Background
The iron-based amorphous soft magnetic alloy is an alloy strip which is generally prepared by rapidly cooling by using a single-roller rotary quenching method, and has excellent soft magnetic properties such as low coercive force (H) because the iron-based amorphous alloy does not have defects such as crystal boundary and the like for pinning magnetic domainsc) High effective magnetic permeability (mu)e) Compared with the traditional silicon steel soft magnetic material, the iron-based amorphous alloy can reduce the no-load loss by 80 percent when being applied to the transformer, greatly save energy and promote the development of electronic products towards the direction of energy conservation and high efficiency. Meanwhile, the iron-based amorphous alloy strip is formed at one time, the processes of cold rolling, hot rolling and the like in the production process of silicon steel are not needed, the production flow is short, the cost is low, and the large-scale production of the soft magnetic material is facilitated.
A typical iron-based amorphous soft magnetic alloy metglas (fesib) has received extensive attention and application since its development. But its saturation magnetic induction (B)s1.56T), the obstacles such as transformer cores, motor rotors and magnetic switches are very large when making magnetic components. Therefore, many researchers have invested much effort in trying to improve the saturation induction of fe-based amorphous alloys.
The American Allied-Signal company successfully developed Metglas2605Co alloy, BsAs high as 1.80T, the alloy contains 18 percent of Co atoms, so that the production cost is extremely high, and the mass production is not facilitated. In addition, U.S. Pat. No. 4,264,619 discloses an Fe-B-C alloy, B of whichsMore than 1.7T, but the alloy has poor soft magnetic property and is too brittle to be applied in practice. Hitachi metal in patent CN1721563A discloses a Fe-Si-B-C alloy (H)B1) Of which BsThe temperature reaches more than 1.6T, but a carburizing process is required in the preparation process, so that the production cost is improved, and the controllability of the product quality is reduced.
The iron-based amorphous soft magnetic alloy with high saturation induction density reported at present has extremely high iron content and does not contain nonmagnetic macro atoms, so that the amorphous forming capability is poor, and therefore, a multi-component system, such as an Fe-Si-B-P-C system, is generally selected. The Xinri iron-making company discloses in patent CN101589169A an Fe-Si-B-P-C alloy with an iron content of 78-86% (atomic percent, at.%), wherein the P content is 6-20% (atomic percent, at.%), and too high a P content greatly increases the difficulty of alloy smelting and strip preparation. In addition, this company discloses in patent CN1356403A an Fe-Si-B-P-C alloy with a higher iron content, but this alloy has poor amorphous forming ability, cannot ensure that the quenched ribbon has a complete amorphous structure, and has poor soft magnetic properties. Qingdao Yunlu company discloses a Fe-Si-B-P-C alloy with iron content of 82.9-84.9% (atomic percent, at.%) in Chinese patent CN106636982A, but the strip prepared by using industrial raw materials has surface crystallization and poor soft magnetic property, and complete amorphous strips can be prepared only by removing slag in the smelting process, so that the process is complicated.
In summary, there still is a lack of iron-based amorphous soft magnetic alloy and a preparation method thereof, which can ensure that the iron-based amorphous soft magnetic alloy has high saturation magnetic induction intensity and has low cost and process requirements.
Disclosure of Invention
In order to solve the technical problems, the invention provides an iron-based amorphous soft magnetic alloy with high saturation magnetic induction intensity and a preparation method thereof. The method fully combines the advantages of low cost, large scale and industrialization of a steel-making process, particularly a molten steel refining process, combines the characteristics of the iron-based amorphous soft magnetic alloy on the basis, and pertinently integrates and optimizes the process flow and parameters, so that the method has the advantages of simple process, low energy consumption, high efficiency and greatly reduced cost, and the prepared amorphous alloy still has high saturation magnetic induction intensity and excellent soft magnetic performance.
