KR101034862B1 - Non-heat Treatment Type Aluminum Alloy for overhead conductor - Google Patents

Abstract

[0001] The present invention relates to an aluminum alloy material for a working transmission line having high heat resistance and high conductivity, and more particularly, to an aluminum alloy material for a working transmission line, 0.05, Y 0.01 to 0.03, and MM 0.01 to 0.03 are added to the aluminum alloy material for a non-heat-treated working power transmission line. Accordingly, various kinds of fine precipitates can be formed in the matrix to improve the heat resistance. In addition to improving the conductivity by minimizing the addition amount of the additive elements that may cause the component segregation, the heat treatment for forming the fine precipitates It is possible to improve the productivity several times as compared with the conventional production process, and it is advantageous in that the product cost can be lowered

Processing Transmission line Aluminum alloy High heat resistance High conductivity Non-heat treatment Additive element

Description

[0001] The present invention relates to a non-heat treatment type aluminum alloy for overhead conductor,

The present invention relates to an aluminum alloy material for machined transmission line, in which Y, MM (Misch metal) and Zr are added as heat resistance improving factor elements and at the same time, the addition amount is minimized to reduce segregation of additional elements, To an economical aluminum alloy material for a working transmission line, having high heat resistance and high conductivity.

Generally, an aluminum alloy material that combines both high heat resistance and high conductivity is indispensable for aluminum materials required for processing transmission lines for increasing transmission capacity.

Metallurgically, the heat resistance of a material can be achieved by uniformly and finely distributing precipitates, such as intermetallic compounds, in the matrix, thereby suppressing the movement of grain boundaries at high temperatures.

Further, the high conductivity property minimizes the addition amount of the additive alloy element, and further, the added alloy elements are not dissolved in the matrix metal as possible, and the alloy can be formed by precipitation with an intermetallic compound.

In order to realize the high heat resistance and high conductivity required in the case of aluminum for processing transmission line to increase current transmission capacity, a large amount of Zr component is added at 0.25 to 0.3 weight ratio as a heat resistance property improving factor, and it is heat treated for a long time at high temperature, Fine Al ₃ Zr precipitates having a size of several hundreds of nanometers are uniformly distributed in the aluminum matrix, thereby suppressing the movement of grain boundaries and improving the conduction characteristics.

However, the melting point of the Zr element is 1,852 ° C, which is much higher than that of the base component Al (melting point 660 ° C), and the specific gravity is also about three times larger (the specific gravity of Zr is 6.49 and the specific gravity of Al is 2.70) And Zr are mutually non-solid, they are not easily alloyed with the Al component, resulting in various metallurgical problems in manufacturing.

The biggest problem among them is the fatal Zr component segregation in the material. Segregation of constituents in the manufacture of alloy metal materials is not very desirable from the standpoint that the material properties originally designed as the target are not properly realized and that the material properties can be weakened. In particular, . This is because when the wire diameter is reduced by drawing, the local segregation in the thin wire leads to the disconnection of the wire.

Since the atomic radius of the Zr atom is much larger than that of 14.3 nm of Al at 14 nm and the melting point is also very high, the diffusion rate of Zr atoms in the Al base in the heat treatment is very slow, and in order to precipitate the Al ₃ Zr- Lt; 0 > C or more for 48 hours or longer. This heat treatment process not only has a large effect on the increase of the unit price of the product, but also has a problem of significantly reducing the productivity because it uses a batch-type heat treatment furnace.

Accordingly, the present invention solves the problem that the conventional heat resistance improving factor causes various problems in the manufacturing process. Heretofore, a method of securing the heat resistance characteristic depending on only the Zr element has been adopted. However, It is possible to add Y, MM (Misch metal) and Zr as the factor elements, minimize the addition amount at the same time, significantly reduce the segregation of the additive elements, omit the heat treatment step, The object of the present invention is to provide an aluminum alloy material for a high-conductivity non-heat-treated processed power transmission line.

In order to achieve the above object, the present invention provides an aluminum alloy material for a working power transmission line, which comprises Zr 0.01 to 0.05, Y 0.01 to 0.03, and MM 0.01 to 0.03 in terms of parts by weight based on aluminum alloy, 0.03 is added to the aluminum alloy material for the non-heat-treated working power transmission line.

The aluminum alloy material for the high heat-resistant high-conductivity processed transmission line preferably has a tensile strength of 16.2 (kgf / mm 2) or more, an electrical conductivity of 60% (IACS) or more, and a heat resistance of 90% or more.

According to the present invention, various heat resistant characteristics improving elements such as Y, MM (Misch metal), and Zr elements are added to form various types of fine precipitates in a matrix to improve heat resistance. It is possible to improve the conductivity by minimizing the addition amount of the additive elements which may cause the segregation of components and also to improve the productivity several times as compared with the conventional production process by eliminating the heat treatment step for forming the fine precipitates, There is an effect that can be.

