Fe-based amorphous alloys and Fe-based amorphous alloy thin tapes

Abstract

The Fe-based amorphous alloy contains, by atomic percent: B: 8.0% or more and 18.0% or less, Si: 2.0% or more and 9.0% or less, C: 0.10% or more and 5.00% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, P: 0.010% or more and less than 1.000%, S: 0.001% or more and 0.020% or less, and N: 0.0010% or more and 0.2000% or less, with the remainder consisting of impurities, and the microstructure of the Fe-based amorphous alloy is amorphous.

Description

Technical Field

[0001] Field of Invention The present invention relates to an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon, and particularly to an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon having excellent soft magnetic properties and workability. Prior Art

[0002] Background of the Invention As a method for continuously manufacturing a ribbon or wire by rapidly cooling an alloy from a molten state, there are known a centrifugal rapid cooling method, a single roll method, a double roll method, etc. These methods manufacture a ribbon or wire by spraying molten metal from an orifice or the like onto the inner peripheral surface or outer peripheral surface of a rapidly rotating metal cylinder to rapidly solidify the molten metal. Further, by reasonably selecting the alloy composition, an amorphous alloy similar to liquid metal can be obtained, and a material having excellent magnetic properties or mechanical properties can be manufactured.

[0003] Among amorphous alloys, Fe-based amorphous alloys are particularly promising as materials for cores of power transformers or high-frequency transformers. In order to make these materials have high performance, there is a strong demand for further reducing the iron loss of Fe-based amorphous alloys and further increasing the saturation magnetic flux density. However, it is very difficult to obtain an Fe-based amorphous alloy having an iron loss W13 / 50 of 0.100 W / kg or less and a saturation magnetic flux density of 1.60 T or more at a magnetic flux density of 1.3 T and a frequency of 50 Hz.

[0004] Further, Fe-based amorphous alloys are sometimes obtained in the form of ribbons with a thickness of 0.1 mm or less. In order to use an Fe-based amorphous alloy ribbon for a core of a power transformer or a high-frequency transformer, the ribbon is sometimes bent. However, if an Fe-based amorphous alloy ribbon with poor workability is bent, cracks may occur in the bent portion. Therefore, in order to improve the yield rate when processing a ribbon into a core or the like, an Fe-based amorphous alloy ribbon is required to have excellent workability.

[0005] Patent Document 1 describes an Fe-based amorphous alloy ribbon, the composition of its main elements is expressed as FeaMbSicBd (80 < a ≤ 82, 0.05 ≤ b ≤ 1, 2 ≤ c ≤ 7, 12 ≤ d ≤ 16, a + b + c + d = 100, M is at least one of Co and Ni), and as impurities, it contains P: 0.008 - 0.1%, Mn: 0.15 - 0.5%, and S: 0.004 - 0.05% by mass%, and this Fe-based amorphous alloy ribbon has excellent soft magnetic properties under alternating current.

[0006] Patent document 2 describes an Fe-based amorphous alloy strip containing, by atomic percent: B: 5-25%, Si: 1-30%, and N: 0.001-0.2%, with the remainder consisting of Fe and unavoidable impurities.

[0007] Patent document 3 describes an amorphous alloy strip containing Fe, Si, B, C, Mn, S, and unavoidable impurities, and having the following composition: when the total mass of Fe, Si, B, and C is 100.0 atomic%, Si is 3.0 atomic% or more and 10.0 atomic% or less, B is 10.0 atomic% or more and 15.0 atomic% or less, and C is 0.2 atomic% or more and 0.4 atomic% or less; furthermore, the content of Mn is greater than 0.12 mass% and less than 0.15 mass%, and the content of S is greater than 0.0034 mass% and less than 0.0045 mass%; the thickness of the amorphous alloy strip is 10 μm or more and 40 μm or less, and the width is 100 mm or more and 300 mm or less.

[0008] Patent document 4 describes an amorphous soft magnetic alloy with Fe 100-xy-zSi xB yP z (atomic %) as the main component, where x, y, and z satisfy 0.5≦x≦15, 5≦y≦25, z≦15, and 18≦x+y+z≦30, respectively. Furthermore, relative to this main component, it contains Mn: 0.01% by mass or more and 0.3% by mass, Al: 0.0001% by mass or more and 0.01% by mass, Ti: 0.001% by mass or more and 0.03% by mass, Cu: 0.005% by mass or more and 0.2% by mass, and S: 0.001% by mass or more and 0.05% by mass.

[0009] Patent document 1 describes how, by limiting the amounts of Fe, Si, B, and C to a narrower range in a composition system containing trace amounts of P, Mn, and S, iron loss can be improved, and the iron loss W 13 / 50 can be stably kept below 0.100 W / kg. However, no research has been conducted on the improvement of workability (bending failure diameter).

