Preparation method and application of a superalloy part with a complex structure that is easy to detect flaws

Abstract

The present invention belongs to the technical field of powder metallurgy, and relates to a preparation method and application of a high-temperature alloy component with a complex structure that is easy to detect flaws. Coarse powder and fine powder are mixed as raw materials, and the mixed powder is pre-pressed by cold isostatic pressing to obtain a formed ingot blank. The formed ingot blank is placed in a steel jacket, and low-carbon steel powder is used to fill the voids in the steel jacket. After degassing and sealing welding treatment of the entire steel jacket, a component with a steel jacket is obtained by hot isostatic pressing. After heat treatment and machining treatment, a component with a steel jacket is obtained. After ultrasonic flaw detection of the component with a steel jacket, the target high-temperature alloy component is obtained through pickling and sandblasting treatment. The high-temperature alloy component prepared by the present invention has a high degree of tissue densification and good grain uniformity; through the preparation method of the present invention, the flaw detection difficulty of high-temperature alloy components with complex structures can be significantly reduced, the accuracy of flaw detection can be improved, and the problem of difficult machining of high-temperature alloy components can be effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of powder metallurgy, and relates to a preparation method and application of a complex structure high-temperature alloy part that is easy to detect flaws. Background Art

[0002] Complex structure high-performance components for aeroengines are usually made of nickel-based high-temperature alloys, and common processing methods include casting, forging, etc. Components made by traditional precision casting generally have poor metallurgical quality, uneven structure, and low mechanical properties. For components with complex shapes, deformation is likely to occur, and it is difficult to control dimensions. The forging method is difficult to achieve the overall forming of complex structure parts, and the cost of making dies is high, making it difficult to meet application requirements. Hot isostatic pressing technology has become an emerging technology for manufacturing important components for engines due to its many advantages such as high material utilization rate, uniform structure of formed parts, and the ability to directly form complex structure parts.

[0003] However, when using hot isostatic pressing, medium-sized powders with a particle size of 53μm - 150μm are usually used as raw materials, which results in the unusability of fine powders and coarse powders produced by the powder-making process, and the production cost of parts is relatively high. At the same time, due to the great difficulty and high cost of processing complex structure metal jackets, the manufacturing cost of parts is further increased. In addition, after the high-temperature alloy parts for aeroengines are manufactured, they usually need to be subjected to ultrasonic immersion flaw detection before delivery to ensure that there are no large-sized inclusions inside the parts. For irregular components with complex shapes, the flaw detection is relatively difficult, mainly manifested as follows:

[0004] (1) During the flaw detection process, it is difficult to accurately control the distance and angle between the probe and the workpiece surface, and it is impossible to ensure that the probe can reach all positions of the workpiece accurately, which greatly increases the difficulty and cost of flaw detection; (2) It is impossible to accurately locate and evaluate internal defects of complex components, which makes it difficult to guarantee the accuracy and precision of detection. In addition, although the hot isostatic pressing technology can achieve the overall forming of complex components, due to the existence of a blind zone of about 3mm in ultrasonic immersion flaw detection, after flaw detection, the parts need to be further machined to remove the blind zone on the surface of the parts, and the machining difficulty is also great, making it difficult to guarantee the final forming accuracy of the parts.

[0005] In view of this, this invention is specifically proposed. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and propose a preparation method and application of a complex structure high-temperature alloy part that is easy to detect flaws, so as to solve the problems of high manufacturing cost, low material utilization rate, great difficulty in ultrasonic flaw detection, and poor forming accuracy of complex structure high-temperature alloy parts for current aeroengines.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] On the one hand, the present invention provides a preparation method for a high-temperature alloy part with a complex structure that is easy to detect flaws, comprising the following steps:

[0009] Step 1: Weigh high-temperature alloy powders with particle size ranges of 15μm - 53μm and 150μm - 212μm according to a set ratio, and then put them into a mixing device for mixing treatment to obtain mixed powders;

[0010] Step 2: Load the mixed powders obtained in Step 1 into a prefabricated rubber sheath. First, perform vacuum plastic sealing on the rubber sheath, and then perform cold isostatic pressing treatment on the entire rubber sheath to obtain a formed ingot blank;

[0011] Step 3: Assemble the formed ingot blank obtained in Step 2 into a prefabricated steel sheath. First, fill low-carbon steel powders in the gap between the steel sheath and the formed ingot blank. Then, after performing degassing and sealing welding treatment on the entire steel sheath, perform hot isostatic pressing treatment to obtain a part with a steel sheath;

