Anti-oxidation nickel-based alloy and preparation method thereof

Abstract

The invention discloses an oxidation-resistant nickel-based alloy and a preparation method thereof, and the nickel-based alloy comprises the following components in percentage by mass: 0.004 to 0.009 percent of C, 0.001 to 0.007 percent of S, 0.003 to 0.008 percent of P, 0.2 to 0.6 percent of Si, 0.3 to 0.7 percent of Mn, 0.001 to 0.003 percent of Mo, 22 to 27 percent of Gr, 60 to 65 percent of Ni, 0.02 to 0.14 percent of Cu, 1.5 to 1.8 percent of Al and the balance of Fe. By adding chromium, nickel, aluminum, nitrogen and other elements, the oxidation resistance of the nickel-based alloy is improved, and the endurance strength and creep strength of steel can be improved through solid solution strengthening by adding chromium. The high-temperature oxidation resistance of metal refers to the resistance of steel to oxidation under a high-temperature condition, and is an important guarantee condition for judging whether the steel can work at the high temperature for a long time or not. By means of the preparation method, the oxidation resistance of the nickel-based alloy can reach 0.06 g / (m < 2 >. H) at the temperature of 1100 DEG C, and then complete oxidation resistance is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of nickel-based alloys, and in particular relates to an oxidation-resistant nickel-based alloy and a preparation method thereof. Background Art

[0002] Heat-resistant steel is widely used in metallurgy, mining, electric power, cement machinery and other industrial sectors, such as boiler burners in thermal power plants, grates in pellet sintering machines, lifting plates in clinker kiln coolers, and heat-resistant parts of thermal equipment in the cement industry. These heat-resistant steel parts will undergo oxidation reactions when they come into contact with oxidizing gases (O2, H2O, CO2, SO2, etc.) under special working conditions, such as high temperature, abrasive wear, etc., which will have an adverse effect on industrial production and the service life of parts. Therefore, the material is required to have not only a certain wear resistance, but also good oxidation resistance to meet the requirements of its performance.

[0003] Nickel-based alloys have a high chromium content, which allows them to be used in many corrosive and high-temperature environments, while the addition of aluminum further improves their strength and oxidation resistance. The alloy has excellent high-temperature oxidation resistance, good high-temperature mechanical properties and corrosion resistance, and is easy to form, process and weld. It can be made into plates, tubes, wires, strips, rods, forgings, etc., and has been widely used in the fields of petrochemicals, metallurgy, heat treatment, environmental protection, etc. However, the oxidation resistance of existing nickel-based alloys at high temperatures is still insufficient, so nickel-based alloys with better oxidation resistance are needed.

[0004] The patent document with announcement number CN117987690A discloses an oxidation-resistant and corrosion-resistant nickel-based high-temperature alloy and its preparation method and application, belonging to the technical field of nickel-based high-temperature alloys. The oxidation-resistant and corrosion-resistant nickel-based high-temperature alloy provided by the present invention comprises the following chemical components by mass percentage: C: 0.05-0.15%, Cr: 16-18%, Co: 9-11%, W: 2.5-3%, Mo: 1-2%, Al: 3.5-4%, Ti: 3.5-4%, Nb: 0.8-1.5%, Ta: 1-3%, B: 0.002-0.015%, Zr: 0.002-0.04% and the remainder Ni. The oxidation rate of the oxidation-resistant and corrosion-resistant nickel-based high-temperature alloy provided by the patent at 850°C is ≤0.012g / (m 2 ·h), oxidation rate at 900℃≤0.06g / (m 2 h).

[0005] The patent document with announcement number CN118007006A discloses a wear-reducing and oxidation-resistant nickel-based alloy and a preparation method thereof. The nickel-based alloy includes a nickel-based alloy matrix with W solid solution, metallic silver and ceramic CrAlSiN; the preparation method includes: depositing an aluminum layer on NiCr alloy powder to form an aluminum-coated nickel-based alloy powder, ball-milling and mixing with silver azide and WSi2 powder, using the thermal effect of a high-energy laser beam to cause the silver azide and WSi2 to decompose in sequence, inducing an in-situ reaction between Cr-Si-Al-N at high temperature to form a layered wear-reducing ceramic CrAlSiN, and the decomposed high-melting-point W is solid-dissolved in the nickel-based alloy matrix to form a nickel-based alloy with W solid solution reinforced by metallic silver and ceramic CrAlSiN, and during the friction process, friction heat induces the formation of a self-lubricating phase Ag2WO4 between Ag-WO, and at the same time, CrAlSiN and W can effectively prevent high-temperature oxidation of the alloy.

