阅读说明：本技术 一种高导电率软铝单丝及其制备方法 (High-conductivity soft aluminum monofilament and preparation method thereof ) 是由 陈保安 陈新 赵丽丽 祝志祥 张强 丁一 杨长龙 李悦悦 潘学东 韩钰 张宏宇 于 2019-10-30 设计创作，主要内容包括：本发明提出了一种高导电率软铝单丝,其包括按质量百分比计的下述组分：B 0.01％-0.02％、Er 0.05％-0.2％、Si≤0.06％、Fe≤0.2％、(V+Ti+Cr+Mn)≤0.015％,其余为Al和不可避免的杂质；本发明提供的高导电率硬铝导线延伸率可达35％,导电率可达63.5％IACS,可降低线路损耗4％以上,本发明提供的制备方法操作简单,可靠性高,适用于流水线生产。(The invention provides a high-conductivity soft aluminum monofilament, which comprises the following components in percentage by mass: 0.01 to 0.02 percent of B, 0.05 to 0.2 percent of Er, less than or equal to 0.06 percent of Si, less than or equal to 0.2 percent of Fe, (V + Ti + Cr + Mn) less than or equal to 0.015 percent, and the balance of Al and inevitable impurities; the elongation of the high-conductivity duralumin conductor provided by the invention can reach 35%, the conductivity can reach 63.5% IACS, the line loss can be reduced by more than 4%, and the preparation method provided by the invention is simple to operate, high in reliability and suitable for flow line production.)

1. The high-conductivity soft aluminum monofilament is characterized in that the monofilament is prepared from raw materials of industrial pure aluminum with purity of more than or equal to 99.7%, Al-B intermediate alloy and Al-Er intermediate alloy, and comprises the following components in percentage by mass: 0.01 to 0.02 percent of B, 0.05 to 0.2 percent of Er0.05 percent of Si, less than or equal to 0.06 percent of Fe, less than or equal to 0.2 percent of (V + Ti + Cr + Mn), and the balance of Al and inevitable impurities.

2. A soft aluminum monofilament with high conductivity as claimed in claim 1, wherein said soft aluminum monofilament comprises: 0.01 percent of B, 0.05 percent of Er, less than or equal to 0.05 percent of Si, less than or equal to 0.15 percent of Fe, (V + Ti + Cr + Mn) less than or equal to 0.015 percent, and the balance of aluminum and inevitable impurities.

3. A soft aluminum monofilament with high conductivity as claimed in claim 1, wherein said soft aluminum monofilament comprises: 0.01-0.02% of B, 0.05-0.2% of Er, 0.06% of Si, 0.18% of Fe, (V + Ti + Cr + Mn) is 0.013%, and the balance of aluminum and inevitable impurities.

4. A soft aluminum monofilament with high conductivity as claimed in claim 1, wherein said soft aluminum monofilament comprises: 0.02% of B, 0.2% of Er, 0.04% of Si, 0.15% of Fe, (V + Ti + Cr + Mn) is 0.015%, and the balance is aluminum and inevitable impurities.

5. The method for preparing a high-conductivity soft aluminum monofilament as claimed in claims 1 to 4, wherein the method comprises the steps of mixing the raw materials:

(1) smelting;

(2) refining;

(3) casting;

(4) and (6) rolling.

6. The method for preparing the soft aluminum monofilament with high conductivity as claimed in claim 5, wherein the step 1) comprises melting the raw materials at 730-760 ℃ and standing for 15-30 min.

7. The method for preparing the soft aluminum monofilament with high conductivity as claimed in claim 5, wherein the aluminum ingot and the Al-B intermediate alloy are smelted at 740-760 ℃, and after standing for 15-20min, the Al-Er intermediate alloy is added at 730-750 ℃ for smelting, and then standing for 20-30 min.

8. The method for preparing a soft aluminum monofilament with high conductivity as claimed in claim 5, wherein the step 2) comprises: blowing N into the molten liquid obtained in the step 1) with the temperature reduced to 710-730 DEG C₂5-10min or 0.3% -0.5% of C₂Cl₆Standing for 15-20min, and removing slag.

