WO2010121517A1

WO2010121517A1 - High-elongation rate aluminum alloy material for cable and preparation method thereof

Info

Publication number: WO2010121517A1
Application number: PCT/CN2010/071654
Authority: WO
Inventors: 林泽民; 余乐华; 万有梅
Original assignee: 安徽欣意电缆有限公司
Priority date: 2009-04-24
Filing date: 2010-04-09
Publication date: 2010-10-28
Also published as: CN101525709B; RU2011147346A; CA2773050A1; JP2012524837A; CN101525709A; AU2010239014A1; AU2010239014B2; RU2550063C2; US20120211130A1; EP2468907A4; EP2468907A1

Abstract

A high-elongation rate aluminum alloy material and preparation method thereof. The high-elongation aluminum alloy material contains, in weight percentage, 0.30-1.20% of iron, 0.03-0.10% of silicon, 0.01-0.30% of rare earth elements, namely cerium and lanthanum, and the remaining aluminum and inevitable impurities. The aluminum alloy is made from materials through a fusion casting process and a half-annealing treatment. An aluminum alloy conductor made thereof has a high-elongation rate and good safety and stability in use.

Description

High elongation aluminum alloy material for cable and preparation method thereof

Technical field

The invention belongs to the field of non-ferrous metal materials, and particularly relates to a high elongation aluminum alloy material for cables and a preparation method thereof.

Background technique

At present, most of the wire and cable use copper as a conductor, which limits the development of wire and cable due to lack of copper resources, high copper price and high installation cost of copper cables. Because aluminum is rich in resources and low in cost, it is a trend to use aluminum instead of copper as a conductor for wire and cable.

technical problem

However, when ordinary electrical aluminum is used as the conductor, the elongation, flexibility and creep resistance of the wire and cable are poor, and the safety and stability of use are low. Therefore, the use of ordinary electrical aluminum instead of copper as a conductor cannot meet the development of wire and cable.

Technical solution

It is an object of the present invention to provide a high elongation aluminum alloy material for a cable. When the aluminum alloy of the present invention is used as a conductor, the wire and cable have a high elongation and high safety and stability in use.

In order to achieve the above object, the present invention adopts the following technical solution: a high elongation aluminum alloy material for cable, which comprises the following components in a percentage by weight: 0.30 to 1.20% iron, 0.03 to 0.10% silicon, 0.01 ～0.30% of rare earth elements, the rare earth elements are lanthanum and cerium, and the balance is aluminum and unavoidable impurities.

Another object of the present invention is to provide a method of preparing a high elongation aluminum alloy material comprising the steps of:

1) First, add 92-98 parts by weight of aluminum-containing and iron-containing aluminum alloy and 0.73 to 5.26 parts by weight of aluminum-iron alloy, and heat to 710-750 ° C for melting; then heat to 720-760 ° C, add 1 to 3 weight. a rare earth aluminum alloy and 0.17 to 0.67 parts by weight of a boron aluminum alloy, the rare earth aluminum alloy being an alloy of aluminum and a rare earth element lanthanum and cerium; and then adding 0.04 to 0.06 parts by weight of a refining agent for 8 to 20 minutes; After standing for 20 to 40 minutes, casting is performed;

2) The aluminum alloy body obtained by the semi-annealing treatment is kept at 280-380 ° C for 4 to 10 hours, and then taken out and naturally cooled to ambient temperature.

The aluminum alloy material further includes unavoidable impurity elements, and the total content of impurities in the aluminum alloy is <0.3% by weight.

Further, the content of calcium in the impurities is <0.02%, and the content of other single impurity elements is <0.01% to reduce the influence of the impurity element on the electrical conductivity of the aluminum alloy.

Beneficial effect

The high elongation aluminum alloy for cable used in the present invention is a novel Al-Fe alloy material, and has the following advantages:

1) The content of iron in the invention is controlled between 0.30 and 1.20%, which can improve the strength of the aluminum alloy, and also improve the creep resistance and thermal stability of the aluminum alloy, and the creep resistance is improved by 300 compared with the ordinary electrician. %; and iron can also enhance the toughness of the aluminum alloy, ensuring that the compaction coefficient of the aluminum alloy in the process of tightening and twisting reaches 0.93 or more, which is not achievable by ordinary electrician aluminum, and is made of the aluminum alloy. Compared with the ordinary electrical aluminum conductor under the condition of the outer diameter of the same conductor, the compacted core can increase the conductor cross section, improve the electrical conductivity of the conductor and increase the stability of the conductor, and can save processing costs.

