Fe-BASED AMORPHOUS ALLOY AND THIN Fe-BASED AMORPHOUS ALLOY STRIP

Abstract

This Fe-based amorphous alloy has an amorphous structure and contains, in terms of at%, 8.0-18.0% B, 2.0-9.0% Si, 0.10-5.00% C, 78.00-86.00% Fe, not less than 0.010 but less than 1.000% P, 0.006-0.020% S, and 0.0010-0.2000% N, with the remainder being impurities.

Description

TITLE OF INVENTION: Fe-BASED AMORPHOUS ALLOY AND Fe-BASED AMORPHOUS ALLOY RIBBON TECHNICAL FIELD

[0001] The present invention relates to an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon, and particularly relates to an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon excellent in workability. BACKGROUND ART

[0002] As methods for continuously manufacturing thin strips (ribbons) or wires by rapidly cooling an alloy in a molten state, a centrifugal quenching method, a single roll method, a twin roll method, and the like have been known. These methods involve rapidly solidifying a molten metal by ejecting the molten metal from an orifice or the like onto either an inner circumferential surface or an outer circumferential surface of a metal drum rotating at a high speed, thereby manufacturing ribbons or wires. Furthermore, it is possible to obtain an amorphous alloy similar to a liquid metal through the appropriate selection of an alloy composition, thereby enabling the manufacturing of a material with excellent magnetic properties or mechanical properties.

[0003] In particular, Fe-based amorphous alloys have relatively low iron loss and relatively high saturation magnetic flux density as compared to non-Fe-based amorphous alloys, and are thus regarded as promising for applications such as cores for a power transformer and a high-frequency transformer. Incidentally, the Fe-based amorphous alloys may be obtained as ribbons having a thickness of 0.1 mm or less. In order to utilize an Fe-based amorphous alloy ribbon for applications such as cores for a power transformer and a high-frequency transformer, the ribbon may be subjected to bending. However, in a case where the Fe-based amorphous alloy ribbon having poor workability is subjected to bending, cracking may occur at the bent portion. Therefore, in order to improve the yield in processing the ribbon into a core or the like, excellent workability is demanded for the Fe-based amorphous alloy ribbon.

[0005] Patent Document 1 describes an Fe-B-Si-C amorphous alloy ribbon in which a base element is Fe, B, Si, and C are used as alloying constituent elements, and contents of P, Mn, and S as impurities are, in weight%, P: 0.008% or more and 0.1% or less, Mn: 0.15% or more and 0.5% or less, and S: 0.004% or more and 0.05% or less, respectively.

[0006] Patent Document 2 describes an Fe-based amorphous alloy ribbon containing, in atom%, B: 5% to 25%, Si: 1% to 30%, and N: 0.001% to 0.2%, with a remainder composed of Fe and unavoidable impurities.

[0007] Patent Document 3 describes an amorphous alloy ribbon containing Fe, Si, B, C, Mn, S, and unavoidable impurities, having a composition in which, when a total amount of Fe, Si, B, and C is 100.0 atom%, Si is 3.0 atom% or more and 10.0 atom% or less, B is 10.0 atom% or more and 15.0 atom% or less, and C is 0.2 atom% or more and 0.4 atom% or less, in which a content of Mn is more than 0.12 mass% and less than 0.15 mass%, a content of S is more than 0.0034 mass% and less than 0.0045 mass%, and a thickness is 10 pm or more and 40 pm or less, and a width is 100 mm or more and 300 mm or less.

[0008] In Patent Document 1, by using B, Si, and C as alloying constituent elements and specifying the contents of P, Mn, and S, it is described that low-grade materials can be used, and a reduction in alloy cost during manufacturing of the ribbon can be achieved; however, no consideration has been given to the improvement of workability (critical bending diameter).

[0009] Patent Document 2 describes that by incorporating N into Fe-B-Si-based and FeB-Si-C-based amorphous alloys, impurity elements said to be crystallization-promoting elements (such as Al) are concentrated in a surface oxide layer, thereby preventing crack propagation in the amorphous alloy ribbon and significantly improving workability. It is further described that a critical bending diameter is reduced by approximately 40% in all cases due to the effect of N incorporation, resulting in reduction of brittleness. However, there is no description about S (sulfur) incorporation.

