Non-vacuum smelting method for low-cost iron-based amorphous nanocrystalline mother alloy based on high-aluminum niobium silicon iron

Abstract

The invention relates to the technical field of amorphous nanocrystalline mother alloy smelting, and discloses a low-cost iron-based amorphous nanocrystalline mother alloy non-vacuum smelting method based on high-aluminum niobium silicon iron, which comprises the steps of material distribution and heating smelting in a furnace, alloying and primary refining, slagging and secondary soft argon blowing refining as well as slagging-off and tapping. By means of the argon blowing process and the secondary refining slagging process in a non-vacuum smelting system, the exogenous inclusions introduced by the high-aluminum niobium silicon iron can be removed to the maximum extent. The production cost of the master alloy can be remarkably reduced, the cleanliness of the master alloy can be improved, and the method has economical efficiency and practicability and is suitable for industrial large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of amorphous and nanocrystalline master alloy smelting technology, specifically a low-cost non-vacuum smelting method for iron-based amorphous and nanocrystalline master alloys based on high-alumina niobium ferrosilicon. Background Technology

[0002] Commercial iron-based amorphous and nanocrystalline soft magnetic materials belong to the category of high-performance soft magnetic materials. Their common alloy composition system is Fe-Cu-Nb-Si-B, such as the classic Fe... 73.5 Cu1Nb3Si 13.5 B9 alloy belongs to this system. The preparation process of this type of material is quite special. First, an amorphous ribbon is made through rapid solidification technology, and then the amorphous ribbon is heat-treated to finally obtain a composite structure composed of "amorphous matrix and nanocrystals". In the formation of this composite structure, copper (Cu) plays an important role in providing a site for grain nucleation, while niobium (Nb) and other elements can inhibit grain growth, thereby ensuring that the material structure can be uniformly refined to the nanoscale.

[0003] Iron-based amorphous and nanocrystalline soft magnetic alloys possess numerous outstanding advantages. Firstly, they exhibit extremely high permeability, reaching tens or even hundreds of thousands, while possessing very low coercivity. This makes magnetization and demagnetization easier, resulting in reduced energy loss. Secondly, these materials exhibit extremely low losses at high frequencies. This is due to the combined effect of their nanostructure, high resistivity, and thin-strip morphology, which effectively suppresses eddy current effects. Therefore, in the frequency range of kHz to hundreds of kHz, their performance surpasses that of ferrites and silicon steel. Thirdly, they possess high saturation magnetic induction, exceeding 1.2 T, a figure superior to ferrites, which is crucial for miniaturizing electronic devices. Fourthly, these materials also exhibit excellent temperature and time stability, and good resistance to DC bias. Currently, iron-based amorphous and nanocrystalline soft magnetic materials have been widely used in medium- and high-frequency small- and medium-power electronic devices, such as high-frequency transformers, common-mode inductors, and noise filters in switching power supplies; photovoltaic inverters and current transformers in smart meters in the new energy field; and they also play an important role in special applications such as automotive electronics, wireless charging, and magnetic shielding. They successfully overcome the performance shortcomings of silicon steel (high saturation magnetic induction but high high-frequency loss) and ferrite (suitable for high-frequency environments but low saturation magnetic induction), becoming a key material driving the development of power electronic devices towards higher frequencies, higher efficiency, and smaller size.

[0004] However, iron-based amorphous nanocrystalline soft magnetic alloys face a high raw material cost issue. The main reason for this is that iron-based amorphous nanocrystalline strips are typically thin (generally less than 20 μm), which places extremely high demands on the cleanliness of the raw materials used in smelting. Looking at the raw material cost composition, the main smelting raw materials for commercially available iron-based amorphous nanocrystalline alloys include industrial pure iron, industrial silicon, high-grade low-aluminum ferroniobium, ferroboron, and electrolytic copper. Among these, high-grade low-aluminum ferroniobium (niobium content not less than 60 wt%) accounts for over 69% of the total cost of the iron-based amorphous nanocrystalline master alloy raw materials. This factor significantly restricts the reduction of the cost of iron-based amorphous nanocrystalline soft magnetic alloys.

