cooled with the furnace.

[0037] S5. The heat treatment system of the FGH4097 alloy in this embodiment is as follows: keep at (1200±10)℃ for 4h, air cool; keep at (910±10)℃ for 3h, air cool; keep at (750±10)℃ for 8h, air cool; keep at (700±10)℃ for 17h, air cool.

[0038] S6. The heat-treated FGH4097 alloy was subjected to ultrasonic water immersion testing. Flat bottom holes are inspected to ensure that the equivalent size of the defect does not exceed

[0039] S7. According to the preparation method of this embodiment, two FGH4097 powder high-temperature alloy discs are obtained, namely disc 1# and disc 2#. The size of disc 1# is approximately 169 mm in diameter and 102 mm in height; the size of disc 2# is approximately 169 mm in diameter and 122 mm in height.

[0040] The tensile, impact, endurance, creep and fatigue properties of the 1# and 2# disks prepared in this embodiment were tested by ultrasonic water immersion testing. The results are shown in Tables 1-6.

[0041] Table 1 Tensile properties of FGH4097 powder high temperature alloy discs prepared by the present invention

[0042]

[0043]

[0044] From the results in Table 1, it can be seen that the tensile properties of the FGH4097 powder high-temperature alloy discs prepared by the present invention are better than the industry standard and are similar to the original technical approach (China High-temperature Alloy Handbook (Part 2)).

[0045] Table 2 Impact properties of FGH4097 powder high temperature alloy discs prepared by the present invention

[0046]

[0047] It can be seen from the results in Table 2 that the impact properties of the FGH4097 powder high-temperature alloy disc prepared by the present invention are better than those of the industry standard and the original technical approach (China High-temperature Alloy Handbook (Part 2)).

[0048] Table 3 Low cycle fatigue properties of FGH4097 powder high temperature alloy discs prepared by the present invention

[0049]

[0050] It can be seen from the results in Table 3 that the low cycle fatigue properties of the FGH4097 powder high temperature alloy disc prepared by the present invention meet the industry standards.

[0051] Table 4 Creep properties of FGH4097 powder high temperature alloy discs prepared by the present invention

[0052]

[0053]

[0054] It can be seen from the results in Table 4 that the creep properties of the FGH4097 powder high-temperature alloy disc prepared by the present invention are better than those of the industry standard and the original technical approach (China High-temperature Alloy Handbook (Part 2)).

[0055] Table 5 Combined durability performance of FGH4097 powder high temperature alloy disc prepared by the present invention

[0056]

[0057] It should be noted that the above-mentioned original technical approach refers to:

[0058] By controlling the processing parameters in step S2, such as the rotation speed of 12000r / min and the cleanliness of the equipment environment, the powder particle size of the obtained finished powder is in the range of 50-150um, the number of non-metallic inclusions allowed per 1kg of powder is not more than 20, the size is not more than 150um, and the oxygen content does not exceed 0.007%. The temperature of the hot isostatic pressing process is (1200±10)℃, the pressure is 120MPa, and the holding time is 2h.

[0059] It can be seen from the results in Table 5 that the combined endurance performance of the FGH4097 powder high temperature alloy disc prepared by the present invention is better than the industry standard.

[0060] Ultrasound results comparison, the original technical approach Flat bottom hole ultrasonic detection defect, the present invention embodiment 1 and embodiment 2 both adopt Flat bottom hole ultrasonic detection defect, Example 1 and Example 2 did not find excessive signal, the signal average is The maximum attenuation of the bottom wave is 3.7 dB (the industry generally has no requirements, and the strictest standard is no more than 6 dB), which shows that the cleanliness of the disks in Example 1 and Example 2 is relatively high.

[0061] The corroded and uncorroded FGH4097 powder high temperature alloy discs prepared in Example 1 and Example 2 of the present invention were subjected to metallographic examination at a magnification of 100x. The results are as follows: Figure 2-3 . Figure 2 The metallographic structure photographs of the FGH4097 powder high temperature alloy discs prepared in Examples 1 and 2 of the present invention in an uncorroded state; Figure 3 The metallographic structure photographs of the corrosion state of the FGH4097 powder high-temperature alloy disks prepared in Example 1 and Example 2 of the present invention.

[0062] The results show that the FGH4097 powder high temperature alloy disc produced by the present invention has a uniform grain structure of level 6 to 7. No original powder particle boundaries, heat-induced holes, residual microscopic holes, microscopic holes caused by overheating and inclusions are found, which is better than the industry standard.

[0063] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for preparing a nickel-based powder high-temperature alloy structural part, characterized in that: The following steps are involved: Preparation of powder high temperature alloy master alloy; Based on the powder high temperature alloy master alloy, a plasma rotating electrode atomization method is used to prepare powder, wherein the oxygen content of the powder does not exceed 0.005%, and the powder particle size is 50-100 um; The powder is subjected to vacuum degassing, casing, sealing welding, hot isostatic pressing, heat treatment, machining and non-destructive testing to obtain a nickel-based powder high-temperature alloy structural part; the defect equivalent size of the nickel-based powder high-temperature alloy structural part does not exceed φ0.4mm.

2. The preparation method according to claim 1, characterized in that The vacuum degree of the vacuum degassing process is controlled at 1×10 -2 Below Pa, the temperature is controlled at 400-480℃.

3. The preparation method according to claim 1, characterized in that: The temperature of the hot isostatic pressing process is (1200±5)°C, the pressure is ≥130MPa, the heat preservation time is 4-5h, and then the furnace is cooled.

4. The preparation method according to claim 1, characterized in that: The heat treatment process is as follows: (1200±10)°C for 4 hours, air cooling; (910±10)°C for 3 hours, air cooling; (750±10)°C for 8 hours, air cooling; (700±10)°C for 17 hours, air cooling.

5. The preparation method according to claim 1, characterized in that: The non-destructive testing process is to use ultrasonic water immersion flaw detection, and the diameter of the flat bottom hole is φ0.4mm.

6. The preparation method according to claim 1, characterized in that: The powder prepared by the plasma rotating electrode atomization method has an upper limit of particle size of 150 mesh or 180 mesh and a lower limit of particle size of 270 mesh.

7. The preparation method according to claim 6, characterized in that: The number of inclusions in each 1 kg of the powder does not exceed 10.

8. The preparation method according to claim 1, characterized in that: The powder high-temperature alloy master alloy is prepared by a single process of vacuum induction melting, or by a triple process of vacuum induction melting, electroslag remelting and vacuum consumable melting.

9. The preparation method according to claim 1, characterized in that: The powder high temperature alloy master alloy is FGH4097 master alloy.

10. A nickel-based powder high-temperature alloy structural part, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

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