JPH07155907A - Production of copper alloy rod for electric conductive wire - Google Patents

Abstract

PURPOSE:To produce a copper alloy rod for electric conductive wire which can be rolled by cold-rolling process and shows the excellent wire-drawing characteristic and can cast the rod for electric conductive wire holding excellent electric conductive characteristic at a high speed. CONSTITUTION:The copper alloy composed of 0.003-0.05wt.% in total of at least one kind selected from iron, cobalt, manganese and silicon and the balance copper, is intermittently drawn out at the prescribed time interval while being solidified in a casting nozzle 3 and the continuous wire-like rod 6 is formed to produce the copper alloy rod for electric conductive wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a copper alloy rod for a conductive wire, and more particularly to an improved method for producing a copper alloy rod capable of producing a thin copper wire having excellent conductive characteristics with high efficiency.

[0002]

2. Description of the Related Art Copper is widely used as a wire material because of its excellent electrical conductivity. In recent years, technological innovation has progressed remarkably especially in the communication field and the automobile field, and further miniaturization and higher functionality are required for electric equipment and electronic equipment. Is required.

Copper wire is manufactured according to the order of melting, casting, rolling, and wire drawing of the raw material, but the biggest problem in manufacturing due to thinning of the copper wire is disconnection at the time of wire drawing, and the manufacturing efficiency is It is no exaggeration to say that it is decided by. Most of the disconnection at the time of wire drawing is caused by an internal defect generated during casting of the conductive wire rod.

There are various methods for casting conductive wire rods, and in the case of small-scale production, there is an intermittent drawing type continuous casting apparatus using nozzles or dies of heat-resistant ceramics such as graphite or silicon carbide. Often used. Such a continuous casting apparatus is a method in which the molten metal 2 held in the molten metal gutter 1 is intermittently drawn downward from a casting nozzle 3 provided at a lower end portion of the molten metal gutter 1 as shown in FIG. In this case, the molten metal 2 is solidified in the casting nozzle 3 while the drawing is stopped, and the formed casting rod 6 is cooled by the cooling spray 4. Next, the portion solidified by the drawing pinch roll 5 is drawn out downward, and the drawing is stopped again to wait for the molten metal 2 to solidify in the casting nozzle 3.

The apparatus shown in FIG. 2 has a casting nozzle 1 in which the molten metal 11 held in the molten metal gutter is provided on the molten metal surface.
2, the casting rod 13 solidified in the casting nozzle 12 is cooled by the cooling spray 14 and then pulled up by the pulling pinch roll 15. Further, in the apparatus shown in FIG. 3, the molten metal 21 held in the molten metal gutter 20 is replaced by the molten metal gutter 2
The casting rod 22 is pulled out horizontally from the casting nozzle 22 provided on the side of 0. The casting rod 23 solidified in the casting nozzle 22 is cooled by the cooling spray 24 and then pulled out by the pulling pinch roll 25. Has become.

[0006]

However, the casting rod by the intermittent drawing continuous casting method using the nozzle or die of heat resistant ceramic such as graphite or silicon carbide is essentially suitable for small-scale production. However, the diameter is small, the casting speed is slow, and hot rolling is impossible. Therefore, the cast rod manufactured in this manner is cold-rolled to a predetermined diameter and then processed into a wire of a desired size through a wire drawing process and a thin wire process. However, if the casting speed is increased to increase the productivity of such conductive wire rods, structural defects in the rods increase, but these structural defects cause cracks in the cold rolling process, and structural defects remain as they are. Therefore, there is a problem that the wire drawing process or the thin wire process is easily broken.

According to the present invention, in the intermittent drawing continuous casting method suitable for small-scale production, the casting speed must be slowed down in order to suppress the occurrence of casting defects in the casting rod, thus increasing the production efficiency. It was made in order to solve the problem of not being able to perform, by casting a wire rod for a conductive wire that can be rolled by a cold rolling process and develops excellent wire drawing characteristics and retains excellent conductive characteristics at a high speed. It is an object of the present invention to provide a method for producing a copper alloy rod for a conductive wire, which can be manufactured.

[0008]

The object of the present invention is as follows.
Predetermined time intervals while solidifying a copper alloy containing at least one selected from iron, cobalt, manganese, and silicon in a total amount of 0.003 to 0.05% by weight with the balance being copper in the casting nozzle. It is achieved by a method for producing a copper alloy rod for a conductive wire, which is characterized in that it is intermittently drawn out to form a continuous linear rod.

