JP2002066698A - Manufacturing equipment for metal thin strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing equipment for a metal thin strip capable of supplying a molten metal from a tundish to a cooling roll stably without occurrence of clogging of a nozzle in a manufacturing equipment for the metal thin strip wherein the molten metal is poured from the nozzle of the tundish to the cooling face of the rotating cooling roll and rapidly cooled. SOLUTION: By winding an induction heating coil 37 around the body 31 of the tundish 31 and the nozzle 32 of its bottom portion, the molten metal inside the body is heated so as to maintain the temperature, and the molten metal passing through a narrow slot 33 formed on the nozzle 32 is heated for preventing occurring of the clogging in pouring the molten metal 50 to the cooling face of the cooling roll 41, thereby forming stably the metal thin strip for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a metal ribbon for pouring molten metal from a nozzle at the bottom of a tundish or crucible to a cooling surface of a cooling roll, and more particularly to a tundish or crucible. The present invention relates to a metal ribbon manufacturing apparatus in which an induction heating coil is wound around a main body and a bottom nozzle.

[0002]

2. Description of the Related Art The production of strip-shaped castings by quenching a molten metal has already been carried out, and many techniques have been proposed and put into practical use. Among them, Japanese Patent Laid-Open No. 5-2
22488, JP-A-6-84624, JP-A-8-2
29641, the method described in the examples of JP-A-2000-79449, that is, the method of pouring the molten metal from the tundish to the surface of the cooling roll with its head has a thickness of 0.05 mm or less. Such an extremely thin metal ribbon cannot be obtained. This is because if the width of the slot provided in the nozzle of the tundish is reduced in order to obtain an extremely thin metal ribbon, molten metal having a high viscosity will not flow out of the slot.

[0003] An apparatus for obtaining an extremely thin metal ribbon as described above,
Many techniques have been proposed for the manufacturing method, including the following.

(Conventional Example 1) Japanese Patent Publication No. 59-42586 discloses an apparatus for manufacturing a thin metal strip having a thickness of 0.05 mm × 50 mm, which (a) is movable at a surface speed of 100 to 2000 m / min. A cooling body, (b) a reservoir including heating means for maintaining the molten metal above its melting point, and a reservoir in communication with the slotted nozzle, (c) disposed proximate to the cooling surface, in a direction of movement of the cooling surface. An apparatus for continuous strip production of metal has been published, comprising a nozzle with a slot having a width of 0.2 to 1 mm, and (d) means for discharging molten metal in a reservoir from the nozzle. Then, as shown in FIG. 5 which is a perspective view of an example of the apparatus, the continuous strip manufacturing apparatus 100 includes a cooling roll 10.
7. An induction heating coil 10 as a heating means for maintaining the temperature of the metal above its melting point, comprising a reservoir 108 for holding the molten metal.
9 is provided. Further, the reservoir 108 is provided with means (not shown) for applying pressure to the molten metal contained therein and discharging the molten metal from the nozzle 110. Then, the molten metal flows through the cooling roll 10 through the nozzle 110.
7, the molten metal is immediately solidified to form the strip 111. It is noted that the reservoir 108 and the nozzle 110 are integrally formed of silica.

(Conventional Example 2) FIG.
FIG. 5 is a longitudinal sectional view of a nozzle for manufacturing a quenched ribbon shown in Japanese Patent Publication No. 5 (JP-A-5). When the molten metal is supplied from the nozzle at the bottom of the tundish, a heating element 203 for preheating is embedded at the tip of the nozzle slit 202 of the nozzle body 201 for quenching the ribbon to prevent nozzle clogging and nozzle cracking. The molten metal is poured into the surface of the cooling roll 204 via the nozzle slit 202 to form a quenched metal ribbon 250.

[0006]

In the continuous strip manufacturing apparatus 100 of the first conventional example, an induction heating coil 109 is provided on the outer periphery of a reservoir 108 of molten metal.
No induction heating coil is provided around 0, and this is the same in other drawings in which specific examples other than the above-described manufacturing apparatus 100 are shown. The molten metal in the reservoir 108 has a width of 0.2 mm formed at the tip of the nozzle 110.
Since the molten metal is poured from the slot of 1 mm to 1 mm, at the time of supplying the molten metal to the reservoir 108, the molten metal is likely to solidify in the slot and clog the nozzle easily. As the length increases, nozzle clogging may occur gradually.