[0012] Step 4: Perform heat treatment on the part with a steel sheath obtained in Step 3;

[0013] Step 5: Perform machining on the part with a steel sheath after heat treatment in Step 4 to remove the outer surface oxide layer, and retain at least 3mm of the steel layer to obtain a steel part with a surface roughness Ra ≤ 1.6μm;

[0014] Step 6: Perform flaw detection on the steel part obtained in Step 5;

[0015] Step 7: Perform pickling on the steel part after flaw detection in Step 6. After removing the steel layer on the outer surface of the steel part, perform sandblasting treatment to obtain the target high-temperature alloy part.

[0016] Further, in Step 1, high-temperature alloy powders with particle size ranges of 15μm - 53μm and 150μm - 212μm are weighed according to a mass ratio of 2 - 4:1 - 2 and put into a mixer. When mixing, the rotation speed of the mixer is set to 60r / min - 150r / min, and the mixing time is set to 20min - 60min.

[0017] Further, in Step 2, the rubber sheath is designed according to the specifications of the target high-temperature alloy part. After the mixed powders are first loaded into the rubber sheath and tamped, vacuum plastic sealing is performed. The density of the tamped mixed powders is ≥ 35%.

[0018] Further, in Step 2, the cold isostatic pressing treatment includes the following two stages:

[0019] The first stage: The pressure increase rate is set to 8 MPa / min to 10 MPa / min, the final pressure of pressure increase is set to 130 MPa to 160 MPa, and the pressure holding time is set to 8 min to 20 min;

[0020] The second stage: The pressure increase rate is set to 3 MPa / min to 6 MPa / min, the final pressure of pressure increase is set to 180 MPa to 220 MPa, and the pressure holding time is set to 25 min to 60 min.

[0021] Further, in step 3, the formed ingot blank and the steel ladle sleeve are in clearance fit, the clearance fit ≥ 3 mm, the material of the steel ladle sleeve is 20 steel or 45 steel, and the wall thickness is 4 mm to 6 mm;

[0022] The specific process of placing the formed ingot blank into the steel ladle sleeve for assembly is as follows: First, the bottom plate and the outer ring of the steel ladle sleeve are welded by argon arc welding. After loading low-carbon steel powder with a layer thickness of 3 mm to 4 mm at the bottom of the steel ladle sleeve and vibrating it solid, then, the formed ingot blank is placed in the steel ladle sleeve to ensure that the center of the formed ingot blank is consistent with the center of the steel ladle sleeve. The top plate and the nozzle of the steel ladle sleeve are welded by argon arc welding. The gap between the steel ladle sleeve and the formed ingot blank is filled with low-carbon steel powder and vibrated solid. The density of the low-carbon steel powder after vibration ≥ 68%, and finally, the degassing pipe is welded;

[0023] The low-carbon steel powder is 20 steel powder or 45 steel powder, and the particle size range is 150 μm to 212 μm.

[0024] Further, in step 3, the heating temperature of the degassing seal welding treatment is 400 °C to 480 °C, the heat preservation time is 2 h to 6 h, and the vacuum degree in the whole steel ladle sleeve after the degassing seal welding treatment is 1.0x10 -4 Pa to 1.0x10 -3 Pa. After the degassing seal welding treatment is completed, the degassing pipe is clamped and sealed by welding.

[0025] Further, in step 3, the temperature of the hot isostatic pressing treatment is 1180 °C to 1240 °C, the pressure is 130 MPa to 170 MPa, the pressure holding time is 2 h to 4 h, and after the hot isostatic pressing treatment is completed, it is cooled with the furnace. The density of the strip steel ladle sleeve part after the hot isostatic pressing treatment ≥ 99.8%.

[0026] Further, in step 4, the heat treatment system is as follows: The solution temperature is 980 °C to 1250 °C, the heat preservation time is 1 h to 2 h, and the cooling method is air cooling; The aging temperature is 700 °C to 870 °C, the heat preservation time is 4 h to 20 h, and the cooling method is air cooling.

[0027] Further, in step 6, the detection frequency of the flaw detection is 8 MHz to 12 MHz.