9. The method for preparing a soft aluminum monofilament with high conductivity as claimed in claim 5, wherein the step 3) comprises: the aluminum alloy liquid is poured into the die at the temperature of 700-720 ℃.

10. The method for preparing the soft aluminum monofilament with high conductivity as claimed in claim 5, wherein the soft aluminum monofilament is obtained by heat preservation at 300-350 ℃ for 4-8h after the rolling in the step 4).

11. The method for preparing the soft aluminum monofilament with high conductivity as claimed in claim 10, wherein the round aluminum alloy rod with a diameter of 9.5mm is obtained by 5 passes of rolling at 530 ℃ and 540 ℃, and then the monofilament with a diameter of 3-4mm is obtained by 8-12 passes of drawing.

Technical Field

The invention relates to a preparation method of an electrical conductor material, in particular to a high-conductivity soft aluminum monofilament and a preparation method thereof.

Background

The characteristics of energy centralized distribution and economic development determine that large-capacity, low-loss and long-distance power transmission must be carried out. The rapid development of power grid construction also puts higher requirements on the performance of overhead conductors. The steel-cored aluminum strand of one of the most applied conductors in the overhead transmission line accounts for more than 80% of the whole conductor type, so that the optimization of the performance of the steel-cored aluminum strand is required by the development of electric energy and has great economic benefit.

Chinese patent CN201610388851 discloses a low-cost 63% IACS high-conductivity duralumin conductor and its manufacturing method, however, its conductivity and elongation still cannot meet the requirement of power grid construction development.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a high-conductivity soft aluminum monofilament and a preparation method thereof.

The technical scheme provided by the invention is as follows:

the high-conductivity soft aluminum monofilament is prepared by taking industrial pure aluminum with the purity of more than or equal to 99.7%, Al-B intermediate alloy and Al-Er intermediate alloy as raw materials, and comprises the following components in percentage by mass: 0.01 to 0.02 percent of B, 0.05 to 0.2 percent of Er0.05 percent of Si, less than or equal to 0.06 percent of Fe, less than or equal to 0.2 percent of (V + Ti + Cr + Mn), and the balance of Al and inevitable impurities.

Further, the soft aluminum monofilament comprises: 0.01 percent of B, 0.05 percent of Er, less than or equal to 0.05 percent of Si, less than or equal to 0.15 percent of Fe, (V + Ti + Cr + Mn) less than or equal to 0.015 percent, and the balance of aluminum and inevitable impurities.

Further, the soft aluminum monofilament comprises: 0.01-0.02% of B, 0.05-0.2% of Er, 0.06% of Si, 0.18% of Fe, (V + Ti + Cr + Mn) is 0.013%, and the balance of aluminum and inevitable impurities.

Further, the soft aluminum monofilament comprises: 0.02% of B, 0.2% of er, 0.04% of Si, 0.15% of Fe, (V + Ti + Cr + Mn) 0.015%, and the balance of aluminum and inevitable impurities.

The preparation method of the high-conductivity soft aluminum monofilament comprises the following steps:

(1) smelting;

(2) refining;

(3) casting;

(4) and (6) rolling.

Further, the step 1) comprises the steps of melting the raw materials at 730-760 ℃ and standing for 15-30 min.

Further, the aluminum ingot and the Al-B intermediate alloy are smelted at the temperature of 740-.

Further, the step 2) comprises: blowing N into the molten liquid obtained in the step 1) with the temperature reduced to 710-730 DEG C₂5-10min or 0.3% -0.5% of C₂Cl₆Standing for 15-20min, and removing slag.

Further, the step 3) comprises: the aluminum alloy liquid is poured into the die at the temperature of 700-720 ℃.

Further, after the rolling in the step 4), the soft aluminum monofilament is obtained by heat preservation for 4-8h at the temperature of 300-350 ℃.

Further, the product is obtained by 5-pass rolling at 530 ℃ and 540 DEG C

The aluminum alloy round bar is obtained by drawing 8-12 times

A monofilament.

