Heat treatment method for additive manufacturing high-temperature alloy and additive manufacturing high-temperature alloy part

Abstract

The invention provides a heat treatment method for an additive manufacturing high-temperature alloy, and relates to the technical field of additive manufacturing, and the heat treatment method comprises the following steps: carrying out first stress relief annealing treatment on an additive manufacturing high-temperature alloy part; wherein the additive manufacturing high-temperature alloy part is a laser powder laying additive manufacturing high-temperature alloy part; performing post-treatment on the additive manufacturing high-temperature alloy part subjected to the first stress relief annealing treatment so as to separate the additive manufacturing high-temperature alloy part from the substrate; carrying out second stress relief annealing treatment on the post-treated additive manufacturing high-temperature alloy part; performing hot isostatic pressing treatment on the additive manufacturing high-temperature alloy part subjected to the second stress relief annealing treatment so as to reduce the residual stress of the additive manufacturing high-temperature alloy part; and the additive manufacturing high-temperature alloy part subjected to hot isostatic pressing treatment is subjected to solution treatment, a strengthening phase is separated out, and the additive manufacturing high-temperature alloy part subjected to heat treatment is obtained. According to the method, through two-time stress relief annealing treatment, the phenomenon that the additive manufacturing high-temperature alloy cracks due to the fact that the temperature of one-time stress relief annealing is high is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and specifically relates to a heat treatment method for additively manufactured high-temperature alloys and an additively manufactured high-temperature alloy part. Background Art

[0002] Laser additive manufacturing technology is a very convenient and flexible processing and manufacturing method. Compared with traditional material removal-cutting processing technology, it is a "bottom-up" manufacturing method. This technology is very suitable for preparing components with complex structures.

[0003] High-temperature alloys refer to a type of metal material based on iron, nickel, and cobalt that can work for a long time at high temperatures above 600°C and under certain stresses. They have excellent high-temperature strength, good oxidation resistance and thermal corrosion resistance, good fatigue performance, fracture toughness and other comprehensive properties, and are mainly used in the aerospace and energy fields. However, due to the high strength of high-temperature alloys, defects such as internal and external micropores and microcracks are easily generated during the additive manufacturing process, and there are large residual stresses. In order to ensure that the additively manufactured high-temperature alloys have high mechanical properties, they need to be heat treated. However, traditional heat treatment processes are based on casting or forging processes and are not suitable for the control of the microstructure and properties of additively manufactured alloys.

[0004] The existing heat treatment methods for additively manufactured high-temperature alloys are suitable for high-temperature alloys with low high-temperature strength such as GH5188, GH4169 or GH3625. With the increase in engine thrust, additively manufactured high-temperature alloys with a service environment above 800°C have emerged. The existing heat treatment methods are prone to cracking of additively manufactured high-temperature alloys with a service environment above 800°C. Summary of the invention

[0005] Therefore, the present invention provides a heat treatment method for additively manufactured high-temperature alloys and additively manufactured high-temperature alloy parts, which can solve the problem in the prior art that additively manufactured high-temperature alloys easily cause cracking in a service environment above 800°C.

[0006] In order to solve the above problems, the present invention provides a heat treatment method for additively manufacturing a high-temperature alloy, comprising the following steps:

[0007] First stress relief annealing treatment: performing a first stress relief annealing treatment on the additively manufactured high temperature alloy part to obtain the additively manufactured high temperature alloy part after the first stress relief annealing treatment;

[0008] Wherein, the additively manufactured high-temperature alloy part is a laser powder additively manufactured high-temperature alloy part;

[0009] Post-processing: performing post-processing on the additively manufactured high-temperature alloy part after the first stress relief annealing treatment, so as to separate the additively manufactured high-temperature alloy part from the substrate, thereby obtaining the additively manufactured high-temperature alloy part after post-processing;

[0010] Second stress relief annealing treatment: performing a second stress relief annealing treatment on the additively manufactured high temperature alloy part after the post-treatment to obtain the additively manufactured high temperature alloy part after the second stress relief annealing treatment;

[0011] Hot isostatic pressing: performing hot isostatic pressing on the additively manufactured high-temperature alloy part after the second stress relief annealing treatment to reduce the residual stress of the additively manufactured high-temperature alloy part, thereby obtaining the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment;

[0012] Solution treatment: The additively manufactured high-temperature alloy part after the hot isostatic pressing treatment is subjected to solution treatment to precipitate a strengthening phase to obtain the additively manufactured high-temperature alloy part after heat treatment.

