JP2009167461A - Copper alloy conductor, cable and trolley wire using the same, and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper alloy conductor which has achieved further high electroconductivity while maintaining or improving the strength; a cable and a trolley wire using the same; and a method for manufacturing the copper alloy conductor. <P>SOLUTION: A copper alloy wire 17 is made by working the copper alloy conductor which contains 0.01 to 0.1 mass% (100 to 1,000 mass ppm) oxygen, contains tin in an amount of 2.5 times to 4.5 times the oxygen content by mass ratio, and has an oxide of the tin dispersed in a crystal structure of the copper alloy conductor as fine oxides which occupy 80% or more by a volume dispersion rate and have an average grain size of 1 μm or less. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is, for example, a copper alloy conductor used for various types of electronic / electric equipment and industrial cables, trolley wires for overhead wires (train wires) for feeding electric railway vehicles via pantographs, and the like, and The present invention relates to a cable and a trolley wire using the copper alloy conductor, and a method for producing the copper alloy conductor.

Copper alloy conductors for train wires (trolley wires), or conductors for equipment cables used in various equipment cables, etc., hard copper wires with high electrical conductivity, and copper alloy materials with wear and heat resistance ( Copper alloy wire) is used.
As a copper alloy material, a copper base material containing Sn in an amount of 0.25 to 0.35 mass% has been proposed (Patent Document 1). Shinkansen and conventional trolley lines (train overhead lines) It is used as a conductor for equipment cables.

In recent years, for example, the speed of trains has been further increased, for example, the achievement of the maximum speed of commercial operation at a speed of 270 to 300 km / h on the Shinkansen or the maximum speed of 130 km / h on the conventional line. In order to cope with such high speed, it is required to further increase the overhead wire tension of the train trolley wire, and the overhead wire tension tends to be increased from 1.5 tons to 2.0 tons or more.
In recent years, especially in large urban railways, the train passage density (the number of trains traveling on a track per unit length) tends to become higher in order to further increase the transportation capacity. When multiple electric railway vehicles are traveling simultaneously on one line, the equivalent circuit is proportional to the number of vehicles for one trolley wire (and track rail as a return wire) that is a feeder line. It can be considered that the total number of motors connected in parallel is the amount of power (mainly the amount of current) that needs to be supplied to many railway vehicles traveling on one line. As the train passing density increases, it tends to increase. For this reason, a further increase in current capacity of the trolley wire has been demanded.

Further, conductors used as cables for various electric / electronic devices are required to have further improved bending resistance and strength in consideration of the usage environment. Further, in order to satisfy the demands for reducing the weight, size and power consumption of various electric and electronic devices themselves, the cables used therefor are required to achieve higher conductivity.
Furthermore, for industrial cables, it is increasingly used conductors that improve strength and heat resistance while minimizing the decrease in conductivity, and that have even better bending resistance in consideration of the usage environment. It is strongly demanded.

Therefore, in order to satisfy these requirements, there has been an increasing demand for the realization of a copper alloy conductor having high strength and high conductivity.
There are mainly two types of high-strength copper alloy conductors, a solid solution strengthened alloy and a precipitation strengthened alloy. Examples of the solid solution strengthened alloy include a Cu—Ag alloy (high concentration silver), a Cu—Sn alloy, a Cu—Sn—In alloy, a Cu—Mg alloy, and a Cu—Sn—Mg alloy. Examples of precipitation strengthening alloys include Cu—Zr alloys, Cu—Cr alloys, Cu—Cr—Zr alloys, and the like.
The solid solution strengthened alloy can improve the strength as the content of the solid solution strengthening element is increased. However, the electrical conductivity is extremely lowered accordingly. For this reason, it has been extremely difficult to produce a copper alloy conductor having high strength and good conductivity with conventional Cu-Sn alloys.
Moreover, although the precipitation strengthening type alloy is extremely high in strength, an excessive load is applied to the rolling roll during the continuous casting and rolling, so it is practically impossible to manufacture by continuous casting and rolling. It could only be produced by a batch processing method such as extrusion. Not only the heat treatment for precipitating the precipitation strengthened material in the intermediate process is necessary, but the productivity is low compared to the case of the solid solution strengthened alloy that can be manufactured by continuous casting and rolling, In addition, the manufacturing cost tends to be high due to this.

