JPH10323742A - Soft magnetic amorphous metal thin band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft magnetic amorphous metal alloy thin band which is excellent in a surface property even if the boron content is less than usual, wide and having 0.1 w/kg of the iron loss W13/50 . SOLUTION: An amorphous metal thin band quenched/solidified, which is obtained through expanding a basin formed by injecting a molten metal from a nozzle 4 with a slit like opening onto a cooling roll 2 rotating with a high speed by expanding the basin 3 on the cooling roll 2, and the composition of which is shown by a formula Fe B Si C, wherein a, b, c and d have the following relation: 75<=a<=81, 7<=b<=11.5, 8<=c<=15, 0.5<=d<=1.5 and a+b+c+d=100, and the iron loss W13/50 is 1 w/kg or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amorphous metal ribbon (including an alloy), and more particularly to a so-called soft magnetic amorphous material which is cast by quenching a liquid by a single roll method or the like and has excellent magnetization characteristics. Related to thin metal strips.

[0002]

2. Description of the Related Art In recent years, molten metal (liquid) has been quenched by a single roll method or a twin roll method to produce an amorphous metal ribbon (hereinafter simply referred to as a ribbon). In such a technique for manufacturing a ribbon directly from a molten metal, it is important how the thickness and surface properties are made uniform. In particular, since the ribbons used as the transformer material are laminated and used, the superiority and inferior surface properties of the individual ribbons determine the characteristics of the entire transformer. In other words, the deterioration of ribbon quality reduces the weight (occupancy rate) of the ribbon occupied in a transformer of a fixed volume, and the number of sheets used increases in order to exhibit the same performance as a transformer using good quality. Therefore, it is necessary to increase the size of the transformer. Now possible to obtain an excellent amorphous metal strip for transformer magnetization characteristics, it consists of three elements of Fe-B-Si, typically a composition of Fe ₇₈ B ₁₃ Si _9.

[0003] However, although the ribbon having the above composition has excellent magnetizing properties, it is not preferable in that it contains a large amount of boron (B), is expensive, and uses a large amount of a small amount of resources. For this reason, it is desired to obtain an inexpensive ribbon having a smaller amount of boron than the ribbon having the above-described composition and having better magnetization characteristics. However, when the amount of boron is reduced to 11.5% or less, the magnetization characteristics are deteriorated. In particular, the iron loss W _13/50 (watt) satisfying 0.1 W / kg or less is obtained by a single roll method or a twin roll method. There is no example manufactured by. Iron loss W _13/50 is 0.1W
/ Kg or less (1.3T, iron loss at 50 Hz excitation) is intended for a large iron loss exceeding 0.1 W / kg, the energy is wasted when a transformer is used, and a thinner than before. This is because the material becomes equivalent to a material such as a band or an electromagnetic steel sheet.

[0004] Further, the above-mentioned deterioration of the surface properties of the ribbon is as follows.
Air adsorbed on the surface of a high-speed rotating cooling roll (hereinafter simply referred to as a roll) enters in a layered manner between a molten metal pool on the roll (hereinafter referred to as a paddle) and the roll surface (boundary). It is said that the air is trapped inside the ribbon which is solidifying on the roll as it is. The mechanism by which the air layer enters this boundary is that the paddle is vibrated by some external force, changes the wetting angle formed between the roll surface and the paddle, and an air entangled portion (air pocket) into which air can easily enter is formed at the boundary. What can be done periodically. As a result, the produced ribbon has a fish-scale pattern (fish
Scale) is formed, and the surface properties of the ribbon are deteriorated. In particular, when the amount of B (boron) is as small as 10 or less in the composition ratio, it becomes difficult to make the composition amorphous, and in addition, when the surface property of the ribbon during solidification is poor,
Since the heat of the ribbon is not efficiently conducted to the roll and the ribbon is not quenched, it becomes more difficult to make the ribbon amorphous. Therefore, in the above-mentioned Fe—B—Si alloy, the iron loss W _13/50 is 0.1 W / kg or less, and the surface roughness Ra is 0.8 μm.
Hereinafter, the magnetic flux density B ₈ or more 1.50T, and / or those space factor when the laminated transformer satisfies more than 88% is at present, not obtained yet.

