CN114480921A - Heat-resistant aluminum alloy monofilament material for overhead conductor and preparation method thereof - Google Patents

Abstract

的铝合金圆杆经过10‑15道次拉拔，获得

铝合金单丝；时效处理。本发明的优点：提高耐热铝合金单丝导电率的同时对强度和耐热性均有有益作用；优化了制备工艺参数，由此制备出的耐热铝合金单丝可以在保证力学性能和耐热性能的前提下显著提高导电率至61.8％IACS。A heat-resistant aluminum alloy monofilament material for overhead conductors, characterized in that the composition system includes aluminum, boron, erbium, indium alloy elements and impurity elements in the raw materials of iron, silicon, vanadium, titanium, chromium, and manganese; The content of the iron is as follows: boron: 0.01～0.02%, erbium: 0.08～0.12%, indium: 0.05～0.1%, silicon: 0.03～0.06%, iron: 0.08～1.2%, (vanadium + titanium + chromium + manganese) ≤ 0.005%, the rest is the content of aluminum and other unavoidable trace impurities. A preparation method of a heat-resistant aluminum alloy monofilament material for overhead conductors, smelting, refining, casting, rolling, and drawing:

After 10-15 passes of drawing, the aluminum alloy round rod obtained

Aluminum alloy monofilament; aging treatment. The advantages of the invention are: while improving the electrical conductivity of the heat-resistant aluminum alloy monofilament, it has beneficial effects on strength and heat resistance; the preparation process parameters are optimized, and the heat-resistant aluminum alloy monofilament prepared thereby can ensure mechanical properties and On the premise of heat resistance, the electrical conductivity is significantly improved to 61.8% IACS.

Description

A kind of heat-resistant aluminum alloy monofilament material for overhead conductor and preparation method thereof

technical field

The invention belongs to the technical field of electrical conductor materials, and relates to the invention of a heat-resistant aluminum alloy monofilament material for overhead wires and a preparation method thereof.

Background technique

At present, the energy saving and environmental protection of the power grid needs to be paid attention to, and it is urgent to develop and apply high-conductivity aluminum alloy wires with low loss and high safety and reliability.

The active steel-cored aluminum stranded wire is made of hard aluminum conductor material, which has poor heat resistance and low current-carrying capacity. For urban and rural power grid reconstruction projects, in order to expand the transmission system, the existing steel-cored aluminum stranded wire must increase the number of conductors. Section, need to replace all towers, rebuild, which is difficult to achieve for lines located in densely populated areas. Therefore, using heat-resistant aluminum alloy wires to increase the transmission capacity by replacing the same cross-sectional area capacity-enhancing wires has become one of the effective technologies.

The heat-resistant aluminum alloy wire is a special capacity-enhancing wire with good performance. The large-capacity heat-resistant aluminum alloy wire is used to increase the capacity of the existing line. Under the principle of not replacing the tower as much as possible, it can not only improve the transmission capacity of the line, but also Can reduce the overall cost of the project. At present, the heat-resistant aluminum alloy wire products in the domestic and foreign markets are mainly 60% IACS heat-resistant aluminum alloy wires. The application of 61% IACS heat-resistant aluminum alloy wires is relatively small. Meet the green development needs of long-distance, large-capacity transmission line construction projects and power grid capacity expansion and reconstruction projects. Therefore, how to improve the electrical conductivity of heat-resistant aluminum alloy and reduce the loss of transmission lines while ensuring a high current carrying capacity has become the most urgent technical demand for heat-resistant aluminum wire.

SUMMARY OF THE INVENTION

The purpose of the present invention is to develop an aluminum-erbium-indium-boron heat-resistant aluminum alloy monofilament material using industrial aluminum ingots with a purity of 99.7% as a raw material, so as to solve the problem of the electrical conductivity of the existing heat-resistant aluminum alloy monofilament and wire products. The technical problems of low and high transmission line losses.

By adding trace amounts of erbium, indium, and boron to improve the microstructure and comprehensive properties of the alloy, a new product with a conductivity of not less than 61.8% IACS (20°C), a tensile strength of not less than 160MPa, an elongation of not less than 2%, and a long-term resistance Heat-resistant aluminum alloy monofilament for overhead conductors with a thermal temperature of 150°C (residual rate of room temperature strength after 230°C heat preservation for 1 hour ≥ 90%).

