Iron-based amorphous nanocrystalline alloy and its manufacturing method

Abstract

The present invention relates to a compound of formula Fe (100-a-b-c-d-e) B a S b P c C d Cu e (In the formula, d+(b / c)=0.85 to 1.3, and the viscosity coefficient η is (3.0 to 8.0)×10 -3 The present invention provides an iron-based amorphous nanocrystalline alloy having a kinematic viscosity coefficient η of 0.1 Pa / s, and a manufacturing method thereof. In the present invention, the content of the alloying elements is changed to adjust the kinematic viscosity coefficient η, thereby making it possible to control the viscosity of the molten steel within a certain range, thereby improving the purity of the molten steel and ensuring the continuity of the casting and the surface quality of the strip.

Description

[Technical Field]

[0001] [Cross reference] This application claims priority to a Chinese patent application filed with the China Patent Office on December 22, 2021, with application number 202111583663.7 and title "Iron-based amorphous nanocrystalline alloy and manufacturing method thereof," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of magnetic materials, and in particular to an iron-based amorphous nanocrystalline alloy and a method for producing the same. [Background technology]

[0003] Currently, soft magnetic materials used in transformers, motor or generator magnetic cores, current sensors, magnetic sensors, and pulsed power magnetic components include silicon steel, ferrite, amorphous alloys, and nanocrystalline alloys. Among these soft magnetic materials, silicon steel is inexpensive and has high magnetic flux density and machinability, but is prone to high losses at high frequencies, making it difficult to thin the plate thickness. Ferrite has a low saturation magnetic flux density, which has limited its use in high-power, high-saturation magnetic induction conditions. Co-based amorphous alloys are not only expensive, but also have a low saturation magnetic flux density. Therefore, when used in high-power devices, they tend to result in large components, thermodynamic instability, and significant losses during use.

[0004] Iron-based amorphous alloys offer advantages such as low saturation magnetic flux density and low loss at high power output, making them ideal magnetic materials. Therefore, there is an urgent need to develop amorphous iron-based magnetic alloys with high saturation magnetic induction. Currently, the primary method for producing these materials is to increase the Fe content in the iron-based amorphous alloy. However, to mitigate the problem of decreased thermal stability of the alloy as the Fe content increases, elements such as Sn, S, C, and P are added. U.S. Patent No. 6,416,879 reports that adding P to an amorphous Fe-Si-BCP system increases the Fe content and thus the saturation magnetic induction. However, the patent also discloses that the addition of P reduces long-term thermal stability. Therefore, the amorphous alloys in the patent are not produced by casting from their molten state. Japanese Patent Publication No. 2009052064 describes an amorphous alloy ribbon with high saturation magnetic induction. It states that the addition of Cr and Mn controls the height of the C precipitate layer, resulting in high thermal stability. U.S. Patent No. 7,425,239 describes that magnetic properties other than high ductility are achieved by selecting a certain level of Si:C ratio in Fe-Si-BC. However, the ribbon produced by the above patent has many defects such as crack lines, slag lines, scratches, and inclusions on the surface, as shown in Figures 1 and 2. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide an iron-based amorphous nanocrystalline alloy that has high purity in molten steel, effectively improves defects on the surface of a ribbon, effectively improves the lamination factor, and enables production of products with good performance.

[0006] The present application has been made in view of the above circumstances, and provides an iron-based amorphous nanocrystalline alloy represented by the following formula (I): Fe (100-a-b-c-d-e) B a Si b P c C d Cu e (Formula I) (wherein a, b, c, d, and e represent the atomic percent content of each component element, and satisfy the following conditions: 1≦a≦12, 0.2≦b≦6, 2≦c≦6, 0.5≦d≦4, 0.6≦e≦2, a+b+c+d+e=100, and d+(b / c)=0.85 to 1.3.)

[0007] Preferably, 5≦a≦12, 0.8≦b≦6, 2≦c≦5, 0.5≦d≦3, and 0.6≦e≦1.3.

[0008] Preferably, 8≦a≦12, 0.8≦b≦1.5, 3≦c≦5, 0.7≦d≦1.2, and 0.6≦e≦1.3.

[0009] Preferably, the atomic percent of Fe is 83 or greater.

[0010] Preferably, in the iron-based amorphous nanocrystalline alloy, the impurity elements Al is 50 ppm or less, Mn is 100 ppm or less, and Ti is 80 ppm or less.

