JP2018144084A - Method for producing ferrous boron-based alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a ferrous boron-based alloy excellent in mass productivity and moldability.SOLUTION: Provided is a method for producing a ferrous boron based alloy where, upon the production of a rapidly solidified alloy where an alloy molten metal essentially consisting of iron and boron is rapidly cooled on the surface of a cooling roll made of a metal rotating at a roll surface speed of 10 to 100 m/sec, a tap nozzle whose bottom part is disposed with column multiorifices in which a plurality of orifices having an orifice diameter of Φ0.6 mm or higher to below Φ2.0 mm in 2 to 4 holes are arranged by one line or more on one straight along the rotary direction of a cooling roll at the bottom is used.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing an iron-based boron alloy.

  In recent years, materials with low iron loss and high saturation magnetic flux density have been demanded from the market for noise filters and transformer materials used as electronic parts, and iron-based amorphous materials as soft magnetic materials with high magnetic permeability and low iron loss. Also, iron-based amorphous alloy ribbons with a thickness of 17 μm to 22 μm, which are produced by rapid solidification of molten iron, which is also made of iron, boron, silicon, etc., which are also called iron-based nanocrystalline materials, are high-placing conventional silicon steel plates. As a high-efficiency soft magnetic material, it is used as a wound core for large transformers, and the demand is growing year by year.

  Also, crystallization heat treatment of flaky quenched alloy ribbons with a thickness of around 20μm obtained by rapid solidification of the molten alloy mainly composed of iron, boron and neodymium (a kind of rare earth element) as the iron base material. Then, it is pulverized into isotropic rare earth iron-based boron-based magnetic powder, mixed and kneaded with resin, and then molded isotropic bonded magnets are applied to various electronic industrial product fields such as DC small motors and various sensors. Has been.

According to Non-Patent Document 1, an iron-based boron silicon-based amorphous alloy conventionally has an amorphous structure unless it is a rapidly solidified alloy ribbon having a thickness of 17 μm to 22 μm at a rapid solidification rate of 10 ⁴ to 10 ⁶ K / sec. Although it was not obtained, it has been disclosed that the addition of phosphorus reduces the rapid solidification rate and an iron-based amorphous alloy ribbon having a thickness of 50 μm or more can be obtained. However, the addition of phosphorus causes a decrease in the saturation magnetic flux density Bs. In addition, phosphorus-added alloys have few applications in the industrial field because the phosphorus component is volatilized when the alloy is melted and the contamination in the furnace is significant.

Non-Patent Document 2 discloses a method for directly obtaining an iron-based amorphous alloy powder by a novel improved water atomization method. However, since the wet process combines gas atomization method and cooling by high-speed water flow, a dry process is disclosed. Compared with the single-roll liquid quenching method that can be made amorphous, the yield is reduced due to the addition of a powder drying process, and the amount that can be dissolved and discharged at a time is limited to about 300 kg / batch at the maximum because of the atomization method, improving production efficiency. This is a hindrance to cost reduction and is limited to application fields where the soft magnetic performance of the iron-based amorphous alloy powder is indispensable. Furthermore, since Si in the molten alloy during rapid solidification is preferentially oxidized prior to Fe and forms SiO ₂ on the powder surface, a part of Si, which is an essential element for obtaining soft magnetic properties, is taken away as an oxide. In addition, in order to reduce oxidation, it is necessary to devise such as adding Cr that causes a decrease in magnetic flux density. In addition, in the hard magnetic iron-based boron-based alloy composition containing rare earth elements that are active against oxygen, the rare earth component generates RE ₂ O ₃ by oxidation, so hard magnetic properties (permanent magnet properties) cannot be obtained. It is limited to an alloy composition system of less.

Patent Document 1, Patent Document 2 and Patent Document 3 describe a method for producing a quenched alloy ribbon having a thickness of 50 μm or more. In any case, the molten alloy discharged from the slit nozzle is rapidly cooled and solidified by a cooling roll. By doing so, it provides a rapidly quenched alloy of a strip material to be applied to a wound iron core, a stacked iron core, etc., and is not suitable for application to an iron-based soft magnetic powder for a dust core or the like.
In addition, it is not easy to accurately process a slit width of 0.4 mm as described in Examples of Patent Document 1, Patent Document 2, and Patent Document 3, and in parallel with two rows and three rows. Since it is more difficult to slit, there is a problem that, when a hot water nozzle made of BN material is adopted, the cost of slitting is higher than that of the nozzle body, and the cost of consumables during the rapid solidification of the molten metal increases.

  In Patent Document 4, a plurality of openings are arranged on a moving cooling substrate (rotating cooling roll) at a substantially right angle to the moving direction, and each has an angle of 10 to 80 ° with respect to the moving direction. Although a method for producing a metal ribbon is disclosed in which molten metal is ejected from a (perforated nozzle) and rapidly solidified, this Patent Document 5 discloses a width direction when producing a wide quench ribbon. The invention was made for the purpose of reducing the thickness variation of the metal ribbons in the production of iron-based boron-based alloys suitable for producing powders that are excellent in production efficiency and excellent in formability by grinding. Not suitable. Further, it is difficult to process a plurality of elongated parallelogram, trapezoidal, or elliptical openings having an angle of 10 to 80 °, and there is a problem that the nozzle processing cost increases.

In Patent Document 5, the average thickness is increased by increasing the (B + C) concentration by 10 atomic% or more and increasing the amorphous formation ability, and by suppressing the precipitation of the Nd ₂ Fe ₂₃ B ₃ phase, which is a nonmagnetic phase, by adding Ti. In addition to obtaining a hard magnetic alloy composed of the Nd ₂ Fe ₁₄ B phase, which has excellent performance as a permanent magnet, even if it is a rapidly solidified alloy with a thickness of more than 40 μm and 90 μm or less, a rapid solidification with an average thickness of more than 40 μm and 90 μm or less Although it is disclosed that an isotropic bonded magnet magnetic powder with excellent formability can be obtained by using an alloy, the (B + C) concentration is limited to 10 atomic percent or more and less than 20 atomic percent, Nd ₂ not only does not provide high Br type hard magnetic powder (permanent magnet powder) with a residual magnetic flux density Br of 0.9T or higher, which is expected for DC brushless motors, etc., but also plays a role in hard magnetism due to its boron-rich composition. automatic the ratio of total metal structure Fe ₁₄ B phase is limited to 80 vol% Intrinsic coercive force HcJ ≧ 800 kA / m to applications directed is expected, it is difficult to produce a maximum energy product (BH) max ≧ 120kJ / m 3 of the hard magnetic alloy permanent magnet properties are obtained (permanent magnets).