In order to eliminate or avoid such disadvantages in the prior art, a copper base material containing 0.001 to 0.1% by mass (10 to 1000 ppm) of oxygen and a mass of Sn exceeding 0.15 to 0.70 or less. %, The average grain size of the crystal grains constituting the crystal structure is 100 μm or less, and 80% or more of the Sn oxide in the matrix of the crystal structure is 1 μm or less. There has been proposed a copper alloy conductor having a structure dispersed as a fine oxide (Patent Document 2).
According to this invention, it is possible to improve both the strength and conductivity of the copper alloy conductor itself by refining the crystal structure formed by dispersing the Sn oxide.
That is, by dispersing Sn oxide with a fine grain size in the crystal structure, the movement of crystals and grain boundaries due to heat (latent heat) is suppressed, so-called pinning effect, so that the strength of the copper alloy conductor In addition to this, the growth of each crystal grain during hot rolling can be suppressed and the crystal structure can be kept fine.

Japanese Patent Publication No.59-43332 JP 2006-193807 A

  By the way, in recent years, as described above, in copper alloy conductors used for cables, trolley wires, etc., there has been a strong demand for further improvement in conductivity while maintaining or improving strength. Furthermore, it is an urgent task to further improve the technology regarding the configuration of the copper alloy conductor and the manufacturing method thereof.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a copper alloy conductor that achieves further high conductivity while maintaining or improving strength, and a cable and a trolley wire using the copper alloy conductor. And a method for producing the copper alloy conductor.

The copper alloy conductor of the present invention is a copper alloy conductor containing 0.01% by mass to 0.1% by mass (100 ppm by mass to 1000% by mass) of oxygen, and tin is contained in an amount of 2. The tin oxide is contained in a mass ratio of 5 to 4.5 times and is a fine oxide having an average particle size of 1 μm or less at a volume dispersion of 80% or more in the crystal structure of the copper alloy conductor. It is characterized by being dispersed.
The cable of the present invention is characterized in that the surface of a product made of the copper alloy conductor is covered with an insulating coating.
Moreover, the trolley wire of this invention is characterized by using said copper alloy conductor.
Moreover, the manufacturing method of the copper alloy conductor of the present invention includes a copper base material containing 0.01 mass% to 0.1 mass% (100 mass ppm to 1000 mass ppm) of oxygen, and tin content of the oxygen. The step of making a copper alloy melt by adding 2.5 to 4.5 times the mass ratio with respect to the above, and forming a cast material by performing continuous casting using the copper alloy melt And a step of rapidly cooling the temperature of the cast material formed by casting the molten copper alloy to a temperature lower by 15 ° C. or more than the melting point of the molten copper alloy, and after setting the cast material to 900 ° C. or less, And a step of subjecting the cast material to hot rolling while adjusting the temperature so that the final rolling temperature is 500 ° C. or more and 600 ° C. or less.

According to the copper alloy conductor of the present invention, it is a copper alloy conductor containing 0.01 to 0.1 mass% (100 to 1000 mass ppm) of oxygen, and tin is 2.5 times the content of oxygen. The tin oxide is contained in a mass ratio of ˜4.5 times and is dispersed as a fine oxide having an average particle size of 1 μm or less at a volume dispersion of 80% or more in the crystal structure of the copper alloy conductor. As a result, the appropriate value of the ratio of the tin content relative to the oxygen content, which was not clear in the past, can be clearly set, and as a result, the strength of the copper alloy conductor itself is maintained. Alternatively, it is possible to achieve higher conductivity while improving.
Moreover, according to the method for producing a copper alloy conductor of the present invention, tin is added to a copper base material containing 0.01 to 0.1 mass% (100 to 1000 mass ppm) of oxygen with respect to the oxygen content. And adding the copper alloy in a mass ratio of 2.5 times or more to 4.5 times or less to make a copper alloy molten metal, and performing continuous casting using the copper alloy molten metal, and the copper alloy molten metal A step of rapidly cooling the temperature of the cast material formed by casting to a temperature lower than the melting point of the molten copper alloy by 15 ° C. or more, and after setting the cast material to 900 ° C. or less, the final rolling temperature for the cast material Since the hot rolling process is performed while adjusting the temperature so that the temperature becomes 500 ° C. or more and 600 ° C. or less, in the production process, the relative content of tin with respect to the oxygen content as described above The appropriate value of the ratio can be clearly set and adjusted, and as a result While maintaining or improving the strength of the copper alloy conductor itself obtained by this manufacturing method, it is possible to achieve the further high conductivity index.

