JPH11117051A - Production of thunder resistant electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the boundary density strength between an Al layer and Zn plating layer and the ductility of this Zn plating layer by using an Al coated steel wire as a base wire and immersing this base wire into a molten Zn bath, thereby forming the Zn plating layer in the state of metallically bonding to the Al layer on the outer periphery of the base wire. SOLUTION: The Al coated steel wire 2 is inserted through a flux applying mean 3, by which a flux mixture composed of ZnCl2 and NH4 Cl is adhered to its surface. The Al coated steel wire 2 is then immersed into the molten Zn bath 6. At this time, the molten Zn plating layer in the state of metallically bonding to the Al layer is formed on the outer periphery of the Al coated steel sire 2 by the flux action of the flux mixture. Next, the Al coated steel wire 2 after the hot dip coating is inserted into a rapid cooling device 8 and is subjected to a rapid cooling treatment, by which the thunder resistant electric wire 10 is manufactured. The sagging down of the molten Zn plating layer is obviated, the surface of the thunder resistant electric wire 10 is smoothed and the Zn crystals in the plating layer are made finer by the rapid cooling treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a lightning-resistant electric wire, and more particularly to a method for manufacturing a Zn layer or Z
The present invention relates to a method for manufacturing a lightning-resistant electric wire coated with an n-alloy layer.

[0002]

2. Description of the Related Art A lightning-resistant electric wire used for an overhead power line such as an overhead power transmission line or an overhead ground wire containing an optical fiber has an Al-coated steel wire formed by coating the outer periphery of a steel wire with Al (or an Al alloy) as a bus bar. The composite wire has a three-layer structure in which the outer periphery of the bus is coated with Zn, which is a low-melting metal.

Here, Zn formed on the outer periphery of an Al-coated steel wire
The coating layer is usually coated using an electroplating method. The Zn coating by the electroplating method is a method of charging an electrolytic solution containing Zn ions and then depositing Zn on the outer periphery of the Al-coated steel wire using the Zn plate as an anode and the Al-coated steel wire as a cathode.

[0004] When performing electroplating, it is required that Al on the surface of the Al-coated steel wire be sufficiently cleaned and activated, and therefore, pretreatment is generally performed. As preprocessing,
The use of chemicals is more efficient.

[0005]

However, in this case, a controlled facility is required for treating the waste liquid of the chemical. Further, since the electroplating speed is generally not so high, in order to increase the coating thickness, it is necessary to increase the current density and lengthen the plating time.

An example of the plating time when Zn plating is performed using the electroplating method will be described below. Outer diameter is 3.6
When a lightning-resistant wire having an outer diameter of 4.06 mm is manufactured using a 6-mm Al-coated steel wire, the amount of Zn deposited per meter of the lightning-resistant wire is 17.2 g. Here, assuming that the current density of Zn plating is 50 A / dm ² (a general value at the time of manufacturing a Zn electroplated steel sheet), since the deposition rate of Zn is 1.2 g / A · hr, 17.2 g of Zn is deposited. 17.
This will take two minutes.

In other words, when Zn is coated on the outer periphery of an Al-coated steel wire using an electroplating method, the equipment capacity and equipment become large, and a chemical waste treatment is required as a pretreatment, so that a controlled waste liquid treatment equipment is required. There are various restrictions on productivity, such as the need to reduce the line speed, and the production cost is very high.

Further, since the adhesion strength of the Zn plating layer to the Al layer on the surface of the Al-coated steel wire is relatively low, and the Zn plating layer itself is brittle, the ductility of the plating layer is insufficient depending on the material such as a thick plating material. In addition, there has been a problem that cracks and peeling defects are likely to occur in post-processes such as wire drawing, twisting, and overhead wire.

Therefore, the present invention solves the above-mentioned problems, and
An object of the present invention is to provide a method for producing a lightning-resistant electric wire having a high interface adhesion strength between a layer and a Zn plating layer, good ductility of the Zn plating layer, and high productivity and low production cost.

[0010]

According to a first aspect of the present invention, there is provided a method for manufacturing a lightning-resistant electric wire, comprising forming a Zn layer or a Zn alloy layer around an Al-coated steel wire. The coated steel wire is used as the bus, and the bus is
It is immersed in a bath to form a Zn plating layer on the outer periphery of the bus bar in a state of being metallically bonded to the Al layer.

According to a second aspect of the present invention, the surface of the bus
2. The method for producing a lightning-resistant wire according to claim 1, wherein a mixed flux of nCl ₂ and NH ₄ Cl is attached and then immersed in the molten Zn bath.

According to a third aspect of the present invention, the bus is 440-400.
1.0 to 2.5 in the molten Zn bath maintained at 460 ° C.
The method for manufacturing a lightning-resistant wire according to claim 1 or 2, wherein the lightning-resistant wire is immersed for 2 seconds.

