JP6736029B2 - Method for manufacturing alloy castings - Google Patents

Description

The present invention relates to a method for manufacturing an alloy casting material.

Conventionally, alloy wires such as copper alloy wires have been used as conductors of electric wires (for example, Patent Documents 1 and 2). Patent Documents 1 and 2 disclose that a copper alloy wire having a predetermined wire diameter is manufactured by subjecting a continuous cast material to a material and subjecting it to plastic working such as extrusion, rolling, and wire drawing. As a continuous casting method, Patent Document 1 discloses a horizontal continuous casting method in which a molten alloy is drawn in a horizontal direction to manufacture a cast wire rod.

JP, 2005-021138, A JP, 2010-084163, A

It is desirable to be able to industrially mass-produce an alloy cast material having excellent surface properties by reducing casting defects.
As described in Patent Documents 1 and 2, ultra-fine wires having a wire diameter of 0.1 mm (100 μm) or less are required for copper alloy wires used as conductors of electric wires. In order to industrially mass-produce such ultrafine wires, it is desired that the material is unlikely to break during the plastic working performed until reaching the final wire diameter.

Here, in the above-mentioned horizontal continuous casting method, typically, a melting furnace that melts raw materials to produce a molten metal, holds the molten metal from the melting furnace, and holds a mold provided on the bottom side of the outer peripheral surface. A casting apparatus including a furnace is used. The molten metal in the holding furnace decreases as the cast wire is manufactured. Therefore, when the production amount of the cast wire rod reaches a predetermined amount, continuous casting can be continued by pouring a predetermined amount of molten metal from the melting furnace into the holding furnace. The pouring amount is set so that the level of the molten metal remaining in the holding furnace satisfies the preset standard level. The inventors of the present invention have studied the use of the ultrafine wire as described above by producing a cast wire rod by relatively increasing the amount of molten metal poured from the melting furnace to the holding furnace in such continuous casting. When the pouring amount is, for example, about half to one-third of the holding amount of the holding furnace, the pouring frequency can be reduced because the pouring amount is large, and the workability is excellent. However, when a cast wire rod obtained by intermittently pouring such a large amount of metal was used as a material for ultrafine wire, it was found that a wire breakage easily occurred during plastic working until reaching the final wire diameter. .. In addition, it was found that the cast wire rod used as a material had casting defects such as blowholes and surface defects, and locally had a portion with poor surface quality.

Then, it aims at providing the manufacturing method of the alloy casting material which can manufacture the alloy casting material excellent in surface property.

A method for manufacturing an alloy casting material according to an aspect of the present disclosure,
Continuous production of an alloy casting material having the above-mentioned predetermined composition while continuously supplying a solid raw material so that the above-mentioned predetermined composition is obtained, to a molten alloy formed of an alloy having a predetermined composition held in a melting and holding furnace. Equipped with a process
The supply rate and the casting rate of the solid raw material are controlled so that the maximum fluctuation amount per minute on the molten metal surface in the melting and holding furnace is within 10% of the reference molten metal surface height.

The above method for producing an alloy cast material can produce an alloy cast material having excellent surface properties.

It is a schematic explanatory drawing which shows an example of the casting apparatus utilized for enforcing the manufacturing method of the alloy casting material of embodiment. It is a schematic explanatory view which shows another example of the casting apparatus utilized for implementation of the manufacturing method of the alloy casting material of embodiment.

The present inventors have obtained the knowledge that, with respect to the above-mentioned cast material that is easily broken during plastic working, there are many casting defects on the wire surface in the above-mentioned pouring timing and the portion manufactured in the vicinity thereof. It was Further, it has been found that, at the pouring time and its vicinity, it is easy to involve an atmospheric gas such as oxygen during pouring to increase the amount of gas contained in the cast material and to easily include foreign matter. From this, the following is considered as one of the causes that the casting defect is likely to occur locally. If a large amount of molten metal is intermittently poured from the melting furnace to the holding furnace, the entrained gas and the additional molten metal itself may reach near the mold of the holding furnace due to the momentum when the molten metal is introduced. In this case, the molten metal having an inappropriate temperature due to the inclusion of the above-mentioned gas and the additional molten metal, and the molten metal in which the above-mentioned gas is engulfed locally and temporarily generated from the mold, blowholes, It is considered that it is easy to obtain a cast material that contains foreign matter and the like generated due to fluctuations in the hot water temperature. Examples of the foreign matter include the above gases, inevitable impurities in the molten metal, products (eg, oxides) produced by the reaction of the constituent materials of the inner wall of the holding furnace, and the like. The foreign matter including the constituent material of the inner wall is largely changed by the large amount of molten metal as described above, and the molten metal surface in the holding furnace is largely changed, and a part of the inner wall repeats the contact state with the molten metal and the non-contact state with the inner wall. Are thought to be produced by damage. From the above, in continuous casting, in order to reduce the occurrence of the casting defects, a large amount of molten metal is not intermittently poured, but a large fluctuation of the molten metal surface in the holding furnace or a large fluctuation of the molten metal temperature does not occur. It was found that it is preferable to supply the raw materials as described above.
The present invention is based on the above findings.