[0006] However, the oxidation rate of the nickel-based alloy prepared by the above patent at 1100°C still needs to be improved. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides an oxidation-resistant nickel-based alloy and a preparation method thereof.

[0008] The present invention is achieved through the following technical solutions.

[0009] The present invention provides

[0010] An oxidation-resistant nickel-based alloy comprises the following components in mass fraction: C: 0.004-0.009%, S: 0.001-0.007%, P: 0.003-0.008%, Si: 0.2-0.6%, Mn: 0.3-0.7%, Mo: 0.001-0.003%, Gr: 22-27%, Ni: 60-65%, Cu: 0.02-0.14%, Al: 1.5-1.8%, N: 0.04-0.09%, and the rest is Fe.

[0011] Preferably, an oxidation-resistant nickel-based alloy comprises the following components, in mass fraction: C: 0.006-0.008%, S: 0.003-0.006%, P: 0.004-0.006%, Si: 0.36-0.48%, Mn: 0.44-0.65%, Mo: 0.001-0.002%, Gr: 23-25%, Ni: 61-64%, Cu: 0.025-0.13%, Al: 1.62-1.66%, N: 0.06-0.08%, and the rest is Fe.

[0012] A method for preparing an oxidation-resistant nickel-based alloy comprises the following steps:

[0013] S1: Melt the raw materials according to their components;

[0014] S2: Refining:

[0015] S3: Casting:

[0016] S4: After heat treatment, an oxidation-resistant nickel-based alloy is obtained.

[0017] Preferably, in step S1, the raw materials are placed in a vacuum furnace according to their components, and the loading order is: Fe, Cr, Ni, Al, Mn, Si, C. The remaining components can be placed in any order. After the loading is completed, the vacuum furnace cover is closed, and the vacuum pump is turned on to evacuate the vacuum before smelting.

[0018] Preferably, in step S1, the raw materials are kept at 400-600° C. for 3 hours before being placed in a vacuum furnace for smelting.

[0019] Preferably, after the vacuum pump is turned on to evacuate the vacuum, smelting begins when the pressure in the vacuum furnace is less than 20 Pa, and the vacuum furnace is connected to the vacuum pump via a Roots pump.

[0020] Preferably, in step S1, after starting smelting, the power of the vacuum furnace is controlled at 120-180 W and maintained for 7-12 minutes, and then the power is increased to 270-350 W after molten steel is produced at the bottom of the vacuum furnace. When half of the raw material is visually melted, the power is increased to 390-420 W, and the total smelting time is controlled to be 30-50 minutes.

[0021] Preferably, in step S2, the vacuum is evacuated to below 1 Pa during the refining process, and the power of the vacuum furnace is increased to 480-520 W to make the molten metal boil, and the boiling is maintained for 7-13 minutes.

[0022] Preferably, in step S3, the casting temperature is controlled at 1230-1250°C.

[0023] Preferably, in step S4, a vacuum heat treatment furnace is used for heat treatment, the vacuum degree during the heat treatment is less than 1 Pa, the temperature is 1150-1300° C., and after being kept warm for 2 hours, the alloy is taken out of the furnace and water-cooled to obtain an oxidation-resistant nickel-based alloy.

[0024] The beneficial effects of the present invention are:

[0025] The present invention increases the oxidation resistance of the nickel-based alloy by adding elements such as chromium, nickel, aluminum, and nitrogen. The addition of chromium can also improve the long-term strength and creep strength of the steel by solid solution strengthening. The high-temperature oxidation resistance of a metal refers to the resistance of steel to oxidation under high temperature conditions, and is an important guarantee for whether the steel can work at high temperatures for a long time. Through the preparation method of the present invention, the oxidation resistance of the nickel-based alloy can be increased to 0.06 g / (m2 ·h), thereby achieving complete antioxidant properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart of the present invention;

[0027] Figure 2 It is a structural schematic diagram of the vacuum furnace of the present invention being connected to a vacuum pump via a Roots pump;

[0028] Figure 3 This is a metallographic image of the alloy of Example 3 of the present invention before heat treatment, magnified 500 times;

[0029] Figure 4 This is a metallographic image of the alloy of Example 3 of the present invention after heat treatment, magnified 500 times;

[0030] Figure 5 is a schematic diagram of a nickel-based alloy prepared in Example 1 of the present invention;