Hereinafter, a copper alloy conductor according to the present embodiment, a cable using the copper alloy conductor, a trolley wire, and a method for producing the copper alloy conductor will be described with reference to the drawings.
FIG. 1 is a diagram showing a flow of main steps in the method of manufacturing a copper alloy conductor according to the present embodiment.

In the method for producing a copper alloy conductor according to the present embodiment, the copper base material 11 containing 0.01 to 0.1% by mass (100 to 1000 ppm by mass) of oxygen, Sn (tin) 12 as the oxygen content On the other hand, it is added and melted at a ratio of 2.5 times to 4.5 times in terms of mass ratio, and a melting step F1 for producing the copper alloy molten metal 13 is cast into the cast material 14 by casting the copper alloy molten metal 13. The casting process F2 and the hot rolling process F3 to which the cast material 14 is subjected to a multi-stage (multi-stage) hot rolling process to obtain the rolled material 15, and the rolled material 15 is washed, wound, and roughed wire 16 The main steps include a cleaning / winding step F4 and a cold wire drawing F5 which is cold drawn while feeding the wound rough drawn wire 16 to obtain a copper alloy wire 17. It is out. Then, the copper alloy wire 17 manufactured by this manufacturing method is further processed into a desired shape such as a wire, a stranded wire, a strip, a plate, and the like.
The melting step F1 to the cleaning / winding step F4 can be performed using existing general continuous rolling equipment (SCR continuous casting equipment) or the like. However, the process conditions and the like in each process performed using the equipment are not general, and it is a matter of course that the settings and methods are described in detail below.

That is, the manufacturing method of the copper alloy wire 17 which is the copper alloy conductor according to the present embodiment is more specifically described. First, in the melting step F1, oxygen is 0.01 to 0.1 mass% (100 to 1000 mass ppm). ) By adding Sn12 at a mass ratio of 2.5 to 4.5 times with respect to the oxygen content of the copper base material 11, the molten copper alloy 11 is melted. 13 is obtained. At this time, Sn12 is oxidized and generated and dispersed as Sn oxide (SnO ₂ ). That Sn
80% or more of the oxide is a fine oxide having an average particle size of 1 μm or less. Note that the copper base material 11 may contain an inevitable oxide.

Here, if the Sn content (substantial addition amount) is less than 2.5 times the oxygen content, a large number of coarse Cu oxides exist in the crystal structure of the copper alloy conductor, The average grain size of the entire crystal structure is also coarse. As a result, there is an extremely high possibility that the electrical conductivity cannot be further improved while maintaining or improving the strength. On the other hand, when the Sn content exceeds 4.5 times the oxygen content, the conductivity clearly starts to decrease. For this reason, it is desirable to add Sn12 at a mass ratio of 2.5 to 4.5 times the oxygen content of the copper base material 11 as described above.

  Subsequently, in the casting process F2, the cast material 14 is formed by subjecting the copper alloy molten metal 13 obtained in the melting process F1 of the previous process to continuous casting rolling of the SCR method. As the process conditions of this continuous casting and rolling, the casting temperature (1100 ° C. to 1150 ° C.) lower than the casting temperature (1120 ° C. to 1200 ° C.) in the case of general continuous casting is set, and the mold is forcibly cooled. By doing so, the cast material 14 cast in the casting step F2 is rapidly cooled to a temperature that is at least 15 ° C. lower than the solidification temperature of the copper alloy molten metal 13.

  By setting the casting process and the cooling process as described above, the size of the Sn oxide that crystallizes (or precipitates) in the cast material 14 or the size of the crystal grains of the cast material 14 does not require cooling. Even when the temperature is set or when cooling is performed, the temperature can be reduced more reliably than when the temperature drop is not made 15 ° C. or higher than the solidification temperature of the molten copper alloy 13.

