JP2006021248A - Method and apparatus for manufacturing quenched thin strip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for stably mass-producing a quenched thin strip of desired characteristics by preventing the choke of a nozzle. <P>SOLUTION: A water-cooled roll to form a quenched thin strip by solidifying molten metal and a tundish 25 to feed the molten metal to the water-cooled roll are installed in a hermetic container. A heat insulating mechanism 30 to insulate the tundish 25 and a nozzle 27 thereof substantially at the melting point of the molten metal is provided. The heat insulating mechanism 30 comprises temperature sensors 31, 32 as temperature measurement means to measure the temperature of the body 26 of the tundish 25 and the nozzle 27, respectively and heaters 33, 34 as heating means to heat the tundish 25 and the nozzle 27, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a quenched ribbon 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 fed through a nozzle onto a water-cooled roll rotating about 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, refer to Patent Document 1).
JP 2002-205148 A

However, in the above-described conventional configuration, it is inevitable that the molten metal temperature decreases from when the molten metal is fed into the tundish until it passes through the nozzle, and the molten metal solidifies to partially or completely block the nozzle runner. I had to do it.
As a countermeasure, it is conceivable to preheat the molten metal in anticipation of a temperature drop. In such a case, the molten metal is not rapidly cooled to the target temperature within a predetermined time, and a desired structure (for example, amorphization) or It becomes impossible to obtain the rapid cooling rate, and it becomes difficult to stably and continuously manufacture the quenched thin plate.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method and apparatus capable of stably mass-producing a quenched thin plate having desired characteristics while preventing nozzle clogging.

In order to achieve the above object, the present invention proposes the following means.
The invention according to claim 1 is a rapid cooling in which a molten metal is supplied onto a water cooling roll from a molten metal supply section through a nozzle in an airtight container, and the molten metal is rotated while being rapidly cooled by the water cooling roll to form a rapidly cooled ribbon. A method for producing a ribbon, wherein the molten metal supply unit and the nozzle are kept at a substantially melting point temperature of the molten metal.
According to a second aspect of the present invention, in the method for producing a quenched ribbon according to the first aspect, among the quenched ribbons formed by continuing to supply the molten metal from the molten metal supply unit onto the water-cooled roll, an initial stage is provided. The quenching ribbon formed in (1) and the quenching ribbon formed in the later stage are removed.
According to a third aspect of the present invention, in the method for producing a quenched ribbon according to the first or second aspect, the molten metal supply unit has a pressure corresponding to at least five times the head pressure generated at the maximum molten metal height. It is characterized by being.

According to a fourth aspect of the present invention, in the airtight container, the molten metal is supplied to the water cooling roll from the molten metal supply section through the nozzle, and the molten metal is rapidly cooled by the water cooling roll and formed into a rapidly cooled ribbon. A ribbon manufacturing apparatus based on temperature measurement means for measuring temperatures of the molten metal supply unit and the nozzle, heating means for heating the molten metal supply unit and the nozzle, and a temperature measurement result of the temperature measurement means. And a controller for controlling the heating means.
According to a fifth aspect of the present invention, there is provided the quenching ribbon manufacturing apparatus according to the fourth aspect, wherein the molten metal supply section, the nozzle, and the water cooling roll are partitioned by a partition in the airtight container. An inert gas introduction unit is connected to the supply unit and the nozzle side.

According to a sixth aspect of the present invention, in the apparatus for manufacturing a quenched ribbon according to the fourth or fifth aspect, the distance between the tip of the nozzle and the surface of the water-cooled roll is such that hot water should be discharged from the tip of the nozzle. In addition, the size is smaller than the size of the molten metal in which surface tension is generated.
The invention according to claim 7 is the manufacturing apparatus of the quenched ribbon according to any one of claims 4 to 6, wherein the nozzle is configured such that a nozzle tip is detachably attached to the nozzle body. Features.

According to an eighth aspect of the present invention, in the apparatus for manufacturing a quenched ribbon according to any one of the fourth to seventh aspects, the molten metal supply unit is provided with a regulating body that controls the molten metal discharged from the molten metal. It is characterized by.
The invention according to claim 9 is the manufacturing apparatus of the quenched ribbon according to any one of claims 4 to 8, wherein the molten metal supply unit temporarily stores the molten metal and supplies the molten metal to the water cooling roll. The tundish is provided with a melting function of melting the rapidly quenched ribbon raw metal to produce the molten metal.

