Vacuum induction deep desulfurization process for superalloy

Abstract

This application belongs to the field of metallurgical technology, and particularly relates to a vacuum induction deep desulfurization process for high-temperature alloys. Insufficient contact between the melt and the desulfurizing agent, poor reaction kinetics, and difficulty in effectively separating desulfurization products are significant factors contributing to the difficulty in deep desulfurization of high-temperature alloys during vacuum induction melting. Existing technologies use calcium-magnesium-based desulfurizing agents or calcium oxide crucibles for in-situ desulfurization, which suffers from low desulfurization efficiency due to high-temperature volatilization, short crucible life, and limited mass transfer. The embodiments of this application overcome the technical bottleneck of diffusion-limited mass transfer in slag-metal reactions under vacuum by employing a porous desulfurizing agent combined with electromagnetic stirring to drive the high-temperature alloy melt through the porous desulfurizing agent, achieving a simultaneous improvement in desulfurization efficiency and depth.

Description

Technical Field

[0001] This application belongs to the field of metallurgical technology, and in particular relates to a vacuum induction deep desulfurization process for high-temperature alloys. Background Technology

[0002] Nickel-based superalloys, as strategic national materials, are core materials for critical equipment such as hot-end components of aero-engines and core structural components of nuclear power reactors. Their thermal strength, oxidation resistance, and corrosion resistance at high temperatures around 1000℃ directly determine the service performance and safe lifespan of the equipment. Sulfur, one of the most critical harmful impurities in nickel-based superalloys, can have a fatal impact on alloy performance even at the ppm level. Sulfur easily segregates at grain boundaries to form a low-melting-point Ni3S2 phase, leading to hot brittleness, significantly reducing its creep resistance, fatigue strength, and machinability, and in severe cases, causing premature component failure. With the increasing demands for thrust-to-weight ratio and service life in aerospace and other fields, the sulfur content control of nickel-based superalloys has progressed from the traditional ≤10ppm to a deep desulfurization level of ≤1ppm, becoming one of the core restrictive technologies hindering the domestic production of high-end alloys.

[0003] Currently, vacuum induction melting (VIM) is the core process in the preparation of nickel-based superalloys. Existing desulfurization technologies mainly rely on adding calcium and magnesium-based desulfurizing agents such as NiCa and NiMg, or using calcium oxide crucibles for in-situ desulfurization. However, these technical solutions have many insurmountable drawbacks: First, the desulfurization efficiency is low (usually below 90%), and the volatiles easily contaminate the furnace and cause secondary pollution to subsequent furnaces, making it difficult to stably control the sulfur content below 5 ppm; Second, although calcium oxide crucibles can achieve desulfurization by reacting Ca with S to generate CaS, CaO is extremely prone to hydration and expansion, leading to crucible expansion and damage. Moreover, it is prone to pulverization and detachment at high temperatures, introducing inclusions. Its service life is usually no more than 5 furnaces, which cannot meet the needs of industrial mass production; Third, traditional blocky CaO-based fluxes have a small specific surface area and insufficient contact with the alloy melt. The desulfurization reaction is limited by diffusion and mass transfer, making it difficult to achieve deep desulfurization. At the same time, flux agglomeration easily forms large-sized inclusions, reducing the purity of the alloy; Fourth, some technologies improve slag flowability by adding fluorite (CaF2), but fluorite easily introduces fluorine impurities and exacerbates furnace lining erosion, leading to increased oxygen and nitrogen content in the alloy and further deteriorating material properties.

[0004] Furthermore, existing desulfurization processes generally suffer from the contradiction of difficulty in simultaneously achieving desulfurization and purity. At the same time, frequent replacement of desulfurizing agents or damage to crucibles leads to low production efficiency and high costs, further hindering the large-scale and stable production of high-end nickel-based superalloys. Summary of the Invention

[0005] This application provides a vacuum induction deep desulfurization process for high-temperature alloys to solve the following technical problem: how to achieve deep desulfurization of high-temperature alloys in vacuum induction melting.

[0006] This application provides a vacuum induction deep desulfurization process for high-temperature alloys, characterized by the following steps: A porous desulfurizing agent containing CaO is placed in the smelting area. The sulfur-containing high-temperature alloy raw material is placed in the area to be melted, and the area to be melted is evacuated to a first vacuum level. The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt; The high-temperature alloy melt is heated to the desulfurization reaction temperature to obtain the heated high-temperature alloy melt; Maintain the vacuum level of the area to be melted at the second vacuum level; The heated high-temperature alloy melt is driven by electromagnetic stirring to pass through the porous desulfurizing agent at a flow rate of 0.2 m / s to 0.5 m / s. This causes the sulfur in the heated high-temperature alloy melt to react with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is then discharged through the pores of the porous desulfurizing agent, resulting in a desulfurized high-temperature alloy melt.

[0007] Optionally, the porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid, which is composed of multiple grid plates with a thickness of 20mm to 80mm and a spacing of 20mm to 30mm between adjacent grid plates.

[0008] Optionally, the grating plate has a CaO content of 60wt%~90wt%, an Al2O3 content of 10wt%~40wt%, a porosity of ≥70%, and a pore size of 0.2mm~2mm.

[0009] Optionally, the grid consists of three layers of grid panels.

[0010] Optionally, the thickness of the grating plate is 30mm~50mm, the spacing between the grating plates is 25mm, the CaO content of the grating plate is 60wt%, the Al2O3 content is 40wt%, the pore size of the grating plate is 0.8mm~1.5mm, and the porosity is 75%.

[0011] Optionally, the grid panels of the grid have a honeycomb structure.

[0012] Optionally, the specific surface area of ​​the grid plates is ≥5m². 2 / g.

[0013] Optionally, the specific surface area of ​​the grid plates is 8m². 2 / g~10m 2 / g.