JP-A-5-329587 JP-A-7-113151 JP-A-8-124731 JP 63-220950 A Japanese Patent Application 2002-140236

Creation of new bulk metallic glass / amorphous thick plate with high saturation magnetic flux density (Tohoku University, Metallic Glass Research Center) Akihiro Makino, Ken Kubota, Kei Tsuneharu Production of amorphous soft magnetic powder by new water atomization method (SWAP method) (Kubota, Kubota Technology Development Laboratory Co., Ltd.) Isao Endo, etc.

  Iron-based boron-based alloys produced by a rapid solidification method of a molten metal that rapidly cools the molten alloy with a rotating metal cooling roll, regardless of whether it is a soft magnetic alloy or a hard magnetic alloy. Conventionally, relaxation of the rapid solidification rate by adjusting the alloy composition has been used as the main method to ensure this, but this method causes a decrease in soft magnetic properties and high magnetic properties, or there is a problem in productivity. The production method of iron-based boron-based alloys with high productivity and excellent powder formability that can reduce the production cost regardless of the alloy composition is stronger than the electronic parts market such as various passive elements, motors, sensors, etc. It is desired.

  Iron-based boron-based alloy compositions with boron-rich compositions and iron-based boron-based alloy compositions with added elements that increase the ability to form amorphous elements such as phosphorus, such as Nb, Zr, and V. And impedes the high performance of iron-based hard magnetic powder. However, when trying to increase the average hot water rate during rapid solidification without increasing the compositional measures such as the above-mentioned additive elements to increase productivity, α-Fe, which leads to a decrease in magnetic properties, precipitates in the structure of the rapidly solidified alloy. The additive element that suppresses the precipitation of -Fe is required. Also, to obtain a rapidly solidified alloy with a thickness of 40 μm or more that can obtain magnetic powder with excellent formability by grinding, it is necessary to reduce the roll surface speed of the cooling roll, but if the roll surface speed is reduced, the average As with increasing the tapping rate, α-Fe precipitates in the structure of the rapidly solidified alloy, and it is not possible to obtain an iron-based boron-based quenched alloy that exhibits good magnetic performance.

  Therefore, an object of the present invention is to provide a method for producing an iron-based boron-based alloy having excellent mass productivity and formability.

  The method for producing an iron-based boron-based alloy according to the present invention comprises preparing a molten alloy containing iron and boron as essential elements, and on the surface of a metallic cooling roll rotating at a roll surface speed of 5 m / sec to 100 m / sec. When preparing a rapidly solidified alloy that rapidly cools the molten alloy, a plurality of orifices with an orifice diameter of Φ0.6 mm or more and less than Φ2.0 mm and having two or more holes and less than 4 holes are aligned in a line along the rotation direction of the cooling roll. Using a hot water discharge nozzle having a vertical multi-orifice at the bottom, the distance between the hot water nozzle and the cooling roll is set to 0.16 mm or more and less than 20 mm, and the average hot water per unit time from the single row of multi-orifice A rapidly solidified alloy having an average thickness of 40 μm or more and less than 160 μm is manufactured by ejecting the molten alloy from the hot water nozzle to the surface of the cooling roll at a rate of 0.6 g / min or more and 6 kg / min.

In the method for producing an iron-based boron-based alloy according to the present invention, the composition of the molten alloy has a composition formula T _loo-x-yz-n Q _x Si _y RE _z M _n (T is Fe, Co and Ni). At least one element selected from the group, which is a transition metal element that always contains Fe, Q is one or more elements that are selected from the group consisting of B and C, and must always contain B, RE is a rare earth element, M is One or more elements selected from the group consisting of P, Al, Ti, V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au, and Pb) The composition ratios x, y, z, and n satisfy 5 ≦ x <20 atomic%, 0 ≦ y <15 atomic%, 0 ≦ z <16 atomic%, and 0 ≦ n <10 atomic%, respectively. It is preferable to do.

  In the method for producing an iron-based boron-based alloy according to the present invention, it is preferable that an interval D in the alignment direction of each orifice in the tandem multi-orifice is 0.2 mm or more and less than 10 mm.

  In the method for producing an iron-based boron-based alloy according to the present invention, it is preferable that the column multi-orifice has a plurality of orifices, and an interval E between adjacent rows is 3 mm or more.

  In the method for producing an iron-based boron-based alloy according to the present invention, it is preferable that a tapping pressure of the molten metal ejected from the tapping nozzle is 2 kPa or more and less than 60 kPa.

Alternatively, the method for producing an iron-based boron-based alloy according to the present invention includes a composition formula T _loo-x-yz-n Q _x Si _y RE _z M _n ( T is at least one element selected from the group consisting of Fe, Co, and Ni, and is a transition metal element that always contains Fe, and Q is at least one element that is selected from the group consisting of B and C and must always contain B Element, RE is rare earth element, M is P, Al, Ti, V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au, and Pb One or more selected elements), and the composition ratios x, y, z and n are respectively 5 ≦ x <10 atomic%, 0 ≦ y <15 atomic%, 3 ≦ z <16 atomic%, A rapidly solidified alloy is prepared by preparing a molten alloy having a composition satisfying 0 ≦ n <10 atomic% and rapidly cooling the molten alloy on the surface of a metallic cooling roll rotating at a roll surface speed of 10 m / sec to 100 m / sec. Made A tapping nozzle with a multi-orifice at the bottom that has multiple orifices with a diameter of Φ0.6 mm or more and less than Φ2.0 mm, with two or more holes and less than 4 holes aligned in a line along the rotation direction of the cooling roll. And the distance between the hot water nozzle and the cooling roll is set to 0.16 mm or more and less than 20 mm, and the average hot water discharge rate per unit time from the single row of multi-orifice is set to 0.6 g / min or more and 6 kg / min. By jetting the molten alloy from the hot water nozzle onto the surface of the cooling roll, the average thickness of the crystal phase including the RE ₂ Fe ₁₄ B phase in the range of 1% by volume to less than 95% by volume and the balance being amorphous is 40 μm. It is characterized by producing a rapidly solidified alloy having a thickness of less than 160 μm.

  The method for producing an iron-based boron-based alloy according to the present invention includes a material for the cooling roll, copper or an alloy containing copper as a main component, an alloy containing Mo or Mo as a main component, or an alloy containing W or W as a main component. In addition, it is preferable that the roll surface has an arithmetic average roughness Ra of 1 nm or more and less than 10 μm.