[0028] On the other hand, the present invention also provides an application of a preparation method for a superalloy workpiece with a complex structure that is easy to detect flaws, which is applied to the preparation of GH4099 alloy workpieces, GH4169 alloy workpieces or MAR M247 alloy workpieces.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention selects a mixed powder of coarse powder (particle size range: 150 μm - 212 μm) and fine powder (particle size range: 15 μm - 53 μm) prepared by the plasma rotating electrode method as the raw material, which can achieve the purpose of reducing raw material costs and clearing inventory; at the same time, the use of a mixture of coarse and fine powders can effectively fill the gaps between particles and promote the close packing of powders, thereby improving the density of the material after hot isostatic pressing; in addition, by setting an appropriate ratio of coarse powder to fine powder, the organizational structure can be significantly optimized to obtain an excellent structure with uniform and fine grains.

[0031] (2) The present invention uses cold isostatic pressing to pre-press the mixed powder, which can cause the powder particles to rearrange, break and form strong mechanical meshing, which is beneficial to improving the density, forming quality and mechanical properties of the workpiece after hot isostatic pressing; at the same time, due to the uniform and fine grain structure of the superalloy prepared by the present invention, it is not easy to generate clutter during ultrasonic flaw detection, which can significantly improve the accuracy of detection.

[0032] (3) In the present invention, only a steel ladle sleeve with clearance fit needs to be designed according to the size of the formed ingot blank, and there is no need to prepare a metal sleeve with a complex shape, which can reduce the difficulty and cost of sleeve production; in addition, by adding low-carbon steel powder, the complex shape is converted into a simple cylindrical shape, which greatly reduces the flaw detection difficulty of the workpiece and can significantly improve the material utilization rate of the formed workpiece.

[0033] (4) The workpiece prepared by the present invention can directly obtain a superalloy workpiece with a complex structure with high surface quality and near-net shape only through pickling and sandblasting after ultrasonic flaw detection, effectively solving the problem of difficult machining of superalloy workpieces. Description of the Drawings

[0034] The drawings here are incorporated into the specification and form a part of this specification, and are used together with the specification to explain the principles of the present invention.

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0036] Figure 1 Flow chart of the preparation method of a superalloy workpiece with a complex structure that is easy to detect flaws provided by the present invention;

[0037] Figure 2 Metallographic structure diagram of the GH4169 alloy workpiece prepared by using Example 1 of the present invention;

[0038] Figure 3 Metallographic structure diagram of the MAR M247 alloy workpiece prepared by using Example 2 of the present invention;

[0039] Figure 4 Metallographic structure diagram of the GH4099 alloy workpiece prepared by using Example 3 of the present invention. Detailed implementation manners

[0040] Here, the exemplary embodiments will be described in detail. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present invention. On the contrary, they are only examples consistent with some aspects of the present invention detailed in the appended claims.

[0041] The present invention provides a preparation method of a superalloy workpiece with a complex structure that is easy to detect flaws. As Figure 1 shown, it includes the following steps:

[0042] Step 1: After weighing spherical superalloy powders with particle size ranges of 15 μm to 53 μm and 150 μm to 212 μm according to a mass ratio of 2 to 4:1 to 2, put them into a mixer for mixing treatment to obtain mixed powders. When mixing, the rotation speed of the mixer is set to 60 r / min to 150 r / min, and the mixing time is set to 20 min to 60 min.

[0043] Step 2: Design a rubber sheath according to the shape and size of the target superalloy workpiece. After packing the mixed powders obtained in Step 1 into the rubber sheath and vibrating them to compactness, perform vacuum plastic sealing. The compactness of the mixed powders after vibration is ≥ 35%. Then, perform cold isostatic pressing treatment on the entire rubber sheath to obtain a formed ingot blank.

[0044] Specifically, the cold isostatic pressing treatment includes the following two stages:

[0045] The first stage: The pressure increase rate is set to 8 MPa / min to 10 MPa / min, the final pressure increase point pressure is set to 130 MPa to 160 MPa, and the pressure holding time is set to 8 min to 20 min;

[0046] The second stage: The pressure increase rate is set to 3 MPa / min to 6 MPa / min, the final pressure increase point pressure is set to 180 MPa to 220 MPa, and the pressure holding time is set to 25 min to 60 min.

[0047] Step 3: First, design a 20# steel or 45# steel jacket with a wall thickness of 4 mm to 6 mm and a clearance of not less than 3 mm in each direction of the characteristic dimensions of the formed ingot blank. Then, place the formed ingot blank obtained in Step 2 into the prefabricated steel jacket for assembly, fill the gap between the formed ingot blank and the steel jacket with low-carbon steel powder, perform degassing and sealing welding on the entire steel jacket, and finally, perform hot isostatic pressing on the steel jacket to obtain a steel jacketed part.

