JP2001254160A - Method of manufacturing aluminum alloy wire, and aluminum alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aluminum alloy capable of giving an alloy wire excellent in strength, elongation, electric conductivity and heat resistance, and also to provide a method for manufacturing such an aluminum alloy wire, by which manufacturing yield can be increased and heat treatment conditions can be easily set. SOLUTION: The aluminum alloy has a composition which contains, by weight, 0.08-1.5% Mg, 0.09-1.5% Si, 0.008-0.15% Zr and 0.002-0.05% Ti and in which the ratio between the number of Mg atoms that of Si atoms, Mg/Si, is regulated to 0.1-3.0. The roughly continuously drawn aluminum alloy wire can be manufacturing by using a wire rod of the aluminum alloy having the above composition and subjecting this wire rod to solution heat treatment at 430-630 deg.C for 0.5-10 h, cooling down to ordinary temperature at >=5 deg.C/s cooling rate, cold working at >=70% reduction of area, and heat treatment at a temp. of 110-360 deg.C for 0.4-20 h.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy excellent in strength, conductivity and heat resistance and suitable as a conductor or an armor rod of a power cable, and a method for producing the alloy wire.

[0002]

2. Description of the Related Art A conductive heat-resistant aluminum alloy used as a conductor of a power transmission line is an alloy obtained by adding Zr or Si to aluminum as a main component. Aluminum alloy wires (UTAI), special heat-resistant aluminum alloy wires (XTAI) and the like have been put to practical use. However, the strength of these heat resistant aluminum alloy wires is pure aluminum hard aluminum wire (HA
It is equivalent to I), and it is difficult to construct a supporting tower, so it is necessary to wire electric wires over long distances, in mountainous areas, crossing rivers and straits, or in severe environments such as severe snowfall and strong winds It is hard to say that the exposed applications have satisfactory mechanical strength. Cu on the heat-resistant aluminum alloy wire
Alloys having increased strength by adding elements such as iron and Mg have also been developed. However, since the strength of the alloy wire is increased to the limit by strong working after heat treatment, elongation is remarkably small, and there is a defect that the reliability of the clamp portion and the like is lacking because the notch sensitivity is high when external damage is caused. there were.

Therefore, a method of manufacturing an aluminum alloy wire using an alloy obtained by adding a small amount of Zr to a high-strength Al-Mg-Si alloy has been developed (Japanese Patent No. 2944907).
However, this method also has many problems to be solved, such as the occurrence of cracks in the rough drawn wire during continuous casting and rolling, and the process control is complicated because the optimum heat treatment conditions are significantly different depending on the components.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a method of manufacturing an aluminum alloy wire which is excellent in strength, elongation, electrical conductivity and heat resistance, has a high production yield, and can easily set heat treatment conditions. To provide a suitable aluminum alloy.

[0005]

The inventor of the present invention has made intensive studies to achieve the above object, and has found that Al-Mg-Si
At the same time as adding Ti to the Zr-based alloy,
When the ratio of the number of atoms of g and Si is adjusted to a specific range, A
Solved the drawbacks of the method for manufacturing l-Mg-Si-Zr alloy wire, and found that an aluminum alloy wire having high strength, high heat resistance and high electrical conductivity can be stably manufactured with good yield, and the present invention was completed. I came to.

That is, the present invention relates to the following method for manufacturing an aluminum alloy wire and an aluminum alloy. (1) Mg 0.08 to 1.5% by weight, Si 0.09 to
1.5% by weight, 0.008 to 0.15% by weight of Zr and 0.002 to 0.05% by weight of Ti,
The rough wire drawn from an aluminum alloy having a ratio of the number of i atoms, Mg / Si of 0.1 to 3.0, was measured at 430 ° C to 6 ° C.
Solution treatment at a temperature of 30 ° C. for 0.5 to 10 hours, 5 ° C. /
Cooling to room temperature at a cooling rate of not less than seconds, then performing cold working with a cross-sectional area reduction rate of 70% or more,
A method for producing an aluminum alloy wire, comprising performing a heat treatment at a temperature of 0 ° C. for 0.4 to 20 hours.

(2) The aluminum alloy is Cu 0.00
The method for producing an aluminum alloy wire according to the above (1), comprising at least one of 4 to 0.3% by weight and 0.08 to 1.5% by weight of Fe.

(3) When the aluminum alloy is Mg0.1
To 1.0% by weight, 0.1 to 1.0% by weight of Si, 0.
0.1-0.1% by weight and 0.002-0.05% by weight of Ti, the ratio of the number of Mg atoms to the number of Si atoms, Mg / Si
Is 0.2 to 2.0. The method for producing an aluminum alloy wire according to the above (1).