[0010] Patent Document 3 describes that in an Fe-B-Si-C-based amorphous alloy ribbon, adjusting the contents of Mn and S enables continuous tapping of molten metal from a tapping nozzle over an extended period of time; however, no consideration has been given to the improvement of workability (critical bending diameter). Citation List Patent Documents

[0011] Patent Document 1: Japanese Unexamined Patent Application, First Publication No. H09-95760 Patent Document 2: Japanese Unexamined Patent Application, First Publication No. 2006-316348 Patent Document 3: PCT International Publication No. WO 2016 / 084741 SUMMARY OF INVENTION Technical Problem

[0012] The present invention has been made in view of the above circumstances, and an object thereof is to provide an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon excellent in workability. Solution to Problem

[0013] In order to achieve the aforementioned object, the present invention adopts the following configurations. [1] An Fe-based amorphous alloy containing, in atom%: 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 0.020% or less; and N: 0.0010% or more and 0.2000% or less, in which the Fe-based amorphous alloy has a balance including impurities, and has an amorphous micro structure. [2] The Fe-based amorphous alloy according to [1] containing Si: 2.0 atom% or more and less than 5.0 atom%. [3] The Fe-based amorphous alloy according to [1] containing N: 0.0030 atom% or more and 0.2000 atom% or less. [4] The Fe-based amorphous alloy according to [2] containing N: 0.0030 atom% or more and 0.2000 atom% or less. [5] The Fe-based amorphous alloy according to [3], in which a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less. [6] The Fe-based amorphous alloy according to [4], in which a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less. [7] The Fe-based amorphous alloy according to [1] containing B: 13.0 atom% or more and 18.0 atom% or less. [8] The Fe-based amorphous alloy according to [7] containing Si: 2.0 atom% or more and less than 5.0 atom%. [9] The Fe-based amorphous alloy according to [7] containing N: 0.0030 atom% or more and 0.2000 atom% or less.

[10] The Fe-based amorphous alloy according to [8] containing N: 0.0030 atom% or more and 0.2000 atom% or less.

[11] The Fe-based amorphous alloy according to [9], in which a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less.

[12] The Fe-based amorphous alloy according to

[10] , in which a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less.

[13] The Fe-based amorphous alloy according to any one of [1] to

[12] , in which Fe is substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.

[14] The Fe-based amorphous alloy according to any one of [1] to

[12] , in which an iron loss W13 / 50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is 0.100 W / kg or less, and a saturation magnetic flux density is 1.60 T or higher.

[15] An Fe-based amorphous alloy ribbon composed of the Fe-based amorphous alloy according to any one of [1] to

[12] .

[16] The Fe-based amorphous alloy ribbon according to

[15] , in which Fe is substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.

[17] The Fe-based amorphous alloy ribbon according to

[15] , in which an iron loss W13 / 50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is 0.100 W / kg or less, and a saturation magnetic flux density is 1.60 T or higher.

[18] The Fe-based amorphous alloy ribbon according to

[15] , in which a critical bending diameter is 4 mm or less. Advantageous Effects of Invention

[0014] According to each of the above-described aspects of the present invention, it is possible to provide an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon excellent in workability. DESCRIPTION OF EMBODIMENTS

[0015] The present inventors have found that it is possible to obtain an Fe-based amorphous alloy having excellent workability with a critical bending diameter of 4 mm or less by restricting the content of S, which is an element that degrades brittleness, and adjusting the contents of amorphous-forming elements such as B, C, and Si, while improving amorphous-forming ability.

[0016] Hereinafter, an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon, which are embodiments of the present invention, will be described.

[0017] In the present embodiment, “excellent in workability” means that, in a case where the Fe-based amorphous alloy is formed into a ribbon, the critical bending diameter thereof is small.

[0018] The Fe-based amorphous alloy of the present embodiment contains, in atom%: 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 0.020% or less; and N: 0.0010% or more and 0.2000% or less, the Fe-based amorphous alloy having a balance including impurities, and an amorphous micro structure.

[0019] The Fe-based amorphous alloy of the present embodiment may contain Si: 2.0 atom% or more and less than 5.0 atom%. In addition, the Fe-based amorphous alloy of the present embodiment may contain N: 0.0030 atom% or more and 0.2000 atom% or less.

[0020] Furthermore, in a case where the Fe-based amorphous alloy of the present embodiment contains S and N, a ratio of the N content to the S content (N / S) may be 0.2 or more and 15 or less. Furthermore, the Fe-based amorphous alloy of the present embodiment may contain B: 13.0 atom% or more and 18.0 atom% or less. Furthermore, in the Fe-based amorphous alloy of the present embodiment, Fe may be substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less. Furthermore, the Fe-based amorphous alloy ribbon of the present embodiment is composed of the above-described Fe-based amorphous alloy.

