JP2005342734A - Method for producing rapid-cooled strip and its apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a rapid-cooled strip and its apparatus with which the rapid-cooled strip having high purity and thickness larger than a prescribed thickness can be mass-produced. <P>SOLUTION: This apparatus for producing the rapid-cooled strip is the one for producing the alloy-made rapid-cooled strip M, e.g. for using a magnet material, such as an amorphous, or a blank for powder producing, such as a hydrogen storage alloy, and comprises: a cold-crucible melting furnace for producing molten alloy by melting at least two kinds of metals; a water-cooling roll 20 for forming the alloy-made rapid-cooled hoop M by solidifying this molten alloy in contact with the molten alloy; and a tundish 25 for supplying the molten alloy produced with the cold-crucible melting furnace into the water-cooling roll 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a quench zone and an apparatus therefor.

Conventionally, as a method for producing a raw material for powder production such as amorphous magnetic material (magnet material, hydrogen storage alloy), raw metal melted in a melting furnace is temporarily stored in a tundish, A method is known in which a molten metal is supplied on a water-cooled roll rotating around an axis, and the molten metal is rotated and solidified while being cooled, and a quenching zone formed thereby is collected in a collection box (for example, , See Patent Document 1).
JP 2002-205148 A

In recent years, it has been demanded to continuously mass-produce a quench zone made of an alloy having a high purity and a predetermined thickness.
However, when the metal is melted in the melting furnace, the melting furnace reacts with the molten metal, and the constituent elements of the melting furnace are mixed into the molten metal as impurities, or the gas released from the melting furnace becomes a contamination source. As a result, the molten metal is contaminated, resulting in a problem that the purity of the alloy is lowered.

In addition, the conventional rapid solidification method represented by, for example, the melt drag method or the like is to produce a quenching zone called a so-called thin strip having a thickness of less than 1 mm from the viewpoint of imparting desired characteristics by rapid cooling. It has not been assumed from the beginning to form a quenching zone having a predetermined thickness exceeding 1 mm.
That is, the quenching zone having a certain thickness or more is only manufactured at a laboratory level such as casting with a mold, and it is difficult to mass-produce.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method of manufacturing a quenching zone and an apparatus thereof capable of easily mass-producing a quenching zone having a high purity and a predetermined thickness or more. There is.

In order to achieve the above object, the present invention proposes the following means.
The manufacturing method of the quenching zone according to claim 1 includes an alloying step of generating a molten alloy by a cold crucible melting furnace provided with a water-coolable conductive segment and an induction heating coil disposed therearound, and the alloy And a casting step of supplying a molten alloy produced by the crystallization step onto a rotating water-cooled roll and rotating the molten alloy while cooling with the water-cooled roll to form a quench zone.

The invention according to claim 2 is characterized in that, in the casting step in the method of manufacturing a quench zone according to claim 1, the free solidification surface side of the molten alloy supplied onto the water cooling roll is pressed by another water cooling roll. To do.
The invention according to claim 3 is an apparatus for manufacturing a quench zone in which a molten metal is supplied onto a rotating water-cooled roll, and the melt is rotated while being cooled by the water-cooled roll, thereby forming a quench zone. A cold crucible melting furnace is provided as a melting furnace for generating molten alloy to be supplied to the steel.

According to a fourth aspect of the present invention, in the quench zone manufacturing apparatus according to the third aspect, the tundish has a flow rate adjusting body that adjusts the supply amount of the molten alloy to the water-cooled roll to be substantially constant. It is characterized by that.
According to a fifth aspect of the present invention, in the quench zone manufacturing apparatus according to the fourth aspect, the tundish has a heating means.
According to a sixth aspect of the invention, in the quench zone manufacturing apparatus according to the fourth aspect, the tundish has a conductive segment capable of water cooling and an induction heating coil disposed around the conductive segment. It is characterized by that.

According to this invention, since the molten alloy produced using a cold crucible melting furnace is supplied to a water-cooled roll suitable for mass production in a quench zone, it is possible to effectively avoid contamination of impurities in the melting furnace, and to achieve high purity. Thus, it is possible to easily mass-produce a quenching zone having a predetermined thickness.
In addition, when the free solidification surface side of the molten alloy is pressed in the casting process using a water-cooled roll, a uniform thickness quenching zone can be stably produced.