[0011] Preferably, the iron-based amorphous nanocrystalline alloy has a viscosity coefficient η of (3.0 to 8.0) × 10 -3 Pa / s.

[0012] Preferably, d+(b / c)=0.86 to 1.2, and the viscosity coefficient η is (4.1 to 6.9)×10 -3 Pa / s.

[0013] Preferably, N<100 and M<200 in the iron-based amorphous nanocrystalline alloy. Here, N represents the frequency of slag lines, and when the width of the iron-based amorphous nanocrystalline alloy ribbon is 80 to 122 mm, the frequency of slag lines within one continuous meter is expressed as N=m×L (where m is the number of slag lines and L is the length of the slag lines (unit: mm)). M represents the frequency of impurities within a unit area of ​​3 mm×3 mm, and is expressed as M=n×h (where n is the number of impurities and h is the height of the impurities (unit: μm)).

[0014] The present invention also provides a method for producing an iron-based amorphous nanocrystalline alloy, which includes the steps of blending raw materials to obtain a component blending ratio, melting the mixture, leaving the mixture to stand, and then rapidly cooling the mixture using a single roll. Preferably, the standing time is 30 to 50 minutes.

[0015] The present application relates to a compound of the general formula Fe (100-a-b-c-d-e) B a Si b P c C d Cu e (wherein d + (b / c) = 0.85 to 1.3) In this application, by changing the content of the alloying elements, the viscosity range of the molten steel can be controlled, the purity of the molten steel can be increased, and the continuity of the casting and the surface quality of the strip material can be ensured. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a photograph showing slag line defects in an iron-based amorphous nanocrystalline alloy produced by a conventional technique. [Figure 2] FIG. 2 is a photograph showing inclusion defects in an iron-based amorphous nanocrystalline alloy produced by a conventional technique. [Figure 3] FIG. 3 is a graph showing the effect of elements in 1873 K molten steel on the viscosity of the molten iron. [Figure 4] Figure 4 shows a photograph of the surface defect protrusions and a schematic diagram showing their sizes. [Figure 5] FIG. 5 is a schematic diagram showing the manufacturing process flow of the iron-based amorphous nanocrystalline alloy according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] In order to further clarify the present invention, preferred embodiments of the present invention will be described below with reference to the embodiments. However, it should be understood that these descriptions are merely for the purpose of further clarifying the features and advantages of the present invention and do not limit the scope of the claims of the present invention.

[0018] From the above, the present invention mainly explains the difficulty of casting P-containing molten steel. Research has revealed that the reason why P-containing iron-based amorphous alloys are difficult to cast is due to the increase in P content. That is, to ensure high saturation magnetic induction, the content of high-melting-point oxide element Si in molten steel decreases, while the content of low-melting-point oxides in molten steel increases, making them difficult to separate from the molten steel. Furthermore, the oxides are discharged as slag along with the molten steel during the casting process, making casting difficult.

[0019] Therefore, in this invention, we investigated and improved the problem of strip surface defects caused by the poor thermal stability of P-containing components. We found that controlling the η parameter, which is the kinematic viscosity of molten steel, to adjust the fluidity of the molten steel and the viscosity of the slag to obtain a liquid with sufficient molten steel purity fundamentally suppresses the occurrence of strip surface defects. These defects occur early in the casting process and grow over time. When they become large enough, cracks form at the defect location, and casting stops midway through the process of crack initiation, growth, and fracture. Therefore, η control can ensure an extension of the casting time. Furthermore, η control reduces the occurrence rate of defects within 30 minutes of the start of casting by 70% and can even delay the time of defect occurrence by 1 hour, thereby effectively improving the yield rate of strip material.

[0020] These two improvements allow for the production of a ribbon with high saturation magnetic induction that can be molded by casting, and also effectively reduces defects on the ribbon surface, resulting in a good amorphous ribbon. Therefore, in the manufacturing process of products such as iron cores and transformers at the application stage, the lamination factor is effectively improved, resulting in products with better performance.

[0021] The present application has been made in view of the above circumstances, and provides an iron-based amorphous nanocrystalline alloy represented by formula (I). Fe (100-a-b-c-d-e) B a Si b P c C d Cu e (Formula I) (wherein a, b, c, d, and e represent the atomic percent content of each component element, and satisfy the following conditions: 1≦a≦12, 0.2≦b≦6, 2≦c≦6, 0.5≦d≦4, 0.6≦e≦2, a+b+c+d+e=100, and d+(b / c)=0.85 to 1.3.)

