A nickel-based intermediate alloy, a preparation method and application thereof

Abstract

The application discloses a nickel-based intermediate alloy and a preparation method and application thereof, and belongs to the technical field of metallurgy.The nickel-based intermediate alloy comprises the following components: C: 0.06-0.2%; Cr: 10-45%; Al: 1-5%; Co: 0-5%; Mo: 0-5%; Ti: <=1.0%; the balance is Ni and inevitable impurities, and the sum of the contents of Co and Mo is <=5% by mass.The nickel-based intermediate alloy is not affected by other alloy elements in a target alloy, and the increase of inclusions caused by slagging is avoided, harmful impurity elements such as oxygen, nitrogen, sulfur, zinc and lead are efficiently removed, the purity of raw materials used in the target alloy is maximized at a lower cost, and the ultra-high-purity smelting of the target alloy is realized.

Description

Technical Field

[0001] This application relates to the field of alloys, and more specifically, to a nickel-based master alloy, its preparation method, and its application. Background Technology

[0002] Controlling the introduction of impurity elements from raw materials is a key method in the preparation of ultra-high purity nickel-based superalloys. In large-scale production, using pretreated intermediate alloys is a highly efficient and low-cost method for controlling impurity element introduction. Although this process has been widely applied, due to the large number of nickel-based superalloy grades, the many constituent elements, large content fluctuations, and significant differences in the purity of raw materials for different alloys, no effective intermediate alloy and its processing method have been found specifically for nickel-based superalloys. Therefore, there is an urgent need to provide an efficient intermediate alloy and its preparation process to control the introduction of impurity elements in nickel-based superalloys. Summary of the Invention

[0003] This invention is based on the inventors' discovery and understanding of the following facts and problems: using a pre-treated intermediate alloy is a highly efficient and low-cost method for controlling the introduction of impurity elements. However, there are numerous grades of nickel-based superalloys, with many constituent elements, large fluctuations in content, and significant differences in the purity of the metal raw materials for different alloys. No effective intermediate alloys or processes have been found specifically for nickel-based superalloys.

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a nickel-based master alloy, its preparation method, and its application. The nickel-based master alloy is unaffected by the negative influence of other alloying elements in the target alloy, avoids the increase in inclusions caused by slag formation, and efficiently removes harmful impurity elements such as oxygen, nitrogen, sulfur, zinc, and lead. This facilitates maximizing the purity of raw materials used in the target alloy at a lower cost, achieving ultra-high purity smelting of the target alloy.

[0005] This invention provides a nickel-based master alloy comprising: C: 0.06–0.2%; Cr: 10–45%; Al: 1–5%; Co: 0–5%; Mo: 0–5%; Ti: ≤1.0%; the balance being Ni and unavoidable impurities, by mass; wherein the sum of the contents of Co and Mo is ≤5%.

[0006] The advantages and technical effects of the nickel-based master alloy in this invention are as follows: The nickel-based master alloy contains elements C, Cr, Al, and Ni, and may also contain at least one element selected from Co and Mo. It comprehensively considers the general content of impurity elements in the raw materials of each alloying element, the influence of each element on chemical reactions such as deoxidation, desulfurization, and denitrification, and the content of each element in the target alloy, which is beneficial to maximizing the purity of the raw materials used in the target alloy. By optimizing the mass percentage content of elements in the master alloy, it is beneficial to achieve ultra-pure smelting of the master alloy, which is widely applicable to various grades of nickel-based high-temperature alloys, maximizing the purity of the raw materials used in the target alloy. The more complex the alloying elements, the more difficult it is to accurately control chemical reactions such as deoxidation, desulfurization, and denitrification. Therefore, by first preparing a nickel-based master alloy with a relatively simple elemental composition, smelting and purification can be achieved more effectively, without being negatively affected by other alloying elements in the target alloy, and harmful impurity elements such as oxygen, nitrogen, sulfur, zinc, and lead can be efficiently removed; this is beneficial to maximizing the purity of the raw materials used in the target alloy at a lower cost, achieving ultra-high purity smelting of the target alloy.

[0007] In this embodiment of the invention, carbon (C) is required for deoxidation and denitrification reactions. Al (Al) is required for deoxidation and desulfurization reactions. Co (Co) and mo (Mo) can improve the metallurgical activity of oxygen and nitrogen. Ti (Ti) affects the deoxidation and desulfurization effect of the alloy; therefore, the Ti content needs to be controlled to ≤1.0%. If the intermediate alloy does not contain chromium (Cr), it cannot provide high-purity chromium for the target alloy, thus preventing the target alloy from achieving ultra-purity. If the Cr content is too high, for example, >50%, the melting point, viscosity, and other physical properties of the intermediate alloy do not meet the process conditions required for the purification melting and casting of the intermediate alloy in a vacuum induction furnace. If the intermediate alloy does not contain Al, it is extremely unfavorable for the desulfurization reaction. If the Al content is too high, for example, >5%, it will be affected by the Al content requirement of the target alloy, and the maximum utilization of the intermediate alloy cannot be achieved when smelting the target alloy.

[0008] In some embodiments, the nickel-based master alloy is used to prepare the target alloy, and the nickel-based master alloy satisfies the following relationship:

[0009] ω Cr ≥1.0*ω target alloy Cr,

[0010] Where, ω Cr This refers to the mass percentage of Cr in a nickel-based master alloy multiplied by 100; ω 目标合金Cr This refers to the mass percentage of Cr in the target alloy multiplied by 100.