(4) The rough wire drawn from the aluminum alloy is subjected to a solution treatment at a temperature of 450 ° C. to 620 ° C. for 0.5 to 10 hours, and cooled to a normal temperature at a cooling rate of 5 ° C./sec or more. (3) The method for producing an aluminum alloy wire according to the above (3), which comprises performing cold working with a cross-sectional area reduction rate of 70% or more, and then performing heat treatment at a temperature of 120 ° C to 350 ° C for 0.5 to 20 hours.

(5) 0.08-1.5% by weight of Mg, S
i 0.09 to 1.5% by weight, Zr 0.008 to 0.15
% By weight and 0.002-0.05% by weight of Ti,
The ratio of the number of Mg atoms to the number of Si atoms, Mg / Si is 0.1 to
An aluminum alloy that is 3.0.

(6) When the aluminum alloy is Mg0.1
To 1.0% by weight, 0.1 to 1.0% by weight of Si, 0.
0.1-0.1% by weight and 0.002-0.05% by weight of Ti, the ratio of the number of Mg atoms to the number of Si atoms, Mg / Si
Is 0.2 to 2.0, the aluminum alloy wire of the above (5).

(7) The aluminum alloy wire according to (5) or (6), containing at least one of 0.004 to 0.3% by weight of Cu and 0.08 to 1.5% by weight of Fe.

(8) The aluminum alloy according to (5), (6) or (7), wherein an alloy wire produced from the aluminum alloy is used as a conductor of a power cable.

(9) A method for producing an aluminum alloy wire, comprising subjecting a rough drawn wire produced from an aluminum alloy to a solution treatment, cooling to room temperature, performing cold working, and then heat treating. The aluminum alloy according to the above (5), (6) or (7), which is characterized by the following.

In particular, 0.1-1.0% by weight of Mg, Si
0.1 to 1.0 wt%, Zr 0.01 to 0.1 wt% and Ti 0.002 to 0.05 wt%, the ratio of the number of Mg atoms to Si atoms, Mg / Si is 0.2 to Rough wire drawn from an aluminum alloy of 2.0
Solution treatment at a temperature of ~ 620 ° C for 0.5-10 hours,
Cooling to room temperature at a cooling rate of not less than 120 ° C./sec.
By performing the heat treatment at a temperature of 350 ° C. for 0.5 to 20 hours, a high-quality aluminum alloy wire can be efficiently manufactured.

[0016]

According to the present invention, Mg of 0.08 to
1.5 wt%, Si 0.09 to 1.5 wt%, Zr0.
008 to 0.15% by weight and Ti 0.002 to 0.0
5% by weight, the ratio of the number of Mg atoms to the number of Si atoms, Mg /
Aluminum alloy with 0.1 to 3.0 Si, or 0.004 to 0.3% by weight of Cu and / or F
(e) A rough drawn wire is manufactured by a continuous casting and rolling method from an aluminum alloy to which 0.08 to 1.5% by weight is added. By adding Ti as a component of the alloy, the solidification structure becomes fine isotropic crystals (equiaxed crystals) in the continuous casting and rolling process, so that the alloy wire cracks during rolling performed subsequent to casting. It becomes difficult.

Next, the rough drawn wire is subjected to a solution treatment at a temperature of 430 ° C. to 630 ° C. for 0.5 to 10 hours, and cooled to a room temperature at a cooling rate of 5 ° C./sec or more to obtain Mg, Si, Z
All or a part of each element of r, Cu and Fe is forcibly dissolved in the aluminum base. As a result, a structure having sufficient strength and heat resistance can be formed in the alloy wire by the subsequent cold working and heat treatment after the cold working.

In the subsequent cold working at a cross-sectional area reduction rate of 70% or more, Mg, Cu and Fe dissolved in the aluminum base increase the working hardness and increase the strength of the alloy wire. The structure introduced by this processing is stabilized up to a high temperature by the solid solution of Zr, and the alloy wire thus obtained is an alloy wire having both advantages of high strength and excellent heat resistance. Further, in the heat treatment after the cold working, the residual stress of the strongly worked structure is relaxed, and a part of Mg and Si precipitates as Mg ₂ Si to suppress a decrease in the strength of the alloy wire, and at the same time, suppress the aluminum base. The solid solubility of Mg, Si, and Fe therein decreases, and the conductivity improves.

