TWI898555B - Fe-based amorphous alloy and Fe-based amorphous alloy thin strip - Google Patents

Abstract

The Fe-based amorphous alloy contains, in atomic %, the following: B: 8.0% to 18.0%, Si: 2.0% to 9.0%, C: 0.10% to 5.00%, Fe: 78.00% to 86.00%, P: 0.010% to less than 1.000%, S: 0.006% to 0.020%, and N: 0.0010% to 0.2000%, with the remainder being composed of impurities. The structure of the Fe-based amorphous alloy is amorphous.

Description

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

Field of the Invention This invention relates to an Fe-based amorphous alloy and a Fe-based amorphous alloy ribbon, and more particularly to an Fe-based amorphous alloy and a Fe-based amorphous alloy ribbon having excellent workability.

Background of the Invention Known methods for continuously producing thin ribbons or wires by rapidly cooling an alloy from a molten state include the centrifugal quenching method, the single-roll method, and the double-roll method. These methods produce thin ribbons or wires by rapidly solidifying the molten metal by spraying it from an orifice or the like onto the inner or outer circumference of a high-speed rotating metal cylinder. Furthermore, by carefully selecting the alloy composition, amorphous alloys similar to liquid metal can be obtained, enabling the production of materials with excellent magnetic and mechanical properties.

In particular, Fe-based amorphous alloys have relatively low iron loss and relatively high saturation flux density compared to amorphous alloys other than Fe-based alloys. Therefore, they are expected to be used as cores for power transformers or high-frequency transformers.

Furthermore, Fe-based amorphous alloys are sometimes obtained as thin ribbons with a thickness of less than 0.1 mm. To use these ribbons in cores for power transformers and high-frequency transformers, for example, they are sometimes bent. However, bending Fe-based amorphous alloy ribbons with poor workability can cause cracks in the bent areas. Therefore, to improve the yield when processing these ribbons into cores, Fe-based amorphous alloy ribbons must possess excellent workability.

Patent Document 1 describes an Fe-B-Si-C amorphous alloy ribbon, the base element of which is Fe, with B, Si, and C as alloying elements. Furthermore, the contents of P, Mn, and S as impurities are, by weight, P: 0.008% to 0.1%, Mn: 0.15% to 0.5%, and S: 0.004% to 0.05%, respectively.

Patent Document 2 describes an Fe-based amorphous alloy ribbon containing, in atomic %, 5 to 25% B, 1 to 30% Si, and 0.001 to 0.2% N, with the remainder being Fe and inevitable impurities.

Patent Document 3 describes an amorphous alloy ribbon containing Fe, Si, B, C, Mn, S, and inevitable impurities, and having the following composition: when the total amount 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 Mn content is greater than 0.12 mass % and less than 0.15 mass %, and the S content is greater than 0.0034 mass % and less than 0.0045 mass %; the amorphous alloy ribbon has a thickness of 10 μm or more and 40 μm or less, and a width of 100 mm or more and 300 mm or less.

Patent Document 1 states that by using B, Si, and C as alloying elements and specifying the contents of P, Mn, and S, it is possible to use lower-grade materials and reduce alloy costs when manufacturing the thin strip. However, no research was conducted on improving workability (bending failure diameter).

Patent Document 2 describes that by incorporating nitrogen into Fe-B-Si and Fe-B-Si-C amorphous alloys, impurity elements (such as Al), known as crystallization-promoting elements, are concentrated in the surface oxide layer, thereby preventing the propagation of cracks in the amorphous alloy ribbon and significantly improving workability. Furthermore, the patent describes that the addition of nitrogen reduces the bending failure diameter by approximately 40%, thereby improving brittleness. However, there is no mention of incorporating sulfur (S) into the amorphous alloys.

While Patent Document 3 describes adjusting the Mn and S contents in an Fe-B-Si-C amorphous alloy ribbon to achieve continuous, prolonged molten metal ejection from a nozzle, it does not investigate improving workability (bending failure diameter). [Prior Art Document] [Patent Document]

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

Summary of the Invention [Problem to be Solved by the Invention] The present invention was made in view of the above-mentioned situation. Its purpose is to provide an Fe-based amorphous alloy and Fe-based amorphous alloy ribbon with excellent workability.