The invention provides a heat-resistant aluminum alloy monofilament material for overhead wires, which is characterized in that the composition system includes aluminum, boron, erbium, indium alloy elements and impurity elements in the raw materials of iron, silicon, vanadium, titanium, chromium and manganese. .

The content of each mass fraction is: boron: 0.01-0.02%, erbium: 0.08-0.12%, indium: 0.05-0.1%, silicon: 0.03-0.06%, iron: 0.08-1.2%, (vanadium + titanium + chromium + Manganese)≤0.005%, the rest is the content of aluminum and other unavoidable trace impurities.

A preparation method of a heat-resistant aluminum alloy monofilament material for overhead wires, characterized in that: the specific preparation process is as follows:

(1) Smelting: industrial pure aluminum ingots with a purity of ≥99.7% are added to the melting furnace, and the melting temperature is 730-750 ° C; Add aluminum-erbium intermediate alloy and pure indium ingot at ~750°C, stir 10-15m indium after complete melting, and let stand for 20-30m indium.

(2) Refining: Blow in nitrogen at 710-730°C, blowing time 5-15m indium, or add 0.3%-0.5% hexachloroethane for degassing refining, let stand for 10-20m indium and then remove slag.

(3) Casting: pour the aluminum alloy liquid into a metal mold preheated at 250-300°C at 700-720°C, and cast it into an aluminum ingot with a side length of 20-25mm in cross section.

的铝合金圆杆，并喷水快速冷却。(4) Rolling: The aluminum ingot is placed at 480-510°C for 3-6 hours and then rolled, and rolled for 6 passes.

Aluminum alloy round rod, and spray water for rapid cooling.

的铝合金圆杆经过10-15道次拉拔，获得

铝合金单丝。(5) Drawing:

After 10-15 passes of drawing, the aluminum alloy round rod is obtained.

Aluminium alloy monofilament.

(6) Aging: The monofilament is kept at 90-120°C for 0.5-2 hours.

的铝合金圆杆，并喷水快速冷却。The step (4) can also be realized by extrusion, and the specific process is as follows: the aluminum ingot is placed at 480-510° C. for 3-6 hours and then rolled for 3-6 hours.

Aluminum alloy round rod, and spray water for rapid cooling.

Advantages of the present invention:

The heat-resistant aluminum alloy monofilament material for overhead wires and the preparation method thereof of the present invention, through the compound addition of erbium element and indium element, under a certain preparation process, Al3 _- erbium phase and indium particles are generated, and after the combination of the two elements The coupling effect improves electrical conductivity on the basis of ensuring strength and heat resistance.

Due to the addition of a trace amount of rare earth erbium element in the heat-resistant alloy, the aluminum ₃ erbium phase can be generated by heat treatment before rolling. The aluminum ₃ erbium phase has good high temperature stability, which can improve the strength and strength of the heat-resistant aluminum alloy monofilament. Heat resistance, and erbium element can react with iron and silicon elements to form a second phase, from iron and silicon elements from solute atoms to the second phase, which reduces lattice distortion and improves the conductivity of heat-resistant aluminum alloy monofilaments. It has beneficial effects on strength and heat resistance; adding trace indium elements can precipitate indium particles after aging, and improve the strength of heat-resistant aluminum alloy monofilaments. On the basis of this alloy composition formula, the preparation process parameters are optimized, and the heat-resistant aluminum alloy monofilament prepared from this can significantly increase the electrical conductivity to 61.8%IACS (20℃) on the premise of ensuring the mechanical properties and heat-resistant properties. .

Detailed ways

The role and mechanism of each alloying element are as follows:

Boron (boron): Among the many influencing factors, chemical composition is the most basic factor affecting the conductivity of aluminum conductors. Therefore, reducing the influence of impurity elements on conductivity is the key to improving the conductivity of aluminum conductors. If the impurity element exists in the state of solute atom, it has a greater influence on the electrical conductivity. Boriding treatment is an effective method to reduce the content of harmful impurities in aluminum alloy conductor materials, that is, after adding a certain amount of boron element to the aluminum alloy, it can react with the transition group impurity elements chromium, manganese, vanadium and titanium, so that The atomic state of the solute is transformed into a combined state and deposited at the bottom of the melt, thereby improving the electrical conductivity of the aluminum alloy.

