JPH05311284A - Copper alloy trolley wire - Google Patents

Abstract

PURPOSE:To improve the tensile strength and collecting and sliding wear resistance of a trolley wire as well as its pressure weldability by specifying Cr, Zr, Si, Cu, O or the like. CONSTITUTION:The objective copper alloy trolley wire is formed of a compsn. constituted of, by weight, 0.15 to 0.8% Cr, 0.01 to 0.25% Zr. 0.01 to 0.1% Si and <=10ppm O, and the balance Cu or furthermore constituted of 0.001 to 0.05% Mg. This trolley wire is excellent in tensile strength and collecting and sliding wear resistance and is furthermore improved in pressure weldability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trolley wire of a train line in a high speed electric railway.

[0002]

2. Description of the Related Art Generally, pure copper or a copper alloy wire containing 0.3% by weight of Sn has been used as a trolley wire for an electric railway in an electric railway.

However, as seen on the Shinkansen,
In recent years, electric vehicles that are newly manufactured tend to become even faster, and accordingly, it is necessary to increase the overhead wire tension of the trolley wire, and a trolley wire having even higher tension is required.

The above high-tension trolley wire has been proposed at present, and, for example, in JP-A-3-56632 and JP-A-3-56633, the weight percentage is Zr: 0.00.
1 to 0.35% and Cr: 0.01 to 1.2%, and if necessary, Mg: 0.3% or less, Zn: 1.5
% Or less, Ag: 0.2% or less, Cd: 0.5% or less, including one or more kinds in total of 1.5% or less, and the balance: Cu and Sn: 100 ppm or less, Si: 50 ppm. Hereinafter, P: 50 ppm or less, Fe: 100 ppm or less, Ni:
100ppm or less, Pb: 20ppm or less, As: 20ppm
Hereinafter, Sb: 20 ppm or less, Bi: 20 ppm or less, S:
A copper alloy trolley wire having a composition of inevitable impurities limited to 10 ppm or less is described.

These pure copper or copper alloy trolley wires are produced by first producing pure copper or a copper alloy ingot having a predetermined composition, and then hot rolling or hot extruding the ingot to obtain pure copper or coarse copper alloy having a large diameter and a short length. It is manufactured by producing a rolled coil, press-bonding the large-diameter and short-length pure copper or copper alloy rough rolled coil, and then wire-drawing to a predetermined size.

[0006]

However, the above-mentioned Japanese Unexamined Patent Application Publication No.
The trolley wire described in Japanese Patent Laid-Open No. 56632 and Japanese Patent Application Laid-Open No. 3-56633 is not sufficiently satisfactory in current collecting sliding wear resistance and tensile strength. If the tensile strength of the pressure contact portion is low, the trolley wire in an overhead wire state may be broken at the pressure contact portion, which may cause an accident.

[0007]

Therefore, the present inventors have
As a result of conducting research to obtain a copper alloy trolley wire which is made of a copper alloy having a composition excellent in pressure contact property and which has further excellent current collecting sliding wear resistance and tensile strength, Cr: 0.1
5 to 0.8%, Zr: 0.01 to 0.25%, Si:
0.01-0.1%, and if necessary M
g: In a copper alloy containing 0.001 to 0.05%, if the oxygen content is limited to 10 ppm or less, the current collecting sliding wear resistance and the tensile strength will be further improved and the pressure contact property will be improved. I got the knowledge that it would be done.

The present invention has been made on the basis of such findings, and in weight%, Cr: 0.15 to 0.8.
%, Zr: 0.01 to 0.25%, Si: 0.01 to
Characterized by a copper alloy trolley wire having a composition containing 0.1%, oxygen: 10 ppm or less, Mg: 0.001 to 0.05% if necessary, and the balance Cu and unavoidable impurities. It is a thing.

To produce the copper alloy trolley wire of the present invention, a reducing gas is blown into a molten copper obtained by dissolving ordinary oxygen-free copper through a graphite nozzle, and the reducing gas is blown on the way. At this point, copper oxide is temporarily added, and then a reducing gas is blown in to make an extremely low oxygen copper melt with an oxygen content of 0.5 ppm or less, and a predetermined amount of C is added to this extremely low oxygen copper melt.
After adding r, and further adding a predetermined amount of Zr, Si and Mg, casting is performed to produce a cylindrical or prismatic ingot.

