WO2022196672A1

WO2022196672A1 - Method for producing fe-si-b-based thick rapidly solidified alloy thin strip

Info

Publication number: WO2022196672A1
Application number: PCT/JP2022/011505
Authority: WO
Inventors: 裕和金清
Original assignee: Ｈｉｌｌｔｏｐ株式会社
Priority date: 2021-03-17
Filing date: 2022-03-15
Publication date: 2022-09-22
Also published as: JPWO2022196672A1

Abstract

A method for producing an alloy thin strip, wherein an Fe-Si-B-based alloy melt, which essentially contains iron (Fe), boron (B) and silicon (Si), is spouted from a tapping nozzle onto the surface of a cooling roll and the cooling roll is rotated such that the surface speed thereof is 15 to 50 m/sec, thereby rapidly cooling the alloy melt on the surface of the cooling roll so as to produce an alloy thin strip. With respect to this method for producing a rapidly solidified alloy thin strip, the tapping nozzle is provided with slits that are arranged in two to four rows in the formation direction of the alloy thin strip, while having a width of not less than 0.2 mm but less than 1.2 mm; the cooling roll has a curvature of not less than 8 × 10^-4 but less than 2 × 10^-3; and a rapidly solidified alloy thin strip, which has an average thickness of not less than 30 μm but less than 70 μm and an average width of not less than 50 mm but less than 200 mm, while containing 90% by volume or more of an amorphous alloy structure, is produced by flowing a cooling water that is not less than 5°C but less than 60°C through the cooling roll at a cooling water flow rate of not less than 0.3 m³/min but less than 20 m³/min.

Description

Method for producing Fe--Si--B system thick plate rapidly solidified alloy ribbon

The present invention relates to a method for producing a rapidly solidified Fe-Si-B thick alloy ribbon.

In recent years, the market has demanded materials with low iron loss and high saturation magnetic flux density for various passive elements such as inductors and reactors used as electronic components, as well as transformers. Materials with high magnetic permeability and low iron loss compared to electrical steel sheets include iron-based amorphous materials and iron-based nanocrystalline materials, which are soft magnetic materials made mainly of iron (Fe), boron (B), and silicon (Si). materials are known. Fe-Si-B system rapidly solidified alloy ribbons with a thickness of about 17 μm to 25 μm, which are produced by the molten metal rapid solidification method using such soft magnetic materials, are used as wound cores for inductors, transformers, etc. Demand is expanding year by year as a substitute for electrical steel sheets.

In addition, the iron-based amorphous alloy has excellent soft magnetic properties, with iron loss about 1/10 and magnetic permeability more than 3 times that of electromagnetic steel sheets (silicon steel sheets) used as laminated cores for motors. Therefore, in addition to the inductors and transformers described above, it is expected to contribute to the miniaturization and efficiency improvement of motors by using it as a wound iron core for motors. However, iron-based amorphous alloys with a thickness of about 17 μm to 25 μm cannot be punched to form a laminated core, and the lamination factor decreases. It is only applied to motors with

Conventionally, Fe-Si-B amorphous alloys could not be obtained unless they were rapidly solidified alloy ribbons with a thickness of 17 to 25 μm at a very high rapid solidification rate of 10 ⁴ to 10 ⁶ K/sec. However, Non-Patent Document 1 discloses that the rapid solidification rate is reduced by adding phosphorus (P), and an iron-based amorphous alloy ribbon having a thickness of about 50 μm can be obtained. However, in the case of phosphorus-added alloys, the addition of phosphorus not only causes a decrease in the saturation magnetic flux density Bs, but also causes the phosphorus component to volatilize when the alloy is melted, resulting in significant contamination inside and outside the molten metal quenching device. Therefore, there are still few examples of application in the industrial field.

Patent document 1 and patent document 2 disclose a quenched alloy ribbon having a thickness (50 μm or more) that allows punching by a multiple slit method in which molten alloy is discharged from a plurality of slit nozzles onto a rotating cooling roll. is disclosed. However,

Patent Documents

1 and 2 disclose a manufacturing apparatus for mass-producing an iron-based amorphous alloy having such a plate thickness at a low cost while stably maintaining the homogeneity and uniform quality of the amorphous alloy. It does not disclose specifications or operating parameters.

Patent Documents

3 and 4 disclose a method of producing an iron-based amorphous alloy with a plate thickness of 30 μm or more by alternately tapping molten metal from multiple slit nozzles to two cooling rolls. The production equipment used in this method requires two cooling rolls, which not only significantly increases production and running costs, but also greatly affects the plate thickness and quenching conditions of the iron-based amorphous alloy. and control of the gap on the surface of the cooling roll becomes extremely difficult compared to a conventional single roll molten metal quenching apparatus having only one cooling roll.

Patent Document 5 discloses a cooling roll used in a single-roll molten metal quenching apparatus for producing an iron-based amorphous alloy having a thickness of 30 μm or more. There is the problem of getting taller. Further, Patent Document 5 describes increasing the flow rate of cooling water as the thickness of the amorphous foil strip increases, but does not clarify the optimum roll cooling water flow rate. Furthermore, it is recommended that the diameter of the roll be different according to the thickness of the amorphous ribbon. Considering the production efficiency, it is difficult to apply it as a mass-production device.

Patent Document 6 discloses a method for producing a thin metal strip that uses a multi-hole nozzle to prevent the thickness of the thin metal strip from becoming non-uniform when producing a wide quenched thin strip. The invention of Patent Document 6 is characterized by the shape of the nozzle opening, but there is a problem that the nozzle processing cost rises due to the difficulty of processing, and it is difficult to use at the mass production level.

