Apparatus for manufacturing rough drawing wire

Abstract

To prevent oxidization of molten metal while heating the molten metal within a casting trough, by increasing the degree of airtightness within the casting trough.SOLUTION: An apparatus for manufacturing a rough drawing wire comprises: a holding furnace for holding molten metal, which is made by melting a metallic material, in a molten state; a tundish for storing the molten metal transferred from the holding furnace; a casting trough for transferring the molten metal in the holding furnace to the tundish; and an electric heater which is provided outside the casting trough and which is used to heat the molten metal in the holding furnace.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an apparatus for manufacturing rough-drawn wire, and more particularly to an apparatus for manufacturing rough-drawn wire provided with a trough having an electric heater.

Background Art

[0002] As one of the methods for manufacturing rough-drawn wire, the continuous casting and rolling method is known. This method includes a casting process and a rolling process. In the casting process, a square bar-shaped casting is manufactured by solidifying a molten metal material (molten metal). In the rolling process, a round bar-shaped rolled material is manufactured by pressing and stretching the casting. Such a rolled material is subjected to a surface purification treatment or the like to manufacture rough-drawn wire.

[0003] For the purpose of improving the softening characteristics of the casting and controlling impurities in the casting, an element such as titanium is continuously supplied to the molten metal. The addition of such an element is performed while heating the molten metal using a heating means between the holding furnace and the tundish.

[0004] For example, Patent Document 1 discloses a technique in which a heating furnace is provided between a holding furnace and a tundish, and an element is added to the molten metal while heating the molten metal in the heating furnace.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In Patent Document 1, a casting ladle is provided between a heating furnace and a tundish, and it is necessary to transfer the molten metal with elements added in the heating furnace to the tundish. However, during the transfer from the heating furnace to the tundish, the molten metal in the casting ladle is likely to come into contact with air, so there is a risk of oxidation of the molten metal. Also, in Patent Document 1, since it is necessary to newly provide a heating furnace, the configuration of the rough drawing wire manufacturing apparatus becomes complicated and the equipment investment becomes high.

[0007] When not providing a heating furnace as in Patent Document 1, the molten metal is transferred by a casting ladle provided between a holding furnace and a tundish. For example, it is conceivable to heat the molten metal by supplying high-temperature gas inside this casting ladle. However, there is a risk that oxygen in the air mixes into the inside of the casting ladle and the molten metal is oxidized. Such a risk is not limited to the case of adding elements to the molten metal, and also applies to the case of not adding elements to the molten metal, such as when manufacturing pure copper.

[0008] The main object of the present application is to provide a technique capable of increasing the sealing degree inside a casting ladle and preventing oxidation of the molten metal while heating the molten metal inside the casting ladle.

[0009] Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

Means for Solving the Problems

[0010] A rough drawing wire manufacturing apparatus according to an embodiment includes a holding furnace for holding a molten metal obtained by melting a metal material in a molten state, a tundish for storing the molten metal transferred from the holding furnace, a casting ladle for transferring the molten metal in the holding furnace to the tundish, and an electric heater provided outside the casting ladle and for heating the molten metal in the casting ladle.

Effects of the Invention

[0011] According to an embodiment, it is possible to increase the sealing degree inside the casting ladle and prevent oxidation of the molten metal while heating the molten metal inside the casting ladle.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, members having the same function are denoted by the same reference numerals, and repeated explanations thereof are omitted. Further, in the following embodiments, explanations of the same or similar parts are not repeated in principle unless particularly necessary.

[0014] In addition, the X direction, Y direction, and Z direction described in the present application intersect each other and are orthogonal to each other. In the present application, the Z direction is described as the vertical direction or height direction of a certain structure. Further, expressions such as "plan view" or "plan view" used in the present application mean that the plane composed of the X direction and the Y direction is the "plane", and this "plane" is viewed from the Z direction.