[0005] High-alumina niobium ferrosilicon, also known as niobium-iron alloy, is mainly produced from tailings after tantalum extraction from tantalum-niobium ore. The preparation process involves roughing processes such as aluminothermic or electric furnace reduction, followed by refining. The niobium content of this material ranges from 15 to 30 wt%. Due to its relatively low niobium content and high aluminum (Al) content (over 0.6 wt%), the unit cost of niobium is more than 13% lower than that of conventional high-grade low-alumina niobium ferrosilicon. Furthermore, low-grade niobium ferrosilicon also contains a certain amount of silicon (approximately 10 wt%) and iron, a characteristic that is highly advantageous for further reducing the preparation cost of iron-based amorphous nanocrystalline master alloys. Based on these factors, this application proposes a low-cost, non-vacuum smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon, aiming to reduce the production cost of iron-based amorphous nanocrystalline products. Summary of the Invention

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a low-cost non-vacuum smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon.

[0007] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a low-cost non-vacuum smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon, comprising the following steps: S1. Charging and Heating Melting in Furnace: Weigh the raw materials according to the mass fraction. After processing, add 15-50% of the total amount of industrial pure iron and industrial silicon and all of the ferroboron into the non-vacuum medium-frequency induction furnace. After charging, increase the heating power of the non-vacuum medium-frequency induction furnace to 350-400 kW and the heating temperature to 1495-1535℃. S2. Alloying and primary refining: First, high-alumina niobium iron silicon and iron oxide powder with a mass ratio of 100:0.8~1.5 are mixed evenly by mechanical mixing to obtain a mixture. Then, the mixture is added to the molten steel in a non-vacuum medium-frequency induction furnace, and the mixture is stirred manually to promote rapid melting. The heating power of the medium-frequency induction furnace is controlled to carry out argon blowing process. S3. Slag Formation and Secondary Soft Argon Blowing Refining: Add 0.4~1.5 wt% of slag-forming agent by weight of molten steel into the medium-frequency induction furnace and completely cover the surface of the molten steel. Then reduce the heating power of the medium-frequency furnace to 50~150 kW and simultaneously perform soft argon blowing for 20~40 minutes, with an argon blowing pressure range of 0.1~0.4 MPa. S4. Slag Removal and Steel Tapping: Power off and cool down the molten steel until the temperature drops to 1255~1285℃. Remove impurities and then pour the molten steel into the ingot mold to obtain an iron-based amorphous nanocrystalline master alloy.

[0008] Further, in step S1, the following raw materials are weighed by weight: 10-25 parts high-alumina niobium iron silicon, 50-70 parts industrial pure iron, 3-8 parts industrial silicon, 2-6 parts ferroboron, and 1-3 parts electrolytic copper, wherein the purity of the raw materials is not less than 98%; The processing method is as follows: industrial pure iron is cut into blocks with dimensions of 50 mm×50 mm×50 mm~100 mm×100 mm×100 mm. High-alumina niobium iron silicon, industrial silicon, ferroboron, and electrolytic copper are crushed to a particle size of 10~30 mm. Then, all raw materials are placed in a drying oven and dried at 120~150℃ for 2~3 hours to remove moisture and oil from the surface of the raw materials.

[0009] Furthermore, the composition of the high-alumina niobium-iron-silicon is as follows: Nb content is 15~30 wt%, Si content is 10~25 wt%, Al content is 0.6~1.6 wt%, total impurity content is 0.05~0.12 wt%, and the balance is Fe.

[0010] Furthermore, in step S1, the furnace material distribution method is as follows: first, the industrial silicon blocks are evenly spread on the bottom of the medium-frequency induction furnace, then the cut blocks of industrial pure iron are neatly placed in the center of the medium-frequency induction furnace, and finally, all the granular ferroboron is slowly poured into the gaps between the industrial pure iron blocks.

[0011] Furthermore, during the removal of primary refining slag from the surface of the molten steel in step S2, 0.2-0.5% of the molten steel mass of refining agent is added to the molten steel, and stirring is continued for 10-15 minutes. After the reaction is completed, the mixture is allowed to stand for 5-8 minutes, and the slag that has floated to the surface is completely removed using a slag skimmer.