[0010] Patent document 2 describes how, by including nitrogen (N) in Fe-B-Si and Fe-B-Si-C amorphous alloys, impurities (such as Al), known as crystallization-promoting elements, are concentrated in the surface oxide layer. This prevents the propagation of cracks in amorphous alloy strips and significantly improves processability. Furthermore, it describes how, based on the effect of containing N, the bending failure diameter is reduced by approximately 40%, thereby improving brittleness. However, no research has been conducted on maintaining the iron loss W13 / 50 stably below 0.100 W / kg.

[0011] Although Patent Document 3 describes how molten metal can be continuously ejected from the nozzle for a long time by adjusting the content of Mn and S in the Fe-B-Si-C amorphous alloy strip, no research has been conducted on simultaneously improving saturation magnetic flux density and iron loss as well as improving machinability (bending failure diameter).

[0012] Patent document 4 describes a method that uses Fe-Si-BP as the main component and specifies the contents of Mn, Al, Ti, Cu, and S, thereby making it difficult to form a crystalline phase and exhibiting excellent soft magnetic properties. However, no research has been conducted on the improvement of processability (bending failure diameter). [Previous Technical Documents] [Patent Literature]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 2006-312777 [Patent Document 2] Japanese Patent Application Publication No. 2006-316348 [Patent Document 3] International Publication No. 2016 / 084741 [Patent Document 4] Japanese Patent Application Publication No. 2009-174034 Summary of the Invention

[0014] Invention Summary [The problem the invention aims to solve] The present invention was made in view of the above circumstances, and its objective is to provide an Fe-based amorphous alloy and a Fe-based amorphous alloy strip with low iron loss, high magnetic flux density and excellent machinability.

[0015] [Methods used to solve problems] To address the aforementioned issues, the present invention employs the following configuration. [1] An Fe-based amorphous alloy, containing, in atomic percent: B: Above 8.0% and below 18.0% Si: 2.0% or more and 9.0% or less C: Above 0.10% and below 5.00% Mn: ≥0.05% and ≤0.60% Fe: 78.00% or higher and 86.00% or lower P: ≥0.010% and <1.000% S: ≥0.006% and ≤0.020%, and N: ≥0.0010% and ≤0.2000% The remaining part consists of impurities, and The microstructure of this Fe-based amorphous alloy is amorphous. [2] An Fe-based amorphous alloy, containing, in atomic percent: B: 13.0% or higher and 18.0% or lower Si: 2.0% or more and 6.0% or less C: Above 0.10% and below 3.00% Mn: ≥0.05% and ≤0.60% Fe: 78.00% or higher and 86.00% or lower P: ≥0.010% and <1.000% S: ≥0.006% and ≤0.020%, and N: ≥0.0010% and ≤0.2000%, the remainder consists of impurities, and The microstructure of this Fe-based amorphous alloy is amorphous. [3] The Fe-based amorphous alloy described in [1] contains, in atomic percent: Si: 2.0% or more and 5.0% or less, and N: 0.0030% or more and 0.2000% or less. [4] The Fe-based amorphous alloy described in [2] contains, in atomic percent: Si: 2.0% or more and 5.0% or less, and N: 0.0030% or more and 0.2000% or less. [5] As described in [1], Fe is an amorphous alloy in which at least one of Ni, Cr and Co is used to replace Fe in the range of less than 10.0 atomic percent. [6] As described in [2], Fe is an amorphous alloy in which at least one of Ni, Cr and Co is used to replace Fe in the range of less than 10.0 atomic%. [7] As described in [1], the Fe-based amorphous alloy has an iron loss W13 / 50 of less than 0.100 W / kg when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T, and a saturation magnetic flux density of more than 1.60 T. [8] As described in [2], the Fe-based amorphous alloy has an iron loss W13 / 50 of less than 0.100 W / kg when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T, and a saturation magnetic flux density of more than 1.60 T. [9] A Fe-based amorphous alloy strip, which is composed of any of the Fe-based amorphous alloys described in [1] to [8].

[10] As described in [9], the diameter of the bending failure of the Fe-based amorphous alloy thin strip is less than 4 mm.

[0016] [Invention Effects] According to the present invention, an Fe-based amorphous alloy and a Fe-based amorphous alloy strip with low iron loss, high magnetic flux density and excellent machinability can be provided. Implementation

[0017] Forms used to implement inventions The inventors have discovered that by limiting the content of sulfur (S), an element that worsens brittleness, and by adjusting the content of amorphous forming elements such as boron (B), cinnamon (C), silicon (Si), phosphorus (P), and nitrogen (N), not only can the amorphous forming ability be improved, but also an Fe-based amorphous alloy with excellent machinability and a bending fracture diameter of 4 mm or less can be obtained. Furthermore, it has been discovered that by optimizing the nitrogen (N) content, excellent machinability with a bending fracture diameter of 4 mm or less can be obtained. Further, it has been discovered that by containing mn in the range of 0.05% to 0.60%, excellent soft magnetic properties and machinability can be simultaneously achieved; specifically, an iron loss W13 / 50 of 0.100 W / kg or less, a saturation magnetic flux density of 1.60 T or more, and a bending fracture diameter of 4 mm or less can be achieved.

