A rare earth modified manganese-containing corrosion-resistant high-entropy alloy and a preparation method thereof

Abstract

The application discloses a rare earth modified corrosion-resistant high-entropy alloy containing manganese and a preparation method thereof and belongs to the technical field of high-entropy alloy smelting. The high-entropy alloy is composed of Fe, Mn, Cr, Ni and RE, wherein RE includes Ce or Y, the atomic ratio of RE and the sum of the other four elements is x:(100-x), wherein x is 0.01-0.5, and the atomic ratio of the other four elements Fe, Mn, Cr and Ni is 40:20:20:20. The Mn element and the other four elements are smelted in two steps, so that the solid solution of RE and Mn can be effectively prevented, the prepared alloy can modify MnS inclusions into RE-O-S inclusions, the pitting potential of the material in a chloride solution is improved, the compactness of a passivation film is enhanced, and the occurrence of pitting is inhibited.

Description

Technical Field

[0001] This invention relates to a rare earth-modified manganese-containing corrosion-resistant high-entropy alloy and its preparation method, belonging to the field of high-entropy alloy smelting technology. Background Technology

[0002] Traditional materials, when used in specialized fields, often fail to meet the demanding service conditions in terms of mechanical properties or corrosion resistance, thus affecting the long-term stability and safety of engineering structures, and directly impacting material lifespan and maintenance costs. To address this challenge, high-entropy alloys have emerged. With their stable high mixing entropy and solid solution structure, high-entropy alloys overcome the limitations of traditional alloys, significantly expanding the possibilities for alloy design. Exhibiting excellent comprehensive mechanical properties, corrosion resistance, and wear resistance, high-entropy alloys are strong candidates for developing specialized equipment.

[0003] Rare earth elements are hailed as "industrial vitamins." Rare earth microalloying can refine the grain size of materials or form second-phase particles, and can also alter the electrochemical properties of alloys, forming a denser oxide film on the alloy surface. It is an effective method to simultaneously improve the mechanical properties and corrosion resistance of materials. This makes rare earth elements of significant application value in advanced materials design and manufacturing, with wide applications in steel, magnesium alloys, and aluminum alloys.

[0004] However, due to the volatility of rare earth elements and the high melting point of rare earth oxides, it is difficult to control the uniformity of composition during the smelting process, resulting in material non-uniformity and deterioration of performance. Therefore, controlling the volatilization of rare earth elements and the uniformity of ingots during the smelting process is of great significance for the preparation of high-entropy alloys. Summary of the Invention

[0005] This invention aims to provide a rare earth-modified manganese-containing corrosion-resistant high-entropy alloy and its preparation method. By optimizing the smelting process, the problem of difficulty in controlling the uniformity of composition during the smelting process of high-entropy alloys, which leads to a deterioration in alloy performance, is solved. The resulting alloy has better pitting corrosion resistance and passivation film protection.

[0006] Currently, rare earth doping is an effective method to improve the corrosion resistance of materials. Among rare earth elements, Ce and Y are common and relatively inexpensive, making them economical. Doping with trace amounts of rare earth elements does not alter the original single-phase structure of the high-entropy alloy. Furthermore, in this invention, the addition of Mn and Cr elements aims to improve the mechanical properties of the alloy. However, because MnS and MnCr2O4 inclusions easily form inside the alloy, leading to Cr segregation and MnS pitting corrosion, the alloy's corrosion resistance is poor. The addition of rare earth elements can adsorb O and S elements and eliminate Mn and Cr elements, resulting in a more uniform elemental composition within the material and the formation of more corrosion-resistant rare earth inclusions, improving the performance of the passivation film and thus effectively enhancing the alloy's corrosion resistance.

[0007] The reason for selecting a rare earth element content of 0.01~0.5 at.% in this invention is that the solid solubility of rare earth elements in materials is limited, and their content is usually within 0.5 at.%. Excessive rare earth elements will lead to an increase in inclusions and defects in the material, significantly reduce the plasticity of the material, and increase the cost.