[0031] Figure 6 is a schematic diagram of a nickel-based alloy prepared in Example 2 of the present invention;

[0032] Figure 7 is a schematic diagram of a nickel-based alloy prepared in Example 3 of the present invention;

[0033] Figure 8 is a schematic diagram of the nickel-based alloy prepared in Comparative Example 1;

[0034] In the figure: 1-vacuum furnace, 2-vacuum pump, 3-Roots pump. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0036] Embodiment 1:

[0037] like Figure 1 , 2 As shown, an oxidation-resistant nickel-based alloy includes the following components, in mass fraction: C: 0.006%, S: 0.003%, P: 0.004%, Si: 0.36%, Mn: 0.44%, Mo: 0.001%, Gr: 23%, Ni: 63%, Cu: 0.13%, Al: 1.65%, N: 0.06%, and the rest is Fe.

[0038] A method for preparing an oxidation-resistant nickel-based alloy comprises the following steps:

[0039] S1: Melt the raw materials according to their components;

[0040] S2: Refining:

[0041] S3: Casting:

[0042] S4: After heat treatment, an oxidation-resistant nickel-based alloy is obtained.

[0043] In the step S1, the raw materials are placed in the vacuum furnace 1 according to their components, and the loading order is Fe, Cr, Ni, Al, Mn, Si, and C. The remaining components can be placed in any order, wherein N is added through high nitrogen ferrochrome. In the loading order, the raw materials that are easy to melt are placed first, the raw materials that are difficult to melt are placed in the middle, and the raw materials that are easily oxidized are placed last. Putting the raw materials that are easy to melt first will produce molten steel first, and the molten steel will wrap the raw materials that are difficult to melt, thereby accelerating the melting speed of the difficult-to-melt metals. After the loading is completed, the cover of the vacuum furnace 1 is closed, and the vacuum pump 2 is turned on to evacuate and then start smelting.

[0044] In step S1, the raw materials are placed in the vacuum furnace 1 for smelting and kept at 400°C for 3 hours to remove moisture and oil.

[0045] In the step S1, after the vacuum pump 2 is turned on to evacuate, smelting is started when the pressure in the vacuum furnace 1 is less than 20 Pa. The vacuum furnace 1 is connected to the vacuum pump 2 via a Roots pump 3 to achieve a lower vacuum degree.

[0046] In the step S1, after the smelting starts, the power of the vacuum furnace 1 is controlled at 120W and maintained for 7 minutes. After molten steel is produced at the bottom of the vacuum furnace 1, the power is increased to 270W. When half of the raw material is visually melted, the power is increased to 390W. The total smelting time can be controlled within 30 minutes. Too long a time will result in excessive burnout of elements.

[0047] In step S2, the vacuum is evacuated to below 1 Pa during the refining process, and the power of the vacuum furnace 1 is increased to 480 W to make the molten metal boil, and maintained for 7 minutes. At this time, the gas in the molten steel will be rolled out by the boiling molten steel and pumped away by the vacuum pump, so that the gas content of the alloy is reduced.

[0048] In the step S3, the casting temperature is controlled at 1230°C. If the temperature is too high, the elements may be further burned and may react with the mold to produce harmful impurities. If the temperature is too low, the molding may be poor.

[0049] In step S4, a vacuum heat treatment furnace is used for heat treatment. The vacuum degree during the heat treatment is less than 1 Pa and the temperature is 1150° C. After being kept warm for 2 hours, the alloy is taken out of the furnace and rapidly cooled with water to obtain an oxidation-resistant nickel-based alloy.

[0050] Embodiment 2:

[0051] like Figure 1 , 2As shown, an oxidation-resistant nickel-based alloy includes the following components, in mass fraction: C: 0.006%, S: 0.003%, P: 0.005%, Si: 0.36%, Mn: 0.44%, Mo: 0.001%, Gr: 25%, Ni: 64%, Cu: 0.13%, Al: 1.62%, N: 0.06%, and the rest is Fe.

[0052] A method for preparing an oxidation-resistant nickel-based alloy comprises the following steps:

[0053] S1: Melt the raw materials according to their components;

[0054] S2: Refining:

[0055] S3: Casting:

[0056] S4: After heat treatment, an oxidation-resistant nickel-based alloy is obtained.