First, the contents of the embodiments of the present invention will be listed and described.
(1) A method for manufacturing an alloy cast material according to one aspect of the present invention comprises:
Continuous production of an alloy casting material having the above-mentioned predetermined composition while continuously supplying a solid raw material so that the above-mentioned predetermined composition is obtained, to a molten alloy formed of an alloy having a predetermined composition held in a melting and holding furnace. Equipped with a process
The supply rate and the casting rate of the solid raw material are controlled so that the maximum fluctuation amount per minute on the molten metal surface in the melting and holding furnace is within 10% of the reference molten metal surface height.

“Continuously supplying” includes a constant supply mode in which the solid raw material is supplied so as not to substantially include a time period in which the supply of the solid material is interrupted, and a frequent supply mode in which intermittent supply is frequently performed. In the frequent supply mode, the supply of the solid raw material is interrupted under the condition that the maximum fluctuation amount per minute on the above-mentioned molten metal surface (hereinafter sometimes referred to as molten metal fluctuation range) satisfies the above-mentioned specific range. The time is very short, for example less than 1 minute.
The "standard molten metal surface height" is a value that is set according to the amount that can be held in the melting and holding furnace, the amount that is actually to be held, the production amount of alloy castings, and the like.

In the method for producing an alloy casting material described above, a melting and holding furnace capable of melting the raw material and holding the molten metal is used, and the solid raw material is supplied to the molten alloy held in the furnace. Then, while the solid raw material is melted in the furnace to prepare and add a new molten alloy, the molten alloy is continuously discharged from the same furnace to continuously produce the alloy casting material. In the supply of the solid raw material, the gas entrainment, the fluctuation of the hot water temperature, and the fluctuation of the molten metal surface caused by the above-mentioned large amount of pouring are substantially not caused. Further, in the above-mentioned method for producing an alloy cast material, since the supply rate of the solid raw material and the casting rate are controlled so that the variation level of the molten metal fills a specific range, the variation of the molten metal surface and the temperature of the molten metal accompanying the supply of the solid material are controlled. Fluctuations can be sufficiently small, preferably substantially eliminated. For example, even when the mold is provided on the bottom side of the melting and holding furnace, which will be described later, fluctuations in hot water temperature near the mold can be reduced. Therefore, the above method for producing an alloy cast material can reduce casting defects and produce an alloy cast material having excellent surface properties. In addition, the above-mentioned method for producing an alloy cast material is capable of continuously producing the alloy cast material having excellent surface properties, and is suitable for industrial mass production. Furthermore, if the alloy cast material obtained by the method for producing the alloy cast material described above is made of, for example, an ultrafine wire material, it is difficult to break the wire during drawing, and the method for producing the alloy cast material described above is a plastic work material such as an ultrafine wire. Contribute to the improvement of industrial mass productivity.

(2) As an example of the method for producing the above alloy casting material,
As the solid raw material, there is a mode in which a parent phase raw material which becomes a parent phase metal in the alloy having the predetermined composition and an additive raw material which becomes an additional element are prepared and supplied independently.

In the above embodiment, the solid raw material is independent of the matrix raw material and the additive raw material, and the preparation of the solid raw material is easier than when the solid raw material is an alloy material having a predetermined composition. Further, the feed rate of the mother phase raw material and the feed rate of the additive raw material can be controlled independently, and the feed rate can be easily adjusted so as to satisfy a predetermined composition.

(3) As an example of the method for producing the above alloy casting,
The alloy having the predetermined composition may be a copper alloy.

According to the above-mentioned form, an alloy cast material suitable for a material of a superfine copper alloy wire can be manufactured.

(4) As an example of the method for producing the above alloy casting material,
The solid raw material may be in the form of one or more kinds selected from wire rods, granular materials, and plate materials.

When the wire rod or plate material is used as the solid raw material in the above-described embodiment, the supply speed can be adjusted easily and accurately by adjusting the feeding speed of the wire rod or plate material wound in a coil shape. If a wire or plate is used, the above-mentioned constant supply form can be performed. When the solid raw material is a granular material in the above embodiment, the supply rate can be easily and accurately adjusted by using a commercially available powdery or granular material supply device. When using the granular material, the frequent supply form is easy to use as described later.