[0018] The following describes the Fe-based amorphous alloy and the Fe-based amorphous alloy strip as embodiments of the present invention.

[0019] In this embodiment, excellent soft magnetic properties mean that it has low iron loss and high saturation magnetic flux density. Furthermore, excellent machinability means that the thin strip composed of Fe-based amorphous alloy has a small bending failure diameter.

[0020] The Fe-based amorphous alloy of this embodiment contains, by atomic percent: B: 8.0% or more and 18.0% or less, Si: 2.0% or more and 9.0% or less, C: 0.10% or more and 5.00% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, P: 0.010% or more and less than 1.000%, S: 0.006% or more and 0.020% or less, and N: 0.0010% or more and 0.2000% or less, with the remainder consisting of impurities. Furthermore, the microstructure of this Fe-based amorphous alloy is amorphous.

[0021] Furthermore, the Fe-based amorphous alloy of this embodiment contains, in atomic percent: B: 13.0% or more and 18.0% or less, Si: 2.0% or more and 6.0% or less, C: 0.10% or more and 3.00% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, P: 0.010% or more and less than 1.000%, S: 0.006% or more and 0.020% or less, and N: 0.0010% or more and 0.2000% or less, with the remainder consisting of impurities. Moreover, the microstructure of this Fe-based amorphous alloy is amorphous.

[0022] Furthermore, in this embodiment of the Fe-based amorphous alloy, at least one of the elements Ni, Cr, and Co can be used to replace Fe within a range of less than 10.0 atomic percent. Furthermore, the Fe-based amorphous alloy strip of this embodiment is composed of the aforementioned Fe-based amorphous alloy.

[0023] First, the reasons for limiting the content of each element in the Fe-based amorphous alloy of this embodiment will be explained.

[0024] In the Fe-based amorphous alloy of this embodiment, boron (B) is included to form an amorphous phase and improve its thermal stability. By optimizing the content of this element, the alloy structure can be stably made into an amorphous phase, further improving its soft magnetic properties. For example, the saturation magnetic flux density can be stably maintained at 1.60 T or higher. When B is less than 8.0 atomic%, the ability to form an amorphous phase cannot be improved, and an amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy. It is difficult to stably maintain the iron loss at 0.100 W / kg or lower while maintaining the saturation magnetic flux density at 1.60 T or higher. On the other hand, even if B is greater than 18.0 atomic%, the ability to form an amorphous phase cannot be improved, and it is difficult to stably maintain the saturation magnetic flux density at 1.60 T or higher. Therefore, B is set at 8.0 atomic% or higher and 18.0 atomic% or lower. The lower limit of B is preferably 10.0 atomic%, and more preferably 13.0 atomic%. The upper limit of B should be 16.0 atoms, and further preferably 15.0 atoms.

[0025] Similar to B, in the Fe-based amorphous alloy of this embodiment, Si and C are included to form an amorphous phase and improve its thermal stability. By optimizing the content of Si and C, the alloy structure can be stably made into an amorphous phase, which can further improve the soft magnetic properties. When Si is less than 2.0 atomic% and C is less than 0.10 atomic%, the ability to form an amorphous phase cannot be improved, and an amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy. It is difficult to stably maintain the saturation magnetic flux density at 1.60 T or more while keeping the iron loss below 0.100 W / kg. On the other hand, even if Si is greater than 9.0 atomic% and C is greater than 5.00 atomic%, the ability to form an amorphous phase cannot be improved, and it is difficult to stably keep the iron loss below 0.100 W / kg. Therefore, Si is 2.0 atomic% or more and 9.0 atomic% or less, and C is 0.10 atomic% or more and 5.00 atomic% or less. The lower limit of Si is preferably 3.0 atoms, and more preferably 4.0 atoms. The upper limit of Si is preferably 8.0 atoms, and more preferably 7.0 atoms. The lower limit of C is preferably 0.50 atoms, and more preferably 1.00 atoms. The upper limit of C is preferably 4.00 atoms, and more preferably 3.00 atoms.

[0026] In the Fe-based amorphous alloy of this embodiment, Mn is included to improve soft magnetic properties. By optimizing the Mn content, for example, it is possible to stably maintain the iron loss at 0.100 W / kg or below while maintaining the saturation magnetic flux density at 1.60 T or above. When Mn is less than 0.05 atomic%, it is difficult to stably maintain the saturation magnetic flux density at 1.60 T or more while keeping the iron loss below 0.100 W / kg. On the other hand, if Mn is greater than 0.60 atomic%, it is difficult to stably keep the iron loss below 0.100 W / kg. Therefore, Mn should be between 0.05 atomic% and 0.60 atomic%. The lower limit of Mn should preferably be 0.10 atomic%, and more preferably 0.20 atomic%. The upper limit of Mn should preferably be 0.50 atomic%, and more preferably 0.40 atomic.