According to a tenth aspect of the present invention, in the apparatus for producing a quenched ribbon according to any one of the fourth to ninth aspects, the molten metal supply section is disposed on a crucible formed of a conductive material and an outer periphery thereof. The induction heating coil, and the tundish that temporarily stores the molten metal generated by the melting furnace and supplies the molten metal to the water-cooling roll, and the induction heating coil. Is characterized in that a current having a frequency capable of causing a magnetic field to penetrate into the molten metal in the crucible is supplied.
According to an eleventh aspect of the present invention, in the apparatus for manufacturing a quenched ribbon according to the ninth or tenth aspect, the control unit selectively uses the temperature of the molten metal supply unit and the molten metal temperature in the molten metal supply unit. And controlling melting power and heat retention power.
According to a twelfth aspect of the present invention, in the manufacturing apparatus for a quenched ribbon according to any one of the fourth to eleventh aspects, a plurality of protrusions are provided at intervals on the tip of the nozzle, and It is characterized in that a hot water outlet is opened at the front end surface.
A thirteenth aspect of the present invention is the quenching ribbon manufacturing apparatus according to any one of the fourth to twelfth aspects of the present invention, wherein the molten metal supply section is provided with the molten metal before the molten metal is supplied to the nozzle. The inclusion removing means for removing the inclusions is provided.

According to the present invention, the following effects can be obtained.
Even without overheating the molten metal, it is possible to effectively prevent the molten metal from solidifying in the nozzle or at the tip of the nozzle, and it becomes possible to stably mass-produce a rapidly cooled thin plate having desired characteristics.
Can prevent the mixing of lots in the rapid cooling ribbon formed in the early and late stages of the hot water where the conditions such as the flow and temperature of the molten metal supplied to the water cooling roll are not stable, improving the reliability and stability of the quality .
The discharge pressure from the nozzle can be reduced to a level that can ignore the fluctuation of the molten metal height, and the collision speed of the molten metal against the water-cooled roll can be kept substantially constant. , Heat transfer characteristics and the like can be stabilized.

It is possible to effectively prevent the molten metal from contracting, separating, and partially peeling, which can occur when the molten metal is supplied from the nozzle of the molten metal supply onto the water-cooled roll, and various problems caused by the molten metal becoming fine particles. It can be avoided.
After the end of pouring, the nozzle is usually not completely or partially closed so that it can be reused, but only the nozzle tip can be replaced without replacing the nozzle with the molten metal supply unit integrated with the nozzle. The next hot water can be easily resumed simply by exchanging.

By regulating the opening of the nozzle with a regulating body to regulate the hot water, when the molten metal supply part is equipped with a melting furnace and a tundish, the unstable state at the beginning of the hot water can be minimized. In the case where the molten metal supply part is one that performs melting in a tundish, it is possible to prevent molten metal leakage from the nozzle.
Power sources for heat insulation and melting furnace can be used in combination, and not only it is not necessary to install a melting furnace separately, but also the power source can be omitted to save labor.

Since the stirring action, which is a feature of induction heating, can be generated in the molten metal supply section, no mechanical stirring means is required, and even if the molten metal is made of alloy, the dissolution of the added substance is promoted and the separation is performed due to the difference in specific gravity. Can be effectively prevented.
The temperature of the molten metal supply section is monitored until the raw metal melts, and the molten metal temperature is monitored after melting, so there is no risk of overheating of the molten metal supply section, and the melting furnace of the molten metal supply section Or / and the control as a tundish is also stabilized.
Compared to the case where there is no protrusion at the tip of the nozzle, the area of the end surface around the outlet is reduced, and as a result, excessive growth of molten droplets coming out from the outlet is suppressed. It is possible to equalize the amount of molten metal supplied from each outlet to the water-cooling roll by preventing coalescence of molten metal jets or molten metal jets.
Since the molten metal supply section is equipped with inclusion removal means, even if the molten metal contains an inclusion that does not melt into the molten metal even if it is above the melting point of the molten metal, the molten metal from which this inclusion has been removed is used as a nozzle. Can supply. Therefore, the quenching ribbon can be stably manufactured without partially or completely blocking the runner of the nozzle by this inclusion.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2, a quenching ribbon manufacturing apparatus 10 according to the first embodiment of the present invention is a quenching ribbon that becomes a powder manufacturing material such as a magnet material such as an amorphous material or a hydrogen storage alloy. A water-cooled roll 20 that contacts the molten metal to solidify the molten metal to form a quenched ribbon, and a tundish (molten supply unit) 25 that supplies the molten metal to the water-cooled roll 20. It is installed in the airtight container 51.

The water cooling roll 20 is cooled, for example, by circulating water as a refrigerant, and is rotatably supported by a support shaft 21 as shown in FIG. The support shaft 21 is connected to a motor m as a drive source.
And when the water cooling roll 20 is rotating counterclockwise as shown in FIG. 1, when the molten metal supplied from the tundish 25 comes into contact, the molten metal is solidified by being rotated while being cooled. As indicated by the chain line, a quenched ribbon M is formed.