2) The content of silicon in the present invention is controlled between 0.03% and 0.10%, which ensures a certain amount of silicon to enhance the strength of the aluminum alloy.

3) The rare earth element in the present invention can reduce the content of silicon, thereby reducing the influence of iron, especially silicon, on the electrical conductivity of the aluminum alloy to a very low level, and the addition of the rare earth element also improves the crystal in the aluminum alloy material. The structure of the structure improves the process performance of the aluminum alloy and is beneficial to the processing of the aluminum alloy.

4) The rare earth element in the present invention is mainly composed of lanthanum and cerium, and the performance in 3) can be satisfactorily achieved.

5) The boron element in the present invention can react with impurity elements such as Ti, V, Mn, Cr, etc., and is precipitated after being formed, thereby reducing the influence of impurity elements such as Ti, V, Mn, Cr on the electrical conductivity of the aluminum alloy. Conducive to improve the electrical conductivity of aluminum alloy.

6) In the preparation of the aluminum alloy in the invention, the alloy material is semi-annealed to improve the adverse effect of the stress on the conductor structure during the drawing and stranding process, so that the conductivity reaches or exceeds 61% IACS (for ordinary electricians) The conductivity standard of the aluminum conductor is 61% IACS), and the annealing treatment can greatly improve the elongation and flexibility of the aluminum alloy. The elongation of the cable made of the aluminum alloy of the invention reaches 30%, and the flexibility is better than that of the copper cable. The height is 25%, the bending radius is only 7 times the outer diameter, and the bending radius of the copper cable is 15 times the outer diameter.

Embodiments of the invention

Example 1:

First, the melting process

1, ingredients
5100kg aluminum ingot (0.07% Si content, 0.13% Fe content), 40.4kg aluminum-iron alloy (22% Fe content), 5.6kg rare earth alloy (10% rare earth content), 8.8kg boron aluminum alloy (3.5% B content), 2.3 kg of refining agent (23% Na ₃ Al•F6+47% KCl+30% NaCl).

2. When the feeding method is added, the aluminum-iron alloy is added with the aluminum ingots evenly and batchwise from the cupola to ensure the composition is as uniform as possible.

3. Insulation process When the aluminum alloy liquid flows into the holding furnace, the temperature is controlled at 710-750 °C; when adding rare earth aluminum alloy and boron aluminum alloy to the above aluminum alloy liquid, the temperature should be raised to 720-760 °C, and the temperature should not exceed 760 °C. Increasing the temperature at this time is beneficial to the melting of the rare earth aluminum alloy and the boron aluminum alloy, thereby improving the treatment effect of the rare earth and boron.

4. Rare earth treatment and boronization treatment
4.1 Adding 1/3 rare earth aluminum alloy to the holding furnace aluminum alloy liquid 30 minutes before filling.
4.2 The remaining 2/3 rare earth aluminum alloy and boron aluminum alloy were added to the holding furnace aluminum alloy liquid 5 minutes before filling.
The rare earth aluminum alloy and the boron aluminum alloy are added in different time periods in order to make the rare earth and boron elements fully function and improve the effect.
4.3 The position of the rare earth aluminum alloy and the boron aluminum alloy is uniformly distributed in the holding furnace.

5, refining (de-slag, degassing, stirring, slag)
5.1 In order to ensure uniform distribution of the composition of the aluminum alloy liquid in the whole furnace, the aluminum alloy liquid should be stirred and stirred to the corner of the furnace for 5 minutes.
5.2 When the aluminum alloy liquid is filled in the furnace, 2.3 kg of powder refining agent (23% Na ₃ Al•F6+47%KCl+30% NaCl) is blown into the bottom of the aluminum alloy liquid through a high-purity nitrogen gas through the pipeline. The bottom of the aluminum alloy liquid moves, so that the gas and the slag are uniformly floated along the surface of the aluminum alloy liquid for 3 to 5 minutes. The floating alumina slag should be completely removed from the furnace to minimize the introduction of new impurities introduced by the refining agent.