[0027] In Fe-based amorphous alloys, a Fe content of 70 atomic% or more is generally sufficient to achieve a saturation magnetic flux density that is practically adequate for common iron cores. However, to obtain a high saturation magnetic flux density of 1.60 T or more, the Fe content needs to be 78.00 atomic% or more. On the other hand, if the Fe content is greater than 86.00 atomic%, it is difficult to form an amorphous phase, making it difficult to obtain the good soft magnetic properties characteristic of amorphous alloys (ensuring that the iron loss W13 / 50 is stably below 0.100 W / kg). Therefore, in the Fe-based amorphous alloy of this embodiment, the Fe content is 78.00 atomic% or more and 86.00 atomic% or less. The lower limit of Fe is preferably 79.00 atomic%, more preferably 80.00 atomic%, and the upper limit of Fe is preferably 85.00 atomic%, more preferably 84.00 atomic%.

[0028] In the Fe-based amorphous alloy of this embodiment, by replacing a portion of Fe with at least one of Ni, Cr, or Co within a range of 10.0 atomic% or less, soft magnetic properties such as iron loss can be improved while maintaining a high saturation magnetic flux density. The reason for setting an upper limit on the substitution amount of these elements is that if it exceeds 10.0 atomic%, the saturation magnetic flux density decreases or the raw material cost increases. When replacing Fe with one or more of Ni, Cr, or Co, the total content of Ni, Cr, Co, and Fe must be 78.00 atomic% or more and 86.00 atomic% or less, or 79.00 atomic% or more and 84.00 atomic% or less.

[0029] Furthermore, the Fe-based amorphous alloy of this embodiment needs to contain, in atomic percent: P: 0.010% or more and less than 1.000%, S: 0.006% or more and less than 0.020%, and N: 0.0010% or more and less than 0.2000%.

[0030] Similar to B, Si, and C, P is included to form an amorphous phase and improve its thermal stability. By optimizing the P content, the alloy structure can be stably made into an amorphous phase, further improving soft magnetic properties. When P is less than 0.010 atomic%, the ability to form an amorphous phase cannot be improved, and an amorphous alloy cannot be stably obtained in Fe-based amorphous alloys, making it difficult to maintain iron loss stably below 0.100 W / kg. On the other hand, even if P is 1.000 atomic% or more, the ability to form an amorphous phase cannot be improved, and it is difficult to maintain iron loss stably below 0.100 W / kg. Therefore, P is 0.010 atomic% or more and less than 1.000 atomic%. The lower limit of P is preferably 0.050 atomic%, and more preferably 0.010 atomic%. The upper limit of P is preferably 0.900 atomic%, and more preferably 0.800 atomic%.

[0031] In the Fe-based amorphous alloy of this embodiment, sulfur (S) is an element that worsens brittleness. By optimizing the S content, when producing Fe-based amorphous alloy strips, the bending failure diameter can be less than 4 mm. Therefore, the S content is 0.006 atomic% or more and 0.020 atomic% or less. The upper limit of S is preferably 0.016 atomic%, more preferably 0.014 atomic%, and more preferably 0.010 atomic%.

[0032] In the Fe-based amorphous alloy of this embodiment, nitrogen (N) is included to improve amorphous formation capability and workability. By optimizing the N content, when producing Fe-based amorphous alloy strips, the bending failure diameter can be less than 4 mm. When N is less than 0.0010 atomic%, the improvement in workability cannot be obtained. On the other hand, if N is greater than 0.20 atomic%, the amorphous formation capability becomes saturated, raising concerns about increased iron loss. Therefore, N is set at 0.0010 atomic% or more and 0.2000 atomic% or less. The lower limit of N is preferably 0.0020 atomic%, and more preferably 0.0030 atomic%. The upper limit of N is preferably 0.1500 atomic%, and more preferably 0.1000 atomic%.

[0033] The remaining portion of the Fe-based amorphous alloy in this embodiment is an impurity. In the Fe-based amorphous alloy of this embodiment, for example, when steel is used as the Fe source, it may contain less than 0.100 atomic% of impurity elements found in the steel material as impurities. For example, it may contain less than 0.100 atomic% of O, Al, Ti, etc., as impurities.

[0034] The Fe-based amorphous alloy of this embodiment possesses an amorphous structure. This allows for the acquisition of excellent soft magnetic properties. Whether or not an amorphous structure exists can be confirmed, for example, by X-ray diffraction measurement using a Co-type X-ray tube. That is, if no distinct diffraction peak is obtained in the X-ray diffraction measurement, it can be confirmed that the Fe-based amorphous alloy possesses an amorphous structure. Here, "no distinct diffraction peak is obtained in the X-ray diffraction measurement" means the absence of a diffraction peak with a full width at half maximum (FWHM) of 4° or less for α-Fe(110).