[0013] Furthermore, in the step of the first stress relief annealing treatment: the volume fraction of the γ′ phase in the additively manufactured high-temperature alloy part is greater than 50%.

[0014] Further, in the step of the first stress relief annealing treatment:

[0015] In a vacuum furnace, heating the additively manufactured high-temperature alloy part to 530-580° C., keeping the temperature for 9-11 hours, and cooling the part to obtain the additively manufactured high-temperature alloy part after the first stress relief annealing treatment;

[0016] Preferably, the vacuum degree of the vacuum furnace is less than 0.20 Pa;

[0017] Preferably, the heating rate is 2-3°C / min;

[0018] Preferably, the cooling method is furnace cooling; further preferably, the furnace cooling is performed to below 100°C.

[0019] Furthermore, in the post-processing step: using a slow wire cutting method to separate the additively manufactured high-temperature alloy part from the substrate;

[0020] Preferably, the cutting speed is 3-5 mm / min.

[0021] Further, in the step of the second stress relief annealing treatment:

[0022] In a vacuum furnace, heating the additively manufactured high-temperature alloy part after the post-treatment to 580-620° C., keeping the temperature for 9-11 hours, and cooling the part to obtain the additively manufactured high-temperature alloy part after the second stress relief annealing treatment;

[0023] Preferably, the vacuum degree of the vacuum furnace is less than 0.20 Pa;

[0024] Preferably, the heating rate is 1-2°C / min;

[0025] Preferably, the cooling method is furnace cooling; further preferably, the furnace cooling is performed to below 300°C.

[0026] Further, in the step of hot isostatic pressing:

[0027] In a hot isostatic pressing furnace, heating the additively manufactured high-temperature alloy part after the second stress relief annealing treatment to 980-1050° C. and simultaneously increasing the pressure to 100-120 MPa, maintaining the temperature and pressure for 1-2.5 hours, and then cooling to obtain the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment;

[0028] Preferably, the vacuum degree of the hot isostatic pressing furnace before heating is ≤60Pa;

[0029] Preferably, the heating rate is 5-8°C / min;

[0030] Preferably, the cooling method is furnace cooling; further preferably, furnace cooling to below 200°C;

[0031] Preferably, before heating, the process also includes: introducing argon gas to pressurize to 0.5-1.0 MPa, and then exhausting the gas to clean the furnace; further preferably, the furnace is cleaned no less than twice.

[0032] Furthermore, in the step of solution treatment:

[0033] Heating the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment to 1260-1300° C., keeping the temperature for 2-4 hours, and cooling to obtain the additively manufactured high-temperature alloy part after the heat treatment;

[0034] Preferably, the heating rate is 10-20°C / min;

[0035] Preferably, the cooling method is furnace cooling; further preferably, the furnace cooling is performed to below 200°C.

[0036] Furthermore, after the solution treatment step, the method further comprises:

[0037] removing the support portion of the additively manufactured high-temperature alloy part after the solid solution treatment;

[0038] Preferably, the support portion is removed by wire cutting; further preferably, the cutting speed is 6-7 mm / min.

[0039] On the other hand, the present invention provides an additively manufactured high-temperature alloy part, which is an additively manufactured high-temperature alloy part after heat treatment; at room temperature, the additively manufactured high-temperature alloy part has a tensile yield strength of more than 900 MPa and a tensile strength of more than 1300 MPa.

[0040] Furthermore, the additively manufactured high-temperature alloy part is obtained by using any of the heat treatment methods described above.