[0012] Furthermore, in step S2, the heating power of the medium-frequency induction furnace and the argon blowing process are maintained at 200~300 kW. At the same time, argon blowing refining is started. Then, the remaining industrial silicon raw materials are added to the primary refining slag on the surface of the molten steel. At the same time, the heating power of the medium-frequency induction furnace is adjusted to 200~250 kW. Then, the argon blowing process is maintained for 10~20 minutes. When the temperature of the molten steel in the furnace drops to 1395~1425℃, the primary refining slag on the surface of the molten steel is manually removed, and all the electrolytic copper raw materials are added. At the same time, the heating power of the medium-frequency furnace is increased to 250~350 kW, so that the temperature of the molten steel in the furnace rises to 1485~1515℃, and the argon blowing process is maintained for 5~10 minutes.

[0013] Furthermore, in step S3, the slag-forming agent consists of 40-55% CaO, 15-25% SiO2, 10-20% Al2O3, and 5-15% MgO; the particle size range of the slag-forming agent is 10-60 mesh.

[0014] Furthermore, in step S4, the temperature of the molten metal after impurity removal is adjusted to 1420~1460℃, and the molten metal is poured into a steel ingot mold preheated to 300~400℃. After the molten metal is poured, it is cooled to room temperature by natural cooling.

[0015] Furthermore, in step S4, power outage cooling involves stopping the heating power supply to the medium-frequency induction furnace and allowing the molten steel to cool down naturally; then, a slag removal tool is used manually to thoroughly remove all refining slag from the surface of the molten steel.

[0016] (iii) Beneficial technical effects This invention utilizes argon blowing and secondary refining slag-forming processes in a non-vacuum smelting system to maximize the removal of exogenous inclusions introduced by high-alumina niobium ferrosilicon. Iron oxide powder reacts with Al, an impurity element in the high-alumina niobium ferrosilicon, to generate Al2O3, a dealuminizing product. After the primary refining slag on the surface of the molten steel is manually removed, the added slag-forming agent further adsorbs the Al2O3 dealuminizing product and inclusions inherent in the high-alumina niobium ferrosilicon, enhancing the impurity removal effect. The synergistic effect of the primary argon blowing process and the secondary soft argon blowing process promotes the aggregation and floating of low-density inclusions in the molten steel, forming easily removable slag, thereby significantly improving the cleanliness of the molten steel. The core reaction formula is as follows: (Fe₂O₃) + [Al] = (Al₂O₃) + [Fe When using iron oxide powder to perform a dealumination reaction on high-alumina niobium ferrosilicon, there is a problem of Nb, a precious metal, being burned off in the molten steel. To address this, this invention utilizes the reducing properties of silicon. After the dealumination process, industrial silicon is spread on the surface of the primary refining slag and heated to melt it. This operation promotes the return of niobium oxide formed from burn-off in the refining slag to the molten steel. The specific chemical reaction formula is as follows: (NbO2) + [Si] = (SiO2) + [Nb] This invention proposes a low-cost non-vacuum smelting method for iron-based amorphous nanocrystalline master alloys using high-alumina niobium ferrosilicon as raw material. This method successfully achieves the replacement of high-grade low-alumina niobium ferrosilicon with high-alumina niobium ferrosilicon as the smelting raw material for iron-based amorphous nanocrystalline master alloys through four core process steps: in-furnace charging and heating smelting, alloying and primary refining, slag formation and secondary soft blowing argon refining, and slag removal and tapping.