Patent Document 7 discloses a method of producing a brazing ribbon with a thickness of 50 to 200 μm using a single-roll molten metal quenching apparatus, but the brazing ribbon obtained by this method is a crystalline Ni-based alloy. Therefore, it does not disclose a technique for producing a rapidly solidified alloy having an amorphous structure with a thickness of about 50 μm.

In Patent Document 8, for the purpose of reducing hysteresis loss, which is the main factor of iron loss in a wide amorphous alloy ribbon, an Fe-based amorphous alloy ribbon having wavy unevenness formed on the free surface is produced by a single roll method. is disclosed. Although Patent Document 8 describes the temperature distribution in the width direction of the molten metal nozzle and the roughness of the chill roll surface, it discloses a manufacturing technology for an iron-based rapidly solidified alloy having an amorphous structure that can be applied to a laminated core. not a thing

In this way, there are several techniques for producing rapidly quenched Fe-Si-B molten alloys with a thickness of 30 μm or more using conventional slit nozzles, in addition to improving the alloy's ability to form amorphous by adding phosphorus (P). A proposal has been made to use a multi-slit tapping nozzle in which a row of slits is arranged perpendicular to the direction of rotation of the chill roll. However, if the molten metal is ejected from a plurality of rows of slits, for example, and the rate at which the molten metal is ejected increases, it becomes difficult to rapidly cool the molten alloy with the cooling rolls, making it difficult to obtain an amorphous structure. For this reason, as a solution to this problem, conventional measures have been devised, such as devising a cooling channel structure for the cooling rolls, arranging two cooling rolls in parallel, and supplying molten metal alternately. All of these measures complicate the configuration of the molten metal quenching equipment, so there is no established molten metal quenching technology for mass-producing Fe-Si-B-based molten metal quenching alloys with a thickness of 30 μm or more at a low cost and in a stable manner. However, there is no track record of mass-production level provision to the market.

JP-A-5-329587 JP-A-7-113151 Japanese Patent No. 5114241 Japanese Patent No. 5270295 JP 2015-205290 A JP-A-63-220950 JP-A-63-157793 Japanese Patent No. 6107140

At present, the Fe-Si-B-based amorphous material that is being applied to transformers, etc. has a thickness of around 20 μm, which is not at a level that can be used for laminated cores. In addition, the prior art that makes it possible to increase the thickness of the Fe-Si-B system amorphous material either invites a decrease in soft magnetic properties or has problems in terms of productivity and cost. Therefore, there is a need for a method of mass-producing alloy ribbons made of Fe-Si-B based amorphous materials that are inexpensive and have high performance, and which can be made thicker from Fe-Si-B based amorphous materials regardless of the alloy composition. , is highly desired in the electronic component market.

Therefore, the present invention provides an Fe-Si-B thick plate rapidly solidified alloy thin strip that can be easily mass-produced at low cost and is suitable for laminated cores of motors and the like. The object is to provide a method for manufacturing an obi.

Fig. 6 is a schematic configuration diagram of an apparatus used in a conventional method for producing a rapidly solidified Fe-Si-B alloy ribbon. As shown in FIG. 6, the molten alloy supplied from the nozzle 52 of the molten metal container 51 to the surface of the cooling roll 54 is rapidly cooled on the cooling roll 54 and then peeled off from the cooling roll 54, resulting in Fe—Si A -B system melt-quenched alloy ribbon is obtained. On the surface of the cooling roll 54, the molten alloy is rapidly cooled to obtain an amorphous structure so that the molten alloy is quickly passed between the melting point and the glass transition temperature of the alloy so that crystallization does not occur. Since the rapidly solidified alloy that has undergone primary cooling is in a supercooled state, it may recrystallize due to self-heating due to latent heat of solidification.

For this reason, in the conventional mass production process of the Fe-Si-B system rapid solidification alloy, primary cooling is performed in a state where the molten metal ejected onto the surface of the cooling roll 54 sticks to the surface of the cooling roll 54 for about half the circumference. The latent heat of solidification is removed. The rapidly solidified alloy ribbon 55 composed of an amorphous structure formed by primary cooling is subjected to secondary cooling in a solid phase state and separated from the cooling roll 54 .

In the above-described prior art, the molten metal is brought into contact with the cooling roll 54 about halfway around because if the rapidly solidified alloy ribbon 55 is separated from the cooling roll 54 immediately after being rapidly solidified, the rapidly solidified alloy ribbon is in a supercooled state. This is to prevent the solidification latent heat of 55 from being released and recrystallization. However, if the distance from the supply position of the molten metal on the surface of the cooling roll 54 to the separation position is increased in this way, the time until the molten metal is resupplied to the separation position by the rotation of the cooling roll 54 becomes shorter. If the molten metal supply rate per hit becomes high, the molten metal is repeatedly supplied to the chill roll 54 in a state where the surface temperature of the chill roll 54 is not sufficiently lowered. As a result, the surface temperature of the cooling roll 54 may rise excessively, making it impossible to continue rapid cooling of the molten metal.

The present invention has clarified through various tests the heat removal capacity required of the cooling roll in order to form a rapidly solidified alloy structure that does not recrystallize due to the release of solidification latent heat. That is, the present invention does not complicate the structure of the manufacturing apparatus by clarifying the preferable conditions of the surface speed, curvature, cooling water amount, and cooling water temperature of the cooling roll according to the size of the rapidly solidified alloy ribbon. , Fe--Si--B system molten metal quenching alloy ribbons that can be suitably used for laminated cores of motors, etc., can be easily mass-produced at low cost.

