JPS605863A - Production of high yield heat resistant aluminum alloy for electrical conduction - Google Patents

Abstract

PURPOSE:To obtain an Al alloy for electrical conduction having excellent strength, electrical conductivity, heat resistance and toughness in particular by casting an Al alloy contg. Zr and Cu at a prescribed cooling rate after melting then hot working the casting and working the hot worked alloy while cooling respectively under specified conditions, coiling the worked alloy and subjecting the alloy to aging followed by cold working. CONSTITUTION:An Al alloy contg. 0.25-0.5% Zr and 0.01-0.2% Cu is melted and is then cast at a cooling rate of >=5 deg.C/sec from the casting temp. of the T deg.C expressed by the equation or above. The hot working of the Al alloy after casting is started at a temp. of >=500 deg.C to prevent precipitation of coarse grained Zr and while the hot worked alloy is cooled at a cooling rate of >=50 deg.C/sec, the alloy is worked and is coiled at a temp. of <=150 deg.C. The worked and coiled Al alloy member is aged for 14-400hr at 250-350 deg.C to precipitate and disperse finely Zr and thereafter the member is cold worked, by which the intended high yield heat resistant Al alloy for electrical conduction is obtd.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a method for manufacturing a high-strength, heat-resistant aluminum alloy for conductive use.
In particular, the present invention relates to a method for producing a conductive aluminum alloy that has excellent strength, electrical conductivity, heat resistance, and toughness.

(Background technology) In recent years, heat-resistant steel core aluminum alloy stranded wires (hereinafter referred to as TAC5R) have been used to increase the power transmission capacity and improve the reliability of power systems by operating one circuit in the event of an accident during two-line operation. has been done.

In this way, when TAC5R is further used for long-span power transmission lines such as overhead ground wires and strait crossings (e.g., long-span heat-resistant copper-core aluminum stranded wires (hereinafter referred to as KTAC3R)), it is necessary to use high-strength At alloy. There is a need for a high-strength, heat-resistant aluminum alloy wire for conductive use that has both the tensile strength and the heat resistance of a heat-resistant aluminum alloy.

Conventionally, work-hardened aluminum alloys have been used to improve strength through cold working for such aluminum alloy wires, but depending on the manufacturing method, desired strength, elongation, conductivity, heat resistance,
Since it was not possible to obtain a balance in toughness, a more stable method for manufacturing alloy assemblies was desired.

(Disclosure of the Invention) The present invention has been made to solve the problems mentioned above, and is aimed at producing a high-strength, heat-resistant aluminum alloy for electrical conduction that has excellent overall performance in terms of strength, electrical conductivity, heat resistance, and toughness. The purpose is to provide a method.

The high-strength 1 heat-suppressing aluminum alloy for electrocardiogram manufactured by the present invention is, for example, heat-resistant high-strength AC3R1 special steel core heat-resistant high-strength AC8R
This is a conductive aluminum alloy product that has both strength and heat resistance and is used for heat-resistant, high-strength aluminum alloy busbars, etc.

In the present invention, Zr in the aluminum alloy is dissolved in At during continuous casting and rolling, but is finely precipitated and dispersed by subsequent heat treatment to improve heat resistance and strength. Zr amount 0
．． The range of 25 to 0.5% is specified, but if it is less than 0.25%, it will precipitate. If the amount is small, it will not be effective in improving heat resistance and strength, and if it exceeds 0.5%, unless the molten metal temperature is raised significantly, it will crystallize as coarse particles in the molten metal stage, and finely dispersed particles will be formed by aging later. Not only does it not form, but it is also heat resistant.
In order to cause a decrease in strength, it is necessary to raise the molten metal temperature significantly. If, for example, 0.696 Zr is added, the molten metal temperature needs to be 805°C or higher, and it is difficult to cast at such a molten metal temperature. If you try to do so, you will not be able to obtain a sound ingot due to casting defects.

In addition, in the present invention, the reason why Cu' is specified as 0.01 to 0.2% is that it is added to promote the aging characteristics of the A7-Zr system and improve its strength and heat resistance.
If it is less than 0.01%, there is no effect, and if it exceeds 0.2%, corrosion resistance deteriorates. In the present invention, the casting temperature is T=3
It is expressed as 00XZ1-%+625. When the cooling rate is 13 or more, the cooling rate during casting is 5°'CAcc or more.
The reason for stipulating that Zr be produced is to make Zr a solid solution without being released in the molten metal stage, and to disperse it finely through aging in the subsequent process, which is an essential condition for improving strength and heat resistance. be. If the casting temperature is below T°C (+: 1M or the cooling rate during casting is less than 5°C Aec), the added Zr may crystallize or precipitate during casting.
Strength and heat resistance deteriorate.

The reason for specifying the hot working start temperature as 500℃ or higher is 5.
When the temperature is less than 00° C., Zl- is coarsely precipitated, and the strength and heat resistance are deteriorated.

The cooling rate during hot working was specified as 50°C/sec or higher, which is a necessary condition to finely precipitate Zl- by aging in the post-process, and to suppress the precipitation of Zr during hot working. , and is effective in introducing dislocations.

At 50°C/sec, Zr precipitates coarsely during hot working, there are few dislocations, and the strength and heat resistance deteriorate.

The area reduction rate during hot working is preferably 9096 or more, and if it is less than 90%, the toughness will deteriorate.

The winding temperature is specified to be 150℃ or less, which is 150℃.
If the temperature exceeds , a temperature difference will occur between the inside of the coil and the surface of the coil.
This is because the temperature inside the coil becomes too high, causing variations in characteristics and resulting in a lack of product stability.