[0021] First, the reason why the content of each element is limited in the Fe-based amorphous alloy of the present embodiment will be described.

[0022] B is contained in the Fe-based amorphous alloy of the present embodiment in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. Optimization of the content of this element enables the alloy microstructure to be stably maintained in an amorphous phase, thereby further improving soft magnetic properties. For example, the saturation magnetic flux density can be stably set to 1.60 T or higher. In a case where B is less than 8.0 atom%, an improvement in amorphous phase-forming ability cannot be achieved, and the amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy, resulting in difficulty in stably achieving a saturation magnetic flux density of 1.60 T or higher while stably maintaining an iron loss of 0.100 W / kg or less. In contrast, in a case where B is more than 18.0 atom%, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve a saturation magnetic flux density of 1.60 T or higher. Therefore, B is set to 8.0 atom% or more and 18.0 atom% or less. The lower limit of B is preferably 10.0 atom%, and still more preferably 13.0 atom%. The upper limit of B is preferably 16.0 atom%, and still more preferably 15.0 atom%.

[0023] Similar to B, Si and C are contained in the Fe-based amorphous alloy of the present embodiment in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. Optimization of the contents of Si and C element enables the alloy microstructure to be stably maintained in an amorphous phase, thereby further improving soft magnetic properties. In a case where Si is less than 2.0 atom% and C is less than 0.10 atom%, an improvement in amorphous phase-forming ability cannot be achieved, and the amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy, resulting in difficulty in stably achieving a saturation magnetic flux density of 1.60 T or higher while stably maintaining an iron loss of 0.100 W / kg or less. In contrast, in a case where Si is more than 9.0 atom% or C is more than 5.00 atom%, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve an iron loss of 0.100 W / kg or less. Si is set to 2.0 atom% or more and 9.0 atom% or less, and C is set to 0.10 atom% or more and 5.00 atom% or less. The lower limit of Si is preferably 3.0 atom%, and still more preferably 4.0 atom%. The upper limit of Si is preferably 6.0 atom%, still more preferably 5.0 atom%, and particularly preferably less than 5.0 atom%. The lower limit of C is preferably 0.50 atom%, and still more preferably 1.00 atom%. The upper limit of C is preferably 4.00 atom%, and still more preferably 3.00 atom%.

[0024] In the Fe-based amorphous alloy, in a case where the content of Fe is usually 70 atom% or more, a practically applicable level of saturation magnetic flux density for a general magnetic core can be obtained, but in order to obtain a high saturation magnetic flux density of 1.60 T or higher, it is necessary to set Fe to 78.00 atom% or more. In contrast, in a case where the content of Fe is more than 86.00 atom%, it is difficult to form an amorphous phase, and it is difficult to obtain good soft magnetic properties (iron loss W13 / 50 is stably 0.100 W / kg or less) unique to an amorphous alloy. Therefore, in the Fe-based amorphous alloy of the present embodiment, the Fe content is set to 78.00 atom% or more and 86.00 atom% or less. The lower limit of Fe is preferably 79.00 atom%, and still more preferably 80.00 atom%. The upper limit of Fe is preferably 85.00 atom%, and more preferably 84.00 atom%.

[0025] In the Fe-based amorphous alloy of the present embodiment, substitution of Fe in part with at least one of Ni, Cr, or Co in a range of 10.0 atom% or less enables an improvement of soft magnetic properties such as iron loss, with a high saturation magnetic flux density maintained. The reason why the upper limit is set for the substitution content of these elements is that, in a case where the content is more than 10.0 atom%, the saturation magnetic flux density is lowered and the raw material cost is increased. In a case where Fe is substituted with one or more of Ni, Cr, and Co, the total of the content of Fe and the contents of Ni, Cr, and Co is only sufficient to be 78.00 atom% or more and 86.00 atom% or less, and may be 79.00 atom% or more and 84.00 atom% or less.

[0026] Moreover, the Fe-based amorphous alloy of the present embodiment needs to contain, in atom%, P: 0.010% or more and less than 1.000%, and S: 0.006% or more and 0.020% or less.

[0027] Similar to B, Si, and C, P is contained in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. Optimization of the content of P enables the alloy microstructure to be stably maintained in an amorphous phase, thereby further improving soft magnetic properties. In a case where P is less than 0.010 atom%, an improvement in amorphous phase-forming ability cannot be achieved, and the amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy, resulting in difficulty in stably maintaining an iron loss of 0.100 W / kg or less. In contrast, in a case where P is 1.000 atom% or more, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve an iron loss of 0.100 W / kg or less. Therefore, P is set to 0.010 atom% or more and less than 1.000 atom%. The lower limit of P is preferably 0.050 atom%, and still more preferably 0.010 atom%. The upper limit of P is preferably 0.900 atom%, and still more preferably 0.800 atom%.