The technical scheme provided by the invention is as follows:
a preparation method of a high saturation induction density iron-based amorphous soft magnetic alloy comprises the following steps:
(1) preparing primary molten steel:
(a) pretreating and desulfurizing blast furnace molten iron by molten iron, and then carrying out decarburization and dephosphorization treatment in a converter;
(b) deoxidizing and adding ferrosilicon, ferroboron, ferrophosphorus and carburant in the tapping process, and carrying out main alloying to obtain primary molten steel;
or smelting the scrap steel in an electric furnace to obtain primary molten steel;
(2) carrying out external refining on the primary molten steel to further deoxidize, desulfurize, remove impurities, control the content of residual elements, and finely adjust alloy components to obtain required refined molten steel;
(3) rapidly cooling the refined molten steel by using a single-roller rotary quenching technology to obtain an amorphous strip;
(4) and carrying out heat treatment on the amorphous strip to obtain the amorphous strip.
Further, in the step (2), the off-furnace refining firstly passes through a ladle refining furnace (LF) for further deoxidation, desulfurization, inclusion removal and molten steel purification to obtain alloy with high alloy purity; and then decarbonizing and degassing under vacuum condition by using a vacuum degassing method (RH/VD), and strictly controlling the components of the molten steel by fine adjustment of alloy components, so that the alloy yield is high, and the temperature of the molten steel can be controlled, thereby being beneficial to the preparation of amorphous strips.
Further, the mass percentage content of the main components in the refined molten steel is between 93.02% and 95.78% of Fe, between 1.01% and 2.43% of Si, between 1.67% and 2.58% of B, between 0.92% and 2.03% of P, between 0.12% and 0.28% of C; the mass percentage of the trace elements is less than or equal to 0.008 percent of S, less than or equal to 0.012 percent of Mn, less than or equal to 0.005 percent of Ti and less than or equal to 0.005 percent of Al.
Further, the single-roller rotary quenching technology is adopted in the step (3), the linear speed of a copper roller is 20-60 m/s, and the thickness of the obtained amorphous strip is 15-50 mu m.
Further, the linear speed of the copper roller in the step (3) is 30-40 m/s, and the thickness of the strip is 25-35 mu m.
Further, the step (4) adopts an isothermal heat treatment method, the heat preservation temperature is 240-420 ℃, and the heat preservation time is 10-300 min.
Further, the heat preservation temperature in the step (4) is 320-360 ℃, and the heat preservation time is 30-60 min.
The invention also aims to provide the iron-based amorphous soft magnetic alloy with high saturation induction density prepared by the method.
Further, the chemical formula of the alloy is FeaSibBcPdCeMfWherein M is S, Mn, Ti and Al, and subscripts a, b, c, d, e and f respectively represent the atom percentage of each component; and satisfies the following conditions: a is more than or equal to 81.3 and less than or equal to 86.1, b is more than or equal to 1.8 and less than or equal to 4.2, c is more than or equal to 7.9 and less than or equal to 11.6, d is more than or equal to 1.5 and less than or equal to 3.2, e is more than or equal to 0.5 and less than or equal to 1.1, a + b + c + d + e is 100, and f is less than or equal to 0.03 percent.
Furthermore, the magnetic induction intensity of the alloy is more than or equal to 1.62T, the coercive force is less than or equal to 4.5A/m, and the effective magnetic conductivity under 1KHz is more than or equal to 10000. Furthermore, the alloy has saturation magnetic induction intensity of more than or equal to 1.65T, coercive force of less than or equal to 3.3A/m and effective magnetic conductivity of more than or equal to 11000.