The tundish 25 temporarily stores the molten metal inside, and supplies the molten metal inside the water cooling roll 20. Therefore, as shown in FIG. 3, the tundish 25 includes a cylindrical main body 26, a bottom portion 26a that closes the lower portion of the main body 26, and a nozzle 27 that is connected to the lower surface of the bottom portion 26a. Yes.
The nozzle 27 extends so that the outlet is directed to the vicinity of the top of the water-cooled roll 20 as shown in FIGS. 1 and 2, and as shown in FIG. 3, the nozzle provided at the lower part of the tundish 25 It consists of a main body 27a and a nozzle tip portion 27b that is detachably attached to the tip of the main body 27a by fastening means (not shown) such as bolts and nuts.

Around the lower half of the tundish 25 and the periphery of the nozzle 27, there is provided a heat retaining mechanism 30 that keeps the tundish 25 and the nozzle 27 at a substantially melting point of the molten metal.
As shown in FIG. 3, the heat retaining mechanism 30 heats the temperature sensors 31, 32 as temperature measuring means for measuring the temperatures of the main body 26 and the nozzle 27 of the tundish 25, and the tundish 25 and the nozzle 27, respectively. It consists of heaters 33 and 34 as heating means.

The temperature sensor 31 is provided around the substantially lower half of the tundish 25, and the temperature sensor 32 is embedded in the nozzle body 27a. The heater 33 and the heater 34 are disposed outside the temperature sensors 31 and 32.
And based on the measured temperature of the temperature sensors 31 and 32, the heaters 33 and 34 heat the main body 26 and the nozzle 27, respectively, so that the molten metal in the main body 26 is kept warm so as not to solidify. This heat insulation heating is controlled by the control unit 50.

The upper end of the main body 26 is closed by a lid 28, and an inert gas introduction part 35 for introducing an inert gas is connected to the upper part of the main body 26.
As shown in FIG. 1, the inert gas introduction part 35 has one end connected to the main body 26 of the tundish 25 and the other end connected via an on-off valve 36 or the like disposed outside the airtight container 51. When the molten metal is connected to an inert gas cylinder (not shown) and the molten metal is supplied from the tundish 25 to the water-cooled roll 20, the collision speed of the molten metal against the water-cooled roll 20 is increased by setting the inside pressure of the tundish 25 to a desired pressure. It is for making it substantially constant regardless of the size.

The pressure at that time is, for example, about five times as large as the pressure generated when the molten metal reaches the maximum molten metal height in the tundish 25 (the initial molten metal height at the time of so-called quenching ribbon production). Yes.
In addition, although argon gas etc. are employ | adopted as inert gas, for example, other things may be sufficient if it is an inert gas which does not have a bad influence on molten metal.

The tundish 25 is provided with a regulating body 37 for regulating the hot water.
As shown in FIGS. 1 and 2, the restricting body 37 has a rod shape penetrating through the main body 26 in the vertical direction, and an upper portion thereof is connected to a cylinder 38 erected on the lid body 28. .
When the regulating body 37 is driven forward by the cylinder 38 when the molten metal is stored in the tundish 25, a blocking portion 37a provided at the tip of the regulating body 37 is provided as shown in FIG. When the nozzle 27 is closed and the hot water is discharged, the closed portion 37 a is driven backward to open the nozzle 27, whereby the molten metal is discharged from the nozzle 27.

The tundish 25 further has a melting furnace function.
That is, the main body 26 is formed of a conductive material to constitute a crucible, and an induction heating coil that also functions as the heaters 33 and 34 is disposed on the outer periphery of the crucible (main body 26). Then, by heating the crucible, the raw metal of the quenched ribbon M charged in the crucible is melted to generate a molten metal.
The crucible (main body 26) is provided with detection means 39 for detecting the molten metal temperature. When the metal in the main body 26 is melted, the temperature sensor 31 detects the temperature of the crucible, while the crucible is in a molten state. After that, the detection means 39 detects the molten metal temperature.

When the tundish 25 functions as a melting furnace, the temperature is controlled by the temperature sensor 31, and the controller 50 controls the energization of the coils (heaters 33 and 34) to generate the molten metal. In other words, after functioning as a normal tundish that is supplied to the water-cooled roll after the molten metal is temporarily stored after the (melting), the temperature is controlled by the detection means 39 to the coils (heaters 33 and 34). Is controlled by the control unit 50 to keep the molten metal warm.
That is, the control unit 50 controls the melting power and the heat retaining power by selectively using the temperature of the tundish 25 and the molten metal temperature in the tundish 25.