[0028] S is an element that degrades brittleness in the Fe-based amorphous alloy of the present embodiment. Optimization of the content of S enables achieving a critical bending diameter of 4 mm or less in a case where the Fe-based amorphous alloy is formed into a ribbon. Therefore, S is set to 0.006 atom% or more and 0.020 atom% or less. The upper limit of S is preferably 0.016 atom%, still more preferably 0.014 atom%, and still more preferably 0.010 atom%.

[0029] The Fe-based amorphous alloy of the present embodiment may contain, in atom%, N: 0.0010% or more and 0.2000% or less.

[0030] N may be contained in the Fe-based amorphous alloy of the present embodiment in order to improve amorphous-forming ability and workability. Optimization of the content of N enables achieving a critical bending diameter of 4 mm or less in a case where the Fe-based amorphous alloy is formed into a ribbon. By setting N to 0.0010 atom% or more, an improvement effect on workability can be obtained. In contrast, in a case where N is more than 0.2000 atom%, the effect of the amorphous-forming ability may be saturated, and iron loss may increase. Therefore, N may be contained in a range of 0.0010 atom% or more and 0.2000 atom% or less. N is preferably 0.0020 atom% or more. N is still more preferably 0.0030 atom% or more. N is preferably 0.1500 atom% or less. N is still more preferably 0.1000 atom% or less.

[0031] In a case where the Fe-based amorphous alloy of the present embodiment contains S and N, a ratio of the N content to the S content (atomic ratio) (N / S) may be 0.2 or more and 15 or less. By setting the ratio of the N content to the S content (N / S) to 0.2 or more and 15 or less, workability can be further improved. In addition, the soft magnetic properties can also be enhanced. The lower limit of (N / S) may be 0.4, or furthermore, may be 0.6. The upper limit of (N / S) may be 13, or furthermore, may be 11.

[0032] The balance in the Fe-based amorphous alloy according to the present embodiment is impurities. For example, in a case where a steel material is used as an Fe source, the Fe-based amorphous alloy according to the present embodiment may contain impurity elements contained in the steel material as impurities. For example, Mn, Al, Ti, O, and the like may be contained as impurities in a total of less than 0.10 atom%. The approximate amounts of elements contained as impurities are as follows: Mn is less than 0.05 atom%, Al is less than 0.01 atom%, Ti is less than 0.005 atom%, and O is less than 0.05 atom%.

[0033] The Fe-based amorphous alloy of the present embodiment has an amorphous microstructure. As a result, excellent soft magnetic properties can be obtained. Whether or not the Fe-based amorphous alloy has an amorphous microstructure can be confirmed by, for example, X-ray diffraction measurement with an X-ray diffractometer using a Co tube. That is, in a case where a clear diffraction peak cannot be obtained in the X-ray diffraction measurement, it can be confirmed that the Fe-based amorphous alloy has an amorphous microstructure. Here, the phrase “a clear diffraction peak cannot be obtained in the X-ray diffraction measurement” means that there is no peak with a half width (full width at half maximum) of 4° or less for the diffraction peak of a-Fe(110).

[0034] The Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present embodiment preferably have a saturation magnetic flux density of 1.60 T or higher and an iron loss (iron loss W13 / 50) of 0.100 W / kg or less at a magnetic flux density of 1.3 T and a frequency of 50 Hz, in a case where the saturation magnetic flux density and iron loss are measured by the method described below. As a result, the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon exhibit excellent soft magnetic properties.

[0035] The iron loss is measured using a single strip tester (SST). The iron loss measurement conditions are a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss measurement are collected from six locations over the total length of a ribbon from a single lot. Each sample for iron loss measurement is a ribbon sample cut into a length of 120 mm. These ribbon samples for iron loss measurement are annealed in a magnetic field (magnetic field: 800 A / m, magnetic field applied in casting direction) at 360°C for 1 hour and subjected to measurement. The atmosphere during annealing is a nitrogen atmosphere. On the other hand, the saturation magnetic flux density is measured using a vibrating sample magnetometer (VSM). The samples for the VSM are thin pieces collected from the center portion of the width of each of the ribbon samples from the six locations.