[0057] In the step S1, the raw materials are placed in the vacuum furnace 1 according to their components, and the loading order is Fe, Cr, Ni, Al, Mn, Si, and C. The remaining components can be placed in any order, wherein N is added through high nitrogen ferrochrome. In the loading order, the raw materials that are easy to melt are placed first, the raw materials that are difficult to melt are placed in the middle, and the raw materials that are easily oxidized are placed last. Putting the raw materials that are easy to melt first will produce molten steel first, and the molten steel will wrap the raw materials that are difficult to melt, thereby accelerating the melting speed of the difficult-to-melt metals. After the loading is completed, the cover of the vacuum furnace 1 is closed, and the vacuum pump 2 is turned on to evacuate and then start smelting.

[0058] In step S1, the raw materials are placed in the vacuum furnace 1 for smelting and kept at 600°C for 3 hours to remove moisture and oil.

[0059] In the step S1, after the vacuum pump 2 is turned on to evacuate, smelting is started when the pressure in the vacuum furnace 1 is less than 20 Pa. The vacuum furnace 1 is connected to the vacuum pump 2 via a Roots pump 3 to achieve a lower vacuum degree.

[0060] In the step S1, after the smelting starts, the power of the vacuum furnace 1 is controlled at 180W and maintained for 12 minutes. After molten steel is produced at the bottom of the vacuum furnace 1, the power is increased to 350W. When half of the raw material is visually melted, the power is increased to 420W. The total smelting time can be controlled within 50 minutes. Too long a time will result in excessive burnout of elements.

[0061] In step S2, the vacuum is evacuated to below 1 Pa during the refining process, and the power of the vacuum furnace 1 is increased to 520 W to make the molten metal boil, and the temperature is maintained for 13 minutes. At this time, the gas in the molten steel will be rolled out by the boiling molten steel and pumped away by the vacuum pump, so that the gas content of the alloy is reduced.

[0062] In the step S3, the casting temperature is controlled at 1250°C. If the temperature is too high, the elements are easily further burned and are more likely to react with the mold to produce harmful impurities. If the temperature is too low, the molding is likely to be poor.

[0063] In step S4, a vacuum heat treatment furnace is used for heat treatment. The vacuum degree during the heat treatment is less than 1 Pa and the temperature is 1300° C. After being kept warm for 2 hours, the alloy is taken out of the furnace and rapidly cooled with water to obtain an oxidation-resistant nickel-based alloy.

[0064] Embodiment 3:

[0065] like Figure 1 , 2 As shown, an oxidation-resistant nickel-based alloy includes the following components, in mass fraction: C: 0.008%, S: 0.006%, P: 0.006%, Si: 0.472%, Mn: 0.647%, Mo: 0.001%, Gr: 25%, Ni: 63%, Cu: 0.025%, Al: 1.66%, N: 0.079%, and the rest is Fe.

[0066] A method for preparing an oxidation-resistant nickel-based alloy comprises the following steps:

[0067] S1: Melt the raw materials according to their components;

[0068] S2: Refining:

[0069] S3: Casting:

[0070] S4: After heat treatment, an oxidation-resistant nickel-based alloy is obtained.

[0071] In the step S1, the raw materials are placed in the vacuum furnace 1 according to their components, and the loading order is Fe, Cr, Ni, Al, Mn, Si, and C. The remaining components can be placed in any order, wherein N is added through high nitrogen ferrochrome. In the loading order, the raw materials that are easy to melt are placed first, the raw materials that are difficult to melt are placed in the middle, and the raw materials that are easily oxidized are placed last. Putting the raw materials that are easy to melt first will produce molten steel first, and the molten steel will wrap the raw materials that are difficult to melt, thereby accelerating the melting speed of the difficult-to-melt metals. After the loading is completed, the cover of the vacuum furnace 1 is closed, and the vacuum pump 2 is turned on to evacuate and then start smelting.

[0072] In step S1, the raw materials are placed in the vacuum furnace 1 for smelting and kept at 500°C for 3 hours to remove moisture and oil.

[0073] In the step S1, after the vacuum pump 2 is turned on to evacuate, smelting is started when the pressure in the vacuum furnace 1 is less than 20 Pa. The vacuum furnace 1 is connected to the vacuum pump 2 via a Roots pump 3 to achieve a lower vacuum degree.

[0074] In the step S1, after the smelting starts, the power of the vacuum furnace 1 is controlled at 150W and maintained for 10 minutes. After molten steel is produced at the bottom of the vacuum furnace 1, the power is increased to 300W. When half of the raw material is visually melted, the power is increased to 400W. The total smelting time can be controlled within 40 minutes. Too long a time will result in excessive burnout of elements.