[0048] Specifically, the specific process of placing the formed ingot blank into the steel jacket for assembly is as follows: First, weld the bottom plate and the outer ring of the steel jacket by argon arc welding. After filling 3 mm to 4 mm thick low-carbon steel powder at the bottom of the steel jacket and vibrating it solid, then place the formed ingot blank in the steel jacket to ensure that the center of the formed ingot blank coincides with the center of the steel jacket. Weld the top plate and the jacket nozzle of the steel jacket by argon arc welding, fill the internal gap of the steel jacket with low-carbon steel powder and vibrate it solid. The density of the vibrated low-carbon steel powder is ≥68%. Finally, weld the degassing pipe. A round hole with a diameter of 20 mm is left at the top plate of the jacket for welding the powder filling jacket nozzle and the degassing pipe. The low-carbon steel powder is 20# steel powder or 45# steel powder, and the particle size range is 150 μm to 212 μm.

[0049] Specifically, the heating temperature for degassing and sealing welding is 400°C to 480°C, the holding time is 2 h to 6 h, and the vacuum degree in the entire steel jacket after degassing and sealing welding is 1.0x10 -4 Pa to 1.0x10 -3 Pa. After the degassing and sealing welding is completed, the degassing pipe is sealed by crimping and welding twice.

[0050] Specifically, the temperature for hot isostatic pressing is 1180°C to 1240°C, the pressure is 130 MPa to 170 MPa, the holding time is 2 h to 4 h, and it is cooled in the furnace after the hot isostatic pressing is completed. The density of the steel jacketed part after hot isostatic pressing is ≥99.8%, and the shape of the steel jacketed part is cylindrical.

[0051] Step 4: Heat-treat the steel jacketed part obtained in Step 3. Among them, the solution temperature is 980°C to 1250°C, the holding time is 1 h to 2 h, and the cooling method is air cooling; the aging temperature is 700°C to 870°C, the holding time is 4 h to 20 h, and the cooling method is air cooling.

[0052] Step 5: Machine-process the heat-treated steel jacketed part obtained in Step 4 to remove the outer surface oxide layer and retain at least 3 mm of steel layer to obtain a steel part with a surface roughness Ra ≤ 1.6 μm.

[0053] Step 6: Perform flaw detection on the steel-bonded workpiece obtained in Step 5, preferably ultrasonic immersion flaw detection, where the flaw detection frequency is 8 MHz to 12 MHz.

[0054] Step 7: Pickle the steel-bonded workpiece after flaw detection in Step 6. After removing the steel layer on the outer surface of the steel-bonded workpiece, perform sandblasting to obtain the target superalloy workpiece.

[0055] Specifically, when pickling the steel-bonded workpiece, the volume ratio of HF, HNO3, and H2O in the pickling solution is 1:3:6.

[0056] According to the embodiments of the present invention, the preparation method of the present invention is used to prepare superalloy workpieces with various complex structures.

[0057] In order to verify the beneficial effects brought by the preparation method of the present invention, it is further illustrated through the following examples. Example 1

[0058] This example provides a preparation method for a complex-structure GH4169 superalloy workpiece that is easy to detect flaws, specifically including the following steps:

[0059] Step 1: Weigh spherical superalloy powders with particle size ranges of 15μm to 53μm and 150μm to 212μm in a mass ratio of 2:1, and then put them into a mixer for mixing to obtain mixed powders. When mixing, the rotation speed of the mixer is set to 60r / min, and the mixing time is set to 60min.

[0060] Step 2: Design a rubber sleeve according to the shape and size of the final superalloy workpiece. After filling the mixed powders obtained in Step 1 into the sleeve and tamping them, perform vacuum plastic sealing. The density of the tamped mixed powders is ≥35%, and then perform cold isostatic pressing on the entire rubber sleeve. After demolding, obtain a formed ingot blank.

[0061] Specifically, the cold isostatic pressing process includes the following two stages:

[0062] The first stage: The pressure increase rate is set to 8MPa / min, the final pressure increase point is set to 130MPa, and the pressure holding time is set to 20min;

[0063] The second stage: The pressure increase rate is set to 3MPa / min, the final pressure increase point is set to 180MPa, and the pressure holding time is set to 25min.