[0036] Moreover, the Fe-based amorphous alloy ribbon of the present embodiment can have a critical bending diameter of 4 mm or less. The critical bending diameter is obtained by placing a ribbon composed of an Fe-based amorphous alloy in a bending tester in accordance with JIS Z 2248:2006 (Metallic materials-Bend test), pressing both ends of the test piece toward each other until they are in close contact, and measuring the diameter of the test piece at the point of fracture (critical bending diameter).

[0037] Hereinafter, the Fe-based amorphous alloy and a method for manufacturing the Fe-based amorphous alloy ribbon of the present embodiment will be described. The Fe-based amorphous alloy of the present embodiment can be usually obtained in the form of a ribbon. This Fe-based amorphous alloy ribbon can be manufactured by a method of melting an alloy composed of the components described in the above embodiment, ejecting a molten metal through a slot nozzle or the like onto a cooling plate moving at a high speed, and rapidly quenching and solidifying the molten metal, such as a single roll method or a twin roll method. The roll used in these roll methods is made of metal, and rapid quenching and solidification of the alloy can be performed by rotating the roll at a high speed and causing the molten metal to collide with a roll surface or a roll inner surface.

[0038] The single roll device also includes a centrifugal quenching device using the inner wall of a drum, a device using an endless-type belt, improved types thereof to which an auxiliary roll or a roll surface temperature controller is attached, and a casting device under reduced pressure or in vacuum or in an inert gas.

[0039] In the present embodiment, the dimensions such as the sheet thickness and the sheet width of the ribbon are not particularly limited, and the sheet thickness of the ribbon is preferably, for example, 10 pm or more and 100 pm or less. The sheet width is preferably 10 mm or more. The Fe-based amorphous alloy ribbon obtained as described above can be used for applications such as cores for a power transformer and a high-frequency transformer.

[0040] Furthermore, the Fe-based amorphous alloy of the present embodiment can be in the form of powder in addition to the ribbon. In order to obtain a powdery Fe-based amorphous alloy, it is possible to adopt a method of ejecting a molten alloy or droplets of a molten alloy at a high speed onto a rotating roll or into a liquid such as cooling water from a nozzle of a crucible filled with the molten alloy having the above-described composition, and quenching and solidifying the molten alloy or the droplets.

[0041] An Fe-based amorphous alloy powder having excellent soft magnetic properties can be obtained by the above-described method.

[0042] The Fe-based soft magnetic alloy powder obtained as described above can be applied to applications such as cores for a power transformer, a high-frequency transformer, and a coil by compacting the Fe-based soft magnetic alloy powder with a die or the like, molding the Fe-based soft magnetic alloy powder into a desired shape, and sintering and integrating the Fe-based soft magnetic alloy powder as necessary. As described above, according to the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present embodiment, workability can be enhanced by optimizing the contents of B, Si, and C, further containing S, and further setting the content of Fe to 78.00% or more.

[0044] In the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present embodiment, it is preferable that an iron loss (iron loss W13 / 50) at a magnetic flux density of 1.3 T and a frequency of 50 Hz is 0.100 W / kg or less, and that a saturation magnetic flux density is 1.60 T or higher. As a result, the Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present embodiment can exhibit excellent soft magnetic properties. Therefore, the alloy can be suitably used for applications such as cores for a power transformer and a high-frequency transformer.

[0045] Moreover, since the Fe-based amorphous alloy ribbon of the present embodiment can have a critical bending diameter of 4 mm or less, there is no risk of the alloy ribbon being damaged in a case where the Fe-based amorphous alloy ribbon is processed into a core for a power transformer or a high-frequency transformer. Therefore, the productivity of cores for a power transformer and a high-frequency transformer can be improved. The critical bending diameter of the Fe-based amorphous alloy ribbon of the present embodiment is more preferably 2 mm or less. Examples

[0046] Hereinafter, examples of the present invention are described.

[0047] (Example 1) Alloys of various components illustrated in Table 1A and Table IB were melted in an argon atmosphere, quenched by a single roll device, and cast to prepare ribbons of an Fe-based amorphous alloy. The casting atmosphere was in the atmosphere. Note that the single roll device used includes a cooling roll made of a copper alloy having a diameter of 300 mm, a high-frequency power source for melting a sample, a quartz crucible having a slot nozzle at the tip, and the like. In the present experiment, a slot nozzle having a length of 10 mm and a width of 0.6 mm was used. The peripheral speed of the cooling roll was set to 24 m / sec. As a result, the sheet thickness of the obtained ribbon was about 20 pm, the sheet width was 10 mm since the sheet width depends on the length of the slot nozzle, and the length was approximately 100 m.

