TW202542337A - Fe-based amorphous alloy and Fe-based amorphous alloy thin strip - Google Patents

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, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, 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 the Fe-based amorphous alloy is amorphous.

Description

Fe-based amorphous alloy and Fe-based amorphous alloy thin strip

Field of Invention This invention relates to an Fe-based amorphous alloy and Fe-based amorphous alloy strips, and more particularly to an Fe-based amorphous alloy with excellent machinability and Fe-based amorphous alloy strips.

Background of the Invention Methods for continuously manufacturing thin strips or wires by rapidly cooling an alloy from its molten state include centrifugal quenching, single-roller methods, and double-roller methods. These methods produce thin strips or wires by rapidly solidifying the molten metal by spraying it from an orifice onto the inner or outer circumference of a high-speed rotating metal cylinder. Furthermore, by rationally selecting the alloy composition, it is possible to obtain amorphous alloys similar to liquid metals, enabling the manufacture of materials with excellent magnetic or mechanical properties.

In particular, compared with non-Fe amorphous alloys, Fe-based amorphous alloys have relatively low iron loss and relatively high saturation magnetic flux density, making them promising candidates for applications such as cores in power transformers or high-frequency transformers.

Furthermore, Fe-based amorphous alloys can be obtained in the form of thin strips with a thickness of less than 0.1 mm. To use these Fe-based amorphous alloy strips in the cores of power transformers or high-frequency transformers, bending is sometimes performed. However, if Fe-based amorphous alloy strips with poor machinability are bent, cracks may occur at the bends. Therefore, to improve the yield when processing these strips into cores, Fe-based amorphous alloy strips must possess excellent machinability.

Patent document 1 describes an Fe-B-Si-C amorphous alloy thin strip, the base element of which is Fe, and B, Si and C are used as alloying elements. Furthermore, the contents of impurities P, Mn and S are respectively, by weight %: P: more than 0.008% and less than 0.1%, Mn: more than 0.15% and less than 0.5%, and S: more than 0.004% and less than 0.05%.

Patent document 2 describes an Fe-based amorphous alloy ribbon 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.

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; and 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.

In Patent 1, by using B, Si, and C as alloying elements and specifying the content of P, Mn, and S elements, it is possible to use low-grade materials, thereby reducing the alloy cost when manufacturing this thin strip. However, no research has been conducted on improving processability (bending failure diameter).

Patent document 2 describes how incorporating nitrogen (N) into Fe-B-Si and Fe-B-Si-C amorphous alloys concentrates impurity elements (such as Al), known as crystallization-promoting elements, in the surface oxide layer. This prevents the propagation of cracks in the amorphous alloy ribbons, significantly improving processability. Furthermore, it describes how the bending failure diameter is reduced by approximately 40% due to the presence of N, thus improving brittleness. However, no description is made of incorporating sulfur (S) into the amorphous alloy.

While Patent 3 describes a method for continuously ejecting molten metal from a nozzle over a long period by adjusting the Mn and S content in an Fe-B-Si-C amorphous alloy strip, no research has been conducted on improving machinability (bending failure diameter). [Previous Art Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Application Publication No. Hei 9-95760 [Patent Document 2] Japanese Patent Application Publication No. 2006-316348 [Patent Document 3] International Publication No. 2016/084741

Summary of the Invention [Problem Solved by the Invention] This invention was made in view of the above-mentioned situation, and its problem is to provide an Fe-based amorphous alloy and Fe-based amorphous alloy strip with excellent machinability.