On the other hand, the distance X between the nozzle 27 of the tundish 25 and the water cooling roll 20 is selected as follows.
When the molten metal is discharged, as shown in the conceptual diagram of FIG. 4, the molten metal is sent out from the nozzle 27 of the tundish 25. The dimension is such that both the nozzle tip 27b and the water-cooled roll 20 can be connected to each other by the molten metal N in which tension is generated.

That is, at the time of pouring, assuming that the size of the molten metal N (diameter when a molten ball is used) drooping from the nozzle tip 27b is D, the density thereof is ρ, and the surface tension is γ, the mass m is expressed by the following formula 1. Calculated.
m = ρ · 4 / 3π ( D / 2) 3 = ρ · πD 3/6 ... ( Equation 1)
Since the weight (m · g) of the molten metal ball is supported by the surface tension of the peripheral portion of the outlet (also referred to as nozzle hole) of the nozzle tip portion 27b, the following equations 2 and 3 are obtained. .
^{ρ · πD 3/6 (g} ) ≦ πd · γ ... ( Equation 2)
D ≦ 3 · {(6γ · ρ) / ρ · g} ^1/3 (Formula 3)

Since the above formula 3 assumes the case where the diameter D is the maximum diameter (Dmax), if the distance is larger than the numerical value, the molten metal can be supported stably even if surface tension occurs in the molten metal. become unable.
Therefore, the distance X between the nozzle tip and the water cooling roll needs to be smaller than Dmax. Moreover, the maximum diameter (Dmax) varies depending on the size of the nozzle hole diameter as well as the type of the molten metal M.

Specifically, when the hole diameter of the nozzle tip is 1 mm and iron (Fe) is used as the molten metal M, ρ = 7015 (kg / m ³ ) and γ = 1.722 (N / m). _Therefore , D _Fe ≦ 5.5 × 10 ⁻³ (m). That is, the distance X is 5.5 mm or less.
When titanium (Ti) is used as the molten metal with the same hole diameter as above, ρ = 4110 (kg / m ³ ) and γ = 1.65 (N / m), so that D _Ti ≦ 6 3 × 10 ⁻³ (m), that is, the distance X is 6.3 mm or less.

Next, an embodiment of a method for manufacturing a quenched ribbon according to the present invention will be described below in relation to the operation of the manufacturing apparatus 10 for a quenched ribbon having the above-described configuration.
First, it is assumed that the molten metal is stored in the tundish 25, and the nozzle 27 is closed because the regulating body 37 is in the forward drive position, so that the molten metal has not yet discharged from the tundish 25. It shall be in

Further, in the tundish 25, the heat retaining mechanism 30 keeps the molten metal in the tundish 25 at a substantially melting point temperature, and the inside of the tundish 25 is pressurized to a desired height by introducing the gas from the inert gas introducing unit 35. It has become.
On the other hand, since water is circulated through the water cooling roll 20, it is rotated at a high speed in a cooled state.

In this state, when the regulating body 37 is driven backward by the cylinder 38 in the tundish 25 and the closed state of the nozzle 27 is released, the molten metal begins to be discharged from the tundish 25.
When the molten metal is supplied onto the water-cooled roll 20, the molten metal is temporarily rotated along with the rotation of the water-cooled roll 20 while being rapidly cooled. ) And the quenched ribbon M is continuously manufactured.

However, the quenching ribbon M is not collected at the initial time when the quenching ribbon M is started to be formed.
After determining that the conditions such as the flow of the molten metal and the temperature are stable, for example, after the elapse of a predetermined time, the rapidly formed ribbon M that is continuously formed is recovered in the recovery box 52. Then, when the molten metal remaining in the tundish 25 is reduced and the formation of the quenching ribbon M is finished (late stage), for example, when a predetermined time has elapsed from the start of the hot water, the quenching ribbon M is collected in the collection box 52. quit.
The timing for removing the quenching ribbon formed in these initial and late stages may be performed based on, for example, a change in the amount of molten metal discharged in the tundish 25.

According to this method of manufacturing a quenched ribbon, the tundish 25 and its nozzle 27 are kept warm at the substantially melting point temperature of the molten metal by the heat retaining mechanism 30, so that the nozzle 27 can be effectively prevented from being clogged. The hot spring can be performed well.
In addition, since it is not necessary to raise the temperature of the molten metal to a temperature far exceeding the melting point temperature, it is possible to stably mass-produce the quenched thin plate M having desired characteristics under the desired rapid cooling conditions.