The iron-based boron-based alloy manufactured by the above-described iron-based boron-based alloy manufacturing method is heat-treated at a constant temperature of 150 ° C. or more and less than 900 ° C., and then pulverized to an average powder particle size of 20 μm or more and less than 200 μm, An iron-based boron-based alloy powder having a tap density of 4.0 g / cm ³ or more can be obtained.

  According to the present invention, it is possible to provide a method for producing an iron-based boron-based alloy that is excellent in mass productivity and formability.

  According to the present invention, an iron-based boron-based alloy melt containing iron and boron as essential elements is rapidly cooled on a metal cooling roll surface rotating at a roll surface speed of 10 m / sec to 100 m / sec. In this case, a hot water discharge nozzle provided with a multi-orifice at the bottom of which a plurality of orifices having an orifice diameter of Φ0.6 mm or more and less than Φ2.0 mm and having two or more holes and less than 4 holes arranged in a straight line along the rotation direction of the cooling roll is arranged at the bottom. Using a single roll rapid solidification method (commonly known as melt spinning method) that uses a single-hole hot water discharge nozzle without reducing the rapid solidification rate at the same roll surface speed, a hot water discharge nozzle with an orifice diameter of Φ1 mm or less Can achieve a high tapping rate exceeding 0.5 g / min per unit time, and by arranging multiple rows of multi-strands, the productivity can be further increased. Solidification method can be realized.

  In addition, an iron-based boron-based alloy having a thickness of 40 μm or more and less than 160 μm can be obtained by using a tapping nozzle adopting a tandem multi-orifice. The iron-based boron-based alloy has an average powder particle size of 20 μm or more and less than 200 μm. It is possible to produce an alloy powder having an excellent formability with a tap density of 4.0 g / cm 3 or more by pulverizing.

  In addition, circular orifices that can be easily machined with a drilling machine or the like can greatly reduce machining costs compared to parallelogram, trapezoidal, triangular, and elliptical orifices and slit hot water nozzles.

The present invention mainly aims to reduce the cost of the rapid solidification process aiming to expand the application field of high-performance iron-based soft magnetic powder and iron-based hard magnetic powder to general-purpose applications, leading to a decrease in magnetic performance. Even if the average hot water discharge rate per unit time is greatly improved, α-Fe does not precipitate, and a rapidly solidified alloy consisting of an amorphous structure can be realized regardless of the alloy composition measures, and the average thickness is 40 μm. After obtaining an iron-based boron-based alloy characterized by being less than 160 μm, it is pulverized and excellent in formability to obtain a tap density of 4.0 g / cm ³ or more by pulverizing to an average powder particle size of 20 μm or more and less than 200 μm An iron-based boron-based alloy powder can be provided.

(A) is sectional drawing which shows the example of whole structure of the apparatus used when manufacturing the rapid solidification alloy applied to the iron-based boron series alloy of the alloy composition containing the rare earth elements by this invention, (b) is rapid solidification FIG. (C) is an enlarged view of the bottom surface of the hot water nozzle and shows the arrangement of the tandem multi-orifice. (A) is an enlarged view of a portion where rapid solidification is performed in a conventional single-roll molten metal rapid solidification method. (B) is an enlarged view of the bottom surface of the tap nozzle in the conventional single roll molten metal rapid solidification method. 2 is a powder X-ray diffraction profile of a rapidly solidified alloy obtained in Example 1. FIG. 3 is a powder X-ray diffraction profile of a rapidly solidified alloy obtained in Comparative Example 13.

  The molten metal ejected from the conventional single-hole tap nozzle forms a puddle with the same width as the hole diameter on the surface of the chill roll to a hole diameter x 2 times, and the width of this puddle is a rapidly solidified alloy ribbon. Therefore, the inventor increases the thickness of the rapidly solidified alloy ribbon by increasing the thickness of the stacked pool by arranging a plurality of holes on a straight line along the rotation direction of the roll. As a result of investigating manufacturing conditions that can increase the rate of hot water per hour at the same time, the thickness of the rapidly solidified alloy ribbon can be increased by stacking hot water pools that could only be achieved with a slit-type hot water nozzle. In a multi-orifice in which multiple orifices with 2 holes or more but less than 4 holes are aligned in a line along the rotation direction of the cooling roll, the orifice diameter is Φ0.6 mm or more and less than Φ2.0. of The distance D is set to 0.2 mm or more and less than 10 mm, and the distance between the hot water nozzle and the cooling roll is set to 0.15 mm or more and less than 20 mm, so that the puddle made of the molten metal ejected from each hole arranged in a straight line is the same as the hole diameter. Rapid solidification without overlapping of α-Fe with an average thickness of 40 μm or more and less than 160 μm and with a width of 0.6 mm to 4 mm that is easy to pulverize without overlapping using a slit nozzle. It has been found that an alloy ribbon can be obtained.

  Furthermore, when increasing the row hot water rate of the multi-columns of the multi-columns, the puddle formed by the molten metal ejected from the adjacent multi-strands is brought into contact by setting the row interval E between the multi-strands to 3 mm or more. Without the need to know, that it is easy to pulverize to produce multiple rows of rapidly solidified alloy ribbons with a width of about 0.6mm to 4mm, the average hot water discharge rate per unit time is 0.6g / min to 6kg / min Multiple rows of multi-orifices can be arranged, and a production method has been realized that can multiply the average hot water discharge rate per unit time from 0.6 g / min to 6 kg / min.

The iron-based boron-based alloy obtained by the production method according to the present invention is an iron-based boron-based alloy in which iron and boron are essential, and the composition formula T _loo-x-yz-n Q _x Si _y RE _z M _n (T is at least one element selected from the group consisting of Fe, Co, and Ni, and is a transition metal element that always contains Fe, and Q is one or more elements that are selected from the group consisting of B and C and always contain B) Element, RE is rare earth element, M is P, Al, Ti, V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au and Pb The composition ratio x, y, z, and n are 5 ≦ x <20 atomic%, 0 ≦ y <15 atomic%, and 0 ≦ z <16 atomic%, respectively. 0 ≦ n <10 atomic% is satisfied.

The iron-based boron-based alloy obtained by the production method according to the present invention is an iron-based boron-based alloy in which iron and boron are essential, and the composition formula T _loo-x-yz-n Q _x Si _y RE _z M _n (T is at least one element selected from the group consisting of Fe, Co, and Ni, and is a transition metal element that always contains Fe, and Q is one or more elements that are selected from the group consisting of B and C and always contain B) Element, RE is rare earth element, M is P, Al, Ti, V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au and Pb The composition ratio x, y, z, and n are 5 ≦ x <10 atomic%, 0 ≦ y <15 atomic%, and 3 ≦ z <16 atomic%, respectively. 0 ≦ n <10 atomic% is satisfied.