[0022] In this formula, Fe is a ferromagnetic element. To ensure a high saturation magnetic induction (Bs, in this application, Bs ≥ 1.75 T), the atomic percentage of Fe must be greater than 83%, i.e., (100-abcde) ≥ 83. Fe, an essential element, can improve saturation magnetic induction and reduce material costs. If the Fe content is less than 78 atomic %, the desired saturation magnetic induction cannot be achieved. If the Fe content is 86 atomic % or more, it becomes difficult to form an amorphous phase by rapid cooling, resulting in the formation of coarse α-Fe crystal grains. As a result, a uniform nanocrystalline structure cannot be obtained, leading to a deterioration in soft magnetic properties.

[0023] Si can suppress the precipitation of Fe and B compounds in the crystallized nanocrystalline structure, thereby stabilizing the nanocrystalline structure. In the present application, the Si content is 0.2 to 6%. If the Si content exceeds 8%, the saturation magnetic induction and amorphous-forming ability decrease, resulting in poor soft magnetic properties. In particular, if the Si content is 0.8% or more, the amorphous-forming ability is improved, enabling stable and continuous production of thin ribbons. As a constituent element of high-melting-point oxides during the smelting process of molten steel, Si has the main function of forming high-melting-point slag to improve the separability of the steel slag, enveloping and floating low-melting-point oxides together, thereby increasing the purity of the molten steel. In addition, Si forms a dense oxide film on the surface of molten steel to block contact between the molten steel and air, thereby reducing the kinetic conditions for the formation of low-melting-point oxides. In a preferred embodiment, the Si content is 0.8 to 6%, more preferably 0.8 to 1.5%.

[0024] B, an essential element, can improve the ability to form an amorphous phase. If the B content is less than 5%, it is difficult to form an amorphous phase by rapid cooling. If the B content exceeds 12%, it does not contribute to the formation of a uniform nanocrystalline structure, resulting in a deterioration in soft magnetic properties. In the present application, the B content is 1 to 12%, and in a preferred embodiment, the B content is 5 to 12%, and more preferably the B content is 8 to 12%.

[0025] P, an essential element, can improve the amorphous phase forming ability. If the P content is less than 1%, it is difficult to form an amorphous phase by rapid cooling. If the P content exceeds 8%, the saturation magnetic induction and soft magnetic properties will decrease. In the present application, the P content is set to 2 to 6%. If the P content is 2 to 5%, the amorphous phase forming ability can be improved. More specifically, the P content is 3 to 5%.

[0026] Among these, B and P are both constituent elements of low-melting-point oxides that are unfavorable for the separation of steel slag, and the less B2O3 and P2O5 produced during the smelting process, the better the purity of the molten steel, the lower the viscosity, and the better the fluidity of the molten steel during the casting process. Therefore, to ensure performance, it is necessary to adjust the viscosity of the molten steel by adjusting the element content.

[0027] The carbon element can enhance the amorphous formation ability. Furthermore, the addition of carbon can reduce the metalloid content and reduce material costs. If the carbon content exceeds 5%, embrittlement occurs, resulting in a decrease in soft magnetic properties. In particular, if the carbon content is 3% or less, element segregation caused by carbon volatilization can be suppressed. In this composition system, carbon can improve the activity of molten steel and promote the progress of the slag reaction process.

[0028] Cu, an essential element, is advantageous for nanocrystallization. If the Cu content is less than 0.6%, it is disadvantageous for nanocrystallization. In the present application, the Cu content is set to 0.5 to 4%. In a preferred embodiment, the Cu content is set to 0.5 to 3%, more specifically, the Cu content is set to 0.7 to 1.2%. If the Cu content exceeds 1.4%, the amorphous phase becomes non-uniform, which is disadvantageous for the formation of a uniform nanocrystalline structure, resulting in a deterioration of soft magnetic properties. In particular, when embrittlement of nanocrystalline alloys is taken into consideration, it is desirable to control the Cu content to 1.3% or less.

[0029] In addition, the Cu content contributes to the formation of numerous fcc-Cu clusters and bcc-(Fe) crystal nuclei during quenching and promotes the precipitation of bcc-(Fe) crystal nuclei during heat treatment, thereby improving saturation magnetic induction and forming a nanocrystalline structure with small, uniformly distributed grain sizes over a wide crystallization temperature range. The impurity elements Al, Mn, and Ti can cause heterogeneous nucleation during the cooling process of molten steel, so their contents are controlled to a certain level. Specifically, Al ≤ 50 ppm, Mn ≤ 100 ppm, and Ti ≤ 80 ppm. The ferromagnetic elements Co and Ni can be used to partially replace Fe while maintaining high Bs performance. Co can replace up to 15 atomic percent of Fe, and Ni can replace up to 10 atomic percent of Fe.