[0064] Step 3: Design a 20 steel jacket with a wall thickness of 4 mm and a clearance of not less than 3 mm in each direction from the characteristic dimensions of the formed ingot blank. Place the formed ingot blank obtained in Step 2 into the steel jacket for assembly, and fill the voids with low-carbon steel powder. Then, after degassing and sealing welding the entire steel jacket, perform hot isostatic pressing to obtain a steel jacketed part.

[0065] Specifically, the specific process of placing the formed ingot blank into the steel jacket for assembly is as follows: First, weld the bottom plate and the outer ring of the steel jacket by argon arc welding. After loading low-carbon steel powder with a layer thickness of 3 mm to 4 mm at the bottom of the steel jacket and vibrating it compactly, then place the formed ingot blank in the steel jacket, ensuring that the center of the formed ingot blank coincides with the center of the steel jacket. Weld the top plate and the jacket nozzle of the steel jacket by argon arc welding, fill the internal voids of the steel jacket with low-carbon steel powder and vibrate it compactly. The density of the vibrated low-carbon steel powder is ≥68%. Finally, weld the degassing pipe. A round hole with a diameter of 20 mm is left at the jacket top plate for welding the powder-loading jacket nozzle and the degassing pipe. The low-carbon steel powder is 20 steel powder with a particle size range of 150 μm to 212 μm.

[0066] Specifically, the heating temperature for degassing and sealing welding is 400 °C, the holding time is 6 h, and the vacuum degree inside the entire steel jacket after degassing and sealing welding is 5.1x10 -4 Pa. After the degassing and sealing welding is completed, the degassing pipe is clamped and sealed welded twice.

[0067] Specifically, the temperature for hot isostatic pressing is 1180 °C, the pressure is 170 MPa, the holding time is 3 h, and after the hot isostatic pressing is completed, it is cooled with the furnace.

[0068] Step 4: Heat-treat the steel jacketed part obtained in Step 3. Among them, the solution treatment temperature is 980 °C, the holding time is 2 h, and the cooling method is air cooling; the aging temperature is 700 °C, the holding time is 10 h, and the cooling method is air cooling.

[0069] Step 5: Machine-process the heat-treated steel jacketed part obtained in Step 4 to remove the outer surface oxide layer and retain at least 3 mm of steel layer to obtain a cylindrical steel part with a surface roughness Ra ≤ 1.6 μm.

[0070] Step 6: Perform ultrasonic immersion flaw detection on the steel part obtained in Step 5. Among them, the detection frequency is 8 MHz.

[0071] Step 7: Pickle the steel part after flaw detection in Step 6 to remove the steel layer on the outer surface of the steel part. Among them, the volume ratio of HF, HNO3, and H2O in the pickling solution is 1:3:6. After sandblasting, a GH4169 superalloy part with a complex structure is obtained. Its metallographic structure is as Figure 2 shown. Example 2

[0072] This example provides a preparation method for a complex - structure MAR M247 superalloy part that is easy to detect flaws, specifically including the following steps:

[0073] Step 1: After weighing superalloy spherical powders with particle size ranges of 15μm - 53μm and 150μm - 212μm according to a mass ratio of 2:1, put them into a mixer for mixing treatment to obtain mixed powders. When mixing, the rotation speed of the mixer is set to 90r / min, and the mixing time is set to 40min.

[0074] Step 2: Design a rubber sheath according to the shape and size of the finally formed superalloy part. After filling the mixed powders obtained in Step 1 into the rubber sheath and tamping them, conduct vacuum plastic sealing. The apparent density of the tamped mixed powders is ≥35%, and then perform cold isostatic pressing on the entire rubber sheath to obtain a formed ingot blank.

[0075] Specifically, the cold isostatic pressing treatment includes the following two stages:

[0076] The first stage: The pressure - increasing rate is set to 9MPa / min, the final pressure of pressure - increasing is set to 145MPa, and the pressure - holding time is set to 12min;

[0077] The second stage: The pressure - increasing rate is set to 5MPa / min, the final pressure of pressure - increasing is set to 200MPa, and the pressure - holding time is set to 40min.