  Hereinafter, preferred embodiments of the present invention will be described.

[Alloy composition]
The transition metal T containing Fe as an essential element occupies the remaining content of the above elements. Even if a part of Fe is replaced with one or two of Co and Ni which are ferromagnetic elements like Fe, desired hard magnetic properties can be obtained. However, if the substitution amount with respect to Fe exceeds 30%, the magnetic flux density is significantly reduced, so the substitution amount is limited to a range of 0% to 30%.

When the composition ratio x of Q (= B + C) is less than 5 atomic%, the ability to form amorphous material is greatly reduced, and α-Fe precipitates during the rapid solidification of the melt. A high-performance soft magnetic material cannot be obtained. In the case of a hard magnetic composition containing rare earth elements, the residual magnetic flux density Br is lowered and a high-performance hard magnetic material cannot be obtained.
In the case of a soft magnetic composition, if the composition ratio x exceeds 20 atomic%, the Fe component ratio decreases, leading to a decrease in magnetic flux density, making it difficult to obtain a high-performance soft magnetic material. In the case of a hard magnetic material containing rare earth elements, if the composition ratio x exceeds 10 atomic%, the abundance ratio of the RE ₂ Fe ₁₄ B phase responsible for the hard magnetic characteristics decreases, leading to a decrease in hard magnetic characteristics. Therefore, in the case of a soft magnetic composition, the composition ratio x is in the range of 5 atomic% to less than 20 atomic%, and the composition ratio x is preferably 7 atomic% to less than 19 atomic%, and is preferably 8 atomic% to 19 atomic%. More preferably, it is less than. In addition, in the case of a hard magnetic composition containing rare earth elements, the composition ratio x is in the range of 5 atomic% or more and less than 10 atomic%, and the composition ratio x is preferably 5.5 atomic% or more and less than 10 atomic%, preferably 5.5 atomic% or more. More preferably, it is less than 9 atomic%.

  When the substitution rate of C for B in Q increases, the melting point of the molten alloy decreases, and the amount of refractory used during rapid solidification decreases, so the process cost for rapid solidification can be reduced. If it exceeds 50%, the amorphous forming ability is greatly reduced, which is not preferable, and the substitution rate is limited to 0% to 50%. Preferably it is 0% to 30%, more preferably 0% to 20%.

  In the present invention, Si is effective as an element that improves the amorphous forming ability by simultaneously adding Fe and B and increases the magnetic permeability of the iron-based boron-based rapidly solidified alloy, but the addition amount of Si is 15 atomic%. If the value exceeds 1, the saturation magnetic flux density Bs is significantly reduced. Further, in the case of an iron-based boron-based rapidly solidified alloy that does not contain a rare earth element RE and exhibits soft magnetism, y is preferably 2 atomic percent or more and less than 15 atomic percent from the viewpoint of improving the magnetic permeability. More preferably, it is 2.5 atomic% or more and less than 12 atomic%.

  In the present invention, 1 selected from the group consisting of P, Al, Ti, V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au, and Pb You may add the additional element M more than a seed | species. This additive element not only improves productivity during rapid solidification, but also improves the productivity of amorphous formation, refinement of rapidly solidified metal structure, etc., and in the case of hard magnetic compositions containing rare earths, the demagnetization curve Improves squareness and coercivity HcJ. However, if the addition amount of these elements M exceeds 10 atomic%, the magnetization is reduced, so the composition ratio n of M is limited to 0 atomic% or more and less than 10 atomic%, and the composition ratio n is 0 atomic% or more. It is preferably less than 7 atomic%, and the composition ratio n is more preferably 0 atomic% or more and less than 5 atomic%.

In the case of an iron-based boron-based alloy having hard magnetism containing a rare earth element, the rare earth element RE is one or more rare earth metals substantially free of La and Ce. When the RE composition ratio y is less than 3 atomic%, the existence ratio of the RE ₂ Fe ₁₄ B phase, which is responsible for the hard magnetic properties, is significantly reduced, so that an intrinsic coercive force HcJ exceeding 200 kA / m cannot be obtained, and a practically usable hard It is not a magnetic material (permanent magnet). In addition, when the RE composition ratio y exceeds 16 atomic%, the entire grain boundary phase of the RE ₂ Fe ₁₄ B phase is occupied by a very active RE-rich phase with respect to oxygen. It is assumed that the composition ratio y of RE is limited to a range of 3 atomic% or more and less than 16 atomic% because there is a risk of ignition / explosion and the corrosion resistance of the powder itself is remarkably deteriorated so that the hard magnetic characteristics are deteriorated with time. The composition ratio y is preferably 4 atom% or more and 15 atom%, and more preferably 6 atom% or more and less than 14 atom%.

[Rapid solidification equipment for molten alloy]
According to a preferred embodiment of the present invention, the molten alloy is brought into contact with the surface of a metal cooling roll that rotates at high speed, thereby removing heat from the molten alloy and rapidly solidifying it. In order to bring an appropriate amount of molten alloy into contact with the surface of the chill roll, a plurality of orifices with an orifice diameter of Φ0.6 mm or more and less than Φ2.0 mm that are 2 holes or more and less than 4 holes are aligned along the rotation direction of the chill roll. 1mm or less in conventional single roll rapid solidification method using a single hole hot water discharge nozzle without reducing the rapid solidification rate at the same roll surface speed by using a hot water discharge nozzle arranged at the bottom of one or more rows of multi-orifices arranged in a row A high tapping rate exceeding 0.5 g / min per unit time obtained with a tapping nozzle with an orifice diameter of 5 mm / min can be realized, but the orifice diameter affects the feed rate of the molten metal supplied to the roll surface. Φ0.6mm or more and less than Φ2.0 is good, and when Φ0.6mm or less, the molten metal supply rate per orifice is 0.1kg / min or less, and the hot water nozzle with 4-hole tandem multi-orifice is arranged. However, the total amount is about 0.4 kg / min, not only the productivity of the rapid solidification process is very bad, but also causes nozzle clogging. When Φ2.0 or more, the molten metal supply rate per orifice hole is 1500 g / min or more. Since the hot water pool is not formed on the roll, it becomes a droplet (splash) and a rapidly solidified alloy ribbon is not formed, so rapid solidification that can generate an amorphous structure cannot be achieved, so the orifice diameter is Φ0.6 mm or more and Φ2.0 mm Limited to less than. The orifice diameter is preferably Φ0.7 mm or more and less than Φ1.8 mm, and more preferably Φ0.7 mm or more and less than Φ1.5 mm.