[0030] To solve the problem of molten steel purity, the present invention adjusts the element content through compositional design and further limits the viscosity coefficient based on the element content. The viscosity coefficient controls the slag system components, the component content ratios within the slag system, the slag system state, the timing and weight of slag discharge, etc., thereby precipitating all low-melting-point oxides that are difficult to discharge from the molten steel. This improves the purity of the molten steel, resulting in molten steel with excellent casting properties. This method is also used to control the purity of the molten steel to resolve surface defects in strips caused by inclusions in the molten steel. This specification focuses on how to establish a relationship between the element content and the kinetic viscosity η of the molten steel through the element content ratio. By adjusting the kinetic viscosity coefficient η by changing the element content, the viscosity of the molten steel can be controlled within a certain range, ensuring casting continuity and strip surface quality. The viscosity, diffusion, electrical conductivity, etc. of molten steel are liquid transport properties that are not only fundamental for studying the structure of molten metals but also crucial for smelting. In a flowing liquid, the speed of directional movement in each layer is not uniform. Relative motion occurs between adjacent layers, resulting in friction between the layers, preventing continuity of movement and slowing the liquid flow velocity. This is a viscous phenomenon. The kinematic viscosity of molten steel is the frictional force per unit area acting between parallel liquid layers under a unit velocity gradient. It is expressed in units of Pa.s, where η is the unit. The reciprocal of viscosity (φ = 1 / η) indicates the fluidity. While many factors affect the viscosity of molten steel, at a given temperature, it is primarily related to the content of its constituent elements (Figure 3 shows the effect of elements on the viscosity of molten steel at 1873 K). Low concentrations of N, O, and S generally increase the viscosity of molten steel. For example, a w[O] = 0.05% can increase viscosity by 30–50%. Ni, Cr, Si, Mn, P, C, etc. can sometimes lower viscosity, but if molten steel that has been used for deoxidation or contains these elements is oxidized, the oxides will not float up smoothly, resulting in an increase in viscosity.

[0031] The viscosity of the molten steel was measured using a damped vibration viscometer. To ensure comparability between different components, all viscosities reported in this application were measured at the same temperature of 1450°C. Because there has been little research on the viscosity, fluidity, and casting processability of molten steel for P-containing amorphous nanocrystalline alloys, this application focuses on these points. Controlling η ensures the fluidity of the molten steel within a certain range and fundamentally suppresses the occurrence of surface defects in the ribbon. This control extends the casting time, and these defects tend to occur early in the casting process and continue to occur over time. When the defects become large enough, cracks form at the defect locations, causing casting to stop during the process of crack initiation, growth, and fracture. This control reduces the probability of defect occurrence by 70% before 30 minutes of casting and delays the time of defect occurrence to one hour, thereby effectively improving the pass rate of the ribbon. Furthermore, surface quality defects of the ribbon can be significantly improved, the state of surface slag lines can be significantly improved, and the frequency N of slag line occurrence can be reduced (this frequency is calculated as the number m of slag lines within 1 continuous meter of a ribbon with a width of 80 to 122 mm × length L (unit: mm), where N = m × L). Furthermore, the improvement in the state of adhesion of impurities such as slag on the ribbon surface is characterized by the frequency M of impurities within a unit area of ​​3 mm × 3 mm, which is defined as M = n × h (number of impurities n × height of impurity h (µm)), as shown in Figure 4. In the present application, in the iron-based amorphous nanocrystalline alloy, N<100 and M<200.

[0032] In this way, by improving defects such as slag lines and impurities on the ribbon surface, the ribbon lamination factor is significantly improved from 84% to 89%. The level of the lamination factor has a significant impact on product performance - loss, and a high lamination factor reduces the loss of the ribbon product. The loss of this composition system meets the following conditions: iron core Ps loss is less than 0.35 W / kg and excitation Ss is less than 0.4 Va / Kg under the conditions of 50 Hz and 1.5 T.

[0033] In the present application, the formula Fe (100-a-b-c-d-e) B a Si b P c C d Cu e(wherein Fe, Si and B contribute to the formation of an iron-based amorphous alloy with a high saturation magnetic induction).