  Subsequently, in the hot rolling step F3, the temperature of the cast material 14 is 900 ° C. or lower, more preferably 750 ° C. to 900 ° C., which is 50 ° C. to 100 ° C. lower than the general hot rolling temperature in continuous casting rolling. The cast material 14 is subjected to multi-stage hot rolling in a state adjusted to ° C. In the final rolling in the multi-stage rolling, hot rolling is performed with the rolling temperature adjusted to 500 ° C to 600 ° C. The rolling material 15 is formed through such hot rolling.

  At this time, if the final rolling temperature is less than 500 ° C., surface scratches due to the rolling process frequently occur, and there is a high possibility that the surface quality of the rolled material 15 or the copper alloy wire 17 as the final product is deteriorated. . Further, if the final rolling temperature is higher than 600 ° C., the crystal structure of the formed rolled material 15 is likely to become a coarse structure having a grain size exceeding 1 μm or larger. However, according to the manufacturing method according to the present embodiment, by setting the process conditions as described above, the crystal structure of the formed rolled material 15 is 1 μm without causing surface scratches due to rolling. The average particle size can be as follows.

Subsequently, in the cleaning / winding step F <b> 4, the rolled material 15 is cleaned and wound to form the rough drawn wire 16.
And finally, in the cold wire drawing F5, while the wound rough drawing wire 16 is sent out, the rough drawing wire 16 is kept cold at a temperature of −193 ° C. to 100 ° C. by using, for example, liquid nitrogen. Drawing is performed, and the rough drawn wire 16 is used as a copper alloy wire 17.
Thus, the copper alloy wire 17 formed by drawing the copper alloy conductor according to the present embodiment into a wire shape is manufactured.

Alternatively, it is also possible to twist a plurality of copper alloy wires 17 that have been continuously cast and rolled as described above, drawn, and formed into a wire shape into a so-called stranded wire (not shown). is there.
Alternatively, a coating made of an insulating material is provided on the surface of the copper alloy wire 17 or stranded wire formed in the above-described wire shape, and the entire surface of the copper alloy wire 17 or stranded wire is almost completely insulated. Thus, it is possible to form cables for various electronic / electrical devices and industrial use.
Alternatively, a plating film of Sn (tin), Ni (nickel), Ag (silver) or the like is deposited on the surface of the copper alloy wire 17 or the stranded wire formed in the above-described wire shape by various plating methods or the like. May be.

  The copper alloy conductor according to the present embodiment manufactured by such a manufacturing method is a copper alloy conductor containing 0.01 to 0.1 mass% (100 to 1000 mass ppm) of oxygen, and Sn is oxygen. The Sn oxide is contained in a mass ratio of 2.5 times to 4.5 times the content of the copper, and the Sn oxide is averaged in a volume structure of 80% or more in the crystal structure of the entire copper alloy conductor. It is dispersed as a fine oxide having a particle size of 1 μm or less.

In the copper alloy conductor and the cable and trolley wire and the copper alloy conductor manufacturing method according to the present embodiment, oxygen is contained in the copper base material 11 in an amount of 0.01 to 0.1% by mass (100 to 1000% by mass). ppm), and by containing an appropriate amount of Sn at a mass ratio of 2.5 to 4.5 times the oxygen content, the generation of coarse Cu (copper) oxide is suppressed. As a result, the crystal grain size in the crystal structure of the entire copper alloy conductor of the copper alloy wire 17 can be reduced to 1 μm or less, and further improvement in conductivity can be achieved.
This is because when the Sn content is less than 2.5 times the oxygen content, a large number of coarse Cu oxides are generated in the crystal structure, and due to the presence, the crystal grain size of the entire crystal structure However, by making it 2.5 times or more, the generation of coarse Cu oxide is suppressed and the crystal grain size is made as fine as 1 μm or less. Because you can. Further, when the Sn content exceeds 4.5 times the oxygen content, oxygen is insufficient due to such excessive Sn addition, and surplus Sn that cannot form an oxide is generated. Although it becomes a factor causing a decrease in conductivity by solid solution in the copper base material 11, by making the Sn content 4.5 times or less of the oxygen content, generation of excess Sn and Sn resulting therefrom This is because it is possible to avoid the occurrence of solid solution and to eliminate the decrease in conductivity or to further improve the conductivity.