[0007] Further, the nozzle 2 for manufacturing a quenched ribbon of the conventional example 2
In No. 01, the heating element 203 for preheating is embedded in the tip of the nozzle slit 202, but no heating means is provided in the nozzle body 201, and a decrease in the temperature of the molten metal 200 in the nozzle body 201 is inevitable. In addition, since the heating element 203 for preheating such as silicon carbide is used for heating the molten metal, the heating in the nozzle slit 202 is due to the heat transfer from the nozzle slit 202 whose temperature has been raised to the molten metal. It does not directly heat the metal and has poor response to temperature adjustment. Further, the preheating elements 203 having different thermal expansion coefficients are provided in the nozzle slits 202.
, The nozzle is easily cracked.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and causes a nozzle clogging in a metal ribbon manufacturing apparatus in which molten metal is poured from a slot of a nozzle of a tundish onto a cooling surface of a cooling roll rotating and rapidly cooled. It is an object of the present invention to provide a metal ribbon manufacturing apparatus capable of pouring a molten metal stably from a tundish to a cooling roll without causing the molten metal to flow.

[0009]

Means for Solving the Problems The above-mentioned problems can be solved by the structure of claim 1. The means for solving the problems will be described as follows.

The metal strip manufacturing apparatus according to the first aspect of the present invention is a metal strip manufacturing apparatus in which molten metal is poured from a nozzle at the bottom of a tundish or crucible to a cooling surface of a cooling roll rotating and rapidly cooled. Is an apparatus in which an induction heating coil is wound around the outer periphery of a main body and a nozzle. In such a metal ribbon manufacturing apparatus, the molten metal in the tundish or crucible itself is directly induction-heated, so that the molten metal is convected in the tundish or crucible to be uniformly heated to a certain temperature, and also to the nozzle. Since the molten metal itself is induction-heated even in the provided narrow slot, nozzle clogging does not occur at all even when the molten metal is discharged from the melting furnace body to the tundish or when the molten metal is poured from the nozzle to the cooling roll.

The metal ribbon manufacturing apparatus according to claim 2 is a device in which the body of the tundish or crucible and the nozzle are wound by independent induction heating coils. Such a thin metal ribbon manufacturing apparatus is capable of inductively heating a tundish or a crucible for keeping the temperature of the molten metal inside, and heating a nozzle having a narrow slot width so that the heat of the molten metal is easily taken away by an optimum frequency of a high frequency. can do. Claim 3 dependent on claim 1
In the apparatus for manufacturing a metal ribbon, at least one of the body and the nozzle of the tundish or crucible is made of boron nitride. In such a thin metal ribbon manufacturing apparatus, the heat of the main body is easily transmitted to the nozzle due to the high thermal conductivity of boron nitride, and a temperature difference is hardly generated in the molten metal from that surface as well.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, a metal ribbon manufacturing apparatus according to the present invention is capable of pouring molten metal from a slot formed in a nozzle of a tundish or crucible to a rotating cooling roll and rapidly cooling the molten metal. In a manufacturing apparatus, an induction heating coil is wound around a main body of a tundish or crucible and an outer peripheral portion of a nozzle.

The induction heating coil wound around the outer periphery of the main body of the tundish or crucible and the nozzle can be wound continuously with one induction heating coil. In this case, the number of turns of the induction heating coil in the main body portion and the nozzle portion is set so that an optimum heating state is obtained in each case. Further, as is well known, the capacity of an object to be heated, the depth of penetration of high frequency, and the like differ depending on the frequency used. Therefore, the tundish or crucible main body and the nozzle may be independently heated by different induction heating coils, thereby heating the molten metal in the main body and the molten metal in the nozzle at a high frequency of an optimum frequency. It becomes possible to do.

Further, the body and nozzle of the tundish or crucible may be made of a material that does not easily react with the molten metal, and the tundish or crucible is made of a commonly used material. However, among them, boron nitride is excellent in thermal conductivity and is the most preferable material especially for a nozzle.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a metal ribbon manufacturing apparatus according to the present invention.