(5) As an example of a method for manufacturing the above alloy casting material,
The solid raw material is supplied so as to be melted on the molten metal side of the melting and holding furnace,
An example is a mode in which the alloy casting material is continuously produced by tapping in a horizontal direction from a mold provided on the bottom side of the melting and holding furnace.

The said form can be said to be a form which utilizes the horizontal continuous casting method mentioned above. The above-mentioned form is immediately after the solid raw material is melted, and even if a transient molten metal whose composition or hot water temperature may be unstable occurs, the region where this transient molten metal exists is on the molten metal surface side, that is, the bottom of the melting and holding furnace. The position can be sufficiently separated from the mold provided on the side. Therefore, in the molten alloy near the mold, the fluctuation of the molten metal temperature due to the solid raw material is unlikely to occur, and preferably does not substantially occur. Therefore, in the above-mentioned form, an alloy casting material having excellent surface properties can be manufactured with high productivity.

(6) As an example of the method for producing the above alloy casting material,
Withdrawing the molten alloy upward from the mold provided on the upper side of the melting and holding furnace, continuously casting the alloy casting material,
The solid raw material may be supplied to a region in the melting and holding furnace which is separated from a region near the mold.

The above-mentioned form can be said to be a form using the up-drawing continuous casting method. In this form, it can be said that the mold is on the melt surface side, but the molten alloy directly used for casting is located on the melt surface side. Therefore, in the configuration in which the solid raw material is supplied toward the molten metal surface and melted on the molten metal surface side, when the above-mentioned composition, the molten metal temperature, or the like may cause an unstable molten metal, the transient molten metal also has a region near the mold. Will exist in. However, in the above-mentioned embodiment, since the region partitioned from the region in the vicinity of the mold is the supply region of the solid raw material, the molten alloy near the mold is caused by the transient molten metal that may exist near the supply region of the solid raw material. Fluctuations in the hot water temperature are unlikely to occur, and preferably do not substantially occur. Therefore, in the above-mentioned form, an alloy casting material having excellent surface properties can be manufactured with high productivity.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of the present invention will be specifically described with reference to FIGS. 1 and 2 as appropriate. 1 and 2, the transient molten metal 13 and the molten alloy 15 near the mold are virtually shown by a chain double-dashed line for convenience of description, but there is actually no clear boundary.
[Embodiment 1]
(Outline of manufacturing method)
In the method for manufacturing an alloy casting material according to the embodiment, the molten alloy 10 that is held in the melting and holding furnace 3 and is made of an alloy having a predetermined composition is tapped from the melting and holding furnace 3 to form the alloy casting material 1 having a predetermined composition. Is continuously manufactured. One of the features of the method for manufacturing an alloy cast material of the first embodiment is that continuous casting is performed while continuously supplying the solid raw material 100 so as to have a predetermined composition. In particular, the molten metal surface 10f in the melting and holding furnace 3 is prevented from fluctuating as much as possible, and the molten alloy 10 (FIG. 1, FIG. In FIG. 2, the supply amount of the solid raw material 100 and the production amount of the alloy casting material 1 are adjusted so that the temperature of the molten alloy 15 near the mold 4 does not fluctuate as much as possible. Quantitatively, the supply rate of the solid raw material 100 and the alloy casting material 1 are controlled so that the maximum fluctuation amount per minute on the molten metal in the melting and holding furnace 3 is within 10% of the reference molten metal height H ₀ . Control the production speed. This control aims to make the production amount of the molten alloy produced from the solid raw material 100 and the production amount of the cast alloy material 1 produced from the molten alloy 10 as equal as possible.

(Outline of equipment for implementing the manufacturing method)
In order to carry out the method for manufacturing the alloy cast material of the embodiment, for example, the casting apparatuses 2A and 2B shown in FIGS. 1 and 2 can be used. Each of the casting apparatuses 2A and 2B continuously melts and holds the melting and holding furnace 3 having a tapping portion, a pinch roll 5 for drawing out or sending out the alloy casting material 1 to be manufactured in a predetermined direction, and a solid raw material 100 in the melting and holding furnace 3. And a control device 8 for controlling the supply speed of the solid raw material 100 and the production speed of the alloy casting 1. .. In the casting apparatuses 2A and 2B, the mold 4 is attached to the molten metal outlet of the melting and holding furnace 3. In the casting devices 2A and 2B, the feeding speed of the solid raw material 100 is adjusted by the feeding devices 6 and 7A or the feeding devices 6 and 7B, and the speed at which the alloy casting material 1 is drawn out (corresponding to the casting speed) is controlled by the rotation speed of the pinch roll 5. Adjusted. The control device 8 controls the supply devices 6 and 7A or the supply devices 6 and 7B and the pinch roll 5 so that the supply speed and the casting speed are synchronized. Other detailed configurations will be described later.