[0008] This invention provides a rare earth-modified manganese-containing corrosion-resistant high-entropy alloy composed of Fe, Mn, Cr, Ni, and RE, wherein RE includes Ce or Y, and the atomic ratio of RE to the sum of the other four elements is x∶(100-x), where x takes the value of 0.01~0.5; the atomic ratio of the other four elements Fe, Mn, Cr, and Ni is 40∶20∶20∶20.

[0009] Furthermore, the high-entropy alloy uses bulk raw materials with a purity greater than 99.95% for all its elements.

[0010] This invention provides a method for preparing the above-mentioned Fe-Mn-Cr-Ni-RE high-entropy alloy, specifically including the following steps:

[0011] S1. Weigh the raw materials according to the chemical composition and atomic ratio of the high-entropy alloy, then grind off the oxide scale and ultrasonically clean them in alcohol to remove impurities.

[0012] S2. Divide the raw materials prepared in step S1 into two portions. The first portion includes Fe, Cr, Ni and RE elements, and the second portion contains only pure Mn element. Place the two portions of raw materials into two copper crucibles in the electric arc furnace respectively.

[0013] S3. After using a mechanical pump to create a vacuum, start the molecular pump to continue evacuating to 1×10⁻⁶. -3 Pa~3×10 -3 Pa, then close the valve and molecular pump; fill with high-purity argon gas to make the furnace pressure 0.3-0.5 atm;

[0014] S4. Turn on the welding current and voltage, and after igniting the arc, first heat and melt the sponge titanium block. After the titanium block cools down, observe the surface color. If the surface still shows a silvery-white metallic luster, it proves that there is no air residue in the furnace cavity. Then melt the Fe, Cr, Ni, and RE raw materials placed in step S2.

[0015] S5. Use tools to move the ingot obtained in step S4 into a crucible containing raw material Mn and continue smelting;

[0016] S6. Cast the ingot melted in step S5 into an 85mm×10mm×6mm mold. After cooling for 10~20 minutes, open the mold and take out the sample.

[0017] S7. Heat-treat the obtained sample.

[0018] Furthermore, in step S1, since Mn has a low melting point and is easily volatile, an additional 1% to 5% of Mn needs to be weighed out during preparation to compensate for it.

[0019] Furthermore, in step S2, the first batch of raw materials is placed in the copper crucible from bottom to top in the following order: Ni, Fe, RE, Cr, and RE is coated by the other three raw materials.

[0020] Furthermore, in step S4, the raw material is first preheated from the edge with a small flame, and then melted evenly with a large flame for 20-30 seconds; the melting is repeated 3-6 times, and the alloy ingot is turned over with an auxiliary tool before each melting.

[0021] Furthermore, in step S5, the melting process is repeated 5 to 6 times, and the alloy ingot is flipped over using an auxiliary tool before each melting process.

[0022] Further, in step S7, the heat treatment process is as follows: homogenization treatment at 1200~1300℃ for 2~5 hours, cold rolling for 50~80%, followed by recrystallization annealing at 1000~1100℃ for 0.5~1 hours.

[0023] The beneficial effects of this invention are:

[0024] (1) This invention improves the traditional preparation method and obtains a stable Fe-Mn-Cr-Ni-RE high-entropy alloy containing rare earth elements: the alloy obtained by the traditional preparation method will cause rare earth elements to dissolve in the matrix or only accumulate in a very small amount in the inclusions, which will result in the inability to suppress the inclusions such as MnS in the alloy that are detrimental to pitting corrosion resistance; while the preparation method designed in this invention can effectively prevent RE and Mn from dissolving in the matrix first by melting Mn element and the other four elements in two steps. The prepared alloy can modify MnS inclusions into RE-OS inclusions, which increases the pitting potential of the material in chloride solution and enhances the density of the passivation film, thus suppressing the occurrence of pitting corrosion; the pitting corrosion resistance is better than that of the Fe-Mn-Cr-Ni-RE high-entropy alloy prepared by the traditional method.