(Embodiment) FIG. 1 is a longitudinal sectional view of a melting and casting chamber 1 of a metal ribbon manufacturing apparatus. A melting chamber 3 in which a tundish 31 is provided by a partition 2;
The cooling and solidifying chamber 4 in which the cooling roll 41 is provided is defined. A vacuum exhaust pipe 38 and an argon (Ar) gas introducing pipe 39 as an inert gas are connected to the melting chamber 3, and a vacuum exhaust pipe 48 and an Ar gas introducing pipe 49 are connected to the cooling and solidifying chamber 4.

In the melting chamber 3, a tundish 31 is inserted from above into an opening 2h provided in the partition wall 2, and the tundish 31 has a temperature of 1200 to 1600 ° C.
Of molten metal 30 is accommodated. The melting chamber 3 is further provided with a melting furnace body 36 provided with a crucible 35, and the metal is melted at a position shown by a solid line, and is tilted by a mechanism not shown as shown by a dashed line. Then, the molten metal is replenished into the tundish 31 in which the amount of the molten metal is reduced.

The cooling and solidifying chamber 4 is provided with a water-cooled cooling roll 41 having a diameter of 400 mm and located just below the nozzle 32 of the tundish 31. Is 0.5 mm. The cooling roll 41 has a rotation speed of 1600.
It is rotated in the direction indicated by the arrow at １1900 rpm.

By disposing a sealing member 34 between the flange 31f provided on the outer peripheral surface of the tundish 31 and the peripheral portion of the opening 2h of the partition 2, the space between the melting chamber 3 and the tundish 31 is sealed. The melting chamber 3 and the cooling and solidifying chamber 4 are communicated by a slot 33 provided in a nozzle 32 of the tundish 31. The slot 33 is formed in an elongated rectangular shape in a direction perpendicular to the running direction of the outer peripheral cooling surface of the cooling roll 41, and the short side of the rectangle, that is, the slot width is 0.4 mm, the long side of the rectangle,
That is, the slot length is 50 mm.

A hollow induction heating coil 37 through which cooling water flows is wound around the outer periphery of the tundish 31 and the nozzle 32 at the bottom thereof. FIG. 2 is an enlarged perspective view showing the tundish 31 and the nozzle 32, and FIG. 3 is a longitudinal sectional view of a lower half thereof. That is, one induction heating coil 37 is continuously wound around the tundish 31 and the nozzle 32.
Are connected to a frequency converter (not shown) for generating high frequency (10 kHz). The nozzle 32 is made of boron nitride.

Melt casting room 1 of thin metal sheet manufacturing apparatus of the embodiment
Is configured as described above, and its operation will be described below.

Referring to FIG. 1, after the melting chamber 3 is evacuated to a vacuum, Ar gas is introduced to a pressure of 1 × 10 ^-1 Pa, and the raw material metal is heated to a temperature of crucible 35 of melting furnace 36. It is heated to 1200 to 1600 ° C. and dissolved. Then, a high frequency is applied to the induction heating coil 37 of the tundish 31 and the nozzle 32, and the melting furnace body 36 is tilted to discharge the molten metal 30 to the tundish 31.
At this time, since the molten metal 30 is induction-heated, it does not solidify even in the narrow slot 33 of the nozzle 32,
Does not cause nozzle clogging. In addition, tundish 3
The molten metal 30 is also induction-heated in the main body 1 and generates convection, so that the molten metal 30 is uniformly maintained at a temperature of, for example, 1200 ° C.

On the other hand, after the cooling and solidifying chamber 4 is evacuated,
r gas is introduced and maintained at a pressure of 1 × 10 ^-1 Pa, and the cooling rolls 41
It is rotated in the direction indicated by the arrow at a rotation speed of 0 to 1900 rpm. When the preparation is completed, the pressure of the Ar gas in the melting chamber 3 is increased to pressurize the molten metal 30 in the tundish 31, and the molten metal is poured from the slot 33 of the nozzle 32 to the outer peripheral cooling surface of the cooling roll 41. And when pouring starts,
The pouring pressure of the molten metal, that is, the sum of the pressure of the head of the molten metal in the tundish 31 and the pressure of the melting chamber 3 is constant, and the differential pressure between the sum pressure and the pressure of the cooling and solidifying chamber 4 is constant. Then, pouring is continued by controlling the applied pressure of the Ar gas, but no nozzle clogging occurs. Then, the molten metal is rapidly cooled on the cooling surface of the cooling roll 41, so that the amorphous alloy ribbon 5 having a smooth surface and a width of 50 mm and a thickness of 10 μm is formed.
0 are continuously manufactured in a long ribbon shape.

