CN115216671A

CN115216671A - Modified aluminum alloy single wire and preparation method thereof

Info

Publication number: CN115216671A
Application number: CN202210687029.6A
Authority: CN
Inventors: 李冬青; 蔡松林; 顾建; 刘绪良; 刘鹏; 刘胜春; 司佳钧; 刘臻; 张暕
Original assignee: State Grid Corp of China SGCC; China Electric Power Research Institute Co Ltd CEPRI; State Grid Beijing Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; China Electric Power Research Institute Co Ltd CEPRI; State Grid Beijing Electric Power Co Ltd
Priority date: 2022-06-16
Filing date: 2022-06-16
Publication date: 2022-10-21

Abstract

The invention provides a modified aluminum alloy single wire and a preparation method thereof, wherein the aluminum alloy single wire is prepared from the following components in percentage by mass: 0.66 to 0.86 percent of magnesium element, 0.54 to 0.84 percent of silicon element, 0.10 to 0.30 percent of scandium element, 0.10 to 0.30 percent of dysprosium element and the balance of aluminum element; according to the technical scheme provided by the invention, the electric conductivity of the modified aluminum alloy single line obtained by doping rare earth elements scandium and dysprosium is still more than 54% IACS at 20 ℃, the tensile strength is higher than 360MPa, and the effective balance of the aluminum alloy single line in the two aspects of electric conductivity and mechanical property is realized.

Description

Modified aluminum alloy single wire and preparation method thereof

Technical Field

The invention relates to a conductor material, in particular to a modified aluminum alloy single wire and a preparation method thereof.

Background

Overhead transmission lines are important physical carriers for large-area energy allocation and power supply. As a core component of an overhead transmission line, namely a conductor, carries key tasks of conducting current and transmitting electric energy, and bears normal operation load and additional load caused by environmental factors such as strong wind, ice coating and the like, the conductor material used as the overhead conductor has good conductivity and mechanical property. The steel-cored aluminum strand has the obvious advantages of simple structure, convenient erection and maintenance, low manufacturing cost and the like, and is a generally adopted wire type of an overhead transmission line.

In recent years, a power grid rapidly expands the space scale, and simultaneously, more strict requirements are provided for the transmission capacity and the loss level of an overhead transmission line, and how to fully utilize the existing line corridor to transmit more electric energy and reduce the line loss becomes the key point of research in the power industry, while the technical defects of low transmission capacity and large electric energy loss of the traditional steel-reinforced aluminum stranded wire become bottlenecks for limiting capacity increasing and consumption reducing of the line.

The aluminum alloy material is an ideal overhead transmission line conductor material due to small direct current resistance, low density and good corrosion resistance. The aluminum alloy material is used as the overhead conductor, so that the current-carrying capacity of the line can be obviously improved, the sag of the line is reduced, and a large amount of materials and capital investment are saved. However, the poor mechanical properties of the aluminum alloy material limit the scale application of the aluminum alloy material.

The development of high-strength and high-conductivity aluminum alloy materials is an important research direction in the technical field of overhead conductors, and how to simultaneously improve the conductivity and tensile strength of aluminum alloy single lines is a technical problem which needs to be solved urgently at present.

Disclosure of Invention

The invention aims to improve the conductivity and tensile strength of an aluminum alloy single line by using rare earth elements, and doping the rare earth elements scandium and dysprosium for composite modification treatment on the basis of the original alloy components to obtain a modified aluminum alloy single line, so that the modified aluminum alloy single line has higher conductivity and tensile strength to meet the requirements of capacity increase and consumption reduction of an overhead transmission line.

In order to achieve the purpose, the invention comprises two parts of the component design of the aluminum alloy single line and the preparation method of the aluminum alloy single line.

The technical scheme for implementing the purpose is as follows:

(1) Composition design of modified aluminum alloy single line

The invention provides a modified aluminum alloy single wire which comprises the following components in percentage by mass: 0.66 to 0.86 percent of magnesium element, 0.54 to 0.84 percent of silicon element, 0.10 to 0.30 percent of scandium element, 0.10 to 0.30 percent of dysprosium element and the balance of aluminum element.