[Means for Solving the Problem] In order to solve the above-mentioned problem, the present invention adopts the following structure. [1] An Fe-based amorphous alloy, comprising, in atomic percent: B: 8.0% or more and 18.0% or less, Si: 2.0% or more and 9.0% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, 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 structure of the Fe-based amorphous alloy is amorphous. [2] The Fe-based amorphous alloy as described in [1], wherein B: 13.0 atomic percent or more and 18.0 atomic percent or less. [3] The Fe-based amorphous alloy as described in [1], wherein Si is 2.0 atomic% or more and 6.0 atomic% or less. [4] The Fe-based amorphous alloy as described in [2], wherein Si is 2.0 atomic% or more and 6.0 atomic% or less. [5] The Fe-based amorphous alloy as described in [1], wherein N is 0.0030 atomic% or more and 0.2000 atomic% or less. [6] The Fe-based amorphous alloy as described in [2], wherein N is 0.0030 atomic% or more and 0.2000 atomic% or less. [7] The Fe-based amorphous alloy as described in [3], wherein N is 0.0030 atomic% or more and 0.2000 atomic% or less. [8] The Fe-based amorphous alloy as described in [4], wherein N is 0.0030 atomic% or more and 0.2000 atomic% or less. [9] The Fe-based amorphous alloy as described in [1], wherein the ratio of N to S (N/S) is 0.20 or more and 15 or less. [10] The Fe-based amorphous alloy as described in [2], wherein the ratio of N to S (N/S) is 0.20 or more and 15 or less. [11] The Fe-based amorphous alloy as described in [3], wherein the ratio of N to S (N/S) is 0.20 or more and 15 or less. [12] The Fe-based amorphous alloy as described in [4], wherein the ratio of N to S (N/S) is 0.20 or more and 15 or less. [13] The Fe-based amorphous alloy as described in any one of [1] to [12], wherein at least one element selected from Ni, Cr, and Co is used to replace Fe in the range of 10.0 atomic percent or less. [14] The Fe-based amorphous alloy described in any of [1] to [12] has an iron loss W13 _/50 of less than 0.100 W/kg and a saturation magnetic flux density of more than 1.60 T when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T. [15] The Fe-based amorphous alloy described in [13] has an iron loss W13 _/50 of less than 0.100 W/kg and a saturation magnetic flux density of more than 1.60 T when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T. [16] An Fe-based amorphous alloy strip is composed of the Fe-based amorphous alloy described in any of [1] to [12]. [17] The Fe-based amorphous alloy ribbon described in [16] is 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. [18] The Fe-based amorphous alloy ribbon described in [16] has an iron loss W13 _/50 of less than 0.100 W/kg and a saturation magnetic flux density of more than 1.60 T when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T. [19] The Fe-based amorphous alloy ribbon described in [16] has a bending failure diameter of less than 4 mm.

[Invention Effects] According to this invention, an Fe-based amorphous alloy and a Fe-based amorphous alloy strip with excellent machinability can be provided.

Form of the Invention 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), silicon (Si), and nitrogen (N), they can not only improve amorphous forming ability but also obtain Fe-based amorphous alloys with excellent workability and a bending failure diameter of 4 mm or less. Furthermore, they have discovered that by containing mn in the range of 0.05 atomic% to 0.60 atomic%, excellent soft magnetic properties and workability can be simultaneously achieved.

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

In this embodiment, excellent processability means that when Fe-based amorphous alloys are made into thin strips, the bending failure diameter is small. Furthermore, excellent soft magnetic properties mean that they have lower iron loss and higher saturation magnetic flux density.

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, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, 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, and the microstructure of the Fe-based amorphous alloy is amorphous.

Furthermore, the boron content in the Fe-based amorphous alloy of this embodiment can be 13.0 atomic% or more and 18.0 atomic% or less. Furthermore, the silicon content in the Fe-based amorphous alloy of this embodiment can be 2.0 atomic% or more and 6.0 atomic% or less.

Furthermore, when the Fe-based amorphous alloy of this embodiment contains both S and N, the N/S ratio can be 0.20 or more and 15 or less. Furthermore, the Fe-based amorphous alloy of this embodiment can replace Fe with at least one element selected from Ni, Cr, and Co, within a range of 10.0 atomic percent or less. Furthermore, the Fe-based amorphous alloy strip of this embodiment is composed of the aforementioned Fe-based amorphous alloy.