[0011] In some embodiments, the nickel-based master alloy is used to prepare the target alloy, and the nickel-based master alloy satisfies the following relationship:

[0012]

[0013] Where, ω Cr This refers to the mass percentage of Cr in a nickel-based master alloy multiplied by 100; ω 目标合金Cr This refers to the mass percentage of Cr in the target alloy multiplied by 100; ω [M] This refers to the mass percentage of any non-Ni metallic element in a nickel-based master alloy multiplied by 100; ω 目标合金[M] It refers to the mass percentage of any non-Ni metal element in the target alloy multiplied by 100.

[0014] In some embodiments, the nickel-based master alloy satisfies the following relationship:

[0015] 2.146*ω Cr +7.951*ω Al +54.167*ω C +12.426*(ω Co +ω Mo )≥60,

[0016] Where, ω Cr This refers to the mass percentage of Cr in a nickel-based master alloy multiplied by 100; ω Al This refers to the mass percentage of Al in a nickel-based master alloy multiplied by 100; ω C This refers to the mass percentage of carbon in a nickel-based master alloy multiplied by 100; ω Co This refers to the mass percentage of Co in a nickel-based master alloy multiplied by 100; ω Mo This refers to the mass percentage of Mo in a nickel-based master alloy multiplied by 100.

[0017] This invention provides a method for preparing a nickel-based master alloy, comprising the following steps:

[0018] (1) According to the composition ratio of nickel-based master alloy, the raw materials of elements other than Al are batched, melted, and after the melt is cleared, the alloy melt is heated to the refining temperature and refined.

[0019] (2) Add Al raw material to the alloy melt obtained in step (1);

[0020] (3) Adjust the temperature of the alloy melt obtained in step (2), add pre-melted slag to the alloy melt, and stir and refine it.

[0021] (4) Adjust the temperature of the alloy melt obtained in step (3), pour it, and obtain a nickel-based master alloy.

[0022] In this invention, by smelting and producing a master alloy, harmful impurity elements such as oxygen, nitrogen, sulfur, zinc, and lead can be efficiently removed from raw materials such as nickel, chromium, molybdenum, and cobalt without the negative impact of other alloying elements and without increasing inclusions due to slag formation. The master alloy is used to purify metallic chromium with high impurity content and can be applied to the field of nickel-based superalloys. Based on the impurity element content of metallic chromium and the removal mechanisms of oxygen, nitrogen, sulfur, and other impurity elements, a master alloy smelting process is formulated to effectively remove impurity elements introduced from metallic chromium, thereby achieving the preparation of high-purity nickel-based superalloys using metal raw materials of ordinary purity. With the same raw materials, by preparing the master alloy before preparing the target alloy, the oxygen, nitrogen, and sulfur content of the target alloy can be reduced by 2–3 ppm, 3–5 ppm, and 5–7 ppm, respectively, compared to the directly prepared target alloy.

[0023] In some embodiments, in step (1), the refining temperature is 200-250°C higher than the liquidus temperature; the refining time is 80-90 minutes.

[0024] And / or, in step (3), the temperature of the alloy melt obtained in step (2) is adjusted to 1580-1600℃;

[0025] And / or, in step (3), the stirring and refining time is 15 to 30 minutes;

[0026] And / or, in step (4), the temperature of the alloy melt obtained in step (3) is adjusted to be 120-150°C higher than the liquidus temperature.

[0027] In some embodiments, in step (3), the pre-melted slag comprises: CaF2: 30-40%; CaO: 30-40%; Al2O3: 8-12%; MgO: 5-8%; BaO: 8-10%; SiO2 < 0.5%, by mass;

[0028] And / or, in step (3), the slag ratio is 1.5 to 2.

[0029] This invention provides an application of a nickel-based master alloy for preparing nickel-based superalloys. In this invention, the nickel-based master alloy is widely applicable to various grades of nickel-based superalloys, maximizing the purity of the raw materials used in the target alloy.

[0030] This invention provides a method for preparing a nickel-based superalloy, comprising the following steps:

[0031] 1) The intermediate alloy and raw materials other than Al, Ti, Zr, B, and Hf are batched according to the composition ratio of the nickel-based superalloy, melted, and after the melt is cleared, the alloy melt is heated to the refining temperature and refined; the intermediate alloy is the nickel-based intermediate alloy described in the embodiment of the present invention.

[0032] 2) Add the remaining raw materials to the alloy melt obtained in step 1), melt until clear, and stir to refine;

[0033] 3) Adjust the temperature of the alloy melt obtained in step 2), pour it, and obtain a nickel-based high-temperature alloy.

[0034] In this embodiment of the invention, an intermediate alloy is prepared first, and then a nickel-based high-temperature alloy is prepared with other elements. This is beneficial to maximize the purity of the raw materials used in the target alloy at a lower cost, and to achieve ultra-high purity smelting of the target alloy.

[0035] In some embodiments, in step 1), the nickel-based superalloy comprises: Cr: 5-30%; Al: 0.5-7%; C: 0.04-0.2%; Ti: 0.1-4.0%; at least one of Co, Mo, W, Ta, Nb, Zr, B, and Hf, wherein the sum of the contents of Co, Mo, W, Ta, Nb, Zr, B, and Hf is 5-30%; the balance is Ni and unavoidable impurities, by mass.