[0014] Optionally, the desulfurization reaction temperature is 1520℃~1600℃, the first vacuum degree and the second vacuum degree are ≤10Pa respectively, and the stirring frequency of the electromagnetic stirrer is 2Hz~4Hz.

[0015] Optionally, the sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169.

[0016] The technical solution provided in this application has the following advantages compared with the prior art: Insufficient contact between the melt and the desulfurizing agent, poor reaction kinetics, and difficulty in effectively separating desulfurization products are important factors leading to the difficulty in deep desulfurization of high-temperature alloys during vacuum induction melting.

[0017] In this embodiment, a porous desulfurizing agent containing CaO is placed in the melting zone, providing a large specific surface area and abundant reaction sites for the desulfurization reaction. This significantly increases the contact area between the melt and the desulfurizing agent and provides a discharge channel for the reaction product, calcium sulfide, preventing product accumulation from hindering the reaction. Sulfur-containing high-temperature alloy raw materials are placed in the melting zone and evacuated to a first vacuum level, establishing a low-oxygen environment in the early stages of melting, reducing oxidation loss of the high-temperature alloy raw materials, and creating favorable initial conditions for subsequent desulfurization. Heating and melting the sulfur-containing high-temperature alloy raw materials yields a high-temperature alloy melt, transforming the solid raw material into a liquid state and providing a fluid medium for the migration and reaction of sulfur. Heating the high-temperature alloy melt to the desulfurization reaction temperature yields a heated high-temperature alloy melt, providing the necessary activation energy for the chemical reaction between CaO and sulfur, ensuring the reaction is feasible. The kinetic rate maintains the vacuum level in the melting zone at a second vacuum level, effectively reducing the partial pressure of sulfur in the gas phase, increasing the thermodynamic driving force of the desulfurization reaction, and reducing the consumption of CaO desulfurizer by the oxidizing atmosphere. The heated high-temperature alloy melt, driven by electromagnetic stirring, flows through the porous desulfurizer at a velocity of 0.2 m / s to 0.5 m / s, causing the sulfur in the heated high-temperature alloy melt to react with the CaO in the porous desulfurizer to form calcium sulfide. The calcium sulfide is then discharged through the pores of the porous desulfurizer, resulting in a desulfurized high-temperature alloy melt. This achieves sufficient contact between the melt and the active sites inside the desulfurizer, strengthens the sulfur mass transfer process, promotes the continuous desulfurization reaction, and enables timely separation of desulfurization products. Ultimately, this solves the technical problem of difficult deep desulfurization of high-temperature alloys in vacuum induction melting, yielding a high-purity high-temperature alloy with extremely low sulfur content. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within the range. For example, a range description of 1 to 6 or 1~6 covers all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms used herein, including terms such as "include" to indicate, but not limited to, "first," "second," etc., are used only to distinguish different entities or steps and do not imply an actual order or relationship; and / or to indicate that multiple situations can exist alone or simultaneously; expressions such as "at least one," "more than one," etc., refer to any combination of the corresponding objects, including combinations of single or multiple objects. Proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as a correspondence between the antecedent and consequent of a proportional expression, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0020] This application provides a vacuum induction deep desulfurization process for high-temperature alloys, characterized by the following steps: A porous desulfurizing agent containing CaO is placed in the smelting area. The sulfur-containing high-temperature alloy raw material is placed in the area to be melted, and the area to be melted is evacuated to a first vacuum level. The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt; The high-temperature alloy melt is heated to the desulfurization reaction temperature to obtain the heated high-temperature alloy melt; Maintain the vacuum level of the area to be melted at the second vacuum level; The heated high-temperature alloy melt is driven by electromagnetic stirring to pass through the porous desulfurizing agent at a flow rate of 0.2 m / s to 0.5 m / s. This causes the sulfur in the heated high-temperature alloy melt to react with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is then discharged through the pores of the porous desulfurizing agent, resulting in a desulfurized high-temperature alloy melt.

[0021] Porous desulfurizing agent: In the embodiments of this application, it refers to a solid material with a through-pore structure.

[0022] A porous desulfurizing agent containing CaO is placed in the melting zone, providing reaction sites for the desulfurization reaction. A sulfur-containing high-temperature alloy raw material is placed in the melting zone, and the zone is evacuated to a first vacuum level to remove air and prevent oxygen and nitrogen from reacting with the alloy raw material. The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt, thus changing the raw material from a solid to a liquid state and allowing sulfur to migrate freely within the melt. The high-temperature alloy melt is heated to the desulfurization reaction temperature, providing the thermodynamic conditions required for the desulfurization reaction between sulfur and CaO. The vacuum level in the melting zone is maintained at a second vacuum level to maintain a low-pressure environment, thereby reducing the partial pressure of sulfur in the gas phase and promoting desulfurization. The desulfurization reaction proceeds in the direction of calcium sulfide formation. Driven by electromagnetic stirring, the heated high-temperature alloy melt flows through the porous desulfurizing agent at a flow rate of 0.2 m / s to 0.5 m / s. This causes the sulfur in the heated high-temperature alloy melt to react with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is then discharged through the pores of the porous desulfurizing agent, resulting in a desulfurized high-temperature alloy melt. The high specific surface area of ​​the porous desulfurizing agent increases the contact area between sulfur and CaO, thereby enhancing the mass transfer process. The forced flow driven by electromagnetic stirring allows the high-temperature alloy melt to continuously flow through the porous desulfurizing agent, constantly renewing the reaction interface and avoiding diffusion limitations. The calcium sulfide is discharged through the pores, preventing its retention in the high-temperature alloy melt and thus preventing sulfur reversion. Ultimately, deep desulfurization of the high-temperature alloy is achieved in vacuum induction melting.