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

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, and the soft magnetic properties can be further improved. For example, the saturation magnetic flux density can be stably made above 1.60 T. When the boron content is less than 8.0 atomic percent, 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 below 0.100 W/kg while maintaining the saturation magnetic flux density above 1.60 T. On the other hand, even if B is greater than 18.0 atomic%, it is not possible to improve the ability to form amorphous phases, and it is difficult to make the saturation magnetic flux density stably above 1.60 T. Therefore, B is made to be 8.0 atomic% or more and 18.0 atomic% or less. The lower limit of B is preferably 10.0 atomic%, and more preferably 13.0 atomic%. The upper limit of B is preferably 16.0 atomic%, and more preferably 15.0 atomic%.

Similar to B, in the Fe-based amorphous alloy of this embodiment, Si is included to form an amorphous phase and improve its thermal stability. By optimizing the Si content, 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%, 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 maintain the saturation magnetic flux density stably above 1.60 T while keeping the iron loss stably below 0.100 W/kg. On the other hand, even if Si is greater than 9.0 atomic%, it is not possible to improve the ability to form amorphous phases, and it is difficult to keep the iron loss stable at 0.100 W/kg or less. Therefore, Si should be 2.0 atomic% or more and 9.0 atomic% or less. The lower limit of Si should preferably be 3.0 atomic%, and more preferably 4.0 atomic%. The upper limit of Si should preferably be 6.0 atomic%, and more preferably 5.0 atomic%, and especially preferably less than 5.0 atomic%.

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

In Fe-based amorphous alloys, a Fe content of 70 atomic% or more is generally sufficient to achieve a practical level of saturation magnetic flux density 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 (keeping the iron loss W13 _/50 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%, and more preferably 80.00 atomic%. The upper limit of Fe should be 85.00 atomic%, and more preferably 84.00 atomic%.

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 the range of 10.0 atomic% or less, soft magnetic properties such as iron loss can be improved while maintaining 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.

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

In the Fe-based amorphous alloy of this embodiment, sulfur (S) is an element that worsens brittleness. By optimizing the S content, the bending failure diameter can be reduced to 4 mm or less when producing Fe-based amorphous alloy strips. 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% or less.

In the Fe-based amorphous alloy of this embodiment, nitrogen (N) is included to improve amorphous material forming ability and workability. By optimizing the N content, when producing Fe-based amorphous alloy strips, the bending failure diameter can be 4 mm or less. When N is less than 0.0010 atomic%, the improvement in workability cannot be obtained. On the other hand, if N is greater than 0.2000 atomic%, the amorphous material forming ability becomes saturated, raising concerns about increased iron loss. Therefore, N is 0.0010 atomic% or more and 0.2000 atomic% or less. It is preferable that N is 0.0020 atomic% or more. It is further preferable that N is 0.0030 atomic% or more. It is preferable that N is 0.1500 atomic% or less. It is further preferable that N is 0.1000 atomic% or less.

In the case where the Fe-based amorphous alloy of this embodiment contains S and N, the ratio of N to S (atomic ratio) (N/S) can be 0.20 or more and 15 or less. By making the ratio of N to S (N/S) 0.20 or more and 15 or less, the machinability can be further improved. Furthermore, the soft magnetic properties can also be improved. The lower limit of (N/S) can be 0.40, and further can be 0.60. The upper limit of (N/S) can be 13, and further can be 11.

The remainder in the Fe-based amorphous alloy of 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 impurity elements found in the steel material as impurities. For example, it may contain a total of less than 0.10 atomic% of C, P, Al, Ti, O, etc., as impurities. The standards for the amount of each element contained as an impurity are: C less than 0.03 atomic%, P less than 0.01 atomic%, Al less than 0.01 atomic%, Ti less than 0.005 atomic%, and O less than 0.04 atomic%.

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

When determining the saturation magnetic flux density and iron loss of the Fe-based amorphous alloy and Fe-based amorphous alloy strip of this embodiment using the method described below, the saturation magnetic flux density should preferably be 1.60 T or higher, and the iron loss (iron loss W _13/50 ) at a magnetic flux density of 1.3 T and a frequency of 50 Hz should preferably be 0.100 W/kg or lower. Therefore, the Fe-based amorphous alloy and Fe-based amorphous alloy strip of this embodiment exhibit excellent soft magnetic properties.