[0034] Smelting of master alloy: The alloy and its chemical composition of the present application are Fe (100-a-b-c-d-e) B a Si b P c C d Cu e (where a, b, c, d, and e represent the atomic percent content of each component element, with 1≦a≦12, 0.2≦b≦6, 2.0≦c≦6.0, 0.5≦d≦4, 0.6≦e≦1.3, and a+b+c+d+e=100.) The industrial raw materials required for the master alloy are single Fe, single Cu, elemental Si, single C, and Fe-B and Fe-P alloys, and the purities of the raw materials are shown in Table 1. [Table 1]

[0035] The raw materials are weighed to a fixed mass ratio and placed in a medium-frequency induction heating furnace. The materials are melted under argon gas as a protective gas. After melting, the materials are allowed to stand for 30 minutes to ensure uniformity of the molten steel composition without segregation. After standing, the viscosity of the molten steel is measured at 1450°C using a damped vibration viscometer. The molten steel is then poured into a copper roll quenching furnace at 1400°C to 1500°C, and an amorphous nanocrystalline ribbon is obtained by copper roll quenching. During the manufacturing process, the time at which defects begin to appear is recorded as a macroscopic measure of the quality of the molten steel. At the time of defect onset, the characteristics of the slag lines are analyzed using an optical electron microscope, and the characteristics of the impurity protrusions are analyzed using a scanning electron microscope. The produced amorphous nanocrystalline ribbon is then wound into a loop sample with an inner diameter of 65 mm and an outer diameter of 70 mm, and the heat treatment performance of the ribbon is evaluated.

[0036] After the heat treatment, the performance evaluation and analysis are carried out as follows. 1) Measurement of saturation magnetic induction and coercivity: The saturation magnetic intensity Bs and coercivity of the annealed alloy ribbon are measured using a vibrating sample magnetometer (VSM) and a soft magnetic DC measuring device. This device is based on the principle of electromagnetic induction and obtains a curved relationship between the magnetic moment of the sample and changes in the external magnetic field. Measurements are performed in the magnetic field range of -10,000 to 10,000 Oe. Prior to measurement, the device is calibrated with a prepared Ni standard, the magnetic sample to be tested is pulverized, approximately 0.030 g of the sample is taken, tightly wrapped in tin foil, and placed in a copper mold for measurement. 2) Measurement of loss power and excitation power: Measurements are performed using a BH analyzer. By setting the sample parameters (effective magnetic circuit length, effective cross-sectional area, number of turns, etc.) and test conditions (test frequency, magnetic field strength, maximum magnetic flux density, maximum induced voltage, etc.), a BH curve is output and various magnetic property parameters, including the loss power (Ps) and excitation power (Ss), are measured.

[0037] To further clarify the present invention, the iron-based amorphous nanocrystalline alloy provided in the present invention will be described in detail below with reference to examples, but the scope of protection of the present invention is not limited by the following examples. [Example]

[0038] 1) Relationship between viscosity coefficient η and the content of the main element, Si: The raw materials were weighed to a certain mass ratio and then placed in a medium-frequency induction heating furnace and melted under argon gas as a protective gas. After melting, the materials were left to stand for 30 minutes to ensure that the molten steel had a uniform composition without segregation. After the standing time, the viscosity of the molten steel was measured at 1450°C using a damped vibration viscometer.

[0039] To determine η and element content, the four main elements Si, B, P, and C, which are closely related to the state of the slag, were analyzed. In 1), the element content and viscosity coefficient η that provide advantages to the performance of the ribbon were determined by investigating the relationship between Si element and η and the relationship between parameters related to ribbon casting. The specific element blending ratios used in the examples are shown in Table 2 below. [Table 2]