A great deal of research has been conducted on paddle vibration which deteriorates the surface properties of such a ribbon.
It is reported that there are different types of vibration. One of them is
The kinematic cause (capillary wave) is that the air impinges on the paddle, causing the surface film of the paddle to vibrate (capillary wave). The other one is that the air hits the paddle and the surface of the molten metal becomes uneven. This is due to a chemically reactive cause (Marangony effect), which oscillates and oscillates as a result of uneven surface tension.

On the other hand, methods for preventing deterioration of the surface properties of the ribbon due to these causes have also been studied in the past, such as diluting the air colliding with the paddle or replacing the air with a low-density inert gas or reducing gas. A number of methods have been disclosed. For example, JP-A-51-109221 discloses a method for producing an improved alloy filament in a reduced-pressure chamber.
However, this manufacturing method is effective in a laboratory or when manufacturing a small amount of thin ribbon, but has a problem that equipment cost and running cost are high for mass production. JP-A-59-209457 has proposed to improve the facility problem of the method described in JP-A-51-109221 and to use a low-density and high-temperature inert gas. However, low-density inert gases such as helium, krypton, and xenon, which are effective for this method, are very expensive, and also have a problem in running cost. Further, Japanese Patent Application Laid-Open No. 60-37249 discloses that, when producing a ribbon in an exothermic reducing atmosphere, inexpensive carbon monoxide is burned into a low-density reducing gas, and the running cost is reduced. Was solved. However, since carbon monoxide is a gas that causes an explosion hazard and poisoning of the human body, there is another safety problem. As a method for solving all of these problems, German Published Patent Application (DD 266046)
There is a ribbon manufacturing apparatus described in A1), and a method has been proposed in which CO ₂ gas is sprayed near the paddle to greatly improve the surface properties of the ribbon. However, the method is also 100m
When the width of the ribbon is not less than m, there is another problem that stable surface roughness (measured by the center line average roughness measurement method specified in JIS, the smaller the value, the more preferable) cannot be obtained. Was. In addition, the method is good for producing a ribbon of about several tens to several hundreds of g on a laboratory scale, but there is no report on the production on an industrial scale of several hundred kg to several tens ton.

[0007]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a soft material having excellent surface properties, a wide width and a _core loss _W13 / ₅₀ of 0.1 W / kg even if the boron content is lower than usual. It is an object to provide a magnetic amorphous metal alloy ribbon.

[0008]

SUMMARY OF THE INVENTION The inventor, in order to achieve the above object, in the chemical formula comprising _{Fe a B b Si c C d} , 75
≦ a ≦ 81, 7 ≦ b ≦ 11.5, 8 ≦ c ≦ 15, 0.5
Using the molten alloy of ≦ d ≦ 1.5 and a + b + c + d = 100 as the starting molten metal, we have made intensive studies on the utilization technology of CO ₂ gas and succeeded in producing a soft magnetic amorphous metal ribbon with excellent surface properties. did.

That is, according to the present invention, a molten metal is injected from a nozzle having a slit-shaped opening on a cooling roll rotating at a high speed to form a pool on the cooling roll, and the pool is spread and solidified by rapid cooling. an amorphous metal strip, _{composition, Fe a B b Si c C} d of formula with 75 ≦ a ≦ 81,
7 ≦ b ≦ 11.5, 8 ≦ c ≦ 15, 0.5 ≦ d ≦ 1.5
And a + b + c + d = 100, and iron loss W _13/50
Is 0.1 W / kg or less. However, all of a, b, c, and d are atomic%.

[0010] The present invention also provides a surface roughness Ra of 0.8 μm.
m or less, the magnetic flux density B ₈ of 1.50T or more, and / or a soft magnetic amorphous metal strip characterized by comprising the space factor when the laminated transformer as 88% or more. further,
The present invention is characterized in that the surface of the cooling roll is cleaned by blowing CO ₂ gas to which ultrasonic vibration has been applied, on the upstream side of the cooling pool position in the rotation direction of the cooling roll. It is a magnetic amorphous metal ribbon.