[0075] In step S2, the vacuum is evacuated to below 1 Pa during the refining process, and the power of the vacuum furnace 1 is increased to 500 W to make the molten metal boil, and maintained for 10 minutes. At this time, the gas in the molten steel will be rolled out by the boiling molten steel and pumped away by the vacuum pump, so that the gas content of the alloy is reduced.

[0076] In step S3, the casting temperature is controlled at 1240°C. If the temperature is too high, the elements may be further burned and may react with the mold to produce harmful impurities. If the temperature is too low, the molding may be poor.

[0077] In step S4, a vacuum heat treatment furnace is used for heat treatment. The vacuum degree during the heat treatment is less than 1 Pa and the temperature is 1250° C. After being kept warm for 2 hours, the alloy is taken out of the furnace and rapidly cooled with water to obtain an oxidation-resistant nickel-based alloy.

[0078] Figure 3 , 4 The metallographic images of the oxidation-resistant nickel-based alloy prepared in Example 3 before and after heat treatment are shown in FIG. Figure 3 , 4 It can be seen that the intergranular precipitates are significantly reduced after heat treatment.

[0079] Comparative Example 1:

[0080] An oxidation-resistant nickel-based alloy includes the following components in mass fraction: C: 0.056%, S: 0.002%, P: 0.005%, Si: 0.37%, Mn: 0.51%, Mo: 0.002%, Gr: 23%, Ni: 63%, Cu: 0.12%, Al: 1.18%, and the rest is Fe. The preparation method of the oxidation-resistant nickel-based alloy is the same as that of Example 3.

[0081] The oxidation-resistant nickel-based alloys prepared in Examples 1-3 and Comparative Example 1 were cut into 30*15*5mm specimens, and the surfaces were polished to a smooth surface with a roughness of Ra0.8μm to obtain experimental specimens. Each experimental specimen was subjected to an oxidation resistance test for 100h at 1100°C in an air medium according to the GB / T13303-91 standard. The weight gain method was used for the test, and the weighing time was 20h, 40h, 60h, 80h, and 100h, respectively. The results are shown below.

[0082] Table 1 Oxidation resistance of nickel-based alloys in Example 1 Oxidation resistance test results

[0083]

[0084] Table 2 Oxidation resistance of nickel-based alloys in Example 2 Oxidation resistance test results

[0085]

[0086] Table 3 Oxidation resistance of nickel-based alloys in Example 3 Oxidation resistance test results

[0087]

[0088] Table 4 Oxidation resistance of nickel-based alloy of comparative example 1 Oxidation resistance test results

[0089]

[0090] It can be seen from Table 1-4 that the average oxidation rate of Example 1-3 over 100 hours is the highest at 0.24 g / (m 2 ·h), which is lower than 0.52g / (m 2 ·h), wherein Example 3 is the best example, and the average oxidation rate in 100h reaches 0.06g / (m 2 h).

[0091] According to GB / T13303-91 "Determination of oxidation resistance of steel", oxidation resistance can be divided into five levels based on oxidation rate: 1. Complete oxidation resistance: <0.1g / (m 2 ·h); 2. Antioxidant property: 0.1-1.0g / (m 2 ·h); 3. Secondary antioxidant capacity: 1.0-3.0g / (m 2 ·h); 4: Weak antioxidant: 3.0-10g / (m 2 ·h); 5. No anti-oxidation: >10g / (m 2 ·h). The better the oxidation resistance, the more stable its performance at high temperature. The oxidation resistance of ordinary Inconel 601 alloy reaches 0.5g / (m 2 ·h) reaches the oxidation resistance level. The present invention can achieve the oxidation resistance of nickel-based alloy to 0.06g / (m 2 h), improved by one level to achieve full oxidation resistance.

[0092] In this application, the role of adding chromium is as follows: chromium can form a dense and stable oxide film Cr2O3 with strong adhesion, thereby improving the oxidation resistance of steel. Chromium can also strengthen the steel through solid solution to improve the long-term strength and creep strength.

[0093] The role of adding nickel: Nickel can expand the γ phase area and reduce the δ phase area, so that the steel structure can obtain austenite structure at room temperature, and the structure does not undergo phase change at high temperature, thus obtaining better high-temperature growth resistance. Nickel also exhibits solid solution strengthening, promoting carbon atom segregation and precipitation around dislocations, thereby inhibiting the movement of dislocations and improving high-temperature strength. In terms of oxidation resistance, since nickel is not easily oxidized, in the matrix structure, nickel can form a layer of nickel-rich protective film with stable chemical properties on the surface of the grains, so nickel also plays a certain antioxidant role.