6. Rapid analysis and static insulation before the furnace When the iron content of the aluminum alloy liquid after the slag is in compliance with the requirements, the standing time is 20 to 40 minutes.

7. Continuous casting and rolling process control
7.1 temperature control
7.1.1 Top ladle temperature: 720 ~ 730 ° C
7.1.2 Casting mill temperature of the rolling mill: 450 ~ 490 ° C
7.1.3 Aluminum rod finishing temperature is about 300 °C
7.2 Control of cooling water of continuous casting machine The ratio of water volume inside and outside the casting wheel is 3:2, and the amount of secondary cooling water is adjusted according to the temperature of the casting bar.
7.3 caster voltage: 60 ~ 90V
7.4 rolling mill current: 200 ~ 280A; rolling mill speed: 7.5 ~ 8.5m / min.

Second, semi-annealing process

The aluminum alloy rod rolled from the aluminum alloy material is kept at 280 ° C to 300 ° C for 10 hours in an annealing furnace, and then taken out and naturally cooled to ambient temperature.

The aluminum alloy material thus obtained contains, according to the weight percentage, the following components: Fe 0.3%, Si 0.03%, Ce 0.008%, La 0.002%, B0.005%, Ca 0.015%, Cu 0.002%, Mg 0.005%, Zn 0.002%, Ti 0.002%, V0.005%, Mn 0.002%, Cr 0.001%, and the balance is Al.

Since the boron (B) element reacts with an impurity element such as Ti, V, Mn, Cr, etc., the compound is formed and precipitated, and thus the content of boron element in the finally obtained aluminum alloy material is lower than the actually added amount.

It can be seen from the above that the content of impurities in the aluminum alloy material is <0.3% in total, and the content of other single impurity elements is <0.01% except for Ca < 0.02%.

The performance test data of the high elongation aluminum alloy material in this example is as follows:

Tensile strength and elongation are tested according to the test method described in ASTM B577. Conductivity is measured according to ASTM. The test method described in B193, the flexibility is in accordance with the test method of "partial discharge test after bending test" described in GB 12706.1, and the creep is tested according to the creep test of the "Wire and Cable" manual.

The performance of the high elongation aluminum alloy material in this example is: tensile strength 106 MPa, elongation 28%, electrical conductivity 63.0% IACS, 6 times bending radius after partial discharge test pass, creep resistance is increased by 310% compared with electrical aluminum.

Example 2

First, the melting process

1, ingredients
5110kg aluminum ingot (0.10% Si content, 0.13% Fe content), 258kg aluminum-iron alloy (23.2% Fe content), 166.5kg rare earth alloy (9.8% rare earth content), 10kg boron aluminum alloy (3.3% B content), 2.3kg Refining agent (23% Na ₃ Al•F6+47%KCl+30% NaCl)

Second, semi-annealing process

The aluminum alloy rod rolled from the aluminum alloy material is kept in an annealing furnace at 360 ° C to 380 ° C for 4 hours, and then taken out and naturally cooled to ambient temperature.

The aluminum alloy material thus obtained contains, according to the weight percentage, the following components: Fe 1.2%, Si 0.08%, Ce 0.19%, La 0.10%, B 0.004%, Ca 0.01%, Cu 0.002%, Mg 0.004%, Zn 0.003%, Ti 0.002%, V0.002%, Mn 0.005%, Cr 0.002%, and the balance is Al.

Tensile strength and elongation are tested according to the test method described in ASTM B577. Conductivity is measured according to ASTM. The test method described in B193, the flexibility is in accordance with the test method of "partial discharge test after bending test" described in GB12706.1, and the creep is in accordance with the method of creep test of the "Wire and Cable" manual.

The performance of the aluminum alloy material with high conductivity, high elongation, high flexibility and high creep resistance in this example is: partial discharge test after tensile strength 92 MPa, elongation 36%, electrical conductivity 61.0% IACS, 7 times bending radius Qualified and creep resistant is increased by 330% compared to electrical aluminum.