The M of the aluminum alloy used in the present invention
The g content is between 0.08 and 1.5% by weight. If the Mg content is less than 0.08% by weight, the strength of the alloy wire due to cold working is insufficiently increased, while if it is more than 1.5% by weight, the conductivity of the alloy wire is reduced. The preferred Mg content is 0.1.
The content is 1 to 1.0% by weight, more preferably 0.2 to 0.8% by weight, and still more preferably 0.3 to 0.7% by weight.

The content of Si is 0.09 in the aluminum alloy.
~ 1.5% by weight. If it is less than 0.09% by weight, the increase in strength of the alloy wire by cold working becomes insufficient, and the precipitation of Mg ₂ Si due to heat treatment after cold working hardly occurs. On the other hand, when the Si content is more than 1.5% by weight, the electrical conductivity and the heat resistance decrease. The preferred Si content is 0.1-1.
0% by weight, more preferably 0.2 to 0.8% by weight, still more preferably 0.3 to 0.7% by weight.

The Zr content in the aluminum alloy is 0.00
8 to 0.15% by weight. If the content is less than 0.008% by weight, the heat resistance of the obtained alloy wire is not sufficient, while if it is more than 0.15% by weight, the electrical conductivity decreases. The preferred Zr content is 0.01 to 0.1% by weight, more preferably 0.02 to 0.08% by weight, and still more preferably 0.0 to 0.08% by weight.
3 to 0.07% by weight.

The content of Ti in the aluminum alloy is 0.00
2 to 0.05% by weight. When the content is less than 0.002% by weight, there is no effect of refining the solidified structure.
If it is more than 05% by weight, the electric conductivity is remarkably reduced. The preferred Ti content is 0.005 to 0.05% by weight, more preferably 0.01 to 0.03% by weight.

When Cu is used, its content is 0.004 to 0.3% by weight in the aluminum alloy. If the content is less than 0.004% by weight, the strength of the alloy wire due to cold working is insufficiently increased, and if it is more than 0.3% by weight, the conductivity of the alloy wire is reduced. A more preferred Cu content is 0.005 to 0.2% by weight, still more preferably 0.005 to 0.2% by weight.
8 to 0.15% by weight, particularly preferably 0.01 to
0.10% by weight.

When Fe is used, its content is 0.08 to 1.5% by weight in the aluminum alloy. If the content is less than 0.08% by weight, the strength of the alloy wire due to cold working is insufficiently increased, while if it is more than 1.5% by weight, the conductivity and heat resistance of the obtained alloy wire are reduced. More preferred F
e content is 0.1 to 1.0% by weight, more preferably 0.02 to 0.15% by weight, particularly preferably 0.02 to 0.15% by weight.
3 to 0.10% by weight.

The ratio of the number of Mg atoms to the number of Si atoms contained in the alloy, Mg / Si is 0.1 to 3.0, preferably 0.1 to 3.0.
It is adjusted to 2 to 2.0, more preferably 0.5 to 1.6, and still more preferably 0.8 to 1.5. When the ratio is less than 0.1, the heat resistance and the electrical conductivity of the alloy wire obtained by excessively adding Si to the Mg ₂ Si precipitated during the heat treatment after the cold working are reduced, while the ratio is less than 3.0. Is too large for Mg ₂ Si
In contrast to this, Mg becomes excessive and not only decreases the conductivity of the alloy wire but also lowers the deposition rate of Mg ₂ Si, so that the optimal heat treatment conditions differ significantly depending on the components used.

The aluminum alloy used in the present invention may contain ordinary impurities (such as Zn) which are usually contained (about 0.001% by weight or less).
It is desirable to keep the content of elements that lower the conductivity, such as V and Mn, low. Boron treatment by addition of an Al-B or Al-Ti-B mother alloy may be performed at the stage of the base metal.

A rough drawn wire is manufactured from an aluminum alloy having such a composition by a continuous casting and rolling method. The continuous casting and rolling method of the rough drawing wire used in the present invention is not particularly limited,
Well-known methods such as the Properch method, the Hesley method, the SCR method, and the Speedem method can be adopted. Preferable is the Properch method, for example, pouring molten metal into a gap formed between a rotating water-cooled copper mold wheel and a steel belt, and continuously removing the solidified aluminum alloy bar while the wheel rotates about 3/4, The bar is directly introduced into a multi-high rolling mill to finish it into a rough drawing line.

For example, a diameter of 8 mm
A rough drawing line of about 15 mm is obtained, but the casting temperature is 7
00-900 degreeC is preferable. The bar obtained is 100
It is desirable to perform rolling at a cross-sectional area reduction rate of 80% or more until the temperature becomes lower than or equal to ° C.