[0036] And / or, in step 1), the refining temperature is 200-250°C higher than the liquidus temperature; the refining time is 65-75 minutes.

[0037] And / or, in step 2), the stirring and refining time is 15 to 30 minutes;

[0038] And / or, in step 3), the temperature of the alloy melt obtained in step 2) is adjusted to be 120-150°C higher than the liquidus temperature. Detailed Implementation

[0039] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0040] An embodiment of the present invention provides a nickel-based master alloy comprising: C: 0.06–0.2%; Cr: 10–45%; Al: 1–5%; Co: 0–5%; Mo: 0–5%; Ti: ≤1.0%; the balance being Ni and unavoidable impurities, by mass; wherein the sum of the contents of Co and Mo is ≤5%.

[0041] The nickel-based master alloy of this invention contains elements C, Cr, Al, and Ni, and may also contain at least one element selected from Co and Mo. It comprehensively considers the general content of impurity elements in the raw materials of each alloying element, the influence of each element on chemical reactions such as deoxidation, desulfurization, and denitrification, and the content of each element in the target alloy, which is beneficial to maximizing the purity of the raw materials used in the target alloy. By optimizing the mass percentage content of elements in the master alloy, it is beneficial to achieve ultra-pure smelting of the master alloy, which is widely applicable to various grades of nickel-based high-temperature alloys, maximizing the purity of the raw materials used in the target alloy. The more complex the alloying elements, the more difficult it is to accurately control chemical reactions such as deoxidation, desulfurization, and denitrification. Therefore, by first preparing a nickel-based master alloy with a relatively simple elemental composition, smelting and purification can be achieved more effectively, unaffected by the negative influence of other alloying elements in the target alloy, and harmful impurity elements such as oxygen, nitrogen, sulfur, zinc, and lead can be efficiently removed. This is beneficial to maximizing the purity of the raw materials used in the target alloy at a lower cost, achieving ultra-high purity smelting of the target alloy.

[0042] In this embodiment of the invention, carbon (C) is required for deoxidation and denitrification reactions. Al (Al) is required for deoxidation and desulfurization reactions. Co (Co) and mo (Mo) can improve the metallurgical activity of oxygen and nitrogen. Ti (Ti) affects the deoxidation and desulfurization effect of the alloy; therefore, the Ti content needs to be controlled to ≤1.0%. If the intermediate alloy does not contain chromium (Cr), it cannot provide high-purity chromium for the target alloy, thus preventing the target alloy from achieving ultra-purity. If the Cr content is too high, for example, >50%, the melting point, viscosity, and other physical properties of the intermediate alloy do not meet the process conditions required for the purification melting and casting of the intermediate alloy in a vacuum induction furnace. If the intermediate alloy does not contain Al, it is extremely unfavorable for the desulfurization reaction. If the Al content is too high, for example, >5%, it will be affected by the Al content requirement of the target alloy, and the maximum utilization of the intermediate alloy cannot be achieved when smelting the target alloy.

[0043] In some embodiments, the nickel-based master alloy is used to prepare the target alloy, and the nickel-based master alloy satisfies the following relationship (1):

[0044] ω Cr ≥1.0*ω 目标合金Cr (1),

[0045] Where, ω Cr This refers to the mass percentage of Cr in a nickel-based master alloy multiplied by 100; ω 目标合金Cr This refers to the mass percentage of Cr in the target alloy multiplied by 100. Preferably, the target alloy is a nickel-based high-temperature alloy.

[0046] The nickel-based master alloy is used to prepare the target alloy, and the nickel-based master alloy satisfies the following relationship (2):

[0047]

[0048] Where, ω Cr This refers to the mass percentage of Cr in a nickel-based master alloy multiplied by 100; ω 目标合金Cr This refers to the mass percentage of Cr in the target alloy multiplied by 100; ω [M] This refers to the mass percentage of any non-Ni metallic element in a nickel-based master alloy multiplied by 100; ω 目标合金[M] This refers to the mass percentage of any non-Ni metal element in the target alloy multiplied by 100. Preferably, the target alloy is a nickel-based high-temperature alloy. In this embodiment of the invention, by limiting the chromium content in the intermediate alloy to be greater than or equal to the chromium content in the target alloy, and the ratio of the chromium content in the intermediate alloy to the content of any non-Ni metal element to be greater than or equal to the ratio of the chromium content in the target alloy to the content of any non-Ni metal element, it can be ensured that when the chromium in the target alloy is entirely introduced by the intermediate alloy, other metal elements will not exceed the control limit. If any of these formulas are not met, additional chromium raw materials need to be added during the smelting of the target alloy, reducing the purity of the target alloy.

[0049] In some embodiments, the nickel-based master alloy satisfies the following relationship (3):

[0050] 2.146*ω Cr +7.951*ω Al +54.167*ω C +12.426*(ω Co +ω Mo )≥60 (3),

[0051] Where, ω Cr This refers to the mass percentage of Cr in a nickel-based master alloy multiplied by 100; ω Al This refers to the mass percentage of Al in a nickel-based master alloy multiplied by 100; ω C This refers to the mass percentage of carbon in a nickel-based master alloy multiplied by 100; ω Co This refers to the mass percentage of Co in a nickel-based master alloy multiplied by 100; ω Mo This refers to the mass percentage of Mo in the nickel-based master alloy multiplied by 100. In this embodiment of the invention, by limiting the product of the mass percentages of chromium, aluminum, carbon, cobalt, and molybdenum multiplied by 100 and the constant coefficients of the corresponding elements, it is possible to ensure that the melting point and viscosity of the master alloy composition meet the process conditions required for the purification melting and casting of the master alloy in a vacuum induction furnace. This is beneficial for the preparation of the master alloy and for improving the purity of the target alloy.