According to a fourth aspect of the present invention, there is provided the method for manufacturing a lightning-resistant wire according to the first aspect, wherein the quenching treatment is performed immediately after the hot-dip Zn plating layer is formed.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a lightning-resistant electric wire in which a Zn layer or a Zn alloy layer is formed on the outer periphery of an Al-coated steel wire, wherein the Al-coated steel wire is used as a bus, and ZnCl After adhering a mixed flux of ₂ and NH ₄ Cl, the bus bar is immersed in a molten Zn bath to form a molten Zn plating layer in a state of being metallically bonded to the Al layer on the outer periphery of the bus bar. Is subjected to a quenching treatment.

The reasons for limiting the above numerical ranges will be described below.

The reason why the temperature of the molten Zn bath is 440 to 460 ° C. and the immersion time is 1.0 to 2.5 seconds is that the temperature of the molten Zn bath is lower than 440 ° C. and the immersion time is less than 1.0 second. Is too short, the temperature of the Al-coated steel wire with the flux adhered to the surface becomes insufficient, and the Zn plating layer only adheres to the Al layer. No Zn alloy layer is formed, and a Zn plating layer having high interface adhesion strength cannot be formed. Further, when the temperature of the molten Zn bath is higher than 460 ° C. and the immersion time is longer than 2.5 seconds, the elution of Al on the surface of the Al-coated steel wire becomes severe, so that the Al layer becomes thinner and the Zn plating layer becomes thinner. Cannot be formed.

According to the above construction, in the method for manufacturing a lightning-resistant electric wire in which a Zn layer or a Zn alloy layer is formed on the outer periphery of an Al-coated steel wire, the Al-coated steel wire is used as a bus, and the bus is used as a molten Zn bath. To form a Zn plating layer in a state of being metallically bonded to the Al layer on the outer periphery of the
The interfacial adhesion strength between the l layer and the Zn plating layer is high, and Z
A lightning-resistant electric wire with good ductility of the n-plated layer can be obtained.

[0018]

Embodiments of the present invention will be described below.

FIG. 1 is a schematic view of a lightning-resistant electric wire manufacturing apparatus according to the present invention.

As shown in FIG. 1, first, an Al-coated steel wire 2 sent from a feeder 1 is passed through a flux applying means 3. At this time, although not shown, the Al-coated steel wire 2 sent from the feeder 1 was subjected to solvent degreasing, mechanical polishing,
After performing a degreasing treatment such as a caustic treatment, it is inserted into the flux coating means 3.

If the Al-coated steel wire 2 before passing through the flux applying means 3 is not subjected to a degreasing treatment, the adhesion between the Al-coated steel wire 2 and the mixed flux in the next step is deteriorated, and a good result is obtained. A Zn plating layer cannot be obtained.

Next, a mixed flux of ZnCl ₂ and NH ₄ Cl is adhered to the surface of the Al-coated steel wire 2 inserted into the flux applying means 3.

Thereafter, the Al-coated steel wire 2 having the mixed flux adhered to its surface is guided into a hot-dip Zn plating bath 5 via a guide roller 4 and immersed in a hot-dip Zn bath 6. Due to the flux action of this mixed flux, the Al-coated steel wire 2
A hot-dip Zn plating layer in a state of being metallically bonded to the Al layer is formed on the outer periphery of the substrate. At this time, in order to improve plating properties,
The Al-coated steel wire 2 having the mixed flux adhered to the surface may be heated using a heating means (not shown), and the surface may be dried and then immersed in the molten Zn bath 6.

Here, when the Al-coated steel wire 2 having no mixed flux adhered to the surface is immersed in the molten Zn bath 6, the molten Zn plating layer only adheres to the Al layer,
Since no Al—Zn alloy layer is formed at the interface between the Al layer and the hot-dip Zn plating layer, the hot-dip Zn plating layer is easily peeled off.

Next, the Al-coated steel wire 2 after the hot-dip plating is
The lightning wire 10 is inserted through the guide roller 7 into the quenching device 8 and subjected to a quenching process to produce the lightning-resistant wire 10. By this quenching treatment, while the sagging of the hot-dip Zn plating layer is eliminated,
The surface of the lightning-resistant wire 10 becomes smooth, and Zn crystal grains in the hot-dip Zn plating layer become fine.

Thereafter, the lightning-resistant wire 10 is wound around the winder 11 via the guide roller 9.

The plating layer formed on the outer periphery of the Al-coated steel wire 2 is not particularly limited to the Zn plating layer, but may be, for example, an Al—Zn alloy plating layer.

That is, according to the method for manufacturing a lightning-resistant electric wire of the present invention, an Al-coated steel wire is used as a bus, and the bus is
Since the Zn plating layer in a state of being metallically bonded to the Al layer is formed on the outer periphery of the bus bar by being immersed in a bath, the adhesion strength of the Zn plating layer to the Al layer on the surface of the Al-coated steel wire is high, and There is no possibility that the Zn plating layer will be peeled off during the process.