Example 3

First, the melting process

1, ingredients
5125kg aluminum ingot (0.12% Si content, 0.12% Fe content), 107kg aluminum-iron alloy (21.9% Fe content), 118kg rare earth alloy (10.1% rare earth content), 14.8kg boron aluminum alloy (3.0% B content), 2.8kg Refining agent (23% Na ₃ Al•F6+ 47% KCl + 30% NaCl).

3. Insulation process When the aluminum alloy liquid flows into the holding furnace, the temperature is controlled at 710-750 °C. When adding rare earth aluminum alloy and boron aluminum alloy to the above aluminum alloy liquid, the temperature should be raised to 720-760 °C, and the temperature should not exceed 760 °C. Increasing the temperature at this time is beneficial to the melting of the rare earth aluminum alloy and the boron aluminum alloy, thereby improving the treatment effect of the rare earth and boron.

4. Rare earth treatment and boronization treatment
4.1 Adding 1/3 rare earth aluminum alloy to the holding furnace aluminum alloy liquid 30 minutes before filling.
4.2 The remaining 2/3 rare earth aluminum alloy and boron aluminum alloy were added to the holding furnace aluminum alloy liquid 5 minutes before filling.
4.3 The location of the rare earth aluminum alloy and boron aluminum alloy should be evenly distributed in the holding furnace.

5, refining (de-slag, degassing, stirring, slag)
5.1 In order to ensure uniform distribution of the composition of the aluminum alloy liquid in the whole furnace, the aluminum alloy liquid should be stirred and stirred to the corner of the furnace for 5 minutes.
5.2 When the aluminum alloy liquid is filled in the furnace, 2.8 kg of powder refining agent (23% Na ₃ Al•F 6+47% KCl+30% NaCl) is blown into the bottom of the aluminum alloy liquid through high-purity nitrogen through a pipe, and the inlet should be blown. Moving at the bottom of the aluminum alloy liquid, the gas and the slag are uniformly floated along the surface of the aluminum alloy liquid for 3 to 5 minutes. The floating alumina slag should be completely removed from the furnace to minimize the introduction of new impurities introduced by the refining agent.

Second, semi-annealing process

The aluminum alloy rod rolled from the aluminum alloy material is kept in an annealing furnace at 300 ° C to 320 ° C for 8 hours, and then taken out and naturally cooled to ambient temperature.

The aluminum alloy material thus obtained contains the following components in terms of weight percentage: Fe 0.55%, Si 0.10%, Ce 0.15%, La 0.06%, B0.007%, Ca 0.013%, Cu 0.003%, Mg 0.004%, Zn 0.004%, Ti 0.002%, V 0.004%, Mn 0.003%, Cr 0.002%, and the balance is Al.

Tensile strength and elongation are tested according to the test method described in ASTM B577. Conductivity is measured according to ASTM. The test method described in B193, the flexibility according to the test method of "partial discharge test after bending test" described in GB 12706.1, creep according to the "wire and cable" manual creep test method.

The properties of the high elongation aluminum alloy material in this example are: tensile strength 110 MPa, elongation 30.2%, electrical conductivity 62.6% IACS, 6 times bending radius after partial discharge test pass, creep resistance is increased by 330% compared with electrical aluminum.

Example 4

First, the melting process

1, ingredients
5005kg aluminum ingot (0.08% Si content, 0.13% Fe content), 182kg aluminum-iron alloy (21% Fe content), 90.5kg rare earth alloy (9.8% rare earth content), 30kg boron aluminum alloy (3.5% B content), 2.0kg Refining agent (23% Na ₃ Al•F6+47% KCl+30% NaCl).

5, refining (de-slag, degassing, stirring, slag)
5.1 In order to ensure uniform distribution of the composition of the aluminum alloy liquid in the whole furnace, the aluminum alloy liquid should be stirred and stirred to the corner of the furnace for 5 minutes.
5.2 When the aluminum alloy liquid is filled in the furnace, 2.0kg of powder refining agent (23% Na ₃ Al•F6+47%KCl+30% NaCl) is blown into the bottom of the aluminum alloy liquid through high-purity nitrogen gas through the pipeline. The bottom of the aluminum alloy liquid moves, so that the gas and the slag are uniformly floated along the surface of the aluminum alloy liquid for 3 to 5 minutes. The floating alumina slag should be completely removed from the furnace to minimize the introduction of new impurities introduced by the refining agent.