[0094] The role of adding aluminum: Aluminum can significantly improve the high-temperature oxidation resistance of steel. When a certain amount of aluminum is added to the material, a dense, strong and stable Al2O3 oxide film will be formed on the surface during high-temperature oxidation. The Al2O3 protective film is not volatile, so aluminum can significantly improve the operating temperature and oxidation resistance effect.

[0095] The role of adding nitrogen: Nitrogen can stabilize and promote the formation of austenite. The effect of nitrogen in expanding the austenite zone is 30 times that of nickel.

[0096] Since chromium and aluminum are both very easy to oxidize elements, in order to ensure that chromium and aluminum are less oxidized during the smelting process, a vacuum smelting furnace is used for smelting. The raw materials used in the present invention include: pure nickel, pure chromium, pure iron, industrial pure aluminum, and high nitrogen ferrochrome. The vacuum furnace used is a ZG-0.05WB semi-continuous vacuum furnace.

Claims

1. An oxidation resistant nickel-based alloy, characterized in that: In units of mass fraction, it includes the following components: C: 0.004-0.009%, S: 0.001-0.007%, P: 0.003-0.008%, Si: 0.2-0.6%, Mn: 0.3-0.7%, Mo: 0.001-0.003%, Gr: 22-27%, Ni: 60-65%, Cu: 0.02-0.14%, Al: 1.5-1.8%, and the rest is Fe.

2. An oxidation resistant nickel-based alloy as claimed in claim 1, characterized in that: In terms of mass fraction, it includes the following components: C: 0.006-0.008%, S: 0.003-0.006%, P: 0.004-0.006%, Si: 0.36-0.48%, Mn: 0.44-0.65%, Mo: 0.001-0.002%, Gr: 23-25%, Ni: 61-64%, Cu: 0.025-0.13%, Al: 1.62-1.66%, N: 0.06-0.08%, and the rest is Fe.

3. A method for preparing an oxidation resistant nickel-based alloy according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1: Melt the raw materials according to their components; S2: Refining: S3: Casting: S4: After heat treatment, an oxidation-resistant nickel-based alloy is obtained.

4. The method for preparing an oxidation-resistant nickel-based alloy according to claim 3, characterized in that: In the step S1, raw materials are placed into a vacuum furnace (1) according to their components, and the loading order is Fe, Cr, Ni, Al, Mn, Si, and C. The remaining components can be placed in any order. After the loading is completed, the cover of the vacuum furnace (1) is closed, and the vacuum pump (2) is turned on to evacuate the vacuum before starting smelting.

5. The method for preparing an oxidation-resistant nickel-based alloy according to claim 4, characterized in that: In the step S1, the raw materials are placed in the vacuum furnace (1) for smelting and kept at 400-600°C for 3 hours.

6. The method for preparing an oxidation-resistant nickel-based alloy according to claim 4, characterized in that: In the step S1, after the vacuum pump (2) is turned on to evacuate the vacuum, smelting begins when the pressure in the vacuum furnace (1) is less than 20 Pa. The vacuum furnace (1) is connected to the vacuum pump (2) via a Roots pump (3).

7. The method for preparing an oxidation-resistant nickel-based alloy according to claim 3, characterized in that: In the step S1, after the smelting starts, the power of the vacuum furnace (1) is controlled to be 120-180W and maintained for 7-12 minutes, and then the power is increased to 270-350W after molten steel is produced at the bottom of the vacuum furnace (1). When half of the raw material is visually melted, the power is increased to 390-420W, and the total smelting time is controlled to be 30-50 minutes.

8. The method for preparing an oxidation-resistant nickel-based alloy according to claim 3, characterized in that: In the step S2, the vacuum is evacuated to below 1 Pa during the refining process, and the power of the vacuum furnace (1) is increased to 480-520 W to make the molten metal boil, and the boiling is maintained for 7-13 minutes.

9. The method for preparing an oxidation-resistant nickel-based alloy according to claim 3, characterized in that: In step S3, the casting temperature is controlled at 1230-1250°C.

10. The method for preparing an oxidation-resistant nickel-based alloy according to claim 3, characterized in that: In step S4, a vacuum heat treatment furnace is used for heat treatment. The vacuum degree during the heat treatment is less than 1 Pa, the temperature is 1150-1300° C., and after being kept warm for 2 hours, the alloy is taken out of the furnace and water-cooled to obtain an oxidation-resistant nickel-based alloy.

Images