[0041] Compared with the prior art, the present invention has at least the following beneficial effects:

[0042] 1. On the one hand, the present invention provides a heat treatment method for additively manufactured high-temperature alloys, comprising: performing a first stress relief annealing treatment on the additively manufactured high-temperature alloy part, performing a post-treatment to separate the additively manufactured high-temperature alloy part from a substrate, and then performing a second stress relief annealing treatment, hot isostatic pressing treatment and solid solution treatment in sequence to obtain the additively manufactured high-temperature alloy part after heat treatment; based on the above heat treatment method, it should be noted that the present invention preliminarily reduces the residual stress of the additively manufactured high-temperature alloy part through a first stress relief annealing treatment, removes the substrate through a post-treatment to facilitate subsequent steps, and then performs a more stable second stress relief annealing treatment, and then further reduces the residual stress through hot isostatic pressing treatment, and finally precipitates a strengthening phase through solid solution treatment to improve the strength of the additively manufactured high-temperature alloy; wherein, through two stress relief annealing treatments, it is avoided that the additively manufactured high-temperature alloy cracks due to the high temperature of the first stress relief annealing.

[0043] 2. On the other hand, the present invention provides an additively manufactured high-temperature alloy part, which is an additively manufactured high-temperature alloy part obtained by the above-mentioned heat treatment method. At room temperature, the tensile yield strength of the additively manufactured high-temperature alloy part is above 900 MPa and the tensile strength is above 1300 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0045] Figure 1 It is the organization diagram of the additively manufactured high-temperature alloy in the deposited state (i.e. before heat treatment); where: (a) is the macroscopic organization, (b) is the microscopic dislocation organization;

[0046] Figure 2 is a microstructure diagram of the additively manufactured high-temperature alloy component after heat treatment in Example 1; wherein: (a) is a macroscopic structure, and (b) is a microscopic dislocation structure;

[0047] Figure 3 is a microstructure diagram of the additively manufactured high-temperature alloy component after heat treatment in Example 2; wherein: (a) is a macroscopic structure, and (b) is a microscopic dislocation structure;

[0048] Figure 4 is a microstructure diagram of the additively manufactured high-temperature alloy component after heat treatment in Example 3; wherein: (a) is a macroscopic structure, and (b) is a microscopic dislocation structure;

[0049] Figure 5 is a microstructure diagram of the additively manufactured high temperature alloy part after heat treatment in Comparative Example 1;

[0050] Figure 6 This is the organizational diagram of the additively manufactured high-temperature alloy part after heat treatment in Example 2. DETAILED DESCRIPTION

[0051] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0052] The present invention provides a heat treatment method for additively manufacturing a high-temperature alloy, comprising the following steps:

[0053] First stress relief annealing treatment: performing a first stress relief annealing treatment on the additively manufactured high temperature alloy part to obtain an additively manufactured high temperature alloy part after the first stress relief annealing treatment; wherein the additively manufactured high temperature alloy part is a laser powder additively manufactured high temperature alloy part; and the volume fraction of the γ′ phase in the additively manufactured high temperature alloy part is greater than 50%;

[0054] The specific step is: placing the additively manufactured high-temperature alloy part in a vacuum furnace, evacuating to a vacuum degree of less than 0.20Pa, heating to 530-580°C, keeping warm for 9-11 hours, cooling with the furnace to below 100°C, and obtaining the additively manufactured high-temperature alloy part after the first stress relief annealing treatment; wherein the heating rate is 2-3°C / min.

[0055] Post-processing: performing post-processing on the additively manufactured high-temperature alloy part after the first stress relief annealing treatment, so as to separate the additively manufactured high-temperature alloy part from the substrate, thereby obtaining the additively manufactured high-temperature alloy part after post-processing;

[0056] This step specifically includes: separating the additively manufactured high-temperature alloy part from the substrate by using a slow-wire cutting method; wherein the cutting speed is 3-5 mm / min.

[0057] Second stress relief annealing treatment: performing a second stress relief annealing treatment on the additively manufactured high temperature alloy part after post-treatment to obtain the additively manufactured high temperature alloy part after the second stress relief annealing treatment;

[0058] The specific step is: placing the additively manufactured high-temperature alloy part after post-treatment in a vacuum furnace, evacuating to a vacuum degree of less than 0.20Pa, heating to 580-620°C, keeping warm for 9-11 hours, cooling with the furnace to below 300°C, and obtaining the additively manufactured high-temperature alloy part after the second stress relief annealing treatment; wherein the heating rate is 1-2°C / min.