When a tundish having a flow control body is provided between the cold crucible melting furnace and the water-cooled roll, the amount of molten alloy supplied to the water-cooled roll can be made substantially constant, and a quenching zone with a constant thickness and width can be formed. It can be formed continuously and stably.
Further, when the tundish is provided with a heating means, the molten alloy can be kept near its melting temperature, and the molten alloy can be stably supplied without causing clogging.
Further, when the tundish is configured to include a water-coolable conductive segment and an induction heating coil disposed around the tundish, the reactivity between the tundish and the molten alloy temporarily stored therein is reduced. As a result, the contamination of the molten alloy in the tundish can be effectively avoided.

Embodiments of the present invention will be described below with reference to the drawings.
First, in an alloying process, two or more kinds of raw materials are melted in a cold crucible melting furnace (not shown) to produce a molten alloy, and an ingot or a molten raw material is made in a casting process.
The cold crucible melting furnace includes a furnace body as a crucible formed of pure copper or a copper alloy having a high thermal conductivity, and an induction heating coil disposed around the furnace body. Hereinafter, the cold crucible melting furnace is also referred to as “C / C melting furnace”.

Although not shown in detail, the furnace body is formed in a cylindrical shape extending in the vertical direction by arranging a plurality of vertically-divided conductive segments electrically insulated from each other in the circumferential direction. In the upper left part of the furnace body, a pouring gate is provided.
Note that a cooling water channel (not shown) is provided inside the conductive segment, and the cooling water is supplied to the cooling water channel so that when the raw material metal is melted in the C / C melting furnace, the furnace main body 12. Can be cooled below the reaction temperature.
The molten alloy usually has a melting point lower than the melting point of the raw metal, and can be melted in a refractory melting furnace in a subsequent process.

The induction heating coil generates an alternating magnetic field when a high-frequency alternating current flows, and induction metal heats the raw metal put in the furnace body by the generated alternating magnetic field to melt it by Joule heat. The source metal and the additive metal are made of at least two kinds of metals such as Fe, Ti, Zr, etc., but may be other metals as long as they are active metals, refractory metals, etc. .
A cooling water passage (not shown) is also provided in the induction heating coil, so that the induction heating coil is not overheated by the cooling water flowing through the cooling water passage.

Next, the casting process will be described.
1 and 2 show a quench zone manufacturing apparatus according to an embodiment of the present invention. For example, a quench zone made of an alloy that becomes a material for powder production such as a magnet material such as an amorphous material or a hydrogen storage alloy is shown. A melting furnace 11 for producing an alloy melt by melting the ingot produced in the alloying step, or a holding furnace 11 for holding the alloy melt, and an alloy supplied to the outer peripheral surface. A water-cooled roll 20 that solidifies the molten metal to form an alloy quench zone M, and a tundish 25 that supplies the molten metal generated by the melting furnace 11 to the water-cooled roll 20 are configured.

The water cooling roll 20 is cooled and is rotatably supported by a support shaft (not shown).
In the illustrated example, when the molten alloy supplied from the tundish 25 described later contacts the outer peripheral surface of the water-cooled roll 20 that rotates counterclockwise, the molten alloy is cooled and solidified to form a quenching zone M. It is formed. Therefore, although not shown in detail, the water cooling roll 20 is cooled by circulating water as a refrigerant, for example.

The tundish 25 temporarily stores the molten alloy poured from the melting furnace 11 inside, and supplies the molten alloy inside to the water cooling roll 20. Therefore, the tundish 25 is composed of a main body 26 having an open top and a bottomed cylindrical shape, and a nozzle 27 protruding from the front lower portion of the main body 26.
The nozzle 27 extends so that the outlet is directed to the vicinity of the top of the water-cooled roll 20.

These tundish 25 and nozzle 27 are made of a refractory material such as ceramics or graphite.
Heating means 28 such as a heater is provided inside the tundish 25 and the nozzle 27, and is kept at a melting point temperature so that the molten metal stored does not solidify and block the nozzle 27.

The melting furnace 11 can pour the molten metal into the tundish 25 by winding the suspension portion 17 by a driving device (not shown) and tilting it around the fulcrum 15 as shown by the chain line in FIG. .
Therefore, when the molten alloy in the tundish 25 is reduced to a predetermined amount, the suspension 17 is wound up so that the molten alloy generated in the melting furnace 11 is replenished to the tundish 25 sequentially. Can do.

