A nickel-phosphorus master alloy for aerospace-grade high-temperature alloy and a preparation method thereof

Abstract

The present invention discloses a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy, which is composed of the following elements in mass proportion: P 5% to 25%, Fe not more than 0.05%, Si not more than 0.01%, C not more than 0.01%, S not more than 0.01%, O not more than 0.01%, N not more than 0.005%, and the balance is Ni; the present invention also discloses a method for preparing the nickel-phosphorus master alloy, which comprises the following steps: step 1, compacting and paving red phosphorus on the bottom of a crucible, evenly placing a nickel plate on the upper layer of red phosphorus, and performing argon filling, oxygen reduction, and smelting to obtain a melt; step 2, casting and cooling the melt to obtain a nickel-phosphorus alloy ingot. The nickel-phosphorus master alloy of the present invention forms a Ni-based master alloy with a mass proportion of 5% to 25% of the P element by limiting the component content, and the melting point is closer to the high-temperature alloy matrix nickel, which can meet the aerospace-grade high-temperature alloy smelting requirements and is suitable for the field of alloy preparation technology.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy preparation, and in particular relates to a nickel-phosphorus master alloy for aerospace-grade high-temperature alloys and a preparation method thereof. Background Art

[0002] High-temperature alloys such as GH4169, GH2761 and GH2130 are mainly used to manufacture aviation engine components such as turbine blades, combustion chambers, turbine disks, etc., all of which need to maintain excellent creep resistance and stability under high temperature and high pressure. Adding an appropriate amount of phosphorus can improve the long-lasting creep performance of certain high-temperature alloys.

[0003] However, in the process of high-temperature alloy smelting, directly adding elemental phosphorus can easily lead to a large number of quality and safety problems. Since elemental phosphorus has low melting and boiling points, adding it directly to the melt will cause the melt to boil and splash, and lead to large amounts of phosphorus evaporation, low yields, and unstable composition. In addition, during the addition process, phosphorus is exposed to oxygen and high temperature environment at the same time, which can easily generate highly toxic yellow phosphorus and P2O5 gas, causing health hazards to operators.

[0004] Therefore, in order to avoid the above problems, it is urgent to develop a nickel-phosphorus intermediate alloy that can meet the smelting requirements of aerospace-grade high-temperature alloys. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and provide a nickel-phosphorus master alloy for aerospace-grade high-temperature alloys. The nickel-phosphorus master alloy forms a Ni-based master alloy with a P element mass ratio of 5% to 25% by limiting the content of each component. Compared with elemental red phosphorus, the melting point is significantly improved and closer to the melting point of the high-temperature alloy matrix nickel, which can meet the smelting requirements of aerospace-grade high-temperature alloys and solve the problem of burning and volatilization of high-temperature alloys when elemental phosphorus is added during the smelting process.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy, characterized in that the nickel-phosphorus master alloy is composed of the following elements in percentage by mass: P 5% to 25%, Fe not more than 0.05%, Si not more than 0.01%, C not more than 0.01%, S not more than 0.01%, O not more than 0.01%, N not more than 0.005%, and the balance is Ni.

[0007] The present invention forms a nickel-phosphorus master alloy with Ni as a matrix and P element which improves the long-lasting creep performance of the high-temperature alloy, and limits the content of each component to increase the melting point from 260°C of elemental red phosphorus to 880°C-1200°C, which is closer to the melting point (1455°C) of nickel, a matrix of the high-temperature alloy. This not only avoids the safety problems of spontaneous combustion loss and generation of P2O5 toxic gas in a high-temperature environment, but also effectively avoids metallurgical problems such as easy burning and volatilization of elemental phosphorus in the high-temperature alloy during smelting.

[0008] The above-mentioned nickel-phosphorus master alloy for aerospace-grade high-temperature alloy is characterized in that the nickel-phosphorus master alloy is composed of the following elements in proportion by mass: P 15%~25%, Fe not more than 0.05%, Si not more than 0.01%, C not more than 0.01%, S not more than 0.01%, O not more than 0.005%, N not more than 0.003%, and the balance is Ni.

[0009] At the same time, the present invention also discloses a method for preparing the above-mentioned nickel-phosphorus master alloy for aerospace-grade high-temperature alloy, characterized in that the preparation method comprises the following steps: Step 1: compact and flatten the red phosphorus on the bottom of the crucible, evenly place the nickel plate on the upper layer of the red phosphorus, and then fill with argon to reduce oxygen and smelt to obtain a melt; Step 2: Casting and cooling the melt obtained in step 1 to obtain a nickel-phosphorus alloy ingot.