In addition, the present invention is a soft magnetic amorphous metal ribbon characterized in that the CO ₂ gas has a flow rate (Q) satisfying the following formula (1). _{N · W 0/140 ≦ Q} ≦ N · W 0/50 ... (1) However, Q: CO ₂ gas flow rate _{^{(m 3 / min) W 0}} : a width of the ribbon (mm) N: An additional number of slits According to the present invention, before the CO ₂ gas is blown, the cooling roll surface is previously washed by blowing dry air to which ultrasonic vibration is applied, and the contaminated dry air is removed by suction. This is a soft magnetic amorphous metal ribbon.

According to the present invention, a composition having excellent surface properties and a wide composition (particularly, a width of 200 mm or more) is represented by the chemical formula Fe _a
In _{B b Si c C d, 75} ≦ a ≦ 81,7 ≦ b ≦ 11.
5,8 ≦ c ≦ 15,0.5 ≦ d ≦ 1.5 and a + b +
c + d = 100, and iron loss W _13/50 ≦ 0.1 W / k
g, surface roughness Ra ≦ 0.8 μm or less, magnetic flux density B ₈ ≧
1.50 T and / or a soft magnetic amorphous metal ribbon having a space factor of ≧ 88% can be provided. In addition, the soft magnetic amorphous metal ribbon according to the present invention can be manufactured at a low cost with simple equipment modification, low running cost, and the working environment is good, and safe work can be performed.

[0013]

Embodiments of the present invention will be described below. First, a thin strip according to the present invention, the formula Fe _a B _b S
In _{i c C d, 75 ≦ a} ≦ 81,7 ≦ b ≦ 11.5,8 ≦
c ≦ 15, 0.5 ≦ d ≦ 1.5 and a + b + c + d = 1
The reason for limiting to 00 is as follows.

8 ≦ b ≦ 11.5 B is an element that is particularly important for amorphization, and the upper limit is set to 11.5 at.% Because a ribbon beyond that has conventionally existed. It is. The reason why the lower limit is set to 7 atomic% is that if it is less than 7 atomic%, crystallization becomes extremely easy, and even if the surface is purified according to the present invention, the magnetic properties deteriorate. It is because 75 ≦ a ≦ 81 Fe greatly affects the magnetic properties of the ribbon, and if it is less than 75 atomic%, the magnetic flux density of the ribbon becomes too low and is not practical. Also, the upper limit was set to 81 atomic% because:
When the value exceeds this value, the iron loss of the ribbon becomes too large, which is not suitable for practical use. 8 ≦ c ≦ 15 The reason why the lower limit of the Si content is set to 8 atomic% is that if it is less than that, the Curie point becomes low, and the ribbon does not exhibit thermally stable magnetic properties. The reason why the upper limit is set to 15 atomic% is that if the upper limit is exceeded, the magnetic flux density of the ribbon becomes low, which is not practical. The reason why the amount of 0.5 ≦ d ≦ 1.5 C is set in the above range is that if the amount of C is less than 0.5 atomic%, the yield of boron when forming a ribbon becomes low.
If the content exceeds 5 atomic%, the ribbon does not exhibit thermally stable magnetic properties. The reason why the surface roughness Ra is preferably 0.8 μm or less is that if it exceeds 0.8 μm, good magnetic properties cannot be obtained, and a good space factor cannot be obtained. Is easily broken during casting,
This is because industrial production of the ribbon according to the present invention becomes difficult. The surface roughness is set at a cut-off value of 0.1 (characteristic length in which irregularities over a certain length or more are not measured).
It was measured as 8 mm.

The reason why the magnetic flux density B ₈ is preferably not less than 1.50 T (the magnetic flux density of the material in a magnetic field of 800 amps / m) is that if it is less than 1.50 T, the magnetic flux density of the ribbon is too low. This is because a problem may occur in designing and manufacturing the transformer. The reason why the space factor is preferably 88% or more is that if the space factor is less than 88%, when laminated on a transformer, the transformer becomes relatively large, a large number of windings are required, and copper loss increases. is there. Next, the method for producing a soft magnetic amorphous metal ribbon according to the present invention will be described with a background to the invention.