On the other hand, a pressure roll (another water cooling roll) 22 having a smaller diameter than the water cooling roll 20 is rotatably provided above the water cooling roll 20.
The pressing roll 22 can be adjusted by a pressure adjusting mechanism 30 to be described later, the pressing force against the water-cooling roll 20, that is, the pressing force against the molten metal contacting the water-cooling roll 20 or the solidified body that is still deformable. The thickness of the quench zone M formed by the water-cooled roll 20 can be adjusted by changing the pressing force.
Since the axis of the pressing roll 22 is located on the vertical line P passing through the axis of the water-cooled roll 20, the pressure roll 22 contacts the water-cooled roll 20 at the top of the water-cooled roll 20.
The pressing roll 22 is cooled by a coolant such as water in the same manner as the water cooling roll 20.

The pressure adjusting mechanism 30 can change the pressing force of the pressing roll 22 by adjusting the biasing force of the compressed compression spring 31.
Specifically, the pressing roll 22 is rotatably supported at the distal ends of a pair of arms 33 provided so as to be swingable about a shaft 32, and a movable beam member 34 is coupled to a midway position of the arms 33. A rod 35 passes through the movable beam member 34 and is connected to a lower end portion of the rod 35 by screwing a nut 36. The urging force of the compression spring 31 is adjusted by two adjustment nuts 38 that are screwed to the upper end side.

Next, an embodiment of a modification of the alloying process in the method of manufacturing a quenching zone according to the present invention will be described in relation to the operation of the quenching zone manufacturing apparatus configured as described above.
First, consider that the melting furnace 11 of FIGS. 1 and 2 is replaced with a C / C melting furnace.
After charging the raw metal such as a lump or powder, an alternating current is applied to the induction heating coil to generate an alternating magnetic field, thereby starting induction heating of the raw metal in the C / C melting furnace.
Since the furnace body of the C / C melting furnace is cooled by cooling water, when the raw material metal is inductively heated and starts to melt, a part of it solidifies along the wall surface of the furnace body to form a film-like skull (see FIG. The molten metal is generated on the skull. And the center part of a molten metal rises by electromagnetic induction, and it will be in the state which the surrounding surface of a molten metal does not contact with the wall surface of a furnace main body.

Next, an additive metal is added to the melted raw material metal to produce a molten alloy.
At this time, since the dissolved raw metal and the additive metal are stirred together by an alternating magnetic field, mechanical stirring means are not required, and the dissolution of the additive metal is promoted and separation due to the difference in specific gravity can be effectively avoided. it can.
Needless to say, the additive metal may be added together with the raw material metal in advance.

When the metal is alloyed and the molten alloy is generated in the C / C melting furnace, the C / C melting furnace placed at the same position as the melting furnace 11 is changed from the state shown in FIG. 1 to the chain line in FIG. Tilt as shown. However, in normal melting furnaces, the tilting speed could be freely selected according to the condition on the casting side, but in C / C melting furnaces, the formation of skull (solidified matter) on the water-cooled crucible wall is minimized. Therefore, it tilts quickly and the entire amount is poured into the tundish 25.
The molten alloy flowing out from the pouring port of the C / C melting furnace is guided into the tundish 25 through the guide plate 29 and stored therein.
At this time, the molten alloy in the storage state is kept at a substantially melting temperature by the heating means 28, so there is no possibility that the molten alloy solidifies and the nozzle 27 is blocked.

The molten alloy temporarily stored is sequentially supplied from the nozzle 27 toward the water cooling roll 20.
When the storage amount in the tundish 25 is reduced to a certain amount, the C / C melting furnace is tilted from the state shown in FIG. 1 as shown by the chain line in FIG. The molten metal is repeatedly poured into the tundish 25.
On the other hand, in the C / C melting furnace, every time pouring of the tundish 25 is completed, the raw material metal and the additive metal are charged and the molten alloy is continuously generated.

The water cooling roll 20 rotates counterclockwise while being cooled by cooling means using water as a refrigerant. When the molten alloy supplied from the nozzle 27 of the tundish 25 comes into contact with the outer peripheral surface, the molten metal is scraped up on the water-cooled roll 20 as the water-cooled roll 20 rotates, and is temporarily rotated while being rapidly cooled. Thus, an alloy quenching zone M (thick line portion in the figure) is formed, and the quenching zone M is continuously produced.
The quenching body M is peeled off from the water-cooling roll 20 and collected in the collection body 16.

As described above, according to the method of manufacturing the quenching zone, after passing through the alloying step of generating the molten alloy while melting the metal in the C / C melting furnace, the molten alloy generated in the alloying step is temporarily Is stored on the water-cooled roll 20 and supplied to the water-cooled roll 20, and the water-cooled roll 20 is rotated while cooling the molten alloy so as to continuously form the alloy quenching zone M. Thus, the quenching zone M having a thickness of 1 mm or more can be easily mass-produced.
That is, since the molten alloy is generated by the C / C melting furnace, the molten alloy is not in contact with the wall surface of the furnace body of the C / C melting furnace, and the molten alloy is contaminated by other substances (impurities). There is no. In addition, a decrease in melting point due to alloying reduces the reactivity of the molten alloy with respect to the tundish 25, thereby further preventing contamination of the molten alloy.