[0023] Existing technologies employ calcium-magnesium-based desulfurizers or calcium oxide crucibles for in-situ desulfurization, which suffers from low desulfurization efficiency due to high-temperature volatilization, short crucible lifespan, and limited mass transfer. This application's embodiments overcome the technical bottleneck of diffusion-limited mass transfer in slag-metal reactions under vacuum by using a porous desulfurizer combined with electromagnetic stirring to drive the high-temperature alloy melt through the porous desulfurizer, achieving a simultaneous improvement in desulfurization efficiency and depth.

[0024] The flow rate of the high-temperature alloy melt after being heated by electromagnetic stirring includes, but is not limited to, 0.2 m / s, 0.3 m / s, 0.4 m / s, 0.5 m / s, etc.

[0025] In some embodiments, the porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid, which is composed of multiple grid plates with a thickness of 20mm to 80mm and a spacing of 20mm to 30mm between adjacent grid plates.

[0026] CaO-Al2O3 composite porous structure grid: In this embodiment, it refers to a grid-like solid material with a porous structure made of CaO and Al2O3, wherein the CaO-Al2O3 composite porous structure grid is composed of multiple layers of grid plates. Grid plate: In this embodiment, it refers to the plate-like structural unit constituting the CaO-Al2O3 composite porous structure grid. The porous desulfurizing agent is defined as a CaO-Al2O3 composite porous structure grid, which is composed of multiple grid plates with a thickness of 20mm to 80mm and a spacing of 20mm to 30mm between adjacent grid plates. Al2O3 acts as a stabilizer to inhibit the high-temperature pulverization of CaO, thereby extending the service life of the porous desulfurizing agent. The multi-layer grid plate structure forms multiple reaction zones, increasing the number of contacts between the high-temperature alloy melt and the porous desulfurizing agent, thus improving desulfurization efficiency. The 20mm to 80mm thickness of the grid plates ensures sufficient structural strength, and the 20mm to 30mm spacing between adjacent grid plates provides a flow channel for the high-temperature alloy melt, ensuring that the high-temperature alloy melt can smoothly penetrate the CaO-Al2O3 composite porous structure grid, ultimately achieving deep desulfurization of high-temperature alloys in vacuum induction melting.

[0027] The thickness of the grating: including but not limited to 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, etc. The spacing between two adjacent grating layers: including but not limited to 20mm, 22mm, 25mm, 28mm, 30mm, etc.

[0028] In some embodiments, the grating plate has a CaO content of 60wt%~90wt%, an Al2O3 content of 10wt%~40wt%, a porosity of ≥70%, and a pore size of 0.2mm~2mm.

[0029] Porosity: In the embodiments of this application, porosity refers to the percentage of pore volume in the grating plate to the total volume of the grating plate.

[0030] The CaO content of the grating plate is limited to 60wt%~90wt%, the Al2O3 content is limited to 10wt%~40wt%, the porosity of the grating plate is limited to ≥70%, and the pore size of the grating plate is limited to 0.2mm~2mm. The CaO content of 60wt%~90wt% ensures that the grating plate has sufficient desulfurization active sites. The Al2O3 content of 10wt%~40wt% ensures that the grating plate is structurally stable at high temperatures, thereby inhibiting the high-temperature pulverization of CaO. The porosity of ≥70% provides sufficient reaction interface area, thereby enhancing the mass transfer process. The pore size of 0.2mm~2mm ensures that the high-temperature alloy melt can flow smoothly through the grating plate, while providing sufficient residence time for the desulfurization reaction to proceed fully. Ultimately, deep desulfurization of high-temperature alloys is achieved in vacuum induction melting.

[0031] The CaO content of the grating plate includes, but is not limited to, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, and 90wt%. The Al₂O₃ content of the grating plate includes, but is not limited to, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, and 40wt%. The porosity of the grating plate includes, but is not limited to, 70%, 72%, 75%, 78%, and 80%. The pore size of the grating plate includes, but is not limited to, 0.2mm, 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, and 2.0mm.

[0032] In some embodiments, the grille consists of three layers of grille panels.

[0033] The grid is defined as consisting of three layers of grid plates, thus forming a three-stage series desulfurization reaction zone. The high-temperature alloy melt passes through the first, second, and third layers of grid plates in sequence, thereby achieving staged desulfurization. The three-layer grid plate structure controls the flow resistance while ensuring the desulfurization depth, thereby avoiding the obstruction of the flow of the high-temperature alloy melt due to too many layers, thus ensuring a balance between desulfurization efficiency and production efficiency, and ultimately achieving deep desulfurization of high-temperature alloys in vacuum induction melting.

[0034] In some embodiments, the thickness of the grating is 30mm to 50mm, the spacing between the gratings is 25mm, the CaO content of the grating is 60wt%, the Al2O3 content is 40wt%, the pore size of the grating is 0.8mm to 1.5mm, and the porosity is 75%.

[0035] The thickness of the grating plate is limited to 30mm~50mm, the spacing between grating plates is limited to 25mm, the CaO content of the grating plate is limited to 60wt%, the Al2O3 content of the grating plate is limited to 40wt%, the pore size of the grating plate is limited to 0.8mm~1.5mm, and the porosity is limited to 75%. Thus, the thickness of the grating plate of 30mm~50mm optimizes material usage while ensuring structural strength. The spacing between grating plates of 25mm ensures smooth flow of the high-temperature alloy melt. The ratio of 60wt% CaO content to 40wt% Al2O3 content achieves the best balance between desulfurization activity and structural stability. The matching of 0.8mm~1.5mm pore size and 75% porosity optimizes mass transfer efficiency and flow resistance, thereby forming a verified optimal parameter combination, ultimately achieving deep desulfurization of high-temperature alloys in vacuum induction melting.

[0036] In some embodiments, the grid plates of the grid have a honeycomb structure.