Moreover, according to the said embodiment, since the quenching ribbon M formed in the initial stage and the quenching ribbon M formed in the latter stage are removed, the reliability and stability of quality are improved. To do.
That is, immediately after the tundish 25 is discharged, the flow and temperature of the molten metal are not stable, and when the amount of the molten metal in the tundish 25 is reduced, an inert gas is mixed into the molten metal. Therefore, as described above, if the quenching ribbon M formed in the early stage and the quenching ribbon M formed in the later stage are respectively removed, the lots of the quenching ribbon M are removed. Mixing can be prevented, and the reliability and stability of quality are improved.

On the other hand, when the molten metal collides with the water-cooling roll 20 at the time of discharging the molten metal, the thickness and width dimension of the formed quenching ribbon, and its heat transfer characteristics may be greatly affected. The collision speed is related to the magnitude of the nozzle pressure discharged.
In the above embodiment, the inert gas introduction part 35 is connected to the tundish 25, and the inside of the tundish 25 at the time of tapping is the pressure generated when the molten metal has the maximum molten metal height in the tundish 25. Since the inert gas atmosphere has a pressure corresponding to about 5 times, the fluctuation of the molten metal discharge pressure accompanying the fluctuation of the molten metal height can be ignored from the start of the hot water to the end of the hot water, and the water cooling roll 20 It is possible to make the collision speed of the molten metal to be substantially constant, to stabilize the thickness and width of the quenched ribbon, and to suppress variations in heat transfer characteristics.

Further, when the molten metal is supplied onto the water-cooled roll 20 from the nozzle 27 of the tundish 25, if the distance between the nozzle tip and the water-cooled roll 20 is larger than the expected value, the flow is reduced to the molten metal flow. (The cross-sectional shape of the flowing molten metal becomes smaller), separation, and peeling (the molten metal is scattered without being attached to the water-cooled roll 20 by the wind generated by the rotation of the water-cooled roll 20), resulting in fine particles. Therefore, there is a possibility that the desired quenched ribbon M cannot be formed.
On the other hand, according to the above embodiment, the distance X (see FIG. 4) between the nozzle 27 and the water-cooling roll 20 is set to a state where the hot water should be discharged from the nozzle tip portion 27b and the surface tension is generated. Since the size is smaller than the size, it is possible to effectively prevent the formation of fine particles by preventing the occurrence of contraction, separation, and separation, and the desired quenching ribbon M can be reliably formed.

In the conventional tundish, a solidified substance adheres to a part of the nozzle hole after pouring out water, and when it is remarkable, it is completely blocked, and it is necessary to replace it with the nozzle when it is used next time.
In contrast, in the above embodiment, the nozzle tip 27b is detachably attached to the nozzle body 27a provided in the tundish 25, so that the tundish is replaced integrally with the nozzle as in the prior art. Therefore, it can be easily used by replacing only the nozzle tip 27.

In addition, a heater 33 as a heating means of the heat retaining mechanism 30 is formed of a coil for induction heating, and not only the molten metal in the tundish 25 is kept warm by induction heating of the coil, but also the raw metal in the tundish 25 Therefore, it is possible to use a power source for heat insulation and a melting furnace in combination.
Therefore, it is not only necessary to install a melting furnace separately, but also its power source can be omitted, so that labor can be saved.

When the tundish 25 is used as a melting furnace and the raw metal is not yet melted, accurate temperature measurement cannot be performed even if the temperature in the crucible (space) is measured. If it is attempted to control at the temperature in the main body 26), the crucible may be overheated and the control content may become unstable.
On the other hand, in the above embodiment, when the tundish 25 is used as a melting furnace, the temperature is monitored by the temperature sensor 31 provided in the tundish 25 until the raw metal is melted. Since the temperature sensor 31 is switched to the detecting means 39 and the molten metal temperature in the tundish 25 is detected by the detecting means 39, there is no possibility of overheating the crucible, and the melting furnace can be controlled stably. .

In addition, in particular, when the tundish 25 is used only for storage, the opening degree of the nozzle 27 is adjusted by the regulating body 37 to regulate the molten metal discharge. It can be limited, and stable hot water can be discharged.
On the other hand, when the tundish 25 is used as a melting furnace, if the nozzle 27 is closed by the regulating body 37, even if the raw material metal is melted, leakage of hot water from the nozzle 27 can be prevented.

When induction heating is performed using the tundish 25 as a melting furnace, generally, in the case of a container in which the depth of the tundish 25 is greater than or equal to the penetration depth, the magnetic field hardly penetrates the molten metal in the container. Therefore, it is necessary to forcibly stir the molten metal, and in the case of manufacturing the quenched ribbon M made of an alloy, the molten metal made of the alloy is used for the purpose of promoting the dissolution of the added substance and preventing the separation due to the difference in specific gravity between the two. Need to be stirred.
On the other hand, in the above embodiment, when induction heating is performed by the induction heating coil that forms the heater 33 as the heating means, the frequency is selected so that the magnetic field can sufficiently penetrate the crucible and the molten metal can be generated reliably. Therefore, the stirring action, which is a feature of induction heating, can be generated satisfactorily, no mechanical stirring means is required, and even in the case of an alloy molten metal, the dissolution of additive substances and the difference in specific gravity are increased. Can be effectively prevented.