[0035] When the saturation magnetic flux density and iron loss of the Fe-based amorphous alloy and Fe-based amorphous alloy strip of this embodiment were measured using the method described below, the saturation magnetic flux density was 1.60T or higher, and the iron loss (iron loss W 13 / 50) at a magnetic flux density of 1.3T and a frequency of 50Hz was 0.100W / kg or lower, indicating excellent soft magnetic properties.

[0036] Iron loss was measured using a Single Strip Tester (SST). The measurement conditions were set to a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss measurement were collected from six locations along the entire length of a batch of strips. The samples used were strips cut to a length of 120 mm. These strip samples were annealed at 360°C in a magnetic field (magnetic field: 800 A / m, applied in the casting direction) for 1 hour before measurement. The gas environment during annealing was a nitrogen atmosphere. Meanwhile, saturation magnetic flux density was measured using a Vibrating Sample Magnetometer (VSM). Samples for the VSM were thin strips obtained from the central portion of the width of the strip samples collected from the aforementioned six locations.

[0037] Furthermore, the Fe-based amorphous alloy strip of this embodiment can achieve a bending failure diameter of less than 4 mm. The bending failure diameter is obtained by means of the following method: according to the bending test method for metallic materials in JIS Z 2248:2006, the strip made of Fe-based amorphous alloy is placed in a bending test machine, the two ends of the specimen are pressed together until they are in close contact, and the diameter of the specimen at the time of fracture (bending failure diameter) is measured.

[0038] The following describes the manufacturing method of the Fe-based amorphous alloy and the Fe-based amorphous alloy strip according to this embodiment. The Fe-based amorphous alloy of this embodiment can generally be obtained in the form of a strip. This Fe-based amorphous alloy strip can be manufactured using, for example, a single-roll method or a double-roll method. In these methods, the alloy composed of the components described in the above embodiment is melted, and the molten liquid is ejected through a slit nozzle or the like onto a high-speed moving cooling plate, causing the molten liquid to rapidly solidify. The rollers used in these roller methods are made of metal, and by rotating the rollers at high speed, the molten liquid collides with the surface or inner surface of the rollers, thereby enabling the alloy to rapidly solidify.

[0039] The single-roller device also includes a centrifugal quenching device using the inner wall of a cylinder, a device using an annular belt, and an improved version of such devices that includes an auxiliary roller or roller surface temperature control device, or a casting device under reduced pressure or in a vacuum or in an inactive gas.

[0040] In this embodiment, there are no particular limitations on the thickness and width of the strip. For example, the thickness of the strip should preferably be 10 μm or more and 100 μm or less. Also, the width should preferably be 10 mm or more. The Fe-based amorphous alloy strips obtained as described above can be used as core materials in power transformers or high-frequency transformers.

[0041] Furthermore, the Fe-based amorphous alloy of this embodiment can be obtained not only in the form of thin strips but also in the form of powder. To obtain the powdered Fe-based amorphous alloy, the following method can be used: the alloy melt or droplets are sprayed at high speed from the nozzle of a crucible filled with the alloy melt of the above composition into a rotating roller or a liquid such as cooling water, causing it to rapidly solidify.

[0042] Using the above method, Fe-based amorphous alloy powder with excellent soft magnetic properties can be obtained.

[0043] The Fe-based soft magnetic alloy powder obtained as described above can be compacted into the target shape using molds or the like, and then sintered as needed to form a single piece, which can then be used as the core of power transformers, high-frequency transformers, coils, etc.

[0044] As explained above, the Fe-based amorphous alloy and Fe-based amorphous alloy strip according to this embodiment, by optimizing the content of B, Si and C, and containing P, S and N, and further making the Fe content 78.00% or more, have an iron loss (iron loss W 13 / 50) of less than 0.100 W / kg at a magnetic flux density of 1.3T and a frequency of 50Hz, and a saturation magnetic flux density of more than 1.60T. They can exhibit excellent soft magnetic properties and are suitable for use in the cores of power transformers or high-frequency transformers.

[0045] Furthermore, the Fe-based amorphous alloy strip of this embodiment can achieve a bending failure diameter of less than 4 mm. Therefore, when the Fe-based amorphous alloy strip is processed into the core of a power transformer or high-frequency transformer, there is no concern about the alloy strip breaking, which can improve the productivity of the core of the power transformer or high-frequency transformer. [Example]

[0046] The embodiments of the present invention will be described below.