[0010] The invention compacts the red phosphorus and places the nickel plate on the red phosphorus, thereby preventing the rapid volatilization of phosphorus vapor formed after the low-melting-point red phosphorus is melted, which is beneficial to the control of the phosphorus yield.

[0011] The above-mentioned method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloys is characterized in that the mass purity of the red phosphorus and the nickel plate in step 1 is greater than 99.9%, the particle size of the red phosphorus is 30 mesh to 80 mesh, the length and width of the nickel plate are both 30 mm to 100 mm, and the thickness of the nickel plate is 5 mm to 10 mm.

[0012] The present invention strictly controls the purity and specifications of red phosphorus and nickel plates, thereby ensuring the purity of the nickel-phosphorus alloy on the one hand and controlling the melting speed of the raw materials during smelting on the other hand, and preventing the red phosphorus from escaping after forming phosphorus vapor due to the melting time being too long due to the nickel block being too large.

[0013] The above-mentioned method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloys is characterized in that the process of argon filling and oxygen reduction in step one is: evacuating to -0.1MPa, then filling with argon gas with a volume purity of more than 99.99% to 0MPa, and after multiple cycles of vacuuming and filling with argon gas, continuously introducing argon gas at a flow rate of 0.5L / min~1.0L / min.

[0014] The present invention removes air by multiple gas washings and continuously introduces inert gas argon to prevent red phosphorus from reacting with oxygen in a high temperature environment to generate toxic gas P2O5, thereby ensuring a safe and efficient smelting process and controlling the pressure during smelting to reduce the escape of phosphorus vapor.

[0015] The above-mentioned method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy is characterized in that the smelting process in step 1 is: heating to 1000° C. to 1500° C. for smelting after the argon gas flow rate is stable, and stirring for 20 min to 30 min after the red phosphorus and the nickel plate are melted.

[0016] The present invention can control the smelting temperature to avoid the rapid volatilization of red phosphorus to form a large amount of phosphorus vapor due to excessively high temperature, or the difficulty in melting the nickel plate due to low temperature, which causes the smelting time to be too long; and the diffusion of nickel and phosphorus elements can be promoted by stirring the melt for a certain period of time after melting, which is beneficial to the homogenization of the components.

[0017] The above-mentioned method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloys is characterized in that the casting process in step 2 is: casting into a mold through a chute, the mold having multiple channels and a molding area, the length and width of the molding area are both 50mm~200mm, and the depth of the molding area is 30mm~50mm.

[0018] The present invention can obtain a plurality of smaller-sized nickel-phosphorus alloy blocks by casting the melt into a mold with multiple channels and forming areas, and setting the size of the forming area, thereby eliminating the subsequent crushing process, facilitating direct use for high-temperature alloy smelting, effectively improving the production efficiency of the high-temperature alloy, and reducing the production cost.

[0019] Compared with the prior art, the present invention has the following advantages: 1. The present invention forms a Ni-based master alloy in which the mass proportion of P element is 5% to 25% by limiting the content of each component. Compared with elemental red phosphorus, the melting point is significantly improved and is closer to the melting point of nickel, a high-temperature alloy matrix. It can meet the smelting requirements of aerospace-grade high-temperature alloys and avoid the phenomenon of burning and volatilization caused by adding elemental phosphorus during the smelting process of the high-temperature alloy.

[0020] 2. The present invention adopts a smelting + casting process to prepare the nickel-phosphorus master alloy, which effectively shortens the preparation process, reduces the chemical reactions and control links involved, and can improve production stability; at the same time, by controlling the impurity content of the raw materials, removing the air in the furnace body by the method of filling with argon to reduce oxygen, and smelting in an argon environment with a stable flow rate, it is possible to avoid the loss of red phosphorus, improve the recovery rate of phosphorus during smelting, and reduce the impurity content of the nickel-phosphorus master alloy, thereby improving the yield of the nickel-phosphorus master alloy, and thus ensuring the product quality of the downstream material high-temperature alloy; in addition, the smelting process does not come into contact with the air, which can avoid the generation of P2O5 toxic gas and ensure the safety of the production process.

[0021] 3. The nickel-phosphorus master alloy preparation method proposed in the present invention is simple and safe, and is more suitable for large-scale, large-batch, and industrialized production compared to the preparation methods in the prior art.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a microscopic image of the nickel-phosphorus master alloy prepared in Example 1 of the present invention.

[0024] Figure 2 This is a distribution diagram of the Ni element in the nickel-phosphorus master alloy prepared in Example 1 of the present invention.

[0025] Figure 3 This is a distribution diagram of the P element in the nickel-phosphorus master alloy prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] Example 1 The nickel-phosphorus master alloy of this embodiment is composed of the following elements in the following mass proportions: P 15%, and the balance Ni and unavoidable impurities.

