JPS6052546A - Heat resistant aluminum alloy for electrical conduction and its production - Google Patents

Abstract

PURPOSE:To provide a titled Al alloy which has particularly the strength equiv. to the strength of the conventional heat resistant Al alloy for electrical conduction and has remarkably improved heat resistance without decreasing electrical conductivity by incorporating Ni, Fe, and Be respectively at a prescribed ratio and the balance Al and ordinary impurities. CONSTITUTION:The above-described Al alloy contains, by weight %, 0.5-5.7% Ni, 0.1-2.0% Fe and 0.03-1.0% Be and consists of the balance Al and ordinary impurities. Such heat resistant Al alloy for electrical conduction is cast by casting the Al alloy having the above-described compsn. by ordinary continuous or semi- continuous casting. The resulted casting ingot in then hot-rolled to a roughly drawn wire which is cold-drawn and is heat-treated for 0.5-10hr at 200-500 deg.C Namely, the strength and electrical conductivity of the drawn article are adjusted and the heat resistance is provided thereto by such heat treatment. The resulted heat resistant Al alloy for electrical conduction has the remarkable effect of increasing power transmission capacity when used for a conductor such as a steel cored heat resistant Al alloy stranded wire.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-resistant aluminum alloy for conductive use and its manufacturing method, and in particular, it has a strong strength equivalent to that of the conventional heat-resistant aluminum alloy for conductive use (AJ!-Zr alloy). However, heat resistance has been elegantly improved without significantly reducing conductivity.

Conventionally, copper-core aluminum wires using conductors with a temperature of 4°C have been used for overhead power transmission lines.
In particular, for power transmission lines where heat resistance is required, cored heat-resistant aluminum alloy stranded wires using conductors made of solid-solution type steel heat aluminum alloy using solid solution/r heat-resistant machines of F-Zr alloy are used. It is used. In recent years, there has been a demand for improved heat resistance due to the increase in electricity demand, and in response to this demand, we have developed a heat-resistant aluminum alloy for conductive use with increased -C solid solution 7rfi.
ゝ) In place of the heat-resistant mechanism of solid solution 7r) (it!; 7
A heat-resistant aluminum alloy for conductive use has been developed that utilizes the heat-resistant mechanism of r.

However, solid solution 7r part 1:! An increase in Z leads to a decrease in electrical conductivity, and in order to take advantage of the heat resistance mechanism of the precipitated Z, it is necessary to
Since it requires heat treatment at a temperature of 00 to 450° C. for a long time, it has the disadvantage of high cost. g: The usable screen temperature of these alloys when energized is approximately 300°C, and further improvement in heat resistance is strongly desired.

In view of this, as a result of various studies, the present invention has a strength equivalent to that of conventional heat-resistant aluminum alloy for conductivity (Af-1''r alloy), and has heat resistance without significantly lowering the conductivity. We have developed a heat conductive aluminum alloy with significantly improved properties and a method for producing it.

That is, the alloy of the present invention is Nio, 5-5.7W1%, FQO1
1-2. OW [%, [3e O, 03-1, Owl:%
and the remainder (and normal impurities).

Mata manufacturing method of the present invention 1tN! 0.5-5.7wt%
, FeO,1=2,0wt%, BeO,03-1,0
After continuous or semi-continuous casting, an aluminum alloy consisting of normal impurities is hot-rolled to form a rough drawn wire, which is then cold-drawn to form a rough drawn wire.
It is characterized by heat treatment at a temperature of 0.000C for 0.5 to 10 hours.

However, the reason why the alloy composition is limited as described above in the present invention is as follows.

The reason for limiting the N1 content to 0.5 to 5.7 wt% (hereinafter wt% is simply abbreviated as %) is that the addition of Ni makes the A soft
This is to improve the strength and heat resistance +41 as a eutectic structure in which Ni AC3 is dispersed in the mixture, but if the content is less than 0.5%, the strength and heat resistance are insufficient. If it exceeds .7%, primary NiA will be present in the metal structure.
This is because the Puntoli 1 phase of E3 is crystallized, which not only impairs workability but also lowers ductility.

[The e content was limited to 0.1 = 2.0% because of the addition of N1 (Although the strength and heat resistance are improved by dispersing N1Af! and 3 in J, /'! Pure△(
Therefore, the strength is insufficient, and in order to obtain high strength, Ni
It is necessary to increase the Ni content, and for this reason, FC is added to strengthen Δ(71~) and reduce the Ni content.
[2] The effect is insufficient if the e content is less than 0.1%.
This is because if it exceeds 0%, the conductivity will drop significantly.

In addition, corrosion resistance of 1J was improved by limiting the lee content to 0.03 and 1.0%, but if it is less than 0.03%, the effect will be small. This is because if it exceeds 1.0%, the conductivity will drop significantly.

Other impurities include ordinary electrical A (contained in the base metal), and impurities of this level do not impair the properties of the alloy in any way.

The alloy of the present invention has the above-mentioned composition and is cast by conventional continuous or semi-continuous casting, and the obtained ingot is hot rolled into a rough drawn wire, which is then cold wire drawn and then rolled to a
It is produced by heat treatment at a temperature of 0.5 to 10 hours.

0.5-1 at a temperature of 200-500℃ after cold wire drawing
The purpose of heat treatment for 0 hours is to improve strength and conductivity as well as impart heat resistance. ! ! temperature is 2
Even if the temperature is lower than 00°C, the conductivity cannot be recovered even if the treatment time is less than 0.5 hours, and especially if the treatment time is short, the heat resistance cannot be improved. Also, even if the processing temperature exceeds 500℃, the processing time will be 10
Even if the time is exceeded, the strength decreases significantly.