[0017] Based on the above method, the Nb element recovery rate exceeds 98.5% in the non-vacuum smelting process, and the final prepared iron-based amorphous nanocrystalline master alloy has an aluminum content of ≤44 ppm, exhibiting high purity. This method not only significantly reduces the production cost of the master alloy but also improves its purity, combining economic efficiency and practicality, making it suitable for large-scale industrial application. Attached Figure Description

[0018] Figure 1 This is a flowchart of a low-cost, vacuum-free smelting method for iron-based amorphous and nanocrystalline master alloys based on high-alumina niobium ferrosilicon. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Unless otherwise specified, all components of the iron-based amorphous nanocrystalline master alloy formulation of this invention are commercially available. Example 1 A low-cost, vacuum-free smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon includes the following steps: S1. Charging and Heating Melting in Furnace: Weigh the raw materials according to the mass fraction. After processing, add 15% of the total amount of industrial pure iron and industrial silicon and all of the ferroboron to the non-vacuum medium-frequency induction furnace. After charging, increase the heating power of the non-vacuum medium-frequency induction furnace to 350 kW and the heating temperature to 1495℃. S2. Alloying and primary refining: First, high-alumina niobium iron silicon and iron oxide powder with a mass ratio of 100:0.8 are mixed evenly by mechanical mixing to obtain a mixture. Then, the mixture is added to the molten steel in a non-vacuum medium-frequency induction furnace, and the mixture is stirred manually to promote rapid melting. The heating power of the medium-frequency induction furnace is controlled to carry out argon blowing process. S3. Slag Formation and Secondary Soft Argon Blowing Refining: Add 0.4 wt% of slag-forming agent by weight of the molten steel into the medium-frequency induction furnace and completely cover the surface of the molten steel. Then reduce the heating power of the medium-frequency furnace to 50 kW and simultaneously perform soft argon blowing for 20 min with an argon blowing pressure of 0.1 MPa. S4. Slag Removal and Steel Tapping: Power off and cool down the molten steel until the temperature drops to 1255℃. Remove impurities and then pour the molten steel into the ingot mold to obtain an iron-based amorphous nanocrystalline master alloy.

[0021] In step S1, the following raw materials are weighed by weight: 10 parts high-alumina niobium iron silicon, 50 parts industrial pure iron, 3 parts industrial silicon, 2 parts ferroboron, and 1 part electrolytic copper. The purity of all the raw materials is not less than 98%. The processing method is as follows: industrial pure iron is cut into blocks with dimensions of 50 mm×50 mm×50 mm~100 mm×100 mm×100 mm. High-alumina niobium iron silicon, industrial silicon, ferroboron, and electrolytic copper are crushed to a particle size of 10~30 mm. Then, all raw materials are placed in a drying oven and dried at 120℃ for 2 hours to remove moisture and oil from the surface of the raw materials.

[0022] The composition of high-alumina niobium-iron-silicon is as follows: Nb content is 15~30 wt%, Si content is 10~25 wt%, Al content is 0.6~1.6 wt%, total impurity content is 0.05~0.12 wt%, and the balance is Fe.

[0023] In step S1, the furnace material distribution method is as follows: first, the industrial silicon blocks are evenly spread on the bottom of the medium-frequency induction furnace, then the cut blocks of industrial pure iron are neatly placed in the center of the medium-frequency induction furnace, and finally, all the granular ferroboron is slowly poured into the gaps between the industrial pure iron blocks.

[0024] In step S2, when removing the primary refining slag from the surface of the molten steel, add 0.2% of the molten steel mass of refining agent to the molten steel and continue stirring for 10 minutes. After the reaction is complete, let it stand for 5 minutes and use a slag skimmer to completely remove the slag that has floated to the surface.

[0025] In step S2, the heating power of the medium-frequency induction furnace and the argon blowing process are maintained at 200 kW. At the same time, argon blowing refining is started. Then, the remaining industrial silicon raw materials are added to the primary refining slag on the surface of the molten steel. The heating power of the medium-frequency induction furnace is adjusted to 200 kW. The argon blowing process is then maintained for 10 minutes. When the temperature of the molten steel in the furnace drops to 1395℃, the primary refining slag on the surface of the molten steel is manually removed, and all the electrolytic copper raw materials are added. At the same time, the heating power of the medium-frequency furnace is increased to 250~350 kW, so that the temperature of the molten steel in the furnace rises to 1485℃. The argon blowing process is then maintained for 5 minutes.