[0025] (2) The rare earth element content in this invention is relatively low, and the main elements are all commonly used alloys, so the material cost is low. Attached Figure Description

[0026] Figure 1 This is a flowchart of the preparation process of the present invention;

[0027] Figure 2 It is the (Fe) prepared in Example 1 of this invention. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 Morphology and composition of high-entropy alloy inclusions;

[0028] Figure 3 The (Fe) prepared in Example 1 and Comparative Example 2 of this invention 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 High-entropy alloys and Fe from Comparative Example 1 40 Mn 20 Cr 20 Ni 20 Polarization curves of high-entropy alloys in 3.5 wt.% NaCl solution;

[0029] Figure 4 It is the (Fe) prepared in Example 1 of this invention. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 Impedance spectral curves of the high-entropy alloy and Comparative Examples 1 and 2 in 3.5 wt.% NaCl solution;

[0030] Figure 5 It is the (Fe) prepared in Example 2 of this invention. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 Morphology and composition of high-entropy alloy inclusions;

[0031] Figure 6 The (Fe) prepared in Example 2 and Comparative Example 3 of this invention 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 Polarization curves of high-entropy alloys in 3.5 wt.% NaCl solution;

[0032] Figure 7 The (Fe) prepared in Example 2 and Comparative Example 3 of this invention 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 Impedance spectral curves of high-entropy alloys in 3.5 wt.% NaCl solution;

[0033] Figure 8 It is the (Fe) prepared in Example 3 of this study. 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 SEM and EDS images of alloy inclusions;

[0034] Figure 9 The (Fe) prepared in Example 3 and Comparative Example 4 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 Potentiodynamic polarization curves of the alloy in 3.5 wt% NaCl solution. Detailed Implementation

[0035] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments.

[0036] Comparative Example 1

[0037] Fe mentioned in this invention 40 Mn 20 Cr 20 Ni 20The high-entropy alloy is prepared by vacuum arc melting. During melting, the alloy is placed in the same copper crucible in the order of Ni, Fe, Mn, and Cr from bottom to top, and melted six times. Before each melting, the ingot is turned over and cast into a mold. The mold size and heat treatment process are the same as those of this invention.

[0038] Comparative Example 2

[0039] This example shows (Fe) obtained using a traditional process. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 The high-entropy alloy is prepared by vacuum arc melting. During melting, the alloys are placed in the same copper crucible in the order of Ni, Fe, Ce, Mn, and Cr from bottom to top, and melted six times. Before each melting, the ingot is turned over and cast into a mold. The heat treatment process is the same as that of this invention.

[0040] Unlike the present invention, the traditional process uses a single crucible and can obtain an ingot in one melting process, while the present invention separates rare earth elements from other elements, resulting in a material with better performance.

[0041] Comparative Example 3

[0042] This example shows (Fe) obtained using a traditional process. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 The high-entropy alloy is prepared by vacuum arc melting. During melting, the alloys are placed in the same copper crucible in the order of Ni, Fe, Y, Mn, and Cr from bottom to top, and melted six times. Before each melting, the ingot is turned over and cast into a mold. The heat treatment process is the same as that of this invention.

[0043] Comparative Example 4

[0044] This example shows (Fe) obtained using a traditional process. 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 The high-entropy alloy is prepared by vacuum arc melting. During melting, the alloys are placed in the same copper crucible in the order of Ni, Fe, Ce, Mn, and Cr from bottom to top, and melted six times. Before each melting, the ingot is turned over and cast into a mold. The heat treatment process is the same as that of this invention. Example 1

[0045] This embodiment is a Fe-Mn-Cr-Ni-RE system high-entropy alloy, composed of five elements: Fe, Mn, Cr, Ni, and Ce, with a composition of (Fe... 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 .

[0046] The above (Fe) 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 The preparation method of high-entropy alloys includes the following steps:

[0047] S1, according to (Fe) 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 The chemical composition and mass fraction of the high-entropy alloy were determined by weighing the raw materials, then removing the oxide scale, and ultrasonically cleaning in alcohol for 3 minutes to remove impurities. During preparation, an additional 5% of Mn needs to be weighed to compensate for its volatilization.