This ingot is preferably placed under a reducing atmosphere at 8
After heating to 50 ° C. to 1050 ° C. and hot working to produce a coarse wire, this coarse wire is subjected to hot pressure welding or cold pressure welding, and then 80
After being kept at 0 to 1050 ° C. for 0.1 to 2 hours, a quenching treatment is performed, and cold working is performed to produce a trolley wire having a predetermined cross-sectional dimension.

Next, the reason why the component composition of the copper alloy forming the trolley wire of the present invention is limited as described above will be explained.

(A) Cr, Zr Cr and Zr are components that improve wear resistance and further improve heat resistance strength by being present as dispersed particles in the Cu matrix, but the Cr content is not more than 0. 8%
When the Zr content exceeds 0.25%, the dispersed particles become large, the strength of the press contact portion of the finished wire after processing is lowered, the arc generation rate becomes high, and the current collecting sliding wear resistance is increased. Decrease, while the Cr content is less than 0.15%, Zr
If the content is less than 0.01%, the desired effect cannot be obtained.
Therefore, Cr: 0.15 to 0.8%, Zr: 0.0
It was set so as to fall within a range of 1 to 0.25%.

(B) Si Si improves the press contact strength and further improves the sliding wear characteristics. However, if the content is less than 0.01%, the desired effect cannot be obtained. If the content exceeds 0.1%, the conductivity decreases, so the Si content was set to 0.01 to 0.1%.

(C) Mg Mg, like Si, also has the effect of improving sliding wear characteristics, but if its content is less than 0.001%, the desired effect cannot be obtained, while if Mg is less than 0. If the content exceeds 0.05%, the compatibility with the current collector becomes poor, so the content was set to 0.001 to 0.05%.

(D) Oxygen If oxygen exceeds 10 ppm, Cr, Zr, S
A crystallized substance mainly composed of i, Mg and an oxide is formed, and the size thereof tends to be 2 μm or more. If a crystallized substance of 2 μm or more remains in the trolley wire substrate, the joint and the vicinity thereof after pressure welding Oxygen content is 10ppm because strength decreases, arc generation rate increases, and trolley wire damage becomes severe.
Defined below.

[0016]

[Embodiment] As a raw material, electrolytic copper having an oxygen content of 20 ppm was prepared, charged into a graphite crucible and melted in an Ar gas atmosphere. CO gas at a flow rate of 10 l / min was blown through the graphite nozzle for 10 minutes continuously, then 1000 g of Cu ₂ O powder was momentarily blown through the graphite nozzle, and further the CO gas was continuously blown for 10 minutes. O by inserting
₂ : An extremely low oxygen copper melt of 0.5 ppm or less was prepared, Cr was added to this melt, Zr, Si and Mg were further added and stirred, and then the obtained copper alloy melt was cast into a mold. A cylindrical copper alloy ingot having a diameter of 250 mm and a length of 3 m was obtained.

The columnar copper alloy ingot is heated in a CO gas atmosphere under the conditions of temperature: 900 ° C. and holding for 1 hour to produce a rough rolled wire having a diameter of 25 mm and a length of 300 m. Was hot-pressed into a long hot-rolled wire, which was then held in a CO gas atmosphere at a temperature of 950 ° C. for 1 hour and then subjected to a solution treatment by water cooling.

The surface oxide of the roughly rolled wire having a diameter of 25 mm subjected to the solution treatment is removed, and cold drawing is repeated 8 times to finally produce a wire having a diameter of 12 mm. The obtained copper alloy wire was further charged into a light volatilization annealing furnace and subjected to an aging precipitation treatment of keeping at 450 ° C. for 1.5 hours, and the trolley wires 1 to 8 of the present invention having the component compositions shown in Table 1 were obtained.
Comparative trolley wires 1 to 7 and conventional trolley wires were manufactured.

Regarding these trolley wires, JIS E 2
The tensile strength of the portion other than the pressure contact portion and the tensile strength in the pressure contact portion are measured by the method shown in 101, and the strength of the pressure contact portion is 95% or more of the tensile strength of the portion other than the pressure contact portion. A, 8 which has secured strength
B, 85% if secured from 5% to less than 95%
Those less than were judged to be C, and the results are shown in Table 2. Further, the electrical conductivity was measured by a four-terminal method according to JIS C 3001 at a measurement length of 1 m, and the current collecting sliding wear characteristics were measured using the device shown in FIG. 1 below.