The present invention will be described in detail below with reference to Examples.

Electrical A (base metal and A (-6% Fe, Δ) with purity of 99.8%
(-10%Ni, Δ(-5%Bc) mother alloys were used to blend and melt alloys having the compositions shown in Table 1.

This was casted using a belt-and-wheel continuous casting machine, and the resulting ingot was subsequently hot-rolled to a diameter of 9.5mm.
A rough line of 5 mm was used. This roughly drawn wire was cold-drawn into a wire with a diameter of 4.5 mm, and the wire was heat-treated at various temperatures to produce conductors.

The electrical conductivity, tensile strength, heat resistance, and corrosion resistance of this conductor were measured. These results are also listed in Table 1 in comparison with a conventional conductive heat-resistant aluminum alloy (An-zr alloy).

The conductivity was calculated by measuring resistance using a Kelvin double bridge, and the strength was measured using an Amsler type tester.

Heat resistance was expressed as the temperature at which the strength decreased by 10% after 1 hour of heat treatment. Corrosion resistance was measured using 5% Na (a spray test was conducted for 100 days and expressed as the weight loss rate).

6-Table 1 Production method NO alloy composition (%) Heat treatment Ni Fe Be Af Temperature (°C) Bi) iJ (
hr) Method of the present invention 1 0.8 0.5 0.05 Remaining
200 8n 2 II 1.4 0.08, + 6
〃3 3.1 1.0 0.36 〃4n 4 II
1,8 0.33 n 350 2〃5 5.6 1.
3 0.82 n 450 3〃6 〃1.0 0.9
0〃6 Comparative method 7 0.3 〃0.31 〃350 4〃 8
6.5 〃 〃 n n 9 3,0 0.05 /l,.

// 1Q n 3. Q tt u 〃11 /j 1.0 0.01 , /II 12 1
/ n i,5 n n 13 1/ n O,3〃100 n i4 nn n n 55Q n i5 n /7 1J 11 35Q 00iJl
i(i 11 n // II i5 Conventional method 17(
Af2-0.2 Fe-0,3Zr) --Conductivity Tensile strength 10% softening Corrosion resistance%IAC8)
(Kg/mtrr”) Temperature (%) (%)60.6
17.5 380 0.5260.2 17.8 4
00 0.6i60.2 17.2 > 500 0.
4360.0 18.1 :〉500 0.7258.
2 17.2 > 500 0.6458.9 18,
0 1:n500 0.5561.6 1? ,0 24
0 0.6254.1 17,9 440 0.785
9.8 14.4 > 500 0.7256.6 1
7.6 >, 500 Q, 6659.9 18.0 >
500 2.7856.9 17.7), 500 0
．． 4855.1 17.2 480 0.5660.3
14.6 >, 500 0.6254.2 25.
1 290 0.5859.9 15.2 Knee 50
0' 0.7158.2 16,9 320 0.5
57- As is clear from Table 1, the alloy of the present invention was prepared using the method of the present invention N091.
~6! Conductor manufactured by IJ
C3 or higher, tensile strength 17.2Kg/mm2 or higher”-1
It shows the characteristics of 10% softening temperature of 380℃ or higher and weight loss rate of 0.72% or lower,
, 17, the heat resistance is significantly superior, and the other properties are not significantly different.

On the other hand, as shown in Comparative Method No. 7-12, those which are outside the composition range of the alloy of the present invention are inferior in electrical conductivity, tensile strength, heat resistance, and corrosion resistance. That is, the heat resistance was not improved in Comparative Method No. 7, which had a low N1 content, and Comparative Method No. 8, which had a high Ni content, and Comparative Method N, which had a high e content.
Comparative method No. 0.12, which has a high content of Be, 10, and 3e, all showed a severe decrease in conductivity, while comparative method No. 9, which had a low e content, did not improve the strength, and Comparative method No. 11, which has less corrosion resistance, has improved corrosion resistance by 4f.

Further, as can be seen from Comparative Method No. 13-16, even within the composition range of the alloy of the present invention, if the heat treatment conditions after cold wire drawing are different, any of the conductivity, strength, and heat resistance will be inferior. That is, the conductivity did not recover in Comparative Method No. 13, which had a low heat treatment temperature, and Comparative Method No. 13, which had a high heat treatment temperature.

14 and comparative method N with long heat treatment time (1 and 16 have deteriorated strength, comparative method N0115T with short heat treatment time:
has poor electrical conductivity, strength and heat resistance.

As described above, according to the present invention, the strength is equivalent to that of the conventional heat-resistant aluminum alloy for conductivity (ΔfA-Zr alloy), and the heat resistance can be significantly improved with almost no decrease in conductivity. It is used for conductors such as core heat-resistant aluminum 11 alloy stranded wires, and has a remarkable effect on increasing power transmission capacity.

9-

Claims (2)

[Claims] (1) Ni 0.5-5.7wt%, FeO,1
~2. A conductive heat-resistant aluminum 11 alloy containing 03 to 1.0 wt% of B e O, and the remainder Δ (and normal impurities. (2) N i 0.5 = 5.7wt%, Fe Oo
l ~2. Owt%, B a O,03-1,0wt%
to the remainder (and the usual impurities)
1 alloy was continuously cast to 31 tons or half inch, hot-rolled to form a rough wire, which was then cold-drawn to form a 20-inch wire.
Heat treatment at a temperature of 0 to 500°C for 0.5 to 10 hours T! I
! A method for producing a heat-resistant aluminum alloy for conductive use.