[0059] Hot isostatic pressing treatment: performing hot isostatic pressing treatment on the additively manufactured high-temperature alloy part after the second stress relief annealing treatment to reduce the residual stress of the additively manufactured high-temperature alloy part, thereby obtaining the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment;

[0060] The specific step is as follows: placing the additively manufactured high-temperature alloy part after the second stress relief annealing treatment in a hot isostatic pressing furnace, evacuating to a vacuum degree of ≤60Pa, pressurizing with argon to 0.5-1.0MPa and then exhausting to clean the furnace, the number of furnace cleaning times is not less than 2 times, and then heating to 980-1050℃ at a rate of 5-8℃ / min, and at the same time increasing the pressure to 100-120MPa, keeping the temperature and pressure for 1-2.5h, naturally cooling to below 200℃ with the furnace, and then taking out of the furnace to obtain the additively manufactured high-temperature alloy part after hot isostatic pressing treatment.

[0061] Solution treatment: The additively manufactured high-temperature alloy parts after hot isostatic pressing are subjected to solution treatment to precipitate strengthening phases to obtain additively manufactured high-temperature alloy parts after heat treatment;

[0062] The specific step is: placing the additively manufactured high-temperature alloy part after hot isostatic pressing treatment in a vacuum furnace, and after vacuuming, heating it to 1260-1300°C at a rate of 10-20°C / min, keeping it warm for 2-4 hours, cooling it to below 200°C with the furnace, and removing the support part by slow wire cutting after taking it out of the furnace to obtain the additively manufactured high-temperature alloy part after heat treatment; wherein, the cutting speed is 6-7mm / min.

[0063] Based on the above method, the present invention preliminarily reduces the residual stress of the additively manufactured high-temperature alloy part through a first stress relief annealing treatment, removes the substrate through post-treatment to facilitate subsequent steps, and then performs a second stress relief annealing treatment with higher stability, and then further reduces the residual stress through hot isostatic pressing treatment, and finally improves the strength of the additively manufactured high-temperature alloy by precipitating a strengthening phase through solid solution treatment; wherein, through two stress relief annealing treatments, cracking of the additively manufactured high-temperature alloy caused by a high temperature of a single stress relief annealing is avoided.

[0064] On the other hand, the present invention provides an additively manufactured high-temperature alloy part, which is an additively manufactured high-temperature alloy part after heat treatment; at room temperature, the tensile yield strength of the additively manufactured high-temperature alloy part is above 900 MPa, and the tensile strength is above 1300 MPa.

[0065] The present invention is further described below with reference to specific embodiments and comparative examples.

[0066] Example 1

[0067] This embodiment provides a heat treatment method for additively manufactured high-temperature alloys, wherein the chemical composition of the additively manufactured high-temperature alloy part before heat treatment is shown in Table 1, wherein the volume fraction of the γ′ phase is greater than 50%;

[0068] Table 1 Chemical composition (wt%) of the additively manufactured nickel-based high-temperature alloy parts in Example 1

[0069] Al Co Cr Mo+Ta+W Ti B C Ni 4.3％ 8.0％ 8％ 15.5％ 1％ 0.015％ 0.01％ margin

[0070] The specific steps include:

[0071] First stress relief annealing treatment: placing the additively manufactured high-temperature alloy part in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 530°C at a rate of 2°C / min, keeping the temperature for 9 hours, and then cooling to below 100°C with the furnace to obtain the additively manufactured high-temperature alloy part after the first stress relief annealing treatment;

[0072] Post-processing: The additively manufactured high-temperature alloy parts are separated from the substrate by wire cutting, where the cutting speed is 3 mm / min.