[0040] As can be seen from the table above, silicon is a constituent element of high-melting-point oxides during the smelting process of molten steel. It functions to improve the separation of steel slag by forming high-melting-point slag, which envelops low-melting-point oxides and floats together with them, improving the purity of the molten steel. It also functions to form a dense oxide film on the surface of the molten steel, blocking contact between the molten steel and air and reducing the kinetic conditions for the formation of low-melting-point oxides. When the silicon content was low, the formation of high-melting-point oxides was reduced, preventing them from floating up. This prevented the steel slag from effectively separating from the molten steel, significantly increasing the viscosity coefficient of the molten steel. As a result, as the viscosity of the molten steel increased, the slag flowed out with the molten steel during the casting process, causing defects and scratches on the ribbon surface. It also precipitated on the ribbon surface, forming impurity slag inclusions. Both of these factors adversely affected the stacking coefficient of the ribbon, resulting in reduced loop performance after heat treatment. According to the table above, the silicon content is preferably in the range of 0.8 to 1.5%. Within this composition range, the viscosity coefficient was in the range of 5.3 to 6.9, the time to occurrence of casting defects exceeded 50 minutes, the slag line was in the range of 80 to 120, and M was in the range of 15 to 100. Because the Si content was low, the Fe content in Comparative Examples 1 to 3 was quite high, which was advantageous for Bs, but resulted in a state with a lot of slag. A high Si content would have been advantageous overall for the slag state, but because the Fe content was low, Bs was low at less than 1.75T, and the requirements could not be met.

[0041] 2) Relationship between viscosity coefficient η and the content of the main element B: The raw materials were weighed to a certain mass ratio and then placed in a medium-frequency induction heating furnace and melted under argon gas as a protective gas. After melting, the materials were left to stand for 30 minutes to ensure that the molten steel had a uniform composition without segregation. After the standing time, the viscosity of the molten steel was measured at 1450°C using a damped vibration viscometer.

[0042] To determine η and element content, the four main elements Si, B, P, and C, which are closely related to the state of the slag, were analyzed. In 2), the element content and viscosity coefficient η that provide advantages to the performance of the ribbon were determined by examining the relationship between element B and η, as well as the relationship between parameters related to ribbon casting. The element blending ratios in specific examples are shown in Table 3 below: [Table 3]

[0043] Table 3 shows that the slag produced by the B element during the smelting process of molten steel is the low-melting-point oxide B2O3. Furthermore, during experiments, the viscosity coefficient remained between 5% and 7% when the B element content was between 0 and 15% atomic percent, indicating that the B element content does not significantly affect the viscosity coefficient of molten steel. Considering the time to occurrence of casting defects and performance indicators such as Bs, a B content below 8% reduces the system's ability to form amorphous structures, resulting in a decrease in the amorphousness of the ribbon. Under the same stacking coefficient, the Ps and Ss performance of the ribbon also declines. However, a B content above 12% reduces the Fe content, and Bs declines below 1.75T. Based on the above analysis, the B content is limited to 8-12%.

[0044] 3) Relationship between viscosity coefficient η and content of P, the main element: The raw materials were weighed to a certain mass ratio and then placed in a medium-frequency induction heating furnace and melted under argon gas as a protective gas. After melting, the materials were left to stand for 30 minutes to ensure that the molten steel had a uniform composition without segregation. After the standing time, the viscosity of the molten steel was measured at 1450°C using a damped vibration viscometer.

[0045] To determine η and element content, the four main elements Si, B, P, and C, which are closely related to the state of the slag, were analyzed. In 3), the element content and viscosity coefficient η that provide advantages to the performance of the ribbon were determined by investigating the relationship between the P element and η, as well as the relationship between parameters related to ribbon casting. The blending ratios of elements in specific examples are shown in Table 4 below. [Table 4]

[0046] Table 4 shows that P, as a constituent element of low-melting-point oxides, has a significant effect on the viscosity of molten steel, which is a flow characteristic. Furthermore, these studies revealed that P in this composition system has a strong effect on the amorphous-forming ability, and increasing the P element significantly improves the amorphous-forming ability. When the P element content was low, the amorphous-forming ability was low, resulting in a low ribbon density. This also led to a low ribbon stacking factor, which resulted in significant defects such as inclusions and slag lines during the casting process, leading to earlier casting defects and reduced overall ribbon quality. As the P content increased from 3 to 5%, the amorphous-forming ability improved, the density increased, and the casting defect time of the ribbon was delayed to 60 minutes or more. This increased the stacking factor, reduced surface defects, and optimized performance. Furthermore, as the P content continued to increase, some of the low-temperature slag generated by P was not covered by the high-temperature slag generated by Si, preventing it from floating up with the high-temperature slag, resulting in the retention of low-melting-point oxides in the molten steel. In addition, the higher the P content, the higher the content of low melting point oxides, which has an adverse effect on the occurrence of ribbon casting defects and the appearance of the ribbon, such as slag lines and inclusions. As can be seen from the performance and lamination results, when the P content exceeds 6%, the performance begins to deteriorate, so the atomic percentage of the P element is controlled to 3-5%.