[0037] The grid plate is defined as a honeycomb structure, which provides the maximum specific surface area for the same volume, thereby maximizing the contact area between sulfur and CaO. The hexagonal pores of the honeycomb structure are evenly distributed and interconnected, thus ensuring the uniformity of the high-temperature alloy melt flow and avoiding local flow dead zones. The honeycomb structure has excellent structural stability, thus preventing the pore structure from collapsing at high temperatures, thereby ensuring the service life of the porous desulfurizer, and ultimately achieving deep desulfurization of high-temperature alloys in vacuum induction melting.

[0038] In some embodiments, the specific surface area of ​​the grid plates is ≥5m². 2 / g.

[0039] The specific surface area of ​​the grating plates is limited to ≥5m². 2 / g, thus the specific surface area is ≥5m² 2 The / g grid plate provides a sufficient solid-liquid reaction interface, thereby enhancing the mass transfer process of sulfur from the high-temperature alloy melt to the interior of the porous desulfurizing agent. The high specific surface area increases the dispersion of CaO, thereby increasing the effective collision probability between sulfur and CaO, and thus increasing the desulfurization reaction rate, ultimately achieving deep desulfurization of high-temperature alloys in vacuum induction melting.

[0040] The specific surface area of ​​the grating plates: including but not limited to 5m² 2 / g、6m 2 / g、7m 2 / g、8m 2 / g、9m 2 / g, 10m 2 / g etc.

[0041] In some embodiments, the specific surface area of ​​the grid plates is 8m². 2 / g~10m 2 / g.

[0042] The specific surface area of ​​the grating plates is limited to 8m². 2 / g~10m 2 / g, thus the specific surface area is 8m² 2 / g~10m 2 The range of / g has been verified in practice, ensuring desulfurization efficiency while controlling preparation costs. The specific surface area is 8m². 2 / g~10m 2 / g balances the desulfurization reaction rate with the calcium sulfide discharge rate, thereby preventing calcium sulfide from accumulating and clogging the pores inside the porous desulfurizing agent, thus ensuring the continuous desulfurization capacity of the porous desulfurizing agent, and ultimately achieving deep desulfurization of high-temperature alloys in vacuum induction melting.

[0043] In some embodiments, the desulfurization reaction temperature is 1520℃~1600℃, the first vacuum degree and the second vacuum degree are ≤10Pa respectively, and the stirring frequency of the electromagnetic stirrer is 2Hz~4Hz.

[0044] Stirring frequency: In the embodiments of this application, it refers to the frequency of the alternating magnetic field of the electromagnetic stirrer.

[0045] The desulfurization reaction temperature is limited to 1520℃~1600℃, the first vacuum degree and the second vacuum degree are each limited to ≤10Pa, and the stirring frequency of the electromagnetic stirrer is limited to 2Hz~4Hz. Thus, the desulfurization reaction temperature of 1520℃~1600℃ ensures that the desulfurization reaction between sulfur and CaO has sufficient thermodynamic driving force. The first vacuum degree of ≤10Pa is consistent with the second vacuum degree to maintain a stable low-pressure environment. The stirring frequency of 2Hz~4Hz generates a moderate electromagnetic stirring force, thereby driving the heated high-temperature alloy melt to pass through the porous desulfurizing agent at a flow rate of 0.2m / s~0.5m / s, thereby ensuring sufficient contact between the high-temperature alloy melt and the porous desulfurizing agent, and finally realizing deep desulfurization of high-temperature alloys in vacuum induction melting.

[0046] Desulfurization reaction temperature: including but not limited to 1520℃, 1540℃, 1560℃, 1580℃, 1600℃, etc. First vacuum degree and second vacuum degree: including but not limited to 0.1Pa, 1Pa, 5Pa, 10Pa, etc. Stirring frequency of electromagnetic stirring: including but not limited to 2Hz, 2.5Hz, 3Hz, 3.5Hz, 4Hz, etc.

[0047] In some embodiments, the sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169.

[0048] The sulfur-containing high-temperature alloy raw material is limited to nickel-based high-temperature alloy K4169. As a commonly used material for high-end components such as aero-engine blades, the sulfur content of nickel-based high-temperature alloy K4169 is subject to strict control. The vacuum induction deep desulfurization process for high-temperature alloys is optimized for the chemical composition and physical properties of nickel-based high-temperature alloy K4169 to ensure the selectivity and effectiveness of the desulfurization reaction. This provides ultra-low sulfur billets for high-end alloy components such as aero-engine blades, and ultimately achieves deep desulfurization of high-temperature alloys in vacuum induction melting.

[0049] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0050] Example 1 The porous desulfurizing agent is placed in the smelting area. The porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid. The grid consists of 3 layers of grid plates with a thickness of 30 mm and a spacing of 25 mm between adjacent layers. The grid plates have a CaO content of 60 wt%, an Al2O3 content of 40 wt%, a porosity of 75%, a pore size of 0.8 mm to 1.5 mm, a honeycomb structure, and a specific surface area of ​​8.5 m² / g.

[0051] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 5 Pa.

[0052] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0053] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1550°C, to obtain the heated high-temperature alloy melt.

[0054] The vacuum level of the area to be melted is maintained at a second vacuum level of 5 Pa.

[0055] The heated high-temperature alloy melt is driven by electromagnetic stirring to flow through the porous desulfurizing agent at a flow rate of 0.3 m / s. The stirring frequency of the electromagnetic stirring is 3 Hz, so that the sulfur in the heated high-temperature alloy melt reacts with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is discharged through the pores of the porous desulfurizing agent to obtain the desulfurized high-temperature alloy melt, which is then held at the temperature for 60 min for refining.

[0056] Metallurgical effects: Sulfur content decreased from the initial 12ppm to 0.8ppm, with a desulfurization rate of 93.3%; oxygen content decreased from the initial 85ppm to 70ppm, a reduction of 17.6%; nitrogen content decreased from the initial 60ppm to 51ppm, a reduction of 15.0%; after 20 consecutive uses, the porous desulfurizing agent showed no pulverization or detachment, and its structural integrity remained good.