[0015] (Embodiment 1) FIG. 1 is a schematic diagram of a manufacturing apparatus 1 for rough-drawn wire in Embodiment 1. As shown in FIG. 1, the manufacturing apparatus 1 for rough-drawn wire includes a melting furnace 2, a holding furnace 3, a casting apparatus 4, a rolling apparatus 5, a winding apparatus 6, a transfer trough 10, and a casting trough 20. The main features of Embodiment 1 are in the casting trough 20 and the surrounding structure, which will be described in detail later with reference to FIGS. 2 to 4.

[0016] The melting furnace 2 is provided to form a molten metal by melting a metal material. The metal material is, for example, copper, and the molten metal is, for example, molten copper. The melting furnace 2 has a furnace body and a gas burner disposed around the furnace body. The metal material charged into the furnace body is heated to a temperature above the melting point by the heat of the gas burner and melts. When the metal material is copper, the temperature of the molten metal is adjusted to be, for example, within the range of 1100°C or higher and 1200°C or lower.

[0017] The transfer trough 10 is connected to the melting furnace 2 and the holding furnace 3 and is provided to transfer the molten metal from the melting furnace 2 to the holding furnace 3.

[0018] The holding furnace 3 is provided to hold the molten metal in a molten state. The holding furnace 3 has a furnace body and a gas burner disposed around the furnace body. The heat of the gas burner can keep the molten metal in a molten state. Also, the transfer amount of the molten metal to the casting device 4 is controlled in the holding furnace 3.

[0019] The casting trough 20 is connected to the holding furnace 3 and the tundish 41 of the casting device 4 and is provided to transfer the molten metal from the holding furnace 3 to the tundish 41 of the casting device 4.

[0020] The casting device 4 has a tundish 41, a pouring nozzle 42, a casting wheel 43, guide rollers 44, and a belt 45. The casting device 4 is a belt-wheel type continuous casting device. In the casting device 4, a rod-shaped (square rod-shaped) casting 7 is continuously manufactured by cooling and solidifying the molten metal.

[0021] The molten metal held in the holding furnace 3 is transferred to the tundish 41 via the casting trough 20. The tundish 41 is provided to store the molten metal to be supplied to the mold. The molten metal accumulated in the tundish 41 is supplied to the casting wheel 43 via the pouring nozzle 42 attached to the tundish 41. The casting wheel 43 is a disk-shaped metal member and performs a rotational movement in the rotational direction R1 shown in FIG. 1 with the center of the disk as the rotation axis.

[0022] The belt 45 is made of, for example, stainless steel. The belt 45 is an endless belt and is wound around a plurality of guide rollers 44. The belt 45 is tensioned by the plurality of guide rollers 44 and circulates while contacting a part of the outer peripheral surface of the mold wheel 43.

[0023] Grooves (not shown) are formed on the outer peripheral surface of the mold wheel 43. When the belt 45 contacts a part of the outer peripheral surface of the mold wheel 43, a casting space surrounded by the groove of the mold wheel 43 and the belt 45 is formed. This casting space functions as a mold for the casting material 7. The mold wheel 43 and the belt 45 are cooled by, for example, cooling water. Therefore, by supplying molten metal from the pouring nozzle 42 into the casting space (mold), the molten metal is cooled and solidified, and a casting material 7 having substantially the same cross-sectional shape as the casting space is manufactured.

[0024] The rolling device 5 is a roller-type continuous rolling device. The casting material 7 manufactured by the casting device 4 is supplied to the rolling device 5. In the rolling device 5, by hot-rolling the casting material 7, a rod-shaped (round bar-shaped) rolled material 8 is continuously manufactured.

[0025] By performing a surface purification treatment such as pickling or reduction cleaning on the rolled material 8, a rough wire 9 is manufactured. Thereafter, the rough wire 9 is wound, for example, spirally by the winding device 6. Note that the outer diameter of the rough wire 9 is, for example, 6 mm or more and 30 mm or less. The rough wire 9 manufactured in this way can be further drawn according to various applications and used as a conductor constituting a part of, for example, an electric wire or a cable.