The object of the present invention is to eject a molten Fe-Si-B alloy essentially containing iron (Fe), boron (B) and silicon (Si) from a tapping nozzle onto the surface of a chill roll, A method for producing an alloy ribbon by rotating at a speed of 15 m/sec or more and 50 m/sec or less to quench the molten alloy on the surface of the chill roll, wherein the tapping nozzle comprises: Slits with a width of 0.2 mm or more and less than 1.2 mm are formed in two or more rows and four or less rows along the forming direction of the alloy ribbon, and the cooling roll has a curvature of 8 × 10 ^-4 or more and 2 × 10 ^-3 and less than 5 ° C. or more and less than 60 ° C. is passed through the cooling roll at a cooling water amount of 0.3 m ³ /min or more and less than 20 m ³ /min, so that the average thickness is 30 μm or more and less than 70 μm. This is achieved by a method for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon that has a width of 50 mm or more and less than 200 mm and contains an amorphous alloy structure of 90% by volume or more. In this method for producing a rapidly solidified Fe-Si-B thick plate alloy ribbon, the slits of the tapping nozzle have the same length in the range of 45 mm or more and less than 200 mm, and the distance between them is 0.5 mm or more and 5.0 mm. mm, and the distance from the tip of the tapping nozzle to the surface of the cooling roll is preferably 0.15 mm or more and less than 30 mm.

Alternatively, the above object of the present invention is achieved by ejecting a molten Fe-Si-B alloy essentially containing iron (Fe), boron (B) and silicon (Si) from a tapping nozzle onto the surface of a chill roll, is rotated at a surface speed of 15 m/sec or more and 50 m/sec or less to quench the molten alloy on the surface of the cooling roll to produce an alloy ribbon, the tapping nozzle is formed with a single slit having a width of 0.5 mm or more and less than 1.5 mm, and the cooling roll has a curvature of 8 × 10 ^-4 or more and less than 4.0 × 10 ^-3 , and a cooling temperature of 5 ° C or more and less than 60 ° C. By passing water through the cooling roll at a cooling water amount of 0.05 m ³ /min or more and less than 0.3 m ³ /min, the average thickness is 30 μm or more and less than 70 μm and the average width is 5 mm or more and less than 50 mm. It is achieved by a method for producing a rapidly solidified Fe--Si--B-based thick-plate, rapidly-solidified alloy ribbon containing at least vol %. In this method for producing a rapidly solidified Fe-Si-B thick plate alloy ribbon, the length of the slit of the tapping nozzle is preferably 4 mm or more and less than 50 mm. The distance to the surface is preferably 0.15 mm or more and less than 30 mm.

In each method of manufacturing the Fe-Si-B system thick plate rapidly solidified alloy ribbon described above, the cooling roll is made of a material containing any one of Cu, Mo or W as a main component, and has a surface arithmetic mean roughness Ra is 10 nm or more and less than 20 μm, the length is 50 mm or more and less than 400 mm longer than the length of the slit, and the thickness from the surface to the cooling water flow path is preferably 5 mm or more and less than 50 mm.

The pressure of the molten alloy ejected from the slit is preferably 2 kPa or more and less than 60 kPa.

The molten alloy has a composition formula of T _loo-x-y-z-n Q _x Si _y M _n (T is at least one element selected from the group consisting of Fe, Co and Ni, and Fe is A transition metal element that must be included, Q is one or more elements selected from the group consisting of B and C and must include B, 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 and n are each 5 ≤ x < 20 atomic % , 2≦y<15 atomic %, 0≦n<10 atomic %, and the composition ratio C/(B+C) of Q is 0 or more and less than 0.2.

90% by volume or more of amorphous structure with a thickness of 30 μm or more and less than 70 μm, which can be used as a laminated core that can be easily applied to motors, etc. It is possible to obtain a rapidly solidified Fe--Si--B-based thick plate alloy ribbon.

In addition, after punching, wire cutting, laser cutting, etc., the above-mentioned Fe-Si-B thick plate rapidly solidified alloy ribbon is processed into a desired shape, and then the laminated iron core is laminated using a method such as resin bonding or caulking. can be obtained. The produced laminated core can be further processed by wire cutting, laser cutting, or the like to obtain split cores that can be used for motors.

According to the method for producing the rapidly solidified Fe-Si-B thick plate alloy ribbon of the present invention, the rapidly solidified Fe-Si-B thick plate alloy ribbon suitable for laminated cores of motors and the like can be easily produced at low cost. Mass production is possible.

1 is a schematic configuration diagram of an apparatus used in a method for producing a rapidly solidified Fe—Si—B thick alloy ribbon according to an embodiment of the present invention. FIG. It is an enlarged drawing which shows the principal part of the apparatus shown in FIG. 1, (a) is sectional drawing, (b) is a bottom view. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining the details of a method for producing a rapidly solidified Fe—Si—B thick plate alloy ribbon according to an embodiment of the present invention. 2 is an enlarged view showing another essential part of the device shown in FIG. 1, where (a) is a vertical cross-sectional view and (b) is a cross-sectional view taken along the line AA of (a). FIG. FIG. 4 is an enlarged view of a main part of an apparatus used in a method for producing a rapidly solidified Fe—Si—B thick alloy ribbon according to another embodiment of the present invention, where (a) is a cross-sectional view and (b) is a bottom view; be. 1 is a schematic configuration diagram of an apparatus used in a conventional method for producing a rapidly solidified Fe—Si—B alloy ribbon. FIG. 1 is an X-ray diffraction pattern of a Fe--Si--B system rapidly solidified alloy ribbon obtained in an example of the present invention. 4 is an X-ray diffraction pattern of a Fe--Si--B system rapidly solidified alloy ribbon obtained in another example of the present invention. 4 is an X-ray diffraction pattern of a Fe--Si--B system rapidly solidified alloy ribbon obtained in still another example of the present invention. 1 is an X-ray diffraction pattern of a Fe--Si--B system rapidly solidified alloy ribbon obtained in a comparative example of the present invention. 4 is an X-ray diffraction pattern of a Fe--Si--B system rapidly solidified alloy ribbon obtained in another comparative example of the present invention. 4 is an X-ray diffraction pattern of a Fe--Si--B system rapidly solidified alloy ribbon obtained in still another comparative example of the present invention.