[0052] In some embodiments, the target alloy is a nickel-based superalloy comprising: Cr: 5-30%; Al: 0.5-7%; C: 0.04-0.2%; Ti: 0.1-4.0%; at least one of Co, Mo, W, Ta, Nb, Zr, B, and Hf, wherein the sum of the contents of Co, Mo, W, Ta, Nb, Zr, B, and Hf is 5-30%; and the balance is Ni and unavoidable impurities, by mass.

[0053] A method for preparing a nickel-based master alloy according to an embodiment of the present invention includes the following steps:

[0054] (1) According to the composition ratio of nickel-based master alloy, the raw materials of elements other than Al are batched, melted, and after the melt is cleared, the alloy melt is heated to the refining temperature and refined.

[0055] (2) Add Al raw materials to the alloy melt obtained in step (1) according to the composition ratio of nickel-based master alloy;

[0056] (3) Adjust the temperature of the alloy melt obtained in step (2), add pre-melted slag to the alloy melt, and stir and refine it.

[0057] (4) Adjust the temperature of the alloy melt obtained in step (3), pour it, and obtain a nickel-based master alloy.

[0058] In this invention, by smelting and producing a master alloy, harmful impurity elements such as oxygen, nitrogen, sulfur, zinc, and lead can be efficiently removed from raw materials such as nickel, chromium, molybdenum, and cobalt without the negative impact of other alloying elements and without increasing inclusions due to slag formation. The master alloy is used to purify metallic chromium with high impurity content and can be applied to the field of nickel-based superalloys. Based on the impurity element content of metallic chromium and the removal mechanisms of oxygen, nitrogen, sulfur, and other impurity elements, a master alloy smelting process is formulated to effectively remove impurity elements introduced from metallic chromium, thereby achieving the preparation of high-purity nickel-based superalloys using metal raw materials of ordinary purity. With the same raw materials, by preparing the master alloy before preparing the target alloy, the oxygen, nitrogen, and sulfur content of the target alloy can be reduced by 2–3 ppm, 3–5 ppm, and 5–7 ppm, respectively, compared to the directly prepared target alloy.

[0059] In some embodiments, in step (1), the refining temperature is 200-250°C higher than the liquidus temperature; the refining pressure is ≤5Pa; the refining time is 80-90min; the melting is carried out in a vacuum induction furnace; the raw material for carbon is graphite; the raw material for nickel is electrolytic nickel; the raw material for chromium is metallic chromium; the raw material for cobalt is metallic cobalt; and the raw material for molybdenum is metallic molybdenum.

[0060] In some embodiments, in step (2), the raw material for aluminum is electrolytic aluminum.

[0061] In some embodiments, in step (3), the temperature of the alloy melt obtained in step (2) is adjusted to 1580-1600°C; and / or, in step (3), the stirring and refining time is 15-30 min.

[0062] In some embodiments, in step (3), the pre-melted slag comprises: CaF2: 30-40%; CaO: 30-40%; Al2O3: 8-12%; MgO: 5-8%; BaO: 8-10%; SiO2 < 0.5% by mass. Preferably, the pre-melted slag comprises: CaF2: 35-38%; CaO: 35-38%; Al2O3: 10-12%; MgO: 5-6%; BaO: 8-9%; SiO2 < 0.1% by mass; and / or, in step (3), the slag ratio is 1.5-2. In this embodiment of the invention, CaO and BaO in the pre-melted slag participate in the desulfurization reaction, improving the desulfurization capacity of the pre-melted slag for nickel-based alloys. Other oxides adjust the melting point and viscosity of the pre-melted slag to match the melting temperature of the intermediate alloy melt. By optimizing the composition and content of the pre-melted slag, the desulfurization effect can be further improved while minimizing the generation of foreign inclusions. This allows for the preparation of high-purity target alloys using metal raw materials of ordinary purity. The slag ratio refers to the percentage ratio of slag volume to molten metal volume multiplied by 100. If the slag ratio is too high, the slag volume is too large, easily mixing into the molten metal and forming a large number of inclusions; if the slag ratio is too low, the desulfurization effect is poor.

[0063] In some embodiments, in step (4), the temperature of the alloy melt obtained in step (3) is adjusted to be 120-150°C higher than the liquidus temperature; the casting is cast into ingots with a single weight of 10-30 kg; after casting, the riser of the ingot is removed and the grade and furnace information are marked.

[0064] This invention discloses an application of a nickel-based master alloy used in the preparation of nickel-based superalloys. In this embodiment, the nickel-based master alloy is widely applicable to various grades of nickel-based superalloys, maximizing the purity of the raw materials used in the target alloy.

[0065] In some embodiments, the nickel-based superalloy comprises: Cr: 5-30%; Al: 0.5-7%; C: 0.04-0.2%; Ti: 0.1-4.0%; at least one of Co, Mo, W, Ta, Nb, Zr, B, and Hf, wherein the sum of the contents of Co, Mo, W, Ta, Nb, Zr, B, and Hf is 5-30%; the balance is Ni and unavoidable impurities, by mass. In this embodiment of the invention, an intermediate alloy is prepared first, and then the nickel-based superalloy is prepared with other elements. This is because chromium generally has insufficient purity in its raw metals, and other elements have a significant negative impact on the smelting and purification of the intermediate alloy. Furthermore, the more complex the element composition, the more difficult it is to precisely control chemical reactions such as deoxidation, desulfurization, and denitrification. Therefore, by first preparing an intermediate alloy with a relatively simple elemental composition, induction furnace smelting and purification can be achieved more effectively. This is beneficial for maximizing the purity of the raw materials used in the target alloy at a lower cost, thus achieving ultra-high purity smelting of the target alloy.

[0066] An embodiment of the present invention provides a method for preparing a nickel-based superalloy, comprising the following steps:

[0067] 1) According to the composition ratio of the nickel-based superalloy, the master alloy and raw materials of elements other than Al, Ti, Zr, B, and Hf are batched, melted, and after clearing, the alloy melt is heated to the refining temperature for refining; the master alloy is the nickel-based master alloy described in the embodiment of the present invention; specifically, the nickel-based superalloy contains Zr, B, or Hf, and its raw materials are removed during batching in step 1); the nickel-based superalloy does not contain Zr, B, or Hf, and the batching in steps 1) and 2) does not involve the addition of Zr, B, or Hf raw materials;

[0068] 2) Add the remaining raw materials to the alloy melt obtained in step 1) according to the composition ratio of nickel-based superalloy, melt and refine by stirring;

[0069] 3) Adjust the temperature of the alloy melt obtained in step 2), pour it, and obtain a nickel-based high-temperature alloy.

[0070] In this embodiment of the invention, an intermediate alloy is prepared first, and then a nickel-based high-temperature alloy is prepared with other elements. This is beneficial to maximize the purity of the raw materials used in the target alloy at a lower cost, and to achieve ultra-high purity smelting of the target alloy.

[0071] In some embodiments, in step 1), the nickel-based superalloy comprises: Cr: 5-30%; Al: 0.5-7%; C: 0.04-0.2%; Ti: 0.1-4.0%; at least one of Co, Mo, W, Ta, Nb, Zr, B, and Hf, wherein the sum of the contents of Co, Mo, W, Ta, Nb, Zr, B, and Hf is 5-30%; the balance is Ni and unavoidable impurities, by mass.

[0072] And / or, in step 1), the refining temperature is 200-250°C higher than the liquidus temperature; the refining pressure is ≤3Pa; the refining time is 65-75min; the melting is carried out in a vacuum induction furnace; in step 1), recycled material of the same grade is also added for batching.

[0073] In some embodiments, the raw material for carbon is graphite; the raw material for nickel is electrolytic nickel; the raw material for molybdenum is metallic molybdenum; the raw material for aluminum is electrolytic aluminum; the raw material for titanium is sponge titanium; the raw material for niobium is metallic niobium; the raw material for boron is nickel-boron alloy; and the raw material for zirconium is metallic zirconium.

[0074] In some embodiments, in step 1), a portion of the carbon element raw material is batched according to the composition ratio of the nickel-based superalloy. Optionally, 20% of the carbon element raw material is added according to the composition ratio of the nickel-based superalloy. In step 2), the remaining carbon element raw material is added. Optionally, 80% of the carbon element raw material is added according to the composition ratio of the nickel-based superalloy. In this embodiment of the invention, the carbon element raw material is fed into the furnace in two stages to ensure the accuracy of carbon content control.

[0075] In some embodiments, in step 1), a portion of the nickel element raw material is prepared according to the composition ratio of a nickel-based superalloy. In this embodiment of the invention, the boron element raw material is a nickel-boron alloy, and nickel element is also introduced, so in step 1), a portion of the nickel element raw material is prepared according to the composition ratio of a nickel-based superalloy.

[0076] In some embodiments, in step 2), the stirring refining time is 15–30 min. In this embodiment of the invention, stirring refining completes alloying.

[0077] In some embodiments, in step 3), the temperature of the alloy melt obtained in step 2) is adjusted to be 120-150°C higher than the liquidus temperature.

[0078] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0079] Example 1

[0080] Nickel-based superalloys include: Cr: 12-13%; Al: 5.5-6.5%; C: 0.1-0.2%; Ti: 0.5-1.0%; Mo: 3.5-4.5%; Nb: 1.8-2.8%; Zr: 0.05-0.1%; B: 0.005-0.015%; Ni: balance.

[0081] Nickel-based master alloys include: C: 0.15–0.17%; Cr: 29–31%; Al: 1.8–2.0%; Mo: 3–3.5%; Ni: balance. Nickel-based master alloys satisfy the relationships (1)–(3).

[0082] 1. A method for preparing nickel-based master alloys, comprising the following steps:

[0083] (1) The raw materials with a total weight of 2803Kg: graphite, electrolytic nickel, metallic chromium and metallic molybdenum were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was clear, the alloy melt was heated to the refining temperature of 1602℃ and the furnace pressure was 1.9Pa to start refining. The refining was carried out for 90 minutes.

[0084] (2) Add 57 kg of electrolytic aluminum to the alloy melt.

[0085] (3) Adjust the temperature of the alloy melt to 1591℃, add 52Kg of pre-melted slag to the alloy melt, the composition of the pre-melted slag is CaF2: 35~38%; CaO: 35~38%; Al2O3: 10~12%; MgO: 5~6%; BaO: 8~9%; SiO2<0.1%, stir and refine for 25min.

[0086] (4) Adjust the temperature of the alloy melt to 1514℃, pour it into a single ingot weighing 26.3Kg, remove the riser of the ingot, mark the grade and furnace information, and complete the preparation of the nickel-based master alloy.

[0087] The impurity element contents of nickel-based master alloys are shown in Table 1.

[0088] Table 1

[0089]

[0090] 2. A method for preparing nickel-based superalloys, comprising the following steps:

[0091] 1) The raw materials with a total weight of 2591.6Kg, including some graphite, electrolytic nickel, the above-mentioned intermediate alloy, metallic molybdenum, metallic niobium, and recycled materials of the same grade, were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was cleared, the alloy melt was heated to the refining temperature of 1597℃ and the furnace pressure was 2.2Pa to start refining. The refining was carried out at this temperature for 70 minutes.

[0092] 2) Add graphite, electrolytic aluminum, metallic titanium, metallic zirconium, and nickel-boron alloy with a total weight of 108.4 kg to the alloy melt. After melting and refining, stir for 15 min.

[0093] 3) After the alloy melt is heated to 1524℃, pouring begins to complete the preparation.

[0094] The oxygen, nitrogen, sulfur, zinc and lead composition of the finished nickel-based superalloys is shown in Table 2.

[0095] Table 2

[0096] element O N S Zn Pb Content in ppm 3.2 2.9 3.1 0.63 1.0

[0097] Example 2

[0098] Nickel-based superalloys include: Cr: 8-10%; Al: 5.25-5.75%; C: 0.13-0.17%; Ti: 1.25-1.75%; Co: 9-11%; Mo: 2.25-2.75%; W: 9-11%; Zr: 0.03-0.08%; B: 0.01-0.12%; Ta: 1.25-1.75%; Ni: balance.

[0099] The nickel-based master alloy comprises: C: 0.15–0.17%; Cr: 29–31%; Al: 2.6–2.8%; Co: 2.0–2.3%; Mo: 1.5–1.8%; Ni: balance. The nickel-based master alloy satisfies the relationships (1)–(3).

[0100] 1. A method for preparing nickel-based master alloys, comprising the following steps:

[0101] (1) The raw materials with a total weight of 2779.9Kg, namely graphite, electrolytic nickel, metallic chromium, metallic molybdenum and metallic cobalt, were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was cleared, the alloy melt was heated to the refining temperature of 1598℃ and the furnace pressure was 1.4Pa to start refining. The refining was carried out for 90 minutes.

[0102] (2) Add 80.1 kg of electrolytic aluminum to the alloy melt.

[0103] (3) Adjust the temperature of the alloy melt to 1586℃, add 52Kg of pre-melted slag to the alloy melt, the composition of the pre-melted slag is CaF2: 35~38%; CaO: 35~38%; Al2O3: 10~12%; MgO: 5~6%; BaO: 8~9%; SiO2<0.1%, stir and refine for 25min.

[0104] (4) Adjust the temperature of the alloy melt to 1509℃, pour it into a single ingot weighing 27.1Kg, remove the riser of the ingot, mark the grade and furnace information, and complete the preparation of nickel-based master alloy.

[0105] The impurity element contents of nickel-based master alloys are shown in Table 3.

[0106] Table 3

[0107]

[0108] 2. A method for preparing nickel-based superalloys, comprising the following steps:

[0109] 1) The raw materials with a total weight of 2746.6Kg, including some graphite, electrolytic nickel and intermediate alloy, metallic molybdenum, electrolytic cobalt, metallic tungsten, metallic tantalum, and recycled materials of the same grade, were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was cleared, the alloy melt was heated to the refining temperature of 1615℃ and the furnace pressure was 1.3Pa to start refining. The refining was carried out at this temperature for 70 minutes.

[0110] 2) Add a total weight of 123.4 kg of graphite, electrolytic aluminum, metallic titanium, metallic zirconium, and nickel-boron alloy to the alloy melt. After melting and refining, stir for 15 min.

[0111] 3) After adjusting the temperature of the alloy melt to 1541℃, pouring begins to complete the preparation.

[0112] The oxygen, nitrogen, sulfur, zinc and lead composition of the finished nickel-based superalloys is shown in Table 4.

[0113] Table 4

[0114] element O N S Zn Pb Content in ppm 4.0 2.6 2.9 0.77 1.4

[0115] Example 3

[0116] Nickel-based superalloys include: Cr: 7.5–8.0%; Al: 5.8–6.0%; C: 0.12–0.14%; Ti: 1.1–1.3%; Co: 8.5–9.0%; Mo: 0.9–1.0%; W: 9.0–9.5%; Ta: 2.8–3.0%; Zr: 0.04–0.05%; B: 0.01–0.02%; Hf: 1.0–1.2%; Ni: balance.

[0117] The nickel-based master alloy includes: C: 0.18-0.20%; Cr: 19-21%; Al: 3.2-3.4%; Co: 2.8-3.0%; Ni: balance; the nickel-based master alloy satisfies the relations (1)-(3).

[0118] 1. A method for preparing nickel-based master alloys, comprising the following steps:

[0119] (1) The raw materials with a total weight of 2773.9Kg, namely graphite, electrolytic nickel, metallic chromium and metallic cobalt, were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was clear, the alloy melt was heated to the refining temperature of 1628℃ and the furnace pressure was 1.7Pa to start refining. The refining was carried out for 90 minutes.