[0026] <The casting trough 20 and the surrounding structure> Hereinafter, with reference to FIGS. 2 to 4, the casting trough 20 and the surrounding structure will be described in detail. FIG. 2 shows a plan view of the casting trough 20 as viewed from above. FIG. 3 is a cross-sectional view taken along line A-A shown in FIG. 2. FIG. 4 is a cross-sectional view taken along line B-B shown in FIG. 2. Note that in FIG. 2, the illustration of the heat-resistant member 23 provided above the casting trough 20 and the electric heater 30 is omitted.

[0027] As shown in FIG. 3, the molten metal held in the holding furnace 3 passes through the inside of the casting runner 20 and is transferred to the tundish 41. As described above, this molten metal is a metal material melted in the melting furnace 2. The casting runner 20 is provided with an addition section 21 for adding a first element different from the elements contained in the metal material to the molten metal inside the casting runner 20.

[0028] The first element is an active metal, such as titanium (Ti), aluminum (Al), chromium (Cr), zirconium (Zr), or magnesium (Mg). The first element is added to the molten metal in the form of a wire formed linearly. The addition of such a first element is performed while heating the molten metal using heating means between the holding furnace 3 and the tundish 41. The temperature of the molten metal is maintained, for example, within a range of 1100°C or higher and 1200°C or lower.

[0029] Further, the first element is not limited to the above-mentioned active metals, and may be, for example, tin (Sn) or indium (In). Also, the element added to the molten metal inside the casting runner 20 is not limited to one type of the first element, and may be a plurality of types.

[0030] As shown in FIGS. 3 and 4, an electric heater 30 and a heat-resistant member 23 are provided outside the casting runner 20. The electric heater 30 and the heat-resistant member 23 are provided, for example, above the casting runner 20 (in the Z direction in FIG. 3) so as to face the upper part of the casting runner 20. The heat-resistant member 23 is made of, for example, refractory bricks and is provided so as to cover the outside (for example, the upper part) of the casting runner 20. The electric heater 30 is fixed to the inner surface of the heat-resistant member 23 and at a portion facing the upper part of the casting runner 20. Thereby, the sealing degree inside the casting runner 20 can be increased, and oxidation of the molten metal inside the casting runner 20 can be prevented while heating the molten metal inside the casting runner 20.

[0031] By passing an electric current through the electric heater 30, heat energy is generated from the electric heater 30. The molten metal in the casting runner 20 can be heated by this heat energy. That is, the electric heater 30 is a heating device capable of converting electric energy into heat energy.

[0032] As an example of such a heating device, an electric device provided with means for using heat generated by the electric resistance of a heating element as heat energy by passing an electric current through the heating element can be cited. Further, as another example of the heating device, an electric device provided with means for using infrared rays generated from a heating element as heat energy by passing an electric current through the heating element can be cited.

[0033] When using a heating means using high-temperature gas, it is necessary to provide an inlet for the high-temperature gas or the like in the casting trough 20, and there was a risk that the airtightness inside the casting trough 20 would decrease and air would enter the inside of the casting trough 20. In the first embodiment, since the electric heater 30 is provided outside the casting trough 20, there is no need to provide an inlet for the high-temperature gas or the like, and the airtightness inside the casting trough 20 can be increased. Therefore, oxidation of the molten metal inside the casting trough 20 can be prevented while heating the molten metal inside the casting trough 20. Such a combination of the casting trough 20 and the electric heater 30 can be effectively used even when no first element is added to the molten metal in the casting trough 20, such as pure copper.

[0034] Further, when a first element is added to the molten metal in the casting trough 20 and an active metal is used as the first element, oxidation of the first element can be prevented while heating the molten metal inside the casting trough 20. Conventionally, when adding a first element to molten metal, there has been a problem that the first element oxidizes and the amount of the first element in the molten metal decreases. Therefore, it is necessary to add an extra amount of the first element in anticipation of the amount to be oxidized, resulting in a problem of poor yield. There is also a problem that the uniformity of the first element in the molten metal decreases.