At present, if the amount of B (boron) in the amorphous metal ribbon for an Fe-B-Si transformer is less than 11.5% by weight, magnetic properties such as iron loss deteriorate. Also, when attempting to obtain a wide ribbon having the composition by a single roll method, the ribbon was easily broken and could not be easily produced. This is because, when the amount of boron is reduced, the metal ribbon having the above-mentioned composition is hardly amorphized at the time of solidification, not only deteriorating magnetic properties but also embrittlement of the ribbon itself. Therefore,
The inventor has conducted intensive studies on the causes of the deterioration of the magnetic properties and the embrittlement of the ribbon, and has obtained the following conclusions.

That is, when observing the surface of the ribbon, many crater-shaped depressions are present. This is because gas is generated between the paddle, which is a molten metal, and the roll surface during the solidification process during the production of the ribbon. It is inferred that heat is not efficiently transmitted from the paddle to the cooling roll due to the intervening heat insulating effect. If this dent can be reduced dramatically,
Heat transfer is performed smoothly, cooling speed is improved, and iron loss W
_It was thought that an ideal amorphous metal ribbon of 0.1 / W was obtained at 13/50. In addition, the inventor has understood the meaning of "making the vicinity of the paddle a CO ₂ gas atmosphere" described in the above-mentioned German Published Patent Application as follows.
CO ₂ is heated by the external heat of the molten metal or the like to cause a gas decomposition reaction of the following formula, and the active oxygen generated by this decomposition uniformly forms an oxide film represented by the following formula on the paddle surface.

CO ₂ → CO + O (O) + (Fe, Si, B) → (Fe ₂ SiO ₄ , Si
O ₂ , B ₂ O ₃ ) Due to the formation of this uniform oxide film, the temperature at the interface of the molten metal decreases, and the viscosity increases. As a result, on the upstream side of the paddle, the contact angle between the paddle and the roll approaches 90 degrees, the incoming air is rebounded, and the entrainment of air into the paddle is reduced. Thus, air pockets normally occurring on the surface of the ribbon are reduced, and the surface roughness of the ribbon is improved.

According to further studies by the inventor,
It has also been found that air entrained in the paddle expands to form the air pocket. When the atmosphere of CO ₂ gas is used, the CO ₂ gas becomes high temperature of 1200 ° C. or more before the CO ₂ enters the paddle, the thermal expansion in the paddle is reduced, and the formation of air pockets can be prevented. . However, since the air layer and fine particles generated by the rotation air and the fine particles generated by the high-speed rotation of the roll adhere to the surface of the roll, and the air layer and the fine particle dust formed are strong, the vicinity of the paddle is C
It cannot be easily removed just by setting it to an O ₂ gas atmosphere. When the air layer and the fine particle dust enter the paddle as they are, the effect of spraying the CO ₂ gas is reduced.

Therefore, the inventor firstly defined this air layer as:
CO ₂ as well as blowing gas, it adds ultrasound, as well as broken by an impact energy of ultrasonic, consider how to peeling particulate dust on the roll surface, further, in this blowing, CO ₂ The gas was adsorbed on the roll surface to complete the present invention. Specifically, FIG.
This is performed by using the apparatus shown in FIG.

It has a built-in ultrasonic generator 7 and CO ₂
It is a simple one consisting of a pressure header 5 for injecting a gas 6 onto the surface of the chill roll 2. However, in the present invention, a great effect can be achieved by arranging the device at an appropriate position of the roll 2 (the distance indicated by the symbol 9 is upstream of the paddle 3 in the rotation direction 8 of the roll 2). Was. Also, the CO ₂ supplied from the pressure header 5
The gas 6 also exerted an effect of adsorbing on the surface of the roll 2. In general, the ultrasonic oscillator has a frequency of 20 to 50.
Those having a capacity of 100 to 200 db (800 to 1500 watts / m ² ) at kHz are used,
900-1100 watts / m ² at 0 kHz is more preferred. If it is too strong, turbulence will occur, and if it is too weak, the air layer cannot be destroyed.