Further, the mass percent of the magnesium element is 0.76-0.86%.

Further, the mass percent of the silicon element is 0.54-0.64%.

Further, the weight percentage of scandium element is 0.20% -0.30%.

Further, the mass percent of dysprosium element is 0.10% -0.20%.

Further, the aluminum alloy single wire comprises the following components in percentage by mass: 0.80 to 0.84 percent of magnesium element, 0.54 to 0.60 percent of silicon element, 0.20 to 0.25 percent of scandium element, 0.10 to 0.15 percent of dysprosium element and the balance of aluminum element.

Further, the aluminum alloy single wire comprises the following components in percentage by mass: 0.82% of magnesium element, 0.56% of silicon element, 0.20% of scandium element, 0.10% of dysprosium element and the balance of aluminum element.

(2) Preparation method of modified aluminum alloy single wire

The invention also provides a preparation method of the modified aluminum alloy single line, which comprises the steps of adding the three alloy components of aluminum, magnesium and silicon into smelting equipment in the form of blocky simple substances, adding the two alloy components of scandium and dysprosium into the smelting equipment in the form of intermediate alloy, and carrying out resistance smelting, continuous casting and rolling, drawing and forming and artificial aging.

Resistance smelting: adding lumpy simple substances of aluminum, magnesium and silicon and intermediate alloys of scandium and dysprosium according to a preset proportion, and melting to form an alloy melt; continuous casting and rolling: enabling the alloy melt to flow through a continuous casting and rolling die to obtain a solid aluminum alloy round rod; drawing and forming: drawing the aluminum alloy round rod for multiple times to obtain an aluminum alloy single wire; artificial aging: and carrying out aging heat treatment on the aluminum alloy single line.

Further, the resistance melting step comprises: weighing massive simple substances of aluminum, magnesium and silicon, an aluminum-5% magnesium-2% scandium intermediate alloy and an aluminum-20% dysprosium intermediate alloy according to component requirements, melting at a constant temperature at a first preset temperature, then filling argon and stirring to obtain a uniform alloy melt, and preserving heat at a second preset temperature.

Further, the continuous casting and rolling step comprises the following steps: and when the alloy melt flows out along the inner cavity of the continuous casting and rolling die, cooling by adopting a circulating water system to obtain the solid aluminum alloy round rod with a first preset size.

Further, the drawing step comprises: and (3) putting the aluminum alloy round rod into a drawing die of a wire drawing machine, and drawing the aluminum alloy round rod with the first preset size to an aluminum alloy single wire with the second preset diameter through four-pass drawing.

Furthermore, the drawing amount of each pass of the four-pass drawing is 20.5-24.2%, the drawing speed is 3-10 m/s, and the drawing temperature is 35-60 ℃.

Further, the artificial aging step comprises: and (3) treating the aluminum alloy single wire subjected to drawing forming in an aging heat treatment furnace for 6-10 h, and cooling to room temperature to obtain the aluminum alloy single wire.

Further, the temperature of the aging heat treatment furnace is 160-180 ℃.

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

1) According to the modified aluminum alloy single wire provided by the invention, rare earth elements scandium and dysprosium are doped in the components of the aluminum alloy single wire, scandium and dysprosium are utilized as homologous elements, a synergistic effect is generated between scandium and dysprosium, the mechanical property of the aluminum alloy single wire can be greatly improved under the total low doping amount, and the total low doping amount of scandium and dysprosium does not adversely affect the conductivity of the aluminum alloy single wire.

2) In addition, after scandium and dysprosium with low doping amount are blended into the aluminum-magnesium-silicon alloy matrix, the aluminum-magnesium-silicon alloy matrix can be subjected to segregation at the extended dislocation to reduce the stacking fault energy, extended dislocations are easily formed in the aluminum-magnesium-silicon alloy matrix and have larger width, so that dislocation initiated in the deformation process is difficult to slip, dislocation plugging is caused, the processing and hardening efficiency of the aluminum alloy single line can be improved, and the mechanical property of the aluminum alloy single line is further improved.

