JP2996378B2 - Manufacturing method of copper alloy rod for conductive wire rolled by cold rolling - Google Patents

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 rolled by cold rolling, and more particularly to a method for producing a copper alloy rod capable of efficiently producing a fine copper wire having excellent conductive properties. It relates to an improved manufacturing method.

[0002]

2. Description of the Related Art Copper is widely used as a wire material because of its excellent electrical conductivity. In recent years, especially in the telecommunications and automotive fields, technological innovation has progressed remarkably, and electric equipment and electronic equipment have also been required to be further reduced in size and advanced in function. Is required.

[0003] Copper wires are manufactured in the order of melting, casting, rolling and drawing wires, but the biggest problem with the thinning of copper wires is disconnection during drawing, which leads to poor manufacturing efficiency. It is not an exaggeration to say that it is determined by. Most of such disconnections at the time of wire drawing are caused by internal defects generated at the time of casting the rod for conductive wire.

There are various methods for casting a rod for a conductive wire. In the case of small-scale production, a continuous casting apparatus of an intermittent drawing method using a nozzle or a die of a heat-resistant ceramic such as graphite or silicon carbide is used. Often used. Such a continuous casting apparatus is, for example, a method of intermittently pulling a molten metal 2 held by a molten metal gutter 1 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, while the drawing is stopped, the molten metal 2 is solidified in the casting nozzle 3, and the formed casting rod 6 is cooled by the cooling spray 4. Next, a portion solidified by the drawing pinch roll 5 is drawn downward, the drawing is stopped again, and the molten metal 2 is waited for solidification in the casting nozzle 3.

In the apparatus shown in FIG. 2, a molten metal 11 held by a molten metal gutter is cast on a casting nozzle 1 provided on the molten metal surface.
The casting rod 13 solidified in the casting nozzle 12 is cooled by a cooling spray 14 and then pulled up by a drawing pinch roll 15. Further, the apparatus shown in FIG. 3 converts the molten metal 21 held in the molten metal gutter 20 into the molten metal gutter 2.
The casting rod 23 solidified in the casting nozzle 22 is cooled by a cooling spray 24 and then drawn out by a pinch roll 25 for drawing. Has become.

[0006]

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

According to the present invention, in an intermittent drawing continuous casting method suitable for small-scale production, the casting speed must be reduced in order to suppress the occurrence of casting defects in the casting rod, and therefore the production efficiency is increased. It is made to solve the problem that it is not possible to cast a rod for conductive wire that can be rolled by the cold rolling process and exhibits 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 is rolled by cold rolling.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
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 and a balance of copper is solidified in a casting nozzle for a predetermined time interval. This is achieved by a method of manufacturing a copper alloy rod for a conductive wire that is rolled by cold rolling, wherein the rod is intermittently drawn to form a continuous linear rod.

The copper alloy used in the method for producing a copper alloy rod for a conductive wire rolled by cold rolling according to the present invention contains at least one of iron, cobalt, manganese, and silicon in a total amount of 0.1%. 003 to 0.05% by weight, with the balance being copper. Normally, pure copper is 9
Although it has a purity of 9.997% or more, by adding the above components to such copper, it is possible to greatly improve the casting speed and at the same time reduce the structural defects of the cast rod. is there. However, if the addition amount is less than 0.003% by weight, a sufficient effect is not exhibited, and if it exceeds 0.05% by weight, the structural state of the rod is not further improved and the electric conductivity is deteriorated. It is not desirable because it increases the cost.

The method for producing a copper alloy rod for a conductive wire rolled by cold rolling according to the present invention is to produce a copper alloy rod by an intermittent drawing continuous casting method using the above copper alloy. However, as a device for performing the continuous casting method, a conventionally known device can be appropriately used. For such an apparatus, a casting nozzle made of graphite or heat-resistant ceramics such as silicon carbide can be preferably used.

[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 suitable for producing a fine wire having excellent electric conductivity is greatly increased, It is possible to suppress the occurrence of structural defects.

[0012]

EXAMPLE In a graphite crucible furnace covered with a layer of charcoal, an electrolytic copper ingot was melted under an inert gas atmosphere, and a master alloy containing iron, cobalt, manganese, or silicon was added thereto. A molten copper alloy having the composition shown in Table 1 was obtained, and the molten metal was withdrawn by a continuous casting apparatus having the structure shown in FIG. 1 for 0.5 seconds, and subsequently, the operation of stopping for 4.5 seconds was repeated, and the withdrawal speed was 300 mm / min. To produce cast rods (1 to 31) having a diameter of 20 mm.

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

[0014]

[Table 1]

[0015] Using these cast rods, rolling is performed to a diameter of 9.5 mm by a cold rolling mill, and a diameter of 2.6 is performed by a large wire drawing machine.
mm, to a diameter of 0.6 mm by a small wire drawing machine, to a diameter of 0.1 mm by a fine wire drawing machine, and further to a diameter of 0.04 mm by an extra fine wire drawing machine. The results of examining the number of disconnections are shown in Table 2. Table 2 also shows the results of measuring the conductivity (% IACS) of the obtained copper wire.

[0016]

[Table 2]

From these results, it is found that the drawability of the control pure copper rod is good when the drawing speed is set to a low speed, but the drawability deteriorates when the drawing speed is set to a high speed. On the other hand, although the copper alloy rod obtained by the method of the present invention has a slightly reduced conductivity, there is no occurrence of disconnection at the time of drawing regardless of the drawing speed, It can be seen that the drawability is greatly improved.

Further, it can be seen that all copper alloy rods out of the alloy composition range in the method of the present invention are inferior in either conductivity or drawability.

[0019]

According to the method for producing a copper alloy rod for a conductive wire rolled by cold rolling according to the present invention, although the conductivity is slightly lower than that of pure copper, the casting of the rod for a conductive wire is performed at a much higher speed than pure copper. Since there is no obstacle during casting and cold rolling, and the wire drawing is extremely good and the productivity of fine wires is improved, there is an effect that the manufacturing cost of electric wires is reduced.

[Brief description of the 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 apparatus for a conductive wire rod.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molten gutter 2 Molten metal 3 Casting nozzle 4 Cooling spray 5 Drawing pinch roll 6 Casting rod 11 Molten 12 Casting nozzle 13 Casting rod 14 Cooling spray 15 Drawing out pinch roll 20 Melt gutter 21 Molten 22 Casting nozzle 23 Casting rod 24 Cooling Spray 25 Pinch Roll for Drawing

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C22C 1/02 503 C22C 1/02 503B 9/00 9/00 (72) Inventor Toshihiro Fujino 2771 Ooka, Ooka, Numazu-shi, Shizuoka Yazaki Electric Wire Co., Ltd. In-house (56) References JP-A-61-169149 (JP, A) JP-A-58-65554 (JP, A) JP-A-1-312047 (JP, A) JP-A-59-197355 (JP, A) JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 11/00 B22D 11/04 111 B22D 11/04 114 B22D 11/04 115 H01B 1/02 C22C 9/00-9 / 10 C22C 1/02 503

Claims (1)

(57) [Claims] 1. A total amount of at least one selected from iron, cobalt, manganese, and silicon of 0.003 to 0.03.
5 containing by weight%, the copper alloy and the balance being copper and intermittently withdrawn at predetermined time intervals while solidifying inside the casting nozzle, and forming a continuous linear rod cold
A method for producing a copper alloy rod for a conductive wire that is rolled by hot rolling .