JPS61207542A - High tensile heat resisting aluminum alloy - Google Patents

Abstract

PURPOSE:To obtain a high tensile heat resisting aluminum alloy suitable for use in production of overhead power transmission lines by blending specific percentage of Fe, Mg, Cu, and Zr with an Al alloy. CONSTITUTION:The aluminum alloy has a composition consisting of, by weight, 0.2-0.6% Fe, 0.03-0.15% Mg, 0.06-0.3% Cu, 0.04-0.2% Zr and the balance Al with impurities such as Si or the like in an amount usually contained in Al metal, in which the total amount of Fe, Cu and Mg is <0.7 and the weight ratio of Cu to Mg is 1.8-2.3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an aluminum alloy suitably used for manufacturing overhead power transmission lines and the like.

Conventional technology Traditionally, when transmitting large amounts of power at high voltage to remote locations,
It is necessary to increase power transmission capacity while reducing the weight of the wire itself, and steel-core aluminum wire (ACSR) is often used. In particular, when heat resistance is required, such as in large-capacity power transmission, a heat-resistant aluminum alloy for electrical use is used (TAC3R), which has a trace amount of zirconium added to improve heat resistance.

However, since such zirconium-added alloys do not have sufficient tensile strength, high-strength alloys with improved strength are made by adding several selected elements from iron, silicon, magnesium, cobalt, nickel, helium, rare earth metals, etc. A high-strength heat-resistant aluminum alloy has been developed and put into practical use as a steel-core high-strength heat-resistant aluminum alloy 1 hot wire (KTA'C3R).

However, such high-strength, heat-resistant aluminum alloys require the addition of large amounts of subcomponents to increase mechanical strength, and are often subjected to annealing or solution treatment during the rough drawing stage to increase heat resistance and conductivity. Moreover, complicated indexes were required, such as intermediate annealing after wire drawing. Therefore, there are disadvantages in that the conductivity is not sufficient, the corrosion resistance is very poor, and the manufacturing cost of the electric wire is high.

Let's solve the problem in question.

The present invention improves the above-mentioned drawbacks and improves mechanical strength.
The present invention aims to provide an aluminum alloy that has excellent properties in terms of heat resistance, electrical conductivity, and corrosion resistance and is suitable for manufacturing steel-core aluminum stranded wires.

■-Keisha Kaidan ↓ Kumeinu Keiso The purpose of the present invention is to use 0.2 to 0.6% by weight of iron,
Magnesium 0.03~0.15% by weight, copper 0.06~
It is an alloy consisting of 0.3% by weight of zirconium, 0.04-0.2% by weight of zirconium, and the balance of aluminum and impurities such as silicon in amounts normally contained in aluminum base metal. The total amount is 0.7% by weight or less, and the weight specific force of copper and magnesium is 8 to 2.
This is achieved by aluminum alloys such as those within the range of 3.

In the alloy of the present invention, the addition of iron is effective in improving heat resistance, conductor strength, and wire drawability, but if the amount is less than 0.2% by weight, it has little effect. , also 0,
If it exceeds 6% by weight, the effect will not be significantly increased, and on the contrary, it will be disadvantageous in terms of conductivity and corrosion resistance.

Addition of magnesium improves the strength and corrosion resistance of the conductor, but if the amount is less than 0.03% by weight, it has little effect, while if it exceeds 0.15% by weight, although it is effective, it impairs conductivity and heat resistance. This is not desirable because the decrease will be significant.

Copper is used to increase the strength of the conductor, but if the amount added is less than 0.06% by weight, the effect is not significant;
If it exceeds % by weight, corrosion resistance, heat resistance and conductivity will be significantly reduced.

Furthermore, if the amount of zirconium added is less than 0.04% by weight, the improvement in heat resistance will be insufficient, and if it exceeds 0.2% by weight, the heat resistance will be significantly reduced.

Furthermore, if the total amount of iron, magnesium and copper exceeds 0.7% by weight, the conductivity and corrosion resistance will decrease significantly,
Practically undesirable. The weight ratio of copper and magnesium is 1.
If it is within the range of 8 to 2.3, the decrease in corrosion resistance caused by the presence of copper can be minimized by the presence of magnesium, and an alloy with a good balance between corrosion resistance and heat resistance can be obtained. If,
If this value is greater than 2.3, the corrosion resistance is unsatisfactory, and if this value is less than 8, the heat resistance is insufficient.

Example Electrical aluminum ingot (silicon 0.04% by weight, iron 0
．． 12% by weight, copper 0.001% by weight, manganese 0°00
1% by weight, titanium and vanadium 0.001% by weight,
After melting aluminum (purity: 99.83% by weight) in an electric furnace, each component was added to produce an alloy having the composition shown in Table 1, and cast using a copper mold with a diameter of 30 fins. These ingots were hot rolled into rough drawn wires with a diameter of 9.5 mm, which were further cold drawn and drawn down to a diameter of 4.0 m to obtain filament bodies for testing.

Table 2 shows the results of measuring the tensile strength, electrical conductivity, heat resistance, and corrosion resistance of the test specimens thus obtained.

The test conditions for each test are as follows.

Tensile strength: Based on Instron type tensile testing machine.

Electrical conductivity: Based on Kelvin double brisody.

Heat resistance: Displayed as the ratio of the tensile strength after heating to the tensile strength before heating when heat treated at 230°C for 1 hour.

Corrosion resistance: Using a sulfur dioxide gas corrosion tester, SO2□
Concentration 500PPM, 8 hours of operation, 16 hours of rest, 60 hours
It is expressed as the ratio of the tensile strength after repeated cycles to the tensile strength before corrosion.

Table-1 Composition (wt%) Table-2 Characteristics Note) Among the comparative examples, 11k19 to IVk1.13 are KT
For AC5R, N014 is for TAC3R, floor 15 is for AC3
It is for R.

In Tables 1 and 2, the properties of the alloys of 11 kll to Na8, which are examples of the present invention, are
When compared with the alloys of n9 to 15, all of the comparative alloys have unbalanced properties in terms of tensile strength, electrical conductivity, heat resistance, and corrosion resistance, and are unsatisfactory in terms of performance. On the other hand, the alloys of the present invention all show excellent corrosion resistance of 97.8% or more, and also have superior tensile strength, electrical conductivity, and heat resistance to none of the comparative examples. It has comparable value. This shows that the aluminum alloy of the present invention has an excellent balance of properties that could not be achieved with conventional techniques.

Effects of the Invention The high-strength, heat-resistant aluminum alloy of the present invention contains iron, magnesium, copper, and zirconium in specific proportions, and has high tensile strength, conductivity, and This method has the advantage that it is possible to obtain electric wires with excellent heat resistance and corrosion resistance. Therefore,
The conductive wire manufactured using the alloy of the present invention not only has a good balance of properties but also has the advantage of being low in manufacturing cost.

Claims (1)

[Claims] Iron 0.2-0.6% by weight, Magnesium 0.03-0
．． An alloy consisting of 15% by weight of aluminum, 0.06 to 0.3% by weight of copper, 0.04 to 0.2% by weight of zirconium, and the balance consisting of aluminum and impurities such as silicon in amounts normally contained in aluminum bullion. , the total amount of iron, magnesium and copper is 0.7% by weight or less, and the weight ratio of copper and magnesium is within the range of 1.8 to 2.3. Superior high strength heat resistant aluminum alloy.