Next, the inventor of the present invention has proposed that the width and the width be 100 mm or more.
In the production of obi 4, the above CO_Two Blowing of gas 6 onto the roll surface
This will result in non-uniform
I knew it. Therefore, as a countermeasure, CO_Two Gas 6
A spraying technique that reaches the position corresponding to both ends of the ribbon 4
I thought about the art. Specifically, as shown in the plan view of FIG.
And CO from the pressure header 5_Two Out of gas 6
The length L of the slit-shaped opening 10 provided in the mouth is determined by
The width W of the band 4 is 1 to 1.4 times, and the opening thickness d is
0.2 to 0.7 mm. Also, at that time, pressure
・ CO in header 5 _Two The pressure of gas 6 is 10 to 30 kPa
In that case, you can get a bigger spray effect
Came.

Further, the inventor has studied to further promote the effect of spraying the CO ₂ gas, and has appropriately selected the gas flow rate. In other words, the inventor has applied various operations such as the length L and thickness d, the number of slits, the width W of the ribbon 4, and the roll peripheral speed that affect the properties of the ribbon 4 to be cast. The factors were studied diligently, and an appropriate region for the following CO gas flow rate was determined.

[0024] _{N · W 0/140 ≦ Q} ≦ N · W 0/50 where, Q: CO ₂ gas flow rate ^{(m 3 / min), W} 0:
The width (mm) of the ribbon, N: the number of slits. The reason why the number of slits is plural is that if the number of the headers is plural, many slits perpendicular to the traveling direction of the ribbon 4 are provided.

FIG. 3 shows an experimental result of obtaining the above relational expression. When casting a ribbon 4 having a width (W ₀ ) of 200 mm and 50 mm, one or three slit-shaped openings (aperture thickness d = 0.5 mm constant) having the same opening length L as the ribbon 4 are provided. , By variously changing the flow rate of the CO ₂ gas 6,
This is a summary of the gas blowing effect. The numerical value 50 on the horizontal axis is the width of the ribbon 50 mm × the number of slits 1, and the numerical value 150 is the width of the ribbon 50 mm × the number of slits 3 and the numerical value 20.
0 is the width of the thin strip 200 mm x the number of slits 1 and the numerical value 600
Means 200 mm width of the ribbon × 3 slits. Than 3, is less than the flow rate Q is N · W _0/140, ultrasonic waves are not generated, and the CO ₂ concentration is less than 20% of the recovered gas after blowing in (remaining air), the cleaning effect of the roll 2 It is clear that this cannot be expected.

In addition to the above invention, the inventor considered removing the air layer or reducing particulate dust before blowing the CO ₂ gas 6. And in the present invention,
Ultrasonic waves were applied to the dry air 11 as a means to destroy the air layer by the impact energy, and also to remove the fine particle dust on the roll surface. That is, it is also possible to immediately suction and remove the air layer, the fine particle dust, the water vapor, and the like that have been peeled off in advance, and then continuously spray the CO ₂ gas 6 to uniformly adsorb the surface of the roll 2 to clean the surface around the paddle 3. I did it. At that time, this also CO ₂ gas 6 to generate ultrasound to break the following rotation air layer remaining, and the effective adsorption to the roll surface of the CO ₂ gas 6. Here, the reason why dry air is used is that the density and dew point of other gases are not appropriate and effective ultrasonic waves cannot be obtained. Also, the suction of the used dry air after that,
This is because polluted air is quickly removed by keeping the discharge flow of the stripping air constant, and thereafter, the CO ₂ gas is easily adsorbed on the surface of the roll 2.

[0027]

【Example】

 (Embodiment 1) The ribbon manufacturing apparatus according to the present invention shown in FIG.
Using the following conditions, cast a ribbon 4 of a molten metal alloy
did. Molten metal: Fe₈₀B_TenSi₉ C₁ (Atomic%) Temperature: 1300 ° C Length of slit-shaped opening of casting nozzle (width W of ribbon): 20
0 mm Roll (made of water-cooled copper alloy): 1 m outer diameter Roll peripheral speed: 25 m / sec Slit opening length L of pressure header: 150 m
m Pressure header slit opening thickness d: 0.3 m
m Gas pressure in pressure header: 0.2kgf / cm
^Two Also, a means for cleaning the roll surface, that is, the above ultrasonic generator
7 with built-in CO_Two The pressure header 5 for gas 6
At the upstream side in the rotation direction of the roll 2 from the position of the paddle 3, the circumference is
It was arranged at a position of 50 mm. CO_Two Flow rate of gas 6
Is 0.8 Nm ^Three / Min, and the applied ultrasonic wave is
1 kW / m at 25 kHz wavenumber^Two (150db)
Was. After spraying, the atmosphere gas at the paddle position
CO_Two The concentration was 20% (the balance was air).