Iron loss was measured using a Single Strip Tester (SST). The measurement conditions were set at a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss testing were collected from six locations along the entire length of a batch of strips. The iron loss test samples were cut into 120 mm long strips. These strip samples were annealed at 360°C in a magnetic field (magnetic field: 800 A/m, applied in the casting direction) for one hour before measurement. The gas environment during annealing was a nitrogen gas environment. Meanwhile, saturated magnetic flux density was measured using a Vibration Sample Magnetometer (VSM). The sample used in the VSM device is a thin sheet obtained by collecting the thin strip samples from the central part of the width of the above 6 locations.

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 placing the Fe-based amorphous alloy strip in a bending tester according to JIS Z 2248:2006, the method for bending test of metallic materials, pressing the two ends of the specimen together until they are tightly joined, and measuring the diameter of the specimen at the point of fracture (bending failure diameter).

The following describes the Fe-based amorphous alloy and the manufacturing method of the Fe-based amorphous alloy strip of 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 methods such as the single-roller method or the double-roller method, whereby an alloy composed of the components described in the above embodiment is melted, and the molten liquid is ejected through a narrow-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 and causing the molten liquid to collide with the roller surface or inner surface, the alloy can be rapidly solidified.

The single-roll device also includes a centrifugal quenching device using the inner wall of a cylinder, a device using an annular belt, and a casting device with an auxiliary roller or roller surface temperature control device as an improvement of such devices, in a reduced pressure or vacuum, or in an inert gas.

In this embodiment, there are no particular limitations on the thickness and width of the strip. The strip thickness is preferably 10 μm or more and 100 μm or less. The strip width is preferably 10 mm or more. The Fe-based amorphous alloy strip obtained as described above can be used for applications such as cores in power transformers or high-frequency transformers.

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

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

The Fe-based soft magnetic alloy powder obtained as described above can be compacted into the desired shape using molds or the like, and then sintered into a single unit as needed, thus enabling its application in applications such as power transformers, high-frequency transformers, and coil cores.

As described above, the Fe-based amorphous alloy and Fe-based amorphous alloy strip according to this embodiment improve machinability by optimizing the content of B and Si, containing an appropriate amount of Mn, and further containing S and N, and further making the Fe content 78.00% or more.

Furthermore, the iron loss (iron loss W _13/50 ) of the Fe-based amorphous alloy and Fe-based amorphous alloy strip of this embodiment at a magnetic flux density of 1.3T and a frequency of 50Hz should preferably be 0.100W/kg or less, and the saturation magnetic flux density should preferably be 1.60T or more. Therefore, the Fe-based amorphous alloy and Fe-based amorphous alloy strip of this embodiment can exhibit excellent soft magnetic properties. This makes them suitable for use in the cores of power transformers or high-frequency transformers.

Furthermore, the Fe-based amorphous alloy strip of this embodiment achieves a bending failure diameter of 4 mm or less. Therefore, when processing the Fe-based amorphous alloy strip into cores for power transformers or high-frequency transformers, there are no concerns about alloy strip breakage, thus improving the manufacturability of power transformer or high-frequency transformer cores. The bending failure diameter of the Fe-based amorphous alloy strip of this embodiment is preferably 2 mm or less. [Example]

The following describes embodiments of the present invention.

(Example 1) Fe-based amorphous alloy strips were produced by melting alloys of 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 10mm long and 0.6mm wide slit nozzle was used. The circumferential speed of the cooling roller was set to 24m/s. The resulting thin strip had a thickness of approximately 20 μm, and since the strip width depends on the length of the slit nozzle, it was 10 mm wide and approximately 100 m long.

The obtained Fe-based amorphous alloy thin strip was subjected to X-ray diffraction 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° and below 120°. Based on the shape of the X-ray diffraction pattern, it was determined whether a crystalline phase was formed in the metal microstructure.

Furthermore, the saturation magnetic flux density and iron loss of the Fe-based amorphous alloy strips were measured using a Single Strip Tester (SST). The iron loss was measured under the following conditions: magnetic flux density 1.3T and frequency 50Hz. Samples for iron loss testing were collected from six locations along the entire length of a batch of strips. The iron loss samples were cut into 120mm long strips. These iron loss test strip samples were annealed at 360°C in a magnetic field (magnetic field: 800 A/m, applied in the casting direction) for one hour before measurement. The gas environment during annealing was set to a nitrogen gas environment. On the other hand, the sample used in the VSM device is a thin sheet obtained by collecting the thin strip samples from the above 6 locations from the center of the width.