[0057] Example 2 The porous desulfurizing agent is placed in the smelting area. The porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid. The grid consists of 3 layers of grid plates. The thickness of the grid plates is 20 mm, the spacing between two adjacent grid plates is 20 mm, the CaO content of the grid plates is 60 wt%, the Al2O3 content is 40 wt%, the porosity of the grid plates is 70%, the pore size of the grid plates is 0.2 mm, the grid plates have a honeycomb structure, and the specific surface area of ​​the grid plates is 5 m² / g.

[0058] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 10 Pa.

[0059] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0060] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1520°C, to obtain the heated high-temperature alloy melt.

[0061] The vacuum level of the area to be melted is maintained at a second vacuum level of 10 Pa.

[0062] The heated high-temperature alloy melt is driven by electromagnetic stirring to flow through the porous desulfurizing agent at a flow rate of 0.2 m / s. The stirring frequency of the electromagnetic stirring is 2 Hz, so that the sulfur in the heated high-temperature alloy melt reacts with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is discharged through the pores of the porous desulfurizing agent to obtain the desulfurized high-temperature alloy melt, which is then held at the temperature for 60 min for refining.

[0063] Metallurgical effects: Sulfur content decreased from the initial 12ppm to 1.0ppm, with a desulfurization rate of 91.7%; oxygen content decreased from the initial 85ppm to 72ppm, a reduction of 15.3%; nitrogen content decreased from the initial 60ppm to 52ppm, a reduction of 13.3%; after 20 consecutive uses, the porous desulfurizing agent showed no pulverization or detachment, and its structural integrity remained good.

[0064] Example 3 The porous desulfurizing agent is placed in the smelting area. The porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid. The grid consists of 3 layers of grid plates. The thickness of the grid plates is 80 mm, the spacing between two adjacent grid plates is 30 mm, the CaO content of the grid plates is 90 wt%, the Al2O3 content is 10 wt%, the porosity of the grid plates is 80%, the pore size of the grid plates is 2 mm, the grid plates have a honeycomb structure, and the specific surface area of ​​the grid plates is 10 m² / g.

[0065] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 0.1 Pa.

[0066] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0067] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1600℃, to obtain the heated high-temperature alloy melt.

[0068] The vacuum level of the area to be melted is maintained at a second vacuum level of 0.1 Pa.

[0069] The heated high-temperature alloy melt is driven by electromagnetic stirring to flow through the porous desulfurizing agent at a flow rate of 0.5 m / s. The stirring frequency of the electromagnetic stirring is 4 Hz, so that the sulfur in the heated high-temperature alloy melt reacts with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is discharged through the pores of the porous desulfurizing agent to obtain the desulfurized high-temperature alloy melt, which is then held at the temperature for 60 min for refining.

[0070] Metallurgical effects: Sulfur content decreased from the initial 12ppm to 0.5ppm, with a desulfurization rate of 95.8%; oxygen content decreased from the initial 85ppm to 68ppm, a reduction of 20.0%; nitrogen content decreased from the initial 60ppm to 49ppm, a reduction of 18.3%; after 20 consecutive uses, the porous desulfurizing agent showed no pulverization or detachment, and its structural integrity remained good.

[0071] Example 4 The porous desulfurizing agent is placed in the smelting area. The porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid. The grid consists of 3 layers of grid plates. The thickness of the grid plate is 50 mm, the spacing between two adjacent grid plates is 25 mm, the CaO content of the grid plate is 75 wt%, the Al2O3 content is 25 wt%, the porosity of the grid plate is 72%, the pore size of the grid plate is 1 mm, the grid plate has a honeycomb structure, and the specific surface area of ​​the grid plate is 8 m² / g.

[0072] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 1 Pa.

[0073] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0074] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1560°C, to obtain the heated high-temperature alloy melt.

[0075] The vacuum level of the area to be melted is maintained at a second vacuum level, which is 1 Pa.

[0076] The heated high-temperature alloy melt is driven by electromagnetic stirring to flow through the porous desulfurizing agent at a flow rate of 0.4 m / s. The stirring frequency of the electromagnetic stirring is 3 Hz, so that the sulfur in the heated high-temperature alloy melt reacts with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is discharged through the pores of the porous desulfurizing agent to obtain the desulfurized high-temperature alloy melt, which is then held at the temperature for 60 min for refining.

[0077] Metallurgical effects: Sulfur content decreased from the initial 12ppm to 0.6ppm, with a desulfurization rate of 95.0%; oxygen content decreased from the initial 85ppm to 69ppm, a reduction of 18.8%; nitrogen content decreased from the initial 60ppm to 50ppm, a reduction of 16.7%; after 20 consecutive uses, the porous desulfurizing agent showed no pulverization or detachment, and its structural integrity remained good.

[0078] Example 5 The porous desulfurizing agent is placed in the smelting area. The porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid. The grid consists of 3 layers of grid plates. The thickness of the grid plates is 40 mm, the spacing between two adjacent grid plates is 22 mm, the CaO content of the grid plates is 80 wt%, the Al2O3 content is 20 wt%, the porosity of the grid plates is 78%, the pore size of the grid plates is 1.5 mm, the grid plates have a honeycomb structure, and the specific surface area of ​​the grid plates is 9 m² / g.

[0079] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 5 Pa.

[0080] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0081] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1580°C, to obtain the heated high-temperature alloy melt.

[0082] The vacuum level of the area to be melted is maintained at a second vacuum level of 5 Pa.

[0083] The heated high-temperature alloy melt is driven by electromagnetic stirring to flow through the porous desulfurizing agent at a flow rate of 0.35 m / s. The stirring frequency of the electromagnetic stirring is 2.5 Hz, so that the sulfur in the heated high-temperature alloy melt reacts with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is discharged through the pores of the porous desulfurizing agent to obtain the desulfurized high-temperature alloy melt, which is then held at the temperature for 60 min for refining.