As a result, it is presumed that the air layer adhering to the surface of the roll 2 was destroyed by a thickness of about 10 μm by the so-called knife effect of CO ₂ gas, and that an additional 10 μm could be destroyed by the effect of ultrasonic waves. The properties of the obtained ribbon 4 include:
As shown in FIG. 6, the surface roughness (Ra) in the width direction of the ribbon 4 was significantly improved, and Ra <0.8 μm was stably achieved.

[0029] In FIG. 6, as a comparative example, also shown results when the case using the air and CO ₂ gas atmosphere instead of CO ₂ gas. These results clearly show the effect of blowing the CO ₂ gas 6 according to the present invention. (Embodiment 2) By changing only the following conditions from Embodiment 1, CO2
Example 1 Spraying ₂ gas 6 on a fixed area of the roll surface
The ribbon 4 was further enlarged and cast from a molten metal alloy.

Length of slit-shaped opening (L) of pressure header 5: 220 mm Thickness of slit-shaped opening (d) of pressure header 5: 0.
5mm result, the air layer adhering to the surface of the roll 2, CO ₂
Destruction about 10μm thickness by so-called knife effect of gas 6,
As an effect of the ultrasonic wave, it can be estimated that 10 μm was further destroyed. As a property of the obtained ribbon 4, as shown in FIG. 7, the surface roughness (Ra) in the width direction was significantly improved,
Ra <0.8 μm was stably achieved.

FIG. 7 shows a case where the pressure header 5 having a slit-shaped opening length (L) of 70 mm (the gas pressure and the slit interval are the same as in the embodiment) and a CO ₂ gas without ultrasonic vibration. The case of an atmosphere is also shown as a comparative example. Further, casting was performed with the blowing gas and the slit-shaped opening length of the pressure header 5 changed variously, and the results shown in Table 1 were obtained (Table 1 also shows the results of Example 2 and Comparative Example above). is there).

[0032]

[Table 1]

It is clear from Table 1 and FIG. 7 that the properties of the obtained ribbon 4 are superior when the apparatus and the method according to the present invention are applied, as compared with the case where other methods and apparatuses are used. . In Table 1, B8 is the magnetic flux density (tesla) when magnetized with a magnetizing force of 800 amps / m. (Example 3) The ribbon 4 made of a molten metal alloy was cast as in Example 2 except that the flow rate of the CO ₂ gas 6 was changed. That is, preferred in the present invention and the CO ₂ gas flow rate (the relationship equation _{"N · W 0/140 ≦ Q} ≦ N
・ W _0/50 ”was selected and sprayed. Specifically, it is 1.5 m ³ / min.

As a result, the air layer adhering to the surface of the cooling roll 2 is destroyed by about 10 μm thickness by the so-called knife effect of the CO ₂ gas 6, and as a result of the ultrasonic wave, the air layer is further reduced to 10 μm
It is estimated that was able to be destroyed. Casting was also performed by changing the blowing gas and the slit-shaped opening length of the pressure header 5 in various ways, and the results are shown in Table 2 (Table 2).
Also shows the results of Example 3.)

[0035]

[Table 2]

From Table 2, it is clear that the properties of the cast ribbon 4 can be further improved than the results of Examples 1 and 2 by selecting an appropriate spray amount of the CO ₂ gas 6 according to the present invention. is there. In addition, W _13/50 in Table 2 is a frequency 5 so that the maximum magnetic flux density is 1.3 T (tesla).
This is the iron loss (watt (W) / kg) when magnetized at 0 Hz. (Example 4) After the surface of the roll 2 was preliminarily washed with dry air before blowing the CO ₂ gas 6, a ribbon 4 made of a molten metal alloy was cast under substantially the same conditions as in Example 1.