[0035] In the first embodiment, since it is not necessary to add an extra amount of the first element in anticipation of the amount to be oxidized, a decrease in yield can be suppressed. In addition, the uniformity of the first element in the molten metal can also be improved. Further, the configuration of the rough wire manufacturing apparatus 1 can be simplified as compared with the case of providing a heating furnace such as Patent Document 1, for example.

[0036] As shown in FIGS. 2 and 3, the casting trough 20 is provided with a gas injection portion 22 that reaches the inside of the casting trough 20. The gas injection portion 22 is configured using, for example, a porous plug. Also, the casting trough 20 may be provided with a plurality of gas injection portions 22. Although not shown here, the gas injection portion 22 is connected to gas supply equipment such as a pump provided outside the manufacturing apparatus 1 for roughing wires. An inert gas can be supplied from the gas injection portion 22 into the inside of the casting trough 20 by the gas supply equipment. The inert gas is, for example, argon (Ar) or nitrogen (N 2 ) or the like.

[0037] The inert gas passes through the molten metal from the gas injection portion 22 and is supplied into the inside of the casting trough 20. Therefore, oxidation of the molten metal inside the casting trough 20 can be further prevented. Also, when an active metal is used as the first element added from the addition portion 21, oxidation of the first element can be further prevented.

[0038] Also, by filling the inside of the casting trough 20 with an inert gas, the air pressure inside the casting trough 20 can be controlled to be higher than the air pressure outside the casting trough 20. For example, there are locations where the relative sealing degree is low, such as the connection location of the addition portion 21. There is a risk that air may enter the inside of the casting trough 20 from such locations, and the molten metal and the first element may be oxidized by the oxygen in the air. Here, by raising the air pressure inside the casting trough 20, the inert gas is discharged from the locations with low sealing degree to the outside of the casting trough 20, and the entry of air into the inside of the casting trough 20 can be suppressed.

[0039] Further, it is preferable that the addition section 21 is located away from the holding furnace 3. Since the holding furnace 3 is maintained at a high temperature, if the addition section 21 is installed near the holding furnace 3, the equipment constituting the addition section 21 is likely to be damaged. Also, for example, after manufacturing a copper alloy by adding a first element to pure copper using the rough wire manufacturing apparatus 1, there may be a case where pure copper without adding the first element is to be manufactured. In that case, it is necessary to clean the copper alloy remaining inside the casting trough 20. If the cleaning range of the copper alloy can be narrowed, the production of pure copper can be started in a short time. That is, the throughput of the rough wire manufacturing apparatus 1 can be improved.

[0040] Therefore, it is preferable that the addition section 21 is provided as far as possible on the downstream side of the casting trough 20. In Embodiment 1, the addition section 21 is provided, for example, on the downstream side of the casting trough 20 from the gas injection section 22 and is provided between the gas injection section 22 and the tundish 41.

[0041] Also, as shown in FIGS. 2 and 3, in Embodiment 1, a plurality of electric heaters 30 are provided above the casting trough 20. The plurality of electric heaters 30 are arranged, for example, in a state where adjacent electric heaters 30 are separated along the direction from the holding furnace 3 toward the tundish 41. Thereby, it becomes easier to adjust the temperature of the molten metal transferred inside the casting trough 20 to a predetermined temperature. The casting trough 20 is divided into a plurality of regions 1A, 2A, 3A, and 4A in the direction (X direction) from the holding furnace 3 toward the tundish 41. An electric heater 30 is provided in each of the plurality of regions 1A, 2A, 3A, and 4A. The electric heaters 30 in the plurality of regions 1A, 2A, 3A, and 4A can be controlled individually. Therefore, the temperature heated by the electric heater 30 can be changed for each of the plurality of regions 1A, 2A, 3A, and 4A. Note that the number of electric heaters 30 provided in each of the plurality of regions 1A, 2A, 3A, and 4A can be appropriately changed as needed.