[0047] 4) Relationship between viscosity coefficient η and the content of the main element C: The raw materials were weighed to a certain mass ratio and then placed in a medium-frequency induction heating furnace and melted under argon gas as a protective gas. After melting, the materials were left to stand for 30 minutes to ensure that the molten steel had a uniform composition without segregation. After the standing time, the viscosity of the molten steel was measured at 1450°C using a damped vibration viscometer.

[0048] To determine η and element content, the four main elements Si, B, P, and C, which are closely related to the state of the slag, were analyzed. In 4), the element content and viscosity coefficient η that provide advantages to the performance of the ribbon were determined by investigating the relationship between the C element and η, and the relationship between parameters related to ribbon casting. The element blending ratios in specific examples are shown in Table 5 below: [Table 5]

[0049] As can be seen from Table 5, carbon does not participate in the slag formation reaction in molten steel. Instead, it acts to increase the activity of silicon in the molten steel, producing more high-melting-point oxides, improving the purity of the molten steel and reducing its viscosity, thereby ensuring its fluidity. As can be seen from the data in the table, without carbon in the composition, the viscosity coefficient of the molten steel was 10.2, resulting in poor fluidity and early defects during the casting process. This resulted in increased slag lines and impurity defects in the ribbon, resulting in a low stacking coefficient and reduced performance. As the carbon content increased, the quality of the molten steel improved significantly, the viscosity decreased, and the fluidity increased. This reduced the amount of slag and other oxides present in the molten steel. This resulted in improved ribbon quality and improved performance. To ensure the Bs value, the carbon content was limited to 0.7-0.9%.

[0050] 5) Relationship between viscosity coefficient η and the content of the main elements C+Si / P: The four experimental examples above confirmed that the three elements that most significantly affect the viscosity coefficient are Si, P, and C. However, these three elements do not have independent effects, but rather act together to affect the slag system. The relationship between C + Si / P and η was then verified. Each raw material was weighed to a constant mass ratio and then placed in a medium-frequency induction furnace. The materials were melted under argon gas as a protective gas. After melting, the materials were allowed to stand for 30 minutes to ensure uniform composition without segregation. After the standing time, the viscosity of the molten steel was measured at 1450°C using a damped vibration viscometer.

[0051] To determine η and element content, the four main elements Si, B, P, and C, which are closely related to the state of the slag, were analyzed. In 5), the element content and viscosity coefficient η that provide benefits to ribbon performance were determined by investigating the relationship between the interconnections of the main elements and η, as well as the relationship between parameters related to ribbon casting. The element blending ratios in specific examples are shown in Table 6 below. [Table 6]

[0052] As can be seen from Table 6, when the sum of C and (Si / P) is 0.86 to 1.2, the viscosity coefficient is 4.1 to 6.9, ensuring that the viscosity coefficient of the molten steel is optimal within this range, and further ensuring optimal fluidity of the molten steel. Within this range, the time t indicates that the time at which defects occur is the latest. Furthermore, after 60 minutes, the ribbon surface performance parameters, for example, the number of defects N in the ribbon is less than 100 and M is less than 200, indicating that these components can significantly improve performance compared to other components. Correspondingly, the ribbon stacking coefficient increased to 85 to 90, and the loop performance was Ps≦0.35 W / kg and Ss≦0.4 VA / kg.

[0053] The above description of the embodiments is merely used to help understand the method and gist of the present invention. Those skilled in the art may make some improvements and modifications to the present invention without departing from the principles of the present invention. Please note that these improvements and modifications are also included in the scope of the claims of the present invention.