[Means for Solving the Problem] To solve the above-mentioned problem, the present invention adopts the following structure. [1] An Fe-based amorphous alloy comprising, in atomic %, the following: 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, 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 less than 0.020%, and N: 0.0010% or more and less than 0.2000%, with the remainder being composed of impurities, and the structure of the Fe-based amorphous alloy being amorphous. [2] The Fe-based amorphous alloy as described in [1], wherein Si: 2.0 atomic % or more and less than 5.0 atomic %. [3] The Fe-based amorphous alloy as described in [1], wherein N is 0.0030 atomic % or more and 0.2000 atomic % or less. [4] The Fe-based amorphous alloy as described in [2], wherein N is 0.0030 atomic % or more and 0.2000 atomic % or less. [5] The Fe-based amorphous alloy as described in [3], wherein the ratio of the amount of N to the amount of S (N/S) is 0.2 or more and 15 or less. [6] The Fe-based amorphous alloy as described in [4], wherein the ratio of the amount of N to the amount of S (N/S) is 0.2 or more and 15 or less. [7] The Fe-based amorphous alloy as described in [1], wherein B is 13.0 atomic % or more and 18.0 atomic % or less. [8] The Fe-based amorphous alloy as described in [7], wherein Si is 2.0 atomic % or more and less than 5.0 atomic %. [9] The Fe-based amorphous alloy as described in [7], wherein the N content is 0.0030 atomic % or more and 0.2000 atomic % or less. [10] The Fe-based amorphous alloy as described in [8], wherein the N content is 0.0030 atomic % or more and 0.2000 atomic % or less. [11] The Fe-based amorphous alloy as described in [9], wherein the ratio of the amount of N to the amount of S (N/S) is 0.2 or more and 15 or less. [12] The Fe-based amorphous alloy as described in [10], wherein the ratio of the amount of N to the amount of S (N/S) is 0.2 or more and 15 or less. [13] The Fe-based amorphous alloy as described in any one of [1] to [12], wherein Fe is replaced by at least one element selected from Ni, Cr, and Co in a range of 10.0 atomic % or less. [14] The Fe-based amorphous alloy as described in any one of [1] to [12], wherein the iron loss W13 _/50 when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T is less than 0.100 W/kg, and the saturated magnetic flux density is greater than 1.60 T. [15] An Fe-based amorphous alloy ribbon, comprising the Fe-based amorphous alloy as described in any one of [1] to [12]. [16] The Fe-based amorphous alloy ribbon as described in [15], wherein Fe is replaced by at least one element selected from Ni, Cr, and Co in an amount of less than 10.0 atomic %. [17] The Fe-based amorphous alloy ribbon described in [15] has a metal loss W _13/50 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 saturated magnetic flux density of more than 1.60 T. [18] The Fe-based amorphous alloy ribbon described in [15] has a bending failure diameter of less than 4 mm.

[Effects of the Invention] According to the above-described aspects of the present invention, a Fe-based amorphous alloy and Fe-based amorphous alloy ribbon with excellent workability can be provided.

Aspects of the Invention The inventors have discovered that by limiting the content of S, an element that degrades brittleness, and adjusting the contents of amorphous-forming elements such as B, C, and Si, they can not only improve amorphous-forming properties but also produce a Fe-based amorphous alloy with excellent workability, with a bending failure diameter of 4 mm or less.

Hereinafter, Fe-based amorphous alloys and Fe-based amorphous alloy ribbons as embodiments of the present invention will be described.

In this embodiment, excellent workability means that when the Fe-based amorphous alloy is made into a thin ribbon, its bending failure diameter is small.

The Fe-based amorphous alloy of this embodiment contains, in atomic %, the following: B: 8.0% to 18.0%, Si: 2.0% to 9.0%, C: 0.10% to 5.00%, Fe: 78.00% to 86.00%, P: 0.010% to less than 1.000%, S: 0.006% to 0.020%, and N: 0.0010% to 0.2000%, with the remainder being composed of impurities. The structure of the Fe-based amorphous alloy is amorphous.

The Si content of the Fe-based amorphous alloy of this embodiment can be 2.0 atomic % or more and less than 5.0 atomic %. Also, the N content of the Fe-based amorphous alloy of this embodiment can be 0.0030 atomic % or more and 0.2000 atomic % or less.

Furthermore, when the Fe-based amorphous alloy of this embodiment contains S and N, the ratio of the amount of N to the amount of S (N/S) can be 0.2 or more and 15 or less. Furthermore, the Fe-based amorphous alloy of this embodiment can contain B in an amount of 13.0 atomic % or more and 18.0 atomic % or less. Furthermore, the Fe-based amorphous alloy of this embodiment can be substituted for Fe with at least one element selected from Ni, Cr, and Co within a range of 10.0 atomic % or less. The Fe-based amorphous alloy ribbon of this embodiment is formed from the above-described 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 described.