[0027] The preparation method of this embodiment comprises the following steps: Step 1, compact and flatten red phosphorus with a mass purity greater than 99.9% and a particle size of 30-80 meshes on the bottom of a crucible in a closed device, evenly place a nickel plate with a mass purity greater than 99.9% on the upper layer of the red phosphorus, close the closed device, and then evacuate to -0.1MPa, and then fill with argon gas with a purity of more than 99.99% to 0MPa, and after 3 cycles of evacuating and filling with argon, continue to pass argon gas at a flow rate of 0.8L / min, and after the argon flow rate stabilizes, turn on the heating system and heat it to 1150°C for smelting, and stir for 25 minutes after the red phosphorus and the nickel plate are melted to obtain a melt; the length and width of the nickel plate are both 30mm-100mm, and the thickness of the nickel plate is 5mm-10mm; Step 2: Cast the melt obtained in step 1 into a mold having multiple channels and forming areas through a chute, and after cooling, obtain multiple high-homogeneity nickel-phosphorus master alloy ingots with a size of 100 mm×100 mm×40 mm.

[0028] The nickel-phosphorus master alloy ingot obtained in this example was subjected to element detection, and the results are shown in Table 1.

[0029] Table 1 Element mass ratio (%) of the nickel-phosphorus master alloy ingot prepared in Example 1

[0030] As shown in Table 1, the nickel-phosphorus master alloy ingot has a low content of impurity elements, which can avoid affecting the performance of downstream high-temperature alloy materials.

[0031] The nickel-phosphorus master alloy ingot obtained in this embodiment was subjected to microstructure and energy spectrum analysis. Figures 1 to 3 As shown, the Ni and P elements are evenly distributed in the nickel-phosphorus master alloy ingot without segregation.

[0032] Example 2 The nickel-phosphorus master alloy of this embodiment is composed of the following elements in the following mass proportions: P 5%, and the balance Ni and inevitable impurities.

[0033] The preparation method of this embodiment comprises the following steps: Step 1, compact and flatten red phosphorus with a mass purity greater than 99.9% and a particle size of 30-80 meshes on the bottom of a crucible in a sealed device, evenly place a nickel plate with a mass purity greater than 99.9% on the upper layer of the red phosphorus, close the sealed device, and then evacuate to -0.1MPa, then fill with argon gas with a purity volume purity of more than 99.99% to 0MPa, and after 3 cycles of evacuating and filling with argon, continue to introduce argon gas at a flow rate of 0.5L / min, and after the argon flow rate stabilizes, turn on the heating system and heat it to 1500°C for smelting, stir for 20 minutes after the red phosphorus and the nickel plate are melted, and obtain a melt; the length and width of the nickel plate are both 30mm-100mm, and the thickness of the nickel plate is 5mm-10mm; Step 2: Cast the melt obtained in step 1 into a mold having multiple channels and forming areas through a chute, and after cooling, obtain multiple high-homogeneity nickel-phosphorus master alloy ingots with a size of 50 mm×50 mm×30 mm.

[0034] The nickel-phosphorus master alloy ingot obtained in this example was subjected to element detection, and the results are shown in Table 2.

[0035] Table 2 Element mass ratio of the nickel-phosphorus master alloy ingot prepared in Example 2 (%)

[0036] As shown in Table 2, the nickel-phosphorus master alloy ingot has a low content of impurity elements, which can avoid affecting the performance of downstream high-temperature alloy materials.

[0037] Example 3 The nickel-phosphorus master alloy of this embodiment is composed of the following elements in the following mass proportions: P 20%, and the balance Ni and inevitable impurities.

[0038] The preparation method of this embodiment comprises the following steps: Step 1, compact and flatten red phosphorus with a mass purity greater than 99.9% and a particle size of 30-80 meshes on the bottom of a crucible in a closed device, evenly place a nickel plate with a mass purity greater than 99.9% on the upper layer of the red phosphorus, close the closed device, and then evacuate to -0.1MPa, then fill with argon gas with a purity volume purity of more than 99.99% to 0MPa, and after 3 cycles of evacuating and filling with argon, continue to introduce argon gas at a flow rate of 0.5L / min, and after the argon flow rate stabilizes, turn on the heating system and heat it to 1200°C for smelting, and stir for 27 minutes after the red phosphorus and the nickel plate are melted to obtain a melt; the length and width of the nickel plate are both 30mm-100mm, and the thickness of the nickel plate is 5mm-10mm; Step 2: Cast the melt obtained in step 1 into a mold having multiple channels and forming areas through a chute, and after cooling, obtain multiple high-homogeneity nickel-phosphorus master alloy ingots with a size of 150 mm×150 mm×45 mm.