[0047] (Example 1) Fe-based amorphous alloy strips were obtained by melting alloys with the various compositions shown in Tables 1A and 1B in an argon gas environment, rapidly cooling them using a single-roller apparatus, and then casting them. The casting gas environment was atmospheric. Furthermore, the single-roller apparatus used consisted of a 300mm diameter copper alloy cooling roller, a high-frequency power supply for sample melting, and a quartz crucible with a slit nozzle at the front end. In this experiment, a slit nozzle with a length of 10mm and a width of 0.6mm was used. The circumferential speed of the cooling roller was set to 24m / s. As a result, the thickness of the obtained strip was approximately 20μm, the width of the strip depended on the length of the slit nozzle, and was 10mm, with a length of approximately 100m.

[0048] X-ray diffraction was performed on the obtained Fe-based amorphous alloy thin strip to obtain the X-ray diffraction pattern. The X-ray source for the X-ray diffraction was set to Co-Kα (wavelength λ = 0.17902 nm), and the scanning range was set to 2θ = 10° or higher and 120° or lower. Based on the shape of the X-ray diffraction pattern, it was determined whether a crystalline phase had formed in the metal microstructure.

[0049] Furthermore, the saturation magnetic flux density and iron loss of Fe-based amorphous alloy strips were measured using a Single Strip Tester (SST). The iron loss measurement conditions were a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss measurement were collected from six locations along the entire length of a batch of strips. The iron loss samples were strips cut to a length of 120 mm. These iron loss strip samples were annealed at 360°C in a magnetic field (magnetic field: 800 A / m, applied in the casting direction) for 1 hour before measurement. The gas environment during annealing was a nitrogen atmosphere. On the other hand, the samples used in the VSM device were thin slices obtained from the central portion of the width of the strip samples collected from the aforementioned six locations.

[0050] The average values ​​of the data from the six locations are shown in Table 1 regarding the measurement results of saturation magnetic flux density and iron loss.

[0051] Furthermore, the bending failure diameter of Fe-based amorphous alloy thin strips was determined. The bending failure diameter was determined according to JIS Z 2248:2006, the method for testing bending of metallic materials. The Fe-based amorphous alloy thin strip was placed in a bending testing machine, and the bending failure diameter at fracture was measured. The results are shown in Table 1.