[0026] In step S3, the slag-forming agent consists of 50% CaO, 20% SiO2, 20% Al2O3, and 10% MgO; the particle size range of the slag-forming agent is 10-60 mesh.

[0027] In step S4, the temperature of the molten metal after impurity removal is adjusted to 1420℃, and the molten metal is poured into a steel ingot mold preheated to 300℃. After the molten metal is poured, it is cooled to room temperature by natural cooling.

[0028] In step S4, power outage cooling means stopping the heating power supply to the medium-frequency induction furnace and allowing the molten steel to cool down naturally; manual slag removal tools are used to completely remove all refining slag from the surface of the molten steel.

[0029] Example 2 A low-cost, vacuum-free smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon includes the following steps: S1. Charging and Heating Melting in Furnace: Weigh the raw materials according to the mass fraction. After processing, add 30% of the total amount of industrial pure iron and industrial silicon and all of the ferroboron to the non-vacuum medium-frequency induction furnace. After charging, increase the heating power of the non-vacuum medium-frequency induction furnace to 380 kW and the heating temperature to 1520℃. S2. Alloying and primary refining: First, high-alumina niobium iron silicon and iron oxide powder with a mass ratio of 100:1 are mixed evenly by mechanical mixing to obtain a mixture. Then, the mixture is added to the molten steel in a non-vacuum medium-frequency induction furnace, and the mixture is stirred manually to promote rapid melting. The heating power of the medium-frequency induction furnace is controlled to carry out argon blowing process. S3. Slag Formation and Secondary Soft Argon Blowing Refining: Add 1 wt% of slag-forming agent by weight of the molten steel into the medium-frequency induction furnace and completely cover the surface of the molten steel. Then reduce the heating power of the medium-frequency furnace to 100 kW and simultaneously perform soft argon blowing for 30 min with an argon blowing pressure of 0.2 MPa. S4. Slag Removal and Steel Tapping: Power off and cool down the molten steel until the temperature drops to 1260℃. Remove impurities and then pour the molten steel into the ingot mold to obtain an iron-based amorphous nanocrystalline master alloy.

[0030] In step S1, the following raw materials are weighed by weight: 15 parts high-alumina niobium iron silicon, 60 parts industrial pure iron, 5 parts industrial silicon, 4 parts ferroboron, and 2 parts electrolytic copper. The purity of all the raw materials is not less than 98%. The processing method is as follows: industrial pure iron is cut into blocks with dimensions of 50 mm×50 mm×50 mm~100 mm×100 mm×100 mm. High-alumina niobium iron silicon, industrial silicon, ferroboron, and electrolytic copper are crushed to a particle size of 10~30 mm. Then, all raw materials are placed in a drying oven and dried at 130℃ for 2.5 h to remove moisture and oil stains from the surface of the raw materials.

[0031] The composition of high-alumina niobium-iron-silicon is as follows: Nb content is 15~30 wt%, Si content is 10~25 wt%, Al content is 0.6~1.6 wt%, total impurity content is 0.05~0.12 wt%, and the balance is Fe.

[0032] In step S1, the furnace material distribution method is as follows: first, the industrial silicon blocks are evenly spread on the bottom of the medium-frequency induction furnace, then the cut blocks of industrial pure iron are neatly placed in the center of the medium-frequency induction furnace, and finally, all the granular ferroboron is slowly poured into the gaps between the industrial pure iron blocks.

[0033] In step S2, when removing the primary refining slag from the surface of the molten steel, add 0.3% of the molten steel mass of refining agent to the molten steel and continue stirring for 15 minutes. After the reaction is complete, let it stand for 6 minutes and use a slag skimmer to completely remove the slag that has floated to the surface.

[0034] In step S2, the heating power of the medium-frequency induction furnace and the argon blowing process are maintained at 250 kW. At the same time, argon blowing refining is started. Then, the remaining industrial silicon raw materials are added to the primary refining slag on the surface of the molten steel. At the same time, the heating power of the medium-frequency induction furnace is adjusted to 220 kW. Then, the argon blowing process is maintained for 15 minutes. When the temperature of the molten steel in the furnace drops to 1410℃, the primary refining slag on the surface of the molten steel is manually removed, and all the electrolytic copper raw materials are added. At the same time, the heating power of the medium-frequency furnace is increased to 300 kW, so that the temperature of the molten steel in the furnace rises to 1500℃, and the argon blowing process is maintained for 5 minutes.