(Solid raw material)
<Composition>
The composition of the solid raw material 100 may be selected according to the constituent alloy of the alloy casting material 1 to be manufactured. As a specific alloy, a copper alloy containing Cu as a mother phase metal (containing additive elements, the balance being Cu and inevitable impurities), an aluminum alloy containing Al as a mother phase metal (containing additive elements, the balance being Al and inevitable impurities) ) And the like.

The additive element of the copper alloy may be one or more elements selected from Ag, Sn, Zn and the like. Specific copper alloys include binary alloys such as Cu-Ag alloys, Cu-Sn alloys, and Cu-Zn alloys. The content of the additive element is% by mass, and Ag is 0.05% or more and 15% or less, Sn is 0.05% or more and 1% or less, and Zn is 1% or more and 40% or less. When a copper alloy is used, a copper alloy wire used as a conductor of an electric wire, particularly an alloy casting material 1 suitable for a material of a superfine wire having a wire diameter of 100 μm or less can be manufactured.

<shape>
As the solid raw material 100, it is possible to use a solid raw material having an appropriate shape that can be continuously supplied so that the fluctuation range of the molten metal surface satisfies a specific range. For example, one or more kinds selected from a wire material, a granular material, and a plate material can be mentioned. If the material is a wire material, a granular material, or a plate material, the supply speed can be easily and accurately adjusted by using an appropriate supply device (supply devices 6, 7A in FIG. 1) described later. Various sizes (wire diameter, particle size, plate thickness and plate width) and various shapes of wire rods and granular materials can be used. It is manufactured by adjusting the supply speed in consideration of size and shape. It is easy to equalize the production amount of the molten alloy and the production amount of the cast alloy material 1. An example of the wire rod is a round wire having a wire diameter of 5 mm or more and 30 mm or less. Examples of the granular material include spherical particles having an average particle size of 0.5 mm or more and 10 mm or less. Commercially available wire rod, granular material, and plate material can be used. It is possible to use a plurality of materials having different shapes, such as only the wire material, only the granular material, only the plate material, or a combination of the wire material and the granular material.

The wire material or the plate material is a coil material wound in a coil shape, and a supply device capable of rewinding and unwinding the coil material, for example, supply devices 6 and 7B including delivery rolls 62 and 72 as shown in FIGS. If used, it is possible to provide a constant supply mode in which the supply can be performed without substantial interruption. 1 and 2, a coil material (a mother phase raw material 160 and an additional raw material 172 described later) is illustrated as an example of the solid raw material 100. One end of the wire or plate can be surely melted by immersing it in the molten alloy 10 as shown in FIGS.

When using the granular material, for example, a storage tank for storing the granular material (eg, a hopper or the like, not shown), and a cylindrical guide for introducing a predetermined amount of the granular material from the storage tank toward the molten metal surface 10f A continuous supply is performed using a supply device 7A including a part 74 and a transfer device (e.g., a commercially available vibrating feeder device (not shown)) that transfers the granular material from the storage tank to the guide part 74. It can be mentioned. Here, if the granular material is constantly charged, it depends on the size of the granular material, but since the melting time of each particle is relatively short, the components in the vicinity of the supply region of the granular material in the molten alloy 10 are typically melted. Immediately after that, a large difference occurs between the composition of the transient molten metal 13 in which the composition and the molten metal temperature may be unstable, and the composition of the molten alloy 15 near the mold 4, so that the alloy casting material 1 having a predetermined composition can be obtained. It may not be possible to manufacture stably. Under the condition that the level fluctuation range satisfies a specific range, if the one-time supply amount is increased to some extent and supplied at a high frequency, the difference between the above components can be easily reduced, and it is considered to be practical. .. Therefore, when the granular material is used, the control device 8 may be configured so that the supply device 7A supplies a predetermined amount of the granular material to the melting and holding furnace 3 at a predetermined interval. By doing so, it is possible to adopt a frequent supply mode in which intermittent supply is performed with high frequency. Under the condition that the level fluctuation range satisfies a specific range, the opening/closing timing of the storage tank, the transport speed of the transport device, etc. may be adjusted to set the amount of granular material input (kg/min) per minute. .. By immersing the open end 74o of the guide portion 74 in the molten alloy 10 so that the open end 74o is located near the molten metal surface 10f as shown in FIG. In addition to suppressing the fluctuation of the surface 10f, it is easy to prevent the charged granular material from reaching the molten alloy 15 near the mold 4.