  The number of holes in the tandem multi-orifice depends on the thickness of the rapidly solidified alloy, and one hole cannot obtain the thickness of the rapidly solidified alloy with an average thickness of 40 μm or more, so two or more holes are required. Since the thickness of the alloy is 160 μm or more and a rapid solidification rate capable of generating an amorphous structure cannot be achieved, the number is limited to 2 or more and less than 4 holes.

  When the molten alloy is ejected onto the surface of the cooling roll through the hot water nozzle provided at the bottom of the multi-orifice, the distance between the hot water nozzle and the cooling roll is 160 μm (0.16 mm). ) If it is not set above, the bottom of the hot water nozzle and the rapidly solidified alloy ribbon will interfere with each other, so it is limited to 0.16mm or more. In addition, when the distance between the hot water nozzle and the cooling roll exceeds 20 mm, the molten metal ejected from each of the orifices arranged in tandem fluctuates and receives cooling by the entrainment wind of the rotating cooling roll. The position is limited to less than 20 mm because a rapidly solidified alloy ribbon having an average thickness of 40 μm or more and less than 160 μm cannot be obtained. The thickness is preferably 0.2 mm or more and less than 10 mm, more preferably 0.3 mm or more and less than 5 mm.

  Since the orifices arranged in tandem at the lower part of the hot water nozzle affect the straightness of the molten alloy that is ejected, the molten metal is injected perpendicularly to the roll surface, and the adhesiveness of the molten alloy is increased and stabilized. Since the molten metal can be maintained in a rapidly solidified state, the orifice length should be 0.5 mm or more and less than 30 mm. If the orifice length is less than 0.5 mm, straightness of molten metal injection cannot be obtained, and rapid solidification on the roll surface becomes unstable. On the other hand, when the orifice length is 30 mm or more, the molten alloy solidifies while passing through the orifice and causes nozzle clogging. The orifice length is preferably 0.7 mm or more and less than 20 mm.

  When the distance D between the orifices in the tandem multi-orifice shown in (c) of FIG. 1 is 0.2 mm or less, the molten metal ejected from each orifice comes into contact before reaching the cooling roll, and the average thickness is 40 μm or more and less than 160 μm. The rapidly solidified alloy ribbon cannot be obtained. In addition, when D is 10 mm or more, molten metal is ejected from each orifice, and the puddles formed on the surface of the cooling roll cannot overlap, so that a rapidly solidified alloy ribbon with an average thickness of 40 μm or more and less than 160 μm is obtained. Absent. D is preferably 0.5 mm or more and 8 mm or less, and more preferably 1 mm or more and less than 6 mm.

  As shown in FIG. 1 (c), it is possible to further increase the tapping rate by arranging a plurality of column multi-orifices, but if the column interval E between the column multi-orifices is within 3 mm, adjacent column multi-orifices Limit to 3 mm or more because the hot water pool formed by the molten metal spouted from E is preferably 5 mm or more, more preferably 7 mm or more in consideration of the heat removal property of the cooling roll. However, if E is too large, a larger number of tandem multi-orifices cannot be arranged, so that it is preferably 20 mm or less, and more preferably 15 mm or less.

  After the molten alloy supplied to the surface of the cooling roll is cooled by the cooling roll, the alloy melt is separated from the surface of the cooling port, and a ribbon-like rapidly solidified alloy is formed.

  In the present invention, in the case of an iron-based boron-based rapidly solidified alloy containing a rare earth element that is very easily oxidized, it is important to prevent oxidation of the molten alloy during melting of the alloy and during rapid solidification of the molten alloy. A rapidly solidified alloy is produced using the quenching apparatus shown in FIG.

  In order to prevent oxidation of the molten alloy, the quenching apparatus shown in FIG. 1 is evacuated to 20 Pa or less, preferably 10 Pa or less, more preferably 1 Pa or less, and then an inert gas is introduced to an absolute pressure of 10 kPa to 101.3 kPa. It is necessary to set the oxygen concentration in the rapid cooling apparatus to 500 ppm or less, preferably 200 ppm or less, and more preferably 100 ppm or less, and then perform a process for producing a rapidly solidified alloy. As the inert gas, a rare gas such as helium or argon or nitrogen can be used. However, since nitrogen relatively easily reacts with rare earth elements and iron, it is preferable to use a rare gas such as helium or argon.

  The apparatus shown in FIG. 1 includes a melting chamber 1 and a quenching chamber 2 for a raw material alloy that can maintain a vacuum or an inert gas atmosphere and adjust the pressure. FIG. 1A is an overall configuration diagram, and FIG. 1B is an enlarged view of a portion where rapid solidification is performed.

  As shown in FIG. 1 (a), the melting chamber 1 has a melting furnace 3 for melting a raw material 20 blended so as to have a desired alloy composition at a high temperature, and a hot water storage container 4 having a hot water discharge nozzle 5 at the bottom. A blended material supply device 8 is provided for feeding the blended material into the melting furnace 3 while suppressing the entry of air. The hot water storage container 4 stores a molten alloy 21 of a raw material alloy. The quenching chamber 2 includes a rotary cooling roll 7 for rapidly cooling and solidifying the molten metal 21 discharged from the hot water nozzle 5.

  In this apparatus, the atmosphere in the melting chamber 1 and the quenching chamber 2 and the pressure thereof are controlled within a predetermined range. Therefore, the atmospheric gas supply ports lb, 2b and 8b and the gas exhaust ports la, 2a. And 8a are provided at appropriate places in the apparatus.

  The melting furnace 3 can be tilted, and the molten metal 21 is appropriately poured into the hot water storage container 4 through the funnel 6. The molten metal 21 is heated in the hot water storage container 4 by a heating device (not shown). The hot water discharge nozzle 5 of the hot water storage container 4 is disposed in the partition wall between the melting chamber 1 and the quenching chamber 2 and ejects the molten metal 21 in the hot water storage container 4 onto the surface of the cooling roll 7 positioned below.

  In a preferred embodiment, the cooling roll 7 has a copper or copper-based alloy, Mo or Mo as a main component, which is excellent in thermal conductivity and durability, as a material of the cooling roll in producing the iron-based boron-based alloy. Or an alloy mainly composed of W or W is used. Furthermore, it is preferable that the arithmetic average roughness Ra of the roll surface is 1 nm or more and less than 10 μm, because the adhesion between the hot water pool and the roll surface is improved, and the molten metal quenching ability by the cooling roll is increased. Ra is preferably 1 nm or more and less than 1 μm, and more preferably 1 nm or more and less than 700 nm.

