Recycling and remelting method based on nickel-based powder high-temperature alloy powder state return material

Abstract

The invention discloses a nickel-based powder superalloy powder-state return scrap recycling and remelting method which comprises the following steps: packaging powder-state return scraps by using a metal foil bag, putting the packaged powder-state return scraps into a crucible of a vacuum induction melting furnace, vacuumizing, and carrying out low-power power transmission melting; gradually adding the packaged powder-state return scrap into the crucible or adding the packaged powder-state return scrap into the crucible by several times until the packaged powder-state return scrap is completely added into the crucible, and carrying out full-power power transmission smelting; after melting the melt, heating to a refining temperature, increasing the vacuum degree, and refining; carrying out electromagnetic stirring on the refined powder-state return scrap melt, and then cooling to a pouring temperature; and the powder-state return scrap melt is poured into a steel mold after being subjected to slag blocking through a slag blocking plate and filtered through a two-stage filter, and a powder-state return scrap remelting master alloy ingot is obtained. According to the method, the 100% powder state return scrap is directly adopted for smelting, and the content of oxygen, nitrogen and hydrogen elements in the prepared 100% powder state return scrap remelting ingot is low.

Description

Technical Field

[0001] The invention belongs to the technical field of recycling return materials in a powder metallurgy process, and specifically relates to a recycling and remelting method based on nickel-based powder high-temperature alloy return materials in powder form. Background Art

[0002] As we all know, nickel-based powder high-temperature alloy has the advantages of uniform structure, no macro-segregation, high strength and good fatigue resistance. It is the preferred material for manufacturing turbine disks, the hot end rotating parts of advanced aircraft engines. Its quality directly affects the performance and life of the engine and is closely related to aviation safety. The preparation process of powder turbine disks is complicated, the production process is long, and a large amount of return materials are often generated during the production process. These return materials mainly include powders with unqualified particle size, unqualified disks, residual materials of dissected disks, turnings, grinding chips, etc. Among them, powders with unqualified particle size account for a high proportion of the total return materials, usually reaching more than 30%. If these return materials cannot be recycled in time, it will cause a huge waste of precious metal resources such as nickel and cobalt.

[0003] At present, the most efficient and economical method in the recycling of returned material resources is to use returned material smelting to prepare master alloy ingots. However, for nickel-based powder high-temperature alloy powder returned materials, there are two major technical difficulties in the implementation of this method: First, the nickel-based powder high-temperature alloy powder returned materials are in powder form, and the powder particle size is small. When re-smelted in a vacuum melting furnace, the powder is easy to enter the sealing ring and vacuum pump during the vacuuming process, resulting in air leakage and serious damage to the vacuum melting equipment; second, the nickel-based powder high-temperature alloy powder returned materials have a large specific surface area, and will absorb a large amount of gas when exposed to the air, resulting in a high content of impurity elements such as O and N on the surface of the returned materials, thereby reducing the purity of the master alloy ingot and posing a threat to the reliable service of the alloy. The above two major technical difficulties seriously restrict the utilization rate of nickel-based powder high-temperature alloy powder returned materials. Therefore, it is extremely urgent to develop a recycling and remelting method based on nickel-based powder high-temperature alloy powder returned materials.

[0004] In the prior art, there are mainly the following methods for recycling powdered return materials:

[0005] (1) The powdered return material is preformed by sintering, bonding agent or extrusion to form a block material, and then smelted to obtain a master alloy ingot. For example, the invention patent with application publication number CN114472885A discloses a method for recycling metal powder return material, which uses a polymer material sheath to cover the powdered return material and then extrude it. Although this method can avoid direct smelting of powdered return material and damage to the vacuum system of the smelting equipment, due to the high strength of the powdered high-temperature alloy powder, the blank obtained by cold extrusion has low strength, which is very easy to cause crushing and powdering during the process of feeding and loading, and is easily sucked away by the vacuum pump group in the vacuum induction melting furnace, causing damage to the equipment; at the same time, the efficiency of this method is low, and the pressing efficiency of twice per minute is difficult to meet the needs of on-site smelting, and the use of extrusion increases production costs.