[0048] X-ray diffraction measurement was performed on the obtained Fe-based amorphous alloy ribbon to obtain an X-ray diffraction pattern. The X-ray source for X-ray diffraction measurement was Co-Ka (wavelength X = 0.17902 nm), and the scan range was 20 = 10° or more and 120° or less. From the shape of the X-ray diffraction pattern, it was determined whether or not a crystalline phase was formed in the metallographic structure.

[0049] The saturation magnetic flux density and iron loss of the Fe-based amorphous alloy ribbon were measured using a single strip tester (SST). Note that the iron loss measurement conditions are a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss measurement were collected from six locations over the total length of a ribbon from a single lot. Each sample for iron loss measurement was a ribbon sample cut into a length of 120 mm. These ribbon samples for iron loss measurement were annealed in a magnetic field (magnetic field: 800 A / m, magnetic field applied in casting direction) at 360°C for 1 hour and subjected to measurement. The atmosphere during annealing was a nitrogen atmosphere. On the other hand, the samples for the VSM were thin pieces collected from the center portion of the width of each of the ribbon samples from the six locations. 5

[0050] The measurement result for the saturation magnetic flux density and iron loss represents the average value of the data from six locations, as illustrated in Tables 1A and IB.

[0051] 10           Moreover, the critical bending diameter was measured for the Fe-based amorphous alloy ribbon. The critical bending diameter was measured by placing an Fe-based amorphous alloy ribbon in a bending tester in accordance with JIS Z 2248:2006 (Metallic materials-Bend test) and measuring the critical bending diameter at the point of fracture. Tables 1A and IB show the results. 15

[0052] [Table 1A] No. Chemical composition (balance: impurities) Saturation magnetic flux density Bs (T) Iron loss Wl3 / 50 (W / kg) Critical bending diameter (mm) Fe (atom%) B (atom%) Si (atom%) C (atom%) P (atom%) S (atom%) N (atom%) N / S Inventive Example 1 80.150 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.62 0.093 2 Inventive Example 2 81.465 13.8 3.2 1.50 0.020 0.007 0.0080 1.1 1.64 0.093 1 Inventive Example 3 81.022 13.2 4.0 0.80 0.960 0.006 0.0120 2.0 1.63 0.092 3 Inventive Example 4 82. 560 13.3 3.2 0.50 0.400 0.020 0.0200 1.0 1.65 0.094 3 Inventive Example 5 81.606 13.3 3.4 1.30 0.200 0.014 0.1800 12.9 1.64 0.094 2 Inventive Example 6 80.076 15.1 3.5 0.90 0.400 0.019 0.0050 0.3 1.62 0.094 3 Inventive Example 7 83.274 8.4 5.1 2.50 0.700 0.006 0.0200 3.3 1.66 0.097 3 Inventive 8 84.273 9.8 5.2 0.20 0.500 0.007 0.0200 2.9 1.66 0.096 2 Example Inventive Example 9 78.350 11.7 8.0 1.80 0.060 0.010 0.0800 8.0 1.60 0.098 2 Inventive Example 10 81.469 10.0 7.3 1.20 0.010 0.006 0.0150 2.5 1.63 0.097 1 Inventive Example 11 80.695 12.2 5.8 1.00 0.100 0.015 0.1900 12.7 1.62 0.098 2 Inventive Example 12 80.676 11.3 5.6 2.10 0.300 0.019 0.0050 0.3 1.62 0.098 3 Inventive Example 13 80.114 12.3 4.8 2.40 0.300 0.006 0.0800 13.3 1.62 0.099 1 Inventive Example 14 80.633 15.2 3.8 0.13 0.200 0.007 0.0300 4.29 1.63 0.092 2 Inventive Example 15 80.238 14.0 2.9 2.80 0.050 0.009 0.0030 0.33 1.62 0.093 2 Inventive Example 16 80.692 13.4 3.8 1.80 0.300 0.006 0.0020 0.33 1.62 0.093 4 Inventive Example 17 80.390 14.0 3.9 1.60 0.100 0.008 0.0020 0.25 1.62 0.092 4 Inventive Example 18 80.434 13.8 4.9 0.50 0.300 0.008 0.0580 7.25 1.62 0.094 2 Inventive Example 19 80.081 9.8 8.8 1.20 0.100 0.011 0.0080 0.73 1.62 0.097 3 Inventive Example 20 85.541 10.4 3.0 0.60 0.400 0.009 0.0500 5.56 1.67 0.096 3 Inventive Example 21 81.020 9.1 8.0 0.90 0.960 0.012 0.0080 0.67 1.62 0.098 4 Inventive Example 22 81.286 10.5 6.3 1.20 0.700 0.006 0.0080 1.33 1.63 0.097 3 Inventive Example 23 80.291 10.8 7.2 1.50 0.200 0.007 0.0020 0.29 1.61 0.097 4