For example, if the tundish 25 is an iron crucible, the crucible temperature is 750 ° C. (curie point or higher), and the frequency is 1000 (Hz), the penetration depth = 16 (mm) [resistivity = 100 × 10 ⁻⁸ (Ω M)], the vacuum permeability = 4π × 10 ⁻⁷ , and when the container has a thickness of about 5 mm, the magnetic field is sufficiently penetrated to the molten metal and a good stirring function is obtained.
The method for determining the penetration depth is as follows: penetration depth: δ (m), frequency: f (Hz), resistivity: R, permeability: μ
δ = {2 · R / (2πf · μ))} ^1/2 .
Therefore, the molten metal can be satisfactorily stirred by selecting the frequency of the coil current based on the material of the crucible, its thickness, and the penetration depth.

Next, a quenching ribbon manufacturing apparatus according to a second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that a melting furnace (molten supply unit) 11 is provided separately from the tundish 41 (molten supply unit).
The melting furnace 11 includes a furnace body 12 and a heating coil 13 around the furnace body 12, and a pouring port 14 is provided on the left side of the furnace body 12 in FIG. 5.

The melting furnace 11 can be poured into the tundish 41 with the molten metal in the melting furnace 11 by tilting as shown by a chain line with a fulcrum (not shown) as a fulcrum by a driving mechanism (not shown) in the hermetic vessel 51. ing.
Therefore, the tundish 41 according to this embodiment does not have the lid 28 in the first embodiment, and the upper part is open.

  However, in the airtight container 51, the melting furnace 11, the tundish 41 and the nozzle 43, and the water cooling roll 20 are provided with the melting chamber 11 including the melting furnace 11, the tundish 41 and the nozzle 43, and the water cooling roll 20. Since the inert gas introduction part 36 is connected to the melting chamber on the side of the melting furnace 11, the tundish 41 and the nozzle 43, the inside of the tundish 41 at the time of tapping is An inert gas atmosphere having a pressure corresponding to about 5 times the pressure generated at the maximum molten metal height can be obtained, and with respect to the molten metal pressure from the nozzle 43, the influence of the fluctuation of the molten metal height can be ignored. The collision speed of the molten metal against the water-cooled roll 20 can be kept substantially constant.

Next, a quenching ribbon manufacturing apparatus according to a third embodiment of the present invention will be described with reference to FIG.
In this embodiment, the difference from the first and second embodiments is the nozzle provided in the tundish. Therefore, only the nozzle 101 which is a characteristic part of this embodiment will be described below.

As shown in FIGS. 6A and 6B, the tip 101A of the nozzle 101 has a plurality of (three in this embodiment) protruding portions 102 protruding toward the water-cooling roll 20 at equal intervals. Are provided integrally.
Each protrusion 102 is formed with a molten metal flow passage 103 that allows the inside and outside of the nozzle 101 to communicate with each other, and a hot water outlet 103 </ b> A is opened at the center of the tip surface 102 </ b> A of the protrusion 102.
According to such a configuration, only the tip surface 102A of the protruding portion 102 can contact the molten metal droplet 110 coming out of the pouring outlet 103A with the nozzle tip, so that the nozzle as shown in FIG. Compared to the case where the front end surface 201A of the 201 is flat over the entire surface, the diameter of the molten metal droplet 110 exiting from the hot water outlet 103A is limited (suppressed) to a certain value or less.

That is, the molten metal discharged from the hot water outlet 103A is supplied onto the water-cooled roll 20 as molten metal droplets 110 having a diameter larger than the diameter of the hot water outlet 103A. According to the nozzle 101 of this embodiment, FIG. As shown to a), since the molten metal droplet 110 is suppressed by the magnitude | size which a little swells from the outer edge of the protrusion part 102, as shown in FIG.6 (c), the molten metal droplet 110 is excessive along the front end surface 201A. Never grow up.
As a result, the molten metal droplets 110 and the molten metal jets 111 adjacent to each other or the coalescence of the molten metal jets 111 can be prevented, and the amount of molten metal supplied from the hot water outlet 103A to the water cooling roll 20 can be equalized. Thus, it is possible to produce a quenched ribbon having a stable width and thickness.