[Alloy composition]
The composition formula of the molten alloy used in the method for producing the rapidly solidified Fe—Si—B thick plate alloy ribbon of the present embodiment is represented by T _loo-x-y-z-n Q _x Si _y M _n . be. Q is one or more elements selected from the group consisting of B and C and necessarily containing B; Further, M is one 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. These are the above elements. The composition ratios x, y and n are 5≦x<20 atomic %, 2≦y<15 atomic % and 0≦n<10 atomic %, respectively. Also, the composition ratio C/(B+C) of Q is 0 or more and less than 0.2.

The transition metal T, which contains Fe as an essential element, accounts for the remaining content of Q, Si, and M. Desired hard magnetic properties can be obtained by replacing part of Fe with one or both of Co and Ni, which are ferromagnetic elements like Fe. However, if the amount of replacement with respect to Fe exceeds 30%, the magnetic flux density will drop significantly, so the amount of replacement is limited to the 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 molten metal. If it exceeds 20 atomic %, the component ratio of Fe decreases, so that the magnetic flux density decreases, making it difficult to obtain a high-performance soft magnetic material. Therefore, the composition ratio x is 5 atomic % or more and less than 20 atomic %. The composition ratio x is preferably 7 atomic % or more and less than 19 atomic %, more preferably 8 atomic % or more and less than 19 atomic %.

When the substitution ratio of C to B in Q increases, the melting point of the molten alloy is lowered and the amount of wear of the refractory used during rapid solidification is reduced, so the process cost related to rapid solidification can be suppressed. However, when C/(B+C) exceeds 0.2, the ability to form amorphous is lowered, and α-Fe is precipitated by heterogeneous nucleation on the roll surface side surface layer of the rapidly solidified alloy. At this time, α-Fe is oriented in the plane of the rapidly solidified alloy ribbon, and the α-Fe(200) peak becomes large. Even if there is, it is not preferable because it becomes a starting point of cracking and chipping during punching. Therefore, C/(B+C) is 0 or more and less than 0.2, preferably 0 or more and less than 0.15, and more preferably 0 or more and less than 0.1.

When Si is added simultaneously with Fe and B, it is effective as an element that improves the ability to form amorphous material and increases the magnetic permeability of iron-based boron-based rapidly solidified alloys. Since the saturation magnetic flux density Bs is greatly reduced, y should be less than 15 atomic %. Moreover, y is preferably 2 atomic % or more from the viewpoint of improving magnetic permeability. y is more preferably 2.5 atomic % or more and less than 12 atomic %.

The addition of M improves the productivity during rapid solidification by improving the ability to form amorphous material and refining the rapid solidification metal structure. However, when the composition ratio n of M exceeds 10 atomic %, the saturation magnetic flux density Bs is lowered, so n is limited to 0 atomic % or more and less than 10 atomic %. n is preferably 0 atomic % or more and less than 7 atomic %, more preferably 0 atomic % or more and less than 5 atomic %.

[Molten alloy rapid cooling and solidification equipment (single roll molten metal rapid cooling equipment)]
FIG. 1 is a schematic configuration diagram of a single-roll molten-metal quenching apparatus used in a method for manufacturing a Fe--Si--B-based thick-plate, quench-solidified alloy ribbon according to one embodiment of the present invention. A single roll molten metal quenching apparatus 1 shown in FIG.

The melting furnace 2 supplies the molten alloy 3 in which the raw materials are melted to the hot water storage container 5 by rotating the tilting shaft 4 . The hot water storage container 5 is provided with a hot water nozzle 6 at the bottom, and the molten alloy 3 is jetted onto the surface (outer peripheral surface) of the cooling roll 8 from a slit 7 formed at the lower end of the hot water nozzle 6 . The cooling roll 8 is supplied with cooling water to rapidly cool the molten alloy in contact with the surface thereof to form a rapidly solidified alloy ribbon 9 .

In this single roll molten metal quenching apparatus 1, the slits 7 of the tapping nozzle 6 are multi-slits formed in two rows along the forming direction of the rapidly solidified alloy ribbon 9. The single-roll molten metal quenching device 1 equipped with such a multi-slit is preferably used for producing a Fe-Si-B system thick plate rapidly solidified alloy ribbon having a thickness of 30 µm or more and less than 70 µm and a width of 50 mm or more and less than 200 mm. . A rapidly solidified alloy ribbon having such a size is suitable for manufacturing laminated cores applied to, for example, motors for EVs, compressors, generators, and the like.