After the obtained rough drawn wire is subjected to a solution treatment at a temperature of 430 ° C. to 630 ° C. for 0.5 to 10 hours, it is cooled to a normal temperature at a cooling rate of 5 ° C./sec or more. If the solution treatment temperature of the rough drawn wire is lower than 430 ° C., the added element is not sufficiently dissolved. On the other hand, if the temperature is higher than 630 ° C., the crystal grains become coarse, the surface of the rough drawn wire is oxidized, and Mg is preferentially oxidized on the surface of the rough drawn wire. Characteristics may be degraded. The preferred solution treatment temperature is 450 ° C to 620 ° C, more preferably 480 ° C to 6 ° C.
00 ° C.

If the solution treatment time is less than 0.5 hour, the added element does not form a solid solution sufficiently, and if the solution treatment time is more than 10 hours, the crystal grains become coarse, the rough line surface is oxidized, and the Mg on the rough line surface is Mg.
Not only does the preferential oxidation of the solution proceed, but an unnecessarily long solution treatment increases the production cost. The preferred solution treatment time is 1 to 8 hours.

If the cooling rate after the solution treatment is less than 5 ° C./sec, the precipitation of Mg, Si, Fe, etc. proceeds during the cooling, and not only the added element cannot be sufficiently dissolved, but also Decreases workability in cold working. A preferred cooling rate is at least 8 ° C./sec. The upper limit is not particularly limited, but is preferably about 100 ° C./sec. The cooling method is not particularly limited, but is performed, for example, by immersing in water or the like.

Subsequently, the rough drawn wire is subjected to cold working at a normal temperature (0 to 30 ° C.) with a cross-sectional area reduction rate (a ratio of a reduced cross-sectional area to a cross-sectional area before processing) of 70% or more. If the cross-sectional area reduction rate is less than 70%, sufficient work hardening cannot be obtained, and the strength of the obtained alloy wire is insufficient. Further, sufficient work hardening cannot be obtained by warm working or hot working. The cross-sectional area reduction rate of the preferred cold working is 80% or more. The upper limit is not particularly limited, but is approximately 98%.

The cold working method may be any working method such as drawing using a normal hole die, rolling using a roll, and swaging, but the preferred working method is drawing using a hole die. is there.

[0034] The cold-worked wire is further heated to 110 ° C to 3 ° C.
Heat treatment is performed at a temperature of 60 ° C. for 0.4 to 20 hours. If the heat treatment temperature is lower than 110 ° C., it takes a very long time to generate a compound of Mg and Si, so that the heat treatment cost increases. If the temperature is higher than 360 ° C., softening due to overaging becomes remarkable, and strength and elongation decrease.

On the other hand, if the heat treatment time is less than 0.4 hours, the strength and conductivity of the obtained alloy wire are not sufficiently improved, while if the heat treatment time is more than 20 hours, the alloy wire is overaged and the strength and elongation are reduced. Instead, the heat treatment cost increases. Preferred heat treatment conditions are 120 to 350 ° C. and 0.5 to 20.
Time, more preferably at 150 ° C. to 300 ° C. for 1 to 10 hours.

The aluminum alloy wire thus obtained has, for example, a diameter of 3.5 mm and a tensile strength of 260 Mpa.
Above, elongation 5% or more, conductivity 56% or more, and heat resistance 2
It can have a performance of 50 ° C. or more. Alternatively, it has a diameter of 3.5 mm, a tensile strength of 300 Mpa or more, and an elongation of 4
% Or more, conductivity of 53% or more, and heat resistance of 230 ° C. or more.

[0037]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. Example 1 An alloy having a composition shown in Table 1 was continuously cast and rolled by a propelting method to obtain a rough drawn wire having an outer diameter of 9.5 mm. At that time, the presence or absence of rolling cracks was visually checked with an overcurrent flaw detector. Table 1 shows the results. After subjecting the rough drawn wire to a solution treatment at 620 ° C. for 0.5 hour, it was cooled to room temperature at a rate of 10 ° C./sec. Next, a cold working with a cross-sectional area reduction rate of 90% was performed to obtain an aluminum alloy wire (strand), and further, a wire heat treatment was performed at 350 ° C. for 0.5 hour to obtain a conductive aluminum alloy wire. The resulting alloy wire was evaluated for tensile strength, elongation, electrical conductivity, and heat resistance. Tensile strength and elongation were measured based on JISZ2241, and conductivity was measured based on JISH0505. The heat resistance was measured at a temperature at which the tensile strength was reduced to 90% of that before heating by heating for 1 hour. Table 2 shows the results.