<morphology according to composition>
The solid raw material 100 may be in an independent form in which a parent phase raw material 160 which is a parent phase metal in an alloy having a predetermined composition and an additional raw material 170 or 172 which is an additional element are independent from each other. In the independent form, a commercially available wire rod, granular material, plate material or the like composed of a matrix metal and an additive element can be used. Therefore, the solid raw material 100 can be easily prepared in the independent form as compared with the single form in which an alloy material having a predetermined composition is used as the solid raw material 100. Further, it is expected that a high-purity material as the parent phase raw material 160 or the additional raw material 170 or 172 can be easily used, and the occurrence of casting defects due to impurities can be reduced as compared with the above-mentioned single form. As an example, when manufacturing the alloy casting material 1 of a copper alloy, as the mother phase raw material 160, a material composed of oxygen-free copper having an oxygen concentration of 10 ppm or less by mass can be used. Further, in the independent mode, the mother phase raw material 160 and the additive raw material 170 or 172 can be independently supplied, so that the supply rate can be easily controlled according to the shape and size of the raw material. It is easy to make the matrix raw material 160 and the additive raw material 170 different in shape and size, or equal in shape. FIG. 1 illustrates a case where the mother phase raw material 160 is a coil wire and the additive raw material 170 is a granular material, and the shapes of the two are different. In FIG. 2, the matrix raw material 160 and the additive raw material 172 are both coil wire rods, and the case where the shapes of both are the same is illustrated. In the independent mode, a supply device is used according to the total number of the mother phase raw material 160 and the additive raw material 170 or 172.

The solid raw material 100 may be in a single form such as a wire rod, a granular material, or a plate material made of an alloy having a predetermined composition. In the stand-alone form, the supply device can be one.

<Bread level fluctuation range>
The reference molten metal height H ₀ is the height from the bottom surface 3d of the melting and holding furnace 3 to the molten metal surface 10f in the melting and holding furnace 3, and the amount that can be held by the melting and holding furnace 3 will be actually held. The amount can be appropriately set depending on the amount, the production amount of the alloy casting material 1, and the like. For example, the reference molten metal surface height H _0, the height H ₃ of the internal space of the melting and holding furnace 3, and the like 80% lower than about 70% or more _(Fig. 1, the distance from FIG 2 the bottom 3d to the opening edge) be able to.

Before the start of continuous casting, a predetermined planned amount of molten alloy 10 is held in the melting and holding furnace 3 so as to satisfy the reference molten metal surface height H ₀ . The molten alloy 10 at this time can be prepared by preparing raw materials so as to have a predetermined composition and melting them in the melting and holding furnace 3. In a state where the melting and holding furnace 3 is filled with a predetermined amount of the molten alloy 10, the solid raw material 100 is arranged in the supply devices 6, 7A, 7B and the like so as to be continuously supplied, and continuous casting is started. The molten alloy 10 in the melting and holding furnace 3 decreases as the alloy casting material 1 is manufactured, and increases as the raw material is supplied. Along with this increase or decrease, the actual molten metal height H ₁₀ in the melting and holding furnace 3 changes. In order to reduce the occurrence of casting defects due to this fluctuation, in the method for manufacturing an alloy cast material of the embodiment, the maximum fluctuation amount per minute (maximum fluctuation height) on the molten metal surface 10f is the reference molten metal surface height. The feed rate and the casting rate are adjusted so as to be within 10% of H ₀ . In other words, the actual molten metal surface height _{H 10} is the reference bath level height _{H 0} of 0.9 times the height _{H i} above, the reference molten metal surface height _{H 0} of 1.1 times the height _{H s} or less and The feed rate and the casting rate are adjusted so that When using the casting devices 2A and 2B, the control device 8 controls, as the supply speed of the solid raw material 100, the rotation speed of the feeding roll 62 provided in the supply device 6 (the supply speed of the mother phase raw material 160) and the supply device 7A. The opening/closing timing of the storage tank and the transport speed of the transport device (the supply speed of the added raw material 170) or the rotation speed of the delivery roll 72 (the supply speed of the added raw material 172) provided in the supply device 7B are controlled. Moreover, the control device 8 controls the rotation speed (casting speed) of the pinch roll 5 as the casting speed.

It is desired that the fluctuation level of the molten metal level be as small as possible. Therefore, it is preferable that the maximum fluctuation amount per minute on the molten metal surface 10f is within 8% of the standard molten metal surface height H ₀ , within 5%, within 1%, and 0%. Setting the maximum fluctuation amount to 0% corresponds to controlling the supply speed and the production amount so that the molten metal height H ₁₀ does not substantially fluctuate and always becomes the reference molten metal height H _0. ..