3) The preparation method of the modified aluminum alloy single wire provided by the invention can further improve the synergistic effect of the two effects through the drawing forming process, and obtains the excellent effect of the aluminum alloy single wire shown in figure 1, wherein the tensile strength is improved from 320MPa to 367MPa on the basis of maintaining the 20 ℃ electric conductivity to be 54.2% IACS.

Drawings

FIG. 1 is a comparison graph of tensile strength-drawing times curves of an original alloy and a modified aluminum alloy compositely doped with rare earth elements scandium and dysprosium.

Detailed Description

The technical scheme provided by the invention is specifically described in detail through specific examples, and except for other descriptions, the components in the technical scheme provided by the invention are respectively calculated by mass percent, and the two kinds of intermediate alloys characterized by an aluminum-5% magnesium-2% scandium intermediate alloy and an aluminum-20% dysprosium intermediate alloy contain 5% magnesium element, 2% scandium element and 20% dysprosium element, and the balance is aluminum element.

The embodiment of the invention provides a modified aluminum alloy single wire, which comprises the following components in percentage by mass: 0.66 to 0.86 percent of magnesium element, 0.54 to 0.84 percent of silicon element, 0.10 to 0.30 percent of scandium element, 0.10 to 0.30 percent of dysprosium element and the balance of aluminum element.

Wherein the used ingredients comprise lumpy simple substances of aluminum, magnesium and silicon, an aluminum-5 percent of magnesium-2 percent of scandium master alloy and an aluminum-20 percent of dysprosium master alloy.

Example 1

The modified aluminum alloy single line containing 0.82% of magnesium element, 0.56% of silicon element, 0.20% of scandium element, 0.10% of dysprosium element and the balance of aluminum element is prepared.

The preparation method comprises the following steps:

the method comprises the steps of putting batched aluminum, magnesium and silicon blocky simple substances, aluminum-5% magnesium-2% scandium intermediate alloy and aluminum-20% dysprosium intermediate alloy which are weighed according to component requirements into a crucible of a resistance smelting furnace, heating the resistance smelting furnace to 900 ℃ and keeping the temperature, filling argon into alloy melt after all the batched materials are completely melted, stirring with a graphite rod, conveying the obtained uniform metal melt into the crucible of a heat preservation furnace through a diversion trench, and preserving heat at 800 ℃.

And then the molten metal in the crucible is sent to the front end of a continuous casting and rolling die through a diversion trench, the molten metal flows out along a cavity at the rear end of the die under the action of rollers in the continuous casting and rolling die, and the molten metal is gradually cooled under the action of a peripheral circulating water system in the flowing-out process to obtain the solid aluminum alloy round rod with the diameter of 9.5 mm.

Placing the aluminum alloy round rod into a feed inlet of a drawing die of a high-speed wire drawing machine, drawing the obtained aluminum alloy round rod by four times under external tension, and then sequentially decreasing the diameter of the aluminum alloy round rod of 9.5mm from 7.2mm, 5.6mm and 4.4mm to 3.5mm, wherein the drawing speed is 5m/s, and the drawing temperature is 50 ℃.

And winding the aluminum alloy single wire subjected to drawing forming on a coil shaft, raising the temperature of the coil shaft to 170 ℃ in an aging heat treatment furnace, putting the whole coil shaft into the aging furnace, preserving the heat for 8 hours, taking out the coil shaft, and carrying out air cooling to room temperature to obtain the modified aluminum alloy single wire.

The modified aluminum alloy single line sample obtained is detected according to the national standard GB/T228.1-2010, the electric conductivity of the modified aluminum alloy single line sample is 54.2 percent IACS at 20 ℃, the tensile strength is 367MPa, and the electric conductivity and the mechanical property are both superior to those of the sample in the prior art.

Example 2

The modified aluminum alloy single line containing 0.66 percent of magnesium element, 0.54 percent of silicon element, 0.10 percent of scandium element, 0.10 percent of dysprosium element and the balance of aluminum element is prepared.