[0048] S2. Divide the raw materials prepared in step S1 into two portions. The first portion contains four elements: Fe, Cr, Ni, and Ce. The second portion contains only pure Mn. Place the two portions of raw materials into two copper crucibles in the electric arc furnace. The first portion of raw materials is placed in the copper crucible in the following order from bottom to top: Ni, Fe, Ce, Cr, with Ce being surrounded by the other three elements. Then close the furnace door tightly.

[0049] S3. After using a mechanical pump to create a vacuum, start the molecular pump to continue creating a vacuum up to 3 × 10⁻⁶. -3 Then, shut off the valves and molecular pump. Introduce high-purity argon gas to bring the furnace pressure to 0.4 atm.

[0050] S4. Turn on the current and voltage, and after igniting the arc, first heat and melt the sponge titanium block. After the titanium block cools, observe the surface color. If the surface still shows a silvery-white metallic luster, it proves that there is no residual air in the furnace cavity. Then, melt the first batch of Fe, Cr, Ni, Ce raw materials placed in step S2. Each melting time is 20 seconds, for a total of 5 times. Before each melting, flip the ingot.

[0051] S5. Use tools to move the alloy ingot into a crucible containing pure Mn raw material, and continue to melt it 6 times, each melting for 20 seconds. Turn the ingot over before melting.

[0052] S6. Cast the molten ingot into an 85mm×10mm×6mm mold. After cooling for 10 minutes, open the mold and remove the sample.

[0053] S7. The obtained sample is homogenized at 1200℃ for 2 hours, cold rolled by 70%, and then recrystallized and annealed at 1000℃ for 1 hour.

[0054] Figure 2 This is the (Fe) prepared in this embodiment. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 SEM and EDS images of the alloy inclusions show that the Ce content in the inclusions is 20.45 at%, with the remainder being 42.08 at% O, 9.08 at% S, 12.01 at% Fe, 5.69 at% Ni, 6.79 at% Cr, and 3.90 at% Mn.

[0055] Figure 3 The (Fe) prepared in Example 1, Comparative Example 1, and Comparative Example 2 are as follows. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 The potentiodynamic polarization curves of the alloy in 3.5 wt% NaCl solution show that the corrosion resistance of the alloy prepared in this invention is significantly higher than that of Comparative Examples 1 and 2, and the pitting potential is increased by 190 mV compared with Comparative Example 2.

[0056] Figure 4 The (Fe) prepared in Example 1, Comparative Example 1, and Comparative Example 2 are as follows. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Ce 0.1 The impedance spectrum of the alloy in 3.5 wt% NaCl solution shows that the radius of the Nyquist plot is larger than that of Comparative Examples 1 and 2. Compared with the alloys prepared in Comparative Examples 1 and 2, the passivation film thickness calculated from the impedance spectrum is increased by 1.2 nm and 0.5 nm, respectively. Example 2

[0057] This embodiment is a Fe-Mn-Cr-Ni-RE system high-entropy alloy, composed of five elements: Fe, Mn, Cr, Ni, and Y, with a composition of (Fe... 40 Mn 20 Cr 20 Ni 20 )99.9 Y 0.1 .

[0058] The above (Fe) 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 The preparation method of high-entropy alloys includes the following steps:

[0059] S1, according to (Fe) 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 The chemical composition and mass fraction of the high-entropy alloy were determined by weighing the raw materials, removing the oxide scale, and ultrasonically cleaning in alcohol for 3 minutes to remove dust. During preparation, an additional 5% of Mn needs to be weighed to compensate for its volatilization.

[0060] S2. Divide the raw materials prepared in step S1 into two portions. The first portion contains four elements: Fe, Cr, Ni, and Y. The second portion contains only pure Mn. Place the two portions of raw materials into two copper crucibles in the electric arc furnace. The first portion of raw materials is placed in the copper crucible in the following order from bottom to top: Ni, Fe, Y, Cr, with Y being surrounded by the other three elements. Then close the furnace door tightly.

[0061] S3. After using a mechanical pump to create a vacuum, start the molecular pump to continue creating a vacuum up to 3 × 10⁻⁶. -3 Then, shut off the valves and molecular pump. Introduce high-purity argon gas to bring the furnace pressure to 0.4 atm.