[0035] In step S3, the slag-forming agent consists of 50% CaO, 25% SiO2, 20% Al2O3, and 5% MgO; the particle size range of the slag-forming agent is 10-60 mesh.

[0036] In step S4, the temperature of the molten metal after impurity removal is adjusted to 1440℃, and the molten metal is poured into a steel ingot mold preheated to 350℃. After the molten metal is poured, it is cooled to room temperature by natural cooling.

[0037] In step S4, power outage cooling means stopping the heating power supply to the medium-frequency induction furnace and allowing the molten steel to cool down naturally; manual slag removal tools are used to completely remove all refining slag from the surface of the molten steel.

[0038] Example 3 A low-cost, vacuum-free smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon includes the following steps: S1. Charging and Heating Melting in Furnace: Weigh the raw materials according to the mass fraction. After processing, add 50% of the total amount of industrial pure iron and industrial silicon and all of the ferroboron to the non-vacuum medium-frequency induction furnace. After charging, increase the heating power of the non-vacuum medium-frequency induction furnace to 400 kW and the heating temperature to 1535℃. S2. Alloying and primary refining: First, high-alumina niobium iron silicon and iron oxide powder with a mass ratio of 100:1.5 are mixed evenly by mechanical mixing to obtain a mixture. Then, the mixture is added to the molten steel in a non-vacuum medium-frequency induction furnace, and the mixture is stirred manually to promote rapid melting. The heating power of the medium-frequency induction furnace is controlled to carry out argon blowing process. S3. Slag Formation and Secondary Soft Argon Blowing Refining: Add 1.5 wt% of slag-forming agent by weight of the molten steel into the medium-frequency induction furnace and completely cover the surface of the molten steel. Then reduce the heating power of the medium-frequency furnace to 150 kW and simultaneously perform soft argon blowing for 40 min with an argon blowing pressure of 0.4 MPa. S4. Slag Removal and Steel Tapping: Power off and cool down the molten steel until the temperature drops to 1285℃. Remove impurities and then pour the molten steel into the ingot mold to obtain an iron-based amorphous nanocrystalline master alloy.

[0039] In step S1, the following raw materials are weighed by weight: 25 parts high-alumina niobium iron silicon, 70 parts industrial pure iron, 8 parts industrial silicon, 6 parts ferroboron, and 3 parts electrolytic copper. The purity of all the raw materials is not less than 98%. The processing method is as follows: industrial pure iron is cut into blocks with dimensions of 50 mm×50 mm×50 mm~100 mm×100 mm×100 mm. High-alumina niobium iron silicon, industrial silicon, ferroboron, and electrolytic copper are crushed to a particle size of 10~30 mm. Then, all raw materials are placed in a drying oven and dried at 150℃ for 3 hours to remove moisture and oil from the surface of the raw materials.

[0040] The composition of high-alumina niobium-iron-silicon is as follows: Nb content is 15~30 wt%, Si content is 10~25 wt%, Al content is 0.6~1.6 wt%, total impurity content is 0.05~0.12 wt%, and the balance is Fe.

[0041] In step S1, the furnace material distribution method is as follows: first, the industrial silicon blocks are evenly spread on the bottom of the medium-frequency induction furnace, then the cut blocks of industrial pure iron are neatly placed in the center of the medium-frequency induction furnace, and finally, all the granular ferroboron is slowly poured into the gaps between the industrial pure iron blocks.

[0042] In step S2, when removing the primary refining slag from the surface of the molten steel, add 0.5% of the molten steel mass of refining agent to the molten steel and continue stirring for 15 minutes. After the reaction is complete, let it stand for 8 minutes and use a slag skimmer to completely remove the slag that has floated to the surface.