(Casting equipment)
The casting apparatus 2A, 2B shown in FIGS. 1 and 2 has a mold 4 provided on the bottom side of the melting and holding furnace 3 and taps horizontally from the mold 4 to continuously produce the alloy cast material 1. 1 shows a continuous casting device. In FIGS. 1 and 2, a melting and holding member having an L-shaped cross-section, which is provided with a tubular tap portion that projects outward from the outer peripheral surface in a bottom side region of the outer peripheral surface of the cylindrical furnace body and has a mold 4 attached to an end surface thereof. Although the furnace 3 is illustrated, the shape of the melting and holding furnace 3 can be changed as appropriate. 1 and 2 show the state in which the upper portion of the melting and holding furnace 3 is open, but a lid portion (not shown) having a supply hole for the solid raw material 100 can be provided. As the melting and holding furnace 3, the lid portion, the mold 4, the pinch roll 5, the feeding devices 6, 7A, 7B, the control device 8 and the like, known devices and commercial products can be used.

In the horizontal continuous casting device, if the solid raw material 100 is supplied so as to be melted on the side of the molten metal 10f of the melting and holding furnace 3, the molten metal caused by the supply of the solid raw material 100 and the transient molten metal 13 is supplied to the molten alloy 15 near the mold 4. Temperature fluctuations are less likely to occur, and preferably substantially not. When the supply region of the solid raw material 100 is on the molten metal surface 10f side, the existing region of the transient molten metal 13 that may occur immediately after melting can be on the molten metal surface 10f side away from the mold 4, and is provided on the mold 4 side for casting. This is because the existing region of the molten alloy 10 directly used and the existing region of the transient molten metal 13 can be sufficiently separated. The solid raw material 100 may be supplied from above the melting and holding furnace 3 toward the molten metal surface 10f. In particular, one end of the coil wire material that is the parent phase raw material 160 or the additive raw material 172 of FIG. 2 and the open end 74o of the guide portion 74 that guides the additive raw material 170 of FIG. It is preferable to arrange the solid raw material 100 so as to be located near 10f.

As another casting apparatus, for example, a mold is provided on the upper side of the melting and holding furnace, and the molten alloy is drawn upward from this mold to continuously cast an alloy casting material (not shown). ) Etc. can be used. In the up-drawing type continuous casting apparatus, a mold is typically provided in a lid portion that covers the opening of the melting and holding furnace. If the solid raw material is supplied from above the melting and holding furnace toward the molten metal surface and melted, for example, by providing a supply hole for the solid raw material in the lid portion, and a transient molten metal existence region that may occur immediately after the melting of the solid raw material, The existing region of the molten alloy directly used for casting is located on the molten metal surface side. Under this condition, the alloy melt directly used for casting is likely to have a change in the melt temperature due to the transient melt. Therefore, when using the up-drawing type continuous casting device, a partition (not shown) is provided in the melting and holding furnace, and the region near the molten metal surface is used as a region where the transient molten metal exists and the mold directly used for casting. It is partitioned into the area where the molten alloy is located nearby. Then, it is preferable to supply the solid raw material to a region where the transient molten metal is present, which is separated from the region near the mold in the melting and holding furnace. The partition part may be a plate material, and may be supported by the lid part or the inner wall of the melting and holding furnace. It is preferable to adjust the length of the partition so that the lower end of the partition reaches the position of not more than ½, and further not more than ⅓ of the reference molten metal height from the bottom of the melting and holding furnace. Further, it is preferable that the partition portion has a shape capable of enclosing a region where the molten alloy is present near the mold, or that the width of the partition portion is wide enough to divide the inside of the melting and holding furnace. By doing so, even if the solid raw material is continuously supplied, the molten metal temperature near the mold is unlikely to change due to the transient molten metal, and preferably substantially does not occur.

<Other conditions>
Examples of the atmosphere during casting include an air atmosphere, a reducing atmosphere containing a reducing gas such as CO, and an inert atmosphere containing an inert gas such as argon or nitrogen. When the atmosphere is used, the atmosphere control is unnecessary. When the reducing atmosphere or the inert atmosphere is used, the oxygen content of the molten alloy 10 can be effectively reduced. When the molten alloy 10 such as a copper alloy is used, the molten metal surface 10f can be covered with a reducing covering agent. By doing so, the oxygen content of the molten alloy 10 can be effectively reduced even in the atmosphere. By controlling the atmosphere, using a reducing agent, and the like, it is easier to reduce casting defects due to the increase in oxygen content. If charcoal pieces or charcoal powder is used as the covering agent, the solid raw material 100 can be supplied through the gaps formed between the charcoal pieces.