The invention has the beneficial effects that:
the method combines the advantages of low cost, large scale and simple operation of the steelmaking process, the primary molten steel is obtained by utilizing the smelting of iron ores in a blast furnace and a converter or utilizing the smelting of scrap steel in an electric furnace and then removing impurities, the components are controllable, the cost is low, the impurities are few, the main alloying is directly carried out by utilizing the temperature of the molten steel in the tapping process, the remelting is not needed, and the energy consumption is greatly reduced; the method combines the characteristics of short flow and one-step forming of the iron-based amorphous alloy strip, regulates and optimizes the content of each main component and residual component through alloy component fine adjustment and deslagging processes in the preparation process of the refined molten steel, effectively removes impurities in the raw materials, and enables the quality of the refined molten steel to be excellent. On the basis, the single-roller rotary quenching method is adopted to directly prepare the high-saturation-magnetic-induction-intensity iron-based amorphous soft magnetic alloy by utilizing the refined molten steel, so that the process flow is greatly simplified, complex flows such as cold rolling, hot rolling and the like are not needed, the production energy consumption is effectively reduced, the production efficiency is improved, the production cost is greatly reduced, and the large-scale industrialization can be realized. In addition, the alloying is carried out by utilizing the high-temperature physical heat of the molten iron, so that the production energy consumption and the cost can be further reduced. The magnetic induction intensity of the iron-based amorphous alloy prepared by the invention is more than or equal to 1.62T, the coercive force is less than or equal to 4.5A/m, and the effective magnetic conductivity under 1KHz is more than or equal to 10000, which shows that the iron-based amorphous alloy has good comprehensive magnetic performance.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings, examples and comparative examples, which are intended to facilitate the understanding of the present invention and are not intended to limit the present invention in any way.
The preparation process of the iron-based amorphous alloy strip is shown in figure 1. The iron ore is smelted by a blast furnace to obtain molten iron, the molten iron is desulfurized by a pretreatment process, blown in a converter for decarbonization and dephosphorization, and deoxidized and added with ferrosilicon, ferroboron, ferrophosphorus and a carburant in the tapping process, and alloying is carried out by utilizing the high-temperature physical heat of the molten iron to obtain primary molten steel, or the waste steel and the molten iron are smelted by an electric furnace to obtain the primary molten steel. The alloying by utilizing the high-temperature physical heat of the molten iron can reduce energy consumption. The primary molten steel is further refined outside the furnace, and degassing, desulfurization, decarburization, inclusion removal and the like are carried out, and fine adjustment of alloy components is carried out, so that the required refined molten steel is obtained. Then, the amorphous alloy strip is prepared by a single-roller rotary quenching method, and the method can be used for one-step forming, is short in process and is easy to operate.
As mentioned above, the mass percentage of the main component of the refined molten steel can be effectively controlled to be between 93.02 percent and 95.78 percent of Fe, between 1.01 percent and 2.43 percent of Si, between 1.67 percent and 2.58 percent of B, between 0.92 percent and 2.03 percent of P, between 0.12 percent and 0.28 percent of C, and the mass percentage of other trace elements of S, Mn, Ti and Al can be controlled to be less than 0.03 percent. Therefore, the refined molten steel can be used for preparing the iron-based amorphous soft magnetic alloy with high iron content and high saturation magnetic induction intensity, and the additional addition of ferrosilicon, ferrophosphorus and iron-carbon alloy can be reduced, so that the cost can be further reduced.
A series of iron-based amorphous alloy components with high iron content are designed based on refined molten steel, and the chemical formula of the iron-based amorphous alloy components is as follows: feaSibBcPdCeMfWherein M is other trace elements in the refined molten steel, S, Mn, Ti and Al are used, subscripts a, b, c, d, e and f respectively represent the atom percentage content of each corresponding component, and 81.3-86.1 of a, 1.8-4.2 of b, 7.9-11.6 of c, 1.5-3.2 of d, 0.5-1.1 of e, 100 of a + b + c + d + e and less than or equal to 0.03 percent of f. Preferably, the mass percent of the iron in the alloy is between 93.64 and 95.11 percent.