[0084] Metallurgical effects: Sulfur content decreased from the initial 12 ppm to 0.7 ppm, with a desulfurization rate of 94.2%; oxygen content decreased from the initial 85 ppm to 71 ppm, a reduction of 16.5%; nitrogen content decreased from the initial 60 ppm to 51 ppm, a reduction of 15.0%; after 20 consecutive uses, the porous desulfurizing agent showed no pulverization or detachment, and its structural integrity remained good.

[0085] Comparative Example Comparative Example 1 Without using a porous desulfurizing agent, sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 5 Pa.

[0086] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0087] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1550°C, to obtain the heated high-temperature alloy melt.

[0088] The vacuum level of the area to be melted is maintained at a second vacuum level of 5 Pa.

[0089] The heated high-temperature alloy melt was stirred by electromagnetic stirring at a frequency of 3 Hz for 60 minutes to obtain a refined high-temperature alloy melt.

[0090] Metallurgical effects: Sulfur content decreased from the initial 12ppm to 11.5ppm, with a desulfurization rate of 4.2%; oxygen content was 83ppm; nitrogen content was 58ppm; data on the service life of desulfurizers without porous structures.

[0091] Comparative Example 2 A blocky CaO-based flux is placed in the melting area, wherein the CaO content of the blocky CaO-based flux is 60wt% and the specific surface area of ​​the blocky CaO-based flux is 0.5m² / g.

[0092] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 5 Pa.

[0093] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0094] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1550°C, to obtain the heated high-temperature alloy melt.

[0095] The vacuum level of the area to be melted is maintained at a second vacuum level of 5 Pa.

[0096] The heated high-temperature alloy melt was stirred by electromagnetic stirring at a frequency of 3 Hz for 60 minutes to obtain a refined high-temperature alloy melt.

[0097] Metallurgical effects: The sulfur content decreased from the initial 12 ppm to 8 ppm, with a desulfurization rate of 33.3%; the oxygen content was 80 ppm; the nitrogen content was 57 ppm; the blocky CaO-based flux showed pulverization and flaking after 3 heats.

[0098] Comparative Example 3 The NiCa alloy desulfurizer is placed in the melting area, the Ca content of the NiCa alloy desulfurizer is 20wt%, and the amount of NiCa alloy desulfurizer added is 1.0% of the alloy mass.

[0099] A sulfur-containing high-temperature alloy raw material is placed in the melting area. The sulfur-containing high-temperature alloy raw material is a nickel-based high-temperature alloy K4169. The melting area is evacuated to a first vacuum degree, which is 5 Pa.

[0100] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0101] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1550°C, to obtain the heated high-temperature alloy melt.

[0102] The vacuum level of the area to be melted is maintained at a second vacuum level of 5 Pa.

[0103] The heated high-temperature alloy melt was stirred by electromagnetic stirring at a frequency of 3 Hz for 60 minutes to obtain a refined high-temperature alloy melt.

[0104] Metallurgical effects: The sulfur content decreased from the initial 12 ppm to 4 ppm, with a desulfurization rate of 66.7%; the oxygen content was 88 ppm; and the nitrogen content was 62 ppm. The NiCa alloy desulfurizer volatilized at high temperatures, polluting the furnace.

[0105] Comparative Example 4 The calcium oxide crucible is used as the melting zone, and the CaO content of the calcium oxide crucible is 95 wt%.

[0106] The sulfur-containing high-temperature alloy raw material is placed in the calcium oxide crucible. The sulfur-containing high-temperature alloy raw material is nickel-based high-temperature alloy K4169. The calcium oxide crucible is evacuated to a first vacuum degree, which is 5 Pa.

[0107] The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt.

[0108] The high-temperature alloy melt is heated to the desulfurization reaction temperature, which is 1550°C, to obtain the heated high-temperature alloy melt.

[0109] The vacuum level of the calcium oxide crucible is maintained at a second vacuum level of 5 Pa.

[0110] The heated high-temperature alloy melt was stirred by electromagnetic stirring at a frequency of 3 Hz for 60 minutes to obtain a refined high-temperature alloy melt.

[0111] Metallurgical effects: The sulfur content decreased from the initial 12 ppm to 5 ppm, with a desulfurization rate of 58.3%; the oxygen content was 90 ppm; the nitrogen content was 65 ppm; the calcium oxide crucible exhibited hydration expansion, pulverization, and flaking after 4 furnace uses.

[0112] Experimental methods for evaluating results: 1. Sulfur content detection method The sulfur content of high-temperature alloy melt was determined using a high-frequency infrared carbon-sulfur analyzer. The sampling method was as follows: after the holding refining process, a liquid metal sample was taken from the induction crucible of the vacuum induction furnace, rapidly cooled, and then used to prepare the analytical sample. Each sample was measured three times, and the average value was taken as the final sulfur content data. The desulfurization rate was calculated using the formula: Desulfurization rate (%) = (Initial sulfur content - Sulfur content after treatment) / Initial sulfur content × 100%.

[0113] 2. Oxygen content detection methods The oxygen content of high-temperature alloy melts was determined using an inert gas melting-infrared absorption method. The sampling method was as follows: after the holding refining process, liquid metal samples were taken from the induction crucible of a vacuum induction furnace, rapidly cooled, and then used to prepare analytical samples. Each sample was measured three times, and the average value was taken as the final oxygen content data. The oxygen content reduction rate was calculated using the following formula: Oxygen content reduction rate (%) = (Initial oxygen content - Post-treatment oxygen content) / Initial oxygen content × 100%.

[0114] 3. Nitrogen content detection methods The nitrogen content of high-temperature alloy melts was determined using the inert gas melting-thermal conductivity method. The sampling method was as follows: after the holding refining process, liquid metal samples were taken from the induction crucible of a vacuum induction furnace, rapidly cooled, and then used to prepare analytical samples. Each sample was measured three times, and the average value was taken as the final nitrogen content data. The nitrogen content reduction rate was calculated using the formula: Nitrogen content reduction rate (%) = (Initial nitrogen content - Nitrogen content after treatment) / Initial nitrogen content × 100%.

[0115] 4. Testing methods for the service life of porous desulfurizers The porous desulfurizer was continuously used in multiple heats of vacuum induction melting. After each heat, the appearance of the porous desulfurizer was visually inspected, and the number of heats in which pulverization or flaking occurred was recorded. If no pulverization or flaking occurred after 20 consecutive heats, the service life was recorded as more than 20 heats, and the structural integrity of the porous desulfurizer was also recorded.

[0116] 5. Specific surface area testing methods The specific surface area of ​​the porous desulfurizer was determined using the BET method (Brunauer-Emmett-Teller method). Nitrogen was used as the test gas, and the test temperature was liquid nitrogen temperature (-196℃). Before testing, the samples were degassed under vacuum at 300℃ for 4 hours.

[0117] 6. Porosity Detection Methods The porosity of the porous desulfurizing agent was determined using the Archimedes' displacement method. The porous desulfurizing agent sample was immersed in water, and the dry weight, wet weight, and suspended weight of the sample were measured. The ratio of pore volume to total volume was calculated to obtain the porosity.

[0118] 7. Method for determining the flow rate of electromagnetic stirring. The flow rate of the high-temperature alloy melt was measured using an electromagnetic flowmeter. The probe of the electromagnetic flowmeter was placed inside the induction crucible of a vacuum induction furnace, and the flow rate of the high-temperature alloy melt was measured in real time while the electromagnetic stirring was running. The average flow rate during the holding and refining process was taken as the final flow rate data.

[0119] 8. Vacuum Degree Measurement Method An ionization vacuum gauge was used to measure the vacuum level in the melting zone. The ionization vacuum gauge was connected to the vacuum system of the vacuum induction furnace, and the vacuum level was continuously monitored during the vacuuming and heat preservation refining processes. The vacuum level value after stabilization was recorded.

[0120] As shown by the above performance data, the technological advancements of this application's technical solution include: 1. Significant improvement in desulfurization efficiency The desulfurization rates of Examples 1 to 5 all reached over 91.7%, with Example 3 achieving 95.8%, Example 4 achieving 95.0%, Example 1 achieving 93.3%, Example 5 achieving 94.2%, and Example 2 achieving 91.7%. Comparative Example 1, without a porous desulfurizing agent, achieved a desulfurization rate of only 4.2%; Comparative Example 2, using a blocky CaO-based flux, achieved a desulfurization rate of 33.3%; Comparative Example 3, using a NiCa alloy desulfurizing agent, achieved a desulfurization rate of 66.7%; and Comparative Example 4, using a calcium oxide crucible, achieved a desulfurization rate of 58.3%. The desulfurization rate of the technical solution in this application is more than 87.5 percentage points higher than that of Comparative Example 1, more than 58.4 percentage points higher than that of Comparative Example 2, more than 25.0 percentage points higher than that of Comparative Example 3, and more than 33.4 percentage points higher than that of Comparative Example 4.

[0121] 2. Breakthrough progress in sulfur content control After desulfurization, the sulfur content in Examples 1 to 5 was reduced to below 1.0 ppm. In Example 3, the sulfur content was reduced to 0.5 ppm; in Example 4, it was reduced to 0.6 ppm; in Example 5, it was reduced to 0.7 ppm; in Example 1, it was reduced to 0.8 ppm; and in Example 2, it was reduced to 1.0 ppm. The sulfur content after treatment in Comparative Example 1 was 11.5 ppm; in Comparative Example 2, it was 8 ppm; in Comparative Example 3, it was 4 ppm; and in Comparative Example 4, it was 5 ppm. The technical solution of this application achieves a deep desulfurization level with stable sulfur content control at ≤1 ppm, overcoming the technical bottleneck of existing technologies that struggle to reduce sulfur content to below 3 ppm.

[0122] 3. Simultaneous optimization of alloy purity The oxygen content reduction rate in Examples 1 to 5 all exceeded 15.0%, with Example 3 showing a reduction rate of 20.0%, Example 4 showing a reduction rate of 18.8%, Example 1 showing a reduction rate of 17.6%, Example 5 showing a reduction rate of 16.5%, and Example 2 showing a reduction rate of 15.3%. The nitrogen content reduction rate in Examples 1 to 5 all exceeded 13.3%, with Example 3 showing a reduction rate of 18.3%, Example 4 showing a reduction rate of 16.7%, Example 1 showing a reduction rate of 15.0%, Example 5 showing a reduction rate of 15.0%, and Example 2 showing a reduction rate of 13.3%. Comparative Example 1 showed an oxygen content of 83 ppm and a nitrogen content of 58 ppm, with no significant reduction; Comparative Example 2 showed an oxygen content of 80 ppm and a nitrogen content of 57 ppm, with a limited reduction; Comparative Example 3 showed an oxygen content of 88 ppm and a nitrogen content of 62 ppm, with an increase rather than a decrease; and Comparative Example 4 showed an oxygen content of 90 ppm and a nitrogen content of 65 ppm, with an increase rather than a decrease. The technical solution of this application simultaneously reduces both oxygen and nitrogen content while achieving deep desulfurization, resolving the technical contradiction in existing technologies where desulfurization and purity are difficult to balance.

[0123] 4. Significantly extended service life of porous desulfurizers The porous desulfurizing agents in Examples 1 to 5 all achieved a service life of 20 heats, and after 20 heats, no pulverization or flaking occurred, maintaining good structural integrity. The blocky CaO-based flux in Comparative Example 2 had a service life of 3 heats, after which pulverization and flaking occurred; the calcium oxide crucible in Comparative Example 4 had a service life of 4 heats, after which hydration expansion, pulverization, and flaking occurred; the NiCa alloy desulfurizing agent in Comparative Example 3 could not be used continuously due to high-temperature volatilization polluting the furnace. The porous desulfurizing agent in this application has a service life that is more than 17 heats longer than Comparative Example 2 and more than 16 heats longer than Comparative Example 4, achieving the technical requirement of long service life for industrial mass production.