[0039] The nickel-phosphorus master alloy ingot obtained in this example was subjected to element detection, and the results are shown in Table 3.

[0040] Table 3 Element mass ratio of the nickel-phosphorus master alloy ingot prepared in Example 3 (%)

[0041] As shown in Table 3, the nickel-phosphorus master alloy ingot has a low content of impurity elements, which can avoid affecting the performance of downstream high-temperature alloy materials.

[0042] Example 4 The nickel-phosphorus master alloy of this embodiment is composed of the following elements in the following mass proportions: P 25%, and the balance Ni and unavoidable impurities.

[0043] The preparation method of this embodiment comprises the following steps: Step 1, compact and flatten red phosphorus with a mass purity greater than 99.9% and a particle size of 30-80 meshes on the bottom of a crucible in a closed device, evenly place a nickel plate with a mass purity greater than 99.9% on the upper layer of the red phosphorus, close the closed device, and then evacuate to -0.1MPa, and then fill with argon gas with a purity volume purity of more than 99.99% to 0MPa, and after 3 cycles of evacuating and filling with argon, continue to pass argon gas at a flow rate of 1.0L / min, and after the argon flow rate stabilizes, turn on the heating system and heat it to 1000°C for smelting, and stir for 30 minutes after the red phosphorus and the nickel plate are melted to obtain a melt; the length and width of the nickel plate are both 30mm-100mm, and the thickness of the nickel plate is 5mm-10mm; Step 2: Cast the melt obtained in step 1 into a mold having multiple channels and forming areas through a chute, and after cooling, obtain multiple high-homogeneity nickel-phosphorus master alloy ingots with a size of 200 mm×200 mm×50 mm.

[0044] The nickel-phosphorus master alloy ingot obtained in this example was subjected to element detection, and the results are shown in Table 4.

[0045] Table 4 Element mass ratio of the nickel-phosphorus master alloy ingot prepared in Example 4 (%)

[0046] As shown in Table 4, the content of impurity elements in the nickel-phosphorus master alloy ingot is low, which can avoid affecting the performance of downstream high-temperature alloy materials.

[0047] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A nickel-phosphorus master alloy for aerospace-grade high-temperature alloys, characterized in that: The nickel-phosphorus master alloy is composed of the following elements in proportion by mass: P 5% to 25%, Fe not more than 0.05%, Si not more than 0.01%, C not more than 0.01%, S not more than 0.01%, O not more than 0.01%, N not more than 0.005%, and the balance is Ni.

2. The nickel-phosphorus master alloy for aerospace-grade high-temperature alloy according to claim 1, characterized in that: The nickel-phosphorus master alloy is composed of the following elements in proportion by mass: P 15% to 25%, Fe not more than 0.05%, Si not more than 0.01%, C not more than 0.01%, S not more than 0.01%, O not more than 0.005%, N not more than 0.003%, and the balance is Ni.

3. A method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloys as claimed in claim 1 or 2, characterized in that: The preparation method comprises the following steps: Step 1: compact and flatten the red phosphorus on the bottom of the crucible, evenly place the nickel plate on the upper layer of the red phosphorus, and then fill with argon to reduce oxygen and smelt to obtain a melt; Step 2: Casting and cooling the melt obtained in step 1 to obtain a nickel-phosphorus alloy ingot.

4. The method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy according to claim 3, characterized in that: The mass purity of the red phosphorus and the nickel plate in step 1 is greater than 99.9%, the particle size of the red phosphorus is 30 mesh to 80 mesh, the length and width of the nickel plate are both 30 mm to 100 mm, and the thickness of the nickel plate is 5 mm to 10 mm.

5. The method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy according to claim 3, characterized in that: The process of argon filling and oxygen reduction in step 1 is: evacuate to -0.1MPa, then fill with argon gas with a volume purity of more than 99.99% to 0MPa, and after multiple cycles of vacuuming and filling with argon gas, continue to introduce argon gas at a flow rate of 0.5L / min~1.0L / min.

6. The method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy according to claim 3, characterized in that: The smelting process in step 1 is: after the argon gas flow rate is stable, the temperature is raised to 1000°C~1500°C for smelting, and after the red phosphorus and the nickel plate are completely melted, stirring is performed for 20min~30min.

7. The method for preparing a nickel-phosphorus master alloy for aerospace-grade high-temperature alloy according to claim 3, characterized in that: The casting process in step 2 is: casting into a mold through a chute, the mold has multiple channels and a molding area, the length and width of the molding area are both 50mm~200mm, and the depth of the molding area is 30mm~50mm.

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