FIG. 2 is an enlarged view showing the tapping nozzle 6 of the device shown in FIG. 1, where (a) is a cross-sectional view and (b) is a bottom view. The width W1 of the slit 7 shown in FIG. 2(a) is set to 0.2 mm or more and less than 1.2 mm. If the width is less than 0.2 mm, the flow of the molten metal passing through the slit 7 is obstructed, increasing the possibility of nozzle clogging. On the other hand, if the width is 1.2 mm or more, the molten metal tapping rate supplied to the cooling rolls becomes too high, and the cooling rolls cannot sufficiently cool the molten metal, so that the desired amorphous structure may not be obtained. Considering the workability and precision of the slit, the width W1 of the slit 7 is more preferably 0.3 mm or more and less than 1.0 mm, and still more preferably 0.3 mm or more and less than 0.8 mm. The widths W1 of the plurality of slits 7 may be the same or different.

The length L1 of the slit 7 shown in FIG. 2(b) is appropriately selected depending on the width of the cooling roll and the core size of the required motor, etc., and is not necessarily limited. While the application field is limited, if the length is 200 mm or more, the molten metal tapping rate supplied to the cooling roll 8 becomes too high, and the cooling roll 8 cannot sufficiently cool the molten metal, so that the desired amorphous structure cannot be obtained. There is a possibility that it will not. Therefore, the length L1 of the slit 7 is preferably 45 mm or more and less than 200 mm, more preferably 45 mm or more and less than 170 mm, more preferably 45 mm or more and less than 150 mm, in consideration of productivity including running costs and the cost of a single roll molten metal quenching device. preferable. The lengths L1 of the plurality of slits 7 are preferably the same.

The depth D1 of the slit 7 shown in FIG. 2(a) is determined based on the thickness of the bottom of the molten metal tapping nozzle 6. If it is less than 2 mm, the strength of the bottom tends to be insufficient. The possibility of nozzle clogging increases due to the decrease in temperature. Therefore, the depth D1 of the slit 7 is preferably 2 mm or more and less than 15 mm, more preferably 3 mm or more and less than 12 mm, and even more preferably 3 mm or more and less than 10 mm in consideration of the stability (straightness) of tapping.

Although the slits 7 are arranged in two rows in the present embodiment, they may be arranged in three or four rows along the direction in which the rapidly solidified alloy ribbon 9 is formed. If the slits 7 are arranged in more than four rows, the total molten metal discharge rate obtained by summing the slits 7 is too large, and the molten metal cannot be sufficiently cooled by the cooling rolls, making it difficult to obtain an amorphous structure. Two or more rows and four rows or less are preferable. Considering the homogeneity of the rapidly solidified structure, the number of slits 7 is more preferably two or more and three or less. Considering the controllability of the molten metal rate and the production efficiency assuming continuous operation, it is more preferable to have two rows. preferable.

If the interval S1 between the slits 7 shown in FIG. 2(b) is less than 0.5 mm, processing is difficult, while if it is 5 mm or more, it becomes difficult to obtain a rapidly solidified alloy ribbon having a desired thickness. Therefore, the interval S1 between the slits 7 is preferably 0.5 mm or more and less than 5.0 mm. Considering the possibility of the slits falling off when the molten metal is poured, it is preferably 1.0 mm or more and 5.0 mm or less. 1.0 mm or more and 3.0 mm or less is more preferable.

In FIG. 1, the molten metal supplied to the chill roll 8 from the tapping nozzle 6 forms a pool (puddle) on the surface of the chill roll 8, causing a rapid solidification reaction of the molten metal. . If the distance d from the tip of the tapping nozzle 6 to the surface of the cooling roll 8 is 30 mm or more, the formation of paddles is not stable. It is difficult to keep Therefore, the distance d is preferably 0.15 mm or more and less than 30 mm. Considering the equipment cost for precisely controlling the distance d, the distance d is more preferably 0.3 mm or more and less than 30 mm, and considering the homogeneity of the rapidly solidified alloy structure, it is more preferably 0.3 mm or more and less than 20 mm.

As shown in FIG. 4, the molten metal supplied to the surface of the cooling roll 8 is cooled by the rotation of the cooling roll 8 from the pouring position P directly below the slit 7 of the tapping nozzle 6 into a rapidly solidified alloy ribbon 9. While moving to the peeling position Q where it is peeled from the roll 8, primary cooling to rapidly cool the molten alloy to a supercooled liquid state, and secondary cooling to remove the solidification latent heat of the supercooled liquid and prevent recrystallization. is performed. The distance Δs from the pouring position P to the stripping position Q must be sufficient to complete the primary cooling and secondary cooling, but the stripping position Q rotates to the pouring position P again. Therefore, the rotation angle Δα of the cooling roll 8 from the pouring position P to the stripping position Q is a straight line from the pouring position P to the stripping position Q. It is preferable to be as small as possible. In this case, the radius R of the cooling roll 8 is obtained by the following formula.
R＝lim _Δs→0 |Δs/Δα|=|ds/dα|

When the cooling roll 8 is rotated so that the surface speed is 15 m/sec or more and 50 m/sec or less, Δs can be obtained from the time required for the primary cooling and the secondary cooling. A numerical range of 2R is determined. A preferable value of Δs depends on the size of the rapidly solidified alloy ribbon 9. When obtaining the rapidly solidified alloy ribbon 9 having an average thickness of 30 μm or more and less than 70 μm and an average width of 50 mm or more and less than 200 mm, the cooling roll 8 The diameter 2R is 1000 mm or more and less than 2500 mm, preferably 1500 mm or more and less than 2500 mm in consideration of the homogeneity of the rapidly solidified alloy structure, and 1500 mm in consideration of the restrictions on the processing equipment of the chill roll manufactured by forging and the manufacturing cost. It is more preferable to be at least 2300 mm or less.

Since the curvature κ of the cooling roll 8 is the reciprocal of the radius R, the curvature κ when obtaining the rapidly solidified alloy ribbon 9 having an average thickness of 30 μm or more and less than 70 μm and an average width of 50 mm or more and less than 200 mm is 8× It is 10 ⁻⁴ or more and less than 2×10 ⁻³ , preferably 8×10 ⁻⁴ or more and less than 1.3×10 ⁻³ , more preferably 9×10 ⁻⁴ or more and less than 1.3×10 ⁻³ .

In order to complete the primary cooling and secondary cooling within the distance Δs, the amount and temperature of the cooling water of the cooling roll 8 are also important factors. 4A and 4B are schematic configuration diagrams showing an example of the cooling roll 8, where (a) is a vertical cross-sectional view and (b) is a cross-sectional view along AA. The cooling water supplied from one end side (IN side) to the rotating shaft 81 of the cooling roll 8 spreads radially along the flow path 82 , cools the entire surface of the cooling roll 8 , and then joins the rotating shaft 81 . It is discharged from the other end side (OUT side). When obtaining a rapidly solidified alloy ribbon 9 having an average thickness of 30 μm or more and less than 70 μm and an average width of 50 mm or more and less than 200 mm, if the amount of cooling water is less than 0.3 m ³ /min, primary cooling and secondary cooling on the surface of the cooling roll 8 will occur. While it is difficult to complete the secondary cooling, if the cooling water flow rate is 20 m ³ /min or more, the surface temperature of the cooling roll 8 during cooling of the molten metal does not rise, and the temperature on the IN side and the OUT side of the cooling roll 8 does not rise. Since the difference ΔT is small (for example, 1° C. or less), the puddle formed on the surface of the cooling roll 8 becomes unstable. Therefore, the amount of cooling water is 0.3 m ³ /min or more and less than 20 m ³ /min, and in the single roll molten metal quenching device 1 that can be mass-produced assuming continuous operation, 0.5 m ³ /min or more and less than 20 m ³ /min is preferred, and 0.5 m ³ /min or more and less than 15 m ³ /min is more preferred.

The temperature of the cooling water of the cooling roll 8 affects the adhesion between the molten alloy and the cooling roll 8. When the temperature of the cooling water is less than 5°C, the adhesion between the molten alloy and the chill roll 8 is impaired, and the ability of the cooling roll 8 to extract heat from the molten alloy is reduced. The temperature of the cooling water is 5° C. or more and less than 60° C., as it may cause failure of the pump that supplies the rolls 8 . In order to further improve the adhesion between the molten alloy and the cooling roll 8, the lower limit of the cooling water temperature is particularly important, preferably 15°C or higher and lower than 60°C, more preferably 30°C or higher and lower than 60°C.

The adhesion between the molten alloy and the cooling roll 8 is also affected by the material of the cooling roll 8 . Considering the thermal conductivity and melting point of the material, the cooling roll 8 is preferably made of a material containing Cu, Mo or W as its main component. materials are preferred. The term "Cu as the main component" includes not only alloys containing more than 50% by mass of Cu, but also pure copper (the same applies to materials containing Mo or W as the main component).

Since the surface roughness of the chill roll 8 also affects the adhesion between the molten alloy and the chill roll 8, it is preferable that the arithmetic mean roughness Ra of the chill roll surface is 10 nm or more and less than 20 μm, which improves production efficiency and quality. , Ra is more preferably 50 nm or more and less than 10 μm, and still more preferably 100 nm or more and less than 10 μm.

The length L2 in the axial direction of the cooling roll 8 shown in FIG. 4(a) is preferably 50 mm or more and less than 400 mm longer than the length of the slit 7 shown in FIG. 2(b). Taking this into consideration, it is more preferably longer than the slit 7 by 100 mm or more and less than 300 mm, and more preferably 100 mm or more and less than 200 mm.

The ability of the cooling roll 8 to remove heat from the molten alloy is also affected by the thickness T2 from the surface of the cooling roll 8 to the flow path 82 shown in FIG. 4(a). When the thickness T2 is less than 5 mm, it becomes difficult to maintain the mechanical strength of the chill roll 8, while when the thickness T2 is 50 mm or more, the surface temperature of the chill roll 8 in contact with the molten alloy locally rises above the melting point. As a result, the rapidly solidified alloy may adhere to the surface of the chill roll 8, making it impossible to continue the rapid cooling of the molten metal. Therefore, the thickness T2 of the cooling roll 8 is preferably 5 mm or more and less than 50 mm. The thickness T2 is more preferably 10 mm or more and less than 50 mm in consideration of wear due to roll grinding work after the molten metal quenching process, and more preferably 10 mm or more and less than 40 mm in consideration of operational stability in the molten metal quenching process.

The molten alloy ejected from the slit 7 of the tapping nozzle 6 is pressed against the surface of the cooling roll 8 to form a puddle as described above. Since it is difficult to form a desired puddle in the slit 7, the pressure of the molten alloy discharged from the slit 7 is preferably 2 kPa or more and less than 60 kPa. This tapping pressure is more preferably 10 kPa or more and less than 40 kPa, still more preferably 10 kPa or more and less than 30 kPa, in order to generate paddles more stably. The hot water pressure can be adjusted by the head pressure and pressurization force in the hot water storage container 5 shown in FIG.

The above description shows preferred apparatus configurations and cooling conditions for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon having an average thickness of 30 μm or more and less than 70 μm and an average width of 50 mm or more and less than 200 mm. Thus, a rapidly solidified alloy ribbon containing 90% by volume or more of amorphous alloy structure can be obtained. On the other hand, in the case of producing Fe-Si-B system thick plate rapidly solidified alloy ribbon with an average thickness of 30 μm or more and less than 70 μm and an average width of 5 mm or more and less than 50 mm, the single roll molten metal rapid cooling device 1 shown in FIG. A single slit nozzle having a single slit 7 is used as the tapping nozzle 6 in FIG. As preferable conditions in this case, only points different from the above description will be described as follows.

First, the diameter 2R of the chill roll 8 is 500 mm or more and less than 2500 mm, preferably 570 mm or more and less than 2500 mm considering the homogeneity of the rapidly solidified alloy structure. Considering the manufacturing cost, it is more preferably 570 mm or more and less than 1500 mm. That is, the curvature κ of the cooling roll 8 is 8×10 ⁻⁴ or more and less than 4×10 ⁻³ , preferably 8×10 ⁻⁴ or more and less than 3.5×10 ⁻³ , and 1.3×10 ⁻³ or more and 3.5×10 ⁻ Less than ³ is more preferred.

When the cooling water flow rate is less than 0.05 m ³ /min, it becomes difficult to complete primary cooling and secondary cooling on the surface of the cooling roll 8. On the other hand, when the cooling water flow rate is 0.3 m ³ /min or more, 0.05 m ³ /min or more and less than 0.3 m ³ /min is preferable, and 0.05 m ³ /min or more and less than 0.2 m ³ /min is more preferable, because paddles generated during the period become unstable.

The width W2 of the slit 7 shown in FIG. 5(a) is set to 0.5 mm or more and less than 1.5 mm. If the width is less than 0.5 mm, the flow of molten metal passing through the slit 7 is obstructed, increasing the possibility of nozzle clogging. On the other hand, if the width is 1.5 mm or more, the molten metal tapping rate supplied to the cooling rolls becomes too high, and the cooling rolls cannot sufficiently cool the molten metal, so that the desired amorphous structure may not be obtained. Considering the workability and accuracy of the slit, the width W2 of the slit 7 is more preferably 0.5 mm or more and less than 1.2 mm, and still more preferably 0.6 mm or more and less than 1.0 mm.

The length L2 of the slit 7 shown in FIG. 5(b) is appropriately selected according to the width of the cooling roll and the core size of the required motor, etc., and is not necessarily limited. While the application field is limited, if the length is 50 mm or more, the molten metal tapping rate supplied to the cooling roll 8 becomes too high, and the cooling roll 8 cannot sufficiently cool the molten metal, so that the desired amorphous structure cannot be obtained. There is a possibility that it will not. Therefore, the length L2 of the slit 7 is preferably 4 mm or more and less than 50 mm, more preferably 7 mm or more and less than 50 mm, more preferably 10 mm or more and less than 50 mm, in consideration of productivity including running costs and the cost of a single roll molten metal quenching device. preferable.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

200 kg of raw materials containing each element of B, C, Si, Nb, Cu and Fe with a purity of 99.5% or more are blended so as to have the alloy compositions shown in Examples 1-12 and Comparative Examples 13-21 in Table 1 below. It was placed in an alumina crucible and melted by high-frequency induction heating to form a molten alloy. 50 kg of this molten alloy was poured into an alumina hot-water storage container having an inner diameter of 200 mm and a height of 400 mm, which was provided with a BN hot-water nozzle having slits shown in Table 1 at the bottom. After that, by energizing the high-frequency heating coil installed around the hot water storage container, 50 kg of the molten alloy is further heated. The alumina molten metal stopper placed on the top of the was pulled out. As a result, the molten alloy was ejected from the tapping nozzle onto the surface of the chill roll directly below. Chill roll sizes and operating parameters are shown in Table 2. Table 3 shows the average tapping rate of molten metal.

The molten alloy in contact with the surface of the chill roll formed a puddle on the surface of the chill roll and was rapidly solidified at the interface between the paddle and the chill roll to obtain a ribbon-shaped rapidly solidified alloy. Table 3 shows the average thickness and average width of this rapidly solidified alloy ribbon.

For the obtained rapidly solidified alloy ribbon, the X-ray diffraction patterns of the surface in contact with the chill roll surface (roll surface) and the opposite surface (free surface) not in contact with the chill roll surface were measured. , conducted an organizational evaluation. The results are shown in Table 3 as the volume ratio of the amorphous structure. As shown in Table 3, in Examples 1-12, it was confirmed that the amorphous single-phase structure or the amorphous structure occupied the majority, and the free surface side contained fine crystals judged to be α-Fe. did. As representative examples of the X-ray diffraction patterns on the roll surface and the free surface of the rapidly solidified alloy ribbons of Examples, Example 2 is shown in FIG. 7, Example 5 is shown in FIG. 8, and Example 10 is shown in FIG. .

On the other hand, in Comparative Examples 13-21, as shown in Table 3, the volume ratio of the amorphous structure decreased compared to Examples 1-12 due to insufficient quenching ability. As representative examples of the X-ray diffraction patterns on the roll surface and the free surface of the rapidly solidified alloy ribbon of Comparative Example, Comparative Example 13 is shown in FIG. 10 and Comparative Example 17 is shown in FIG. 11, respectively.

In Comparative Example 13 shown in FIG. 10, the halo pattern indicating the iron-based amorphous alloy centered around 45 degrees, which is seen in the amorphous structure, is not observed, and both the roll surface and the free surface are very strong in α-Fe (200). Since a peak indicating strong crystallinity is observed, it is presumed that α-Fe crystals oriented in the in-plane direction of the rapidly solidified alloy ribbon are present. In addition, in Comparative Example 17 shown in FIG. 11, a strong α-Fe crystal peak was confirmed, and it was judged that an amorphous structure was not obtained.