Although the apparatus for manufacturing a metal ribbon according to the present invention has been described above with reference to the embodiments, it is needless to say that the present invention is not limited to this, and various modifications can be made based on the technical concept of the present invention. .

For example, in the embodiment, one induction heating coil 37 is wound around the tundish 31 and the nozzle 32 as shown in FIG. 2, but as shown in FIG. An induction heating coil 37 'is arranged on the main body of the dish 31, and an induction heating coil 37 "is arranged on the nozzle 32,
The tundish 31 and the nozzle 32 may be independently induction-heated, and it is possible to most effectively heat the molten metal that passes through a narrow slot at the time of pouring and is likely to cause a temperature drop.

In the embodiment, the nozzle 32 is made of boron nitride.
1 may be made of the same material, or may be made of a material other than boron nitride, and may be made of, for example, graphite, ceramics, or quartz. Further, in the embodiment, the metal is melted in a melting furnace 36 provided with a crucible 35, and the molten metal is supplied from the melting furnace 36 to the tundish 31 so that the tundish 31 is melted.
In this case, the metal is melted by the crucible wound around the crucible and the bottom nozzle by the induction heating coil, and the obtained molten metal is poured from the bottom nozzle to the cooling roll 41. It may be poured into hot water. In the above description, the case where the metal thin body is formed by pouring the molten metal from the slot provided in the nozzle to the cooling roll has been described, but the present invention is directed to pouring the molten metal from the small holes arranged at relatively close intervals. This includes the case where a thin metal body is formed.

[0027]

The apparatus for manufacturing a metal ribbon according to the present invention is implemented in the form described above, and has the following effects.

According to the first aspect of the invention, since the induction heating coil is wound around the tundish or crucible and the nozzle at the bottom thereof, the temperature of the molten metal in the tundish or crucible is constant. The temperature of the molten metal does not drop in the narrow slot of the nozzle when the molten metal is poured from the melting furnace body into the tundish or when the molten metal is poured from the nozzle to the cooling roll. The belt can be manufactured while maintaining a stable state for a long time.

According to the metal ribbon manufacturing apparatus of the second aspect, the main body of the tundish or crucible and the nozzle are wound by independent induction heating coils, respectively.
The tundish or crucible and the nozzle can be heated most effectively by the high frequency of the frequency suitable for each. According to the apparatus for manufacturing a metal ribbon according to claim 3, since at least the nozzle is made of boron nitride having high thermal conductivity, the temperature difference between the tundish or crucible and the nozzle during heating of the internal molten metal. Hardly occur,
Since it is excellent in thermal shock resistance, it is possible to stably produce a metal ribbon without fear of causing a nozzle crack.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a melting casting chamber of a metal ribbon manufacturing apparatus of an embodiment.

FIG. 2 is an enlarged perspective view of a wound tundish and a nozzle of the induction heating coil shown in FIG. 1;

FIG. 3 is a longitudinal sectional view of a lower half of FIG. 2;

FIG. 4 is a perspective view of a tundish and a nozzle of the tundish of a modified example, and is a view corresponding to FIG. 2;

FIG. 5 is a perspective view of a continuous strip manufacturing apparatus of Conventional Example 1.

FIG. 6 is a longitudinal sectional view of a nozzle for manufacturing a quenched ribbon according to Conventional Example 2.

[Description of Signs] 1 melting casting chamber 2 partition wall 3 melting chamber 4 cooling and solidifying chamber 31 tundish 32 nozzle 33 slot 37 induction heating coil 41 cooling roll 50 metal ribbon

Claims (3)

[Claims] 1. A metal strip manufacturing apparatus for pouring a molten metal from a nozzle at the bottom of a tundish or crucible to a cooling surface of a cooling roll rotating and rapidly cooling the same, wherein the tundish or crucible body and the nozzle An apparatus for manufacturing a metal ribbon, wherein an induction heating coil is wound around an outer peripheral portion. 2. The metal ribbon manufacturing apparatus according to claim 1, wherein the body of the tundish or crucible and the nozzle are wound by independent induction heating coils. 3. The apparatus according to claim 1, wherein the nozzle is made of boron nitride.