[0062] S4. Turn on the current and voltage, and after igniting the arc, first heat and melt the sponge titanium block. After the titanium block cools, observe the surface color. If the surface still shows a silvery-white metallic luster, it proves that there is no residual air in the furnace cavity. Then, melt the first batch of Fe, Cr, Ni, and Y raw materials placed in step S2. Melt for 20 seconds each time, for a total of 5 times. Turn the ingot over before each melting.

[0063] S5. Use tools to move the alloy ingot into a crucible containing pure Mn raw material, and continue to melt it 6 times, each melting for 20 seconds. Turn the ingot over before melting.

[0064] S6. Cast the molten ingot into an 85mm×10mm×6mm mold. After cooling for 10 minutes, open the mold and remove the sample.

[0065] S7. The obtained sample is homogenized at 1200℃ for 2 hours, cold rolled by 70%, and then recrystallized and annealed at 1000℃ for 1 hour.

[0066] Figure 5 It is the (Fe) prepared in Example 2 of this study. 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 SEM and EDS images of the alloy inclusions show that the inclusions contain 32.4 at% Y, with the remainder being 7.2 at% O, 40.4 at% S, 5.22 at% Fe, 2.14 at% Ni, 3.1 at% Cr, and 9.54 at% Mn.

[0067] Figure 6 The (Fe) prepared in Example 2 and Comparative Example 3 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 The potentiodynamic polarization curves of the alloy in 3.5 wt% NaCl solution show that the corrosion resistance of the alloy prepared in this invention is significantly higher than that of the alloy prepared in Comparative Example 3, and the pitting potential is increased by 170 mV compared with Comparative Example 3.

[0068] Figure 7 The (Fe) prepared in Example 2 and Comparative Example 3 40 Mn 20 Cr 20 Ni 20 ) 99.9 Y 0.1 The impedance spectrum of the alloy in 3.5 wt% NaCl solution shows that the radius of the Nyquist plot is also larger, and the passivation film thickness calculated from the impedance spectrum is increased by 0.7 nm compared with the alloy prepared in Comparative Example 3. Example 3

[0069] This embodiment is a Fe-Mn-Cr-Ni-RE system high-entropy alloy, composed of five elements: Fe, Mn, Cr, Ni, and Ce, with a composition of (Fe... 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 .

[0070] The above (Fe) 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 The preparation method of high-entropy alloys includes the following steps:

[0071] S1, according to (Fe) 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 The chemical composition and mass fraction of the high-entropy alloy were determined by weighing the raw materials, then removing the oxide scale, and ultrasonically cleaning in alcohol for 3 minutes to remove impurities. During preparation, an additional 5% of Mn needs to be weighed to compensate for its volatilization.

[0072] S2. Divide the raw materials prepared in step S1 into two portions. The first portion contains four elements: Fe, Cr, Ni, and Ce. The second portion contains only pure Mn. Place the two portions of raw materials into two copper crucibles in the electric arc furnace. The first portion of raw materials is placed in the copper crucible in the following order from bottom to top: Ni, Fe, Ce, Cr, with Ce being surrounded by the other three elements. Then close the furnace door tightly.

[0073] S3. After using a mechanical pump to create a vacuum, start the molecular pump to continue creating a vacuum up to 3 × 10⁻⁶. -3 Then, shut off the valves and molecular pump. Introduce high-purity argon gas to bring the furnace pressure to 0.4 atm.

[0074] S4. Turn on the current and voltage, and after igniting the arc, first heat and melt the sponge titanium block. After the titanium block cools, observe the surface color. If the surface still shows a silvery-white metallic luster, it proves that there is no residual air in the furnace cavity. Then, melt the first batch of Fe, Cr, Ni, Ce raw materials placed in step S2. Each melting time is 20 seconds, for a total of 5 times. Before each melting, flip the ingot.

[0075] S5. Use tools to move the alloy ingot into a crucible containing pure Mn raw material, and continue to melt it 6 times, each melting for 20 seconds. Turn the ingot over before melting.

[0076] S6. Cast the molten ingot into an 85mm×10mm×6mm mold. After cooling for 10 minutes, open the mold and remove the sample.