The difference from the first embodiment is that the gas pressure in the pressure header 5 is 0.3 kgf / cm ² , and the pressure header 5 is located about 150 mm upstream of the paddle 3 in the rotation direction of the roll 2. It is the point where it was arranged. Also,
The used pressure header 5 has an integral structure shown in FIG. 4 (separable type is also shown in FIG. 5), in which dry air 11 is jetted from the slit-shaped opening 10 of the header 5 on the upstream side, and it is sucked into the suction box 12. After that, the CO ₂ gas 6 is injected from the slit-shaped opening 10 on the downstream side. The flow rates of the dry air 11 and the CO ₂ gas 6 are 1.5
Nm ³ / min.

Table 3 shows the casting results. Table 3 shows many results of casting using the conventional method and apparatus in addition to Example 4 as comparative examples.

[0039]

[Table 3]

As can be seen from Table 3, the ribbon 4 cast by the method according to the present invention is superior to the comparative example in all of the roughness, iron loss, magnetic flux density and space factor. The situation is shown in Figs.
Shown in FIG. 8 is a comparison of the magnetic flux density exerted when the ribbon 4 is used for a transformer. As the ribbon 4, Examples 4 (ultrasonic + CO ₂ gas blowing) of the method of the present invention and Conventional method 1 ( These are obtained by three methods, namely, spraying only CO ₂ gas) and Conventional method 2 (simply casting in air). From FIG. 8, it is clear that the magnetic flux density of the ribbon 4 obtained by applying the present invention is much higher than that obtained by the conventional method.
FIG. 9 shows a similar comparison of iron loss. The iron loss is also greatly increased, indicating that the magnetism of the ribbon 4 is improved by the present invention. 10 shows the surface roughness (Ra, unit μm) of the ribbon 4 in the L direction (FIG. 10 (a)).
And C direction (FIG. 10B). As is clear from FIG. 10, the surface roughness of the ribbon 4 was also greatly improved by applying the present invention.

All of the above have been carried out with Fe ₈₀ B ₉ Si ₉ C ₁ (atomic%). Hereinafter, examples relating to the composition will be described. (Example 5) Under the same conditions as in Example 1, ribbons were produced with various compositions. The obtained ribbon was annealed at a temperature of 320 ° C. to 420 ° C. in an inert gas while applying a magnetic field of 20 (0 e) in the longitudinal direction, and the magnetic properties and surface roughness were measured.

Table 4 shows the results. In Table 4, for comparison, No. 12 to 15 show examples of materials cast in the air atmosphere and subjected to the same treatment. In Table 4,
Composition by a chemical formula of _{Fe a B b Si c C d} 75 ≦ a ≦ 8
1, 7 ≦ b ≦ 11.5, 8 ≦ c ≦ 15, 0.5 ≦ d ≦
1.5 and a + b + c + d = 100, ultrasound + C
The ribbon cast by spraying with O ₂ has a roughness Ra of 0.3 to
Iron loss W _13/50 is 0.10 W / kg or less at 0.5 [mu] m, the magnetic flux density B ₈ shows good magnetic properties and higher 1.538T. On the other hand, those out of the composition range and those cast without using CO ₂ all have a roughness Ra of 1.3 to
Either worse with 1.5 [mu] m, or iron loss W _13/50 even not bad roughness is 0.10 W / kg or more, the magnetic flux density B ₈ it can be seen that even has a 1.5T or less.

[0043]

[Table 4]

[0044]

As described above, according to the present invention, the present invention, the composition is the chemical formula _{Fe a B b Si c C d} , 75 ≦ a ≦ 81,7
≦ b ≦ 11.5, 8 ≦ c ≦ 15, 0.5 ≦ d ≦ 1.5 and a + b + c + d = 100, and iron loss W _13/50 ≦ 0.
A soft magnetic amorphous metal ribbon having 1 W / kg, surface roughness Ra ≦ 0.8 μm or less, magnetic flux density B ₈ ≧ 1.50 T, and / or space factor ≧ 88% by weight could be provided. In addition, the ribbon has a width of 200 mm or more, and is particularly effective for a transformer.