The results of the measurements of saturation magnetic flux density and iron loss are shown in Tables 1A and 1B, with the average values of data from the six locations.

Furthermore, the bending failure diameter of the Fe-based amorphous alloy strip was determined. The bending failure diameter was determined according to JIS Z 2248:2006, the method for bending tests of metallic materials. The Fe-based amorphous alloy strip was placed in a bending tester, and the bending failure diameter at fracture was measured. The results are shown in Tables 1A and 1B.

[Table 1A] No. Chemical composition: Residue: Impurities Saturated magnetic flux density Bs(T) Iron loss W _13/50 (W/kg) Bending failure diameter (mm) Fe (atomic%) B (atomic percentage) Si (atomic %) Mn (atomic percentage) S (atomic%) N (atomic %) N/S This invention example 1 79.06 17.8 3.0 0.10 0.006 0.0300 5.00 1.61 0.097 3 This invention example 2 80.21 13.6 5.6 0.57 0.008 0.0100 1.25 1.61 0.097 2 This invention example 3 81.02 14.3 4.6 0.06 0.010 0.0140 1.40 1.62 0.097 2 This invention example 4 81.15 14.2 4.3 0.30 0.020 0.0300 1.50 1.63 0.098 3 This invention example 5 80.26 17.1 2.4 0.21 0.008 0.0190 2.38 1.62 0.096 2 This invention example 6 80.15 14.6 5.1 0.13 0.012 0.0040 0.33 1.62 0.099 3 This invention example 7 85.28 11.6 2.6 0.50 0.010 0.0150 1.50 1.66 0.096 3 This invention example 8 81.20 11.3 7.4 0.07 0.010 0.0200 2.0 1.62 0.098 3 This invention example 9 81.19 9.4 8.8 0.58 0.010 0.0200 2.00 1.62 0.097 3 This invention example 10 81.84 11.4 6.6 0.08 0.018 0.0600 3.33 1.63 0.098 4 This invention example 11 79.13 13.4 7.0 0.45 0.010 0.0060 0.60 1.61 0.098 4 This invention example 12 80.05 11.4 8.3 0.10 0.010 0.1400 14.00 1.62 0.097 2 This invention example 13 80.67 15.4 3.6 0.30 0.008 0.0200 2.50 1.62 0.095 2 This invention example 14 82.05 15.5 2.3 0.14 0.009 0.0040 0.44 1.64 0.097 2 This invention example 15 81.07 13.4 5.4 0.12 0.007 0.0080 1.14 1.62 0.096 2 This invention example 16 83.15 13.6 3.0 0.24 0.007 0.0050 0.71 1.65 0.095 1 This invention example 17 79.21 16.2 4.1 0.48 0.008 0.0020 0.25 1.61 0.098 4 This invention example 18 84.06 13.3 2.5 0.07 0.010 0.0580 5.80 1.66 0.096 1 This invention example 19 83.14 8.5 8.2 0.14 0.012 0.0100 0.83 1.65 0.098 3 This invention example 20 79.21 12.0 8.6 0.16 0.011 0.0200 1.82 1.61 0.097 3 This invention example twenty one 80.26 13.2 6.3 0.23 0.010 0.0020 0.20 1.62 0.098 4 This invention example twenty two 80.10 13.6 6.2 0.07 0.012 0.0180 1.50 1.61 0.097 3