The Fe-based amorphous alloy of this embodiment contains boron to form an amorphous phase and improve its thermal stability. By optimizing the content of this element, the alloy structure can be stably maintained in the amorphous phase, further improving soft magnetic properties. For example, the saturated magnetic flux density can be stably maintained at 1.60 T or above. If the boron content is less than 8.0 atomic percent, the amorphous phase formation ability cannot be improved, and the Fe-based amorphous alloy cannot be stably formed into an amorphous alloy. It is difficult to maintain a saturated magnetic flux density of 1.60 T or above while stably maintaining the iron loss below 0.100 W/kg. On the other hand, even if the B content exceeds 18.0 atomic %, the amorphous phase-forming ability cannot be improved, and it is difficult to stably maintain a saturated magnetic flux density of 1.60 T or higher. Therefore, the B content is preferably set to 8.0 atomic % or higher and 18.0 atomic % or lower. The lower limit of B is preferably 10.0 atomic %, more preferably 13.0 atomic %. The upper limit of B is preferably 16.0 atomic %, more preferably 15.0 atomic %.

Similar to B, the Fe-based amorphous alloy of this embodiment contains Si and C to form an amorphous phase and improve the thermal stability of the amorphous phase. By optimizing the Si and C contents, the alloy structure can be stably maintained in the amorphous phase, further improving the soft magnetic properties. When the Si content is less than 2.0 atomic % and the C content is less than 0.10 atomic %, the amorphous phase formation ability cannot be improved, and the Fe-based amorphous alloy cannot be stably formed into an amorphous alloy. It is difficult to maintain a saturated magnetic flux density of 1.60 T or above while stably maintaining the iron loss below 0.100 W/kg. On the other hand, even if the Si content exceeds 9.0 atomic % and the C content exceeds 5.00 atomic %, the amorphous phase-forming ability cannot be improved, and it is difficult to stably maintain the iron loss below 0.100 W/kg. The Si content is preferably 2.0 atomic % to 9.0 atomic % and the C content is preferably 0.10 atomic % to 5.00 atomic %. The lower limit of the Si content is preferably 3.0 atomic %, more preferably 4.0 atomic %. The upper limit of the Si content is preferably 6.0 atomic %, more preferably 5.0 atomic %, and particularly preferably less than 5.0 atomic %. The lower limit of the C content is preferably 0.50 atomic %, more preferably 1.00 atomic %. The upper limit of the C content is preferably 4.00 atomic %, more preferably 3.00 atomic %.

In Fe-based amorphous alloys, a saturated magnetic flux density practical for conventional iron cores can generally be achieved with an Fe content of 70 atomic % or more. However, to achieve a high saturated magnetic flux density of 1.60 T or more, the Fe content must be 78.00 atomic % or more. On the other hand, if the Fe content exceeds 86.00 atomic %, it is difficult to form an amorphous phase, making it difficult to obtain the good soft magnetic properties unique to amorphous alloys (keeping the iron loss W _13/50 stably below 0.100 W/kg). Therefore, in the Fe-based amorphous alloy of this embodiment, the Fe content is set to 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 is preferably 85.00 atomic %, more preferably 84.00 atomic %.

In the Fe-based amorphous alloy of this embodiment, by partially replacing Fe with at least one of Ni, Cr, and Co within a range of 10.0 atomic % or less, it is possible to improve soft magnetic properties such as iron loss while maintaining a high saturation flux density. The reason for setting an upper limit on the amount of substitution of these elements is that if it exceeds 10.0 atomic %, the saturation flux density decreases or the raw material cost increases. When replacing Fe with one or more of Ni, Cr, and Co, the total content of Ni, Cr, and Co plus the content of Fe is sufficient as long as it is at least 78.00 atomic % and no more than 86.00 atomic %, and can also be at least 79.00 atomic % and no more than 84.00 atomic %.

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

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

In the Fe-based amorphous alloy of this embodiment, S is an element that reduces brittleness. By optimizing the S content, the bending failure diameter of the Fe-based amorphous alloy ribbon can be reduced to 4 mm or less. Therefore, the S content is set to 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 even more preferably 0.010 atomic %.

The Fe-based amorphous alloy of this embodiment may contain N in an amount of 0.0010% to 0.2000% both inclusive, in terms of atomic %.