Unlike the conventional method of forming only fine precipitates of Zr component to improve heat resistance, a large number of heat resistance improving elements such as Y, MM (Misch metal) and Zr elements are added, Thereby improving heat resistance.

Table 1 below summarizes the types of fine precipitates formed depending on the kinds of the additive elements.

<Table 1> Types of fine precipitates by additive elements

Additive element Melting point () Density (g / cc) Precipitate Fe 1,536 7.86 Al ₃ Fe Y 1,509 4.47 Al ₂ Y MM (Misch Metal) ~ 920 6.17 Al ₄ Ce, Al ₄ La Zr 1,852 6.49 Al ₃ Zr

In order to improve the heat resistance, the added amount of the elements is aluminum alloy material for the entire working transmission line, except for Fe and other unavoidable impurities, and is an additive element for improving the heat resistance property, and Zr 0.01-0.05, Y 0.01-0.03, MM to 0.01 to 0.03. Here, MM (misch metal) refers to an alloy of a cerium metal, which is a rare earth element.

The added amount of the added element is in the order of 0.0X to 0.00X, which is very small compared to the conventional case. This is because, when the additive element is added to the Al component in excess of that of the Al component, if the additive element is added in excess, it may cause the segregation of components as in the case of the conventional Zr component, Therefore, it is preferable to suppress the possible addition amount.

Further, there is a great advantage that a heat treatment step for forming a fine precipitate is not necessary by minimizing the addition amount of the additive element. When the heat treatment process is omitted, the productivity can be improved several times as compared with the conventional production process, and the product cost can be greatly reduced.

In the following Table 2, properties of the aluminum alloy material according to the present invention were evaluated according to the addition amount of the ingredient element and the amount of the ingredient element of the conventional aluminum alloy material, and the alloy composition ratio and the electrical conductivity, Heat resistance characteristics are summarized.

Here, the conventional aluminum alloy material has been subjected to a long-time heat treatment at a high temperature of 450 ° C or more for 48 hours or more in order to precipitate the Al ₃ Zr ruthenium phase. In the present invention, a heat treatment process for forming fine precipitates with a small amount of additive elements You do not have to do it.

<Table 2> Composition of aluminum alloy material with high heat resistance and high conductivity

No. Fe Zr Y MM Al Electrical conductivity
(% IACS) The tensile strength
(kgf / mm ² ) Heat resistance
(%) example
foot
persons

synthesis
gold
article
castle One 0.11 0.05 0.01 0.01 Honey. 60.3 17.0 90.5 2 0.11 0.05 0.02 0.02 Honey. 61.0 19.4 91.2 3 0.11 0.05 0.03 0.03 Honey. 60.5 20.9 92.0 4 0.11 0.04 0.01 0.01 Honey. 60.2 21.0 94.0 5 0.11 0.04 0.02 0.02 Honey. 61.2 18.0 90.8 6 0.11 0.04 0.03 0.03 Honey. 60.1 16.9 92.2 7 0.11 0.03 0.01 0.01 Honey. 61.1 17.7 92.0 8 0.11 0.03 0.02 0.02 Honey. 61.0 20.9 92.3 9 0.11 0.03 0.03 0.03 Honey. 60.2 19.4 93.3 10 0.11 0.02 0.03 0.03 Honey. 60.3 20.1 95.5 Bell
Ra
of
synthesis
gold
article
castle 11 0.11 0.2 Honey. 61.2 17.5 92.5 12 0.11 0.25 Honey. 60.8 17.0 93.3 13 0.11 0.3 Honey. 60.5 16.8 92.8 14 0.11 0.35 Honey. 61.5 17.1 91.9

The characteristics of the aluminum alloy material of the processing transmission line for increasing the transmission capacity are strictly defined by KEPCO purchase specifications. The tensile strength of the aluminum wire of the working transmission line is specified to be 16.2 (kgf / mm ² ) or more, the electric conductivity is 60 (% IACS) or more, and the heat resistance is 90 (%) or more. Therefore, products that can be used in the transmission line must satisfy this requirement.

   It can be seen that all of the alloy compositions of the present invention satisfy the specified values. Therefore, instead of significantly reducing the amount of Zr component added in the prior art, only a small amount of other heat resistance improving components were added to satisfy the tensile strength, electrical conductivity and heat resistance characteristics, and the same characteristics as those of conventional products were obtained without heat treatment There is an economical advantage.

Claims (2)

In an aluminum alloy material for a working transmission line, Characterized in that 0.01 to 0.05 parts by weight of Zr, 0.01 to 0.03 parts by weight of Y and 0.01 to 0.03 parts by weight of MM are added as an additive element for improving the heat resistance of aluminum to 100 parts by weight of the aluminum alloy material, Aluminum alloy material for. The non-heat-treated type aluminum ingot according to claim 1, wherein the aluminum alloy material for the working transmission line has a tensile strength of 16.2 (kgf / mm &lt; 2 &gt;) or more, an electrical conductivity of 60 Aluminum alloy material for processing transmission line.