[0077] S7. The obtained sample is homogenized at 1200℃ for 2 hours, cold rolled by 70%, and then recrystallized and annealed at 1000℃ for 1 hour.

[0078] Figure 8 It is the (Fe) prepared in Example 3 of this study. 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05SEM and EDS images of the alloy inclusions show that the Ce content in the inclusions is 13.52 at%, with the remainder being 61.45 at% O, 0.03 at% S, 2.07 at% Fe, 0.98 at% Ni, 0.98 at% Cr, and 20.97 at% Al.

[0079] Figure 9 The (Fe) prepared in Example 3 and Comparative Example 4 40 Mn 20 Cr 20 Ni 20 ) 99.95 Ce 0.05 The potentiodynamic polarization curves of the alloy in 3.5 wt% NaCl solution show that the alloy prepared in this invention has higher corrosion resistance than Comparative Example 4, and the pitting potential is increased by 103 mV compared with Comparative Example 4.

Claims

1. A method for preparing a rare earth modified corrosion resistant high-entropy alloy containing manganese, characterized in that: The rare earth modified manganese-containing corrosion-resistant high-entropy alloy is composed of Fe, Mn, Cr, Ni and RE, wherein RE includes Ce or Y, the atomic ratio of RE to the sum of the other four elements is x:(100-x), wherein x is 0.01-0.5, and the atomic ratio of the other four elements Fe, Mn, Cr and Ni is 40:20:20:

20. The preparation method of the rare earth modified manganese-containing corrosion-resistant high-entropy alloy specifically comprises the following steps: S1, according to the chemical composition and atomic ratio of the high-entropy alloy, the raw materials are weighed, then the oxide scale is polished, and the impurities are removed by ultrasonic cleaning in alcohol; S2, the raw materials prepared in step S1 are divided into two parts, the first part includes Fe, Cr, Ni and RE elements, and the second part only contains pure Mn single element, and the two parts of raw materials are respectively placed in two copper crucibles of the electric arc furnace; S3, after using mechanical pump to vacuum, start molecular pump to continue vacuum to 1 x 10 -3 Pa~3 x 10 -3 Pa, then close valve and molecular pump; fill high purity argon, make pressure in furnace 0.3~0.5 atm; S4, open the welding current and voltage, after the arc is ignited, first heat and smelt the titanium sponge block, observe the surface color after the titanium block is cooled, if the surface still presents silver-white metallic luster, it proves that there is no air residue in the furnace cavity, then smelt the Fe, Cr, Ni and RE raw materials placed in step S2; S5, using tools, move the ingot prepared in step S4 to the crucible containing raw material Mn, and continue to smelt; S6, the ingot melted in step S5 is suction cast into a mold with a size of 85mmx10mmx6mm, after cooling for 10-20 minutes, the mold is opened, and the sample is taken out; S7, the obtained sample is heat treated.

2. The method of claim 1, wherein the method is characterized by: The selected elements of the high-entropy alloy are all block raw materials with a purity greater than 99.95%.

3. The method of claim 1, wherein the method further comprises: In step S1, because the melting point of Mn element is low and volatile, therefore, 1%-5% of Mn needs to be weighed more to compensate. ​ 4. The method of claim 1, wherein the method further comprises: In step S2, the first part of raw materials is placed in the copper crucible from bottom to top in the order of Ni, Fe, RE and Cr, and RE is wrapped by the other three raw materials.

5. The method of claim 1, wherein the method further comprises: In step S4, first preheat the raw materials from the edge with small fire, then smelt uniformly with large fire, and maintain for 20-30 seconds; repeat smelting for 3-6 times, and turn the alloy ingot before each smelting using auxiliary tools.

6. The method of claim 1, wherein the method further comprises: In step S5, repeat smelting for 5-6 times, and turn the alloy ingot before each smelting using auxiliary tools.

7. The method of claim 1, wherein the method further comprises: In step S7, the heat treatment process is: homogenization treatment at 1200-1300℃ for 2-5h, cold rolling by 50-80%, and then recrystallization annealing at 1000-1100℃ for 0.5-1h. ​

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