[0124] 5. Comprehensive improvement in process stability Examples 1 to 5, within a wide range of parameters including a grating thickness of 20mm to 80mm, a grating CaO content of 60wt% to 90wt%, a grating porosity of 70% to 80%, a grating pore size of 0.2mm to 2mm, a grating specific surface area of ​​5m² / g to 10m² / g, a desulfurization reaction temperature of 1520℃ to 1600℃, a first vacuum degree of 0.1Pa to 10Pa, a flow rate of the high-temperature alloy melt after electromagnetic stirring and heating of 0.2m / s to 0.5m / s, and an electromagnetic stirring frequency of 2Hz to 4Hz, all achieved a desulfurization rate of over 91.7%, a sulfur content ≤1.0ppm after desulfurization, an oxygen content reduction rate of over 15.0%, a nitrogen content reduction rate of over 13.3%, and a service life of the porous desulfurizing agent of over 20 heats. The process stability within this parameter range indicates that the technical solution of this application has strong tolerance to process fluctuations and is suitable for industrial-scale production.

[0125] 6. Effective elimination of secondary pollution In Examples 1 to 5, no pulverization, shedding, or volatilization of the porous desulfurizing agent contaminated the furnace. In Comparative Example 3, the NiCa alloy desulfurizing agent caused volatile matter contamination of the furnace, while the blocky CaO-based flux in Comparative Example 2 and the calcium oxide crucible in Comparative Example 4 both exhibited pulverization and shedding. The technical solution of this application uses Al2O3 as a stabilizer to inhibit high-temperature pulverization of CaO and achieves directional discharge of calcium sulfide through the porous structure of the desulfurizing agent, fundamentally eliminating the secondary pollution problem in the prior art.

[0126] In summary, the technical solution of this application, through component design and structural control, simultaneously achieves the following in a single vacuum induction melting process: desulfurization rate >90%, sulfur content ≤1ppm after desulfurization, simultaneous reduction of oxygen content by more than 15%, simultaneous reduction of nitrogen content by more than 13%, service life of porous desulfurizing agent ≥20 furnace cycles, and no secondary pollution. Existing technologies require a VIM+ESR dual-process or a VIM+VAR+ESR triple-process to approach these technical indicators, and the existing dual / triple-processes suffer from drawbacks such as high equipment investment, long production cycles, and cost increases of more than 40%. The technical solution of this application achieves technical effects surpassing existing dual / triple-processes with a single-furnace vacuum induction melting process, significantly reducing production costs and improving production efficiency.

[0127] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A vacuum induction deep desulfurization process for high-temperature alloys, characterized in that, Includes the following steps: A porous desulfurizing agent containing CaO is placed in the smelting area. The sulfur-containing high-temperature alloy raw material is placed in the area to be melted, and the area to be melted is evacuated to a first vacuum level. The sulfur-containing high-temperature alloy raw material is heated and melted to obtain a high-temperature alloy melt; The high-temperature alloy melt is heated to the desulfurization reaction temperature to obtain the heated high-temperature alloy melt; Maintain the vacuum level of the area to be melted at the second vacuum level; The heated high-temperature alloy melt is driven by electromagnetic stirring to pass through the porous desulfurizing agent at a flow rate of 0.2 m / s to 0.5 m / s. This causes the sulfur in the heated high-temperature alloy melt to react with the CaO in the porous desulfurizing agent to form calcium sulfide. The calcium sulfide is then discharged through the pores of the porous desulfurizing agent, resulting in a desulfurized high-temperature alloy melt.

2. The high-temperature alloy vacuum induction deep desulfurization process according to claim 1, characterized in that, The porous desulfurizing agent is a CaO-Al2O3 composite porous structure grid, which is composed of multiple grid plates with a thickness of 20mm to 80mm and a spacing of 20mm to 30mm between adjacent grid plates.

3. The high-temperature alloy vacuum induction deep desulfurization process according to claim 2, characterized in that, The grating plate has a CaO content of 60wt%~90wt%, an Al2O3 content of 10wt%~40wt%, a porosity of ≥70%, and a pore size of 0.2mm~2mm.

4. The high-temperature alloy vacuum induction deep desulfurization process according to claim 2, characterized in that, The grid consists of three layers of grid panels.

5. The high-temperature alloy vacuum induction deep desulfurization process according to claim 4, characterized in that, The thickness of the grating plate is 30mm~50mm, the spacing between the grating plates is 25mm, the CaO content of the grating plate is 60wt%, the Al2O3 content is 40wt%, the pore size of the grating plate is 0.8mm~1.5mm, and the porosity is 75%.

6. The high-temperature alloy vacuum induction deep desulfurization process according to claim 2, characterized in that, The grid plate of the grid has a honeycomb structure.

7. The high-temperature alloy vacuum induction deep desulfurization process according to claim 2, characterized in that, The specific surface area of the grid plates of the grid is ≥ 5 m 2 / g.

8. The high-temperature alloy vacuum induction deep desulfurization process according to claim 7, characterized in that, The specific surface area of the grid plates of the grid is 8 m 2 / g~10 m 2 / g.

9. The high-temperature alloy vacuum induction deep desulfurization process according to claim 1, characterized in that, The desulfurization reaction temperature is 1520℃~1600℃, the first vacuum degree and the second vacuum degree are ≤10Pa respectively, and the stirring frequency of the electromagnetic stirrer is 2Hz~4Hz.

10. The high-temperature alloy vacuum induction deep desulfurization process according to claim 1, characterized in that, The sulfur-containing high-temperature alloy raw material is nickel-based high-temperature alloy K4169.