The Fe-based amorphous alloy of this embodiment contains nitrogen to enhance amorphous-forming properties and workability. By optimizing the nitrogen content, the bending failure diameter can be reduced to 4 mm or less when producing Fe-based amorphous alloy ribbons. By setting the nitrogen content to 0.0010 atomic % or greater, workability can be improved. On the other hand, if the nitrogen content exceeds 0.2000 atomic %, the amorphous-forming properties are saturated, raising concerns about increased iron loss. Therefore, nitrogen can be contained within a range of 0.0010 atomic % to 0.2000 atomic %. Preferably, the nitrogen content is 0.0020 atomic % or greater. Furthermore, preferably, the nitrogen content is 0.0030 atomic % or greater. Preferably, the nitrogen content is 0.1500 atomic % or less. Furthermore, it is preferred that the N content be 0.1000 atomic % or less.

When the Fe-based amorphous alloy of this embodiment contains S and N, the ratio of the N content to the S content (atomic ratio) (N/S) can be 0.2 to 15. By setting the N/S ratio to 0.2 to 15, workability can be further improved. Furthermore, soft magnetic properties can be enhanced. The lower limit of (N/S) can be 0.4, or even 0.6. The upper limit of (N/S) can be 13, or even 11.

The remainder of the Fe-based amorphous alloy of this embodiment is impurities. For example, when a steel material is used as an Fe source, the Fe-based amorphous alloy of this embodiment may contain impurity elements contained in the steel material as impurities. For example, a total of less than 0.10 atomic % of Mn, Al, Ti, O, etc. may be contained as impurities. The standard for the amount of each element contained as an impurity is less than 0.05 atomic %, less than 0.01 atomic % of Al, less than 0.005 atomic %, and less than 0.05 atomic %.

The Fe-based amorphous alloy of this embodiment has an amorphous structure. As a result, excellent soft magnetic properties can be obtained. Whether or not the alloy has an amorphous structure can be confirmed by, for example, performing X-ray diffraction measurement using an X-ray diffraction device with a Co tube. That is, when no clear diffraction peak can be obtained in the X-ray diffraction measurement, it can be confirmed that the Fe-based amorphous alloy has an amorphous structure. Here, "no clear diffraction peak can be obtained in the X-ray diffraction measurement" means that there is no peak with a half-height width (full width at half height) of 4° or less of the diffraction peak of α-Fe (110).

When the saturated magnetic flux density and iron loss of the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of this embodiment are measured using the methods described below, the saturated magnetic flux density is preferably 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 is preferably 0.100 W/kg or lower. As a result, the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon exhibit excellent soft magnetic properties.

Iron loss is measured using an SST (Single Strip Tester). The iron loss measurement conditions are set to a magnetic flux density of 1.3 T and a frequency of 50 Hz. The samples for iron loss measurement are collected from 6 locations along the entire length of a batch of thin strips. The samples for iron loss measurement are cut into thin strip samples with a length of 120 mm. The thin strip samples for iron loss measurement are annealed at 360°C in a magnetic field (magnetic field: 800 A/m, magnetic field applied in the casting direction) for 1 hour and then provided for measurement. The gas environment during the annealing process is set to a nitrogen gas environment. On the other hand, the saturated magnetic flux density is measured using a VSM device (vibrating sample type magnetometer). The samples used in the VSM device are thin slices obtained from the center of the width of the thin strip samples collected from the six locations mentioned above.

Furthermore, the Fe-based amorphous alloy ribbon of this embodiment can achieve a bending failure diameter of 4 mm or less. This bending failure diameter is obtained by placing a Fe-based amorphous alloy ribbon in a bending tester in accordance with JIS Z 2248:2006, metal material bending test methods, pressing the ends of the specimen together until they are firmly in contact, and measuring the specimen diameter at fracture (bending failure diameter).

The following describes a method for manufacturing the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present embodiment. The Fe-based amorphous alloy of the present embodiment can generally be obtained in the form of a ribbon. The Fe-based amorphous alloy ribbon can be manufactured using, for example, a single-roll method or a double-roll method. The above methods involve melting an alloy composed of the components described in the above embodiments, ejecting the molten metal through a slit nozzle or the like onto a high-speed moving cooling plate, and causing the molten metal to rapidly solidify. The roller used in these roller methods is made of metal, and by rotating the roller at high speed, the molten metal collides with the roller surface or the inner surface of the roller, thereby causing the alloy to rapidly solidify.

Single-roll devices also include centrifugal quenching devices using the inner wall of a cylinder, devices using an endless belt, and improved versions of these devices with auxiliary rolls or roll surface temperature control devices, and casting devices under reduced pressure, in a vacuum, or in an inert gas.