FIG. 1 is a schematic view of an apparatus for measuring the current collecting sliding wear characteristic. In FIG. 1, 1 is a rotating body, 2 is a trolley wire, 3 is a current collecting plate (rubbing plate), and 4 is It is an emissometer.

As shown by the trolley wire 2 in FIG. 1, the trolley wires 1 to 8 of the present invention, the comparative trolley wires 1 to 7 and the conventional trolley wire are wound around the rotating body 1 having a diameter of 50 cm, while the iron for pantograph is used. A current collector plate 3 made of a system contact plate (M-39, trade name) is pressed against the trolley wire with a pressing force of 2 kgf, and while the direct current of 20 A, 100 V is applied to the current collector plate 3, the rotor 1 is rotated at a peripheral speed. Rotation at 15 km / hour for 60 minutes was performed to measure current-collecting sliding wear characteristics such as current-collecting plate wear rate, trolley wire cross-sectional area wear rate, and arc generation rate. The measured values are shown in Table 2.
The current collector plate wear rate is obtained by dividing the weight reduction of the current collector plate by the value obtained by converting the number of rotations of the rotating body into a distance, and the trolley wire cross-sectional area wear rate is the diameter of the trolley wire after the test in micrometers. It was determined by accurately measuring and dividing the reduction amount by the rotation speed. Further, since a potential difference of 10 to 20 V occurs when an arc occurs, when the potential difference is 6 V or more and 50 V or less, an arc is generated, and during the current collection wear test, this potential difference is measured for 10 seconds every 2 minutes by an emissometer and continuously measured. It was recorded on a chart, the arc generation time was calculated, and the percentage of the arc generation time for 10 seconds was calculated as the arc generation rate.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

From the results shown in Tables 1 and 2, the trolley wires 1 to 8 of the present invention are superior in tensile strength and current-carrying sliding wear resistance to the conventional trolley wires. Therefore, it can be understood that the manufacturing cost can be reduced.

However, the comparative trolley wires 1 to 7 having a composition out of the range of the present invention exhibit unfavorable characteristics as at least one trolley wire such as tensile strength, pressure contact portion strength or conductivity. I understand.

As described above, as the speed of the electric vehicle is increased, the tension of the contact wire of the trolley wire is increased, and the damage and wear of the trolley wire become severe, so the number of maintenance inspections such as replacement of the trolley wire is increased. By using the trolley wire of the present invention, it is possible to reduce the number of maintenance inspections and bring about an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus for measuring current collection sliding characteristics.

[Explanation of symbols]

 1 rotating body 2 trolley wire 3 current collector plate 4 contact rate meter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inoue Sadao Goto 1-6-1, Otemachi, Chiyoda-ku, Tokyo Sanryo Materials Co., Ltd. (72) Inc. Takuro Iwamura 1-6, Otemachi, Chiyoda-ku, Tokyo No. 1 Sanryo Material Co., Ltd. (72) Inventor Haruhiko Asao 1-6-6 Otemachi, Chiyoda-ku, Tokyo No. 1 Sanryo Material Co., Ltd. (72) Yutaka Koshiba 1-6-Otemachi, Chiyoda-ku, Tokyo No. 1 Sanritsu Material Co., Ltd. (72) Inventor Kenji Yajima 1-297 Kitabukuro-cho, Omiya City, Saitama Prefecture Mitsubishi Materials Corporation Central Research Laboratory

Claims (2)

[Claims] 1. Cr: 0.15 to 0.8% by weight,
Zr: 0.01 to 0.25%, Si: 0.01 to 0.1
%, Oxygen: 10 ppm or less, and the balance consisting of a copper alloy having a composition of Cu and inevitable impurities. 2. Cr: 0.15 to 0.8% by weight,
Zr: 0.01 to 0.25%, Si: 0.01 to 0.1
%, Mg: 0.001 to 0.05%, oxygen: 10 ppm or less, and the balance being a copper alloy having a composition of Cu and unavoidable impurities.