The same procedure as in example 1 was used to prepare modified aluminum alloy single wires by weighing lumpy simple substances of aluminum, magnesium and silicon, an aluminum-5% magnesium-2% scandium master alloy and an aluminum-20% dysprosium master alloy according to the ingredients.

The performance of the modified aluminum alloy single-line sample is detected according to the national standard GB/T228.1-2010, and the detection result is listed in the following table 1.

Example 3

The modified aluminum alloy single line containing 0.76% of magnesium element, 0.54% of silicon element, 0.20% of scandium element, 0.10% of dysprosium element and the balance of aluminum element is prepared.

Example 4

The modified aluminum alloy single line containing 0.80% of magnesium element, 0.54% of silicon element, 0.20% of scandium element, 0.10% of dysprosium element and the balance of aluminum element is prepared.

Example 5

The modified aluminum alloy single line containing 0.84% of magnesium element, 0.60% of silicon element, 0.25% of scandium element, 0.15% of dysprosium element and the balance of aluminum element is prepared.

The same procedure as in example 1 was used to prepare modified aluminum alloy single wires by weighing the lumpy simple substances of aluminum, magnesium and silicon, an aluminum-5% magnesium-2% scandium master alloy and an aluminum-20% dysprosium master alloy according to the ingredients.

Example 6

The modified aluminum alloy single line containing 0.86% of magnesium element, 0.64% of silicon element, 0.30% of scandium element, 0.20% of dysprosium element and the balance of aluminum element is prepared.

The performance of the obtained modified aluminum alloy single-line sample is detected according to the national standard GB/T228.1-2010, and the detection results are listed in the following table 1.

Example 7

The modified aluminum alloy single line containing 0.86% of magnesium element, 0.84% of silicon element, 0.30% of scandium element, 0.30% of dysprosium element and the balance of aluminum element is prepared.

Table 1 shows the mass percentages of the elements of the modified aluminum alloy single wires of examples 1 to 7 of the present invention, and the results of the electric conductivity and tensile strength test of the modified aluminum alloy single wires of each example.

TABLE 1

Note: the modified aluminum alloy single lines of examples 2 to 7 were prepared in the same manner as in example 1, except that the respective elements were different in mass percentage.

Comparative example

FIG. 1 shows that the tensile strength of the modified Al-Mg-Si-Sc-Dy alloy single wire obtained after adding the Al-5% Mg-2% Sc master alloy and the Al-20% Dy master alloy is obviously superior to that of the original Al-Mg-Si alloy single wire. In the initial drawing stage, the tensile strength of the modified aluminum-magnesium-silicon-scandium-dysprosium alloy single line is almost the same as that of the original aluminum-magnesium-silicon alloy single line, the tensile strength of the modified aluminum alloy single line is gradually improved along with the increase of drawing passes until the tensile strength of the modified aluminum alloy single line is 352MPa after the fourth drawing, the tensile strength of the original alloy single line is only 297MPa, and the difference value can reach 55MPa.

The above results show that, in the embodiment 1 of the present invention, while maintaining the excellent conductivity of the aluminum alloy single wire, the tensile strength representing the mechanical property is also improved, and the effective balance between the conductivity and the mechanical property of the aluminum alloy single wire is achieved.

As shown in fig. 1 (a graph of tensile strength-drawing times of the original alloy and the modified aluminum alloy compositely doped with rare earth elements scandium and dysprosium of the present invention), the tensile strength curve of the modified aluminum alloy obtained by four-pass drawing and artificial aging treatment is located above the tensile strength curve of the original alloy, which indicates that the mechanical properties of the obtained modified aluminum alloy single line are superior to those of the original alloy single line.

Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims

1. A modified aluminum alloy single line is characterized in that: the aluminum alloy single wire comprises the following components in percentage by mass: 0.66 to 0.86 percent of magnesium element, 0.54 to 0.84 percent of silicon element, 0.10 to 0.30 percent of scandium element, 0.10 to 0.30 percent of dysprosium element, and the balance of aluminum element.

2. The aluminum alloy single wire as recited in claim 1, wherein: the aluminum alloy single wire comprises the following components in percentage by mass: 0.76 to 0.86 percent of magnesium element.