In this embodiment, the ribbon dimensions, such as thickness and width, are not particularly limited. For example, the ribbon thickness is preferably 10 μm or greater and 100 μm or less. Furthermore, the ribbon width is preferably 10 mm or greater. The Fe-based amorphous alloy ribbon 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 into a powdered form in addition to ribbons. To obtain the powdered Fe-based amorphous alloy, a method can be employed in which the molten alloy or droplets of the molten alloy are ejected at high speed from a nozzle of a crucible filled with the molten alloy of the aforementioned composition into a liquid such as a rotating roll or cooling water, causing the molten alloy or droplets to rapidly cool and 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 is compacted using a mold or the like to form a desired shape, and then optionally sintered to form a single body. This can then be used for applications such as power transformers, high-frequency transformers, and coil cores.

As described above, the Fe-based amorphous alloy and the Fe-based amorphous alloy ribbon according to this embodiment can improve workability by optimizing the contents of B, Si, and C, further containing S, and further increasing the Fe content to 78.00% or more.

The Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of this embodiment preferably has a loss (loss W _13/50 ) of 0.100 W/kg or less at a magnetic flux density of 1.3 T and a frequency of 50 Hz, and a saturated magnetic flux density of 1.60 T or greater. Consequently, the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of this embodiment exhibit excellent soft magnetic properties, making them suitable for use in cores of power transformers and high-frequency transformers.

Furthermore, the Fe-based amorphous alloy ribbon of this embodiment can achieve a bending failure diameter of 4 mm or less. Consequently, when the Fe-based amorphous alloy ribbon is processed into the core of an electric transformer or high-frequency transformer, there is no concern about alloy ribbon breakage, thereby improving the productivity of the core of the electric transformer or high-frequency transformer. The bending failure diameter of the Fe-based amorphous alloy ribbon of this embodiment is preferably 2 mm or less. [Example]

Hereinafter, embodiments of the present invention will be described.

(Example 1) Alloys of the various compositions listed in Tables 1A and 1B were melted in an argon atmosphere, rapidly cooled using a single-roll apparatus, and then cast to produce thin ribbons of Fe-based amorphous alloys. The casting atmosphere was atmospheric air. The single-roll apparatus used consisted of a 300 mm diameter copper alloy cooling roll, a high-frequency power supply for sample melting, and a quartz crucible with a slot nozzle attached to the tip. In this experiment, a slot nozzle with a length of 10 mm and a width of 0.6 mm was used. The circumferential speed of the cooling roll was set at 24 m/s. The resulting thin strip has a thickness of approximately 20 μm. Since the strip width depends on the length of the slit nozzle, the strip width is 10 mm and the length is approximately 100 m.

X-ray diffraction patterns were obtained by X-ray diffraction measurement of the obtained Fe-based amorphous alloy ribbon. The X-ray source for X-ray diffraction measurement was Co-Kα (wavelength λ = 0.17902 nm), and the scanning range was set to 2θ = 10° to 120°. The shape of the X-ray diffraction pattern was used to determine whether a crystalline phase had formed in the metal structure.

In addition, the saturated magnetic flux density and iron loss of the Fe-based amorphous alloy thin strip were measured using an SST (Single Strip Tester). The iron loss measurement conditions were a magnetic flux density of 1.3 T and a frequency of 50 Hz. The samples for iron loss measurement were collected from 6 locations along the entire length of a batch of thin strips. The samples for iron loss measurement were cut into thin strip samples with a length of 120 mm. The thin strip samples for iron loss measurement were annealed at 360°C in a magnetic field (magnetic field: 800 A/m, magnetic field applied in the casting direction) for 1 hour and then provided for measurement. The gas environment during the annealing process was set to a nitrogen gas environment. On the other hand, the samples used for the VSM device are slices obtained from the center of the width of the thin strip samples collected from the six locations mentioned above.

The average values of the saturated magnetic flux density and iron loss measured at six locations are shown in Tables 1A and 1B.