  The diameter of the cooling roll 7 is, for example, Φ200 mm to Φ1000 mm. When the cooling roll 7 is water-cooled, the water-cooling capacity of the water-cooling device provided in the cooling roll is calculated according to the solidification latent heat per unit time and the amount of hot water to be adjusted appropriately. Is done.

[Rapid cooling process]
First, a raw material alloy melt 21 expressed by the above-described composition formula is prepared and stored in the hot water storage container 4 of the melting chamber 1 of FIG. Next, after the molten metal 21 is ejected from a hot water nozzle having an orifice at the bottom on a cooling roll 7 rotating in an inert gas atmosphere from the hot water nozzle 5, the molten alloy is rapidly cooled by contact with the cooling roll. And then solidify.

  When the single roll quenching method is employed as the molten metal rapid solidification method as shown in FIG. 1, the cooling rate of the molten alloy is controlled by the roll surface speed of the cooling roll and the rate of hot water supplied per unit time supplied to the roll surface. It is possible. Moreover, when it has the structure where the temperature of a cooling roll can be adjusted with water cooling, the cooling rate of a molten alloy is controllable also with the flow volume of the cooling water which flows in a cooling roll. For this reason, it is possible to control the rapid solidification rate of the molten alloy by adjusting at least one of the roll surface speed, the amount of hot water and the flow rate of cooling water as required.

In the single roll melt rapid solidification method employed in the present invention, the melt rapid solidification rate can be easily changed by the roll surface speed, for example, 5 × 10 ⁻⁴ ° C./sec at a roll surface speed of 10 m / sec. The rapid solidification rate before and after is obtained, and at 50 m / sec, the rapid solidification rate of 10 ⁻⁶ ° C / sec or more can be reached from the latter half of 10 ⁻⁵ ° C / sec. The roll surface speed of the chill roll made of either the copper or copper-based alloy of the previous period, Mo or Mo-based alloy, or W or W-based alloy as the main raw material is 10 m. / sec or more and less than 100m / sec is good. If it is less than 10 m / sec, the rapid solidification rate of the molten metal is slow and a rapidly cooled alloy structure consisting of coarse crystal grains is obtained, and good soft magnetic properties and hard magnetic properties cannot be obtained. In addition, at 100 m / sec or more, the molten metal spouted from the nozzle orifice is solidified due to the entrainment wind caused by high-speed rotation, so that the puddle formed on the roll surface does not adhere to the roll surface and the molten metal cannot be rapidly cooled. . A preferable roll surface speed is 12 m / sec or more and less than 70 m / sec, and a more preferable roll surface speed is 14 m / sec or more and less than 60 m / sec.

The time for which the molten alloy 21 is cooled by the cooling roll 7 corresponds to the time from when the alloy comes into contact with the outer peripheral surface of the rotating cooling roll 7 until it leaves, during which the temperature of the alloy decreases and the supercooling liquid It becomes a state. Thereafter, the supercooled alloy leaves the cooling roll 7 and flies through the inert gas atmosphere. While the alloy is in the form of a ribbon, the temperature is further reduced as a result of the heat being taken away by the atmospheric gas. The absolute pressure of the atmospheric gas is preferably set in the range of 10 kPa to 101.3 kPa (normal pressure).
Note that in the case of a soft magnetic iron-based boron-based alloy containing no rare earth element, it is not always necessary to have an inert gas atmosphere, and the molten metal solidification and quenching may be performed in the atmosphere.

[Heat treatment]
In a preferred embodiment, the strain in the alloy can be removed and crystallized by heat-treating the iron-based boron-based alloy or the iron-based boron alloy at a constant temperature of 150 ° C. or higher and lower than 900 ° C.
In the case of strain removal, it is preferably 550 ° C. or lower which is lower than the crystallization temperature of the amorphous phase. 500 ° C. or lower is more preferable. For the purpose of crystallization of the amorphous phase, it is preferable to perform a heat treatment at a temperature of 550 ° C. or higher and lower than 900 ° C. More preferably, it is 600 ° C. or more and 800 ° C. or less, and further preferably 600 ° C. or more and 750 ° C. or less. Regarding the heat treatment atmosphere, heat treatment in a vacuum or an inert gas is preferable in the case of an alloy composition containing a rare earth element, and heat treatment in the atmosphere is also allowed in the case of an alloy composition not containing a rare earth element.

[Crushing]
An iron-based boron-based alloy powder excellent in formability having a tap density of 4.0 g / cm ³ or more obtained by grinding the iron-based boron-based alloy of the present invention to an average powder particle size of 20 μm or more and less than 200 μm can be obtained. When applied to the above, it is preferable to grind so that the average particle size is 100 μm or less, and the more preferable average particle size of the powder is 20 μm to 100 μm. In addition, when applied to compression molding applications, it is preferable to grind so that the particle size is 200 μm or less, and the more preferable average crystal grain size of the powder is 50 μm or more and 150 μm or less. More preferably, the particle size distribution has two peaks, and the average crystal particle size is 50 μm or more and 130 μm or less.

  The surface of the pulverized iron-based boron-based alloy powder is subjected to a surface treatment such as a coupling treatment or a phosphoric acid treatment, or a glass coating treatment, thereby improving formability in a molded product regardless of the molding method. It is possible to improve corrosion resistance, heat resistance, and electrical insulation.

  Examples of the present invention will be described below.

(Example)
After inserting 100 kg of raw material containing each element of B, C, Si, Cr, Nb, P, Cu and Fe with a purity of 99.5% or more into each alumina composition shown in Table 1 below into an alumina crucible After melting by high-frequency induction heating, forming an alloy melt, the alloy is transferred to an alumina hot water storage vessel having an inner diameter of 200 mm and a height of 400 mm to which a BN hot water nozzle having a multi-orifice shown in Table 1 is connected at the lower part. 50kg of molten metal was poured. A cooling roll made of the metal shown in Table 1 having a diameter of 600 mm and a width of 200 mm is disposed immediately below the hot water nozzle.

  After that, by energizing the high-frequency heating coil installed around the hot water storage container, the alloy molten metal 50 kg was further heated, and after the molten metal temperature reached 50 ° C. higher than the melting point of the composition alloy, the top of the hot water nozzle At the position where the molten alloy was set to the distance between the outlet nozzle and the roll shown in Table 1 from the multi-orifice arranged in the bottom of the outlet nozzle at the same time as the roll surface speed shown in Table 1 It spouted onto the surface of the rotating cooling roll. The surface roughness Ra of the cooling roll was adjusted to the value shown in Table 1.

  The molten alloy in contact with the surface of the cooling roll forms a puddle on the surface of the cooling roll, rapidly solidifies the molten metal at the interface between the puddle and the cooling roll, and has a strip shape having the average thickness and average width shown in Table 2 A rapidly solidified alloy was obtained. Table 2 shows the average tapping rate representing the production efficiency of the rapidly solidified alloy and the average tapping rate per column of multi-orifice.

  As a result of investigation by powder X-ray diffraction, it was confirmed that the obtained rapidly solidified alloy had an amorphous single phase structure. FIG. 3 shows a powder X-ray diffraction profile of Example 1 as a representative example. Table 2 shows the constituent phases of the rapidly solidified alloy evaluated by powder X-ray diffraction.

In an alloy composition system containing rare earth elements, Nd, Pr, B, Ti, Co, Ti, Nb, with a purity of 99.5% or more so as to have the compositions shown in Table 1 below in order to prevent oxidation of the molten alloy. After evacuating 200 g of raw material containing each element of Zr and Fe to 10 ⁻² Pa or less, argon gas was introduced to an absolute pressure of 80 kPa, and a mother alloy was prepared by high frequency melting. Thereafter, 100 kg of the mother alloy crushed to about 100 mm square was inserted into an alumina crucible.

Thereafter, after evacuating to 10 ⁻² Pa or less, argon gas was introduced to an absolute pressure of 70 kPa, and then high frequency heating was performed to remelt the mother alloy in the alumina crucible to form a molten alloy. Thereafter, 50 kg of the molten alloy was poured into an alumina hot water storage vessel having an inner diameter of 200 mm and a height of 400 mm, to which a BN hot water nozzle having a multi-orifice shown in Table 1 arranged in the lower part was connected. A cooling roll made of the metal shown in Table 1 having a diameter of 600 mm and a width of 200 mm is disposed immediately below the hot water nozzle.

  Then, while maintaining an argon gas atmosphere with an absolute pressure of 70 kPa, by energizing a high-frequency heating coil installed around the hot water storage container, 50 kg of the molten alloy was further heated. After reaching a temperature higher than 80 ° C above the melting point, pull out the alumina melt stopper placed at the top of the tapping nozzle, and set the molten alloy to the tapping nozzle / roll distance shown in Table 1 from the tandem multi-orifice placed at the bottom of the tapping nozzle. In the same position, it was ejected onto the surface of the cooling roll rotating at the roll surface speed described in Table 1. The surface roughness Ra of the cooling roll was adjusted to the value shown in Table 1.

  The molten alloy containing a rare earth element in contact with the surface of the cooling roll forms a puddle on the surface of the cooling roll, rapidly solidifies the molten metal at the interface between the puddle and the cooling roll, and has the average thickness and average width shown in Table 2. A ribbon-like rapidly solidified alloy was obtained. Table 2 shows the average tapping rate representing the production efficiency of the rapidly solidified alloy and the average tapping rate per column of multi-orifice.

As a result of investigation by powder X-ray diffraction, it was confirmed that the obtained rapidly solidified alloy had a quenched alloy structure in which an amorphous phase and a crystal phase presumed to be a Nd ₂ Fe ₁₄ B type tetragonal compound were mixed. Table 2 shows the constituent phases of the rapidly solidified alloy evaluated by powder X-ray diffraction.

  Next, in the examples of the rare earth element-containing composition, the rapidly solidified alloy was cut to a length of about 20 mm, and several g was wrapped in niobium foil, and then subjected to crystallization heat treatment in a vacuum atmosphere of 1 Pa or less. Table 3 shows the crystallization heat treatment conditions for each sample.

After the heat treatment for crystallization, the crystal phase of the rapidly solidified alloy ribbon was confirmed by powder X-ray diffraction, and it was composed of Nd ₂ Fe ₁₄ B type tetragonal compound and crystal phase presumed to be α-Fe. It was.

  Table 3 shows the magnetic property results obtained by measuring the room temperature magnetic properties of the rapidly solidified alloy ribbon after the crystallization heat treatment using a vibrating sample magnetometer (VSM).

  After pulverizing a rare earth-free iron-based boron-based alloy that has not been subjected to crystallization heat treatment and a rapidly solidified alloy containing rare earth that has been subjected to crystallization heat treatment to an average powder particle size of 75 μm, the tap density evaluated by a tap denser is Table 4 shows.

(Comparative example)
After blending each element of B, C, Si, Cr, Nb, P, Cu and Fe with a purity of 99.5% or more so as to have each alloy composition shown in Table 1 below, it is rapidly solidified by the same method as in the examples. An alloy was made. Table 1 shows the setting state of the tandem multi-orifice, the cooling roll material, the hot water nozzle / roller distance, the roll surface speed, and the roll surface roughness Ra.

  Table 2 shows the average thickness and average width of the rapidly solidified alloy ribbon obtained in the comparative example, the average hot water rate representing the production efficiency of the rapidly solidified alloy, and the average hot water rate per one row of multi-orifice.

  As a result of investigation by powder X-ray diffraction, it was confirmed that the obtained rapidly solidified alloy had an amorphous single phase or a structure in which an amorphous phase and α-Fe were mixed. FIG. 4 shows a powder X-ray diffraction profile of Comparative Example 1 as a representative example. Table 2 shows the constituent phases of the rapidly solidified alloy evaluated by powder X-ray diffraction.

  In an alloy composition system containing rare earth elements, Nd, Pr, B, Ti, Co, Ti, Nb, with a purity of 99.5% or more so as to have the compositions shown in Table 1 below in order to prevent oxidation of the molten alloy. After blending each element of Zr and Fe, a rapidly solidified alloy was produced by the same method as in the examples. Table 1 shows the setting state of the tandem multi-orifice, the cooling roll material, the hot water nozzle / roller distance, the roll surface speed, and the roll surface roughness Ra.

  Table 2 shows the average thickness and width of the rapidly solidified alloy ribbons containing rare earth elements obtained in the comparative examples, the average hot water rate indicating the production efficiency of the rapidly solidified alloy, and the average hot water rate per one row of multi-orifice columns. Show.

As a result of investigation by powder X-ray diffraction, it was confirmed that the obtained rapidly solidified alloy had a quenched alloy structure in which an amorphous phase and a crystal phase presumed to be Nd ₂ Fe ₁₄ B type tetragonal compound were mixed. . Table 2 shows the constituent phases of the rapidly solidified alloy evaluated by powder X-ray diffraction.

  Next, for the comparative example of the rare earth element-containing composition, the rapidly solidified alloy was cut to a length of about 20 mm, and several g was wrapped in niobium foil, and then subjected to crystallization heat treatment in a vacuum atmosphere of 1 Pa or less. Table 3 shows the crystallization heat treatment conditions for each sample.

After the heat treatment for crystallization, the crystal phase of the rapidly solidified alloy ribbon was confirmed by powder X-ray diffraction, and it was composed of Nd ₂ Fe ₁₄ B type tetragonal compound and crystal phase presumed to be α-Fe. It was.

  Table 3 shows the magnetic property results obtained by measuring the room temperature magnetic properties of the rapidly solidified alloy ribbon after the crystallization heat treatment using a vibrating sample magnetometer (VSM).

  Table 4 shows the tap density evaluated by a tap denser after grinding a rapidly solidified alloy containing a rare earth-free iron-based boron-based alloy that has not been subjected to crystallization heat treatment and a rare earth that has been subjected to crystallization heat treatment to an average powder particle size of 75 μm. Shown in

  The method for producing an iron-based boron-based alloy of the present invention includes, for example, iron-based boron-based soft magnetic powders for isotropic bonded magnets used for iron-based boron-based soft magnetic powders used in dust cores and small DC brushless motors. Applied to the powder.

  The method for producing an iron-based boron-based alloy according to the present invention is a molten metal rapid solidification method in which a molten metal is rapidly cooled with a rotating metal cooling roll without depending on a countermeasure with an alloy composition that causes a decrease in magnetic performance. Iron-based boron-based alloys with high performance and excellent formability, because the average hot water rate during rapid solidification of molten metal can be greatly improved, regardless of whether they are soft magnetic alloys or hard magnetic alloys. It is possible to provide magnetic powder to the market at a low cost, and the applicability in the electronic component market such as various passive elements, motors, sensors, etc. is extremely high.

lb, 2b, 8b, and 9b Atmospheric gas supply ports la, 2a, 8a, and 9a gas exhaust ports 1 Melting chamber 2 Quenching chamber 3 Melting furnace 4 Hot water storage vessel 5 Hot water discharge nozzle 6 Funnel 7 Rotating cooling roll 21 Molten metal 22 Alloy ribbon 23 Orifice 24 Parallel multi-orifice 25 Cooling roll rotation direction

Claims (8)

  An alloy melt containing iron and boron as essential elements is prepared, and an orifice is used to produce a rapidly solidified alloy that rapidly cools the molten alloy on the surface of a metal cooling roll rotating at a roll surface speed of 5 m / sec to 100 m / sec. Using a tapping nozzle with a multi-orifice arranged at the bottom of a plurality of orifices with a diameter of Φ0.6 mm or more and less than Φ2.0 mm and having two or more holes and less than 4 holes aligned in a line along the rotation direction of the cooling roll. The distance between the hot water nozzle and the cooling roll is set to 0.16 mm or more and less than 20 mm, and the hot water discharge rate is set to 0.6 g / min or more and 6 kg / min as an average hot water rate per unit time from the single row of multi-orifices. An iron-based boron-based alloy manufacturing method for manufacturing a rapidly solidified alloy having an average thickness of 40 μm or more and less than 160 μm by ejecting the molten alloy from a nozzle onto the surface of the cooling roll. The composition of the molten alloy, the composition formula _{T loo-x-y-z} -n Q x Si y RE z M n (T is at least one element selected from the group consisting of Fe, Co and Ni Transition metal element that always contains Fe, Q is one or more elements selected from the group consisting of B and C, RE is rare earth element, M is rare earth element, M is P, Al, Ti, V, Cr, Mn, Nb , Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au, and Pb), and the composition ratio x, y, z, and n Of the iron-based boron-based alloy according to claim 1 satisfying 5 ≦ x <20 atomic%, 0 ≦ y <15 atomic%, 0 ≦ z <16 atomic%, and 0 ≦ n <10 atomic%, respectively. Production method.   The method for producing an iron-based boron-based alloy according to claim 1 or 2, wherein an interval D in the alignment direction of each orifice in the tandem multi-orifice is 0.2 mm or more and less than 10 mm.   The method for producing an iron-based boron-based alloy according to any one of claims 1 to 3, wherein the tandem multi-orifice has a plurality of orifices, and an interval E between adjacent rows is 3 mm or more.   The method for producing an iron-based boron-based alloy according to any one of claims 1 to 4, wherein a molten metal ejected from the molten metal nozzle has a molten metal pressure of 2 kPa or more and less than 60 kPa. In an iron-based boron-based alloy in which iron and boron are essential, the composition formula T _loo-x-yz-n Q _x Si _y RE _z M _n (T is at least selected from the group consisting of Fe, Co, and Ni) One element, transition metal element that always contains Fe, Q is one or more elements selected from the group consisting of B and C, RE always contains B, RE is a rare earth element, M is P, Al, Ti, One or more elements selected from the group consisting of V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, Ag, Hf, Zr, Ta, W, Pt, Au, and Pb), and the composition ratio A molten alloy having a composition in which x, y, z, and n satisfy 5 ≦ x <10 atomic%, 0 ≦ y <15 atomic%, 3 ≦ z <16 atomic%, and 0 ≦ n <10 atomic%, respectively. When preparing a rapidly solidified alloy that rapidly cools the molten alloy on the surface of a metal cooling roll rotating at a roll surface speed of 10 m / sec to 100 m / sec, an orifice diameter of Φ0.6 mm or more and less than Φ2.0 mm is prepared. 2 holes or more 4 holes not Using a hot water discharge nozzle with a plurality of full orifices arranged in a line along the rotation direction of the cooling roll in a straight line and a multi-orifice arranged at the bottom, the distance between the hot water discharge nozzle and the cooling roll is 0.16 mm or more and 20 mm By setting the average hot water discharge rate per unit time from the column multi-orifice one row is 0.6 g / min or more and 6 kg / min, and jetting the molten alloy from the hot water nozzle onto the surface of the cooling roll. An iron-based boron-based alloy for producing a rapidly solidified alloy having a crystal phase containing RE ₂ Fe ₁₄ B phase in the range of 1% by volume to less than 95% by volume and the balance being amorphous and having an average thickness of 40 μm to less than 160 μm Production method. The cooling roll material is either copper or an alloy containing copper as a main component, Mo or an alloy containing Mo as a main component, or an alloy containing W or W as a main component. The method for producing an iron-based boron-based alloy according to any one of claims 1 to 6, wherein the thickness Ra is 1 nm or more and less than 10 µm. An iron-based boron-based alloy manufactured by the method for manufacturing an iron-based boron-based alloy according to any one of claims 1 to 7 is heat-treated at a constant temperature of 150 ° C or higher and lower than 900 ° C, and then the average powder particle size is 20 µm. Iron-based boron-based alloy powder pulverized to less than 200 μm to a tap density of 4.0 g / cm ³ or more.