[0052] [Table 1] No. Chemical composition (atomic %) Remaining part: impurities Saturation magnetic flux density Bs(T) Iron loss W 13 / 50 (W / kg) Bending failure diameter (mm) Fe B Si C Mn P S N Example of the present invention 1 81.106 14.3 3.7 0.20 0.18 0.50 0.008 0.006 1.64 0.093 2 Example of the present invention 2 80.760 13.9 4.1 0.50 0.40 0.30 0.020 0.020 1.63 0.090 3 Example of the present invention 3 80.565 13.5 4.3 0.70 0.14 0.60 0.015 0.180 1.62 0.093 3 Example of the present invention 4 80.534 12.3 5.7 0.50 0.55 0.40 0.006 0.010 1.63 0.095 2 Example of the present invention 5 78.140 11.9 7.9 1.70 0.20 0.05 0.010 0.100 1.60 0.095 3 Example of the present invention 6 81.000 10.2 7.8 0.50 0.30 0.10 0.020 0.080 1.62 0.096 4 Example of the present invention 7 80.105 11.7 6.3 1.00 0.10 0.60 0.015 0.180 1.62 0.096 2 Example of the present invention 8 84.600 8.9 5.2 1.10 0.14 0.010 0.010 0.040 1.66 0.096 2 Example of the present invention 9 80.502 10.1 7.4 0.90 0.16 0.90 0.008 0.030 1.62 0.098 2 Example of the present invention 10 80.673 15.1 2.9 1.00 0.20 0.10 0.007 0.020 1.62 0.090 2 Example of the present invention 11 81.537 13.2 3.7 1.10 0.15 0.30 0.008 0.005 1.64 0.092 2 Example of the present invention 12 78.967 17.3 2.8 0.40 0.12 0.40 0.007 0.006 1.60 0.092 2 Example of the present invention 13 80.985 15.0 2.1 1.40 0.20 0.30 0.009 0.006 1.63 0.092 2 Example of the present invention 14 80.165 13.6 3.4 2.50 0.12 0.20 0.010 0.005 1.62 0.094 3 Example of the present invention 15 80.459 14.2 3.9 0.90 0.12 0.40 0.011 0.010 1.62 0.095 2 Example of the present invention 16 79.733 14.7 4.2 0.60 0.55 0.20 0.007 0.010 1.60 0.090 2 Example of the present invention 17 79.742 14.8 3.0 2.20 0.20 0.02 0.008 0.030 1.60 0.094 2 Example of the present invention 18 79.920 14.0 2.9 2.10 0.15 0.90 0.010 0.020 1.61 0.092 2 Example of the present invention 19 80.483 10.2 8.0 0.80 0.30 0.20 0.007 0.010 1.61 0.096 2 Example of the present invention 20 81.224 10.1 3.9 4.50 0.15 0.10 0.006 0.020 1.64 0.095 2 Example of the present invention twenty one 83.074 10.6 5.2 0.70 0.10 0.30 0.006 0.020 1.65 0.096 2 Example of the present invention twenty two 85.221 10.5 3.2 0.80 0.15 0.06 0.009 0.060 1.66 0.095 2 Example of the present invention twenty three 83.389 9.7 4.0 2.30 0.40 0.20 0.006 0.005 1.65 0.095 1 Example of the present invention twenty four 82.389 9.8 4.8 2.40 0.20 0.40 0.009 0.002 1.64 0.095 4 Example of the present invention 25 80.192 13.5 4.8 1.20 0.20 0.10 0.006 0.002 1.61 0.091 3 Example of the present invention 26 80.289 14.9 2.8 1.30 0.30 0.40 0.009 0.002 1.62 0.093 4 Comparative Example 1 [77.574] 14.5 6.5 1.00 0.20 0.20 0.006 0.020 1.59 0.094 2 Comparative Example 2 [86.214] 9.8 3.2 0.50 0.20 0.06 0.006 0.020 1.66 0.104 2 Comparative Example 3 82.260 [7.5] 7.8 2.20 0.13 0.05 0.010 0.050 1.65 0.104 2 Comparative Example 4 78.370 [18.3] 2.4 0.50 0.20 0.20 0.010 0.020 1.59 0.098 2 Comparative Example 5 81.954 14.8 [1.8] 1.20 0.12 0.10 0.006 0.020 1.65 0.102 2 Comparative Example 6 81.042 8.3 [9.5] 0.70 0.14 0.30 0.008 0.010 1.64 0.106 2 Comparative Example 7 81.360 13.2 4.8 [0.06] 0.15 0.40 0.010 0.020 1.64 0.104 2 Comparative Example 8 81.422 8.1 4.9 [5.20] 0.15 0.20 0.008 0.020 1.64 0.106 2 Comparative Example 9 80.844 12.9 5.0 1.10 [0.04] 0.06 0.006 0.050 1.63 0.108 2 Comparative Example 10 81.104 12.3 4.7 1.00 [0.65] 0.20 0.006 0.040 1.64 0.102 2 Comparative Example 11 80.807 13.8 3.8 1.40 0.15 [0.008] 0.015 0.020 1.63 0.102 2 Comparative Example 12 80.210 12.6 5.3 0.60 0.15 [1.10] 0.010 0.030 1.62 0.104 3 Comparative Example 13 80.645 12.2 5.5 1.30 0.20 0.08 [0.025] 0.050 1.62 0.098 6 Comparative Example 14 80.693 12.8 3.9 2.30 0.20 0.10 0.006 [0.0008] 1.62 0.098 5 Comparative Example 15 81.212 12.0 4.8 1.20 0.15 0.40 0.018 [0.220] 1.63 0.102 2 The underlined part indicates that it is outside the scope of this invention.

[0053] As shown in Table 1, the alloy compositions of Examples 1 to 26 of this invention all meet the scope of this invention. Therefore, the saturation magnetic flux density is 1.60T or higher, and the iron loss (iron loss W 13 / 50) at a magnetic flux density of 1.3T and a frequency of 50Hz is 0.100W / kg or lower, thus simultaneously achieving high saturation magnetic flux density and low iron loss. Furthermore, the bending failure diameter is 4mm or lower, and the machinability is also good.

[0054] On the other hand, the alloy compositions of Comparative Examples 1 to 15 do not meet the scope of the present invention, therefore the iron loss (iron loss W 13 / 50) is greater than 0.100 W / kg, or the saturation magnetic flux density is less than 1.60 T, or the bending failure diameter is greater than 4 mm.

[0055] That is, in Comparative Example 1, the Fe content is relatively low and the saturation magnetic flux density is less than 1.60T. In Comparative Example 2, the Fe content was too high, and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg.

[0056] In Comparative Example 3, the B content was lower and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg. In Comparative Example 4, the B content was too high, and the saturation magnetic flux density was less than 1.60T.

[0057] In Comparative Example 5, the Si content was lower and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg. In Comparative Example 6, the Si content was too high, and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg.

[0058] In Comparative Example 7, the C content was lower and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg. In Comparative Example 8, the C content was too high, and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg.

[0059] In Comparative Example 9, the Mn content was lower and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg. In Comparative Example 10, the Mn content was too high, and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg.

[0060] In Comparative Example 11, the P content was lower and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg. In Comparative Example 12, the P content was too high, and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg.

[0061] In Comparative Example 13, the sulfur content was too high, and the bending failure diameter was greater than 4 mm.

[0062] In Comparative Example 14, the N content was low, and the bending failure diameter was greater than 4 mm. In Comparative Example 15, the nitrogen content was too high, and the iron loss (iron loss W 13 / 50) was greater than 0.100 W / kg.