[0043] In step S2, the heating power of the medium-frequency induction furnace and the argon blowing process are maintained at 300 kW. At the same time, argon blowing refining is started. Then, the remaining industrial silicon raw materials are added to the primary refining slag on the surface of the molten steel. At the same time, the heating power of the medium-frequency induction furnace is adjusted to 250 kW. Then, the argon blowing process is maintained for 20 minutes. When the temperature of the molten steel in the furnace drops to 1425℃, the primary refining slag on the surface of the molten steel is manually removed, and all the electrolytic copper raw materials are added. At the same time, the heating power of the medium-frequency furnace is increased to 350 kW, so that the temperature of the molten steel in the furnace rises to 1515℃. The argon blowing process is maintained for 10 minutes.

[0044] In step S3, the slag-forming agent consists of 50% CaO, 20% SiO2, 20% Al2O3, and 10% MgO; the particle size range of the slag-forming agent is 10-60 mesh.

[0045] In step S4, the temperature of the molten metal after impurity removal is adjusted to 1460℃, and the molten metal is poured into a steel ingot mold preheated to 400℃. After the molten metal is poured, it is cooled to room temperature by natural cooling.

[0046] In step S4, power outage cooling means stopping the heating power supply to the medium-frequency induction furnace and allowing the molten steel to cool down naturally; manual slag removal tools are used to completely remove all refining slag from the surface of the molten steel.

[0047] Comparative Example 1: All industrial silicon was added in step S1, but not in step S2. The remaining steps were the same as in Example 1.

[0048] Comparative Example 2: In step S2, the mass ratio of high-alumina niobium iron silicon to iron oxide powder is 100:2.2, and the remaining steps are the same as in Example 2.

[0049] Comparative Example 3: The soft blowing argon process was removed in step S3, and the remaining steps were the same as in Example 3.

[0050] The mass content of Si, B, Cu, and Nb, the Nb element yield, and the content of Al element, an internal impurity, in the iron-based amorphous nanocrystalline master alloy were detected, and the results are shown in the table below. Table 1. Detection results of the mass content (wt%) of Si, B, Cu, and Nb.

[0051] Table 2. Results of Nb recovery and Al content detection.

[0052] As shown in Table 1, the Si content in Examples 1-3 was 8.73-8.74 wt%, while that in Comparative Examples 1-3 was 8.69-8.71 wt%, which is 0.02-0.05 wt% lower than that in the Examples. In Comparative Example 1, all industrial silicon was added in advance, resulting in partial burn-off at high temperatures. In Comparative Example 2, excessive iron oxide caused a slight silicon oxidation reaction, leading to a decrease in Si content. The Nb content in Examples 1-3 was 5.63-5.66 wt%, while that in Comparative Examples 1-3 was 5.57-5.60 wt%, which is 0.03-0.09 wt% lower than that in the Examples. The process parameters in Comparative Examples 1-3 all resulted in partial oxidation of Nb or loss with the slag. The losses of B and Cu were relatively small.

[0053] As shown in Table 2, the Nb yield in Examples 1-3 was 98.52-98.94%, while that in Comparative Examples 1-3 was 97.52-97.72%. The Al content of impurities in Examples 1-3 was 40-44 ppm, while that in Comparative Examples 1-3 was 49-65 ppm. The process and parameters of Comparative Examples 1-3 led to a decrease in Nb yield and an increase in Al content.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-cost, vacuum-free smelting method for iron-based amorphous nanocrystalline master alloys based on high-alumina niobium ferrosilicon, characterized in that, Includes the following steps: S1. Charging and Heating Melting in Furnace: Weigh the raw materials according to the mass fraction. After processing, add 15-50% of the total amount of industrial pure iron and industrial silicon and all of the ferroboron into the non-vacuum medium-frequency induction furnace. After charging, increase the heating power of the non-vacuum medium-frequency induction furnace to 350-400 kW and the heating temperature to 1495-1535℃. S2. Alloying and primary refining: First, high-alumina niobium iron silicon and iron oxide powder with a mass ratio of 100:0.8~1.5 are mixed evenly by mechanical mixing to obtain a mixture. Then, the mixture is added to the molten steel in a non-vacuum medium-frequency induction furnace, and the mixture is stirred manually to promote rapid melting. The heating power of the medium-frequency induction furnace is controlled to carry out argon blowing process. S3. Slag Formation and Secondary Soft Argon Blowing Refining: Add 0.4~1.5 wt% of slag-forming agent by weight of molten steel into the medium-frequency induction furnace and completely cover the surface of the molten steel. Then reduce the heating power of the medium-frequency furnace to 50~150 kW and simultaneously perform soft argon blowing for 20~40 minutes, with an argon blowing pressure range of 0.1~0.4 MPa. S4. Slag Removal and Steel Tapping: Power off and cool down the molten steel until the temperature drops to 1255~1285℃. Remove impurities and then pour the molten steel into the ingot mold to obtain an iron-based amorphous nanocrystalline master alloy.

2. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S1, the following raw materials are weighed by weight: 10-25 parts of high-alumina niobium iron silicon, 50-70 parts of industrial pure iron, 3-8 parts of industrial silicon, 2-6 parts of ferroboron, and 1-3 parts of electrolytic copper. The purity of all the raw materials is not less than 98%. The processing method is as follows: industrial pure iron is cut into blocks with dimensions of 50 mm×50 mm×50 mm~100 mm×100 mm×100 mm. High-alumina niobium iron silicon, industrial silicon, ferroboron, and electrolytic copper are crushed to a particle size of 10~30 mm. Then, all raw materials are placed in a drying oven and dried at 120~150℃ for 2~3 hours to remove moisture and oil from the surface of the raw materials.

3. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 2, characterized in that, The composition of high-alumina niobium-iron-silicon is as follows: Nb content is 15~30 wt%, Si content is 10~25 wt%, Al content is 0.6~1.6 wt%, total impurity content is 0.05~0.12 wt%, and the balance is Fe.

4. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S1, the furnace material distribution method is as follows: first, the industrial silicon blocks are evenly spread on the bottom of the medium-frequency induction furnace, then the cut blocks of industrial pure iron are neatly placed in the center of the medium-frequency induction furnace, and finally, all the granular ferroboron is slowly poured into the gaps between the industrial pure iron blocks.

5. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S2, when removing the primary refining slag from the surface of the molten steel, add 0.2-0.5% of the refining agent by weight of the molten steel to the molten steel and continue stirring for 10-15 minutes. After the reaction is complete, let it stand for 5-8 minutes and use a slag skimmer to completely remove the slag that has floated to the surface.

6. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S2, the heating power of the medium-frequency induction furnace and the argon blowing process are maintained at 200~300 kW. At the same time, argon blowing refining is started. Then, the remaining industrial silicon raw materials are added to the primary refining slag on the surface of the molten steel. At the same time, the heating power of the medium-frequency induction furnace is adjusted to 200~250 kW. Then, the argon blowing process is maintained for 10~20 minutes. When the temperature of the molten steel in the furnace drops to 1395~1425℃, the primary refining slag on the surface of the molten steel is manually removed, and all the electrolytic copper raw materials are added. At the same time, the heating power of the medium-frequency furnace is increased to 250~350 kW, so that the temperature of the molten steel in the furnace rises to 1485~1515℃. The argon blowing process is maintained for 5~10 minutes.

7. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S3, the slag-forming agent consists of 40-55% CaO, 15-25% SiO2, 10-20% Al2O3, and 5-15% MgO; the particle size range of the slag-forming agent is 10-60 mesh.

8. The method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S4, the temperature of the molten metal after impurity removal is adjusted to 1420~1460℃, and the molten metal is poured into a steel ingot mold preheated to 300~400℃. After the molten metal is poured, it is cooled to room temperature by natural cooling.

9. A method for non-vacuum smelting of a low-cost iron-based amorphous nanocrystalline master alloy based on high-alumina niobium ferrosilicon according to claim 1, characterized in that, In step S4, power outage cooling means stopping the heating power supply to the medium-frequency induction furnace and allowing the molten steel to cool down naturally; manual slag removal tools are used to completely remove all refining slag from the surface of the molten steel.

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