Next, a quenching ribbon manufacturing apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS.
The fourth embodiment is different from the first to third embodiments in that inclusion removal means 301 for removing the inclusion P in the molten metal before the molten metal reaches the nozzles 27 and 43 is provided. Therefore, only the inclusion removal means 301 that is a characteristic part of this embodiment will be described below.
Here, the inclusion P in the molten metal is a solid material that does not dissolve in the molten metal, such as a metal oxide or a metal carbide, even at a temperature equal to or higher than the melting point of the molten metal.

  The inclusion removing means 301 shown in FIG. 7 has a filter 302 installed inside the tundish 25, 41, and the inclusion P is separated by this filter 302. The filter 302 is made of a heat-resistant material having a melting point higher than the melting point of the molten metal, and there are a plurality (three in this embodiment, as shown in FIG. 7) in the molten metal supply path 303 from the tundish 25, 41 to the nozzles 27, 43. is set up. Here, the mesh size of the filter 302 is set so that the filter 302A installed on the upstream side is coarse and the filters 302B and 302C installed on the downstream side are fine, and the mesh size of the filter 302C installed on the most downstream side is set. Is smaller than the minimum inner diameter of the nozzles 27 and 43. Moreover, the filter 302 is installed so that it may incline with respect to the side wall of the molten metal supply path 303, as shown in FIG.

In the inclusion removal means 301 configured in this manner, the inclusion P having a large size can be removed by the upstream filter 302A, and therefore, the clogging of the downstream filters 302B and 302C can be prevented, and these filters can be prevented. The inclusion P can be removed stably by 302.
Further, since the mesh size of the filter 302C installed on the most downstream side is smaller than the minimum inner diameter of the nozzles 27 and 43, the inclusions P having a size that cannot pass through the nozzles 27 and 43 can be completely removed. , 43 can be prevented from being troubled.
Furthermore, since the filter 302 is installed so as to be inclined with respect to the side wall of the molten metal supply path 303, the contact area between the molten metal and the filter 302 is increased, and the inclusions P can be removed efficiently.

The inclusion removing means 301 shown in FIG. 8 is used for removing the inclusion P having a specific gravity larger than that of the molten metal.
A holding tank 311 capable of holding a certain amount of molten metal is provided on the upstream side of the tundish 25, 41, and the holding tank 311 is provided with a gate 312 having an opening on the bottom surface side, and a first space partitioned by the gate 312. The molten metal is supplied to 311A, and a discharge port 313 for discharging the molten metal to the tundish 25, 41 is provided in the upper part of the second space 311B.

  In the inclusion removal means 301 configured as described above, the molten metal gently flows as a laminar flow in the second space 311B of the holding tank 311, and the inclusion P having a specific gravity larger than that of the molten metal is settled and separated by the difference in specific gravity. The molten metal from which the inclusions P are removed is discharged to the tundish 25, 41 from the discharge port 313 provided in the upper part of the second space 311B. Therefore, the inclusion P can be removed with a very simple configuration.

The inclusion removing means 301 shown in FIG. 9 is used for removing the inclusion P having a specific gravity smaller than that of the molten metal.
The basic configuration is the same as that of FIG. 8 described above, and a new weir 314 having a bottom surface opened is provided in the second space 311B on the downstream side of the gate 312, and the first dam is formed between the discharge port 313 and the weir 314. A three-space 311C is formed.

  In the inclusion removal means 301 configured as described above, the molten metal flows gently in a laminar flow in the second space 311B of the holding tank 311 and the inclusion P having a specific gravity smaller than that of the molten metal is levitated and separated due to the specific gravity difference. The The molten metal from which the inclusions P are removed in the second space 311B is supplied to the third space 311C through the opening on the bottom surface side of the weir 314, and is discharged from the discharge port 313 to the tundish 25, 41. Therefore, the inclusion P can be removed with a very simple configuration.

Here, in the inclusion removal means 301 as shown in FIG. 8 and FIG. 9 using the specific gravity difference, if a flocculant for aggregating the inclusions P is added to the molten metal, minute inclusions that are easily turbid in the molten metal. By aggregating P and increasing the size, it becomes effective because it becomes easy to separate.
In consideration of the specific gravity and state of the inclusions P, it is preferable to provide the inclusion removal means 301 and other inclusion removal means shown in FIGS. 7 to 9 as an alternative or in combination.

  In addition, in the said embodiment, the specific structure of an airtight container, a tundish and its nozzle, a water cooling roll, a melting furnace, and an inclusion removal means is not limited to the example of illustration.