(Use)
INDUSTRIAL APPLICABILITY The method for manufacturing an alloy cast material according to the embodiment can be used for manufacturing an alloy cast material such as a long wire rod or a plate material. The obtained alloy casting material 1 is appropriately subjected to plastic working such as wire drawing and rolling, heat treatment, etc., and used as a material such as various conductors and contact materials as a wire or plate material having a predetermined shape and size. Available.

(Alloy casting material)
The alloy cast material 1 having a predetermined composition can be manufactured by the method for manufacturing an alloy cast material of the embodiment. The alloy casting material 1 is typically a wire rod or a plate. The size (wire diameter, cross-sectional area, etc.) and shape of the wire material, and the size (plate thickness, board width, etc.) of the plate material can be appropriately selected. Examples of the wire include a round wire having a circular cross-sectional shape and a diameter of about 8 mm to 30 mm, a rectangular wire having a cross-sectional shape of 10 mm ^{2 to} 500 mm ^{2 and the} like. .. It is advisable to adjust the shape and size of the tap hole (here, the shape and size of the mold 4, and the shape and size of the shape defining member in the free casting method) so that the desired shape and size can be obtained.

For example, if the solid raw material 100 that becomes a copper alloy having a predetermined composition is used, a copper alloy cast material can be obtained as the alloy cast material 1. The copper alloy cast material can be used as a material of a copper alloy wire used as a conductor of an electric wire or the like. In particular, since this copper alloy cast material has few casting defects and excellent surface properties, it is suitable as a material for ultra-fine copper alloy wire having a wire diameter of 0.1 mm or less, 0.05 mm or less, 0.03 mm or less, for example. Available for

[Test Example 1]
Continuous casting was performed using a molten copper alloy and a horizontal continuous casting device to produce a copper alloy casting material. The obtained cast material was subjected to wire drawing to produce a copper alloy wire (wire drawn material). The surface properties and wire drawability of the obtained cast material and wire drawn material were examined.

(No. 1-1, 1-2: No pouring)
Sample No. 1-1, No. The casting material 1-2 was produced in the following manner using the casting apparatus 2A including the melting and holding furnace 3 and the mold 4, the feeders 6 and 7A, and the controller 8 shown in FIG.
As the solid raw material 100, pure copper wire (diameter 8 mm or more and 12.5 mm or less) and pure silver grains (average particle size 1 mm or more and 5 mm or less) were prepared. Before the start of continuous casting, a molten metal composed of a copper alloy having the composition shown in Table 1 was prepared and held in the melting and holding furnace 3. This molten metal was prepared in such an amount that the standard molten metal surface height H ₀ was satisfied (here, 700 kg). To the molten metal in the melting and holding furnace 3, pure copper wire (matrix raw material 160) is continuously supplied by the supply device 6 so that the composition shown in Table 1 is obtained, and pure silver grains (addition raw material 170 are supplied by the supply device 7A). ) Is continuously supplied.

In this test, the supply device 6, so that the maximum fluctuation amount per minute (mm/min) on the molten metal surface 10f in the melting and holding furnace 3 becomes substantially equal to the reference molten metal surface height H ₀ (mm). 7A and the driving conditions of the pinch roll 5 were adjusted. Then, the feed rate of the solid raw material (the feeding length of the pure copper wire per minute, the pure silver grain per minute, so that the actual molten metal height H ₁₀ is always equal to the reference molten metal height H ₀ And the casting speed (production length per minute) of the copper alloy casting material were controlled. In this test, a cast material (round wire) having a wire diameter of 22 mm was manufactured. The production amount of the cast material was 1000 kg.

(No. 1-101, 1-102: with pouring)
Sample No. The casting materials 1-101 and 1-102 were manufactured as follows.
Electrolytic copper and pure silver particles were prepared as raw materials, adjusted so as to have the composition shown in Table 1, and melted in a melting furnace to prepare a molten copper alloy having the composition shown in Table 1. The produced molten copper alloy was transferred from the melting furnace to a holding furnace and held therein. In this test, the initial holding amount in the holding furnace was 700 kg, and when the production amount of the cast material reached 250 kg, 250 kg of molten metal was repeatedly performed to produce a cast material (round wire) having a wire diameter of 22 mm. The molten metal for pouring was separately prepared in the melting furnace. The production amount of the cast material was 1000 kg.

When the surface properties of the produced casting material were confirmed, Sample No. 1-1, No. The cast materials of 1-2 had no visually recognizable casting defects.

The cast material produced was subjected to wire drawing to produce a wire drawn material having a wire diameter of 28 μm, and the surface properties were examined. The surface properties of the drawn wire material were evaluated by the number of flaws (count) detected by a commercially available eddy current flaw detector. The number of flaws was divided into small and large and examined depending on whether the maximum flaw size was 100 μm or more. In addition, the number of wire breakages that occurred during the production of a wire drawing material having a wire diameter of 28 μm was examined, and a value obtained by dividing the production amount (1000 kg in this case) of the wire drawing material by the number of wire breakage (times) was evaluated as wire drawability (kg/time). The evaluation results are shown in Table 1.