[0120] (2) Add 96.1 kg of electrolytic aluminum to the alloy melt.

[0121] (3) Adjust the temperature of the alloy melt to 1593℃, add 52Kg of pre-melted slag to the alloy melt, the composition of the pre-melted slag is CaF2: 35~38%; CaO: 35~38%; Al2O3: 10~12%; MgO: 5~6%; BaO: 8~9%; SiO2<0.1%, stir and refine for 25min.

[0122] (4) Adjust the temperature of the alloy melt to 1533℃, pour it into a single ingot weighing 25.4Kg, remove the riser of the ingot, mark the grade and furnace information, and complete the preparation of the intermediate alloy.

[0123] The impurity element contents of nickel-based master alloys are shown in Table 5.

[0124] Table 5

[0125]

[0126] 2. A method for preparing nickel-based superalloys, comprising the following steps:

[0127] 1) The raw materials with a total weight of 2709.5Kg, including some graphite, electrolytic nickel and intermediate alloy, metallic molybdenum, electrolytic cobalt, metallic tungsten, metallic tantalum, and recycled materials of the same grade, were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was cleared, the alloy melt was heated to the refining temperature of 1629℃ and the furnace pressure was 1.1Pa to start refining. The refining was carried out at this temperature for 70 minutes.

[0128] 2) Add a total weight of 130.5 kg of graphite, electrolytic aluminum, metallic titanium, metallic zirconium, metallic hafnium, and nickel-boron alloy to the alloy melt, and stir and refine for 15 min.

[0129] 3) After adjusting the temperature of the alloy melt to 1556℃, pouring begins to complete the preparation.

[0130] The oxygen, nitrogen, sulfur, zinc and lead composition of the finished nickel-based superalloys is shown in Table 6.

[0131] Table 6

[0132] element O N S Zn Pb Content in ppm 2.6 1.4 1.8 0.55 0.96

[0133] Comparative Example 1

[0134] The composition and preparation method are basically the same as those of the nickel-based superalloy in Example 1, except that a nickel-based master alloy is not used.

[0135] 1. A method for preparing nickel-based superalloys, comprising the following steps:

[0136] 1) The raw materials with a total weight of 2576.9Kg, namely graphite, electrolytic nickel, metallic chromium, metallic molybdenum, metallic niobium, and recycled materials of the same grade, were melted in a 3T vacuum induction furnace according to the composition ratio. After the melt was cleared, the alloy melt was heated to the refining temperature of 1592℃ and the furnace pressure was 1.8Pa to start refining. The refining was carried out at this temperature for 160min.

[0137] 2) Add graphite, electrolytic aluminum, metallic titanium, metallic zirconium, and nickel-boron alloy with a total weight of 123.1 kg to the alloy melt, and stir and refine for 40 min.

[0138] 3) After adjusting the temperature of the alloy melt to 1519℃, pouring begins to complete the preparation.

[0139] The oxygen, nitrogen, sulfur, zinc and lead composition of the finished nickel-based superalloys is shown in Table 7.

[0140] Table 7

[0141]

[0142]

[0143] Comparative Example 2

[0144] The composition and preparation method are basically the same as those of the nickel-based superalloy in Example 1, except that the composition of the nickel-based master alloy includes C: 0.10-0.11%; Cr: 10-11%; Al: 1.8-2.0%; Mo: 3-3.5%; Ni: balance; ω Cr <1.0*ω 目标合金Cr The relation (1) is not satisfied.

[0145] The nickel-based master alloy has an oxygen content of 6.1 ppm, a nitrogen content of 3.0 ppm, and a sulfur content of 4.2 ppm.

[0146] The nickel-based superalloy has an oxygen content of 6.4 ppm, a nitrogen content of 4.9 ppm, and a sulfur content of 7.4 ppm.

[0147] Comparative Example 3

[0148] The composition and preparation method are basically the same as those of the nickel-based superalloy in Example 1, except that the composition of the nickel-based master alloy includes C: 0.11-0.12%; Cr: 13-14%; Al: 1.0-1.1%; Mo: 0.9-1.0%; Ni: balance;

[0149] 2.146*ω Cr +7.951*ω Al +54.167*ω C +12.426*(ω Co +ω Mo)≈57.72<60, which does not satisfy relation (3).

[0150] The nickel-based master alloy has an oxygen content of 10.9 ppm, a nitrogen content of 7.5 ppm, and a sulfur content of 6.4 ppm.

[0151] The nickel-based superalloy has an oxygen content of 7.1 ppm, a nitrogen content of 6.6 ppm, and a sulfur content of 8.9 ppm.

[0152] Comparative Example 4

[0153] The composition and preparation method are basically the same as those of the nickel-based superalloy in Example 1, except that the pre-melted slag does not contain BaO, and the relative proportions of other components remain unchanged.

[0154] The sulfur content of the nickel-based master alloy is 12.6 ppm.

[0155] The nickel-based superalloy has an oxygen content of 5.2 ppm, a nitrogen content of 4.1 ppm, and a sulfur content of 9.7 ppm.

[0156] Comparative Example 5

[0157] The composition and preparation method are basically the same as those of the nickel-based superalloy in Example 1, except that the slag ratio is 3.

[0158] The sulfur content of the intermediate alloy is 4.4 ppm.