Erbium (Erbium): The addition of rare earth erbium in the present invention can significantly improve the electrical conductivity, strength and heat resistance of the aluminum alloy. Through the heat treatment of erbium and aluminum, the precipitated phase of aluminum ₃ erbium is formed, thereby improving the strength of the alloy; aluminum ₃ erbium is a high temperature resistant phase, so the heat resistance of the alloy can be guaranteed; because erbium element can also react with iron and silicon impurity elements, making impurities Elements are transformed from solute atoms into second phases, reducing lattice distortion and thus improving the electrical conductivity of the alloy.

Indium (Indium): Indium has good ductility, strong plasticity, low melting point, high boiling point, low resistance, excellent corrosion resistance, and good electrical conductivity. In the present invention, the microstructure and mechanical properties of the alloy can be obviously changed after adding indium, and the indium element will be precipitated to form indium particles through aging treatment, thereby strengthening the aluminum alloy.

Silicon (silicon): Silicon is one of the impurity elements in industrial aluminum. Silicon can react with aluminum, iron, and RE elements to form a second phase, reduce lattice distortion, and improve the electrical conductivity, mechanical properties and heat resistance of aluminum alloy conductor materials. performance is beneficial.

Iron (iron): Aluminum contains a certain amount of iron, which is an impurity in industrial aluminum. Iron is detrimental to the mechanical properties of cast aluminum because it usually occurs as coarse primary crystals, or in the form of aluminum-iron-silicon compounds, which increase the hardness of aluminum to a certain extent, but reduce the plasticity of aluminum. Studies have shown that iron increases the strength of aluminum conductors without significantly reducing their conductivity. However, there are also data that in actual production, too high iron in aluminum conductors will significantly increase the resistivity, so attention should also be paid to controlling the content of iron.

Chromium, manganese, vanadium, titanium (manganese, chromium, vanadium, titanium): these elements are impurity elements in the alloy, which have a great influence on the electrical conductivity of the aluminum alloy. When the titanium, vanadium, manganese, and chromium impurity elements in aluminum conductors exist in solid solution state, they can easily absorb free electrons in the conductor material and fill their incomplete electron layers. This reduction in the number of conduction electrons results in a reduction in the conductivity of the aluminum conductor. Research has shown that every 1% (chromium + titanium + manganese + vanadium) is 5 times more detrimental than every 1% silicon is to aluminum conductivity. It can be seen that strictly controlling the content of these elements has important practical significance for ensuring the quality of aluminum conductors.

Example 1

A heat-resistant aluminum alloy monofilament material for overhead conductors, the composition and mass fraction thereof are:

铝合金单丝，单丝在120℃保温0.5小时后室温冷却。所制备出的耐热铝合金单丝导电率为61.8％IACS(20℃)，抗拉强度为168MPa，延伸率为2.0％，230℃保温1小时后的室温强度残存率为92％，满足长期运行温度为150℃的要求。A pure aluminum ingot with a purity of 99.7% was added with aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot, so that the final content of alloying elements was as shown above. After smelting, refining, casting, rolling or extrusion, the round aluminum rod is obtained, and it is obtained after 10 times of drawing.

Aluminum alloy monofilament, the monofilament is kept at 120°C for 0.5 hours and then cooled at room temperature. The prepared heat-resistant aluminum alloy monofilament has a conductivity of 61.8% IACS (20°C), a tensile strength of 168MPa, an elongation of 2.0%, and a room temperature strength residual rate of 92% after being kept at 230°C for 1 hour. Operating temperature of 150°C is required.

Example 2

A heat-resistant aluminum alloy monofilament material for overhead conductors, the composition and mass fraction thereof are:

铝合金单丝，单丝在90℃保温2小时后室温冷却。所制备出的耐热铝合金单丝导电率为61.92％IACS(20℃)，抗拉强度为160MPa，延伸率为2.3％，230℃保温1小时后的室温强度残存率为90％，满足长期运行温度为150℃的要求。A pure aluminum ingot with a purity of 99.7% was added with aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot, so that the final content of alloying elements was as shown above. After smelting, refining, casting, rolling or extrusion, the round aluminum rod is obtained, which is obtained after 15 times of drawing.