[0053] [Table IB] No. Chemical composition (balance: impurities) Saturation magnetic flux density Bs (T) Iron loss Wl3 / 50 (W / kg) Critical bending diameter (mm) Fe (atom%) B (atom%) Si (atom%) C (atom%) P (atom%) S (atom%) N (atom%) 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 109 82.966 9.7 5.2 2.10 0.008 0.010 0.0160 1.6 1.66 0.110 2 Example 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 Underlined portions indicate that those fall outside the scope of the present invention.

[0054] As illustrated in Tables 1A and IB, in all inventive Examples 1 to 23, since the alloy composition satisfied the range of the present invention, the saturation magnetic 5 flux density was 1.60 T or higher, the iron loss (iron loss W13 / 50) at a magnetic flux density of 1.3 T and a frequency of 50 Hz was 0.100 W / kg or less, and a high saturation magnetic flux density and a low iron loss could be simultaneously exhibited. In addition, the critical bending diameter was 4 mm or less, and workability was also good.

[0055] 10           On the other hand, in each of Comparative Examples 101 to 115, since the alloy composition did not satisfy the range of the present invention, the iron loss (iron loss W13 / 50) was more than 0.100 W / kg, the saturation magnetic flux density was less than 1.60 T, or the critical bending diameter was more than 4 mm.

[0056] 15            That is, in Comparative Example 101, the Fe content was low, resulting in a saturation magnetic flux density of less than 1.60 T. In Comparative Example 102, the Fe content was excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In Comparative Example 103, the B content was low, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In Comparative Example 104, the B content was excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg.

[0058] In Comparative Example 105, the Si content was low, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In Comparative Example 106, the Si content was excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg.

[0059] In Comparative Example 107, the C content was low, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In Comparative Example 108, the C content was excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg.

[0060] In Comparative Example 109, the P content was low, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In Comparative Example 110, the P content was excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In addition, the critical bending diameter was more than 4 mm.

[0061] In Comparative Example 111, the S content was excessive, resulting in a critical bending diameter of more than 4 mm. In addition, the iron loss (iron loss W13 / 50) was more than 0.100 W / kg. In Comparative Example 112, the N content was low, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg. In addition, the critical bending diameter was more than 4 mm. In Comparative Example 113, the N content was excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg.

[0063] In Comparative Example 114, the S content was excessive, resulting in a critical bending diameter of more than 4 mm. In addition, the iron loss (iron loss W13 / 50) was more than 0.100 W / kg. In Comparative Example 115, the S content and the N content were excessive, resulting in an iron loss (iron loss W13 / 50) of more than 0.100 W / kg.

[0064] Note that, as a result of X-ray diffraction measurement performed on the Fe-based amorphous alloy ribbons, it cannot be said that a crystalline phase was formed in the metallographic structure in all Inventive Examples 1 to 23, and Comparative Examples 101 to 115 from the fact that a clear diffraction peak was not observed, and the entire structure was amorphous.

[0065] (Example 2) With respect to the alloys illustrated in No. 1 of Table 1A, the ribbons were cast using alloys having various components in which Fe was substituted in part with at least one of Ni, Cr, or Co under the same device and conditions as those in Example 1. Note that specific components of the used alloys are illustrated in the following table. As a result, the obtained ribbon had a sheet thickness, a sheet width, and a length of about 20 pm, 10 mm, and about 100 m, respectively. The saturation magnetic flux density, iron loss, and critical bending diameter of the obtained ribbon were evaluated. The sample collection method and measurement conditions used for these characterizations were the same as those in Example 1. The measurement results are shown in Table 2. Note that the display format in Table 2 is the same as in Tables 1A and IB. 5

[0066] [Table 2] No. Chemical composition (balance: impurities) Saturation magnetic flux density Bs (T) Iron loss W13 / 50 (W / kg) Critical bending diameter (mm) Fe (atom%) Ni (atom%) Cr (atom%) Co (atom%) B (atom%) Si (atom%) C (atom%) P (atom%) S (atom%) N (atom%) N / S Inventive Example 24 79.150 1.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.61 0.096 2 Inventive Example 25 77.150 3.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.61 0.096 2 Inventive Example 26 78.150 2.00 14.1 4.0 1.40 0.300 0.020 0.0300 1.5 1.64 0.094 2 Inventive Example 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 Inventive Example 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 Inventive Example 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 Inventive Example 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

