JPH07300658A - Method for manufacturing trolley wire with excellent abrasion resistance - Google Patents

Abstract

(57) [Summary] [Constitution] Sn: 0.1-0.5 wt% is contained, Cr: 0.1-0.5 wt%, Zn: 0.1-1.0 w
A copper alloy containing 1 or 2 of t% and the balance of Cu and unavoidable impurities is hot-worked at a temperature of 700 ° C. or higher while being water-cooled immediately after continuous casting. A method for producing a trolley wire having excellent wear resistance, which comprises the steps of: reheating at 400 to 550 ° C. for 0.5 to 5 hours. [Effect] It is possible to efficiently manufacture a long trolley wire product that is more abrasion resistant than conventional products.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a railway trolley wire having improved wear resistance.

[0002]

2. Description of the Related Art Conventionally, as a material of a trolley wire for transportation and transportation equipment such as railways and cranes, pure copper wire excellent in conductivity,
In most cases, Sn-containing copper alloy wire or the like is used.

[0003]

However, the pure copper wire has low strength, and the Sn-containing copper alloy wire has the following problems.
Although the strength is improved as compared with the pure copper wire, it is not necessarily sufficient in terms of wear resistance, and there is a problem that the amount of wear increases due to an arc during current collection in a pantograph, especially during high-speed operation.

[0004]

As a result of various studies in view of the above points, the present invention has developed a method for producing a trolley wire having excellent wear resistance.

That is, according to the present invention, Sn: 0.1 to 0.5 w
t%, Cr: 0.1-0.5 wt%, Z
n: a copper alloy containing one or two of 0.1 to 1.0 wt% and the balance being Cu and inevitable impurities,
Immediately after continuous casting, while performing water cooling, a step of hot working at a temperature of 700 ° C or higher, and then 400 to 55
A method for producing a trolley wire having excellent wear resistance, which comprises a step of reheating at 0 ° C for 0.5 to 5 hours.

[0006]

The present invention has found that the wear resistance can be improved by hot working at a temperature of 700 ° C. or higher while immediately performing water cooling without cooling to room temperature after continuous casting. As is usually done, cold working only after continuous casting or hot working by cooling to room temperature and then reheating is sufficient abrasion resistance (when energized). ) Cannot be obtained. In particular, a copper alloy containing Cr (that is, Sn: 0.1 to 0.5 wt% and Cr: 0.
Copper alloy containing 1 to 0.5 wt% or further Zn:
In the case of a copper alloy containing 0.1 to 1.0 wt%), the effect of the present invention is remarkable, but this is performed by hot working while cooling with water in a state where Cr is in solid solution after continuous casting. It is considered that this is because the Cr precipitation state when reheated to 400 to 550 ° C. later results in a structure that is less likely to wear during energization.

In the present invention, the hot working (starting) temperature is limited to 700 ° C. or higher because sufficient abrasion resistance cannot be obtained at less than 700 ° C. At least a part of the hot working may be performed at 700 ° C or higher, and the hot working finish temperature may be less than 700 ° C. In the present invention, the reheating condition is 400 to 550 ° C.
Therefore, the reason for limiting to within the range of 0.5 to 5 hours is that sufficient abrasion resistance cannot be obtained at a temperature outside the above range or less than 0.5 hours, and if it exceeds 5 hours, abrasion resistance is not obtained. This is because the properties are rather deteriorated and it is not economical to heat for a longer time. In the present invention, the contents of Sn, Cr and Zn are 0.1 to 0.5 wt% and 0.1 to 0.
The limits of 5 wt% and 0.1 to 1.0 wt% are that the wear resistance and strength are not sufficient below the lower limits, and the wear resistance is saturated above the upper limits. This is because the conductivity decreases as well. In the present invention, impurities that are usually contained in a copper alloy, for example, 0.05 wt% or less of O, P, Zr, Li, B, A
It does not matter if g, Fe, Bi, Ni, etc. are contained, and the case where such impurities are contained is also within the scope of the present invention.

[0008]

EXAMPLES Next, examples of the present invention will be described.

Example 1 After melting the raw materials mixed in the alloy composition shown in Table 1, continuous casting was performed so as to form a substantially quadrangular ingot having a cross section of 80 × 80 mm, and immediately after that, a 900 ° C. water-soluble lubricant was used for casting. While cooling (water cooling), hot rolling was performed to a diameter of about 21 mm to obtain a rough drawn wire. The temperature of the rough wire (the temperature at the end of hot rolling) was 100 ° C, but after cooling to room temperature, the wire was drawn to an outer diameter of 19 mm, then heated at 450 ° C for 3 hours and cooled to room temperature. After that, the wire was further drawn to an outer diameter of 17 mm, and a copper alloy trolley wire having a cross-sectional area of 170 mm ² having the shape shown in FIG. 1 was obtained by peeling and wire drawing using a modified die. The processing step is referred to as "A".

[Example 2] The hot rolling start temperature was changed to 900 ° C to 7
A copper alloy trolley wire having the same shape and size as in Example 1 was obtained by the same method as in Example 1 except that the temperature was 50 ° C. (working step: “A”).

[Example 3] The heating temperature after wire drawing was 450 until the outer diameter was 19 mm.
Except 550 ° C instead of ° C and heating for 3 hours,
According to the same method as in the first embodiment, the same shape as in the first embodiment,
A copper alloy trolley wire having dimensions was obtained (processing step: "A").

[0009]

[Comparative Example 1] The hot rolling start temperature was changed to 900 ° C and 6
A copper alloy trolley wire having the same shape and size as in Example 1 was obtained by the same method as in Example 1 except that the temperature was 50 ° C. (working step: “A”).

[Comparative Example 2] The heating temperature after wire drawing to an outer diameter of 19 mm was 45
350 ° C instead of 0 ° C (Comparative Example 2-1), or 6
Example 1 above except that the temperature was set to 00 ° C (Comparative Example 2-2).
A copper alloy trolley wire having the same shape and dimensions as in Example 1 was obtained by the same method as in Example 1 (working step: "A").

[Comparative Example 3] The same as the above, except that the heating time after wire drawing to an outer diameter of 19 mm was changed from 3 hours to 0.3 hours (Comparative Example 3-1) or 6 hours (Comparative Example 3-2). By the same method as in Example 1, a copper alloy trolley wire having the same shape and dimensions as in Example 1 was obtained (working step: "A").

Comparative Example 4 An ingot continuously cast into a size of 80 × 80 mm was once cooled to room temperature, then reheated to 900 ° C. and cooled (water-cooled) with a water-soluble lubricant in the same manner as in Example 1 above. After hot rolling to a diameter of about 21 mm and obtaining a rough drawn wire, a copper alloy trolley wire having the same shape and size as in Example 1 was obtained by the same method as in Example 1 above. This processing step is referred to as (B).

[Comparative Example 5] A copper ingot having the same shape and size as in Example 1 was prepared by the same method as in Example 1 after the ingot continuously cast into a size of 21 mm in diameter was cooled to room temperature to form a rough wire. I got a trolley wire. This processing step is referred to as (C).

COMPARATIVE EXAMPLE 6 In Example 1, when the ingot was rolled from 900 ° C., it was hot-rolled to a diameter of about 21 mm without water cooling to obtain a rough-drawn wire, and then the same working process as in Example 1 was performed. A copper alloy trolley wire having the same shape and size as in Example 1 was obtained. This processing step is referred to as (D).

[0010]

[Prior art] As the material of the trolley wire, conventionally used pure copper (tough pitch copper) or Sn-containing copper alloy is used.
By the same processing method (processing step (C)) as in Comparative Example 5, a copper alloy trolley wire having the same shape and size as in Example 1 was obtained. The characteristics of these trolley wires are summarized in Table 1.
Note that the amount of wear is 10 current including the conventional trolley wire.
2 amps of normal sintered friction strip at 0 amp and speed of 50 km / h
The amount of wear of the trolley wire after pressing it with a load of Kg and passing it 500 times was measured and expressed as a relative value when the amount of wear of pure copper was 100%. As is clear from Table 1, the invention sample No. Comparative Examples Nos. 1 to 3 are comparative example Nos. 1 to 6, Conventional Example No. Wear resistance is superior to those of 1-2.

[0011]

[Table 1]

[0012]

As described above, according to the method of the present invention, it is possible to efficiently produce a long product of a trolley wire, which is more excellent in abrasion resistance than a conventional product, and has a remarkable industrial effect. Is.

[Brief description of drawings]

1 is a cross-sectional view of an abrasion resistant trolley wire obtained according to an example of the present invention.

Claims (1)

[Claims] 1. Sn: 0.1-0.5 wt% is contained,
Further, Cr: 0.1 to 0.5 wt%, Zn: 0.1 to 1.
A copper alloy containing one or two of 0 wt% and the balance of Cu and unavoidable impurities is hot-worked at a temperature of 700 ° C or higher while being water-cooled immediately after continuous casting. Process and then at 400-550 ° C, 0.5
Method for producing trolley wire with excellent abrasion resistance, characterized by including a step of reheating for 5 hours