Compared with the closest prior art, the technical scheme provided by the invention has the following beneficial effects:

(1) the technical scheme provided by the invention is to develop an Al-Er-B soft aluminum monofilament with the conductivity of not less than 63.5 percent IACS (20 ℃) and the elongation of not less than 20 percent by taking an industrial aluminum ingot with the purity of 99.7 percent as a raw material and introducing Er and B elements to improve the microstructure and the comprehensive performance of the alloy, thereby effectively solving the technical problems of low conductivity and low elongation of the existing soft aluminum monofilament and lead products.

(2) The tensile strength of the soft aluminum monofilament provided by the invention can reach 75-90MPa, and the mechanical property of the soft aluminum monofilament is effectively improved.

Detailed Description

The technical solutions provided by the present invention are described below clearly and completely, and it is obvious that the described embodiments are only a part of the present invention, and not all of it.

The invention aims to develop a high-conductivity Al-Er-B soft aluminum monofilament with the conductivity of more than 63.5 percent IACS (20 ℃), the tensile strength of 75-90MPa and the elongation of more than 20 percent by taking an industrial aluminum ingot with the purity of 99.7 percent as a raw material and adding trace Er and B elements to improve the microstructure and the comprehensive performance of an alloy.

The action and mechanism of each alloy element are as follows:

b: if the impurity elements exist in a solid solution state, the influence on the conductivity is very large, and the invention provides an effective method for reducing the impurity content, namely boronization treatment, namely, Al-B intermediate alloy is added into the aluminum alloy, and B can react with transition group impurity elements such as Cr, Mn, V, Ti and the like, so that the impurity elements are converted into a compound state from the solid solution state and are deposited at the bottom of a melt, and the conductivity of the aluminum alloy is improved.

Er: the rare earth Er added in the invention can react with impurity elements such as Fe, Si and the like, so that the impurity elements are converted into a second phase from solid solution atoms, the lattice distortion is reduced, and an Al3Er precipitated phase can be formed through heat treatment, thereby improving the conductivity and the strength of the alloy.

Si: silicon is one of impurity elements in industrial aluminum, and Si can react with elements such as Fe, Re and the like to generate a second phase, so that the mechanical property of the aluminum alloy is improved.

Fe: iron is a major impurity in industrial aluminum. Iron usually appears as coarse primary crystals or as aluminum-iron-silicon compounds, which increase the hardness of aluminum to some extent but reduce the plasticity of aluminum, so care should be taken to control the iron content.

V, Mn, Cr, Ti: when impurity elements such as Ti, V, Mn, and Cr in the aluminum conductor exist in a solid solution state, free electrons in the conductor material are easily absorbed and the incomplete electron layer is filled. The reduction of the number of conduction electrons leads to the reduction of the conductivity of the aluminum conductor, so that the strict control of the contents of the elements has important practical significance for ensuring the quality of the aluminum conductor.

The preparation process of the high-conductivity Al-Er-B soft aluminum monofilament comprises the following steps:

(1) smelting: adding an industrial pure aluminum ingot with the purity of more than or equal to 99.7 percent into a 740-760 ℃ smelting furnace, adding Al-B intermediate alloy for boronization after pure aluminum is completely melted, and standing for 15-20 min; cooling to 730-.

(2) Refining: cooling to 710-₂5-10min, or adding 0.3% -0.5% C₂Cl₆Standing for 15-20min, and removing slag.

(3) Casting: cooling to 700-720 ℃ and pouring the aluminum alloy liquid into the metal mold.

(4) Rolling: rolling at 530 ℃ and 540 ℃ for 5 passes to form an aluminum alloy round rod with the diameter of 9.5 mm;

drawing the aluminum alloy round rod with the diameter of 9.5mm for 8-12 times to obtain the monofilament with the diameter of 3-4mm, and preserving the heat for 4-8h at the temperature of 300-350 ℃ to obtain the Al-Er-B soft aluminum monofilament with high conductivity.

And (3) the steps (3) to (4) can also adopt a continuous casting and rolling method to obtain the aluminum alloy round rod with the diameter of 9.5 mm.