[0067] As is clear from the results of samples 24 to 30 in Table 2, it was found that even in a case where Fe was substituted in part with at least one of Ni, Cr, or Co in a range of 10   10.0 atom% or less, the saturation magnetic flux density was 1.60 T or higher, and the iron loss W13 / 50 was stably maintained to 0.100 W / kg or less. In addition, the critical bending diameter was 4 mm or less, and workability was also good. Moreover, in any of the samples, no clear diffraction peak was observed in the X-ray diffraction measurement, and it was confirmed that the samples were amorphous. 15

[0068] As is clear from the above examples, it has been demonstrated that, according to the Fe-based amorphous alloy of the present invention, workability can be enhanced by optimizing the contents of B, Si, and C, further containing S, and further setting the content of Fe to 78.00% or more. It has also been demonstrated that an iron loss (iron loss W13 / 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 saturation magnetic flux density of 1.60 T or higher can be achieved, so that it is possible to exhibit excellent soft magnetic properties, and that the alloy can be suitably used for applications such as cores for a power transformer and a high-frequency transformer.

[0069] It has also been demonstrated that, according to the Fe-based amorphous alloy ribbon of the present invention, a critical bending diameter of 4 mm or less can be achieved. It has also been demonstrated that an iron loss (iron loss W13 / 50) of 0.100 W / kg or less and a saturation magnetic flux density of 1.60 T or higher can be achieved. As a result, it has also been demonstrated that, in a case where the Fe-based amorphous alloy ribbon is processed into a core for a power transformer or a high-frequency transformer, there is no risk of the alloy ribbon being damaged, so that it is possible to improve the productivity of cores for a power transformer and a high-frequency transformer. INDUSTRIAL APPLICABILITY

[0070] The Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present disclosure have high industrial applicability due to excellent workability.

Claims

1. An Fe-based amorphous alloy comprising, in atom%: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 0.020% or less; andN: 0.0010% or more and 0.2000% or less, whereinthe Fe-based amorphous alloy has a balance comprising impurities, and has an amorphous micro structure.

2. The Fe-based amorphous alloy according to claim 1 comprising Si: 2.0atom% or more and less than 5.0 atom%.

3. The Fe-based amorphous alloy according to claim 1 comprising N: 0.0030 atom% or more and 0.2000 atom% or less.

4. The Fe-based amorphous alloy according to claim 2 comprising N: 0.0030 atom% or more and 0.2000 atom% or less.

5. The Fe-based amorphous alloy according to claim 3, wherein a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less.

6. The Fe-based amorphous alloy according to claim 4, wherein a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less.

7. The Fe-based amorphous alloy according to claim 1 comprising B: 13.0 atom% or more and 18.0 atom% or less.

8. The Fe-based amorphous alloy according to claim 7 comprising Si: 2.0atom% or more and less than 5.0 atom%.

9. The Fe-based amorphous alloy according to claim 7 comprising N: 0.0030 atom% or more and 0.2000 atom% or less.

10. The Fe-based amorphous alloy according to claim 8 comprising N: 0.0030 atom% or more and 0.2000 atom% or less.

11. The Fe-based amorphous alloy according to claim 9, wherein a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less.

12. The Fe-based amorphous alloy according to claim 10, wherein a ratio of an N content to an S content (N / S) is 0.2 or more and 15 or less.

13. The Fe-based amorphous alloy according to any one of claims 1 to 12, wherein Fe is substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.

14. The Fe-based amorphous alloy according to any one of claims 1 to 12, wherein an iron loss W13 / 50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is 0.100 W / kg or less, and a saturation magnetic flux density is 1.60 T or higher.

15. An Fe-based amorphous alloy ribbon composed of the Fe-based amorphous alloy according to any one of claims 1 to 12.

16. The Fe-based amorphous alloy ribbon according to claim 15, wherein Fe is substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.

17. The Fe-based amorphous alloy ribbon according to claim 15, wherein an iron loss W13 / 50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is 0.100 W / kg or less, and a saturation magnetic flux density is 1.60 T or higher.

18. The Fe-based amorphous alloy ribbon according to claim 15, wherein a critical bending diameter is 4 mm or less.