Example 1
Preparation of alloy Fe based on refined molten steel82.35Si3.7B10.2P2.8C0.95(at.%), the procedure was as follows:
(1) preparing primary molten steel:
(a) pretreating and desulfurizing blast furnace molten iron by molten iron, and then carrying out decarburization and dephosphorization treatment in a converter;
(b) deoxidizing and adding ferrosilicon, ferroboron, ferrophosphorus and carburant in the tapping process, and carrying out main alloying to obtain primary molten steel; the primary molten steel comprises the following components in percentage by weight: 2.0% of Si, 2.0% of B, 1.56% of P, 0.21% of C, 0.010% of Mn, 0.006% of S, 0.003% of Ti and 0.003% of Al;
(2) the primary molten steel can be further deoxidized, desulfurized and inclusion-removed by a ladle refining furnace (LF), and the molten steel is purified to obtain alloy with high alloy purity; decarbonizing and degassing under vacuum condition by using a vacuum degassing method (RH/VD), and strictly controlling the components of the molten steel through fine adjustment of alloy components to obtain the required refined molten steel; the percentage composition of the refined molten steel is as follows: 2.12% of Si, 2.25% of B, 1.76% of P, 0.23% of C, 0.012% of Mn, 0.008% of S, 0.005% of Ti and 0.005% of Al;
(3) controlling the temperature of the molten steel at 1250-;
(4) the amorphous strip is placed in a tubular vacuum annealing furnace and is subjected to isothermal heat treatment at the temperature of 280-320 ℃ for 10 minutes, so that the magnetic property of the alloy strip is optimized.
Example 2
Preparation of alloy Fe based on refined molten steel83.95Si2.8B9.8P2.6C0.85(at.%), the procedure was as follows:
(1) preparing primary molten steel:
(a) pretreating and desulfurizing blast furnace molten iron by molten iron, and then carrying out decarburization and dephosphorization treatment in a converter;
(b) deoxidizing and adding ferrosilicon, ferroboron, ferrophosphorus and carburant in the tapping process, and carrying out main alloying to obtain primary molten steel; the primary molten steel comprises the following components in percentage by weight: 1.45% of Si, 2.0% of B, 1.55% of P, 0.18% of C, 0.010% of Mn, 0.006% of S, 0.003% of Ti and 0.003% of Al;
(2) the primary molten steel can be further deoxidized, desulfurized and inclusion-removed by a ladle refining furnace (LF), and the molten steel is purified to obtain alloy with high alloy purity; decarbonizing and degassing under vacuum condition by using a vacuum degassing method (RH/VD), and strictly controlling the components of the molten steel through fine adjustment of alloy components to obtain the required refined molten steel; the percentage composition of the refined molten steel is as follows: si 1.58%, B2.13%, P1.62%, C0.21%, Mn 0.012%, S0.008%, Ti 0.005%, Al 0.005%;
(3) controlling the temperature of the molten steel at 1250-;
(4) the amorphous strip is placed in a tubular vacuum annealing furnace and is subjected to isothermal heat treatment at 260-300 ℃ for 10 minutes, so that the magnetic property of the alloy strip is optimized.
Example 3
Preparation of alloy Fe based on refined molten steel85.25Si2.2B9.5P2.3C0.75(at.%), the procedure was as follows:
(1) preparing primary molten steel: smelting the scrap steel in an electric furnace to obtain the primary smelting composition in percentage by weight: 1.15% of Si, 1.95% of B, 1.32% of P, 0.15% of C, 0.010% of Mn, 0.006% of S, 0.003% of Ti and 0.003% of Al;
(2) the primary molten steel can be further deoxidized, desulfurized and inclusion-removed by a ladle refining furnace (LF), and the molten steel is purified to obtain alloy with high alloy purity; decarbonizing and degassing under vacuum condition by using a vacuum degassing method (RH/VD), and strictly controlling the components of the molten steel through fine adjustment of alloy components to obtain the required refined molten steel; the percentage composition of the refined molten steel is as follows: si 1.23%, B2.05%, P1.42%, C0.18%, Mn 0.012%, S0.008%, Ti 0.005%, Al 0.005%;
(3) controlling the temperature of the molten steel at 1250-;
(4) the amorphous strip is placed in a tubular vacuum annealing furnace and is subjected to isothermal heat treatment at the temperature of 240 ℃ and 280 ℃ for 10 minutes, so that the magnetic property of the alloy strip is optimized.