[0006] (2) Use a certain proportion of the same grade of block material for melting to prepare a master alloy ingot. For example, the invention patent with application publication number CN116160021A discloses a method for manufacturing a high-temperature alloy powder remelting master alloy. Through the first furnace production method and the second furnace production method, the block material and the powder material in the furnace are staggered and stacked, and then the remelted ingot of the powder return material is obtained. This method requires the addition of a certain proportion of block material, and the powder return material and the block material need to be added alternately, which is difficult to operate and cannot achieve 100% recycling of the powder return material.

[0007] (3) Powdered return materials are used in the powder making stage, and there is no need to go through the process of remelting into a master alloy ingot. For example, the invention patent with application publication number CN113458402A discloses a method for preparing high-temperature alloy powder using nickel-based high-temperature alloy powder return materials. This method uses powdered return materials for recycling in the powder making stage. The prepared product is not a master alloy but a powder, and the proportion of powdered return materials is 20-75%, which is a low recycling rate. Summary of the invention

[0008] In order to solve the problems existing in the prior art, the present invention provides a method for recycling and remelting a powdered return material of a nickel-based powder high-temperature alloy, which comprises the following steps in order:

[0009] Step 1: Make a metal foil bag according to the design requirements, and use the metal foil bag to package a certain amount of powdered return material to obtain packaged powdered return material;

[0010] Step 2: putting the packaged powdered return material into the crucible of the vacuum induction melting furnace, and evacuating the vacuum induction melting furnace to a certain vacuum degree; after the evacuation is completed, the packaged powdered return material in the crucible is subjected to low-power power supply melting to form a molten pool; after the low-power power supply melting is completed, the packaged powdered return material is gradually added to the crucible or the packaged powdered return material is added in several times; after all the packaged powdered return material is added to the crucible, the packaged powdered return material in the crucible is subjected to full-power power supply melting to obtain a melted powdered return material melt;

[0011] Step 3: Continue to power-smelt the powdered return material melt after melting in the crucible until it is clear, and then heat it to the refining temperature; after heating to the refining temperature, increase the vacuum degree of the vacuum induction melting furnace; after the vacuum degree is increased to a certain value, refine the powdered return material melt after melting in the crucible to obtain a refined powdered return material melt;

[0012] Step 4: Performing an enhanced electromagnetic stirring treatment on the refined powdered return material melt in the crucible to further alloy the powdered return material melt;

[0013] Step 5: Stop supplying power to the crucible, and allow the powdered return material melt in the crucible that has undergone enhanced electromagnetic stirring to stand and cool down; after the temperature drops to the pouring temperature, pour the powdered return material melt in the crucible into the middle package, and after the powdered return material melt is filtered through a slag retaining plate, a primary ceramic filter, and a secondary ceramic filter, pour it into a steel mold to obtain a powdered return material remelted master alloy ingot.

[0014] Preferably, in step one, the material of the metal foil bag is any one or more of cobalt foil, tungsten foil, molybdenum foil, titanium foil, nickel foil, iron foil, copper foil, niobium foil and tantalum foil; the metal foil bag is rectangular with a length of 400-800 mm and a width of 200-400 mm; the thickness of the metal foil is 0.03-0.5 mm.

[0015] In any of the above schemes, preferably, in step 1, the sum of the weights of each metal foil bag and the powdered return material packaged therein is 5-75 kg; and the particle size of the powdered return material is 25-500 μm.

[0016] In any of the above schemes, preferably, in step 2, the capacity of the crucible is 3000 kg, the mass of the packaged powder return material first added to the crucible is 30-50% of the capacity of the crucible, and the vacuum degree of the vacuum induction melting furnace does not exceed 20 Pa.

[0017] In any of the above schemes, it is preferred that in step 2, the process parameters of the low-power power transmission smelting are: power transmission power 100-400kW, smelting time 1-3h; the packaged powder return material is added to the crucible in 2-5 times, and the mass of the packaged powder return material added each time is 300-1000kg; the process parameters of the full-power power transmission smelting are: power transmission power 800-1200kW, smelting time 0.5-1h.

[0018] In any of the above schemes, it is preferred that in step three, the process parameters of power transmission smelting to chemical purification are: power transmission power 800-1200kW, smelting time 0.5-1h; the vacuum degree of the vacuum induction melting furnace is increased to not exceed 5Pa; the process parameters of refining are: refining temperature 1450-1600℃, refining time 10-30min.

[0019] In any of the above schemes, preferably, in step 4, the process parameters of the enhanced electromagnetic stirring treatment are: stirring power 120-350 kW, stirring frequency 100-300 Hz, stirring time 4-8 min, and the stirring temperature is the same as the refining temperature.

[0020] In any of the above schemes, preferably, in step five, the pouring temperature is 1420-1500°C; the porosity of the first-level ceramic filter is 15PPI, and the porosity of the second-level ceramic filter is 30PPI; and the amount of powdered return material added to the obtained powdered return material remelting master alloy ingot is 100%.

[0021] In any of the above schemes, it is preferred that the method is suitable for the recovery and remelting of any one of the powder return materials including FGH91 high-temperature alloy powder return materials, FGH95 high-temperature alloy powder return materials, FGH96 high-temperature alloy powder return materials, FGH99 high-temperature alloy powder return materials, FGH720Li high-temperature alloy powder return materials, FGH101 high-temperature alloy powder return materials, and FGH109 high-temperature alloy powder return materials.

[0022] In the present invention, the vacuum induction melting furnace, crucible, vacuum pump, temperature measuring instrument, etc. used can adopt existing equipment according to actual conditions, and no special requirements are made on the equipment model. Step 3, during the refining process, the vacuum degree is increased so that the vacuum degree does not exceed 5Pa, which can further remove the gas elements such as oxygen and nitrogen adsorbed by the powdered return material. Step 4, the powdered return material melt after refining in the crucible is subjected to enhanced electromagnetic stirring treatment to further alloy the powdered return material melt, and at the same time, small-sized non-metallic inclusions are caused to float. After the powdered return material melt is subjected to enhanced electromagnetic stirring treatment, its composition is more uniform. Step 5, stop supplying power to the crucible, and let the powdered return material melt stand and cool down. The solubility of gas elements such as oxygen and nitrogen in the alloy can be reduced by standing and cooling down; before the melt is poured into the steel mold, two-stage filtration is required, that is, the melt is filtered through a primary ceramic filter and a secondary ceramic filter in turn, and the use of two-stage filtration can further improve the purity of the alloy.

[0023] The recycling and remelting method of the nickel-based powder high-temperature alloy powder return material of the present invention involves many process parameters, and the various process parameters must work together to achieve the expected technical effect of the present invention, especially the material and size of the metal foil bag, the mass of each metal foil bag and the powder return material packaged therein, the particle size of the powder return material, the amount of the packaged powder return material put into the crucible, the porosity of the ceramic filter, etc. are very critical parameters.

[0024] The existing technology has many defects in the remelting or recycling of powdered return materials, such as: the use of adhesives to bond the powdered return materials will affect the purity of the remelted ingots of the powdered return materials; the proportion of powdered return materials added when using block materials for melting is usually no more than 70%, and the recycling rate is low; when using extrusion molding, the strength of the blank is not high, which is easy to cause re-powdering, thereby affecting the vacuum system of the equipment; and the production efficiency of the above methods is low and the production cost is high. In view of the above technical problems, the present invention has developed a recycling and remelting method based on nickel-based powder high-temperature alloy powder return material. The method innovatively uses metal foil bags such as cobalt foil, tungsten foil, molybdenum foil, titanium foil, nickel foil, iron foil, copper foil, niobium foil and tantalum foil to pre-package the powder return material, and then performs subsequent smelting, refining, electromagnetic stirring, double filtration and pouring processes, thereby achieving an ultra-high recycling rate of 100% of the powder return material. The prepared powder return material remelted master alloy ingot can be used to produce engine turbine disks, that is, the turbine disk is completely made of powder return material without adding other materials, and the produced turbine disk has excellent comprehensive performance.

[0025] The recycling and remelting method of the nickel-based powder high-temperature alloy powder return material of the present invention has the following beneficial effects:

[0026] (1) No block material or solid material is needed, and 100% powdered return material is directly used for smelting. The material can be continuously added under vacuum environment without adding any additives or binders, which can ensure the purity of the remelted ingot of powdered return material.

[0027] (2) The metal foil used has the characteristics of high strength and high toughness. Only a small amount of metal foil is needed to achieve the pre-packaging effect. The metal foil materials used are all the main component elements of nickel-based powder high-temperature alloys, which have little effect on the composition of the remelted ingot of the powder return material. The process operation is simple and easy, and no additional pre-forming treatment or additional additives are required.

[0028] (3) The size of the metal foil bag is reasonably designed, and the weight of a single metal foil bag and the powdered return material it encapsulates is reasonably designed. In combination with smelting, refining, enhanced electromagnetic stirring, double filtration and other processes, small-sized inclusions are filtered and adsorbed; at the same time, the gas adsorbed in the powdered return material is removed by increasing the vacuum degree, refining, enhanced electromagnetic stirring and other processes, of which 90% of oxygen, 50% of nitrogen and 50% of hydrogen can be removed.

[0029] (4) The smelting time required for smelting a whole furnace of powdered return material is relatively short. Each furnace can remelt a large number of powdered return materials. The operation is simple and the cost is low. It can anticipate and solve the difficulties that may arise in engineering applications. The gas element content in the prepared 100% powdered return material remelted ingot is low, among which the oxygen content is ≤9ppm, the nitrogen content is ≤5ppm, and the hydrogen content is ≤1ppm, which meets the technical requirements of the alloy.

[0030] (5) The cost of packaging powdered return materials with metal foil bags is greatly reduced to only 10-50% of the cost of cold isostatic pressing, cold extrusion with jackets, adhesives, etc., while the melting efficiency can be increased by 50-100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A process flow chart of a preferred embodiment of a method for recycling and remelting a powdered return material of a nickel-based high-temperature powder alloy according to the present invention;

[0032] Figure 2 for Figure 1 The microscopic morphology photograph of inclusions in the powdered return material remelted master alloy ingot prepared in the embodiment shown;

[0033] Figure 3 for Figure 1 The microstructure of the precipitation phase of the remelted master alloy ingot of the powdered return material prepared in the embodiment shown;

[0034] Figure 4 for Figure 1Surface scanning diagram of C element in the powdered return material remelted master alloy ingot prepared in the embodiment shown;

[0035] Figure 5 for Figure 1 Scanning image of Ti element in powdered return material remelted master alloy ingot prepared in the embodiment shown;

[0036] Figure 6 for Figure 1 Surface scanning diagram of Mo element in the remelted master alloy ingot of powdered return material prepared in the embodiment shown. DETAILED DESCRIPTION

[0037] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0038] Embodiment 1:

[0039] like Figure 1 As shown, according to a preferred embodiment of the method for recycling and remelting the powdered return material of the nickel-based powder high-temperature alloy of the present invention, the following steps are included in order:

[0040] Step 1: Make a metal foil bag according to the design requirements, and use the metal foil bag to package a certain amount of powdered return material to obtain packaged powdered return material;

[0041] Step 2: putting the packaged powdered return material into the crucible of the vacuum induction melting furnace, and evacuating the vacuum induction melting furnace to a certain vacuum degree; after the evacuation is completed, the packaged powdered return material in the crucible is subjected to low-power power supply melting to form a molten pool; after the low-power power supply melting is completed, the packaged powdered return material is gradually added to the crucible or the packaged powdered return material is added in several times; after all the packaged powdered return material is added to the crucible, the packaged powdered return material in the crucible is subjected to full-power power supply melting to obtain a melted powdered return material melt;

[0042] Step 3: Continue to power-smelt the powdered return material melt after melting in the crucible until it is clear, and then heat it to the refining temperature; after heating to the refining temperature, increase the vacuum degree of the vacuum induction melting furnace; after the vacuum degree is increased to a certain value, refine the powdered return material melt after melting in the crucible to obtain a refined powdered return material melt;

[0043] Step 4: Performing an enhanced electromagnetic stirring treatment on the refined powdered return material melt in the crucible to further alloy the powdered return material melt;

[0044] Step 5: Stop supplying power to the crucible, and allow the powdered return material melt in the crucible that has undergone enhanced electromagnetic stirring to stand and cool down; after the temperature drops to the pouring temperature, pour the powdered return material melt in the crucible into the middle package, and after the powdered return material melt is filtered through a slag retaining plate, a primary ceramic filter, and a secondary ceramic filter, pour it into a steel mold to obtain a powdered return material remelted master alloy ingot.