Aluminum alloy monofilament, the monofilament is kept at 90°C for 2 hours and then cooled at room temperature. The prepared heat-resistant aluminum alloy monofilament has a conductivity of 61.92% IACS (20°C), a tensile strength of 160MPa, an elongation of 2.3%, and a room temperature strength residual rate of 90% after being kept at 230°C for 1 hour. Operating temperature of 150°C is required.

Example 3

A heat-resistant aluminum alloy monofilament material for overhead conductors, the composition and mass fraction thereof are:

铝合金单丝，单丝在100℃保温1.5小时后室温冷却。所制备出的耐热铝合金单丝导电率为61.85％IACS(20℃)，抗拉强度为166MPa，延伸率为2.1％，230℃保温1小时后的室温强度残存率为91％，满足长期运行温度为150℃的要求。A pure aluminum ingot with a purity of 99.7% was added with aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot, so that the final content of alloying elements was as shown above. After smelting, refining, casting, rolling or extrusion, the round aluminum rod is obtained, which is obtained after 12 times of drawing.

Aluminum alloy monofilament, the monofilament is kept at 100°C for 1.5 hours and then cooled at room temperature. The prepared heat-resistant aluminum alloy monofilament has a conductivity of 61.85% IACS (20°C), a tensile strength of 166MPa, an elongation of 2.1%, and a room temperature strength residual rate of 91% after 1 hour at 230°C. Operating temperature of 150°C is required.

Example 4

A heat-resistant aluminum alloy monofilament material for overhead conductors, the composition and mass fraction thereof are:

铝合金单丝，单丝在110℃保温1小时后室温冷却。所制备出的耐热铝合金单丝导电率为61.82％IACS(20℃)，抗拉强度为168MPa，延伸率为2.2％，230℃保温1小时后的室温强度残存率为92％，满足长期运行温度为150℃的要求。A pure aluminum ingot with a purity of 99.7% was added with aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot, so that the final content of alloying elements was as shown above. After smelting, refining, casting, rolling or extrusion, the round aluminum rod is obtained, and it is obtained after 13 passes of drawing.

Aluminum alloy monofilament, the monofilament is kept at 110°C for 1 hour and then cooled at room temperature. The prepared heat-resistant aluminum alloy monofilament has a conductivity of 61.82% IACS (20°C), a tensile strength of 168MPa, an elongation of 2.2%, and a room temperature strength residual rate of 92% after being kept at 230°C for 1 hour. Operating temperature of 150°C is required.

Example 5

A heat-resistant aluminum alloy monofilament material for overhead conductors, the composition and mass fraction thereof are:

铝合金单丝，单丝在105℃保温1小时后室温冷却。所制备出的耐热铝合金单丝导电率为61.87％IACS(20℃)，抗拉强度为163MPa，延伸率为2.2％，230℃保温1小时后的室温强度残存率为91％，满足长期运行温度为150℃的要求。A pure aluminum ingot with a purity of 99.7% was added with aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot, so that the final content of alloying elements was as shown above. After smelting, refining, casting, rolling or extrusion, the round aluminum rod is obtained, which is obtained after 14 times of drawing.

Aluminum alloy monofilament, the monofilament is kept at 105°C for 1 hour and then cooled at room temperature. The prepared heat-resistant aluminum alloy monofilament has a conductivity of 61.87% IACS (20°C), a tensile strength of 163MPa, an elongation of 2.2%, and a room temperature strength residual rate of 91% after 1 hour at 230°C. Operating temperature of 150°C is required.

Claims (8)

1. The utility model provides a heat-resisting aluminum alloy monofilament material for overhead wire which characterized in that: the component system comprises aluminum, boron, erbium, indium alloy elements and impurity elements in iron, silicon, vanadium, titanium, chromium, manganese-aluminum-boron-erbium-indium-iron-silicon-vanadium-titanium-chromium-manganese raw materials;

the components and the mass fraction are respectively as follows: 0.01-0.02% of boron, 0.08-0.12% of erbium, 0.05-0.1% of indium, 0.03-0.06% of silicon, 0.08-1.2% of iron, less than or equal to 0.005% of (vanadium + titanium + chromium + manganese), and the balance of aluminum and inevitable other trace impurities.