[Table 1B] No. Chemical composition: Residue: Impurities Saturated magnetic flux density Bs(T) Iron loss W _13/50 (W/kg) Bending failure diameter (mm) Fe (atomic%) B (atomic percentage) Si (atomic %) Mn (atomic percentage) S (atomic%) N (atomic %) N/S Comparative example 101 77.72 15.8 6.3 0.15 0.010 0.0200 2.00 1.59 0.098 3 Comparative example 102 86.11 9.7 4.1 0.07 0.007 0.0150 2.14 1.66 0.104 3 Comparative example 103 83.46 7.6 8.6 0.32 0.006 0.0100 1.67 1.64 0.105 3 Comparative example 104 78.37 18.3 2.8 0.52 0.008 0.0080 1.00 1.60 0.102 2 Comparative example 105 81.32 16.6 1.8 0.26 0.007 0.0120 1.71 1.63 0.104 2 Comparative example 106 79.36 11.2 9.3 0.11 0.008 0.0180 2.25 1.61 0.103 2 Comparative example 107 80.84 13.3 5.8 0.04 0.010 0.0150 1.50 1.62 0.102 2 Comparative example 108 79.24 13.8 6.3 0.63 0.012 0.0200 1.67 1.60 0.103 3 Comparative example 109 81.33 14.2 4.1 0.23 0.024 0.1200 5.00 1.62 0.104 5 Comparative example 110 81.54 13.2 4.8 0.46 0.008 0.0008 0.10 1.63 0.103 5 Comparative example 111 81.58 12.0 6.0 0.18 0.018 0.2200 12.22 1.63 0.103 3 Comparative example 112 80.82 14.3 4.6 0.25 0.022 0.0040 0.18 1.62 0.101 5 Comparative example 113 80.14 15.1 4.2 0.34 0.012 0.2100 17.50 1.62 0.101 3 The bottom line indicates that the scope of this invention is beyond.

As shown in Table 1A, the alloy compositions of Examples 1 to 22 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.

On the other hand, as shown in Table 1B, the alloy compositions of Comparative Examples 101 to 113 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.

That is, in Comparative Example 101, the Fe content is low and the saturation magnetic flux density is less than 1.60T. In Comparative Example 102, the Fe content is too high and the iron loss (iron loss W _13/50 ) is greater than 0.100W/kg.

In Comparative Example 103, the B content was lower, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 104, the B content was too high, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

In Comparative Example 105, the Si content was low, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 106, the Si content was excessive, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

In Comparative Example 107, the Mn content was low, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 108, the Mn content was excessive, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

In Comparative Example 109, the sulfur content was too high, and the bending failure diameter was greater than 4 mm. Also, the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

In Comparative Example 110, the nitrogen content was lower, and the bending failure diameter was greater than 4 mm. Furthermore, the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 111, the nitrogen content was excessive, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

In Comparative Example 112, the sulfur content was excessive, and the bending failure diameter was greater than 4 mm. Furthermore, the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 113, the nitrogen content was excessive, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

Furthermore, X-ray diffraction analysis was performed on the Fe-based amorphous alloy thin strips. The results showed that no clear diffraction peaks were observed in Examples 1-22 of the present invention and Comparative Examples 101-113. Therefore, it cannot be said that a crystalline phase was formed in the metal structure, and the whole structure is an amorphous phase.

(Example 2) Using alloys with compositions where at least one of Ni, Cr, or Co is used to replace a portion of Fe in each of the alloys shown in Table 1A, No. 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 thickness, width, and length of the obtained thin strips were 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 these characteristic evaluations 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 in Tables 1A and 1B.

[Table 2] No. Chemical composition: Residue: Impurities Fe (atomic%) Ni (atomic %) Cr (atomic %) Co (atomic%) B (atomic percentage) Si (atomic %) Mn (atomic percentage) S (atomic%) N (atomic %) N/S This invention example twenty three 79.67 1.00 15.4 3.6 0.30 0.006 0.0200 3.3 This invention example twenty four 77.67 3.00 15.4 3.6 0.30 0.006 0.0200 3.3 This invention example 25 78.67 2.00 15.4 3.6 0.30 0.006 0.0200 3.3 This invention example 26 75.67 3.00 2.00 15.4 3.6 0.30 0.006 0.0200 3.3 This invention example 27 74.67 3.00 3.00 15.4 3.6 0.30 0.006 0.0200 3.3 This invention example 28 73.67 3.00 4.00 15.4 3.6 0.30 0.006 0.0200 3.3 This invention example 29 71.67 2.00 4.00 3.00 15.4 3.6 0.30 0.006 0.0200 3.3

Based on the results of samples No. 23-29 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 W _13/50 can be stably kept below 0.100 W/kg. Furthermore, the bending failure diameter is below 4 mm, and the processability is also good. Moreover, no clear diffraction peaks were observed in X-ray diffraction measurements of any of the samples, confirming them as amorphous.