3. The aluminum alloy element wire as recited in claim 1, wherein: the aluminum alloy single wire comprises the following components in percentage by mass: 0.54 to 0.64 percent of silicon element.

4. The aluminum alloy element wire as recited in claim 1, wherein: the aluminum alloy single wire comprises the following components in percentage by mass: 0.20 to 0.30 percent of scandium element.

5. The aluminum alloy element wire as recited in claim 1, wherein: the aluminum alloy single wire comprises the following components in percentage by mass: dysprosium element 0.10-0.20%.

6. The aluminum alloy element wire as recited in claim 1, wherein: the aluminum alloy single wire comprises the following components in percentage by mass: 0.80 to 0.84 percent of magnesium element, 0.54 to 0.60 percent of silicon element, 0.20 to 0.25 percent of scandium element, 0.10 to 0.15 percent of dysprosium element and the balance of aluminum element.

7. The aluminum alloy element wire as recited in claim 6, wherein: the aluminum alloy single wire comprises the following components in percentage by mass: 0.82% of magnesium element, 0.56% of silicon element, 0.20% of scandium element, 0.10% of dysprosium element and the balance of aluminum element.

8. A preparation method of a modified aluminum alloy single wire is characterized by comprising the following steps: the preparation method comprises the following steps:

resistance smelting: adding lumpy simple substances of aluminum, magnesium and silicon and intermediate alloys of scandium and dysprosium according to a preset proportion, and melting to form an alloy melt;

continuous casting and rolling: enabling the alloy melt to flow through a continuous casting and rolling die to obtain a solid aluminum alloy round rod;

drawing and forming: drawing the aluminum alloy round bar for multiple times to obtain an aluminum alloy single line;

artificial aging: and carrying out aging heat treatment on the aluminum alloy single line.

9. The method for producing an aluminum alloy single wire as defined in claim 8, wherein: adding the lumpy simple substances of aluminum, magnesium and silicon and the scandium and dysprosium intermediate alloy according to a preset proportion, and melting to form an alloy melt, wherein the step of adding the bulk simple substances of aluminum, magnesium and silicon and the scandium and dysprosium intermediate alloy comprises the following steps:

weighing the massive simple substances of aluminum, magnesium and silicon, the intermediate alloy of aluminum, 5 percent of magnesium, 2 percent of scandium and the intermediate alloy of aluminum and 20 percent of dysprosium according to component requirements, melting at a constant temperature at a first preset temperature, then filling argon and stirring to obtain a uniform alloy melt, and preserving heat at a second preset temperature.

10. The method for producing an aluminum alloy single wire as defined in claim 8, wherein: the alloy melt flows through the continuous casting and rolling die to obtain the solid aluminum alloy round rod, and the method comprises the following steps:

when the alloy melt flows out along the inner cavity of the continuous casting and rolling die, a circulating water system is adopted for cooling, and the solid aluminum alloy round rod with the first preset size is obtained.

11. The method for producing an aluminum alloy single wire as defined in claim 10, wherein: drawing the aluminum alloy round bar for multiple times to obtain an aluminum alloy single line comprises the following steps:

and (3) putting the aluminum alloy round rod into a drawing die of a wire drawing machine, and drawing the aluminum alloy round rod with the first preset size to an aluminum alloy single wire with the second preset diameter through four-pass drawing.

12. The method for producing an aluminum alloy single wire as defined in claim 11, wherein: the drawing amount of each pass of the four-pass drawing is 20.5-24.2%, the drawing speed is 3-10 m/s, and the drawing temperature is 35-60 ℃.

13. The method for producing an aluminum alloy single wire as defined in claim 8, wherein: the aging heat treatment of the aluminum alloy single line comprises the following steps:

and (3) treating the aluminum alloy single wire subjected to drawing forming in an aging heat treatment furnace for 6-10 h, and cooling to room temperature to obtain the aluminum alloy single wire.

14. The method for producing an aluminum alloy single wire as defined in claim 13, wherein: the temperature of the aging heat treatment furnace is 160-180 ℃.