As shown in Table 1, a large amount of molten metal was not intermittently supplied during continuous casting, the solid raw material was continuously supplied, and the supply rate and the casting rate were controlled so that the molten metal height did not fluctuate as much as possible. Sample No. 1-1, No. As for No. 1-2, there are few casting defects on the surface as described above, and it is understood that 1-2 is substantially absent in this test, and a high-quality cast material having excellent surface properties can be manufactured. Further, it is understood that when plastic working is performed using this cast material as a raw material, a plastic processed material having excellent surface properties can be obtained. Here, an ultrafine wire drawing material having a wire diameter of 28 μm and having very few surface defects (small flaw detection count) or substantially no surface defects has been obtained. It can be seen that there are very few disconnections in the production of this ultra-fine wire drawing material. Here, the wire drawability is 2 kg/time or more, and the sample No. 1-101, No. The wire drawability of 1-102 is about 8 times or more, and about 10 times or more.

From the above test, in continuous casting of the alloy, while continuously supplying the solid raw material, the supply rate and the casting rate are controlled so that the maximum fluctuation amount per minute on the molten metal surface is as small as possible, It was shown that an alloy cast material having excellent surface properties can be obtained. It was also shown that this alloy cast material can be suitably used as a material for ultrafine wire rods having a wire diameter of 100 μm or less, further 50 μm or less. Further, from the above test, by performing the above-mentioned specific control, it is difficult to break the wire even when the additive element such as Ag is small (here, 0.6 mass%) to large (here, 2 mass%), and the surface is not broken. It was shown that an alloy cast material (here, a copper alloy wire such as a Cu-Ag alloy) suitable for a material of a plastically worked material such as a drawn wire having excellent properties was obtained.

The present invention is not limited to these exemplifications, but is defined by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.
For example, in Test Example 1, the component (Ag amount) of the copper-silver alloy can be changed, or the alloy other than the copper alloy can be changed.

1 alloy casting material 10 alloy molten metal 10f molten metal surface 13 transient molten metal 15 alloy molten metal near the mold 2A, 2B casting equipment 3 melting and holding furnace 3d bottom surface 4 mold 5 pinch roll 100 solid raw material 160 mother phase raw material 170,172 additive raw material 6,7A , 7B feeding device 62, 72 feeding roll 74 guide part 74o opening end 8 control device

Claims (6)

Continuous production of an alloy casting material having the above-mentioned predetermined composition while continuously supplying a solid raw material so that the above-mentioned predetermined composition is obtained, to a molten alloy formed of an alloy having a predetermined composition held in a melting and holding furnace. Equipped with a process
The solid raw material comprises a parent phase raw material which is a parent phase metal in the alloy of the predetermined composition, and an additive raw material which is an additive element in the alloy of the predetermined composition,
The mother phase raw material is a wire rod, and with one end of the wire rod immersed in the alloy melt, the wire rod is supplied to the alloy melt,
The additive raw material is a granular material, in a state in which the opening end of the guide portion for introducing the granular material into the molten alloy is immersed in the molten alloy, the granular material is supplied to the molten alloy,
A method for producing an alloy casting material, in which the supply rate and the casting rate of the solid raw material are controlled such that the maximum fluctuation amount per minute on the molten metal surface in the melting and holding furnace is within 10% of the standard molten metal surface height. .. The method for manufacturing an alloy cast material according to claim 1 , wherein the alloy having the predetermined composition is a copper alloy. The copper alloy is a Cu-Ag alloy containing 0.05% by mass or more and 15% by mass or less of Ag,
The mother phase raw material is a pure copper wire,
The method for manufacturing an alloy cast material according to claim 2, wherein the granular material is pure silver particles. The wire diameter of the wire is 5 mm or more and 30 mm or less,
The method for producing an alloy cast material according to any one of claims 1 to 3, wherein an average particle diameter of the granular material is 0.5 mm or more and 10 mm or less. The solid raw material is supplied so as to be melted on the molten metal side of the melting and holding furnace,
5. The alloy casting material according to claim 1, wherein the alloy casting material is continuously produced by tapping the molten metal in a horizontal direction from a mold provided on the bottom side of the melting and holding furnace. Method. Withdrawing the molten alloy from a mold provided on the upper side of the melting and holding furnace, continuously casting the alloy casting material,
The method for producing an alloy casting material according to any one of claims 1 to 4, wherein the solid raw material is supplied to a region in the melting and holding furnace which is separated from a region near the mold.

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