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 and Si, containing an appropriate amount of Mn, further containing S and N, and further increasing the Fe content to 78.00% or more, improves machinability. Furthermore, at a magnetic flux density of 1.3T and a frequency of 50Hz, the iron loss (iron loss W _13/50 ) is below 0.100W/kg, and the saturation magnetic flux density is above 1.60T, exhibiting excellent soft magnetic properties, making it suitable for use in the cores of power transformers or high-frequency transformers.

Furthermore, according to the Fe-based amorphous alloy strip of this invention, the bending failure diameter is less than 4 mm. Also, the iron loss (iron loss W _13/50 ) is less than 0.100 W/kg, and the saturation magnetic flux density is greater than 1.60 T. 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 alloy strip breakage, thus improving the manufacturability of power transformer or high-frequency transformer cores. [Industrial Applicability]

The Fe-based amorphous alloys and Fe-based amorphous alloy strips disclosed herein have high industrial applicability due to their excellent machinability.

(without)

Claims (19)

An Fe-based amorphous alloy, comprising, in atomic percent: B: 8.0% or more and 18.0% or less, Si: 2.0% or more and 9.0% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, S: 0.006% or more and 0.020% or less, and N: 0.0010% or more and 0.2000% or less, the remainder consisting of impurities, and the microstructure of the Fe-based amorphous alloy is amorphous. For example, in the Fe-based amorphous alloy of Request 1, B is 13.0 atomic% or more and 18.0 atomic% or less. For example, in the Fe-based amorphous alloy of Request 1, the Si content is 2.0 atomic% or more and 6.0 atomic% or less. For example, in the Fe-based amorphous alloy of claim 2, the Si content is 2.0 atomic% or more and 6.0 atomic% or less. For example, in the Fe-based amorphous alloy of Request 1, N is ≥0.0030 atomic% and ≤0.2000 atomic%. For example, in the Fe-based amorphous alloy of claim 2, N is ≥0.0030 atomic% and ≤0.2000 atomic%. For example, in the Fe-based amorphous alloy of claim 3, N is 0.0030 atomic% or more and 0.2000 atomic% or less. For example, in the Fe-based amorphous alloy of claim 4, N is ≥0.0030 atomic% and ≤0.2000 atomic%. For example, in the Fe-based amorphous alloy of claim 1, the ratio of N to S (N/S) is 0.20 or more and 15 or less. For example, in the Fe-based amorphous alloy of claim 2, the ratio of N to S (N/S) is 0.20 or more and 15 or less. For example, in the Fe-based amorphous alloy of claim 3, the ratio of N to S (N/S) is 0.20 or more and 15 or less. For example, in the Fe-based amorphous alloy of claim 4, the ratio of N to S (N/S) is 0.20 or more and 15 or less. For any of the Fe-based amorphous alloys in claims 1 to 12, Fe is replaced by at least one of the elements Ni, Cr, and Co in the range of less than 10.0 atomic percent. For any of the Fe-based amorphous alloys in claims 1 to 12, 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. For example, the Fe-based amorphous alloy in claim 13 has an iron loss W13 _/50 of less than 0.100 W/kg and a saturation magnetic flux density of more than 1.60 T when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T. A Fe-based amorphous alloy strip, comprising any of the Fe-based amorphous alloys as claimed in claims 1 to 12. For example, in the Fe-based amorphous alloy thin strip of claim 16, Fe is replaced by at least one of the elements Ni, Cr, and Co in the range of less than 10.0 atomic percent. For example, the Fe-based amorphous alloy thin strip in Request 16 has an iron loss W _13/50 of less than 0.100 W/kg and a saturation magnetic flux density of more than 1.60 T when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T. For example, the Fe-based amorphous alloy thin strip in claim 16 has a bending failure diameter of less than 4 mm.