[0159] The nickel-based superalloy has an oxygen content of 8.8 ppm, a nitrogen content of 7.3 ppm, and a sulfur content of 4.4 ppm.

[0160] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0161] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A nickel-based master alloy, characterized in that, Includes: C: 0.06~0.2%; Cr: 10~45%; Al: 1~5%; Co: 0~5%; Mo: 0~5%; Ti: ≤1.0%; the balance is Ni and unavoidable impurities, by mass; wherein the sum of the contents of Co and Mo is ≤5%; The nickel-based master alloy is used to prepare the target alloy, and the nickel-based master alloy satisfies the following relationship: ， in, This refers to the mass percentage of Cr element in a nickel-based master alloy. 100; This refers to the mass percentage of Cr element in the target alloy. 100; The nickel-based master alloy satisfies the following relationship: ， in, This refers to the mass percentage of Cr element in a nickel-based master alloy. 100; This refers to the mass percentage of Al in a nickel-based master alloy. 100; This refers to the mass percentage of carbon in a nickel-based master alloy. 100; This refers to the mass percentage of Co in a nickel-based master alloy. 100; This refers to the mass percentage of Mo in a nickel-based master alloy. 100; The preparation method of the nickel-based master alloy includes the following steps: (1) According to the composition ratio of nickel-based master alloy, the raw materials of elements other than Al are batched, melted, and after the melt is cleared, the alloy melt is heated to the refining temperature and refined. (2) Add Al raw material to the alloy melt obtained in step (1); (3) Adjust the temperature of the alloy melt obtained in step (2), add pre-melted slag to the alloy melt, and stir and refine it; (4) Adjust the temperature of the alloy melt obtained in step (3), pour it, and obtain a nickel-based master alloy; In step (3), the pre-melted slag comprises: CaF2: 30~40%; CaO: 30~40%; Al2O3: 8~12%; MgO: 5~8%; BaO: 8~10%; SiO2 < 0.5%, by mass; In step (3), the slag ratio is 1.5~2.

2. The nickel-based master alloy according to claim 1, characterized in that, The nickel-based master alloy is used to prepare the target alloy, and the nickel-based master alloy satisfies the following relationship: ， in, This refers to the mass percentage of Cr element in a nickel-based master alloy. 100; This refers to the mass percentage of Cr element in the target alloy. 100; It refers to the mass percentage of any non-Ni metallic element in a nickel-based master alloy. 100; This refers to the mass percentage of any non-Ni metallic element in the target alloy.

100.

3. A method for preparing a nickel-based master alloy according to any one of claims 1-2, characterized in that, Includes the following steps: (1) According to the composition ratio of nickel-based master alloy, the raw materials of elements other than Al are batched, melted, and after the melt is cleared, the alloy melt is heated to the refining temperature and refined. (2) Add Al raw material to the alloy melt obtained in step (1); (3) Adjust the temperature of the alloy melt obtained in step (2), add pre-melted slag to the alloy melt, and stir and refine it; (4) Adjust the temperature of the alloy melt obtained in step (3), pour it, and obtain a nickel-based master alloy; In step (3), the pre-melted slag comprises: CaF2: 30~40%; CaO: 30~40%; Al2O3: 8~12%; MgO: 5~8%; BaO: 8~10%; SiO2 < 0.5%, by mass; In step (3), the slag ratio is 1.5~2.

4. The method for preparing the nickel-based master alloy according to claim 3, characterized in that, In step (1), the refining temperature is 200-250°C higher than the liquidus temperature; the refining time is 80-90 minutes. And / or, in step (3), the temperature of the alloy melt obtained in step (2) is adjusted to 1580~1600℃; And / or, in step (3), the stirring and refining time is 15~30min; And / or, in step (4), the temperature of the alloy melt obtained in step (3) is adjusted to be 120~150℃ higher than the liquidus temperature.

5. An application of a nickel-based master alloy according to any one of claims 1-2, characterized in that, The nickel-based master alloy is used to prepare nickel-based high-temperature alloys.

6. A method for preparing a nickel-based superalloy, characterized in that, The process includes the following steps: 1) The master alloy and raw materials other than Al, Ti, Zr, B and Hf are batched according to the composition ratio of the nickel-based superalloy, melted, and after the melt is cleared, the alloy melt is heated to the refining temperature and refined; the master alloy is the nickel-based master alloy according to any one of claims 1-2. 2) Add the remaining raw materials to the alloy melt obtained in step 1), melt until clear, and stir to refine; 3) Adjust the temperature of the alloy melt obtained in step 2), pour it, and obtain a nickel-based high-temperature alloy.

7. The method for preparing the nickel-based superalloy according to claim 6, characterized in that, In step 1), the nickel-based superalloy comprises: Cr: 5~30%; Al: 0.5~7%; C: 0.04~0.2%; Ti: 0.1~4.0%; at least one of Co, Mo, W, Ta, Nb, Zr, B, and Hf, wherein the sum of the contents of Co, Mo, W, Ta, Nb, Zr, B, and Hf is 5~30%; the balance is Ni and unavoidable impurities, by mass. And / or, in step 1), the refining temperature is 200~250°C higher than the liquidus temperature; the refining time is 65~75 minutes; And / or, in step 2), the stirring and refining time is 15-30 minutes; And / or, in step 3), the temperature of the alloy melt obtained in step 2) is adjusted to be 120~150℃ higher than the liquidus temperature.

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