Comparative example 1
Preparation of alloy Fe based on high purity raw materials83.95Si2.8B9.8P2.6C0.85The method comprises the following steps:
(1) according to the composition of alloy components, 50g of master alloy is prepared in advance, and 40.08g of high-purity iron block, 0.79g of high-purity silicon, 1.07g of high-purity boron and high-purity iron phosphorus (Fe) are accurately weighed3P) 5.20g of alloy and 2.86g of high-purity Fe-3.6% C alloy, and smelting by using a high-vacuum induction smelting furnace to obtain high-purity master alloy, keeping the temperature of alloy melt for 20 minutes, and ensuring that the alloy components are uniformly mixed;
(2) rapidly solidifying the master alloy under the condition of 40m/s of copper roller rotation speed by using a single-roller rotary quenching method to prepare an amorphous strip;
(3) the amorphous strip is placed in a tubular vacuum annealing furnace and is subjected to isothermal heat treatment at 260-300 ℃ for 10 minutes, so that the magnetic property of the alloy strip is optimized.
Comparative example 2
Preparation of alloy Fe based on industrial raw materials83.95Si2.8B9.8P2.6C0.85The method comprises the following steps:
(1) according to the composition of alloy components, 50g of master alloy is pre-prepared, 37.23g of high-purity iron block, 0.81g of simple substance silicon, 6.03g of iron boron alloy, 3.54g of iron phosphorus alloy and 2.39g of iron carbon alloy are accurately weighed, a high-purity master alloy is prepared by smelting in a high-vacuum induction smelting furnace, the temperature of an alloy melt is kept for 20 minutes, and the alloy components are uniformly mixed;
(2) rapidly solidifying the master alloy under the condition of 40m/s of copper roller rotation speed by using a single-roller rotary quenching method to prepare an amorphous strip;
(3) the amorphous strip is placed in a tubular vacuum annealing furnace and is subjected to isothermal heat treatment at 260-300 ℃ for 10 minutes, so that the magnetic property of the alloy strip is optimized.
The quality and structural characterization results of the quenched ribbon are shown in table 1 below.
TABLE 1 analysis of the production process, quality of the quenched ribbons and crystallization of examples 1 to 3 and comparative examples 1 to 2
As can be seen from Table 1, the provided Fe-based amorphous alloy composition is suitable for preparing strips, easy to form strips and good in strip quality. The strips prepared from the refined molten steel and the high-purity raw materials are all complete amorphous structures measured by XRD (X-ray diffraction), as shown in figure 1, while the strips prepared from the industrial raw materials have obvious crystallization peaks at about 45 degrees, which shows that the process can effectively control the content of impurities, and the refined molten steel is used for preparing the high-saturation-magnetic-induction-intensity iron-based amorphous soft magnetic alloy.
Magnetic properties of examples 1 to 3 and comparative examples 1 to 2: saturation magnetic induction (B)s) Coercive force (H)c) And effective permeability (. mu.) ofe) The test data are shown in table 2 below.
TABLE 2 magnetic properties after optimal heat treatment of examples 1-3 and comparative examples 1-2
As can be seen from Table 2, the Fe-based amorphous alloy prepared based on the refined molten steel has a high BsAnd mueAnd low HcThe comprehensive magnetic property of the iron-based amorphous soft magnetic alloy prepared by the embodiment is excellent. As shown by the hysteresis loop of example 2 in FIG. 3, the alloy strip combines a high BsAnd low HcAnd has excellent magnetic properties. Comparing example 2 with comparative examples 1-2, it can be found that the performance of the alloy strip prepared based on the refined molten steel is equivalent to that of the strip prepared from the high-purity raw material, while the soft magnetic performance of the strip prepared from the low-purity raw material is obviously poorer, as shown in fig. 4, the effective magnetic permeability of the strip prepared from the low-purity raw material is obviously lower than that of the strip prepared from the high-purity raw material and the refined molten steel, which indicates that the process can effectively control the content of impurities, so that the high-saturation magnetic induction intensity iron-based amorphous soft magnetic alloy with excellent magnetic performance can be obtained.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any modification, equivalent replacement, and improvement made by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention.