JP2009195967A - Apparatus and method for manufacturing amorphous alloy foil strip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for manufacturing an amorphous alloy foil strip, which can manufacture a thick amorphous alloy foil strip on an industrial scale. <P>SOLUTION: The apparatus 1 for manufacturing an amorphous alloy foil strip S is equipped with a pair of cooling rolls 13a and 13b, a driving means 11 which rotates the cooling rolls, and a crucible 14 which supplies molten alloy metal to the outer circumferential face of the cooling roll 13a and the outer circumferential face of the cooling roll 13b in sequence. The crucible 14 is movable along a rail 16. The molten alloy metal is supplied to the cooling roll 13a and the cooling roll 13b alternately while the cooling rolls 13a and 13b are rotated and water-cooled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method of an amorphous alloy foil strip, and more particularly to a manufacturing apparatus and a manufacturing method of an amorphous alloy foil strip provided with a cooling roll.

  Conventionally, it has been studied to use an iron-based amorphous alloy with low power loss for the iron core of a transformer or a motor, and some transformers have been put into practical use. However, it has not been put to practical use in motors, and transformers are limited to wound iron cores. This is because the thickness of the amorphous alloy foil strip produced on an industrial scale is as thin as 25 μm or less. If thick foil strips are manufactured industrially, they can be applied to motors and iron core transformers. Thickening the foil strip improves the work efficiency of the iron core machining process and increases the space factor. Further, the mechanical strength of the iron core is remarkably increased by improving the rigidity of the foil strip. In other words, it can be applied to motors and stacked iron cores in which foil strips are laminated to form an iron core.

  The most common method for producing amorphous alloys is to rapidly cool the molten alloy by bringing the molten alloy into contact with the outer surface of the roll while rotating a metal or alloy roll with high thermal conductivity at high speed. Then, a roll liquid quenching method for solidifying in a foil strip shape. However, the amorphous foil strip that can be produced by the roll liquid quenching method has severe restrictions, and it has not been possible to produce a thick foil strip having a sufficient thickness.

  Therefore, the present inventors have developed a multiple slit nozzle method in which a plurality of slits are arranged along the circumferential direction of the roll, and disclosed in Patent Document 1. According to this multiple slit nozzle method, the molten alloy discharged from each slit forms a plurality of hot water pools (paddles) corresponding to the number of slits in a narrow space between the nozzle and the roll. The portion of the first paddle that was in contact with the roll counted from the upstream side was cooled on the outer peripheral surface of the roll, and the supercooled fluid layer with increased viscosity was pulled out by the roll, and then pulled out from the downstream paddle. High viscosity layers overlap. The slit interval is set so that the next paddle overlaps in the supercooled liquid state of the high-viscosity layer formed on the upstream side, so an integrated amorphous alloy foil strip with no boundary between layers is obtained. It is done. At this time, the thickness of the foil strip becomes a thicker amorphous alloy foil strip as compared with the case where a conventional single slit nozzle is used.

  However, the multiple slit nozzle method also has the following problems. That is, the roll liquid quenching method includes a method using a non-water cooling roll and a method using a water cooling roll. The non-water-cooled roll cools the molten alloy by the heat capacity of the roll itself. When the non-water-cooled roll is used, the molten alloy can be efficiently cooled in a state where the roll temperature at the initial stage of production is low, and a certain amount of thick amorphous alloy foil strip can be produced. However, the non-water-cooled roll cannot be used for a long time because the cooling efficiency decreases as the roll temperature rises. For this reason, the amorphous alloy foil strip is not suitable for industrial mass production.

  For the above reasons, it is preferable to use a water-cooled roll industrially. Since the water-cooling roll has a built-in water-cooling mechanism, the heat can be exhausted through the cooling water even if the heat capacity of the roll itself is small. However, it has been difficult to mass-produce a thick amorphous alloy having a thickness exceeding 25 μm even on a water-cooled roll on an industrial scale.

JP 60-108144 A Japanese Utility Model Publication No. 6-86847 Japanese Patent Publication No. 61-059817

  An object of the present invention is to provide an amorphous alloy foil strip manufacturing apparatus and an amorphous alloy foil strip manufacturing method capable of manufacturing an amorphous alloy foil strip having a large plate thickness on an industrial scale. It is.

  According to one aspect of the present invention, the first cooling roll, the second cooling roll, the driving means for rotating the first and second cooling rolls, the outer peripheral surface of the first cooling roll, and the There is provided an apparatus for producing an amorphous alloy foil strip, characterized by comprising supply means for sequentially supplying molten alloy to the outer peripheral surface of the second cooling roll.

  According to another aspect of the present invention, supplying the molten alloy to the outer peripheral surface of the first cooling roll while rotating the first cooling roll, and supplying the molten metal by interrupting the supply of the temporary molten metal There is provided a method for producing an amorphous alloy foil strip characterized by alternately performing the step of restarting the supply of molten metal to the outer peripheral surface of a rotating second cooling roll after moving the apparatus.

  According to the present invention, an amorphous alloy foil strip manufacturing apparatus and an amorphous alloy foil strip manufacturing method capable of manufacturing an amorphous alloy foil strip having a large plate thickness on an industrial scale are provided. be able to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment of the present invention will be described.
FIG. 1 is a front view illustrating an apparatus for manufacturing an amorphous alloy foil strip according to this embodiment.
FIG. 2 is a cross-sectional view illustrating a portion where the molten alloy contacts the cooling roll in FIG.
FIG. 3 is a conceptual diagram showing a path of cooling water flowing through the cooling roll in FIG.

  As shown in FIG. 1, an amorphous alloy foil strip manufacturing apparatus 1 according to this embodiment mainly manufactures an iron-based amorphous alloy foil strip (hereinafter also simply referred to as “foil strip”) S. Is. In the manufacturing apparatus 1, two cooling rolls 13a and 13b (hereinafter collectively referred to as “cooling roll 13”) are provided on both sides of the driving means 11. The cooling rolls 13a and 13b are respectively rotated. The shaft is supported by shaft members 12a and 12b, and a motor (not shown) is built in drive means 11, and rotates cooling roll 13 via a pair of rotating shaft members 12a and 12b. 12 and the cooling roll 13 are supported by bearings 41, 41a, and 41b.

  The cooling rolls 13a and 13b are made of a metal or alloy having high thermal conductivity, and are made of, for example, copper or a copper alloy.

  In the manufacturing apparatus 1, a crucible 14 for holding the molten alloy A (see FIG. 2) is provided, and the molten alloy A in the crucible 14 is placed outside the crucible 14 at the lower end of the crucible 14. A nozzle 15 that discharges toward is attached. Here, the crucible is interpreted in a broad sense and includes all means for storing and supplying molten metal. A material that can receive molten alloy from an alloy melting device and supply the molten alloy to a cooling roll through a nozzle is called a crucible.

  Further, the manufacturing apparatus 1 is provided with a rail 16 extending in a direction from the cooling roll 13a toward the cooling roll 13b. As a result, the crucible 14 is guided by the rail 16, and the molten alloy A can be discharged from a direction perpendicular to the outer peripheral surface of the cooling roll 13a and from a direction perpendicular to the outer peripheral surface of the cooling roll 13b. It is possible to move between the positions. The discharge port of the nozzle 15, that is, the nozzle opening 17 is oriented in a direction perpendicular to the outer peripheral surface of the roll, and a slight gap is maintained between the outer peripheral surface of the cooling roll 13 a or 13 b. The crucible 14, the nozzle 15 and the rail 16 constitute supply means for the molten alloy A.

  As shown in FIG. 2, the nozzle 15 is a multi-slit nozzle. That is, the shape of the discharge port of the nozzle 15 is a shape in which a plurality of, for example, two slits 17 a and 17 b are arranged along the circumferential direction of the cooling roll 13. The longitudinal direction of each slit 17a and 17b is the same as the axial direction (roll width direction) of the cooling roll 13. Further, the distance between the slits 17a and b is, for example, 10 mm (millimeters) or less, for example, 6 mm or less. The nozzle 15 may be a multiple slit nozzle in which three or more slits are formed at the discharge port, or a single slit nozzle in which only one slit is formed.

  The nozzle 15 is formed of a refractory material that is difficult to wet the molten alloy A, and is formed of, for example, boron nitride, zirconia, or alumina. Thereby, it is difficult for the molten metal A to close the slit. That is, hot water runs out. In addition to the above-mentioned refractory material, even a refractory material that gets wet with the molten alloy can be used as the material of the nozzle 15 if the surface is coated with a material that is difficult to wet the molten alloy by spraying or the like. For example, silicon nitride is excellent in strength and thermal shock resistance. Further, the composite material of silicon carbide and boron carbide is conductive in addition to heat resistance, and it is easy to maintain the temperature of the nozzle during standby. However, since these materials react with iron in the molten alloy, it is necessary to coat them with a substance that is difficult to wet, such as boron nitride, zirconia, or alumina.

  FIG. 3 shows a simplified path of the cooling water W in the production of the amorphous alloy foil strip of the present invention. In FIG. 3, the cooling water W that cools the cooling roll 13 is supplied from a water storage tank 42 to a water channel 24 inside the cooling roll by a pump (not shown) via a water supply pipe 25, and then drains after flowing through the water channel 24. It is returned to the water storage tank via the pipe 26. In order to keep the cooling water below a predetermined temperature, for example, room temperature, during the casting, means 43 for cooling the cooling water W is provided in the water tank 42 in the middle of the path of the cooling water W, for example. As a cooling means, there are a method of installing a device applying a heat pump, a method of introducing a material having a temperature lower than room temperature, such as ice.

  Next, an operation of the manufacturing apparatus 1 according to this embodiment configured as described above, that is, a method for manufacturing an amorphous alloy foil strip according to this embodiment will be described.

First, as shown in FIG. 1, by driving the driving means 11, the cooling rolls 13a and 13b are rotated via the rotating shaft members 12a and 12b. Next, the molten alloy A is discharged from the crucible 14 through the nozzle 17 disposed close to the outer peripheral surface of the one cooling roll 13a at a predetermined interval. Thereby, the paddle P is formed between the nozzle 17 and the cooling roll 13a. If it does so, the part which is contacting the cooling roll among the molten alloys which form the paddle P will be cooled, a viscosity will become high, and it will be pulled out from the paddle P by rotation of the cooling roll 13a. The drawn alloy is a supercooled liquid at this point, but is rapidly cooled by a roll to become the glass transition temperature or lower and becomes an amorphous alloy foil strip S. In the case of an iron-based alloy, the cooling rate required for the foil strip (or supercooled liquid) drawn from the paddle to be amorphous is, for example, 1 × 10 ⁵ ° C./second or more.

  In the present embodiment, as shown in FIG. 2, two slits 17 are formed in the nozzle 15. For this reason, the plate | board thickness of the foil strip formed becomes thick compared with the case where a single slit is used, even if the circumferential speed of a cooling roll is the same. This is because the heat flow transmitted to the cooling roll can be dispersed by dividing the paddle.

  The heat transferred from the molten alloy and the foil strip to the cooling roll 13a to form the amorphous alloy foil strip is transmitted from the outer peripheral portion of the cooling roll 13a to the inside, and is transmitted to the cooling water W flowing in the water channel 24. . That is, the heat of the molten alloy A is discharged through the route of the molten alloy A → the cooling roll 13a → the cooling water W.

  When the temperature of the cooling roll 13a reaches a predetermined value as the foil strip S is cast, the nozzle 15 is closed and the discharge of the molten alloy A is stopped. Next, the crucible 14 is moved along the rail 16, and the nozzle 15 is disposed in proximity to the outer peripheral surface of the other cooling roll 13b. Subsequently, the nozzle 15 is opened again, and the molten alloy A is discharged toward the outer peripheral surface of the cooling roll 13b. Thereby, the foil strip S is cast by the cooling roll 13b by the same operation as that of the cooling roll 13a. That is, as shown in FIG. 4, the cooling roll used for casting of the foil strip S is switched from the cooling roll 13a to the cooling roll 13b. During this time, the cooling roll 13a is in a standby state, but the cooling water W is continuously supplied to the cooling roll 13a to cool the cooling roll 13a.

  Further, when the temperature of the cooling roll 13b reaches a predetermined value, the cooling roll used for casting the foil strip S is switched from the cooling roll 13b to the cooling roll 13a. By this time, the cooling roll 13a has returned to the temperature before casting, and the casting of the foil strip S can be resumed. During this time, the cooling water W is continuously supplied to the cooling roll 13b in the standby state, and the cooling is continued. Hereinafter, similarly, as shown in FIG. 4, the cooling roll 13a and the cooling roll 13b are alternately used, and the foil strip S is continuously manufactured.

  Thus, while rotating the cooling roll 13a, the molten alloy A is supplied to the outer peripheral surface of the cooling roll 13a, and the molten alloy A is not supplied to the outer peripheral surface of the cooling roll 13b. By alternately repeating the step of cooling the foil strip, the foil strip S can be continuously cast using a cooling roll having a temperature equal to or lower than a predetermined value.

Hereinafter, numerical examples in the present embodiment will be shown.
FIG. 5 is a ternary composition diagram illustrating the composition of the iron-based amorphous alloy foil strip produced in this embodiment. The iron-based amorphous foil strip S manufactured in the present embodiment has a width of, for example, 60 mm or more, and a thickness (plate thickness) of, for example, 30 μm (micrometer) or more, for example, 33 μm or more, for example, 40 μm or more. . In the present specification, the thickness of the foil strip is defined by the weight plate thickness. The weight plate thickness is a value obtained by dividing the weight of the foil strip by the area and density of the foil strip.

  Further, as shown in FIG. 5, the composition of the iron-based amorphous alloy foil strip S is obtained by adding, for example, silicon (Si) and boron (B), which are semimetals, to iron (Fe). is there. When this foil strip S is used for electromagnetic applications, the iron concentration is preferably set to 70% atomic% or more. The composition of the foil strip is, for example, the composition in the region R surrounded by the broken line in FIG. 5, that is, the iron content is 70 to 81 atomic%, the silicon content is 3 to 17 atomic%, boron The composition is such that the content is 9 to 23 atomic% and the glass transition temperature Tg is 500 ° C. or higher. Here, the sum of iron, silicon, boron, and unavoidable impurities is 100 atomic%. A part of iron may be substituted with cobalt (Co) or nickel (Ni). The total amount of substitution is 20 atomic% or less. Further, a part of silicon or boron may be substituted with 2.0 atomic% or less of carbon. However, the carbon substitution amount is set such that the glass transition temperature Tg is 500 ° C. or higher.

The reason why the glass transition temperature Tg is a requirement for composition selection is as follows. Conventionally, the easiness of making an alloy amorphous (amorphous forming ability) has been evaluated by the ratio of the melting point Tm of the alloy to the glass transition temperature Tg, Tm / Tg (here, absolute temperature). However, in practice, the contribution of the glass transition temperature Tg is more conspicuous than the melting point Tm, so the region R of the alloy composition is determined by the size of Tg. When the glass transition temperature Tg of the alloy is increased by 50 ° C., the limit thickness of the foil strip that can be made amorphous becomes at least 10% thicker. The measurement of the glass transition temperature Tg was difficult with an iron-based alloy, and thus the crystallization peak temperature T _p1 that was set to substantially the same temperature was used instead. The numerical value in FIG. 5 represents the crystallization peak temperature T _p1 (° C.).

Of the compositions in the region R shown in FIG. 5, specific compositions are shown for a group with a high saturation magnetic flux density, that is, a group with a saturation magnetic flux density Bs of 1.5 T (Tesla) or more and a group with a low hysteresis loss. It is shown in 1. Hysteresis loss, frequency 50 Hz (Hertz), a hysteresis loss _{Wh 13/50} in the magnetic flux density 1.3 T. In Table 1, both _{Wh 13/50} of the composition shown in the right column, when the heat treatment at optimal conditions, the value is less 0.08 W / kg. In addition, the number shown in Table 1 has shown atomic% of each component.

  Further, the foil strip S may contain 0.01 to 1.0% by mass of tin (Sn). Although the crystallization of the foil strip starts from the surface, tin has a strong tendency to segregate on the surface and has the effect of suppressing the crystallization of the foil strip surface layer. Thereby, the deterioration of the magnetic characteristics accompanying crystallization is suppressed.

Next, the manufacturing apparatus and manufacturing method used in the present invention will be described in detail.
The wall thickness of the cooling roll 13 shall be 25 mm or more. Here, as shown in FIG. 6, the thickness of the cooling roll is a distance from the outer peripheral surface of the cooling roll to the inner surface of the roll contacting the cooling water. When the cross section orthogonal to the water channel 24 is, for example, a circular pipe shape, the distance from the portion closest to the outer peripheral surface to the outer peripheral surface is the wall thickness 29 of the cooling roll as shown in FIG. When the cross section of the water channel is rectangular, the distance shown in FIGS. 6B and 6C is the wall thickness 29 of the cooling roll in the case of a rectangle with fins 28, respectively.

  Conventionally, the thickness of the cooling roll has been designed on the premise of continuous casting for a long time. The thinner the thickness, the more advantageous it is for heat removal, and 20 mm or less has been adopted. For example, in Patent Document 2, the thickness of the cooling roll (cooling sleeve) is defined as 3 to 10 mm, and the reason is described. According to this, when the thickness exceeds 10 mm, the cooling rate is greatly reduced, the local embrittlement of the amorphous alloy foil band becomes severe, and in particular, a foil band having a thickness of 25 μm or more that can be bent and bent cannot be obtained. ing. In addition, when the thickness is 3 mm or less, the heat deformation of the cooling roll is large, and the thickness of the quenched foil strip is uneven. Furthermore, the above publication proposes a method of causing a jet of cooling water to collide with the inner surface of a roll as means for thickening the amorphous alloy foil strip. However, even with this method, the effect of increasing the heat transfer coefficient between the roll and water is limited, and it has been difficult to produce an amorphous alloy foil strip having a plate thickness exceeding 30 μm (Patent Document 2).

  The reason why a thick amorphous alloy foil strip cannot be obtained with a conventional thin cooling roll will be explained based on experimental knowledge and heat transfer calculation. FIG. 7 is a schematic diagram of (a) the temperature change of the foil strip (including unsolidified fluid) during casting (corresponding to the distance in the downstream direction from the paddle) and (b) the temperature change of the surface of the cooling roll. It shows. The curves in the figure are: (1) thin roll (conventional method, eg 10 mm) and thin foil strip (eg 25 μm), (2) thin wall roll (conventional method, eg 10 mm) thick It shows the temperature change when manufacturing a thick foil strip (for example, 40 μm) with a thick foil strip (for example, 40 μm) and (3) a thick foil strip (for example, 40 μm) with a roll having a large thickness (for example, 30 mm).

The curve of (1) with respect to the foil strip is obtained when an amorphous alloy foil strip is obtained, and the time t ₁ from the melting point Tm of the alloy to the glass transition temperature Tg is short, and the foil strip is necessary for amorphization. It is cooled at a reasonable cooling rate. On the other hand, (2) is a case of manufacturing a thick foil strip using the same cooling roll, and the gradient of the temperature curve decreases more rapidly than the gradient of (1) as the glass transition temperature Tg is approached. time _{t 2} is much longer. That is, the cooling rate required for amorphization cannot be obtained.

When a thick foil strip is produced using a thick cooling roll (invention), the cooling curve is as shown in (3), and the decrease in gradient in the vicinity of the glass transition temperature Tg is compared to the condition in (2). small. Thus, foil strip at a cooling rate necessary for amorphization Since the time t ₂ to reach the Tg is greatly shorter than t ₃ is cooled, the thick amorphous Shitsuhaku band is formed.

  The standard for designing the thickness of the cooling roll is the thickness of the amorphous alloy foil strip to be manufactured. The thickness of the cooling roll 13 is increased according to the thickness of the foil strip. In order to form a thick foil strip having a plate thickness of 30 μm or more, the thickness of the cooling roll is preferably 25 mm or more. For example, when the thickness of the foil strip S is 45 μm or less, the thickness of the cooling roll 13 is 30 mm, and when the thickness of the foil strip S is 45 to 60 μm, the thickness of the cooling roll is 50 mm, When the plate thickness of the foil strip S is 60 to 120 μm, the thickness of the cooling roll is set to 100 mm.

  In carrying out the present invention, the peripheral speed of the cooling roll is, for example, 10 to 30 m / second, for example, 20 m / second. In the alternate casting method using twin rolls of the present invention, the switching timing is set according to the surface temperature of the cooling roll 13, for example. When the temperature on the paddle upstream side of the cooling roll 13a reaches, for example, 200 ° C., the cooling roll used for casting is switched to the cooling roll 13b. At this time, the measurement position of the cooling roll temperature is, for example, a position separated by 20 cm, for example, upstream from the nozzle 15. Moreover, if the plate | board thickness, width | variety, and casting conditions of foil strip S are constant, it can also switch based on the numerical value measured beforehand.

  According to the inventors' knowledge and heat transfer calculation, when a cooling roll 13 having a diameter of 1.2 m, a width of 40 cm, and a roll thickness of 30 mm is used, a foil strip S having a width of 15 cm and a plate thickness of 33 μm is obtained. It is possible to continue casting for 200 seconds continuously with one cooling roll. That is, it is possible to perform casting almost continuously by switching the cooling roll 13 every 200 seconds. In addition, when producing a foil strip S having a plate thickness of 40 μm, the time for continuous casting with one cooling roll is 140 seconds, and the time for producing the foil strip S having a plate thickness of 45 μm is: 100 seconds.

  In the case of manufacturing an amorphous foil strip using only one conventional cooling roll, it is extremely difficult to continuously cast a foil strip having a plate thickness of more than 30 μm. No matter how the shape, size, and cooling mechanism of the cooling roll are designed within a practical range, the temperature of the outer peripheral surface of the cooling roll continues to rise with the casting time. And if the temperature of a cooling roll outer peripheral surface rises exceeding the above-mentioned limit temperature (for example, 200 degreeC), the cooling rate required for amorphization will no longer be obtained, and a foil strip will begin to crystallize.

  In order to help the understanding of the heat transfer behavior, it will be described with reference to FIG. FIG. 8 shows (a) a thin foil roll (for example, 10 mm thick) with a thick foil strip (for example, a plate thickness of 40 μm), and (b) a thick foil strip (for example with a thickness of 30 mm) ( For example, the transition of the outer peripheral surface temperature of the cooling roll when producing a plate thickness of 40 μm is schematically shown. The temperature measurement position is, for example, 20 cm upstream of the paddle. Both (a) and (b) rise rapidly at the initial stage of casting, and then the rate of temperature rise decreases but increases linearly with a constant gradient.

Further, in the case of a thin cooling roll, the structure of the formed foil strip is amorphous up to the roll surface temperature _Taf1 , but when it exceeds that, crystallization starts. Further, when time elapses, a paddle break occurs at T _pb1 , and the foil strip is not formed thereafter. The tendency is the same in the case of the thick cooling roll, but the time until the crystallization starts and the time until the paddle break occurs are significantly increased. The slope of the straight line is larger for the thick cooling roll.

Further, the surface temperature T _{af of} the cooling roll at which crystallization starts and the roll surface temperature T _{pb at which} paddle break occurs are higher in the thick roll. _{That, T af1 <T af2, T} pb1 <T pb2, a. This is because the thick portion of the thick roll has a heat storage effect. Amorphization requires rapid cooling in the temperature range from the melting point Tm to the glass transition temperature Tg, but when the foil strip is thick, it cannot be handled by a conventional thin roll. Even if the roll diameter is increased, the heat flow in the temperature section cannot be absorbed. This is because the thin roll has a small heat capacity. On the other hand, the thick roll has its own heat capacity and can temporarily store a large amount of heat. Most of this heat is transferred to the cooling water and released during the round of the roll. However, a part is accumulated in the cooling roll and raises the roll temperature. In order to stop heat transfer from the roll to the water, it is effective to increase the diameter and width of the roll. It is also effective to keep the temperature of the cooling water low. By taking these measures, it is possible to lengthen the time during which continuous casting with one cooling roll 13 is possible.

  The diameter and width of the cooling roll 13 can be designed based on the heat transfer mechanism. That is, as the thick portion of the cooling roll 13 becomes thicker, the gradient of the linear portion in the temperature curve of the outer peripheral surface of the cooling roll in FIG. 8 increases. Increasing the diameter and width of the cooling roll 13 is effective for reducing this gradient and increasing the time until casting switching. This is because if the diameter of the cooling roll 13 is increased, the time for which the inner surface of the cooling roll comes into contact with the cooling water during one rotation becomes longer, and the amount of heat transferred from the cooling roll to the cooling water increases.

  In the present embodiment, the diameter of the cooling roll 13 is preferably 0.4 to 2.0 m. By setting the diameter of the cooling roll 13 to 0.4 m or more, a sufficient time is ensured during one rotation of the cooling roll. As a result, the heat transferred from the molten alloy to the outer peripheral surface of the cooling roll 13 is efficiently discharged into the cooling water. On the other hand, by setting the diameter of the cooling roll 13 to 2.0 m or less, the manufacturing apparatus 1 is prevented from being excessively large, operation becomes easy, and the strength of the mechanical parts such as the bearing of the cooling roll 13 is secured. Easy to do.

  Moreover, it is preferable that the width | variety of the cooling roll 13 shall be 1.5 times or more of the width | variety of the foil strip S which it is going to manufacture, for example. Thereby, the heat transmitted from the molten alloy A to the cooling roll 13 spreads in the width direction, and the amount of heat exhausted into the cooling water for each rotation of the cooling roll increases.

In order to further increase the cooling efficiency of the cooling roll, the cooling water W is cooled. The temperature of the cooling water W supplied into the cooling roll 13 is preferably 20 ° C. or less, and more preferably 10 ° C. or less. This is because the lower the temperature of the cooling water, the more efficiently the cooling roll 13 can be cooled and the thickness of the amorphous alloy foil strip that can be manufactured increases.
Further, after the solute is dissolved in the cooling water to lower the freezing point, the temperature of the cooling water W when it is supplied into the cooling roll 13 may be 0 ° C. or lower.

  In order to keep the temperature of the cooling water W supplied to the cooling roll 13 below the room temperature, the cooling water W illustrated in FIG. 3, for example, the water storage tank 42, the cooling means 43, for example, a refrigerator or air conditioning equipment. You may install a used heat pump. The above object can also be achieved by means of putting ice into the water storage tank 43. In addition, when the temperature of the outer peripheral surface of a cooling roll becomes lower than room temperature, there exists a possibility of dew condensation. In order to prevent dew condensation, a gas containing no moisture such as dry air or nitrogen may be sprayed on the outer peripheral surface of the cooling roll. Gas spraying is performed before the start of casting. When casting is started, the temperature of the outer peripheral surface of the cooling roll immediately exceeds room temperature, so that it is not necessary to blow gas.

  Furthermore, it is preferable that the material of the cooling roll 13 has a high thermal conductivity, for example, a material having a higher thermal conductivity than 250 W / mK. More preferably, it is 300 W / mK or more. However, materials with high thermal conductivity tend to be inferior in mechanical strength and wear resistance. Therefore, when the strength or hardness of the outer peripheral surface of the cooling roll is insufficient, only the surface layer of the outer peripheral portion may be cured. Curing of the surface layer can be realized by, for example, ion implantation. In this case, in order to prevent the generation of cracks due to thermal stress, it is preferable to provide a concentration gradient to the implanted ions.

  The nozzle 13 used in the production of the amorphous alloy foil strip of the present invention is a slit nozzle, and the width of the slit measured in the circumferential direction of the cooling roll is 0.2 to 1.2 mm, for example, 0.3 to 0.8 mm. The nozzle type may be a single slit, but a multiple slit is more preferable in terms of productivity. In the case of a single slit nozzle, the peripheral speed of the cooling roll 13 is set to be slow. According to experience, the plate thickness is inversely proportional to the peripheral speed. The peripheral speed of the cooling roll 13 is, for example, 10 to 30 m / second, for example, 15 to 25 m / second. The distance (gap) between the nozzle 15 and the outer peripheral surface of the cooling roll is, for example, 0.1 to 0.4 mm, for example, 0.15 to 0.25 mm. The discharge pressure of the molten alloy A is, for example, 10 to 40 kPa, for example, 20 to 30 kPa.

  When the supply of molten alloy A (pouring) to the outer peripheral surface of the cooling roll 13 is started via the nozzle 15, the temperature of the outer peripheral surface of the cooling roll gradually rises except immediately after the start of pouring. Even if the outer peripheral surface temperature of the cooling roll 13 rises, for example, if it is 200 ° C. or less, the plate thickness of the foil strip is substantially constant, and the cooling rate necessary for amorphization is ensured. That is, an amorphous alloy foil strip S is obtained. Here, the measurement of the temperature of the outer peripheral surface of the cooling roll is performed, for example, at the center of the roll width and 20 cm upstream of the paddle P. For example, a contact-type thermometer is used for measuring the outer peripheral surface temperature of the cooling roll. A specific example is described in Patent Document 3.

  The timing of casting switching can also be determined by measuring the surface temperature of the formed foil strip S. The measurement position is preferably an appropriate position before the foil strip S is peeled from the cooling roll. The above contact thermometer can be used, but in the case of an Fe-based alloy, an infrared radiation thermometer can also be used. Monitoring the temperature of the foil strip S is a more direct means for determining the amorphous nature of the foil strip during casting.

  In addition, in the manufacturing apparatus 1 which concerns on this embodiment, you may cast intermittently using only the cooling roll 13 of one side. That is, when the cooling roll is rotated and the cooling water is supplied, the foil strip is cast. When the outer peripheral surface temperature of the cooling roll reaches a predetermined value, the supply of the molten alloy is stopped. At this time, the rotation of the cooling roll and the supply of cooling water continue. By stopping the casting and continuing the supply of cooling water, the temperature of the outer peripheral surface of the cooling roll is rapidly cooled. Thereafter, the casting is resumed when the temperature of the outer peripheral surface of the roll returns to room temperature, for example. In this way, although intermittently, a thick amorphous alloy foil strip can be produced on an industrial scale using a single cooling roll.

Next, the effect of this embodiment will be described.
In the present embodiment, two cooling rolls 13a and 13b are provided in the amorphous alloy foil strip manufacturing apparatus 1, and the foil strip S is cast by using them alternately. Thereby, about one cooling roll, casting and cooling will be repeated and temperature can be suppressed below to a predetermined value. As a result, an amorphous alloy foil strip having a large plate thickness can be cast almost continuously, and can be manufactured on an industrial scale. Such an amorphous alloy foil strip can be used as, for example, a power transformer and a motor core. It can also be used as a magnetic shield material.

  Further, in the present embodiment, since a multi-slit nozzle is used as the nozzle 15, the plate thickness of the foil strip S can be made uniform and the occurrence of pinholes can be reduced. The surface properties of the foil strips S are microscopically disturbed due to minute vibrations of the paddle P and local defects of the cooling roll 13, and when the disturbance is large, fish scale-like striped patterns and pinholes called fish scales are observed. Is formed on the foil strip S and can be observed with the naked eye. When the multi-slit nozzle method is used, these defects formed in the fluid layer drawn out from the upstream paddle are compensated by the downstream paddle, so that the foil strip S having a good surface property and very few pinholes. Can be manufactured.

As described above, the surface of the amorphous alloy foil strip produced by the multiple slit nozzle method is smooth and has very few pinholes. The number density of pinholes in the foil strip is, for example, 25 pieces / m ² or less, for example, 10 pieces / m ² or less, for example, none. The space factor when foil strips are laminated is improved by reducing pinholes and smoothing the surface. For example, in the present embodiment, a foil strip having a plate thickness of 33 μm or more is manufactured, and when a wound iron core is manufactured using this foil strip, the space factor is 80% or more, and a foil strip having a plate thickness of 40 μm or more is manufactured. When an iron core is produced with this foil strip, the space factor becomes 85% or more. For example, when the plate thickness is 40 μm or more, the space factor is 90% or more. For example, in the case of a foil strip of 50 μm or more, the space factor is 93% or more. A foil strip having a smooth surface and few pinholes is preferable as an electromagnetic iron core material because it has a small hysteresis loss because there are few obstacles to domain wall movement. Furthermore, increasing the space factor has the same significance as increasing the saturation magnetic flux density Bs. For example, increasing the space factor from 80% to 90% has the same practical effect as increasing Bs from 1.60T to 1.78T.

  Moreover, in this embodiment, since the manufacturing apparatus 1 uses the thick cooling roll 13, the mechanical strength of the cooling roll is strong. As a result, it is possible to minimize the occurrence of fluctuations in the sheet thickness and characteristics of the foil strip S due to non-uniform thermal expansion of the cooling roll, and to manufacture a homogeneous amorphous alloy foil strip.

Next, a second embodiment of the present invention will be described.
FIG. 9 is a perspective view showing the structure of the cooling roll 13. As shown in FIG. 9, the cooling roll 13 has a hollow inside, and is on the side opposite to the side where the driving means 11 is disposed (hereinafter referred to as “driving side”) (hereinafter referred to as “water supply side”). An opening 20 is formed at the center of 19. The shape of the opening 20 is circular, and the central axis thereof coincides with the central axis of the cooling roll 13. That is, the cooling roll 13 has an open roll shape.

  Further, FIG. 10 shows a cross section from the outer peripheral surface of the cooling roll 13 toward the central axis. In FIG. 10, a plurality of partition plates 22 extending along the circumferential direction of the cooling roll 13 are formed on the inner peripheral surface 21 of the cooling roll, and the water supply side surface 19, the plurality of partition plates 22, and the drive A water channel 24 is formed between the side surfaces 23 on the side.

  A water supply pipe 25 and a drain pipe 26 are drawn into the cooling roll 13 through the opening 20. The water supply pipe 25 is connected to water supply means (not shown), and the drain pipe 26 is connected to a pump (not shown). The same number of branch pipes 25a as the water passages 24 are branched from the water supply pipe 25, and cooling water is supplied to each water passage 24 through each branch pipe. Further, the same number of branch pipes 26a as the water channels 24 are branched from the drain pipes 26, and cooling water is discharged from each water channel via the branch pipes 26a. The shape of the cross section orthogonal to the longitudinal direction of the branch pipe 26 a is, for example, a streamlined shape along the circumferential direction of the cooling roll 13. Thereby, the cooling roll 13 functions as a water cooling roll through which the cooling water W flows.

  Next, the operation of the second embodiment of the present invention will be described. First, as shown in FIG. 9, by driving the drive means 11, the cooling rolls 13a and 13b are rotated via the rotating shaft members 12a and 12b. At this time, the rotation speed of the cooling roll 13 is set to a rotation speed at which the centrifugal force in the water channel 24 is greater than the gravity.

  In this state, as shown in FIG. 10, the cooling water W is supplied to the water channels of the cooling rolls 13 a and 13 b through the water supply pipe 25. Thereby, the cooling water W in each water channel 24 rotates with the cooling roll 13, and reaches the whole of each water channel 24. That is, the cooling water W sticks to the inner surface of the cooling roll 13 by centrifugal force and does not fall on the upper part of the cooling roll 13. At this time, the distal end portion of the branch pipe 26a is inserted into the cooling water W.

  On the other hand, by operating a pump (not shown), the cooling water is discharged from each water channel 24 through the drain pipe 26. Thereby, a certain amount of cooling water W is held in the cooling roll 13. At this time, since the water channel 24 is opened toward the center of the cooling roll 13, the surface of the cooling water W on the center side of the cooling roll 13 is a free surface.

And as shown in FIG. 9, the crucible 14 is arrange | positioned by the side of the one cooling roll 13, for example, the cooling roll 13a, with the rail 16. As shown in FIG. And molten alloy A is discharged toward the outer peripheral surface of a cooling roll through the slit 17 from the nozzle 15, and is made to contact the outer peripheral surface of the cooling roll 13a. Thereby, the paddle P is formed between the slit 17 and the cooling roll 13a. Then, the portion of the molten alloy A forming the paddle P that is in contact with the cooling roll 13a is cooled to increase the viscosity, and is dragged to the outer peripheral surface of the cooling roll 13a to move in the rotation direction of the cooling roll 13a. On the other hand, it is cooled by the cooling roll 13a to become a supercooled metal fluid, then solidifies, becomes a temperature lower than the glass transition point, and becomes an amorphous alloy foil strip S. The cooling rate at this time is, for example, 1 × 10 ⁵ ° C./second or more.

  The heat transferred from the molten alloy A to the cooling roll 13a is transferred from the cooling roll 13a to the cooling water W through the inside of the roll. Then, the heat transmitted to the cooling water W is discharged to the outside of the cooling roll together with the cooling water W through the drain pipe 26. That is, the heat of the molten alloy A is transmitted through the route of the molten alloy A → the cooling roll 13a → the cooling water W.

  As the foil strip S is cast, the temperature of the cooling roll 13a gradually increases. When the temperature of the outer peripheral surface of the cooling roll reaches a predetermined value, the nozzle 15 is closed and the discharge of the molten alloy A is stopped. Next, the crucible 14 is moved along the rail 16 to be positioned on the side of the other cooling roll 13, that is, the cooling roll 13b. And the nozzle 15 is opened and the molten alloy A is discharged toward the outer peripheral surface of the cooling roll 13b. Thereby, the foil strip S is cast by the cooling roll 13b by the same operation as the operation of the cooling roll 13a described above. That is, as shown in FIG. 4, the cooling roll used for casting of the foil strip S is switched from the cooling roll 13a to the cooling roll 13b. During this time, the cooling roll 13a is in a standby state, but the cooling water W is continuously supplied to the cooling roll 13a to cool the cooling roll 13a.

  When the temperature of the cooling roll 13b reaches a predetermined value, the cooling roll used for casting the foil strip S is switched from the cooling roll 13b to the cooling roll 13a. By this time, the cooling roll has been sufficiently cooled, and the casting of the foil strip S can be resumed. During this time, the cooling water W is continuously supplied to the cooling roll 13b in the standby state, and cooling is continued. Hereinafter, similarly, as shown in FIG. 4, the cooling rolls 13 a and 13 b are alternately used to continuously manufacture the foil strip S.