[0063] Furthermore, X-ray diffraction measurements were performed on the Fe-based amorphous alloy thin strips. The results showed that no clear diffraction peaks were observed in Examples 1-26 of this invention and Comparative Examples 1-15. Therefore, it cannot be said that a crystalline phase was formed in the metal structure, and the whole system was an amorphous phase.

[0064] (Example 2) Using alloys with various compositions obtained by replacing a portion of Fe with at least one of Ni, Cr, or Co, as shown in No. 1 of Table 1, thin strips were cast using the same apparatus and conditions as in Example 1. Furthermore, the specific compositions of the alloys used are shown in Table 2. As a result, the obtained thin strips had a thickness, width, and length of approximately 20 μm, 10 mm, and approximately 100 m, respectively. The saturation magnetic flux density, iron loss, and bending failure diameter of the obtained thin strips were evaluated. The sample collection method and measurement conditions used for evaluating these properties were the same as in Example 1. The measurement results are shown in Table 2. Furthermore, the display method in Table 2 is the same as that in Table 1.

[0065] [Table 2] No. Chemical composition (atomic %) Remaining part: impurities Saturation magnetic flux density Bs(T) Iron loss W 13 / 50 (W / kg) Bending failure diameter (mm) Fe Ni Cr Co B Si C Mn P S N Example of the present invention 27 79.674 1.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.61 0.090 2 Example of the present invention 28 77.674 3.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.62 0.090 2 Example of the present invention 29 78.674 2.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.64 0.088 2 Example of the present invention 30 75.674 3.00 2.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.60 0.092 2 Example of the present invention 31 74.674 3.00 3.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.62 0.090 2 Example of the present invention 32 73.674 3.00 4.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.63 0.089 2 Example of the present invention 33 71.674 2.00 4.00 3.00 15.1 2.9 1.00 0.20 0.10 0.006 0.020 1.63 0.089 2

[0066] Based on the results of samples No. 27-33 in Table 2, it can be seen that even when replacing a portion of Fe with at least one of Ni, Cr, or Co within the range of less than 10.0 atomic percent, the saturation magnetic flux density is still above 1.60 T, and the iron loss W13 / 50 can be stably kept below 0.100 W / kg. Furthermore, the bending failure diameter is less than 4 mm, and the workability is also good. Moreover, no clear diffraction peaks were observed in X-ray diffraction measurements of any of the samples, confirming them as amorphous.

[0067] Based on the above embodiments, it can be seen that the Fe-based amorphous alloy of the present invention, by optimizing the content of B, Si, and C, containing P, S, and N, and further increasing the Fe content to 78.00% or more, exhibits excellent soft magnetic properties, resulting in an iron loss (iron loss W 13 / 50) of less than 0.100 W / kg and a saturation magnetic flux density of more than 1.60 T at a magnetic flux density of 1.3 T and a frequency of 50 Hz. This makes it suitable for use in the cores of power transformers or high-frequency transformers. Furthermore, it also improves machinability.

[0068] Furthermore, according to the Fe-based amorphous alloy strip of the present invention, the iron loss (iron loss W 13 / 50) is less than 0.100 W / kg, the saturation magnetic flux density is greater than 1.60 T, and the bending failure diameter is less than 4 mm. Therefore, it is clear that when the Fe-based amorphous alloy strip is processed into the core of a power transformer or high-frequency transformer, there is no concern about the alloy strip breaking, thus improving the productivity of the core of the power transformer or high-frequency transformer. [Industrial Applicability]

[0069] The Fe-based amorphous alloy strip disclosed herein has high magnetic flux density due to its low iron loss and excellent machinability, thus making it highly usable in industry.

Claims

1. An Fe-based amorphous alloy, comprising, in atomic percent: B: 13.0% or more and 18.0% or less, Si: 2.0% or more and 6.0% or less, C: 0.10% or more and 3.00% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 84.600% or less, P: 0.010% or more and less than 1.000%, S: 0.006% or more and 0.020% or less, and N: 0.0010% or more and 0.2000% or less, the remainder being composed of impurities, and the Fe-based amorphous alloy having an amorphous microstructure and a bending failure diameter of 2 mm or less.

2. The Fe-based amorphous alloy of claim 1 contains, in atomic percent: Si: 2.0% or more and 5.0% or less, and N: 0.0030% or more and 0.2000% or less.

3. For the Fe-based amorphous alloy of claim 1, wherein at least one of the elements Ni, Cr, and Co is used to replace Fe in the range of less than 10.0 atomic percent.

4. For the Fe-based amorphous alloy as requested in item 1, the iron loss W13 / 50 when magnetized at a frequency of 50Hz and a magnetic flux density of 1.3T is less than 0.100W / kg, and the saturation magnetic flux density is more than 1.60T.

5. An Fe-based amorphous alloy strip, comprising any one of the Fe-based amorphous alloys as claimed in claims 1 to 4.