[0073] Second stress relief annealing treatment: placing the additively manufactured high-temperature alloy part after post-treatment in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 580°C at a rate of 1°C / min, keeping the temperature for 9 hours, and cooling to below 300°C with the furnace to obtain the additively manufactured high-temperature alloy part after the second stress relief annealing treatment;

[0074] Hot isostatic pressing treatment: the additively manufactured high-temperature alloy parts after the second stress relief annealing treatment are cleaned, and then placed in a hot isostatic pressing furnace, evacuated to a vacuum degree of ≤60Pa, pressurized with argon to 0.5MPa and then exhausted to wash the furnace, the number of furnace washing times is not less than 2 times, and then the temperature is raised to 980°C at a rate of 5°C / min, and the pressure is raised to 100MPa at the same time, and the temperature and pressure are maintained for 1h, and the furnace is naturally cooled to below 200°C, and then taken out of the furnace to obtain the additively manufactured high-temperature alloy parts after hot isostatic pressing treatment;

[0075] Solution treatment: The additively manufactured high-temperature alloy parts after hot isostatic pressing are placed in a vacuum furnace. After vacuuming, the temperature is raised to 1270°C at a rate of 10°C / min, kept at this temperature for 3 hours, and cooled to below 200°C with the furnace. After being taken out of the furnace, the support part is removed by wire cutting to obtain the additively manufactured high-temperature alloy parts after heat treatment; the cutting speed is 6mm / min.

[0076] The microstructure of the additively manufactured high-temperature alloy part before heat treatment in this embodiment is as follows Figure 1 As shown in Figure 2, the microstructure of the additively manufactured high-temperature alloy parts after heat treatment is as follows: Figure 2 As shown, it can be seen that no cracks appear in the additively manufactured high-temperature alloy part after heat treatment; at room temperature, the additively manufactured high-temperature alloy part after heat treatment in this embodiment has a tensile yield strength of 995 MPa and a tensile strength of 1450 MPa.

[0077] Example 2

[0078] This embodiment provides a heat treatment method for additively manufactured high-temperature alloys, wherein the chemical composition of the additively manufactured high-temperature alloy part before heat treatment is shown in Table 2, wherein the volume fraction of the γ′ phase is greater than 50%;

[0079] Table 2 Chemical composition of the additively manufactured nickel-based high-temperature alloy parts in Example 2 (wt%)

[0080] Al Co Cr Mo+Ta+W Ti B C Ni 4.0％ 8.0％ 8％ 15％ 0.8％ 0.015％ 0.01％ margin

[0081] The specific steps include:

[0082] First stress relief annealing treatment: placing the additively manufactured high-temperature alloy part in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 580°C at a rate of 3°C / min, keeping the temperature for 11 hours, and then cooling to below 100°C with the furnace to obtain the additively manufactured high-temperature alloy part after the first stress relief annealing treatment;

[0083] Post-processing: The additively manufactured high-temperature alloy part is separated from the substrate by wire cutting, where the cutting speed is 5 mm / min.

[0084] Second stress relief annealing treatment: placing the additively manufactured high-temperature alloy part after post-treatment in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 620°C at 2°C / min, keeping the temperature for 11 hours, and cooling to below 300°C with the furnace to obtain the additively manufactured high-temperature alloy part after the second stress relief annealing treatment;

[0085] Hot isostatic pressing treatment: the additively manufactured high-temperature alloy parts after the second stress relief annealing treatment are cleaned, and then placed in a hot isostatic pressing furnace, evacuated to a vacuum degree of ≤60Pa, and then vented to clean the furnace after filling with argon gas to 1MPa. The number of furnace cleaning times is not less than 2 times, and then the temperature is increased to 1020°C at a rate of 8°C / min, and the pressure is increased to 120MPa at the same time, and the temperature and pressure are maintained for 2.5h. The parts are naturally cooled to below 200°C with the furnace, and then taken out of the furnace to obtain the additively manufactured high-temperature alloy parts after hot isostatic pressing treatment;

[0086] Solution treatment: The additively manufactured high-temperature alloy parts after hot isostatic pressing are placed in a vacuum furnace. After vacuuming, the temperature is raised to 1260°C at a rate of 20°C / min, kept at this temperature for 2 hours, and cooled to below 200°C with the furnace. After being taken out of the furnace, the support part is removed by wire cutting to obtain the additively manufactured high-temperature alloy parts after heat treatment; the cutting speed is 7mm / min.

[0087] The microstructure of the additively manufactured high-temperature alloy part obtained after heat treatment in this embodiment is as follows: Figure 3 As shown, it can be seen that no cracks appear in the additively manufactured high-temperature alloy part after heat treatment; at room temperature, the additively manufactured high-temperature alloy part of this embodiment after heat treatment has a tensile yield strength of 939 MPa and a tensile strength of 1363 MPa.

[0088] Example 3

[0089] This embodiment provides a heat treatment method for additively manufactured high-temperature alloys, wherein the chemical composition of the additively manufactured high-temperature alloy part before heat treatment is shown in Table 3, wherein the volume fraction of the γ′ phase is greater than 50%;

[0090] Table 3 Chemical composition (wt%) of the additively manufactured nickel-based high-temperature alloy parts in Example 3

[0091] Al Co Cr Mo+Ta+W Ti B C Ni 4.5％ 8.0％ 10％ 18％ 0.5％ 0.015％ 0.01％ margin

[0092] The specific steps include:

[0093] First stress relief annealing treatment: placing the additively manufactured high-temperature alloy part in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 550°C at a rate of 2.5°C / min, keeping the temperature for 10 hours, and then cooling to below 100°C with the furnace to obtain the additively manufactured high-temperature alloy part after the first stress relief annealing treatment;

[0094] Post-processing: The additively manufactured high-temperature alloy parts are separated from the substrate by wire cutting, where the cutting speed is 4 mm / min.

[0095] Second stress relief annealing treatment: placing the additively manufactured high-temperature alloy part after post-treatment in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 600°C at a rate of 1.5°C / min, keeping the temperature for 10 hours, and cooling to below 300°C with the furnace to obtain the additively manufactured high-temperature alloy part after the second stress relief annealing treatment;

[0096] Hot isostatic pressing treatment: the additively manufactured high-temperature alloy parts after the second stress relief annealing treatment are cleaned, and then placed in a hot isostatic pressing furnace, evacuated to a vacuum degree of ≤60Pa, pressurized with argon to 0.8MPa and then exhausted to wash the furnace, the number of furnace washing times is not less than 2 times, and then the temperature is raised to 1050°C at a rate of 6°C / min, and the pressure is raised to 120MPa at the same time, and the temperature and pressure are maintained for 2h, and the furnace is naturally cooled to below 200°C, and then taken out of the furnace to obtain the additively manufactured high-temperature alloy parts after hot isostatic pressing treatment;

[0097] Solution treatment: The additively manufactured high-temperature alloy parts after hot isostatic pressing are placed in a vacuum furnace. After vacuuming, the temperature is raised to 1300°C at a rate of 15°C / min, kept warm for 4 hours, and cooled to below 200°C with the furnace. After being taken out of the furnace, the support part is removed by wire cutting to obtain the additively manufactured high-temperature alloy parts after heat treatment; the cutting speed is 7mm / min.

[0098] The microstructure of the additively manufactured high-temperature alloy part obtained after heat treatment in this embodiment is as follows: Figure 4 As shown, it can be seen that no cracks appear in the additively manufactured high-temperature alloy part after heat treatment; at room temperature, the additively manufactured high-temperature alloy part after heat treatment in this embodiment has a tensile yield strength of 938 MPa and a tensile strength of 1480 MPa.

[0099] Comparative Example 1

[0100] This comparative example provides a heat treatment method for additively manufactured high-temperature alloys, wherein the additively manufactured high-temperature alloy part before heat treatment is the same as that in Example 1;

[0101] The specific steps include:

[0102] Stress relief annealing: Place the additively manufactured high-temperature alloy parts into a vacuum heat treatment furnace, heat them up with the furnace, keep them at 900°C for 2 hours, fill them with 1500mbar argon gas, cool them to room temperature, and then take them out of the furnace;

[0103] Post-processing: Remove the additively manufactured high-temperature alloy parts from the substrate by wire cutting or sawing, remove supports and perform surface sandblasting;

[0104] Heat treatment: The post-processed additively manufactured high-temperature alloy parts are placed in a vacuum heat treatment furnace, heated up with the furnace, kept at 1100°C for 2 hours, filled with 1500mbar argon gas, cooled to room temperature and then taken out of the furnace.