Comparative Example 21 shown in FIG. 12 shows the X-ray diffraction pattern of a rapidly solidified alloy ribbon produced under the same conditions as in Example 10, except for the cooling water temperature of the chill roll. The adhesion between the chill roll and the molten alloy is poor during rapid cooling of the molten metal, and the rapid cooling of the molten metal becomes uneven, resulting in a decrease in the overall molten metal quenching rate, and the α-Fe (200) on the free surface side exhibits very strong crystallinity. A peak is observed.

The rapidly solidified Fe-Si-B thick plate alloy ribbon obtained by the present invention can be suitably used as a low core loss laminated core that can be easily applied to reactors, various motors, generators, and the like. In addition, instead of the electromagnetic steel sheets that are widely used in various transformers and motors, etc., we have developed Fe-Si-B amorphous alloys that can be used for laminated cores, which feature low iron loss and high magnetic permeability, at low cost on a mass production scale. can be offered to the market at

REFERENCE SIGNS LIST 1 single roll molten metal quenching device 2 melting furnace 3 molten alloy 4 tilting shaft 5 hot water storage container 6 tapping nozzle 7 slit 8 cooling roll 9 rapidly solidified alloy ribbon

Claims

A molten Fe-Si-B alloy essentially containing iron (Fe), boron (B) and silicon (Si) is ejected from a tapping nozzle onto the surface of a chill roll, and the chill roll is moved at a surface speed of 15m/sec or more to 50m. /sec or less, and quenching the molten alloy on the surface of the cooling roll to produce an alloy ribbon,
The tapping nozzle has slits with a width of 0.2 mm or more and less than 1.2 mm formed in two or more rows and four or less rows along the forming direction of the alloy ribbon,
The cooling roll has a curvature of 8 × 10 -4 or more and less than 2 × 10 -3 ,
Cooling water at a temperature of 5°C or higher and lower than 60°C is passed through the cooling roll at a cooling water rate of 0.3 m 3 /min or higher and lower than 20 m 3 /min, resulting in an average thickness of 30 µm or higher and lower than 70 µm and an average width of 50 mm or higher. A method for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon having a length of less than 200 mm and containing an amorphous alloy structure of 90% by volume or more.
The slits of the tapping nozzle have the same length in the range of 45 mm or more and less than 200 mm, and the distance between them is 0.5 mm or more and less than 5.0 mm,
2. The method for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon according to claim 1, wherein the distance from the tip of the tapping nozzle to the surface of the cooling roll is 0.15 mm or more and less than 30 mm.
A molten Fe-Si-B alloy essentially containing iron (Fe), boron (B) and silicon (Si) is ejected from a tapping nozzle onto the surface of a chill roll, and the chill roll is moved at a surface speed of 15m/sec or more to 50m. /sec or less, and quenching the molten alloy on the surface of the cooling roll to produce an alloy ribbon,
The tapping nozzle has a single slit with a width of 0.5 mm or more and less than 1.5 mm,
The cooling roll has a curvature of 8 × 10 -4 or more and less than 4.0 × 10 -3 ,
Cooling water at a temperature of 5°C or higher and lower than 60°C is passed through the cooling roll at a cooling water rate of 0.05 m 3 /min or higher and lower than 0.3 m 3 /min, so that the average thickness is 30 µm or higher and lower than 70 µm, and the average width is 5 mm or higher. A method for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon, which is less than 50 mm and contains an amorphous alloy structure of 90% by volume or more.
The length of the slit of the tapping nozzle is 4 mm or more and less than 50 mm,
4. The method for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon according to claim 3, wherein the distance from the tip of the tapping nozzle to the surface of the cooling roll is 0.15 mm or more and less than 30 mm.
The cooling roll is made of a material mainly composed of Cu, Mo or W, has a surface arithmetic mean roughness Ra of 10 nm or more and less than 20 μm, and a length of 50 mm or more and less than 400 mm than the length of the slit. 4. The method for producing a rapidly solidified Fe--Si--B thick plate alloy ribbon according to claim 1 or 3, wherein the thin strip is formed to be long and has a thickness of 5 mm or more and less than 50 mm from the surface to the flow path of the cooling water.
The method for producing a rapidly solidified Fe-Si-B thick plate alloy ribbon according to claim 1 or 3, wherein the molten alloy jetted from the slit has a tapping pressure of 2 kPa or more and less than 60 kPa.
The composition formula of the molten alloy is T loo-x-y-z-n Q x Si y M n (T is at least one element selected from the group consisting of Fe, Co and Ni, and Fe must be containing transition metal elements, Q is one or more elements selected from the group consisting of B and C and must contain B, M is P, Al, Ti, V, Cr, Mn, Nb, Cu, Zn, Ga, Mo, one or more elements selected from the group consisting of Ag, Hf, Zr, Ta, W, Pt, Au and Pb), and the composition ratios x, y and n are each 5 ≤ x < 20 atomic%, The Fe-Si-B system thickness according to claim 1 or 3, wherein 2 ≤ y < 15 atomic %, 0 ≤ n < 10 atomic %, and the composition ratio C / (B + C) of Q is 0 or more and less than 0.2. A method for manufacturing a rapidly solidified alloy ribbon.
The Fe-Si-B system thick plate rapidly solidified alloy ribbon produced by the method for producing a rapidly solidified Fe-Si-B system thick plate alloy ribbon according to claim 1 or 3 is processed into a desired shape. laminated core.