  The mechanism for cooling the cooling roll used in the second embodiment of the present invention is heat transfer by convection of cooling water. Since the cooling roll 13 rotates at a high speed, a strong centrifugal force acts on the cooling water. The magnitude of this centrifugal force is 50 to 150 times that of gravity. For this reason, the temperature of the portion of the cooling water close to the roll rises, and a large buoyancy acts on this portion where the density is reduced. This becomes the driving force and forced convection occurs. For this reason, although the cooling water is almost stationary relative to the roll, it has a sufficient heat transfer effect.

  Furthermore, an advantage of employing an open roll as the cooling roll is that no air bubbles remain on the inner surface of the roll. Air bubbles rise by strong centrifugal force and disappear on the free surface. In the method of flowing water through a built-in water channel, the material of the foil strip formed due to the influence of uneven cooling due to residual air may be partially deteriorated. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the first embodiment described above.

  Next, Modification 1 of the second embodiment of the present invention will be described. The cooling roll used there has an open roll structure in which the inside is hollow and one side surface is open. Moreover, the some water path 24 extended in the circumferential direction of a cooling roll is formed by providing the partition plate 22 in an internal peripheral surface. Furthermore, as shown to Fig.11 (a), the branch pipe 25a of the water supply pipe 25 and the branch pipe 26a of the drainage pipe 26 are provided for every water channel 24 provided with the valve | bulb 44. As shown in FIG. Thereby, the flow volume of a cooling water can be made for every flow path 24, ie, for every position in the width direction of the cooling roll 13, and a heat flow rate can be controlled. Moreover, it can set to different water temperature for every water channel. By utilizing this, the temperature distribution in the width direction of the cooling roll 13 can be made uniform, and the cooling ability in the width direction of the cooling roll can be made uniform.

  FIG. 11A also shows a cross section of the cooling roll 30 used in the first modification. In FIG. 11B, for example, three fins 28 are provided in one water channel. Each of the partition plate 27 and the fin 28 extends in the circumferential direction, and the cross-sectional shape orthogonal to the longitudinal direction is a triangle. The height of the fin is made smaller than the height of the partition plate so as to be submerged. By providing the fins 28, the heat transfer efficiency can be further increased.

Next, Modification 2 of the second embodiment of the present invention will be described.
FIG. 12 is a cross-sectional view illustrating the periphery of the cooling roll of the amorphous alloy foil strip manufacturing apparatus 3 according to this embodiment. As shown in FIG. 12, in the manufacturing apparatus 3 for the amorphous alloy foil strip according to the embodiment of the present modification, as in the manufacturing apparatus 2 (see FIG. 9) according to the second embodiment, the driving means 11 (see FIG. 9), a pair of cooling rolls 33 is provided.

  And the drain pipe 26 (refer FIG. 9) is not drawn in the inside of the cooling roll 33, The through-hole 34 which flows cooling water toward the outer peripheral direction from a water supply side to the part far from the drive side of the cooling roll 33. Is formed. A convex portion 35 having a convex cross section is provided along the outer peripheral surface of the cooling roll at a portion closer to the drive side than the through hole 34 on the outer peripheral surface of the cooling roll 33. Further, a flange 36 is provided so as to cover an end portion of the cooling roll 33 on the water supply side, that is, a portion where the through hole 34 and the convex portion 35 are formed. The flange 36 is not in contact with the cooling roll 33 and is fixed to the floor surface. A drain port 37 is provided at the bottom of the flange 36.

  Furthermore, a lead-in port is provided on the side surface of the flange 36, and the water supply pipe 39 is drawn into the cooling roll 33 through the lead-in port 38 and the opening 20. The water supply pipe 39 is not provided with a branch pipe, and the cooling water W is supplied to the drive side portion in the cooling roll 33. Furthermore, the partition plate 22 (see FIG. 10) is not formed on the inner peripheral surface of the cooling roll 33. The configuration other than the above in the present embodiment is the same as that of the manufacturing apparatus 2 (see FIG. 9) according to the second embodiment of the present invention described above.

Next, the operation of the manufacturing apparatus 3 according to this embodiment will be described.
In the present embodiment, the cooling water W supplied into the cooling roll 33 via the water supply pipe 25 sticks to the inner peripheral surface of the cooling roll 33 by centrifugal force, and the circumferential direction of the cooling roll 33 with the rotation of the cooling roll 33. And moving from the drive side to the water supply side along the axial direction of the cooling roll 33. In this process, heat exchange is performed with the cooling roll 33. Then, the cooling water W is discharged to the outside of the cooling roll 33 through the through hole 34 by centrifugal force. The cooling water W discharged from the through hole 34 is received by the flange 36, collected at the lower portion of the flange 36 by gravity, and discharged through the drain port 37. Operations other than those described above in the present embodiment are the same as those in the second embodiment of the present invention described above. That is, the foil strip S is cast by using a pair of cooling rolls 33 alternately.

Next, the effect of this embodiment will be described.
In the present embodiment, since it is not necessary to insert a drain pipe into the cooling water W that rotates at high speed inside the cooling roll 33, vibration due to water resistance or the like hardly occurs, and mechanical reliability is high. Moreover, the water flow of the cooling water W is stabilized. The effects of the present embodiment other than those described above are the same as those of the above-described second embodiment of the present invention.

  Note that fins may be provided inside the cooling roll 33 in order to increase the contact area with the cooling water W. In this case, a cut is formed in the fin so that the cooling water W can move along the axial direction of the cooling roll 33. This facilitates the discharge of the cooling water W whose temperature has risen.

  As described above, the present invention has been described with reference to the embodiments and the modifications, but the present invention is not limited to these embodiments and modifications. For example, those in which the person skilled in the art appropriately added, deleted, or changed a design, or added, omitted, or changed a process for each of the above-described embodiments and modifications are the gist of the present invention. As long as it is provided, it is included in the scope of the present invention. In addition, the above-described embodiments and modifications can be implemented in combination with each other. For example, a method of providing a plurality of crucibles corresponding to the number of cooling rolls and sequentially supplying hot water by another hot water supply means, using a manufacturing apparatus provided with three or more cooling rolls, sequentially providing a plurality of openings in one crucible A method of supplying hot water to a plurality of cooling rolls is included in the scope of the present invention.