[0078] Step 3: Design a 45 - steel sheath with a wall thickness of 5mm and a clearance of not less than 3mm in each direction matching the characteristic size of the formed ingot blank according to the size of the formed ingot blank. Put the formed ingot blank obtained in Step 2 into the steel sheath for assembly, and fill low - carbon steel powders in the voids. Then, conduct degassing and sealing - welding treatment on the entire steel sheath and perform hot isostatic pressing treatment to obtain a part with a steel sheath.

[0079] Specifically, the specific process of putting the formed ingot blank into the steel sheath for assembly is as follows: First, weld the bottom plate and the outer ring of the steel sheath by argon arc welding. After loading low - carbon steel powders with a layer thickness of 3mm - 4mm at the bottom of the steel sheath and tamping them, then place the formed ingot blank in the steel sheath to ensure that the center of the formed ingot blank coincides with the center of the steel sheath. Weld the top plate and the sheath nozzle of the steel sheath by argon arc welding, fill the internal voids of the steel sheath with low - carbon steel powders and tamp them. The apparent density of the tamped low - carbon steel powders is ≥68%. Finally, weld the degassing pipe. A circular hole with a diameter of 20mm is left at the top plate of the sheath for welding the sheath nozzle and the degassing pipe for powder loading. The low - carbon steel powders are 45 - steel powders with a particle size range of 150μm - 212μm.

[0080] Specifically, the heating temperature for the degassing and sealing welding treatment is 440 °C, the heat preservation time is 4 h, and the vacuum degree inside the entire ladle sleeve after the degassing and sealing welding treatment is 3.7x10 -4 Pa. After the degassing and sealing welding treatment is completed, the degassing pipe is subjected to two clamping and sealing weldings.

[0081] Specifically, the temperature for the hot isostatic pressing treatment is 1200 °C, the pressure is 150 MPa, the pressure holding time is 4 h, and after the hot isostatic pressing treatment is completed, it is cooled with the furnace.

[0082] Step 4: Heat-treat the steel sleeve parts obtained in Step 3. Among them, the solution temperature is 1250 °C, the heat preservation time is 1.5 h, and the cooling method is air cooling; the aging temperature is 870 °C, the heat preservation time is 20 h, and the cooling method is air cooling.

[0083] Step 5: Machine-process the heat-treated steel sleeve parts obtained in Step 4 to remove the outer surface oxide layer, and retain at least 3 mm of the steel layer to obtain a cylindrical steel part with a surface roughness Ra ≤ 1.6 μm.

[0084] Step 6: Perform ultrasonic immersion flaw detection on the steel parts obtained in Step 5. Among them, the detection frequency is 10 MHz.

[0085] Step 7: Pickle the steel parts after flaw detection in Step 6 to remove the steel layer on the outer surface of the steel parts. Among them, the volume ratio of HF, HNO3, and H2O in the pickling solution is 1:3:6, and a MAR M247 superalloy part with a complex structure is obtained through sandblasting treatment. Its metallographic structure is as Figure 3 shown. Example 3

[0086] This example provides a preparation method for a complex structure GH4099 superalloy part that is easy to detect flaws, specifically including the following steps:

[0087] Step 1: After weighing spherical superalloy powders with particle size ranges of 15 μm to 53 μm and 150 μm to 212 μm according to a mass ratio of 2:1, put them into a mixer for mixing treatment to obtain mixed powders. When mixing, the rotation speed of the mixer is set to 150 r / min, and the mixing time is set to 20 min.

[0088] Step 2: Design a rubber sleeve according to the shape and size of the finally formed superalloy part. After filling the mixed powders obtained in Step 1 into the rubber sleeve and vibrating them solid, perform vacuum plastic sealing. The apparent density of the vibrated mixed powders ≥ 35%, and then perform cold isostatic pressing treatment on the entire rubber sleeve to obtain a formed ingot blank.

[0089] Specifically, the cold isostatic pressing treatment includes the following two stages:

[0090] The first stage: The pressure increase rate is set to 10 MPa / min, the final pressure of pressure increase is set to 160 MPa, and the pressure holding time is set to 8 min;

[0091] The second stage: The pressure increase rate is set to 6 MPa / min, the final pressure of pressure increase is set to 220 MPa, and the pressure holding time is set to 60 min.

[0092] Step 3: Design a 20 steel jacket with a wall thickness of 6 mm and a clearance of not less than 3 mm in each direction with the characteristic dimensions of the formed ingot blank according to the size of the formed ingot blank. Place the formed ingot blank obtained in Step 2 into the steel jacket for assembly, and fill the voids with low-carbon steel powder. Then, after degassing and sealing welding treatment of the entire steel jacket, perform hot isostatic pressing treatment to obtain a steel jacketed part.