[0054] The above description of the disclosed embodiments will enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art. The generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. The present invention may include the following embodiments. <1> Represented by the following formula (I): Fe (100-a-b-c-d-e) B a Si b P c C d Cu e (I) In the formula, a, b, c, d, and e represent the atomic percent contents of the respective component elements, and an iron-based amorphous nanocrystalline alloy is characterized in that it satisfies the following conditions: 1≦a≦12, 0.2≦b≦6, 2≦c≦6, 0.5≦d≦4, 0.6≦e≦2, a+b+c+d+e=100, and d+(b / c)=0.85 to 1.3. <2> 5≦a≦12, 0.8≦b≦6, 2≦c≦5, 0.5≦d≦3, 0.6≦e≦1.3. <1> 1. An iron-based amorphous nanocrystalline alloy according to claim 1. <3> The above-mentioned is characterized in that 8≦a≦12, 0.8≦b≦1.5, 3≦c≦5, 0.7≦d≦1.2, and 0.6≦e≦1.3. <1> 1. An iron-based amorphous nanocrystalline alloy according to claim 1. <4> The atomic percent of Fe is 83 or more. <1> 1. An iron-based amorphous nanocrystalline alloy according to claim 1. <5> In the iron-based amorphous nanocrystalline alloy, the impurity element Al is 50 ppm or less, the impurity element Mn is 100 ppm or less, and the impurity element Ti is 80 ppm or less. <1> 1. An iron-based amorphous nanocrystalline alloy according to claim 1. <6> The iron-based amorphous nanocrystalline alloy has a viscosity coefficient η of (3.0 to 8.0) × 10 -3 Pa / s range. <1> 1. An iron-based amorphous nanocrystalline alloy according to claim 1. <7> d+(b / c)=0.86~1.2, and the viscosity coefficient η is (4.1~6.9)×10 -3 Pa / s range. <1> 1. An iron-based amorphous nanocrystalline alloy according to claim 1. <8> The iron-based amorphous nanocrystalline alloy is characterized in that N<100, M<200 (where N represents the frequency of occurrence of slag lines, and when the width of the iron-based amorphous nanocrystalline alloy ribbon is 80 to 122 mm, the frequency of occurrence of slag lines within a continuous 1 meter is expressed as N=m×L (where m is the number of slag lines and L is the length of the slag lines in mm), and M represents the frequency of impurities within a unit area of ​​3 mm×3 mm, and is expressed as M=n×h (where n is the number of impurities and h is the height of the impurities in μm)). <1> ~ <6> 1. The iron-based amorphous nanocrystalline alloy according to any one of claims 1 to 9. <9> The aforementioned <1> A method for producing the iron-based amorphous nanocrystalline alloy according to claim 1, comprising: A manufacturing method including the steps of blending and melting the raw materials to a predetermined component blending ratio, leaving the mixture to stand, and then rapidly cooling the mixture using a single roll. <10> The standing time is 30 to 50 minutes. <9> The manufacturing method described in

Claims

1. It is represented by the following formula (I): ｦe （１００－ａ－ｂ－ｃ－ｄ－ｅ） B ａ ｳi ｂ P ｃ 3 ｄ Cu ｅ (9) In the formula, a, b, c, d, and e represent the atomic percent contents of the respective component elements, and the following conditions are satisfied: 8≦a≦12, 0.8≦b≦1.5, 3≦c≦5, 0.7≦d≦0.9, 0.6≦e≦1.3, and d+(b / c)=0.85 to 1.

3.

2. 2. The iron-based amorphous nanocrystalline alloy of claim 1, wherein the atomic percent of Fe is 83 or more.

3. 2. The iron-based amorphous nanocrystalline alloy according to claim 1, wherein the impurity element Al is 50 ppm or less, the impurity element Mn is 100 ppm or less, and the impurity element Ti is 80 ppm or less.

4. The iron-based amorphous nanocrystalline alloy has a viscosity coefficient η of (3.0 to 8.0) × 10 at a temperature of 1450°C. －３ The iron-based amorphous nanocrystalline alloy according to claim 1, characterized in that its viscosity is in the range of Pa·s.

5. d+(b / c)=0.86 to 1.2, and the viscosity coefficient η is (4.1 to 6.9) × 10 at a temperature of 1450°C. －３ The iron-based amorphous nanocrystalline alloy according to claim 1, characterized in that its viscosity is in the range of Pa·s.

6. 5. The iron-based amorphous nanocrystalline alloy according to claim 1, wherein the iron-based amorphous nanocrystalline alloy satisfies the following conditions: N<100, M<200 (where N represents the frequency of occurrence of slag lines, and when the width of the iron-based amorphous nanocrystalline alloy ribbon is 80 to 122 mm, the frequency of occurrence of slag lines within a continuous meter is expressed as N=m×L (where m is the number of slag lines and L is the length of the slag lines in mm), and M represents the frequency of impurities within a unit area of ​​3 mm×3 mm, and M=n×h (where n is the number of impurities and h is the height of the impurities in μm)).

7. 10. A method for producing the iron-based amorphous nanocrystalline alloy of claim 1, comprising: A manufacturing method including the steps of blending and melting the raw materials to a predetermined component blending ratio, leaving the mixture to stand, and then rapidly cooling the mixture using a single roll.

8. The method according to claim 7, wherein the standing time is 30 to 50 minutes.

Images