[0045] In step 1, the material of the metal foil bag is cobalt foil; the metal foil bag is rectangular, with a length of 600 mm and a width of 300 mm; the thickness of the metal foil is 0.3 mm. The total weight of each metal foil bag and the powdered return material packaged therein is 40 kg; the particle size of the powdered return material is 50-250 μm.

[0046] In step 2, the capacity of the crucible is 3000kg, the mass of the packaged powder return material added to the crucible for the first time is 40% of the capacity of the crucible, and the vacuum degree of the vacuum induction melting furnace is 20Pa. The process parameters of the low-power power transmission melting are: power transmission power 250kW, melting time 2h; adding the packaged powder return material to the crucible in 5 times, and the mass of the packaged powder return material added each time is 300kg; the process parameters of the full-power power transmission melting are: power transmission power 1000kW, melting time 0.8h.

[0047] In step 3, the process parameters of power transmission smelting to chemical purification are: power transmission power 1000kW, smelting time 0.8h; the vacuum degree of the vacuum induction melting furnace is increased to 5Pa; the process parameters of refining are: refining temperature 1550℃, refining time 20min. Increasing the vacuum degree during the refining process so that the vacuum degree does not exceed 5Pa can further remove gas elements such as oxygen and nitrogen adsorbed by the powdered return material.

[0048] In step 4, the process parameters of the enhanced electromagnetic stirring treatment are: stirring power 230kW, stirring frequency 200Hz, stirring time 6min, and stirring temperature is the same as the refining temperature. The powdered return material melt after refining in the crucible is subjected to enhanced electromagnetic stirring treatment to further alloy the powdered return material melt and promote the floating of small-sized non-metallic inclusions. After the enhanced electromagnetic stirring treatment, the powdered return material melt has a more uniform composition.

[0049] In step 5, the pouring temperature is 1460°C; the porosity of the first-level ceramic filter is 15PPI, and the porosity of the second-level ceramic filter is 30PPI; the amount of powdered return material added to the obtained powdered return material remelting master alloy ingot is 100%. Stop supplying power to the crucible, and let the powdered return material melt stand and cool down. The solubility of gas elements such as oxygen and nitrogen in the alloy can be reduced by standing and cooling down; before the melt is poured into the steel mold, two-stage filtration is required, that is, the melt is filtered through the first-level ceramic filter and the second-level ceramic filter in turn. The use of two-stage filtration can further improve the purity of the alloy.

[0050] The method of this embodiment is used for the recovery and remelting of the powdered return material of FGH96 high-temperature alloy. The vacuum induction melting furnace, crucible, vacuum pump, temperature measuring instrument, etc. used in this embodiment can adopt existing equipment according to actual conditions, and no special requirements are made on the equipment model. The method of this embodiment involves many process parameters, and the various process parameters must work together to achieve the expected technical effect of this embodiment, especially the material and size of the metal foil bag, the quality of each metal foil bag and the powdered return material packaged therein, the particle size of the powdered return material, the amount of powdered return material put into the crucible after packaging, the porosity of the ceramic filter, etc. are very critical parameters.

[0051] In this embodiment, the contents of oxygen, nitrogen and hydrogen in the powdered return material (powder) and the powdered return material remelted master alloy ingot (rod) are tested, and the test samples are 8 pieces respectively. The oxygen content is tested by infrared absorption method, and the test conditions of the samples are the same; the nitrogen content is tested by thermal conductivity method, and the test conditions of the samples are the same; the hydrogen content is tested by thermal conductivity method, and the test conditions of the samples are the same. The test results of the oxygen, nitrogen and hydrogen content in the powdered return material are shown in Table 1, and the test results of the oxygen, nitrogen and hydrogen content in the powdered return material remelted master alloy ingot are shown in Table 2. By comparing Table 1 and Table 2, it can be seen that the contents of oxygen, nitrogen and hydrogen in the powdered return material remelted master alloy ingot prepared by the method of this embodiment are greatly reduced.

[0052] Table 1 Test results of oxygen, nitrogen and hydrogen content in powdered return material

[0053] Sample No. O(％) N(％) H(％) Pink-001 0.010 0.0008 0.00054 Pink-002 0.017 0.0015 0.0010 Pink-003 0.0099 0.0007 0.00071 Pink-004 0.0095 0.0007 0.00077 Pink-005 0.028 0.0019 0.0016 Pink-006 0.0078 0.0007 0.00061 Pink-007 0.0065 0.0006 0.00048 Pink-008 0.0082 0.0007 0.00057

[0054] Table 2 Test results of oxygen, nitrogen and hydrogen content in powdered return remelting master alloy ingot

[0055] Sample No. O(％) N(％) H(％) Stick-001 0.0008 0.0003 0.00005 Stick-002 0.0006 0.0004 0.00006 Stick-003 0.0007 0.0003 0.00006 Stick-004 0.0006 0.0003 0.00006 Stick-005 0.0007 0.0003 0.00005 Stick-006 0.0007 0.0003 0.00006 Stick-007 0.0007 0.0003 0.00006 Stick-008 0.0009 0.0004 0.00006

[0056] In this embodiment, the inclusions in the powder state return material remelting master alloy ingot (rod shape) are detected by electrolysis. The detection results are shown in Table 3. The microscopic morphology of the inclusions in the powder state return material remelting master alloy ingot is as follows: Figure 2 shown.

[0057] Table 3 Detection results of inclusions in powdered return material remelting master alloy ingot

[0058]

[0059] From Table 3 and Figure 2 It can be seen that the total amount of inclusions in the 4.208kg powdered return material remelted master alloy ingot is 0.80mg, and the maximum particle size of the inclusions is 249.7μm. It can be seen that the content of inclusions is very small, and the particle size of the inclusions is also very small. Such inclusions have basically no effect on the subsequent preparation of the turbine disk and the performance of the turbine disk. Figure 3 The microstructure of the precipitation phase of the remelted master alloy ingot of the powder return material is shown in Figure 1. The inclusions in the remelted master alloy ingot include C, Ti and Mo elements, and the surface scans of C, Ti and Mo elements are shown in Figure 2. Figure 4 , Figure 5 and Figure 6 shown.

[0060] In view of the problems existing in the prior art, this embodiment innovatively uses metal foil bags such as cobalt foil to pre-package the powdered return material, and then carries out subsequent smelting, refining, electromagnetic stirring, double filtration and pouring processes, thereby achieving an ultra-high recycling rate of 100% of the powdered return material. The prepared remelted master alloy ingot of the powdered return material can be used to produce engine turbine disks, that is, the turbine disks are completely made of powdered return material without adding other materials, and the produced turbine disks have excellent comprehensive performance.

[0061] The recycling and remelting method of the powdered return material of the nickel-based powder high-temperature alloy in this embodiment has the following beneficial effects: no block material or solid material is required, and 100% powdered return material is directly used for smelting; the metal foil material used is the main component element of the nickel-based powder high-temperature alloy, and has basically no effect on the composition of the powdered return material remelting ingot; the size of the metal foil bag is reasonably designed, and the weight of a single metal foil bag and the powdered return material it encapsulates is reasonably designed, combined with smelting, refining, enhanced electromagnetic stirring, double filtration and other processes, so that small-sized inclusions are filtered and adsorbed, and at the same time, gases such as oxygen, nitrogen, and hydrogen in the powdered return material are removed; the smelting time required to melt a whole furnace of powdered return material is short, and each furnace can remelt a large number of powdered return materials, which is simple to operate, low cost, and high efficiency, and can anticipate and solve difficulties that may arise in engineering applications.

[0062] Embodiment 2:

[0063] According to another preferred embodiment of the method for recycling and remelting the powdered return material of the nickel-based powder high-temperature alloy of the present invention, it is used for recycling the powdered return material of FGH95 high-temperature alloy. Its process steps, equipment used, test methods, technical principles, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0064] In step 1, the material of the metal foil bag is tungsten foil; the metal foil bag is rectangular, with a length of 400 mm and a width of 200 mm; the thickness of the metal foil is 0.03 mm. The total weight of each metal foil bag and the powdered return material packaged therein is 5 kg; the particle size of the powdered return material is 25-50 μm.

[0065] In step 2, the capacity of the crucible is 3000kg, the mass of the packaged powder return material first added to the crucible is 50% of the capacity of the crucible, and the vacuum degree of the vacuum induction melting furnace is 20Pa. The process parameters of the low-power power transmission melting are: power transmission power 100kW, melting time 3h; gradually add the packaged powder return material to the crucible, and the mass of the packaged powder return material added each time is 650kg; the process parameters of the full-power power transmission melting are: power transmission power 800kW, melting time 1h.

[0066] In step three, the process parameters of power transmission smelting to chemical purification are: power transmission power 800kW, smelting time 1h; the vacuum degree of the vacuum induction melting furnace is increased to 5Pa; the process parameters of refining are: refining temperature 1450°C, refining time 30min.

[0067] In step 4, the process parameters of the enhanced electromagnetic stirring treatment are: stirring power 120 kW, stirring frequency 300 Hz, stirring time 8 min, and the stirring temperature is the same as the refining temperature.

[0068] In step five, the pouring temperature is 1420° C.; the porosity of the primary ceramic filter is 15 PPI, and the porosity of the secondary ceramic filter is 30 PPI; and the amount of powdered return material added to the obtained powdered return material remelting master alloy ingot is 100%.

[0069] Embodiment three:

[0070] According to another preferred embodiment of the method for recycling and remelting the powdered return material of the nickel-based powder high-temperature alloy of the present invention, it is used for recycling the powdered return material of the FGH720Li high-temperature alloy. Its process steps, equipment used, test methods, technical principles, beneficial effects, etc. are basically the same as those of the first embodiment, except that:

[0071] In step 1, the material of the metal foil bag is molybdenum foil; the metal foil bag is rectangular, with a length of 800 mm and a width of 400 mm; the thickness of the metal foil is 0.5 mm. The total weight of each metal foil bag and the powdered return material packaged therein is 75 kg; the particle size of the powdered return material is 250-500 μm.

[0072] In step 2, the capacity of the crucible is 3000kg, the mass of the packaged powder return material added to the crucible for the first time is 30% of the capacity of the crucible, and the vacuum degree of the vacuum induction melting furnace is 20Pa. The process parameters of the low-power power transmission melting are: power transmission power 400kW, melting time 1h; adding the packaged powder return material to the crucible twice, and the mass of the packaged powder return material added each time is 1000kg; the process parameters of the full-power power transmission melting are: power transmission power 1200kW, melting time 0.5h.

[0073] In step three, the process parameters of power transmission smelting to chemical purification are: power transmission power 1200kW, smelting time 0.5h; the vacuum degree of the vacuum induction melting furnace is increased to 5Pa; the process parameters of refining are: refining temperature 1600°C, refining time 10min.

[0074] In step 4, the process parameters of the enhanced electromagnetic stirring treatment are: stirring power 350 kW, stirring frequency 100 Hz, stirring time 4 min, and the stirring temperature is the same as the refining temperature.

[0075] In step five, the pouring temperature is 1500° C.; the porosity of the primary ceramic filter is 15 PPI, and the porosity of the secondary ceramic filter is 30 PPI; and the amount of powdered return material added to the obtained powdered return material remelting master alloy ingot is 100%.

[0076] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventor has recorded a large amount of experimental data. Due to space limitations, the specific experimental data will not be disclosed here.

[0077] It is not difficult for those skilled in the art to understand that the recycling and remelting method of the nickel-based powder high-temperature alloy powder return material of the present invention includes any combination of the invention content and specific implementation methods of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for recycling and remelting a powdered return material of a nickel-based high-temperature alloy comprises the following steps in order: Step 1: Make a metal foil bag according to the design requirements, and use the metal foil bag to package a certain amount of powdered return material to obtain packaged powdered return material; Step 2: Put the packaged powdered return material into the crucible of the vacuum induction melting furnace, and evacuate the vacuum induction melting furnace to a certain vacuum degree; after the vacuuming is completed, the packaged powdered return material in the crucible is subjected to low-power power transmission melting to form a molten pool; after the low-power power transmission melting is completed, the packaged powdered return material is gradually added to the crucible or the packaged powdered return material is added in several times; After all the packaged powdered return materials are added to the crucible, the packaged powdered return materials in the crucible are smelted at full power to obtain a melted powdered return material melt; Step 3: Continue to power-smelt the powdered return material melt after melting in the crucible until it is clear, and then heat it to the refining temperature; after heating to the refining temperature, increase the vacuum degree of the vacuum induction melting furnace; after the vacuum degree is increased to a certain value, refine the powdered return material melt after melting in the crucible to obtain a refined powdered return material melt; Step 4: Performing an enhanced electromagnetic stirring treatment on the refined powdered return material melt in the crucible to further alloy the powdered return material melt; Step 5: Stop supplying power to the crucible, and allow the powdered return material melt in the crucible that has undergone enhanced electromagnetic stirring to stand and cool down; after the temperature drops to the pouring temperature, pour the powdered return material melt in the crucible into the middle package, and after the powdered return material melt is filtered through a slag retaining plate, a primary ceramic filter, and a secondary ceramic filter, pour it into a steel mold to obtain a powdered return material remelted master alloy ingot.

2. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 1, characterized in that: In step 1, the material of the metal foil bag is any one or more of cobalt foil, tungsten foil, molybdenum foil, titanium foil, nickel foil, iron foil, copper foil, niobium foil and tantalum foil; the metal foil bag is rectangular, with a length of 400-800 mm and a width of 200-400 mm; the thickness of the metal foil is 0.03-0.5 mm.

3. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 2, characterized in that: In step 1, the sum of the weight of each metal foil bag and the powdered return material packaged therein is 5-75 kg; the particle size of the powdered return material is 25-500 μm.

4. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 3 is characterized in that: In step 2, the capacity of the crucible is 3000 kg, the mass of the packaged powder return material first added to the crucible is 30-50% of the capacity of the crucible, and the vacuum degree of the vacuum induction melting furnace does not exceed 20 Pa.

5. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 4, characterized in that: In step 2, the process parameters of the low-power power transmission smelting are: power transmission power 100-400kW, smelting time 1-3h; the packaged powder return material is added to the crucible in 2-5 times, and the mass of the packaged powder return material added each time is 300-1000kg; the process parameters of the full-power power transmission smelting are: power transmission power 800-1200kW, smelting time 0.5-1h.

6. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 5, characterized in that: In step three, the process parameters of power transmission smelting to chemical purification are: power transmission power 800-1200kW, smelting time 0.5-1h; the vacuum degree of the vacuum induction melting furnace is increased to not exceed 5Pa; the process parameters of the refining are: refining temperature 1450-1600℃, refining time 10-30min.

7. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 6, characterized in that: In step 4, the process parameters of the enhanced electromagnetic stirring treatment are stirring power 120-350 kW, stirring frequency 100-300 Hz, stirring time 4-8 min, and the stirring temperature is the same as the refining temperature.

8. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to claim 7, characterized in that: In step five, the pouring temperature is 1420-1500° C.; the porosity of the primary ceramic filter is 15 PPI, and the porosity of the secondary ceramic filter is 30 PPI; and the amount of powdered return material added to the obtained powdered return material remelting master alloy ingot is 100%.

9. The method for recycling and remelting the powdered return material of nickel-based high-temperature powder alloy according to any one of claims 1 to 8, characterized in that: The method is suitable for the recovery and remelting of any one of the powder return materials including FGH91 high temperature alloy powder return materials, FGH95 high temperature alloy powder return materials, FGH96 high temperature alloy powder return materials, FGH99 high temperature alloy powder return materials, FGH720Li high temperature alloy powder return materials, FGH101 high temperature alloy powder return materials and FGH109 high temperature alloy powder return materials.

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