[Brief description of the drawings]

FIG. 1 is a side view showing an apparatus for manufacturing an amorphous metal ribbon according to the present invention and a situation around a paddle.

FIG. 2 is a plan view of FIG.

FIG. 3 is a diagram showing experimental results of determining an appropriate flow rate of CO ₂ gas.

FIG. 4 is a side view showing another embodiment (integrated type) of the apparatus for manufacturing an amorphous metal ribbon according to the present invention.

FIG. 5 is a side view showing another embodiment (separation type) of the apparatus for manufacturing an amorphous metal ribbon according to the present invention.

FIG. 6 is a diagram showing a surface roughness distribution (Example and Comparative Example) in the width direction of an amorphous alloy ribbon.

FIG. 7 is a view showing a surface roughness distribution in the width direction of the amorphous alloy ribbon (Example and Comparative Example).

FIG. 8 is a diagram showing magnetic flux densities (Examples and Comparative Examples) exhibited when an amorphous alloy ribbon is used for a transformer.

FIG. 9 is a diagram showing iron loss (Example and Comparative Example) exhibited when an amorphous alloy ribbon is used for a transformer.

FIG. 10 is a view showing the surface roughness of an amorphous alloy ribbon.
(A) corresponds to the L direction of the ribbon, and (b) corresponds to the C direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Nozzle (casting nozzle) 2 Cooling roll (roll) 3 Paddle (pool) 4 Thin strip (amorphous metal thin strip) 5 Pressure header (header) 6 CO ₂ gas 7 Ultrasonic oscillator 8 Roll rotation direction 9 Roll circumference 10 Slit opening 11 Dry air 12 Suction box 13 Gas suction direction 14 Air header 15 Suction blower 16 Ventilation blower 17 Tundish

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kennori Matsuki 1 Kawasaki-cho, Chuo-ku, Chiba Kawasaki Steel Engineering Co., Ltd. (72) Inventor Masao Yukimoto 2-3-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo Saki Steel Corporation

Claims (7)

[Claims] 1. An amorphous metal formed by injecting molten metal from a nozzle having a slit-shaped opening on a cooling roll rotating at a high speed to form a pool on the cooling roll, expanding the pool and rapidly solidifying it. a ribbon, _{composition, Fe a B b Si c C} d of formula with 75 ≦ a ≦ 8
1, 7 ≦ b ≦ 11.5, 8 ≦ c ≦ 15, 0.5 ≦ d ≦
1.5 and a + b + c + d = 100, and iron loss W
_13. A soft magnetic amorphous metal ribbon, wherein _13/50 is 0.1 W / kg or less. However, a, b, c, and d are atomic%. 2. The soft magnetic amorphous metal ribbon according to claim 1, wherein the surface roughness Ra is 0.8 μm or less. 3. The soft magnetic amorphous metal ribbon according to claim 1, wherein the magnetic flux density B ₈ is 1.50 T or more. 4. The method according to claim 1, wherein an occupying ratio when stacked on the transformer is 88% or more.
The soft magnetic amorphous metal ribbon according to any one of the above. 5. The cooling roll is characterized in that the surface of the cooling roll is cleaned by blowing CO ₂ gas to which ultrasonic vibration is applied, on the upstream side in the rotation direction of the cooling roll from the pool position. The soft magnetic amorphous metal ribbon according to claim 1. 6. The soft magnetic amorphous metal ribbon according to claim 5, wherein the CO ₂ gas has a flow rate (Q) satisfying the following equation (1). _{N · W 0/140 ≦ Q} ≦ N · W 0/50 ... (1) However, Q: CO ₂ gas flow rate _{^{(m 3 / min) W 0}} : a width of the ribbon (mm) N: number of slits 7. Before blowing the CO ₂ gas,
7. The soft magnetic amorphous metal thin film according to claim 5, wherein the surface of the cooling roll is cleaned by blowing dry air to which ultrasonic vibration is applied, and the contaminated dry air is removed by suction. band.