Further, since the molten Zn plating layer formed by immersing the busbar in the molten Zn bath is rapidly cooled immediately after formation, the Zn crystal grains in the molten Zn plating layer are refined and the ductility of the Zn plating layer is reduced. Good, wire drawing,
There is no possibility that cracks will occur in the Zn plating layer in a post process such as a stranded wire or an overhead wire.

[0030]

【Example】

(Example 1) First, the surface of an Al-coated steel wire having an outer diameter of 2.6 mmφ, which was previously degreased chemically or mechanically, was placed on a surface of 60 to 70 mm.
A mixed flux of ZnCl ₂ and NH ₄ Cl maintained at 0 ° C. is deposited.

Thereafter, the Al-coated steel wire having the mixed flux adhered to the surface thereof was melted by using molten Zn held at 450 ± 10 ° C.
It is immersed in a bath for 1.0 to 2.5 seconds to form a molten Zn plating layer on the outer periphery of the Al-coated steel wire in a state of being metallically bonded to the Al layer.

Immediately thereafter, the hot-dip Zn plating layer is rapidly cooled to produce a lightning-resistant electric wire having an outer diameter of 2.8 mmφ.

(Comparative Example 1) Using the same Al-coated steel wire as in Example 1, a lightning-resistant wire having an outer diameter of 2.8 mmφ is manufactured by electroplating.

The cross sections of the lightning-resistant electric wires of Example 1 and Comparative Example 1 are observed.

As a result, the interface between the Al layer and the Zn plating layer of the lightning-resistant electric wire of Example 1 had an Al thickness of about 10 μm.
-A Zn alloy layer was formed. On the other hand, at the interface between the Al layer and the Zn plating layer of the lightning-resistant wire of Comparative Example 1, A
No l-Zn alloy layer was observed.

Next, the lightning-resistant electric wires of Example 1 and Comparative Example 1 were reduced in diameter until the diameter became 1/2 (until the thickness became 1.3 mm).
Crush.

As a result, in the lightning-resistant electric wire of Example 1, since the Al—Zn alloy layer was formed at the interface between the Al layer and the Zn plating layer, the interface adhesion strength was high, and the peeling of the Zn plating layer was observed. Was not done. Further, since the molten Zn plating layer is rapidly cooled to make the Zn crystal grains in the Zn plating layer fine, the ductility of the Zn plating layer is good, and
No crack was observed in the plating layer.

On the other hand, in the lightning-resistant electric wire of Comparative Example 1, since the Al—Zn alloy layer was not formed at the interface between the Al layer and the Zn plating layer, the interface adhesion strength between the Al layer and the Zn plating layer. Was low, and peeling of the Zn plating layer was observed. Further, since the Zn crystal grains in the Zn plating layer remain coarse, the ductility of the Zn plating layer is not good,
Cracks were observed in the plating layer.

[0039]

In summary, according to the present invention, according to the present invention, an Al-coated steel wire is used as a bus bar, and the bus bar is immersed in a molten Zn bath, and a Zn plating layer is formed on the outer periphery of the bus bar and is metallically bonded to an Al layer. By forming, an excellent effect that the adhesion strength of the Zn plating layer to the Al layer on the surface of the Al-coated steel wire is high, and there is no possibility that the Zn plating layer is peeled off in a post process or the like.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for manufacturing a lightning-resistant wire according to the present invention.

[Explanation of symbols]

 2 Al-coated steel wire 6 Fused Zn bath 10 Lightning-resistant wire

Claims (5)

[Claims] 1. A Zn layer or a Zn layer on an outer periphery of an Al-coated steel wire.
In the method for manufacturing a lightning-resistant electric wire formed with an alloy layer, the Al-coated steel wire is used as a bus bar, and the bus bar is immersed in a molten Zn bath, and the Zn is bonded to the outer periphery of the bus bar in a metallurgy with the Al layer. A method for manufacturing a lightning-resistant electric wire, comprising forming a plating layer. 2. The surface of said bus bar is provided with ZnCl ₂ and NH ₄
2. The method for manufacturing a lightning-resistant wire according to claim 1, wherein the mixed flux of Cl is adhered and then immersed in the molten Zn bath. 3. The method according to claim 1, wherein the bus is immersed in the molten Zn bath maintained at 440 to 460 ° C. for 1.0 to 2.5 seconds. 4. The method for manufacturing a lightning-resistant wire according to claim 1, wherein a quenching treatment is performed immediately after forming the hot-dip Zn plating layer. 5. A Zn layer or a Zn layer on the outer periphery of an Al-coated steel wire.
In the method for manufacturing a lightning-resistant electric wire having an alloy layer formed thereon, the Al-coated steel wire is used as a bus bar, and ZnCl
After adhering a mixed flux of ₂ and NH ₄ Cl, the bus bar is immersed in a molten Zn bath to form a molten Zn plating layer in a state of being metallically bonded to the Al layer on the outer periphery of the bus bar. A method for producing a lightning-resistant wire, comprising subjecting a lightning-resistant wire to quenching.