Second, semi-annealing process

The aluminum alloy rod rolled from the aluminum alloy material is incubated at 340 ° C to 360 ° C for 6 hours in an annealing furnace, and then taken out and naturally cooled to ambient temperature.

The aluminum alloy material thus obtained contains the following components in terms of weight percent: Fe 0.80%, Si 0.04%, Ce 0.10%, La 0.06%, B0.008%, Ca 0.011%, Cu 0.005%, Mg 0.004%, Zn0.006% Ti 0.003%, V0.003%, Mn 0.005%, Cr 0.002%, and the balance is Al.

The properties of the high elongation aluminum alloy material in this example are: tensile strength 97 MPa, elongation 35.2%, electrical conductivity After 62.0% IACS, 6 times bending radius, the partial discharge test was qualified, and the creep resistance was increased by 330% compared with the electrical aluminum.

Claims

A high elongation aluminum alloy material for a cable, characterized by comprising the following components in a weight percentage: 0.30 to 1.20% iron, 0.03 to 0.10% silicon, and 0.01 to 0.30% rare earth element, The rare earth elements are lanthanum and cerium, and the balance is aluminum and unavoidable impurities.
The high elongation aluminum alloy material for a cable according to claim 1, wherein the total content of impurities in the aluminum alloy is <0.3% by weight.
The high elongation aluminum alloy material for cable according to claim 2, wherein the content of calcium in the impurities is <0.02% by weight, and the content of other single impurity elements is <0.01%.
The high elongation aluminum alloy material for a cable according to claim 1, wherein the content of the niobium is 0.005 to 0.20% by weight, and the content of niobium is 0.001 to 0.15%.
A method of preparing a high elongation aluminum alloy material for a cable according to claim 1, comprising the steps of:

1) Casting

First, adding 92 to 98 parts by weight of an aluminum alloy containing silicon and iron and an aluminum-iron alloy of 0.73 to 5.26 parts by weight, heating to 710 to 750 ° C for melting; heating to 720 to 760 ° C, adding 1 to 3 parts by weight of rare earth Aluminum alloy and 0.17-0.67 parts by weight of boron aluminum alloy, the rare earth aluminum alloy is an alloy of aluminum and rare earth elements lanthanum and cerium; then 0.04-0.06 parts by weight of a refining agent is added for 8-20 minutes; then standing still After 20 to 40 minutes, casting is performed;

2) Semi-annealing

The cast aluminum alloy body is kept at 280-380 ° C for 4 to 10 hours, and then taken out and naturally cooled to ambient temperature.
The method for preparing a high elongation aluminum alloy material for a cable according to claim 5, wherein the silicon-containing and iron-containing aluminum alloy has a silicon content of 0.07 to 0.12% and an iron content of 0.12 to 0.13. %, the content of iron in the aluminum-iron alloy is 20-24%, the content of boron in the boron-aluminum alloy is 3-4%, and the content of lanthanum and cerium in the rare earth aluminum alloy is 9-11%.
The method for preparing a high elongation aluminum alloy material for a cable according to claim 5, wherein the aluminum and the aluminum-iron alloy are melted and then flowed into the holding furnace, and the aluminum alloy liquid in the holding furnace is filled for three minutes before filling. One weight of the rare earth aluminum alloy, the aluminum alloy liquid in the holding furnace is filled with boron aluminum alloy and the remaining rare earth aluminum alloy 5 minutes before filling.
The method of preparing a high elongation aluminum alloy material for a cable according to claim 5, wherein the powder refining agent is 23% Na 3 Al•F6+47% KCl+30% NaCl.
The method for preparing a high elongation aluminum alloy material for a cable according to claim 5, wherein the temperature of the upper ladle is 720 to 730 ° C during casting, and the temperature of the casting strip of the rolling mill is 450 to 490 ° C. The rolling temperature was 300 °C.