It is a front view which illustrates the manufacturing apparatus of the amorphous alloy foil strip which concerns on the 1st Embodiment of this invention. FIG. 3 is a cross-sectional view illustrating a portion where the molten alloy contacts the cooling roll in FIG. 2. It is a conceptual diagram which illustrates the path | route of the cooling water which cools a cooling roll in FIG. It is a timing chart which illustrates the manufacturing method of the amorphous alloy foil strip concerning a 1st embodiment, taking time on a horizontal axis and taking a cooling roll on a vertical axis. It is a ternary composition diagram illustrating the composition of the iron-based amorphous alloy foil strip produced in the present invention. Explanatory drawing which defines the thickness of the cooling roll in this invention It is a schematic diagram which illustrates temporal transition of (a) foil strip temperature during casting, and (b) temporal transition of roll outer peripheral surface temperature during casting, and is a figure for comparing the following conditions. (1) A thin foil strip with a small thickness roll, (2) a thick foil strip with a small thickness roll, and (3) a thick foil strip with a large thickness roll. The temporal transition is the temperature change of the foil strip and roll surface from the paddle position to the peeling position. It is a schematic diagram which compares the time change of the roll surface temperature during casting a thick foil strip with (a) when a thin roll is used, and (b) when a thick roll is used. It is a perspective view which illustrates the manufacturing apparatus of the amorphous alloy foil strip which concerns on the 2nd Embodiment of this invention. It is sectional drawing which illustrates the periphery of the cooling roll shown in FIG. It is sectional drawing of the periphery of the cooling roll in FIG. 9, (a) The branch pipe which provided the valve | bulb, (b) The roll with a fin is illustrated. It is sectional drawing of the cooling roll periphery in the amorphous alloy foil strip manufacturing apparatus which concerns on the modification of the 2nd Embodiment of this invention.

Explanation of symbols

1, 2, 3 Manufacturing device, 11 Driving means, 12a, 12b, Rotating shaft member, 13a, 13b Cooling roll, 14 Crucible, 15 Nozzle, 16 Rail, 17 Nozzle, 17a, 17b Discharge port (slit opening), 19 Open roll side surface, 20 Open roll opening, 21 Inner peripheral surface, 22 Partition plate, 23 Side surface, 24 Water channel, 25 Water supply pipe, 25a Branch pipe, 26 Drain pipe, 26a Branch pipe, 27 Partition plate, 28 Fin, 33 Cooling Roll, 34 Through-hole, 35 Convex part, 36 Flange, 37 Drain port, 38 Draw-in port, 39 Water supply pipe, 41, 41a, 41b Bearing, 42 Water storage tank, 43 Cooling means, 44 Valve, A alloy melt, P paddle, R region, S foil strip, W cooling water

Claims (18)

A first cooling roll;
A second cooling roll;
Driving means for rotating the first and second cooling rolls;
Supply means for sequentially supplying molten alloy to the outer peripheral surface of the first cooling roll and the outer peripheral surface of the second cooling roll;
An apparatus for producing an amorphous alloy foil strip, comprising:   The said 1st and 2nd cooling roll is a water cooling roll with which cooling water distribute | circulates inside, The manufacturing apparatus of the amorphous alloy foil strip of Claim 1 characterized by the above-mentioned.   The first and second cooling rolls are hollow inside, the central portion of one side surface is open, the cooling water is supplied through the opening portion, and is pivotally supported on the other side surface. The apparatus for producing an amorphous alloy foil strip according to claim 2, wherein:   The apparatus for producing an amorphous alloy foil strip according to claim 2 or 3, further comprising means for cooling the cooling water.   The thickness of the said 1st and 2nd cooling roll is 25 mm or more, The manufacturing apparatus of the amorphous alloy foil strip as described in any one of Claims 1-4 characterized by the above-mentioned.   The diameter of the first and second cooling rolls is 0.4 to 2.0 meters, and the width of the first cooling roll is 1.5 times the width of the amorphous alloy foil strip to be manufactured. The apparatus for producing an amorphous alloy foil strip according to any one of claims 1 to 5, wherein:   The amorphous alloy foil strip according to any one of claims 1 to 6, wherein the supply means includes a nozzle in which a plurality of slits are arranged along a circumferential direction of the cooling roll. Manufacturing equipment.   A step of supplying molten alloy to the outer peripheral surface of the first cooling roll while rotating the first cooling roll; a second rotating portion after the supply of the temporary molten metal is interrupted and the molten metal supply device is moved; A method for producing an amorphous alloy foil strip, characterized in that the step of restarting the supply of molten metal to the outer peripheral surface of a cooling roll is performed alternately.   9. The method for producing an amorphous alloy foil strip according to claim 8, wherein in each step, the cooling water is also circulated through a cooling roll in which the supply of the molten metal is interrupted.   For the first and second cooling rolls, use is made of a cooling roll having a hollow inside and having an opening at the center of one side surface, and supplying the cooling water through the opening, 10. The method for producing an amorphous alloy foil strip according to claim 9, wherein the first and second cooling rolls are pivotally supported on a side surface.   The method for producing an amorphous alloy foil strip according to claim 9 or 10, wherein the cooling water is cooled.   The manufacturing of the amorphous alloy foil strip according to any one of claims 8 to 11, wherein a cooling roll having a wall thickness of 25 mm or more is used for the first and second cooling rolls. Method.   For the first and second cooling rolls, a cooling roll having a diameter of 0.4 to 2.0 m and a width of 1.5 times or more the width of the amorphous alloy foil strip to be manufactured is used. The method for producing an amorphous alloy foil strip according to any one of claims 8 to 12, wherein:   In the first step, the molten alloy is discharged toward the outer peripheral surface of the first cooling roll by a nozzle in which a plurality of slits are arranged along the circumferential direction of the first cooling roll, In any one of 2 processes, molten alloy is discharged toward an outer peripheral surface with the nozzle in which the several slit was arranged along the circumferential direction of a said 2nd cooling roll, The any one of Claims 8-13 characterized by the above-mentioned. A method for producing the amorphous alloy foil strip according to claim 1.   The method for producing an amorphous alloy foil strip according to any one of claims 8 to 14, wherein a plate thickness of the amorphous alloy foil strip is 33 µm or more.   The composition of the alloy is such that the iron content is 70 to 81 atomic%, the silicon content is 3 to 17 atomic%, the boron content is 9 to 23 atomic%, and the glass transition point is 500. The method for producing an amorphous alloy foil strip according to any one of claims 8 to 15, wherein the composition has a composition of not lower than ° C.   17. The method for producing an amorphous alloy foil strip according to claim 16, wherein 0.01 to 1.0% by mass of tin is contained in the alloy. The method for producing an amorphous alloy foil strip according to any one of claims 8 to 17, wherein the number density of pinholes is 25 pieces / m ² or less.

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