  Here, the volume dispersion ratio of Sn oxide in the entire crystal structure is the smallest when the Sn content is less than 2.5 times the oxygen content, and as the Sn content increases more than 80%, for example, 80% or more. Tend to be larger. Further, when the Sn content exceeds 4.5 times the oxygen content, there is almost no change in the volume dispersion of the Sn oxide, but Sn is not fixed in the crystal structure of the copper base material 11 as described above. A decrease in conductivity that is presumed to be caused by melting occurs. Also from the viewpoint of the volumetric dispersion rate of such Sn oxides, by making the Sn content 2.5 to 4.5 times the oxygen content, the crystal grain size can be reduced as described above. Combined with the action, the volume dispersion of the fine Sn oxide of 1 μm or less can be made as high as 80% or more, so that the strength of the copper alloy wire 17 made of this copper alloy conductor can be maintained or further increased. Improvements as well as further improvements in electrical conductivity can be achieved.

  As described above, according to the copper alloy conductor, the cable using the copper alloy conductor, the trolley wire, and the copper alloy conductor manufacturing method according to the embodiment of the present invention, the copper alloy conductor (the copper alloy wire 17 as an example in the present embodiment). ), The electrical conductivity can be further improved while maintaining or improving the mechanical strength and bending resistance.

The copper alloy conductor as described in the above embodiment is made of a plurality of types of rough drawn wires with different settings such as the amount of Sn added to the copper base material 11 and the final rolling temperature of hot rolling, They were subjected to cold drawing to obtain a copper alloy wire 17. Then, using these copper alloy wires 17 as the samples of Examples 1 and 2 and Comparative Examples 1 and 2, the tensile strength (MPa) and electrical conductivity (% IACS) of each of these samples were examined. .
FIG. 2 is a diagram collectively showing the oxygen content, the Sn content, the Sn oxide content ratio, and the Sn oxide size of the copper alloy conductors according to Examples 1 and 2 and Comparative Examples 1 and 2. FIG. It is a figure which shows the tensile strength and electrical conductivity of the copper alloy wire which concerns on Examples 1 and 2 and Comparative Examples 1 and 2 as a graph.

  In Examples 1 and 2, a copper base material 11 containing 0.035% by mass of oxygen was used. And with respect to the copper base material 11, in the sample of Example 1, 0.1 mass% of Sn12 was contained to make a copper alloy molten metal 13 with a Sn oxide content ratio of 2.8. Moreover, in the sample of Example 2, 0.15 mass% of Sn12 was contained to make a copper alloy molten metal 13 having a Sn oxide content ratio of 4.3 (F1).

  Then, SCR continuous casting is performed at 1100 ° C. to 1150 ° C., which is lower than the general SCR continuous casting temperature of 1120 ° C. to 1200 ° C., and the copper mold is forcibly water-cooled. The alloy was rapidly cooled to a temperature 100 ° C. lower than the solidification temperature of the molten alloy 13 (F2).

  Subsequently, the cast material 14 is subjected to multi-stage hot rolling in a state adjusted to 500 ° C. to 600 ° C., which is 50 ° C. to 100 ° C. lower than a general hot rolling temperature in continuous casting rolling, and rolled. It was set as material 15 (F3).

Subsequently, the rolled material 15 was washed and wound to form a rough drawn wire 16. The diameter of the wound rough drawn wire 16 was about 8 mm (F4).
Finally, the wound wire 16 was fed out and cold rolled at a temperature of about 30 ° C. to produce a copper alloy wire 17 having a predetermined wire diameter (F5).

Thus, as collectively shown in FIG. 2, as a sample of Example 1, a copper base material 11 containing 0.035% by mass of oxygen and containing 0.1% by mass of Sn12 was used. An alloy wire 17 was obtained. Moreover, as a sample of Example 2, the copper alloy wire 17 containing 0.15% by mass of Sn12 in the copper base material 11 containing 0.035% by mass of oxygen was obtained.
Moreover, as a sample of Comparative Example 1, Sn12 was 0.3% by mass in a copper base material 11 containing 0.035% by mass of oxygen by a manufacturing method different from the manufacturing methods of Examples 1 and 2 above. A copper alloy wire 17 having a Sn oxide content ratio of 8.1 was obtained. Moreover, as a sample of Comparative Example 2, Sn12 was added in an amount of 0.3% by mass in a copper base material 11 containing 0.001% by mass of oxygen by a manufacturing method different from the manufacturing methods of Examples 1 and 2 described above. The copper alloy wire 17 having a Sn oxide content ratio of 300 was obtained.