In addition, since the molten alloy stored in the tundish 25 is kept near the melting temperature by the heating means 28, the molten alloy can be stably supplied to the water-cooled roll 20 without closing the nozzle 27.
Furthermore, in the casting process, the pressure roll 22 provided above the water-cooled roll 20 presses the free solidification surface side of the molten alloy (or the solidified body of the deformable alloy melt) on the water-cooled roll 20, A quench zone M having a uniform thickness can be formed.

In the above embodiment, the specific configurations of the tundish 25 and its nozzle 27, the water-cooled roll 20, and the melting furnace 11 are not limited to the illustrated examples, regardless of the difference in the alloying process.
For example, as shown in FIG. 3, a partition plate (flow rate adjusting body) 41 may be provided in the tundish 25. The partition plate 41 extends in the vertical direction on the nozzle 27 side with respect to the guide plate 26, and forms a predetermined gap 42 with the inner bottom surface 26 </ b> A of the main body 26. Thereby, the inside of the main body 26 is partitioned into a hot water storage section 26a and a supply section 26b.

In such a configuration, when molten alloy is poured from the melting furnace 11 into the tundish 25, the molten alloy is guided along the guide plate 29 to the hot water storage part 26a side of the main body 26 and then to the hot water storage part 26a side. From the nozzle 27 to the supply section 26b side, the supply amount of the molten alloy from the nozzle 27 to the water-cooled roll 20 can be stabilized substantially constant.
Thereby, the quenching zone M with a constant thickness and width can be formed continuously and stably.

  Furthermore, in the said embodiment, although the tundish 25 is comprised with refractory materials, such as ceramics or graphite, when using the metal which cannot avoid reaction with the tundish 25 by high melting-point of an alloy, By forming the tundish 25 with a configuration similar to that of the C / C melting furnace, that is, with a configuration including a water-cooled metal segment and an induction heating coil disposed around the tundish 25, a high-purity quench zone M is formed. Is possible.

1 is an overall view showing a quench zone manufacturing apparatus according to an embodiment of the present invention. It is explanatory drawing which shows the state which pours the molten metal produced | generated by the melting furnace in a quenching zone apparatus into a tundish. It is sectional drawing which shows other embodiment of the tundish which concerns on this invention.

Explanation of symbols

11 Melting furnace 13 Induction heating coil 20 Water-cooled roll 22 Pressing roll (another water-cooled roll)
25 Tundish 27 Nozzle 28 Heating means 30 Pressure adjusting mechanism 41 Partition plate (flow rate adjusting body)
M quenching zone

Claims (6)

An alloying process for generating a molten alloy by a cold crucible melting furnace having a water-coolable conductive segment and an induction heating coil disposed around the conductive segment;
A molten metal melt produced by the alloying process is supplied onto a rotating water-cooled roll, and the molten metal is cooled while being cooled by the water-cooled roll to form a quenching zone. Quench zone manufacturing method.   The method for producing a quenching zone according to claim 1, wherein in the casting step, the free solidification surface side of the molten alloy supplied onto the water-cooled roll is pressed by another water-cooled roll. A cooling zone manufacturing apparatus that supplies molten metal onto a rotating water cooling roll and forms a quench zone by rotating the molten metal while cooling the molten metal with the water cooling roll,
As a melting furnace for generating molten alloy to be supplied to the water-cooled roll, a cold-crucible melting furnace having a water-coolable conductive segment and an induction heating coil disposed therearound is used. Manufacturing equipment. A tundish that temporarily stores the molten alloy generated by the cold crucible melting furnace and then supplies the molten metal to the water-cooled roll,
4. The apparatus for manufacturing a quenching zone according to claim 3, wherein the tundish has a flow rate adjusting body that adjusts a supply amount of the molten alloy to the water-cooling roll to be substantially constant.   5. The apparatus for manufacturing a quenching zone according to claim 4, wherein the tundish has a heating means. The said tundish has the electroconductive segment in which water cooling is possible, and the induction heating coil arrange | positioned around this electroconductive segment, The manufacturing apparatus of the quenching zone of Claim 4 characterized by the above-mentioned.

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