2. The heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 1, wherein: the components and the mass fraction thereof are as follows: 0.02% of boron, erbium: 0.12%, indium: 0.05%, silicon: 0.03%, iron: 0.12%, vanadium + titanium + chromium + manganese: 0.005%, aluminum: the balance;

pure aluminum ingot with a purity of 99.7%, aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot were added so that the final contents of alloying elements were as indicated above.

3. The heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 1, wherein: the components and the mass fraction thereof are as follows: boron: 0.01%, erbium: 0.08%, indium: 0.1%, silicon: 0.06%, iron: 0.08%, vanadium + titanium + chromium + manganese: 0.002%, aluminum: the balance;

pure aluminum ingot with a purity of 99.7%, aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot were added so that the final contents of alloying elements were as indicated above.

4. The heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 1, wherein: the components and the mass fraction thereof are as follows: boron: 0.012%, erbium: 0.10%, indium: 0.08%, silicon: 0.05%, iron: 0.10%, vanadium + titanium + chromium + manganese: 0.004%, aluminum: the balance;

pure aluminum ingot with a purity of 99.7%, aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot were added so that the final contents of alloying elements were as indicated above.

5. The heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 1, wherein: the components and the mass fraction thereof are as follows: boron: 0.015%, erbium: 0.11%, indium: 0.09%, silicon: 0.04%, iron: 0.09%, vanadium + titanium + chromium + manganese: 0.004%, aluminum: the balance;

pure aluminum ingot with a purity of 99.7%, aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot were added so that the final contents of alloying elements were as indicated above.

6. The heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 1, wherein: the components and the mass fraction thereof are as follows: 0.018% of boron, 0.09% of erbium, 0.07% of indium, 0.05% of silicon, iron: 0.11%, vanadium + titanium + chromium + manganese: 0.003%, aluminum: the balance;

pure aluminum ingot with a purity of 99.7%, aluminum-boron master alloy, aluminum-erbium master alloy and pure indium ingot were added so that the final contents of alloying elements were as indicated above.

7. A method for preparing a heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 1, wherein the method comprises the steps of: the preparation process comprises the following steps:

(1) adding an industrial pure aluminum ingot with the purity of more than or equal to 99.7% into a smelting furnace, wherein the smelting temperature is 730-750 ℃; after the pure aluminum is completely melted, adding an aluminum-boron intermediate alloy at 730-750 ℃ for boronizing treatment; adding an aluminum-erbium intermediate alloy and a pure indium ingot at 730-750 ℃, stirring 10-15 m indium after complete melting, and standing 20-30 m indium;

(2) blowing nitrogen at 710-730 ℃ for 5-15 m indium or adding 0.3% -0.5% hexachloroethane for degassing and refining, standing for 10-20m indium, and then slagging off;

(3) pouring aluminum alloy liquid into a metal mold preheated at the temperature of 250-300 ℃ at the temperature of 700-720 ℃ and casting into an aluminum ingot with the cross section of side length of 20-25 mm;

(4) placing the aluminum ingot at 480-510 ℃ for heat preservation for 3-6 hours, rolling, and rolling for 6 times

The aluminum alloy round rod is sprayed with water for rapid cooling;

(5)

the aluminum alloy round bar is obtained by drawing for 10 to 15 times

Aluminum alloy monofilaments;

(6) the monofilament is subjected to heat preservation for 0.5-2 hours at the temperature of 90-120 ℃.

8. The method for preparing the heat-resistant aluminum alloy monofilament material for overhead conductors as claimed in claim 3, wherein the method comprises the following steps: the forming process of the aluminum alloy round rod in the step (4) is realized by an extrusion mode, and the specific process comprises the following steps: placing the aluminum ingot at 480-510 ℃ for heat preservation for 3-6 hours, rolling, and extruding to obtain the aluminum ingot

The aluminum alloy round bar is sprayed with water for rapid cooling.