That is, in the samples of Examples 1 and 2, both the ratio of the Sn oxide to the oxygen amount and the size (particle diameter) of the Sn oxide were within the numerical range described in the above embodiment. In contrast, the sample of Comparative Example 1 has the Sn oxide size in the numerical range described in the above embodiment, but the content ratio of the Sn oxide to the oxygen amount is different from that in the above embodiment. We deliberately deviated from the numerical range described in. In the sample of Comparative Example 2, both the size of the Sn oxide and the content ratio of the Sn oxide to the oxygen amount were deliberately deviated from the numerical range described in the above embodiment.
With respect to the copper alloy wire 17 of each sample, the tensile properties and the electrical conductivity were evaluated.

  As a result, as shown in FIG. 3, the copper alloy wires 17 of Examples 1 and 2 both improved the conductivity to about 100% IACS while maintaining the tensile strength (strength) at 200 MPa to 500 MPa. It was confirmed that it had a higher conductivity than the copper alloy wires 17 of Comparative Examples 1 and 2 and maintained high strength.

From the experiment using such a sample, according to the copper alloy wire 17 and the manufacturing method thereof according to this example, the mechanical strength and the bending resistance characteristics of the copper alloy conductor (copper alloy wire 17 in this example) are maintained. It has been confirmed that further improvement in conductivity can be achieved while improving.

It is a figure which shows the flow of the main processes in the manufacturing method of the copper alloy conductor which concerns on this Embodiment. It is a figure which shows collectively oxygen content, Sn content, the ratio of an oxide, and the size of an oxide of the copper alloy conductor which concerns on Examples 1, 2 and Comparative Examples 1, 2. It is a figure which shows the tensile strength and electrical conductivity of the copper alloy wire which concerns on Examples 1, 2 and Comparative Examples 1, 2 as a graph.

Explanation of symbols

11 Copper base material 12 Sn (tin)
13 Copper alloy molten metal 14 Cast material 15 Rolled material 16 Rough drawn wire 17 Copper alloy wire F1 Melting process F2 Casting process F3 Hot rolling process F4 Cleaning and winding process F5 Cold wire drawing process

Claims (6)

A copper alloy conductor containing oxygen in an amount of 0.01% by mass to 0.1% by mass,
Tin is contained at a mass ratio of 2.5 to 4.5 times with respect to the oxygen content, and the tin oxide is dispersed in a volume of 80% or more in the crystal structure of the copper alloy conductor A copper alloy conductor characterized by being dispersed as a fine oxide having an average particle size of 1 μm or less at a rate. The copper alloy conductor according to claim 1,
A copper alloy conductor obtained by processing the copper alloy conductor into a wire, and providing a surface of the wire with a tin, nickel, or silver plating film. The copper alloy conductor according to claim 2,
A copper alloy conductor comprising a plurality of the wire rods twisted together. A cable comprising a product made of the copper alloy conductor according to any one of claims 1 to 3 and coated with an insulating film. A trolley wire comprising the copper alloy conductor according to any one of claims 1 to 3. In a copper base material containing 0.01% by mass to 0.1% by mass of oxygen, tin is contained in a mass ratio of 2.5 to 4.5 times the oxygen content. Adding, making a copper alloy melt,
Continuous casting is performed using the molten copper alloy to form a cast material, and the temperature of the cast material formed by casting the molten copper alloy is rapidly cooled to a temperature that is 15 ° C. or lower than the melting point of the molten copper alloy. And a process of
And a step of performing hot rolling while adjusting the temperature so that the final rolling temperature is 500 ° C. or more and 600 ° C. or less with respect to the casting material after setting the casting material to 900 ° C. or less. A method for producing a copper alloy conductor.

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