[0042] The temperature of the molten metal in the casting runner 20 is preferably maintained within a predetermined temperature range throughout the casting runner 20. However, for example, when an inert gas is supplied from the gas injection section 22 into the interior of the casting runner 20, since the inert gas passes through the molten metal, there is a risk that the temperature of the molten metal will decrease. In the example of FIG. 3, there is a risk that the temperature of the molten metal in regions 3A and 4A will be lower than the temperature of the molten metal in regions 1A and 2A. To compensate for this temperature drop, the thermal energy from the electric heater 30 in regions 3A and 4A is made greater than the thermal energy from the electric heater 30 in regions 1A and 2A. Thereby, a temperature drop of the molten metal in regions 3A and 4A can be prevented.

[0043] As described above, according to the rough wire manufacturing apparatus 1 in Embodiment 1, by providing the electric heater 30 outside the casting runner 20 to heat the molten metal inside the casting runner 20, the degree of sealing inside the casting runner 20 can be increased, and oxidation of the molten metal can be prevented while heating the molten metal inside the casting runner 20.

[0044] Although the present invention has been specifically described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof.

Explanation of Reference Numerals

[0045] 1 Rough wire manufacturing apparatus 2 Melting furnace 3 Holding furnace 4 Casting apparatus 5 Rolling apparatus 6 Take-up apparatus 7 Casting material 8 Rolled material 9 Rough wire 10 Transfer runner 20 Casting runner 21 Addition section 22 Gas injection section 30 Electric heater 41 Tundish 42 Pouring nozzle 43 Casting wheel 44 Guide roller 45 Belt Regions 1A, 2A, 3A, 4A

Claims

1. A holding furnace for holding a molten metal material in a molten state, a tundish for storing the molten metal transferred from the holding furnace, a casting runner for transferring the molten metal in the holding furnace to the tundish, and an electric heater provided outside the casting runner for heating the molten metal in the casting runner. A rough wire manufacturing apparatus comprising the above components.

2. In the rough wire manufacturing apparatus according to Claim 1, the casting runner is provided with a gas injection part reaching the inside of the casting runner, and an inert gas can be supplied from the gas injection part into the inside of the casting runner. A rough wire manufacturing apparatus.

3. In the rough wire manufacturing apparatus according to Claim 2, by filling the inside of the casting runner with the inert gas, the air pressure inside the casting runner can be controlled to be higher than the air pressure outside the casting runner. A rough wire manufacturing apparatus.

4. In the rough wire manufacturing apparatus according to Claim 2, further comprising a plurality of the electric heaters, the casting runner is divided into a plurality of regions in the direction from the holding furnace to the tundish, each of the plurality of regions is provided with the electric heater, and the temperature heated by the electric heater can be changed for each of the plurality of regions. A rough wire manufacturing apparatus.

5. In the rough wire manufacturing apparatus according to Claim 1, the casting runner is provided with an addition part for adding a first element different from the elements contained in the metal material into the molten metal in the casting runner. A rough wire manufacturing apparatus.

6. In the rough wire manufacturing apparatus according to Claim 5, the first element is an active metal. A rough wire manufacturing apparatus.

7. In the rough wire manufacturing apparatus according to Claim 5, the metal material is copper, the molten metal is molten copper, and the first element is Ti, Al, Cr, Zr, Mg, Sn or In. A rough wire manufacturing apparatus.

8. In the rough wire manufacturing apparatus according to Claim 5, the casting runner is provided with a gas injection part reaching the inside of the casting runner, an inert gas can be supplied from the gas injection part into the inside of the casting runner, and the addition part is provided between the gas injection part and the tundish. A rough wire manufacturing apparatus.

9. In the rough wire manufacturing apparatus according to Claim 1, the electric heater is provided at the upper part of the casting runner. A rough wire manufacturing apparatus.

10. In the rough wire manufacturing apparatus according to Claim 9, Further comprising a heat-resistant member provided on the upper part of the casting gutter, The electric heater is a manufacturing apparatus for rough drawing wires, which is fixed to a portion of the inner surface of the heat-resistant member that faces the upper part of the casting gutter.

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