[0105] Hot isostatic pressing: Place the additively manufactured high-temperature alloy parts after heat treatment into the hot isostatic pressing equipment. After the equipment is evacuated and the argon gas is transported, gas pressurization and heating of the parts are started. The process requirements are: temperature 1200℃, pressure 150MPa, insulation and pressure holding time 3h. After the insulation and pressure holding are completed, natural cooling is carried out. When the temperature in the furnace is not higher than 500℃ and the pressure is not higher than 80MPa, high-pressure argon recovery is started. When the pressure in the furnace drops to 40MPa, high-pressure recovery is stopped, and the temperature drops to 200℃ with the furnace, and pressure relief is started until the pressure in the furnace is 0.

[0106] The microstructure of the additively manufactured high-temperature alloy component obtained in this comparative example after heat treatment is as follows: Figure 5 As shown, it can be seen that a large number of coarse cracks are formed inside the additively manufactured alloy part (sample) after heat treatment, and subsequent mechanical properties testing cannot be carried out.

[0107] Comparative Example 2

[0108] This comparative example provides a heat treatment method for additively manufactured high-temperature alloys, wherein the additively manufactured high-temperature alloy part before heat treatment is the same as that in Example 1;

[0109] The specific steps include:

[0110] First stress relief annealing treatment: placing the additively manufactured high-temperature alloy part in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 600°C at 2°C / min, keeping the temperature for 9 hours, and then cooling to below 100°C with the furnace to obtain the additively manufactured high-temperature alloy part after the first stress relief annealing treatment;

[0111] Post-processing: The additively manufactured high-temperature alloy parts are separated from the substrate by wire cutting, where the cutting speed is 3 mm / min.

[0112] Second stress relief annealing treatment: placing the additively manufactured high-temperature alloy part after post-treatment in a vacuum furnace, evacuating to a vacuum degree of <0.20 Pa, heating to 850°C at a rate of 1°C / min, keeping the temperature for 6 hours, and cooling to below 300°C with the furnace to obtain the additively manufactured high-temperature alloy part after the second stress relief annealing treatment;

[0113] Hot isostatic pressing treatment: the additively manufactured high-temperature alloy parts after the second stress relief annealing treatment are cleaned, and then placed in a hot isostatic pressing furnace, evacuated to a vacuum degree of ≤60Pa, pressurized with argon to 0.5MPa and then exhausted to wash the furnace, the number of furnace washing times is not less than 2 times, and then the temperature is increased to 1100°C at a rate of 5°C / min, and the pressure is increased to 100MPa at the same time, and the temperature and pressure are maintained for 1h, and the furnace is naturally cooled to below 200°C, and then taken out of the furnace to obtain the additively manufactured high-temperature alloy parts after heat treatment;

[0114] The microstructure of the heat-treated additively manufactured high-temperature alloy parts obtained in this comparative example is as follows: Figure 6 As shown, it can be seen that a large number of microcracks are formed inside the sample. The formation of these cracks results in the yield strength of the additively manufactured high-temperature alloy being only 750MPa and the tensile strength being 820MPa under room temperature tensile conditions, which cannot meet the use requirements.

[0115] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A heat treatment method for additively manufacturing a high-temperature alloy, characterized in that: The following steps are involved: First stress relief annealing treatment: performing a first stress relief annealing treatment on the additively manufactured high temperature alloy part to obtain the additively manufactured high temperature alloy part after the first stress relief annealing treatment; Wherein, the additively manufactured high-temperature alloy part is a laser powder additively manufactured high-temperature alloy part; Post-processing: performing post-processing on the additively manufactured high-temperature alloy part after the first stress relief annealing treatment, so as to separate the additively manufactured high-temperature alloy part from the substrate, thereby obtaining the additively manufactured high-temperature alloy part after post-processing; Second stress relief annealing treatment: performing a second stress relief annealing treatment on the additively manufactured high temperature alloy part after the post-treatment to obtain the additively manufactured high temperature alloy part after the second stress relief annealing treatment; Hot isostatic pressing: performing hot isostatic pressing on the additively manufactured high-temperature alloy part after the second stress relief annealing treatment to reduce the residual stress of the additively manufactured high-temperature alloy part, thereby obtaining the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment; Solution treatment: The additively manufactured high-temperature alloy part after the hot isostatic pressing treatment is subjected to solution treatment to precipitate a strengthening phase to obtain the additively manufactured high-temperature alloy part after heat treatment.