Furthermore, the bending failure diameter of the Fe-based amorphous alloy ribbon was measured. The bending failure diameter was determined in accordance with JIS Z 2248:2006, "Metallic Materials - Bending Test Methods." The Fe-based amorphous alloy ribbon 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 Remaining part: Impurities Saturation magnetic flux density Bs(T) Iron loss W _13/50 (W/kg) Bending failure diameter (mm) Fe (atomic%) B (atomic %) Si (atomic %) C (atomic %) P (atomic %) S (atomic %) N (atomic %) N/S Examples of this invention 1 80.150 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.62 0.093 2 Examples of this invention 2 81.465 13.8 3.2 1.50 0.020 0.007 0.0080 1.1 1.64 0.093 1 Examples of this invention 3 81.022 13.2 4.0 0.80 0.960 0.006 0.0120 2.0 1.63 0.092 3 Examples of this invention 4 82.560 13.3 3.2 0.50 0.400 0.020 0.0200 1.0 1.65 0.094 3 Examples of this invention 5 81.606 13.3 3.4 1.30 0.200 0.014 0.1800 12.9 1.64 0.094 2 Examples of this invention 6 80.076 15.1 3.5 0.90 0.400 0.019 0.0050 0.3 1.62 0.094 3 Examples of this invention 7 83.274 8.4 5.1 2.50 0.700 0.006 0.0200 3.3 1.66 0.097 3 Examples of this invention 8 84.273 9.8 5.2 0.20 0.500 0.007 0.0200 2.9 1.66 0.096 2 Examples of this invention 9 78.350 11.7 8.0 1.80 0.060 0.010 0.0800 8.0 1.60 0.098 2 Examples of this invention 10 81.469 10.0 7.3 1.20 0.010 0.006 0.0150 2.5 1.63 0.097 1 Examples of this invention 11 80.695 12.2 5.8 1.00 0.100 0.015 0.1900 12.7 1.62 0.098 2 Examples of this invention 12 80.676 11.3 5.6 2.10 0.300 0.019 0.0050 0.3 1.62 0.098 3 Examples of this invention 13 80.114 12.3 4.8 2.40 0.300 0.006 0.0800 13.3 1.62 0.099 1 Examples of this invention 14 80.633 15.2 3.8 0.13 0.200 0.007 0.0300 4.29 1.63 0.092 2 Examples of this invention 15 80.238 14.0 2.9 2.80 0.050 0.009 0.0030 0.33 1.62 0.093 2 Examples of this invention 16 80.692 13.4 3.8 1.80 0.300 0.006 0.0020 0.33 1.62 0.093 4 Examples of this invention 17 80.390 14.0 3.9 1.60 0.100 0.008 0.0020 0.25 1.62 0.092 4 Examples of this invention 18 80.434 13.8 4.9 0.50 0.300 0.008 0.0580 7.25 1.62 0.094 2 Examples of this invention 19 80.081 9.8 8.8 1.20 0.100 0.011 0.0080 0.73 1.62 0.097 3 Examples of this invention 20 85.541 10.4 3.0 0.60 0.400 0.009 0.0500 5.56 1.67 0.096 3 Examples of this invention twenty one 81.020 9.1 8.0 0.90 0.960 0.012 0.0080 0.67 1.62 0.098 4 Examples of this invention twenty two 81.286 10.5 6.3 1.20 0.700 0.006 0.0080 1.33 1.63 0.097 3 Examples of this invention twenty three 80.291 10.8 7.2 1.50 0.200 0.007 0.0020 0.29 1.61 0.097 4

[Table 1B] No. Chemical composition Remaining part: Impurities Saturation magnetic flux density Bs(T) Iron loss W _13/50 (W/kg) Bending failure diameter (mm) Fe (atomic%) B (atomic %) Si (atomic %) C (atomic %) P (atomic %) S (atomic %) N (atomic %) N/S Comparative example 101 77.674 14.8 6.0 1.20 0.300 0.006 0.0200 3.3 1.59 0.098 2 Comparative example 102 86.775 8.8 3.2 0.80 0.400 0.007 0.0180 2.6 1.67 0.130 3 Comparative example 103 80.090 7.8 8.0 3.50 0.500 0.010 0.1000 10.0 1.62 0.110 3 Comparative example 104 78.712 18.2 2.3 0.70 0.050 0.008 0.0300 3.8 1.60 0.105 2 Comparative example 105 83.084 13.7 1.8 1.30 0.100 0.008 0.0080 1.0 1.66 0.120 3 Comparative example 106 80.142 10.1 9.2 0.40 0.100 0.008 0.0500 6.3 1.61 0.130 2 Comparative example 107 80.866 12.4 6.6 0.07 0.040 0.006 0.0180 3.0 1.61 0.120 2 Comparative example 108 80.794 10.5 3.5 5.10 0.080 0.006 0.0200 3.3 1.61 0.130 2 Comparative example 109 82.966 9.7 5.2 2.10 0.008 0.010 0.0160 1.6 1.66 0.110 2 Comparative example 110 80.444 12.0 5.5 1.00 1.020 0.008 0.0280 3.5 1.61 0.140 5 Comparative example 111 82.168 11.2 4.8 1.50 0.300 0.022 0.0100 0.5 1.65 0.130 6 Comparative example 112 81.689 13.1 4.2 0.70 0.300 0.010 0.0009 0.9 1.64 0.110 5 Comparative example 113 81.375 11.3 4.7 2.00 0.400 0.015 0.2100 14.0 1.64 0.130 2 Comparative example 114 80.679 13.9 3.8 1.30 0.300 0.021 0.0020 0.1 1.62 0.120 5 Comparative example 115 79.459 12.8 5.6 1.60 0.200 0.021 0.3200 15.2 1.61 0.130 2 The underlined portion indicates that it is outside the scope of this invention.