[0093] Specifically, the specific process of placing the formed ingot blank into the steel jacket for assembly is as follows: First, weld the bottom plate and the outer ring of the steel jacket by argon arc welding. After loading low-carbon steel powder with a layer thickness of 3 mm - 4 mm at the bottom of the steel jacket and vibrating it solid, then place the formed ingot blank in the steel jacket to ensure that the center of the formed ingot blank coincides with the center of the steel jacket. Weld the top plate and the jacket nozzle of the steel jacket by argon arc welding, fill the internal voids of the steel jacket with low-carbon steel powder and vibrate it solid. The density of the vibrated low-carbon steel powder is ≥68%. Finally, weld the degassing pipe. A round hole with a diameter of 20 mm is left at the jacket top plate for welding the powder-loading jacket nozzle and the degassing pipe. The low-carbon steel powder is 20 steel powder, and the particle size range is 150 μm - 212 μm.

[0094] Specifically, the heating temperature of the degassing and sealing welding treatment is 480 °C, the heat preservation time is 2 h, and the vacuum degree inside the entire steel jacket after the degassing and sealing welding treatment is 4.2x10 -4 Pa. After the degassing and sealing welding treatment is completed, the degassing pipe is subjected to two clamping and sealing weldings.

[0095] Specifically, the temperature of the hot isostatic pressing treatment is 1240 °C, the pressure is 130 MPa, the pressure holding time is 2 h, and after the hot isostatic pressing treatment is completed, it is cooled with the furnace.

[0096] Step 4: Perform heat treatment on the steel jacketed part obtained in Step 3. Among them, the solution temperature is 1160 °C, the heat preservation time is 1 h, and the cooling method is air cooling; the aging temperature is 850 °C, the heat preservation time is 4 h, and the cooling method is air cooling.

[0097] Step 5: Perform machining on the heat-treated steel jacketed part obtained in Step 4 to remove the outer surface oxide layer and retain at least 3 mm of steel layer to obtain a cylindrical steel part with a surface roughness Ra ≤ 1.6 μm.

[0098] Step 6: Perform ultrasonic immersion flaw detection on the steel-bonded part obtained in Step 5, where the detection frequency is 12 MHz.

[0099] Step 7: Pickle the steel-bonded part after flaw detection in Step 6 to remove the steel layer on the outer surface of the steel-bonded part. The volume ratio of HF, HNO3, and H2O in the pickling solution is 1:3:6, and a high-temperature GH4099 alloy part with a complex structure is obtained through sandblasting. Its metallographic structure is as Figure 4 shown.

[0100] Combined with Figures 2 to 4 it can be seen that high-temperature GH4169, MAR M247, and GH4099 alloy parts with near-net-shaped complex structures can be prepared by the preparation method provided by the present invention. After testing, the structures of the parts are dense and the grains are uniform. At the same time, the steel-bonded part obtained through hot isostatic pressing during the preparation process is cylindrical, with low flaw detection difficulty and high accuracy.

[0101] The above are only specific embodiments of the present invention, which 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. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0102] 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 method for preparing a complex structure high temperature alloy part that is easy to detect, characterized in that: The steps include: Step 1, weighing high-temperature alloy powders with a particle size range of 15 μm to 53 μm and 150 μm to 212 μm according to a set ratio and putting them into a mixing device for mixing to obtain a mixed powder; Step 2, the mixed powder obtained in step 1 is loaded into a prefabricated rubber sheath, the rubber sheath is first vacuum-sealed, and then the entire rubber sheath is cold isostatically pressed to obtain a formed ingot; Step 3, placing the formed ingot obtained in step 2 into a prefabricated steel ladle sleeve for assembly, first filling the gap between the steel ladle sleeve and the formed ingot with low carbon steel powder, then performing a degassing and sealing welding treatment on the entire steel ladle sleeve, and then performing a hot isostatic pressing treatment to obtain a cylindrical steel ladle sleeve-equipped part; Step 4, heat treating the steel jacketed product obtained in step 3; Step 5, machining the steel strip jacketed product after the heat treatment in step 4 to remove the outer surface oxide layer and retain at least 3 mm of the steel layer to obtain a cylindrical steel strip product with a surface roughness Ra≤1.6 μm; Step 6, performing flaw detection on the strip steel product obtained in step 5; Step 7, pickling the strip steel workpiece after the flaw detection in step 6, removing the steel layer on the outer surface of the strip steel workpiece, and then sandblasting to obtain the target high-temperature alloy workpiece; the volume ratio of HF, HNO3 and H2O in the pickling solution is 1:3:

6.