The reason for specifying that aging be carried out at a temperature of 250 to 350°C for 15 to 4.00 hours is because this aging causes Zr to become finely 4Ji.
This is to improve the strength and heat resistance by dispersing the 1j14.
effective in improving strength and heat resistance (350'C4・0
If the time exceeds 0 hours, the precipitated particles will become coarse and the strength and heat resistance will deteriorate.

Moreover, in the second invention of the present invention, Mg:O, 4 to 02%
The purpose of adding is to further accelerate aging and further improve strength and heat resistance.If it is less than 0.01%, it is not effective (if it exceeds 0.296%, the effect is not only saturated, but also
Workability also deteriorates.

In the third aspect of the present invention, Y: 0.0005 to 0.
The reason why 0196 is included is to further improve the strength and heat resistance, and if it is less than 0.0005%, it is not effective (0
If it exceeds .01%, not only will the effect be saturated, but the cost will increase significantly, making it impractical.

In the fourth invention of the present invention, the aging temperature increase rate is set to 10
The reason for setting it below 0"(7)n- is to further improve the strength and thermal properties, and the temperature is 100℃/111-
By setting the temperature increase rate as below, it is possible to increase the amount of Zr that is finely precipitated during the temperature rise, and to disperse the Zr precipitation finely and in a large amount at the aging temperature.

In the fifth invention of the present invention, before the statute of limitations, 10 to 50
The reason why cold working is performed at a reduction rate of 10% is to further improve the strength and heat resistance, and if the area reduction is less than 10%, the effect will not be seen, and if it exceeds 50%, it will be saturated. When such cold working is performed, the aging temperature is often lowered by 5 to 30°C compared to the case where no cold working is performed.

The impurity in the M alloy in the present invention is Fe, which is defined in JISI (2) 10 of ordinary At ingots for electrical use.

There is no problem even if S i , Mn , T i , and V are included, for example, Fe: 0.08-0.25, -
5i: 0.04-0.09, Mn: 0.001-
0.003. Ti+V: 0.001 to 0008.

Furthermore, in order to refine the structure, T i 01005~
Although 0.1% may be added, B should be added at 0.1% from the viewpoint of heat resistance.
It is necessary to keep it below 0.002%.

In addition, in order to improve the electrical conductivity, Be: 0.0005~(
Monthly % can be added.

Example Alloys with compositions shown in Table 1 were heated to 3'000m+n2 lli
Table 11.
Casting and rolling were performed under the conditions shown below to obtain a rough wire of 9.5 mml. These roughly drawn wires were aged under the conditions shown in Table 1 and then cold worked at an area reduction rate of 82% to obtain wire rods.

The tensile strength, elongation, electrical conductivity, heat resistance and bending value of the obtained aluminum alloy wire are shown in Table 1.

Heat resistance was determined by measuring the tensile strength at room temperature after heating at 230"C for 1 hour, and expressed as a percentage of the tensile strength of the sample before heating. The bending value was measured using a fixed die with the same bending radius as the wire diameter. A wire was sandwiched between the wires, one 9o0 bend was made, and the number of bends was expressed as the number of times it took to break.

From Table 1, No, ], -No, ], according to the present invention
It can be seen that all samples No. 1 are superior in overall performance in terms of tensile strength, elongation, electrical conductivity, heat resistance, and bending value compared to the conventional examples.

Procedural amendment February 3, 1980 Kazuo Wakakage, Commissioner of the Patent Office ■, Indication of the case, 1981,) 'Hsu, Kou No. 114.757 No. 2
, Title of the invention: Process for producing high-strength aluminum alloy for electrical conductivity 36 Relationship with the case of the person making the amendment Address of the patent applicant: 15-1 Kitahama 5-chome, Higashi-ku, Osaka City Name (213)
President of Sumitomo Electric Industries Co., Ltd. Tetsube Yojo 4.1 Agent address 5, Sumitomo Electric Industries Co., Ltd., 1-1-3 Shimaya, Konohana-ku, Osaka City Date of amendment order Voluntary amendment 6, Specification subject to amendment Column 7 for the detailed explanation of the invention, details of the amendment 118, page 17, line 17 from the opening, line 19, 11 In the present invention, Φ・5 "C/sec or more" = 1 to the present invention Cool, 'I゛-3(]0XZr%10(i25tea
Above) Correct the cooling rate during casting from uI humidification temperature to J by more than 5"C/sec.

Claims (1)

[Claims] ■Zr: 0.25 to 0.5%, Cu: 0.
After melting an alloy consisting of old ~ 0.2% balance normal impurities and Kl, T ・-30' OX Zr 96 + 625
5'C/
Casting at a cooling rate of sec or more, followed by 500
``C: Start hot working at a temperature above, process while cooling at a cooling rate of 50℃ Acc or above, wind up at a temperature below 150''C, then at a temperature of 250 to 350''C, It is characterized by applying cold working after aging for 15 to 4,00 hours. A method for manufacturing a high-strength, heat-resistant aluminum alloy for conductive use. ■Mg: Claim No. 0.01 to 0.2% (
1) A method for producing a high-strength, heat-resistant aluminum alloy for electrocardiography as described in section 1). (2) A method for producing a high-strength 1TjJ thermal aluminum alloy for electrical conductivity according to claim (1) or (2), which contains Y: 0.0005 to 0.01%. (2) A method for manufacturing a high-strength, heat-resistant aluminum alloy for electrocardiography according to claim (1), (2), or (3), wherein the temperature increase rate during aging is 100° C./hr or less. ■Aging is performed after cold working with an area reduction rate of 10 to 50%Claims (1), (2), and (3)
) or (4), the method for producing a high-strength, heat-resistant aluminum alloy for electrical conductivity.