It is a whole longitudinal cross-sectional view which shows the manufacturing apparatus of the quenching thin strip which concerns on 1st Embodiment of this invention. It is the side view similarly seen from the left of FIG. It is an enlarged view which shows the principal part of a tundish. It is explanatory drawing which shows the relationship between the nozzle of a tundish and a rapid cooling roller. It is explanatory drawing of the principal part which shows the manufacturing apparatus of the quenching thin strip which concerns on 2nd Embodiment of this invention. (A), (b) is the principal part of the nozzle in the manufacturing apparatus of the quenching thin strip which concerns on 3rd Embodiment of this invention, (c) is sectional drawing which shows a comparative example with this nozzle. It is the schematic which shows the tundish provided with the inclusion removal means in the manufacturing apparatus of the quenching thin strip which concerns on 4th Embodiment of this invention. It is the schematic which shows the other example of an inclusion removal means. It is the schematic which shows the other example of an inclusion removal means.

Explanation of symbols

10 Rapid cooling ribbon production equipment
11 Melting furnace 20 Water-cooled rolls 25, 41 Tundish 26 Main body (crucible)
27, 43, 101 Nozzle 27a Nozzle body 27b Nozzle tip 30 Insulation mechanism 31, 32 Temperature measuring means (temperature sensor)
33, 34 Heating means (coil for induction heating)
35 Inert gas introduction part 37 Restrictor 39 Detection means 42 Bulkhead 50 Control part 51 Airtight container 102 Projection part 102A Projection end surface 103A Hot water outlet 301 Inclusion removal means M Rapid cooling ribbon P Inclusion

Claims (13)

In the airtight container, the molten metal is supplied to the water cooling roll from the molten metal supply unit via the nozzle, and the molten metal is rapidly cooled by the water cooling roll and formed into a quenched thin ribbon. ,
A method for producing a quenched ribbon, wherein the molten metal supply section and the nozzle are kept at a substantially melting point temperature of the molten metal.   Among the quenching ribbons formed by continuing to supply molten metal from the melt supply unit onto the water-cooling roll, the quenching ribbons formed at an early stage and the quenching ribbons formed at a later stage The method for producing a quenched ribbon according to claim 1, wherein the strip is removed.   The method for producing a quenched ribbon according to claim 1 or 2, wherein the molten metal supply section has a pressure corresponding to at least five times the head pressure generated at the maximum molten metal height. In the airtight container, a molten ribbon is supplied from a molten metal supply unit onto a water-cooled roll through a nozzle, and the molten metal is rapidly cooled by the water-cooled roll and rotated to form a quenched ribbon. ,
Temperature measuring means for measuring the temperature of the molten metal supply section and the nozzle;
Heating means for heating the molten metal supply section and the nozzle;
And a control unit for controlling the heating unit based on a temperature measurement result of the temperature measuring unit. In the airtight container, the molten metal supply unit, the nozzle, and the water cooling roll are partitioned by a partition,
The apparatus for producing a quenched ribbon according to claim 4, wherein an inert gas introduction unit is connected to the molten metal supply unit and the nozzle side.   The distance between the tip of the nozzle and the surface of the water-cooling roll is smaller than the size of the molten metal that is in a state to be poured from the tip of the nozzle and has surface tension. 6. The apparatus for producing a quenched ribbon according to claim 4 or 5.   The apparatus for producing a quenched ribbon according to any one of claims 4 to 6, wherein the nozzle is configured such that a nozzle tip is detachably attached to a nozzle body.   The apparatus for manufacturing a quenched ribbon according to any one of claims 4 to 7, wherein the molten metal supply unit is provided with a regulating body that controls the molten metal discharged from the molten metal.   The molten metal supply unit has a melting function for generating the molten metal by melting the raw metal of the quenching ribbon in a tundish that temporarily stores the molten metal and supplies the molten metal to the water cooling roll. The apparatus for producing a quenched ribbon according to any one of claims 4 to 8. The molten metal supply unit temporarily stores a melting furnace including a crucible formed of a conductive material and an induction heating coil disposed on the outer periphery thereof, and the molten metal generated by the melting furnace. And a tundish for supplying to the water-cooled roll,
10. The method of manufacturing a quenching ribbon according to claim 4, wherein the induction heating coil is supplied with a current having a frequency capable of causing a magnetic field to penetrate into the molten metal in the crucible. apparatus.   The quenching thin according to claim 9 or 10, wherein the control unit controls the melting power and the heat retaining power by selectively using the temperature of the molten metal supply unit and the molten metal temperature in the molten metal supply unit. Band manufacturing equipment.   The quenching thin according to any one of claims 4 to 11, wherein a plurality of projecting portions are provided at a distance from each other at the tip of the nozzle, and a hot water outlet is opened at a tip surface of each projecting portion. Band manufacturing equipment.   13. The inclusion removal means for removing inclusions in the molten metal before the molten metal is supplied to the nozzle is provided in the molten metal supply unit. Equipment for manufacturing the quenched ribbon described.

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