As shown in Tables 1A and 1B, the alloy compositions of Examples 1-23 of the present invention all meet the requirements of the present invention. Consequently, they achieve a saturated magnetic flux density of 1.60 T or higher, and a loss factor (loss W _13/50 ) of less than 0.100 W/kg at a flux density of 1.3 T and a frequency of 50 Hz. This demonstrates the combined advantages of high saturated magnetic flux density and low loss factor. Furthermore, their bending failure diameter is less than 4 mm, demonstrating excellent workability.

On the other hand, the alloy compositions of Comparative Examples 101 to 115 do not meet the scope of the present invention, and therefore the iron loss (iron loss W _13/50 ) is greater than 0.100 W/kg, or the saturated magnetic flux density is less than 1.60 T, or the bending failure diameter is greater than 4 mm.

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

In Comparative Example 103, the B content was low, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 104, the B content was excessive, 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 C content was low, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 108, the C content was excessive, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg.

In Comparative Example 109, the P content was low, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 110, the P content was excessive, and the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. Furthermore, the bending failure diameter was greater than 4 mm.

In Comparative Example 111, the S content was excessive, resulting in a bending failure diameter exceeding 4 mm. Furthermore, the steel loss (steel loss W _13/50 ) exceeded 0.100 W/kg.

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

In Comparative Example 114, the S content was excessive, resulting in a bending failure diameter greater than 4 mm. Furthermore, the iron loss (iron loss W _13/50 ) was greater than 0.100 W/kg. In Comparative Example 115, the S and N contents were excessive, resulting in an iron loss (iron loss W _13/50 ) greater than 0.100 W/kg.

Furthermore, X-ray diffraction measurements were performed on the Fe-based amorphous alloy ribbons. No clear diffraction peaks were observed in Examples 1 to 23 of the present invention and Comparative Examples 101 to 115. Therefore, it cannot be said that a crystalline phase has formed in the metal structure, and the entire structure is amorphous.

(Example 2) Alloys with various compositions, in which at least one of Ni, Cr, and Co replaced a portion of the Fe in each of the alloys listed in Table 1A, were cast using the same apparatus and conditions as in Example 1. The specific compositions of the alloys used are shown in Tables 4 to 6. The resulting ribbons had a thickness, width, and length of approximately 20 μm, 10 mm, and 100 m, respectively. The saturated magnetic flux density, iron loss, and bending failure diameter of the resulting ribbons were evaluated. The sample collection method and measurement conditions used for these property evaluations were the same as in Example 1. The measurement results are shown in Table 2. The presentation of Table 2 follows the same principles as in Table 1.

[Table 2] No. Chemical composition Remaining part: Impurities Saturation magnetic flux density Bs(T) Iron loss W _13/50 (W/kg) Bending failure diameter (mm) Fe (atomic%) Ni (atomic %) Cr (atomic %) Co (atomic%) B (atomic %) Si (atomic %) C (atomic %) P (atomic %) S (atomic %) N (atomic %) N/S Examples of this invention twenty four 79.150 1.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.61 0.096 2 Examples of this invention 25 77.150 3.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.61 0.096 2 Examples of this invention 26 78.150 2.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.64 0.094 2 Examples of this invention 27 75.150 3.00 2.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.61 0.096 2 Examples of this invention 28 74.150 3.00 3.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.62 0.094 2 Examples of this invention 29 73.150 3.00 4.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.63 0.093 2 Examples of this invention 30 71.150 2.00 4.00 3.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.63 0.093 2

The results for Samples 24-30 in Table 2 show that even when a portion of Fe is replaced with at least one of Ni, Cr, or Co within a range of 10.0 atomic % or less, the saturated magnetic flux density remains above 1.60 T, and the iron loss W _13/50 remains stably below 0.100 W/kg. Furthermore, the bending failure diameter is below 4 mm, indicating good workability. Furthermore, no clear diffraction peaks were observed in any of the samples in X-ray diffraction analysis, confirming their amorphous nature.