2. The method for preparing a complex structure high temperature alloy part that is easy to detect according to claim 1, characterized in that: In step 1, high-temperature alloy powders with a particle size range of 15μm to 53μm and 150μm to 212μm are weighed at a mass ratio of 2 to 4:1 to 2 and put into a mixer. During mixing, the speed of the mixer is set to 60r / min to 150r / min, and the mixing time is set to 20min to 60min.

3. The method for preparing a complex structure high temperature alloy part that is easy to detect according to claim 1, characterized in that: In step 2, the rubber sheath is designed according to the specifications of the target high-temperature alloy part, the mixed powder is first loaded into the rubber sheath and vibrated, and then vacuum-sealed, and the density of the mixed powder after vibration is ≥35%.

4. The method for preparing a complex structure high temperature alloy part that is easy to detect according to claim 1, characterized in that: In step 2, the cold isostatic pressing process includes the following two stages: The first stage: the pressure increase rate is set to 8MPa / min~10MPa / min, the pressure increase end point pressure is set to 130MPa~160MPa, and the pressure holding time is set to 8min~20min; The second stage: the pressure increasing rate is set to 3MPa / min~6MPa / min, the pressure increasing end point pressure is set to 180MPa~220MPa, and the pressure holding time is set to 25min~60min.

5. The method for preparing a high-temperature alloy product with a complex structure that is easy to detect according to claim 1 is characterized in that: In step 3, the formed ingot and the steel ladle sleeve are clearance-matched, the clearance is ≥3mm, the steel ladle sleeve is made of 20 steel or 45 steel, and the wall thickness is 4mm-6mm; The specific process of assembling the formed ingot into the steel ladle is as follows: first, the bottom plate and the outer ring of the steel ladle are welded by argon arc welding, low-carbon steel powder with a layer thickness of 3 mm to 4 mm is loaded into the bottom of the steel ladle and then vibrated, then, the formed ingot is placed in the steel ladle, ensuring that the center of the formed ingot is consistent with the center of the steel ladle, the top plate and the ladle mouth are welded by argon arc welding, the gap between the steel ladle and the formed ingot is filled with low-carbon steel powder and vibrated, and the density of the low-carbon steel powder after vibration is ≥68%, and finally, the degassing pipe is welded; The low carbon steel powder is 20 steel powder or 45 steel powder, and the particle size range is 150 μm to 212 μm.

6. The method for preparing a complex structure high temperature alloy part that is easy to detect according to claim 1, characterized in that: In step 3, the heating temperature of the degassing and sealing treatment is 400℃~480℃, and the insulation time is 2h~6h. After the degassing and sealing treatment, the vacuum degree in the entire ladle jacket is 1.0x10-4Pa~1.0x10-3Pa. After the degassing and sealing treatment is completed, the degassing pipe is clamped and sealed.

7. The method for preparing a high-temperature alloy product with a complex structure that is easy to detect according to claim 1, characterized in that: In step 3, the temperature of the hot isostatic pressing treatment is 1180°C to 1240°C, the pressure is 130MPa to 170MPa, the holding time is 2h to 4h, and the hot isostatic pressing treatment is completed and cooled with the furnace. The density of the steel jacketed product after the hot isostatic pressing treatment is ≥99.8%.

8. The method for preparing a complex structure high temperature alloy part that is easy to detect according to claim 1, characterized in that: In step 4, the heat treatment system is: the solution temperature is 980°C to 1250°C, the holding time is 1h to 2h, and the cooling method is air cooling; the aging temperature is 700°C to 870°C, the holding time is 4h to 20h, and the cooling method is air cooling.

9. The method for preparing a high-temperature alloy product with a complex structure that is easy to detect according to claim 1, characterized in that: In step 6, the detection frequency of the flaw detection is 8 MHz to 12 MHz.

10. Application of a method for preparing a complex structure high temperature alloy part that is easy to detect, characterized in that: Application of the preparation method according to any one of claims 1 to 9 in the preparation of GH4099 alloy parts, GH4169 alloy parts or MAR M247 alloy parts.

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