2. The heat treatment method for additively manufactured high-temperature alloy according to claim 1, characterized in that: In the step of the first stress relief annealing treatment: the volume fraction of the γ′ phase in the additively manufactured high-temperature alloy part is greater than 50%.

3. The heat treatment method for additively manufactured high-temperature alloy according to claim 1, characterized in that: In the step of the first stress relief annealing treatment: In a vacuum furnace, heating the additively manufactured high-temperature alloy part to 530-580° C., keeping the temperature for 9-11 hours, and cooling the part to obtain the additively manufactured high-temperature alloy part after the first stress relief annealing treatment; Preferably, the vacuum degree of the vacuum furnace is less than 0.20 Pa; Preferably, the heating rate is 2-3°C / min; Preferably, the cooling method is furnace cooling; further preferably, the furnace cooling is performed to below 100°C.

4. The heat treatment method for additively manufactured high-temperature alloy according to claim 1, characterized in that: In the post-processing step: using a slow wire cutting method to separate the additively manufactured high-temperature alloy part from the substrate; Preferably, the cutting speed is 3-5 mm / min.

5. The heat treatment method for additively manufactured high-temperature alloy according to claim 1, characterized in that: In the step of the second stress relief annealing treatment: In a vacuum furnace, heating the additively manufactured high-temperature alloy part after the post-treatment to 580-620° C., keeping the temperature for 9-11 hours, and cooling the part to obtain the additively manufactured high-temperature alloy part after the second stress relief annealing treatment; Preferably, the vacuum degree of the vacuum furnace is less than 0.20 Pa; Preferably, the heating rate is 1-2°C / min; Preferably, the cooling method is furnace cooling; further preferably, the furnace cooling is performed to below 300°C.

6. The heat treatment method for additively manufactured high-temperature alloy according to claim 1, characterized in that: In the step of hot isostatic pressing: In a hot isostatic pressing furnace, heating the additively manufactured high-temperature alloy part after the second stress relief annealing treatment to 980-1050° C. and simultaneously increasing the pressure to 100-120 MPa, maintaining the temperature and pressure for 1-2.5 hours, and then cooling to obtain the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment; Preferably, the vacuum degree of the hot isostatic pressing furnace before heating is ≤60Pa; Preferably, the heating rate is 5-8°C / min; Preferably, the cooling method is furnace cooling; further preferably, furnace cooling to below 200°C; Preferably, before heating, the process also includes: introducing argon gas to pressurize to 0.5-1.0 MPa, and then exhausting the gas to clean the furnace; further preferably, the furnace is cleaned no less than twice.

7. The heat treatment method for additively manufactured high-temperature alloy according to claim 1, characterized in that: In the step of solution treatment: Heating the additively manufactured high-temperature alloy part after the hot isostatic pressing treatment to 1260-1300° C., keeping the temperature for 2-4 hours, and cooling to obtain the additively manufactured high-temperature alloy part after the heat treatment; Preferably, the heating rate is 10-20°C / min; Preferably, the cooling method is furnace cooling; further preferably, the furnace cooling is performed to below 200°C.

8. The heat treatment method for additively manufactured high-temperature alloy according to any one of claims 1 to 7, characterized in that: After the solution treatment step, the method further comprises: removing the support portion of the additively manufactured high-temperature alloy part after the solid solution treatment; Preferably, the support portion is removed by wire cutting; further preferably, the cutting speed is 6-7 mm / min.

9. An additively manufactured high-temperature alloy part, characterized in that: The additively manufactured high-temperature alloy part is an additively manufactured high-temperature alloy part after heat treatment; at room temperature, the tensile yield strength of the additively manufactured high-temperature alloy part is above 900 MPa, and the tensile strength is above 1300 MPa.

10. The additively manufactured high temperature alloy part according to claim 9, characterized in that: The additively manufactured high-temperature alloy part is obtained by the heat treatment method described in any one of claims 1 to 8.

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