The above examples demonstrate that the Fe-based amorphous alloy of the present invention improves workability by optimizing the contents of B, Si, and C, further including S, and increasing the Fe content to 78.00% or higher. Furthermore, it is shown that the iron loss (iron loss W _13/50 ) at a magnetic flux density of 1.3 T and a frequency of 50 Hz is below 0.100 W/kg, and the saturated magnetic flux density is above 1.60 T, exhibiting excellent soft magnetic properties. This makes it suitable for use in cores for power transformers and high-frequency transformers.

Furthermore, the Fe-based amorphous alloy ribbon of the present invention has a bending failure diameter of 4 mm or less. Furthermore, it has been shown that the iron loss (iron loss W _13/50 ) is 0.100 W/kg or less, and the saturated magnetic flux density is 1.60 T or greater. This demonstrates that when processing Fe-based amorphous alloy ribbon into cores for power transformers or high-frequency transformers, there is no concern about alloy ribbon breakage, thereby improving the productivity of cores for power transformers or high-frequency transformers. [Industrial Applicability]

The Fe-based amorphous alloy and Fe-based amorphous alloy ribbon disclosed herein have high industrial applicability due to their excellent workability.

(without)

Claims (19)

An Fe-based amorphous alloy comprising, in atomic %, the following: B: 8.0% to 18.0%; Si: 2.0% to 9.0%; C: 0.10% to 5.00%; Fe: 78.00% to 86.00%; P: 0.010% to less than 1.000%; S: 0.006% to 0.020%; and N: 0.0010% to 0.2000%; The remainder is composed of impurities, and the structure of the Fe-based amorphous alloy is amorphous. The Fe-based amorphous alloy of claim 1, wherein Si is greater than or equal to 2.0 atomic % and less than 5.0 atomic %. The Fe-based amorphous alloy of claim 1, wherein the nitrogen content is greater than or equal to 0.0030 atomic % and less than or equal to 0.2000 atomic %. The Fe-based amorphous alloy of claim 2, wherein the nitrogen content is greater than or equal to 0.0030 atomic % and less than or equal to 0.2000 atomic %. The Fe-based amorphous alloy of claim 3, wherein the ratio of the amount of nitrogen to the amount of sulfur (N/S) is greater than or equal to 0.2 and less than or equal to 15. The Fe-based amorphous alloy of claim 4, wherein the ratio of the amount of nitrogen to the amount of sulfur (N/S) is greater than or equal to 0.2 and less than or equal to 15. The Fe-based amorphous alloy of claim 1, wherein B is greater than or equal to 13.0 atomic % and less than or equal to 18.0 atomic %. The Fe-based amorphous alloy of claim 7, wherein Si is greater than or equal to 2.0 atomic % and less than 5.0 atomic %. The Fe-based amorphous alloy of claim 7, wherein the nitrogen content is greater than or equal to 0.0030 atomic % and less than or equal to 0.2000 atomic %. The Fe-based amorphous alloy of claim 8, wherein the nitrogen content is greater than or equal to 0.0030 atomic % and less than or equal to 0.2000 atomic %. The Fe-based amorphous alloy of claim 9, wherein the ratio of the amount of N to the amount of S (N/S) is greater than or equal to 0.2 and less than or equal to 15. The Fe-based amorphous alloy of claim 10, wherein the ratio of the amount of nitrogen to the amount of sulfur (N/S) is greater than or equal to 0.2 and less than or equal to 15. The Fe-based amorphous alloy of any one of claims 1 to 12, wherein Fe is replaced by at least one element selected from Ni, Cr, and Co in a range of 10.0 atomic % or less. The Fe-based amorphous alloy of any one of claims 1 to 12 has a metal loss W _13/50 of 0.100 W/kg or less when magnetized at a frequency of 50 Hz and a magnetic flux density of 1.3 T, and a saturated magnetic flux density of 1.60 T or more. A Fe-based amorphous alloy ribbon is made of the Fe-based amorphous alloy according to any one of claims 1 to 12. As in claim 15, the Fe-based amorphous alloy strip is substituted for Fe with at least one element selected from Ni, Cr, and Co in a range of 10.0 atomic % or less. For example, the Fe-based amorphous alloy thin strip of claim 15 has an iron loss W _13/50 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 saturated magnetic flux density of greater than 1.60 T. For example, the Fe-based amorphous alloy thin strip of claim 15 has a bending failure diameter of less than 4 mm. For example, the Fe-based amorphous alloy thin strip of claim 18 has a bending failure diameter of less than 2 mm.