The copper alloy used in the method for producing a copper alloy rod for a conductive wire of the present invention includes iron, cobalt, manganese,
And a total amount of at least one selected from silicon is 0.0
It is contained in an amount of 03 to 0.05% by weight with the balance being copper. Usually, pure copper has a purity of 99.997% or more, but by adding the above-mentioned components to such copper, it is possible to significantly improve the casting speed and at the same time reduce the structural defects of the cast rod. Is something that can be done. However, if the addition amount is less than 0.003% by weight, a sufficient effect does not appear, and if the addition amount exceeds 0.05% by weight, the structural condition of the rod is not further improved and the electrical conductivity deteriorates. It is not desirable because it will increase the cost.

The manufacturing method of the copper alloy rod for conductive wire of the present invention is to manufacture the copper alloy rod by the intermittent drawing continuous casting method using the above copper alloy.
As a device for carrying out such a continuous casting method, a conventionally known device can be appropriately used. A casting nozzle made of graphite or heat-resistant ceramics such as silicon carbide can be preferably used for such a device.

[0011]

According to the production method of the present invention, even if the casting speed of a copper alloy rod for a conductive wire having a relatively small diameter, which is suitable for producing a fine wire having excellent electrical conductivity, is significantly increased, The occurrence of structural defects can be suppressed.

[0012]

[Example] In a graphite crucible furnace coated with a charcoal grain layer, electrolytic copper ingot was melted under an inert gas atmosphere, and a master alloy containing iron, cobalt, manganese, or silicon was added to each. A molten copper alloy having a composition as shown in Table 1 was obtained, which was drawn for 0.5 seconds by the continuous casting apparatus having the structure shown in FIG. 1 and then continuously stopped for 4.5 seconds, and the drawing speed was 300 mm / min. Continuous casting was performed to produce casting rods (1 to 31) having a diameter of 20 mm.

For comparison, an electrolytic copper ingot is melted by an apparatus similar to the above, and the drawing speed is 50 mm / min, 150
Cast rods (32 to 34) each having a diameter of 20 mm were manufactured in the same manner as above except that the rods were set to mm / min and 300 mm / min.

[0014]

[Table 1]

A cold rolling mill was used to roll these casting rods to a diameter of 9.5 mm, and a large wire drawing machine was used to roll them to a diameter of 2.6 mm.
to a diameter of 0.6 mm with a small wire drawing machine, to a diameter of 0.1 mm with a fine wire drawing machine, and to a diameter of 0.04 mm with an ultrafine wire drawing machine. The results of examining the number of breaks are shown in Table 2. The results of measuring the conductivity (% IACS) of the obtained copper wire are also shown in Table 2.

[0016]

[Table 2]

From these results, the control pure copper rod has good wire drawability when the drawing speed is low, but the drawing speed becomes high when the drawing speed is high, and the fine wire is extremely manufactured. In contrast, the copper alloy rod obtained by the method of the present invention has a slightly reduced conductivity, but there is no occurrence of wire breakage during wire drawing regardless of the high drawing speed, It can be seen that the wire drawability is greatly improved.

It is also found that the copper alloy rods out of the alloy composition range in the method of the present invention are inferior in either conductivity or wire drawability.

[0019]

According to the method for manufacturing a copper alloy rod for a conductive wire of the present invention, although the conductivity is slightly lower than that of pure copper, the conductive wire rod can be cast at a much higher speed than that of pure copper. Since there are no obstacles and the wire drawability is extremely good and the productivity of the thin wire is improved, there is an effect that the manufacturing cost of the electric wire is reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a casting nozzle structure in a continuous casting device for a conductive wire rod.

FIG. 2 is a cross-sectional view showing another example of a casting nozzle structure in a continuous casting device for a conductive wire rod.

FIG. 3 is a cross-sectional view showing still another example of a casting nozzle structure in a continuous casting device for a conductive wire rod.

[Explanation of symbols]

 1 molten metal gutter 2 molten metal 3 casting nozzle 4 cooling spray 5 drawing pinch roll 6 casting rod 11 molten metal 12 casting nozzle 13 casting rod 14 cooling spray 15 drawing pinch roll 20 molten metal gutter 21 molten metal 22 casting nozzle 23 casting rod 24 cooling Spray 25 Pinch roll for drawing

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location // C22C 9/00 9/05 9/06 9/10 (72) Inventor Toshihiro Fujino Shizuoka Prefecture 2771 Ooka, Numazu City, Yazaki Electric Cable Co., Ltd.

Claims (1)

[Claims] 1. A total amount of at least one selected from iron, cobalt, manganese, and silicon is 0.003 to 0.0.
A copper alloy for conductive wires, characterized in that a copper alloy containing 5% by weight and the remainder being copper is intermittently drawn out at a predetermined time interval while being solidified in a casting nozzle to form a continuous linear rod. Rod manufacturing method.