Examples 2 to 10 and Comparative Examples 1 to 10 Using alloys having the compositions shown in Table 1, the solution treatment conditions and cooling rates shown in Table 1 and the cold treatments and reductions of the cross-sectional area reduction rates shown in Table 2 were carried out. Under the conditions of wire heat treatment, a conductive aluminum alloy wire was obtained in the same manner as in Example 1. In the same manner as in Example 1, the presence or absence of rolling cracks, tensile strength, elongation, conductivity, and heat resistance were evaluated. Table 1 shows the state of occurrence of cracks during continuous casting and rolling, and Table 2 shows the properties (tensile strength, elongation, conductivity, and heat resistance) of the aluminum alloy wire for conductivity. Comparative Examples 8 to 10
For, cracks occurred during continuous casting and rolling, and the subsequent evaluation could not be performed.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

According to the method of the present invention, for example, a diameter of 3.
Tensile strength of 260 Mpa or more, 5% or more elongation, conductivity of 56% or more and heat resistance of 250 ° C. or more, or tensile strength of 300 Mpa or more, elongation of 4% or more, conductivity of 53% or more with 5 mm wire High-strength heat-resistant aluminum alloy wire with high quality, which has both heat resistance and heat resistance of 230 ° C or higher, does not crack during alloy rolling, and the optimal heat treatment conditions do not differ significantly depending on the components. It can be manufactured easily, with good yield, and stably.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C22F 1/00 630 C22F 1/00 630A 650 650A 661 661A 685 685Z 691 691B 691C 692 692A

Claims (9)

[Claims] 1. An alloy containing 0.08 to 1.5% by weight of Mg and 0.1% by weight of Si.
09-1.5% by weight, Zr 0.008-0.15% by weight
430, a rough wire drawn from an aluminum alloy containing 0.002 to 0.05% by weight of Ti and having a ratio of the number of Mg atoms to the number of Si atoms, and Mg / Si of 0.1 to 3.0.
Solution treatment at a temperature of from 0 to 630 ° C for 0.5 to 10 hours,
Cool to room temperature at a cooling rate of 5 ° C./sec or more, then perform cold working with a cross-sectional area reduction rate of 70% or more, and then 110 ° C.
A method for producing an aluminum alloy wire, comprising performing a heat treatment at a temperature of about 360 ° C. for 0.4 to 20 hours. 2. An aluminum alloy having a Cu content of 0.004 to
2. The method for producing an aluminum alloy wire according to claim 1, wherein the aluminum alloy wire contains at least one of 0.3% by weight and 0.08 to 1.5% by weight of Fe. 3. The method according to claim 1, wherein the aluminum alloy is Mg 0.1-1.
0 wt%, Si 0.1-1.0 wt%, Zr0.01-
0.1% by weight and 0.002 to 0.05% by weight of Ti, and the ratio of the number of Mg atoms to the number of Si atoms, Mg / Si is 0.1%.
2. The method for producing an aluminum alloy wire according to claim 1, wherein the number is 2 to 2.0. 4. A wire drawn from an aluminum alloy is subjected to a solution treatment at a temperature of 450 ° C. to 620 ° C. for 0.5 to 10 hours, and cooled to a normal temperature at a cooling rate of 5 ° C./second or more.
4. The method for producing an aluminum alloy wire according to claim 3, wherein the aluminum alloy wire is subjected to cold working at a cross-sectional area reduction rate of 70% or more, and then heat-treated at a temperature of 120C to 350C for 0.5 to 20 hours. 5. An alloy containing 0.08 to 1.5% by weight of Mg and 0.1% by weight of Si.
09-1.5% by weight, Zr 0.008-0.15% by weight
And an alloy containing 0.002 to 0.05% by weight of Ti, and the ratio of the number of Mg atoms to the number of Si atoms, and Mg / Si is 0.1 to 3.0. 6. The method according to claim 1, wherein the aluminum alloy is Mg 0.1-1.
0 wt%, Si 0.1-1.0 wt%, Zr0.01-
0.1% by weight and 0.002 to 0.05% by weight of Ti, and the ratio of the number of Mg atoms to the number of Si atoms, Mg / Si is 0.1%.
6. The aluminum alloy wire according to claim 5, which is 2 to 2.0. 7. 0.004 to 0.3% by weight of Cu and F
7. The aluminum alloy wire according to claim 5, wherein the aluminum alloy wire contains at least one of 0.08 to 1.5% by weight. 8. The aluminum alloy according to claim 5, wherein an alloy wire manufactured from the aluminum alloy is used as a conductor of a power cable. 9. A method for producing an aluminum alloy wire, which comprises subjecting a rough drawn wire produced from an aluminum alloy to a solution treatment, cooling to room temperature, cold working, and then heat treating. The aluminum alloy according to claim 5, 6 or 7, wherein